阅读说明：本技术 减压干燥装置、基板处理装置以及减压干燥方法 (Reduced pressure drying apparatus, substrate processing apparatus, and reduced pressure drying method ) 是由 辻雅夫 西冈贤太郎 高村幸宏 实井祐介 于 2019-06-27 设计创作，主要内容包括：本发明提供一种即使在排气量小的情况下,也能够高精度地调节减压速度的技术。在本发明的减压干燥装置中,将腔室(20)内和泵(30)连接的排气配管部(40)具有在腔室和泵之间并列配置的大径配管(44)和小径配管(45)。小径配管的管径比大径配管的管径小。在减压干燥处理中,控制部能够在小径阀控制模式和大径阀控制模式之间进行切换,在小径阀控制模式中,使大径阀(440)的开度固定并调节小径阀(450)的开度,在大径阀控制模式中,调节大径阀的开度。由此,在减压排气量小的情况下,能够通过调节小径阀的开度而高精度地调节流路面积。在减压排气量大的情况下,通过调节能够大幅调节流路面积的大径阀的开度,能够响应性良好地调节减压速度。(The invention provides a technology capable of adjusting a decompression speed with high precision even under the condition of small exhaust gas volume. In the decompression drying device of the present invention, an exhaust piping part (40) connecting the inside of a chamber (20) and a pump (30) has a large-diameter piping (44) and a small-diameter piping (45) arranged in parallel between the chamber and the pump. The small-diameter piping has a smaller diameter than the large-diameter piping. In the pressure reduction drying process, the control unit can switch between a small-diameter valve control mode in which the opening degree of the large-diameter valve (440) is fixed and the opening degree of the small-diameter valve (450) is adjusted, and a large-diameter valve control mode in which the opening degree of the large-diameter valve is adjusted. Thus, when the amount of depressurized exhaust gas is small, the flow path area can be adjusted with high accuracy by adjusting the opening degree of the small-diameter valve. When the decompression exhaust gas amount is large, the decompression speed can be adjusted with good responsiveness by adjusting the opening degree of the large-diameter valve that can greatly adjust the flow passage area.)

1. A reduced pressure drying apparatus for drying a substrate having a treatment liquid adhered thereto under reduced pressure,

the decompression drying device includes:

a chamber accommodating the substrate and forming a processing space around the substrate;

a pump for sucking and exhausting gas in the chamber;

an exhaust piping section that connects the chamber and the pump in a flow path; and

a control unit for controlling the operation of each unit,

the exhaust piping section includes: a large-diameter piping equipped with a large-diameter valve; and a small-diameter piping to which a small-diameter valve having a smaller diameter than the large-diameter valve is attached,

the large-diameter valve and the small-diameter valve can change the flow passage area in the pipe by changing the opening degree,

the large-diameter pipe and the small-diameter pipe are arranged in parallel between the chamber and the pump,

the control unit is configured to be switchable between a small-diameter valve control mode in which the opening degree of the small-diameter valve is adjusted while the opening degree of the large-diameter valve is fixed, and a large-diameter valve control mode in which the opening degree of the large-diameter valve is adjusted, in the pressure reduction drying process.

2. The reduced-pressure drying apparatus according to claim 1,

the control unit executes the small-diameter valve control mode first and then executes the large-diameter valve control mode in the decompression drying process.

3. The reduced-pressure drying apparatus according to claim 1,

the small-diameter valve control mode includes a first small-diameter valve control mode in which the large-diameter valve is closed.

4. The reduced-pressure drying apparatus according to claim 1,

the small-diameter valve control mode includes a second small-diameter valve control mode in which the opening degree of the large-diameter valve is fixed.

5. The reduced-pressure drying apparatus according to claim 1,

the exhaust gas piping portion further includes:

a plurality of chamber connection pipes, one end of which opens in the chamber; and

a first common pipe directly or indirectly connected to the other ends of all the chamber connecting pipes,

an upstream end of the large-diameter pipe and an upstream end of the small-diameter pipe are connected to the first common pipe, respectively.

6. The reduced-pressure drying apparatus according to claim 1,

the decompression drying apparatus has a plurality of the pumps,

the exhaust piping further includes a second common piping directly or indirectly connected to all of the pumps,

a downstream end of the large-diameter pipe and a downstream end of the small-diameter pipe are connected to the second common pipe, respectively.

7. The reduced-pressure drying apparatus according to any one of claims 1 to 6,

a plurality of the large-diameter pipes provided in the exhaust pipe portion,

the small-diameter piping of the exhaust piping part is one.

8. A substrate processing apparatus for coating and developing a resist solution on a substrate,

the substrate processing apparatus includes:

a coating unit that coats the resist solution on the substrate before the exposure processing;

the reduced-pressure drying apparatus according to any one of claims 1 to 7, wherein the substrate to which the resist solution is attached is dried under reduced pressure; and

and a developing unit that performs a developing process on the substrate subjected to the exposure process.

9. A reduced pressure drying method for drying a substrate by sucking and exhausting gas from a chamber containing the substrate to which a processing liquid is adhered via an exhaust pipe section by a pump to reduce the pressure in the chamber,

the exhaust piping section includes: a large-diameter piping equipped with a large-diameter valve; and a small-diameter piping to which a small-diameter valve having a smaller diameter than the large-diameter valve is attached,

according to the decompression treatment, the following steps are switched:

a step a) of adjusting the opening degree of the small-diameter valve while fixing the opening degree of the large-diameter valve while performing suction and exhaust by the pump; and

and a step b) of adjusting the opening degree of the large-diameter valve while performing suction and exhaust by the pump.

10. The reduced-pressure drying method according to claim 9, wherein,

in the pressure reduction treatment, the step a) is performed first, and then the step b) is performed.

Technical Field

The present invention relates to a technique for drying a substrate to which a processing liquid has adhered under reduced pressure.

Background

Conventionally, in a process of manufacturing a substrate for precision electronic devices such as a substrate for Flat Panel Displays (FPD) such as a semiconductor wafer, a liquid crystal Display device, and an organic Electroluminescence (EL) Display device, a glass substrate for a photomask, a substrate for a color filter, a substrate for a recording disk, a substrate for a solar cell, and a substrate for electronic paper, a reduced pressure drying apparatus has been used to dry a processing liquid applied to the substrate. Such a decompression drying apparatus has a chamber for accommodating a substrate and an exhaust device for exhausting gas in the chamber. A conventional decompression drying apparatus is described in, for example, patent document 1.

When a thin film is formed by drying a treatment liquid such as a photoresist applied to a substrate, bumping (bumping) may occur when a rapid pressure reduction is performed. Bumping occurs due to rapid evaporation of solvent components in the photoresist applied to the surface of the substrate. If bumping occurs during the reduced-pressure drying process, a defoaming phenomenon occurs in which small bubbles are formed on the surface of the photoresist. Therefore, in the reduced-pressure drying process, the pressure in the chamber is not rapidly reduced in the initial stage, and it is necessary to gradually reduce the pressure.

Patent document 1: japanese patent laid-open publication No. 2006-261379

In order to change the pressure in the chamber in stages, it is necessary to adjust the decompression rate. In the reduced-pressure drying apparatus described in patent document 1, during the pressure reduction process, an inert gas is supplied into the chamber while the gas in the chamber is discharged, thereby adjusting the pressure reduction rate. Further, in order to appropriately adjust the decompression rate, a valve capable of changing the opening degree in multiple stages is provided between the supply source of the inert gas and the chamber. As another method of adjusting the decompression rate in the chamber, a valve capable of changing the opening degree in multiple stages may be provided between the chamber and the exhaust device to adjust the amount of exhaust gas from the chamber. In this case, the amount of exhaust gas from the chamber can be adjusted in stages.

When the amount of exhaust gas from the chamber is adjusted by changing the opening degree of the valve, the amount of exhaust gas is determined according to the flow passage area of the valve. The accuracy of adjustment of the opening degree of the valve is substantially constant regardless of the size of the opening degree. That is, the accuracy of adjustment of the exhaust gas amount is substantially constant when the opening degree is large and the exhaust gas amount is large, and when the opening degree is small and the exhaust gas amount is small. However, as in the initial stage of the reduced pressure drying process described above, when the exhaust gas amount is small, it is particularly necessary to adjust the pressure reduction rate with high accuracy.

Disclosure of Invention

The present invention has been made in view of the above circumstances, and an object thereof is to provide a technique for adjusting a decompression speed with high accuracy even when an amount of exhaust gas is small in a decompression drying device having a valve whose opening degree can be changed.

In order to solve the above problem, a first aspect of the present invention is a reduced pressure drying apparatus for drying a substrate to which a processing liquid has adhered under reduced pressure, the reduced pressure drying apparatus including: a chamber accommodating the substrate and forming a processing space around the substrate; a pump for sucking and exhausting gas in the chamber; an exhaust piping section that connects the chamber and the pump in a flow path; and a control unit that controls operations of the respective units, the exhaust piping unit including: a large-diameter piping equipped with a large-diameter valve; and a small-diameter pipe to which a small-diameter valve having a smaller pipe diameter than the large-diameter valve is attached, the large-diameter valve and the small-diameter valve being capable of changing a flow passage area in the pipe by changing an opening degree, the large-diameter pipe and the small-diameter pipe being arranged in parallel between the chamber and the pump, the control unit being capable of switching between a small-diameter valve control mode in which the opening degree of the large-diameter valve is fixed and the opening degree of the small-diameter valve is adjusted and a large-diameter valve control mode in which the opening degree of the large-diameter valve is adjusted, in the pressure reduction drying process.

In a second aspect of the present invention, in the reduced pressure drying apparatus according to the first aspect, the control unit executes the small-diameter valve control mode first and then executes the large-diameter valve control mode in the reduced pressure drying process.

A third aspect of the present invention provides the decompression drying device of the first or second aspect, wherein the small-diameter valve control mode includes a first small-diameter valve control mode for closing the large-diameter valve.

A fourth aspect of the present invention provides the decompression drying apparatus of any one of the first to third aspects, wherein the small-diameter valve control mode includes a second small-diameter valve control mode in which an opening degree of the large-diameter valve is fixed.

A fifth aspect of the present invention provides the reduced-pressure drying apparatus according to any one of the first to fourth aspects, wherein the exhaust pipe portion further includes: a plurality of chamber connection pipes, one end of which opens in the chamber; and a first common pipe directly or indirectly connected to the other ends of all the chamber connection pipes, wherein an upstream end of the large-diameter pipe and an upstream end of the small-diameter pipe are connected to the first common pipe.

A sixth aspect of the present invention provides the decompression drying device of any one of the first to fifth aspects, wherein the decompression drying device includes a plurality of the pumps, the exhaust pipe further includes a second common pipe directly or indirectly connected to all the pumps, and a downstream end of the large-diameter pipe and a downstream end of the small-diameter pipe are respectively connected to the second common pipe through flow paths.

A seventh aspect of the present invention provides the vacuum drying apparatus of any one of the first to sixth aspects, wherein the exhaust pipe portion includes a plurality of the large-diameter pipes, and the exhaust pipe portion includes one small-diameter pipe.

An eighth aspect of the present invention is a substrate processing apparatus for applying and developing a resist solution to a substrate, the substrate processing apparatus comprising: a coating unit that coats the resist solution on the substrate before the exposure processing; the reduced-pressure drying apparatus according to any one of the first to seventh aspects, wherein the substrate to which the resist solution is attached is dried under reduced pressure; and a developing unit that performs a developing process on the substrate subjected to the exposure process.

A ninth aspect of the present invention is a reduced pressure drying method for drying a substrate by sucking and exhausting gas from a chamber containing the substrate to which a processing liquid is attached by a pump through an exhaust pipe section, and reducing pressure in the chamber, wherein the exhaust pipe section includes: a large-diameter piping equipped with a large-diameter valve; and a small-diameter piping to which a small-diameter valve having a smaller diameter than the large-diameter valve is attached, and which switches the following steps in accordance with the progress of the pressure reduction treatment: a step a) of adjusting the opening degree of the small-diameter valve while fixing the opening degree of the large-diameter valve while performing suction and exhaust by the pump; and a step b) of adjusting the opening degree of the large-diameter valve while performing suction and exhaust by the pump.

In the tenth aspect of the present invention, in the reduced-pressure drying method according to the ninth aspect, in the reduced-pressure treatment, the step a) is performed first, and then the step b) is performed.

According to the first to tenth aspects of the present invention, in the small-diameter valve control mode, the flow passage area can be adjusted with high accuracy by adjusting the opening degree of the small-diameter valve, and the desired decompression speed can be approached. On the other hand, in the large-diameter valve control mode, the opening degree of the large-diameter valve capable of adjusting the flow passage area in a wide range is adjusted, whereby the decompression speed can be adjusted with good responsiveness.

In particular, according to the second and tenth aspects of the present invention, in the initial stage of the pressure reduction process, the flow passage area can be adjusted with high accuracy by adjusting the opening degree of the small diameter valve, and the desired pressure reduction speed can be approached. On the other hand, in the final stage of the pressure reduction treatment, the opening degree of the large-diameter valve capable of greatly adjusting the flow passage area is adjusted, whereby the pressure reduction speed can be adjusted with good responsiveness.

In particular, according to the fifth aspect of the present invention, when a plurality of openings are provided, the first common pipe is connected to all the openings, so that the suction/exhaust forces from all the openings can be made uniform.

In particular, according to the sixth aspect of the present invention, when a plurality of pumps are provided, the second common pipe is connected to all the pumps, so that the suction/discharge pressures on the downstream sides of all the large-diameter pipes and the small-diameter pipes can be made uniform.

In particular, according to the seventh aspect of the present invention, when the capacity of the chamber is large, the maximum flow path area in the exhaust pipe portion can be increased without reducing the accuracy of adjustment of the flow path area in the small-diameter pipe.

Drawings

Fig. 1 is a schematic view showing a configuration of a substrate processing apparatus according to a first embodiment.

Fig. 2 is a schematic diagram showing the structure of the vacuum drying apparatus according to the first embodiment.

Fig. 3 is a perspective view showing a three-dimensional structure of a piping part of the reduced pressure drying apparatus according to the first embodiment.

Fig. 4 is a flowchart showing the flow of the reduced pressure drying process according to the first embodiment.

Fig. 5 is a diagram showing the operation of the large-diameter valve and the small-diameter valve in each control mode of the first embodiment.

Fig. 6 is a diagram showing an example of a target reduced-pressure waveform of the first embodiment.

Fig. 7 is a perspective view showing a three-dimensional structure of a piping part of a vacuum drying apparatus according to a modification.

Fig. 8 is a schematic diagram showing the structure of a piping part of a vacuum drying apparatus according to another modification.

Fig. 9 is a schematic diagram showing a structure of a piping part of a vacuum drying apparatus according to still another modification.

Description of the reference numerals:

1 decompression drying device

9 substrate processing apparatus

20. 20A, 20B, 20C Chamber

23. 23A, 23B exhaust port

25 pressure sensor

30. 30A, 30B, 30C pump

40. 40A, 40B, 40C piping section

41. 41A, 41B, 41C chamber connecting piping

42. 42C collective piping

43. 43A, 43C first common piping

44. 44A, 44B, 44C large-diameter piping

45. 45A, 45B, 45C small-diameter piping

46. 46A, 46C second common pipe

47. 47A, 47B, 47C exhaust pipe

48. 48A independent exhaust pipe

50 inert gas supply unit

60 control part

70 input unit

93 coating part

96 developing part

440. 440A, 440B, 440C large diameter valve

450. 450A, 450B, 450C small diameter valve

G substrate

Detailed Description

Embodiments of the present invention will be described below with reference to the drawings.

<1 > first embodiment >

<1-1 > Structure of substrate processing apparatus >

Fig. 1 is a schematic diagram showing the configuration of a substrate processing apparatus 9 including a reduced-pressure drying apparatus 1 according to a first embodiment. The substrate processing apparatus 9 of the present embodiment is an apparatus for applying a resist solution to a glass substrate G for a liquid crystal display device (hereinafter, referred to as a substrate G), exposing the substrate, and developing the substrate after exposure.

The substrate processing apparatus 9 includes a carrying-in section 90 as a plurality of processing sections, a cleaning section 91, a dehydration drying section 92, a coating section 93, a reduced-pressure drying apparatus 1 as a reduced-pressure drying section, a pre-drying section 94, an exposure section 95, a developing section 96, a rinsing section 97, a post-drying section 98, and a carrying-out section 99. The processing units of the substrate processing apparatus 9 are arranged adjacent to each other in this order. As indicated by broken line arrows, the substrates G are transported to the respective processing units by a transport mechanism (not shown) in the above-described order according to the progress of the processing.

The loading unit 90 loads the substrate G to be processed in the substrate processing apparatus 9 into the substrate processing apparatus 9. The cleaning unit 91 cleans the substrate G carried into the carrying-in unit 90 to remove organic contamination including fine particles, metal contamination, grease, a natural oxide film, and the like. The dehydration drying unit 92 heats the substrate G, and vaporizes the cleaning liquid adhering to the substrate G in the cleaning unit 91, thereby drying the substrate G.

The coating section 93 applies the treatment liquid to the surface of the substrate G subjected to the drying treatment in the dehydration drying section 92. In the coating portion 93 of the present embodiment, a photosensitive photoresist liquid (hereinafter, simply referred to as a resist liquid) is coated on the surface of the substrate G. Then, the reduced-pressure drying apparatus 1 evaporates the solvent of the resist solution applied to the surface of the substrate G by reducing the pressure, thereby drying the substrate G. The prebaking unit 94 heats the substrate G subjected to the reduced-pressure drying process in the reduced-pressure drying apparatus 1, and cures the resist liquid component on the surface of the substrate G. Thereby, a thin film of the processing liquid, i.e., a resist film is formed on the surface of the substrate G.

Next, the exposure unit 95 performs an exposure process on the surface of the substrate G on which the resist liquid film is formed. The exposure unit 95 irradiates a mask on which a circuit pattern is drawn with far ultraviolet rays, and transfers the pattern to the resist liquid film. The developing unit 96 performs a developing process by immersing the substrate G, on which the pattern is exposed in the exposure unit 95, in a developing solution.

The rinse unit 97 rinses the substrate G subjected to the developing process in the developing unit 96 with a rinse liquid. Thereby, the development process is stopped. The post-drying unit 98 heats the substrate G, and vaporizes the rinse liquid adhering to the substrate G in the rinse unit 97, thereby drying the substrate G. The substrate G processed in each processing unit of the substrate processing apparatus 9 is conveyed to the carrying-out unit 99. Then, the substrate G is carried out from the carrying-out section 99 to the outside of the substrate processing apparatus 9.

The substrate processing apparatus 9 of the present embodiment includes the exposure section 95, but the exposure section may be omitted in the substrate processing apparatus of the present invention. In this case, the substrate processing apparatus may be used in combination with a separate exposure apparatus.

<1-2 > Structure of vacuum drying apparatus >

Fig. 2 is a schematic diagram showing the structure of the vacuum drying apparatus 1 according to the present embodiment. Fig. 3 is a perspective view showing a three-dimensional structure of the piping part 40. As described above, the reduced-pressure drying apparatus 1 is an apparatus for drying a substrate G coated with a treatment liquid such as a resist liquid under reduced pressure. As shown in fig. 2, the decompression drying device 1 includes a chamber 20, a pump 30, a piping part 40, an inert gas supply part 50, a control part 60, and an input part 70.

The chamber 20 is a mechanism for accommodating the substrate G and forming a processing space cut off from the outside around the substrate G. The chamber 20 has a base portion 21 and a lid portion 22. The base portion 21 is a plate-shaped member that extends substantially horizontally. The lid 22 is a cylindrical member with a lid that covers the upper side of the base portion 21. A substrate G is accommodated in a housing formed by the base portion 21 and the lid portion 22. Further, a seal 221 is provided at the lower end of the lid 22. This cuts off communication between the inside and the outside of the chamber 20 at the contact portion between the base portion 21 and the lid portion 22.

The base portion 21 is provided with an exhaust port 23. A piping section 40 is connected to the exhaust port 23. This allows the gas in the chamber 20 to be discharged from the gas outlet 23 to the outside of the chamber 20 through the pipe portion 40. The chamber 20 of the present embodiment is provided with four exhaust ports 23. However, the number of the exhaust ports 23 provided in the chamber 20 may be one to three, or five or more. In the present embodiment, the base portion 21 is provided with the exhaust port 23, but the exhaust port 23 may be provided in the lid portion 22.

A support mechanism 24 is provided inside the chamber 20. The support mechanism 24 has a support plate 241, a plurality of support pins 242, and a support post 243. The support plate 241 is a plate-shaped member that extends substantially horizontally. A plurality of support pins 242 are provided on the support plate 241. The support pins 242 extend upward from the support plate 241, respectively. The plurality of support pins 242 mount the substrate G on the upper end thereof, and support the substrate G from the rear surface. The plurality of support pins 242 are arranged in a horizontally dispersed manner. Thereby, the substrate G is stably supported. The support column 243 is a member that supports the support plate 241. The lower end of the support column 243 is fixed to the base portion 21. The lower end of the support column 243 may be fixed to another member such as an elevator.

Further, a pressure sensor 25 for measuring the pressure in the chamber 20 is provided in the chamber 20. The pressure sensor 25 of the present embodiment is provided on the base portion 21, but the pressure sensor may be provided on the chamber connection pipe 41 or the collective pipe 42 of the pipe portion 40.

The pump 30 is an exhaust device for exhausting the gas in the chamber 20. As shown in fig. 2 and 3, the pump 30 is connected to the inner space of the chamber 20 via a pipe portion 40. Therefore, when the pump 30 is driven, the gas in the chamber 20 is discharged to the outside of the decompression drying device 1 through the piping portion 40. The pump 30 is driven at a constant output to suck and exhaust the gas in the chamber 20. Thereby, the pressure inside the chamber 20 is reduced. The exhaust speed from the chamber 20 is adjusted by valves 440 and 450 described later.

The pipe portion 40 is an exhaust pipe portion that connects the inside of the chamber 20 and the pump 30. The pipe portion 40 includes four chamber connection pipes 41, two collective pipes 42, a first common pipe 43, two large-diameter pipes 44, a small-diameter pipe 45, a second common pipe 46, two exhaust pipes 47, and four independent exhaust pipes 48.

The upstream end portions (one ends) of the chamber connecting pipes 41 are open in the chambers 20. That is, the upstream ends of the four chamber connecting pipes 41 respectively serve as the four exhaust ports 23 in the chamber 20. The downstream end (the other end) of the two chamber connecting pipes 41 is connected to the upstream end of one collecting pipe 42. The downstream ends of the other two chamber connecting pipes 41 are connected to the upstream end of the other collecting pipe 42.

In fig. 2, for convenience of explanation, the upstream side of the chamber connecting pipe 41 is shown as being thick, and the downstream side is shown as being thin. However, as shown in fig. 3, the actual chamber connecting pipe 41 has a substantially constant thickness from the upstream side to the downstream side.

The downstream end of one of the collective pipes 42 is connected to one end of the first common pipe 43. The downstream end of the other collective pipe 42 is connected to the other end of the first common pipe 43. Thus, the first common pipe 43 is indirectly connected to the other ends of all the chamber connecting pipes 41. That is, all the exhaust ports 23 are indirectly connected to the first common pipe 43. As a result, when the pump 30 is driven, the suction and exhaust forces from all the exhaust ports 23 can be made uniform.

One of the two large-diameter pipes 44 connects one end of the first common pipe 43 and one end of the second common pipe 46 to each other. The other of the two large-diameter pipes 44 connects the other end of the first common pipe 43 to the other end of the second common pipe 46. The small-diameter pipe 45 connects the center of the first common pipe 43 to the center of the second common pipe 46. That is, the first common pipe 43 and the second common pipe 46 are connected to each other by two large-diameter pipes 44 and one small-diameter pipe 45. Specifically, two large-diameter pipes 44 and one small-diameter pipe 45 are arranged in parallel between the first common pipe 43 and the second common pipe 46.

The large-diameter valves 440 are attached to the two large-diameter pipes 44, respectively. The large-diameter valve 440 can change the flow passage area (opening area of the flow passage) in the large-diameter pipe 44 by changing the opening degree. In the present embodiment, the two large diameter valves 440 operate at the same opening degree. That is, when the control unit 60 sets the opening degrees of the large diameter valves 440 to 20%, the opening degrees of both the large diameter valves 440 are adjusted to 20%.

The small-diameter valve 450 is attached to the small-diameter pipe 45. The small-diameter valve 450 can change the flow passage area (opening area of the flow passage) in the small-diameter pipe 45 by changing the opening degree. The small-diameter valve 450 has a smaller tube diameter than the large-diameter valve 440. That is, the flow passage area when the opening degree of the small-diameter valve 450 is maximum is smaller than the flow passage area when the opening degree of the large-diameter valve 440 is maximum.

The large-diameter valve 440 and the small-diameter valve 450 of the present embodiment are, for example, butterfly valves whose opening degrees are adjusted by changing the valve angle. The large-diameter valve 440 and the small-diameter valve 450 may be valves whose opening degrees can adjust the flow rate of the depressurized exhaust gas. Therefore, a ball valve (ball type valve) or other valve may be used instead of the butterfly valve.

Thus, the large-diameter pipe 44 and the small-diameter pipe are arranged in parallel between the chamber 20 and the pump 30. In the decompression drying device 1, the flow passage area of the pipe portion 40 is changed by changing the opening degrees of the valves 440 and 450, and the amount of exhaust gas is adjusted. Since the large-diameter valve 440 and the small-diameter valve 450 have different valve diameters, the accuracy of the flow path area that can be adjusted by the valve opening degree is different. Specifically, the small-diameter valve 450 can adjust the flow passage area more precisely than the large-diameter valve 440. Therefore, in the decompression drying device 1, the large diameter valve 440 and the small diameter valve 450 are used separately, and the exhaust gas amount is roughly adjusted by the large diameter valve 440 and the exhaust gas amount is finely adjusted by the small diameter valve 450.

The upstream ends of the two exhaust pipes 47 are connected to the second common pipe 46. Two upstream end portions of the four independent exhaust pipes 48 are connected to the downstream end portion of one exhaust pipe 47. The upstream ends of the other two independent exhaust pipes 48 are connected to the downstream end of the other exhaust pipe 47. Downstream ends of the four exhaust pipes 47 are connected to the pumps 30, respectively. Thereby, all the pumps 30 are indirectly connected to the second common pipe 46. As a result, even when the suction/exhaust forces of the pump 30 vary, the pressure becomes uniform in the second common pipe 46, and therefore, the suction/exhaust forces at the downstream end portions of the two large-diameter pipes 44 and the downstream end portion of the small-diameter pipe 45 can be made uniform.

When the pump 30 is driven in a state where both the two large-diameter valves 440 and the one small-diameter valve 450 are closed, the gas inside the second common pipe 46, the exhaust pipe 47, and the independent exhaust pipe 48 is discharged from the pump 30 to the outside of the pipe portion 40. This reduces the internal gas pressure of the second common pipe 46, the exhaust pipe 47, and the independent exhaust pipe 48.

When at least one of the two large-diameter valves 440 and the one small-diameter valve 450 is opened, the first common pipe 43 and the second common pipe 46 are communicated via the pipes 44 and 45 having the opened valves 440 and 450. Therefore, when the pump 30 is driven and at least one of the two large-diameter valves 440 and the one small-diameter valve 450 is opened, the gas in the chamber 20 is discharged from the pump 30 to the outside of the pipe portion 40 through the chamber connection pipe 41, the collective pipe 42, the pipe having the opened valves 440 and 450, the second common pipe 46, the exhaust pipe 47, and the independent exhaust pipe 48, among the large-diameter pipe 44 and the small-diameter pipe 45, from the exhaust port 23.

The inert gas supply unit 50 supplies an inert gas into the chamber 20. The inert gas supply unit 50 includes an inert gas supply pipe 51, an inert gas supply source 52, and an opening/closing valve 53. One end of the inert gas supply pipe 51 is connected to the internal space of the chamber 20, and the other end is connected to an inert gas supply source 52. The inert gas supply source 52 of the present embodiment supplies dried nitrogen gas as the inert gas. The on-off valve 53 is attached to the inert gas supply pipe 51. Therefore, when the on-off valve 53 is opened, the inert gas is supplied from the inert gas supply source 52 into the chamber 20. When the open/close valve 53 is closed, the supply of the inert gas from the inert gas supply source 52 to the chamber 20 is stopped.

The inert gas supply unit 50 may supply other dried inert gas such as argon gas instead of nitrogen gas. The decompression drying device 1 may have an atmosphere supply unit for supplying atmospheric air instead of the inert gas supply unit 50.

The control unit 60 controls each unit in the vacuum drying apparatus 1. As schematically shown in fig. 2, the control unit 60 is constituted by a computer having an arithmetic processing unit 61 such as a CPU, a memory 62 such as a RAM, and a storage unit 63 such as a hard disk drive. The control unit 60 is electrically connected to the pressure sensor 25, the four pumps 30, the two large-diameter valves 440, the small-diameter valve 450, the opening/closing valve 53, and the input unit 70.

The control unit 60 temporarily reads a computer program or data stored in the storage unit 63 into the memory 62, and the arithmetic processing unit 61 performs arithmetic processing based on the computer program and data to control the operation of each unit in the vacuum drying apparatus 1. Thereby, the reduced-pressure drying process in the reduced-pressure drying device 1 is performed. The controller 60 may control only the vacuum drying apparatus 1, or may control the entire substrate processing apparatus 9.

The input unit 70 is an input mechanism for a user to input a target pressure value and a target arrival time. The input unit 70 of the present embodiment may be an input panel provided in the substrate processing apparatus 9, and the input unit 70 may be another type of input mechanism (for example, a keyboard, a mouse, or the like). When the target pressure value and the target arrival time are input to the input section 70, the control section 60 acquires the data.

<1-3 > regarding the arrangement of piping parts

Next, the arrangement of the piping unit 40 according to the present embodiment will be described in more detail with reference to fig. 3. As shown in fig. 3, hereinafter, the vertical direction is referred to as the vertical direction, the direction perpendicular to the vertical direction is referred to as the horizontal direction, the direction in which the large-diameter valve 440 and the small-diameter valve 450 extend in the horizontal direction is referred to as the front-rear direction, and the direction perpendicular to the front-rear direction in the horizontal direction is referred to as the left-right direction.

In the present embodiment, the pump 30 is disposed below and behind the chamber 20. The chamber connection pipe 41 extends downward from the exhaust port 23 and then is bent in the front-rear direction. The downstream end of the chamber connecting pipe 41 is connected to the downstream end of another chamber connecting pipe 41 arranged in the front-rear direction. Then, the connection portion of the two chamber connection pipes 41 is connected to the upstream end of the collective pipe 42.

The collecting pipes 42 extend in the left-right direction from the upstream end, are bent, and extend rearward. The downstream end of the collection pipe 42 and the upstream end of the large-diameter pipe 44 are connected to each other in a straight flow path. Then, the connection portion between the collective pipe 42 and the large-diameter pipe 44 is also connected to one of the two ends of the first common pipe 43. By making the connection portion between the collective pipe 42 and the large-diameter pipe 44 linear in this way, the flow path resistance when the gas flows from the collective pipe 42 to the large-diameter pipe 44 can be reduced. This makes it easy to suck the gas in the chamber 20 when the large-diameter pipe 44 is used for pressure reduction and evacuation.

One of the large-diameter pipes 44 connects one end of the first common pipe 43 and one end of the second common pipe 46 to each other. The other end of the large-diameter pipe 44 connects the other end of the first common pipe 43 to the other end of the second common pipe 46. On the other hand, the small-diameter pipe 45 connects the center of the first common pipe 43 to the center of the second common pipe 46. Therefore, the small-diameter pipes 45 are located at equal distances from the downstream ends of the two collecting pipes 42. Therefore, when the small-diameter pipe 45 is used to perform the pressure reduction and the exhaust, the pressure reduction and the exhaust force of the two collecting pipes 42 due to the exhaust from the small-diameter pipe 45 can be made uniform.

The upstream ends of the two exhaust pipes 47 are connected to positions at a constant distance from the end of the second common pipe 46. Further, upstream end portions of the two independent exhaust pipes 48 are connected to downstream end portions of the exhaust pipes 47. The independent exhaust pipes 48 extend in the front-rear direction and then extend downward. The downstream end of each independent exhaust pipe 48 is connected to the pump 30.

As described above, the pipe portions 40 of the present embodiment are symmetrically arranged in the left-right direction. This allows the four exhaust ports 23 to uniformly perform suction and exhaust.

The extending direction of each pipe may be appropriately changed in consideration of the positions of other mechanisms in the vacuum drying apparatus 1.

The pipe diameters of the pipe portions 40 are as follows. The pipe diameters of the chamber connection pipe 41 and the independent exhaust pipe 48 are 150mm, respectively. The piping diameters of the collective piping 42, the first common piping 43, the large-diameter piping 44, the second common piping 46, and the exhaust piping 47 are 200mm, respectively. The small-diameter pipe 45 has a pipe diameter of 50 mm.

The piping diameter of the collective piping 42 is larger than the piping diameter of the chamber connection piping 41, and the gas flowing from the chamber connection piping 41 to the collective piping 42 can be efficiently discharged. Further, by providing the collective piping 42, the large-diameter piping 44, and the second common piping 46 as continuous pipes having the same diameter, the flow path resistance at the connecting portion between the pipes can be reduced. Thus, when the large-diameter valve 440 is opened to discharge a large flow rate of gas, the gas flowing from the collective pipe 42 to the second common pipe 46 through the large-diameter pipe 44 can be efficiently discharged.

In the present embodiment, the pipe diameter of the small-diameter pipe 45 is 25% of the pipe diameter of the large-diameter pipe 44. That is, the flow passage area of the small-diameter pipe 45 is 6.25% of the flow passage area of the large-diameter pipe 44. Therefore, for example, if the large-diameter valve 440 and the small-diameter valve 450 are the same type of valve, the large-diameter valve 440 and the small-diameter valve 450 can be selected on the basis that the flow passage area when the small-diameter valve 450 attached to the small-diameter pipe 45 is at the maximum opening degree is smaller than 10% of the flow passage area when the large-diameter valve 440 is at the maximum opening degree. Thus, the accuracy of adjusting the flow path area of the small-diameter valve 450 can be adjusted to 10 times or more the accuracy of adjusting the flow path area of the large-diameter valve 440.

The ratio of the pipe diameters of the large-diameter pipe 44 and the small-diameter pipe 45 is not limited to the above example. Preferably, the flow passage area of the small-diameter pipe 45 is 50% or less of the flow passage area of the large-diameter pipe 44. In this way, the accuracy of adjusting the flow path area of the small-diameter valve 450 is better than the accuracy of adjusting the flow path area of the large-diameter valve 440, and therefore, high-accuracy control by the small-diameter valve 450 can be performed.

<1-4 > flow of vacuum drying treatment >

Next, the reduced-pressure drying process in the reduced-pressure drying apparatus 1 will be described with reference to fig. 4. Fig. 4 is a flowchart showing the flow of the reduced-pressure drying process in the reduced-pressure drying apparatus 1. Fig. 5 is a diagram showing the operation of the large-diameter valve and the small-diameter valve in each control mode. Fig. 6 is a diagram showing an example of a target reduced-pressure waveform.

As shown in fig. 4, the decompression drying device 1 first performs a learning step (step ST 101). In the learning step, the decompression drying device 1 acquires decompression curve data indicating a change in pressure in the chamber 20 due to the decompression exhaust gas for each opening degree of the valves 440 and 450 determined in advance.

In the learning step of step ST101, after the pressure in the chamber 20 reaches 100000(Pa), which is the atmospheric pressure, by opening the atmosphere, the pump 30 is driven and the valves 440 and 450 are opened at a predetermined opening degree. Then, until a predetermined time elapses after the valves 440 and 450 are opened, the pressure sensor 25 measures the pressure change in the chamber 20. Thereby, the control unit 60 acquires the pressure reduction curve data. By performing such pressure measurement for each opening degree determined in advance, decompression curve data is acquired for each of the plurality of opening degrees. The pressure reduction curve data is stored in the storage unit 63 as table data indicating a correspondence relationship between the elapsed time and the pressure value for each opening degree of the valves 440 and 450, for example.

As shown in fig. 5, the decompression drying device 1 can switch between a small-diameter valve control mode in which the opening degree of the large-diameter valve 440 is fixed and the opening degree of the small-diameter valve 450 is adjusted, and a large-diameter valve control mode in which the opening degree of the large-diameter valve is adjusted. In the learning step of step ST101, the decompression curve data is acquired for a plurality of patterns.

More specifically, the small-diameter valve control mode includes a first small-diameter valve control mode and a second small-diameter valve control mode. In the first small-diameter valve control mode, the large-diameter valve 440 is closed and the opening degree of the small-diameter valve 450 is adjusted. In the second small-diameter valve control mode, the opening degree of the large-diameter valve 440 is fixed and the opening degree of the small-diameter valve 450 is adjusted. In the second small-diameter valve control mode, for example, the opening degree of the large-diameter valve 440 is fixed to an opening degree greater than 0% and equal to or less than 30%, and the opening degree of the small-diameter valve 450 is adjusted. In this way, the flow path area can be controlled with high accuracy by the small diameter valve 450 while ensuring a decompression exhaust amount of a certain amount or more.

In addition, the large-diameter valve control modes include a first large-diameter valve control mode, a second large-diameter valve control mode, and a third large-diameter valve control mode. In the first large-diameter valve control mode, the small-diameter valve 450 is closed and the opening degree of the large-diameter valve 440 is adjusted. In the second large diameter valve control mode, the opening degree of the small diameter valve 450 is fixed to the maximum opening degree and the opening degree of the large diameter valve 440 is adjusted. In the third large-diameter valve control mode, the large-diameter valve 440 and the small-diameter valve 450 are simultaneously adjusted to the same opening degree. The large-diameter valve control mode also includes a mode in which the small-diameter valve 450 is fixed at an opening degree greater than 0% and smaller than the maximum opening degree, and the opening degree of the large-diameter valve 440 is adjusted.

In the small-diameter valve control mode, the flow passage area can be accurately adjusted by adjusting the opening degree of the small-diameter valve 450, and the desired pressure reduction speed can be approached. On the other hand, in the large-diameter valve control mode, the opening degree of the large-diameter valve 440, which can adjust the flow passage area in a wide range, is adjusted, whereby the decompression speed can be adjusted with good responsiveness.

In the present embodiment, the first, second, and third small-diameter valve control modes are executed in the learning step of step ST101 and the reduced-pressure drying step of step ST105, which will be described later. In the present invention, at least one of the small-diameter valve control modes and the large-diameter valve control mode may be executed in the decompression drying step.

In the learning step of the present embodiment, as the first small-diameter valve control mode, for example, the opening degree of the large-diameter valve 440 is set to 0%, and the pressure reduction curve data is acquired for the case where the opening degree of the small-diameter valve 450 is 5%, 7%, 8%, 10%, 12%, 15%, 20%, 50%, and 100%. In the second large diameter valve control mode, for example, the opening degree of the small diameter valve 450 is set to 100%, and the pressure reduction curve data is acquired for the case where the opening degrees of the two large diameter valves 440 are 5%, 7%, 8%, 10%, 12%, 15%, 20%, 50%, and 100%. Further, as the third large diameter valve control mode, for example, the pressure reduction curve data is acquired for the case where the opening degrees of the two large diameter valves 440 and the small diameter valve 450 are both 5%, 7%, 8%, 10%, 12%, 15%, 20%, 50%, and 100%.

In the present embodiment, after the learning step of step ST101, the substrate G is subjected to a reduced-pressure drying process. First, a target pressure value and a target arrival time are input to the input unit 70 (step ST 102). In the present embodiment, a plurality of sets of target pressure values and target arrival times, which are times until the target pressure values are reached, are input to the input unit 70. Fig. 6 shows an example of a target reduced-pressure waveform R composed of the plurality of sets of target pressure values and target arrival times.

In the target reduced-pressure waveform R of the example of fig. 6, in the first period T1, the initial pressure value is 100000Pa of the atmospheric pressure, the target pressure value is 10000Pa, and the target arrival time is 20 sec. In the second period T2, the target pressure value is 1000Pa and the target arrival time is 10 sec. In the third period T3, the target pressure value is 400Pa and the target arrival time is 10 sec. In addition, in the fourth period T4, the target pressure value is 20Pa, and the target arrival time is 5 sec. After the target pressure value is reached in the fourth period T4, the pressure in the chamber 20 is returned to the atmospheric pressure by the inert gas purge in the fifth period T5. As shown in the target reduced-pressure waveform R of the example of fig. 6, by performing the pressure reduction step by step, bumping of the treatment liquid applied to the surface of the substrate G can be suppressed.

Next, the substrate G is carried into the chamber 20 (step ST 103). At this time, the lid portion 22 of the chamber 20 is raised by a chamber opening/closing mechanism (not shown) in a state where the valves 440 and 450 and the opening/closing valve 53 are closed. Thereby opening the chamber 20. Then, the substrate G coated with the processing liquid is carried into the chamber 20 and placed on the support pins 242. Then, the lid 22 is lowered by the chamber opening/closing mechanism. Thereby, the chamber 20 is closed, and the substrate G is accommodated in the chamber 20.

In the present embodiment, the substrate G carrying-in process of step ST103 is performed after the input process of step ST102, but the order of step ST102 and step ST103 may be reversed.

Next, the opening degrees of the valves 440 and 450 in the decompression drying process are set based on the target pressure value and the target arrival time input in step ST102 (step ST 104). In the reduced-pressure drying step of step ST105, which will be described later, the interior of the chamber 20 is reduced in pressure, thereby drying the substrate G to which the processing liquid has adhered. In the opening degree setting step of step ST104, the control unit 60 selects the control mode for each period based on the target reduced pressure waveform R composed of the target pressure value and the target arrival time, and selects the reduced pressure curve data approximate to the waveform for each period along the target reduced pressure waveform R. Then, the control unit 60 sets the opening degrees of the valves 440 and 450 in each period based on the opening degrees of the valves 440 and 450 in the selected pressure reduction curve data.

In this case, as a method of setting the opening degrees of the valves 440 and 450, for example, the opening degree of the most approximate pressure reduction curve data may be directly set as the opening degree of the valves 440 and 450, or the opening degrees of the valves 440 and 450 may be calculated by considering the weighting with reference to the opening degrees of the two approximate pressure reduction curve data. The opening degrees of the valves 440 and 450 may be set by other methods.

Here, mode selection in the reduced-pressure drying step will be described. In the first period T1 in which the pressure reduction is started from the atmospheric pressure, the pressure reduction is easily performed, but the pressure reduction rate greatly changes due to a slight change in the flow passage area. In addition, bumping is most likely to occur in the first period T1, which is the first initial stage in the reduced-pressure drying process. Therefore, it is required to control the decompression rate with high accuracy. Therefore, during this period, the pressure is reduced and the exhaust is performed by the small-diameter valve control mode in which the flow passage area is adjusted with high accuracy. Thus, in the first period T1 in which the decompression speed is less likely to be stable, the flow passage area can be accurately adjusted by adjusting the opening degree of the small diameter valve 450, and the desired decompression speed can be approached. In the fourth period T4 in which the target pressure value is the lowest, which is the final stage of the decompression drying process, the decompression exhaust force needs to be increased, and therefore the decompression exhaust is performed in the large-diameter valve control mode. Thus, by adjusting the opening degree of the large-diameter valve 440, which can adjust the flow passage area in a wide range, the decompression speed can be adjusted with good responsiveness and can approach a desired decompression speed.

In the present embodiment, first, the first small-diameter valve control mode is selected during the first period T1 in which the pressure is reduced from the atmospheric pressure. Next, the third major diameter valve control mode is selected in the second period T2 in which the start pressure value is 10000Pa and the target pressure value is 1000Pa and the third period T3 in which the start pressure value is 1000Pa and the target pressure value is 400 Pa. Then, in a fourth period T4 in which the target pressure value is 20Pa which is the lowest, the second large-diameter valve control mode is selected.

That is, in the first period T1, the control unit 60 closes the large diameter valve 440 and selects the opening degree of the small diameter valve 450 based on the pressure reduction curve data of the first small diameter valve control pattern obtained in the learning step of step ST 101. Similarly, in the second period T2 and the third period T3, the control unit 60 selects the opening degrees of the large-diameter valve 440 and the small-diameter valve 450 based on the pressure reduction curve data of the third large-diameter valve control pattern obtained in the learning step of step ST 101. In the fourth period T4, the control unit 60 sets the small-diameter valve 450 to the maximum opening degree and selects the opening degree of the large-diameter valve 440 based on the pressure reduction curve data of the second large-diameter valve control pattern obtained in the learning step of step ST 101.

After selecting and setting the opening degrees of the valves 440 and 450 in the respective periods T1 to T4, the controller 60 performs the pressure-reducing drying process using the set opening degrees (step ST 105). In this case, in the present embodiment, the opening degree of each of the valves 440 and 450 is feedback-controlled with reference to a preset opening degree and with reference to the pressure in the chamber 20 measured by the pressure sensor 25. Further, the reduced-pressure drying step may be performed without changing the set opening degree.

In the present embodiment, the opening degrees of the valves 440 and 450 in the periods T1 to T4 are set before all of the periods T1 to T5, but the present invention is not limited to this. Before the start of each of the periods T1 to T4, the opening degree in each period may be set using the pressure in the chamber 20 measured by the pressure sensor 25 as an initial pressure value. In this way, even when the final pressure value in the preceding period is different from the target pressure value, it is possible to perform appropriate control in the following period.

In the reduced-pressure drying step of step ST105, the controller 60 controls the opening degrees of the valves 440 and 450 by the set opening degrees and the feedback control in the first period T1 to the fourth period T4 as described above. After the fourth period T4 ends, the controller 60 closes all the valves 440 and 450 to stop the exhaust from the chamber 20. Next, the open/close valve 53 is opened to purge the inert gas from the inert gas supply source 52 into the chamber 20. Thereby, the air pressure in the chamber 20 is increased to the atmospheric pressure. When the pressure in the chamber 20 reaches the atmospheric pressure, the on-off valve 53 is closed. This completes the reduced pressure drying step.

Thereafter, the substrate G is carried out of the chamber 20 (step ST 106). In step ST106, as in step ST103, the lid 22 of the chamber 20 is raised by the chamber opening/closing mechanism with the valves 440 and 450 and the opening/closing valve 53 closed. Thereby opening the chamber 20. Then, the substrate G subjected to the reduced pressure drying process is carried out of the chamber 20.

Even if a plurality of vacuum drying apparatuses 1 are manufactured in the same design, the vacuum drying process is performed at the same opening degree of the valves 440 and 450 due to manufacturing errors, and the like, and the vacuum speed in the chamber 20 in each vacuum drying apparatus 1 varies. In addition, when the installation environment of the decompression drying device 1 is different, the decompression speed in the chamber 20 is different even if the opening degrees of the valves 440 and 450 are the same. Therefore, there is a possibility that a deviation occurs between a desired decompression rate and an actual decompression rate due to an installation environment of the decompression drying device 1.

In the present embodiment, the learning step of step ST101 is performed before the reduced-pressure drying process of the substrate G performed in steps ST102 to ST 106. Thus, the reduced pressure curve data is acquired under the same installation environment as that in the reduced pressure drying process of the substrate G by the reduced pressure drying apparatus 1. By performing the reduced pressure drying process based on the reduced pressure profile data, it is possible to suppress the occurrence of a deviation between a desired reduced pressure rate and a real reduced pressure rate. That is, regardless of individual differences of the apparatuses or installation environments, the pressure reduction treatment can be performed at a pressure reduction rate closer to a desired pressure reduction rate.

The learning step of step ST101 may not be performed every time the substrate G is dried under reduced pressure in steps ST102 to ST 106. The learning process may be performed when the reduced-pressure drying apparatus 1 is set or moved, or may be performed during regular maintenance.

In the present embodiment, the opening degrees in the respective periods T1 to T4 are set in advance by the learning step in step ST101 and the opening degree setting step in step ST 104. However, the present invention is not limited thereto. The learning step in step ST101 may be omitted, and the opening degrees of the valves 440 and 450 in the decompression drying step may be determined by mode selection based on the initial pressure value and the target pressure value in each period of the target decompression waveform R and feedback control based on the measurement result of the pressure sensor 25.

<2. modification >

While one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and for example, the following modifications may be implemented.

Fig. 7 is a perspective view showing a three-dimensional structure of a piping unit 40A of a decompression drying device according to a modification. The pipe portion 40A includes four chamber connection pipes 41A, a first common pipe 43A, two large-diameter pipes 44A to which large-diameter valves 440A are attached, a small-diameter pipe 45A to which small-diameter valves 450A are attached, a second common pipe 46A, two exhaust pipes 47A, and four independent exhaust pipes 48A.

In the example of fig. 7, the pump 30A is disposed below and behind the chamber 20A, as in the above-described embodiments. The chamber connection pipe 41A extends downward from the exhaust port 23A and then bends in the front-rear direction. Then, the two downstream-side ends of the chamber connecting pipe 41A are connected to one end of the first common pipe 43A extending in the left-right direction. Further, the other two downstream ends of the chamber connecting pipe 41A are connected to the other end of the first common pipe 43A.

Upstream end portions of the two large-diameter pipes 44A and the small-diameter pipes 45A are connected to side portions of the first common pipe 43A. Downstream end portions of the two large-diameter pipes 44A are connected to two end portions of a second common pipe 46A extending in the left-right direction. The downstream end of the small-diameter pipe 45A is connected to the center of the second common pipe 46A.

The upstream end of the exhaust pipe 47A is connected to the connection point of the one large-diameter pipe 44A and the second common pipe 46A. The upstream ends of the two independent exhaust pipes 48A are connected to the downstream ends of the exhaust pipes 47A. The independent exhaust pipes 48A extend in the front-rear direction and then extend downward. The downstream end of each independent exhaust pipe 48A is connected to the pump 30A.

In the above embodiment, the chamber connection pipe 41 is connected to the first common pipe 43 via the collective pipe 42. However, as shown in the example of fig. 7, the chamber connection pipe 41A may be directly connected to the first common pipe 43A. The piping unit 40 in the above embodiment is different from the piping unit 40A in the example of fig. 7 in the connection position between the pipes. However, the piping portions 40A in the example of fig. 7 are also arranged symmetrically in the left-right direction, and the four exhaust ports 23A can equally perform suction and exhaust. Thus, the position of the connection between the pipes can be changed as appropriate.

Fig. 8 is a schematic diagram showing the configuration of a piping section 40B of a vacuum drying apparatus according to another modification. The pipe portion 40B includes one chamber connection pipe 41B, one large-diameter pipe 44B to which the large-diameter valve 440B is attached, one small-diameter pipe 45B to which the small-diameter valve 450B is attached, and one exhaust pipe 47B. The small diameter valve 450B has a smaller pipe diameter than the large diameter valve 440B.

The upstream end of the chamber connection pipe 41B opens into the chamber 20B. The downstream end of the exhaust pipe 47B is connected to the pump 30B. Upstream ends of the large-diameter pipe 44B and the small-diameter pipe 45B are connected to downstream ends of the chamber connecting pipe 41B. Downstream ends of the large-diameter pipe 44B and the small-diameter pipe 45B are connected to an upstream end of the exhaust pipe 47B. That is, the large-diameter pipe 44B and the small-diameter pipe 45B are arranged in parallel between the chamber 20B and the pump 30B.

As shown in the example of fig. 8, there may be only one exhaust port 23B connecting the inside of the chamber and the piping unit 40B. The number and arrangement of the exhaust ports 23B can be appropriately changed according to the shape and size of the chamber. In the above embodiment, the exhaust port 23B is provided in the bottom surface of the chamber 20B, but the present invention is not limited thereto. The exhaust port 23B may be provided in a sidewall or an upper surface of the chamber 20B.

Fig. 9 is a schematic diagram showing a configuration of a piping section 40C of a vacuum drying apparatus according to still another modification. The pipe portion 40C includes eight chamber connection pipes 41C, two collective pipes 42C, a first common pipe 43C, three large-diameter pipes 44C to which large-diameter valves 440C are attached, two small-diameter pipes 45C to which small-diameter valves 450C are attached, a second common pipe 46C, and two exhaust pipes 47C. The small diameter valve 450C has a smaller tube diameter than the large diameter valve 440C.

The upstream end of the chamber connecting pipe 41C opens into the chamber 20C. The downstream ends of the four chamber connecting pipes 41C are connected to the upstream end of the collecting pipe 42C. The downstream ends of all the collective pipes 42C and the upstream ends of all the large-diameter pipes 44C and all the small-diameter pipes 45C are connected to the first common pipe 43C. Downstream ends of all the large-diameter pipes 44C and all the small-diameter pipes 45C, and upstream ends of all the exhaust pipes 47C are connected to the second common pipe 46. The downstream ends of the exhaust pipes 47C are connected to the pumps 30C, respectively.

As shown in the example of fig. 8, the number of the large-diameter pipes 44B and the small-diameter pipes 45B may be one. As shown in the example of fig. 9, the number of the large-diameter pipes 44C may be three or more, and the number of the small-diameter pipes 45C may be two or more. That is, the number of the large-diameter piping and the small-diameter piping may be one or plural.

In the above embodiment, the two large diameter valves are operated at the same opening degree, but the present invention is not limited to this. In the case where a plurality of large diameter valves are provided, only a part of the large diameter valves may be opened to control the opening degree thereof according to a required pressure reducing and exhausting force. The same applies to the case where a plurality of small diameter valves are provided.

Further, although the reduced-pressure drying apparatus of the above embodiment is a part of the substrate processing apparatus, the reduced-pressure drying apparatus of the present invention may be an independent apparatus which is not provided together with other processing units. Further, the reduced-pressure drying apparatus of the above embodiment is an apparatus for drying a substrate to which a resist liquid has adhered, but the reduced-pressure drying apparatus of the present invention may be an apparatus for drying a substrate to which another processing liquid has adhered.

The vacuum drying apparatus of the above embodiment is a vacuum drying apparatus for a liquid crystal Display device, but the vacuum drying apparatus of the present invention may be a vacuum drying apparatus for a liquid crystal Display device, or other Flat Panel Display (FPD) substrates such as an organic Electroluminescence (EL) Display device, semiconductor wafers, photomask glass substrates, color filter substrates, recording disk substrates, solar cell substrates, or other precision electronic device substrates.

In addition, the respective members appearing in the above-described embodiment or modification may be appropriately combined within a range in which no contradiction occurs.