Substrate processing apparatus and substrate processing method

Abstract

To provide a substrate processing device which suppresses particles generated on a surface of a substrate when drying the substrate using a process fluid in a supercritical state, and a substrate processing method.SOLUTION: A substrate processing device 1 which dries a substrate W in which a liquid film is formed on a pattern formation surface using a supercritical fluid comprises: a processing container 10 in which the substrate is stored and to which the supercritical fluid is supplied; a substrate holding section 20 including a base part 22 which supports the substrate from below in a state where the pattern formation surface is turned upward, and holding the substrate in the processing container; a first detection section 51 which detects an inclination of the base part to a horizontal plane; a posture adjustment mechanism 28 which adjusts the inclination of the base part to the horizontal plane; and a control section 100 which controls the posture adjustment mechanism based on a detection result of the first detection section, thereby leveling the base part.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

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

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present disclosure provides a technique capable of suppressing particles generated on the surface of a substrate when drying the substrate using a processing fluid in a supercritical state.

Means for Solving the Problems

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

[0006] According to this disclosure, when drying a substrate using a supercritical processing fluid, it is possible to suppress the generation of particles on the substrate surface. [Brief explanation of the drawing]

[0007] [Figure 1] This is a longitudinal cross-sectional side view of a substrate processing apparatus according to one embodiment. [Figure 2] This is a schematic longitudinal cross-sectional side view showing an example of the configuration of a posture adjustment mechanism. [Figure 3] This is a plan view from below of the substrate holder, illustrating the irradiation position of the detection light, etc. [Figure 4] This is a plan view from above of the substrate holder, illustrating the irradiation position of the detection light, etc. [Figure 5] This is a plan view from above of the substrate holding portion, illustrating the arrangement of the suction pads in the first modified embodiment. [Figure 6] This is a longitudinal cross-sectional side view of a substrate processing apparatus according to a second modified embodiment, which is equipped with a distance measuring sensor for detecting the tilt of the lid. [Figure 7] Figure 6 is a front view of the lid, illustrating the position where the detection light is irradiated onto the lid. [Figure 8] This is a longitudinal cross-sectional side view of a substrate processing apparatus according to a third modified embodiment, which is equipped with a tilt sensor for detecting the inclination of the lid. [Figure 9] Figure 8 is a front view of the lid, illustrating the placement of the tilt sensor on the lid. [Modes for carrying out the invention]

[0008] A supercritical drying apparatus 1, as one embodiment of a substrate processing apparatus, will be described with reference to the attached drawings. For the sake of convenience, directions will be indicated using the XYZ Cartesian coordinate system shown in each figure as needed. The X and Y directions are mutually orthogonal horizontal directions, and the Z direction is the vertical direction.

[0009] As shown in Figure 1, the supercritical drying apparatus 1 has a processing container 10 formed as a supercritical chamber. A processing space 12 is formed inside the processing container 10. The processing container 10 has an opening 14 on its side that serves as an entrance to the processing space 12.

[0010] The processing vessel 10 has a fluid supply section 16 and a fluid discharge section 18. The processing fluid is supplied to the fluid supply section 16 from a source of supercritical processing fluid (e.g., carbon dioxide in a supercritical state) (see arrow) and discharged into the processing space 12 from the fluid supply section 16. The fluid supply section 16 consists of, for example, a bar nozzle. The processing fluid is discharged to the outside of the processing space 12 via the fluid discharge section 18 (see arrow). A detailed explanation of the processing fluid supply system and discharge system is omitted, but any known configuration in a supercritical drying apparatus can be adopted.

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

[0012] At least three (four in the illustrated example) support pins 26 are provided on the upper surface of the base portion (base body) 22 so as to protrude upward. The support pins 26 can be raised and lowered vertically, for example, by a linear actuator 260 (see Figure 2) built into the base portion (base body) 22. The support pins 26 can be used mainly to fine-tune the height position and orientation (tilt relative to the horizontal plane) of a substrate W such as a semiconductor wafer that is supported by the support pins 26. Here, the part of the base portion 22 excluding the support pins 26 (the plate-shaped part) is also referred to as the base body.

[0013] Between the base portion 22 and the lid 24, an attitude adjustment mechanism 28 is provided for adjusting the inclination of the base portion 22 with respect to the horizontal plane. As shown in Figure 2, the attitude adjustment mechanism 28 can consist of, for example, a base body 281 with a U-shaped (square bracket-shaped) cross section and a total of eight movable push pins 282 attached to the base body 281. Each movable push pin 282 can be moved vertically by a linear actuator 283. The linear actuator 283 may be, for example, a ball screw. The eight movable push pins 282 are divided into two sets. As schematically shown in Figure 4, the first set of four movable push pins 282 is provided on one side of the lid 24, and the 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 portion 22 with respect to the horizontal plane (specifically, both the direction and amount of inclination) 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 posture adjustment mechanism 28 is not limited to that shown in Figure 2; any configuration can be adopted as long as the inclination of the base portion 22 with respect to the horizontal plane can be freely adjusted.

[0014] The substrate holding part 20 can move forward and backward horizontally between a "processing position (the position shown in FIGS. 6 and 8 described later)" and a "retracted position (the 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 container 10 to seal the opening 14, and the base part 22 is accommodated 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 exits outside the processing space 12.

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

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

[0017] Below the substrate holding unit 20 at the retracted position, a substrate lifter 60 that can move up and down in the vertical direction by a substrate lifter moving mechanism (not shown) is provided. The substrate lifter 60 has three or more (three in the illustrated example) lift pins 62. By raising the substrate lifter 60 to the raised position, the substrate W supported by the substrate holding unit 20 (specifically, the support pins 26) can be supported and lifted by the tips of the lift pins 62. To enable this, the base portion 22 is provided with through holes through which the lift pins 62 can pass. The positions of the through holes are indicated by reference numeral 62P in FIGS. 3 and 4.

[0018] When the substrate lifter 60 is in the raised position, it is possible to transfer the substrate W between a substrate transfer arm (not shown) that has entered the supercritical drying apparatus 1 from the back side to the front side in the Y direction in FIG. 1 and the substrate lifter 60. That is, when loading the substrate W, the following steps (S1) to (S3) can be executed to load the substrate W before processing. (S1) With the substrate holding unit 20 positioned at the retracted position, the empty substrate lifter 60 is positioned at the raised position. (S2) The substrate transfer arm (not shown) places the substrate W on the lift pins 62 of the substrate lifter 60. (S3) After the substrate transfer 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 unloading the processed substrate W, the reverse procedure of the above may be executed.

[0019] The substrate lifter 60 may be configured to be movable only in the vertical direction. In this case as well, it is possible to avoid interference between the substrate lifter 60 and its peripheral components. Instead of this, the substrate 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 surface in FIG. 1). By doing so, it becomes easy to avoid interference between the substrate 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 or laser. 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 sensor 51 is located below the base portion 22 of the substrate holding portion 20 in the retracted position (the position shown in Figure 1), and measures the vertical distance (distance measured along the Z direction) from each of the first distance measuring sensors 51 to the lower surface of the base portion 22 of the substrate holding portion 20.

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

[0023] As long as the sensor light from 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 sensor 52. In other words, it is sufficient if some kind of notch is provided in the base portion 22.

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

[0025] The fourth distance measuring sensor 54 is located above the four corners of the base 30 and measures the vertical distance from each of the fourth distance measuring sensors 54 to the four corners of the base 30. Based on the measurement values ​​from the fourth distance measuring sensors 54, the inclination of the base 30 with respect to the horizontal plane (the inclination of the upper surface of the base 30) can be detected.

[0026] In Figure 3, an example of the irradiation position 51p of the sensor light of the first distance measuring sensor 51 onto the lower surface of the base portion 22 is shown by a black circle. The 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 measuring sensor 51 is near the periphery of the substrate W in a plan view. The irradiation positions 51p are located on the circumference of a circle centered on the center of the substrate W, and are positioned at angular positions that divide the circumference into N equal parts (N is the number of first distance measuring sensors, which is 4 in the illustrated example).

[0027] Based on the detection value of the first distance measuring sensor 51, the tilt direction and amount of tilt (tilt angle) of the base portion 22 with respect to the horizontal plane (a plane perpendicular to the direction of gravity) can be determined. It is clear that the tilt direction and amount of tilt of the base portion 22 can be determined if N is 3 or greater, but here, the measurement reliability is increased by redundancy by setting N=4.

[0028] Furthermore, the first distance measuring sensor 51 is calibrated (by mechanical calibration, electrical calibration, or computational calibration) when the supercritical drying apparatus 1 is installed. For example, if the surface to be measured (in this case, the lower surface of the base portion 22) is horizontal, the detected values ​​of the first distance measuring sensor 51 will all be the same. The same applies to the second to fourth distance measuring sensors.

[0029] In Figure 3, examples of the irradiation positions 52p of the sensor light of the second distance measuring sensor 52 onto the underside of the substrate W are shown by white circles. There is one irradiation position 52p of the sensor light of the second distance measuring sensor 52 at the center of the substrate W and four near the periphery. The four irradiation positions 52p near the periphery of the substrate W are located on the circumference of a circle centered at the center of the substrate W and are positioned at angular positions that divide the circumference into four equal parts.

[0030] Based on the detection value of the second distance measuring sensor 52, the tilt direction and amount of tilt (tilt angle) of the substrate W with respect to the horizontal plane can be determined. Because an IPA liquid film is present on the surface of the substrate W, it is difficult to accurately measure the tilt of the substrate W itself from the surface side of the substrate W. However, by irradiating the back surface of the substrate W with detection light, it becomes possible to accurately measure the tilt of the substrate W.

[0031] Furthermore, since the irradiation position 52p of the second distance measuring sensor is also set at the center of the substrate W, if the substrate W is deflected, that deflection can also be detected. The number of second distance measuring sensors 52 is not limited to five and can be changed according to the required redundancy.

[0032] As shown in Figure 3, it is preferable to attach the two arms 38 to both sides of the cover 24 of the substrate holder 20. This makes it easier to design the device (parts layout) in a way that ensures the arms 38 do not interfere with (collide with) the first distance measuring sensor 51 and the second distance measuring sensor 52 within their range of movement.

[0033] In Figure 4, an example of the irradiation position 53p of the sensor light of the third distance measuring sensor 53 onto the upper surface of the substrate W (more specifically, the surface of the liquid paddle on the upper surface) is shown by a hatched circle. Similar to the second distance measuring sensor 52, the irradiation positions 53p of the sensor light of the third distance measuring sensor 53 are set at one in 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 measuring sensor 53 is located at a position shifted by 45 degrees around the center of the substrate W from the irradiation position 52p of the sensor light of the second distance measuring sensor 52, but it is not limited to this.

[0034] Based on the detection value of the third distance sensor 53, the height and uniformity of the liquid level of the liquid film (paddle) 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 container 10. If the liquid level is too low, premature drying may occur, resulting in poor drying. If the liquid level is uneven, localized contact of the liquid with the lower surface of the ceiling wall may occur. Furthermore, if the liquid level is uneven, the thickness of the liquid film may also be uneven, which may result in localized drying failure, massive particle generation, or pattern collapse.

[0035] Furthermore, the four support pins 26 provided on the upper surface of the base portion 22 can be positioned, for example, 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 arranged at angular positions that divide the circumference of a circle centered on the center of the substrate W into four equal parts.

[0036] As shown in Figure 1, the supercritical drying apparatus 1 has a control unit 100. The control unit 100 is, for example, a computer and comprises an arithmetic unit 101 and a storage unit 102. The storage unit 102 stores programs that control various processes performed 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 programs may be those recorded on a storage medium readable by a computer and installed from that storage medium to the storage unit 102 of the control unit 100. Examples of storage mediums readable by a computer include hard disks (HDs), flexible disks (FDs), compact disks (CDs), magnetic optical disks (MOs), and memory cards.

[0037] Next, the operation of the supercritical drying apparatus 1 will be described, particularly from the moment the substrate W is passed from the substrate transport arm (not shown) to the support pins 26 of the substrate holding unit 20 in the retracted position via the substrate lifter 60, until the moment the substrate holding unit 20 moves from the retracted position to the processing position for processing the substrate W. This substrate W has, for example, an IPA paddle (liquid film) formed on its surface (pattern forming surface), and the recesses in the pattern on its surface are filled with IPA. This substrate W has been subjected to, for example, a series of chemical treatments in a single-wafer washing apparatus (not shown): (1) chemical treatment such as wet etching and chemical washing, (2) rinsing treatment to wash away the chemical treatment with a rinsing solution, and (3) IPA replacement treatment to replace the rinsing solution with IPA and form an IPA paddle (liquid film). In many cases, multiple supercritical drying apparatuses 1 and multiple single-wafer washing apparatuses are combined to form one substrate processing (liquid treatment and drying) system, and within this substrate processing system, the substrate is transported by the substrate transport arm.

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

[0039] <Adjustment process 1: Leveling the base 30> First, detection light is shone from the first to third distance measuring sensors 51 to 53 onto the substrate W, which is placed with its surface (pattern forming surface) facing upward on the support pins 26 of the substrate holding part 20 in the retracted position, and detection light from the fourth distance measuring sensor 54 is shone onto the four corners of the upper surface of the base 30. Then, based on the detection result of the fourth distance measuring sensor 54, the tilt of the base 30 with respect to the horizontal plane is detected. If the tilt exceeds the allowable range, the base 30 is leveled by appropriately operating one or more of the four lifting actuators 32. Note that leveling (tilt adjustment) of the base 30 is not limited to this timing immediately before substrate processing, but may also be performed after substrate processing, during standby (for example, when waiting for the next substrate W to be loaded after the substrate W has been unloaded from the supercritical drying apparatus 1). Leveling of the base 30 can be performed at any timing during the operation of the supercritical drying apparatus 1, for example, during the supercritical drying process.

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

[0041] <Adjustment process 3: Leveling 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 second distance measuring sensor 52, the inclination of the substrate W on the base portion 22 relative to the horizontal plane is detected. If the inclination exceeds the allowable range, the substrate W is leveled by operating the support pins 26 provided on the base portion 22.

[0042] <Adjustment process 4: Height adjustment of 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 on the surface of the substrate W on the base unit 22 is detected. If the height exceeds the allowable range, the height of the substrate W is lowered to the appropriate height by operating the support pins 26 provided on the base unit 22.

[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 the pedestal 30 relative to the horizontal plane, the inclination of the base portion 22 relative to the horizontal plane, the inclination of the substrate W relative to the horizontal plane, and the surface height of the IPA paddles on the surface of the substrate W, which are determined from the detection values ​​of the first to fourth distance measuring sensors 51 to 54, the 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 carried out by known methods described in the applicant's prior applications (e.g., Japanese Patent Application Publication No. 2020-170873, and many others). For example, the process involves supplying a processing fluid (e.g., carbon dioxide) in a supercritical state into a processing space 12 from a source (not shown) to increase the pressure inside the processing space 12 to a predetermined level (pressure-boosting step), and then circulating the supercritical fluid within the processing space 12 to replace the IPA on the substrate W with the processing fluid (circulation step). Once the replacement is complete, the processing fluid is discharged from the processing space 12 to reduce the pressure inside the processing space 12 to atmospheric pressure. This causes the supercritical processing fluid to vaporize, allowing the substrate W to be dried while preventing pattern collapse. If the surface of the substrate W is tilted, the in-plane uniformity of the IPA film thickness deteriorates, which leads to a deterioration in the in-plane uniformity of the supercritical fluid replacement, which may result in pattern collapse or deterioration of the particle level. However, according to this embodiment, the surface of the substrate W can be stably kept horizontal, and desirable processing results can be obtained.

[0045] It is preferable to perform all of the following adjustments before processing each substrate W: (1) adjusting the inclination of the base 30 with respect to the horizontal plane (leveling the base 30), (2) adjusting the inclination of the base portion 22 with respect to the horizontal plane (leveling the base portion 22), (3) adjusting the inclination of the substrate W with respect to the horizontal plane (leveling the substrate W), and (4) adjusting the surface height of the IPA paddles on the surface of the substrate W (adjusting the substrate height). However, performing all adjustments takes a certain amount of time. If too much time is spent on adjustments, the IPA paddles may dry out, causing the paddle film thickness to thin, or the paddles to partially disappear, exposing the surface of the substrate W. In this case, pattern collapse or deterioration of the particle level may occur.

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

[0047] As a first modified embodiment, suction pads 70 may be provided on the upper surface of the base portion 22 at the position shown in Figure 5. The position for placing the suction pads 70 can be, for example, near the position where the second distance sensor 52 illuminates the lower surface of the substrate W in a plan view. In addition, since there is a through hole (position 52p in Figure 3) in the center of the base portion 22 for allowing detection light from the second distance sensor 52 to pass through, three suction pads 70 are arranged to surround this through hole. When suction pads 70 are provided, the leveling and height adjustment of the substrate can be performed by the following procedure. That is, first, the support pins 26 are raised and lowered based on the detection result of the second distance sensor 52 to level the substrate W. At this time, if the displacement of the substrate W corresponding to the amount of raising and lowering of the support pins 26 is not detected by the second distance sensor 52, it is determined that the substrate W is warped. Then, by using the suction pad 70 closest to the support pin 26, which does not exhibit any displacement of the substrate W corresponding to the amount of upward or downward movement of the support pin 26, the substrate W can be brought into close contact with the support pin 26. This makes it possible to adjust the height of the substrate W using the support pin 26.

[0048] For example, each suction pad 70 may be provided so as to be able to move up and down relative to the base portion 22. In this case, in addition to leveling and adjusting the height of the substrate W, the warping of the substrate W can also be corrected. In this case, the suction pads 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] If the substrate W is always held in place by the suction pad 70 regardless of the degree of warping of the substrate W, then the support pins 26 do not need to be provided. If the decision to use or not use the suction pad 70 is made depending on the degree of warping of the substrate W, then, for example, the height of the support pins 26 may be lowered when using the suction pad 70.

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

[0051] The configuration of the second modified embodiment is shown in Figures 6 and 7. The second modified embodiment includes a plurality of fifth distance measuring sensors 55 as a lid tilt detection device. The fifth distance measuring sensor 55, like the first to fourth distance measuring sensors 51 to 54, can be an optical distance measuring sensor using infrared light or a laser, and is fixed to the machine frame 40 itself or to a sensor holder (not shown) fixed to the machine frame 40. As shown in Figure 6, when the substrate holding part 20 is in the processing position, the fifth distance measuring sensor 55 irradiates sensor light to a plurality (preferably three or more, four in the illustrated example) of irradiation positions 55p set on the front surface 24F (which is a vertical surface) of the lid 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 determined, and based on this, the tilt of the lid 24 can be detected. By setting three or more irradiation positions 55p, the tilt of the lid 24 in any direction can be detected.

[0052] The configuration of the third modified embodiment is shown in Figures 8 and 9. The third modified embodiment has one or more tilt sensors 56 as a lid tilt detection device. If the tilt sensor 56 is a multi-axis sensor (capable of detecting angular positions around two or more axes facing different directions), then only one tilt sensor 56 is needed, and in this case, the tilt sensor 56 (56F) can be provided, for example, on the front surface 24F of the lid 24. If the tilt sensor 56 is a uni-axis sensor (capable of detecting angular positions around only one axis), then 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 when the substrate holding portion 20 is in the processing position, the lid 24 protrudes forward of the front surface of the processing container 10 so that the side surface 24S of the lid 24 is not covered by the processing container 10.

[0053] According to the second and third modified embodiments described above, the tilt of the base portion 22 can be detected based on the tilt of the lid 24 during or immediately before the start of the drying process of the substrate W where the substrate holding portion 20 is located in the processing position. Therefore, for example, if the base portion 22 (i.e., the substrate W on top of it) tilts due to inappropriate interference between the substrate holding portion 20 and the processing container 10, it is possible to detect that such an event has occurred. When an abnormal tilt of the base portion 22 is detected, the control unit 100 may generate an alarm to notify the operator that an abnormality has occurred, or it may stop the operation of the supercritical drying apparatus 1.

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

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

[0056] W board 10 Processing containers 20 Board holding part 22 Base section 51 First detection unit

Claims

1. A substrate processing apparatus for drying a substrate on which a liquid film has been formed on the pattern-forming surface using a supercritical fluid, A processing vessel containing the substrate and supplied with the supercritical fluid, A base portion that supports the substrate from below with the pattern forming surface facing upward, and a substrate holding portion that holds the substrate within the processing container, Equipped with, The processing container has an opening for housing the substrate, The substrate holding portion is A lid that is connected to the base portion and closes the opening, A tilt sensor is provided on the lid to detect the inclination of the base portion with respect to the horizontal plane, A substrate processing apparatus having

2. The substrate holding part is movable between the processing position and the retracted position. When the substrate holding portion is in the processing position, the lid closes the opening and the base portion is housed in the processing container. When the substrate holding portion is in the retracted position, the lid opens the opening and the base portion retracts outside the processing container. The substrate processing apparatus according to claim 1.

3. The substrate processing apparatus according to claim 1, wherein the tilt sensor is provided on the front surface of the lid, or on a portion of the side surface of the lid that is not covered by the processing container.

4. The substrate processing apparatus according to claim 1, further comprising a posture adjustment mechanism for adjusting the inclination of the base portion with respect to the horizontal plane.

5. The substrate processing apparatus according to claim 2, wherein the tilt sensor is provided so as to be able to detect the tilt of the base portion based on the tilt of the lid immediately before the start of the drying process of the substrate in which the substrate holding portion is located at the processing position.

6. The substrate processing apparatus according to claim 2, wherein the tilt sensor is provided so as to be able to detect the tilt of the base portion based on the tilt of the lid during the drying process of a substrate in which the substrate holding portion is located at the processing position.

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