Substrate Processing Apparatus and Control Method Thereof

Abstract

The present invention provides a substrate processing apparatus and a control method thereof that can improve the cleanliness of a wafer after drying treatment using a supercritical processing fluid. The substrate processing apparatus includes: a processing container having a processing space capable of accommodating a substrate in a state where the surface is wetted with a liquid; a processing fluid supply unit that supplies a supercritical processing fluid toward the liquid into the processing space; a first exhaust pipeline connected to a first exhaust source and exhausting the processing space using a first exhaust pressure; a second exhaust pipeline connected to a second exhaust source different from the first exhaust source, connected to the first exhaust pipeline between the first exhaust source and the processing space, and exhausting the processing space using a second exhaust pressure via the first exhaust pipeline; and a control unit that controls the second exhaust pressure. The supercritical processing fluid contacts the liquid to dry the substrate. The control unit makes the second exhaust pressure higher than the first exhaust pressure during a period when the processing fluid supply unit stops supplying the processing fluid to the processing space.

Description

Technical Field

[0001] The present disclosure relates to a substrate processing apparatus and a control method thereof. Background Art

[0002] In a manufacturing process of a semiconductor device in which a laminated structure of an integrated circuit is formed on the surface of a semiconductor wafer (hereinafter referred to as a wafer) or the like as a substrate, a liquid treatment process is performed in which a cleaning liquid such as a chemical solution is used to remove minute dust, a natural oxide film, etc. on the wafer surface, and the wafer surface is treated with a liquid. There is known a method of using a processing fluid in a supercritical state when removing a liquid or the like attached to the surface of a wafer in the liquid treatment process (for example, refer to Patent Document 1).

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2013-12538 Summary of the Invention

[0006] Problems to be Solved by the Invention

[0007] The present disclosure provides a substrate processing apparatus and a control method thereof that can improve the cleanliness of a wafer after a drying process using a processing fluid in a supercritical state.

[0008] Solutions for Solving the Problems

[0009] A substrate processing apparatus according to one aspect of the present disclosure includes: a processing container having a processing space capable of accommodating a substrate in a state where the surface is wetted with a liquid; a processing fluid supply unit that supplies a processing fluid in a supercritical state toward the liquid in the processing space; a first exhaust pipeline connected to a first exhaust source and exhausting the processing space using a first exhaust pressure; a second exhaust pipeline connected to a second exhaust source different from the first exhaust source, connected to the first exhaust pipeline between the first exhaust source and the processing space, and exhausting the processing space using a second exhaust pressure via the first exhaust pipeline; and a control unit that controls the second exhaust pressure. The processing fluid in the supercritical state contacts the liquid to dry the substrate. The control unit makes the second exhaust pressure higher than the first exhaust pressure during a period when the processing fluid supply unit stops supplying the processing fluid to the processing space.

[0010] Effects of the Invention

[0011] According to the present disclosure, the cleanliness of a wafer after a drying process using a processing fluid in a supercritical state can be improved. Brief Description of the Drawings

[0012] Figure 1 This is a cross-sectional top view showing an example of the overall structure of the cleaning processing system.

[0013] Figure 2 This is an external perspective view showing an example of the processing container of the supercritical processing apparatus.

[0014] Figure 3 This is a cross-sectional view showing an example of the processing container.

[0015] Figure 4 This is a cross-sectional view (Part 1) showing the periphery of the maintenance opening of the processing container.

[0016] Figure 5 This is a cross-sectional view (Part 2) showing the periphery of the maintenance opening of the processing container.

[0017] Figure 6 This is a diagram showing an example of the structure of the entire system of the supercritical processing apparatus according to the first embodiment.

[0018] Figure 7 This is a block diagram showing the functional structure of the control unit according to the first embodiment.

[0019] Figure 8 This is a diagram showing the drying mechanism of IPA.

[0020] Figure 9 This is a cross-sectional view (Part 1) showing an example of the foreign matter removal process using an ejector.

[0021] Figure 10 This is a cross-sectional view (Part 2) showing an example of the foreign matter removal process using an ejector.

[0022] Figure 11 This is a cross-sectional view (Part 3) showing an example of the foreign matter removal process using an ejector.

[0023] Figure 12 This is a cross-sectional view (Part 4) showing an example of the foreign matter removal process using an ejector.

[0024] Figure 13 This is a diagram showing an example of the structure of the entire system of the supercritical processing apparatus according to the second embodiment.

[0025] Figure 14 This is a partial cross-sectional view of the processing container according to the third embodiment. Detailed Embodiments

[0026] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. In each drawing, the same or corresponding structures may sometimes be denoted by the same or corresponding reference numerals and description thereof may be omitted.

[0027] [Structure of Cleaning Processing System]

[0028] Figure 1 This is a cross-sectional top view showing an example of the overall structure of the cleaning processing system 1.

[0029] The cleaning processing system 1 includes: a plurality of cleaning devices 2 (two cleaning devices 2 in the Figure 1 example shown), which supply a cleaning liquid to the wafer W and perform a cleaning process on the wafer W; and a plurality of supercritical processing devices 3 (six supercritical processing devices 3 in the Figure 1 example shown), which cause a liquid for preventing drying (isopropyl alcohol (IPA) in this embodiment) attached to the wafer W after the cleaning process to contact a processing fluid in a supercritical state (carbon dioxide (CO 2 )) and remove the liquid.

[0030] In this cleaning processing system 1, the carrier 100 is placed on the placement unit 11, and the wafer W stored in the carrier 100 is transferred to the cleaning processing unit 14 and the supercritical processing unit 15 via the feeding / discharging unit 12 and the transfer unit 13. As the carrier 100, for example, a FOUP (Front-Opening Unified Pod) is used. In the cleaning processing unit 14 and the supercritical processing unit 15, the wafer W is first fed into the cleaning device 2 provided in the cleaning processing unit 14 to undergo a cleaning process, and then is fed into the supercritical processing device 3 provided in the supercritical processing unit 15 to undergo a drying process for removing IPA from the wafer W. In Figure 1 , the reference numeral "121" denotes a first transfer mechanism that transfers the wafer W between the carrier 100 and the transfer unit 13, and the reference numeral "131" denotes a transfer rack that temporarily places the wafer W transferred between the cleaning processing unit 14 and the supercritical processing unit 15 and the feeding / discharging unit 12 and serves as a buffer.

[0031] The opening of the transfer section 13 is connected to the wafer transfer path 162, and a cleaning processing section 14 and a supercritical processing section 15 are provided along the wafer transfer path 162. In the cleaning processing section 14, one cleaning device 2 is arranged on each side of the wafer transfer path 162, and a total of two cleaning devices 2 are provided. On the other hand, in the supercritical processing section 15, three supercritical processing devices 3 that function as substrate processing devices for performing a drying process of removing IPA from the wafer W are arranged on each side of the wafer transfer path 162, and a total of six supercritical processing devices 3 are provided. A second transfer mechanism 161 is arranged in the wafer transfer path 162, and the second transfer mechanism 161 is configured to be movable within the wafer transfer path 162. The wafer W placed on the transfer rack 131 is picked up by the second transfer mechanism 161, and the second transfer mechanism 161 feeds the wafer W into the cleaning device 2 and the supercritical processing device 3. In addition, the number and arrangement of the cleaning device 2 and the supercritical processing device 3 are not particularly limited, and an appropriate number of cleaning devices 2 and supercritical processing devices 3 are arranged in an appropriate manner according to the number of wafers W processed per unit time and the processing time of each cleaning device 2 and each supercritical processing device 3, etc.

[0032] The cleaning device 2 is configured as, for example, a single-piece device that cleans the wafer W one by one by rotary cleaning. In this case, while keeping the wafer W in a horizontal state and rotating the wafer W around the vertical axis, a cleaning chemical solution and a rinsing solution for washing away the chemical solution can be supplied to the processing surface of the wafer W at an appropriate time, thereby performing the cleaning process of the wafer W. The chemical solution and the rinsing solution used in the cleaning device 2 are not particularly limited. For example, an SC1 solution (i.e., a mixed solution of ammonia water and hydrogen peroxide) as an alkaline chemical solution can be supplied to the wafer W to remove fine particles and organic contaminants from the wafer W. Then, deionized water (DIW) as a rinsing solution is supplied to the wafer W, and the SC1 solution can be washed away from the wafer W. Then, a diluted hydrofluoric acid aqueous solution (DHF) as an acidic chemical solution can be supplied to the wafer W to remove the natural oxide film, and then DIW is also supplied to the wafer W to wash away the diluted hydrofluoric acid aqueous solution from the wafer W.

[0033] Moreover, after the cleaning process using the chemical solution is completed, the cleaning device 2 stops the rotation of the wafer W and supplies IPA as a liquid for preventing drying to replace the DIW remaining on the processing surface of the wafer W. At this time, a sufficient amount of IPA is supplied to the wafer W, and the surface of the wafer W on which the semiconductor pattern is formed becomes a state filled with IPA, and a liquid film of IPA is formed on the surface of the wafer W. The wafer W maintains the state filled with IPA and is sent out from the cleaning device 2 by the second transfer mechanism 161.

[0034] In this way, the IPA applied to the surface of the wafer W serves to prevent the wafer W from drying. In particular, in order to prevent so-called pattern collapse from occurring on the wafer W due to the evaporation of IPA during the transfer of the wafer W from the cleaning apparatus 2 to the supercritical treatment apparatus 3, the cleaning apparatus 2 applies a sufficient amount of IPA to the wafer W so that an IPA film having a relatively thick thickness is formed on the surface of the wafer W.

[0035] The wafer W sent out from the cleaning apparatus 2 is sent into the processing container of the supercritical treatment apparatus 3 in a state filled with IPA by the second transfer mechanism 161, and the drying treatment of IPA is performed in the supercritical treatment apparatus 3.

[0036] [Supercritical treatment apparatus]

[0037] Next, the details of the drying treatment using a supercritical fluid performed in the supercritical treatment apparatus (substrate treatment apparatus) 3 will be described. First, a structural example of the processing container into which the wafer W is sent in the supercritical treatment apparatus 3 will be described.

[0038] Figure 2 is an external perspective view showing an example of the processing container 301 of the supercritical treatment apparatus 3, Figure 3 is a cross-sectional view showing an example of the processing container 301.

[0039] The processing container 301 houses the wafer W and processes the wafer W using a high-pressure processing fluid such as a supercritical fluid. The processing container 301 includes: a container main body 311, which is in a frame shape and is used to house the wafer W; a transfer port 312, which is used to transfer the wafer W into and out of the container main body 311; a holding plate 316, which horizontally holds the wafer W to be processed; and a first lid member 315, which supports the holding plate 316 and seals the transfer port 312 when the wafer W is sent into the container main body 311. In addition, a maintenance opening 321 is provided at a position different from the transfer port 312 in the container main body 311. Except during maintenance, etc., the maintenance opening 321 is blocked by a second lid member 322.

[0040] The container main body 311 houses the wafer W and performs processing on the wafer W using a processing fluid. The container main body 311 is a container in which a processing space 319 capable of housing a wafer W having a diameter of, for example, 300 mm is formed inside. The above-described transfer port 312 and the maintenance opening 321 (for example, an opening having the same size and shape as the transfer port 312) are respectively formed at both ends of the processing space 319 and are both in communication with the processing space 319.

[0041] In addition, a discharge port 314 is provided in the wall portion on the conveyance port 312 side in the container body 311. The discharge port 314 is connected to a discharge-side supply pipe line 65 (see Figure 6 ) for allowing a processing fluid to flow, which is provided on the downstream side of the processing container 301. In addition, although two discharge ports 314 are illustrated in Figure 2 , the number of the discharge ports 314 is not particularly limited.

[0042] Insertion holes 325 and 323 into which a first locking plate 327 described later is inserted are respectively formed in a first upper module 312a and a first lower module 312b that are respectively located above and below the conveyance port 312. The respective insertion holes 325 and 323 penetrate the first upper module 312a and the first lower module 312b in the vertical direction (the direction perpendicular to the surface of the wafer W).

[0043] The holding plate 316 is a thin plate-like member configured to be horizontally disposed in the processing space 319 of the container body 311 while holding the wafer W, and is connected to the first lid member 315. In addition, a discharge port 316a is provided on the first lid member 315 side of the holding plate 316.

[0044] A first lid member storage space 324 is formed in a region near the front side (negative Y direction) in the container body 311. When the holding plate 316 is inserted into the processing container 301 to perform supercritical processing on the wafer W, the first lid member 315 is stored in the first lid member storage space 324. In this case, the first lid member 315 closes the conveyance port 312 to seal the processing space 319.

[0045] The first locking plate 327 is provided near the front side of the processing container 301. The first locking plate 327 serves as a restricting member that restricts the movement of the first lid member 315 due to the pressure inside the container body 311 when the holding plate 316 is moved to the processing position. The first locking plate 327 is inserted into the insertion hole 323 of the first lower module 312b and the insertion hole 325 of the first upper module 312a. At this time, since the first locking plate 327 serves as a latch, the first lid member 315 and the holding plate 316 are restricted in their front-rear direction ( Figure 2 and Figure 3movement in the Y direction). Further, the first locking plate 327 moves in the vertical direction between a locking position where it is inserted into the insertion holes 323 and 325 and presses the first cover member 315 and an open position where it retracts downward from the locking position to open the first cover member 315 by means of a lifting mechanism 326. In this example, a restricting mechanism for restricting the movement of the first cover member 315 due to the pressure inside the container body 311 is constituted by the first locking plate 327, the insertion holes 323 and 325, and the lifting mechanism 326. In addition, allowances for inserting and removing the first locking plate 327 are provided in the insertion holes 323 and 325 respectively, so a minute gap C1 (refer to Figure 3 ) is formed between the insertion holes 323 and 325 and the first locking plate 327 in the locking position. Further, for the convenience of illustration, the gap C1 is exaggeratedly drawn in Figure 3 .

[0046] The maintenance opening 321 is provided in the wall surface of the container body 311 and is at a position opposite to the transfer port 312. Thus, the maintenance opening 321 and the transfer port 312 are opposite to each other, so that when the container body 311 is sealed by the first cover member 315 and the second cover member 322, the pressure in the processing space 319 is applied to the inner surface of the container body 311 substantially evenly. Therefore, stress concentration on a specific part of the container body 311 is prevented. However, the maintenance opening 321 may also be provided at a position other than the position opposite to the transfer port 312, for example, on the side wall surface with respect to the advancing direction (Y direction) of the wafer W.

[0047] The second upper module 321a and the second lower module 321b are respectively located above and below the maintenance opening 321. Insertion holes 335 and 333 for inserting the second locking plate 337 are respectively formed in the second upper module 321a and the second lower module 321b. Each of the insertion holes 335 and 333 penetrates the second upper module 321a and the second lower module 321b in the vertical direction (the direction perpendicular to the surface of the wafer W, the Z direction).

[0048] A second cover member storage space 334 is formed in the inner (positive Y direction) region of the container body 311. Except during maintenance, etc., the second cover member 322 is stored in the second cover member storage space 334 and closes the maintenance opening 321. In addition, a supply port 313 is provided in the second cover member 322. The supply port 313 is connected to a first supply pipeline 63 (refer to Figure 6 ) provided on the upstream side of the processing container 301 and through which the processing fluid flows. Further, two supply ports 313 are illustrated in Figure 2 , but the number of the supply ports 313 is not particularly limited.

[0049] The second locking plate 337 functions as a restricting member that restricts the movement of the second lid member 322 due to the pressure inside the container body 311. The second locking plate 337 is inserted into the insertion holes 333 and 335 around the maintenance opening 321. At this time, since the second locking plate 337 functions as a latch, it restricts the movement of the second lid member 322 in its front-rear direction (Y direction). Further, the second locking plate 337 is configured to move between a locking position where it is inserted into the insertion holes 333 and 335 and presses the second lid member 322 and an open position where it retracts downward from the locking position to open the second lid member 322 in the vertical direction. In the present embodiment, the second locking plate 337 is formed to be manually moved, but a lifting mechanism substantially the same as the lifting mechanism 326 may be provided to move it automatically. Further, a margin for inserting and removing the second locking plate 337 is provided in the insertion holes 333 and 335, and thus a minute gap C2 (see Figure 3 ) is formed between the insertion holes 333 and 335 and the second locking plate 337 in the locking position. Further, for convenience of illustration, the gap C2 is exaggerated in Figure 3 .

[0050] In the present embodiment, the second lid member 322 is connected to the first supply pipeline 63, and a plurality of openings 332 are provided in the second lid member 322. The second lid member 322 functions as a fluid supply manifold that supplies the processing fluid from the first supply pipeline 63 to the inside of the container body 311. Thereby, when the second lid member 322 is removed during maintenance, maintenance operations such as cleaning of the openings 332 can be easily performed. Further, a fluid discharge manifold 318 communicating with the discharge port 314 is provided in the wall portion on the side of the transfer port 312 in the container body 311. A plurality of openings are also provided in the fluid discharge manifold 318.

[0051] The second lid member 322 and the fluid discharge manifold 318 are arranged to face each other. The second lid member 322 that functions as a fluid supply unit substantially supplies the processing fluid into the container body 311 in a horizontal direction. Here, the horizontal direction refers to the direction perpendicular to the vertical direction in which gravity acts, and is usually the direction parallel to the direction in which the flat surface of the wafer W held on the holding plate 316 extends. The fluid discharge manifold 318 that functions as a fluid discharge unit for discharging the fluid in the container body 311 guides and discharges the fluid in the container body 311 to the outside of the container body 311 through the discharge port 316a provided in the holding plate 316. Among the fluids discharged to the outside of the container body 311 through the fluid discharge manifold 318, in addition to the processing fluid supplied into the container body 311 through the second lid member 322, it also contains IPA dissolved from the surface of the wafer W into the processing fluid. In this way, the processing fluid is supplied into the container body 311 from the opening 332 of the second lid member 322, and in addition, the fluid is discharged from the container body 311 through the opening of the fluid discharge manifold 318, thereby forming a laminar flow of the processing fluid that flows substantially parallel to the surface of the wafer W in the container body 311.

[0052] In addition, the side surface on the transfer port 312 side and the side surface on the maintenance opening 321 side in the container body 311 are respectively connected to the vacuum suction pipes 348 and 349. The vacuum suction pipes 348 and 349 are respectively in communication with the surface on the first lid member accommodation space 324 side and the surface on the second lid member accommodation space 334 side in the container body 311. The vacuum suction pipes 348 and 349 function to suck the first lid member 315 and the second lid member 322 toward the container body 311 side respectively using the vacuum suction force.

[0053] In addition, a bottom surface side fluid supply unit 341 for supplying the processing fluid into the container body 311 is formed on the bottom surface of the container body 311. The bottom surface side fluid supply unit 341 is connected to the second supply pipeline 64 (refer to Figure 6 ) that supplies high-pressure fluid into the container body 311. The bottom surface side fluid supply unit 341 substantially supplies the processing fluid into the container body 311 from below upward. The processing fluid supplied from the bottom surface side fluid supply unit 341 returns from the back surface of the wafer W to the surface of the wafer W via the discharge port 316a provided in the holding plate 316, and is discharged from the fluid discharge manifold 318 together with the processing fluid from the second lid member 322 via the discharge port 316a provided in the holding plate 316. Preferably, the position of the bottom surface side fluid supply unit 341 is, for example, provided below the wafer W introduced into the container body 311, and more preferably, below the central portion of the wafer W. Thereby, the processing fluid from the bottom surface side fluid supply unit 341 can be evenly returned to the surface of the wafer W.

[0054] AsFigure 3 As shown in Figure 3 , heaters 345 composed of resistance heating elements such as strip heaters are provided on the upper and lower surfaces of the container body 311. The heaters 345 are connected to the power supply unit 346, and the output of the power supply unit 346 can be increased or decreased to maintain the temperature of the container body 311 and the processing space 319 within a range of, for example, 100°C to 300°C.

[0055] [Structure around the maintenance opening]

[0056] Next, with reference to Figure 4 and Figure 5 , the structure around the maintenance opening 321 will be further described. Figure 4 and Figure 5 are cross-sectional views showing the periphery of the maintenance opening 321.

[0057] As shown in Figure 4 and Figure 5 , a recess 328 is formed in the side wall of the second lid member 322 on the side of the processing space 319 so as to surround a position corresponding to the peripheral edge of the maintenance opening 321. A sealing member 329 is embedded in the recess 328, so that the sealing member 329 is disposed on the side wall surface of the second lid member 322 that abuts against the peripheral side wall surface of the maintenance opening 321.

[0058] The sealing member 329 is formed in a ring shape so as to be able to surround the maintenance opening 321. In addition, the cross-sectional shape of the sealing member 329 is U-shaped. For the Figure 4 and Figure 5 shown sealing member 329, the U-shaped notch 329a is formed along the inner circumferential surface of the ring-shaped sealing member 329. In other words, an internal space (notch 329a) surrounded by a U-shape is formed in the sealing member 329.

[0059] The second lid member 322 provided with the sealing member 329 is used to block the periphery of the maintenance opening 321, so that the sealing member 329 is disposed between the opposing surfaces of the second lid member 322 and the container body 311 in a manner that blocks the gap between the second lid member 322 and the processing space 319. Moreover, since this gap is formed around the maintenance opening 321 in the container body 311, the notch 329a formed along the inner circumferential surface of the sealing member 329 is in a state of being in communication with the processing space 319.

[0060] The sealing member 329 that connects the notch 329a to the processing space 319 is exposed to the atmosphere of the processing fluid. However, sometimes the processing fluid dissolves components such as resin and rubber and impurities contained therein. Therefore, the sealing member 329 is made of a resin that is corrosion-resistant to liquid IPA and the processing fluid at least on the inner side of the notch 329a that opens at least toward the processing space 319. Examples of such resins include polyimide, polyethylene, polypropylene, p-xylene, and polyether ether ketone (PEEK). Preferably, a non-fluorine-based resin that has less impact on the semiconductor device even if a small amount of components dissolve in the processing fluid is used.

[0061] Here, the function of the processing container 301 including the sealing member 329 when processing the wafer W with a high-pressure processing fluid in the processing container 301 will be described.

[0062] First, when no high-pressure processing fluid is supplied to the processing space 319 and the pressure in the container main body 311 does not rise, the second lid member 322 is attracted toward the container main body 311 by the suction force from the vacuum suction pipe 349 (refer to Figure 2 and Figure 3 ). At this time, as Figure 4 shown, the second lid member 322 and the side wall surfaces of the container main body 311 are directly opposed to each other and crush the sealing member 329, thereby hermetically blocking the periphery of the maintenance opening 321. The sealing member 329 crushed by the second lid member 322 and the container main body 311 deforms in the direction of narrowing the notch 329a. For the case where the notch 329a is not completely closed, at this time point, the atmosphere in the processing space 319 flows into the notch 329a through the gap between the second lid member 322 and the container main body 311.

[0063] On the other hand, when a high-pressure processing fluid is supplied into the processing space 319 from the opening 332, the second lid member 322 moves in a direction away from the maintenance opening 321. That is, the second lid member 322 moves by an amount corresponding to the gap C2 (refer to Figure 3 ) between the insertion holes 335, 333 and the second locking plate 337 around the maintenance opening 321 due to the pressure received from the processing fluid. When the gap between the second lid member 322 and the container main body 311 widens due to the movement of the second lid member 322, the notch 329a is widened by the restoring force of the elastic sealing member 329. As Figure 5 shown, the atmosphere (processing fluid) in the processing space 319 further enters the notch 329a (inner space).

[0064] If the processing fluid enters the notch 329a, the sealing member 329 is widened from the inner side of the notch 329a, and the outer peripheral surface of the sealing member 329 (the surface on the side opposite to the notch 329a) acts on the surface of the concave portion 328 of the second lid member 322 and the side wall surface of the container body 311 with a pressing force. Thereby, the outer peripheral surface of the sealing member 329 is in close contact with the second lid member 322 and the container body 311, so as to airtightly block the gap between the second lid member 322 and the container body 311. Such a sealing member 329 has elasticity that can be deformed by the force received from the processing fluid, and can maintain a state of airtightly blocking the gap against the pressure difference (for example, about 16 to 20 MPa) between the processing space 319 and the outside.

[0065] In addition, in the present embodiment, for the delivery port 312 of the container body 311, similar to the delivery port 312, it is sealed by the first lid member 315.

[0066] That is, as Figure 3 shown, a concave portion 338 is formed on the side wall of the first lid member 315 on the processing space 319 side so as to surround the position corresponding to the peripheral edge of the delivery port 312. A sealing member 339 is embedded in the concave portion 338, so that the sealing member 339 is disposed on the side wall surface of the first lid member 315 that abuts against the side wall surface around the delivery port 312.

[0067] The sealing member 339 is formed in a ring shape so as to be able to surround the delivery port 312. In addition, the cross-sectional shape of the sealing member 339 is U-shaped. In this way, the delivery port 312 is blocked by using the first lid member 315 provided with the sealing member 339, so that the sealing member 339 is disposed between the opposing surfaces of the first lid member 315 and the container body 311 in a manner of blocking the gap between the first lid member 315 and the delivery port 312. In addition, the structure of using the first lid member 315 and the sealing member 339 to block the delivery port 312 is substantially the same as the above-described structure for blocking the maintenance opening 321.

[0068] [Structure of the entire system of the supercritical processing apparatus]

[0069] Figure 6 It is a diagram showing a structural example of the entire system of the supercritical processing apparatus 3 according to the first embodiment.

[0070] A fluid supply tank 51 is provided at a position upstream of the treatment container 301, and a treatment fluid is supplied from the fluid supply tank 51 to a supply pipeline through which the treatment liquid flows in the supercritical treatment device 3. Between the fluid supply tank 51 and the treatment container 301, a flow control valve 52a, a throttle member 55a, a filter 57, and a flow control valve 52b are provided in sequence from the upstream side to the downstream side. In addition, the terms "upstream side" and "downstream side" mentioned here are based on the flow direction of the treatment fluid in the supply pipeline.

[0071] The flow control valve 52a is a valve that adjusts the opening and closing of the supply of the treatment fluid from the fluid supply tank 51. In the open state, it allows the treatment fluid to flow to the downstream supply pipeline, and in the closed state, it does not allow the treatment fluid to flow to the downstream supply pipeline. When the flow control valve 52a is in the open state, a high-pressure treatment fluid of about 16 to 20 MPa (megapascals) is supplied from the fluid supply tank 51 to the supply pipeline through the flow control valve 52a. The throttle member 55a functions to adjust the pressure of the treatment fluid supplied from the fluid supply tank 51, and can allow the treatment fluid with the pressure adjusted to about 16 MPa to flow to the supply pipeline downstream of the throttle member 55a. The filter 57 removes foreign substances contained in the treatment fluid sent from the throttle member 55a, and allows the clean treatment fluid to flow downstream.

[0072] The flow control valve 52b is a valve that adjusts the opening and closing of the supply of the treatment fluid to the treatment container 301. The first supply pipeline 63 extending from the flow control valve 52b to the treatment container 301 is connected to the supply port 313 shown above Figure 2 and Figure 3 The treatment fluid from the flow control valve 52b is supplied into the container main body 311 of the treatment container 301 through the supply port 313 and the second lid member 322 shown above Figure 2 and Figure 3 shown.

[0073] In addition, for the supercritical treatment device 3 shown above Figure 6 the supply pipeline branches between the filter 57 and the flow control valve 52b. That is, the supply pipeline between the filter 57 and the flow control valve 52b branches into the following pipelines and extends: a supply pipeline (the second supply pipeline 64) connected to the treatment container 301 through the flow control valve 52c and the throttle member 55b, a supply pipeline connected to the purge device 62 through the flow control valve 52d and the check valve 58a, and a supply pipeline connected to the outside through the flow control valve 52e and the throttle member 55c.

[0074] The second supply pipeline 64 connected to the treatment container 301 through the flow control valve 52c and the throttle member 55b is the same as the above Figure 2 andFigure 3 is connected to the bottom-side fluid supply section 341 shown, and the processing fluid from the flow-through on-off valve 52c passes through Figure 2 and Figure 3 the bottom-side fluid supply section 341 shown and is supplied into the container main body 311 of the processing container 301. The second supply pipeline 64 can also be used as an auxiliary flow path for supplying the processing fluid to the processing container 301. For example, when supplying a relatively large amount of processing fluid to the processing container 301, such as at the initial stage of starting to supply the processing fluid to the processing container 301, the flow-through on-off valve 52c can be adjusted to the open state, and the processing fluid whose pressure has been adjusted by the throttle member 55b is supplied to the processing container 301.

[0075] The supply pipeline connected to the purge device 62 via the flow-through on-off valve 52d and the one-way valve 58a is a flow path for supplying an inert gas such as nitrogen to the processing container 301 and is used during the period when the supply of the processing fluid from the fluid supply tank 51 to the processing container 301 is stopped. For example, when filling the processing container 301 with an inert gas to keep it in a clean state, the flow-through on-off valve 52d and the flow-through on-off valve 52b are adjusted to the open state, and the inert gas sent from the purge device 62 to the supply pipeline is supplied to the processing container 301 via the one-way valve 58a, the flow-through on-off valve 52d, and the flow-through on-off valve 52b.

[0076] The supply pipeline connected to the outside via the flow-through on-off valve 52e and the throttle member 55c is a flow path for discharging the processing fluid from the supply pipeline. For example, when turning off the power of the supercritical processing device 3 and discharging the processing fluid remaining in the supply pipeline between the flow-through on-off valve 52a and the flow-through on-off valve 52b to the outside, the flow-through on-off valve 52e is adjusted to the open state, and the supply pipeline between the flow-through on-off valve 52a and the flow-through on-off valve 52b is communicated with the outside.

[0077] At a position downstream of the processing container 301, a flow-through on-off valve 52f, an exhaust adjustment valve 59, a concentration measurement sensor 60, and a flow-through on-off valve 52g are provided in order from the upstream side to the downstream side.

[0078] The flow-through on-off valve 52f is a valve that adjusts the opening and closing of discharging the processing fluid from the processing container 301. When discharging the processing fluid from the processing container 301, the flow-through on-off valve 52f is adjusted to the open state, and when not discharging the processing fluid from the processing container 301, the flow-through on-off valve 52f is adjusted to the closed state. In addition, the supply pipeline (discharge-side supply pipeline 65) extending between the processing container 301 and the flow-through on-off valve 52f is connected to Figure 2 and Figure 3 the discharge port 314 shown. The fluid in the container main body 311 of the processing container 301 passes through Figure 2 andFigure 3 It is conveyed toward the flow control valve 52f with respect to the fluid discharge header 318 and the discharge port 314 shown. The flow control valve 52f is an example of a first control valve.

[0079] The exhaust control valve 59 is a valve that controls the discharge amount of the fluid from the processing vessel 301, and can be configured by, for example, a back pressure valve. The opening degree of the exhaust control valve 59 is appropriately adjusted under the control of the control unit 4 according to the desired discharge amount of the fluid from the processing vessel 301. In the present embodiment, the process of discharging the fluid from the processing vessel 301 is performed until, for example, the pressure of the fluid in the processing vessel 301 becomes a preset pressure. Therefore, the exhaust control valve 59 can adjust the opening degree so as to change from the open state to the closed state when the pressure of the fluid in the processing vessel 301 reaches the preset pressure, and stop discharging the fluid from the processing vessel 301. The exhaust control valve 59 is an example of a back pressure valve.

[0080] The concentration measurement sensor 60 is a sensor that measures the IPA concentration contained in the fluid sent from the exhaust control valve 59.

[0081] The flow control valve 52g is a valve that controls the opening and closing of the fluid discharged from the processing vessel 301 to the outside. When the fluid is discharged to the outside, the flow control valve 52g is adjusted to the open state, and when the fluid is not discharged, the flow control valve 52g is adjusted to the closed state. In addition, an exhaust control needle valve 61a and a check valve 58b are provided on the downstream side of the flow control valve 52g. The exhaust control needle valve 61a is a valve that controls the discharge amount of the fluid sent via the flow control valve 52g to the outside, and the opening degree of the exhaust control needle valve 61a is adjusted according to the desired discharge amount of the fluid. The check valve 58b is a valve that prevents the reverse flow of the discharged fluid, and functions to reliably discharge the fluid to the outside.

[0082] In addition, with respect to Figure 6 the supercritical processing apparatus 3 shown, the supply line branches between the concentration measurement sensor 60 and the flow control valve 52g. That is, the supply line between the concentration measurement sensor 60 and the flow control valve 52g branches into the following lines and extends: a supply line connected to the outside via the flow control valve 52h, a supply line connected to the outside via the flow control valve 52i, and a supply line connected to the outside via the flow control valve 52j.

[0083] The flow control valves 52h and 52i are also valves that regulate the opening and closing of the fluid discharge to the outside, similar to the flow control valve 52g. An exhaust adjustment needle valve 61b and a check valve 58c are provided on the downstream side of the flow control valve 52h to adjust the discharge amount of the fluid and prevent the backflow of the fluid. A check valve 58d is provided on the downstream side of the flow control valve 52i to prevent the backflow of the fluid. The flow control valve 52j is also a valve that regulates the opening and closing of the fluid discharge to the outside. A throttle member 55d is provided on the downstream side of the flow control valve 52j, enabling the fluid to be discharged to the outside from the flow control valve 52j via the throttle member 55d. Among them, in Figure 6 the example shown, the destinations of the fluids conveyed to the outside via the flow control valves 52g, 52h, and 52i are different from the destinations of the fluids conveyed to the outside via the flow control valve 52j. Therefore, the fluid can be conveyed to a recovery device (not shown) via, for example, the flow control valves 52g, 52h, and 52i. On the other hand, the fluid can also be discharged to the atmosphere via the flow control valve 52j.

[0084] The supply pipelines on the downstream sides of the flow control valves 52g, 52h, and 52i branch into two, namely the first exhaust pipeline 66 and the second exhaust pipeline 67. The first exhaust pipeline 66 is connected to the exhaust pipeline of a factory or the like. A first exhaust source is provided in the exhaust pipeline of a factory or the like. The second exhaust pipeline 67 is connected to the exhaust pipeline of a factory or the like via an ejector 71a. The ejector 71a receives the flow of a fluid such as air from a fluid supply source 72a, reduces the pressure inside the second exhaust pipeline 67, and performs forced exhaust. A flow control valve 52k is provided between the ejector 71a and the fluid supply source 72a. The flow control valve 52k is a valve that regulates the opening and closing of the fluid supply from the fluid supply source 72a to the ejector 71a. In the state where the flow control valve 52k is closed, the fluid does not flow through the ejector 71a, so the ejector 71a does not perform forced exhaust on the second exhaust pipeline 67. In the state where the flow control valve 52k is open, the fluid flows through the ejector 71a, and the ejector 71a performs forced exhaust on the second exhaust pipeline 67. Therefore, if the flow control valve 52k is adjusted to the open state while the discharge side supply pipeline 65 between the second exhaust pipeline 67 and the processing container 301 is open, the inside of the discharge side supply pipeline 65 is forced to exhaust. A first exhaust source is provided in the exhaust pipeline of a factory or the like. The ejector 71a is included in the second exhaust source. The flow control valve 52k is an example of the second on-off valve. The exhaust pressure generated by the ejector 71a during operation is higher than the exhaust pressure of the exhaust pipeline of a factory or the like. The exhaust pressure of the exhaust pipeline of a factory or the like is an example of the first exhaust pressure, and the exhaust pressure generated by the ejector 71a is an example of the second exhaust pressure. The second exhaust source may have a vacuum pump instead of the ejector 71a.

[0085] When discharging fluid from the self-processing container 301, one or more of the flow control valves 52g, 52h, 52i, and 52j are adjusted to the open state. In particular, when the power supply of the supercritical processing device 3 is turned off, the flow control valve 52j can be adjusted to the open state, so that the fluid remaining in the supply pipeline between the concentration measurement sensor 60 and the flow control valve 52g is discharged to the outside.

[0086] In addition, a pressure sensor for detecting the pressure of the fluid and a temperature sensor for detecting the temperature of the fluid are provided in the above-mentioned supply pipeline. Figure 6 In the example shown, a pressure sensor 53 is provided between the processing container 301 and the flow control valve 52f, and a temperature sensor 54 for detecting the temperature of the fluid inside the processing container 301, that is, inside the container main body 311, is provided. The pressure sensor and the temperature sensor can also be provided at various parts of the supply pipeline as needed.

[0087] In addition, for the supercritical processing device 3, a heater H is provided at any part where the processing fluid flows. Figure 6 In, heaters H are shown in the supply pipeline on the upstream side of the processing container 301 (that is, between the flow control valve 52a and the throttle member 55a, between the throttle member 55a and the filter 57, between the filter 57 and the flow control valve 52b, and between the flow control valve 52b and the processing container 301), but heaters H can also be provided at other parts including the processing container 301 and the supply pipeline on the downstream side of the processing container 301. Therefore, heaters H can also be provided in the entire flow path from the supply of the processing fluid from the fluid supply tank 51 to the discharge to the outside. In addition, in particular, from the viewpoint of adjusting the temperature of the processing fluid supplied to the processing container 301, it is preferable to provide the heater H at a position where the temperature of the processing fluid flowing on the upstream side of the processing container 301 can be adjusted.

[0088] Figure 7 It is a block diagram showing the functional structure of the control unit 4. The control unit 4 receives measurement signals from various elements shown Figure 6 and sends control instruction signals to various elements shown Figure 6 . For example, the control unit 4 receives the measurement results of the pressure sensor 53, the temperature sensor 54, and the concentration measurement sensor 60. In addition, the control unit 4 sends control instruction signals to the flow control valves 52a - 52k, the exhaust adjustment valve 59, and the exhaust adjustment needle valves 61a - 61b. In addition, the signals that the control unit 4 can receive and send are not particularly limited.

[0089] [Supercritical drying process]

[0090] Next, the drying mechanism of IPA using a processing fluid in a supercritical state will be described.

[0091] Figure 8 It is a diagram for explaining the drying mechanism of IPA, and is an enlarged cross-sectional view schematically showing a pattern P which is a concave portion of a wafer W.

[0092] For the supercritical processing apparatus 3, at the initial stage when a processing fluid R in a supercritical state is introduced into the container main body 311 of the processing container 301, as Figure 8 shown in (a) of, only IPA is filled between the patterns P.

[0093] The IPA between the patterns P comes into contact with the processing fluid R in a supercritical state and thus gradually dissolves in the processing fluid R. As Figure 8 shown in (b) of, it is gradually replaced by the processing fluid R. At this time, between the patterns P, in addition to IPA and the processing fluid R, there is also a mixed fluid M in a state where IPA and the processing fluid R are mixed.

[0094] Then, as the replacement from IPA to the processing fluid R proceeds between the patterns P, IPA is removed from between the patterns P. Finally, as Figure 8 shown in (c) of, only the processing fluid R in a supercritical state fills between the patterns P.

[0095] After removing IPA from between the patterns P, the pressure inside the container main body 311 is reduced to atmospheric pressure. Thus, as Figure 8 shown in (d) of, the processing fluid R changes from a supercritical state to a gas state, and only gas occupies between the patterns P. In this way, IPA between the patterns P is removed, and the drying process of the wafer W is completed.

[0096] Based on the mechanism shown in (a) to Figure 8 (d) of the above Figure 8 the supercritical processing apparatus 3 of the present embodiment performs the drying process of IPA as follows.

[0097] That is, the substrate processing method using the supercritical processing apparatus 3 includes: a step of feeding a wafer W filled with IPA for preventing drying in the pattern P into the container main body 311 of the processing container 301; a step of supplying a processing fluid in a supercritical state to the container main body 311 via a fluid supply unit (that is, a fluid supply tank 51, a flow control on-off valve 52a, a flow control on-off valve 52b, and a second lid member 322); and a step of performing a drying process of removing IPA from the wafer W using the processing fluid in a supercritical state inside the container main body 311.

[0098] That is, first, the wafer W that has undergone the cleaning process in the cleaning device 2 is transported to the supercritical processing device 3. In this cleaning device 2, for example, the removal of fine particles and organic contaminants using SC1 liquid, which is an alkaline chemical solution, the rinse cleaning using deionized water (DIW) as a rinse liquid, the removal of the native oxide film using a dilute hydrofluoric acid aqueous solution (DHF) as an acidic chemical solution, the rinse cleaning using DIW are sequentially performed, and finally, IPA fills the wafer surface. Then, the wafer W is sent out from the cleaning device 2 while maintaining this state and is transported to the processing container 301 of the supercritical processing device 3.

[0099] This transportation to the processing container 301 is performed, for example, using the second transfer mechanism 161 (refer to Figure 1 ). When transporting the wafer to the processing container 301, after the second transfer mechanism 161 transfers the wafer W to the holding plate 316 waiting at the transfer position, it retreats from the upper position of the holding plate 316.

[0100] Next, the holding plate 316 is slid in the horizontal direction to move the holding plate 316 to the processing position inside the container body 311. At this time, the first lid member 315 is housed in the first lid member housing space 324 and covers the transfer port 312. Next, using the suction force from the vacuum suction pipe 348 (refer to Figure 2 and Figure 3 ), the first lid member 315 is attracted to the container body 311, and the transfer port 312 is blocked by the first lid member 315. Next, the first locking plate 327 is raised to the locking position by the lifting mechanism 326, and the front surfaces of the first locking plate 327 and the first lid member 315 are brought into contact to restrict the movement of the first lid member 315. Details will be described later. There is a case where foreign matter is sucked from the discharge side supply pipeline 65 into the processing space 319 due to the suction force of the vacuum suction pipe 348.

[0101] Next, before the IPA filled on the surface of the wafer W dries, the flow control valves 52b and 52c are opened, and high-pressure processing fluid is supplied to the processing space 319 via the first supply pipeline 63 and the second supply pipeline 64. As a result, the pressure in the processing space 319 is increased to, for example, about 14 MPa to 16 MPa. As the processing space 319 is pressurized, the sealing member 339 having a U-shaped cross section in the recess 338 provided in the first lid member 315 is widened, and the gap between the first lid member 315 and the container body 311 is hermetically blocked.

[0102] On the other hand, within the processing space 319, when the processing fluid supplied into the processing space 319 comes into contact with the IPA filled in the wafer W, the filled IPA gradually dissolves in the processing fluid and is gradually replaced by the processing fluid. Then, as the replacement from IPA to the processing fluid proceeds between the patterns on the wafer W, the IPA is removed from between the patterns, and finally only the processing fluid in the supercritical state fills between the patterns P. As a result, the surface of the wafer W is replaced from the liquid IPA to the processing fluid, and no interface is formed between the liquid IPA and the processing fluid in the equilibrium state. Therefore, the fluid on the surface of the wafer W can be replaced with the processing fluid without causing pattern collapse.

[0103] After that, when a preset time has elapsed after supplying the processing fluid into the processing space 319 and the surface of the wafer W has been replaced with the processing fluid, the flow control valve 52f is opened to discharge the atmosphere in the processing space 319 from the fluid discharge header 318 toward the outside of the container body 311. As a result, the pressure inside the container body 311 gradually decreases, and the processing fluid in the processing space 319 changes from the supercritical state to the gaseous state. At this time, since no interface is formed between the supercritical state and the gas, the wafer W can be dried without the surface tension acting on the patterns formed on the surface of the wafer W.

[0104] According to the above process, after the supercritical processing of the wafer W is completed, in order to discharge the gas and the processing fluid remaining in the processing space 319, an inert gas such as nitrogen is supplied from the supply line connected to the purge device 62 toward the fluid discharge header 318 for purging. Moreover, when the supply of the inert gas corresponding to the preset time is performed to complete the purging and the pressure inside the container body 311 is restored to the atmospheric pressure, the first locking plate 327 is lowered to the open position. Then, the holding plate 316 is moved horizontally to the transfer position, and the wafer W that has completed the supercritical processing is sent out using the second transfer mechanism 161.

[0105] However, during the above-described supercritical processing, the second locking plate 337 is always raised to the locked position. As a result, the second locking plate 337 abuts against the rear surface of the second lid member 322, restricting the movement of the second lid member 322. Moreover, when the high-pressure processing fluid is not supplied into the processing space 319 and the pressure inside the container body 311 does not increase, the second lid member 322 and the side wall surface of the container body 311 directly face each other to crush the sealing member 329, thereby hermetically blocking the periphery of the maintenance opening 321.

[0106] On the other hand, when a high-pressure processing fluid is supplied to the processing space 319, the second lid member 322 moves in the direction away from the processing space 319 (the positive Y direction) by an amount corresponding to the gap C2 between the insertion holes 335, 333 around the maintenance opening 321 and the second locking plate 337. By moving the second lid member 322, the gap between the second lid member 322 and the container body 311 is widened. In this case, the notch 329a is widened due to the restoring force of the elastic sealing member 329. Therefore, the outer peripheral surface of the sealing member 329 is in close contact with the second lid member 322 and the container body 311, thereby airtightly blocking the gap between the second lid member 322 and the container body 311. Thus, during the above-described supercritical processing, the second lid member 322 maintains the state of blocking the maintenance opening 321.

[0107] [Foreign matter removal processing]

[0108] Next, the foreign matter removal processing using the ejector 71a will be described.

[0109] As described above, by the suction force from the vacuum suction pipe 348 (refer to Figure 2 and Figure 3 ), the first lid member 315 is attracted to the container body 311, and the first lid member 315 blocks the transfer port 312. In addition, although fine particles may be generated due to friction between the first locking plate 327 and the first upper module 312a and the first lower module 312b during lifting, such fine particles can be removed by the suction force from the vacuum suction pipe 348. However, sometimes foreign matters such as residues generated during the supercritical processing remain in the discharge-side supply pipe line 65, and when the processing space 319 is made into a negative pressure via the vacuum suction pipe 348, there is a case where the foreign matters remaining in the discharge-side supply pipe line 65 are sucked into the processing space 319. If the next supercritical processing of the wafer W is performed with the foreign matters sucked into the processing space 319, the sucked foreign matters will adhere to the wafer W.

[0110] Therefore, in the present embodiment, the ejector 71a is used to remove the foreign matters remaining in the discharge-side supply pipe line 65. Figures 9 to 12 It is a cross-sectional view showing an example of the foreign matter removal processing using the ejector 71a.

[0111] In the standby state, as shown in (a) of Figure 9 , the first lid member 315 blocks the transfer port 312. At this time, the first locking plate 327 is located at the open position, and the inside of the processing space 319 becomes, for example, atmospheric pressure. In such a standby state, foreign matters 350 such as residues may exist in the processing space 319 and in the discharge-side supply pipe line 65.

[0112] After that, as shown in Figure 9As shown in FIG. (b), in order to receive the wafer W in the processing container 301, the first lid member 315 and the holding plate 316 are slid forward (negative Y direction). As a result, the first lid member 315 is separated from the transfer port 312, and the holding plate 316 is taken out from the processing space 319.

[0113] Next, as Figure 10 shown in FIG. (a), the wafer W is transferred to the holding plate 316. In addition, during the separation of the first lid member 315 and the holding plate 316 from the transfer port 312, the control unit 4 adjusts the flow control valve 52k to the open state. As a result, the ejector 71a starts to operate, and the exhaust pressure of the ejector 71a is higher than the exhaust pressure of the exhaust pipe line in the factory or the like, so that the foreign matter 350 in the processing space 319 and the discharge side supply pipe line 65 is discharged to the outside.

[0114] Next, as Figure 10 shown in FIG. (b), the control unit 4 adjusts the flow control valve 52k to the closed state. As a result, the operation of the ejector 71a stops, and the exhaust pressure of the ejector 71a is lower than the exhaust pressure of the exhaust pipe line in the factory or the like. Next, the first lid member 315 and the holding plate 316 are slid inward (positive Y direction), and the holding plate 316 is moved to the processing position in the container main body 311. In addition, the vacuum suction pipe 348 (see Figure 2 and Figure 3 ) operates. Next, the first locking plate 327 is raised to the locking position by the lifting mechanism 326. As a result, the first lid member 315 is attracted to the container main body 311, and the movement of the first lid member 315 is restricted by the first locking plate 327.

[0115] After that, supercritical processing is performed. During the supercritical processing, as Figure 11 shown in FIG. (a), various fine particles 351 are generated in the processing space 319, but most of the fine particles 351 are discharged to the outside through the discharge side supply pipe line 65. The fine particles 351 are, for example, fine particles from the IPA filled in the wafer W or fine particles attached to the wafer W.

[0116] At the end of the supercritical processing, purging is performed as described above. When the pressure in the container main body 311 returns to atmospheric pressure, as Figure 11 shown in FIG. (b), the first locking plate 327 is lowered to the open position.

[0117] Next, as Figure 12 shown in FIG. (a), in order to take out the wafer W, the first lid member 315 and the holding plate 316 are slid forward (negative Y direction). As a result, the first lid member 315 is separated from the transfer port 312, and the holding plate 316 on which the wafer W is placed is taken out from the processing space 319.

[0118] Next, asFigure 12 As shown in FIG. (b), the wafer W is sent out by the second transfer mechanism 161. In addition, while the first lid member 315 and the holding plate 316 are separated from the transfer port 312, the control unit 4 adjusts the flow control valve 52k to the open state. As a result, the ejector 71a starts to operate, and the exhaust pressure of the ejector 71a is higher than the exhaust pressure of the exhaust pipe line in a factory or the like, so that the fine particles 351 in the processing space 319 and the discharge side supply pipe line 65 are discharged to the outside.

[0119] After that, the control unit 4 adjusts the flow control valve 52k to the closed state. As a result, the operation of the ejector 71a stops, and the exhaust pressure of the ejector 71a is lower than the exhaust pressure of the exhaust pipe line in a factory or the like. Then, the holding plate 316 is slid in the horizontal direction, and the holding plate 316 is moved to the processing position in the container main body 311, thereby becoming a standby state ( Figure 9 FIG. (a)). At this time, a part of the fine particles 351 in the processing space 319 and the discharge side supply pipe line 65 may exist as foreign matter 350.

[0120] According to the first embodiment, the first lid member 315 can be firmly attracted to the container main body 311 side by the suction force of the vacuum suction pipe 348. In addition, before the first lid member 315 is attracted to the container main body 311 side, the foreign matter removal process using the ejector 71a can be performed. Therefore, even if the foreign matter 350 remains in the discharge side supply pipe line 65 after the supercritical treatment of one wafer W, the foreign matter 350 can be removed from the discharge side supply pipe line 65 during the period until the next wafer W is transferred to the processing space 319. Therefore, it is possible to suppress the suction of the foreign matter 350 into the processing space 319 when the suction force by the vacuum suction pipe 348 is exerted after the next wafer W is transferred to the processing space 319, and improve the cleanliness of the wafer W.

[0121] In addition, the foreign matter removal process can be performed while the first lid member 315 and the holding plate 316 are separated from the transfer port 312. That is, the foreign matter removal process can be performed during the period when the supply of the supercritical state processing fluid to the processing space 319 is stopped and the drying process is not performed. Therefore, there is no need to provide a time for the foreign matter removal process outside the time for the drying process, and it is possible to suppress the reduction in productivity and improve the cleanliness of the wafer W.

[0122] (Second Embodiment)

[0123] Next, the second embodiment will be described. The second embodiment is different from the first embodiment in that an ejector is also provided in the supply pipe line on the fluid supply tank 51 side. Figure 13 FIG. is a structural example diagram of the entire system of the supercritical processing apparatus 3 according to the second embodiment.

[0124] As Figure 13 shown, in the second embodiment, the first supply pipeline 63 and the second supply pipeline 64 are connected to an exhaust pipeline of a factory or the like via an ejector 71b. For example, the first supply pipeline 63 is connected to the ejector 71b between the pressure sensor 53c and the flow control valve 52b, and the second supply pipeline 64 is connected to the ejector 71b between the pressure sensor 53c and the flow control valve 52c. The ejector 71b receives a fluid such as air flowing from the fluid supply source 72b, and decompresses the interiors of the first supply pipeline 63 and the second supply pipeline 64 to perform forced exhaust. A flow control valve 52l is provided between the ejector 71b and the fluid supply source 72b. The flow control valve 52l is a valve that adjusts the opening and closing of the supply of the fluid from the fluid supply source 72b to the ejector 71b, and is controlled by the control unit 4. When the flow control valve 52l is in the closed state, the fluid does not flow through the ejector 71b, so the forced exhaust of the first supply pipeline 63 and the second supply pipeline 64 using the ejector 71b is not performed. When the flow control valve 52l is in the open state, the fluid flows through the ejector 71b, and the forced exhaust of the first supply pipeline 63 and the second supply pipeline 64 using the ejector 71b is performed. Therefore, in a state where the first supply pipeline 63 and the second supply pipeline 64 are open, if the flow control valve 52l is adjusted to the open state, the interiors of the first supply pipeline 63 and the second supply pipeline 64 are forcibly exhausted. A vacuum pump may be used instead of the ejector 71b.

[0125] Other structures are the same as those in the first embodiment.

[0126] For example, the foreign matter removal process using the ejector 71b and the foreign matter removal process using the ejector 71a can be performed at the same time. According to the second embodiment, even when foreign matter 350 enters the first supply pipeline 63 and the second supply pipeline 64, it is possible to suppress the suction back of the foreign matter 350 from the first supply pipeline 63 and the second supply pipeline 64 to the processing space 319.

[0127] In addition, when the first supply pipeline 63 and the second supply pipeline 64 are located near the vacuum suction pipe 349, in particular, it is preferable to perform the foreign matter removal process using the ejector 71b even after maintenance is completed. This is because there is a possibility that the foreign matter 350 may be sucked back into the processing space 319 due to the suction force of the vacuum suction pipe 349.

[0128] (Third Embodiment)

[0129] Next, the third embodiment will be described. The third embodiment is different from the first embodiment in that an exhaust pipeline for an inert gas is provided. Figure 14 It is a partial cross-sectional view showing the processing container 301 of the third embodiment.

[0130] As Figure 14 shown, in the third embodiment, a discharge port 362 is provided in the wall portion on the conveyance port 312 side in the container main body 311. The discharge port 362 is connected to an exhaust gas pipeline 69 for an inert gas through which an inert gas flows, provided on the downstream side of the processing container 301. For example, the exhaust gas pipeline 69 is provided independently of the discharge side supply pipeline 65. Further, Figure 14 one discharge port 362 is illustrated, but the number of the discharge ports 362 is not particularly limited. Further, an inert gas discharge header 361 communicating with the discharge port 362 is provided in the wall portion on the conveyance port 312 side in the container main body 311.

[0131] Other configurations are the same as those in the first embodiment.

[0132] The supercritical treatment can also be performed while supplying an inert gas such as nitrogen, helium, neon, or argon to the processing container 301. In this case, the inert gas discharge header 361 and the discharge port 362 can be used for exhausting the inert gas through the exhaust gas pipeline 69.

[0133] The discharge header, the discharge port 362, and the exhaust gas pipeline 69 may also be provided in the second embodiment.

[0134] As described above, the preferred embodiments and the like have been described in detail, but the present invention is not limited to the above-described embodiments and the like, and various modifications and substitutions can be added to the above-described embodiments without departing from the scope described in the claims.

Claims

1. A substrate processing apparatus, wherein, the substrate processing apparatus includes: a processing container having a processing space capable of accommodating a substrate with its surface wetted by a liquid; a processing fluid supply unit that supplies a supercritical processing fluid into the processing space toward the liquid; a first exhaust pipeline connected to a first exhaust source, and exhausting the processing space using a first exhaust pressure; a second exhaust pipeline connected to a second exhaust source different from the first exhaust source, connected to the first exhaust pipeline between the first exhaust source and the processing space, and exhausting the processing space through the first exhaust pipeline using a second exhaust pressure; and a control unit that controls the second exhaust pressure, the supercritical processing fluid contacts the liquid to dry the substrate, the control unit makes the second exhaust pressure higher than the first exhaust pressure during a period when the substrate is not loaded into the processing container before the processing fluid supply unit starts supplying the processing fluid and / or during a period when the substrate is unloaded from the processing container after the processing fluid supply unit stops supplying the processing fluid.

2. The substrate processing apparatus according to claim 1, wherein, the control unit makes the second exhaust pressure higher than the first exhaust pressure after the drying of the substrate is completed.

3. The substrate processing apparatus according to claim 1 or 2, wherein, the control unit makes the second exhaust pressure higher than the first exhaust pressure before the processing fluid supply unit starts supplying the processing fluid.

4. The substrate processing apparatus according to claim 1 or 2, wherein, the substrate processing apparatus includes a first on-off valve provided in the first exhaust pipeline, the second exhaust pipeline is connected between the first on-off valve and the first exhaust source.

5. The substrate processing apparatus according to claim 4, wherein, the substrate processing apparatus includes a back pressure valve provided between the first on-off valve provided in the first exhaust pipeline and the first exhaust source, the second exhaust pipeline is connected between the back pressure valve and the first exhaust source.

6. The substrate processing apparatus according to claim 5, wherein, when the control unit makes the second exhaust pressure higher than the first exhaust pressure, the control unit sets the first on-off valve and the back pressure valve to an open state.

7. The substrate processing apparatus according to claim 1 or 2, wherein, the first exhaust pipeline includes: a first exhaust pipe through which the processing fluid flows; and a second exhaust pipe through which an inert gas flows.

8. The substrate processing apparatus according to claim 1 or 2, wherein, the second exhaust source includes an ejector.

9. The substrate processing apparatus according to claim 8, wherein, the substrate processing apparatus includes: an exhaust fluid supply unit that supplies fluid to the ejector; and a second on-off valve provided between the exhaust fluid supply unit and the ejector and controlled by the control unit.

10. The substrate processing apparatus according to claim 1 or 2, wherein, the second exhaust source includes a vacuum pump.

11. A control method for a substrate processing apparatus, wherein, the substrate processing apparatus includes: A processing container having a processing space capable of accommodating a substrate in a state where its surface is wetted with a liquid; A processing fluid supply unit that supplies a supercritical processing fluid toward the liquid in the processing space; A first exhaust pipeline connected to a first exhaust source, and exhausting the processing space using a first exhaust pressure; A second exhaust pipeline connected to a second exhaust source different from the first exhaust source, connected to the first exhaust pipeline between the first exhaust source and the processing space, and exhausting the processing space via the first exhaust pipeline using a second exhaust pressure; and A control unit that controls the second exhaust pressure, The supercritical processing fluid contacts the liquid to dry the substrate, During the period when the substrate is not carried into the processing container before the processing fluid supply unit starts supplying the processing fluid and / or during the period when the substrate is carried out of the processing container after the processing fluid supply unit stops supplying the processing fluid, the second exhaust pressure is higher than the first exhaust pressure.

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