阅读说明：本技术 基板的保持装置、吸附判定和释放方法、研磨装置和方法、除液方法、弹性膜及供气装置 (Substrate holding device, method for determining adsorption and release, polishing device and method, liquid removing method, elastic film, and gas supply device ) 是由 锅谷治 山木晓 福岛诚 于 2019-08-05 设计创作，主要内容包括：本发明提供能更高精度地判定基板吸附的基板保持装置及具备该基板保持装置的基板研磨装置,另外,提供能更高精度地判定基板吸附的基板吸附判定方法及利用该基板吸附判定方法的基板研磨方法。基板保持装置具备：顶环主体,能安装具有能吸附基板的面的弹性膜,当安装弹性膜时,在弹性膜与顶环主体之间形成多个区域；第一管线,与多个区域中的第一区域连通；第二管线,与多个区域中的与第一区域不同的第二区域连通；压力调整单元,能经由第一管线而送入流体对第一区域加压,并能经由第二管线使第二区域为负压；及判定部,基于送入到第一区域的流体的体积或与第一区域的压力对应的测定值进行基板是否吸附于弹性膜的判定,在判定时,不从第一区域排气。(The invention provides a substrate holding device capable of determining substrate adsorption with higher precision and a substrate polishing device provided with the substrate holding device, and further provides a substrate adsorption determination method capable of determining substrate adsorption with higher precision and a substrate polishing method using the substrate adsorption determination method. The substrate holding device includes: a top ring main body to which an elastic film having a surface capable of adsorbing a substrate can be attached, the elastic film forming a plurality of regions between the elastic film and the top ring main body when the elastic film is attached; a first line in communication with a first zone of the plurality of zones; a second line communicating with a second region different from the first region among the plurality of regions; a pressure adjusting unit capable of feeding a fluid through the first line to pressurize the first region and capable of making the second region negative in pressure through the second line; and a determination unit that determines whether or not the substrate is adsorbed to the elastic membrane based on the volume of the fluid supplied to the first region or a measurement value corresponding to the pressure in the first region, and does not evacuate the first region during the determination.)

1. A substrate holding device is characterized by comprising:

a top ring main body to which an elastic film having a surface capable of adsorbing a substrate is attachable and which has a plurality of regions formed between the elastic film and the top ring main body when the elastic film is attached;

a first line in communication with a first zone of the plurality of zones;

a second line communicating with a second region of the plurality of regions different from the first region;

a pressure adjusting means capable of pressurizing the first region by feeding a fluid through the first line and capable of making the second region negative pressure through the second line; and

a determination unit that determines whether or not the substrate is adsorbed to the elastic film based on a volume of the fluid supplied to the first region or a measurement value corresponding to a pressure in the first region,

when the determination is made, the exhaust from the first region is not performed.

2. The substrate holding apparatus according to claim 1,

the determination unit performs the determination by using: the volume of the fluid sent into the first region is small or the pressure of the first region is high in the case where the substrate is adsorbed, as compared with the case where the substrate is not adsorbed to the elastic membrane.

3. The substrate holding apparatus according to claim 1,

the pressure adjusting unit has a pressurizing mechanism that feeds fluid to the first region via the first line,

the determination unit includes a position sensor that detects a portion of the pressurizing mechanism that moves when the fluid is supplied to the first region as a measurement value corresponding to a volume of the fluid supplied to the first region.

4. The substrate holding apparatus according to claim 1,

the determination unit has a pressure gauge for measuring the pressure in the first region.

5. The substrate holding apparatus according to claim 1,

the pressure adjusting unit has a pressurizing mechanism that feeds fluid to the first region via the first line,

the determination unit includes:

a position sensor that detects a part of the pressurizing mechanism that moves when the fluid is sent into the first region as a measurement value corresponding to a volume of the fluid sent into the first region; and

a pressure gauge that measures a pressure of the first region.

6. The substrate holding apparatus according to claim 5,

the determination unit determines that the substrate is not adsorbed to the elastic film based on a detection result of the position sensor,

the determination unit determines that the substrate is adsorbed to the elastic film based on a measurement result of the pressure gauge.

7. The substrate holding apparatus according to claim 6,

the pressurizing mechanism is provided with a cylinder and a counterweight main body of a piston of the cylinder,

the weight body moves downward by gravity, and feeds a fluid into the first region.

8. The substrate holding apparatus according to claim 7,

the piston is movable up and down in contact with an inner surface of the cylinder,

the interior of the cylinder is divided into a lower space and an upper space by the piston,

the cylinder is provided with:

a first opening provided in the lower space and connected to the first pipeline;

a second opening provided in the lower space;

a third opening provided in the upper space, through which a piston rod connecting the counterweight main body and the piston passes; and

a fourth opening provided in the upper space.

9. The substrate holding apparatus according to claim 8,

when the determination is made, the second opening is closed and the fourth opening is opened,

after the determination is made, the second opening is opened, and the upper space is sucked from the fourth opening, thereby raising the counterweight.

10. The substrate holding apparatus according to claim 8,

the first line is connected to the first opening of the cylinder and a polishing pressure control unit that pressurizes the first region when polishing the substrate attached to the elastic membrane,

the substrate holding device is provided with a switching means for switching between communication between the first region and the first opening of the pressurization mechanism via the first line and communication between the first region and the polishing pressure control unit via the first line.

11. A substrate polishing apparatus is characterized by comprising:

the substrate holding apparatus of claim 1; and

and a polishing table configured to polish the substrate held by the substrate holding device.

12. A method for determining substrate adsorption in a substrate holding apparatus,

pressurizing a first region formed between a top ring main body and an elastic membrane of a substrate holding device by applying a negative pressure to the first region and feeding a fluid into the first region,

determining whether or not the substrate is adsorbed to the elastic membrane based on a volume of the fluid supplied to the first region or a measured value corresponding to the pressure in the first region,

when the determination is made, the exhaust from the first region is not performed.

13. A method for polishing a substrate, comprising the steps of:

a step of making the substrate held by the conveying mechanism adsorbed on the substrate holding device;

a step of determining whether or not the substrate is adsorbed to the elastic film of the substrate holding device by the substrate adsorption determination method according to claim 12; and

and polishing the substrate when it is determined that the substrate is adsorbed.

14. A method of polishing a wafer by using a polishing head having a center-side pressure chamber and an outer-side pressure chamber formed of an elastic membrane, the method of polishing the wafer being characterized in that,

bringing a central portion of the elastic membrane into contact with a central portion of an upper surface of the wafer,

bringing a peripheral portion of the elastic membrane into contact with a peripheral portion of the upper surface of the wafer, thereby removing the liquid from the upper surface of the wafer,

and pressing the lower surface of the wafer to a grinding surface by using the elastic membrane so as to grind the lower surface of the wafer.

15. The method of grinding a wafer according to claim 14,

the center portion of the elastic membrane is brought into contact with the center portion of the upper surface of the wafer in a state where the pressure in the center-side pressure chamber is made higher than the pressure in the outer-side pressure chamber.

16. The method of grinding a wafer according to claim 15,

the central side pressure chamber is communicated with the cylinder, and a balance weight is placed on a piston of the cylinder.

17. A method of polishing a wafer by using a polishing head having a center-side pressure chamber and an outer-side pressure chamber formed of an elastic membrane, the method of polishing the wafer being characterized in that,

bringing the elastic membrane into contact with the upper surface of the wafer, and thereafter,

forming a vacuum in the outer pressure chamber and the center pressure chamber in this order to move the liquid present on the upper surface of the wafer outward, and thereafter,

pressing the lower surface of the wafer against a polishing surface with the elastic membrane to remove liquid from the upper surface of the wafer,

and polishing the lower surface of the wafer by bringing the lower surface of the wafer into sliding contact with the polishing surface by the polishing head.

18. The method of grinding a wafer according to claim 17,

and supplying a compressed gas into the center-side pressure chamber and the outer pressure chamber in this order, thereby pressing the lower surface of the wafer against the polishing surface by the elastic membrane, and removing the liquid from the upper surface of the wafer.

19. The method of grinding a wafer according to claim 17,

the outside pressure chamber and the center side pressure chamber include at least a first pressure chamber, a second pressure chamber, and a third pressure chamber, the second pressure chamber being located outside the first pressure chamber, the third pressure chamber being located outside the second pressure chamber,

and forming a vacuum in the third pressure chamber, the second pressure chamber, and the first pressure chamber in this order, thereby moving the liquid present on the upper surface of the wafer outward.

20. A method for polishing a wafer by using a polishing head, characterized in that,

removing the liquid from the upper surface of the wafer on the carrier device,

holding the wafer on the carrier by the polishing head,

and pressing the lower surface of the wafer to a grinding surface by using the grinding head so as to grind the lower surface of the wafer.

21. The method of grinding a wafer according to claim 20,

the step of removing the liquid from the upper surface of the wafer on the transfer device includes the steps of: the wafer is tilted by the carrier device to remove the liquid from the upper surface of the wafer.

22. The method of grinding a wafer according to claim 20,

the step of removing the liquid from the upper surface of the wafer on the transfer device includes the steps of: the wafer is oscillated by the carrier device to remove the liquid from the upper surface of the wafer.

23. The method of grinding a wafer according to claim 20,

the step of removing the liquid from the upper surface of the wafer on the transfer device includes the steps of: and a jet of gas is delivered to the upper surface of the wafer on the carrying device, thereby removing the liquid from the upper surface of the wafer.

24. A method for polishing a wafer by using a polishing head having an elastic membrane, characterized in that,

bringing the elastic membrane into contact with the upper surface of the wafer,

removing the liquid from the upper surface of the wafer by causing the liquid present on the upper surface of the wafer to flow into the liquid flow path formed in the elastic film,

and pressing the lower surface of the wafer to a grinding surface by using the elastic membrane so as to grind the lower surface of the wafer.

25. The method of grinding a wafer according to claim 24,

the elastic membrane has a contact surface contacting the upper surface of the wafer,

the liquid flow path has an opening portion that opens at the contact surface, and a lateral hole that is connected to the opening portion and extends inside the elastic membrane, the lateral hole opening at an outer side surface of the elastic membrane.

26. The method of grinding a wafer according to claim 24,

the step of causing the liquid present on the upper surface of the wafer to flow into the liquid flow path is a step of: sucking the liquid existing on the upper surface of the wafer through the liquid flow path,

the liquid flow path communicates with a suction line connected to the elastic membrane.

27. The method of grinding a wafer according to claim 24,

the elastic membrane has a contact surface contacting the upper surface of the wafer,

the liquid flow path is a groove formed in the contact surface.

28. The method of grinding a wafer according to claim 27,

the width of the groove in the interior of the elastic membrane is greater than the width of the groove at the contact surface.

29. An elastic membrane for pressing a wafer against a polishing surface, the elastic membrane comprising:

a contact portion having a contact surface contactable with the wafer; and

an outer wall portion connected to the contact portion,

the contact portion has an opening portion that opens at the contact surface, and a lateral hole that is connected to the opening portion and extends in the contact portion.

30. The elastic film of claim 29,

the transverse hole is opened on the outer side surface of the elastic membrane.

31. The elastic film of claim 29,

the lateral hole is opened on a surface of the contact portion opposite to the contact surface.

32. An elastic membrane for pressing a wafer against a polishing surface, the elastic membrane comprising:

a contact portion having a contact surface contactable with the wafer; and

an outer wall portion connected to the contact portion,

the contact portion has a groove formed in the contact surface.

33. The elastic film of claim 32,

the width of the groove in the contact portion is greater than the width of the groove in the contact surface.

34. A substrate polishing apparatus is characterized by comprising:

a top ring body;

an elastic film having a first surface facing the top ring main body and a second surface opposite to the first surface and capable of holding a substrate by suction;

a pressure adjusting device capable of pressurizing and depressurizing a space between the top ring main body and the first surface of the elastic membrane via a first valve provided in a first line communicating with the space; and

and a constant-volume gas supply device capable of supplying a constant volume of gas to the space via a second valve provided in the first line.

35. The apparatus according to claim 34, wherein the polishing head is provided with a polishing head,

when the substrate is adsorbed to the second surface of the elastic membrane, the second valve is closed, the first valve is opened, and the pressure adjusting device reduces the pressure in the space,

closing the second valve and opening the first valve when the substrate is polished, and pressurizing the space by the pressure adjusting device,

when the substrate is released from the second surface of the elastic film, the first valve is closed, the second valve is opened, and the quantitative gas supply device supplies a certain amount of gas to the space.

36. The apparatus according to claim 34, wherein the polishing head is provided with a polishing head,

in the constant-volume gas supply device, a weight connected to a piston in a cylinder moves downward by gravity, and a constant volume of gas corresponding to the area of the piston and the stroke of the piston is supplied from the cylinder to the space.

37. The apparatus according to claim 36, wherein the polishing unit is provided with a polishing unit,

the quantitative gas supply device has the cylinder, the piston, and the weight,

the piston is movable up and down in contact with an inner surface of the cylinder,

the interior of the cylinder is divided into a lower space and an upper space by the piston,

the cylinder is provided with a first opening at a position corresponding to the lower space, a second opening and a third opening at a position corresponding to the upper space,

the first opening is connected to a second line connected to the first line via the second valve,

the second opening is connected to a third line,

a piston rod connecting the weight and the piston passes through the third opening,

the lower space can be opened to the atmosphere by opening a third valve provided in the second line,

the upper space can be depressurized and opened to the atmosphere via the third line.

38. The apparatus according to claim 37, wherein the polishing unit is provided with a polishing unit,

the upper space is depressurized and the lower space is opened to the atmosphere when the substrate is adsorbed to the second surface of the elastic film and the substrate is polished,

when the substrate is released from the second surface of the elastic membrane, the upper space is opened to the atmosphere, and the third valve is closed.

39. The apparatus according to claim 34, wherein the polishing head is provided with a polishing head,

the constant-volume gas supply device compresses an airbag housed in a chamber, thereby supplying a constant volume of gas corresponding to the volume of the chamber from the airbag to the space.

40. The apparatus according to claim 39, wherein the polishing unit is provided with a polishing unit,

the quantitative gas supply device has the airbag and the chamber,

a fourth opening and a fifth opening are arranged in the chamber,

a fourth line connecting the first line and the balloon via the second valve passes through the fourth opening,

said fifth opening being connected to a fifth line,

the airbag can be opened to the atmosphere by opening a fourth valve provided in the fourth line,

the chamber is capable of being pressurized and depressurized via the fifth line.

41. The apparatus according to claim 40, wherein the polishing unit is provided with a polishing unit,

the chamber is depressurized to open the bladder to the atmosphere when the substrate is adsorbed to the second surface of the elastic film and when the substrate is polished,

upon releasing the substrate from the second side of the elastic membrane, the chamber is pressurized, closing the fourth valve.

42. A substrate release method for releasing a substrate, which is sucked and held on a second surface of an elastic film of a top ring, from the elastic film, the substrate release method comprising:

a gas supply step of supplying a predetermined amount of gas into a space between a top ring main body in the top ring and the first surface of the elastic film, thereby generating a gap between the elastic film and the substrate; and

and a fluid ejecting step of ejecting a fluid to the gap.

43. The substrate release method according to claim 42,

in the gas supply step, a weight coupled to a piston in a cylinder is moved downward, whereby a certain amount of gas corresponding to the area of the piston and the stroke of the piston is supplied from the cylinder to the space.

44. The substrate release method according to claim 42,

in the gas supply step, the airbag housed in the chamber is compressed, whereby a certain amount of gas corresponding to the volume of the chamber is supplied from the airbag to the space.

45. A quantitative gas supply device connected to a substrate holding device, the substrate holding device comprising:

a top ring body;

an elastic film having a first surface facing the top ring main body and a second surface opposite to the first surface and capable of holding a substrate by suction; and

a pressure adjusting device capable of pressurizing and depressurizing a space between the top ring main body and the first surface of the elastic membrane via a first valve provided in a first line communicating with the space,

the quantitative gas supply apparatus is characterized in that,

the quantitative gas supply means can supply a certain amount of gas to the space via a second valve provided in the first line.

Technical Field

The present invention relates to a substrate holding device, a substrate adsorption determination method, a substrate polishing device, a substrate polishing method, a method of removing liquid from an upper surface of a wafer to be polished, and an elastic film for pressing the wafer against a polishing pad, a substrate release method, and a quantitative gas supply device.

Background

In a substrate polishing apparatus (for example, japanese patent No. 3705670 (patent document 1)), a substrate is transferred from a substrate transfer apparatus to a top ring (substrate holding apparatus), and polishing of the substrate is performed in a state where the substrate is held by the top ring. The top ring has a structure in which a diaphragm is provided below a top ring main body (base plate) and a substrate is adsorbed on a lower surface of the diaphragm.

Disclosure of Invention

The present invention aims to provide a more excellent substrate holding device, a substrate adsorption determination method, a substrate polishing device, a substrate polishing method, a method for removing liquid from the upper surface of a wafer to be polished, an elastic film for pressing the wafer against a polishing pad, a substrate release method, and a quantitative gas supply device.

Provided is a substrate holding device, which is provided with: a top ring main body to which an elastic film having a surface capable of adsorbing a substrate is attachable and which has a plurality of regions formed between the elastic film and the top ring main body when the elastic film is attached; a first line in communication with a first zone of the plurality of zones; a second line communicating with a second region of the plurality of regions different from the first region; a pressure adjusting unit capable of pressurizing the first region by feeding a fluid through the first line and capable of changing the second region to a negative pressure through the second line; and a determination unit that determines whether or not the substrate has been adsorbed to the elastic membrane based on a volume of the fluid that has been sent into the first region or a measurement value corresponding to a pressure in the first region, and the substrate holding device does not perform evacuation from the first region when the determination is performed.

A method of polishing a wafer using a polishing head having a center-side pressure chamber and an outer-side pressure chamber formed by an elastic membrane, wherein a center portion of the elastic membrane is brought into contact with a center portion of an upper surface of the wafer, and thereafter, an outer peripheral portion of the elastic membrane is brought into contact with an outer peripheral portion of the upper surface of the wafer, thereby removing a liquid from the upper surface of the wafer, and the elastic membrane presses a lower surface of the wafer against a polishing surface, thereby polishing the lower surface of the wafer.

Provided is a substrate polishing apparatus, which comprises: a top ring body; an elastic film having a first surface facing the top ring main body and a second surface located on a side opposite to the first surface and capable of holding a substrate by suction; a pressure adjusting device capable of pressurizing and depressurizing a space between the top ring main body and the first surface of the elastic membrane via a first valve provided in a first line communicating with the space; and a constant-volume gas supply device capable of supplying a constant volume of gas to the space via a second valve provided in the first line.

Drawings

Fig. 1 is a schematic plan view of a substrate processing apparatus including a substrate polishing apparatus.

Fig. 2 is a schematic perspective view of the substrate polishing apparatus 300.

Fig. 3 is a schematic cross-sectional view of a substrate polishing apparatus 300.

Fig. 4A is a diagram illustrating in detail delivery of the substrate from the conveyance mechanism 600b to the top ring 1.

Fig. 4B is a diagram illustrating in detail the delivery of the substrate from the conveyance mechanism 600B to the top ring 1.

Fig. 4C is a diagram illustrating in detail the substrate transfer from the conveyance mechanism 600b to the top ring 1.

Fig. 5 is a diagram illustrating in detail delivery of the substrate from the conveyance mechanism 600b to the top ring 1.

Fig. 6 is a diagram schematically showing the structure of the top ring 1 and the pressure control device 7.

Fig. 7 is a diagram illustrating pressure determination according to the first embodiment.

Fig. 8A is a diagram showing a case where the substrate adsorption is successful.

Fig. 8B is a diagram showing a case where the substrate adsorption fails.

Fig. 9 is a flowchart showing an example of a procedure for determining substrate adsorption in the first embodiment.

Fig. 10 is a diagram illustrating pressure determination according to the second embodiment.

Fig. 11A is a diagram showing a case where the substrate adsorption is successful.

Fig. 11B is a diagram showing a case where the substrate adsorption fails.

Fig. 12 is a flowchart showing an example of a procedure for determining substrate adsorption in the second embodiment.

Fig. 13 is a diagram illustrating a modification of fig. 10.

Fig. 14 is a diagram illustrating pressure determination according to the third embodiment.

Fig. 15A is a diagram showing a case where the substrate adsorption is successful.

Fig. 15B is a diagram showing a case where the substrate adsorption fails.

Fig. 16 is a flowchart showing an example of a procedure for determining substrate adsorption in the third embodiment.

Fig. 17 is a diagram illustrating pressure determination according to the fourth embodiment.

Fig. 18 is a diagram showing the pressure control device 7 during standby, that is, before substrate suction determination.

Fig. 19A is a diagram showing a case where the substrate adsorption is successful.

Fig. 19B is a diagram showing a case where the substrate adsorption fails.

Fig. 20 is a view showing a state during polishing.

Fig. 21 is a flowchart showing an example of a procedure for determining substrate adsorption in the fourth embodiment.

Fig. 22 is a diagram illustrating a modification of fig. 17.

Fig. 23A is a diagram illustrating pressure determination using an integrating flowmeter.

Fig. 23B is a diagram showing a case where the substrate adsorption is successful.

Fig. 23C is a diagram showing a case where the substrate adsorption fails.

Fig. 24 is a schematic view showing an embodiment of a polishing apparatus.

Fig. 25 is a sectional view showing the polishing head.

Fig. 26 is a plan view of the carrier device for carrying the wafer to the polishing head shown in fig. 24.

Fig. 27 is a schematic view showing a polishing head when removing liquid from the upper surface of a wafer.

Fig. 28 is a schematic view showing a state in which the elastic film of the polishing head pushes out the liquid present on the upper surface of the wafer to the outside.

Fig. 29 is a schematic view showing a state in which the elastic membrane of the polishing head pushes out the liquid present on the upper surface of the wafer further to the outside.

Fig. 30 is a diagram for explaining an embodiment in which a combination of a cylinder and a weight is used instead of the pressure regulator to expand the center portion of the elastic membrane.

Fig. 31 is a schematic view showing another embodiment of the elastic membrane.

Fig. 32 is a schematic view showing still another embodiment of the elastic membrane.

Fig. 33 is a diagram illustrating another embodiment of a method of removing liquid from the top surface of a wafer.

Fig. 34 is a diagram further illustrating the embodiment shown in fig. 33.

Fig. 35 is a diagram further illustrating the embodiment shown in fig. 33.

Fig. 36 is a diagram further illustrating the embodiment shown in fig. 33.

Fig. 37 is a diagram illustrating still another embodiment of a method for removing liquid from the upper surface of a wafer.

Fig. 38 is a diagram further illustrating the embodiment shown in fig. 37.

Fig. 39 is a diagram further illustrating the embodiment shown in fig. 37.

Fig. 40 is a diagram illustrating still another embodiment of a method for removing liquid from the upper surface of a wafer.

Fig. 41 is a diagram further illustrating the embodiment shown in fig. 40.

Fig. 42 is a diagram illustrating still another embodiment of a method of removing liquid from the upper surface of a wafer.

Fig. 43 is a diagram further illustrating the embodiment shown in fig. 42.

Fig. 44 is a cross-sectional view showing an embodiment of an elastic membrane capable of removing liquid from the upper surface of a wafer.

FIG. 45 is a schematic view showing the situation in which the elastic membrane shown in FIG. 44 is removing liquid from the upper surface of the wafer.

Fig. 46 is a cross-sectional view showing another embodiment of an elastic membrane capable of removing liquid from the upper surface of a wafer.

Fig. 47 is a schematic view showing the situation in which the elastic membrane shown in fig. 46 is removing liquid from the upper surface of the wafer.

Fig. 48 is a cross-sectional view showing still another embodiment of an elastic membrane capable of removing liquid from the upper surface of a wafer.

Fig. 49 is a bottom view of the elastic membrane shown in fig. 48.

FIG. 50 is a schematic view showing the situation in which the elastic membrane shown in FIG. 48 is removing liquid from the upper surface of the wafer.

Fig. 51 is a cross-sectional view schematically showing the polishing head.

Fig. 52 is a diagram illustrating a state in which the polishing head is being cleaned.

Fig. 53 is a diagram for explaining a situation where the polishing head is prevented from applying an appropriate force to the wafer due to a liquid present between the upper surface of the wafer and the elastic film of the polishing head.

Fig. 54 is a schematic plan view of a substrate processing apparatus including a substrate polishing apparatus.

Fig. 55 is a schematic perspective view of the substrate polishing apparatus 300.

Fig. 56 is a schematic sectional view of the peripheral portion of the top ring 1.

Fig. 57A is a diagram for explaining in detail the substrate transfer from the conveyance mechanism 600b to the top ring 1.

Fig. 57B is a diagram for explaining in detail the substrate transfer from the conveyance mechanism 600B to the top ring 1.

Fig. 57C is a diagram for explaining in detail the substrate transfer from the conveyance mechanism 600b to the top ring 1.

Fig. 58 is a diagram illustrating in detail delivery of the substrate from the conveyance mechanism 600b to the top ring 1.

Fig. 59A is a diagram illustrating in detail delivery of the substrate from the top ring 1 to the conveyance mechanism 600 b.

Fig. 59B is a diagram illustrating in detail delivery of the substrate from the top ring 1 to the conveyance mechanism 600B.

Fig. 59C is a diagram illustrating in detail delivery of the substrate from the top ring 1 to the conveyance mechanism 600 b.

Fig. 60 is a diagram illustrating in detail delivery of the substrate from the top ring 1 to the conveyance mechanism 600 b.

Fig. 61 is a diagram showing a schematic configuration of a substrate polishing apparatus 300 including a quantitative gas supply device 16 according to a seventh embodiment.

Fig. 62 is a diagram schematically showing an operating state of the substrate polishing apparatus 300 when the substrate is transferred from the conveyance mechanism 600b to the top ring 1.

Fig. 63 is a diagram schematically showing an operating state of the substrate polishing apparatus 300 at the time of polishing a substrate.

Fig. 64 is a diagram schematically showing an operating state of the substrate polishing apparatus 300 when the substrate is released.

Fig. 65 is a diagram showing a schematic configuration of a substrate polishing apparatus 300 including the quantitative gas supply device 16 according to the eighth embodiment.

Fig. 66 is a diagram schematically showing an operating state of the substrate polishing apparatus 300 when the substrate is transferred from the conveyance mechanism 600b to the top ring 1.

Fig. 67 is a diagram schematically showing an operating state of the substrate polishing apparatus 300 at the time of polishing a substrate.

Fig. 68 is a diagram schematically showing an operating state of the substrate polishing apparatus 300 when the substrate is released.

Detailed Description

(first to fourth embodiments)

Patent document 1 discloses a substrate adsorption determination method for determining whether or not a substrate is adsorbed on a film. The method provides the membrane with an upwardly directed protrusion. Further, the following is utilized: when the substrate is not adsorbed, a gap exists between the lower surface of the top ring main body and the convex part of the diaphragm; when the substrate is sucked, the substrate presses the diaphragm upward, and the convex portion of the diaphragm comes into contact with the lower surface of the top ring body, thereby eliminating the gap.

However, sometimes the surface of the membrane or the substrate itself is wetted. In this way, when the diaphragm or the substrate is wet, even if the substrate is attracted, the force with which the substrate presses the diaphragm is dispersed, and the convex portion of the diaphragm may not sufficiently contact the lower surface of the top ring body. This may cause the substrate to be erroneously determined as not being adsorbed.

Therefore, it is also conceivable to narrow the gap between the convex portion of the diaphragm and the top ring in advance. However, this has the following problems: when polishing is performed in a state where the membrane has attracted the substrate, the polishing rate of only the portion of the substrate corresponding to the convex portion becomes high, and uniform polishing becomes difficult.

The first to fourth embodiments are made in view of such problems, and the problems of the first to fourth embodiments are: provided are a substrate holding device capable of determining with higher accuracy that a substrate has been adsorbed, and a substrate polishing device provided with such a substrate holding device, and further provided are a substrate adsorption determination method capable of determining with higher accuracy that a substrate has been adsorbed, and a substrate polishing method using such a substrate adsorption determination method.

According to the first to fourth embodiments, the following means is provided.

According to this aspect, there is provided a substrate holding apparatus including: a top ring main body to which an elastic film having a surface capable of adsorbing a substrate is attachable and which has a plurality of regions formed between the elastic film and the top ring main body when the elastic film is attached; a first line in communication with a first zone of the plurality of zones; a second line communicating with a second region of the plurality of regions different from the first region; a pressure adjusting means capable of pressurizing the first region by feeding a fluid through the first line and capable of making the second region negative pressure through the second line; and a determination unit that determines whether or not the substrate is adsorbed to the elastic film based on a volume of the fluid supplied to the first region or a measurement value corresponding to a pressure in the first region, and the substrate holding device does not perform evacuation from the first region when the determination is performed.

The determination unit may perform the determination by using: the volume of the fluid sent into the first region is small or the pressure of the first region is high in the case where the substrate is adsorbed, as compared with the case where the substrate is not adsorbed to the elastic film.

The pressure adjustment unit may include a pressurizing mechanism that feeds the fluid into the first region via the first line, and the determination unit may include a position sensor that detects a portion of the pressurizing mechanism that moves when the fluid is fed into the first region as a measurement value corresponding to a volume of the fluid fed into the first region.

The determination unit may have a pressure gauge for measuring the pressure in the first region.

The pressure adjustment unit may include a pressurizing mechanism that feeds the fluid into the first region via the first line, and the determination unit may include: a position sensor that detects a part of the pressurizing mechanism that moves when the fluid is sent into the first region as a measurement value corresponding to a volume of the fluid sent into the first region; and a pressure gauge that measures the pressure of the first region.

The determination unit may determine that the substrate is not attached to the elastic membrane based on a detection result of the position sensor, and the determination unit may determine that the substrate is attached to the elastic membrane based on a measurement result of the pressure gauge.

The pressurizing mechanism may include a cylinder and a weight body coupled to a piston of the cylinder, and the weight body may move downward by gravity to send the fluid into the first region.

The piston may be vertically movable in a state of being in contact with an inner surface of the cylinder, the cylinder may be partitioned into a lower space and an upper space by the piston, and the cylinder may include: a first opening provided in the lower space and connected to the first pipeline; a second opening provided in the lower space; a third opening provided in the upper space, through which a piston rod connecting the counterweight main body and the piston passes; and a fourth opening provided in the upper space.

When the determination is made, the second opening may be closed and the fourth opening may be opened, and after the determination is made, the second opening may be opened and the upper space may be sucked from the fourth opening to raise the counterweight.

The first line may be connected to the first opening of the cylinder and a polishing pressure control unit that pressurizes the first region when polishing the substrate attached to the elastic membrane, and the substrate holding device may be provided with a switching means that switches whether to communicate the first region with the first opening of the pressurization mechanism via the first line or to communicate the first region with the polishing pressure control unit via the first line.

According to another aspect, there is provided a substrate polishing apparatus including the substrate holding apparatus and a polishing table configured to polish the substrate held by the substrate holding apparatus.

According to another aspect, there is provided a substrate adsorption determination method in a substrate holding apparatus, wherein a second region formed between a top ring main body and an elastic membrane in the substrate holding apparatus is set to a negative pressure, and a fluid is supplied to a first region formed between the top ring main body and the elastic membrane, the first region being different from the second region, thereby pressurizing the first region, and a determination is made as to whether or not the substrate is adsorbed to the elastic membrane based on a volume of the fluid supplied to the first region or a measurement value corresponding to a pressure of the first region, and when the determination is made, air is not discharged from the first region.

According to another aspect, there is provided a substrate polishing method including the steps of: a step of making the substrate held by the conveying mechanism adsorbed on the substrate holding device; a step of determining whether or not the substrate is adsorbed to the elastic film of the substrate holding device by the substrate adsorption determination method; and polishing the substrate when it is determined that the substrate is adsorbed.

Hereinafter, the description will be specifically made with reference to the drawings.

(first embodiment)

Fig. 1 is a schematic plan view of a substrate processing apparatus including a substrate polishing apparatus. The substrate processing apparatus processes various substrates in a process of manufacturing a magnetic film in a semiconductor wafer having a diameter of 300mm or 450mm, a flat panel, an image sensor such as a CMOS (Complementary Metal oxide semiconductor) or a CCD (Charge Coupled Device), or an MRAM (magnetic Random Access Memory).

The substrate processing apparatus includes: a substantially rectangular-shaped housing 100; a load port 200 for placing a substrate cassette for storing a plurality of substrates; one or more (four in the version shown in fig. 1) substrate polishing apparatuses 300; one or more (two in the illustrated version of fig. 1) substrate cleaning apparatuses 400; a substrate drying device 500; the conveyance mechanisms 600a to 600d, and the control unit 700.

The load port 200 is configured to abut the housing 100. The load port 200 can be loaded with an open cassette, a Standard Mechanical Interface (SMIF) Pod, or a Front Opening Unified Pod (FOUP). SMIF pod and FOUP are sealed containers that house substrate cassettes inside and are covered with partition walls, thereby ensuring an environment independent of the external space.

The housing 100 accommodates a substrate polishing apparatus 300 for polishing a substrate, a substrate cleaning apparatus 400 for cleaning the polished substrate, and a substrate drying apparatus 500 for drying the cleaned substrate. The substrate polishing apparatus 300 is arranged along the longitudinal direction of the substrate processing apparatus, and the substrate cleaning apparatus 400 and the substrate drying apparatus 500 are also arranged along the longitudinal direction of the substrate processing apparatus.

The conveyance mechanism 600a is disposed in a region surrounded by the load port 200, the substrate polishing apparatus 300 located on the load port 200 side, and the substrate drying apparatus 500. Further, the conveyance mechanism 600b is disposed in parallel with the substrate polishing apparatus 300, the substrate cleaning apparatus 400, and the substrate drying apparatus 500.

The transfer mechanism 600a receives the substrate before polishing from the load port 200 and delivers the substrate to the transfer mechanism 600b, or receives the substrate after drying from the substrate drying apparatus 500.

The conveyance mechanism 600b is, for example, a linear conveyance device, and delivers the substrate before polishing received from the conveyance mechanism 600a to the substrate polishing apparatus 300. As described later, the top ring (not shown) in the substrate polishing apparatus 300 receives the substrate from the conveyance mechanism 600b by vacuum suction. The substrate polishing apparatus 300 releases the polished substrate to the transfer mechanism 600b, and the substrate is delivered to the substrate cleaning apparatus 400.

Further, a transfer mechanism 600c is disposed between the two substrate cleaning apparatuses 400, and the transfer mechanism 600c transfers substrates between the substrate cleaning apparatuses 400. Further, a conveyance mechanism 600d is disposed between the substrate cleaning apparatus 400 and the substrate drying apparatus 500, and the conveyance mechanism 600d transfers substrates between the substrate cleaning apparatus 400 and the substrate drying apparatus 500.

The controller 700 may control the operation of each device of the substrate processing apparatus, and may be disposed inside the housing 100, outside the housing 100, or in each of the substrate polishing apparatus 300, the substrate cleaning apparatus 400, and the substrate drying apparatus 500.

Fig. 2 and 3 are a schematic perspective view and a schematic cross-sectional view of the substrate polishing apparatus 300, respectively. The substrate polishing apparatus 300 includes: a top ring 1, a top ring shaft 2 having the top ring 1 connected to a lower portion thereof, a polishing table 3 having a polishing surface 3a, a nozzle 4 for supplying a polishing liquid to the polishing table 3, a top ring head 5, and a support shaft 6.

The top ring 1 is for holding a substrate W, and as shown in fig. 3, the top ring 1 includes a top ring main body (also referred to as a carrier or a base plate) 11, an annular retainer ring 12, a flexible diaphragm 13 (elastic film) that can be attached to the lower side of the top ring main body 11 and inside the retainer ring 12, an air bag 14 provided between the top ring main body 11 and the retainer ring 12, and a pressure control device 7.

The guard ring 12 is provided on the outer peripheral portion of the top ring body 11. The peripheral edge of the held substrate W is surrounded by the retainer ring 12, and the substrate W does not fly out of the top ring 1 during polishing. The guard ring 12 may be a single member or may be a double ring structure including an inner ring and an outer ring provided outside the inner ring. In the latter case, the outer ring may be fixed to the top ring body 11, and the bladder 14 may be provided between the inner ring and the top ring body 11.

The diaphragm 13 is disposed opposite to the top ring body 11. A plurality of concentric circular regions are formed between the upper surface of the diaphragm 13 and the top ring body 11. By making one or more regions negative pressure, the lower surface of the film 13 can hold the upper surface of the substrate W.

The air bag 14 is provided between the top ring body 11 and the guard ring 12. The retainer ring 12 is movable relative to the top ring body 11 in the vertical direction by the airbag 14.

The pressure control device 7 adjusts the pressure in each region formed between the top ring body 11 and the diaphragm 13 by supplying a fluid between the top ring body 11 and the diaphragm 13, or by evacuating or opening to the atmosphere. Further, the pressure control device 7 determines whether or not the substrate W is adsorbed on the diaphragm 13. The structure of the pressure control device 7 will be described in detail later.

In fig. 2, the lower end of the top ring shaft 2 is connected to the center of the upper surface of the top ring 1. The top ring shaft 2 is moved up and down by an unillustrated lift mechanism, and the lower surface of the substrate W held by the top ring 1 is brought into contact with or separated from the polishing pad 3 a. Further, the top ring 1 is rotated by rotating the top ring shaft 2 by a motor not shown, and the substrate W held thereby is also rotated.

A polishing pad 3a is provided on the upper surface of the polishing table 3. The lower surface of the polishing table 3 is connected to the rotating shaft, and the polishing table 3 is rotatable. The polishing liquid is supplied from the nozzle 4, and the substrate W and the polishing table 3 are rotated while the lower surface of the substrate W is in contact with the polishing pad 3a, thereby polishing the substrate W.

One end of the top ring head 5 of fig. 3 is coupled to the top ring shaft 2, and the other end is coupled to the support shaft 6. The top ring 1 reciprocates between a substrate delivery position (not shown) and a polishing pad 3a by swinging the top ring head 5 by rotating the support shaft 6 by a motor (not shown).

Next, an operation when delivering and receiving a substrate from the conveyance mechanism 600b of fig. 1 to the top ring 1 of fig. 2 and 3 will be described.

Fig. 4A to 4C and fig. 5 are views for explaining in detail the substrate transfer from the conveyance mechanism 600b to the top ring 1. Fig. 4A to 4C are diagrams of the conveyance mechanism 600b and the top ring 1 as viewed from the side, and fig. 5 is a diagram of the conveyance mechanism 600b and the top ring 1 as viewed from above.

As shown in fig. 4A, a substrate W is placed on a hand 601 of the conveyance mechanism 600 b. The retainer ring stage 800 is used for transferring the substrate W. The retainer ring stage 800 has an push-up pin 801 that pushes up the retainer ring 12 of the top ring 1. Further, the guard ring stage 800 may have a release nozzle, but is not illustrated.

As shown in fig. 5, the hand 601 supports a part of the outer periphery of the lower surface of the substrate W. Also, the upper push pin 801 and the hand 601 are configured not to contact each other.

In the state shown in fig. 4A, the top ring 1 is lowered, and the conveying mechanism 600b is raised. The push-up pins 801 push up the guard ring 12 due to the lowering of the top ring 1, and the substrate W approaches the diaphragm 13. When the conveyance mechanism 600B further ascends, the upper surface of the substrate W comes into contact with the lower surface of the film 13 (fig. 4B).

In this state, the area formed between the diaphragm 13 and the top ring body 11 is set to a negative pressure, whereby the substrate is adsorbed on the lower surface of the diaphragm 13 of the top ring 1. However, depending on the case, the substrate W may not be adsorbed on the lower surface of the diaphragm 13 or may fall after being adsorbed once. Therefore, in the present embodiment, determination (substrate suction determination) as to whether or not the substrate W is already sucked to the membrane 13 is performed as described later.

Thereafter, the conveyance mechanism 600b is lowered (fig. 4C).

Next, the top ring 1 will be explained.

Fig. 6 is a diagram schematically showing the structure of the top ring 1 and the pressure control device 7. The diaphragm 13 has peripheral walls 13a to 13e extending upward toward the top ring body 11. The peripheral walls 13a to 13e form concentric circular regions 131 to 135 defined by the peripheral walls 13a to 13e between the upper surface of the diaphragm 13 and the lower surface of the top ring body 11. Further, it is preferable that no hole is formed in the lower surface of the diaphragm 13.

Flow paths 141 to 145 having one ends communicating with the regions 131 to 135 are formed so as to penetrate the top ring body 11. Further, an air bag 14 made of an elastic film is provided directly above the guard ring 12, and a flow path 146 having one end communicating with the air bag 14 is similarly formed. The other ends of the flow paths 141 to 146 are connected to a pressure control device 7. The flow paths 141 to 146 may be provided with pressure sensors and flow sensors.

The pressure control device 7 includes valves V1 to V6 and pressure regulators R1 to R6 provided in the respective flow paths 141 to 146, a control unit 71, a pressure adjusting unit 72, and a determination unit 73 for determining substrate adsorption.

The controller 71 controls the valves V1 to V6, the pressure regulators R1 to R6, and the pressure adjusting unit 72.

The pressure adjusting means 72 is connected to one end of the flow paths 141 to 146, and adjusts the pressures of the areas 131 to 135 and the air bag 14, respectively, under the control of the control unit 71. Specifically, the pressure adjusting means 72 supplies a fluid such as air through the flow paths 141 to 146 to pressurize the regions 131 to 135 and the air bag 14, or reduces the pressure of the regions 131 to 135 and the air bag 14 by evacuation, or opens the regions 131 to 135 and the air bag 14 to the atmosphere.

In fig. 6, for example, in order to pressurize the region 135, the control unit 71 controls the pressure adjustment unit 72 so that the valve V5 is opened to supply air to the region 135. This case will be briefly described as (the control unit 71) pressurizing the region 135.

In the present embodiment, the substrate suction determination is performed by using the region 131. Therefore, the pressure adjusting unit 72 has a pressurizing mechanism 150, and the pressurizing mechanism 150 can pressurize the region 131 by feeding a fluid (gas or liquid) into the region 131.

The pressure determination will be described in detail below.

Fig. 7 is a diagram illustrating pressure determination according to the first embodiment. In the following drawings, the whole is depicted in a simplified manner. The pressurizing mechanism 150 in the present embodiment performs pressurization by a cylinder driving method, and includes a pressurizing-side cylinder 21, a pressurizing piston 22, a driving-side cylinder 23, a driving pressure generating unit 24, a driving piston 25, a connecting member 26, and a plate 27. The determination unit 73 includes a position sensor 28.

The pressure-side cylinder 21 is cylindrical with an open front end 21a and extends in the horizontal direction, and a flow path 141 is connected to an opening 21c formed in a closed surface 21b (bottom surface). The pressurizing piston 22 is disc-shaped and slidably contacts the inner surface of the pressurizing cylinder 21. The pressurizing piston 22 is provided with a fluid seal (not shown), and the fluid does not move inside or outside the pressurizing cylinder 21.

The drive-side cylinder 23 is disposed separately from and opposite to the pressure-side cylinder 21. The driving side cylinder 23 is also cylindrical with an open front end 23a and extends in the horizontal direction, and a driving pressure generating section 24 is connected to an opening 23c formed in the closed surface 23b (bottom surface). The driving piston 25 is disc-shaped and slidably contacts the inner surface of the driving cylinder 23. A fluid seal (not shown) is provided in the driving piston 25, and fluid does not move inside or outside the driving side cylinder 23.

The center portion of the pressurizing piston 22 and the center portion of the driving piston 25 are connected by a rod-shaped connecting member 26, and the pressurizing piston 22 and the driving piston 25 are integrated.

The plate 27 is an annular member fitted and fixed to the coupling member 26. The diameter of the plate 27 is larger than the inner diameters of the pressure-side cylinder 21 and the drive-side cylinder 23.

With the above configuration, the pressurizing piston 22 and the driving piston 25, which have been integrated, can move in the range where the plate 27 is located between the top end 23a of the driving side cylinder 23 and the top end 21a of the pressurizing side cylinder 21. In a standby state before the substrate suction determination is performed, the plate 27 is located near the distal end 23a of the driving-side cylinder 23 (e.g., a position where one surface of the plate 27 contacts the distal end 23a of the driving-side cylinder 23), and this position is set as the origin.

The position sensor 28 includes an origin detection sensor 28a, a substrate presence detection sensor 28b, and a substrate absence detection sensor 28 c. The origin detection sensor 28a is disposed near the tip 23a of the driving side cylinder 23. The substrate detection sensor 28b is disposed near the center of the distal end 23a of the drive-side cylinder 23 and the distal end 21a of the pressure-side cylinder 21. The substrate absence detection sensor 28c is disposed near the tip end 21a of the pressurizing side cylinder 21. In this way, the substrate absence detection sensor 28c, the substrate presence detection sensor 28b, and the origin detection sensor 28a are arranged in this order from the side close to the region 131. The position sensor 28 may be any sensor that can detect the position of the plate 27 directly, as long as it can detect the position of the plate 27.

Each position sensor 28 detects plate 27. More specifically, the origin detection sensor 28a detects the presence of the plate 27 at the position of the origin. The presence-of-substrate detection sensor 28b detects the presence of the plate 27 at a predetermined position (described later in detail) when the substrate W is adsorbed to the membrane 13. The substrate absence detection sensor 28c detects the presence of the plate 27 at a predetermined position when the substrate W is not adsorbed to the diaphragm 13, in other words, a predetermined position set near the tip end 21a of the pressure-side cylinder 21.

When the substrate W is sucked (fig. 4B), the control unit 71 sets a negative pressure in any one or more regions (regions 132 to 135 in the present embodiment) other than the region 131. Thus, the substrate W is adsorbed on the lower surface of the diaphragm 13 (see fig. 8A), but may fail in some cases (see fig. 8B). Therefore, as described below, it is determined whether or not the substrate adsorption is successful.

The driving pressure generating portion 24 applies a pressure P1 to the driving piston 25. Thereby, the driving piston 25, the pressurizing piston 22, and the plate 27 are pushed in and moved in a direction approaching the region 131. As a result, the air in the pressurizing cylinder 21 is sent to the area 131, and the area 131 is pressurized. In addition, no venting is required from region 131 at this time.

Fig. 8A is a diagram showing a case where the substrate adsorption is successful. When the substrate W is sucked, even if the region 131 is pressurized, the regions 132 to 135 are set to the negative pressure, and therefore the substrate W does not fall off the diaphragm 13 (in other words, the pressure P1 is set to a level at which the sucked substrate W does not fall off). Therefore, even if the region 131 is pressurized, the diaphragm 13 does not expand, and the increase in volume of the region 131 is small.

Therefore, as the pressurizing piston 22 moves toward the region 131, the pressure in the region 131 (more precisely, the pressure in the space formed by the region 131, the flow path 141, the pressurizing cylinder 21, and the pressurizing piston 22, the same applies hereinafter) increases. When the pressure in the region 131 reaches P1, the pressure in the region 131 and the pressure from the driving pressure generating unit 24 are balanced, and the movement of the pressurizing piston 22 (i.e., the plate 27) is stopped.

At this time, the pressurizing piston 22 does not reach the closed surface 21b of the pressurizing cylinder 21 and the plate 27 does not reach the distal end 21a of the pressurizing cylinder 21, but the plate 27 is stopped at a position between the distal end 25a of the driving piston 25 and the distal end 21a of the pressurizing cylinder 21. The presence of the plate 27 at this position is detected by the presence of the substrate detection sensor 28b, and the determination unit 73 determines that the substrate W has been adsorbed.

Further, it is sufficient to know in advance to which position the plate 27 moves when the substrate W is adsorbed, and to dispose the substrate detection sensor 28b so as to be able to detect the plate 27 at that position.

Fig. 8B is a diagram showing a case where the substrate adsorption fails. When the region 131 is pressurized without the substrate W being adsorbed, the diaphragm 13 expands, and the volume of the region 131 increases. At this time, the pressure P2 is generated by the repulsive force of the diaphragm 13. However, the pressure P2 is less than the pressure P1 from the drive pressure generating portion 24. Therefore, the plate 27 moves until the pressurizing piston 22 reaches the closing surface 21b of the pressurizing cylinder 21 (or until the plate 27 reaches the top end 21a of the pressurizing cylinder 21). The presence of the plate 27 at this position is detected by the substrate absence detection sensor 28c, and the determination unit 73 determines that the substrate W is not adsorbed.

Thus, the volume of the pressurized fluid fed into the region 131 is relatively small when the substrate W is adsorbed (fig. 8A), and the volume of the pressurized fluid fed into the region 131 is relatively large when the substrate W is not adsorbed (fig. 8B). The presence or absence of substrate adsorption can be determined by setting the position of the detection plate 27 to a value corresponding to the volume.

Further, the plate 27 moves from the origin to a position where there is no substrate detection sensor 28c through a position where there is a substrate detection sensor 28 b. Therefore, even when the substrate W is not adsorbed, the substrate detection sensor 28b temporarily detects the plate 27. That is, the substrate detection sensor 28b detects the plate 27 at least temporarily regardless of whether or not the substrate W is adsorbed. Therefore, it is preferable that the determination unit 73 determines that the substrate W is adsorbed when the substrate detection sensor 28b detects the plate 27 not temporarily but for a predetermined time.

Alternatively, the determination unit 73 may determine the pressure P1 applied by the driving pressure generation unit 24 based on the detection results of the substrate detection sensors 28b and 28c with respect to the plate 27 after a predetermined time (expected to be the time required for the plate 27 to move from the origin to the position of the substrate detection sensor 28c without the substrate W being sucked) or longer has elapsed.

Fig. 9 is a flowchart showing an example of a procedure for determining substrate adsorption in the first embodiment. Further, assume that: initially, the plate 27 is located at the origin, which is confirmed by the origin detection sensor 28 a.

First, the driving pressure generating unit 24 applies the pressure P1 to pressurize the region 131 by the pressurizing piston 22 (step S1).

When the substrate detection sensor 28b detects the plate 27 for the predetermined time (yes in step S2), the determination unit 73 determines that the suction of the substrate W is successful (step S3). On the other hand, when the substrate detection sensor 28b detects the plate 27 temporarily (no in step S2) and thereafter the substrate detection sensor 28c does not detect the plate 27 (step S4), the determination unit 73 determines that the suction of the substrate W has failed (step S5).

In this way, in the first embodiment, the presence or absence of substrate adsorption can be determined with high accuracy by utilizing the difference in the volume of the pressurized fluid sent to the region 131, that is, the difference in the amount of movement of the plate 27, depending on whether or not the substrate W is adsorbed.

Although the example in which the origin detection sensor 28a, the substrate presence detection sensor 28b, and the substrate absence detection sensor 28c are used as the position sensors 28 is shown, a linear gauge sensor may be used to always grasp the position of the plate 27. The detection by the position sensor 28 may be a part of the pressing mechanism 150 that moves when pressing the region 131, and may not necessarily be the plate 27.

The substrate suction determination described above can be performed at an arbitrary timing of the substrate W, but is effective particularly for determination before polishing. This is because the adsorption may be performed before polishing when the top ring cleaning water or the like is still present on the substrate W, and the possibility of failure of the substrate adsorption is higher than after polishing.

(second embodiment)

In a second embodiment to be described next, the structure of the pressing mechanism 150 is different from that of the first embodiment.

Fig. 10 is a diagram illustrating pressure determination according to the second embodiment. The pressurizing mechanism 150 in the present embodiment pressurizes the air by a counterweight driving method, and includes an air cylinder 31, a counterweight 32, and a stopper 33. The determination unit 73 includes the position sensor 34.

The cylinder 31 is cylindrical with an open top end 31a and extends in the vertical direction, and a flow path 141 is connected to an opening 31c formed in a closed surface 31b (bottom surface).

The weight 32 is constituted by a weight main body 32a, a piston 32b, and an upper surface plate 32 c. The piston 32b is directly connected to and integrated with the weight main body 32a, and also functions as a piston of the cylinder 31. The weight body 32a has a cylindrical shape and a diameter smaller than the inner diameter of the cylinder 31. Therefore, the weight main body 32a can move up and down in the cylinder 31. The piston 32b is disc-shaped having a diameter larger than that of the weight main body 32a, and slidably contacts the inner surface of the cylinder 31. The piston 32b is provided with a fluid seal (not shown), and fluid does not move inside and outside the cylinder 31. The upper surface plate 32c has a disk shape with a diameter larger than the inner diameters of the weight main body 32a and the cylinder 31.

The stopper 33 is disposed above the cylinder 31, and supports the lower surface of the upper surface plate 32c of the counterweight 32 on the upper surface of the shoulder 33a, thereby preventing the counterweight 32 from falling. When the stopper 33 is released (i.e., the shoulder 33a is inclined around the shaft 33b of the stopper 33), the counterweight 32 falls. The stopper 33 may be released by the control unit 71 or manually.

The weight body 32a and the stopper 33 may be regarded as an alternative to the driving pressure generating portion 24 in the first embodiment, and the piston 32b may be regarded as an alternative to the pressurizing piston 22 in the first embodiment.

The position sensor 34 includes an origin detection sensor 34a, a substrate presence detection sensor 34b, and a substrate absence detection sensor 34 c. The origin detection sensor 34a is disposed slightly above the shoulder 33a of the stopper 33. The substrate detection sensor 34b is disposed between the stopper 33 and the distal end 31a of the cylinder 31. The substrate absence detection sensor 34c is disposed slightly above the tip end 31a of the cylinder 31. Similarly to the first embodiment, the substrate absence detection sensor 34c, the substrate presence detection sensor 34b, and the origin detection sensor 34a are arranged in this order from the side close to the region 131.

Each position sensor 34 detects the upper surface plate 32c of the counterweight 32. More specifically, the origin detection sensor 34a detects the presence of the upper surface plate 32c at a position where the counterweight 32 is supported by the stopper 33 (the position is taken as the origin). The presence of the upper surface plate 32c at a predetermined position (described later in detail) when the substrate W is adsorbed to the membrane 13 is detected by the substrate detection sensor 34 b. The substrate absence detection sensor 34c detects the presence of the upper surface plate 32c at a position where the substrate W is not adsorbed to the diaphragm 13, that is, at a predetermined position set near the tip end 31a of the air cylinder 31.

In the present embodiment, whether or not the substrate adsorption is successful is determined as follows.

To make the determination, the stopper 33 is released. Thereby, the weight 32 falls by gravity, and the piston 32b is pushed in and moves in a direction approaching the region 131. As a result, the air in the cylinder 31 is sent to the area 131, and the area 131 is pressurized. In addition, no venting is required from region 131 at this time.

Fig. 11A is a diagram showing a case where the substrate adsorption is successful. When the substrate W is sucked, even if the region 131 is pressurized, the regions 132 to 135 are set to have a negative pressure, and therefore, the substrate W does not fall off the diaphragm 13 (in other words, the weight of the weight 32 is set to such an extent that the sucked substrate W does not fall off). Therefore, even if the region 131 is pressurized, the diaphragm 13 does not expand, and the increase in volume of the region 131 is small.

Therefore, as the piston 32b moves toward (downward of) the region 131, the pressure in the region 131 (more precisely, the pressure in the space formed by the region 131, the flow path 141, the cylinder 31, and the piston 32b, which will be the same hereinafter) increases. Further, the pressure in the region 131 is balanced with the pressure generated by the weight 32, and the movement of the piston 32b is stopped. Of course, the upper surface plate 32c also stops.

At this time, the piston 32b does not reach the closing surface 31b of the cylinder 31 and the upper surface plate 32c does not reach the top end 31a of the cylinder 31, but the upper surface plate 32c stops at a position between the origin and the top end 31a of the cylinder 31. The presence of the upper surface plate 32c at this position is detected by the substrate detection sensor 34b, and the determination unit 73 determines that the substrate W has been adsorbed.

Further, it is sufficient to know in advance to which position the upper surface plate 32c has moved when the substrate W is attracted, and to dispose the substrate detection sensor 34b so as to be able to detect the upper surface plate 32c at that position.

Fig. 11B is a diagram showing a case where the substrate adsorption fails. When the region 131 is pressurized without the substrate W being adsorbed, the diaphragm 13 expands, and the volume of the region 131 increases. At this time, the pressure P2 is generated by the repulsive force of the diaphragm 13. However, the pressure P2 is less than the pressure generated by the counterweight 32. Therefore, the weight 32 falls until the piston 32b reaches the closing surface 31b of the cylinder 31 or the upper surface plate 32c reaches the top end 31a of the cylinder 31. The presence of the upper surface plate 32c at this position is detected by the substrate absence detection sensor 34c, and the determination unit 73 determines that the substrate W is not adsorbed.

As described above, the volume of the pressurized fluid fed into the region 131 is relatively small in the case where the substrate W is adsorbed (fig. 11A), and the volume of the pressurized fluid fed into the region 131 is relatively large in the case where the substrate W is not adsorbed (fig. 11B). By detecting the position of the upper surface plate 32c as a value corresponding to the volume, the presence or absence of substrate adsorption can be determined.

The upper surface plate 32c moves from the origin to a position where there is no substrate detection sensor 34c through a position where there is a substrate detection sensor 34 b. Therefore, even when the substrate W is not adsorbed, the substrate detection sensor 34b temporarily detects the upper surface plate 32 c. That is, the substrate detection sensor 34b detects the upper surface plate 32c at least temporarily regardless of whether or not the substrate W is adsorbed. Therefore, it is preferable that the determination unit 73 determines that the substrate W is adsorbed when the substrate detection sensor 34b detects the upper surface plate 32c not temporarily but for a predetermined time.

Alternatively, the determination unit 73 may determine based on the detection results of the presence of the substrate detection sensor 34b and the absence of the substrate detection sensor 34c on the basis of the detection results of the upper surface plate 32c after a predetermined time (expected to be the time required for the upper surface plate 32c to move from the origin to the position of the absence of the substrate detection sensor 34c when the substrate W is not adsorbed) has elapsed after the stopper 33 is released.

Fig. 12 is a flowchart showing an example of a procedure for determining substrate adsorption in the second embodiment. Further, assume that: initially, the counterweight 32 is supported by the stopper 33, the upper surface plate 32c is located at the origin, and this condition is confirmed by the origin detection sensor 34 a.

First, the stopper 33 is released, and the counterweight 32 falls to pressurize the region 131 (step S11).

When the substrate detection sensor 34b detects the upper surface plate 32c for a predetermined time (yes in step S12), the determination unit 73 determines that the suction of the substrate W is successful (step S13). On the other hand, when the substrate detection sensor 34b temporarily detects the upper surface plate 32c (no in step S12) and thereafter, when no substrate detection sensor 34c detects the upper surface plate 32c (step S14), the determination unit 73 determines that the suction of the substrate W has failed (step S15).

In this way, in the second embodiment, the presence or absence of substrate adsorption can be determined with high accuracy by utilizing the difference in the volume of the pressurized fluid sent to the region 131, that is, the difference in the amount of movement (amount of fall) of the upper surface plate 32c depending on whether or not the substrate W is adsorbed.

Although the example in which the origin detection sensor 28a, the substrate presence detection sensor 34b, and the substrate absence detection sensor 34c are used as the position sensors 34 is shown, a linear gauge sensor may be used to always grasp the position of the upper surface plate 32 c. Further, as the position sensor 34, an optical sensor, an encoder, a contact sensor, or the like may be used. The detection by the position sensor 34 may be a part of the pressing mechanism 150 that moves when pressing the region 131, and may not necessarily be the upper surface plate 32 c.

Fig. 13 is a diagram illustrating a modification of fig. 10. In fig. 10, the piston 32b and the weight main body 32a are integrated, but as shown in fig. 13, they may be separate members. In this case, the piston 32b provided in the cylinder 31 is connected to the weight main body 32a provided above the cylinder 31 by a piston rod 32d penetrating the upper surface of the cylinder 31. A protrusion 32e is provided on a part (e.g., a lower part) of the weight main body 32a, and the position sensor 34 detects the protrusion 32 e.

In the following embodiments, the description will be given mainly of a configuration in which the piston and the weight main body are integrated, but they may be separate members.

(third embodiment)

In the third embodiment described below, a pressure gauge for measuring the pressure in the region 131 is used instead of the position sensors 28 and 34 described in the first and second embodiments. Hereinafter, the pressing mechanism 150 shown in the second embodiment will be described as an example, but the present invention can also be applied to the first embodiment.

Fig. 14 is a diagram illustrating pressure determination according to the third embodiment. The determination unit 73 in the present embodiment includes a pressure gauge 40. The pressure gauge 40 may be provided in the flow path 141, for example, as long as it can measure the pressure in the region 131, but may be provided in another position. The pressure (initial pressure) of the region 131 when the counterweight 32 is supported by the stopper 33 is P0.

Fig. 15A is a diagram showing a case where the substrate adsorption is successful. When the substrate W is adsorbed, the weight 32 falls to send air into the region 131, but the diaphragm 13 does not expand, and the volume of the region 131 increases little. Therefore, the pressure of the region 131 becomes high due to the fed air. The pressure at this time was set to P11.

Fig. 15B is a diagram showing a case where the substrate adsorption fails. In the case where the substrate W is not adsorbed, the weight 32 falls to send air into the region 131, but accordingly, the diaphragm 13 expands and the volume of the region 131 increases. Therefore, the pressure in the region 131 is slightly higher. The pressure at this time was set to P12. Here, the relationship is pressure P0 < pressure P12 < pressure P11.

Therefore, the determination unit 73 can determine that the substrate W is adsorbed when the pressure measured by the pressure gauge 40 reaches P11. On the other hand, when the measured pressure does not reach P11, the determination unit 73 can determine that the substrate W is not adsorbed.

Further, the pressure of region 131 passes from pressure P0 to pressure P12 to pressure P11. Therefore, even when the substrate W is attracted, the pressure in the region 131 temporarily becomes P12. That is, the pressure of the region 131 becomes P12 at least temporarily regardless of whether the substrate W is adsorbed. Therefore, the determination unit 73 preferably determines that the substrate W is not adsorbed when the pressure reaches P12, but determines whether or not the pressure in the region 131 reaches P11 after a predetermined time or more has elapsed since the end of the time.

Alternatively, the determination unit 73 may determine that the substrate W is not adsorbed when the pressure in the region 131 does not become higher than P12 for a predetermined time period, not temporarily.

Fig. 16 is a flowchart showing an example of a procedure for determining substrate adsorption in the third embodiment. Assume that: initially, the counterweight 32 is supported by the stopper 33, the upper surface plate 32c is located at the origin, and this condition is confirmed by the origin detection sensor 34 a.

First, the stopper 33 is released, and the hammer 32 falls down to pressurize the region 131 (step S21). When the pressure in the region 131 reaches P11 before the predetermined time elapses ("yes" in step S22 and "no" in step S23), the determination unit 73 determines that the suction of the substrate W is successful (step S24). On the other hand, when the pressure in the region 131 does not reach P11 even after the predetermined time has elapsed (yes in step S23), the determination unit 73 determines that the suction of the substrate W has failed (step S25).

In this way, in the third embodiment, the presence or absence of substrate suction can be determined with high accuracy by utilizing the fact that the pressure of the region 131 differs depending on whether or not the substrate W is sucked.

(fourth embodiment)

Fig. 17 is a diagram illustrating pressure determination according to the fourth embodiment. The pressurizing mechanism 150 has a cylinder 41, a counterweight 42, and a stopper 43.

The cylinder 41 is cylindrical and extends in the vertical direction, and has openings 41a and 41b formed in a lower surface 411, an opening 41c formed in an upper surface 412, and an opening 41d formed in a side surface 413. That is, the openings 41a, 41b are located on the lower side of the piston 42b, and the opening 41d is located on the upper side of the piston 42 b. The opening 41b is connected to the channel 141 via the channel 141 a. The opening 41a may be opened or closed by a plug (not shown in fig. 17) or the like. The opening 41d may be opened or connected to a vacuum device (not shown). The opening and closing of the openings 41a and 41d may be switched by the control unit 71 or manually.

The weight 42 is constituted by a weight main body 42a, a piston 42b, and an upper surface plate 42 c. The piston 42b is directly connected to and integrated with the weight main body 42a, and also functions as a piston of the cylinder 41. The weight main body 42a has a cylindrical shape and a diameter smaller than the inner diameter of the cylinder 41. Further, weight main body 42a penetrates opening 41c of cylinder 41, and slidably contacts the inner surface of opening 41 c. The piston 42b is disc-shaped having a diameter larger than that of the weight main body 42a, and slidably contacts the inner surface of the cylinder 41. The upper surface plate 42c is a disk shape having a diameter larger than the inner diameter of the weight main body 42a and the opening 41 c.

The stopper 43 has a shoulder 43a, and the shoulder 43a is located above the upper surface plate 42c of the counterweight 42. Therefore, when the upper surface of the upper surface plate 42c abuts against the lower surface of the shoulder portion 43a, the upper surface plate 42c does not move further upward. The stopper 43 may be coupled to or integrated with the upper surface 412 of the cylinder 41, or may be a member separate from the cylinder 41.

With this configuration, the interior of the cylinder 41 is divided into the lower space a1 and the upper space a2 by the piston 42b of the counterweight 42. The positions of the openings 41a to 41d are not limited to those shown in fig. 17, as long as the openings 41a to 41b are provided in the lower space a1 and the openings 41c and 41d are provided in the upper space a 2. Further, a fluid seal (not shown) is provided in the piston 42b, and fluid does not move between the lower space a1 and the upper space a 2. Similarly, a fluid seal (not shown) is provided in the opening 41c in the upper surface 412 of the cylinder 41, and fluid does not move between the upper space a2 and the outside of the cylinder 41.

The determination unit 73 includes a position sensor 44 and a pressure gauge 45.

The position sensor 44 includes an origin detection sensor 44a and a substrate-less detection sensor 44 b. The origin detection sensor 44a is disposed slightly below the shoulder 43a of the stopper 43. The substrate absence detection sensor 44b is disposed slightly above the upper surface 412 of the cylinder 41. Further, the substrate detection sensor may not be provided.

The origin detection sensor 44a detects that the upper surface plate 42c is present at a position (the position is set as the origin) in contact with the shoulder portion 43 a. The substrate absence detection sensor 44b detects the presence of the upper surface plate 42c at a position where the substrate W is not adsorbed to the diaphragm 13, that is, at a predetermined position set near the upper surface 412 of the air cylinder 41.

The pressure gauge 45 may be provided in the flow path 141a, for example, as long as it can measure the pressure in the region 131, but may be provided in another position.

The pressure control device 7 of the present embodiment further includes a switching unit 151 and a polishing pressure controller 152. The flow path 141 is connected to (the cylinder 41 of) the pressurizing mechanism 150 via a flow path 141a, and is connected to the polishing pressure controller 152 via a flow path 141 b.

The switching means 151 is a switching valve or a three-way valve, and switches between communication between the region 131 and the opening 41b of the cylinder 41 via the flow path 141 and communication between the region 131 and the polishing pressure controller 152 via the flow path 141. In other words, the switching unit 151 switches between communication between the channel 141 and the channel 141a and communication between the channel 141 and the channel 141 b. The switching may be performed by the control unit 71 or manually. The polishing pressure controller 152 applies a pressure for polishing to the region 131 during polishing.

Fig. 18 is a diagram showing the pressure control device 7 during standby, that is, before substrate suction determination. The switching unit 151 communicates the channel 141 with the channel 141 a. In addition, the opening 41a is opened. Then, the upper space a2 is evacuated (sucked) from the opening 41d to have a negative pressure. Thereby, the weight 42 is raised until the upper surface plate 42c abuts on the shoulder 43 a. The pressure in the region 131 at this time is P0. When the upper space a2 is set to a negative pressure, the lower space a1 is opened in advance, thereby preventing the negative pressure from being applied to the diaphragm 13.

Further, the counterweight 42 may be raised by pressurizing the lower space a1 without making the upper space a2 negative. However, at the start of the substrate adsorption determination operation, the diaphragm 13 is also pressurized, and the adsorption determination may be affected. Therefore, the upper space a2 is preferably made negative pressure.

In the present embodiment, whether or not the substrate adsorption is successful is determined as follows. When the determination is made, the opening 41a is closed and the opening 41d is opened. Then, the weight 42 falls by gravity, the piston 42b is pushed in and moves in a direction approaching the region 131, and as a result, the air in the lower space a1 in the cylinder 41 is sent to the region 131, and the region 131 is pressurized. In addition, no venting is required from region 131 at this time.

Fig. 19A is a diagram showing a case where the substrate adsorption is successful. The weight 42 falls to send air to the region 131, but the diaphragm 13 hardly expands, so that the pressure of the region 131 becomes high. The pressure at this time was set to P11. The pressure gauge 40 allows the determination unit 73 to determine that the substrate W has been adsorbed when the pressure in the region 131 reaches P11. In this case, the position sensor 44 may not be used for determination.

When the substrate W is successfully sucked, as shown in fig. 20, the switching unit 151 causes the flow path 141 and the flow path 141b to communicate with each other, and the polishing pressure controller 152 pressurizes the region 131 for polishing. The areas 132 to 135 may be pressurized by the control section 71. In this way, the lower surface of the substrate W is polished by the polishing pad 3 a. At this time, opening 41a is opened, and upper space a2 is set to a negative pressure from opening 41d, thereby placing counterweight 42 in a standby state. That is, the counterweight 42 is returned to the origin while the polishing is performed.

Fig. 19B is a diagram showing a case where the substrate adsorption fails. The weight 42 falls to send air into the area 131, and accordingly, the diaphragm 13 expands and the volume of the area 131 increases. At this time, a pressure is generated by the repulsive force of the diaphragm 13. However, this pressure is less than the pressure generated by the counterweight 42. Therefore, the weight 42 falls until the piston 42b reaches the lower surface 411 of the cylinder 41 or the upper surface plate 42c reaches the upper surface 412 of the cylinder 41. The presence of the upper surface plate 42c at this position is detected by the substrate absence detection sensor 43b, and the determination unit 73 determines that the substrate W is not adsorbed. In this case, the pressure gauge 45 may not be used for the determination.

As described above, in the present embodiment, the success of the chucking of the substrate W is determined based on the pressure in the region 131, in other words, based on the pressure measurement result of the pressure gauge 45. On the other hand, the failure of the suction of the substrate W is determined by the detection of the upper surface plate 42c by the non-substrate detection sensor 43 b.

Fig. 21 is a flowchart showing an example of a procedure for determining substrate adsorption in the fourth embodiment. By closing the opening 41a and opening the opening 41d, the counterweight 42 falls down to pressurize the region 131 (step S31).

When the pressure in the region 131 measured by the pressure gauge 45 reaches P11 (yes in step S32), the determination unit 73 determines that the adsorption of the substrate W is successful (step S33). This is different from the first embodiment (step S2 in fig. 9) and the second embodiment (step S12 in fig. 12) in that it is not necessary to wait for a predetermined time until the suction of the substrate W is successfully determined.

On the other hand, when the upper surface plate 42c is detected by the substrate absence detection sensor 43c (yes at step S4), the determination unit 73 determines that the suction of the substrate W has failed (step S35). This is different from the third embodiment (step S23 in fig. 16) in that it is not necessary to wait for a predetermined time until the suction of the substrate W fails.

When the substrate suction determination is completed, the opening 41a is opened, and the upper space a2 is set to a negative pressure from the opening 41d, thereby placing the counterweight 42 in a standby state.

In this way, in the fourth embodiment, the success of the suction of the substrate W is determined from the pressure measurement result of the pressure gauge 45, and the failure of the suction of the substrate W is determined by the non-substrate detection sensor 43 b. Therefore, the determination result can be obtained quickly.

Fig. 22 is a diagram illustrating a modification of fig. 17. In fig. 17, the piston 42b and the weight main body 32a are integrated, but as shown in fig. 22, they may be separate members. In this case, piston 42b provided in cylinder 41 is coupled to weight main body 42a provided above cylinder 41 by piston rod 42d penetrating opening 41c of upper surface 412 of cylinder 41 c. A protrusion 42e is provided at a part (e.g., a lower part) of the weight main body 42a, and the position sensor 44 detects the protrusion 42 e.

In each of the above embodiments, an integrated flowmeter that measures the integrated amount of the fluid fed into the region 131 may be used instead of the position sensor or the pressure gauge. Specifically, as shown in fig. 23A, the integrated flow meter 81 is provided as the determination unit 73 in the flow path 141. Then, the fluid is fed to the channel 141 so that the region 131 has a predetermined pressure.

When the substrate W is adsorbed, the diaphragm 13 does not expand, and thus the volume of the region 131 increases little (fig. 23B). Therefore, even if the amount of fluid fed into the region 131 is (relatively) small, the region 131 is at a predetermined pressure. On the other hand, when the substrate W is not adsorbed, the diaphragm 13 expands, and thus the volume of the region 131 increases (fig. 23C). Therefore, if a relatively large amount of fluid is not supplied to the region 131, the region 131 does not reach a predetermined pressure. Therefore, whether or not the substrate W is adsorbed can be determined based on the integrated flow rate of the fluid measured by the integrated flow meter 81.

Although the example in which the central region 131 is used for substrate suction determination is shown, other regions may be used for substrate suction determination.

In each embodiment, the substrate suction determination is performed by pressurizing the region 131 and using the point that the increase in volume of the region 131 is small when the substrate suction is successful and the increase in volume of the region 131 is large when the substrate suction is failed. Conversely, the area 131 may be sucked and depressurized, and the substrate suction determination may be performed by using a decrease in the volume of the area 131 when the substrate suction is successful and a decrease in the volume of the area 131 when the substrate suction is failed. In this case, the top ring 1 may be designed so that the diaphragm 13 can be deformed inward (toward the top ring body 11).

The above-described embodiments are described for the purpose of enabling a person having ordinary knowledge in the technical field to which the present invention pertains to practice the present invention. It is needless to say that various modifications of the above-described embodiments can be made by those skilled in the art, and the technical idea of the present invention can be applied to other embodiments. Therefore, the present invention should not be limited to the embodiments described above, but should be set to the maximum scope according to the technical idea defined by the claims.

(fifth embodiment)

Chemical Mechanical Polishing (CMP) is a technique that: the surface of the wafer is polished by pressing the wafer against the polishing surface while supplying the slurry to the polishing surface and bringing the wafer into sliding contact with the polishing surface in the presence of the slurry. In polishing a wafer, the wafer is pressed against a polishing surface by a polishing head. The surface of the wafer is planarized by the chemical action of the slurry and the mechanical action of the abrasive particles contained in the slurry.

Fig. 51 is a cross-sectional view schematically showing the polishing head. The polishing head 600 has an elastic membrane 610 in contact with the upper surface of the wafer W1. The elastic membrane 610 has a shape forming a plurality of pressure chambers 601 to 604, and the pressure in each of the pressure chambers 601 to 604 can be independently adjusted. Therefore, the polishing head 600 can press a plurality of regions of the wafer W1 corresponding to the pressure chambers 601 to 604 with different forces, and can realize a desired film thickness profile of the wafer W1.

When the polishing of the wafer W1 is completed, the polished wafer W1 is transported to the next step by the transport device. As shown in fig. 52, the next wafer W2 is transported by the transport device to the delivery position below the polishing head 600. Simultaneously, the polishing head 600 is cleaned with a liquid (e.g., pure water), and slurry and polishing debris are removed from the polishing head 600. Then, the next wafer W2 is held by the polishing head 600, and is carried to a position above the polishing surface by the polishing head 600. The wafer W2 is pressed against the polishing surface by the polishing head 600 and polished in the presence of the slurry.

However, as shown in fig. 53, the liquid Q used for cleaning the polishing head 600 may exist between the upper surface of the wafer W2 and the elastic film 610 of the polishing head 600. When the liquid Q spreads across the plurality of pressure chambers, the pressure in the adjacent pressure chambers is transmitted to the liquid Q, resulting in an undesirable force being applied to the wafer W2. In the example shown in fig. 53, in order to reduce the polishing rate of the central portion of the wafer W2, the pressure in the central pressure chamber 601 is reduced, but the pressure in the adjacent pressure chambers 602 is applied to the central portion of the wafer W2 via the liquid Q. As a result, the polishing rate of the central portion of the wafer W cannot be reduced. Thus, the presence of the liquid Q between the wafer W2 and the polishing head 600 may prevent the polishing head 600 from applying an appropriate force to the wafer W2.

Accordingly, the fifth embodiment provides a method of: the liquid can be removed from the upper surface of the wafer to be polished, and the polishing head can apply an appropriate force to the wafer. In addition, the fifth embodiment provides an elastic membrane capable of removing liquid from the upper surface of the wafer.

According to the fifth embodiment, the following is provided.

In one aspect, there is provided a method of polishing a wafer using a polishing head having a center-side pressure chamber and an outer-side pressure chamber formed of an elastic membrane, wherein a center portion of the elastic membrane is brought into contact with a center portion of an upper surface of the wafer, and thereafter, an outer peripheral portion of the elastic membrane is brought into contact with an outer peripheral portion of the upper surface of the wafer, thereby removing a liquid from the upper surface of the wafer, and a lower surface of the wafer is pressed against a polishing surface by the elastic membrane, thereby polishing the lower surface of the wafer.

In one aspect, a central portion of the elastic membrane is brought into contact with a central portion of an upper surface of the wafer in a state where a pressure in the center-side pressure chamber is made higher than a pressure in the outer-side pressure chamber.

In one scheme, the central side pressure chamber is communicated with a cylinder, and a balance weight is placed on a piston of the cylinder.

In one aspect, there is provided a method of polishing a wafer by using a polishing head having a center-side pressure chamber and an outer-side pressure chamber formed of an elastic membrane, wherein the elastic membrane is brought into contact with an upper surface of the wafer, thereafter, a vacuum is formed in the outer-side pressure chamber and the center-side pressure chamber in this order of the outer-side pressure chamber and the center-side pressure chamber to move a liquid present on the upper surface of the wafer to the outside, thereafter, a lower surface of the wafer is pressed against a polishing surface by the elastic membrane to remove the liquid from the upper surface of the wafer, and the lower surface of the wafer is brought into sliding contact with the polishing surface by the polishing head to polish the lower surface of the wafer.

In one aspect, compressed gas is supplied into the center-side pressure chamber and the outer pressure chamber in this order, the elastic membrane presses the lower surface of the wafer against the polishing surface, and the liquid is removed from the upper surface of the wafer.

In one aspect, the outer side pressure chamber and the center side pressure chamber include at least a first pressure chamber, a second pressure chamber, and a third pressure chamber, the second pressure chamber is located outside the first pressure chamber, the third pressure chamber is located outside the second pressure chamber, and a vacuum is formed in the third pressure chamber, the second pressure chamber, and the first pressure chamber in this order, so that the liquid present on the upper surface of the wafer moves to the outside.

In one aspect, there is provided a method of polishing a wafer using a polishing head, wherein a liquid is removed from an upper surface of the wafer on a carrier device, the wafer on the carrier device is held by the polishing head, and a lower surface of the wafer is pressed against a polishing surface by the polishing head, thereby polishing the lower surface of the wafer.

In one aspect, the step of removing the liquid from the upper surface of the wafer on the transfer device includes the steps of: the wafer is tilted by the carrier device to remove the liquid from the upper surface of the wafer.

In one aspect, the step of removing the liquid from the upper surface of the wafer on the transfer device includes the steps of: the wafer is oscillated by the carrier device to remove the liquid from the upper surface of the wafer.

In one aspect, the step of removing the liquid from the upper surface of the wafer on the transfer device includes: and removing the liquid from the upper surface of the wafer by delivering a jet of gas to the upper surface of the wafer on the carrier.

In one aspect, there is provided a method of polishing a wafer using a polishing head having an elastic film, wherein the elastic film is brought into contact with an upper surface of the wafer, and a liquid present on the upper surface of the wafer is flowed into a liquid flow path formed in the elastic film, thereby removing the liquid from the upper surface of the wafer, and thereafter, a lower surface of the wafer is pressed against a polishing surface by the elastic film, thereby polishing the lower surface of the wafer.

In one aspect, the elastic membrane has a contact surface that contacts the upper surface of the wafer, the liquid flow path has an opening that opens at the contact surface, and a lateral hole that extends in the elastic membrane and is connected to the opening, and the lateral hole opens at an outer side surface of the elastic membrane.

In one aspect, the step of flowing the liquid present on the upper surface of the wafer into the liquid flow path is a step of: and a step of sucking the liquid present on the upper surface of the wafer through the liquid channel, wherein the liquid channel is communicated with a suction line connected to the elastic membrane.

In one aspect, the elastic membrane has a contact surface that contacts an upper surface of the wafer, and the liquid flow path is a groove formed in the contact surface.

In one aspect, the width of the groove in the interior of the elastic membrane is greater than the width of the groove at the contact surface.

In one aspect, there is provided an elastic film for pressing a wafer against a polishing surface, the elastic film including: a contact portion having a contact surface contactable with the wafer; and an outer wall portion connected to the contact portion, the contact portion having an opening that opens at the contact surface and a lateral hole that is connected to the opening and extends in the contact portion.

In one aspect, the transverse hole opens at an outer side surface of the elastic membrane.

In one aspect, the lateral hole is open on a surface of the contact portion opposite to the contact surface.

In one aspect, there is provided an elastic film for pressing a wafer against a polishing surface, the elastic film including: a contact portion having a contact surface contactable with the wafer; and an outer wall portion connected to the contact portion, and the contact portion has a groove formed in the contact surface.

In one aspect, the width of the groove in the interior of the contact portion is greater than the width of the groove on the contact surface.

A fifth embodiment of the present invention will be described below with reference to the drawings.

Fig. 24 is a schematic view showing an embodiment of a polishing apparatus. As shown in fig. 24, the polishing apparatus includes: a polishing table 3, the polishing table 3 supporting the polishing pad 2; a polishing head 1, the polishing head 1 pressing a wafer W as an example of a substrate against a polishing pad 2; a table motor 6, the table motor 6 rotating the polishing table 3; and a slurry supply nozzle 5, the slurry supply nozzle 5 being configured to supply the slurry onto the polishing pad 2. The surface of the polishing pad 2 constitutes a polishing surface 2a for polishing the wafer W.

The polishing table 3 is coupled to a table motor 6, and configured to rotate the polishing table 3 and the polishing pad 2 integrally. The polishing head 1 is fixed to an end portion of a polishing head shaft 11, and the polishing head shaft 11 is rotatably supported by a head arm 15. The head arm 15 is rotatably supported by a support shaft 16.

The wafer W is polished as follows. While rotating the polishing table 3 and the polishing head 1 in the direction indicated by the arrow in fig. 24, the slurry is supplied from the slurry supply nozzle 5 to the polishing surface 2a of the polishing pad 2 on the polishing table 3. The wafer W is pressed against the polishing surface 2a of the polishing pad 2 by the polishing head 1 while the polishing head 1 rotates while slurry is present between the polishing pad 2 and the wafer W. The surface of the wafer W is polished by the chemical action of the slurry and the mechanical action of the abrasive grains contained in the slurry.

The polishing apparatus further includes an operation control unit 9, and the operation control unit 9 controls the operations of the polishing head 1, the polishing table 3, and the slurry supply nozzle 5. The operation control unit 9 is constituted by at least one computer.

Next, the grinding head 1 will be explained. Fig. 25 is a sectional view showing the polishing head 1. The polishing head 1 includes: a carrier 31, the carrier 31 being fixed to an end of the polishing head shaft 11; an elastic film 34, the elastic film 34 being mounted on the lower portion of the carrier 31; and a guard ring 32, the guard ring 32 being disposed below the carrier 31. The guard ring 32 is disposed around the elastic membrane 34. The retainer ring 32 is an annular structure for holding the wafer W without causing the wafer W to fly out of the polishing head 1 during polishing of the wafer W.

The elastic film 34 includes a contact portion 35, inner wall portions 36a, 36b, and 36c connected to the contact portion 35, and an outer wall portion 36d, wherein the contact portion 35 has a contact surface 35a contactable with the upper surface of the wafer W. The contact portion 35 has substantially the same size and the same shape as the upper surface of the wafer W. The inner wall portions 36a, 36b, and 36c and the outer wall portion 36d are annular walls arranged concentrically. The outer wall portion 36d is located outside the inner wall portions 36a, 36b, and 36c, and is arranged so as to surround the inner wall portions 36a, 36b, and 36 c. In the present embodiment, three inner wall portions 36a, 36b, and 36c are provided, but the present invention is not limited to the present embodiment. In one embodiment, only one or two inner wall portions may be provided, or four or more inner wall portions may be provided.

Four pressure chambers 25A, 25B, 25C, 25D are provided between the elastic membrane 34 and the carrier 31. The pressure chambers 25A, 25B, 25C, 25D are formed by the contact portion 35 of the elastic membrane 34, the inner wall portions 36a, 36B, 36C, and the outer wall portion 36D. That is, pressure chamber 25A is located inside inner wall portion 36a, pressure chamber 25B is located between inner wall portion 36a and inner wall portion 36B, pressure chamber 25C is located between inner wall portion 36B and inner wall portion 36C, and pressure chamber 25D is located between inner wall portion 36C and outer wall portion 36D. The central pressure chamber 25A is circular, and the other pressure chambers 25B, 25C, and 25D are annular. These pressure chambers 25A, 25B, 25C, 25D are concentrically arranged. Pressure chamber 25B is located outside pressure chamber 25A, pressure chamber 25C is located outside pressure chamber 25B, and pressure chamber 25D is located outside pressure chamber 25C.

Gas transfer lines F1, F2, F3, and F4 are connected to the pressure chambers 25A, 25B, 25C, and 25D, respectively. One end of each of the gas transfer lines F1, F2, F3, and F4 is connected to a compressed gas supply source (not shown) as a utility source supply source provided in a factory in which the polishing apparatus is installed. Compressed gas such as compressed air is supplied to the pressure chambers 25A, 25B, 25C, and 25D through the gas transfer lines F1, F2, F3, and F4, respectively.

An annular diaphragm (rolling diaphragm) 37 is disposed between the carrier 31 and the retainer ring 32, and a pressure chamber 25E is formed inside the diaphragm 37. The pressure chamber 25E is connected to the compressed gas supply source via a gas transfer line F5. The compressed gas is supplied into the pressure chamber 25E through the gas transfer line F5, and the pressure chamber 25E presses the retainer ring 32 against the polishing surface 2a of the polishing pad 2.

The gas transfer lines F1, F2, F3, F4, and F5 extend through the rotary joint 40 attached to the head shaft 11. Pressure regulators R1, R2, R3, R4, and R5 are provided in gas transfer lines F1, F2, F3, F4, and F5 that communicate with the pressure chambers 25A, 25B, 25C, 25D, and 25E, respectively. The compressed gas from the compressed gas supply source is supplied into the pressure chambers 25A to 25E independently through the pressure regulators R1 to R5, respectively. The pressure regulators R1 to R5 are configured to regulate the pressure of the compressed gas in the pressure chambers 25A to 25E.

The pressure regulators R1 to R5 can change the internal pressures of the pressure chambers 25A to 25E independently of each other, and thus can independently adjust the polishing pressure applied to the central portion, the inner intermediate portion, the outer intermediate portion, and the edge portion, which are four regions corresponding to the wafer W, and the pressing force applied to the polishing pad 2 by the retainer ring 32. The gas transfer lines F1, F2, F3, F4, and F5 are also connected to atmosphere opening valves (not shown), respectively, and can open the pressure chambers 25A to 25E to the atmosphere. In the present embodiment, the elastic membrane 34 forms four pressure chambers 25A to 25D, but in one embodiment, the elastic membrane 34 may form less than four pressure chambers or more than four pressure chambers.

The pressure regulators R1 to R5 are connected to the operation controller 9. The operation controller 9 transmits the target pressure values of the pressure chambers 25A to 25E to the pressure regulators R1 to R5, and the pressure regulators R1 to R5 operate to maintain the pressures in the pressure chambers 25A to 25E at the corresponding target pressure values.

The polishing head 1 can apply independent polishing pressures to a plurality of regions of the wafer W. For example, the polishing head 1 can press different regions of the front surface of the wafer W against the polishing surface 2a of the polishing pad 2 at different polishing pressures. Therefore, the polishing head 1 can control the film thickness profile of the wafer W to achieve a target film thickness profile.

Vacuum lines L1, L2, L3, L4, and L5 are connected to gas transfer lines F1, F2, F3, F4, and F5, respectively. Vacuum valves V1, V2, V3, V4, and V5 are attached to the vacuum lines L1, L2, L3, L4, and L5, respectively. The vacuum valves V1, V2, V3, V4, and V5 are actuator-driving type valves such as solenoid valves, electric valves, and air valves. The vacuum valves V1 to V5 are connected to the operation controller 9, and the operations of the vacuum valves V1 to V5 are controlled by the operation controller 9. When the vacuum lines L1, L2, L3, L4, L5 are opened, a vacuum is formed in the corresponding pressure chambers 25A, 25B, 25C, 25D, 25E.

When the polishing head 1 holds the wafer W, the vacuum valves V2, V3, and V4 are opened with the contact portion 35 of the elastic membrane 34 in contact with the wafer W, and a vacuum is formed in the pressure chambers 25B, 25C, and 25D. The portions where the contact portions 35 of the pressure chambers 25B, 25C, and 25D are formed are recessed upward, and the polishing head 1 can suck the wafer W by the suction effect of the elastic film 34. When the pressure chambers 25B, 25C, and 25D are supplied with compressed gas to release the chuck effect, the polishing head 1 can release the wafer W.

Fig. 26 is a plan view of the carrier device for carrying the wafer to the polishing head 1 shown in fig. 24. As shown in fig. 26, the wafer W is transported to the polishing head 1 by the transport device 44. The polishing head 1 is movable between a polishing position P1 indicated by a solid line and a transfer position P2 indicated by a broken line in fig. 26. More specifically, the head arm 15 rotates about the support shaft 16, so that the polishing head 1 can move between the polishing position P1 and the delivery position P2. The polishing position P1 is located above the polishing surface 2a of the polishing pad 2, and the delivery position P2 is located outside the polishing surface 2 a.

The transfer device 44 includes a transfer stage 45 on which the wafer W is placed, a lifting device 47 that moves the transfer stage 45 up and down, and a horizontal movement device 49 that moves the transfer stage 45 and the lifting device 47 in a horizontal direction integrally. The wafer W to be polished is placed on the transfer table 45, and is moved to the delivery position P2 by the horizontal movement device 49 together with the transfer table 45. When the polishing head 1 is at the delivery position P2, the lifting device 47 lifts the conveyance stage 45. The polishing head 1 holds the wafer W on the transfer table 45 and moves to the polishing position P1 together with the wafer W.

The slurry supply nozzle 5 supplies the slurry to the polishing surface 2a of the rotating polishing pad 2, and while the polishing head 1 rotates the wafer W, the wafer W is pressed against the polishing surface 2a of the polishing pad 2, and the wafer W is brought into sliding contact with the polishing surface 2 a. The lower surface of the wafer W is polished by the chemical action of the slurry and the mechanical action of the abrasive grains contained in the slurry.

After polishing the wafer W, the polishing head 1 moves to the delivery position P2 together with the wafer W. Then, the polished wafer W is transferred to the transfer table 45. The transfer table 45 moves the wafer W to the next step. At the delivery position P2, the cleaning nozzle 53 is disposed, and the cleaning nozzle 53 supplies a liquid (e.g., a rinse liquid such as deionized water) to the polishing head 1 to clean the polishing head 1. The cleaning nozzle 53 faces the polishing head 1. The polishing head 1 from which the wafer W is released is cleaned by the liquid supplied from the cleaning nozzle 53.

During cleaning of the polishing head 1, the wafer to be polished is moved from the transfer table 45 to the receiving position P2 below the polishing head 1. When the cleaning of the polishing head 1 is completed, the lifting device 47 lifts the carrier table 45 on which the next wafer is placed. Then, the polishing head 1 after cleaning holds the next wafer and moves to the polishing position P1. In this manner, a plurality of wafers are successively ground.

However, in the cleaning of the polishing head 1, the wafer to be polished next moves to the receiving position P2 below the polishing head 1, and therefore the liquid falls onto the upper surface of the wafer. The liquid present on the upper surface of the wafer prevents the polishing head 1 from applying an appropriate force to the wafer as described with reference to fig. 53. One solution is to move the next wafer to the receiving position P2 after the cleaning of the polishing head 1 is finished. However, such an operation lowers the productivity of the polishing apparatus.

Therefore, in the present embodiment, the liquid is removed from the upper surface of the wafer as follows. Fig. 27 is a schematic view showing the polishing head 1 when removing liquid from the upper surface of the wafer. In fig. 27, the detailed structure of the polishing head 1 is omitted. Before holding the wafer W to be polished, the pressure in the pressure chambers 25A, 25B, and 25C on the center side of the polishing head 1 is set higher than the pressure in the pressure chamber 25D on the outer side. More specifically, the operation controller 9 gives a command to the pressure regulators R1, R2, and R3 (see fig. 25) to supply compressed gas into the pressure chambers 25A, 25B, and 25C, and at the same time, the operation controller 9 opens the vacuum valve V4 to form a vacuum in the pressure chamber 25D.

In one embodiment, the operation controller 9 may open an atmosphere opening valve (not shown) connected to the gas transfer lines F1, F2, and F3 to open the inside of the pressure chambers 25A, 25B, and 25C to the atmosphere, and at the same time, the operation controller 9 may open the vacuum valve V4 to form a vacuum in the pressure chamber 25D. In one embodiment, the operation controller 9 may supply compressed gas into the pressure chambers 25A, 25B, and 25C in response to commands from the pressure regulators R1, R2, and R3 (see fig. 25), and at the same time, the operation controller 9 may open an atmosphere opening valve (not shown) connected to the gas transfer line F4 to open the atmosphere in the pressure chamber 25D.

The difference between the pressure in the pressure chambers 25A, 25B, and 25C and the pressure in the pressure chamber 25D expands the central portion of the contact portion 35 of the elastic membrane 34, and the central portion of the contact portion 35 protrudes toward the wafer W. In a state where the center portion of the contact portion 35 protrudes, the polishing head 1 is lowered toward the wafer W, and the elastic membrane 34 is brought into contact with the upper surface of the wafer W. As shown in fig. 28, the center portion of the elastic membrane 34, i.e., the center portion of the contact portion 35, first contacts the center portion of the upper surface of the wafer W. The elastic film 34 pushes the liquid Q present on the upper surface of the wafer W outward.

Further, the polishing head 1 is lowered to bring most of the contact portion 35 into contact with the upper surface of the wafer W. More specifically, as shown in fig. 29, the outer peripheral portion of the elastic membrane 34, that is, the outer peripheral portion of the contact portion 35 is brought into contact with the outer peripheral portion of the upper surface of the wafer W in a state where the central portion of the elastic membrane 34 is constantly in contact with the central portion of the upper surface of the wafer W. The elastic film 34 pushes the liquid Q present on the upper surface of the wafer W further outward, and removes the liquid Q from the upper surface of the wafer W. Thereafter, the elastic film 34 of the polishing head 1 causes the lower surface of the wafer W to slide on the polishing surface 2a in the presence of the slurry on the polishing surface 2a, and performs polishing by chemical action of the slurry and mechanical action of abrasive grains contained in the slurry.

In this way, the liquid Q present on the upper surface of the wafer W is moved outward of the wafer W by the elastic film 34 protruding from the central portion, and is removed from the upper surface of the wafer W. Therefore, the polishing head 1 can hold the wafer W between the elastic film 34 and the upper surface of the wafer W in a state where the liquid Q is substantially absent. As a result, the elastic membrane 34 forming the pressure chambers 25A, 25B, 25C, and 25D can apply a desired force to the wafer W, and the polishing head 1 can realize a desired film thickness profile of the wafer W.

Since the elastic membrane 34 is flexible, the elastic membrane 34 is easily expanded even when the pressure in the pressure chambers 25A, 25B, and 25C is low. If the expansion of the elastic membrane 34 is too large, an excessive load may be applied to the wafer W when the elastic membrane 34 presses the wafer W. Although the pressure regulators R1, R2, and R3 can maintain the pressure in the pressure chambers 25A, 25B, and 25C at a low pressure (for example, at most 25 hPa), a long time may be required to reduce the pressure to a target low pressure, and the pressure in the pressure chambers 25A, 25B, and 25C may be unstable.

Therefore, in one embodiment, as shown in fig. 30, a combination of a cylinder 41 and a counterweight 42 is used instead of the pressure regulators R1, R2, R3 to deliver compressed gas to the pressure chambers 25A, 25B, 25C. The pressure chambers 25A, 25B, and 25C communicate with the common cylinder 41 via gas transfer lines F1, F2, and F3. The cylinder 41 is disposed in a vertical posture. Before the polishing head 1 holds the wafer W, the weight 42 is placed on the piston 41A of the cylinder 41, and presses the piston 41A downward. The gas in the cylinder 41 is sent into the pressure chambers 25A, 25B, and 25C, and thus the center portion of the elastic membrane 34 expands. As in the embodiment shown in fig. 27, a vacuum is formed in the pressure chamber 25D. In one embodiment, the operation controller 9 may open an atmosphere opening valve (not shown) connected to the gas transfer line F4 to open the pressure chamber 25D to the atmosphere.

The expansion of the elastic membrane 34 is adjusted by the diameter of the cylinder 41 and the stroke distance of the piston 41A. When the weight 42 is too light, the piston 41A stops halfway without expanding the elastic film 34, and therefore the weight 42 is used to lower the piston 41A at an appropriate speed. According to the present embodiment, the combination of the cylinder 41 and the weight 42 can stably maintain the low pressure in the pressure chambers 25A, 25B, 25C, and as a result, the expansion of the elastic membrane 34 can be appropriately controlled.

Fig. 31 is a schematic view showing another embodiment of the elastic film 34. In this embodiment, the longitudinal length of the inner wall portions 36a, 36b, 36c is longer than the longitudinal length of the outer wall portion 36d, and the lower ends of the inner wall portions 36a, 36b, 36c are located at a position lower than the lower end of the outer wall portion 36 d. The difference in the longitudinal length between the inner wall portions 36a, 36b, 36c and the outer wall portion 36d causes the central portion of the contact portion 35 of the elastic membrane 34 to protrude toward the wafer W.

Fig. 32 is a schematic view showing another embodiment of the polishing head 1. In the present embodiment, the lower portion of the carrier 31 has a first surface 31a to which inner wall portions 36a, 36b, and 36c are fixed, and a second surface 31b to which an outer wall portion 36d is fixed. The first surface 31a is located at a lower position than the second surface 31 b. The lower ends of the inner wall portions 36a, 36b, and 36c are located lower than the lower end of the outer wall portion 36 d. The difference in height between the first surface 31a and the second surface 31b of the carrier 31 causes the central portion of the contact portion 35 of the elastic membrane 34 to protrude toward the wafer W.

As in the embodiment shown in fig. 27 to 29, the elastic membrane 34 shown in fig. 31 and 32 can push the liquid Q existing on the upper surface of the wafer W outward and remove the liquid Q from the upper surface of the wafer W when contacting the upper surface of the wafer W. In the embodiment shown in fig. 31 and 32, a difference between the pressure in the pressure chambers 25A, 25B, and 25C and the pressure in the pressure chamber 25D may not be provided. Specifically, the pressure regulators R1, R2, R3, and R4 may maintain the same pressure of the compressed gas in the pressure chambers 25A, 25B, 25C, and 25D.

Next, another embodiment of the method for removing the liquid from the upper surface of the wafer W will be described with reference to fig. 33 to 36. The details of the present embodiment not particularly described are the same as those of the above-described embodiment, and therefore, redundant description thereof will be omitted.

As shown in fig. 33, the polishing head 1 is lowered toward the upper surface of the wafer W. The liquid Q is present on the upper surface of the wafer W. As shown in fig. 34, the contact portion 35 of the elastic membrane 34 is brought into contact with the liquid Q on the upper surface of the wafer W, and the contact portion 35 of the elastic membrane 34 is pressed against the upper surface of the wafer W. At this time, a part of the liquid Q is dropped from the upper surface of the wafer W.

As shown in fig. 35, vacuum is formed in the pressure chambers 25D, 25C, and 25B in order from the pressure chamber 25D located on the outer side toward the pressure chamber 25B located on the center side (i.e., in order of the pressing force chambers 25D, 25C, and 25B). The portions of the pressure chambers 25D, 25C, and 25B constituting the contact portions 35 are recessed upward by the vacuum, and a space is formed between the elastic film 34 and the upper surface of the wafer W. The liquid Q on the upper surface of the wafer W flows into these spaces in sequence, and a flow of the liquid Q toward the outside of the wafer W is formed.

Thereafter, the polishing head 1 conveys the wafer W to a position above the polishing pad 2, and presses the lower surface of the wafer W against the polishing surface 2a of the polishing pad 2 by the elastic film 34, as shown in fig. 36. At this time, the operation controller 9 gives a command to the pressure regulators R2, R3, and R4 to supply compressed gas into the pressure chambers 25B, 25C, and 25D in the order from the pressure chamber 25B located on the center side to the pressure chamber 25D located on the outer side (i.e., in the order of the pressure chambers 25B, 25C, and 25D). The liquid Q held in the space between the elastic membrane 34 and the upper surface of the wafer W is pushed by the contact portion 35 of the elastic membrane 34 and moves outward of the wafer W, and is removed from the upper surface of the wafer W.

Thereafter, the elastic film 34 of the polishing head 1 causes the lower surface of the wafer W to slide on the polishing surface 2a in the presence of the slurry on the polishing surface 2a, and performs polishing by chemical action of the slurry and mechanical action of abrasive grains contained in the slurry.

Next, another embodiment of the method for removing the liquid from the upper surface of the wafer W will be described with reference to fig. 37 to 39. The details of the present embodiment not particularly described are the same as those of the above-described embodiment, and therefore, redundant description thereof will be omitted. Fig. 37 is a schematic view showing a modification of the conveyance device 44 shown in fig. 26. The details of the present embodiment not specifically described are the same as those of the embodiment shown in fig. 26, and therefore, redundant description thereof will be omitted.

As shown in fig. 37, the conveying device 44 includes a tilting device 55 for tilting the conveying base 45. The tilting device 55 is held by the lifting device 47 and moves up and down integrally with the conveyance base 45. The tilting device 55 includes a support shaft 55a extending horizontally and a rotating device 55b for rotating the support shaft 55 a. The support shaft 55a is coupled to the conveyance base 45, and the rotating device 55b is fixed to the elevating device 47. The rotating device 55b is configured to be able to rotate the support shaft 55a and the conveying table 45 by a predetermined angle. The rotating device 55b includes an actuator (not shown) such as a servo motor.

The wafer W on the transfer table 45 is moved to the delivery position P2 by the horizontal movement device 49. The polishing head 1 is cleaned by the liquid supplied from the cleaning nozzle 53. The liquid used for cleaning the polishing head 1 drops onto the upper surface of the wafer W on the carrier table 45. Fig. 38 is a view of the conveying device 44 as viewed from the direction indicated by the arrow a shown in fig. 37. As shown in fig. 38, the liquid Q is present on the upper surface of the wafer W. Therefore, as shown in fig. 39, the tilting device 55 tilts the carrier stage 45 and the wafer W integrally before the wafer W is held by the polishing head 1. The liquid Q is dropped from the upper surface of the wafer W tilted, and thereby the liquid Q is removed from the upper surface of the wafer W.

After the liquid Q is removed from the upper surface of the wafer W, the tilting device 55 returns the wafer W to the horizontal posture again. Thereafter, the wafer W is held by the polishing head 1. The polishing head 1 conveys the wafer W to a polishing position P1 (see fig. 26) above the polishing pad 2, and presses the lower surface of the wafer W against the polishing surface 2a of the polishing pad 2 by the elastic film 34. The elastic membrane 34 of the polishing head 1 causes the lower surface of the wafer W to slide on the polishing surface 2a in the presence of the slurry on the polishing surface 2a, and performs polishing by chemical action of the slurry and mechanical action of abrasive grains contained in the slurry.

According to the present embodiment, after the liquid Q is removed from the upper surface of the wafer W, the wafer W is held by the polishing head 1. Therefore, the liquid Q does not exist between the upper surface of the wafer W and the elastic membrane 34 of the polishing head 1, the elastic membrane 34 can apply a desired force to the wafer W, and the polishing head 1 can realize a desired film thickness profile of the wafer W.

Fig. 40 and 41 are schematic views for explaining still another embodiment of the method for removing liquid from the upper surface of the wafer W. The details of the present embodiment not specifically described are the same as those of the embodiment shown in fig. 26, and therefore, redundant description thereof will be omitted.

As shown in fig. 40, the wafer W on the transfer table 45 is moved to the delivery position P2 by the horizontal movement device 49. The polishing head 1 is cleaned by the liquid supplied from the cleaning nozzle 53. The liquid used for cleaning the polishing head 1 drops onto the upper surface of the wafer W on the carrier table 45.

As shown in fig. 41, the horizontal movement device 49 horizontally swings the carrier table 45 and the wafer W before the wafer W is held by the polishing head 1. When the wafer W swings, the liquid Q is dropped from the upper surface of the wafer W, and the liquid Q is removed from the upper surface of the wafer W. In one embodiment, the horizontal movement device 49 may swing the transfer stage 45 and the wafer W in the horizontal direction in a state where the transfer stage 45 and the wafer W are tilted by the tilting device 55. In one embodiment, the tilting device 55 may not be provided.

After the liquid Q is removed from the upper surface of the wafer W, the wafer W is held by the polishing head 1. The polishing head 1 conveys the wafer W to a polishing position P1 (see fig. 26) above the polishing pad 2, and presses the lower surface of the wafer W against the polishing surface 2a of the polishing pad 2 by the elastic film 34. The elastic membrane 34 of the polishing head 1 causes the lower surface of the wafer W to slide on the polishing surface 2a in the presence of the slurry on the polishing surface 2a, and performs polishing by chemical action of the slurry and mechanical action of abrasive grains contained in the slurry.

According to the present embodiment, after the liquid Q is removed from the upper surface of the wafer W, the wafer W is held by the polishing head 1. Therefore, the liquid Q does not exist between the upper surface of the wafer W and the elastic membrane 34 of the polishing head 1, the elastic membrane 34 can apply a desired force to the wafer W, and the polishing head 1 can realize a desired film thickness profile of the wafer W.

Fig. 42 is a schematic view illustrating still another embodiment of the method for removing liquid from the upper surface of the wafer W. The details of the present embodiment not specifically described are the same as those of the embodiment shown in fig. 26, and therefore, redundant description thereof will be omitted.

As shown in fig. 42, the polishing apparatus of the present embodiment includes a gas jet nozzle 57 disposed at a delivery position P2. The gas jet nozzle 57 is inclined with respect to the horizontal direction and is disposed so as to face the upper portion of the transfer table 45 located at the delivery position P2, that is, to face the upper surface of the wafer W on the transfer table 45. The gas jet nozzle 57 is connected to a compressed gas supply source, not shown. In the present embodiment, a plurality of gas jetting nozzles 57 are provided, but in one embodiment, only one gas jetting nozzle 57 may be provided.

The wafer W on the transfer table 45 is moved to the delivery position P2 by the horizontal movement device 49. The polishing head 1 is cleaned by the liquid supplied from the cleaning nozzle 53. The liquid used for cleaning the polishing head 1 drops onto the upper surface of the wafer W on the carrier table 45. As shown in fig. 43, before the wafer W is held by the polishing head 1, the gas jet nozzle 57 sends a jet of gas to the upper surface of the wafer W, and removes the liquid Q from the upper surface of the wafer W.

After the liquid Q is removed from the upper surface of the wafer W, the wafer W is held by the polishing head 1. The polishing head 1 conveys the wafer W to a polishing position P1 (see fig. 26) above the polishing pad 2, and presses the lower surface of the wafer W against the polishing surface 2a of the polishing pad 2 by the elastic film 34. The elastic membrane 34 of the polishing head 1 causes the lower surface of the wafer W to slide on the polishing surface 2a in the presence of the slurry on the polishing surface 2a, and performs polishing by chemical action of the slurry and mechanical action of abrasive grains contained in the slurry.

According to the present embodiment, after the liquid Q is removed from the upper surface of the wafer W, the wafer W is held by the polishing head 1. Therefore, the liquid Q does not exist between the upper surface of the wafer W and the elastic membrane 34 of the polishing head 1, the elastic membrane 34 can apply a desired force to the wafer W, and the polishing head 1 can realize a desired film thickness profile of the wafer W.

Fig. 44 is a cross-sectional view showing an embodiment of the elastic membrane 34 capable of removing liquid from the upper surface of the wafer W. As shown in fig. 44, the elastic membrane 34 has a liquid flow path 60 formed therein. More specifically, the contact portion 35 of the elastic film 34 has a plurality of openings 61 that open onto the contact surface 35a, and a lateral hole 62 that connects to the plurality of openings 61. The contact surface 35a of the elastic membrane 34 is a surface of the elastic membrane 34 that contacts the upper surface of the wafer W. The opening 61 is provided below the pressure chamber 25A located on the center side, and the opening 61 is not provided below the other pressure chambers 25B to 25D. In one embodiment, the opening 61 may be provided below the pressure chambers 25B to 25D. The lateral hole 62 extends in the contact portion 35, and the outer end of the lateral hole 62 opens on the outer side surface 34a of the elastic film 34. Therefore, the contact surface 35a and the outer surface 34a of the elastic film 34 communicate with each other through the liquid flow path 60 formed by the opening 61 and the lateral hole 62.

As shown in fig. 45, the compressed gas is supplied into the pressure chambers 25A to 25D to expand the elastic membrane 34, and the contact surface 35A of the elastic membrane 34 is pressed against the upper surface of the wafer W. The liquid Q (see fig. 44) present on the upper surface of the wafer W flows into the liquid channel 60 from the opening 61, and flows out to the outside of the elastic membrane 34 through the liquid channel 60. As a result, the liquid Q is removed from the upper surface of the wafer W.

After the liquid Q is removed from the upper surface of the wafer W, the wafer W is held by the polishing head 1. The polishing head 1 conveys the wafer W to a polishing position P1 (see fig. 26) above the polishing pad 2, and presses the lower surface of the wafer W against the polishing surface 2a of the polishing pad 2 by the elastic film 34. The elastic membrane 34 of the polishing head 1 causes the lower surface of the wafer W to slide on the polishing surface 2a in the presence of the slurry on the polishing surface 2a, and performs polishing by chemical action of the slurry and mechanical action of abrasive grains contained in the slurry.

According to the present embodiment, the polishing head 1 can hold the wafer W with substantially no liquid Q present between the elastic membrane 34 and the upper surface of the wafer W. As a result, the elastic membrane 34 forming the pressure chambers 25A, 25B, 25C, and 25D can apply a desired force to the wafer W, and the polishing head 1 can realize a desired film thickness profile of the wafer W.

Fig. 46 is a cross-sectional view showing another embodiment of the elastic membrane 34 capable of removing liquid from the upper surface of the wafer W. The details of the present embodiment not specifically described are the same as those of the embodiments shown in fig. 44 and 45, and therefore, redundant description thereof will be omitted. As shown in fig. 46, the liquid flow path 60 communicates with a suction line 70 connected to the elastic membrane 34. More specifically, the lateral hole 62 is connected to both the opening 61 and the suction line 70. One end of the lateral hole 62 is connected to the opening 61, and the other end of the lateral hole 62 is opened to the upper surface 35b of the contact portion 35 (the surface of the contact portion 35 opposite to the contact surface 35 a).

The suction line 70 extends through the carrier 31, and an end of the suction line 70 is connected to the upper surface 35b of the contact portion 35. The suction line 70 communicates with the liquid channel 60 but does not communicate with the pressure chamber 25A. Therefore, the suction line 70 can form a vacuum in the liquid flow path 60 without forming a vacuum in the pressure chamber 25A.

As shown in fig. 47, while the compressed gas is supplied into the pressure chambers 25A to 25D to expand the elastic membrane 34 and further press the contact surface 35A of the elastic membrane 34 against the upper surface of the wafer W, vacuum is formed in the liquid flow path 60 through the suction line 70. The liquid Q (see fig. 46) present on the upper surface of the wafer W is sucked into the liquid channel 60 through the opening 61 and removed from the upper surface of the wafer W.

Fig. 48 is a cross-sectional view showing still another embodiment of the elastic membrane 34 capable of removing liquid from the upper surface of the wafer W. The details of the present embodiment not specifically described are the same as those of the embodiments shown in fig. 44 and 45, and therefore, redundant description thereof will be omitted. As shown in fig. 48, the liquid flow path is constituted by a plurality of grooves 75 formed in the contact surface 35 a.

Fig. 49 is a bottom view of the elastic membrane 34 shown in fig. 48. As shown in fig. 49, the plurality of grooves 75 are annular grooves arranged in concentric circles. However, the shape of the groove 75 is not limited to the present embodiment. For example, the grooves 75 may be linear grooves arranged parallel to each other.

As shown in fig. 50, the compressed gas is supplied into the pressure chambers 25A to 25D to expand the elastic membrane 34, and the contact surface 35A of the elastic membrane 34 is pressed against the upper surface of the wafer W. The liquid Q (see fig. 48) present on the upper surface of the wafer W flows into the groove 75 serving as a liquid flow path. As a result, the liquid Q is removed from the upper surface of the wafer W.

In the present embodiment, in order to prevent the liquid Q temporarily flowing into the groove 75 from flowing out of the groove 75, the width of the groove 75 in the contact portion 35 is larger than the width of the groove 75 on the contact surface 35 a. That is, the entrance of the groove 75 is narrow, and the inside of the groove 75 is widened. The groove 75 having such a cross-sectional shape easily holds the liquid Q therein. The grooves 75 may also be uniformly distributed over the entire contact surface 35a of the elastic membrane 34 in order to remove liquid irregularly present on the upper surface of the wafer W.

The elastic film 34 shown in fig. 44 to 50 can be produced by using a 3D printer (stereo printer).

The above embodiments can be combined as appropriate. For example, the embodiment shown in fig. 27 to 29 may be applied to the embodiment shown in fig. 37 to 39, the embodiment shown in fig. 40 and 41, or the embodiment shown in fig. 42 and 43.

The polishing head 1 according to each of the above embodiments has four pressure chambers 25A, 25B, 25C, and 25D, but the present invention is not limited to these embodiments. The above-described embodiments of removing liquid from the upper surface of the wafer can also be applied to polishing heads having less than four pressure chambers as well as polishing heads having more than four pressure chambers.

The above-described embodiments are described for the purpose of enabling a person having ordinary knowledge in the technical field to which the present invention pertains to practice the present invention. It is needless to say that various modifications of the above-described embodiments can be made by those skilled in the art, and the technical idea of the present invention can be applied to other embodiments. Therefore, the present invention is not limited to the embodiments described above, but is to be interpreted as the maximum scope of the technical idea defined by the claims.

(sixth to eighth embodiments)

Patent document 1 discloses a substrate polishing apparatus including: the substrate is sucked and held by the membrane of the top ring and polished, and thereafter the substrate is released from the membrane. The substrate is released by pressurizing the diaphragm and ejecting a fluid into a gap formed between the diaphragm and the outer periphery of the substrate.

The pressurization of the diaphragm can take into account, for example, a pressure control based on an electropneumatic regulator. When the electro-pneumatic regulator becomes low pressure, control accuracy and responsiveness thereof deteriorate, and therefore, the diaphragm is pressurized with a certain large pressure.

In recent years, with the miniaturization and high stacking of semiconductor processes, substrates on which semiconductor devices are formed are prone to cracking. Therefore, when a large pressure is applied to the diaphragm by an electro-pneumatic regulator or the like at the time of releasing the substrate, the substrate may be subjected to a large stress and may be broken.

The sixth to eighth embodiments have been made in view of such problems, and the problems of the sixth to eighth embodiments are: provided are a substrate polishing apparatus and a substrate release method capable of safely releasing a substrate held by suction, and a quantitative gas supply apparatus connectable to such a substrate polishing apparatus.

According to the sixth to eighth embodiments, the following means is provided.

According to an aspect, there is provided a substrate polishing apparatus including: a top ring body; an elastic film having a first surface facing the top ring main body and a second surface opposite to the first surface and capable of holding a substrate by suction; a pressure adjusting device capable of pressurizing and depressurizing a space between the top ring main body and the first surface of the elastic membrane via a first valve provided in a first line communicating with the space; and a constant-volume gas supply device capable of supplying a constant volume of gas to the space via a second valve provided in the first line.

Preferably, when the substrate is adsorbed to the second surface of the elastic membrane, the second valve is closed, the first valve is opened, and the pressure adjusting device reduces the pressure in the space; while grinding the said base plate, close the said second valve, open the said first valve, the said pressure regulating device pressurizes the said space; when the substrate is released from the second surface of the elastic film, the first valve is closed, the second valve is opened, and the quantitative gas supply device supplies a certain amount of gas to the space.

Preferably, in the constant-rate gas supply device, a weight connected to a piston in a cylinder is moved downward by gravity, so that a constant amount of gas corresponding to an area of the piston and a stroke of the piston is supplied from the cylinder to the space.

Specifically, the constant-volume gas supply device may include the cylinder, the piston, and the weight, the piston is capable of moving up and down in a state of contacting with an inner surface of the cylinder, the interior of the cylinder is divided into a lower space and an upper space by the piston, a first opening is provided in the cylinder at a position corresponding to the lower space, a second opening and a third opening are provided at a position corresponding to the upper space, the first opening is connected to a second line, the second line is connected to the first line via the second valve, the second opening is connected to a third line, and a piston rod connecting the counterweight and the piston passes through the third opening, the lower space can be opened to the atmosphere by opening a third valve provided in the second line, and the upper space can be depressurized and opened to the atmosphere through the third line.

More specifically, the upper space may be depressurized and the lower space may be opened to the atmosphere when the substrate is adsorbed to the second surface of the elastic film and when the substrate is polished; when the substrate is released from the second surface of the elastic membrane, the upper space is opened to the atmosphere, and the third valve is closed.

In addition, it is preferable that the constant-volume gas supply device is configured to supply a constant volume of gas corresponding to a volume of the chamber from the airbag to the space by compressing the airbag housed in the chamber.

Specifically, the constant-volume gas supply device may include the airbag and the chamber, the chamber may be provided with a fourth opening and a fifth opening, a fourth line connecting the first line and the airbag via the second valve may pass through the fourth opening, the fifth opening may be connected to a fifth line, the airbag may be opened to the atmosphere by opening a fourth valve provided in the fourth line, and the chamber may be pressurized and depressurized via the fifth line.

More specifically, the chamber may be depressurized to open the bladder to the atmosphere when the substrate is adsorbed to the second surface of the elastic film and when the substrate is polished; upon releasing the substrate from the second side of the elastic membrane, the chamber is pressurized, closing the fourth valve.

According to another aspect, there is provided a substrate release method for releasing a substrate adsorbed and held on a second surface of an elastic film of a top ring from the elastic film, the method including: a gas supply step of supplying a predetermined amount of gas into a space between a top ring main body in the top ring and the first surface of the elastic film, thereby generating a gap between the elastic film and the substrate; and a fluid ejecting step of ejecting a fluid to the gap.

In the gas supply step, a weight coupled to a piston in a cylinder may be moved downward to supply a predetermined amount of gas corresponding to an area of the piston and a stroke of the piston from the cylinder to the space.

In the gas supply step, a gas of a certain amount corresponding to the volume of the chamber may be supplied from the airbag to the space by compressing the airbag housed in the chamber.

According to another aspect, there is provided a quantitative gas supply device connected to a substrate holding device, the substrate holding device including: a top ring body; an elastic film having a first surface facing the top ring main body and a second surface opposite to the first surface and capable of holding a substrate by suction; and a pressure adjusting device capable of pressurizing and depressurizing a space between the top ring main body and the first surface of the elastic membrane via a first valve provided in a first line communicating with the space, wherein the constant-volume gas supplying device is capable of supplying a constant volume of gas to the space via a second valve provided in the first line.

The sixth to eighth embodiments are specifically described below with reference to the drawings.

(sixth embodiment)

Fig. 54 is a schematic plan view of a substrate processing apparatus including a substrate polishing apparatus. The substrate processing apparatus processes various substrates in a process of manufacturing a magnetic film in a semiconductor wafer having a diameter of 300mm or 450mm, a flat panel, an image sensor such as a CMOS (Complementary Metal oxide semiconductor) or a CCD (Charge Coupled Device), or an MRAM (magnetic Random Access Memory).

The substrate processing apparatus includes: a substantially rectangular-shaped housing 100; a load port 200 for placing a substrate cassette for storing a plurality of substrates; one or more (four in the version shown in fig. 54) substrate polishing apparatuses 300; one or more (two in the illustrated embodiment of fig. 54) substrate cleaning apparatuses 400; a substrate drying device 500; the conveyance mechanisms 600a to 600d, and the control unit 700.

The load port 200 is configured to abut the housing 100. The load port 200 can be loaded with an open cassette, a Standard Mechanical Interface (SMIF) Pod, or a Front Opening Unified Pod (FOUP). SMIF pod and FOUP are sealed containers that house substrate cassettes inside and are covered with partition walls, thereby ensuring an environment independent of the external space.

The housing 100 accommodates a substrate polishing apparatus 300 for polishing a substrate, a substrate cleaning apparatus 400 for cleaning the polished substrate, and a substrate drying apparatus 500 for drying the cleaned substrate. The substrate polishing apparatus 300 is arranged along the longitudinal direction of the substrate processing apparatus, and the substrate cleaning apparatus 400 and the substrate drying apparatus 500 are also arranged along the longitudinal direction of the substrate processing apparatus.

The conveyance mechanism 600a is disposed in a region surrounded by the load port 200, the substrate polishing apparatus 300 located on the load port 200 side, and the substrate drying apparatus 500. Further, the conveyance mechanism 600b is disposed in parallel with the substrate polishing apparatus 300, the substrate cleaning apparatus 400, and the substrate drying apparatus 500.

The transfer mechanism 600a receives the substrate before polishing from the load port 200 and delivers the substrate to the transfer mechanism 600b, or receives the substrate after drying from the substrate drying apparatus 500.

The conveyance mechanism 600b is, for example, a linear conveyance device, and delivers the substrate before polishing received from the conveyance mechanism 600a to the substrate polishing apparatus 300. As will be described later, the top ring (not shown) in the substrate polishing apparatus 300 receives the substrate from the conveyance mechanism 600b by vacuum suction. The substrate polishing apparatus 300 releases the polished substrate to the transfer mechanism 600b, and the substrate is delivered to the substrate cleaning apparatus 400.

Further, a transfer mechanism 600c is disposed between the two substrate cleaning apparatuses 400, and the transfer mechanism 600c transfers substrates between the substrate cleaning apparatuses 400. Further, a conveyance mechanism 600d is disposed between the substrate cleaning apparatus 400 and the substrate drying apparatus 500, and the conveyance mechanism 600d transfers substrates between the substrate cleaning apparatus 400 and the substrate drying apparatus 500.

The controller 700 may control the operation of each device of the substrate processing apparatus, and may be disposed inside the housing 100, outside the housing 100, or in each of the substrate polishing apparatus 300, the substrate cleaning apparatus 400, and the substrate drying apparatus 500.

Fig. 55 and 56 are a schematic perspective view of the substrate polishing apparatus 300 and a schematic sectional view of the peripheral portion of the top ring 1, respectively. The substrate polishing apparatus 300 includes a top ring 1 (substrate holding apparatus) for holding a substrate. As shown in fig. 56, the top ring 1 includes a top ring main body 11 (also referred to as a carrier or a base plate), an annular retainer ring 12, a flexible diaphragm 13 (elastic film) that can be attached to the lower side of the top ring main body 11 and inside the retainer ring 12, an air bag 14 provided between the top ring main body 11 and the retainer ring 12, a pressure adjusting device 15, a quantitative gas supply device 16, a control device 17, and the like. The pressure adjusting device 15, the constant gas supply device 16, and/or the control device 17 may be a device constituting the top ring 1, or may be a device independent of the top ring 1.

The guard ring 12 is provided on the outer peripheral portion of the top ring body 11. The peripheral edge of the held substrate W is surrounded by the retainer ring 12, and the substrate W does not fly out of the top ring 1 during polishing. The guard ring 12 may be a single member, or may be a double ring structure including an inner ring and an outer ring provided outside the inner ring. In the latter case, the outer ring may be fixed to the top ring body 11, and the bladder 14 may be provided between the inner ring and the top ring body 11.

The diaphragm 13 is disposed opposite to the top ring body 11. Specifically, the upper surface of the diaphragm 13 faces the top ring body 11, and a space S is formed between the top ring body 11 and the upper surface. Then, the space S is depressurized to a negative pressure, so that the lower surface of the diaphragm 13 can hold the upper surface of the substrate W. The retainer ring may be a multi-layer ring structure including a plurality of members arranged vertically.

The air bag 14 is provided between the top ring body 11 and the guard ring 12. The retainer ring 12 is movable relative to the top ring body 11 in the vertical direction by the airbag 14.

The pressure adjusting device 15 is connected to a line (pipe) L1 having one end communicating with the space S, and more specifically, a valve V1 is provided in the line L1, and the pressure adjusting device 15 is disposed on the upstream side (the side opposite to the space S) of the valve V1.

The constant-volume gas supply device 16 is connected to the line L1, and more specifically, a valve V2 is provided in the line L1, and the constant-volume gas supply device 16 is disposed upstream of the valve V2 (on the side opposite to the space S).

In other words, one end of the line L1 communicates with the space S, and the other end branches. One of the branched portions is connected to the pressure adjusting device 15 via a valve V1, and the other branched portion is connected to the constant gas supplying device 16 via a valve V2. In this way, the space S is connected to the pressure regulator 15 via the valve V1 and to the constant gas supply device 16 via the valve V2.

When the valve V1 is opened and the valve V2 is closed, the pressure adjusting device 15 can adjust the pressure of the space S by supplying a fluid (gas) to the space S to increase the pressure, by evacuating the space S to reduce the pressure, or by opening the space S to the atmosphere. On the other hand, when the valve V2 is opened and the valve V1 is closed, the constant-volume gas supply device 16 can supply a constant volume of fluid (gas) to the space S. As will be described later, the provision of the constant-volume gas supply device 16 is one of the features of the present embodiment. Specific configuration examples of the quantitative gas supply device 16 will be described in the seventh and eighth embodiments.

The controller 17 controls the respective parts of the top ring 1, for example, opening and closing of the valves V1 and V2; control of the pressure adjusting device 15 and the constant gas supply device 16.

The substrate polishing apparatus 300 further includes: a top ring shaft 2 having a top ring 1 connected to a lower portion thereof, a polishing table 3 having a polishing pad 3a, a nozzle 4 for supplying a polishing liquid to the polishing pad 3a, a top ring arm 5, and a support shaft 6.

In fig. 55, the lower end of the top ring shaft 2 is connected to the center of the upper surface of the top ring 1. The top ring shaft 2 is moved up and down by an unillustrated lift mechanism, and the lower surface of the substrate W held by the top ring 1 is brought into contact with or separated from the polishing pad 3 a. Further, the top ring 1 is rotated by rotating the top ring shaft 2 by a motor not shown, and the substrate W held thereby is also rotated.

A polishing pad 3a is provided on the upper surface of the polishing table 3. The lower surface of the polishing table 3 is connected to the rotating shaft, and the polishing table 3 is rotatable. The polishing liquid is supplied from the nozzle 4, and the substrate W and the polishing table 3 are rotated while the lower surface of the substrate W is in contact with the polishing pad 3a, thereby polishing the substrate W.

The top ring arm 5 in fig. 56 has one end coupled to the top ring shaft 2 and the other end coupled to the support shaft 6. The top ring arm 5 is swung by rotating the support shaft 6 by a motor (not shown), and the top ring 1 reciprocates between a substrate delivery position (not shown) on the polishing pad 3 a.

Next, an operation when the substrate W is transferred from the conveyance mechanism 600b of fig. 54 to the top ring 1 of fig. 55 and 56, that is, an operation when the substrate W is adsorbed to the top ring 1 will be described. When the substrate W is held by the top ring 1, the valve V1 of fig. 56 is opened, and the valve V2 is closed. Therefore, the space S is connected to the pressure adjusting device 15 and disconnected from the constant-volume gas supply device 16.

Fig. 57A to 57C and fig. 58 are views for explaining in detail the substrate transfer from the conveyance mechanism 600b to the top ring 1. Fig. 57A to 57C are schematic cross-sectional views of the conveying mechanism 600b and the top ring 1 viewed from the side, and fig. 58 is a view of the conveying mechanism 600b and the top ring 1 viewed from above.

As shown in fig. 57A, a substrate W is placed on a hand 601 of the conveyance mechanism 600 b. The retainer ring stage 800 is used for transferring the substrate W. The retainer ring stage 800 has an push-up pin 801 that pushes up the retainer ring 12 of the top ring 1. The guard ring stage 800 may have a discharge nozzle, but is not illustrated here.

As shown in fig. 58, the hand 601 supports a part of the outer periphery of the lower surface of the substrate W. Also, the upper push pin 801 and the hand 601 are configured not to contact each other.

In the state shown in fig. 57A, the top ring 1 is lowered, and the conveying mechanism 600b is raised. Due to the lowering of the top ring 1, the push-up pins 801 push up the guard ring 12, and the substrate W approaches the diaphragm 13. When the conveyance mechanism 600B further ascends, the upper surface of the substrate W comes into contact with the lower surface of the film 13 (fig. 57B).

In this state, the pressure adjusting device 15 reduces the pressure in the space S to a negative pressure, and thereby the substrate W is adsorbed on the lower surface of the diaphragm 13 of the top ring 1.

Thereafter, the hand 601 of the conveyance mechanism 600b descends (fig. 57C).

As described above, the substrate W sucked and held on the diaphragm 13 is moved upward of the polishing table 3 by rotating the support shaft 6 and swinging the top ring arm 5. Then, the top ring 1 is lowered, so that the substrate W is brought into contact with the polishing pad 3 a. In this state, the pressure adjusting device 15 pressurizes the space S and the top ring shaft 2 rotates, thereby polishing the substrate W.

Next, an operation when the substrate W is transferred from the top ring 1 of fig. 55 and 56 to the conveyance mechanism 600b of fig. 54, that is, an operation when the substrate W is released (separated) from the top ring 1 will be described. At substrate release, valve V1 of fig. 56 is closed and valve V2 is open. Therefore, the space S is connected to the constant-volume gas supply device 16 and disconnected from the pressure adjustment device 15.

Fig. 59A to 59C and fig. 60 are views for explaining in detail the delivery of the substrate from the top ring 1 to the conveyance mechanism 600 b. Fig. 59A to 59C are schematic cross-sectional views of the conveying mechanism 600b and the top ring 1 viewed from the side, and fig. 60 is a view of the top ring 1 and the guard ring stand 800 viewed from above (however, the conveying mechanism 600b in fig. 59A to 59C is omitted). As shown in these figures, the guard ring stage 800 has, for example, three discharge nozzles 802 facing inward (substrate W side).

Fig. 59A is a state in which the substrate W has been adsorbed to the membrane 13. At this time, the fluid (release shower) is not ejected from the release nozzle 802.

As shown in fig. 59B, the top ring 1 is lowered, and the conveying mechanism 600B is raised. Thus, the hand 601 of the conveyance mechanism 600b is close to the lower surface of the substrate W, but does not contact the substrate W. In addition, the push-up pins 801 push up the guard ring 12.

In this state, the constant-volume gas supply device 16 supplies a constant volume of gas to the space S to pressurize the space S. Thereby, the diaphragm 13 expands, and a gap is generated between the lower surface of the diaphragm 13 and the outer peripheral portion of the substrate W. A fluid such as air is ejected from the discharge nozzle 802 toward the gap. Thereby, the substrate W is released from the film 13 and placed on the hand 601.

In the present embodiment, since a certain amount of gas is supplied to the space S, the amount of expansion of the diaphragm 13 is also constant. Therefore, a gap between the lower surface of the film 13 and the outer peripheral portion of the substrate W can be always generated at the position of the fluid ejection from the discharge nozzle 802. Therefore, the fluid can be reliably ejected from the release nozzle 802 to the gap, and the substrate W can be released from the film 13.

The amount of the gas supplied from the quantitative gas supply device 16 may be set so that a pressure (for example, 1 to 10hPa) is applied to the substrate W, which forms a gap at the position where the fluid is ejected from the discharge nozzle 802 and does not crack the substrate W. Further, since the pressure applied to the substrate W is relatively reduced by the expansion of the diaphragm 13, the stress acting on the substrate W is stably kept low.

Thereafter, as shown in fig. 59C, the hand 601 on which the substrate W is placed is lowered, and the top ring 1 is raised.

In this way, in the sixth embodiment, a certain amount of gas is supplied from the constant-volume gas supply device 16 to the space S, not by the pressure adjustment device 15 for adsorbing or polishing the substrate W. This can reduce the stress applied to the substrate W when the substrate W is released. As a result, the substrate sucked and held on the membrane 13 can be released safely. In addition, in the conventional pressure adjusting device, the maximum pressure at the time of pressurization is 500hPa or 1000hPa, so that it is difficult to cope with a low pressure of 1 to 10 hPa. Therefore, the pressure application time is shortened by 50hPa or more, and the diaphragm is prevented from being excessively expanded.

(seventh embodiment)

Fig. 61 is a diagram showing a schematic configuration of a substrate polishing apparatus 300 including a quantitative gas supply device 16 according to a seventh embodiment. The constant-volume gas supply device 16 includes a cylinder 21 and a weight 24 connected to a piston 22 of the cylinder 21, and supplies the gas in the cylinder 21 to the space S by the weight 24 moving downward by gravity.

Specifically, the constant-volume gas supply device 16 includes a cylinder 21, a piston 22, a piston rod 23, a weight 24, and a vacuum generation source 25.

The cylinder 21 extends in a columnar shape in the vertical direction, and has a hollow inside. The outer periphery of the piston 22 can move up and down in contact with the inner surface of the cylinder 21. The piston rod 23 extends in the vertical direction and penetrates through an opening O3 provided in the upper surface of the cylinder 21. A piston 22 is connected to a lower end of the piston rod 23, and a weight 24 is fixed to an upper end thereof.

The interior of the cylinder 21 is divided into a lower space a1 and an upper space a2 by the piston 22. Since the outer periphery of the piston 22 is always in contact with the inner surface of the cylinder 21, gas hardly flows between the lower space a1 and the upper space a 2.

An opening O1 is provided in the cylinder 21 at a position corresponding to the lower space a 1. A line L2 is connected to the opening O1. Line L2 is connected to line L1 via valve V2. Further, the line L2 is provided with a valve V3, and the lower space a1 can be opened to the atmosphere by opening the valve V3.

Further, an opening O2 is provided in the cylinder 21 at a position corresponding to the upper space a 2. A line L3 is connected to the opening O2. The line L3 is connected to a vacuum generation source 25, and the upper space a2 can be depressurized or opened to the atmosphere through the line L3.

Further, the valve V3 and the vacuum generation source 25 are controlled by the control device 17 of fig. 56.

Fig. 62 is a view schematically showing an operating state of the substrate polishing apparatus 300 when the substrate is transferred from the conveyance mechanism 600b to the top ring 1 (fig. 57A to 57C and fig. 58). At this time, valve V1 of fig. 56 is open and valve V2 is closed. Therefore, the pressure adjusting device 15 is connected to the space S, and the constant-volume gas supply device 16 is disconnected from the space S.

The constant-volume gas supply device 16 is set in a standby state. In the standby state, the valve V3 is opened, and the lower space a1 is opened to the atmosphere. The vacuum generation source 25 reduces the pressure (preferably, vacuum) in the upper space a 2. Thereby, the piston 22 (and the piston rod 23 and the weight 24) is held in a raised state.

Then, the pressure adjusting device 15 reduces the pressure in the space S to a negative pressure, thereby sucking the substrate W on the lower surface of the diaphragm 13 of the top ring 1.

Fig. 63 is a diagram schematically showing an operating state of the substrate polishing apparatus 300 at the time of polishing a substrate. Similarly to fig. 62, the valve V1 in fig. 56 is opened, the valve V2 is closed, and the constant-volume gas supply device 16 is in a standby state. Then, the pressure adjusting device 15 pressurizes the space S, and the substrate W is pressed against the polishing pad 3a of fig. 55 and polished.

Fig. 64 is a diagram schematically showing an operating state of the substrate polishing apparatus 300 when the substrate is released (fig. 59A to 59C and fig. 60). Unlike fig. 62 and 63, the valve V1 of fig. 56 is closed and the valve V2 is opened. Therefore, the constant-volume gas supply device 16 is connected to the space S, and the pressure adjustment device 15 is disconnected from the space S.

Then, the valve V3 of the quantitative gas supply device 16 is closed, and the upper space a2 is opened to the atmosphere via the line L3. Thereby, the weight 24 is free to fall, and the piston 22 moves downward along with it. Since the valve V3 is closed, the gas in the lower space A1 moves to the space S through the lines L2 and L1. As a result, the diaphragm 13 expands downward, and a gap g is formed between the diaphragm 13 and the outer peripheral portion of the substrate W. By ejecting the fluid into the gap, the substrate W is released from the lower surface of the diaphragm 13.

As described above, a certain amount of gas (i.e., the area of the piston 22 × the falling distance of the piston 22 (i.e., the stroke of the piston 22)) can be supplied to the space S. The weight 24 may have a weight enough to completely drop against the pressure in the space S.

(eighth embodiment)

Fig. 65 is a diagram showing a schematic configuration of a substrate polishing apparatus 300 including the quantitative gas supply device 16 according to the eighth embodiment. The constant-rate gas supply device 16 includes an airbag (diffuser) 32, and supplies gas in the airbag 32 to the space S by compressing the airbag 32.

Specifically, the constant-volume gas supply device 16 includes a chamber 31, an airbag 32, and a pressure adjustment unit 33.

The chamber 31 is a hollow having a certain volume therein. The airbag 32 is a balloon-shaped container made of a flexible material such as rubber, and is hermetically housed in the chamber 31.

The chamber 31 is provided with openings O4, O5. Line L4 passes through opening O4. Line L4 connects line L1 to bladder 32 via valve V2. Further, the line L4 is provided with a valve V4, and the airbag 32 can be opened to the atmosphere by opening the valve V4. A line L5 is connected to the opening O5. A pressure adjusting unit 33 is connected to the line L5, and the chamber 31 can be pressurized or depressurized through a line L5. Further, the valve V4 and the pressure adjusting unit 33 are controlled by the control device 17 of fig. 56.

Fig. 66 is a view schematically showing an operating state of the substrate polishing apparatus 300 when the substrate is transferred from the conveyance mechanism 600b to the top ring 1 (fig. 57A to 57C and fig. 58). At this time, valve V1 of fig. 56 is open and valve V2 is closed. Therefore, the pressure adjusting device 15 is connected to the space S, and the constant-volume gas supply device 16 is disconnected from the space S.

The constant-volume gas supply device 16 is set in a standby state. In the standby state, the valve V4 is opened, and the airbag 32 is opened to the atmosphere. Further, the pressure adjusting means 33 depressurizes (preferably, vacuums) the chamber 31 through the line L5. Thereby, the airbag 32 is maintained in a state of being inflated to substantially the same volume as the chamber 31.

Then, the pressure adjusting device 15 reduces the pressure in the space S to a negative pressure, thereby sucking the substrate W on the lower surface of the diaphragm 13 of the top ring 1.

Fig. 67 is a diagram schematically showing an operating state of the substrate polishing apparatus 300 at the time of polishing a substrate. Similarly to fig. 66, the valve V1 in fig. 56 is opened, the valve V2 is closed, and the constant-volume gas supply device 16 is in a standby state. Then, the pressure adjusting device 15 pressurizes the space S, and the substrate W is pressed against the polishing pad 3a of fig. 55 and polished.

Fig. 68 is a view schematically showing an operating state of the substrate polishing apparatus 300 when the substrate is released (fig. 59A to 59C and fig. 60). Unlike fig. 66 and 67, the valve V1 of fig. 56 is closed and the valve V2 is opened. Therefore, the constant-volume gas supply device 16 is connected to the space S, and the pressure adjustment device 15 is disconnected from the space S.

Then, the valve V4 of the quantitative gas supply device 16 is closed, and the pressure adjustment unit 33 pressurizes the chamber 31 via the line L5. Thereby, the airbag 32 is compressed. Since the valve V4 is closed, the gas in the airbag 32 moves to the space S through the lines L4 and L1. As a result, the diaphragm 13 expands downward, and a gap g is formed between the diaphragm 13 and the outer peripheral portion of the substrate W.

In summary, a certain amount of gas (i.e., the volume of the chamber 31) can be supplied to the space S. The airbag 32 may be in the shape of a simple balloon as shown in fig. 64 to 67, a bellows, or the like, and is not particularly limited.

The above-described embodiments are described for the purpose of enabling a person having ordinary knowledge in the technical field to which the present invention pertains to practice the present invention. It is needless to say that various modifications of the above-described embodiments can be made by those skilled in the art, and the technical idea of the present invention can be applied to other embodiments. Therefore, the present invention should not be limited to the embodiments described above, but should be set to the maximum scope according to the technical idea defined by the claims.