阅读说明：本技术 蚀刻方法及等离子体处理装置 (Etching method and plasma processing apparatus ) 是由 浅子龙一 于 2021-05-10 设计创作，主要内容包括：本发明所公开的蚀刻方法包括：(a)使用第1等离子体对氮化钛膜进行蚀刻的工序；及(b)使用第2等离子体对氮化钛膜进行蚀刻的工序。第1等离子体由第1处理气体生成,第2等离子体由第2处理气体生成。第1处理气体及第2处理气体中的一者包含含氯气体及氟碳气体,另一者包含含氯气体且不含氟碳气体。反复执行包括(a)及(b)的循环。关于循环的反复,在氮化钛膜在其膜厚方向上局部被蚀刻的状态下停止。(The etching method disclosed by the invention comprises the following steps: (a) a step of etching the titanium nitride film by using the 1 st plasma; and (b) etching the titanium nitride film using the 2 nd plasma. The 1 st plasma is generated from the 1 st process gas and the 2 nd plasma is generated from the 2 nd process gas. One of the 1 st process gas and the 2 nd process gas includes a chlorine-containing gas and a fluorocarbon gas, and the other includes a chlorine-containing gas and does not include a fluorocarbon gas. A loop including (a) and (b) is repeatedly executed. The repetition of the cycle is stopped in a state where the titanium nitride film is partially etched in the film thickness direction.)

1. An etching method, comprising:

(a) a step of etching the titanium nitride film by using the 1 st plasma; and

(b) a step of etching the titanium nitride film by using the 2 nd plasma,

the 1 st plasma is generated from a 1 st process gas, the 2 nd plasma is generated from a 2 nd process gas,

one of the 1 st process gas and the 2 nd process gas comprises a chlorine-containing gas and a fluorocarbon gas,

the other of the 1 st process gas and the 2 nd process gas comprises a chlorine-containing gas and no fluorocarbon-containing gas,

repeatedly executing a loop including the (a) and the (b),

the repetition of the cycle is stopped in a state where the titanium nitride film is partially etched in the film thickness direction thereof, so that the titanium nitride film provides a bottom surface between the upper surface and the lower surface thereof.

2. The etching method according to claim 1, wherein the substrate having the titanium nitride film further has a phase change material layer,

the titanium nitride film is arranged on the phase change material layer,

the etching method further includes: and etching a portion of the titanium nitride film between the bottom surface and the lower surface and a portion of the phase change material layer in a thickness direction thereof using a 3 rd plasma generated from a 3 rd process gas.

3. The etching method according to claim 2, wherein the 3 rd process gas comprises a bromine-containing gas.

4. The etching method according to claim 2 or 3, wherein the phase change material layer is formed of germanium, antimony, and tellurium.

5. The etching method according to any one of claims 2 to 4, further comprising: and a step of further etching the phase change material layer by using the 4 th plasma generated from the 4 th process gas.

6. The etching method according to claim 5, wherein the 4 th process gas comprises hydrogen gas and hydrocarbon gas.

7. The etching method according to any one of claims 1 to 6, wherein a time length of the (a) and a time length of the (b) in the cycle are 1 second or more and 3 seconds or less, respectively.

8. A plasma processing apparatus includes:

a chamber;

a substrate supporter configured to support a substrate within the chamber;

a gas supply unit configured to supply a 1 st process gas and a 2 nd process gas into the chamber;

a plasma generating section configured to generate plasma from a gas in the chamber; and

a control unit configured to control the gas supply unit and the plasma generation unit,

one of the 1 st process gas and the 2 nd process gas comprises a chlorine-containing gas and a fluorocarbon gas,

the other of the 1 st process gas and the 2 nd process gas comprises a chlorine-containing gas and no fluorocarbon-containing gas,

the control unit repeatedly executes a control loop including:

a 1 st control of controlling the gas supply unit and the plasma generation unit to generate a 1 st plasma from the 1 st process gas in the chamber to etch a titanium nitride film of the substrate supported by the substrate support; and

a 2 nd control of controlling the gas supply unit and the plasma generation unit so that a 2 nd plasma is generated from the 2 nd process gas in the chamber to etch the titanium nitride film,

with respect to the repetition of the control cycle, the titanium nitride film is stopped in a state where it is partially etched in the film thickness direction thereof so that the titanium nitride film provides a bottom surface between the upper surface and the lower surface thereof.

Technical Field

Exemplary embodiments of the present invention relate to an etching method and a plasma processing apparatus.

Background

Japanese patent application laid-open No. 2004-519838 (hereinafter referred to as "patent document 1") which is a method for plasma etching a titanium nitride film for processing a substrate film discloses plasma etching of a titanium nitride film. Specifically, patent document 1 discloses the following: in plasma etching of a titanium nitride film, plasma generated from a gas containing chlorine and fluorocarbon is used.

Disclosure of Invention

The present invention provides the following techniques: the roughness of the bottom surface obtained by partial etching of the titanium nitride film is suppressed, and the difference in etching rate of the titanium nitride film due to the density of the pattern is reduced.

In one exemplary embodiment, an etching method is provided. The etching method comprises the following steps: (a) and a step of etching the titanium nitride film by using the 1 st plasma. The etching method further includes: (b) and a step of etching the titanium nitride film by using the 2 nd plasma. The 1 st plasma is generated from the 1 st process gas and the 2 nd plasma is generated from the 2 nd process gas. One of the 1 st process gas and the 2 nd process gas includes a chlorine-containing gas and a fluorocarbon gas. The other of the 1 st process gas and the 2 nd process gas comprises a chlorine-containing gas and does not contain a fluorocarbon gas. In the etching method, a cycle including (a) and (b) is repeatedly performed. With respect to repetition of the cycle, the titanium nitride film is stopped in a state where it is partially etched in the film thickness direction thereof so that the titanium nitride film provides a bottom surface between the upper surface and the lower surface thereof.

According to an exemplary embodiment, roughness of the bottom surface obtained by partial etching of the titanium nitride film may be suppressed, and a difference in etching rate of the titanium nitride film resulting from the density of the pattern may be reduced.

Drawings

Fig. 1 is a flow chart of an etching method of an exemplary embodiment.

Fig. 2 is a partially enlarged cross-sectional view of an example substrate.

Fig. 3(a) to 3(c) are partially enlarged cross-sectional views of the substrate manufactured in the corresponding steps of the etching method shown in fig. 1.

Fig. 4 is a diagram schematically showing a plasma processing apparatus according to an exemplary embodiment.

Detailed Description

Hereinafter, various exemplary embodiments will be described.

In one exemplary embodiment, an etching method is provided. The etching method comprises the following steps: (a) and a step of etching the titanium nitride film by using the 1 st plasma. The etching method further includes: (b) and a step of etching the titanium nitride film by using the 2 nd plasma. The 1 st plasma is generated from the 1 st process gas and the 2 nd plasma is generated from the 2 nd process gas. One of the 1 st process gas and the 2 nd process gas includes a chlorine-containing gas and a fluorocarbon gas. The other of the 1 st process gas and the 2 nd process gas comprises a chlorine-containing gas and does not contain a fluorocarbon gas. In the etching method, a cycle including (a) and (b) is repeatedly performed. With respect to repetition of the cycle, the titanium nitride film is stopped in a state where it is partially etched in the film thickness direction thereof so that the titanium nitride film provides a bottom surface between the upper surface and the lower surface thereof.

In etching based on plasma generated from a process gas containing a chlorine-containing gas and not containing a fluorocarbon gas, the difference in etching rate of the titanium nitride film due to the density of the pattern is small. However, in etching based on plasma generated from a process gas containing a chlorine-containing gas and not containing a fluorocarbon gas, the roughness of the bottom surface obtained by partial etching of the titanium nitride film becomes large. On the other hand, in etching by plasma generated from a process gas containing a chlorine-containing gas and a fluorocarbon gas, the roughness of the bottom surface obtained by partial etching of the titanium nitride film is suppressed. However, in etching by plasma generated from a process gas containing a chlorine-containing gas and a fluorocarbon gas, the difference in etching rate of the titanium nitride film due to the density of the pattern becomes large. In the above embodiment, plasma etching of the titanium nitride film by the 1 st plasma generated from the 1 st process gas and plasma etching of the titanium nitride film by the 2 nd plasma generated from the 2 nd process gas are alternately performed. Therefore, according to the above embodiment, the roughness of the bottom surface obtained by the partial etching of the titanium nitride film can be suppressed, and the difference in the etching rate of the titanium nitride film due to the density of the pattern can be reduced.

In one exemplary embodiment, the substrate having the titanium nitride film may further have a phase change material layer. The titanium nitride film is arranged on the phase change material layer. In this embodiment, the etching method may further include: and etching the portion between the bottom surface and the lower surface of the titanium nitride film and a portion of the phase change material layer in the thickness direction using the 3 rd plasma generated from the 3 rd process gas.

In one exemplary embodiment, the 3 rd process gas may comprise a bromine-containing gas. According to this embodiment, the phase change material layer can be etched while suppressing damage to the phase change material layer.

In one exemplary embodiment, the phase change material layer may be formed of germanium, antimony, and tellurium.

In one exemplary embodiment, the etching method may further include: and a step of further etching the phase change material layer by using the 4 th plasma generated from the 4 th process gas.

In one exemplary embodiment, the 4 th process gas may include hydrogen gas and hydrocarbon gas.

In an exemplary embodiment, the time length of (a) and the time length of (b) in the cycle may be 1 second or more and 3 seconds or less, respectively. According to this embodiment, the roughness of the bottom surface obtained by the partial etching of the titanium nitride film can be more effectively suppressed, and the difference in the etching rate of the titanium nitride film due to the density of the pattern can be more effectively reduced.

In another exemplary embodiment, a plasma processing apparatus may be provided. The plasma processing apparatus includes a chamber, a substrate support, a gas supply unit, a plasma generation unit, and a control unit. The substrate supporter is configured to support a substrate in the chamber. The gas supply unit is configured to supply a 1 st process gas and a 2 nd process gas in the chamber. The plasma generating unit is configured to generate plasma from the gas in the chamber. The control unit is configured to control the gas supply unit and the plasma generation unit. One of the 1 st process gas and the 2 nd process gas includes a chlorine-containing gas and a fluorocarbon gas. The other of the 1 st process gas and the 2 nd process gas comprises a chlorine-containing gas and does not contain a fluorocarbon gas. The control unit repeatedly executes a control loop including the 1 st control and the 2 nd control. The 1 st control executed by the control section includes the following: the gas supply unit and the plasma generation unit are controlled to generate the 1 st plasma from the 1 st processing gas in the chamber to etch the titanium nitride film of the substrate supported by the substrate support. The 2 nd control performed by the control section includes the following: the gas supply unit and the plasma generation unit are controlled so that the 2 nd plasma is generated from the 2 nd processing gas in the chamber to etch the titanium nitride film. With respect to repetition of the control cycle, the titanium nitride film is stopped in a state where it is partially etched in the film thickness direction thereof so that the titanium nitride film provides a bottom surface between the upper surface and the lower surface thereof.

Hereinafter, various exemplary embodiments will be described in detail with reference to the accompanying drawings. In the drawings, the same or corresponding portions are denoted by the same reference numerals.

Fig. 1 is a flow chart of an etching method of an exemplary embodiment. The etching method (hereinafter, referred to as "method MT") shown in fig. 1 is performed for etching a titanium nitride film of a substrate.

Fig. 2 is a partially enlarged cross-sectional view of an example substrate. The method MT can be applied to the substrate W shown in fig. 2. The substrate W has a titanium nitride film TNF. The substrate W may also have a layer PCL. The layer PCL is a phase change material layer. The titanium nitride film TNF is disposed on the layer PCL. The substrate W including the layer PCL is used, for example, for manufacturing a phase change memory. The layer PCL is formed of a chalcogenide alloy. The layer PCL may comprise germanium (Ge), antimony (Sb) and tellurium (Te). The composition of the layer PCL is, for example, Ge₂Sb₂Te₅。

The substrate W may further have a mask MK. Mask MK is disposed on titanium nitride film TNF. Mask MK has a pattern transferred onto titanium nitride film TNF. That is, the mask MK is patterned to provide a pattern and a space. The mask MK has a region that provides a wide space, i.e., a region in which a pattern is provided at a relatively low density (hereinafter, referred to as "thick region"). Also, the mask MK has a region that provides a narrow space, i.e., a region in which a pattern is provided at a relatively high density (hereinafter, referred to as a "dense region").

Mask MK is formed of a material having an etching rate lower than that of titanium nitride film TNF in steps ST1 and ST2, which will be described later, in steps ST1 and ST 2. Mask MK is formed of, for example, silicon nitride.

The substrate W may also have a base region UR. The layer PCL is disposed on the substrate region UR. The substrate region UR is formed of silicon nitride, for example.

Hereinafter, fig. 3(a) to 3(c) are referred to together with fig. 1 and 2. Fig. 3(a) to 3(c) are partially enlarged cross-sectional views of the substrate manufactured in the corresponding steps of the etching method shown in fig. 1.

As shown in fig. 1, the method MT includes steps ST1 and ST 2. The steps ST1 and ST2 are performed in a state where the substrate W shown in fig. 2 is disposed in the chamber of the plasma processing apparatus. In step ST1, the titanium nitride film TNF is etched by using the 1 ST plasma generated in the chamber. In the next step ST2, the titanium nitride film TNF is etched by the 2 nd plasma generated in the chamber of the plasma processing apparatus. In steps ST1 and ST2, the titanium nitride film TNF is etched in the portion exposed from the mask MK.

In step ST1, the 1 ST plasma is generated from the 1 ST process gas, and in step ST2, the 2 nd plasma is generated from the 2 nd process gas. One of the 1 st process gas and the 2 nd process gas includes a chlorine-containing gas and a fluorocarbon gas. The other of the 1 st process gas and the 2 nd process gas comprises a chlorine-containing gas and does not contain a fluorocarbon gas. Chlorine-containing gases, e.g. containing Cl₂、HCl、CH₃One or more of Cl and ClF. The fluorocarbon gas being, for example, CF₄A gas.

In the method MT, a cycle CY including the steps ST1 and ST2 is repeatedly executed. The repetition of the cycle CY is stopped in a state where the titanium nitride film TNF is partially etched in the film thickness direction, as shown in fig. 3 (a). As a result of repeated execution of the cycle CY, the titanium nitride film TNF provides the bottom surface BS. A bottom surface BS is provided between the upper surface US and the lower surface LS of the titanium nitride film TNF.

Method MT may include procedure STJ. In step STJ, it is determined whether or not the stop condition is satisfied. In the step STJ, for example, it is determined that the stop condition is satisfied when the number of repetitions of the loop CY reaches a predetermined number. When the number of repetitions of the cycle CY reaches a predetermined number, the etching of the titanium nitride film TNF is stopped in a state where the titanium nitride film TNF is partially etched in the film thickness direction as shown in fig. 3 (a). If it is determined in step STJ that the stop condition is not satisfied, the loop CY is executed again. If it is determined in step STJ that the stop condition is satisfied, repetition of the cycle CY is ended.

In etching based on plasma generated from a process gas containing a chlorine-containing gas and not containing a fluorocarbon gas, the difference in etching rate of the titanium nitride film due to the density of the pattern is small. However, in etching based on plasma generated from a process gas containing a chlorine-containing gas and not containing a fluorocarbon gas, the roughness of the bottom surface obtained by partial etching of the titanium nitride film becomes large.

On the other hand, in etching by plasma generated from a process gas containing a chlorine-containing gas and a fluorocarbon gas, the roughness of the bottom surface obtained by partial etching of the titanium nitride film is suppressed. However, in etching by plasma generated from a process gas containing a chlorine-containing gas and a fluorocarbon gas, the difference in etching rate of the titanium nitride film due to the density of the pattern becomes large. Specifically, in etching by plasma generated from a process gas containing a chlorine-containing gas and a fluorocarbon gas, the etching rate of the titanium nitride film in the rough region is low, and the etching rate of the titanium nitride film in the dense region is high.

In the method MT, plasma etching of the titanium nitride film TNF by the 1 st plasma generated from the 1 st process gas and plasma etching of the titanium nitride film TNF by the 2 nd plasma generated from the 2 nd process gas are alternately performed. Therefore, according to the method MT, the roughness of the bottom surface BS obtained by the partial etching of the titanium nitride film TNF can be suppressed, and the difference in the etching rate of the titanium nitride film TNF due to the density of the pattern can be reduced.

In one embodiment, the time length of the process ST1 and the time length of the process ST2 in the cycle CY may be 1 second or more and 3 seconds or less, respectively. According to this embodiment, the roughness of the bottom surface BS obtained by the partial etching of the titanium nitride film TNF can be more effectively suppressed, and the difference in the etching rate of the titanium nitride film TNF due to the density of the pattern can be more effectively reduced.

In one embodiment, the method MT may further include procedure ST 3. The process ST3 is executed after the loop CY is repeatedly executed. The step ST3 is performed in a state where the substrate W shown in fig. 3(a) is disposed in the chamber of the plasma processing apparatus. In the step ST3, a plasma processing apparatus for repeatedly executing the cycle CY may be used. That is, the cycle CY and the process ST3 may be performed using a single plasma processing apparatus. Alternatively, the process ST3 may be performed using a plasma processing apparatus different from the plasma processing apparatus used to repeatedly perform the cycle CY. When the step ST3 is performed using a plasma processing apparatus different from the plasma processing apparatus for repeatedly executing the cycle CY, the substrate W can be conveyed between the plasma processing apparatuses in a depressurized environment. That is, the substrate W can be conveyed between these plasma processing apparatuses without breaking the vacuum.

In step ST3, the titanium nitride film TNF is etched in a portion between the bottom surface BS and the bottom surface LS and in a portion in the thickness direction of the layer PCL by using the 3 rd plasma generated in the chamber of the plasma processing apparatus. Fig. 3 (b) shows an example of the state of the substrate W after the step ST3 is performed.

In step ST3, the 3 rd plasma is generated from the 3 rd process gas. The 3 rd process gas can be selected so that damage to the layer PCL by the 3 rd plasma is less than damage to the layer PCL that may be caused by the repetition of the cycle CY. The 3 rd process gas may include a halogen gas. The 3 rd process gas may contain other gas (e.g., inactive gas such as rare gas) that dilutes the halogen gas. Alternatively, the 3 rd process gas may be a gas containing halogen and C_xH_yX_zA mixture of gases. Here, "X" is a halogen element, and X, y, and z are each an integer of 0 or more. Halogen gases, e.g. Cl₂A gas. C_xH_yX_zThe gas is, for example, hydrogen bromide (HBr gas), CH₃F gas, CHF₃Gas or CF₄A gas. According to step ST3, the layer PCL can be etched while damage to the layer PCL is suppressed.

In one embodiment, the method MT may further include procedure ST 4. The process ST4 is performed after the process ST 3. The step ST4 is performed in a state where the substrate W shown in fig. 3 (b) is disposed in the chamber of the plasma processing apparatus. In the step ST4, a plasma processing apparatus for repeatedly executing the cycle CY or a plasma processing apparatus used in the step ST3 may be used. The cycle CY, the process ST3, and the process ST4 may be performed using a single plasma processing apparatus. Alternatively, the step ST4 may be performed by using a plasma processing apparatus for repeatedly executing the cycle CY and a plasma processing apparatus different from the plasma processing apparatus used in the step ST 3. When the step ST4 is executed using a plasma processing apparatus different from the plasma processing apparatus used in the step ST3, the substrate W can be conveyed between the plasma processing apparatuses in a depressurized environment. That is, the substrate W can be conveyed between these plasma processing apparatuses without breaking the vacuum.

In step ST4, the layer PCL is further etched using the 4 th plasma generated in the chamber of the plasma processing apparatus. As shown in fig. 3(c), in step ST4, layer PCL may be etched to expose base region UR.

In step ST4, the 4 th plasma is generated from the 4 th process gas. The 4 th process gas may contain hydrogen (H)₂Gas), a mixed gas of hydrogen and a hydrocarbon gas (e.g., methane gas), a hydrogen halide gas (e.g., HBr gas), or one or more organic halide gases. The 4 th process gas may be a mixed gas containing one or more of hydrogen, a hydrocarbon gas, a hydrogen halide gas, and one or more organic halide gases. The one or more organic halide gases may comprise CH₃F gas, CHF₃Gas and CF₄More than one of the gases.

Hereinafter, a plasma processing apparatus capable of executing the method MT will be described. Fig. 4 is a diagram schematically showing a plasma processing apparatus according to an exemplary embodiment.

The plasma processing apparatus 1 shown in fig. 4 is an inductively coupled plasma processing apparatus. The plasma processing apparatus 1 includes a chamber 10. A space Sp is provided in the chamber 10. The plasma processing of the substrate W is performed in the space Sp. In one embodiment, the chamber 10 may include a chamber body 12. The chamber body 12 has a generally cylindrical shape (e.g., a generally cylindrical shape). The chamber body 12 is formed of a metal such as aluminum. A space Sp is provided inside the chamber body 12.

The plasma processing apparatus 1 further includes a substrate holder 16. The substrate supporter 16 is configured to support a substrate W in the chamber 10. The substrate support 16 may be supported by the support portion 14. The support 14 is disposed on the bottom of the chamber 10. The support portion 14 may have a generally cylindrical shape. The support portion 14 may be formed of an insulating material. The insulating material of the support 14 may be quartz. The support 14 extends upwardly from the bottom of the chamber 10 within the chamber 10.

In one embodiment, the substrate support 16 may include a lower electrode 18 and an electrostatic chuck 20. The substrate support 16 may also include an electrode plate 19. The electrode plate 19 is formed of a metal such as aluminum. The electrode plate 19 has a substantially circular disk shape.

The lower electrode 18 is provided on the electrode plate 19. The lower electrode 18 is formed of a metal such as aluminum. The lower electrode 18 has a substantially circular disk shape. The lower electrode 18 is electrically connected to an electrode plate 19. A flow path 24 may be provided in the lower electrode 18. The flow path 24 constitutes a temperature adjustment mechanism. The flow path 24 is connected to a cooling unit provided outside the chamber 10 via a pipe 26a and a pipe 26 b. The cooling unit supplies the coolant to the flow path 24 through the pipe 26 a. The refrigerant supplied to the flow path 24 is returned to the cooling unit via the pipe 26 b. The temperature of the substrate W supported by the substrate support 16 is controlled by controlling the temperature of the coolant supplied to the flow path 24.

An electrostatic chuck 20 is disposed on the lower electrode 18. The substrate W is placed on the electrostatic chuck 20. The electrostatic chuck 20 includes a body and an electrode. The body of the electrostatic chuck 20 is formed of a dielectric such as aluminum oxide or aluminum nitride. The electrode of the electrostatic chuck 20 is a film having conductivity, and is provided in the main body of the electrostatic chuck 20. The dc power supply 22 is connected to the electrode of the electrostatic chuck 20 via a switch 23. When a dc voltage from the dc power supply 22 is applied to the electrode of the electrostatic chuck 20, an electrostatic attractive force is generated between the substrate W placed on the electrostatic chuck 20 and the electrostatic chuck 20. Due to the generated electrostatic attractive force, the substrate W is held by the electrostatic chuck 20.

The substrate support 16 may further support an edge ring ER mounted thereon. The edge ring ER has a substantially annular shape. The edge ring ER is formed of, for example, silicon carbide, or quartz. The substrate W is disposed on the electrostatic chuck 20 in a region surrounded by the edge ring ER.

In one embodiment, the plasma processing apparatus 1 may further include a gas supply line 28. The gas supply line 28 supplies a heat transfer gas (e.g., He gas) from the heat transfer gas supply mechanism to a gap between the upper surface of the electrostatic chuck 20 and the back surface of the substrate W.

In one embodiment, the plasma processing apparatus 1 may further include a heater HT. A heater HT may be provided in the substrate holder 16 to adjust the temperature of the substrate W. The heater HT may be disposed in the electrostatic chuck 20. The heater power supply HP is connected to the heater HT. When power is supplied from the heater power supply HP to the heater HT, the heater HT generates heat, and the temperature of the substrate W can be adjusted.

In one embodiment, the plasma processing apparatus 1 may further include a dielectric 194. The dielectric 194 may have a plate shape. Dielectric 194 is disposed over substrate support 16. The dielectric 194 constitutes a ceiling portion that partitions the space Sp.

In one embodiment, the plasma processing apparatus 1 may further include a shield 46. The shield 46 is detachably provided along the inner wall of the chamber 10. The shield 46 can also be provided at the outer periphery of the support portion 14. The shield 46 prevents etch byproducts from adhering to the chamber 10. The shield 46 can be made of, for example, Y₂O₃The ceramic is formed by coating the surface of a member made of aluminum.

In one embodiment, the plasma processing apparatus 1 may further include a baffle member 48. The shutter member 48 is disposed between the support portion 14 and the sidewall of the chamber 10. The shutter member 48 can be formed by, for example, Y₂O₃The ceramic is formed by coating the surface of a plate-like member made of aluminum. The shutter member 48 has a plurality of through holes.

In one embodiment, a vent 12e may be provided at the bottom of the chamber 10. The plasma processing apparatus 1 may further include an exhaust device 50. The exhaust device 50 is connected to the exhaust port 12e via an exhaust pipe 52. The exhaust device 50 may include a vacuum pump such as a turbo molecular pump and a pressure controller (e.g., an automatic pressure control valve). The exhaust device 50 is capable of depressurizing the pressure of the space Sp to a specified pressure.

In one embodiment, the plasma processing apparatus 1 may further include a high-frequency power supply 64. The high-frequency power supply 64 is a power supply that generates high-frequency bias power, which is high-frequency power for introducing ions into the substrate W. The frequency of the high-frequency bias power is, for example, 400kHz to 40.68 MHz. The high-frequency power supply 64 is electrically connected to the lower electrode 18 via a matching unit 68. The matching unit 68 has a circuit for matching the impedance on the load side (lower electrode 18 side) of the high-frequency power supply 64 with the output impedance of the high-frequency power supply 64.

The plasma processing apparatus 1 may further include a gas supply unit 120. The gas supply unit 120 is configured to supply the 1 st process gas and the 2 nd process gas to the space Sp. The gas supply unit 120 may be configured to supply the 3 rd process gas and/or the 4 th process gas to the space Sp in addition to the 1 st process gas and the 2 nd process gas. A gas introduction port 121 may be provided at a sidewall of the chamber 10. The gas supply unit 120 may be connected to the gas introduction port 121 via a pipe 123.

The gas supply unit 120 may include a gas supply source 122, a flow rate controller 124, and an opening/closing valve 126. The gas supply 122 includes a 1 st process gas source and a 2 nd process gas source. The gas supply 122 may also include a 3 rd process gas source and/or a 4 th process gas source. The gas supply source 122 is connected to the space Sp via a flow rate controller 124 and an on-off valve 126. The gas supply source 122 may be connected to the pipe 123 via a flow rate controller 124 and an on-off valve 126. The flow controller 124 is, for example, a mass flow controller or a pressure-controlled flow controller. The gas from the gas supply source 122 is supplied to the space Sp in a state where the flow rate thereof is adjusted by the flow rate controller 124.

The structure of the gas supply unit 120 is not limited to the structure shown in fig. 4. In another embodiment, the gas supply unit 120 may be configured to supply gas from a ceiling portion of the chamber 10 to the space Sp. The gas supply unit 120 may supply gas to the space Sp from a gas inlet formed in, for example, a central portion of the dielectric 194.

The plasma processing apparatus 1 further includes a plasma generating unit. The plasma generator is configured to generate plasma from the gas in the chamber 10. The plasma generator introduces energy for exciting the gas in the chamber 10 into the chamber 10. In one embodiment, the plasma generating part may include an antenna 140. The antenna 140 is a planar high-frequency antenna and is disposed above the dielectric 194. The antenna 140 may be covered by a shielding member 160.

In one embodiment, the antenna 140 may include an inner antenna element 142A and an outer antenna element 142B. The inner antenna element 142A is disposed above the central portion of the dielectric 194. Outer antenna element 142B is disposed so as to surround the outer periphery of inner antenna element 142A. The inner antenna element 142A and the outer antenna element 142B are each formed of a conductor such as copper, aluminum, or stainless steel. The inner antenna element 142A and the outer antenna element 142B may be formed in a spiral shape.

The inner antenna element 142A and the outer antenna element 142B may be integrally fixed by a plurality of holding members 144. Each of the plurality of holders 144 has a rod shape, for example. The plurality of holding members 144 are arranged radially so as to protrude outward from the outer antenna element 142B from the vicinity of the center of the inner antenna element 142A.

The shielding member 160 may include an inner shielding wall 162A and an outer shielding wall 162B. The inner shielding wall 162A is provided between the inner antenna element 142A and the outer antenna element 142B so as to surround the inner antenna element 142A. The outer shielding wall 162B is provided to surround the outer antenna element 142B. The outer shield wall 162B may have a cylindrical shape. In this example, the space above the dielectric 194 is divided into an inner central region of the inner shield wall 162A and a peripheral region between the inner shield wall 162A and the outer shield wall 162B.

The shielding member 160 may further include an inner shielding plate 164A and an outer shielding plate 164B. The inner shield plate 164A may have a circular plate shape. The inner shield plate 164A is disposed above the inner antenna element 142A to close the opening of the inner shield wall 162A. The outer shield plate 164B may have a substantially annular plate shape. The outer shield plate 164B is disposed above the outer antenna element 142B to close the opening between the inner shield wall 162A and the outer shield wall 162B.

High-frequency power supply 150A and high-frequency power supply 150B are connected to inner antenna element 142A and outer antenna element 142B, respectively. The high-frequency power supply 150A and the high-frequency power supply 150B supply high-frequency power of the same frequency or different frequencies to the inner antenna element 142A and the outer antenna element 142B, respectively. The frequency of the high-frequency power supplied from each of the high-frequency power supplies 150A and 150B is, for example, 27 MHz. When the high-frequency power from the high-frequency power supply 150A is supplied to the inner antenna element 142A, the inner antenna element 142A generates an induced magnetic field in the chamber 10. The generated induction magnetic field excites the gas in the chamber 10, and generates a toroidal plasma above the central portion of the substrate W. When the high-frequency power from the high-frequency power supply 150B is supplied to the outer antenna element 142B, the outer antenna element 142B generates an induced magnetic field in the chamber 10. The generated induction magnetic field excites a gas in the chamber 10, and generates a toroidal plasma above the peripheral portion of the substrate W.

In one embodiment, the plasma processing apparatus 1 may further include an actuator 168A and an actuator 168B. The actuators 168A, 168B are used to adjust the electrical length of the inner antenna element 142A and the electrical length of the outer antenna element 142B in accordance with the high-frequency power output from the high-frequency power supplies 150A, 150B, respectively. The actuators 168A and 168B adjust the electrical length of the inner antenna element 142A and the electrical length of the outer antenna element 142B by adjusting the height direction position of the inner shield plate 164A and the height direction position of the outer shield plate 164B, respectively.

The plasma processing apparatus 1 may further include a control unit 80. The controller 80 is configured to control each part of the plasma processing apparatus 1. The control unit 80 may be a computer provided with a processor, a storage device, an input device, a display device, and the like. The control unit 80 executes a control program stored in a storage device, and controls each unit of the plasma processing apparatus 1 based on recipe data stored in the storage device. The method MT can be executed in the plasma processing apparatus 1 by controlling each part of the plasma processing apparatus 1 based on the control unit 80.

The control unit 80 repeatedly executes a control loop including the 1 st control and the 2 nd control. The 1 st control performed by the control section 80 includes the following: the gas supply unit 120 and the plasma generation unit are controlled to generate the 1 st plasma from the 1 st process gas in the chamber 10, thereby etching the titanium nitride film TNF of the substrate W supported by the substrate support 16. In one embodiment, the 1 st control includes the following: the gas supply part 120 is controlled to supply the 1 st process gas into the chamber 10. The 1 st control may further include the following: the exhaust device 50 is controlled to set the pressure in the chamber 10 to a specified pressure. The 1 st control further includes the following: the plasma generation section is controlled to generate plasma from the 1 st process gas in the chamber 10. In the 1 st control, the control unit 80 controls the high-frequency power supply 150A and the high-frequency power supply 150B to supply high-frequency power to the inner antenna element 142A and the outer antenna element 142B, respectively. The 1 st control may further include the following: the high-frequency power supply 64 is controlled to supply high-frequency bias power to the lower electrode 18. The step ST1 is executed by the 1 ST control by the control unit 80.

The 2 nd control performed by the control section 80 includes the following: the gas supply unit 120 and the plasma generation unit are controlled to generate the 2 nd plasma from the 2 nd process gas in the chamber 10, thereby etching the titanium nitride film TNF of the substrate W supported by the substrate support 16. In one embodiment, the 2 nd control includes the following: the gas supply part 120 is controlled to supply the 2 nd process gas into the chamber 10. The 2 nd control may further include the following: the exhaust device 50 is controlled to set the pressure in the chamber 10 to a specified pressure. The 2 nd control further includes the following: the plasma generation section is controlled to generate plasma from the 2 nd process gas in the chamber 10. In the 2 nd control, the control unit 80 controls the high-frequency power supply 150A and the high-frequency power supply 150B to supply high-frequency power to the inner antenna element 142A and the outer antenna element 142B, respectively. The 2 nd control may further include the following: the high-frequency power supply 64 is controlled to supply high-frequency bias power to the lower electrode 18. The step ST2 is executed by the 2 nd control by the control unit 80.

The control section 80 stops repetition of the control cycle to stop etching of the titanium nitride film TNF in a state where the titanium nitride film TNF is partially etched in the film thickness direction. At the end of the control cycle, a bottom surface BS is provided between the upper surface US and the lower surface LS of the titanium nitride film TNF.

In one embodiment, the control section 80 may also execute the 3 rd control. The 3 rd control is executed after the above-described control loop is repeatedly executed. The 3 rd control includes the following: the gas supply unit 120 and the plasma generation unit are controlled to generate the 3 rd plasma from the 3 rd process gas in the chamber 10, thereby etching the titanium nitride film TNF and a part of the layer PCL of the substrate W supported by the substrate support 16. In one embodiment, the 3 rd control includes the following: the gas supply part 120 is controlled to supply the 3 rd process gas into the chamber 10. The 3 rd control may further include the following: the exhaust device 50 is controlled to set the pressure in the chamber 10 to a specified pressure. The 3 rd control further includes the following: the plasma generation section is controlled to generate plasma from the 3 rd process gas in the chamber 10. In the 3 rd control, the control unit 80 controls the high-frequency power supply 150A and the high-frequency power supply 150B to supply high-frequency power to the inner antenna element 142A and the outer antenna element 142B, respectively. The 3 rd control may further include the following: the high-frequency power supply 64 is controlled to supply high-frequency bias power to the lower electrode 18. The step ST3 is executed by the 3 rd control by the control unit 80.

In one embodiment, the control section 80 may also execute the 4 th control. The 4 th control is executed after the 3 rd control. The 4 th control includes the following: the gas supply 120 and the plasma generator are controlled to generate a 4 th plasma from the 4 th process gas in the chamber 10 to further etch the layer PCL of the substrate W supported by the substrate support 16. In one embodiment, the 4 th control includes the following: the gas supply part 120 is controlled to supply the 4 th process gas into the chamber 10. The 4 th control may further include the following: the exhaust device 50 is controlled to set the pressure in the chamber 10 to a specified pressure. The 4 th control further includes the following: the plasma generation section is controlled to generate plasma from the 4 th process gas in the chamber 10. In the 4 th control, the control unit 80 controls the high-frequency power supply 150A and the high-frequency power supply 150B to supply high-frequency power to the inner antenna element 142A and the outer antenna element 142B, respectively. The 4 th control may further include the following: the high-frequency power supply 64 is controlled to supply high-frequency bias power to the lower electrode 18. The step ST4 is executed by the 4 th control by the control unit 80.

While various exemplary embodiments have been described above, the present invention is not limited to the above exemplary embodiments, and various additions, omissions, substitutions, and changes may be made. Moreover, the elements of the different embodiments may be combined to form another embodiment.

For example, in another embodiment, the plasma processing apparatus may be a plasma processing apparatus other than an inductively coupled plasma processing apparatus. Such a plasma processing apparatus may be a capacitively-coupled plasma processing apparatus, an Electron Cyclotron Resonance (ECR) plasma processing apparatus, or a plasma processing apparatus that generates plasma using a surface wave such as a microwave.

From the above description, it is to be understood that various embodiments of the present invention have been described in the present specification for the purpose of illustration, and that various changes may be made without departing from the scope and spirit of the present invention. Therefore, the various embodiments disclosed in the present specification are not limited, and the actual scope and gist are indicated by the appended claims.