Substrate transport device and substrate transport method

Abstract

Provided is a technique that contributes to avoiding collisions between the tip of an end effector and a substrate. This substrate transport device (110) comprises a transport unit (20) and a sensor (30). The transport unit (20) comprises an end effector (21) and inserts the end effector (21) into the inside of a substrate container (C) starting from the tip of the end effector (21) so as to transport a substrate into or out of the substrate container (C). The sensor (30) comprises a light-emitting unit (31) for outputting measurement light (L1) toward the tip of the end effector (21) positioned at a preceding position immediately preceding insertion into the substrate container (C), and a light-receiving unit (32) for receiving the measurement light (L1) from the light-emitting unit (31), and detects the position of the tip of the end effector (21) on the basis of the measurement light (L1) received by the light-receiving unit (32).

Description

Substrate transport device and substrate transport method

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

[0002] Conventionally, substrate transport devices for transporting substrates have been used (for example, see Patent Document 1). In Patent Document 1, the substrate transport device includes an end effector, an arm, an effector sensor, and an arm sensor. A substrate is placed on the end effector. The tip of the arm is connected to the base end of the end effector. The end effector moves horizontally as the arm is displaced horizontally. Furthermore, the end effector also moves vertically as the arm moves vertically.

[0003] When the end effector lifts the substrate, the end effector vibrates due to the end effector hitting the substrate.

[0004] The effector sensor detects the height position of a portion of the end effector that is closer to the connection point with the arm than the portion on which the substrate is placed. The arm sensor detects the height position of the arm. In Patent Document 1, the difference between the detection value of the effector sensor and the detection value of the arm sensor is calculated. The vibration of the end effector appears as the amplitude of this difference.

[0005] Japanese Patent Application Laid-Open No. 2021-64712

[0006] A transport unit may remove a substrate from a substrate container that contains multiple substrates. In this case, the transport unit first inserts the end effector into the substrate container, tip first, to avoid colliding with the substrates inside the substrate container. The transport unit then receives the substrate in the substrate container with the end effector and retracts the end effector from the substrate container. This allows the transport unit to remove the substrate from the substrate container.

[0007] If the end effector is vibrating just before entering the substrate container, it may collide with the substrate as it enters the substrate container. Also, if the height position of the tip of the end effector just before entering is deviated from the desired position, the end effector may collide with the substrate.

[0008] As in Patent Document 1, the height position of the end effector can be confirmed by detecting the height position of the end effector using an effector sensor. However, in Patent Document 1, the effector sensor detects the height position of a portion of the end effector that is closer to the connection point with the arm than the portion on which the substrate is placed. This results in low detection accuracy for the position of the tip of the end effector. Therefore, it is not possible to accurately avoid collision between the tip of the end effector and the substrate when the end effector is inserted into the substrate container.

[0009] Therefore, an object of the present disclosure is to provide a technique that contributes to avoiding collision between the tip of an end effector and a substrate.

[0010] The substrate transport device includes a transport unit that includes an end effector and that moves the end effector from its tip into a substrate container to transport a substrate in and out of the substrate container, an emitter that outputs measurement light toward the tip of the end effector located just before the tip enters the substrate container, and a light receiver that receives the measurement light from the emitter, and a sensor that detects the position of the tip of the end effector based on the measurement light received by the light receiver.

[0011] The substrate transport method includes the steps of moving an end effector of a transport unit toward a substrate container that contains a substrate, emitting measurement light from an emitting unit toward the tip of the end effector located just before the substrate container, and detecting the position of the tip based on the measurement light received by a light receiving unit.

[0012] The substrate transport device and the substrate transport method contribute to avoiding collision between the tip of the end effector and the substrate.

[0013] FIG. 1 is a plan view schematically showing an example of the configuration of a substrate processing apparatus including a substrate transport apparatus according to a first embodiment. FIG. 2 is a block diagram schematically showing an example of the internal configuration of a control unit. FIG. 3 is a front view schematically showing an example of the configuration of a substrate container. FIG. 4 is a diagram schematically showing an example of the configuration of a first transport unit. FIG. 5 is a perspective view schematically showing an example of how the first transport unit removes a substrate. FIG. 6 is a plan view schematically showing an example of how the first transport unit removes a substrate. FIG. 7 is a diagram schematically showing an example of the positional relationship between an end effector, a light receiving unit, and measurement light. FIG. 8 is a flowchart showing an example of the operation of the substrate transport apparatus. FIG. 9 is a perspective view schematically showing a first example of a portion of the configuration of a substrate transport apparatus according to a second embodiment. FIG. 10 is a perspective view schematically showing a first example of a portion of the configuration of a substrate transport apparatus according to the second embodiment. FIG. 11 is a perspective view schematically showing a second example of a portion of the configuration of a substrate transport apparatus according to the second embodiment. FIG. 12 is a diagram schematically illustrating an example of the positional relationship between the first light emitter, the first light receiver, and the first tip end of the first elongated portion. FIG. 13 is a perspective view schematically illustrating a third example of a portion of the configuration of the substrate transport apparatus according to the second embodiment. FIG. 14 is a diagram schematically illustrating an example of the positional relationship between the first light emitter and light receiver and a substrate container. FIG. 15 is a perspective view schematically illustrating a fourth example of a portion of the configuration of the substrate transport apparatus according to the second embodiment. FIG. 16 is a perspective view schematically illustrating a fifth example of a portion of the configuration of the substrate transport apparatus according to the second embodiment. FIG. 17 is a perspective view schematically illustrating a sixth example of a portion of the configuration of the substrate transport apparatus according to the second embodiment. FIG. 18 is a perspective view schematically illustrating a seventh example of a portion of the configuration of the substrate transport apparatus according to the second embodiment. FIG. 19 is a perspective view schematically illustrating the seventh example of a portion of the configuration of the substrate transport apparatus according to the second embodiment.

[0014] Hereinafter, the embodiments will be described in detail with reference to the drawings. In the drawings, the dimensions and numbers of parts are exaggerated or simplified as necessary for ease of understanding. Parts having similar configurations and functions are denoted by the same reference numerals, and duplicate explanations will be omitted below.

[0015] In the following description, the same components are denoted by the same reference numerals, and their names and functions are also the same. Therefore, detailed descriptions of them may be omitted to avoid duplication.

[0016] Furthermore, in the following description, even if ordinal numbers such as "first" or "second" are used, these terms are used for convenience to facilitate understanding of the contents of the embodiments, and are not limited to the order that may result from these ordinal numbers.

[0017] When expressions indicating relative or absolute positional relationships (e.g., "in one direction," "along one direction," "parallel," "orthogonal," "center," "concentric," "coaxial," etc.) are used, unless otherwise specified, the expressions not only strictly represent the positional relationship but also represent a state in which there is a relative displacement in terms of angle or distance within a range in which tolerance or equivalent functionality is obtained. When expressions indicating an equal state (e.g., "identical," "equal," "homogeneous," etc.) are used, the expressions not only represent a state in which there is strict quantitative equality but also represent a state in which there is a difference in which tolerance or equivalent functionality is obtained, unless otherwise specified. When expressions indicating a shape (e.g., "rectangular shape" or "cylindrical shape," etc.) are used, the expressions not only represent a geometrically strict shape but also represent a shape with, for example, irregularities or chamfers within a range in which equivalent effects are obtained. When the expressions "comprise," "include," "have," "includes," "includes," or "have" are used to describe one component, the expressions are not exclusive expressions that exclude the presence of other components. When the phrase "at least one of A, B, and C" is used, the phrase includes A only, B only, C only, any two of A, B, and C, and all of A, B, and C.

[0018] 1 is a plan view schematically showing an example of the configuration of a substrate processing apparatus 100 including a substrate transfer apparatus 110 according to a first embodiment. The substrate processing apparatus 100 is a single-wafer processing apparatus that processes substrates W one by one.

[0019] The substrate W is, for example, a semiconductor wafer, a liquid crystal display substrate, an organic electroluminescence (EL) substrate, an FPD (Flat Panel Display) substrate, an optical display substrate, a magnetic disk substrate, an optical disk substrate, a magneto-optical disk substrate, a photomask substrate, or a solar cell substrate. The substrate W has a thin, flat plate shape. In the following, the substrate W is assumed to be a semiconductor wafer. The substrate W has, for example, a disk shape. The diameter of the substrate W is, for example, about 300 mm, and the film thickness of the substrate W is, for example, about 0.5 mm or more and about 3 mm or less.

[0020] 1, the substrate processing apparatus 100 includes a substrate transfer apparatus 110, a processing block 120, and a control unit 90. The processing block 120 is a section that mainly processes substrates W. In the example of Fig. 1, the substrate transfer apparatus 110 is a section that mainly transports substrates W between the outside of the substrate processing apparatus 100 and the processing block 120. The substrate transfer apparatus 110 may also be called an indexer.

[0021] The substrate transport device 110 includes a first transport unit 20 and a sensor 30. As shown in FIG. 1 , the substrate transport device 110 may be provided with a load port 10. A substrate container C that has been loaded from outside is placed on the load port 10. That is, the load port 10 includes a mounting table on which the substrate container C is placed. The mounting table may be provided with a holding mechanism (not shown) that holds the substrate container C. In the example of FIG. 1 , multiple load ports 10 are arranged along a horizontal arrangement direction Dy. Each substrate container C accommodates multiple substrates W. As an example, the multiple substrates W are accommodated in the substrate container C while being aligned at intervals from each other in the vertical direction. An example of a specific configuration of the substrate container C will be described in detail later.

[0022] The first transport unit 20 is a transport robot, and may also be called an indexer robot. The first transport unit 20 transports substrates W between each substrate container C and the processing block 120. As shown in FIG. 1 , the first transport unit 20 includes an end effector 21. The end effector 21 may also be called a hand. The first transport unit 20 moves the end effector 21 from its tip end into the substrate container C to remove the substrate W from the substrate container C or to transfer the substrate W to the substrate container C.

[0023] 1 , the first transport unit 20 is provided to be movable along the arrangement direction Dy, and can stop at a position facing each substrate container C. While facing the substrate container C, the first transport unit 20 moves the end effector 21 from its tip toward the inside of the substrate container C, and stops the end effector 21 directly below the substrate W. The first transport unit 20 then raises the end effector 21 to lift the unprocessed substrate W, and retracts the end effector 21 supporting the substrate W from the substrate container C. This allows the first transport unit 20 to remove the substrate W from the substrate container C.

[0024] Next, the first transport unit 20 moves along the arrangement direction Dy toward a position where the substrate W can be transferred to and from the processing block 120, and transfers the substrate W to the processing block 120 at that position. The processing block 120 processes the substrate W. The first transport unit 20 then receives the processed substrate W from the processing block 120. Having received the processed substrate W, the first transport unit 20 moves to a position facing the substrate container C. The first transport unit 20 inserts the end effector 21 supporting the substrate W into the substrate container C and then lowers the end effector 21. As a result, the processed substrate W is transferred from the end effector 21 to the substrate container C. The first transport unit 20 then retracts the end effector 21. In this manner, the first transport unit 20 transports the substrate W between each substrate container C and the processing block 120.

[0025] The sensor 30 detects the position of the tip of the end effector 21 located immediately in front of the substrate container C. In the example of Fig. 1, the sensor 30 is provided in a one-to-one correspondence with the substrate container C. A specific example of the sensor 30 will be described in detail later.

[0026] 1, the processing block 120 includes a plurality of processing units 121 and a second transport unit 122. The second transport unit 122 is a transport robot that transports substrates W between the first transport unit 20 and the plurality of processing units 121. In the example of Fig. 1, the second transport unit 122 transfers substrates W to and from the first transport unit 20 via an intermediary part 123. The intermediary part 123 may be a shelf on which the substrates W are placed, or may be a shuttle-type transport unit.

[0027] 1 , a plurality of (for example, four) processing units 121 are arranged to surround the second transport unit 122 in a plan view. This second transport unit 122 may also be called a center robot. A plurality of processing units 121 may be stacked vertically at each position in a plan view. In other words, a plurality of towers TW (four in the figure) each made up of a plurality of processing units 121 stacked vertically may be arranged to surround the second transport unit 122. The processing units 121 perform, for example, various wet or dry processes on substrates W.

[0028] The control unit 90 comprehensively controls the substrate processing apparatus 100. More specifically, the control unit 90 controls the first transport unit 20, the sensor 30, the second transport unit 122, and the processing unit 121. FIG. 2 is a block diagram schematically illustrating an example of the internal configuration of the control unit 90. The control unit 90 is an electronic circuit and includes, for example, a data processing unit 91 and a storage unit 92. The data processing unit 91 and the storage unit 92 may be connected to each other via a bus 93. The data processing unit 91 may be an arithmetic processing device such as a central processing unit (CPU). The storage unit 92 may include a non-transitory storage unit (e.g., a read-only memory (ROM)) 921 and a temporary storage unit (e.g., a random access memory (RAM)) 922. The non-transitory storage unit 921 may store, for example, a program that defines the processing to be performed by the control unit 90. The data processing unit 91 executes this program, allowing the control unit 90 to perform the processing defined in the program. Of course, some or all of the processing performed by the control unit 90 may be performed by hardware such as a dedicated logic circuit.

[0029] 2, the control unit 90 is also connected to a non-transitory storage unit 94 (e.g., a memory such as a flash memory or a hard disk). In the example of Fig. 2, reference data D1 is stored in the storage unit 94. The reference data D1 will also be described in detail later.

[0030] <Substrate container C> The substrate container C may be a FOUP (Front Opening Unified Pod) or SMIF (Standard Mechanical Interface) pod that accommodates substrates W in a sealed state, or an OC (Open Cassette) that accommodates substrates W in an open state. The substrate container C may also be called a carrier.

[0031] FIG. 3 is a front view schematically illustrating an example of the configuration of a substrate container C. The substrate container C has, for example, a box-like shape that opens in one substantially horizontal direction (toward the viewer in FIG. 3 ). Specifically, the substrate container C has a bottom 51, a ceiling 52, and sidewalls 53. The bottom 51 and the ceiling 52 have rectangular plate shapes and face each other with a gap in the vertical direction. The sidewalls 53 connect the periphery of the bottom 51 and the periphery of the ceiling 52 on three sides. Therefore, an opening 55 is formed in a portion where the sidewalls 53 are not provided. The substrate W is transferred into and out of the substrate container C through the opening 55. The substrate container C may be provided with a lid that can open and close the opening 55.

[0032] The substrate container C is placed on the load port 10 so that its opening 55 faces the first transport unit 20 (see also FIG. 1 ). A plurality of protrusion supports 54 for supporting the underside of the substrate W are protruded from the inner surface of the side wall 53. Each protrusion support 54 protrudes inward from the inner surface of the side wall 53. The upper surface of the protrusion support 54 is approximately horizontal. Each protrusion support 54 supports an end of the substrate W. A plurality of protrusion supports 54 are provided at intervals in the vertical direction, and a plurality of substrates W are supported by the protrusion supports 54 on the left and right sides of the page. The plurality of substrates W are accommodated in the substrate container C in a stacked state with intervals in the vertical direction. The number of substrates W accommodated in the substrate container C is arbitrary, for example, 25.

[0033] Since both ends of the substrate W are supported inside the substrate container C, the substrate W may bend as shown in Fig. 3 if the substrate W is thin. Specifically, the substrate W may bend in a downwardly convex shape. In this case, the gap between adjacent substrates W becomes narrower at the center of the substrates W. Since the end effector 21 of the first transport unit 20 enters between adjacent substrates W, narrowing the gap increases the risk of the end effector 21 colliding with the substrate W.

[0034] In this embodiment, the sensor 30 detects the position of the tip of the end effector 21. In the following, the configuration of the first transport unit 20 will be described in detail first, and then the sensor 30 will be described in detail.

[0035] <First Transport Unit> FIG. 4 is a diagram schematically illustrating an example of the configuration of the first transport unit 20. The first transport unit 20 includes an end effector 21 and a transport drive unit 22. A substrate W is placed on the end effector 21. The end effector 21 supports the substrate W. In the examples of FIGS. 1 and 4, the end effector 21 has a plate-like shape and is disposed with its thickness direction aligned along the vertical direction. In the examples of FIGS. 1 and 4, the end effector 21 includes a first elongated portion 211A, a second elongated portion 211B, and a connecting portion 212. The first elongated portion 211A has a plate-like shape and is disposed with its longitudinal direction aligned along the horizontal direction. The second elongated portion 211B has a plate-like shape and is disposed with its longitudinal direction aligned along the horizontal direction. The first long portion 211A and the second long portion 211B are located at approximately the same height. The first long portion 211A and the second long portion 211B are spaced apart in the short direction. The connecting portion 212 connects the base end of the first long portion 211A and the base end of the second long portion 211B to each other. The connecting portion 212 has a plate-like shape and is positioned such that its thickness direction is aligned with the vertical direction. The first long portion 211A, the second long portion 211B, and the connecting portion 212 may be integrally formed from the same material.

[0036] The transport drive unit 22 is controlled by the control unit 90 and moves the end effector 21 three-dimensionally. For example, the transport drive unit 22 includes an advance / retract drive unit 23, an elevation drive unit 24, a rotation drive unit 25, and a movement drive unit 26. The advance / retract drive unit 23 moves the end effector 21 along the longitudinal direction of the first long portion 211A and the second long portion 211B. The advance / retract drive unit 23 includes, for example, multiple arms 231 and multiple motors 232. The multiple arms 231 are rotatably coupled to each other. The tip end of the combined body of the multiple arms 231 is rotatably coupled to the connecting portion 212 of the end effector 21, and the base end of the combined body is rotatably coupled to, for example, the elevation drive unit 24. Each combined body is provided with a motor 232 that changes the coupling angle between the two components. The motors 232 operate in conjunction with each other to move the end effector 21 along the longitudinal direction.

[0037] The lifting / lowering drive unit 24 lifts and lowers the end effector 21. The lifting / lowering drive unit 24 may lift and lower the end effector 21 and the advance / retract drive unit 23 together. The lifting / lowering drive unit 24 includes, for example, a drive source such as a motor, and a power transmission unit that transmits the drive force of the drive source to the end effector 21. The power transmission unit includes, for example, a ball screw mechanism.

[0038] The rotation drive unit 25 rotates the end effector 21 around a predetermined rotation axis. The predetermined rotation axis is an axis along the vertical direction. The rotation drive unit 25 rotates the end effector 21 between a rotation position where the tip of the end effector 21 faces the substrate container C and a rotation position where the tip of the end effector 21 faces the processing block 120. The rotation drive unit 25 may rotate the end effector 21, the advance / retract drive unit 23, and the elevation drive unit 24 together. The rotation drive unit 25 includes, for example, a motor.

[0039] The movement drive unit 26 moves the end effector 21 along the arrangement direction Dy of the load port 10. The movement drive unit 26 may move the end effector 21, the advance / retract drive unit 23, the lift drive unit 24, and the rotation drive unit 25 as a single unit. If the part including the end effector 21, the advance / retract drive unit 23, the lift drive unit 24, and the rotation drive unit 25 is considered to be the first transport unit 20, then it can be said that the movement drive unit 26 moves the first transport unit 20 in the arrangement direction Dy. The movement drive unit 26 is fixed to, for example, the floor surface (bottom of the chamber) of the substrate transport device 110. For example, the movement drive unit 26 includes a drive source such as a motor and a power transmission unit that transmits the driving force of the drive source to the end effector 21. The power transmission unit includes, for example, a ball screw mechanism.

[0040] <Sensor> The sensor 30 is a sensor for detecting the position of the tip of the end effector 21. As shown in Fig. 1, the sensor 30 includes a light-emitting unit 31 and a light-receiving unit 32. The sensor 30 is provided closer to the front than the substrate container C.

[0041] 5 is a perspective view that schematically shows an example of how the first transport unit 20 removes a substrate W, and FIG. 6 is a plan view that schematically shows an example of how the first transport unit 20 removes a substrate W. In the examples of FIGS. 5 and 6 , the tip of the end effector 21 of the first transport unit 20 is located at a position immediately before entering the substrate container C. The "immediately before" position here refers to a position where the end effector 21 faces the opening 55 of the substrate container C in the horizontal direction, and where the tip of the end effector 21 has not yet entered the substrate container C. In this case, the tip of the end effector 21 corresponds to the tips of the first elongated portion 211A and the second elongated portion 211B. The entire end effector 21 located at the immediately before position does not face the substrate W in the substrate container C in the vertical direction. The height position of the end effector 21 differs depending on the substrate W to be loaded or unloaded, and the immediately preceding position (height position) differs depending on the height position of the substrate W to be loaded or unloaded.

[0042] The immediately preceding position is a position where the tip of the end effector 21 has not yet entered the substrate container C. The distance between the substrate container C and the tip of the end effector 21 in a plan view may be, for example, 100 mm or less, 50 mm or less, 20 mm or less, 10 mm or less, 5 mm or less, or 3 mm or less. Plan view here refers to viewing an object with the line of sight along the vertical direction.

[0043] The light-emitting unit 31 outputs measurement light L1 toward the tip of the end effector 21 located immediately before it. The measurement light L1 may be visible light or invisible light. The measurement light L1 may be, for example, infrared light. The light-emitting unit 31 may be a semiconductor light-emitting device such as a laser. The light-emitting unit 31 can also be considered a light source. The light-emitting unit 31 is controlled, for example, by the control unit 90.

[0044] 5, the tip portion irradiated with the measurement light L1 may be a portion within a range having a length of one-fourth the longitudinal length of the end effector 21 from the tip of the end effector 21. As an example, the tip portion may be a portion within a range of 10 mm from the tip of the end effector 21, a portion within a range of 5 mm or less, or a portion within 3 mm. The tip portion irradiated with the measurement light L1 includes at least one of a portion of the first elongated portion 211A and a portion of the second elongated portion 211B.

[0045] 5 and 6, the light-emitting unit 31 is provided to the side of the tip of the end effector 21 located immediately before it. In other words, the light-emitting unit 31 faces the tip of the end effector 21 located immediately before it in the arrangement direction Dy. The light-emitting unit 31 is fixed to, for example, the floor surface of the substrate transport device 110.

[0046] The light-emitting unit 31 can output measurement light L1 that is wider than the thickness (vertical thickness) of the tip of the end effector 21. In the example of Fig. 5, the light-emitting unit 31 has an elongated shape with its longitudinal direction aligned with the vertical direction, and outputs a sheet-like (or strip-like) measurement light L1 that is wide in the vertical direction. In other words, the light-emitting surface 31s of the light-emitting unit 31 has an elongated shape with its longitudinal direction aligned with the vertical direction, and its longitudinal size is wider than the thickness of the end effector 21. The measurement light L1 is emitted from the light-emitting surface 31s. The vertical size of the light-emitting surface 31s corresponds to the vertical width of the measurement light L1.

[0047] 5, the light-emitting surface 31s has a vertical size described below. That is, the light-emitting surface 31s has a size sufficient to irradiate the measurement light L1 onto the tip of the end effector 21 regardless of which substrate W the end effector 21 is positioned immediately in front of in the substrate container C. For example, the upper end of the light-emitting surface 31s of the light-emitting unit 31 (the upper end of the measurement light L1) is above the top substrate W in the substrate container C, and the lower end of the light-emitting surface 31s (the lower end of the measurement light L1) is below the bottom substrate W in the substrate container C. As a specific example, the upper end of the light-emitting surface 31s is above the ceiling 52 of the substrate container C, and the lower end of the light-emitting surface 31s is below the bottom 51 of the substrate container C.

[0048] The light-receiving unit 32 receives the measurement light L1 output by the light-emitting unit 31. In the example of Fig. 5, the light-receiving unit 32 is provided on the opposite side of the light-emitting unit 31 with respect to the tip of the end effector 21 located immediately before it. In other words, the light-emitting unit 31 and the light-receiving unit 32 are provided at an interval in the arrangement direction Dy, and the tip of the end effector 21 located immediately before it is located between the light-emitting unit 31 and the light-receiving unit 32. The light-receiving unit 32 is fixed to the floor of the substrate transport device 110, for example.

[0049] In the example of FIG. 5 , the light receiving unit 32 has an elongated shape with its longitudinal direction aligned vertically. That is, the light receiving surface 32s of the light receiving unit 32 has an elongated shape with its longitudinal direction aligned vertically. The light receiving surface 32s may be formed by light receiving elements (pixels) (not shown) arranged vertically. The measurement light L1 is received by the light receiving surface 32s. Each light receiving element outputs a signal corresponding to the intensity of the measurement light L1 incident thereon. Such a light receiving unit 32 may also be called a line sensor. The light receiving unit 32 outputs a detection signal including signals from multiple light receiving elements to the control unit 90. The detection signal indicates the spatial distribution of the intensity (or light amount) of the measurement light L1 received by the light receiving unit 32.

[0050] The light-receiving surface 32s has a vertical size approximately equal to the vertical size of the light-emitting surface 31s of the light-emitting unit 31. That is, the vertical size of the light-receiving surface 32s is wider than, for example, the thickness of the tip of the end effector 21. The upper end of the light-receiving surface 32s may be higher than the uppermost substrate W in the substrate container C, and may be higher than the ceiling 52 of the substrate container C, for example. The lower end of the light-receiving surface 32s may be lower than the lowermost substrate W in the substrate container C, and may be lower than the bottom 51 of the substrate container C, for example. This allows the light-receiving unit 32 to more appropriately receive the measurement light L1.

[0051] FIG. 7 is a diagram schematically illustrating an example of the positional relationship between the end effector 21, the light receiving unit 32, and the measurement light L1. A portion of the measurement light L1 output from the light emitting unit 31 is blocked by the tip of the end effector 21. Specifically, a portion of the measurement light L1 is blocked by the first tip of the first elongated portion 211A and the second tip of the second elongated portion 211B. In the example of FIG. 7, the portion of the measurement light L1 blocked by the end effector 21 is schematically illustrated by diagonal hatching. Meanwhile, portions of the measurement light L1 above and below the tip of the end effector 21 travel toward the light receiving unit 32 and are received by the light receiving unit 32. Therefore, the light receiving element corresponding to the tip of the end effector 21 hardly receives the measurement light L1, and the other light receiving elements receive the measurement light L1.

[0052] Therefore, the spatial distribution of the intensity of the measurement light L1 received by the light receiving unit 32 reflects the position of the end effector 21. Specifically, the region with low intensity corresponds to the position of the end effector 21. Therefore, the control unit 90 calculates the position of the tip of the end effector 21 based on the measurement light L1 received by the light receiving unit 32 (i.e., the detection signal of the light receiving unit 32). For example, the control unit 90 may determine the height position of the tip of the end effector 21 as the region of the detection signal where the intensity is smaller than a predetermined reference value.

[0053] It should be noted that the functional unit of the control unit 90 that calculates the position of the tip of the end effector 21 can be said to belong to the sensor 30. This functional unit does not necessarily have to be implemented in the control unit 90, and if the sensor 30 has a built-in control unit, it may be implemented in the control unit.

[0054] In the above example, the end effector 21 is coupled to the transport drive unit 22 at its base end (specifically, the connecting portion 212). Therefore, the end effector 21 has a cantilever structure. Because the tip of the end effector 21 corresponds to a free end, the tip may be located lower than the base end of the end effector 21. This phenomenon is caused by various factors, such as the rigidity of the end effector 21, the fixing force between the end effector 21 and the transport drive unit 22, and the rigidity of the transport drive unit 22. The position of the tip of the end effector 21 may move downward due to variations in the device or deterioration over time. In Figure 7, the end effector 21 whose tip is lower than the base end is indicated by a two-dot chain line. If the tip of the end effector 21 is located lower, there is a risk of it colliding with the substrate W when entering the substrate container C.

[0055] The end effector 21 may also vibrate. Specifically, the end effector 21 may vibrate such that its tip reciprocates vertically. In particular, when the transport drive unit 22 is driven at a frequency close to the natural frequency, the vibration of the end effector 21 becomes large. If the tip of the end effector 21 vibrates in this way, there is a risk of it colliding with the substrate W when entering the substrate container C.

[0056] Furthermore, even if the end effector 21 is horizontal, the height position of the tip of the end effector 21 may be shifted due to an error in the lifting / lowering drive unit 24. In this case, too, there is a risk that the tip of the end effector 21 may collide with the substrate W.

[0057] In this embodiment, the sensor 30 (controller 90) detects the position of the tip of the end effector 21 based on the measurement light L1. That is, the sensor 30 detects the position of the tip that is closer to the tip of the end effector 21. Therefore, the controller 90 can determine with higher accuracy whether the position of the tip of the end effector 21 is appropriate immediately before the end effector 21 enters the substrate container C. In other words, the controller 90 can determine with higher accuracy whether the tip of the end effector 21 will collide with the substrate W.

[0058] 8 is a flowchart showing an example of the operation of the substrate transport device 110. The operation of this substrate transport device 110 is realized by the control unit 90 controlling the first transport unit 20 and the sensor 30. Here, as an example, the operation of removing a certain substrate W from a certain substrate container C will be described.

[0059] First, the transport drive unit 22 starts driving the end effector 21 (step S1). Specifically, first, the transport drive unit 22 stops the end effector 21 at a position facing the substrate container C. That is, while the movement drive unit 26 moves the end effector 21 along the arrangement direction Dy, the lift drive unit 24 lifts and lowers the end effector 21 to a height position corresponding to the substrate W to be unloaded. This height position is the height position between the lower surface of the substrate W to be unloaded and the upper surface of the substrate W directly below it. Furthermore, the rotation drive unit 25 rotates the end effector 21 by the advance / retract drive unit 23 to a rotation position that allows the end effector 21 to enter the substrate container C. Next, the advance / retract drive unit 23 moves the end effector 21 horizontally toward the substrate container C.

[0060] With the end effector 21 positioned at the previous position, the sensor 30 detects the position of the tip of the end effector 21 (step S2). Specifically, the light-emitting unit 31 emits measurement light L1 toward the tip of the end effector 21, and the light-receiving unit 32 receives the measurement light L1. The light-receiving unit 32 outputs a detection signal corresponding to the measurement light L1 to the control unit 90. The control unit 90 calculates the position of the tip of the end effector 21 based on the detection signal. Note that the transport driver 22 may stop the tip of the end effector 21 at the previous position, and the sensor 30 may detect the position of the tip of the end effector 21 while the end effector 21 is stopped. Alternatively, the sensor 30 may detect the position of the tip of the end effector 21 while the tip of the end effector 21 is passing through the previous position.

[0061] In addition, here, the sensor 30 continues to detect the position of the tip of the end effector 21 over a predetermined period of time. In other words, the sensor 30 (controller 90) generates time-series data of the position of the tip of the end effector 21. The predetermined period is, for example, several seconds or less, and may be one second or less. When the end effector 21 is vibrating, the detected position fluctuates over time in the time-series data.

[0062] Next, the control unit 90 determines whether the position of the tip of the end effector 21 is appropriate. For example, the control unit 90 determines whether the position fluctuation amount of the end effector 21, which will be described next, is equal to or greater than a fluctuation reference value (step S3). The position fluctuation amount is, for example, the amount of position fluctuation of the tip of the end effector 21, and may be the maximum value of the position fluctuation amount of the tip of the end effector 21 within a predetermined period. The maximum value of the position fluctuation amount is, for example, the amplitude of vibration of the end effector 21. The fluctuation reference value is set in advance to a value that will prevent the end effector 21 from colliding with the substrate W, and may be included in the reference data D1 in the storage unit 94, for example (see FIG. 2).

[0063] When the amount of positional fluctuation is equal to or greater than the fluctuation reference value, the control unit 90 performs a vibration reduction process to reduce the vibration of the end effector 21 (step S4). As a specific example, the control unit 90 stops the operation of the transport drive unit 22 as the vibration reduction process. As a result, the amplitude of the vibration of the end effector 21 decreases over time. Therefore, the amount of positional fluctuation of the end effector 21 eventually falls below the fluctuation reference value.

[0064] The sensor 30 again measures the position of the tip of the end effector 21 (step S2), and the control unit 90 determines whether the position fluctuation amount is greater than or equal to the fluctuation reference value (step S3). If the position fluctuation amount is still equal to or greater than the fluctuation reference value, the control unit 90 continues to execute vibration reduction processing (step S4). One example of this vibration reduction processing is processing that does not drive the first conveying unit 20 until the position fluctuation amount becomes less than the fluctuation reference value.

[0065] On the other hand, when the amount of positional fluctuation is less than the fluctuation reference value, the control unit 90 calculates the difference between the measured position of the end effector 21 and the reference position (step S5). The detected position is the detected position of the tip of the end effector 21 after the amount of positional fluctuation becomes less than the fluctuation reference value, and may be the most recent detected position or the average value of detected positions at multiple timings. The reference position corresponds to the position of the end effector 21 when removing the substrate W to be unloaded. The reference position corresponding to each substrate W is set in advance and may be included in the reference data D1, for example. The control unit 90 reads out the reference position corresponding to the substrate W to be unloaded from the reference data D1, and calculates the difference between the reference position and the measured position.

[0066] Next, the control unit 90 determines whether the difference is equal to or greater than a predetermined reference difference value (step S6). The reference difference value is set in advance to a value that prevents the end effector 21 from colliding with the substrate W, and is included in the reference data D1, for example. If the difference is less than the reference difference value, the control unit 90 does not execute step S7, which will be described later, but controls the transport drive unit 22 to remove the substrate W with the end effector 21 (step S8). Specifically, the advance / retract drive unit 23 moves the end effector 21 horizontally toward the inside of the substrate container C and stops the end effector 21 directly below the substrate W. Next, the elevation drive unit 24 raises the end effector 21, causing the end effector 21 to lift the substrate W. Next, the advance / retract drive unit 23 retracts the end effector 21 from the substrate container C. This removes the substrate W from the substrate container C.

[0067] On the other hand, if the difference is equal to or greater than the reference difference value in step S6, the control unit 90 controls the lifting / lowering drive unit 24 to lift or lower the end effector 21 so that the tip of the end effector 21 approaches the reference position (step S7). For example, the lifting / lowering drive unit 24 lifts or lowers the end effector 21 toward the reference position by an amount equal to the difference. This makes the height position of the end effector 21 appropriate. Next, the control unit 90 controls the transport drive unit 22 to cause the end effector 21 to remove the substrate W (step S8).

[0068] <Effects> As described above, in this embodiment, the sensor 30 is provided independently of the first transport unit 20 and optically detects the position of the tip of the end effector 21 located immediately before the first transport unit 20. Therefore, the position of the tip of the end effector 21 can be obtained with higher accuracy. As described above, the end effector 21 enters the substrate container C from its tip. Therefore, if the position of the tip of the end effector 21 is inappropriate, the tip of the end effector 21 will collide with the substrate W. In this embodiment, the sensor 30 detects the position of the tip of the end effector 21 closest to the tip. Therefore, from the perspective of whether the end effector 21 will collide with the substrate W, the control unit 90 can determine with higher accuracy whether the position of the tip of the end effector 21 is appropriate. In other words, the substrate transport device 110 contributes to avoiding collision between the end effector 21 and the substrate W. Note that the sensor 30 may detect the position of the tip of the end effector 21 itself as the tip of the end effector 21.

[0069] In the above example, the control unit 90 also monitors the amount of positional fluctuation (e.g., the amplitude of vibration) of the end effector 21 (step S3), and when the amount of positional fluctuation is large, reduces the vibration of the end effector 21 (step S4). Therefore, the substrate transport device 110 can more appropriately reduce the possibility of the end effector 21 colliding with the substrate W.

[0070] In the above example, the control unit 90 performs the vibration reduction process by stopping the driving of the first transport unit 20 until the amount of positional fluctuation becomes less than the fluctuation reference value. This allows the substrate transport device 110 to reduce the vibration of the end effector 21 with simple control.

[0071] In the above example, the control unit 90 also monitors the position of the tip of the end effector 21 when the amount of positional fluctuation is small (step S6), and when the position is away from the reference position, adjusts the height position of the end effector 21 so as to move the end effector 21 closer to the reference position (step S7). Therefore, the substrate transport device 110 can further appropriately reduce the possibility of the end effector 21 colliding with the substrate W.

[0072] In the above example, the light-emitting unit 31 and the light-receiving unit 32 are provided on the sides of the end effector 21, and the width (vertical width) of the measurement light L1 is wider than the thickness of the tip of the end effector 21. The width of the measurement light L1 may be wider than the spacing between the substrates W in the substrate container C. Therefore, only a portion of the measurement light L1 is blocked by the end effector 21, and the portion of the measurement light L1 that travels vertically outside the end effector 21 is received by the light-receiving unit 32. This allows the sensor 30 (controller 90) to calculate the height position of the end effector 21 with higher accuracy.

[0073] In the above example, the upper end of the light-emitting surface 31s and the upper end of the light-receiving surface 32s are located above the uppermost substrate W in the substrate container C, and the lower end of the light-emitting surface 31s and the lower end of the light-receiving surface 32s are located below the lowermost substrate W in the substrate container C. Therefore, regardless of which substrate W the first transport unit 20 takes out, the light-emitting unit 31 can output the measurement light L1 to the tip of the end effector 21. Therefore, the sensor 30 can detect the position of the tip of the end effector 21.

[0074] In the above example, the end effector 21 located immediately before the sensor 21 is positioned between the light-emitting unit 31 and the light-receiving unit 32. Therefore, the measurement light L1 from the light-emitting unit 31 is blocked by both the first tip of the first elongated portion 211A and the second tip of the second elongated portion 211B. Conversely, the light-receiving unit 32 receives the measurement light L1 in an area other than the area where the first tip of the first elongated portion 211A and the second tip of the second elongated portion 211B overlap when viewed along the array direction Dy. Therefore, the sensor 30 (controller 90) can obtain the average height position of the first elongated portion 211A and the second elongated portion 211B. More generally, the controller 90 can obtain the average height position of the height position distribution of the end effector 21 in the array direction Dy and monitor the average height position. This allows the control unit 90 to monitor the average height positions of the first tip of the first long portion 211A and the second tip of the second long portion 211B, and to monitor the vibrations of both the first tip of the first long portion 211A and the second tip of the second long portion 211B.

[0075] <Dragging of the End Effector 21> The sensor 30 detects the height position of the tip of the end effector 21. Here, another sensor may be provided to detect the height position of the base end of the end effector 21. For example, the other sensor may be built into the elevation drive unit 24. The other sensor may be an encoder. When the difference between the base end of the end effector 21 measured by the other sensor and the tip end of the end effector 21 measured by the sensor 30 is equal to or greater than a predetermined drooping reference value, the control unit 90 may externally notify the user that abnormal drooping has occurred in the end effector 21. For example, the control unit 90 may externally notify the user of the abnormality using a display or sound output unit (not shown). The display may be a liquid crystal display, and the sound output unit may be, for example, a speaker or a buzzer.

[0076] 5, the light-emitting unit 31 is provided at a position facing the first elongated portion 211A, and the light-receiving unit 32 is provided at a position facing the second elongated portion 211B. However, the positions of the light-emitting unit 31 and the light-receiving unit 32 may be reversed.

[0077] Furthermore, although the vibration reduction process employs non-driving of the first transport unit 20 in the above example, this is not necessarily limited to this. The first transport unit 20 may be provided with a vibrator that applies vibrations to the end effector 21 that are in the opposite phase to the vibrations of the end effector 21. The vibrations of the vibrator can more quickly reduce the vibrations of the end effector 21. For example, a piezoelectric element or an eccentric motor can be used as the vibrator.

[0078] Furthermore, although the above example describes the unloading operation of the substrate W, the same applies to the loading operation. However, during the loading operation, the substrate W is placed on the end effector 21. Therefore, the measurement light L1 from the light-emitting unit 31 is blocked by the tip of the end effector 21 and the substrate W. Therefore, the spatial distribution of the measurement light L1 received by the light-receiving unit 32 depends on the tip of the end effector 21 and the substrate W. Specifically, the area obtained by subtracting the thickness of the substrate W from the area in the spatial distribution of the measurement light L1 that is smaller than the reference value corresponds to the tip of the end effector 21. Since the thickness of the substrate W can be set in advance, the sensor 30 can detect the position of the tip of the end effector 21 based on the spatial distribution of the measurement light L1 and the thickness of the substrate W.

[0079] Second Embodiment A substrate transport apparatus 110 according to a second embodiment is similar to the substrate transport apparatus 110 according to the first embodiment, except for the configuration of the sensor 30. Figures 9 and 10 are perspective views schematically showing a first example of a portion of the configuration of the substrate transport apparatus 110 according to the second embodiment. As shown in Figure 9, the sensor 30 includes a first light emitter 31A, a first light receiver 32A, a second light emitter 31B, a second light receiver 32B, and a sensor movement driver 33.

[0080] The first light-emitting unit 31A outputs measurement light L1 to a first tip of the first elongated portion 211A of the end effector 21 located immediately before the first light-emitting unit 31A. Hereinafter, the measurement light L1 output by the first light-emitting unit 31A will also be referred to as first measurement light L11. In the example of Fig. 9, the first light-emitting unit 31A is provided on the side of the first elongated portion 211A of the end effector 21 located immediately before the first light-emitting unit 31A. An example of the configuration of the first light-emitting unit 31A is similar to that of the light-emitting unit 31 according to the first embodiment.

[0081] The first light receiving unit 32A receives the first measurement light L11 output from the first light emitting unit 31A. In the examples shown in Fig. 9 and Fig. 10, the sensor movement driving unit 33 moves the first light receiving unit 32A between a first measurement position and a first standby position. Fig. 9 shows the first light receiving unit 32A positioned at the first measurement position, and Fig. 10 shows the first light receiving unit 32A positioned at the first standby position.

[0082] The first measurement position is a position where the first light receiving unit 32A is located between the first elongated portion 211A and the second elongated portion 211B of the end effector 21, with the first tip portion located immediately before the first elongated portion 211A. In the example of Fig. 9, the first light receiving unit 32A is located at the first measurement position, aligned with the first light emitter 31A in the arrangement direction Dy, and receives the first measurement light L11 from the first light emitter 31A. The first light receiving unit 32A outputs a first detection signal indicating the spatial distribution of the intensity of the received first measurement light L11 to the control unit 90. An example of the configuration of the first light receiving unit 32A is similar to that of the light receiving unit 32 according to the first embodiment.

[0083] When the first light receiving unit 32A is located at the first measurement position, the end effector 21 cannot move into the substrate container C. This is because the first light receiving unit 32A is located on the movement path of the end effector 21, causing the end effector 21 to collide with the first light receiving unit 32A. The first standby position is a position that avoids the movement path of the end effector 21. For example, the first standby position may be located below the first measurement position, and the upper end of the first light receiving unit 32A may be located below the lower end of the substrate container C.

[0084] The second light-emitting unit 31B outputs measurement light L1 to the second tip of the second elongated portion 211B of the end effector 21, which is positioned immediately before the end effector 21. Hereinafter, the measurement light L1 output by the second light-emitting unit 31B will also be referred to as second measurement light L12. In the examples shown in FIGS. 9 and 10 , the sensor movement driver 33 moves the second light-emitting unit 31B between the second measurement position and the second standby position. FIG. 9 illustrates the second light-emitting unit 31B positioned at the second measurement position, and FIG. 10 illustrates the second light-emitting unit 31B positioned at the second standby position.

[0085] The second measurement position is a position where the second light-emitting unit 31B is located between the first elongated portion 211A and the second elongated portion 211B of the end effector 21, with the second tip portion located immediately before the first elongated portion 211A. When the second light-emitting unit 31B is located at the second measurement position, it outputs the second measurement light L12 toward the second tip portion of the second elongated portion 211B. An example of the configuration of the second light-emitting unit 31B is the same as that of the light-emitting unit 31 according to the first embodiment.

[0086] On the other hand, when the second light-emitting unit 31B is located at the second measurement position, the end effector 21 cannot move into the substrate container C. This is because the second light-emitting unit 31B is located on the movement path of the end effector 21, causing the end effector 21 to collide with the second light-emitting unit 31B. The second standby position is a position that avoids the movement path of the end effector 21. For example, the second standby position may be located lower than the second measurement position, so that the upper end of the second light-emitting unit 31B is lower than the lower end of the substrate container C. At the second standby position, the second measurement light L12 from the second light-emitting unit 31B is not irradiated onto the second elongated portion 211B of the end effector 21.

[0087] The second light receiving unit 32B receives the second measurement light L12 emitted by the second light emitter 31B stopped at the second measurement position. The second light receiving unit 32B outputs a second detection signal indicating the spatial distribution of the intensity of the second measurement light L12 received by the second light receiving unit 32B to the control unit 90. In the example of FIG. 9 , the second light receiving unit 32B is located to the side of the second elongated portion 211B of the end effector 21 whose second tip is located immediately before the second light receiving unit 32B. In the example of FIG. 9 , the second light receiving unit 32B is aligned with the second light emitter 31B located at the second measurement position in the arrangement direction Dy, and the second elongated portion 211B of the end effector 21 whose second tip is located immediately before the second light receiving unit 32B is located between the second light emitter 31B located at the second measurement position and the second light receiving unit 32B. An example of the configuration of the second light receiving unit 32B is the same as that of the light receiving unit 32 according to the first embodiment.

[0088] The sensor movement drive unit 33 may include, for example, a drive source such as a motor and a power transmission unit that transmits the drive force of the drive source to the first light receiving unit 32A and the second light emitting unit 31B. The power transmission unit may include, for example, a ball screw mechanism. The sensor movement drive unit 33 is provided, for example, on the floor surface of the substrate transport device 110. Note that although the sensor movement drive unit 33 moves the first light receiving unit 32A and the second light emitting unit 31B as a unit in the examples shown in FIGS. 9 and 10 , it may also move them individually. The sensor movement drive unit 33 is controlled by the control unit 90. In the example described above, the sensor movement drive unit 33 raises and lowers the first light receiving unit 32A and the second light emitting unit 31B, and therefore may also be considered an elevation drive unit.

[0089] The control unit 90 calculates the position of the first tip of the first long portion 211A based on the first detection signal from the first light receiving unit 32A, and calculates the position of the second tip of the second long portion 211B based on the second detection signal from the second light receiving unit 32B.

[0090] As described above, in the second embodiment, the control unit 90 can obtain the position of the first tip end of the first elongated portion 211A and the position of the second tip end of the second elongated portion 211B individually.

[0091] An example of the operation of the substrate transport device 110 according to the second embodiment is similar to that shown in FIG. 8 . However, in step S2, the sensor movement driver 33 moves the first light-receiving unit 32A and the second light-emitting unit 31B to the first measurement position and the second measurement position, respectively. The first light-emitting unit 31A then outputs the first measurement light L11, and the second light-emitting unit 31B outputs the second measurement light L12. The first light-emitting unit 31A and the second light-emitting unit 31B may output the first measurement light L11 and the second measurement light L12 in parallel (e.g., simultaneously). The first light-receiving unit 32A receives the first measurement light L11, and the second light-receiving unit 32B receives the second measurement light L12. The control unit 90 calculates the position of the first tip of the first long portion 211A based on the first detection signal of the first light receiving unit 32A, and calculates the position of the second tip of the second long portion 211B based on the second detection signal of the second light receiving unit 32B.

[0092] In step S3, the control unit 90 calculates the positional fluctuation amount of the first tip end of the first elongated portion 211A and the positional fluctuation amount of the second tip end of the second elongated portion 211B, and determines whether each positional fluctuation amount is equal to or greater than a fluctuation reference value. If at least one of the positional fluctuation amounts is equal to or greater than the fluctuation reference value, the control unit 90 performs vibration reduction processing (step S4).

[0093] When both of the positional fluctuation amounts are less than the fluctuation reference value, the control unit 90 calculates the difference between the detected position of the first long portion 211A and the reference position, and calculates the difference between the detected position of the second long portion 211B and the reference position (step S5). The control unit 90 determines whether each difference is equal to or greater than the difference reference value (step S6). If at least one of the differences is equal to or greater than the difference reference value, the control unit 90 controls the lifting / lowering drive unit 24 to adjust the position of the end effector 21 (step S7). Specifically, the lifting / lowering drive unit 24 raises and lowers the end effector 21 so that both the first long portion 211A and the second long portion 211B (e.g., both the first tip and the second tip) are located within a predetermined range. The predetermined range is, for example, a predetermined range that includes the reference position. As an example, the predetermined range is a range between an upper position that is above the reference position by the difference reference value and a lower position that is below the reference position by the difference reference value.

[0094] In step S8, first, the sensor movement drive unit 33 moves the first light receiving unit 32A and the second light emitting unit 31B to the first standby position and the second standby position, respectively. Then, the transport drive unit 22 moves the end effector 21 to remove the substrate W from the substrate container C.

[0095] As described above, in the second embodiment, the sensor 30 detects the position of the first tip of the first long portion 211A and the position of the second tip of the second long portion 211B separately. This allows the control unit 90 to monitor both positions separately. For example, the control unit 90 can more reliably reduce vibrations of the first long portion 211A and the second long portion 211B. For example, if a vibrator is provided in the first transport unit 20, the control unit 90 may vibrate the vibrator in the opposite phase to the larger vibration of the first long portion 211A or the second long portion 211B. This allows the vibration of the end effector 21 to be more quickly reduced. Furthermore, for example, after vibration reduction, the control unit 90 can control the lifting / lowering drive unit 24 to more reliably keep the detected positions of both the first long portion 211A and the second long portion 211B within a predetermined range.

[0096] The positions of the first light-emitting unit 31A and the first light-receiving unit 32A may be reversed, and the positions of the second light-emitting unit 31B and the second light-receiving unit 32B may be reversed. Here, the first light-emitting unit 31A and the first light-receiving unit 32A, whichever is located between the first elongated portion 211A and the second elongated portion 211B, is referred to as the first inner optical unit, and the other is referred to as the first outer optical unit. Similarly, the second light-emitting unit 31B and the second light-receiving unit 32B, whichever is located between the first elongated portion 211A and the second elongated portion 211B, is referred to as the second inner optical unit, and the other is referred to as the second outer optical unit. The sensor movement drive unit 33 moves the first inner optical unit between a first measurement position and a first standby position, and moves the second inner optical unit between a second measurement position and a second standby position.

[0097] The sensor 30 can detect the position of the first tip of the first elongated portion 211A when the first inner optical portion is located at the first measurement position, and can detect the position of the second tip of the second elongated portion 211B when the second inner optical portion is located at the second measurement position. Furthermore, the end effector 21 can enter the substrate container C when the first inner optical portion and the second inner optical portion are located at the first standby position and the second standby position, respectively.

[0098] FIG. 11 is a perspective view schematically illustrating a second example of a portion of the configuration of the substrate transport device 110 according to the second embodiment. In the example of FIG. 11 , the first light emitter 31A and the first light receiver 32A are located on the sides of the first elongated portion 211A of the end effector 21, the first tip of which is located immediately before the first elongated portion 211A. Specifically, both the first light emitter 31A and the first light receiver 32A are located on the opposite side of the first elongated portion 211A from the second elongated portion 211B. The first light emitter 31A emits a first measurement light L11 toward the first tip of the first elongated portion 211A. An example of the first light emitter 31A is similar to the light emitter 31 according to the first embodiment. A portion of the first measurement light L11 from the first light emitter 31A is reflected by the side surface of the tip of the first elongated portion 211A. The first light receiver 32A receives the first measurement light L11 reflected by the first elongated portion 211A. An example of the configuration of the first light receiving section 32A is similar to that of the light receiving section 32 according to the first embodiment.

[0099] 11 , the first light-receiving unit 32A may be adjacent to the first light-emitting unit 31A in the horizontal forward / backward direction Dx perpendicular to the arrangement direction Dy. The first light-emitting unit 31A and the first light-receiving unit 32A may be provided in the same housing. Hereinafter, the first light-emitting unit 31A and the first light-receiving unit 32A integrally formed in the same housing will also be referred to as the first light-emitting / light-receiving unit 30A. Note that the positions of the first light-emitting unit 31A and the first light-receiving unit 32A may be reversed.

[0100] FIG. 12 is a diagram schematically illustrating an example of the positional relationship between the first light emitter 31A, the first light receiver 32A, and the first tip of the first elongated portion 211A. In the example of FIG. 12, the first measurement light L11 output from the first light emitter 31A is schematically illustrated by wide diagonal hatching. The light of the first measurement light L11 incident on the tip of the first elongated portion 211A is reflected by the first elongated portion 211A. In the example of FIG. 12, the reflected first measurement light L11 is illustrated by narrow dashed diagonal hatching. The reflected first measurement light L11 is incident on some of the light receiving elements of the first light receiver 32A. Portions of the first measurement light L11 from the first light emitter 31A above and below the first elongated portion 211A proceed without entering the first elongated portion 211A. Therefore, almost no measurement light L1 is incident on the light-receiving elements of the first light-receiving unit 32A other than the above-mentioned part of the light-receiving elements. Therefore, the spatial distribution of the intensity of the first measurement light L11 received by the first light-receiving unit 32A reflects the position of the first tip of the first elongated portion 211A. Specifically, the region with high intensity corresponds to the position of the first tip of the first elongated portion 211A.

[0101] Therefore, the control unit 90 calculates the position of the first tip of the first elongated portion 211A based on the first measurement light L11 received by the first light receiving unit 32A (i.e., the first detection signal of the first light receiving unit 32A). For example, the control unit 90 may determine the region of the first detection signal that is greater than a predetermined reference value as the height position of the first tip of the first elongated portion 211A. As described above, the sensor 30 (control unit 90) can detect the position of the portion of the tip of the end effector 21 that reflects the first measurement light L11.

[0102] The second light emitter 31B and the second light receiver 32B are located on the sides of the second elongated portion 211B of the end effector 21, the second tip of which is located immediately before the second elongated portion 211B. Specifically, both the second light emitter 31B and the second light receiver 32B are located on the opposite side of the second elongated portion 211B from the first elongated portion 211A. The second light emitter 31B emits the second measurement light L12 toward the second tip of the second elongated portion 211B. An example of the second light emitter 31B is similar to that of the light emitter 31 in the first embodiment. A portion of the second measurement light L12 from the second light emitter 31B is reflected by the tip of the second elongated portion 211B. The second light receiver 32B receives the second measurement light L12 reflected by the second elongated portion 211B. An example of the configuration of the second light receiver 32B is similar to that of the light receiver 32 in the first embodiment.

[0103] 11 , the second light-receiving unit 32B may be adjacent to the second light-emitting unit 31B in the forward / backward direction Dx. The second light-emitting unit 31B and the second light-receiving unit 32B may be provided in the same housing. Hereinafter, the second light-emitting unit 31B and the second light-receiving unit 32B formed integrally in the same housing will also be referred to as the second light-emitting / light-receiving unit 30B. Note that the positions of the second light-emitting unit 31B and the second light-receiving unit 32B may be reversed.

[0104] Similar to the first elongated portion 211A, the control unit 90 calculates the position of the second tip of the second elongated portion 211B based on the second measurement light L12 received by the second light receiving unit 32B (i.e., the second detection signal of the second light receiving unit 32B).

[0105] The first measurement light L11 from the first light emitter 31A acts as noise for the second light receiver 32B. Therefore, the first light emitter 31A may be located at a position where the first measurement light L11 is hardly incident on the second light receiver 32B. This reduces noise in the second detection signal. Similarly, the second light emitter 31B may be located at a position where the second measurement light L12 is hardly incident on the first light receiver 32A.

[0106] Alternatively, the wavelength of the first measurement light L11 output by the first light emitter 31A may be different from the wavelength of the second measurement light L12 output by the second light emitter 31B. The wavelength difference may be, for example, 1 nm or more, 10 nm or more, or 100 nm or more. The receptive wavelength band of the first light receiver 32A includes the wavelength of the first measurement light L11 from the first light emitter 31A but does not include the wavelength of the second measurement light L12 from the second light emitter 31B. Similarly, the receptive wavelength band of the second light receiver 32B includes the wavelength of the second measurement light L12 from the second light emitter 31B but does not include the wavelength of the first measurement light L11 from the first light emitter 31A. This also reduces noise. This is true for the first example and other examples described below.

[0107] According to the second example of the second embodiment, the first light-emitting unit 31A, the first light-receiving unit 32A, the second light-emitting unit 31B, and the second light-receiving unit 32B are provided so as to avoid the movement path of the end effector 21. Therefore, the sensor 30 does not obstruct the movement of the end effector 21. Therefore, unlike the first example of the second embodiment, it is not necessary to move the sensor 30 to move the end effector 21 forward or backward. This makes it possible to improve the throughput of the substrate transport device 110 and reduce manufacturing costs.

[0108] Fig. 13 is a perspective view schematically illustrating a third example of a portion of the configuration of the substrate transport device 110 according to the second embodiment. In the example of Fig. 13, a plurality of first light emitters 31A and a plurality of first light receivers 32A are provided. Specifically, the first light emitters 31A and the first light receivers 32A are provided in a one-to-one correspondence. In the example of Fig. 13, the corresponding first light emitters 31A and first light receivers 32A form a first light emitter-receiver 30A. The plurality of first light emitters-receivers 30A are arranged in the vertical direction on the side of the first elongated portion 211A of the end effector 21 located immediately before the first elongated portion 211A.

[0109] Each first light-emitting / receiving unit 30A is provided according to the height position of the substrate W to be loaded or unloaded. Fig. 14 is a diagram schematically illustrating an example of the positional relationship between the first light-emitting / receiving units 30A and the substrate container C. In the example of Fig. 14, the positions of the first long portion 211A and the second long portion 211B when each substrate W is removed are shown by virtual lines. For simplicity, nine substrates W are shown in the example of Fig. 14. In the example of Fig. 14, the topmost first light-emitting / receiving unit 30A is provided at a position where it can detect the position of the first tip of the first long portion 211A when the topmost substrate W in the substrate container C is loaded or unloaded. In the example of Fig. 14, the topmost first light-emitting / receiving unit 30A can detect the position of the first tip of each of multiple substrates W (three in the figure) when they are loaded or unloaded. The range of height positions detectable by the first light-emitting / light-receiving unit 30A is adjusted by the width (vertical width) of the light-emitting surface 31s of the first light-emitting unit 31A and the width (vertical width) of the light-receiving surface 32s of the first light-receiving unit 32A. In the example of Fig. 14, three first light-emitting / light-receiving units 30A are provided, with the topmost first light-emitting / light-receiving unit 30A corresponding to the three substrates W from the top, the central first light-emitting / light-receiving unit 30A corresponding to the three central substrates W, and the bottommost first light-emitting / light-receiving unit 30A corresponding to the three bottom substrates W. When each substrate W is being loaded or unloaded, the position of the first tip end of the first elongated portion 211A is detected by one of the first light-emitting / light-receiving units 30A.

[0110] 13 and 14, a plurality of second light-emitting elements 31B and a plurality of second light-receiving elements 32B are also provided. The plurality of second light-emitting elements 31B and the plurality of second light-receiving elements 32B are similar to the plurality of first light-emitting elements 31A and the plurality of first light-receiving elements 32A, respectively.

[0111] According to the third example of the second embodiment, the vertical dimensions of the first light emitter 31A and the second light receiver 32B are smaller. In order for the first light receiver 32A to properly receive the first measurement light L11 from the first light emitter 31A, the first light emitter 31A and the first light receiver 32A must be installed so that the longitudinal direction of the light-emitting surface 31s of the first light emitter 31A is parallel to the longitudinal direction of the light-receiving surface 32s of the first light receiver 32A. The smaller vertical dimensions of the first light emitter 31A and the first light receiver 32A can reduce the required accuracy in mounting the first light emitter 31A and the first light receiver 32A. This reduces the manufacturing cost of the substrate transport device 110. The same applies to the second light emitter 31B and the second light receiver 32B.

[0112] FIG. 15 is a perspective view schematically illustrating a fourth example of a portion of the configuration of the substrate transfer device 110 according to the second embodiment. In the example of FIG. 15 , a single first light-emitting unit 31A and a single first light-receiving unit 32A are provided. The width of the first measurement light L11 from the first light-emitting unit 31A (the vertical size of the light-emitting surface 31s) is wider than the thickness of the first tip end of the first elongated portion 211A. The width of the first measurement light L11 may be 10 times or less, 5 times or less, or 3 times or less the thickness of the first tip end. The vertical size of the light-receiving surface 32s of the first light-receiving unit 32A is also the same as the size of the light-emitting surface 31s of the first light-emitting unit 31A. In the example of FIG. 15 , the first light-emitting unit 31A and the first light-receiving unit 32A form a first light-emitting / light-receiving unit 30A.

[0113] The substrate transport device 110 further includes a sensor lifting / lowering drive unit 34. The sensor lifting / lowering drive unit 34 is controlled by the control unit 90 and raises and lowers the first light emitter 31A and the first light receiver 32A (e.g., the first light emitter-receiver 30A). The sensor lifting / lowering drive unit 34 includes a drive source such as a motor and a power transmission unit that transmits the drive force of the drive source to the first light emitter-receiver 30A. The power transmission unit includes, for example, a ball screw mechanism.

[0114] The sensor lifting / lowering drive unit 34 raises and lowers the first light-emitting / receiving unit 30A according to the position of the substrate W to be loaded or unloaded in the substrate container C. Specifically, the sensor lifting / lowering drive unit 34 raises and lowers the first light-emitting / receiving unit 30A to a position where it can detect the position of the tip of the end effector 21 located immediately before the substrate W to be loaded or unloaded. For example, when the end effector 21 loads or unloads the top substrate W in the substrate container C, the end effector 21 passes through the immediately before position corresponding to the top substrate W. The sensor lifting / lowering drive unit 34 raises and lowers the first light-emitting / receiving unit 30A to a position where it can irradiate the tip of the end effector 21 located immediately before the top substrate W. The position is set in advance and stored, for example, in the memory unit 94. In this state, the first light emitter 31A emits the first measurement light L11, the first light receiver 32A receives the first measurement light L11 reflected by the first elongated portion 211A, and the control unit 90 calculates the position of the first tip of the first elongated portion 211A based on the first detection signal of the first light receiver 32A. When a substrate W other than the top one is loaded or unloaded, the sensor lifting drive unit 34 similarly lifts or lowers the first light emitter-light receiver 30A.

[0115] 15, a single second light-emitting unit 31B and a single second light-receiving unit 32B are provided. The second light-emitting unit 31B and the second light-receiving unit 32B are similar to the first light-emitting unit 31A and the first light-receiving unit 32A, respectively. The sensor lifting / lowering drive unit 34 also lifts and lowers the second light-emitting unit 31B and the second light-receiving unit 32B in the same way as the first light-emitting unit 31A and the first light-receiving unit 32A.

[0116] According to the fourth example of the second embodiment, it is possible to employ a smaller first light emitter 31A and a smaller first light receiver 32A. This further reduces the precision required for mounting the first light emitter 31A and the first light receiver 32A. In addition, the number of first light emitters 31A and first light receivers 32A is also reduced. This reduces the manufacturing cost of the substrate transport device 110. The same applies to the second light emitter 31B and the second light receiver 32B.

[0117] 16 is a perspective view schematically illustrating a fifth example of a portion of the configuration of the substrate transport device 110 according to the second embodiment. In the example of FIG. 16, the first light emitter 31A and the first light receiver 32A are provided above the first elongated portion 211A of the end effector 21, the first tip of which is located immediately before the first elongated portion 211A. The first light emitter 31A and the first light receiver 32A are fixed to, for example, the chamber of the substrate transport device 110. The first light emitter 31A and the first light receiver 32A can be provided above the movement path of the end effector 21 when loading and unloading the uppermost substrate W in the substrate container C. In this manner, the first light emitter 31A and the first light receiver 32A do not hinder the movement of the end effector 21.

[0118] The first light-emitting unit 31A emits the first measurement light L11 toward the first tip of the first elongated portion 211A of the end effector 21 located immediately before the first light-emitting unit 31A. The first light-emitting unit 31A may emit the first measurement light L11 in a spot or line onto the upper surface of the first elongated portion 211A. The first light-emitting unit 31A emits the first measurement light L11 obliquely downward. The first measurement light L11 reflected by the upper surface of the first elongated portion 211A is received by the first light-receiving unit 32A.

[0119] The first light-receiving unit 32A may be adjacent to the first light-emitting unit 31A in the horizontal direction. In the example of Fig. 16, the first light-receiving unit 32A is adjacent to the first light-emitting unit 31A in the forward / backward direction Dx. The first light-receiving unit 32A may be built into the same housing as the first light-emitting unit 31A to form the first light-emitting / light-receiving unit 30A.

[0120] Because the measurement light L1 travels diagonally downward, the incident region where the measurement light L1 is incident on the upper surface of the first elongated portion 211A varies depending on the height of the first elongated portion 211A. Therefore, the position where the first measurement light L11 reflected by the first elongated portion 211A is incident on the first light-receiving unit 32A also varies depending on the height of the first elongated portion 211A. For example, when the first elongated portion 211A is at its highest position, almost all of the first measurement light L11 is incident on the light-receiving surface 32s of the first light-receiving unit 32A. As the first elongated portion 211A descends, part of the first measurement light L11 deviates from the light-receiving surface 32s of the first light-receiving unit 32A. In this case, the intensity (light amount) of the first measurement light L11 received by the first light-receiving unit 32A varies depending on the height of the first elongated portion 211A.

[0121] Therefore, the sensor 30 (controller 90) may calculate the position of the first tip of the first elongated portion 211A based on the intensity of the first measurement light L11 received by the first light receiving unit 32A. For example, a correspondence relationship between the intensity of the first measurement light L11 and the position of the first tip of the first elongated portion 211A may be set in advance through simulation, experiment, or the like, and correspondence data indicating the correspondence relationship may be stored in, for example, the storage unit 94. The controller 90 may calculate the position of the first tip of the first elongated portion 211A based on the intensity of the first measurement light L11 received by the first light receiving unit 32A and the correspondence data.

[0122] Alternatively, almost all of the first measurement light L11 may be incident on the light-receiving surface 32s of the first light-receiving unit 32A regardless of the height position of the first elongated portion 211A. However, the incident position on the light-receiving surface 32s varies depending on the height position of the first elongated portion 211A. Such an incident position corresponds to, for example, a high-intensity region on the light-receiving surface 32s. Therefore, a correspondence relationship between the incident position of the first measurement light L11 and the position of the first tip of the first elongated portion 211A may be determined in advance through simulation, experiment, or the like, and correspondence data indicating the correspondence relationship may be stored, for example, in the memory unit 94. The control unit 90 may calculate the position of the first tip of the first elongated portion 211A based on the incident position of the first measurement light L11 received by the first light-receiving unit 32A and the correspondence data.

[0123] The second light-emitting unit 31B and the second light-receiving unit 32B are provided above the second elongated portion 211B of the end effector 21, whose second tip is located immediately before the second elongated portion 211B. The positional relationship between the second light-emitting unit 31B, the second light-receiving unit 32B, and the second elongated portion 211B of the end effector 21 is similar to that between the first light-emitting unit 31A, the first light-receiving unit 32A, and the first elongated portion 211A of the end effector 21. The method for calculating the position of the second tip of the second elongated portion 211B is similar to the method for calculating the position of the first tip of the first elongated portion 211A.

[0124] According to the fifth example of the second embodiment, it is possible to employ a small-sized first light-emitting unit 31A and a small-sized first light-receiving unit 32A. The same applies to the second light-emitting unit 31B and the second light-receiving unit 32B.

[0125] When the first transport unit 20 loads a substrate W into the substrate container C, the substrate W is placed on the end effector 21, the tip of which is located immediately before the end effector 21. Therefore, the first light emitter 31A and the second light emitter 31B output measuring light L1 onto the upper surface of the substrate W. The first measuring light L11 from the first light emitter 31A is reflected by a first incident region on the upper surface of the substrate W and received by the first light receiver 32A. The first incident region is a region directly above the first elongated portion 211A. The second measuring light L12 from the second light emitter 31B is reflected by a second incident region on the upper surface of the substrate W and received by the second light receiver 32B. The second incident region is a region directly above the second elongated portion 211B. The intensity and incident position of the first measurement light L11 received by the first light receiving unit 32A change depending on the height position of the first incident region of the substrate W, so the control unit 90 can calculate the height position of the first incident region of the substrate W based on the first detection signal. Similarly, the control unit 90 can calculate the height position of the second incident region of the substrate W based on the second detection signal.

[0126] However, since the reflectance of the top surface of the substrate W may differ from the reflectance of the end effector 21, the correspondence relationship between intensity and position differs from the correspondence relationship when the measurement light L1 is incident on the end effector 21. Correspondence data when the measurement light L1 is incident on the substrate W is set in advance and stored, for example, in the memory unit 94. When the substrate W is loaded into the substrate container C, the control unit 90 reads out the correspondence relationship data for loading the substrate W, and when the substrate W is unloaded from the substrate container C, it reads out the correspondence relationship data for unloading the substrate W.

[0127] 17 is a perspective view schematically illustrating a sixth example of a portion of the configuration of the substrate transport device 110 according to the second embodiment. In the example of FIG. 17, the first light-emitting unit 31A and the first light-receiving unit 32A are provided below the first elongated portion 211A of the end effector 21 whose first tip is located immediately before the first elongated portion 211A, and the second light-emitting unit 31B and the second light-receiving unit 32B are provided below the second elongated portion 211B of the end effector 21 whose second tip is located immediately before the first elongated portion 211A. Therefore, the first light-emitting unit 31A emits the first measurement light L11 toward the lower surface of the first elongated portion 211A, and the second light-emitting unit 31B emits the second measurement light L12 toward the lower surface of the second elongated portion 211B. The first measurement light L11 is reflected by the lower surface of the first elongated portion 211A and received by the first light-receiving unit 32A, and the control unit 90 calculates the position of the first tip of the first elongated portion 211A based on a first detection signal from the first light-receiving unit 32A. The second measurement light L12 is reflected by the lower surface of the second elongated portion 211B and received by the second light-receiving unit 32B, and the control unit 90 calculates the position of the second tip of the second elongated portion 211B based on a second detection signal from the second light-receiving unit 32B.

[0128] According to the sixth example of the second embodiment, the measurement light L1 from the first light-emitting unit 31A and the second light-emitting unit 31B is incident on the lower surface of the end effector 21, regardless of whether the end effector 21 supports a substrate W. Therefore, the control unit 90 can use common correspondence data regardless of whether the substrate W is being loaded or unloaded.

[0129] 18 and 19 are perspective views schematically illustrating a seventh example of a portion of the configuration of the substrate transport apparatus 110 according to the second embodiment. Compared to the substrate transport apparatus 110 according to the fifth example, the substrate transport apparatus 110 according to the seventh example further includes a sensor lifting / lowering drive unit 34. The sensor lifting / lowering drive unit 34 lifts and lowers the sensor 30. Specifically, the sensor lifting / lowering drive unit 34 lifts and lowers the sensor 30 (first light emitter 31A, first light receiver 32A, second light emitter 31B, and second light receiver 32B) depending on the height position of the substrate W to be loaded or unloaded. In short, the sensor lifting / lowering drive unit 34 lifts and lowers the sensor 30 depending on the height position of the position immediately preceding the end effector 21 so that the vertical distance between the end effector 21 and the sensor 30 falls within a predetermined distance range. More specifically, the sensor 30 is moved to a height position that is a predetermined height above a position (specifically, a reference position) immediately before the end effector 21 when loading or unloading the substrate W. The predetermined height is set in advance and is stored in the memory unit 94, for example.

[0130] In the example of Fig. 18, the end effector 21 is located immediately before a substrate W that is located relatively high, and in the example of Fig. 19, the end effector 21 is located immediately before a substrate W that is located relatively low. The sensor lifting drive unit 34 moves the sensor 30 to a height position that corresponds to the reference position that corresponds to each substrate W. For this reason, the sensor 30 shown in Fig. 18 is located higher than the sensor 30 shown in Fig. 19.

[0131] The sensor lifting / lowering drive unit 34 allows the distance between the sensor 30 and the end effector 21 to be within a certain range. In other words, the first light receiving unit 32A and the second light receiving unit 32B can each follow the end effector 21. Therefore, the range of fluctuation of the incident position of the measurement light L1 on each of the first light receiving unit 32A and the second light receiving unit 32B can be narrowed compared to the fifth example. Because the tip of the first light receiving unit 32A can follow the end effector located immediately before it, a smaller first light receiving unit 32A and a smaller second light receiving unit 32B can be used. Furthermore, because the optical path of the first measurement light L11 from the first light emitter 31A to the first light receiving unit 32A is shortened, the sensor 30 (controller 90) can detect the position of the first tip of the first elongated portion 211A with higher accuracy. The same applies to the second light emitter 31B and the second light receiving unit 32B. The seventh example of the second embodiment can be applied to the sixth example of the second embodiment.

[0132] As described above, the substrate transfer apparatus 110 and the substrate transfer method have been described in detail. However, the above description is merely an example in all respects, and this disclosure is not limited thereto. Furthermore, the various modifications described above can be applied in combination as long as they are not mutually inconsistent. It is understood that many modifications not illustrated can be envisioned without departing from the scope of this disclosure.

[0133] For example, in the second embodiment, the first light emitter 31A and the first light receiver 32A may be provided without the second light emitter 31B and the second light receiver 32B. Conversely, the second light emitter 31B and the second light receiver 32B may be provided without the first light emitter 31A and the first light receiver 32A.

[0134] In the above example, the substrate container C is a portable container, but this is not necessarily limited to this. The substrate container C may be a stationary container (shelf) set in the substrate processing apparatus 100.

[0135] The present disclosure includes the following aspects.

[0136] A first aspect is a substrate transport device comprising: an end effector; a transport unit that moves the end effector from the tip end of the end effector into a substrate container to transport substrates in and out of the substrate container; an emitter that outputs measurement light toward the tip end of the end effector located just before the tip end of the end effector enters the substrate container; and a light receiver that receives the measurement light from the emitter, and a sensor that detects the position of the tip end of the end effector based on the measurement light received by the light receiver.

[0137] A second aspect is a substrate transport device according to the first aspect, which includes a control unit that controls the transport unit, and the control unit performs a vibration reduction process to reduce vibration of the end effector when the positional fluctuation amount of the end effector obtained based on the measurement light received by the light receiving unit is greater than a predetermined fluctuation reference value.

[0138] A third aspect is the substrate transport apparatus according to the second aspect, wherein the control unit does not drive the transport unit as the vibration reduction process until the amount of positional fluctuation becomes less than the fluctuation reference value.

[0139] A fourth aspect is a substrate transport device according to any one of the first to third aspects, comprising a control unit that controls the transport unit, and the control unit controls the transport unit so that the position of the end effector obtained based on the measurement light received by the light receiving unit is within a predetermined range.

[0140] A fifth aspect is a substrate transport device according to any one of the first to fourth aspects, wherein the light-emitting unit and the light-receiving unit are provided laterally with respect to the end effector located in the immediately preceding position.

[0141] A sixth aspect is a substrate transport device according to the fifth aspect, wherein the light-emitting unit and the light-receiving unit are provided on opposite sides of the end effector located immediately before the end effector, the light-emitting unit outputs the measurement light that is wider than the thickness of the end effector, and the light-receiving unit receives the measurement light that has passed outside the end effector.

[0142] A seventh aspect is a substrate transport device according to the fifth aspect, wherein the light-emitting unit and the light-receiving unit are provided on the same side of the end effector located immediately before the end effector, the light-emitting unit outputs the measurement light that is wider than the thickness of the end effector, and the light-receiving unit receives the measurement light reflected by the end effector.

[0143] An eighth aspect is a substrate transport device according to any one of the fourth to seventh aspects, wherein the substrate container accommodates a plurality of the substrates arranged vertically, the measurement light is output from the light-emitting surface of the light-emitting unit and received by the light-receiving surface of the light-receiving unit, the upper end of the light-emitting surface and the upper end of the light-receiving surface are located above the topmost substrate of the plurality of substrates, and the lower end of the light-emitting surface and the lower end of the light-receiving surface are located below the bottommost substrate of the plurality of substrates.

[0144] A ninth aspect is a substrate transport device according to any one of the fourth to seventh aspects, wherein the substrate container accommodates a plurality of the substrates arranged in a vertical direction, and a plurality of the light-emitting elements and a plurality of the light-receiving elements are arranged in a vertical direction.

[0145] A tenth aspect is a substrate transport device according to any one of the first to third aspects, wherein the light-emitting unit and the light-receiving unit are provided on the same side in the vertical direction relative to the tip of the end effector located in the immediately preceding position, and the light-receiving unit receives the measurement light reflected by the end effector.

[0146] An eleventh aspect is the substrate transport device according to the tenth aspect, wherein the light-emitting unit and the light-receiving unit are provided below the tip of the end effector located in the immediately preceding position.

[0147] A twelfth aspect is a substrate transport device according to any one of the first to eleventh aspects, wherein the substrate container accommodates a plurality of the substrates, and further comprises a sensor lifting / lowering drive unit that raises and lowers the light-emitting unit and the light-receiving unit depending on the position of the substrate to be transported in or out by the end effector.

[0148] A thirteenth aspect is a substrate transport device according to any one of the first to twelfth aspects, wherein the end effector has a first elongated portion, a second elongated portion spaced apart from the first elongated portion, and a connecting portion connecting the base ends of the first elongated portion and the second elongated portion, and the sensor includes a first light-emitting unit that outputs a first measurement light toward a first tip end of the first elongated portion, a first light-receiving unit that receives the first measurement light, a second light-emitting unit that outputs a second measurement light toward a second tip end of the second elongated portion, and a second light-receiving unit that receives the second measurement light.

[0149] A fourteenth aspect is the substrate transport device according to the thirteenth aspect, further comprising a sensor movement drive unit that moves a first inner optical unit, which is one of the first light-emitting unit and the first light-receiving unit, between a first measurement position and a first standby position, and moves a second inner optical unit, which is one of the second light-emitting unit and the second light-receiving unit, between a second measurement position and a second standby position, wherein the first measurement position is a position between the first elongated portion and the second elongated portion of the end effector positioned at the immediately preceding position, and the first elongated portion of the end effector positioned at the immediately preceding position is positioned between a first outer optical unit, which is the other of the first light-emitting unit and the first light-receiving unit, and the first inner optical unit positioned at the first measurement position, and the first light-emitting unit has a width of the first measurement light that is wider than a thickness of the first tip. the first light-receiving unit receives the first measurement light that has passed outside the first tip, the first standby position is a position that avoids the movement path of the end effector, the second measurement position is a position between the first long portion and the second long portion of the end effector that is located at the immediately preceding position, the second long portion of the end effector that is located at the immediately preceding position is located between a second outer optical portion that is the other of the second light-emitting unit and the second light-receiving unit, and the second inner optical portion that is located at the second measurement position, the second light-emitting unit outputs the second measurement light that is wider than a thickness of the second tip, the second light-receiving unit receives the second measurement light that has passed outside the second tip, and the second standby position is a position that avoids the movement path of the end effector.

[0150] A fifteenth aspect is a substrate transport device according to the thirteenth aspect, wherein the first light-emitting unit and the first light-receiving unit are provided on the opposite side of the first elongated portion from the second elongated portion, and the first light-receiving unit receives the first measurement light reflected at the first tip, and the second light-emitting unit and the second light-receiving unit are provided on the opposite side of the second elongated portion from the first elongated portion, and the second light-receiving unit receives the second measurement light reflected at the second tip.

[0151] A sixteenth aspect is the substrate transport device according to any one of the thirteenth to fifteenth aspects, wherein the first measurement light and the second measurement light have different wavelengths.

[0152] A seventeenth aspect is a substrate transport method comprising the steps of: moving an end effector of a transport unit toward a substrate container that contains a substrate; emitting measurement light from a light-emitting unit toward a tip of the end effector located just before the substrate container; and detecting the position of the tip based on the measurement light received by a light-receiving unit.

[0153] According to the first and seventeenth aspects, the position of the tip of the end effector is detected. Therefore, it is possible to determine with higher accuracy whether the tip of the end effector will collide with the substrate. In other words, the first aspect contributes to avoiding a collision between the end effector and the substrate.

[0154] According to the second aspect, the control unit performs vibration reduction processing, which can further reduce the possibility of collision between the end effector and the substrate.

[0155] According to the third aspect, vibration of the end effector can be reduced with simple control.

[0156] According to the fourth aspect, the possibility of collision between the end effector and the substrate can be further reduced.

[0157] According to the fifth aspect, since the light emitting unit and the light receiving unit are provided on the sides of the end effector, the vertical position of the tip of the end effector can be detected with high accuracy.

[0158] According to the sixth aspect, the position of the tip of the end effector can be detected on average.

[0159] According to the seventh aspect, the position of the portion of the tip of the end effector that reflects the measurement light can be detected.

[0160] According to the eighth aspect, the light-emitting unit can output measurement light to the tip of the end effector whenever the transport unit takes out any substrate W. Therefore, the sensor can detect the position of the tip of the end effector.

[0161] According to the ninth aspect, the precision required for attaching the light emitting unit and the light receiving unit can be reduced.

[0162] According to the tenth aspect, the position of the portion of the tip of the end effector that reflects the measurement light can be detected.

[0163] According to the eleventh aspect, regardless of whether the end effector is supporting a substrate or not, the light-emitting unit can output measurement light to the underside of the end effector, and the light-receiving unit can receive measurement light reflected by the underside of the end effector.

[0164] According to the twelfth aspect, each of the light-emitting unit and the light-receiving unit can be made to follow the end effector located immediately before it, thereby making it possible to more appropriately detect the position of the end effector.

[0165] According to the thirteenth aspect, the position of the first tip end of the first elongated portion and the position of the second tip end of the second elongated portion can be obtained separately.

[0166] According to the fourteenth aspect, the sensor can detect the position of the first tip end of the first elongated portion when the first inner optical portion is located at the first measurement position, and can detect the position of the second tip end of the second elongated portion when the second inner optical portion is located at the second measurement position. Furthermore, the end effector can enter the substrate container when the first inner optical portion and the second inner optical portion are located at the first standby position and the second standby position, respectively.

[0167] According to the fifteenth aspect, the first light-emitting unit, the first light-receiving unit, the second light-emitting unit and the second light-receiving unit are arranged to avoid the movement path of the end effector, so that they do not hinder the movement of the end effector.

[0168] According to the sixteenth aspect, noise can be reduced.

[0169] 110 Substrate transport device 20 Transport unit (first transport unit) 21 End effector 211A First long portion 211B Second long portion 212 Connecting portion 30 Sensor 31 Light emitting portion 31A First light emitting portion 31B Second light emitting portion 31s Light emitting surface 32 Light receiving portion 32A First light receiving portion 32B Second light emitting portion 32s Light receiving surface 33 Sensor movement driving portion 34 Sensor lift driving portion 90 Control portion C Substrate container L1 Measurement light L11 First measurement light L12 Second measurement light

Claims

1. A substrate transport device comprising: a transport unit including an end effector, the end effector entering a substrate container from its tip, and transporting substrates in and out of the container; a light-emitting unit that outputs measurement light toward the tip of the end effector located just before the tip of the end effector enters the substrate container; and a light-receiving unit that receives the measurement light from the light-emitting unit, and a sensor that detects the position of the tip of the end effector based on the measurement light received by the light-receiving unit.

2. A substrate transport device as described in claim 1, comprising a control unit that controls the transport unit, wherein the control unit performs vibration reduction processing to reduce vibration of the end effector when the positional fluctuation amount of the end effector obtained based on the measurement light received by the light receiving unit is greater than a predetermined fluctuation reference value.

3. A substrate transport device according to claim 2, wherein the control unit does not drive the transport unit as the vibration reduction process until the amount of positional fluctuation becomes less than the fluctuation reference value.

4. A substrate transport device as described in any one of claims 1 to 3, comprising a control unit that controls the transport unit, wherein the control unit controls the transport unit so that the position of the end effector obtained based on the measurement light received by the light receiving unit is within a predetermined range.

5. A substrate transport device according to any one of claims 1 to 3, wherein the light emitting unit and the light receiving unit are provided laterally relative to the end effector located in the immediately preceding position.

6. A substrate transport device as described in claim 5, wherein the light-emitting unit and the light-receiving unit are provided on opposite sides of the end effector located immediately before the end effector, the light-emitting unit outputs the measurement light that is wider than the thickness of the end effector, and the light-receiving unit receives the measurement light that has passed outside the end effector.

7. A substrate transport device as described in claim 5, wherein the light-emitting unit and the light-receiving unit are provided on the same side of the end effector located immediately before the end effector, the light-emitting unit outputs measurement light that is wider than the thickness of the end effector, and the light-receiving unit receives the measurement light reflected by the end effector.

8. A substrate transport device as described in claim 4, wherein the substrate container accommodates a plurality of the substrates arranged vertically, the measurement light is output from the light-emitting surface of the light-emitting unit and received by the light-receiving surface of the light-receiving unit, the upper end of the light-emitting surface and the upper end of the light-receiving surface are located above the uppermost substrate of the plurality of substrates, and the lower end of the light-emitting surface and the lower end of the light-receiving surface are located below the lowermost substrate of the plurality of substrates.

9. A substrate transport device according to claim 4, wherein the substrate container accommodates a plurality of the substrates arranged in a vertical direction, and the plurality of light-emitting elements and the plurality of light-receiving elements are arranged in the vertical direction.

10. A substrate transport device as described in any one of claims 1 to 3, wherein the light emitting unit and the light receiving unit are provided on the same side in the vertical direction relative to the tip of the end effector located in the immediately preceding position, and the light receiving unit receives the measurement light reflected by the end effector.

11. A substrate transport device according to claim 10, wherein the light emitting unit and the light receiving unit are provided below the tip of the end effector located in the immediately preceding position.

12. A substrate transport device as described in any one of claims 1 to 3, wherein the substrate container accommodates a plurality of the substrates, and further comprising a sensor lifting / lowering drive unit that raises and lowers the light-emitting unit and the light-receiving unit depending on the position of the substrate to be transported in or out by the end effector.

13. A substrate transport device as described in any one of claims 1 to 3, wherein the end effector has a first elongated portion, a second elongated portion spaced apart from the first elongated portion, and a connecting portion connecting the base ends of the first elongated portion and the second elongated portion, and the sensor includes a first light-emitting unit that outputs a first measuring light toward a first tip end of the first elongated portion, a first light-receiving unit that receives the first measuring light, a second light-emitting unit that outputs a second measuring light toward a second tip end of the second elongated portion, and a second light-receiving unit that receives the second measuring light.

14. A substrate transport device according to claim 13, comprising a sensor movement drive unit that moves a first inner optical unit, which is one of the first light-emitting unit and the first light-receiving unit, between a first measurement position and a first standby position, and moves a second inner optical unit, which is one of the second light-emitting unit and the second light-receiving unit, between a second measurement position and a second standby position, wherein the first measurement position is a position between the first long portion and the second long portion of the end effector located at the immediately preceding position, and the first long portion of the end effector located at the immediately preceding position is located between a first outer optical unit, which is the other of the first light-emitting unit and the first light-receiving unit, and the first inner optical unit located at the first measurement position, and the first light-emitting unit outputs the first measurement light that is wider than the thickness of the first tip, and the first light-receiving unit receives the first measurement light that has passed outside the first tip, a substrate conveying device, wherein the first waiting position is a position that avoids the movement path of the end effector; the second measurement position is a position between the first long portion and the second long portion of the end effector that is located at the immediately preceding position; the second long portion of the end effector that is located at the immediately preceding position is located between a second outer optical portion that is the other of the second light-emitting portion and the second light-receiving portion, and the second inner optical portion that is located at the second measurement position; the second light-emitting portion outputs the second measurement light that is wider than a thickness of the second tip portion; and the second light-receiving portion receives the second measurement light that has passed outside the second tip portion; and the second waiting position is a position that avoids the movement path of the end effector.

15. A substrate transport device as described in claim 13, wherein the first light-emitting unit and the first light-receiving unit are provided on the opposite side of the first elongated portion from the second elongated portion, and the first light-receiving unit receives the first measurement light reflected by the first tip end, and the second light-emitting unit and the second light-receiving unit are provided on the opposite side of the second elongated portion from the first elongated portion, and the second light-receiving unit receives the second measurement light reflected by the second tip end.

16. A substrate transport device according to claim 13, wherein the wavelength of the first measurement light and the wavelength of the second measurement light are different from each other.

17. A substrate transport method comprising the steps of: moving an end effector of a transport unit toward a substrate container that contains a substrate; and emitting measurement light from a light-emitting unit toward the tip of the end effector located just before the substrate container, and detecting the position of the tip based on the measurement light received by a light-receiving unit.

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