Method for cleaning substrate processing apparatus and lock key

Abstract

This prevents contamination of the substrate by particles originating from the lock key and components that come into contact with it. [Solution] A substrate processing apparatus for replacing a liquid film formed on the upper surface of a substrate with a supercritical fluid and drying the substrate comprises a pressure vessel having a drying chamber inside in which the substrate is dried, a lid that closes the opening of the drying chamber, a lock key that restricts the lid from moving from a closed position that closes the opening to an open position that opens the opening, and a cleaning unit that cleans the lock key.

Description

Technical Field

[0001] The present disclosure relates to a substrate processing apparatus and a method for cleaning a lock key.

Background Art

[0002] In the manufacture of semiconductor devices, in order to prevent pattern collapse, a supercritical drying process is performed to dry a substrate whose surface is covered with a liquid such as IPA in a supercritical container by replacing it with a supercritical fluid such as supercritical CO2. A lock key is used to lock a lid that closes the supercritical container so that the supercritical fluid does not leak when a high-pressure supercritical fluid is supplied into the supercritical container (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present disclosure provides a technique for preventing a substrate from being contaminated by particles derived from a lock key and members in contact with it.

Means for Solving the Problems

[0005] According to an embodiment of the present disclosure, a substrate processing apparatus that replaces a liquid film formed on the upper surface of a substrate with a supercritical fluid and dries the substrate, a pressure vessel having a drying chamber inside where the drying of the substrate is performed, a lid that closes an opening of the drying chamber, a lock key that restricts the lid from moving from a closed position where the lid closes the opening to an open position where the lid opens the opening, A cleaning unit for cleaning the aforementioned lock key, A substrate processing apparatus equipped with the above is provided. [Effects of the Invention]

[0006] According to the above embodiment, it is possible to prevent contamination of the substrate by particles originating from the lock key and the components that come into contact with it. [Brief explanation of the drawing]

[0007] [Figure 1] This is a schematic cross-sectional view of a substrate processing apparatus according to one embodiment. [Figure 2] Figure 1 is a schematic longitudinal cross-sectional view of the substrate processing apparatus shown. [Figure 3] This is another schematic longitudinal cross-sectional view of the substrate processing apparatus shown in Figure 1. [Figure 4] This is a flowchart of a substrate processing method according to one embodiment. [Figures 5A-5C] This is a schematic longitudinal cross-sectional view illustrating an example of substrate loading operation in a drying unit incorporated into the substrate processing apparatus shown in Figure 1. [Figure 6A-6B] This is a schematic longitudinal cross-sectional view illustrating an example of fluid flow during the drying process in a drying unit. [Figure 7A] This is a side view of a drying unit showing an example of the configuration and operation of a lid and lock key provided on the drying unit, with the lid in the closed position and the lock key in the locked position. [Figure 7B] Figure 7A is a cross-sectional view of the drying unit along the VIIB-VIIB line. [Figure 8A] Figure 7A is a side view showing the drying unit with the lid in the standby position and the lock key in the unlocked position. [Figure 8B] This is a cross-sectional view of the drying unit shown in Figure 8A, along the line VIIIB-VIIIB. [Figure 9A]A cross-sectional view showing an example of the configuration and operation of the lock key of the drying unit and the members around it, showing the state where the lock key is in the released position. [Figure 9B] A cross-sectional view showing the state where the lock key shown in FIG. 9A has moved to the locked position. [Figure 10] A cross-sectional view showing an example of a configuration in which a resin layer and rolling elements are provided on the surface of the lock key, and is a cross-sectional view in region X in FIG. 9. [Figure 11] A flowchart for explaining an example of the (sub) steps constituting step S4 in the flowchart of FIG. 4. [Figures 12A-12E] A schematic diagram for explaining an example of the mechanism by which wear powder derived from the lock key is generated and adheres to the substrate. [Figures 13A-13B] A schematic diagram for explaining the configuration and operation of the lock key cleaning unit according to the first embodiment. [Figure 14] A schematic diagram for explaining the configuration and operation of the lock key cleaning unit according to the second embodiment. [Figures 15A-15B] A schematic diagram for explaining the configuration and operation of the lock key cleaning unit according to the third embodiment. [Figure 16A-16C] A schematic diagram for explaining the configuration and operation of the lock key cleaning unit according to the fourth embodiment.

Embodiments for Carrying Out the Invention

[0008] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. In each drawing, the same or corresponding components are denoted by the same reference numerals, and the description may be omitted. In this specification, the X-axis direction, Y-axis direction, and Z-axis direction are perpendicular to each other. The X-axis direction and Y-axis direction are horizontal directions, and the Z-axis direction is a vertical direction.

[0009] First, referring to FIGS. 1 to 3, the substrate processing apparatus 1 of the embodiment will be described. As shown in FIG. 1, the substrate processing apparatus 1 includes a loading / unloading station 2 and a processing station 3.

[0010] The loading / unloading station 2 includes a mounting table 21, a conveying section 22, and a delivery section 23. The mounting table 21 is for mounting a plurality of carriers C. Each of the plurality of carriers C houses a plurality of horizontal substrates W at intervals in the vertical direction.

[0011] The substrate W includes a semiconductor substrate such as a silicon wafer or a compound semiconductor wafer, or a glass substrate. The substrate W may further include devices such as electronic circuits formed on the surface of the semiconductor substrate or the glass substrate. The substrate W may have an uneven pattern on its surface.

[0012] Inside the conveying section 22, a first conveying device 22a is arranged. The first conveying device 22a conveys the substrate W inside the conveying section 22 and conveys the substrate W among a plurality of devices arranged adjacent to the conveying section 22.

[0013] The first conveying device 22a includes a first conveying arm for holding the substrate W. The first conveying arm can move in the horizontal direction (both the X-axis direction and the Y-axis direction) and the vertical direction, and can also pivot about a vertical axis. The number of the first conveying arms may be one or more than one.

[0014] The delivery section 23 has a transition device 23a for temporarily accommodating the substrate W.

[0015] The processing station 3 includes a conveying block 31 and a plurality of processing blocks 32. The conveying block 31 has a rectangular parallelepiped shape. Inside the conveying block 31, a second conveying device 31a is arranged. The second conveying device 31a conveys the substrate W among a plurality of devices arranged adjacent to the conveying block 31.

[0016] The second conveying device 31a includes a second conveying arm for holding the substrate W. The second conveying arm can move in the horizontal direction (both the X-axis direction and the Y-axis direction) and the vertical direction, and can also pivot about a vertical axis. The number of the second conveying arms may be one or more than one.

[0017] Multiple processing blocks 32 may be provided. As shown in Figure 1, multiple processing blocks 32 may be symmetrically arranged on both sides of the transport block 31 in the Y-axis direction.

[0018] The processing block 32 includes a liquid film forming unit 32a, a drying unit 32b, and a supply unit 32c. The processing block 32 may have multiple sets (for example, two sets) of the liquid film forming unit 32a, drying unit 32b, and supply unit 32c.

[0019] The liquid film forming unit 32a supplies liquid to the upper surface of a horizontal substrate W. The liquid film forming unit 32a includes, for example, a spin chuck that holds the substrate W horizontally and a nozzle that discharges liquid onto the upper surface of the substrate W. The nozzle supplies liquid to the center of the upper surface of the rotating substrate W. The liquid spreads outwards from the center to the periphery of the upper surface of the substrate W due to centrifugal force. For example, a chemical solution, a rinsing solution, and a drying solution are supplied in this order. Multiple types of chemical solutions may be supplied, and rinsing solution may also be supplied between the supply of one chemical solution and the supply of another.

[0020] The liquid film forming unit 32a, for example, forms a liquid film of a chemical solution on the upper surface of a horizontal substrate W, then replaces the liquid film of the chemical solution with a liquid film of a rinsing solution, and then replaces the liquid film of the rinsing solution with a liquid film of a drying solution. The chemical solution is, for example, SC1 (aqueous solution of ammonia and hydrogen peroxide) or DHF (dilute hydrofluoric acid). The rinsing solution is, for example, DIW (deionized water). The drying solution is, for example, an organic solvent such as IPA (isopropyl alcohol).

[0021] The drying unit 32b dries the substrate W by replacing the liquid film formed on the upper surface of the horizontal substrate W with a supercritical fluid. A supercritical fluid is a fluid that has been subjected to a temperature above its critical temperature and a pressure above its critical pressure. By replacing the liquid film, such as a drying solution, with a supercritical fluid, the collapse of the uneven pattern on the substrate W due to surface tension can be suppressed. Details of the drying unit 32b will be described later.

[0022] The supply unit 32c supplies fluid to the drying unit 32b. Specifically, the supply unit 32c comprises a group of supply equipment including a flow meter, flow regulator, back pressure valve, heater, etc., and a housing that accommodates the group of supply equipment. The supply unit 32c supplies, for example, high-pressure CO2 as the fluid to the drying unit 32b.

[0023] In a plan view, the drying units 32b and supply units 32c, which are included in the same processing block 32, are arranged alternately in the X-axis direction. The supply unit 32c supplies fluid to the adjacent drying unit 32b on the negative X-axis side.

[0024] In a plan view, the processing block 32 protrudes from the transport block 31 in the positive X-axis direction. The supply unit 32c is positioned on this protruding portion. The supply unit 32c is open on three sides (positive Y-axis direction, negative Y-axis direction, and positive X-axis direction), which facilitates maintenance.

[0025] If multiple processing blocks 32 are provided, the second transport device 31a transports a single substrate W between multiple units included in the same processing block 32 (for example, between the liquid film forming unit 32a and the drying unit 32b).

[0026] The substrate processing apparatus 1 includes a control device 4 (shown only in Figure 1). The control device 4 can control the operation of all operable components included in the substrate processing apparatus 1. The control device 4 is, for example, a computer and includes a control calculation unit 41 and a storage unit 42. The storage unit 42 stores programs (including processing recipes) that control various processes performed in the substrate processing apparatus 1. The control calculation unit 41 controls the operation of the substrate processing apparatus 1 by reading and executing the programs stored in the storage unit 42. The control calculation unit 41 may be a CPU (Central Processing Unit) and may consist of one or more circuits.

[0027] Furthermore, such a program may have been recorded on a computer-readable storage medium and installed from that storage medium to the storage unit 42 of the control device 4. The computer-readable storage medium may be one or more of the following: hard disk (HD), flexible disk (FD), compact disk (CD), magnetic optical disk (MO), memory card, RAM (Random Access Memory), ROM (Read Only Memory), or SSD (Solid State Drive).

[0028] Next, the operation of the substrate processing apparatus 1 will be described with reference to Figure 4. Steps S1 to S4 shown in Figure 4 are performed under the control of the control device 4.

[0029] First, the first transport device 22a removes the substrate W from the carrier C and transports the removed substrate W to the transition device 23a. Subsequently, the second transport device 31a removes the substrate W from the transition device 23a and transports the removed substrate W to the liquid film forming unit 32a.

[0030] Next, the liquid film forming unit 32a supplies the chemical solution to the upper surface of the horizontal substrate W (step S1). The chemical solution is supplied to the center of the upper surface of the rotating substrate W and spreads across the entire radial surface by centrifugal force, forming a liquid film.

[0031] Next, the liquid film forming unit 32a supplies rinsing liquid to the upper surface of the horizontal substrate W (step S2). The rinsing liquid is supplied to the center of the upper surface of the rotating substrate W and spreads across the entire radial direction of the upper surface by centrifugal force, forming a liquid film. The liquid film of the chemical solution is replaced by the liquid film of the rinsing liquid.

[0032] Next, the liquid film forming unit 32a supplies drying liquid to the upper surface of the horizontal substrate W (step S3). The drying liquid is supplied to the center of the upper surface of the rotating substrate W and spreads across the entire radial direction of the upper surface by centrifugal force, forming a liquid film. The liquid film of the rinsing liquid is replaced by the liquid film of the drying liquid.

[0033] Next, the second transport device 31a removes the substrate W from the liquid film forming unit 32a and transports the removed substrate W to the drying unit 32b.

[0034] Next, the drying unit 32b replaces the liquid film formed on the upper surface of the horizontal substrate W with a supercritical fluid, thereby drying the substrate W (step S4). By replacing the liquid film, such as the drying solution, with a supercritical fluid, the appearance of a liquid-gas interface in the uneven pattern of the substrate W can be suppressed. As a result, the generation of surface tension can be suppressed, and the collapse of the uneven pattern can be prevented.

[0035] Finally, the second transport device 31a removes the substrate W from the drying unit 32b and transports the removed substrate W to the transition device 23a. Subsequently, the first transport device 22a removes the substrate W from the transition device 23a and stores the removed substrate W in the carrier C.

[0036] Next, the configuration and operation of the drying unit 32b will be explained with reference to Figures 5A to 5C, which show cross-sectional views obtained by cutting the central part of the drying unit 32b in the X direction with a cross-sectional plane parallel to the YZ plane. The drying unit 32b shown in Figures 5A to 5C is positioned on the positive Y-axis side of the transport block 31. In the explanation of the drying unit 32b, the direction in which the substrate W is brought into the drying chamber S (positive Y-axis direction in Figures 5A to 5C) will be considered the front, and the direction in which the substrate W is discharged from the drying chamber S (negative Y-axis direction in Figures 5A to 5C) will be considered the rear.

[0037] The drying unit 32b comprises a pressure vessel 51 with a drying chamber S for the substrate W formed inside, a lid 52 that closes the first opening Sa of the drying chamber S, and a support 53 that is fixed inside the drying chamber S and holds the substrate W horizontally within the drying chamber S. The first opening Sa is the entrance and exit for the substrate W. The substrate W is brought into the drying chamber S through the first opening Sa, dried in the drying chamber S, and then discharged from the drying chamber S through the first opening Sa.

[0038] In one configuration example, the pressure vessel 51 includes a lower wall 51a, an upper wall 51b, a front wall 51c, a rear wall 51d, and a pair of side walls, with a drying chamber S formed inside. In Figures 5A to 5C, one of the side walls is the back wall of the drying chamber S. The drying chamber S is, for example, rectangular in shape. A rectangular first opening Sa is formed in the rear wall 51d, and a rectangular second opening Sb is formed in the front wall 51c.

[0039] The cover 52 is located behind the rear wall 51d. The cover 52 is movable back and forth between a closed position (the position shown in Figure 5C) and an open position (the position shown in Figure 5B). The closed position is the position where the cover 52 closes the first opening Sa. The open position is behind the closed position, where the cover 52 opens the first opening Sa.

[0040] The second opening Sb is closed by a cover 61. The cover 61 can be opened and closed, but remains closed during normal operation of the drying unit 32b, and can be opened, for example, during maintenance of the drying unit 32b.

[0041] The lid 52 can rotate between an open position and a standby position (the position shown in Figure 5A) to facilitate the entry of the second transport device 31a into the drying chamber S. The standby position is a position outside the movement path of the substrate W and the transport arm during the loading and unloading of the substrate W. The lid 52 waits in the standby position during the loading and unloading of the substrate W.

[0042] The support 53 includes a rectifier plate 53a and a support pin 53b provided on the upper surface of the rectifier plate 53a. The rectifier plate 53a is fixed to the wall of the pressure vessel 51. The rectifier plate 53a guides and rectifies the fluid flow in the drying chamber S. The support pin 53b supports the substrate W on its upper surface. At this time, a gap is formed between the substrate W and the rectifier plate 53a.

[0043] Figures 6A and 6B show components related to fluid supply and discharge that were not shown in Figures 5A to 5C, and also show enlarged views of the area around the substrate W. As shown in these figures, the lower wall 51a of the pressure vessel 51 is provided with a discharge port 51g for discharging fluid from the drying chamber S and a supply port 51h for supplying fluid to the drying chamber S. The second lid 61 is provided with a plurality of fluid discharge ports 61a, which are arranged at approximately equal intervals in the direction perpendicular to the plane of the paper (X-axis direction) in Figure 6A.

[0044] As shown in Figures 7A, 7B, 8A, and 8B, the drying unit 32b includes a support frame 54 that supports the pressure vessel 51. The support frame 54 has, for example, a horizontal base plate 54a, a plurality of columns 54b projecting upward from the base plate 54a, and a pair of horizontal plates 54c fixed to the upper surfaces of the plurality of columns 54b. The pressure vessel 51 is fixed on the pair of horizontal plates 54c arranged on both sides in the X direction.

[0045] The drying unit 32b includes a linear motion mechanism 55 that moves the lid 52 back and forth between a closed position and an open position, and a rotary motion mechanism 56 that rotates the lid 52 between an open position and a standby position. The rotary motion mechanism 56 includes, for example, a rotating shaft 56a of the lid 52 and a rotary actuator 56b that rotates the rotating shaft 56a. On the other hand, the linear motion mechanism 55 includes, for example, a slider 55a that holds a bearing of the rotating shaft 56a and a linear motion actuator 55b that moves the slider 55a back and forth.

[0046] The rotation axis 56a of the cover 52 is symmetrically arranged on both sides of the cover 52 in the X-axis direction. The slider 55a is also symmetrically arranged on both sides of the cover 52 in the X-axis direction. The guide 55c of the slider 55a is laid on each of the pair of horizontal plates 54c. The rotary actuator 56b is fixed to one of the sliders 55a and can move back and forth together with the slider 55a. The linear actuator 55b is fixed to one of the horizontal plates 54c.

[0047] The linear actuator 55b is, for example, a pneumatic cylinder, which uses compressed air pressure to press the lid 52 against the pressure vessel 51. The driving force of the linear actuator 55b can crush a sealing member (not shown) that seals the space between the lid 52 and the pressure vessel 51, preventing the lid 52 from obstructing the movement of the lock key 57 when it is fitted into the fitting hole 51i in the upper wall 51b of the pressure vessel 51. The linear actuator 55b may also include a motor and a ball screw that converts the rotational motion of the motor into linear motion of the lid 52.

[0048] The drying unit 32b is equipped with a locking key 57 that restricts the lid 52 from retracting from a closed position to an open position. The locking key 57 is wedge-shaped into a fitting hole 51i of the pressure vessel 51 and restricts (effectively prevents) the retraction of the lid 52. Even when fluid is supplied to the drying chamber S and the pressure in the drying chamber S is increased, the retraction of the lid 52 can be restricted and fluid leakage can be prevented.

[0049] The lower wall 51a and upper wall 51b of the pressure vessel 51 protrude rearward from the rear wall 51d. In these protruding portions, fitting holes 51i penetrate the lower wall 51a and upper wall 51b in the Z-axis direction. Multiple fitting holes 51i are formed at intervals in the X-axis direction. Multiple lock keys 57 are also provided at intervals in the X-axis direction. Each lock key 57 is fitted into the corresponding fitting hole 51i formed in the lower wall 51a and upper wall 51b.

[0050] The number of lock keys 57 is not particularly limited, but for example, there are three. Unlike the case where there are two lock keys 57, the central part of the lid 52 in the X-axis direction can also be held down. As a result, when fluid is supplied to the drying chamber S and the pressure in the drying chamber S is increased, it is possible to suppress the central part of the lid 52 in the X-axis direction from bulging backward compared to the ends in the X-axis direction.

[0051] The drying unit 32b may be equipped with a laser film thickness gauge 58 for measuring the thickness of the liquid film LF formed on the upper surface of the substrate W that is brought into the drying chamber S of the pressure vessel 51.

[0052] The drying unit 32b is equipped with a lifting mechanism 59 that moves the lock key 57 up and down between a locked position (the position shown in Figure 9B) and an unlocked position (the position shown in Figure 9A). The locked position is the position in which the lock key 57 restricts the retraction of the lid 52, and the lock key 57 is fitted into the fitting holes 51i of both the lower wall 51a and the upper wall 51b. The unlocked position is the position in which the lock key 57 allows the retraction of the lid 52, and the lock key 57 is pulled downward from the fitting holes 51i of the upper wall 51b and the lower wall 51a. The unlocked position is set below the lower wall 51a of the pressure vessel 51 in order to prevent interference between the lock key 57 and the substrate W, as well as to provide a lock key cleaning section, which will be described later.

[0053] The lifting mechanism 59 includes, for example, a lifting platform 59a on which a plurality of lock keys 57 are placed, and a linear actuator 59b that raises and lowers the lifting platform 59a. The lifting platform 59a has a horizontal surface 59a1 on which the lock keys 57 are placed. The linear actuator 59b is, for example, a pneumatic cylinder, and raises and lowers the plurality of lock keys 57 by raising and lowering the lifting platform 59a. The linear actuator 59b may also include a motor and a ball screw that converts the rotational motion of the motor into linear motion of the lifting platform 59a.

[0054] In Figure 7B, the area 500R enclosed by the dashed line is equipped with a brush for the lock key cleaning unit, which cleans the lock key 57. The lock key cleaning unit is primarily for removing wear particles adhering to the lock key 57. The specific configuration of the lock key cleaning unit will be described in detail later.

[0055] As shown in Figure 9A, rolling elements 60 may be provided on the lock key 57. The rolling elements 60 are, for example, balls, and are held so as to be rotatable around the center of the ball. The rolling elements 60 may also be rollers.

[0056] When the lifting mechanism 59 raises the lock key 57 from the unlocked position to the locked position, the rolling element 60 rolls in contact with the lid 52 or the pressure vessel 51. The rolling element 60 reduces frictional resistance and suppresses the generation of particles due to friction.

[0057] Multiple rolling elements 60 are also provided on the lower surface 57a of the lock key 57, and roll while in contact with the horizontal surface 59a1 of the lifting mechanism 59. When the lock key 57 is raised, the lock key 57 can move horizontally inside the fitting hole 51i, thereby reducing frictional resistance.

[0058] It is preferable to raise and lower the lock key 57 with its rear surface 57b held vertically. It is also possible to raise the lock key 57 with its rear surface 57b tilted forward, but there is a risk that the corner 57c at the front end of the upper surface of the lock key 57 may strike the rear surface 52a of the lid 52.

[0059] Multiple rolling elements 60 are provided on the rear surface 57b of the lock key 57, spaced apart in the Z-axis direction. This configuration suppresses friction between the lock key 57 and the pressure vessel 51 compared to the case where only one rolling element is provided. This configuration is particularly effective when the rear surface 57b of the lock key 57 is vertically oriented.

[0060] As shown in Figure 9A, the lock key 57 may have an inclined surface 57d on its front surface that slopes forward from the top end downwards, and a vertical surface 57e extending straight down from the lower end of the inclined surface 57d. The formation of the inclined surface 57d prevents the corner 57c of the front end of the upper surface of the lock key 57 from hitting the rear surface 52a of the lid 52.

[0061] The rolling elements 60 are also provided on the inclined surface 57d of the lock key 57 and roll in contact with the rear surface 52a of the cover 52. The rear surface 52a of the cover 52 faces the inclined surface 57d of the lock key 57 and is inclined forward from the top end downwards.

[0062] Next, with reference to Figure 11, we will describe the details of step S4 as described in Figure 4. Steps (substeps) S41 to S45 shown in Figure 11 are carried out under the control of the control device 4.

[0063] First, the second transport device 31a horizontally holds the substrate W on which the drying liquid film LF has formed and transports the substrate W into the drying chamber S inside the pressure vessel 51 (step S41). During this process, the laser film thickness gauge 58 measures the thickness of the liquid film LF. It can be confirmed that the uneven pattern of the substrate W is covered with the liquid film LF.

[0064] Next, the support 53 fixed to the drying chamber S receives the substrate W from the second transport device 31a and supports the received substrate W horizontally. Subsequently, the second transport device 31a exits to the outside through the first opening Sa of the drying chamber S.

[0065] Next, the rotation mechanism 56 rotates the lid 52 from the standby position to the open position. Subsequently, the linear motion mechanism 55 moves the lid 52 forward from the open position to the closed position. As a result, the lid 52 closes the first opening Sa of the drying chamber S.

[0066] Next, the lifting mechanism 59 raises the lock key 57 from the unlocked position to the locked position. The lock key 57 presses the lid 52 from the rear, limiting the lid 52's retraction. Fluid leakage can be suppressed in step S42, which will be described later.

[0067] Next, the supply unit 32c supplies a fluid such as CO2 to the drying chamber S, increasing the pressure in the drying chamber S (step S42). At this time, the fluid is supplied to the drying chamber S from the supply port 51h on the lower wall 51a, as shown in Figure 6A. The fluid is ejected upward from the supply port 53a5 of the flow straightener plate 53a. Although not shown in the figure, in a plan view, multiple supply ports 53a5 are formed at each of the four corners of the flow straightener plate 53a, and the fluid flows from the outside to the inside of the substrate W. Above the substrate, a flow is formed from the periphery of the substrate toward the center. Therefore, the fluid flow can prevent the liquid film LF from spilling onto the outside of the substrate W. In a plan view, the supply ports 53a5 are located on the outside of the substrate W, so even if the supply ports 53a5 eject the fluid straight up, the substrate W will not be blown over. The fluid is not discharged from the drying chamber S but is stored in the drying chamber S while the pressure in the drying chamber S is increasing. The pressure in drying chamber S can be raised to a set pressure that is above the critical pressure.

[0068] Next, the supply unit 32c supplies fluid to the drying chamber S, and a discharge unit (not shown) discharges the fluid from the drying chamber S, maintaining the pressure in the drying chamber S at a set pressure while discharging the drying liquid dissolved in the supercritical fluid from the drying chamber S (step S43). At this time, the fluid is supplied to the drying chamber S from multiple discharge ports 61a provided on the second lid 61 at intervals in the X-axis direction, and as shown in Figure 6B, it flows in a curtain-like manner along the top of the substrate W, then flows through the discharge port 53a4 of the rectifier plate 53a into the space below the rectifier plate 53a, and finally is discharged to the outside of the drying chamber S through the discharge port 51g. As the fluid flows along the top of the substrate W, the liquid forming the liquid film LF is replaced with the supercritical fluid.

[0069] Subsequently, the supply of fluid to the drying chamber S is stopped, and the inside of the drying chamber S is depressurized to approximately atmospheric pressure by opening the chamber S to the atmosphere, causing the supercritical fluid to vaporize and be discharged from the drying chamber S, thereby drying the substrate W (step S44).

[0070] Next, the lifting mechanism 59 lowers the lock key 57 from the locked position to the unlocked position. At this time, as will be described in detail later, the lock key cleaning unit 500 removes any wear particles adhering to the lock key 57.

[0071] Next, the linear motion mechanism 55 moves the lid 52 back from the closed position to the open position. Subsequently, the rotation mechanism 56 rotates the lid 52 from the standby position to the open position.

[0072] Next, the second transport device 31a enters the drying chamber S inside the pressure vessel 51, receives the substrate W from the support 53, and then unloads the received substrate W (step S45).

[0073] For further details of the technical matters described so far in the specification of this application, please refer to Patent Document 1 (Japanese Patent Application Publication No. 2022-030850) issued by the applicant of this application. The technical matters described in Patent Document 1 are also applicable to the substrate processing apparatus 1 of this application.

[0074] The following provides further details about the configuration of lock key 57.

[0075] It is preferable that the rolling elements 60 provided on the lock key 57 be configured so that the rolling elements 60 can retract behind the surface of the lock key 57. When the pressure inside the drying chamber S of the pressure vessel 51 rises to the supercritical pressure of CO2 (approximately 16 MPa), if the lid 52, which is trying to open due to that pressure, is to be supported only by the rolling elements 60 which are in point contact with the lid, the rolling elements 60 may break. If the rolling elements 60 retract so that the lock key 57 and the rolling elements 60 become flush, and as a result the lock key 57 and the member facing it (lid 52, etc.) come into surface contact, there is no risk of the rolling elements 60 breaking.

[0076] To enable the rolling element 60 to retract behind the surface of the lock key 57, one example configuration is to use a ball plunger-like mechanical element (hereinafter referred to as "ball plunger" for simplicity) as shown in Figure 10. The ball plunger has a structure in which balls (rolling elements) 60, spring-biased by a spring 602, are rotatably assembled inside a sleeve 601 (cylindrical body). The diameter of the entrance to the sleeve 601 is slightly smaller than the diameter of the ball 60 to prevent the ball 60 from falling out of the sleeve 601. The sleeve 601 of the ball plunger is housed in a hole formed in the lock key 57. Male threads may be formed on the outer circumferential surface of the sleeve of the ball plunger and attached to a screw hole formed in the lock key 57. To reduce the amount of wear dust generated between the ball and the ball plunger that contacts the ball, the ball may be held in a resin holder or support 603 and housed inside the sleeve of the ball plunger. In this case, the resin holder or support is housed inside the sleeve while spring-biased. When the ball (rolling element) 60 is pressed, the ball 60 retracts into the sleeve 601 while compressing the spring 602.

[0077] If the rolling elements 60 are to be retractable, the materials constituting the rolling elements 60 are not limited to steel materials such as tool steel, but may also be engineering plastics or ceramics.

[0078] In addition to providing rolling elements 60 on the lock key 57, or instead of providing rolling elements 60 on the lock key 57, a resin layer 200 may be provided on the portion of the entire surface of the lock key 57 that is subjected to high loads due to the supercritical pressure in the drying chamber S (specifically, the inclined surface 57d and the rear surface 57b). By providing the resin layer 200, it is possible to prevent the generation of metal wear particles that may occur when metals slide against each other under high surface pressure (details described later). If metal wear particles adhere to the substrate W, there is a high possibility that problems will occur in the substrate W. When both rolling elements 60 and the resin layer 200 are provided, it is preferable to configure them so that the rolling elements 60 can retract to a position where they are flush with the surface of the resin layer 200. Figure 10 schematically shows an example of a configuration in which both rolling elements 60 and the resin layer 200 are provided on the surface of the lock key 57.

[0079] The material forming the resin layer 200 is preferably strong enough not to easily dent even when subjected to relatively high surface pressure, and has a low coefficient of friction. Suitable materials for forming the resin layer 200 are, for example, PEEK (polyetheretherketone), nylon, and high-density polypropylene.

[0080] The resin layer 200 can be formed from a resin plate 1 to several millimeters thick. As shown in Figure 10, by providing complementary irregularities 202 on the resin layer 200 and the lock key 57, it is possible to prevent the resin layer 200 from shifting away from the lock key 57 due to shear force when the lock key 57 slides and contacts the mating material (e.g., the rear surface 52a of the lid 52). In one example configuration, the arrow in Figure 10 indicates the vertical direction (Z-axis direction) of the lock key 57, and the irregularities 202 extend in a direction perpendicular to the vertical direction of the lock key 57. The complementary irregularities 202 are, for example, a T-shaped protrusion provided on the back surface of the resin layer 200 and a T-shaped recess formed on the surface of the lock key 57, but are not limited to these.

[0081] Next, the mechanism by which wear particles originating from the lock key 57 (especially those originating from the resin layer 200) are generated and adhere to the substrate W will be explained with reference to Figures 12A to 12E.

[0082] After the substrate W, which is to be dried, is placed in the drying chamber S of the pressure vessel 51, the lid 52 is closed. Next, as shown in Figure 12A, the lock key 57 is raised from the unlocked position to the locked position. At this time, just before the lock key 57 reaches the locked position, the inclined surface 57d and the rear surface 57b (which has a resin layer 200 on its surface) slide against the rear surface 52a of the lid 52 and the inner surface of the fitting hole 51i (which are made of metal) due to a wedge action. Even if rolling elements 60 are provided, the rolling elements 60 retract inward just before reaching the locked position and become flush with the resin layer 200, so the above sliding occurs. At this time, the weak resin layer 200 may be damaged and wear particles originating from the resin layer may be generated, but the amount of wear particles generated at this time is small.

[0083] Next, when supercritical, high-pressure CO2 is filled into the drying chamber S, the lid 52 is pressed against the lock key 57 with a large force (indicated by the arrow), for example, about 20 tons, as shown in Figure 12B. This causes the lock key 57 to bend, and consequently, sliding occurs under high surface pressure between the surface of the lock key 57 (resin layer 200) and its opposing surface. This sliding damages the weak resin layer 200, generating wear particles originating from the resin layer. Most of the wear particles in question are generated at this time.

[0084] During sliding, the resin layer 200 (made of PEEK in this case) on the surface of the lock key 57 becomes electrically charged, but the metal component sliding against it hardly becomes charged. Therefore, if the amount of wear dust generated is small, as shown in Figure 12C, the wear dust preferentially adheres to the surface of the resin layer 200 of the lock key 57. It hardly adheres to the metal component.

[0085] As the substrate W is processed repeatedly, wear particles accumulate on the surface of the resin layer 200. When an amount of wear particles accumulates that cannot be retained on the surface of the resin layer 200, some of the wear particles will adhere to the surface of the components of the lock key 57 that are in contact with the resin layer 200 (the rear surface 52a of the lid 52 and the inner surface of the fitting hole 51i), as shown in Figure 12D.

[0086] As shown in Figure 12E, for example, wear particles adhering to the inner surface of the fitting hole 51i may fall off when the substrate W is loaded into or unloaded from the pressure vessel 51 and adhere to the surface of the substrate W. This is the mechanism by which wear particles originating from the lock key 57 are generated and adhere to the substrate W.

[0087] Next, several embodiments of the lock key cleaning unit 500 will be described. Here, we will describe an example in which a PEEK resin layer 200 is provided on the surface of the lock key 57.

[0088] [First embodiment of the lock key cleaning unit] The lock key cleaning unit 500A according to the first embodiment will be described with reference to Figures 13A and 13B.

[0089] The lock key cleaning unit 500A according to the first embodiment has a brush 501 that cleans the lock key 57 by brushing it. A single drying unit 32b is provided with three lock keys 57, and at least one pair of brushes 501 is provided for each lock key 57. One of the pair of brushes 501 (also called the "rear brush 501") cleans the rear surface 57b of the lock key 57, and the other (also called the "front brush 501") cleans the front surface (inclined surface 57d and vertical surface 57e) of the lock key 57. In one configuration example, each brush 501 is elongated (long in the X-axis direction), and its width in the X-axis direction (horizontal width) is greater than or equal to the width in the X-axis direction of the corresponding lock key 57.

[0090] The front brush 501 and the rear brush 501 are positioned such that when the lock key 57 is in the unlocked position, they contact the upper end of the inclined surface 57d and the upper end of the rear surface 57b of the corresponding lock key 57. As described above, when the lock key 57 is in the unlocked position, it is preferable that the upper end of the lock key 57 is lower than the lower surface of the lower wall 51a of the pressure vessel 51.

[0091] During brush cleaning, the lifting mechanism 59 moves the lock key 57 up and down at least once, preferably multiple times, to rub the area where the resin layer 200 of the lock key 57 is provided with the brush 501, thereby removing wear particles (hereinafter sometimes denoted by reference numeral P) adhering to the resin layer 200 of the lock key 57.

[0092] The brush 501 may be spring-biased toward the lock key 57 so that it makes secure contact with the lock key 57. This configuration is advantageous for ensuring thorough cleaning of the inclined surface 57d because the lock key 57 is tapered, narrowing towards the top.

[0093] Specifically, for example, as shown in Figure 9A, the brush shaft 502 connected to the brush 501 is supported by a brush guide 503 so as to be slidable in the Y-axis direction. The brush guide 503 is fixed directly to the support frame 54 or to a bracket fixed to the support frame 54. A coil spring 504 is placed in a compressed state between the brush 501 and the brush guide 503 so that the brush 501 is pressed against the lock key 57 by the repulsive force of the coil spring 504.

[0094] When the lock key 57 is rubbed with the brush 501, the resin layer 200 may become charged (or may not become charged) depending on the combination of materials of the resin layer 200 and the brush 501. In this case, if wear particles are attached to the surface of the pressure vessel 51 and the lid 52 that are in contact with the lock key 57 in the locked position, when the lock key 57 is moved to the locked position, the wear particles will move to (and adhere to) the charged resin layer 200. For this reason, the lock key 57 may be moved back and forth between the unlocked position and the locked position one or more times, preferably multiple times, while performing the above-mentioned suction. By doing so, wear particles attached to the surfaces of the pressure vessel 51 and the lid 52 can also be removed.

[0095] To collect the wear particles scraped off the lock key 57 by the brush 501, it is preferable to provide a local exhaust duct 510 in an area where wear particles may be suspended. The local exhaust duct 510 is connected to, for example, a factory exhaust system (exhaust duct) installed in a semiconductor manufacturing plant, and the inside is under negative pressure. Therefore, if a suitable opening 509 (suction opening) is provided in the local exhaust duct 510, most of the wear particles suspended around the local exhaust duct 507 can be collected.

[0096] [Second embodiment of the lock key cleaning unit] Referring to Figure 14, the lock key cleaning unit 500B according to the second embodiment will be described.

[0097] The lock key cleaning unit 500B according to the second embodiment differs from the lock key cleaning unit 500A according to the first embodiment in that it applies suction force to the brush 501 to suck up and collect the wear particles rubbed off by the brush 501. Other aspects may be the same as in the first embodiment.

[0098] In this second embodiment, an air passage 511 used as a suction passage is provided inside the brush 501 (more specifically, the base of the brush where the brush bristles (filaments) are implanted). The upstream end (inlet) of the air passage 511 is surrounded by the brush bristles (filaments).

[0099] The upstream end of the suction line 512 is connected to the air passage 511 of the brush 501. The suction line 512 is equipped with an ejector 513 that applies suction force to the air passage 511 of the brush 501 in order to collect the wear particles scraped off by the brush 501. The downstream end of the suction line 512 is connected to the local exhaust duct 510.

[0100] In the same manner as in the first embodiment, the lock key 57 is raised and lowered by the lifting mechanism 59, and at least at this time, a suction force is applied to the air passage 511 of the brush 501. The wear particles scraped off by the brush 501 are discharged into the factory exhaust system sequentially through the air passage (suction path) 511, the suction line 512, and the local exhaust duct 510. Therefore, there is no risk of the wear particles scraped off by the brush 501 scattering in the space around the lock key 57 in the unlocked position.

[0101] In this second embodiment, as in the first embodiment, a configuration may also be used to directly draw in wear particles that may be floating around the local exhaust duct 510 into the local exhaust duct 510.

[0102] [Third embodiment of the lock key cleaning unit] The lock key cleaning unit 500C according to the third embodiment will be described with reference to Figures 15A and 15B.

[0103] The lock key cleaning unit 500C according to the third embodiment includes, as a brush 501, a pair of charging brushes and a pair of static elimination brushes for each lock key 57. For convenience of explanation, the charging brushes will be referred to as "charging brush 501C" and the static elimination brushes as "static elimination brush 501D".

[0104] The electrostatic brush 501C (specifically, the bristles (filaments) of the electrostatic brush 501C) is made of a material that charges the resin layer 200 when it rubs against it. The static discharge brush 501D (specifically, the bristles (filaments) of the static discharge brush 501D) is made of a material that discharges static electricity from the resin layer 200 when it rubs against it. For example, when the resin layer 200 is PEEK, the bristles of the electrostatic brush 501C are polypropylene, and the material of the static discharge brush 501D is, for example, nylon. The order of materials' ease of charging is well known, and the "triboelectric series," which lists materials from those that easily become positively charged to those that easily become negatively charged in order of ease of charging, is also well known. The material of the bristles of the electrostatic brush 501C and the static discharge brush 501D should be determined in relation to the material constituting the resin layer 200 by referring to the triboelectric series.

[0105] The charging brush 501C and the static elimination brush 501D are positioned adjacent to each other in the vertical direction, with the charging brush 501C positioned above the static elimination brush 501D. As a result, when the lock key 57 is lowered, when the resin layer 200 is divided into multiple parts in the vertical direction, and one part (referred to as a "local part" for simplicity) is viewed locally, the charging brush 501C contacts the local part first, followed by the static elimination brush 501D. Therefore, the local part is rubbed against the resin layer 200 by the static elimination brush 501D while static electricity is eliminated, making it easy to remove any wear particles adhering to the local part (see Figure 15A).

[0106] On the other hand, when the lock key 57 is raised, the static elimination brush 501D first contacts a localized portion of the resin layer 200, and then the charging brush 501C makes contact. As a result, as shown in 15B, when the lock key 57 reaches the locked position, the entire resin layer 200 becomes charged. By bringing the charged resin layer 200 into contact with the surfaces of the pressure vessel 51 and the lid 52, wear particles adhering to the surfaces of the pressure vessel 51 and the lid 52 can be moved to the resin layer 200. The wear particles moved to the resin layer 200 in this way can be removed from the resin layer 200 by the static elimination brush 501D during the process of moving the lock key 57 from the locked position to the unlocked position.

[0107] According to this third embodiment, both the wear particles adhering to the lock key 57 and the wear particles adhering to the pressure vessel 51 and the lid 52 can be efficiently removed.

[0108] In this third embodiment, as in the first embodiment, a local exhaust duct 510 may be provided in an area where wear particles (P) can float in order to collect the wear particles scraped off the lock key 57 by the brush 501 (charging brush 501C, static elimination brush 501D). Also, as in the second embodiment, suction force may be applied to the brush 501 to suck up and collect the wear particles (P) scraped off by the brush 501.

[0109] [Fourth embodiment of the lock key cleaning unit] Next, with reference to Figures 16A to 16C, the lock key cleaning unit 500D according to the fourth embodiment will be described. For the sake of simplicity, we will describe the case in which a pair of opposing brushes 501 are provided for one lock key 57. For the sake of convenience, one of the pair of opposing brushes 501 will be called the first brush 501A, and the other will be called the second brush 501B.

[0110] In this fourth embodiment, as shown in Figure 16B, a brush is used that has an air passage 511 formed in the same way as the brush 501 used in the second embodiment. The air passage 511 of the first brush 501A(501) is connected to a pressurized gas supply source 522 via a gas supply line 520A(520) interposed with an on-off valve 521A(521). The air passage 511 of the second brush 501B(501) is connected to a pressurized gas supply source 522 via a gas supply line 520B(520) interposed with an on-off valve 521B(521). The pressurized gas supply source 522 is, for example, provided as a factory power source and can supply clean air (nitrogen gas may also be used) as the pressurized gas.

[0111] As shown in Figure 16A, when the lock key 57 is in the locked position, as shown in Figure 16B, the on-off valve 521A is opened and the on-off valve 521B is closed, and gas is blown from the first brush 501A to the second brush 501B. Next, the on-off valve 521A is closed and the on-off valve 521B is opened, and gas is blown from the second brush 501B to the first brush 501A. This operation is repeated one or more times, preferably multiple times. This blows away the wear particles adhering to the brush 501. The blown-away, floating wear particles are sucked up and collected by the local exhaust duct 510, which is provided with an opening. With this configuration, it is possible to prevent wear particles that have adhered to the brush 501 (501A, 501B) from re-adhering to the lock key 57, and the cleaning efficiency of the lock key 57 is improved.

[0112] As shown in Figure 16C, the air passage 511 of the brush 501 (501A, 501B) may be used as a suction passage and a discharge passage. The configuration shown in Figure 16C is conceived by combining the configuration shown in Figure 14 with the configuration shown in Figure 16B, and adding valves (on-off valves 525, 521) for switching between suction and discharge. That is, a connection point 517 is set between the brush 501 of the suction line (gas line) 512 and the ejector 513, and a gas supply line 520 with an on-off valve 521 as shown in Figure 16B is connected to this point. Also, an on-off valve 525 is provided slightly downstream of the connection point 517 of the suction line 512. Instead of providing on-off valves 521 and 525, a three-way valve may be provided at the connection point 517.

[0113] By opening the on-off valve 521 and closing the on-off valve 525, the air passage 511 of the brush 501 can be used as a gas discharge passage. By closing the on-off valve 521 and opening the on-off valve 525, the air passage 511 of the brush 501 can be used as a suction passage.

[0114] Gas may be injected from one of a pair of opposing brushes 501 while suction is performed by the other brush. In other words, gas may be injected from the first brush 501A(501) simultaneously with suction by the second brush 501B, and then gas may be injected from the second brush 501B(501) simultaneously with suction by the first brush 501A. In this case, some of the wear particles blown off by the other brush can be recovered through the air passage 511 of the other brush.

[0115] The configuration of the fourth embodiment described above is also applicable to a configuration in which a pair of charging brushes 501C (501) and a static elimination brush 501D (501) are provided for one lock key 57, as in the third embodiment. In this case, it is preferable to inject gas from all (two) brushes on the same side (e.g., the front side) of the lock key 57, and then inject gas from all (two) brushes on the same side (e.g., the rear side) of the lock key 57, in order to prevent a decrease in gas flow velocity due to interference between the injected gas flows.

[0116] In the above embodiment, a resin layer 200 is provided on the surface of the lock key 57 and the wear particles are resin wear particles, but the invention is not limited to this. The surface of the lock key 57 does not have to be provided with a resin layer 200. In this case, metal wear particles may be generated, but even a lock key 57 with such metal wear particles attached can be cleaned by the lock key cleaning unit using the brush described above (however, the function of promoting the removal of wear particles by utilizing the static charge of the resin cannot be used). Wear particles may also be generated from the rolling elements 60 (balls or rollers), but the amount is negligible and can be removed by the brush.

[0117] The above description only explains the cleaning of the lock key 57 on the first opening Sa side, but a cover and lock key are also provided on the second opening Sb side (see the components labeled reference numerals 52' and 57' in Figure 12A). During normal operation, the cover on the second opening Sb side is always in the closed position, and the lock key on the second opening Sb side is always in the locked position. When the internal pressure of the drying chamber S increases, wear particles are generated by the sliding between the cover and lock key on the second opening Sb side due to the mechanism described above. Although there is little possibility that these wear particles will harm the substrate W, a lock key cleaning section may be provided to clean the lock key on the second opening Sb side. Since the second opening Sb is opened, for example, during maintenance, cleaning the lock key before maintenance makes the maintenance work easier.

[0118] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The above embodiments may be omitted, replaced, or modified in various ways without departing from the scope and spirit of the appended claims.

[0119] In each of the above embodiments, cleaning may be performed each time a substrate W is processed. Cleaning may also be performed periodically, for example, when processing of the first substrate W in a processing lot begins, or for example, each time a predetermined number of substrates W are processed. In this case, for example, a brush moving mechanism (not shown) that moves the brush 501 forward and backward relative to the lock key 57 may be provided so that the brush 501 comes into contact with the lock key 57, which moves up and down, only when cleaning is desired. [Explanation of Symbols]

[0120] W board S drying room 51 Pressure vessel 52 Lid 57 Lock Key 500A, 500B, 500C, 500D Cleaning Unit

Claims

1. A substrate processing apparatus for drying a substrate by replacing a liquid film formed on the upper surface of the substrate with a supercritical fluid, A pressure vessel having a drying chamber inside in which the substrate is dried, A lid that closes the opening of the drying chamber, A locking key that restricts the lid from moving from a closed position that closes the opening to an open position that opens the opening, A cleaning unit for cleaning the aforementioned lock key, A substrate processing apparatus equipped with the following:

2. The lock key further comprises a lifting mechanism that raises and lowers the lid between a locked position that restricts the lid from moving from a closed position that closes the opening to an open position that opens the opening, and an unlocked position that allows the lid to move between the closed position and the open position. The substrate processing apparatus according to claim 1, wherein the cleaning unit cleans the lock key when the lock key is being moved by the lifting mechanism.

3. The substrate processing apparatus according to claim 2, wherein the cleaning unit is equipped with a brush, and the lock key is cleaned by being rubbed by the brush when the lock key is moved by the lifting mechanism.

4. The substrate processing apparatus according to claim 3, wherein the brush is spring-biased so as to be pressed against the lock key.

5. The substrate processing apparatus according to claim 3, further comprising a suction unit for sucking up powder scraped off the lock key by the brush.

6. The substrate processing apparatus according to claim 5, wherein the suction portion has a suction port provided on the brush.

7. The substrate processing apparatus according to claim 5, wherein the suction unit has a suction port provided below the brush, and the suction port sucks up powder floating below the brush.

8. The substrate processing apparatus according to claim 3, wherein the brush includes a first brush and a second brush, the first brush being provided to contact a first surface of the lock key that contacts the lid, and the second brush being provided to contact a second surface of the lock key that is opposite to the first surface.

9. The substrate processing apparatus according to claim 3, wherein a resin layer is provided on the surface of the lock key that receives a load applied from the lid when the lock key is in the locked position.

10. The substrate processing apparatus according to claim 9, wherein the brush includes a first brush and a second brush, the first brush is made of a material that charges the resin layer when rubbed against the resin layer, and the second brush is made of a material that discharges the resin layer when rubbed against the resin layer.

11. The first brush is located above the second brush. The substrate processing apparatus according to claim 10.

12. The substrate processing apparatus according to claim 3, further comprising a gas injection unit that sprays gas toward the brush to blow away powder adhering to the brush.

13. The substrate processing apparatus according to claim 8, wherein the first brush is provided with a first gas injection unit that injects gas toward the second brush to blow away powder adhering to the second brush, and the second brush is provided with a second gas injection unit that injects gas toward the first brush to blow away powder adhering to the first brush.

14. A substrate processing apparatus comprising: a pressure vessel having a drying chamber inside in which a substrate is dried by replacing a liquid film formed on the upper surface of the substrate with a supercritical fluid; a lid that closes the opening of the drying chamber; and a lock key that restricts the movement of the lid, wherein the lock key is provided to be vertically movable between a locked position that restricts the movement of the lid from a closed position that closes the opening to an open position that opens the opening, and an unlocked position that allows the lid to move between the closed position and the open position, wherein a cleaning method for cleaning the lock key, The brush is provided in a position where it can contact the lock key when the lock key moves between the locked position and the unlocked position, The lock key is moved between the locked position and the unlocked position, and the brush is used to rub the lock key, thereby removing powder adhering to the surface of the lock key from the lock key. A cleaning method that includes [a specific feature / feature].

15. The cleaning method according to claim 14, further comprising suctioning and collecting the powder scraped off the lock key by the brush.

16. A resin layer is provided on the surface of the lock key. The brush is made of a material that charges the resin layer when it is rubbed, The aforementioned cleaning method is When the lock key is moved from the unlocked position to the locked position, the resin layer is charged by the brush, By bringing the charged resin layer into contact with the lid, the powder adhering to the lid is attached to the resin layer of the lock key by electrostatic attraction, When moving the lock key from the locked position to the unlocked position, the brush removes any powder adhering to the resin layer of the lock key. The cleaning method according to claim 14, further comprising the above.

17. The cleaning method according to claim 14, wherein the cleaning of the lock key is performed before the first substrate of a processing lot is processed, or after a predetermined number of substrates have been processed.

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