TW201921471A - Substrate processing method recording medium and substrate processing system - Google Patents

Abstract

Provided is a substrate processing method capable of improving a precision of a thickness of a liquid film of a processing liquid formed on a surface of a substrate. In the substrate processing method according to the present invention, first, as a liquid film forming process, a process liquid is supplied to the surface of the substrate (W) while rotating the substrate (W) at a first rotation speed to form a liquid film of the process liquid which covers the surface of the substrate (W). After the liquid film forming process, as a supply stop process, the rotation number of the substrate (W) is set to a rotation number equal to or lower than the first rotation number, and supply of the processing liquid to the substrate (W) is stopped. After the supply stop process, as a liquid amount adjustment process, the rotation number of the substrate (W) is set to be a rotation number greater than the first rotation number to reduce an amount of liquid of the processing liquid for forming the liquid film.

Description

Substrate processing method, memory medium and substrate processing system

The invention relates to a substrate processing method, a memory medium and a substrate processing system

In the manufacturing process of a semiconductor device in which a laminated structure in which an integrated circuit is formed on a surface of a substrate, that is, a semiconductor wafer (hereinafter referred to as a wafer), a cleaning solution for removing a wafer surface by a cleaning liquid such as a chemical liquid is provided. Foreign matter or natural oxide film, etc., processing the surface of the wafer with liquid.

There is known a method of using a treatment fluid in a supercritical state when removing a liquid remaining on the surface of a wafer by such a process. For example, Patent Document 1 discloses a substrate processing apparatus that dissolves a wafer by dissolving an organic solvent from a substrate using a supercritical fluid.

In the substrate processing apparatus of Patent Document 1, the surface of the wafer is cleaned by a cleaning liquid such as a chemical solution in the processing device. The surface of the cleaned wafer is coated with an organic solvent as a treatment liquid. The wafer coated with the organic solvent is transported from the cleaning device to the supercritical processing device, and the processing liquid in the supercritical state is used in the supercritical processing device to perform the drying process of the wafer. In this way, by coating the surface of the wafer with the organic solvent until it is dried in the supercritical processing apparatus, the surface of the cleaned wafer is prevented from drying, and the generation of fine particles is prevented.
[Previous Technical Literature]
[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2013-12538

[Problems to be solved by the invention]

However, when the amount of the organic solvent on the surface of the cleaned wafer is too small, the organic solvent may be vaporized until the drying treatment is performed in the supercritical treatment apparatus. Further, when the amount of liquid coating is too large, there is a possibility that particles are generated on the wafer after the drying treatment in the supercritical processing apparatus. Therefore, it is required that the organic solvent on the surface of the cleaned wafer be coated with a desired amount of precision.

The present invention has been made in view of the above, and provides a substrate processing method, a memory medium, and a substrate processing system which can improve the accuracy of the thickness of the liquid film of the processing liquid formed on the surface of the substrate.

[Means to solve the problem]

An embodiment of the present invention provides a substrate processing method, comprising:
a liquid film forming process for rotating a substrate with a first number of rotations, and supplying a processing liquid to a surface of the substrate to form a liquid film of the processing liquid covering a surface of the substrate;
After the liquid film forming process, the number of rotations of the substrate is equal to or less than the number of rotations of the first rotation number, and the supply of the processing liquid to the substrate is stopped; and the liquid amount adjustment process is performed. After the supply stoppage process, the number of rotations of the substrate is made larger than the number of rotations of the first number of rotations, and the amount of the treatment liquid forming the liquid film is lowered.

Furthermore, another embodiment of the present invention provides a memory medium that records a program that is controlled by the computer to control the substrate processing system when executed by a computer for controlling the operation of the substrate processing system. The above substrate processing method is performed.

Furthermore, another embodiment of the present invention provides a substrate processing system having:
a holding portion that maintains the substrate horizontally;
a rotation driving portion that rotates the holding portion;
a processing liquid supply unit that supplies the processing liquid to the substrate held by the holding unit; and a control unit
The control unit controls the rotation driving unit and the processing liquid supply unit to perform a liquid film forming process in which the substrate is rotated by a first number of rotations, and the processing liquid is supplied to a surface of the substrate. Forming a liquid film of the above treatment liquid covering the surface of the substrate;
After the liquid film forming process, the number of rotations of the substrate is equal to or less than the number of rotations of the first rotation number, and the supply of the processing liquid to the substrate is stopped; and the liquid amount adjustment process is performed. After the supply stoppage process, the number of rotations of the substrate is made larger than the second number of rotations of the first number of rotations, and the amount of the treatment liquid forming the liquid film is lowered.

[Effect of the invention]

According to the present invention, the thickness precision of the liquid film of the treatment liquid formed on the surface of the substrate can be improved.

(first embodiment)
Hereinafter, an embodiment of the substrate processing method, the memory medium, and the substrate processing system of the present invention will be described with reference to the drawings. Further, in the configuration shown in the attached drawings of the present specification, the size, the scale, and the like may include a portion changed from an actual object for ease of illustration and understanding.

[Composition of substrate processing system]
As shown in FIG. 1 , the substrate processing system 1 includes a plurality of cleaning devices 2 (in the example shown in FIG. 1 , two cleaning devices 2 ), in which a cleaning liquid is supplied to the wafer W and washed. And a treatment liquid for preventing drying of the wafer W remaining after the cleaning treatment (in the present embodiment, IPA as an example of an organic solvent: isopropyl alcohol) and a treatment fluid in a supercritical state (in this embodiment) In the form, the CO ₂ : carbon dioxide is contacted and removed by the supercritical processing device 3 (in the example shown in FIG. 1 , two supercritical processing devices 3 ).

In the substrate processing system 1, the FOUP 100 is placed on the mounting portion 11, and the wafer W accommodated in the FOUP 100 is received by the loading and unloading unit 12 and the receiving unit 13 in the cleaning processing unit 14 and supercritical processing. Part 15. In the cleaning processing unit 14 and the supercritical processing unit 15, the wafer W is first carried into the cleaning device 2 provided in the cleaning processing unit 14 to be subjected to the cleaning process, and then moved to the supercritical portion. The supercritical processing apparatus 3 of the processing unit 15 receives the drying process of removing the IPA from the wafer W. In FIG. 1, the symbol "121" indicates the first transport mechanism that transports the wafer W between the FOUP 100 and the receiving unit 13, and the symbol "131" indicates that the loading and unloading portion 12 and the cleaning processing portion 14 are temporarily placed. A scaffolding function of the function of the buffer of the wafer W being transported between the supercritical processing units 15.

The wafer conveyance path 162 is connected to the opening of the receiving unit 13, and the cleaning processing unit 14 and the supercritical processing unit 15 are provided along the wafer conveyance path 162. In the cleaning processing unit 14, a single cleaning device 2 is disposed next to each of the wafer transfer paths 162, and a total of two cleaning devices 2 are provided. Further, in the supercritical processing unit 15, a supercritical processing device 3 for performing a drying process of removing IPA from the wafer W is disposed next to the wafer transfer path 162, and a total of two supercritical processing devices 3 are provided. The second transport mechanism 161 is disposed in the wafer transport path 162, and the second transport mechanism 161 is provided to be movable in the wafer transport path 162. The wafer W placed on the receiving scaffold 131 is picked up by the second transport mechanism 161, and the second transport mechanism 161 transports the wafer W to 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 the number of processed wafers W per unit time and the processing time of each cleaning device 2 and each supercritical processing device 3 are not limited. Etc., an appropriate number of cleaning devices 2 and supercritical processing devices 3 are disposed in an appropriate manner.

As shown in Fig. 2, the cleaning device 2 is configured as a one-piece device for washing the wafer W one by one by, for example, rotating and cleaning. That is, as shown in the longitudinal cross-sectional view of FIG. 2, the wafer W is held slightly horizontal by the wafer holding mechanism 23 (holding portion) disposed in the processing chamber 21 outside the processing space. The wafer holding mechanism 23 is rotated about the vertical axis by the motor 20 (rotation driving unit), whereby the wafer W is rotated. Further, the nozzle arm 24 is placed above the rotating wafer W, and the cleaning liquid or the rinsing is supplied to the processing surface of the wafer W at an appropriate timing from the nozzles 25 to 28 provided at the front end portion thereof. The liquid and IPA are washed by the wafer W accordingly. Further, the chemical solution supply path 231 is formed inside the wafer holding mechanism 23, and the back surface of the wafer W is washed by the chemical liquid and the rinse liquid supplied from the chemical liquid supply path 231.

The first chemical liquid nozzle 25, the second chemical liquid nozzle 26, the rinse liquid nozzle 27, and the IPA nozzle 28 are provided at the front end of the nozzle arm 24.

The first chemical liquid nozzle 25 supplies an alkaline chemical solution, that is, an SC1 liquid (that is, a mixed liquid of ammonia and hydrogen peroxide) to the wafer W. The SC1 liquid is a chemical liquid for removing particulates or organic pollutants from the wafer W. Although not shown, the first chemical liquid nozzle 25 is connected to the first chemical liquid supply source via the first chemical liquid supply line, and the first chemical liquid supply valve is provided in the first chemical liquid supply line. By opening the first chemical liquid switching valve, SC1 is supplied to the first chemical liquid nozzle 25 from the first chemical liquid supply source.

The second chemical liquid nozzle 26 supplies an acidic chemical solution (DHF: Diluted Hydro Fluoric Acid) to the wafer W. This DHF is a chemical liquid for removing a natural oxide film formed on the surface of the wafer W. Although not shown, the second chemical liquid nozzle 26 is connected to the second chemical liquid supply source via the second chemical liquid supply line, and the second chemical liquid switching valve is provided in the second chemical liquid supply line. By opening the second chemical liquid switching valve, DHF is supplied to the second chemical liquid nozzle 26 from the second chemical liquid supply source.

The rinse liquid nozzle 27 supplies the rinse liquid, that is, deionized water (DIW, Deionized Water) to the wafer W. The DIW is used to rinse the SCI fluid or the DHF liquid from the wafer W. Although not shown, the rinse liquid nozzle 27 is connected to the rinse liquid supply source via the rinse liquid supply line, and the rinse liquid supply line is provided with the rinse liquid supply valve. The DIW is supplied to the rinse liquid nozzle 27 from the rinse liquid supply source by opening the rinse liquid on-off valve.

The IPA nozzle 28 supplies IPA to the wafer W, which is a treatment liquid for preventing drying. This IPA is a processing liquid for preventing the drying of the wafer W. In particular, the IPA is supplied to the wafer W to prevent the wafer W from being dried during the conveyance of the wafer W from the cleaning device 2 to the supercritical processing device 3. Further, since the so-called pattern collapse occurs in the wafer W by vaporization of the IPA during transportation, the IPA liquid film having a relatively large thickness is formed on the surface of the wafer W, and IPA is used. The coating liquid is on the surface of the wafer W. As shown in FIG. 3, the IPA nozzle 28 is connected to the IPA supply source 30 via the IPA supply line 29, and the IPA supply line 29 is provided with an IPA switching valve 31. By turning on the IPA switching valve 31, the IPA is supplied from the IPA supply source 30 to the IPA nozzle 28. The IPA supply unit 32 (the processing liquid supply unit) is configured by the IPA nozzle 28, the IPA supply line 29, the IPA supply source 30, and the IPA switching valve 31.

Further, the chemical liquid for cleaning the wafer W is not limited to the SC1 liquid and the DHF, and is arbitrary. Further, the DIW may be selectively discharged from the first chemical liquid nozzle 25 and the second chemical liquid nozzle 26 instead of providing the rinse liquid nozzle 27 in the nozzle arm 24.

As shown in FIG. 2, such a chemical solution, DIW, and IPA are received by the inner cup 22 or the outer chamber 21 disposed in the outer chamber 21, and are discharged from the liquid discharge ports 221 and 211. Furthermore, the atmosphere in the outer chamber 21 is exhausted through the exhaust port 212.

The wafer W that has been carried out from the cleaning device 2 is carried into the processing container 301 of the supercritical processing device 3 in the state of the liquid-coated IPA by the second transport mechanism 161 shown in FIG. 1 and is supercritically processed. The device 3 performs a drying process of IPA.

[Supercritical Treatment Device]
Next, the details of the drying process using the supercritical fluid performed in the supercritical processing apparatus 3 will be described. First, a configuration example of a processing container into which the wafer W is carried in the supercritical processing apparatus 3 will be described.

4 is a perspective view showing an appearance of an example of a processing container 301 of the supercritical processing device 3, and FIG. 5 is a cross-sectional view showing an example of the processing container 301.

The processing container 301 accommodates the wafer W and processes the wafer W using a high-pressure processing fluid such as a supercritical fluid. As shown in FIGS. 4 and 5, the processing container 301 includes a container body 311 that houses the wafer W in a frame shape, and a conveyance port 312 for loading and unloading the wafer W into the container body 311. The target wafer W holds the horizontal holding plate 316, and when the holding plate 316 is supported, and the wafer W is carried into the container body 311, the first cover member 315 of the conveyance port 312 is closed. Further, in the container body 311, a maintenance opening 321 is provided at a position different from the conveyance port 312. The maintenance opening 321 is closed by the second cover member 322 except for maintenance or the like.

The container body 311 accommodates the wafer W and processes the wafer W using the processing fluid. The container body 311 is internally formed with a container capable of accommodating a processing space 319 of, for example, a wafer W having a diameter of 300 mm. The conveyance port 312 and the maintenance opening 321 (for example, openings having the same size and shape as the conveyance port 312) are formed at both ends of the processing space 319, and communicate with the processing space 319.

Further, a discharge port 314 is provided in a wall portion of the container body 311 on the side of the conveyance port 312. The discharge port 314 is connected to a discharge side supply line 65 (see FIG. 7) for circulating the processing fluid on the downstream side of the processing container 301, and further, although two discharge ports 314 are illustrated in FIG. The number of 埠314 is not particularly limited.

The first upper block 312a and the first lower block 312b which are positioned on the upper side and the lower side of the transport port 312 are respectively formed with insertion holes 325 and 323 for inserting the first lock plate 327 which will be described later. Each of the insertion holes 325 and 323 penetrates the first upper block 312a and the first lower block 312b in the vertical direction (the direction perpendicular to the surface of the wafer W).

The holding plate 316 is formed in a state in which the wafer W is held, and can be disposed in a horizontal state in a thin plate-like member disposed in the processing space 319 of the container body 311, and is coupled to the first cover member 315. Further, a discharge port 316a is provided on the side of the first cover member 315 of the holding plate 316.

A first cover member accommodating space 324 is formed in a region on the front side (negative side in the Y direction) of the container body 311. When the holding plate 316 is carried into the processing container 301 and the wafer W is supercritically processed, the first lid member 315 is housed in the first lid member accommodating space 324. In this case, the first cover member 315 closes the conveyance port 312 to seal the processing space 319.

The first lock plate 327 is disposed on the front side of the processing container 301. When the holding plate 316 is moved to the processing position, the first lock plate 327 functions as a restricting member that restricts the movement of the first cover member 315 by the pressure in the container body 311. The first lock plate 327 is fitted into the insertion hole 323 of the first lower block 312b and the insertion hole 325 of the first upper block 312a. At this time, since the first lock plate 327 functions as a latch, the first cover member 315 and the holding plate 316 restrict the movement in the front-rear direction (the Y direction in FIGS. 4 and 5). Further, the first lock plate 327 is locked between the insertion position of the first cover member 315 by being fitted into the insertion holes 323 and 325, and is retracted from the lock position to the lower side to open the open position of the first cover member 315. The lifting mechanism 326 moves in the up and down direction. In this example, the first lock plate 327 and the insertion holes 323 and 325 and the elevating mechanism 326 constitute a restriction mechanism that restricts the movement of the first cover member 315 by the pressure in the container body 311. Further, since the insertion holes 323 and 325 are provided with the necessary margins for inserting and detaching the first lock plates 327, a slight difference is formed between the insertion holes 323 and 325 and the first lock plate 327 at the lock position. Clearance C1 (Figure 5). In addition, for convenience of illustration, the gap C1 is exaggerated in FIG.

The maintenance opening 321 is a wall surface of the container body 311 and is disposed at a position facing the conveyance port 312. When the maintenance port 321 and the conveyance port 312 are opposed to each other, when the container body 311 is closed by the first cover member 315 and the second cover member 322, the pressure of the processing space 319 is slightly applied to the container body 311 in a uniform manner. surface. Therefore, the situation in which stress is concentrated on a specific portion of the container body 311 is prevented. However, even if the maintenance opening 321 is provided at a position facing the conveyance port 312, for example, it may be a side wall surface in the forward direction (Y direction) of the wafer W.

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

A second cover member accommodating space 334 is formed in a region on the deep side (positive side in the Y direction) of the container body 311. The second cover member 322 is housed in the second cover member accommodating space 334 except for maintenance, and the maintenance opening 321 is closed. Further, a supply port 313 is provided in the second cover member 322. The supply port 313 is connected to a first supply line 63 (see FIG. 7) that is provided on the upstream side of the processing container 301 to allow the processing fluid to flow. In addition, although the two supply ports 313 are illustrated in FIG. 4, the number of the supply ports 313 is not particularly limited.

The second lock plate 337 functions as a restricting member that restricts the movement of the second cover member 322 by the pressure in the container body 311. The second lock plate 337 is fitted into the fitting holes 333 and 335 around the maintenance opening 321 . At this time, since the second lock plate 337 functions as a latch, the second cover member 322 restricts the movement in the front-rear direction (Y direction). Further, the second lock plate 337 is formed in a locked position in which the second cover member 322 is pressed by being fitted into the fitting holes 333 and 335, and is retracted from the locked position to the lower side to open the open position of the second cover member 322. Move in the up and down direction. In the present embodiment, the second lock plate 337 is manually moved. However, even if the lift mechanism is slightly the same as the lift mechanism 326, it can be automatically moved. Further, since the insertion holes 333 and 335 are provided with the required margins for inserting and detaching the second lock plates 337, respectively, a slight difference is formed between the insertion holes 333 and 335 and the second lock plate 337 at the lock position. Clearance C2 (Figure 5). In addition, for convenience of illustration, the gap C2 is exaggerated in FIG.

In the present embodiment, the second cover member 322 is connected to the first supply line 63, and the second cover member 322 is provided with a plurality of openings 332. The second cover member 322 functions as a fluid supply head that supplies the processing fluid supplied from the first supply line 63 via the supply port 313 to the inside of the container body 311. According to this, when the second cover member 322 is removed during maintenance, maintenance work such as cleaning of the opening 332 can be easily performed. Further, a fluid discharge head 318 that communicates with the discharge port 314 is provided in a wall portion of the container body 311 on the side of the transfer port 312. Even in the fluid discharge head 318, a plurality of openings are provided.

The second cover member 322 and the fluid discharge head 318 are disposed to face each other. The second cover member 322 that functions as a fluid supply unit supplies the processing fluid to the inside of the container body 311 substantially in the horizontal direction. The horizontal direction referred to herein is a direction perpendicular to the vertical direction of gravity, and is generally parallel to the direction in which the flat surface of the wafer W held by the holding plate 316 extends. The fluid discharge head 318 that functions as a fluid discharge portion that discharges the fluid in the container body 311 is discharged from the container body 311 by the fluid in the container body 311 through the discharge port 316a of the holding plate 316. . The fluid discharged to the outside of the container body 311 via the fluid discharge head 318 is contained in addition to the treatment fluid supplied into the container body 311 via the second cover member 322, and also includes dissolution from the surface of the wafer W to the treatment fluid. IPA. In this way, by supplying the processing fluid from the opening 332 of the second cover member 322 to the container body 311, and discharging the fluid from the container body 311 through the opening of the fluid discharge head 318, the container body 311 is discharged. A laminar flow of the treatment fluid flowing slightly parallel to the surface of the wafer W is formed.

Further, in the container body 311, vacuum suction pipes 348 and 349 are connected to the side surfaces on the side of the conveyance opening 312 and the side on the side of the maintenance opening 321, respectively. Each of the vacuum suction pipes 348 and 349 communicates with the surface of the container body 311 on the side of the first cover member accommodation chamber 324 and the surface of the second cover member accommodation space 334 side. Each of the vacuum suction pipes 348 and 349 functions to attract the first cover member 315 and the second cover member 322 to the container body 311 side by the vacuum suction force.

Further, on the bottom surface of the container body 311, a bottom side fluid supply portion 341 for supplying the processing fluid to the inside of the container body 311 is formed. The bottom side fluid supply unit 341 is connected to a second supply line 64 (see FIG. 7) that supplies a processing fluid to the container body 311. The bottom side fluid supply portion 341 supplies the processing fluid to the inside of the container body 311 substantially from the lower side toward the upper side. The processing fluid supplied from the bottom surface side fluid supply portion 341 is wound from the back surface of the wafer W through the discharge port 316a of the holding plate 316 to the surface of the wafer W, simultaneously with the processing fluid from the second cover member 322. It is discharged from the fluid discharge head 318 by being disposed at the discharge port 316a of the holding plate 316. The position of the bottom side fluid supply portion 341 is preferably, for example, introduced below the wafer W in the container body 311, and is preferably as the lower portion of the center portion of the wafer W. According to this, the processing fluid from the bottom side fluid supply portion 341 can be uniformly wrapped around the surface of the wafer W.

As shown in Fig. 5, a heater 345 composed of a resistance heating element such as a heating belt is provided on the upper and lower surfaces of the container body 311. The heater 345 is connected to the power supply unit 346 to increase or decrease the output of the power supply unit 346, and the temperature of the container body 311 and the processing space 319 can be maintained, for example, in the range of 100 ° C to 300 ° C.

Next, the configuration around the maintenance opening 321 will be further described with reference to FIGS. 6(a) and 6(b).

As shown in FIG. 6( a ), a recess 328 is formed in a side wall of the second cover member 322 on the side of the processing space 319 so as to surround a position corresponding to the periphery of the maintenance opening 321 . By inserting the sealing member 329 into the recessed portion 328, the sealing member 329 is disposed on the side wall surface on the side of the second cover member 322 that is in contact with the side wall surface around the maintenance opening 321 .

The sealing member 329 is formed in a ring shape so as to be able to surround the maintenance opening 321 . Further, the cross-sectional shape of the sealing member 329 is U-shaped. In the sealing member 329 shown in FIG. 6(a), the U-shaped opening 329a is formed along the inner circumferential surface of the annular sealing member 329. In other words, the sealing member 329 forms an internal space surrounded by a U-shape.

The second cover member 322 provided with the sealing member 329 seals the periphery of the maintenance opening 321 , and the sealing member 329 is disposed on the second cover member 322 so as to close the gap between the second cover member 322 and the container body 311 . Between the container body 311. Further, since the gap is formed around the maintenance opening 321 in the container body 311, the opening 329a formed along the inner circumferential surface of the sealing member 329 is in communication with the processing space 319.

Although the sealing member 329 whose opening 329a communicates with the processing space 319 is exposed to the atmosphere of the treatment fluid, there is a case where the treatment fluid dissolves the components of the resin or rubber or the impurities contained therein. Then, the sealing member 329 is formed of a resin having corrosion resistance to the liquid IPA or the treatment fluid to at least the inner side of the opening 329a of the processing space 319. Examples of such a resin include polyimine, polyethylene, polypropylene, p-xylene, and polyether ether ketone (PEEK), and are used for a semiconductor device even if a small amount of a component is dissolved in the treatment fluid. A non-fluorine-based resin having a small influence is preferred. Further, it is preferable that a metal spring (not shown) is provided on the inner surface of the U-shaped sealing member 329 (the surface facing the opening 329a). The spring is configured to cause a spring force to act in a direction in which the sealing member 329 is pressed outward (in the direction of the expansion opening 329a).

When the treatment fluid enters the opening 329a, the sealing member 329 is pressed away from the opening 329a to act to face the outer circumferential surface of the sealing member 329 (the surface opposite to the opening 329a) toward the concave portion 328 side of the second cover member 322, and the container The force pushed by the side wall surface of the body 311. Thereby, the outer peripheral surface of the sealing member 329 is in close contact with the second lid member 322 or the container body 311, and the gap between the second lid member 322 and the container body 311 is hermetically sealed. The sealing member 329 has elasticity that can be deformed by a force received from the processing fluid, and can maintain a state in which the gap is hermetically sealed against the pressure difference between the processing space 319 and the outside (for example, about 16 to 20 MPa). Further, as described above, when a metal spring is provided on the inner surface of the sealing member 329, the outer circumferential surface (the surface opposite to the opening 329a) of the sealing member 329 is directed toward the second cover member 322 by the spring force. The surface on the side of the concave portion 328 and the force of pressing the side wall surface of the container body 311 are increased to improve airtightness.

As shown in FIGS. 6(a) and 6(b), a plurality of additional openings 330 are provided in the second cover member 322. The additional opening 330 is supplied to the opening 329a of the sealing member 329 by the processing fluid supplied from the first supply line 63 via the supply port 313. Each of the additional openings 330 is provided in each of the openings 332 of the second cover member 322, and a portion of the processing fluid flowing to the opening 332 is extracted, and the additional opening 330 corresponding to the opening 332 is supplied to the sealing. The opening 329a of the member 329. Further, as shown in FIG. 6(b), it is preferable to add the opening 330 to the side portion of the second cover member 322. In this case, the maintenance opening 321 in the opening 329a of the sealing member 329. The side of the side is also supplied with a treatment fluid.

Further, in the present embodiment, even if the conveyance port 312 of the container body 311 is the same as the conveyance port 312, the first cover member 315 is sealed.

That is, as shown in FIG. 5, the side wall of the processing space 319 side of the first lid member 315 is formed with a concave portion 338 so as to surround the position corresponding to the peripheral edge of the conveying port 312. By inserting the sealing member 339 into the recessed portion 338, the sealing member 339 is disposed on the side wall surface on the side of the first cover member 315 that abuts against the side wall surface around the conveyance port 312.

The sealing member 339 is formed in a ring shape so as to be able to surround the conveying port 312. Further, the cross-sectional shape of the sealing member 339 is U-shaped. In this manner, the first port member 315 provided with the sealing member 339 is used to close the conveyance port 312, and the sealing member 339 is disposed so as to close the gap between the first cover member 315 and the conveyance port 312. 1 between the cover member 315 and the container body 311. In addition, the configuration for closing the conveyance port 312 by using the first cover member 315 and the sealing member 339 is slightly the same as the configuration for closing the maintenance opening 321 described above.

[Configuration of the system of the supercritical processing device]
FIG. 7 is a view showing an example of the configuration of the entire system of the supercritical processing device 3.

As shown in FIGS. 4, 5, and 7, the first cover member 322 is connected to a first supply line 63 for supplying a processing fluid to the processing container 301. A second supply line 64 for supplying a processing fluid to the inside of the processing container 301 is connected to the wall portion of the container body 311. The second supply line 64 is branched from the first supply line 63 on the downstream side of the switching valve 67. Further, at the bottom of the container body 311, a discharge side supply line 65 for discharging the fluid in the processing container 301 is connected.

The first supply line 63 connected to the processing container 301 is connected to the fluid supply tank 51 via an on-off valve 67, a filter 68, and a flow rate adjusting valve 69 that are supplied to the processing container 301 to supply and stop the high-pressure fluid. The fluid supply tank 51 includes a CO ₂ cylinder that stores, for example, liquid CO ₂ , and a booster pump that is configured to increase the liquid CO ₂ supplied from the CO ₂ cylinder and is used as a supercritical state by a syringe pump or a diaphragm pump. . These CO ₂ cylinders or booster pumps are collectively indicated in Figure 7 in the shape of a cylinder.

The supercritical CO ₂ supplied from the fluid supply tank 51 is adjusted in flow rate by the flow rate adjusting valve 69, and is supplied to the processing container 301. The flow rate adjustment valve 69 is constituted by, for example, a needle valve or the like, and also serves as a shutoff portion that cuts off supply of supercritical CO ₂ from the fluid supply tank 51.

Further, the pressure reducing valve 70 of the discharge side supply line 65 is connected to a pressure controller 71 having a measurement result based on the pressure in the processing container 301 obtained from the pressure gauge 66 provided in the processing container 301. The feedback control function of the opening and closing degree is adjusted by comparing with the preset set pressure.

The substrate processing system 1 or the cleaning device 2 and the supercritical processing device 3 having the above-described configuration are connected to the control unit 4 as shown in Figs. 1 and 7 . The control unit 4 is, for example, a computer, and includes a computing unit 18 and a storage unit 19 (not shown). The memory unit 19 stores programs for controlling various processes executed in the substrate processing system 1. The calculation unit 18 controls the operation of the substrate processing system 1 by reading and executing the program stored in the storage unit 19. The program is recorded in a memory medium readable by a computer, and may be installed in the memory unit 19 of the control unit 4 from the memory medium. For a memory medium readable by a computer, for example, a hard disk (HD), a floppy disk (FD), a compact disk (CD), a magneto-optical disk (MO), a memory card, or the like.

In particular, in the supercritical processing apparatus 3, the control unit 4 is provided with the pressure reduction processing container 301 and the first supply line 63 before the wafer W that has been subjected to the extraction process, and avoids the processing from the first supply line 63 toward the processing container 301. The function of generating a control signal by generating a rapid pressure change in the direction of decompression. From this point of view, as shown in FIG. 7, the control unit 4 and the pressure controller 71 that adjusts the opening degree of the pressure reducing valve 70 provided on the discharge side supply line 65, or the on-off valve 67 on the first supply line 63 side. The flow regulating valve 69 is electrically connected.

Next, the action of the present embodiment constituted by such a configuration will be described with respect to the processing method (substrate processing method) of the wafer W in the substrate processing system 1 of the present embodiment.

[washing treatment]
Here, first, a method of cleaning the wafer W in the cleaning device 2 will be described.

<The first liquid cleaning project>
First, the wafer W is held almost horizontally in the wafer holding mechanism 23 of the cleaning device 2. Next, the wafer holding mechanism 23 is rotated about the vertical axis to rotate the wafer W in the horizontal plane. Next, the nozzle arm 24 enters above the rotating wafer W, and the SC1 liquid is supplied to the center portion of the surface of the wafer W from the first chemical liquid nozzle 25 provided at the tip end portion thereof as a chemical liquid for cleaning. The SC1 liquid is diffused by centrifugal force, and the entire area of the surface of the wafer W is covered by the liquid film of the SC1 liquid, whereby the surface of the wafer W is washed by the SC1 liquid. In this case, particulates or organic contaminants can be removed from the wafer W. The SC1 liquid on the surface of the wafer W is scattered radially outward from the outer periphery We of the wafer W. The scattered SC1 liquid is discharged from the liquid discharge ports 221, 211.

<1st flushing project>
After the first chemical liquid cleaning process, the wafer W is rinsed while maintaining the wafer W rotated. In this case, DIW (flushing liquid) is supplied to the center portion of the surface of the rotating wafer W from the rinse liquid nozzle 27 provided at the front end of the nozzle arm 24. Accordingly, the DIW can be flushed by sweeping out the SC1 liquid from the wafer W by centrifugal force diffusion. The DIW or SC1 liquid on the surface of the wafer W is scattered outward from the outer periphery We of the wafer W in the radial direction, and is discharged from the liquid discharge ports 221 and 211.

<The second liquid cleaning project>
After the first rinsing process, the wafer W is washed with the DHF liquid by the chemical solution. In this case, DHF is supplied to the center portion of the surface of the rotating wafer W from the second chemical liquid nozzle 26 provided at the front end of the nozzle arm 24 as a chemical liquid for cleaning. The DHF is diffused by centrifugal force, and the entire area of the surface of the wafer W is covered by the liquid film of DHF, whereby the surface of the wafer W is washed by DHF. In this case, the natural oxide film formed on the wafer W can be removed. The DHF liquid on the surface of the wafer W is scattered outward from the outer periphery We of the wafer W in the radial direction, and is discharged from the liquid discharge ports 221 and 211.

<2nd flushing project>
After the second chemical liquid cleaning process, as shown in FIGS. 8(a) and 9 , the wafer W is rinsed. In this case, similarly to the first flushing process, DIW is supplied to the center portion of the surface of the rotating wafer W from the rinse liquid nozzle 27 provided at the front end of the nozzle arm 24. Accordingly, the DIW can be flushed by sweeping the DHF from the wafer W by centrifugal force diffusion. The DIW or DHF on the surface of the wafer W is scattered outward from the outer periphery We of the wafer W in the radial direction, and is discharged from the liquid discharge ports 221 and 211.

In the second flushing process, for example, the discharge amount of DIW is set to 300 mL/min, and the number of rotations of the wafer W is set to 1000 rpm. Further, as shown in FIG. 8(a), a liquid film of DIW is formed on the surface of the wafer W.

<IPA Liquid Film Formation Engineering>
After the second rinsing process, as shown in FIGS. 8(b) and 9 , the wafer W is rotated by the first number of rotations, and IPA is supplied to the wafer W as a liquid for preventing drying. In this case, first, the number of rotations of the wafer W is lowered to a first number of rotations lower than the number of rotations in the second flushing process. Next, the IPA switching valve 31 is turned on, and the IPA supply source 30 passes through the IPA supply line 29, and the IPA is supplied to the IPA nozzle 28 provided at the front end of the nozzle arm 24. The IPA supplied to the IPA nozzle 28 is supplied from the IPA nozzle 28 to the center portion of the surface of the rotating wafer W. The IPA is diffused by the centrifugal force, and the liquid film of the DIW formed on the processing surface of the wafer W is replaced with IPA. As shown in FIG. 8(b), the surface of the wafer W is formed on the surface of the wafer W. Liquid film of IPA (IPA of the coating liquid). The IPA on the surface of the wafer W is scattered outward from the outer periphery We of the wafer W in the radial direction, and is discharged from the liquid discharge ports 221 and 211.

In the IPA liquid film formation process, for example, the discharge amount of IPA is set to 300 mL/min, the number of rotations of the wafer W is set to 30 rpm, and the discharge of IPA is continued for 15 seconds. As shown in FIG. 9, the number of rotations of the wafer W in the IPA liquid film forming process is smaller than the number of rotations of the wafer W in the liquid amount adjustment process described later. Therefore, the IPA is suppressed from scattering from the periphery We are outside the wafer W, the thickness of the liquid film of the IPA after the IPA liquid film formation process (t1 shown in Fig. 8(b)), and the liquid film of the IPA after the liquid amount adjustment project The thickness (t3 shown in Fig. 8(d)) is thick. That is, the IPA coating amount after the IPA liquid film forming process is larger than the IPA liquid amount after the liquid amount adjusting process.

<Supply stop project>
After the IPA liquid film forming process, as shown in FIG. 8(c) and FIG. 9, the number of rotations of the wafer W is equal to or less than the number of rotations of the first rotation number (here, the rotation of the wafer W is stopped), and the operation is stopped. The wafer W is supplied with an IPA. In this case, first, the rotation of the wafer W is stopped. At this time, it is preferable that the stop of the rotation of the wafer W is performed slowly. Accordingly, it is possible to suppress the situation in which the IPA remaining on the surface of the wafer W is discharged from the surface of the wafer W. Thereafter, the IPA switching valve 31 is closed to stop the supply of the IPA. Even after the supply stop process, on the surface of the wafer W, the IPA liquid film having a thickness of t2 remains, and the thickness t2 of the liquid film is the thickness of the liquid film of the IPA after the formation of the IPA liquid film. T1 is equal or slightly thin, but is thicker than the thickness t3 of the liquid film of IPA after the liquid amount adjustment process described later.

<Liquid volume adjustment project>
After the supply stop process, as shown in FIG. 8(d) and FIG. 9, the number of rotations of the wafer W is made larger than the second number of rotations of the first number of rotations, and the IPA of the liquid film on the surface of the wafer W is lowered. The amount of liquid. In this case, the wafer holding mechanism 23 is rotated about the vertical axis to rotate the stopped wafer W again in the horizontal plane. A part of the IPA of the liquid film on the surface of the wafer W is formed by the centrifugal force generated by the rotation of the wafer W, and is scattered outward from the outer periphery We of the wafer W in the radial direction from the liquid discharge ports 221 and 211. It is discharged. In addition, during this period, the IPA switching valve 31 is maintained in a closed state, and IPA is not supplied to the surface of the wafer W. As a result, the liquid amount of the IPA forming the liquid film is lowered, and the thickness t3 of the liquid film of the IPA is thinner than the thickness t1 of the liquid film after the IPA liquid film formation process and the thickness t2 of the liquid film of the IPA after the supply stop process. Accordingly, the thickness of the liquid film of IPA becomes a desired thickness.

In the liquid amount adjustment process, it is preferable to slowly stop the rotation of the wafer W after a certain period of time (for example, one second later) after the rotation (increase) of the wafer W that has been restarted is resumed. Accordingly, it is possible to prevent the IPA forming the liquid film from being excessively discharged from the surface of the wafer W, and to adjust the thickness t3 of the liquid film of IPA to a desired thickness.

In the liquid amount adjustment process, the thickness of the liquid film of IPA can be adjusted to be arbitrary by adjusting the number of rotations of the wafer W or the time from the restart of the rotation of the wafer W to the stop. Furthermore, in order to shorten the processing time of the wafer W, even if the time to restart the rotation of the wafer W to the stop is set to be short, the setting can adjust the thickness of the liquid film of the IPA to a desired thickness during this time. The number of rotations of the circle W is also possible.

As a result, the cleaning process of the wafer W is completed. At this time, a liquid film of IPA having a desired thickness is formed on the surface of the wafer W to prevent drying of the wafer W.

[Drying treatment]
Next, a method of drying the wafer W in the supercritical processing apparatus 3 will be described. Here, first, the drying mechanism of the IPA will be described using FIG.

<drying mechanism>
In the supercritical processing apparatus 3, when the processing fluid R in the supercritical state is introduced into the container body 311 of the processing container 301, as shown in Fig. 10(a), only the IPA is filled between the patterns P.

The IPA between the patterns P is in contact with the treatment fluid R in the supercritical state, and is gradually dissolved in the treatment fluid R, and is gradually replaced with the treatment fluid R as shown in Fig. 10(b). At this time, between the patterns P, in addition to the IPA and the treatment fluid R, there is a mixed fluid M in a state in which the IPA and the treatment fluid R are mixed.

Further, as the process P is replaced with the treatment fluid R from the IPA, the IPA is removed from the pattern P, and finally, as shown in Fig. 10(c), only the treatment fluid R in the supercritical state is filled. Full pattern P.

After the IPA is removed from between the patterns P, the pressure in the container body 311 is lowered to atmospheric pressure, and as shown in Fig. 10(d), the fluid body R is changed from a supercritical state to a gas state, and only gas is interposed between the patterns P. occupy. As a result, the IPA between the patterns P is removed, and the drying process of the wafer W is completed.

In the background of the mechanism shown in Figs. 10(a) to 10(d), the supercritical processing apparatus 3 of the present embodiment performs the IPA drying process as follows.

<moving into the project>
After the liquid amount adjustment process, the wafer W is carried into the processing container 301 of the supercritical processing apparatus 3 in a state where a liquid film of IPA having a desired thickness is formed.

In this case, first, the wafer W is carried out from the cleaning device 2 by the second transport mechanism 161, and is carried into the processing container 301 of the supercritical processing device 3. At the time of loading, the second transport mechanism 161 retreats from the upper side of the holding plate 316 after the wafer W is taken up to the holding plate 316 which is in the standby position.

Next, the holding plate 316 is slid in the horizontal direction to move the holding plate 316 to the processing position in the container body 311. At this time, the first cover member 315 is housed in the first cover member accommodation space 324 and covers the conveyance port 312. Next, the first cover member 315 is attracted to the container body 311 by the suction force from the vacuum suction pipe 348 (Figs. 4 and 5), and the conveyance port 312 is closed by the first cover member 315. Then, the first lock plate 327 is raised to the lock position by the elevating mechanism 326, and the first lock plate 327 and the front surface of the first cover member 315 are abutted, and the movement of the first cover member 315 is restricted.

<Drying Engineering>
After the project is moved in, the wafer W is dried. In the drying process, the processing fluid pressurized to the processing vessel 301 is supplied, and while the pressure in the processing vessel 301 is maintained at a pressure at which the processing fluid maintains a critical state, the pressurized processing fluid is supplied to the processing vessel 301, and The processing container 301 discharges the treatment fluid. Accordingly, the IPA on the wafer W is replaced with the processing fluid, and thereafter, the pressure in the processing container 301 is lowered, and the wafer W is dried accordingly.

More specifically, before the IPA of the surface of the wafer W is dried by the coating liquid, the switching valve 67 and the flow rate adjusting valve 69 are opened, and the processing space 319 is supplied with high pressure via the first supply line 63 and the second supply line 64. fluid. Accordingly, the pressure in the processing space 319 is increased to, for example, about 14 to 16 MPa. With the pressurization of the processing space 319, the U-shaped sealing member 339 provided in the concave portion 338 of the first cover member 315 is pressed open, and the gap between the first cover member 315 and the container body 311 is hermetically sealed. .

Further, in the processing space 319, when the processing fluid supplied into the processing space 319 comes into contact with the coating liquid at the IPA of the wafer W, the IPA of the coating liquid is gradually dissolved in the processing fluid, and is gradually replaced with the processing fluid. Further, as the IPA is replaced with the processing fluid between the patterns of the wafer W, the IPA is removed from the pattern, and finally the pattern P is filled only by the processing fluid in the supercritical state. As a result, although the surface of the wafer W is replaced with the treatment fluid by the IPA of the liquid, since the interface is formed between the liquid IPA and the treatment fluid in an equilibrium state, the pattern collapse is not caused, and the surface of the wafer W can be The IPA is replaced with a treatment fluid.

Thereafter, when the processing fluid is supplied into the processing space 319 and the surface of the wafer W is replaced by the processing fluid for a predetermined period of time, the pressure reducing valve 70 is opened to discharge the atmosphere in the processing space 319 from the fluid discharge head. The 318 is discharged toward the outside of the container body 311. Accordingly, when the pressure in the container body 311 gradually decreases, the processing fluid in the processing space 319 changes from a supercritical state to a gas state. At this time, since an interface is formed between the supercritical state and the gas, the wafer W can be dried without causing surface tension to act on the surface of the wafer W.

In the above process, after the supercritical treatment of the wafer W is completed, the processing fluid of the gas remaining in the processing space 319 is discharged, so that N ₂ gas is supplied from the flushing gas supply line (not shown) and is directed toward the fluid discharge head 318. rinse. Further, the supply of the N ₂ gas is performed and the flushing is completed only at the time set in advance, and when the inside of the container body 311 is returned to the atmospheric pressure, the first lock plate 327 is lowered to the open position. Then, the holding plate 316 is moved to the receiving position in the horizontal direction, and the wafer W that has finished the supercritical processing is carried out by the second transport mechanism 161.

However, during the above-described supercritical processing, the second lock plate 337 is constantly raised to the locked position. As a result, the second lock plate 337 abuts against the rear surface of the second cover member 322, and the movement of the second cover member 322 is restricted. Further, the high-pressure treatment fluid is not supplied to the treatment space 319, and the pressure in the container body 311 is not increased, and the side wall surfaces of the second cover member 322 and the container body 311 directly crush the sealing member 329 toward each other, and hermetically The periphery of the maintenance opening 321 is closed.

Further, when the processing space 319 is supplied with the high-pressure processing fluid, the second cover member 322 is treated only by the amount of the gap C2 between the insertion holes 335 and 333 around the maintenance opening 321 and the second lock plate 337. The direction of the space 319 (the positive side in the Y direction) moves. By the movement of the second cover member 322, the gap between the second cover member 322 and the container body 311 is widened. In this case, since the opening 329a is widened by the restoring force of the elastic sealing member 329, the outer peripheral surface of the sealing member 329 is in close contact with the second cover member 322 or the container body 311, and the second cover member 322 and the container The gap between the bodies 311 is hermetically sealed. In this way, the second cover member 322 is in a state in which the closed maintenance opening 321 is maintained as it is during the supercritical treatment.

Further, while the high-pressure processing fluid is supplied to the processing space 319 from the first supply line 63, the processing fluid is supplied to the opening 329a of the sealing member 329 from the additional opening 330 provided in the second lid member 322. As a result, the processing fluid is blown to the inside of the sealing member 329, and foreign matter such as dust adhering to the inner surface of the sealing member 329 can be blown. Therefore, the inner surface of the sealing member 329 can be cleaned while performing supercritical treatment. The processing flow system supplied to the opening 329a is supplied to the processing space 319.

[Maintenance method]
Next, the operation at the time of the completion of the above-described supercritical processing and the maintenance of the processing container 301 will be described.

First, the inside of the processing space 319 is opened to atmospheric pressure. Next, the first lock plate 327 is moved from the insertion holes 323 and 325 to the lower side by the elevating mechanism 326 as an open position at which the first cover member 315 is opened. Next, the first cover member 315 and the holding plate 316 are moved to the front side (the negative side in the Y direction). Accordingly, the holding plate 316 is taken out from the processing space 319, and the first cover member 315 is separated from the conveyance port 312 (FIG. 11(a)).

Next, the second lock plate 337 is moved from the insertion holes 333 and 335 to the lower side as an open position at which the second cover member 322 is opened. Next, the second cover member 322 is moved to the deep side (the positive side in the Y direction), and the second cover member 322 is separated from the maintenance opening 321 (FIG. 11(b)).

Then, a cleaning tool, a tool, or the like is inserted from the maintenance opening 321 to perform maintenance work (cleaning, adjustment, and the like) inside the processing space 319. In the present embodiment, since the second lock plate 337 is moved to the lower side, only the second cover member 322 can be removed, and the inside of the processing space 319 can be moved in and out. Therefore, such maintenance work can be easily performed. Further, since the supply port 313 is connected to the second cover member 322, the maintenance work (cleaning, adjustment, etc.) of the supply port 313 or the opening 332 can be easily performed together with the maintenance work in the processing space 319.

After the maintenance work is completed, the second cover member 322 and the first cover member 315 are respectively attached to the container body 311 in the reverse steps described above. In other words, first, the second cover member 322 is moved to the front side (the negative side in the Y direction), and the maintenance opening 321 is covered by the second cover member 322. Next, the second cover member 322 is sucked to the container body 311 side by the suction force from the vacuum suction tube 349. Then, by raising the second lock plate 337, the second lock plate 337 is fitted into the fitting holes 333 and 335 as a lock position for pressing the second cover member 322. Accordingly, the periphery of the maintenance opening 321 is hermetically sealed.

Then, the first cover member 315 and the holding plate 316 are moved to the deep side (the positive side in the Y direction), the holding plate 316 is moved into the processing space 319, and the conveyance port 312 is covered by the first cover member 315. Next, the first cover member 315 is attracted to the container body 311 side by the suction force from the vacuum suction tube 348. Next, the first lock plate 327 is raised by the elevating mechanism 326, and the first lock plate 327 is fitted into the insertion holes 323 and 325 as a lock position. As a result, the periphery of the transfer port 312 is hermetically sealed, and the processing space 319 is sealed again. After that, the above supercritical treatment is performed as needed.

As a result, in the present embodiment, the liquid film of IPA is formed on the surface of the wafer W while the wafer W is rotated by the first rotation number, and then the rotation of the wafer W is stopped, and the IPA is stopped. After the supply, the wafer W is rotated by the second number of rotations larger than the first number of rotations. Accordingly, regardless of the timing of the supply stop of the IPA, the thickness of the liquid film of the IPA can be adjusted by adjusting the number of rotations of the wafer W.

Here, a method of adjusting the thickness of the IPA liquid film by rotating the wafer W at a desired number of rotations and discharging the desired IPA discharge amount (supply amount) to the wafer W for a predetermined period of time may be considered. In this case, after a certain period of time, the rotation of the wafer W is stopped, and the supply of the IPA is stopped. The rotation stop of the wafer W is realized by the control unit 4 transmitting a stop command to the motor 20 that rotationally drives the wafer holding mechanism 23. Accordingly, the time until the rotation of the wafer W is stopped after the control unit 4 transmits the stop command becomes difficult to change. Further, the supply stop of the IPA is realized by the control unit 4 transmitting a closing command to the IPA switching valve 31. More specifically, the valve body driving unit (not shown) that receives the IPA switching valve 31 from the closing command of the control unit 4 moves the valve body to close the internal flow path of the IPA switching valve 31. Accordingly, it is considered that the time from when the control unit 4 transmits the closing command to when the IPA switching valve 31 is closed is easily changed, and it is difficult to maintain stability. Therefore, the thickness of the liquid film of IPA on the surface of the wafer W may vary, and it may be difficult to maintain the desired thickness.

On the other hand, in the present embodiment, as described above, the rotation of the wafer W is stopped, and after the supply of the IPA is stopped, the number of rotations of the wafer W when the IPA is supplied to the wafer W (the first rotation) The second number of rotations of the number rotates the wafer W. Therefore, regardless of the stop of the supply of the IPA, the thickness of the liquid film of the IPA can be adjusted by adjusting the number of rotations of the wafer W. Therefore, it is possible to prevent variations in the thickness of the liquid film of the IPA and to improve the accuracy of the thickness. In this case, it is possible to prevent the IPA from being vaporized until the wafer W after the cleaning process is subjected to the drying treatment in the supercritical processing device 3, and it is possible to prevent the crystal in the supercritical treatment device 3 from being dried. The case where the circle W produces particles.

Further, according to the present embodiment, the rotation of the wafer W is stopped in the supply stop process of stopping the supply of the IPA to the surface of the wafer W. According to this, it is possible to prevent the IPA remaining on the surface of the wafer W from being discharged from the surface of the wafer W by the centrifugal force during the supply stop process, and the liquid film of the IPA on the wafer W can be maintained with the surface tension. Therefore, the thickness of the liquid film at the start of the liquid amount adjustment process can be ensured, and the liquid film of the IPA after the liquid amount adjustment process can be adjusted to a desired thickness.

Further, according to the present embodiment, in the supply stop process of stopping the supply of the IPA to the surface of the wafer W, the supply of the IPA is stopped after the rotation of the wafer W is stopped. That is, even if the control unit 4 simultaneously transmits a stop command to the motor 20 and a closing command to the IPA switch valve 31, the timing at which the IPA switch valve 31 is closed is stopped slower than the rotation of the wafer W. Even in this case, the IPA supplied after the rotation of the wafer W is stopped is dropped from the periphery of the wafer W. According to this, it is possible to suppress the thickness of the liquid film of the IPA at the start of the liquid amount adjustment process from being thick, and to adjust the liquid film of the IPA after the liquid amount adjustment process to a desired thickness.

Further, according to the present embodiment, in the liquid amount adjustment process for reducing the liquid amount of the IPA forming the liquid film, the rotation of the wafer W is stopped after a certain period of time after the number of rotations of the wafer W is increased. Accordingly, it is possible to prevent the IPA forming the liquid film from being excessively discharged from the surface of the wafer W. Therefore, it is possible to prevent the thickness of the liquid film of the IPA from becoming thinner than the desired thickness, and it is possible to improve the precision of the thickness of the liquid film of the IPA.

Further, according to the present embodiment, after the liquid amount adjustment process, the wafer W is carried into the processing container 301 which is maintained at the pressure at which the processing fluid maintains the critical state, and the pressure processing fluid is supplied to the wafer W. At the same time, the treatment fluid is discharged from the processing vessel 301. Accordingly, the IPA forming the liquid film on the wafer W is replaced with the processing fluid, and thereafter, the wafer W can be dried by lowering the pressure in the processing container 301. Therefore, generation of particles on the wafer W can be prevented.

Further, in the above-described embodiment, an example in which the rotation of the wafer W is stopped in the supply stop process will be described. However, the present invention is not limited thereto, and the wafer W may be rotated by the number of rotations of the first rotation number or the number of rotations less than the first rotation number. In this case, the time until the wafer W reaches the second number of rotations in the liquid amount adjustment process can be shortened.

Further, in the above-described embodiment, an example in which the plurality of openings 332 and the plurality of additional openings 330 are provided in the second cover member 322 will be described. However, it is not limited to this. For example, it may be a configuration as shown in Figs. 12(a) and (b). In the modification shown in FIGS. 12(a) and (b), a fluid supply head 350 provided in a tubular shape is provided on the surface of the second lid member 322 on the container body 311 side. The fluid supply head 350 is formed on the surface of the second lid member 322 on the side of the container body 311 and extends in a direction perpendicular to the plane of the paper (the X direction shown in Fig. 4). The fluid supply head 350 is connected to the first supply line 63 via the supply port 313. Further, the fluid supply head 350 is provided with a plurality of openings 332 and a plurality of additional openings 330. Accordingly, the processing fluid supplied from the first supply line 63 can be supplied to the processing space 319 through the opening 332, and can be supplied to the inner surface of the sealing member 329 by adding the opening 330.

(Second embodiment)
Next, a substrate processing method, a memory medium, and a substrate processing system according to a second embodiment of the present invention will be described with reference to FIGS. 13 and 14.

In the second embodiment shown in FIG. 13 and FIG. 14 , the peripheral edge supply portion of the substrate is supplied to rotate the substrate, and the peripheral portion of the substrate is supplied with the processing liquid, and the amount of the liquid for processing the liquid film is reduced. The two liquid amount adjustment projects are mainly different, and the other configurations are slightly the same as those of the first embodiment shown in Figs. 1 to 12 . In FIGS. 13 and 14 , the same portions as those in the first embodiment shown in FIGS. 1 to 12 are denoted by the same reference numerals, and detailed description thereof will be omitted.

In the present embodiment, after the liquid amount adjustment project shown in FIG. 8(d), the peripheral supply process and the second liquid amount adjustment project are performed. Hereinafter, the peripheral supply process and the second liquid amount adjustment process in the liquid processing method according to the present embodiment will be described in more detail.

<Circumference Supply Engineering>
After the liquid amount adjustment process, as shown in FIGS. 13(a) and 14 , the wafer W is rotated by the third rotation number, and IPA is supplied to the peripheral edge portion Wa of the wafer W. In this case, first, the number of rotations of the wafer W is reduced to a third number of rotations lower than the number of rotations (second rotation number) in the liquid amount adjustment process. Next, the IPA nozzle 28 is positioned above the peripheral portion Wa of the wafer W. Next, the IPA switching valve 31 is turned on, and the IPA is supplied from the IPA supply source 30 to the IPA nozzle 28. The IPA supplied to the IPA nozzle 28 is supplied to the peripheral portion Wa of the surface of the rotating wafer W.

In the peripheral supply process, since the wafer W is rotated by the third rotation number at which the liquid coating can be formed, the IPA supplied to the peripheral edge portion Wa is stored in the peripheral edge portion Wa of the wafer W. As a result, as shown in FIG. 13(a), the liquid film of the IPA covering the surface of the wafer W is formed to be raised at the peripheral portion Wa. One of the IPAs supplied to the peripheral portion Wa is scattered outward from the outer periphery We of the wafer W in the radial direction, and is discharged from the liquid discharge ports 221 and 211. Here, the peripheral portion Wa means a region spanning a specific width from the outer periphery We of the wafer W. For example, even in the peripheral supply process, the supply point to the IPA of the wafer W (the position of the IPA nozzle 28) may be located 20 mm inside the periphery We are outside the wafer W. The IPA nozzle 28 can be positioned at a desired supply point by adjusting the entry position of the nozzle arm 24 shown in FIG.

Even in the peripheral supply process, the discharge amount (supply amount) of the IPA toward the peripheral portion Wa of the wafer W is equal to the discharge amount of the IPA toward the wafer W in the IPA liquid film forming process shown in Fig. 8(b). Also. In the peripheral supply process, for example, the discharge amount of the IPA is set to 300 mL/min, the number of rotations of the wafer W is set to 30 rpm, and the discharge of the IPA is continued for 4 seconds. The number of rotations of the wafer W in the peripheral supply process (that is, the third number of rotations) is as shown in FIG. 14 and the number of rotations of the wafer W in the IPA liquid film formation process (that is, the first rotation) Number) is equal. In this case, the IPA is prevented from scattering from the outer periphery We of the wafer W, and the thickness t4 of the liquid film of the IPA at the peripheral portion Wa of the wafer W is higher than the IPA of the inner portion Wb located further inside than the peripheral portion Wa. The thickness of the liquid film is thick t3. That is, the liquid film of the IPA in the inner portion Wb is maintained at the thickness t3 of the liquid film after the liquid amount adjustment process. In addition, the thickness t4 of the liquid film of the IPA of the peripheral portion Wa after the peripheral supply process is thicker than the thickness t5 of the liquid film of the IPA of the peripheral portion Wa after the second liquid amount adjustment process. In other words, the liquid amount of the IPA of the peripheral portion Wa after the peripheral supply process is larger than the liquid amount of the IPA of the peripheral portion Wa after the second liquid amount adjustment process.

<Second liquid volume adjustment project>
After the peripheral supply process, as shown in FIG. 13(b) and FIG. 14, the IPA is stopped from being supplied to the wafer W, and the IPA of the liquid film on the surface of the wafer W is lowered while the wafer W is rotated. Liquid volume. In this case, first, the IPA switching valve 31 is turned off, and the supply of the IPA to the wafer W is stopped. Next, the number of rotations of the wafer W is made larger than the third rotation number, and the fourth rotation number is set to be equal to or less than the second rotation number. As a result, as the centrifugal force generated by the rotation of the wafer W increases, the coating liquid scatters from the outer periphery of the wafer W toward the outer side in the radial direction of the IPA of the peripheral portion Wa of the wafer W from the liquid discharge port. 221, 211 are discharged. In addition, by setting the fourth number of rotations to be equal to or less than the second number of rotations, IPA is prevented from moving from the inner portion Wb of the wafer W to the outer peripheral side. In addition, during this period, the IPA switching valve 31 is maintained in a closed state, and IPA is not supplied to the surface of the wafer W. In this manner, the thickness t3 of the liquid film of the IPA at the inner portion Wb of the wafer W is maintained at the thickness t3 after the liquid amount adjustment project shown in FIG. 8(d), and the IPA at the peripheral portion Wa is lowered. The amount of liquid coating. As a result, the thickness t5 of the liquid film of the IPA of the peripheral portion Wa is thinner than the thickness t4 of the liquid film of the IPA of the peripheral portion Wa after the peripheral edge supply. Therefore, the thickness of the liquid film of the IPA at the peripheral portion Wa becomes a desired thickness, and the total liquid amount of the IPA on the surface of the wafer W is adjusted to a desired amount.

Further, even during the second liquid amount adjustment process, the IPA liquid film is maintained in the shape of the peripheral edge Wa of the wafer W in accordance with the centrifugal force of the rotation of the wafer W and the viscosity of the IPA. In addition, the total liquid amount of the IPA after the second liquid amount adjustment project of the present embodiment is the same as the IPA after the liquid amount adjustment project shown in Fig. 8(d) of the first embodiment. In the case where the amount of liquid coating is equal, the number of revolutions of the wafer W in the liquid amount adjustment process before the peripheral supply of the present embodiment is increased, so that the liquid amount of the IPA after the liquid amount adjustment process can be reduced.

In the second liquid amount adjustment process, the thickness of the liquid film of the IPA at the peripheral edge portion Wa can be adjusted to be arbitrary by adjusting the fourth number of rotations or the time from the start of rotation to the stop of the fourth rotation number. Further, in order to shorten the processing time of the wafer W, even if the time to restart the rotation of the wafer W to the stop is set to be short (for example, 1 second), the liquid of the IPA of the peripheral portion Wa can be set in this time. The number of revolutions of the wafer W in which the thickness of the film is adjusted to a desired thickness may be used.

As a result, the cleaning process of the wafer W is completed. At this time, a liquid film having an IPA having a desired thickness (or a coating amount) is formed on the surface of the wafer W to prevent drying of the wafer W. Further, the liquid film is embossed at the peripheral edge portion Wa of the wafer W, and is maintained in a shape in which the thickness of the peripheral edge portion Wa is thicker than the thickness of the inner portion Wb.

After the cleaning process of the wafer W is completed, the wafer W is dried in the same manner as in the first embodiment.

As described above, according to the present embodiment, the peripheral portion Wa of the wafer W is supplied with IPA while rotating the wafer W. Accordingly, a liquid film ridge of IPA can be formed on the peripheral portion Wa of the wafer W.

Here, until the wafer W after the cleaning process is dried in the supercritical processing apparatus 3, the IPA of the peripheral portion Wa in the surface of the wafer W becomes closer to the inner portion Wb located inside the peripheral portion Wa. The IPA is easier to vaporize. As a result, the peripheral portion Wa of the wafer W is dried first, and the IPA remains in the inner portion Wb. When the peripheral portion Wa of the wafer W is dried first, a so-called pattern collapse occurs in the peripheral portion Wa. In order to prevent the peripheral portion Wa of the wafer W from being dried, a method of thickening the thickness of the liquid film of IPA on the surface of the wafer W as a whole may be considered. However, in this method, since the amount of the IPA on the surface of the wafer W is increased, particles are easily generated on the surface of the wafer W after the drying process in the supercritical processing apparatus 3.

On the other hand, in the present embodiment, as described above, the liquid film ridge of IPA is formed on the peripheral edge portion Wa of the wafer W. Therefore, IPA can be left in the peripheral portion Wa of the wafer W for a long period of time, and the wafer W can be prevented from drying out from the peripheral portion Wa. Therefore, the entire surface of the wafer W after the cleaning process is covered, and it is possible to prevent the IPA from being vaporized until the drying process is performed in the supercritical processing apparatus 3. Further, it is possible to suppress an increase in the thickness of the liquid film of IPA in the inner portion Wb of the wafer W. Accordingly, it is possible to suppress an excessive increase in the amount of IPA on the surface of the wafer W, and it is possible to prevent the occurrence of particles on the wafer W after the drying process in the supercritical processing apparatus 3.

Further, according to the present embodiment, the peripheral supply of the IPA to the peripheral edge portion Wa of the wafer W is performed after the liquid amount adjustment process for reducing the liquid amount of the IPA forming the liquid film. Accordingly, the liquid film of IPA on the surface of the wafer W can be maintained in a shape in which the peripheral portion Wa is raised for a long time. Therefore, it is possible to further prevent the IPA from vaporizing the entire surface of the wafer W until the drying process is performed in the supercritical processing apparatus 3.

In the present embodiment, after supplying the peripheral edge supply of the IPA to the peripheral portion Wa of the wafer W, the second amount of liquid which reduces the amount of liquid of the IPA forming the liquid film on the surface of the wafer W is performed. Adjust the project. Accordingly, the thickness of the liquid film of the IPA at the peripheral portion Wa of the wafer W can be adjusted to improve the accuracy. Therefore, it is possible to further prevent the occurrence of particles on the wafer W after the drying process in the supercritical processing device 3.

In the second liquid amount adjustment process, the fourth rotation number is equal to or less than the number of rotations (second rotation number) of the wafer W before the circumferential supply process. , the wafer W is rotated. According to this, it is possible to suppress the case where the IPA moves from the inner side portion Wb located on the inner side of the peripheral edge portion Wa of the wafer W to the outer peripheral side. Therefore, the thickness of the liquid film of the IPA in the inner portion Wb can be maintained at the thickness after the liquid amount adjustment process, and the accuracy of the thickness of the liquid film can be improved.

In the above-described embodiment, the third rotation number of the wafer W to be supplied to the periphery is set to be equal to the first rotation number of the wafer W in the IPA liquid film formation process. However, the present invention is not limited thereto, and if the liquid film of IPA can be formed in the peripheral portion Wa, the third rotation number may be larger or smaller than the first rotation number.

Furthermore, in the above-described embodiment, an example in which the second liquid amount adjustment project is performed after the peripheral supply project is described will be described. However, it is not limited to this. For example, even after the second rinsing process shown in FIG. 8(a), before the IPA liquid film forming process shown in FIG. 8(b), the peripheral supply process may be performed. Even in this case, the liquid film of IPA can be embossed at the peripheral portion Wa of the wafer W, and the liquid film of such IPA can be maintained even after the second liquid amount adjustment project shown in FIG. 13(b). shape.

Further, by appropriately adjusting the discharge amount or discharge time of the IPA supplied to the peripheral portion Wa of the wafer W in the peripheral supply process, and the number of rotations of the wafer W, the periphery of the wafer W can be accurately adjusted. When the thickness of the liquid film of the IPA of the part Wa is not performed, the second liquid amount adjustment process may not be performed. In this case, even if the IPA discharge amount toward the peripheral portion Wa of the wafer W in the peripheral supply process is smaller than the discharge amount of the IPA toward the wafer W in the IPA liquid film formation process shown in FIG. 8(b), . Further, even if the IPA discharge time to the peripheral edge portion Wa of the wafer W is short (for example, 2 seconds). According to this, it is possible to suppress an excessive increase in the thickness of the liquid film of the IPA of the peripheral portion Wa, and it is possible to prevent the occurrence of particles on the wafer W after the drying in the supercritical processing apparatus 3.

In addition, the present invention is not limited to the above-described respective embodiments and modifications, and constituent elements may be modified and embodied in the implementation stage without departing from the scope of the invention. Further, various inventions can be formed by combining appropriate combinations of the plurality of constituent elements disclosed in the above embodiments and modifications. It is also possible to delete several constituent elements from the entire constituent elements and the entire constituent elements shown in the respective modifications. Further, even if the components that cover different embodiments and modifications are combined as appropriate, they may be combined.

1‧‧‧Substrate processing system

2‧‧‧cleaning device

3‧‧‧Supercritical treatment unit

4‧‧‧Control Department

20‧‧‧Motor

23‧‧‧ Wafer Holding Mechanism

27‧‧‧ rinse liquid nozzle

28‧‧‧IPA nozzle

32‧‧‧IPA Supply Department

301‧‧‧Processing container

W‧‧‧ wafer

Wa‧‧‧The Peripheral Department

Fig. 1 is a transverse plan view of a substrate processing system in a first embodiment.

Figure 2 is a longitudinal cross-sectional view of a cleaning apparatus provided in the substrate processing system shown in Figure 1.

Fig. 3 is a view showing an IPA supply system in the washing apparatus of Fig. 1.

Figure 4 is a perspective view showing the appearance of a processing container of the supercritical processing apparatus.

Fig. 5 is a cross-sectional view showing an example of the processing container shown in Fig. 4;

Fig. 6 (a) is a cross-sectional view showing the periphery of the maintenance opening of the processing container shown in Fig. 5, and Fig. 6 (b) is a view showing the surface of the second cover member of Fig. 6 (a) on the container main body side. .

Fig. 7 is a system diagram of a supercritical processing apparatus in the first embodiment.

Fig. 8(a) is a view for explaining a second rinsing process in the substrate processing method in the first embodiment, and Fig. 8(b) is a view for explaining an IPA liquid film forming process, Fig. 8 (c) is a diagram for explaining the supply stoppage, and FIG. 8(d) is a diagram for explaining the liquid amount adjustment project.

Fig. 9 is a view showing a transition of the number of rotations of the substrate in the substrate processing method of Fig. 8.

FIGS. 10(a) to 10(d) are diagrams for explaining the drying mechanism of the IPA, that is, an enlarged cross-sectional view schematically showing a pattern of a concave portion included in the wafer.

Figure 11 is a cross-sectional view showing a method of repairing a processing container of a supercritical processing apparatus.

Fig. 12 (a) is a cross-sectional view showing a modification of the periphery of the maintenance opening of the processing container shown in Fig. 5, and Fig. 12 (b) is a cross-sectional view showing the second cover member of Fig. 12 (a).

Fig. 13 (a) is a diagram for explaining the IPA liquid-repellent work in the substrate processing method of the second embodiment, and Fig. 13 (b) is a view for explaining the second liquid amount adjustment project.

Fig. 14 is a view showing a transition of the number of rotations of the substrate in the substrate processing method of Fig. 13;

Claims (12)

A substrate processing method comprising: a liquid film forming process for rotating a substrate with a first number of rotations, and supplying a processing liquid to a surface of the substrate to form a liquid film of the processing liquid covering a surface of the substrate; After the liquid film forming process, the number of rotations of the substrate is equal to or less than the number of rotations of the first rotation number, and the supply of the processing liquid to the substrate is stopped; In the liquid amount adjustment process, after the supply stoppage process, the number of rotations of the substrate is made larger than the second rotation number of the first rotation number, and the liquid amount of the treatment liquid forming the liquid film is lowered. The substrate processing method as recited in claim 1, wherein In the supply stop process, the rotation of the substrate is stopped. The substrate processing method as set forth in claim 2, wherein After the supply stop process is stopped and the rotation of the substrate is stopped, the supply of the processing liquid is stopped. The substrate processing method as recited in claim 1, wherein In the supply stop process, the substrate is rotated by the number of rotations of the first rotation number or less. A substrate processing method as set forth in any one of claims 1 to 4, wherein In the liquid amount adjustment process, after the predetermined number of revolutions of the substrate are increased, the rotation of the substrate is stopped. A substrate processing method as set forth in any one of claims 1 to 4, wherein Further, a peripheral supply process is provided in which the processing liquid is supplied while rotating the substrate to face a peripheral portion of the substrate. The substrate processing method as set forth in claim 6, wherein The peripheral supply engineering described above is performed after the above-described liquid amount adjustment project. The substrate processing method as set forth in claim 7, wherein Further, the second liquid amount adjustment process is performed, after the peripheral supply process is performed, the supply of the processing liquid to the substrate is stopped, and the liquid amount of the processing liquid forming the liquid film is lowered while rotating the substrate. The substrate processing method as set forth in claim 8, wherein In the second liquid amount adjustment project, the substrate is rotated by the number of rotations of the second rotation number or less. A substrate processing method as set forth in any one of claims 1 to 4, wherein Further with: After the liquid amount adjustment process is performed, the substrate is carried into the processing container in a state in which the liquid film of the processing liquid is formed; a drying process in which the pressurized processing fluid is supplied to the processing container after the loading operation, and the pressure in the processing container is maintained at a pressure at which the processing fluid maintains a critical state, and the processing container is supplied. The treatment fluid is pressed, and the treatment fluid is discharged from the treatment container to dry the substrate. A memory medium having a program recorded by a computer for controlling an operation of a substrate processing system, wherein the computer controls the substrate processing system to execute one of the claims 1 to 4 Substrate processing method. A substrate processing system having: a holding portion that maintains the substrate horizontally; a rotation driving portion that rotates the holding portion; a processing liquid supply unit that supplies the processing liquid to the substrate held by the holding unit; Control department, The control unit controls the rotation drive unit and the processing liquid supply unit to perform: a liquid film forming process for rotating the substrate by a first number of rotations, and supplying the treatment liquid to a surface of the substrate to form a liquid film of the treatment liquid covering the surface of the substrate; After the liquid film forming process, the number of rotations of the substrate is equal to or less than the number of rotations of the first rotation number, and the supply of the processing liquid to the substrate is stopped; In the liquid amount adjustment process, after the supply stoppage process, the number of rotations of the substrate is made larger than the second rotation number of the first rotation number, and the liquid amount of the treatment liquid forming the liquid film is lowered.