SUBSTRATE PROCESSING APPARATUS AND SUBSTRATE PROCESSING METHOD

Abstract

To suppress the generation of particles on a front surface of a substrate when drying the substrate using processing fluid in a supercritical state.SOLUTION: A substrate processing apparatus using supercritical fluid thereby drying a substrate in which a liquid film is formed on a pattern formation surface, comprises: a processing container which houses the substrate and is supplied with supercritical fluid; a substrate holding section which includes a base portion supporting the substrate from below while the pattern formation surface is directed to an upper direction, and which holds the substrate within the processing container; a first detection section which detects an inclination against a horizontal surface of the base portion; a posture adjustment mechanism which adjusts the inclination against the horizontal surface of the base portion; and a control section which performs horizontal-positioning of the base portion by controlling the posture adjustment mechanism on the basis of a detection result of the first detection section.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] In recent years, in the manufacture of semiconductor devices, a supercritical drying process is being performed in which a substrate, the upper surface of which is wetted with a processing liquid, is brought into contact with a processing fluid in a supercritical state, and the processing liquid is replaced with the processing fluid in the supercritical state to dry the substrate. Patent Document 1 describes a supercritical drying method and an apparatus for carrying out the method. Patent Document 1 describes a method in which a small flow rate of supercritical fluid is first supplied below the substrate in a chamber to prevent damage to the substrate due to initial pressurization, and a large flow rate of supercritical fluid is supplied toward the upper surface of the substrate after the pressure in the chamber reaches a predetermined pressure. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-251550 A Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique capable of suppressing particles from being generated on the surface of a substrate when the substrate is dried using a processing fluid in a supercritical state. [Means for solving the problem]

[0005] According to one aspect of the present disclosure, there is provided a substrate processing apparatus that uses a supercritical fluid to dry a substrate having a liquid film formed on a pattern forming surface, the substrate processing apparatus comprising: a processing vessel that accommodates the substrate and to which the supercritical fluid is supplied; a substrate holding portion that has a base portion that supports the substrate from below with the pattern forming surface facing upward and holds the substrate within the processing vessel; and a first detection portion that detects the inclination of the base portion with respect to a horizontal plane. Effect of the Invention

[0006] According to the present disclosure, when a substrate is dried using a processing fluid in a supercritical state, generation of particles on the surface of the substrate can be suppressed. [Brief description of the drawings]

[0007] [Figure 1] 1 is a vertical sectional side view of a substrate processing apparatus according to an embodiment of the present invention; [Diagram 2] FIG. 4 is a schematic vertical sectional side view showing an example of the configuration of a posture adjustment mechanism. [Diagram 3] 13 is a plan view seen from below the substrate holding part for explaining the irradiation position of the detection light, etc. FIG. [Figure 4] 13 is a plan view seen from above the substrate holding part for explaining the irradiation position of the detection light, etc. FIG. [Diagram 5] 13 is a plan view seen from above a substrate holding part for explaining the arrangement of suction pads in a first modified embodiment. FIG. [Figure 6] 13 is a vertical sectional side view of a substrate processing apparatus according to a second modified embodiment, which is provided with a distance measuring sensor for detecting the inclination of a lid body. FIG. [Figure 7] 7 is a front view of the lid shown in FIG. 6 for explaining the irradiation position of the detection light on the lid. FIG. [Figure 8] 13 is a vertical sectional side view of a substrate processing apparatus according to a third modified embodiment, which is provided with a tilt sensor for detecting the tilt of a lid body. FIG. [Figure 9] 9 is a front view of the lid shown in FIG. 8 for explaining the arrangement of the tilt sensor on the lid. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] A supercritical drying apparatus 1 as an embodiment of a substrate processing apparatus will be described with reference to the accompanying drawings. For ease of explanation, directions will be indicated using an XYZ Cartesian coordinate system shown in each drawing as necessary. The X and Y directions are horizontal directions perpendicular to each other, and the Z direction is a vertical direction.

[0009] 1, the supercritical drying apparatus 1 has a processing vessel 10 formed as a supercritical chamber. A processing space 12 is formed inside the processing vessel 10. The processing vessel 10 has an opening 14, which serves as an entrance to the processing space 12, on its side surface.

[0010] The processing vessel 10 has a fluid supply unit 16 and a fluid discharge unit 18. A processing fluid is supplied to the fluid supply unit 16 from a supply source of supercritical processing fluid (e.g., carbon dioxide in a supercritical state) (not shown) (see arrow), and is discharged from the fluid supply unit 16 into the processing space 12. The fluid supply unit 16 is, for example, a bar nozzle. The processing fluid is discharged to the outside of the processing space 12 via the fluid discharge unit 18 (see arrow). A detailed description of the supply system and discharge system of the processing fluid will be omitted, but any known configuration in a supercritical drying apparatus can be adopted.

[0011] The supercritical drying apparatus has a substrate holding unit 20. In the illustrated embodiment, the substrate holding unit 20 is formed as a tray that is movable in the horizontal direction (X direction), and has a roughly plate-shaped base unit 22 and a lid body 24 connected to one end of the base unit 22.

[0012] At least three (four in the illustrated example) support pins 26 are provided on the upper surface of the base portion (base portion main body) 22 so as to protrude upward. The support pins 26 can be raised and lowered in the vertical direction, for example, by a linear actuator 260 (see FIG. 2) built into the base portion (base portion main body) 22. The support pins 26 can be used mainly to finely adjust the height position and attitude (inclination with respect to the horizontal plane) of a substrate W such as a semiconductor wafer supported by the support pins 26. Note that, here, the portion (plate-shaped portion) of the base portion 22 excluding the support pins 26 is also referred to as the base portion main body.

[0013] Between the base 22 and the lid 24, a posture adjustment mechanism 28 is provided for adjusting the inclination of the base 22 with respect to the horizontal plane. As shown in FIG. 2, the posture adjustment mechanism 28 can be configured, for example, from a base 281 having a U-shaped (square bracket) cross section and a total of eight movable push pins 282 attached to the base 281. Each movable push pin 282 can be moved in the vertical direction by a linear actuator 283. The linear actuator 283 may include, for example, a ball screw. The eight movable push pins 282 are divided into two sets. As shown diagrammatically in FIG. 4, a first set of four movable push pins 282 is provided on one side of the lid 24, and a second set of four movable push pins 282 is provided on the other side of the lid 24. With this configuration, it is clear that the inclination of the base 22 with respect to the horizontal plane (specifically, both the inclination direction and the inclination amount) can be freely adjusted by adjusting the height position (Z-direction position) of the tip of each movable push pin 282. The configuration of the attitude adjustment mechanism 28 is not limited to that shown in FIG. 2, and any configuration can be adopted as long as it allows the inclination of the base portion 22 with respect to the horizontal plane to be freely adjusted.

[0014] The substrate holding part 20 can move horizontally back and forth between a "processing position (position shown in FIGS. 6 and 8 described below)" and a "retracted position (position shown in FIG. 1)." When the substrate holding part 20 is in the processing position, the lid 24 is inserted into the opening 14 of the processing vessel 10 to seal the opening 14, and the base part 22 is housed in the processing space 12. When the substrate holding part 20 is in the retracted position, the lid 24 opens the opening 14, and the base part 22 retracts to the outside of the processing space 12.

[0015] The processing vessel 10 is fixed to a pedestal 30. The pedestal 30 may be configured, for example, in a generally rectangular shape in plan view with the X direction as the long side direction and the Y direction as the short side direction. The pedestal 30 is attached to a machine frame 40 of the substrate processing apparatus via three or more (for example, four) lifting actuators 32. The machine frame 40 may be regarded as an immovable structure to which various components of the supercritical drying apparatus are fixed. The lifting actuators 32 may be provided at the four corners of the rectangular pedestal 30. The lifting actuators 32 may be, for example, a linear actuator having an electric rotary motor and a ball screw or the like.

[0016] A guide rail 34 extending in the horizontal direction (X direction) is provided on the base 30. A running body 36 is provided on the guide rail 34 and moves along the guide rail 34 by a driving force generated by a driving mechanism (not shown, for example, built in the running body 36). The substrate holding part 20 is attached to the running body 36 via an arm 38. Therefore, by moving the running body 36 along the guide rail 34, the substrate holding part 20 can be moved between the processing position and the retracted position described above.

[0017] A substrate lifter 60 that can be raised and lowered in the vertical direction by a substrate lifter movement mechanism (not shown) is provided below the substrate holding part 20 in the retracted position. The substrate lifter 60 has three or more lift pins 62 (three in the illustrated example). By raising the substrate lifter 60 to a raised position, the substrate W supported by the substrate holding part 20 (specifically, the support pins 26) can be supported and lifted by the tips of the lift pins 62. To enable this, the base part 22 is provided with through holes through which the lift pins 62 can pass. The position of the through holes is indicated by reference symbol 62P in Figures 3 and 4.

[0018] When the substrate lifter 60 is in the raised position, the substrate W can be transferred between the substrate lifter 60 and a substrate transport arm (not shown) that has entered the supercritical drying apparatus 1 from the rear side toward the front side in the Y direction of FIG. 1. That is, when the substrate W is loaded, the following procedures (S1) to (S3) are performed to load the substrate W before processing. (S1) With the substrate holder 20 in the retracted position, the empty substrate lifter 60 is positioned in the raised position. (S2) The substrate transport arm (not shown) places the substrate W on the lift pins 62 of the substrate lifter 60. (S3) After the substrate transport arm is retracted from above the base portion 22, the substrate lifter 60 is lowered, thereby transferring the substrate W from the substrate lifter 60 to the support pins 26 of the base portion 22. When the substrate W is unloaded after processing, the above procedures are performed in reverse.

[0019] Board lifter 60 may be configured to be movable only in the vertical direction, and in this case, it is still possible to avoid interference between board lifter 60 and its peripheral components. Alternatively, board lifter 60 may be configured to be movable not only in the vertical direction but also in the Y direction (the depth direction of the paper in FIG. 1). This makes it easier to avoid interference between board lifter 60 and its peripheral components.

[0020] The supercritical drying apparatus 1 has a plurality of distance measuring sensors. The distance measuring sensors can be optical distance measuring sensors using, for example, infrared rays or lasers. The distance measuring sensors are fixed to the machine frame 40 itself or to a sensor holder (not shown) fixed to the machine frame 40. The plurality of distance measuring sensors include a plurality (four in the illustrated example) of first distance measuring sensors 51, a plurality (five in the illustrated example) of second distance measuring sensors 52, a plurality (five in the illustrated example) of third distance measuring sensors 53, and a plurality (four in the illustrated example) of fourth distance measuring sensors 54.

[0021] The first distance measuring sensors 51 are positioned below the base portion 22 of the substrate holding portion 20, which is in the retracted position (the position shown in Figure 1), and measure the vertical distance (the distance measured along the Z direction) from each of the first distance measuring sensors 51 to the underside of the base portion 22 of the substrate holding portion 20.

[0022] The second distance measuring sensors 52 are located below the base 22 of the substrate holding part 20 in the retracted position, and measure the vertical distance from each of the second distance measuring sensors 52 to the bottom surface of the substrate W supported on the base 22 of the substrate holding part 20 (specifically, on the support pins 26). In order to allow the sensor light of the second distance measuring sensors 52 to reach the bottom surface of the substrate W, the base 22 of the substrate holding part 20 is provided with through holes of the same number as the second distance measuring sensors 52. The through holes are located on the optical axis (optical path of the sensor light) of the second distance measuring sensors 52 when the substrate holding part 20 is in the retracted position. The through holes can be provided, for example, at the position indicated by reference symbol 52p in FIG. 3 and FIG. 4.

[0023] As long as the sensor light of the second distance measuring sensor 52 can reach the lower surface of the substrate W, it is not necessary to provide the same number of through holes as the second distance measuring sensors 52. In other words, it is sufficient that the base portion 22 has some kind of cutout.

[0024] The third distance measuring sensors 53 are positioned above the base 22 of the substrate holding part 20 when it is in the retracted position, and measure the vertical distance from each of the third distance measuring sensors 53 to the upper surface of the substrate W supported on the base 22 of the substrate holding part 20 (more specifically, the surface of the liquid film formed on the upper surface of the substrate W).

[0025] The fourth distance measuring sensors 54 are positioned above the four corners of the pedestal 30, and measure the vertical distance from each of the fourth distance measuring sensors 54 to the four corners of the pedestal 30. Based on the measurement value of the fourth distance measuring sensors 54, the inclination of the pedestal 30 with respect to the horizontal plane (the inclination of the upper surface of the pedestal 30) can be detected.

[0026] In Figure 3, an example of an irradiation position 51p of the sensor light of the first distance measurement sensor 51 on the underside of the base part 22 is shown by a black circle. A large circle We shown by a dashed line indicates the position of the periphery (edge) of the substrate W. The irradiation position 51p of the sensor light of the first distance measurement sensor 51 is located near the periphery of the substrate W in a planar view. The irradiation positions 51p are located on the circumference of a circle centered on the center of the substrate W, and are each arranged at an angular position obtained by dividing the circumference into N equal parts (N is the number of first distance measurement sensors, which is 4 in the illustrated example).

[0027] The tilt direction and amount of tilt (tilt angle) of the base unit 22 with respect to the horizontal plane (plane perpendicular to the direction of gravity) can be identified based on the detection value of the first distance measuring sensor 51. It is clear that the tilt direction and amount of tilt of the base unit 22 can be identified if N is 3 or more, but here, N=4 is set for redundancy to increase the reliability of the measurement.

[0028] Note that the first distance measuring sensor 51 is calibrated (mechanically, electrically, or by calculation) when the supercritical drying apparatus 1 is installed so that, for example, if the surface to be measured (here, the lower surface of the base portion 22) is horizontal, the detection values ​​of the first distance measuring sensor 51 are all the same. This is also true for the second to fourth distance measuring sensors.

[0029] 3, white circles indicate examples of irradiation positions 52p of the sensor light of the second distance measurement sensor 52 on the underside of the substrate W. There is one irradiation position 52p of the sensor light of the second distance measurement sensor 52 at the center of the substrate W and four irradiation positions 52p near the periphery of the substrate W. The four irradiation positions 52p near the periphery of the substrate W are located on a circumference of a circle centered at the center of the substrate W and at angular positions obtained by dividing the circumference into four equal parts.

[0030] The tilt direction and amount of tilt (tilt angle) of the substrate W with respect to the horizontal plane can be identified based on the detection value of the second distance measuring sensor 52. Since an IPA liquid film exists on the front surface of the substrate W, it is difficult to accurately measure the tilt of the substrate W itself from the front surface side of the substrate W. However, it is possible to accurately measure the tilt of the substrate W by irradiating the rear surface of the substrate W with detection light.

[0031] In addition, since the irradiation position 52p of the second distance measuring sensor is set at the center of the substrate W, it is possible to detect any bending of the substrate W. The number of the second distance measuring sensors 52 is not limited to five and can be changed according to the required redundancy.

[0032] 3, it is preferable to attach two arms 38 to both sides of the cover 24 of the substrate holder 20. This facilitates device design (component layout) that ensures that the arm 38 does not interfere with (clash with) the first distance measuring sensor 51 and the second distance measuring sensor 52 within its movement range.

[0033] 4, an example of an irradiation position 53p of the sensor light of the third distance measurement sensor 53 on the upper surface of the substrate W (more specifically, the surface of the liquid puddle on the upper surface) is shown by a hatched circle. As with the second distance measurement sensor 52, the irradiation positions 53p of the sensor light of the third distance measurement sensor 53 are set to one at the center of the substrate W and four near the periphery. In the illustrated example, the irradiation position 53p of the sensor light of the third distance measurement sensor 53 is shifted by 45 degrees around the center of the substrate W from the irradiation position 52p of the sensor light of the second distance measurement sensor 52, but this is not limited to this.

[0034] Based on the detection value of the third distance measuring sensor 53, the height and uniformity of the liquid level of the liquid film (puddle) on the upper surface of the substrate W can be detected. If the liquid level is too high, the liquid may come into contact with the lower surface of the ceiling wall that defines the processing space 12 of the processing vessel 10. If the liquid level is too low, drying may be insufficient due to early drying. If the liquid level is non-uniform, the liquid may come into local contact with the lower surface of the ceiling wall. Furthermore, if the liquid level is non-uniform, the thickness of the liquid film may be non-uniform, which may result in localized drying failure, large amounts of particles, or pattern collapse.

[0035] For example, the four support pins 26 provided on the upper surface of the base portion 22 can be provided directly below the irradiation positions 53p (four near the periphery) of the sensor light of the third distance measuring sensor 53. Alternatively, the four support pins 26 may be disposed at angular positions obtained by dividing the circumference of a circle centered on the center of the substrate W into four equal parts.

[0036] As shown in FIG. 1, the supercritical drying apparatus 1 has a control unit 100. The control unit 100 is, for example, a computer, and includes an arithmetic unit 101 and a storage unit 102. The storage unit 102 stores programs for controlling various processes executed in the supercritical drying apparatus 1 (or a substrate processing system including the supercritical drying apparatus 1). The arithmetic unit 101 controls the operation of the supercritical drying apparatus by reading and executing the programs stored in the storage unit 102. The program may be recorded in a computer-readable storage medium and installed from the storage medium into the storage unit 102 of the control unit 100. Examples of computer-readable storage media include a hard disk (HD), a flexible disk (FD), a compact disk (CD), a magnet optical disk (MO), and a memory card.

[0037] Next, the operation of the supercritical drying apparatus 1 will be described, particularly the operation from the time when the substrate W is transferred from the substrate transport arm (not shown) to the support pins 26 of the substrate holder 20 at the retreat position via the substrate lifter 60 until the time when the substrate holder 20 moves from the retreat position to the processing position for processing the substrate W. Note that, for example, this substrate W has an IPA puddle (liquid film) formed on its surface (pattern formation surface), and the inside of the pattern recess on the surface is filled with IPA. For example, this substrate W has been subjected to (1) chemical liquid processing such as wet etching and chemical cleaning, (2) rinsing processing in which the chemical liquid is washed away with a rinsing liquid, and (3) IPA replacement processing in which the rinsing liquid is replaced with IPA to form an IPA puddle (liquid film) in a single-wafer cleaning apparatus (not shown) in sequence. In many cases, a plurality of supercritical drying apparatuses 1 and a plurality of the above-mentioned single-wafer cleaning apparatuses are combined to form one substrate processing (liquid processing and drying) system, and the substrate is transported by the above-mentioned substrate transport arm in this substrate processing system.

[0038] The operations described below are automatically performed under the control of the control unit 100 based on a processing recipe stored in the storage unit 102 of the control unit 100 or transmitted from a host computer of the control unit 100.

[0039] <Adjustment step 1: Leveling the base 30> First, the substrate W placed with its surface (pattern-formed surface) facing upward on the support pins 26 of the substrate holder 20 at the retreated position is irradiated with detection light from each of the first to third distance measuring sensors 51 to 53, and detection light from the fourth distance measuring sensor 54 is irradiated to the four corners of the upper surface of the pedestal 30. Then, based on the detection result of the fourth distance measuring sensor 54, the inclination of the pedestal 30 with respect to the horizontal plane is detected. If the inclination exceeds an allowable range, the leveling of the pedestal 30 is performed by appropriately operating one or more of the four lifting actuators 32. Note that the leveling (inclination adjustment) of the pedestal 30 is not limited to the timing immediately before the substrate processing, and may be performed during standby after the substrate processing (for example, when waiting for the next substrate W to be carried in after the substrate W has been carried out from the supercritical drying apparatus 1). The leveling of the pedestal 30 may be performed at any timing during the operation of the supercritical drying apparatus 1, for example, during the supercritical drying process.

[0040] <Adjustment step 2: Leveling the base portion 22> Next, detection light is again emitted from each of the first to fourth distance measuring sensors 51 to 54. Then, the inclination of the base part 22 with respect to the horizontal plane is detected based on the detection result of the first distance measuring sensor 51. If the inclination exceeds the allowable range, the attitude adjustment mechanism 28 provided in the substrate holding part 20 is operated to adjust the level of the base part 22.

[0041] <Adjustment process 3: Leveling the board W> Next, detection light is emitted from each of the first to fourth distance measuring sensors 51 to 54. Then, the inclination of the substrate W on the base part 22 with respect to the horizontal plane is detected based on the detection result of the second distance measuring sensor 52. If the inclination exceeds the allowable range, the support pins 26 provided on the base part 22 are operated to level the substrate W.

[0042] <Adjustment step 4: Adjusting the height of the substrate W> Next, detection light is emitted from each of the first to fourth distance measuring sensors 51 to 54. Then, based on the detection result of the third distance measuring sensor 53, the height of the surface of the IPA paddle above the surface of the substrate W on the base part 22 is detected. If the height exceeds the allowable range, the support pins 26 provided on the base part 22 are operated to lower the height of the substrate W to an appropriate height.

[0043] <Adjustment process 5: Final confirmation> Next, detection light is emitted from each of the first to fourth distance measuring sensors 51 to 54. If there are no problems with the inclination of pedestal 30 with respect to the horizontal plane, the inclination of base portion 22 with respect to the horizontal plane, the inclination of substrate W with respect to the horizontal plane, and the height of the surface of the IPA paddle above the surface of substrate W, which are determined from the detection values ​​of the first to fourth distance measuring sensors 51 to 54, substrate holding portion 20 can be moved to the processing position, and the supercritical drying process can be started.

[0044] The supercritical drying process can be performed by a known method described in the applicant's prior applications (e.g., JP 2020-170873 A, and many others). For example, the processing space 12 is pressurized to a predetermined pressure by supplying a processing fluid (e.g., carbon dioxide) from a supply source (not shown) of the processing fluid in a supercritical state into the processing space 12 (pressurization process), and then the IPA on the substrate W is replaced with the processing fluid by circulating the supercritical fluid in the processing space 12 (circulation process). When the replacement is completed, the processing fluid is discharged from the processing space 12 and the processing space 12 is depressurized to normal pressure. This causes the processing fluid in the supercritical state to evaporate, and the substrate W can be dried while preventing pattern collapse. If the surface of the substrate W is inclined at this time, the in-plane uniformity of the IPA film thickness is deteriorated, which causes the in-plane uniformity of the supercritical fluid replacement to deteriorate, which may cause pattern collapse or particle level deterioration. However, according to this embodiment, the surface of the substrate W can be stably maintained horizontally, and a desirable processing result can be obtained.

[0045] It is preferable to perform all of the following before processing each substrate W: (1) adjustment of the inclination of the pedestal 30 relative to the horizontal plane (leveling of the pedestal 30), (2) adjustment of the inclination of the base 22 relative to the horizontal plane (leveling of the base 22), (3) adjustment of the inclination of the substrate W relative to the horizontal plane (leveling of the substrate W), and (4) adjustment of the height of the surface of the IPA paddle above the surface of the substrate W (adjustment of the substrate height). However, it takes a certain amount of time to perform all of the adjustments. If the adjustments take too long, the IPA paddle may dry out, causing the film thickness of the paddle to become thin, or the paddle may partially disappear, exposing the surface of the substrate W. In this case, too, pattern collapse or a deterioration in particle levels may occur.

[0046] To prevent the above problems from occurring, when a predetermined time has elapsed since the substrate W was loaded into the substrate holding unit 20, the above adjustments (1) to (4) may be stopped midway, and the substrate holding unit 20 may be moved to the processing position to start the supercritical drying process. In this case, the remaining adjustments may be performed when the next substrate W is loaded into the substrate holding unit 20. That is, for example, when a predetermined time has elapsed after the above adjustments (1) and (2) for the first substrate W have been completed, the adjustments may be terminated at that point, and the above adjustments (3) and (4) may be performed for the second substrate W.

[0047] As a first modified embodiment, a suction pad 70 may be provided on the upper surface of the base portion 22 at a position shown in FIG. 5. The position where the suction pad 70 is provided may be, for example, near the irradiation position of the second distance measuring sensor 52 on the lower surface of the substrate W in a plan view. Since the center of the base portion 22 has a through hole (position 52p in FIG. 3) for passing the detection light from the second distance measuring sensor 52, three suction pads 70 are provided to surround this through hole. When the suction pad 70 is provided, the leveling and height adjustment of the substrate can be performed in the following procedure. That is, first, the support pins 26 are raised and lowered based on the detection result by the second distance measuring sensor 52 to level the substrate W. At this time, if the second distance measuring sensor 52 does not detect the displacement of the substrate W according to the amount of elevation of the support pins 26, it is determined that the substrate W is aligned. Then, the substrate W can be brought into close contact with the support pin 26 by adsorbing the substrate W using the suction pad 70 closest to the support pin 26 where no displacement of the substrate W according to the elevation of the support pin 26 is observed. This makes it possible to adjust the height of the substrate W by the support pin 26.

[0048] For example, each suction pad 70 may be provided so as to be movable up and down relative to the base portion 22. This makes it possible to correct warping of the substrate W in addition to leveling and adjusting the height of the substrate W. In this case, the suction pad 70 can be attached to the base portion 22 via, for example, a linear actuator (not shown). In this case, the third and fourth steps described above can be performed by adjusting the height of each suction pad 70.

[0049] In the case where the substrate W is always adsorbed by the suction pad 70 regardless of the degree of warping of the substrate W, it is not necessary to provide the support pins 26. In the case where it is determined whether or not to use the suction pad 70 depending on the degree of warping of the substrate W, for example, the height of the support pins 26 may be lowered when the suction pad 70 is used.

[0050] As second and third modified embodiments, a device (lid inclination detection device) that indirectly detects the inclination of the base portion 22 with respect to the horizontal plane by detecting the inclination of the lid portion 24 integrated with the base portion 22 may be provided.

[0051] The configuration of the second modified embodiment is shown in FIG. 6 and FIG. 7. The second modified embodiment includes a plurality of fifth distance measuring sensors 55 as a lid body inclination detection device. The fifth distance measuring sensor 55 can be an optical distance measuring sensor using infrared rays or a laser, similar to the first to fourth distance measuring sensors 51 to 54, and is fixed to the machine frame 40 itself or to a sensor holder (not shown) fixed to the machine frame 40. When the substrate holder 20 is located at the processing position as shown in FIG. 6, the fifth distance measuring sensor 55 irradiates sensor light to a plurality of (preferably three or more, four in the illustrated example) irradiation positions 55p set on the front surface 24F (which is a vertical surface) of the lid body 24. Based on the distance between each distance measuring sensor 55 and the irradiation position 55p, the coordinates of each irradiation position 55p can be specified, and the inclination of the lid body 24 can be detected based on this. By setting three or more irradiation positions 55p, the inclination of the lid body 24 in any direction can be detected.

[0052] The configuration of the third modified embodiment is shown in FIG. 8 and FIG. 9. The third modified embodiment has one or more tilt sensors 56 as a lid tilt detection device. When the tilt sensor 56 is a multi-axis sensor (capable of detecting an angular position around two or more axes facing different directions), the number of tilt sensors 56 may be one. In this case, the tilt sensor 56 (56F) can be provided, for example, on the front surface 24F of the lid 24. When the tilt sensor 56 is a single-axis sensor (capable of detecting an angular position around only one axis), the tilt sensor 56 can be provided on two surfaces of the lid 24 facing different directions (for example, the front surface 24F and the side surface 24S (which is perpendicular to the front surface 24F)). When the tilt sensor 56 (56S) is provided on the side surface 24S, it is preferable that the lid 24 protrudes forward from the front surface of the processing vessel 10 when the substrate holder 20 is located at the processing position, so that the side surface 24S of the lid 24 is not covered by the processing vessel 10.

[0053] According to the second and third modified embodiments described above, the inclination of the base portion 22 can be detected based on the inclination of the lid 24 during or immediately before the start of drying processing of the substrate W with the substrate holding portion 20 located at the processing position. Therefore, for example, when the base portion 22 (i.e., the substrate W thereon) is inclined due to inappropriate interference between the substrate holding portion 20 and the processing vessel 10, the occurrence of such an event can be detected. When an abnormal inclination of the base portion 22 is detected, the control portion 100 may generate an alarm to notify an operator that an abnormality has occurred, or may stop operation of the supercritical drying apparatus 1.

[0054] The embodiments disclosed herein should be considered as illustrative and not restrictive in all respects. The above-described embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the appended claims.

[0055] The substrate W is, for example, a semiconductor wafer, but is not limited thereto and may be other substrates (ceramic substrate, glass substrate) used in the field of semiconductor device manufacturing. [Explanation of symbols]

[0056] W substrate 10 Processing vessel 20 Board holding part 22 Base 51 First detection unit

Claims

1. 1. A substrate processing apparatus that dries a substrate having a liquid film formed on a pattern-forming surface thereof by using a supercritical fluid, comprising: a processing vessel that accommodates the substrate and to which the supercritical fluid is supplied; a substrate holding unit having a base portion that supports the substrate from below with the pattern forming surface facing upward, the substrate holding unit holding the substrate in the processing vessel while the substrate is being dried in the processing vessel using a supercritical process; A first detection unit that detects an inclination of the base unit with respect to a horizontal plane; A substrate processing apparatus comprising:

2. an attitude adjustment mechanism for adjusting an inclination of the base portion with respect to a horizontal plane; a control unit that controls the attitude adjustment mechanism based on a detection result of the first detection unit to level the base unit; The substrate processing apparatus of claim 1 , further comprising:

3. the processing vessel has an opening for receiving a substrate; the substrate holder includes a cover connected to the base and closing the opening, the substrate holder is movable between a processing position and a retreat position; when the substrate holding part is in the processing position, the lid body closes the opening and the base part is housed in the processing vessel; when the substrate holder is at the retreat position, the lid opens the opening and the base retreats to the outside of the processing chamber; 3 . The substrate processing apparatus according to claim 1 , wherein the first detection unit is provided at a position capable of detecting an inclination of the base unit with respect to a horizontal plane when the substrate holding unit is at the retracted position.

4. The substrate processing apparatus according to claim 3 , wherein the first detection unit is provided below the base unit of the substrate holding unit in the retracted position.

5. The substrate processing apparatus according to claim 3 , wherein the first detection unit includes three or more optical sensors capable of measuring three or more height positions on the lower surface of the base unit.

6. The substrate processing apparatus according to claim 3 , further comprising a second detection unit configured to detect a height position of a surface of the liquid film formed on the upper surface of the substrate supported by the base unit.

7. The substrate processing apparatus according to claim 6 , wherein the second detection unit is provided above the base unit of the substrate holding unit in the retracted position.

8. the base portion includes a base portion main body, a plurality of support members protruding upward from the base portion main body to support the substrate from below, and a lifting mechanism that raises and lowers the plurality of support members relative to the base portion main body, A substrate processing apparatus as described in claim 6 or 7 when claim 3 cites claim 2, wherein the control unit levels the base portion using the attitude adjustment mechanism based on the detection result of the first detection unit, and then adjusts the height position of the surface of the liquid film using the lifting mechanism based on the detection result of the second detection unit.

9. The substrate processing apparatus according to claim 3 , further comprising a third detection unit configured to detect an inclination of the substrate supported by the base unit with respect to a horizontal plane.

10. The substrate processing apparatus according to claim 9 , wherein the third detection unit is provided below the base unit of the substrate holding unit in the retracted position.

11. The substrate processing apparatus of claim 9 or 10, wherein the third detection unit includes three or more optical sensors capable of measuring three or more height positions on the underside of the base unit, and a notch is provided in the base unit to allow light irradiated from the optical sensors to be irradiated onto the underside of the substrate.

12. A substrate processing apparatus as described in any one of claims 9 to 11 when claim 9 cites claim 8, wherein the control unit performs leveling of the substrate by the lifting mechanism based on the detection result of the third detection unit after leveling of the base portion by the attitude adjustment mechanism based on the detection result of the first detection unit and simultaneously, before, or after adjustment of the height position of the surface of the liquid film by the lifting mechanism based on the detection result of the second detection unit.

13. A substrate processing method for drying a substrate having a liquid film formed on a pattern-formed surface thereof by using a supercritical fluid while the substrate is held by a substrate holder in a processing vessel with the pattern-formed surface facing upward, the method comprising the steps of: a first detection step of detecting an inclination of a base portion of the substrate holding portion, which supports the substrate from below with the pattern-formed surface facing upward, with respect to a horizontal plane; a base portion leveling step of leveling the base portion based on a detection result of the first detection step; A substrate processing method comprising:

14. As a step to be carried out before the drying using the supercritical fluid, a second detection step of detecting a height position of a surface of the liquid film formed on the upper surface of the substrate supported by the base portion; a liquid film height adjusting step of adjusting a height position of a surface of the liquid film based on a detection result of the second detection step after leveling the base part based on a detection result of the first detection step; The method of claim 13 further comprising:

15. As a step to be carried out before the drying using the supercritical fluid, a third detection step of detecting an inclination of the substrate supported by the base portion with respect to a horizontal plane; 15. The substrate processing method of claim 14, further comprising: after leveling the base portion based on the detection result of the first detection process, and simultaneously with, before, or after adjusting the height position of the surface of the liquid film based on the detection result of the second detection process, leveling the substrate based on the detection result of the third detection process.

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