Substrate processing device, teaching method for transfer machine, production method for semiconductor device, substrate transfer system, and program

Abstract

Provided is a technology capable of teaching a transfer machine by using the transfer machine to detect the position of a wafer inside a pod.　The present invention comprises: a robot having a sensor that detects an edge of a substrate, a pivot unit that moves the sensor about a pivot axis, an advancing / retracting drive unit that is supported by the pivot unit, supports the sensor, and enables the distance between the sensor and the pivot axis to be changed, and an end effector that is supported such that movement about the pivot axis is possible and changing of the distance between the end effector and the pivot axis is possible; and a control unit configured so as to be capable of searching for the maximum value of the distance at which the edge of the substrate, when placed in a reference position and not gripped by the end effector, is detected while changing said distance and the rotational angle of the sensor about the pivot axis, and of acquiring the maximum value and the rotational angle at which the maximum value is reached.

Description

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

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

[0002] In some cases, a batch-type vertical substrate processing apparatus is used to process multiple substrates (hereinafter referred to as wafers) at once as part of a semiconductor device manufacturing process. In the substrate processing apparatus that performs these processes, an operator may adjust the teaching position of the robot with respect to transfer position information for a wafer transport container (hereinafter referred to as a pod) and a transfer machine (hereinafter referred to as a robot) (see, for example, Patent Document 1), or a teaching jig may be used to determine the teaching position (see, for example, Patent Document 2).

[0003] JP 7-74229 A JP 2018-22721 A

[0004] The present disclosure provides a technique that enables a robot to detect the position of a wafer in a pod and teach the robot.

[0005] According to one aspect of the present disclosure, there is provided a technology comprising: a robot having a sensor that detects an edge of a substrate; a rotating unit that moves the sensor around a rotating axis; an advance / retreat drive unit that is supported on the rotating unit and supports the sensor, allowing the distance between the sensor and the rotating axis to be changed; and an end effector that is supported so that it can move around the rotating axis and so that the distance from the rotating axis can be changed; and a control unit configured to search for the maximum value of the distance at which an edge of a substrate placed at a reference position without being gripped by the end effector is detected, while changing the rotation angle of the sensor around the rotating axis and the distance, and to acquire the maximum value and the rotation angle at which the maximum value is reached.

[0006] According to the present disclosure, it is possible to detect the position of the wafer in the pod with the robot and teach the robot.

[0007] FIG. 1 is a perspective view of a substrate processing apparatus according to an embodiment of the present disclosure. FIG. 2 is a perspective view of a transfer machine according to an embodiment of the present disclosure. FIG. 3 is a schematic layout diagram viewed from above to explain the arrangement and operation of a transfer machine, pod, and boat provided in a substrate processing apparatus according to an embodiment of the present disclosure. FIG. 4 is a diagram explaining the basic principle of teaching applied in an embodiment of the present disclosure. FIG. 5 is a flow diagram showing steps of basic operations during teaching applied in an embodiment of the present disclosure. FIG. 6 is a diagram explaining an angle determination method (first stage). FIG. 7 is a diagram explaining detection of light beam interruption at the edge of a wafer applied in an embodiment of the present disclosure. FIG. 8 is a diagram explaining an angle determination method (second stage). FIG. 9 is a schematic configuration diagram of a controller of a substrate processing apparatus according to an embodiment of the present disclosure. FIG. 10 is a flow diagram showing substrate processing steps applied in an embodiment of the present disclosure.

[0008] Hereinafter, one embodiment of the present disclosure will be described mainly with reference to FIGS. 1 to 10. It should be noted that all drawings used in the following description are schematic, and the dimensional relationships and ratios of elements shown in the drawings do not necessarily correspond to the actual ones. Furthermore, the dimensional relationships and ratios of elements between multiple drawings do not necessarily correspond to the actual ones. Furthermore, elements that are substantially the same as those described in FIG. 1 are denoted by the same reference numerals, and their description will be omitted. Furthermore, unless otherwise specified in the specification, each element is not limited to one, and multiple elements may be present.

[0009] (1) Configuration of the Substrate Processing Apparatus The entire apparatus will be described with reference to Fig. 1. Fig. 1 shows the main parts of the substrate processing apparatus.

[0010] As shown in FIG. 1 , a substrate processing apparatus 1 according to an embodiment includes a housing 2, which further includes a sub-housing 4 (X1 side) inside the housing 2. A loading platform 9, which serves as a load port for placing a pod 3, is provided on the front (X2 side) of the sub-housing 4, and a boat 15 and a controller 31, which serves as a control unit, are disposed on the rear (X1 side) of the sub-housing 4. The X2-X1 direction is the front-to-rear direction of the processing apparatus 10, the Y2-Y1 direction is the left-to-right direction, and the Z1-Z2 direction is the up-to-down direction. Pods 3, which are sealed substrate containers, are loaded into and unloaded from the substrate processing apparatus 1 by an in-process transport device (not shown).

[0011] A pair of wafer loading / unloading openings 7 are arranged vertically in two tiers, one above the other, on the front wall 5 of the sub-housing 4 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.

[0012] 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.

[0013] 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 (robot) 13 is installed in the front region of the transfer chamber 12. The robot 13 is equipped with wafer loading plates (substrate grippers) 14 for holding the required number of wafers 6 (five in the figure). 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 robot 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.

[0014] 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.

[0015] 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 and the boat 15, allowing the boat 15 and the wafers 6 to be loaded and unloaded. The boat 15 is configured to hold multiple wafers 6 (e.g., between 50 and 175) in a horizontal position with their centers aligned in multiple stages. 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.

[0016] A rotation mechanism 21 is installed on the opposite side of the seal cap 19 from the processing chamber 17, rotating 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.

[0017] A clean unit (not shown) is disposed at a position (the first side surface 4a side of the sub-housing 4) opposite the boat elevator 18 (the second side surface 4b side of the 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 the sub-housing 4 (i.e., the first side surface of the transfer chamber 12) has a clean air outlet. A notch alignment device (not shown) can be installed between the robot 13 and the clean unit as a substrate alignment device that aligns the circumferential position of the wafer 6.

[0018] After circulating through the notch alignment device, robot 13, and boat 15, part of the clean air blown out from the clean unit is sucked in by a local exhaust duct (or a common exhaust duct) or the like 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 part is blown out again into the transfer chamber 12 by the clean unit.

[0019] An example of the configuration of the robot 13 will be described with reference to Fig. 2. Fig. 2 shows a state in which the robot 13 transfers wafers 6 to the boat 15. That is, the wafer loading plate (end effector) 14 of the robot 13 faces the support columns 15a and 15c of the boat 15.

[0020] The robot 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 which is a rotation unit, an X-axis direction drive unit 25, and a V-axis direction drive unit 26 which is an elevation unit. Each of the drive units 23 to 26 can be referred to as a drive system.

[0021] The Z-axis direction drive unit 23 is provided at the lower end or upper end of the guide 22 to move the mount 22 a up and down (Z-axis direction, vertical direction) along the guide 22 .

[0022] 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 clockwise or counterclockwise horizontally (rotate around the Y-axis) while supporting the X-axis drive unit 25 so that the X-axis and Y-axis 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.

[0023] 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 X-axis defines the direction in which the end effector 14 moves protruding from the Y-axis rotation drive unit 24 in order to enter the boat 15 or the pod 3 as "forward."

[0024] 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 end effectors 14 while allowing the spacing between them to be adjusted in the Z-axis direction.

[0025] Before or after being gripped by the end effector 14, the wafers 6 are arranged with their main surfaces substantially parallel to a horizontal plane perpendicular to the pivot axis 40 (described later). Therefore, the robot 13 can use the end effector 14 to remove multiple wafers 6 arranged at predetermined intervals in a direction substantially parallel to the Y-axis from the pod 3 and charge them into the boat 15. After a desired process is performed on the wafers 6 in the process furnace 16, the robot 13 can use the end effector 14 to remove (discharge) the wafers 6 from the boat 15 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 of the end effector 14 and the V-axis drive unit 26 about the Y-axis. 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 end effector 14 and the V-axis drive unit 26, and the Y-axis rotation drive unit 24 has a side surface that is parallel to the X-axis.

[0026] The robot 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. The advance / retract drive units 28a, 28b can move up and down by the Z-axis drive unit 23, which is an elevator unit.

[0027] Sensor rods 27a, 27b are fixed along both side surfaces of Y-axis rotation drive unit 24 at approximately the same height as either of the end effectors 14, and are configured to be bent at approximately a right angle in the direction opposite to the mounting direction of end effector 14 to X-axis drive unit 25, i.e., rearward along the X-axis. Sensor rods 27a, 27b hold fiber sensors 29a, 29b, which are photoelectric sensors having an optical axis in a predetermined tangential direction in rotation around pivot axis 40.

[0028] 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. The fiber sensors 29a and 29b 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 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 as to move in tandem with each other. In this case, only one of the forward and backward drive units 28a and 28b is required. Furthermore, the optical path (optical axis of the laser beam) of the fiber sensors 29a, 29b is perpendicular or approximately perpendicular to the rotation axis of the rotation mechanism 21, i.e., the rotation axis of the boat 15, and is also perpendicular or approximately perpendicular to the extension direction of each support 15a to 15c.

[0029] Here, the optical axis diameter of fiber sensors 29a, 29b is determined by the diameter of the opening on the light-emitting side and the diameter of the opening on the light-receiving side, and by setting both to 0.5 mm or less, an optical axis with a diameter of 0.5 mm or less can be obtained. The optical axis diameter is preferably smaller than the thickness of wafer 6. By setting the optical axis diameter to 0.5 mm or less, even if wafer 6 warps, the laser beam will not be blocked by the thickness of wafer 6, i.e., wafer detection will be possible.

[0030] Furthermore, considering that light diffused off the optical axis may be reflected by the edge of the wafer 6 and affect the intensity of the received light, it is preferable that the fiber sensors 29a, 29b have optical systems with the same characteristics and have the same aperture diameters and beam divergence angles. Also, the fiber sensors 29a, 29b are provided at a distance equal to or greater than the diameter of the wafer 6. By using these characteristics and structure, the laser beams from the fiber sensors 29a, 29b can form optical paths parallel to the tangent to the wafer 6.

[0031] Further, the advance / retract drive units 28a, 28b are arranged on both sides of the Y-axis rotation drive unit 24 and support the sensor rods 27a, 27b so that they can move in the X-axis direction between a protruding position and a retracted position. That is, the end effector 14 and the sensor rods 27a, 27b are arranged back-to-back with respect to the Y-axis rotation drive unit 24 and can move independently on the X-axis. The sensor rods 27a, 27b can be moved by the Z-axis drive unit 23 along the longitudinal direction (up and down direction, Z direction) of the support columns 15a to 15c of the boat 15.

[0032] This allows the robot 13 to map the wafers 6 in the pod 3 using the fiber sensors 29a and 29b. The robot 13 can also use the fiber sensors 29a and 29b to map the wafers 6 in the boat 15 and detect positional deviations in the X and Y axes between the reference position and the current position of the boat 15. Here, the reference position of the boat 15 refers to a vertically installed position in which 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°).

[0033] As shown in Fig. 2, the sensor rods 27a and 27b of the robot 13 are moved by the Y-axis rotation drive unit 24 in a direction approaching the boat 15, i.e., 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 support posts 15a to 15c of the boat 15 is positioned so as to intercept the laser beam emitted from one of the fiber sensors 29a and 29b. In Fig. 2, the support post 15b is positioned closest to the Y-axis of the robot 13, i.e., on the X-axis. When detecting the wafer 6, the position is rotated 180 degrees from this position.

[0034] Next, the arrangement and operation of the robot 13, the pod 3, and the boat 15 of the substrate processing apparatus 1 according to the embodiment of the present disclosure will be described with reference to Fig. 3. In the following description, the operation of each part of the substrate processing apparatus 1 is controlled by a controller 31.

[0035] The pod 3 transported by the pod opener 8 is transferred onto the mounting table 9. At this time, the wafer loading / unloading port 7 is closed by the opening / closing mechanism 11, and the transfer chamber 12 is filled with clean gas. For example, when the chamber is filled with nitrogen gas, the oxygen concentration is set to be significantly lower than the oxygen concentration inside the housing 2, which is the atmospheric atmosphere, and is 20 ppm or less.

[0036] The pod 3 placed on the mounting table 9 has its open end pressed against the wafer loading / unloading port 7 provided on the front of the sub-housing 4, and the cap (not shown) of the pod 3 is removed by the opening / closing mechanism 11, making it possible to load and unload the wafers 6.

[0037] When the pod 3 is opened by the pod opener 8, the robot 13 moves toward the pod 3, and the Z-axis direction driver 23 moves the mount 22a up and down (Z-axis direction, vertical direction) along the guide 22. Next, as described above, the fiber sensors 29a and 29b map the wafers 6 in the pod 3. At this time, normality and abnormality such as protrusion of the wafers are also detected.

[0038] After the wafer 6 detection operation is completed, the robot 13 turns, and the X-axis direction drive unit 25 inserts the end effector 14 into the pod 3, whereby the wafer 6 is unloaded through the wafer loading / unloading opening 7. After the wafer 6 is placed in the boat 15, the robot 13 returns to the pod 3 and places the next wafer in the boat 15.

[0039] When the expected number of wafers have been placed in the boat 15, the sensor rods 27a and 27b of the robot 13 rotate to face the boat 15 and move to a predetermined position. Then, the robot 13 is moved up and down by the Z-axis direction drive unit 23, and the fiber sensors 29a and 29b count the number of wafers 6.

[0040] After the detection operation in the boat 15 is completed, the boat 15 is loaded into the processing furnace 16 so that the furnace opening is airtightly closed with the seal cap 19 .

[0041] After the wafers 6 are processed in the processing furnace 16, the wafers 6 are stored in the pod 3 in the reverse order to the above, except for the step of aligning the notches of the wafers 6, and the pod 3 is then carried out of the housing 2.

[0042] The boat 15 can also naturally cool the wafers 6 after pre-processing at the position indicated by 15d. After cooling, the boat 15 supporting the wafers 6 moves to the position indicated by 15e, where the number of wafers is counted by the fiber sensors 29a and 29b of the robot 13. At this time, normality and abnormality such as protrusion of the wafers are also detected. The wafers are then transported by the robot 13 and unloaded into the pod 3. However, the steps at 15d and 15e are not necessarily performed, and are carried out depending on the configuration of the substrate processing apparatus and the processing process.

[0043] 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. 9, the controller 31 is configured as a computer including a CPU (Central Processing Unit) 32, a 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, such as a touch panel, is connected to the controller 31. An external storage device 38 can also be connected to the controller 31.

[0044] 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 data 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.

[0045] The I / O port 35 is connected to the above-mentioned opening / closing mechanism 11, robot 13, processing furnace 16, boat elevator 18, rotation mechanism 21, and the like.

[0046] 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 wafer 6 by the robot 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.

[0047] 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, or 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. When the term recording media is used in this specification, it may include 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.

[0048] (2) Wafer Teaching Process Next, the teaching principle of the robot 13 with respect to the wafers 6 in the pod and the determination of the teaching position of the robot 13 by a scanning method using the fiber sensors 29a and 29b will be described with reference to FIGS.

[0049] 4 shows the pivot axis 40, which is the center of rotation when the robot 13 is rotated by the Y-axis rotation drive unit 24, the center 50 of the teaching-target wafer 6 in the pod 3, and the rotation circle 60 when the fiber sensors 29a and 29b are rotated. The radius of the rotation circle 60 is D, and the radius of the wafer 6 is r. Here, the angle β° indicates the angle by which the pivot axis 40 of the robot 13 has rotated with respect to the line connecting the pivot axis 40 and the center 50 of the wafer 6. Accompanying this rotation, the fiber sensors 29a and 29b that detect the edge of the teaching-target wafer 6 also move to positions at a rotation angle β°, and the laser beam 101 between the fiber sensors 29c and 29d also has an angle β°.

[0050] Here, X ｅｄｇｅ indicates the distance from the pivot axis 40 to the laser beam 100, which is a tangent to the edge of the teaching target wafer 6, i.e., the detection distance to the edge, and X ｅｄｇｅ (0) is the distance at the rotation angle of the pivot shaft 40 relative to the wafer 6 of 0°, X ｅｄｇｅ(β) indicates the distance at a rotation angle β° of the pivot axis 40. At this time, the intersection point of the broken laser beam 101, which is a tangent to the wafer 6 at a rotation angle β°, and the radius D of the rotation circle 60 at a rotation angle of 0° is defined as A, and the difference between the distance from the pivot axis 40 to A and the radius D at a rotation angle of 0° is defined as Δd. In this case, X ｅｄｇｅ (β) and the radius r of the wafer 6 are the adjacent sides of a right triangle for the rotation angle β°, and the following two equations can be obtained:

[0051] X ｅｄｇｅ (β)=(D-Δd)cosβ...(Formula 1)

[0052] r=(Δd+r)cosβ...(Formula 2)

[0053] From the above formulas 1 and 2, the radius D of the rotation circle 60 and the radius r of the wafer 6 can be expressed as an easy-to-understand formula as in the following formula 3, and the distance X to the laser beam 101 can be calculated as follows: ｅｄｇｅ (β) and the rotation angle β° at that time can be calculated.

[0054] X ｅｄｇｅ (β)=Dcosβ+rcosβ−r (Formula 3)

[0055] 4 illustrates a case where the line connecting the pivot axis 40 and the center 50 of the wafer 6 is perpendicular to the laser beam 100, which is a tangent to the wafer 6. In other words, the position of the robot 13 relative to the wafer 6 in the pod 3 is not shifted in either the X-axis direction or the Y-axis direction. In this case, the detection distance from the pivot axis 40 to the laser beam 100, which is a tangent to the wafer 6, is ｅｄｇｅ (0) > X ｅｄｇｅ (β) relationship, and X ｅｄｇｅ (0) has the greatest distance of any angle of rotation of the rotation shaft 40. In other words, finding the maximum value of this distance leads to determining the teaching position of the robot 13.

[0056] However, in actual teaching position adjustment of the robot 13, the rotation axis 40 and the center 50 of the wafer 6 are often misaligned in the X-axis direction, the Y-axis direction, or both, and an adjustment by an operator is required. Therefore, as an adjustment method, the distance from the rotation axis 40 to the laser beam 100 of the fiber sensors 29a, 29b is calculated by the above-mentioned formula 3 while changing the angle in the Y-axis direction, as when the rotation angle is β° in Figure 4. From these values, the distance X that becomes the maximum value is calculated. ｅｄｇｅ In other words, the rotation angle of the fiber sensors 29a and 29b around the rotation axis 40 and the detection distance X ｅｄｇｅ While changing the distance X, the edge of the wafer 6 placed at the reference position without being gripped by the end effector 14 is detected. ｅｄｇｅ Search for the maximum value of the detection distance X ｅｄｇｅ The teaching position of the robot 13 can be determined by obtaining the maximum value of the rotation angle at which the maximum value is reached.

[0057] Next, a method for determining the rotation angle and detection distance at the teaching position of the robot 13 in an embodiment of the present disclosure will be described using the basic operation process flow of the robot 13 in Fig. 5, the first-stage angle determination method in Fig. 6, the detection state of light beam interruption at the edge of the wafer 6 in Fig. 7, and the second-stage angle determination method in Fig. 8. The operation of each part is controlled by a controller 31.

[0058] (Angle Determination Method / First Stage: Step S1) As shown in FIG. 5, first, the robot 13 starts to approach the wafer 6. Here, the detected distance from the rotation axis 40 to the edge of the wafer 6 is calculated as X θ , which is calculated from the rotation angles α°, β°, and θ°. α , X β , X θ 6 shows the state where the detection distance X to the edge of the wafer 6 is at its maximum value. α , X β , X θ This is explained in terms of the relationship between

[0059] Here, the advance / retract drive units 28a, 28b do not move the fiber sensors 29a, 29b in a predetermined tangential direction in the rotation around the pivot shaft 40, but rather the advance / retract drive units 28a, 28b move the fiber sensors 29a, 29b in the radial direction. The movement of the fiber sensors 29a, 29b in the tangential direction is performed only by the Y-axis rotation drive unit 24, i.e., the rotational movement of the pivot shaft 40. α , X β , X θ The method for calculating the maximum distance for each pattern is shown below. The rotation angle here is α<θ<β.

[0060] First, the edge of the wafer 6 is detected from a position (rotation angle θ°) that is approximately perpendicular to the wafer 6. The edge detection distance of the wafer 6 at this time is X θ Then, when moving to an angle of α°, X α Next, when moving to an angle of β°, β The controller 31 obtains the rotation angle at which the detection distance X is at its maximum value based on the central angle between the start and end of edge detection when the rotation angle is changed. In addition, taking measurement errors into consideration, it is also possible to obtain multiple central angles and obtain the average value of these as the rotation angle at which the detection distance X is at its maximum value.

[0061] (a) X α <X θ <X β In the case of the rotation angle ε° of the line connecting the pivot shaft 40 and the center 50 of the wafer 6, ε<β or β<ε, so β ​​is increased to detect the distance X to the laser beam 104, which is the tangent to the wafer 6. β When becomes larger, since the relationship of β<ε, the detection distance X to the laser beam 104 β Increase β until it becomes maximum. On the other hand, decrease β to β When becomes larger, since the relationship of ε<β, the detection distance X to the laser beam 104 β At this time, the detection distance X to the laser beam 102 is θ , the detection distance X to the laser beam 103 α The length becomes shorter in this order.

[0062] (b) X α <X β <X θ or X β <X α <X θ In the case of the rotation angle ε° of the line connecting the pivot shaft 40 and the center 50 of the wafer 6, α<ε<β is satisfied, so by increasing α and decreasing β, the detection distance X to the laser beam 106, which is the tangent to the wafer 6, is α , the detection distance X to the laser beam 107 β is maximum, that is, the angle at which α=β=ε is found. At this time, the detection distance X θ will be the longest.

[0063] (c) X β <X θ <X α In the case of (a), the rotation angle ε° of the line connecting the pivot shaft 40 and the center 50 of the wafer 6 is ε<α or α<ε, so α is increased to detect the distance X to the laser beam 109, which is the tangent to the wafer 6. α When becomes larger, since the relationship of α<ε, the detection distance X to the laser beam 109 α On the other hand, by decreasing α, the detection distance X α When becomes larger, since the relationship of ε<α, the detection distance X to the laser beam 109 α At this time, the detection distance X to the laser beam 108 is θ , the detection distance X to the laser beam 110 β The length becomes shorter in this order.

[0064] Also, X θ is never the smallest, for example, X θ <X β <X α If the relationship is found to be as follows, the process is stopped as a measurement abnormality and the robot 13 is adjusted by the operator.

[0065] In this way, by changing the tangent to the edge of the laser beam 100 from the fiber sensors 29 a, 29 b, it is possible to find the rotation angle at which the detection distance X is maximized, and the rotation angle relative to the plane of the wafer 6 among the taught positions of the robot 13 can be obtained.

[0066] (Angle determination method / Second stage: Step S2) After the rotation angle and detection distance X are obtained in the above-mentioned step S1, the rotation angle of the pivot shaft 40 is narrowed down with higher precision depending on the strength of the light received by the fiber sensors 29a and 29b, i.e., the state of interruption of the laser beam 100.

[0067] 7 shows the scanning of the optical axis of the fiber sensor 29a or 29b on the X and Z axes when the fiber sensor 29a or 29b approaches the wafer 6. In practice, the X axis is scanned in the X direction by the second-stage angle setting method described later. ｅｄｇｅ Instead of calculating the value of X, the rotation axis 40 is rotated on the axis of Zc, which is the center of the thickness of the wafer 6. ｅｄｇｅ The thickness center Zc of the wafer 6 is detected by moving the Z axis in a zigzag pattern up and down toward the wafer 6 by the Z axis direction actuator 23, and detecting the thickness center Zc every time the rotation shaft 40 is rotated. Specifically, the fiber sensors 29a and 29b are brought closer to the wafer 6 little by little by zigzag scanning the rotation shaft 40, and the X １ The fiber sensors 29a and 29b first stop. Then, they are moved up and down on the Z axis to calculate the center Zc of the height at which the beam is blocked, and return to Zc as indicated by the downward arrow 301. Next, while decreasing the detection distance X as indicated by the arrow 302, ｅｄｇｅ Then, the rotation angle is calculated by detecting the distance X. ２ Then, β2 is obtained while swinging the pivot shaft 40 relative to the wafer 6, and the distance is gradually decreased. ３ , X ４ However, β3 and β4 are obtained while swinging the pivot shaft 40 relative to the wafer 6.

[0068] The dashed line 200 in Figure 7 indicates the location where the laser beam 100 is blocked by the thickness of the wafer 6, in other words, the location where the threshold processing result of the received light intensity becomes zero. The threshold here indicates the percentage reduction in the laser beam 100 compared to 100% when there is no obstacle, in this case, the wafer 6. Figure 7 shows that if the threshold is set to, for example, 30%, when the center of the optical axis of the fiber sensor 29a or 29b is located at the dashed line 200, 70% of the optical axis overlaps with the wafer 6. Furthermore, if the threshold is set to, for example, 50%, the edge of the wafer 6 and the dashed line 200 almost overlap. Note that the threshold should not be set so small that most of the optical axis is blocked by the wafer 6, in order to avoid erroneous determinations due to light that deviates from the optical axis, reflects within the device, and enters the light receiving unit. For example, a threshold value of 30% to 50% as described above is appropriate. Zl is the lower boundary of the wafer 6, and Zu is the upper boundary of the wafer 6. This vertical movement allows the teaching position of the robot 13 to be adjusted in the Z-axis direction.

[0069] 8 shows the position X of the pivot shaft 40 in the X-axis direction shown in FIG. ２ , X ３ , X ４ 10 shows the change in the binarized intensity of the received light depending on the angular width of the turning, that is, whether or not the laser beam 300 is blocked.

[0070] The fiber sensors 29a and 29b determine the angle width of the rotation axis 40 where the intensity of received light by the laser beam 300 is strong when the distance X to the laser beam 100, which is the tangent of the wafer 6, is long, i.e., when the sensor approaches the wafer 6, the angle width of the rotation axis 40 where the intensity of received light by the laser beam 300 is strong becomes narrower, and when the distance X is short, i.e., when the sensor moves away from the wafer 6, the angle width of the rotation axis 40 where the intensity of received light is strong becomes wider. In the second-stage angle determination method, a plurality of rotation angles (for example, β ２ °, β ３ °, β ４ 8, the rotation angle β is the center when the detection distance is X2. ２ °, X ２ When ３ °, X ３ When ４At this time, the fiber sensors 29 a and 29 b can output the amount of received light, which is the intensity of received light, as a continuous quantity, and the control unit 31 acquires the rotation angle at which the detection distance X is at its maximum value based on the rotation angle at which the intensity of received light is maximized when the rotation angle is changed.

[0071] Alternatively, multiple maximum rotation angles may be obtained and their average value may be obtained as the rotation angle at the maximum value. Furthermore, multiple β values ​​may be obtained by varying X, or the pivot shaft 40 may be swung multiple times while keeping X the same. Alternatively, β may be obtained without binarization, at which the analog value of the received light intensity is at a minimum.

[0072] The rotation angle in this second stage is obtained by a method that takes into account the center of the thickness of the wafer 6, so that a rotation angle with higher accuracy can be obtained than the planar rotation angle obtained in the first stage.

[0073] (Determining the teaching position of the robot: Step 3) When the wafer 6 is placed in the pod 3 set on the mounting table 9, the control unit 31 acquires the maximum value of the detection distance X and the rotation angle β° or α° at which the maximum value is reached, and corrects the motion trajectory of the robot 13 when removing the wafer 6 from the mounting table 9 or returning the wafer 6 to the mounting table 9 based on the acquired maximum value of the detection distance X and the rotation angle β° or α° at which the maximum value is reached, thereby determining the teaching position of the robot 13.

[0074] In addition, the control unit 31 can obtain the maximum value of the detection distance X and the rotation angle β° or α° at which the maximum value is reached for at least two of the multiple wafers to be placed, and by interpolating or extrapolating these, can determine the teaching position of the robot 13 for each of the multiple wafers to be placed.

[0075] (5) Substrate Processing Step An example of a substrate processing method for forming a film on a wafer 6 as a manufacturing step of a semiconductor device using the substrate processing apparatus 1 will be described with reference to Fig. 10. In the following description, the operation of each part constituting the substrate processing apparatus is controlled by a controller 31.

[0076] (Substrate 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 placed on the mounting table 9 is pressed against the opening edge 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.

[0077] When the pod 3 is opened by the pod opener 8, the sensor rods 27a, 27b of the robot 13 are moved to the protruding position (in the direction approaching the pod 3) by the forward / backward driving units 28a, 28b. Then, the sensor rods 27a, 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, 29b, thereby detecting the wafers 6 in the pod 3 in order.

[0078] After the mapping operation is completed, the sensor rods 27 a, 27 b 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 end effector 14 is advanced, raised, and retracted, the Y-axis rotary drive unit 24 is turned, and the end effector 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.

[0079] 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 raising the seal cap 19 (boat up) by the boat elevator 18.

[0080] (Film Forming Process) After loading, the wafers 6 are subjected to heat treatment in the processing chamber 17 in the processing furnace 16 .

[0081] (Substrate Unloading Process) Next, the boat 15 on which the heat-treated wafers 6 are placed is unloaded (boat unloading) from the processing chamber 17 to the transfer chamber 12. Then, the boat 15 cools the wafers 6 after the heat treatment as described above with reference to FIG.

[0082] After cooling, the sensor rods 27a, 27b of the robot 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 end effector 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.

[0083] According to this aspect, one or more of the following effects can be obtained.

[0084] In this embodiment, the edges of the substrate are detected using fiber sensors 29a, 29b attached to the sensor rods 27a, 27b of the robot 13, so there is no need for manual work to install a jig, and there is no need to take into account variations in the jig installation position, making fully automatic, highly accurate teaching possible.

[0085] By using the fiber sensors 29a, 29b provided on the sensor rods 27a, 27b of the robot 13, the need for workers to work in the transfer chamber is eliminated, and the risk of particles being generated or hoisted up can be eliminated.

[0086] The angular direction and distance of the pod 3 or wafer 6 can be directly taught using the fiber sensors 29a, 29b without using complex calculations.

[0087] Since the optical axes of the fiber sensors 29a and 29b are smaller than the thickness of the wafer 6, it is possible not only to detect the rotation angle and distance relative to the plane of the wafer 6, but also to obtain the teaching position of the robot 13 taking into account the center of the thickness of the wafer 6.

[0088] With the wafer 6 placed in the pod 3, the teaching position of the robot 13 can be determined by the fiber sensors 29a and 29b, thereby preventing contact with the wafer 6 and the generation of foreign matter such as particles at the end effector 14 when transporting the wafer 6.

[0089] In this embodiment, the gripping of the wafer 6 by the end effector 14 of the robot 13 during transportation means a state in which the wafers are mechanically connected and can be moved while maintaining their relative positions. On the other hand, it can also include a state in which there is no physical contact, such as in a Bernoulli chuck, or a state in which the wafer is held only by static friction (adhesion), such as in a scoop-up effector.

[0090] Although the present disclosure has been specifically described above based on the embodiments, it goes without saying that the present disclosure is not limited to the above embodiments and can be modified in various ways.

[0091] In this embodiment, fiber sensors 29a, 29b are provided on sensor rods 27a, 27b of the robot 13. The device configuration is not limited to this as long as the maximum value of the detection distance X can be obtained. As long as the fiber sensors 29a, 29b do not interfere with the loading and unloading of the wafer, they may be installed around the end effector 14, or at any location on the robot 13. In this case as well, the same effects as those of the above embodiment can be obtained.

[0092] In the above-described embodiment, an example of forming a film using a batch-type substrate processing apparatus that processes multiple substrates at a time has been described. The present disclosure is not limited to the above-described embodiment and can be suitably applied, for example, to a case where a film is formed using a single-wafer substrate processing apparatus that processes one or several substrates at a time. Furthermore, in the above-described embodiment, an example of forming a film using a substrate processing apparatus having a hot-wall processing furnace has been described. The present disclosure is not limited to the above-described embodiment and can be suitably applied to a case where a film is formed using a substrate processing apparatus having a cold-wall processing furnace.

[0093] When using these substrate processing apparatuses, each process can be performed under the same process procedures and conditions as in the above-described embodiment, and the same effects as in the above-described embodiment can be obtained.

[0094] 13: Transfer machine (robot) 14: Wafer mounting plate (end effector) 24: Rotation unit (Y-axis rotation drive unit) 28a, 28b: Advance / retreat drive unit 29a, 29b: Sensor (fiber sensor) 31: Control unit (controller)

Claims

1. A substrate processing apparatus comprising: a robot having a sensor that detects the edge of a substrate; a rotating unit that moves the sensor around a rotating axis; a forward / backward drive unit that is supported on the rotating unit and supports the sensor, allowing the distance between the sensor and the rotating axis to be changed; and an end effector that is supported so that it can move around the rotating axis and so that the distance from the rotating axis can be changed; and a control unit configured to search for the maximum value of the distance at which the edge of the substrate placed at a reference position without being gripped by the end effector is detected while changing the rotation angle of the sensor around the rotating axis and the distance, and to obtain the maximum value and the rotation angle at which the maximum value is reached.

2. A substrate processing apparatus according to claim 1, wherein the sensor is a photoelectric sensor having an optical axis in a predetermined tangential direction in rotation around the pivot axis.

3. A substrate processing apparatus according to claim 1, wherein the forward / backward driving unit moves the sensor in a radial direction without moving the sensor in a predetermined tangential direction in rotation around the rotation axis, and the tangential movement of the sensor is achieved solely by the movement of the rotation unit.

4. A substrate processing apparatus according to claim 1, wherein the substrate is positioned such that the main surface of the substrate is substantially parallel to a horizontal plane perpendicular to the pivot axis before or after being gripped by the end effector.

5. A substrate processing apparatus according to claim 4, wherein the robot further comprises an elevator that enables the forward / backward drive unit to move in the up and down direction of the rotation axis, and wherein a plurality of the substrates are arranged at predetermined intervals in a direction substantially parallel to the rotation axis.

6. A substrate processing apparatus according to claim 1, claim 4 or claim 5, wherein the control unit acquires the maximum value and the rotation angle at which the maximum value is reached when the substrate is placed in a substrate container set on a load port, and is capable of correcting the motion trajectory of the robot when removing the substrate from the load port or returning the substrate to the load port based on the acquired maximum value and the rotation angle at which the maximum value is reached.

7. A substrate processing apparatus according to claim 5, wherein the control unit acquires the maximum value and the rotation angle at which the maximum value is reached for at least two of the plurality of substrates arranged, and by interpolating or extrapolating these, is able to determine the position in the robot coordinate system for each of the plurality of substrates arranged.

8. A substrate processing apparatus according to claim 2, wherein the diameter of the optical axis is smaller than the thickness of the substrate.

9. A substrate processing apparatus according to claim 2, wherein the light-emitting portion and the light-receiving portion of the photoelectric sensor are spaced apart by a distance equal to or greater than the diameter of the substrate.

10. A substrate processing apparatus according to claim 2, claim 8 or claim 9, wherein the light-emitting portion and the light-receiving portion of the photoelectric sensor have substantially the same optical characteristics.

11. A substrate processing apparatus according to claim 1 or claim 9, wherein the control unit is capable of acquiring the rotation angle at which the maximum value is reached based on the midpoint between the start and end of edge detection when the rotation angle is changed.

12. A substrate processing apparatus according to claim 2, wherein the photoelectric sensor is capable of outputting the amount of received light as a continuous amount, and the control unit acquires the rotation angle at which the amount of received light reaches the maximum value based on the angle at which the decrease in the amount of received light due to light blocking is greatest when the rotation angle is changed.

13. A substrate processing apparatus according to claim 11, wherein the control unit acquires a plurality of the central angles and can acquire the average value of the central angles as the rotation angle at which the maximum value is reached.

14. A substrate processing apparatus according to claim 12, wherein the control unit acquires a plurality of maximum angles and can acquire the average value of these angles as the rotation angle at which the maximum value is reached.

15. A method for teaching a transfer machine, comprising: a step of controlling a robot having a sensor that detects the edge of a substrate, a rotation unit that moves the sensor around a rotation axis, a forward / backward drive unit that is supported on the rotation unit and supports the sensor so that the distance between the sensor and the rotation axis can be changed, and an end effector that is supported so that it can move around the rotation axis and so that the distance from the rotation axis can be changed; a step of searching for the maximum value of the distance at which the edge of the substrate that is not gripped by the end effector and placed at a reference position is detected while changing the rotation angle of the sensor around the rotation axis and the distance; and a step of acquiring the maximum value and the rotation angle at which the maximum value is reached.

16. A method for manufacturing a semiconductor device, comprising: a step of controlling a robot having a sensor that detects an edge of a substrate, a rotating unit that moves the sensor around a rotating axis, a forward / backward drive unit that is supported on the rotating unit and supports the sensor so that the distance between the sensor and the rotating axis can be changed, and an end effector that is supported so that it can move around the rotating axis and so that the distance from the rotating axis can be changed; a step of searching for the maximum value of the distance at which the edge of a substrate that is not gripped by the end effector and placed at a reference position is detected while changing the rotation angle of the sensor around the rotating axis and the distance, and transporting the substrate using the robot whose transport position has been taught based on the acquired maximum value and the rotation angle at which the maximum value is obtained; and a step of processing the substrate in a processing chamber.

17. A substrate transfer system comprising: a robot having a sensor that detects the edge of a substrate, a rotating unit that moves the sensor around a rotating axis, a forward / backward drive unit that is supported on the rotating unit and supports the sensor, allowing the distance between the sensor and the rotating axis to be changed, and an end effector that is supported so that it can move around the rotating axis and change the distance from the rotating axis; and a control unit configured to search for the maximum value of the distance at which the edge of a substrate placed at a reference position without being gripped by the end effector is detected while changing the rotation angle of the sensor around the rotating axis and the distance, and to acquire the maximum value and the rotation angle at which the maximum value is reached.

18. A program that causes a computer to cause a robot to execute the following steps: controlling a robot having a sensor that detects the edge of a substrate, a rotating unit that moves the sensor around a rotating axis, a forward / backward drive unit that is supported on the rotating unit and supports the sensor so that the distance between the sensor and the rotating axis can be changed, and an end effector that is supported so that it can move around the rotating axis and so that the distance from the rotating axis can be changed; searching for the maximum value of the distance at which the edge of the substrate that is not gripped by the end effector and placed at a reference position is detected while changing the rotation angle of the sensor around the rotating axis and the distance; and obtaining the maximum value and the rotation angle at which the maximum value is reached.

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