Substrate processing apparatus, teaching method of transfer machine, manufacturing method of semiconductor device, and program

Abstract

To provide a substrate processing apparatus that calculates a positional deviation of a center of a substrate holder with respect to a reference position of the substrate holder, a teaching method of a transfer machine, a manufacturing method of a semiconductor device, and a program.SOLUTION: A substrate processing apparatus includes a control part capable of obtaining a detection result of fiber sensors 29a and 29b as a photoelectric sensor having an optical path set within a rotation radius of a substrate holder while rotating a boat 15 as the substrate holder by a transfer device 13, and calculating a deviation of a center of the substrate holder based on an angle or timing at which the optical path is blocked by the substrate holder. In a teaching step of performing various processes such as cleaning and replacement during a maintenance of the substrate processing apparatus, a teaching process of automatically detecting a center position of the boat 15 after re-installation by the maintenance, obtaining a difference between a reference position and the detected position, correcting wafer transport position information based on the difference, and obtaining new wafer transport position information is performed, as a pre-step of a substrate processing step.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a substrate processing apparatus, a transfer machine teaching method, a semiconductor device manufacturing method, and a program. [Background technology]

[0002] In the substrate processing in the manufacturing process of semiconductor devices, for example, a batch-type vertical substrate processing apparatus is sometimes used to process multiple substrates (semiconductor silicon wafers) at once. Vertical substrate processing apparatuses use a substrate holder (boat) that holds multiple substrates with their centers aligned horizontally in multiple stages. The boat also has multiple holding members (supports) that hold the substrates. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-60924 [Patent Document 2] Japanese Patent Application Publication No. 8-64547 Summary of the Invention [Problem to be solved by the invention]

[0004] Vertical substrate processing apparatuses require periodic maintenance, which may require removing a boat from the apparatus, and there is a risk of the boat being misaligned when reattached.

[0005] The present disclosure provides a technique that can calculate the positional deviation of the center of a substrate holder relative to a reference position of the substrate holder. [Means for solving the problem]

[0006] According to one aspect of the present disclosure, a technology is provided that includes a control unit configured to acquire detection results from a photoelectric sensor having an optical path set within the rotation radius of a substrate holder while rotating the substrate holder, and to calculate the deviation of the center of the substrate holder based on the angle or timing at which the optical path is blocked by the substrate holder. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to calculate the positional deviation of the center of the substrate holder relative to the reference position of the substrate holder. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a perspective view of a substrate processing apparatus according to an embodiment of the present disclosure. [Figure 2] FIG. 1 is a perspective view of a transfer machine according to an embodiment of the present disclosure. [Figure 3] FIG. 2 is a schematic configuration diagram of a controller of a substrate processing apparatus according to an embodiment of the present disclosure. [Figure 4] 10 is a flowchart illustrating a teaching process according to an embodiment of the present disclosure. [Figure 5] FIG. 10 is a plan view illustrating a teaching process according to an embodiment of the present disclosure. [Figure 6] (A) and (C) are explanatory diagrams showing the state in which the support starts to cross the laser beam during the teaching process according to an embodiment of the present disclosure, and (B) and (D) are explanatory diagrams showing the state in which the support finishes crossing the laser beam. [Figure 7] 10 is a graph illustrating a scan result of a Z-axis scan in a teaching process according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, one embodiment of the present disclosure will be described with reference to Figures 1 to 3. Note that all drawings used in the following description are schematic, and the dimensional relationships between elements, the ratios of elements, etc. shown in the drawings do not necessarily match those in reality. Furthermore, the dimensional relationships between elements, the ratios of elements, etc. do not necessarily match between multiple drawings. Unless otherwise specified in the specification, each element is not limited to one, and multiple elements may be present.

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

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

[0012] (1) Configuration of the substrate processing equipment The entire apparatus will be described with reference to Figure 1. Figure 1 shows the main parts of the substrate processing apparatus.

[0013] The substrate processing apparatus 1 includes a housing 2. A pod 3, which is a sealed substrate container, is carried into and out of the substrate processing apparatus 1 by an in-process transport device (not shown).

[0014] A sub-housing 4 is provided extending to the rear end at the bottom near the rear in the front-to-rear direction inside the housing 2. A pair of wafer loading / unloading openings 7 are provided in the front wall 5 of the sub-housing 4, arranged vertically in two tiers, one above the other, for loading and unloading wafers 6 into and out of the sub-housing 4. Pod openers 8 are provided for the upper and lower wafer loading / unloading openings 7, respectively.

[0015] The pod opener 8 includes a mounting table 9 on which the pod 3 is mounted, and an opening / closing mechanism 11 that opens and closes 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 mounted on the mounting table 9 using the opening / closing mechanism 11.

[0016] The sub-housing 4 forms a transfer chamber (loading chamber, loading area) 12 that is airtight from the space in which the pod opener 8 is disposed. A transfer machine 13 is installed in the front region of the transfer chamber 12. The transfer machine 13 is equipped with wafer loading plates (substrate grippers) 14 for holding the required number of wafers 6 (five in the illustration). The wafer loading plates 14 are movable in a horizontal direction, rotatable in a horizontal direction, and movable up and down in a vertical direction. 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 loading plates 14 are also called hands, end effectors, chucks, forks, or tweezers, and may be configured with, for example, five loading plates.

[0017] A vertical processing furnace 16 is installed above the transfer chamber 12. The processing furnace 16 has a processing chamber 17 formed therein, and the lower end of the furnace port near the bottom of the processing chamber 17 is open and can be opened and closed by a furnace port 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-housing 4. A seal cap 19 serving as a lid is attached horizontally to an arm (not shown) connected to the lifting platform of the boat elevator 18. The seal cap 19 supports the boat 15 vertically and can airtightly close the furnace throat 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 the processing chamber 17, allowing the boat 15 and the processing chamber 17 to load and unload the wafers 6. The boat 15 is configured to hold multiple wafers 6 (e.g., between 50 and 175) horizontally and in multiple stages, with their centers aligned. As shown in FIG. 2, the boat 15 includes support columns 15a to 15c for holding the wafers 6. The support columns 15a to 15c have grooves (slots) for holding the wafers 6. Furthermore, at least the outer peripheral side surfaces of the support columns 15a to 15c are cylindrical.

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

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

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

[0022] An example of the configuration of the transfer machine 13 will be described with reference to Fig. 2. Fig. 2 shows a state when the transfer machine 13 transfers the wafers 6 to the boat 15. That is, 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 has a guide 22 provided along the vertical direction (Z-axis direction), a Z-axis direction drive unit 23, a Y-axis rotation drive unit 24, an X-axis direction drive unit 25, and a V-axis direction drive unit 26. The drive units 23 to 26 can be called a drive system.

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

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

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

[0027] The V-axis direction drive unit 26 is provided on the X-axis direction drive unit 25, and is configured to horizontally support the five wafer mounting plates 14 while being able to adjust the spacing between them in the Z-axis direction.

[0028] This allows the transfer machine 13 to remove the wafers 6 from the pod 3 using the wafer loading plate 14 and charge them into the boat 15. After any processing is performed on the wafers 6 in the processing furnace 16, the transfer machine 13 can remove (discharge) the wafers 6 from the boat 15 using the wafer loading plate 14 and charge them into the pod 3. The Y-axis rotation drive unit 24 has an outer shape that provides a rotation radius that is equal to or slightly larger than the minimum rotation radius around the Y-axis of the wafer loading plate 14 and the V-axis 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 loading plate 14 and the V-axis drive unit 26, and the Y-axis rotation drive unit 24 has side surfaces that are parallel to the X-axis.

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

[0030] Sensor rods 27a, 27b extend upward along both side surfaces of Y-axis rotation drive unit 24 to approximately the same height as one of wafer mounting plates 14, and are configured to bend at approximately a right angle in the direction opposite to the mounting direction of wafer mounting plate 14 to X-axis drive unit 25, i.e., backward along the X-axis. Sensor rods 27a, 27b hold fiber sensors 29a, 29b as photoelectric sensors.

[0031] The tips of the sensor rods 27a and 27b are provided with light transmitting and receiving units of fiber sensors 29a and 29b, respectively. The fiber sensors 29a and 29b are a pair of transmission-type sensors, one of which transmits a laser beam and the other of which receives it. They can be arranged so that the optical path (optical axis) formed between the light transmitting and receiving units is parallel to the tangent line of the wafers 6. The fiber sensors 29a and 29b function as mapping sensors that detect interruptions in the optical path to count the number of wafers 6 loaded in the pod 3 or the boat 15, and to detect normal or abnormal conditions such as protrusion of wafers 6 or misalignment of the boat 15. When the sensor rods 27a and 27b advance, the optical axes remain aligned and horizontal. The sensor rods 27a and 27b may be connected to each other by passing through the Y-axis rotation drive unit 24 so that they move in tandem with each other. In this case, only one of the forward and backward drive units 28a and 28b is required. The optical paths (optical axes of the laser beams) of the fiber sensors 29a and 29b are perpendicular or approximately perpendicular to the rotation axis of the rotation mechanism 21, i.e., the rotation axis of the boat 15, and are also perpendicular or approximately perpendicular to the extension direction of each of the pillars 15a to 15c.

[0032] Further, advance / retreat drivers 28a and 28b are disposed on both sides of Y-axis rotation driver 24 and support sensor rods 27a and 27b so that they can move in the X-axis direction between a protruding position and a retracted position. That is, wafer mounting plate 14 and sensor rods 27a and 27b are disposed back-to-back with respect to Y-axis rotation driver 24 and can move independently on the X-axis. Sensor rods 27a and 27b can be moved by Z-axis driver 23 along the longitudinal direction (up-down direction, Z direction) of columns 15a to 15c of boat 15.

[0033] This allows the transfer machine 13 to map the wafers 6 in the pod 3 using the fiber sensors 29a and 29b. The transfer machine 13 can also use the fiber sensors 29a and 29b to map the wafers 6 in the boat 15 and detect the positional deviation in the X and Y axes between the reference position of the boat 15 and the current position. Here, the reference position of the boat 15 refers to a vertically installed position where the center of the boat 15 coincides with the center of rotation of the boat 15 (rotation mechanism 21). The center of rotation of the boat 15 can be considered the reference position. The height (height position information) of each wafer slot (not shown) for holding the wafers 6 at this time may also be included in the reference position. Furthermore, the positive X-axis direction of a coordinate system with the reference position as the origin, e.g., a direction parallel to the optical paths of the fiber sensors 29a and 29b, is set as the reference angle (0°).

[0034] 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 the boat 15, that is, in a direction in which the X-axis faces the center of the boat 15. Furthermore, when the boat 15 is rotated by the rotation mechanism 21, one of the supports 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 FIG. 2, the support 15b is positioned closest to the Y-axis of the transfer machine 13, that is, on the X-axis.

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

[0036] The storage device 34 is composed of, for example, a flash memory, a hard disk drive (HDD), a solid state drive (SSD), etc. Control programs for controlling the operation of the substrate processing apparatus, process recipes describing procedures and conditions for the substrate processing steps described below, and other information are readably stored in the storage device 34. The process recipe is a combination of procedures for the substrate processing steps described below that are executed by the controller 31 in the substrate processing apparatus to obtain a predetermined result, and functions as a program. Hereinafter, the process recipes, control programs, etc. are collectively referred to simply as programs. The process recipes are also simply referred to as recipes. In this specification, the term "program" may refer to a recipe alone, a control program alone, or both. The RAM 33 is configured as a memory area (work area) for temporarily storing programs, data, etc. read by the CPU 32.

[0037] The I / O port 35 is connected to the above-mentioned opening / closing mechanism 11, the transfer machine 13, the processing furnace 16, the boat elevator 18, the rotation mechanism 21, and the like.

[0038] The CPU 32 is configured to read and execute a control program from the storage device 34, and to read a recipe from the storage device 34 in response to an input of an operation command from the input / output device 37. The CPU 32 is configured to control, in accordance with the contents of the read recipe, the opening and closing of the lid of the pod 3, the transfer of the wafers 6 by the transfer machine 13, the supply and exhaust of the processing gas into the processing furnace 16, the flow rate adjustment of the processing gas, the pressure control and temperature adjustment of the processing chamber 17, the lifting and lowering of the boat 15 by the boat elevator 18, the rotation of the boat 15 by the rotation mechanism 21 and the adjustment of the rotation speed, etc.

[0039] The controller 31 can be configured by installing the above-mentioned program stored in the external storage device 38 into a computer. The external storage device 38 includes, for example, a magnetic disk such as an HDD, an optical disk such as a CD, a magneto-optical disk such as an MO, and a semiconductor memory such as a USB memory or an SSD. The storage device 34 and the external storage device 38 are configured as computer-readable recording media. Hereinafter, these will be collectively referred to as recording media. In this specification, the term "recording medium" may refer to only the storage device 34, only the external storage device 38, or both. Note that the program may be provided to the computer using a 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 performed. In particular, when reinstalling the boat 15, the transfer machine 13 loads and unloads wafers 6 into and from the boat 15 based on reference position information. That is, a program for performing the wafer 6 transfer process pre-sets the reference position of the boat 15, and wafer transfer position information indicating the center position of the wafer 6 when transferring the wafer 6 to the boat 15 based on the reference position is set. The wafer 6 is then transferred based on the wafer transfer position information. Therefore, if there is a deviation between the installed position of the boat 15 and the reference position, there is a risk that the wafer 6 or the wafer mounting plate 14 will come into contact with the support columns 15a to 15c of the boat 15.

[0041] In this embodiment, as a pre-process of the substrate processing process, the center position of the boat 15 after reinstallation is automatically detected, the difference between the reference position and the detected position is calculated, and the wafer transport position information is corrected based on the difference, thereby executing a teaching process to calculate new wafer transport position information.

[0042] The teaching process in this embodiment will be described below with reference to the flowchart in Fig. 4 and Figs. 5 to 7. In the following description, the operation and processing of each part constituting the substrate processing apparatus 1 are controlled by the controller 31 in accordance with a teaching program. In Figs. 5 and 6, the dotted line indicates the boat 15' at the reference position, and the solid line indicates the actual boat 15.

[0043] STEP: 01 As a preliminary step to automatic teaching processing, the center position of the boat 15 before removal is acquired as a reference position.

[0044] The reference position can be obtained by manually aligning the boat 15 using a jig to align the center of the boat 15 with the reference position, or by performing the teaching process described below on the boat 15 before removal, and then registering (storing) the center of the boat 15 obtained here as a new reference position.

[0045] 5, the controller 31 drives the Z-axis direction driver 23, the Y-axis rotation driver 24, the X-axis direction driver 25, the V-axis direction driver 26, and the advance / retract drivers 28a and 28b so that a part of the boat 15 is positioned between the sensor rods 27a and 27b. That is, the controller 31 moves the transfer machine 13 so that the optical path of the laser beam 39 emitted from the fiber sensors 29a and 29b is positioned within the rotation radius of the boat 15 at the reference position, or so that the columns 15a to 15c cross the optical axis of the laser beam 39.

[0046] The controller 31 moves the transfer machine 13 to a first height (Z1), and while activating the fiber sensors 29a and 29b, causes the rotation mechanism 21 to rotate the rotation axis of the boat 15 at a constant speed around the center (R-axis direction), thereby performing an R-axis scan.

[0047] When any of the pillars 15a to 15c crosses between the fiber sensors 29a and 29b, for example, from the time when the pillar 15a starts to cross the laser beam 39 (see FIG. 6(A)) until the pillar 15a finishes crossing the laser beam 39 (see FIG. 6(B)), the laser beam 39 is blocked by the pillar 15a, and the light receiving units of the fiber sensors 29a and 29b stop receiving the laser beam 39. The laser beam 39 is blocked by the cylindrical outer periphery of each of the pillars 15a to 15c. That is, the side surface of each of the pillars 15a to 15c enters the optical path of the laser beam 39 from a tangential direction and blocks the laser beam 39, so the timing of blocking can be detected with high accuracy.

[0048] The controller 31 detects the rotation speed of the boat 15 at this time, the time from the start of crossing the laser beam 39 of each of the pillars 15a to 15c to the end of the crossing, and the time (timing) from the end of the crossing to the start of crossing of the next pillar, and stores these in the storage device 34. The controller 31 also performs R-axis scans at a second height (Z2) different from the first height and a third height (Z3) different from the first and second heights, and stores the scan results in the storage device 34. While the R-axis scans are performed at three different heights in STEP:01, they may be performed at two different heights or at four or more different heights. Furthermore, because the optical paths of the laser beams 39 emitted from the fiber sensors 29a and 29b are perpendicular or nearly perpendicular to the rotation axis of the boat 15, the timing of the start and end of the crossing can be detected with high accuracy.

[0049] STEP: 02 Based on the scan results of the R-axis scans at three different heights (Z1 to Z3) performed in STEP: 01, the amount of deviation r on the XY-axis plane between the center of the boat 15 at the first height and the reference position is calculated. The deviation angle (deviation rotation angle) φ0 of the center of the boat 15 relative to the reference angle is also calculated. Furthermore, the angle (direction angle) θ0 indicating the relationship between the deviation direction of the center of the boat 15 and the orientation of the boat 15 (e.g., the direction of the support 15b), i.e., the direction angle θ0, which is a second predetermined rotation angle relative to the reference angle, which is a first predetermined rotation angle, is calculated. The deviation amount r, deviation angle φ0, and direction angle θ0 are similarly calculated for the second and third heights. Below, a method for calculating the deviation amount r, deviation angle φ0, and direction angle θ0 at the first height will be described.

[0050] time t n Point Z(t n ) can be expressed by the following formula: Z(t n )=Z0+re j(ωt+φ0) +Re j(ωt+φ0+θx+θ0) +ja (formula 1) In Equation 1, Z0 indicates the origin of a coordinate system with the reference position as the origin, and can be expressed as X0 + jY0. Also, ω indicates the rotation frequency of the boat 15, R indicates the boat radius, and a indicates the support radius, all of which are known values. Also, θ x indicates the positions of the support pillars 15a to 15c. For example, when the support pillar 15b is used as a reference, θ B =0, and the position of the support 15a at this time is θ B -θ A =94.7±0.37 / 2(deg), and the position of the support 15c is θ C -θ B =94.7±0.37 / 2(deg). Furthermore, in Figure 5, Y obj indicates the distance in the Y-axis direction from the reference position to the optical path of the laser beam 39.

[0051] In this embodiment, as shown in Figures 6(A) to 6(D), the deviation amount r, deviation angle φ0, and direction angle θ0 are calculated using four times: time t1 when the support 15a starts crossing the laser beam 39, time t2 when the support 15a finishes crossing the laser beam 39, time t3 when the support 15b starts crossing the laser beam 39, and time t4 when the support 15b finishes crossing the laser beam 39. Below, the distance (Y obj ) is shown.

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

[0053] Here, time t n Regardless of the above, the distance in the Y-axis direction from the reference position to the optical path of the laser beam 39 (Y obj ) does not change, so (Equation 2) = (Equation 3) = (Equation 4) = (Equation 5), and for example, the following three equations hold.

[0054] 2rcos{ω(t2+t1) / 2+φ0}sin{ω(t2-t1) / 2}+2Rcos{ω(t2+t1) / 2+φ0+θ A +θ0}sin{ω(t2-t1) / 2}=0 (Equation 6) 2rcos{ω(t3+t1) / 2+φ0}sin{ω(t3-t1) / 2}+2Rcos{ω(t3+t1) / 2+φ0+(θ B +θ A ) / 2+θ0}sin{ω(t3-t1) / 2+(θ B -θ A ) / 2}=0(formula 7) 2rcos{ω(t4+t2) / 2+φ0}sin{ω(t4-t2) / 2}+2Rcos{ω(t4+t2) / 2+φ0+(θ B +θ A ) / 2+θ0}sin{ω(t4-t2) / 2+(θ B -θ A ) / 2}=0(Formula 8)

[0055] The above (Equation 6) represents the calculation result of (Equation 3) - (Equation 2) = 0, (Equation 7) represents the calculation result of (Equation 4) - (Equation 2) = 0, and (Equation 8) represents the calculation result of (Equation 5) - (Equation 3) = 0. By solving the simultaneous equations using the three equations (Equation 6) to (Equation 8), the amount of deviation r, deviation angle φ0, and direction angle θ0 can be calculated, and the deviation on the horizontal plane (XY axis direction) between the center of the boat 15 at the first height and the reference position can be calculated. These (Equations 6) to (Equation 8) are nonlinear simultaneous equations, so they can be found using numerical calculations such as Newton's method. If there are four or more variables, nonlinear simultaneous equations equal to or greater than the number of variables are created to calculate the variables.

[0056] The amount of deviation r and the deviation angle φ0 can be used to determine how far the center of the boat 15 is deviated from the reference position when the boat 15 is at a reference angle (first predetermined angle), and the direction in which the center of the boat 15 is deviated from the reference position can be determined from the direction angle θ0 (second predetermined angle). Therefore, if you simply want to determine the amount of deviation, it is not necessary to determine the direction angle θ0.

[0057] Similarly, at the second height and the third height, the amount of deviation r, the deviation angle φ0, and the direction angle θ0 are calculated, and the deviations on the horizontal plane (XY axis directions) of the center of the boat 15 at the second height and the third height from the reference position can be calculated. Furthermore, the inclination of the boat 15 can be calculated based on the centers of the boat 15 at the first height to the third height.

[0058] STEP 03: Once the displacements of the boat 15 in the X and Y axes directions have been calculated, Z-axis scanning is then started for each of the pillars 15a to 15c. Note that the following describes the case where Z-axis scanning is performed on the pillar 15a.

[0059] In the Z-axis scanning process, first, the transfer device 13 and the boat 15 are moved to the Z-axis scanning start position. For example, based on the position and direction of the boat 15 detected in STEP: 02, the transfer device 13 is moved to the lower end of the support 15a, and the boat 15 is rotated so that the wafer slot (not shown) of the support 15a is positioned on the optical path of the laser beam 39, and then the Z-axis scan is performed.

[0060] When the Z-axis scan is performed, the fiber sensors 29a and 29b are activated and the transfer machine 13 is moved upward along the support pillar 15a while the rotation of the boat 15 is stopped. Fig. 7 is a graph showing the Z-axis scan results (detection results of the fiber sensors 29a and 29b) with the vertical axis representing the amount of received light (arbitrary unit) of the laser beam 39 detected by the fiber sensors 29a and 29b and the horizontal axis representing the height (arbitrary unit) of the support pillar 15a. Note that the Z-axis scan may also be performed by moving the transfer machine 13 downward along the support pillar 15a from the top end of the support pillar 15a.

[0061] When the laser beam 39 is interrupted by the support 15a, i.e., when there is no wafer slot on the optical path of the laser beam 39, the amount of the laser beam 39 received by the fiber sensors 29a, 29b is minimum. Also, when a wafer slot is present on the optical path of the laser beam 39, the amount of the laser beam 39 received from one of the fiber sensors 29a, 29b is maximum, and the maximum amount of light received continues until the wafer slot is interrupted. Therefore, the position (height) of the wafer slot can be detected based on the state of reception of the laser beam 39 and the height of the laser beam 39 at that time.

[0062] 7, the amount of light received by the laser beam 39 gradually increases from a minimum to a maximum due to the laser beam 39 having a predetermined diameter. To estimate the actual shape of the wafer slot, for example, the amount of light received by the laser beam 39 is thresholded at an intermediate value between the maximum and minimum amounts of light received.

[0063] When the boat 15 is upright, i.e., when the rotation axis of the boat 15 is vertical, Z-axis scanning produces a scan result in which a trapezoidal waveform 41a, whose height is the difference in light intensity from the minimum to the maximum received light intensity, is repeated at regular intervals. On the other hand, when the boat 15 is tilted, only a portion of the laser beam 39 is received, and the remaining portion is blocked by the wafer slot, resulting in a trapezoidal waveform 41b with a smaller difference in light intensity (height). The amount of received light obtained by Z-axis scanning is associated with the height of the transfer machine 13, i.e., the height of the optical path of the laser beam 39, and stored in the storage device 34. Wafer slot position (height) information calculated based on the amount of received laser beam 39 and the height of the optical path of the laser beam 39 may also be stored in the storage device 34.

[0064] Z-axis scanning is also performed on the support 15b and the support 15c, and the amount of received laser beam 39 is stored in the storage device 34 in association with the height of the optical path of the laser beam 39.

[0065] STEP 04: The controller 31 compares the scan results of the Z-axis scan for each of the pillars 15a to 15c with the slot position information for each of the pillars 15a to 15c at the reference position, and calculates the amount of deviation of each slot in the Z-axis direction (rotation axis direction), i.e., the amount of deviation of the boat 15 in the Z-axis direction from the reference position. Furthermore, based on the height of the trapezoidal waveform obtained by the Z-axis scan, the tilt and shape of the wafer slot, i.e., the tilt and deformation of the boat 15, can also be calculated.

[0066] STEP: 05 The controller 31 calculates position information (height information) of the boat 15 (wafer slot) based on the amount of deviation in the X and Y axes calculated in STEP: 02 and the amount of deviation in the Z axis direction calculated in STEP: 04. In addition, based on the calculated position deviation and height deviation of the center of the boat 15 and the direction angle θ0 of the boat 15, new wafer transfer position information for transferring the wafers 6 to each wafer slot of the boat 15 is calculated.

[0067] That is, the correction amount of the center position of the wafer 6 at the calculated position relative to the center position of the wafer 6 at the reference position is calculated. The calculated correction amount is stored in the memory device 34, or the wafer transfer position information updated based on the correction amount is stored in the memory device 34, and the teaching process is completed.

[0068] (3) Substrate processing process An outline of a substrate processing process for processing substrates using the substrate processing apparatus 1 as a semiconductor manufacturing apparatus will be described below. This substrate processing process is one process for manufacturing, for example, a semiconductor device. In the following description, the operation and processing of each part constituting the substrate processing apparatus 1 are controlled by a controller 31.

[0069] (Board loading process) When the pod 3 is supplied to the substrate processing apparatus 1, the pod 3 is transferred to the mounting table 9. The open end face of the pod 3 mounted on the mounting table 9 is pressed against the edge of the opening of the wafer loading / unloading port 7 in the front wall 5 of the sub-housing 4, and the lid is removed by the opening / closing mechanism 11, opening the wafer entrance / exit.

[0070] When the pod 3 is opened by the pod opener 8, the sensor rods 27a and 27b of the transfer machine 13 are moved to the protruding position (in the direction approaching the pod 3) by the forward / backward driving units 28a and 28b. Then, the sensor rods 27a and 27b are moved up and down at a constant speed by the Z-axis direction driving unit 23, and the wafers 6 are mapped by the fiber sensors 29a and 29b, thereby detecting the wafers 6 in the pod 3 in order.

[0071] After the mapping operation is completed, the sensor rods 27a and 27b are returned to their retracted positions. Then, in accordance with the wafer transfer position information corrected based on the correction amount obtained in the teaching process, the wafer loading plate 14 is advanced, raised, and retracted, the Y-axis rotary drive unit 24 is rotated, and the wafer loading plate 14 is advanced, lowered, and retracted in sequence, thereby picking up the wafer 6 from the pod 3 through the wafer loading / unloading port 7 and loading (charging) it into the boat 15.

[0072] After the loading is completed, the lower end of the processing furnace 16, which had been closed by the furnace port shutter, is opened by the furnace port shutter. Then, the boat 15 holding the wafers 6 is loaded from the transfer chamber 12 into the processing furnace 16 by the boat elevator 18 raising the seal cap 19 (boat up).

[0073] (Film forming process) After loading, the wafers 6 are subjected to heat treatment in the processing chamber 17 in the processing furnace 16 .

[0074] (Substrate unloading process) Next, the boat 15 on which the heat-treated wafers 6 are placed is carried out (boat unloading) from the processing chamber 17 to the transfer chamber 12. Then, the boat 15 cools the wafers 6 after the heat treatment.

[0075] After cooling, the sensor rods 27a, 27b of the transfer machine 13 are moved to the protruding position by the advance / retract drive units 28a, 28b. Then, the sensor rods 27a, 27b are moved up and down by the Z-axis direction drive unit 23, and the fiber sensors 29a, 29b perform a mapping operation of the wafer 6. Then, when the mapping is completed, the sensor rods 27a, 27b return to the stored position, and the wafer 6 is transported by the wafer loading plate 14 in accordance with the wafer transport position information and unloaded into the pod 3. Then, the pod 3 is unloaded to the outside of the housing 2.

[0076] According to this aspect, one or more of the following effects can be obtained.

[0077] In this embodiment, when a boat 15 that has been removed for maintenance or the like is reinstalled, the amount of deviation of the reinstalled boat 15 from its reference position can be automatically detected by the fiber sensors 29a and 29b used for mapping.

[0078] Therefore, it is no longer necessary for an operator to manually set the boat 15 at the reference position using a jig, which reduces the time and amount of work required. Also, it is no longer necessary to use a member for determining the amount of deviation of the boat 15 from the reference position, which reduces manufacturing costs.

[0079] In addition, the transfer machine 13 and the rotation mechanism 21 operate automatically and the teaching process is performed based on a pre-set teaching program, so there is no need for workers to manually operate the transfer machine 13 and the rotation mechanism 21, thereby reducing work effort.

[0080] The teaching process automatically updates the wafer transport position information, thereby preventing damage and particle generation due to the wafer 6 or wafer mounting plate 14 being transported by the transfer machine 13 coming into contact with the support columns 15a to 15c, etc.

[0081] Furthermore, in the teaching process, a Z-axis scan is performed on each of the support columns 15a to 15c of the boat 15, and the inclination of each of the support columns 15a to 15c can be obtained, so that deformation of the boat can be automatically detected.

[0082] Furthermore, since the teaching process is performed automatically, there is no need for an operator to perform work inside the housing 2, and therefore the cleanliness inside the substrate processing apparatus 1 can be maintained.

[0083] In this embodiment, the amount of deviation of the boat 15 from the reference position is calculated using two of the pillars 15a to 15c, but the amount of deviation may be calculated using all three pillars 15a to 15c. In this case, the amount of deviation r, the deviation angle φ0, and the direction angle θ0 can be calculated by solving five simultaneous equations. Even when a boat with four or more pillars is used, the amount of deviation r, the deviation angle φ0, and the direction angle θ0 can be calculated by solving simultaneous equations equal to or greater than the number of variables.

[0084] In addition, in this embodiment, the deviations in the X and Y axes directions are calculated at three different heights, but the deviations calculated at each height may be fitted as a function of the direction of the rotation axis of the boat 15, and the deviation amount r, deviation angle φ0, and direction angle θ0 may be calculated based on the fitting results.

[0085] In this embodiment, the deviation of the center of the boat 15 from the reference position is calculated based on the start and end times, i.e., timing, when the pillars 15a to 15c cross the laser beam 39. On the other hand, the deviation of the center of the boat 15 from the reference position may be calculated based on the angle with respect to the reference angle when the pillars 15a to 15c cross the laser beam 39.

[0086] Furthermore, in this embodiment, the boat 15 is rotated at a constant speed at all times when performing an R-axis scan, but it is sufficient that the boat 15 rotates at a constant speed only while the optical path of the laser beam 39 is blocked, that is, only while any of the supports 15a to 15c is blocking the optical path of the laser beam 39. For example, the rotation of the boat 15 may be slowed down while the optical path of the laser beam 39 is blocked, or the rotation speed of the boat 15 may be variable while the optical path of the laser beam 39 is not blocked. By keeping the rotation speed of the boat 15 constant while the optical path of the laser beam 39 is blocked, the start and end times of the blocking can be accurately detected.

[0087] Furthermore, when there are three or more supports and the amount of deviation r, deviation angle φ0, and direction angle θ0 are to be calculated using three or more supports, an optimal solution (least squares solution) may be calculated using an equation with more than the number of variables. Furthermore, the results of manual teaching may be used as training data to have AI perform calculations based on a predictive model created by machine learning.

[0088] In this embodiment, when calculating the amount of deviation in the X and Y axes, θ A , θ C (θ B -θ A , θ C -θ B ) is a known constant, but θ A , θ C Alternatively, θ may be calculated as the difference between the rotation axis angles of the supports 15a to 15c when the laser beam 39 is blocked. A , φ0+θ, θ C may be directly calculated as the midpoint angle between the start and end of the interception of the laser beam 39 by the supports 15a to 15c. Furthermore, by comparing these with the design values, the displacement of the supports in the tangential direction can be determined, and even if there is a displacement, the positional deviation can be calculated with high accuracy. [Explanation of symbols]

[0089] 1. Substrate processing equipment 15. Boat 29a, 29b Fiber sensor 31 Controller

Claims

1. A substrate processing apparatus having a control unit configured to acquire the detection results of a photoelectric sensor having an optical path set within the rotation radius of a substrate holder while rotating the substrate holder, and to calculate the deviation of the center of the substrate holder based on the angle or timing at which the optical path is blocked by the substrate holder.

2. 2. The substrate processing apparatus according to claim 1, further comprising a processing chamber for heat-treating the substrate held by the plurality of pillars of the substrate holder, wherein the control unit is configured to be able to calculate the deviation based on the angle or timing at which the optical path is blocked by the plurality of pillars.

3. 3. The substrate processing apparatus according to claim 1, further comprising: a photoelectric sensor having an optical path perpendicular or substantially perpendicular to a rotation axis of the substrate holder.

4. 3. The substrate processing apparatus of claim 1, further comprising: a processing chamber for heat-treating a substrate held by multiple pillars of the substrate holder; a transfer chamber adjacent to the processing chamber in which the substrate holder can be placed; a transfer machine for loading and unloading substrates into and from the substrate holder in the transfer chamber; and a rotation drive unit for rotating the substrate holder within the processing chamber.

5. 5. The substrate processing apparatus according to claim 4, wherein the photoelectric sensor is a mapping sensor mounted on the transfer machine, has an optical axis perpendicular or approximately perpendicular to the extension direction of the plurality of pillars, and detects the substrate in the substrate holder by blocking the optical axis.

6. 2. The substrate processing apparatus of claim 1, wherein the deviation is calculated when the rotation axis of the rotation drive unit is at a first predetermined rotation angle, and the control unit determines, based on the deviation, a correction amount for correcting the center position of the substrate to be transferred to the substrate holder when the rotation axis is at a second predetermined rotation angle.

7. 2. 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.

8. 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 blocks the optical path.

9. 2. The substrate processing apparatus of claim 1, wherein the control unit acquires the detection results of the photoelectric sensor while moving the optical path along one of a plurality of pillars of the substrate holder without rotating the substrate holder, and is configured to be able to calculate the position of the slot in the direction of the rotation axis of the substrate holder based on the interruption of the optical path corresponding to the slot of the substrate holder.

10. The substrate processing apparatus according to claim 2 , wherein the control unit calculates the deviation by assuming that at least the outer peripheral side surfaces of the plurality of pillars are cylindrical.

11. The substrate processing apparatus of claim 10, wherein the control unit calculates the deviation using only the rotation angle or timing of the substrate holder when the optical path is blocked by the outer periphery of the plurality of pillars or when the blockage is removed.

12. 3. The substrate processing apparatus of claim 1, wherein the control unit numerically calculates solutions to three or more nonlinear equations including unknowns: a positional deviation of the center of the substrate holder relative to the rotation axis of the substrate holder; and an angular deviation of the substrate holder relative to a reference angle.

13. A method for teaching a transfer machine, comprising: a step of acquiring the detection results of a photoelectric sensor having an optical path set within the rotation radius of a substrate holder while rotating the substrate holder; and a step of calculating the deviation of the center of the substrate holder based on the angle or timing at which the optical path is blocked by the substrate holder.

14. A method for manufacturing a semiconductor device, comprising: a step of correcting a transport position by the amount of deviation calculated by the method of claim 11, and transferring the substrate from a container to a substrate holder; and a step of loading the substrate holder into a processing chamber and processing the substrate.

15. A program that causes a computer provided in a substrate processing apparatus to execute the following steps: while rotating a substrate holder, acquire the detection results of a photoelectric sensor having an optical path set within the rotation radius of the substrate holder; and calculate the deviation of the center of the substrate holder based on the angle or timing at which the optical path is blocked by the substrate holder.

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