Substrate processing apparatus, method for detecting the tilt of a substrate holder, substrate processing method, method for manufacturing a semiconductor device, and program

Abstract

The present invention provides a substrate processing apparatus for detecting the tilt of a substrate holder, a method for detecting the tilt of a substrate holder, a substrate processing method, a method for manufacturing a semiconductor device, and a program. [Solution] The substrate processing apparatus includes a rotating mechanism 21 that rotatably supports a substrate holder 15 having support columns 15a to 15c, a transfer machine 13 that transfers a substrate to the substrate holder and fiber sensors 29a and 29b that are attached to the transfer machine 13 so as to be able to change the distance and relative height between them and the substrate holder and are capable of detecting support columns in the optical path, and a control unit that rotates the substrate holder by the rotating mechanism so that multiple support columns intersect the optical path, calculates the center position of the substrate holder from the detection results of the fiber sensors at multiple heights, and determines whether the inclination of the substrate holder is within a reference value based on the difference in the center position in the height direction.

Description

[Technical Field]

[0001] This disclosure relates to a substrate processing apparatus, a method for detecting the tilt of a substrate holder, a substrate processing method, a method for manufacturing a semiconductor device, and a program. [Background technology]

[0002] In the manufacturing process of semiconductor devices, a batch-type vertical substrate processing device is sometimes used to process multiple substrates (semiconductor silicon wafers) at once. In a vertical substrate processing device, a substrate holder (boat) is used to hold multiple substrates aligned at their centers in a multi-tiered horizontal position. The boat is also equipped with multiple holding members (supports) to hold the substrates. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 6-298315 [Overview of the project] [Problems that the invention aims to solve]

[0004] Vertical PCB processing equipment requires periodic maintenance. During maintenance, the board may be removed from the vertical PCB processing equipment, and there is a risk of misalignment when the board is reinstalled.

[0005] This disclosure provides a technology capable of detecting the tilt of a substrate holder. [Means for solving the problem]

[0006] According to one aspect of the present disclosure, there is provided a technology comprising: a rotation mechanism that rotatably supports a substrate holder having a plurality of pillars; a sensor attached to a transfer machine that transfers a substrate to the substrate holder such that a distance from the sensor to the substrate holder and a relative height of the sensor can be changed, the sensor being configured to be capable of detecting the pillars on an optical path; and a control unit configured to rotate the substrate holder by the rotation mechanism such that the plurality of pillars intersect the optical path, calculate a center position of the substrate holder respectively from detection results of the sensor at a plurality of heights, and determine whether an inclination of the substrate holder is within a reference value based on a difference between the center positions in a height direction. Effects of the Invention

[0007] According to the present disclosure, the inclination of a substrate holder can be detected. Brief Description of the Drawings

[0008] [Figure 1] 1 is a perspective view of a substrate processing apparatus according to an aspect of the present disclosure. [Figure 2] 2 is a perspective view of a transfer machine according to an aspect of the present disclosure. [Figure 3] 3 is a schematic configuration diagram of a controller of the substrate processing apparatus according to an aspect of the present disclosure. [Figure 4] 4 is a flowchart illustrating inclination detection processing according to an aspect of the present disclosure. [Figure 5] 5 is a plan view illustrating inclination detection processing according to an aspect of the present disclosure. [Figure 6] (A) and (C) are explanatory diagrams illustrating a state where a support pillar starts crossing a laser beam in the inclination detection processing according to an aspect of the present disclosure, and (B) and (D) are explanatory diagrams illustrating a state where the support pillar finishes crossing the laser beam. [Figure 7] 6 is a flowchart illustrating inclination detection processing according to a modification of the aspect of the present disclosure. [Figure 8] 7 is a diagram for explaining contact of a support pillar with an optical axis in the inclination detection processing according to an aspect of the present disclosure. Mode for Carrying Out the Invention

[0009] An embodiment of this disclosure will be described below with reference to Figures 1 to 3. Note that the drawings used in the following description are schematic, and the dimensional relationships and proportions of the elements shown in the drawings do not necessarily correspond to reality. Furthermore, the dimensional relationships and proportions of the elements do not necessarily correspond between multiple drawings. Unless otherwise specified in the specification, each element is not limited to one, and there may be multiple elements. Also, in the drawings, identical or corresponding components are denoted by the same or corresponding reference numerals, and redundant explanations are omitted.

[0010] (Overview of substrate processing equipment) The substrate processing apparatus described in this embodiment is used in the manufacturing process of semiconductor devices, and processes (heats) the substrate to be processed by heating it with a heater while the substrate to be processed is housed in a processing chamber. More specifically, it is a vertical substrate processing apparatus that processes multiple substrates simultaneously while they are stacked vertically at predetermined intervals.

[0011] Examples of substrates processed by substrate processing equipment include semiconductor wafer substrates (wafer cassettes, simply referred to as wafers) on which semiconductor devices are fabricated. Examples of heat treatments performed by substrate processing equipment include oxidation, diffusion, annealing, reflow, sintering, film formation by thermal CVD (Chemical Vapor Deposition) reaction, and film quality improvement (treatment) treatments.

[0012] (1) Configuration of substrate processing apparatus The entire apparatus will be explained using Figure 1. Figure 1 shows the main components of the substrate processing apparatus.

[0013] The substrate processing apparatus 1 is equipped with a housing 2. A sealed substrate container, the pod 3, is loaded into and unloaded from the substrate processing apparatus 1 by an in-process transport device (not shown).

[0014] A sub-enclosure 4 is provided at the lower rear end of the enclosure 2. A pair of wafer loading / unloading ports 7 are provided on the front wall 5 of the sub-enclosure 4, arranged vertically in two rows, upper and lower, for loading and unloading wafers 6 into and out of the sub-enclosure 4. Pod openers 8 are provided for each of the upper and lower wafer loading / unloading ports 7.

[0015] The pod opener 8 comprises a mounting base 9 on which the pod 3 is placed, and an opening / closing mechanism 11 for opening and closing the lid of the pod 3. The pod opener 8 is configured to open and close the wafer entrance / exit of the pod 3 by opening and closing the lid of the pod 3, which is placed on the mounting base 9, using the opening / closing mechanism 11.

[0016] The sub-enclosure 4 constitutes an airtight transfer chamber (loading chamber, loading area) 12, separated from the space where the pod opener 8 is located. A transfer machine 13 is installed in the front area of ​​the transfer chamber 12. The transfer machine 13 is equipped with the required number of wafer mounting plates (substrate gripping parts) 14 to hold the wafers 6 (five in the figure). The wafer mounting plates 14 are capable of moving linearly horizontally, rotating horizontally, and moving up and down vertically. The transfer machine 13 is configured to load and unload wafers 6 onto a boat 15, which serves as a substrate holder, located within the transfer chamber 12. The wafer mounting plates 14 are also called hands, end effectors, chucks, forks, or tweezers, and can be composed of, for example, five mounting plates.

[0017] A vertical processing furnace 16 is installed adjacent to and above the transfer chamber 12. The processing furnace 16 forms a processing chamber 17 inside, and the lower end of the furnace opening near the bottom of the processing chamber 17 is open and can be opened and closed by a furnace opening shutter (not shown). The processing chamber 17 heat-treats the wafers 6 held in the boat 15.

[0018] A boat elevator 18 for raising and lowering the boat 15 is installed on the side of the sub-enclosure 4. A seal cap 19, which serves as a lid, is horizontally attached to an arm (not shown) connected to the lifting platform of the boat elevator 18. The seal cap 19 vertically supports the boat 15 and allows the furnace opening to be airtightly closed when the boat 15 is loaded into the processing furnace 16. The transfer chamber 12 is adjacent to the processing chamber 17 and holds the boat 15 between it and the processing chamber 17, and allows for the loading and unloading of wafers 6 together with the boat 15. The boat 15 is configured to hold multiple wafers 6 (for example, 50 to 175 wafers) in a horizontal position in multiple stages, with the wafers 6 aligned at their centers. As shown in Figure 2, the boat 15 is equipped with support columns 15a to 15c as pillars for holding the wafers 6. The support columns 15a to 15c are arranged at equal intervals around the circumference, for example, at 90° intervals. Each of the support columns 15a to 15c is provided with a groove (slot) for holding the wafer 6, and the lower surface of the groove serves as a substrate holding surface for holding the wafer 6. Furthermore, each of the support columns 15a to 15c is formed in a shape that is symmetrical with respect to the plane containing the central axis of the support columns 15a to 15c, passing through the axis of symmetry (center) of the boat 15.

[0019] On the side of the seal cap 19 opposite the processing chamber 17, a rotating mechanism 21 is installed that supports the boat 15 so that it can rotate around a central axis corresponding to the center of the wafer 6. The rotation axis of the rotating mechanism 21 is connected to the boat 15 by passing through the seal cap 19. The rotating mechanism 21 is a rotational drive unit that rotates the boat 15, and is configured to rotate the wafer 6 by rotating the boat 15 within the processing chamber 17.

[0020] A clean unit (not shown) is installed on the side opposite to the boat elevator 18 (the second side 4b of the sub-casing 4) (the first side 4a of the sub-casing 4). The clean unit consists of a supply fan and a dust filter to supply clean air, which is purified air or an inert gas. The first side 4a of the sub-casing 4 (i.e., the first side of the transfer chamber 12) has a clean air outlet. A notch alignment device (not shown), which serves as a substrate alignment device to align the circumferential position of the wafer 6, may be installed between the transfer machine 13 and the clean unit.

[0021] The clean air blown out from the clean unit flows through the notch alignment device, the transfer machine 13, and the boat 15. A portion of it is then drawn in by a local exhaust duct (or common exhaust duct) provided on the second side of the transfer chamber 12 and exhausted to the outside of the housing 2 through the exhaust duct. The second side 4b of the sub-housing 4 (i.e., the second side of the transfer chamber 12) has an exhaust port. The remaining portion is blown back into the transfer chamber 12 by the clean unit.

[0022] An example configuration of the transfer machine 13 will be explained using Figure 2. Figure 2 shows the state when the wafer 6 is transferred to the boat 15 by the transfer machine 13. Specifically, the wafer mounting plate (end effector) 14 of the transfer machine 13 faces the support columns 15a and 15c of the boat 15.

[0023] The transfer machine 13 includes a guide 22 provided along the vertical direction (Z-axis direction), a Z-axis drive unit 23, a Y-axis rotation drive unit 24, an X-axis drive unit 25, and a V-axis drive unit 26. Each of the drive units 23 to 26 can be referred to as a drive system.

[0024] The Z-axis drive unit 23 is provided at the lower or upper end of the guide 22 in order to move the mount 22a vertically (Z-axis direction, vertical direction) along the guide 22.

[0025] The Y-axis rotation drive unit 24 is mounted on the upper surface of the mount 22a so as to be rotatable in the Y-axis direction, in order to rotate it horizontally clockwise or counterclockwise (rotate around the Y-axis) while supporting the X-axis and Y-axis of the X-axis drive unit 25 so as to be perpendicular to each other. The range of rotation is usually sufficient to be about 180 degrees, as the pod 3 is positioned between the direction of the boat 15 and the opposite direction when viewed from the Y-axis.

[0026] The X-axis drive unit 25 is provided integrally with or inside the Y-axis rotation drive unit 24 in order to move back and forth horizontally (in the X-axis direction) while supporting the V-axis drive unit 26. The X-axis is defined as the direction in which the wafer mounting plate 14 moves so as to protrude from the Y-axis rotation drive unit 24 in order to enter the boat 15 or pod 3, which is called "forward".

[0027] The V-axis drive unit 26 is provided on the X-axis drive unit 25 and is configured to horizontally support the five wafer mounting plates 14 while allowing their spacing to be adjusted in the Z-axis direction.

[0028] As a result, the transfer machine 13 can remove the wafer 6 from the pod 3 using the wafer mounting plate 14 and load (charge) it into the boat 15. After the wafer 6 has undergone any processing in the processing furnace 16, the transfer machine 13 can remove (discharge) the wafer 6 from the boat 15 using the wafer mounting plate 14 and load it into the pod 3. The Y-axis rotation drive unit 24 has an external shape such that its rotation radius is equal to or slightly larger than the minimum rotation radius around the Y axis of the wafer mounting plate 14 and the V-axis rotation drive unit 26. For example, the length of the Y-axis rotation drive unit 24 in the X-axis direction is equal to or slightly larger than the combined length of the wafer mounting plate 14 and the V-axis rotation drive unit 26, and it has sides parallel to the X-axis.

[0029] The transfer machine 13 further includes sensor rods 27a and 27b as arms, provided on both sides of the Y-axis rotation drive unit 24, and forward / backward drive units 28a and 28b as sensor drive units that move the sensor rods 27a and 27b in the X-axis direction. Note that only the forward / backward drive unit 28b is shown in Figure 2.

[0030] The sensor rods 27a and 27b extend upward along both sides of the Y-axis rotation drive unit 24 to approximately the same height as either of the wafer mounting plates 14, and are bent at approximately a right angle to the rear of the X-axis, in the opposite direction to the mounting direction of the wafer mounting plate 14 to the X-axis drive unit 25. The sensor rods 27a and 27b hold the fiber sensors 29a and 29b, which function as sensors.

[0031] The tips of the sensor rods 27a and 27b are equipped with light transmitting and receiving sections for fiber sensors 29a and 29b, respectively. The fiber sensors 29a and 29b are a pair of transmissive sensors in which one transmits a laser beam and the other receives it. They can be arranged so that the optical path (optical axis) formed between the light transmitting and receiving sections is parallel to the tangent to the wafer 6, that is, approximately perpendicular to the longitudinal direction of the boat 15. The fiber sensors 29a and 29b are mapping sensors that perform mapping by detecting the interruption of the optical path, such as counting the number of wafers 6 loaded in the pod 3 or boat 15, or detecting normal or abnormal conditions such as wafers flying out or the boat 15 being misaligned. When the sensor rods 27a and 27b move forward, the optical axes remain aligned and horizontal. The sensor rods 27a and 27b may be connected by passing through the Y-axis rotation drive unit 24 so that they interlock with each other, in which case only one of the forward / backward drive units 28a and 28b is needed. Furthermore, the optical paths (optical axes of the laser beams) of the fiber sensors 29a and 29b are perpendicular or nearly perpendicular to the rotation axis of the rotating mechanism 21, i.e., the rotation axis of the boat 15, and are also perpendicular or nearly perpendicular to the extension direction of each support column 15a to 15c.

[0032] Furthermore, the forward and backward drive units 28a and 28b are positioned on both sides of the Y-axis rotation drive unit 24 and support the sensor rods 27a and 27b so that they can move in the X-axis direction between the protruding position and the retracted position. That is, the wafer mounting plate 14 and the sensor rods 27a and 27b are positioned back-to-back with respect to the Y-axis rotation drive unit 24 and can move independently of each other along the X-axis. The sensor rods 27a and 27b can be moved along the longitudinal direction (up and down direction, Z direction) of the support columns 15a to 15c of the boat 15 by the Z-axis drive unit 23.

[0033] This allows the transfer machine 13 to map the wafers 6 in the pod 3 using fiber sensors 29a and 29b. The transfer machine 13 can also use fiber sensors 29a and 29b to map the wafers 6 in the boat 15 and to detect positional deviations in the XY axes between the boat 15's reference position and its current position. Here, the reference position of the boat 15 is the position where the boat 15 is installed vertically with its center aligned with the rotation center of the boat 15 (rotating mechanism 21). It can be defined as the center of the rotation axis (machine center) of the rotating mechanism 21 when the boat 15 is unloaded, extended in the Z-axis direction in the coordinate system (machine coordinates) of the transfer machine 13. The height (height position information) of each wafer slot (not shown) for holding the wafers 6 may also be included in the reference position.

[0034] As shown in Figure 2, the sensor rods 27a and 27b of the transfer machine 13 are moved by the Y-axis rotation drive unit 24 in a direction approaching and away from the boat 15, that is, in a direction in which the X-axis points towards the center of the boat 15. At this time, the forward and backward drive units 28a and 28b drive the sensor rods 27a and 27b (fiber sensors 29a and 29b) so that they can be positioned with a predetermined positioning accuracy only in two positions: a forward position approaching the center of the boat 15 and a backward position moving away from the center of the boat 15. Furthermore, when the boat 15 is rotated by the rotation mechanism 21, one of the support columns 15a to 15c of the boat 15 is positioned so as to block the laser beam emitted from one of the fiber sensors 29a and 29b. In Figure 2, support column 15b is positioned closest to the Y-axis of the transfer machine 13, that is, on the X-axis.

[0035] Furthermore, a controller 31, which is a control unit (controller, control means), is provided at a required location within the enclosure 2, for example, in the corner of the sub-enclosure 4 in Figure 1. As shown in Figure 3, the controller 31 is configured as a computer equipped with a Central Processing Unit (CPU) 32, Random Access Memory (RAM) 33, storage device 34, and I / O ports 35. The RAM 33, storage device 34, and I / O ports 35 are configured to exchange data with the CPU 32 via an internal bus 36. An input / output device 37, configured as, for example, a touch panel, is connected to the controller 31. In addition, an external storage device 38 can be connected to the controller 31.

[0036] The storage device 34 is composed of, for example, flash memory, a hard disk drive (HDD), a solid state drive (SSD), etc. The storage device 34 contains, in a readable format, control programs that control the operation of the substrate processing device, and process recipes that describe the procedures and conditions in the substrate processing process described later. The process recipe functions as a program, combining the procedures in the substrate processing described later so that the controller 31 causes the substrate processing device to execute them and obtain a predetermined result. Hereinafter, process recipes and control programs will be collectively referred to simply as "programs." Similarly, process recipes will be referred to simply as "recipes." In this specification, the term "program" may include only a recipe, only a control program, or both. The RAM 33 is configured as a memory area (work area) where programs and data read by the CPU 32 are temporarily held.

[0037] The I / O port 35 is connected to the aforementioned opening / closing mechanism 11, transfer machine 13, processing furnace 16, boat elevator 18, rotating mechanism 21, etc.

[0038] The CPU 32 is configured to read and execute control programs from the storage device 34, and to read recipes from the storage device 34 in response to input of operation commands from the input / output device 37. The CPU 32 is configured to control operations such as opening and closing the lid of the pod 3, transferring the wafer 6 by the transfer machine 13, supplying and exhausting processing gas into the processing furnace 16, adjusting the flow rate of the processing gas, controlling the pressure and temperature of the processing chamber 17, raising and lowering the boat 15 by the boat elevator 18, and rotating the boat 15 and adjusting its rotation speed by the rotating mechanism 21, in accordance with the contents of the read recipe.

[0039] The controller 31 can be configured by installing the above-mentioned program stored in the external storage device 38 onto a computer. The external storage device 38 includes, for example, magnetic disks such as HDDs, optical disks such as CDs, magneto-optical disks such as MOs, and semiconductor memory such as USB memory and SSDs. The storage device 34 and the external storage device 38 are configured as computer-readable recording media. Hereinafter, these will be collectively referred to simply as recording media. In this specification, the term recording media may include only the storage device 34, only the external storage device 38, or both. The program may also be provided to the computer using communication means such as the Internet or a dedicated line, without using the external storage device 38.

[0040] (2) Teaching process When performing maintenance on the substrate processing apparatus 1, various components are removed from the housing 2 and sub-housing 4, and various processes such as cleaning and replacement are carried out. In particular, when reinstalling the boat 15, the transfer machine 13 loads and unloads wafers 6 onto the boat 15 based on the reference position information. That is, the program for transporting wafers 6 has a reference position of the boat 15 set in advance, and wafer transport position information indicating the center position of the wafer 6 when transporting the wafer 6 to the boat 15 is set based on this reference position, and the wafer 6 is transported based on this wafer transport position information. At this time, if there is a discrepancy between the installation position of the boat 15 and the reference position, there is a risk that the wafer 6 or wafer mounting plate 14 may come into contact with the support pillars 15a to 15c of the boat 15. Therefore, a teaching process is performed to correct the wafer transport position information and obtain new wafer transport position information so that the wafer 6 etc. do not come into contact with the support pillars 15a to 15c.

[0041] On the other hand, if the boat 15 is tilted, or if there is foreign matter on the bottom of the boat 15, simply correcting the wafer transport position information may not be enough to avoid contact between the wafer 6 and the support pillars 15a to 15c, and the wafer 6 may not be transported.

[0042] Therefore, in this embodiment, as a pre-process for the teaching process, the controller 31 automatically detects the tilt of the boat 15 after reinstallation and performs a tilt detection process to determine whether the tilt of the boat 15 is within a range that allows the wafer 6 to be transported.

[0043] The tilt detection process in this embodiment will be explained below with reference to the flowchart in Figure 4 and Figures 5 and 6. In the following explanation, the operation and processing of each part constituting the substrate processing apparatus 1 are controlled by the controller 31 according to the tilt detection program. In Figures 5 and 6, the dashed line shows the boat 15' at the reference position, and the solid line shows the actual boat 15.

[0044] STEP 01 First, the controller 31 moves the transfer machine 13 to a first height (Z1). Here, the first height is, for example, the height of the board holding surface of the first slot (the lowest slot) and the height in the vicinity thereof.

[0045] STEP 02 Next, the center position of the boat 15 is obtained at the first height. As shown in Figure 5, the controller 31 drives the Z-axis drive unit 23, Y-axis rotation drive unit 24, X-axis drive unit 25, V-axis drive unit 26, and forward / backward drive units 28a, 28b so that a part of the boat 15 is positioned between the sensor rods 27a, 27b, that is, so that the sensor rods 27a, 27b are stationary in the forward position. That is, the transfer device 13 is moved so that the optical path of the laser beam 39 emitted from the fiber sensors 29a, 29b is within the rotation radius of the boat 15 at the reference position, or so that the optical axis of the laser beam 39 is crossed by the support columns 15a to 15c.

[0046] The controller 31 activates the fiber sensors 29a and 29b and uses the rotation mechanism 21 to rotate the boat 15 around its axis of rotation (R-axis direction) at a constant speed to perform an R-axis scan. Furthermore, if the sensor rods 27a and 27b are in the forward position and mechanically interfere with (contact with) any of the support columns 15a to 15c, the controller 31 controls the forward / backward drive units 28a and 28b to move the sensor rods 27a and 27b to the reverse position. This prevents damage to the sensor rods 27a and 27b and the fiber sensors 29a and 29b.

[0047] If any of the support columns 15a to 15c crosses between the fiber sensors 29a and 29b, the laser beam 39 is blocked by the support column 15a from the moment the support column 15a begins to cross the laser beam 39 (see Figure 6(A)) until the support column 15a finishes crossing the laser beam 39 (see Figure 6(B)), and the reception of the laser beam 39 by the light-receiving parts of the fiber sensors 29a and 29b stops.

[0048] The controller 31 detects the rotation speed of the boat 15 at this time, the time from the start to the end of the crossing of the laser beam 39 across each support column 15a to 15c, and the time (timing) from the end of the crossing to the start of the crossing of the next support column, and stores them in the memory device 34. At this time, the optical path of the laser beam 39 emitted from the fiber sensors 29a and 29b is in a plane perpendicular to the rotation axis of the boat 15, so the timing of the start and end of the crossing can be detected with high precision.

[0049] STEP:03 Based on the scan results of the R-axis scan performed in STEP:02, the amount of displacement r on the XY-axis plane between the center of the boat 15 and the reference position at the first height is calculated. Also, the displacement angle (displacement rotation angle) φ0 of the center of the boat 15 with respect to the reference angle is calculated. Furthermore, the angle (direction angle) θ0 that shows the relationship between the displacement direction of the center of the boat 15 and the orientation of the boat 15 (for example, the direction of the support column 15b), that is, the direction angle θ0, which is the second predetermined rotation angle with respect to the reference angle, which is the first predetermined rotation angle, is calculated. Based on the displacement amount r, displacement angle φ0, and direction angle θ0, the center position of the wafer 6 at the first height is calculated. The calculation method for the displacement amount r, displacement angle φ0, and direction angle θ0 at the first height is described below.

[0050] As shown in Figures 5 and 8, a horizontal complex plane coordinate system is defined with the X-axis parallel to the optical paths of fiber sensors 29a and 29b. The X-axis is set as the reference angle (0°). At this time, t n A predetermined point Z(t) on the support of boat 15 n ) can be expressed by the following formula. Z(t n )=Z0+re j(ωt+φ0) +Re j(ωt+φ0+θx+θ0) +ae j(ωt+φ0+θx+θ0+α) (Formula 1) In Formula 1, Z0 is the coordinate of the reference position (the rotation axis of the rotation mechanism 21), which can be expressed as X0+jY0. In addition, ω represents the rotation frequency of the boat 15, R represents the distance from the center of the boat 15 to the center of the pillars 15a to 15c, and a represents the distance from the center of the pillar to a predetermined point (pillar radius), all of which are known values. The predetermined points are the positions where the light beam first and last contacts the pillar, and in the case of a D-cut pillar like this example, they correspond to the edges at both ends of the D-cut. Also, θ x represents the arrangement angle of the pillars 15a to 15c. For example, when the pillar 15b is taken as the reference, θ B = 0, the position of the pillar 15a at this time is θ B - θ A = 94.7 (deg), and the position of the pillar 15c can be expressed as θ C - θ B = 94.7 (deg). Further, in FIG. 5, Y obj represents the distance in the Y-axis direction from the reference position to the optical path of the laser beam 39.

[0051] As shown in FIGS. 6(A) to 6(D), at four times: the time t1 when the pillar 15a starts crossing the laser beam 39, the time t2 when the pillar 15a finishes crossing the laser beam 39, the time t3 when the pillar 15b starts crossing the laser beam 39, and the time t4 when the pillar 15b finishes crossing the laser beam 39, Formula 1 is intended to calculate the deviation amount r, the deviation angle φ0, and the direction angle θ0 expressed as follows. The following shows the formula for obtaining the distance in the Y-axis direction from the reference position to the optical path of the laser beam 39 (Y obj ) at times t1 to t4.

[0052] Y obj = Im[Z(t1)] = Y0 + rsin(ωt1+φ0) + R A sin(ωt1+φ0+θ A +θ0)+asin(ωt1+φ0+θ A +θ0+α) (Formula 2) Y obj = Im[Z(t2)] = Y0 + rsin(ωt2+φ0) + R A sin(ωt2+φ0+θ A +θ0)+asin(ωt2+φ0+θA (Equation 3) +θ0-α Y obj =Im[Z(t3)]=Im[Z0+(r+Re j(θB+θ0) )e j(ωt3+φ0) +ja]=Y0+rsin(ωt3+φ0)+R B sin(ωt³ + φ0 + θ) B +θ0)+asin(ωt3+φ0+θ B (Equation 4) (θ0 + α) Y obj =Im[Z(t4)]=Im[Z0+(r+Re j(θB+θ0) )e j(ωt4+φ0) +ja]=Y0+rsin(ωt4+φ0)+R B sin(ωt4+φ0+θ B +θ0)+asin(ωt4+φ0+θ B (Equation 5) +θ0-α

[0053] Here, R A , R B These are the distances from the center of boat 15 to the centers of supports 15a and 15c, respectively. These four simultaneous equations are solved using the displacement r, displacement angle φ0, direction angle θ0, and distance Y. obj By solving for this, we can calculate the displacement of the center of boat 15 at the first height relative to the reference position on the horizontal plane (in the XY axis direction). Since these equations (Equations 2) to (Equations 5) are nonlinear simultaneous equations, they can be solved using numerical calculations such as Newton's method. If there are four or more variables, a system of nonlinear equations equal to or greater than the number of variables is created, and the variables are calculated. Conversely, if there are more equations than variables, the solution can also be obtained using the nonlinear least squares method.

[0054] Furthermore, the amount of displacement r and the displacement angle φ0 allow us to determine how far the center of the boat 15 is shifted from the reference position when the boat 15 is at the reference angle (first predetermined angle), and the direction angle θ0 (second predetermined angle) allows us to determine in which direction the center of the boat 15 is shifted from the reference position. Therefore, if we only need to determine the amount of displacement, we do not necessarily need to determine the direction angle θ0.

[0055] STEP 04 Once the amount of displacement r at the first height is calculated, the controller 31 moves the sensor rods 27a and 27b to their retracted positions and stops them, then moves the transfer machine 13 to the second height (Z2). Here, the second height is, for example, the height of the substrate holding surface of the top slot (the uppermost slot) and the height in the vicinity thereof.

[0056] STEP:05 The controller 31, at the second height, stops the sensor rods 27a and 27b in their forward positions and then acquires the center position of the boat 15. The center position of the boat 15 is acquired in the same manner as in STEP:02. Since the sensor rods 27a and 27b are stopped with a predetermined positioning accuracy in their forward positions, measurement errors at different heights can be suppressed.

[0057] STEP:06 Once the center position of the boat 15 at the second height is obtained, the controller 31 calculates the amount of displacement r between the center of the boat 15 at the second height and the reference position on the XY axis plane, the displacement angle (displacement rotation angle) φ0 with respect to the reference angle, and the angle (direction angle) θ0 that shows the relationship between the displacement direction of the center of the boat 15 and the orientation of the boat 15 (for example, the direction of the support column 15b). The amount of displacement r, the displacement angle φ0, and the direction angle θ0 are calculated in the same way as in STEP:03. Based on the amount of displacement r, the displacement angle φ0, and the direction angle θ0, the center position of the wafer 6 at the second height is calculated.

[0058] STEP:07 The controller 31 calculates the tilt of the boat 15 based on the center position of the wafer 6 at the first height, the center position of the wafer 6 at the second height, and the distance between the first height and the second height.

[0059] STEP 08 The controller 31 compares the calculated tilt of the boat 15 with a preset reference value for tilt and determines whether the tilt is within the reference value. Here, the reference value indicates the limit of tilt at which the wafer 6 and the wafer mounting plate 14 will not come into contact with the support pillars 15a to 15c of the boat 15 when the wafer 6 is transported based on the wafer transport position information. Therefore, if the tilt of the boat 15 is within the reference value, the wafer 6, etc. can be transported without coming into contact with the support pillars 15a to 15c, but if the tilt of the boat 15 is greater than the reference value, the wafer 6, etc. will come into contact with the support pillars 15a to 15c.

[0060] If the controller 31 determines that the tilt of the boat 15 calculated in STEP 07 is within the reference value, it determines that the wafer 6 can be transported and terminates the tilt detection process.

[0061] STEP:09 If it is determined in STEP:08 that the tilt of boat 15 is greater than the reference value, the controller 31 will notify an alarm to indicate that the tilt of boat 15 exceeds the reference value, and then terminate the tilt detection process. The alarm may be a light or sound, or it may be a display on the input / output device 37 indicating that the reference value has been exceeded.

[0062] When an alarm is triggered, the worker reinstalls boat 15 and repeats the tilt detection process from STEP:01 to STEP:09. The tilt detection process is repeated until the tilt of boat 15 is within the standard value.

[0063] If the tilt detection process finishes without an alarm being issued, i.e., if the tilt of the boat 15 is within the range in which the wafer 6 can be transported, the teaching process is executed. The controller 31 calculates the correction amount for the actual center position of the wafer 6 relative to the center position of the wafer 6 at the reference position, and updates the wafer transport position information based on the correction amount.

[0064] Furthermore, in the tilt detection process, a step may be added to measure the height from the reference height to the first slot (the lowest slot) at any of the support columns 15a to 15c, and to determine whether there is any foreign matter at the bottom of the boat 15. The height from the reference height to the first slot measured in advance can be compared with the height from the reference height to the first slot measured in reality, and if they do not match, it can be determined that there is any foreign matter at the bottom of the boat 15.

[0065] Furthermore, in this embodiment, the center position of the boat 15 is calculated using two heights, a first height and a second height. However, the center position of the boat 15 may be calculated at three or more heights, and the tilt of the boat 15 may be calculated based on the difference in the center positions of the boat 15 in the height direction.

[0066] (3) Substrate processing process This section outlines the substrate processing process using the substrate processing apparatus 1, which is a semiconductor manufacturing device. This substrate processing process is one step in the manufacturing of semiconductor devices, and is executed after the tilt detection process determines that the tilt of the boat 15 is within a reference value. In the following description, the operation and processing of each part constituting the substrate processing apparatus 1 are controlled by the controller 31.

[0067] (Circuit board delivery process) When pod 3 is supplied to the substrate processing device 1, pod 3 is transferred to the mounting table 9. Once placed on the mounting table 9, the open end face of pod 3 is pressed against the opening edge of the wafer loading / unloading port 7 on the front wall 5 of the sub-housing 4, and the lid is removed by the opening / closing mechanism 11, opening the wafer loading / unloading port.

[0068] When pod 3 is opened by the pod opener 8, the sensor rods 27a and 27b of the transfer machine 13 are moved to a protruding position (towards pod 3) by the forward and backward drive units 28a and 28b. Then, the sensor rods 27a and 27b are moved up and down at a constant speed by the Z-axis drive unit 23, and the wafers 6 inside pod 3 are detected one by one by mapping the wafers 6 using the fiber sensors 29a and 29b.

[0069] After the mapping operation is completed, the sensor rods 27a and 27b are returned to their retracted positions. Then, according to the wafer transport position information corrected based on the correction amount obtained in the teaching process, the wafer mounting plate 14 moves forward, up, and backward, the Y-axis rotation drive unit 24 rotates, and the wafer mounting plate 14 moves forward, down, and backward in sequence, thereby picking up the wafer 6 from inside the pod 3 through the wafer loading / unloading port 7 and loading (charging) it into the boat 15 from the direction opposite to the support column 15b.

[0070] After loading is complete, the lower end of the processing furnace 16, which had been closed by the furnace opening shutter, is opened by the furnace opening shutter. Subsequently, the boat 15 holding the wafers 6 is loaded from the transfer chamber 12 into the processing furnace 16 as the seal cap 19 is raised (boat up) by the boat elevator 18.

[0071] (Film forming process) After loading, the wafer 6 undergoes heat treatment in the processing chamber 17 within the processing furnace 16.

[0072] (Substrate unloading process) Next, the boat 15 on which the heat-treated wafers 6 are placed is moved from the processing room 17 to the transfer room 12 (boat unloading). Then, the boat 15 cools the wafers 6 after the heat treatment is complete.

[0073] After cooling, the sensor rods 27a and 27b of the transfer machine 13 are moved to their protruding positions by the forward and backward drive units 28a and 28b. Then, the sensor rods 27a and 27b are moved up and down by the Z-axis drive unit 23, and the fiber sensors 29a and 29b perform the mapping operation on the wafer 6. When the mapping is complete, the sensor rods 27a and 27b return to their storage positions, and the wafer 6 is transported by the wafer mounting plate 14 according to the wafer transport position information and delivered to the pod 3. After that, the pod 3 is delivered to the outside of the housing 2.

[0074] According to this embodiment, one or more of the following effects can be obtained.

[0075] In this embodiment, for example, when a boat 15 that has been removed for maintenance is reinstalled, the tilt of the reinstalled boat 15 can be automatically detected by the fiber sensors 29a and 29b used for mapping.

[0076] Therefore, manual measurement of the boat 15's tilt by workers is unnecessary, resulting in reduced working time and workload. Furthermore, since the fiber sensors 29a and 29b serve as both mapping sensors and sensors for detecting the boat 15's tilt, a separate sensor for determining the boat 15's tilt is unnecessary, thus reducing production costs.

[0077] Furthermore, since the shift in the height-direction center position of the boat 15 can be calculated based on the timing when the optical paths of the fiber sensors 29a and 29b are blocked by the outer circumference of the support columns 15a to 15c, or when the blockage is resolved, the processing is simple and the processing time can be shortened. In addition, since the transfer machine 13 and the rotation mechanism 21 operate automatically and perform tilt detection processing based on a pre-set tilt detection program, manual operation of the transfer machine 13 and the rotation mechanism 21 by the worker is unnecessary, thereby reducing the amount of work required.

[0078] Furthermore, if the tilt of boat 15 exceeds a standard value, an alarm is triggered, and the wafer 6 transport process is stopped. Therefore, since it is possible to reinstall boat 15 before the teaching process, the interruption and re-execution of the teaching process is eliminated compared to when an unacceptable tilt is detected during the teaching process, thus reducing the time lost during maintenance work.

[0079] Furthermore, by calculating the tilt of boat 15, the eccentricity of the central axis of boat 15 can also be determined. This allows for the assessment of the risk of contact with other components due to the rotation of boat 15, enabling an evaluation that takes contact risk into account to some extent.

[0080] Furthermore, tilt detection processing and teaching processing prevent the wafer 6 and wafer mounting plate 14 from coming into contact with the support columns 15a to 15c, thus preventing damage and particle generation.

[0081] In this embodiment, the deviations in the XY axis directions are calculated for the first and second heights, respectively. However, the deviations calculated for three or more different heights may be fitted as a function of the rotation axis direction of the boat 15, and the deviation amount r, deviation angle φ0, and direction angle θ0 may be calculated based on the fitting results.

[0082] Furthermore, in this embodiment, the center displacement of the boat 15 relative to the reference position is calculated based on the start and end times, i.e., timing, when the support columns 15a to 15c cross the laser beam 39. Alternatively, the center displacement of the boat 15 relative to the reference position may be calculated based on the angle relative to the reference angle when the support columns 15a to 15c cross the laser beam 39.

[0083] Furthermore, in this embodiment, the boat 15 is rotated at a constant speed while performing the R-axis scan, but this is not essential. The boat 15 only needs to rotate at a constant speed from the time the support column 15a begins to block the laser beam until the support column 15b finishes blocking it, or from the time the support column 15b begins to block the laser beam until the support column 15c finishes blocking it. For example, the rotation of the boat 15 may be reduced until the support column 15a blocks the laser beam, or the rotation speed of the boat 15 may be variable after the support column 15c finishes blocking the laser beam. By keeping the rotation speed of the boat 15 constant during the period when the two support columns pass through the laser beam, the start and end times of the blockage can be accurately detected.

[0084] Furthermore, in this embodiment, the shape of the support column is assumed to be a round bar cut by a plane perpendicular to the radius on its outer circumference when viewed from the center of the boat, but it is not limited to this. As can be seen from Figure 8, it is sufficient that light ray contact always occurs at an angle α due to the edge of the side surface of the support column, and the shape of the surface other than the edge that is not in contact with the light ray is arbitrary. In other words, the support column may be a triangular prism or a rectangular prism. In order to ensure that contact occurs reliably at the edge at angle α, it is preferable that the angle β of the optical axis contact position measured from the Y axis be α or less. In other words, the angle between the start and end of light ray blocking by the support column (2β) should be 2α or less. obj Make it bigger.

[0085] In this embodiment, the tilt of the boat 15 is calculated based on the difference between the center position and height of the boat 15 at the first height and the second height, but the method for determining the tilt of the boat 15 is not limited to this. A modified example of the tilt detection process in this embodiment will be described below with reference to the flowchart in Figure 7.

[0086] STEP 11: Measure the height of the first slot of each support column 15a to 15c. Specifically, the controller 31 controls the rotation mechanism 21 to rotate the boat so that the target support column is closest to the Y axis of the transfer machine 13, and drives the Z-axis drive unit 23, Y-axis rotation drive unit 24, X-axis drive unit 25, V-axis drive unit 26, and forward / backward drive units 28a, 28b of the transfer machine 13 so that the first slot (lowest wafer slot) of support column 15a is positioned in the optical path of the laser beam 39.

[0087] Next, the Z-axis drive unit 23 is controlled to make slight vertical movements of the fiber sensors 29a and 29b near the known height of the first slot, and a position is detected where a change occurs that causes a decrease in the amount of light received by the fiber sensors when they are lowered. In other words, the fiber sensors 29a and 29b detect the boundary between the state in which the optical path of the laser beam 39 passes through the slot and the state in which it is blocked by the support pillars 15a to 15c. This boundary is determined by using the midpoint between the maximum value of the received light (which is a typical value in the state in which the beam passes through) and the minimum value (which is a typical value in the state in which the beam is blocked) as the threshold. In other words, the height of the optical path when the amount of received light reaches this threshold is determined to be the height of the lower surface of the first slot (i.e., the substrate mounting surface).

[0088] The controller 31 stores the height of the lower surface of the first slot obtained for each support column in the storage device 34.

[0089] STEP 12: For each support column 15a to 15c, once the height from the reference height to the first slot is measured, the controller 31 calculates the difference in height between the first slots of support columns 15a and 15c, in the left-right direction when viewed from the rotation axis of the boat 15 to the rotation axis of the transfer machine 13, when the boat 15 is in an orientation that allows the wafer 6 to be transferred, and calculates the left-right tilt of the boat 15 based on the height difference.

[0090] STEP 13 The controller 31 determines whether the left-right tilt of the boat 15 calculated in STEP 12 is within a reference value. The reference value is the same as in the above embodiment, and if the left-right tilt is within the reference value, the wafer 6 and the wafer mounting plate 14 will not come into contact with the support columns 15a and 15c of the boat 15 when the wafer 6 is transported to the boat 15.

[0091] STEP 14: If the tilt of the boat 15 in the left-right direction is determined to be within the standard value, the controller 31 then calculates the tilt of the boat 15 in the depth direction. The depth direction refers to the front-to-back direction when the boat 15 is oriented in a way that allows the wafer 6 to be transferred, and the rotation axis of the boat 15 is viewed from the pivot axis of the transfer machine 13. The tilt in the depth direction is calculated by calculating the difference between the average height of the first slot of the support column 15a and the first slot of the support column 15c and the height of the first slot of the support column 15b, and then calculating the tilt of the boat 15 in the depth direction based on the difference in height.

[0092] STEP 15 The controller 31 determines whether the tilt of the boat 15 in the depth direction, calculated in STEP 14, is within a reference value. If it is determined that the tilt in the depth direction is within a reference value, the tilt detection process is terminated, as the tilt in the depth direction does not hinder the transport of the wafer 6. After the tilt detection process is completed, the wafer 6 is transported to the boat 15 and substrate processing is performed.

[0093] STEP 16: If it is determined in STEP 13 that the tilt of boat 15 in the left-right direction exceeds the reference value, or if it is determined in STEP 15 that the tilt of boat 15 in the depth direction exceeds the reference value, the controller 31 notifies an alarm and terminates the tilt detection process. The content of the alarm is the same as in the above embodiment. The alarm may also be made to distinguish whether the tilt in the left-right direction or the tilt in the depth direction exceeded the reference value. The same effects as in the above modified example can be obtained. Furthermore, since the tilt of boat 15 can be determined only by the detection results of fiber sensors 29a and 29b and calculations, the tilt of boat 15 can be determined quickly and easily.

[0094] Furthermore, this disclosure is not limited to the embodiments and variations described above, but includes a variety of other variations. For example, the embodiments and variations described above are explained in detail for the purpose of making this disclosure easier to understand, and are not necessarily limited to having all of the configurations described.

[0095] For example, the controller 31 described above may be implemented by two hardware components: a main controller that primarily controls the process, and a sub-controller that controls the transport system, such as the transfer machine 13. Furthermore, the sub-controller may control each component of the transfer machine 13 via a PLC (Programmable Logic Controller), and the entire misalignment detection process in this example may be performed by the PLC. This allows preparation for teaching to be done without accessing the main controller, thereby reducing security risks.

[0096] The embodiments and modifications described above illustrate examples of forming films using a batch-type substrate processing apparatus that processes multiple substrates at once. This disclosure is not limited to the embodiments and modifications described above, and can be suitably applied to cases where films are formed using a single-wafer substrate processing apparatus that processes several substrates at once. Furthermore, the embodiments and modifications described above illustrate examples of forming films using a substrate processing apparatus having a hot-wall type processing furnace. This disclosure is not limited to the embodiments and modifications described above, and can be suitably applied to cases where films are formed using a substrate processing apparatus having a cold-wall type processing furnace. [Explanation of Symbols]

[0097] 1. Substrate processing apparatus 6 wafers 13 Transfer machine 15. Circuit board holder 21 Rotation mechanism 29a, 29b Fiber sensor 31 Controllers

Claims

1. A substrate processing apparatus comprising: a rotating mechanism that rotatably supports a substrate holder having multiple columns; a sensor attached to a transfer machine for transferring a substrate to the substrate holder so as to be able to change the distance and relative height between the transfer machine and the substrate holder, and configured to detect the columns in the optical path; and a control unit configured to rotate the substrate holder by the rotating mechanism so as to intersect the optical path, calculate the center position of the substrate holder from the detection results of the sensor at multiple heights, and determine whether the inclination of the substrate holder is within a reference value based on the difference in the center positions in the height direction.

2. The substrate processing apparatus according to claim 1, wherein the optical path is set substantially perpendicular to the longitudinal direction of the substrate holder, and the control unit is configured to calculate the center position of the substrate holder based on the angle or timing at which the optical path is blocked by the plurality of pillars.

3. The substrate processing apparatus according to claim 1 or claim 2, wherein two edges are formed on the sides of the plurality of columns at the plurality of heights, which first and last contact the optical path as the substrate holder rotates.

4. The substrate processing apparatus according to claim 1 or claim 2, further comprising: a processing chamber for heat-treating a substrate held by the plurality of columns of the substrate holder; a transfer chamber adjacent to the processing chamber and capable of arranging the substrate holder; and a transfer machine for loading and unloading the substrate to and from the substrate holder located in the transfer chamber.

5. The substrate processing apparatus according to claim 2, wherein the sensor is also used as a mapping sensor for detecting a substrate in the substrate holder by blocking the optical path.

6. The substrate processing apparatus according to claim 2, wherein the sensor is driven by a sensor drive unit such that it can be stationary with a predetermined positioning accuracy only in two positions: an advanced position in which the sensor approaches the center of the substrate holder and a retracted position in which the sensor moves away from the center of the substrate holder.

7. The substrate processing apparatus according to claim 2 or claim 6, wherein the sensor remains stationary while detecting the interruption of the optical path.

8. The substrate processing apparatus according to claim 6, wherein the control unit controls the sensor drive unit to move the sensor to the retracted position when the sensor in the forward position mechanically interferes with any of the plurality of pillars.

9. The substrate processing apparatus according to claim 1 or claim 2, wherein the inclination of the substrate holder is calculated as the angle of inclination of the substrate holder in the front-rear and left-right directions when the rotation axis of the substrate holder is viewed from the pivot axis of the transfer machine when the substrate holder is in a transferable orientation, or as the amount of positional displacement at the uppermost substrate holding position.

10. The substrate processing apparatus according to claim 1 or 2, wherein the control unit is configured to determine, before teaching, whether the inclination of the substrate holder is within a range that allows substrate transport by the transfer machine.

11. The substrate processing apparatus according to claim 1, wherein the control unit fits the deviations calculated at each of a plurality of different positions in the rotation axis direction of the substrate holder as a function of the rotation axis direction, and finally calculates the deviation.

12. The substrate processing apparatus according to claim 2, wherein the control unit controls the substrate holder to rotate at a constant speed while at least one of the plurality of pillars obstructs the optical path.

13. The substrate processing apparatus according to claim 1 or claim 2, wherein the control unit calculates the deviation of the center position in the height direction using only the rotation angle or timing of the substrate holder when the optical path is blocked by the outer circumference of the plurality of pillars or when the blockage is resolved.

14. The substrate processing apparatus according to claim 1 or 2, wherein the control unit numerically calculates the solution to three or more nonlinear simultaneous equations, the solutions of which include the displacement of the center of the substrate holder with respect to the rotation axis of the substrate holder and the displacement of the angle of the substrate holder with respect to a reference angle as unknowns.

15. A substrate processing apparatus comprising: a sensor attached to a transfer machine for transferring a substrate to a substrate holder, configured to detect the height of the substrate holding surface of each of the multiple columns of the substrate holder; and a control unit configured to determine whether the inclination of the substrate holder is within a reference value based on the detected difference in height.

16. A method for detecting the inclination of a substrate holder, comprising: a step of rotating a substrate holder having multiple columns, such that a rotating mechanism rotatably supports the substrate holder, and the optical path of a sensor attached to a transfer machine for transferring a substrate to the substrate holder so as to be adjustable in distance from the substrate holder and relative height, intersects with the multiple columns; a step of calculating the center position of the substrate holder from the detection results of the sensor at multiple heights; and a step of determining whether the inclination of the substrate holder is within a reference value based on the difference in the center position in the height direction.

17. A substrate processing method comprising: a step of rotating a substrate holder having multiple columns, such that a rotating mechanism rotatably supports the substrate holder, and the optical path of a sensor attached to a transfer machine for transferring a substrate to the substrate holder so as to be adjustable in distance from the substrate holder and relative height, intersects with the multiple columns; a step of calculating the center position of the substrate holder from the detection results of the sensor at multiple heights; a step of determining whether the inclination of the substrate holder is within a reference value based on the difference in the center position in the height direction; a step of transferring the substrate from a container to the substrate holder if the inclination is determined to be within a reference value; and a step of loading the substrate holder into a processing chamber and processing the substrate.

18. A method for manufacturing a semiconductor device, comprising: a step of rotating a substrate holder having multiple columns, such that a rotating mechanism rotatably supports the substrate holder, the optical path of a sensor attached to a transfer machine for transferring a substrate to the substrate holder so as to be adjustable in distance from the substrate holder and relative height, intersects with the multiple columns; a step of calculating the center position of the substrate holder from the detection results of the sensor at multiple heights; a step of determining whether the inclination of the substrate holder is within a reference value based on the difference in the center position in the height direction; a step of transferring the substrate from a container to the substrate holder if the inclination is determined to be within a reference value; and a step of loading the substrate holder into a processing chamber and processing the substrate.

19. A program that causes a computer in a substrate processing device to execute the following processes: a rotation mechanism that rotatably supports a substrate holder having multiple columns, such that the multiple columns intersect with the optical path of a sensor attached to a transfer machine for transferring a substrate to the substrate holder, the distance and relative height between the sensor and the substrate holder being adjustable; a process that calculates the center position of the substrate holder from the detection results of the sensor at multiple heights; and a process that determines whether the inclination of the substrate holder is within a reference value based on the difference in the center position in the height direction.

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