Substrate handling device

Abstract

The substrate transfer apparatus of the present application includes a base, an arm, an end effector provided at a front end of the arm and having a first front end portion and a second front end portion branched into two, a light emitting portion, a light receiving portion, and a control device that controls the operation of the arm. The control device controls the operation of the arm so that light advancing in front of the end effector scans the edges of a plurality of substrates accommodated in a FOUP, and compares a shape pattern of a measurement waveform of output values continuously changed at the light receiving portion with a shape pattern of a reference waveform for comparison according to a relative positional relationship between the light and the substrates in the operation of the arm, and diagnoses at least one of a state of the substrates, a state of the FOUP, and a state of the end effector based on a comparison result.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority and benefit to U.S. Patent Application No. 62 / 456,375, filed June 28, 2019, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] This invention relates to a substrate handling device. Background Technology

[0004] Generally, in semiconductor manufacturing equipment and LCD panel manufacturing equipment, substrate handling devices are used to move semiconductor wafers and glass substrates to desired locations. These substrate handling devices include a robotic arm and an end effector for holding the substrate. For example, in the end effectors disclosed in Japanese Patent No. 6088243, Japanese Patent Publication No. 2004-535681, and Japanese Patent Application Publication No. 2018-111200, the presence or absence of a substrate housed in a FOUP (Front-Opening Unified Pod) is detected by whether a detection light traveling between a pair of branched front ends is blocked by the substrate.

[0005] However, the substrate handling device equipped with the aforementioned end effector detects the presence or absence of the substrate by converting an output value (e.g., output voltage) that continuously varies in the light-receiving section according to the amount of light received into a binary signal. Therefore, it cannot accurately diagnose the state of the substrate (e.g., surface tilt of the substrate). Summary of the Invention

[0006] The present invention was made to solve the problems mentioned above, and its purpose is to diagnose the condition of the substrate housed in the FOUP with high precision in a substrate handling apparatus.

[0007] To achieve the above object, a substrate conveyance device according to one embodiment of the present application includes: a base; a robot arm mounted to the base; an end effector provided at a distal end of the robot arm and having a first distal end portion and a second distal end portion branched into two; a light emitting portion configured to emit light toward the second distal end portion from the first distal end portion; a light receiving portion configured to convert an amount of light received by the second distal end portion into an output value that continuously changes, based on light traveling in a space between the first and second distal end portions and being incident on the second distal end portion; and a control device that controls an operation of the robot arm, the control device being configured to: control the operation of the robot arm such that the light traveling at the distal end of the end effector scans an edge of a plurality of substrates housed in a FOUP, and compare a pattern of shapes of a measured waveform of the output value that continuously changes at the light receiving portion with a pattern of shapes of a reference waveform for comparison, based on a relative positional relationship between the light and the substrates in the operation of the robot arm, and diagnose at least one of a state of the substrates, a state of the FOUP, and a state of the end effector, based on a result of the comparison.

[0008] The control device can be configured to compare a pattern of shapes in one of the intervals with a pattern of shapes in another of the intervals, and determine that a surface of the substrate in the one of the intervals is tilted, when the pattern of shapes in the one of the intervals is not consistent with the pattern of shapes in the other of the intervals.

[0009] The control device can be configured to compare a pattern of shapes of a measured waveform measured this time with a pattern of shapes of a measured waveform measured last time for comparison, and determine that a surface of the substrate in one of the intervals is tilted, when the pattern of shapes in the one of the intervals is not consistent with the pattern of shapes in the one of the intervals of the measured waveform measured last time for comparison.

[0010] The control device can be configured to compare a pattern of shapes of a measured waveform measured this time with a pattern of shapes of a measured waveform measured last time for comparison, and determine that the FOUP is tilted, when the pattern of shapes in all of the intervals of the measured waveform is not consistent with the pattern of shapes in all of the intervals of the measured waveform measured last time for comparison.

[0011] The FOUPs can be arranged at different positions, and the control device can be configured to compare a pattern of shapes of a measured waveform measured in one of the FOUPs with a pattern of shapes of a measured waveform measured in another of the FOUPs for comparison, and determine that the one of the FOUPs is tilted, when the pattern of shapes in all of the intervals of the measured waveform measured in the one of the FOUPs is not consistent with the pattern of shapes in all of the intervals of the measured waveform measured in the other of the FOUPs for comparison.

[0012] Also, the control device can be configured to compare the shape pattern of the measurement waveform measured this time with the shape pattern of the comparison-use measurement waveform measured last time, and determine that the end effector is tilted when the shape pattern in all of the intervals of the measurement waveform measured this time is different from the shape pattern in all of the intervals of the comparison-use measurement waveform measured last time.

[0013] Also, the control device can be configured to compare the shape pattern of the measurement waveform measured this time with the shape pattern of the comparison-use measurement waveform measured last time, and determine that at least one of the intensity of the light from the light-emitting portion and the light-receiving sensitivity of the light-receiving portion is reduced when the output value in all of the intervals of the measurement waveform measured this time is lower than the output value in all of the intervals of the comparison-use measurement waveform measured last time.

[0014] Also, the substrate handling device can further include a display device that displays the diagnosis result.

[0015] Another aspect of the present application relates to a substrate handling device including: a base; a robot arm mounted to the base; an end effector provided at a front end of the robot arm and having a first front end portion and a second front end portion branched into two; a light-emitting portion configured to emit light from the first front end portion toward the second front end portion; a light-receiving portion configured to convert a detected light into a continuously varying output value according to a light-receiving amount of the light that travels in a space between the first and second front end portions and is incident on the second front end portion; and a control device that controls an operation of the robot arm, the control device being configured to control the operation of the robot arm in such a manner that the light traveling at the front end of the end effector scans a target in a horizontal direction with respect to the target, and measure a position of the target in the horizontal direction based on a relative positional relationship between the light and the target in the operation of the robot arm and a measurement waveform of the continuously varying output value of the light-receiving portion.

[0016] The control device can be configured to measure the position of the target in the horizontal direction based on a relative positional relationship between the light and the target in the operation of the robot arm and a measurement waveform of the continuously varying output value of the light-receiving portion.

[0017] The present application has the above-described configuration, and can diagnose a state of a substrate housed in a FOUP with high accuracy in a substrate handling device. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a side view of a substrate handling device according to a first embodiment of the present application.

[0019] Figure 2 It means Figure 1 A top view of the structure of the end effector.

[0020] Figure 3 It means Figure 1 A block diagram outlining the structure of the substrate handling device.

[0021] Figure 4 This is a schematic diagram used to illustrate the action of an end effector.

[0022] Figure 5 This is a schematic diagram used to illustrate the change in the amount of light received when the end effector is in motion.

[0023] Figure 6 This is a graph representing an example of the output waveform when the end effector is in motion.

[0024] Figure 7 This is a graph representing an example of the output waveform when the end effector is in motion.

[0025] Figure 8 This is a graph representing an example of the output waveform when the end effector is in motion.

[0026] Figure 9 This is a top view showing the substrate handling apparatus according to the second embodiment of the present invention.

[0027] Figure 10 This is a graph representing an example of the output waveform when the end effector is in motion.

[0028] Figure 11 This is a diagram used to illustrate the comparison method for measuring waveforms.

[0029] Figure 12 This is a graph showing an example of the output waveform when the end effector in the substrate handling apparatus according to the third embodiment of the present invention is operated. Detailed Implementation

[0030] The preferred embodiments will now be described with reference to the accompanying drawings. Furthermore, in all the drawings, the same or equivalent components will be labeled with the same reference numerals, and repeated descriptions will be omitted. Additionally, for the purpose of understanding the drawings, the various structural components are schematically shown.

[0031] (First Embodiment)

[0032] Figure 1 This is a side view showing the substrate handling apparatus 1 according to the first embodiment of the present invention. Figure 1As shown, the substrate transfer device 1 is used in a semiconductor processing apparatus that is an apparatus for processing semiconductor wafers. As the semiconductor wafers, silicon wafers, sapphire (single-crystal aluminum oxide) wafers, and other various wafers are exemplified. In addition, as the glass wafers, for example, FPD (Flat Panel Display) glass substrates, MEMS (Micro Electro Mechanical Systems) glass substrates are exemplified.

[0033] The semiconductor wafers (hereinafter, also simply referred to as substrates) W before and after processing are housed in a container called a Front Opening Unified Pod (FOUP) 6. The FOUP 6 is a substrate container for a micro environment in a clean environment, and relates to a partial cleaning technology. A plurality of substrates W are housed in the FOUP 6. Each substrate W is housed in each socket (not shown) of the FOUP 6. Each substrate W is arranged at equal intervals in the up-down direction Z in a horizontal state. The FOUP 6 is formed in a substantially box shape on a base 7, and is open to one side. The semiconductor processing apparatus includes a substrate processing device (not shown) that processes the substrates W. As the processing of the substrates W, process treatments such as heat treatment, impurity introduction treatment, thin film formation treatment, photolithography treatment, cleaning treatment, and planarization treatment are exemplified. The substrates W are transferred by the substrate transfer device 1 between the FOUP 6 and the substrate processing device (not shown).

[0034] In the present embodiment, the substrate transfer device 1 is a so-called horizontal multi-joint type 4-axis robot. The substrate transfer device 1 is provided with a horizontal arm at the front end of a robot arm (hereinafter, also simply referred to as "arm") 2 having degrees of freedom in three axial directions of X, Y, and Z, and the end effector 10 that holds the substrate W is provided at the horizontal arm.

[0035] The substrate transfer device 1 has a base 4 fixed to an appropriate position (for example, the floor) of the semiconductor processing apparatus, and a lifting shaft 3 is provided at the base 4. At the base 4, the axis line of the lifting shaft 3 is directed, for example, in the vertical direction. At the base 4, for example, an actuator (not shown) composed of a pneumatic cylinder is built in. The lifting shaft 3 is raised and lowered along the up-down direction on the upper surface side of the base 4 by the action of the actuator.

[0036] The arm 2 includes a first arm 2a and a second arm 2b. The first arm 2a is provided at the upper end of the lifting shaft 3. The first arm 2a extends horizontally from the upper end of the lifting shaft 3. The one end of the first arm 2a is connected so as to be swingable about a vertical axis line L1 with respect to the lifting shaft 3, and, at the lifting shaft 3, for example, an actuator (not shown) composed of an electric motor is built in. The first arm 2a is swung in the horizontal plane with respect to the lifting shaft 3 by the action of the actuator.

[0037] The second arm 2b is provided on the upper surface side of the other end portion of the first arm 2a. The second arm 2b extends horizontally from the other end portion of the first arm 2a. The one end portion of the second arm 2b is linked to the other end portion of the first arm 2a so as to be able to swing about the vertical axis L2. In the other end portion of the first arm 2a, for example, an unillustrated actuator composed of an electric motor is built in. By the action of this actuator, the second arm 2b swings in the horizontal plane with respect to the other end portion of the first arm 2a.

[0038] On the upper surface side of the other end portion of the second arm 2b, an end effector 10 that holds the substrate W is provided. The end effector 10 is linked to the other end portion of the second arm 2b so as to be able to swing about the vertical axis L3. In the other end portion of the second arm 2b, for example, an unillustrated actuator composed of an electric motor is built in. By the action of this actuator, the end effector 10 swings in the horizontal plane with respect to the other end portion of the second arm 2b.

[0039] The control device 5 controls the actions of the respective actuators that drive the lifting shaft 3, the first arm 2a, the second arm 2b, and the end effector 10, for example, in accordance with an input from an operating device (not illustrated) or automatically, and the end effector 10 moves up and down and horizontally. Also, by appropriately controlling the action speed of the actuators, the end effector 10 can move along an arbitrary path in the horizontal plane.

[0040] Figure 2 is a plan view of the end effector 10 as viewed from above. As shown in Figure 2 , the end effector 10 is composed of a plate material that forms a U shape in plan view. In the present embodiment, the plate material is left-right symmetrical with respect to the center line C. The end effector 10 has a single base end portion 10a, and a first front end portion 10b and a second front end portion 10c that branch from the base end portion 10a into two. A space is formed between the first front end portion 10b and the second front end portion 10c. The base end portion 10a of the end effector 10 is fixed to one end of a mounting plate 20, and the end effector 10 extends horizontally from the mounting plate 20. The other end of the mounting plate 20 is linked to the other end portion of the second arm 2b so as to be able to swing about the vertical axis L3.

[0041] The end effector 10 is configured to be able to hold a disc-shaped substrate W. In the present embodiment, the end effector 10 is provided with a pressing surface 11a provided on the upper surface of the base end portion 10a, and two edge grips 11b and 11c provided on the upper surfaces of the first front end portion 10b and the second front end portion 10c. By the two edge grips 11b and 11c, the edge of one end side of the substrate W placed on the end effector 10 is caught, and by the pressing surface 11a, the edge of the other end side of the substrate W is pressed, whereby the substrate W is fixed to the end effector 10.

[0042] The light emitting section 13 is built in the mounting plate 20 of the end effector 10. The light emitting section 13 converts an electric input from the control device 5 to generate detection light. One end of the optical fiber 15a is connected to the light emitting section 13, and the optical fiber 15a is laid from the back surface side of the base end portion 10a of the end effector 10 to the back surface side of the first front end portion 10b. The optical fiber 15a guides the detection light emitted from the light emitting section 13 to the back surface side of the first front end portion 10b of the end effector 10. The light receiving section 14 is built in the mounting plate 20 of the end effector 10. The light receiving section 14 receives the detection light and converts the detection light to an electric output to the control device 5. One end of the optical fiber 15b is connected to the back surface side of the second front end portion 10c of the end effector 10, and the optical fiber 15b is laid to the light receiving section 14 built in the mounting plate 20 of the end effector 10. The optical fiber 15b guides the detection light incident to the back surface side of the second front end portion 10c of the end effector 10 to the light receiving section 14. Further, at both ends of the optical fibers 15a and 15b, an optical condensing element (for example, a convex lens) and an optical diffusing element (for example, a concave lens) not shown can be appropriately arranged as needed.

[0043] Figure 3 is a block diagram showing an outline of the structure of the substrate handling device 1. As shown in Figure 3 , the control device 5 is a robot controller provided with a computer such as a microcontroller, which is connected to the light emitting section 13, the light receiving section 14, the substrate holding section 11 of the end effector 10, and the driving device 30 of the substrate handling device 1 via control lines. The control device 5 is not limited to a single device, but can be composed of a plurality of devices.

[0044] The light emitting section 13 is provided with a light emitting element 16 and a driving circuit 17. The light emitting element 16 generates and emits detection light. As the light emitting element 16, for example, a light emitting diode or a laser diode is used. The driving circuit 17 applies a voltage to the light emitting element 16 to drive the light emitting element. The driving circuit 17 generates a voltage according to a control signal (an electric input) from the control device 5, and drives the light emitting element 16.

[0045] The light receiving section 14 is provided with a light receiving element 18 and an output circuit 19. The light receiving element 18 receives detection light and converts it to an output value which continuously changes according to the amount of light received. In the present embodiment, the light receiving element 18 receives detection light and converts it to an output voltage which continuously changes according to the amount of light received. As the light receiving element 18, for example, a photodiode is used. The output circuit 19 amplifies the output voltage V out and outputs it to the control device 5.

[0046] The light emitting element 16 is connected to the optical fiber 15a by a connector not shown. Similarly, the light receiving element 18 is connected to the optical fiber 15b by a connector not shown. Thus, in the present embodiment, the light emitting section 13 and the light receiving section 14 include the light emitting element 16 and the light receiving element 18, and the light emitting element 16 and the light receiving element 18 constitute a transmission type optical sensor.

[0047] The substrate holding section 11 is constituted by a pressing surface 11a and two edge handles 11b and 11c as shown in the drawing. In the substrate holding section 11, the pressure of the pressing surface 11a which contacts the substrate W is controlled according to a control command of the control device 5. By the two edge handles 11b and 11c, the edge of one end side of the substrate W placed on the end effector 10 is clamped, and by the pressing surface 11a, the edge of the other end side of the substrate W is pressed, whereby the substrate W is held by the end effector 10. Figure 2

[0048] The driving device 30 is constituted by actuators of the lifting shaft 3, the first arm 2a, and the second arm 2b as shown in the drawing. The driving device 30 causes the actuators of the lifting shaft 3, the first arm 2a, and the second arm 2b to act according to a control command of the control device 5, to move the end effector 10 up and down and horizontally. Figure 1

[0049] The control device 5 is provided with an arithmetic section, a storage section, and a servo control section (not shown). The storage section stores basic programs of the control device 5, information of the movement program of the robot, and data of the measured waveform, the reference waveform, and the like. The arithmetic section performs arithmetic processing for the control of the robot, and generates a control command of the robot. The servo control section is configured to control the movement of the driving device 30 and the substrate holding section 11 based on the control command generated by the arithmetic section. In the present embodiment, the control device 5 performs arithmetic processing for diagnosing the state of the substrate W, the state of the FOUP 6, and the like based on data of the measured waveform, the reference waveform, and the like of the output voltage V out of the light receiving section 14 in the arithmetic section, and outputs the result of the arithmetic processing to the display device 40. The display device 40 is a monitor for displaying the result of the diagnosis.

[0050] Next, the movement of the end effector 10 will be described. Figure 4 is a schematic view for describing the movement of the end effector. Here, only the end effector 10 and the substrate W are shown for simplicity, and four substrates W are accommodated in the sockets of the FOUP 6. As shown in Figure 4 , the control device 5 controls the movement of the arm 2 so that the tip of the end effector 10 is scanned in a manner that the tip of the end effector 10 is opposed to each substrate W from the lowermost socket to the uppermost socket of the FOUP 6. Figure 5 ​​The diagram schematically illustrates the change in light B at the bottommost socket of FOUP6, based on the relative positional relationship between the substrate W and light B when the end effector 10 is actuated. Photons of light B (not shown) are scattered and travel forward in the air, therefore... Figure 5 The shape of the light B expands from the first front end 10b toward the second front end 10c.

[0051] First, such as Figure 5 As shown in (a), the light B emitted from the first front end portion 10b of the end effector 10 is relative to the thickness direction of the substrate W. Figure 5 The light B travels in the positive direction of the Y-axis. The light travels in the space between the first front end 10b and the second front end 10c and is received by the second front end 10c of the end effector 10. In this interval, the amount of light incident on the second front end 10c is constant.

[0052] In the next instant, as Figure 5 As shown in (b), photons from the upper portion of light B are reflected at the lower surface of the substrate W, and the reflected light, along with the forward light, is received by the second front end portion 10c of the end effector 10. Figure 5 In (b), the light in light B reflected by the surface below the substrate W and received by the front end 10c is shown by a diagonal line. In this way, the light from the first front end 10b and the reflected light from the substrate W are incident on the second front end 10c, so the amount of light received by the light incident on the front end 10c increases in this section.

[0053] In the next instant, as Figure 5 As shown in (c), the reflected light B reflected from the surface on the lower side of the substrate W is ( Figure 5 The proportion of the portion indicated by the slash in (c) increases. As a result, in this interval, the amount of light incident on the forward end 10c further increases.

[0054] In the next instant, as Figure 5 As shown in (d), light B emitted from the first front end portion 10b of the end effector 10 is incident on the thickness direction of the substrate W, and the incident light B is blocked by the substrate W. Almost all of the light B incident on the thickness direction of the substrate W is reflected or absorbed by a surface parallel to the thickness direction of the substrate W, and light B is not received by the second front end portion 10c of the end effector 10. In this region, the amount of light received by the light incident on the front end portion 10c is reduced.

[0055] In the next instant, as Figure 5As shown in (e), a portion of the light B emitted from the first front end portion 10b of the end effector 10 travels through the space between the first front end portion 10b and the second front end portion 10c, and is received by the front end portion 10c of the end effector 10. Photons from the lower portion of the light B are reflected by the surface on the upper side of the substrate W, and the reflected light, along with the forward light, is received by the front end portion 10c of the end effector 10. Figure 5 In (e), the light in light B reflected by the surface above the substrate W and received by the front end 10c is indicated by a slash. In this way, the light from the first front end 10b and the reflected light from the substrate W are incident on the second front end 10c, so the amount of light incident on the front end 10c increases in this section.

[0056] In the next instant, as Figure 5 As shown in (f), the reflected light B reflected from the upper surface of the substrate W is ( Figure 5 The proportion of the portion indicated by the slash in (f) is reduced. As a result, in this interval, the amount of light incident on the forward end 10c is further reduced.

[0057] Moreover, such as Figure 6 As shown in (g), the light B emitted from the first front end portion 10b of the end effector 10 travels through the space between the first front end portion 10b and the second front end portion 10c, and all of the emitted light B is received by the front end portion 10c of the end effector 10. In this interval, the amount of light incident on the front end portion 10c is constant.

[0058] Figure 6 This is a graph showing an example of the output waveform when the end effector 10 is in operation. The horizontal axis represents the negative Z direction, and the vertical axis represents the output voltage V of the light-receiving unit 14. out The output voltage V here out It is a value corresponding to the amount of light received (the intensity of light). Figure 5 The waveform on the upper side has four shape patterns corresponding to the four substrates W housed in FOUP6. One shape pattern corresponds to... Figure 5 The operation of the end effector 10 shown corresponds to the output voltage V of the light-receiving section 14 in interval a. out It is a constant value (equivalent to) Figure 5 (a)). In interval b, the output voltage V of the light-receiving unit 14. out Rise (equivalent to) Figure 5 (b) and Figure 5 (c)). In interval c, the output voltage V of the light-receiving unit 14. out Reduce (equivalent to) Figure 5 (d)). In interval d, the output voltage V of the light-receiving part 14. out Rise (equivalent to) Figure 5 (e) and Figure 5(f)). In interval e, the output voltage V of the light-receiving section 14. out It is a constant value (equivalent to) Figure 6 (g) Thus, if the edge of the substrate W housed in the FOUP6 ​​is scanned by the light B advancing at the front end of the end effector 10, the output voltage V of the light-receiving section 14 will be... out It changes continuously according to the relative positional relationship between light B and substrate W.

[0059] In the past, such as Figure 7 The waveform on the lower side is shown, with a threshold V set. th The output voltage V of the light receiving unit 14 out Convert to a binary signal V` out The presence or absence of the substrate W is detected by whether the light B from the end effector 10 is blocked by the substrate W. When the substrate W is not housed in the socket, the light B travels through the space between the first front end 10b and the second front end 10c. Thus, the light B is received by the end of the optical fiber 15b on the back side of the second front end 10c of the end effector 10. The output voltage V corresponding to the amount of light received... out Above the threshold V th Therefore, the light-receiving unit 14 outputs a high-level signal V` to the control device 5. out On the other hand, when the substrate W is housed in the socket, the light B traveling in the space between the first front end portion 10b and the second front end portion 10c of the end effector 10 is blocked by the edge of the substrate W. In this case, the detection light B is not received by the end of the optical fiber 15b on the back side of the front end portion 10c of the end effector 10, and therefore the output voltage V corresponding to the amount of light received is... out Below the threshold V th Therefore, the light-receiving unit 14 outputs a low-level signal V` to the control device 5. out Thus, the control device 5 sequentially determines whether each slot within the FOUP6 ​​contains a substrate. However, this conventional method cannot, for example, diagnose conditions such as surface tilt of the substrate W.

[0060] Therefore, in this embodiment, the control device 5 continuously changes the output value (V) corresponding to the amount of light received based on the relative positional relationship between the light B and the substrate W. out The shape pattern of the measured waveform is compared with the shape pattern of the reference waveform used for comparison, thereby diagnosing the state of the substrate W and the state of FOUP6 ​​based on the comparison results.

[0061] <Diagnosis of substrate condition>

[0062] For example, the state of substrate W can be diagnosed during the handling of substrate W. Figure 7 This is a graph representing an example of the output waveform when the state of the diagnostic substrate W is being diagnosed.Figure 7 The graph on the lower side shows the measured waveform (V out ) measured this time. The measured waveform (V out ) has four shape patterns (P1, P2, P3, P4) corresponding to the four substrates W housed in the FOUP 6. Figure 7 The graph on the upper side shows the reference waveform (V ref ) for comparison measured last time. The reference waveform (V ref ) for comparison also has four shape patterns (P1', P2', P3', P4') corresponding to the four substrates W housed in the FOUP 6. Further, the measured waveform and the reference waveform are stored in a storage section of the control device 5 and are read out at the time of diagnosis.

[0063] First, the control device 5 compares the shape patterns (P1, P2, P3, P4) of the measured waveform measured this time with the shape patterns (P1', P2', P3', P4') of the reference waveform for comparison measured last time.

[0064] Next, the control device 5 determines whether the shape pattern in one section of the measured waveform (V out ) measured this time is identical to the shape pattern in one section of the reference waveform (V ref ) for comparison. Here, the shape pattern P3 in the third lower socket of the FOUP 6 in the measured waveform (V out ) measured this time is not identical to the shape pattern P3' in the third lower socket of the FOUP 6 in the reference waveform (V ref ) for comparison measured last time. If the shape pattern P3 of the measured waveform (V out ) is compared with the shape pattern P3' of the reference waveform (V ref ), the section in which the output value of the shape pattern P3 decreases is longer than the section of the shape pattern P3' (f of Figure 3 ). The control device 5 can determine that the substrate W housed in the third lower socket is housed in the FOUP 6 in a tilted state. The result of the diagnosis of the tilt of the surface of the substrate W is displayed on the monitor of the display device 40 (refer to Figure 8 ).

[0065] Further, the control device 5 can determine the tilt of the substrate W only from the measured waveform (V out ) measured this time. In this case, the control device 5 compares the measured waveform (V out) and the shape pattern in the other interval. The control device 5 determines whether the shape pattern in the one interval is consistent with the shape pattern in the other interval. Here, among the four shape patterns (Pl, P2, P3, P4), the shape pattern P3 in the third lower interval of the FOUP 6 is not consistent with the shape pattern P4 in the other interval (for example, the fourth lower interval) of the FOUP 6. The control device 5 can determine that the substrate W housed in the third lower socket is housed in the FOUP 6 in a tilted state.

[0066] <Diagnosis of the state of the FOUP>

[0067] The diagnosis of the state of the FOUP 6 is performed, for example, before the substrate W is moved. Figure 8 is a graph showing one example of an output waveform at the time of diagnosing the state of the FOUP 6. Figure 8 The graph on the lower side of shows a measurement waveform (V out ) measured this time. The measurement waveform (V out ) has four shape patterns (Pl, P2, P3, P4) corresponding to the four substrates W housed in the FOUP 6. Figure 8 The graph on the upper side of shows a reference waveform (V ref ) for comparison measured last time. The reference waveform (V ref ) for comparison also has four shape patterns (Pl', P2', P3', P4') corresponding to the four substrates W housed in the FOUP 6. In addition, the measurement waveform and the reference waveform are stored in a storage section of the control device 5 and are read out at the time of diagnosis.

[0068] First, the control device 5 compares the shape patterns (Pl, P2, P3, P4) of the measurement waveform measured this time with the shape patterns (Pl', P2', P3', P4') of the reference waveform for comparison. The control device 5 determines whether the shape pattern in each interval of the measurement waveform (V out ) measured this time is consistent with the shape pattern in each interval of the reference waveform (V ref ) for comparison measured last time. Here, the shape patterns (Pl, P2, P3, P4) in all intervals of the measurement waveform (V out ) measured this time are not consistent with the shape patterns (Pl', P2', P3', P4') in all intervals of the reference waveform (V ref ) for comparison measured last time. If the shape patterns (Pl, P2, P3, P4) in all intervals of the measurement waveform (V out ) are compared with the shape patterns (Pl', P2', P3', P4') in all intervals of the reference waveform (V ref ) for comparison, the measurement waveform (Vout The entire range of the output value rise of the shape pattern (P1, P2, P3, P4) is longer than the reference waveform (V) used for comparison. ref The intervals of the shape pattern (P1', P2', P3', P4') Figure 3 (g). The control device 5 can determine that FOUP6 ​​is tilted. The diagnostic result of the tilt of FOUP6 ​​is displayed on the display device 40 (refer to g). Figure 9 ) monitor.

[0069] Furthermore, in this embodiment, the previously measured waveform is used as the reference waveform for comparison (V). ref However, the waveform measured under ideal conditions without the substrate W or any tilt can also be used as the reference waveform. Furthermore, the user is not limited to waveforms measured under ideal conditions and can choose any waveform as the reference waveform. Additionally, a waveform measured by one device can be used as a reference waveform in another device.

[0070] (Second Implementation)

[0071] The substrate transport apparatus 1 according to the second embodiment of the present invention will be described. The structure of the substrate transport apparatus 1 is the same as that of the first embodiment, but in this embodiment, the state of a FOUP6 ​​is diagnosed by using the shape pattern of the measurement waveform measured in a plurality of FOUP6. Figure 9 This is a top view showing the substrate handling apparatus 1 according to the second embodiment of the present invention. Figure 9 As shown, in this embodiment, three FOUP6 ​​units are arranged in front of the substrate transport device 1. Here, each base 7 is along... Figure 10 The Y-direction configuration.

[0072] In this embodiment, the control device 5 uses the shape pattern of the measured waveforms obtained from the three FOUP6s to diagnose the state of one FOUP6. Figure 10 This is a graph representing an example of the output waveform when diagnosing the state of a FOUP6. Figure 10 The curve on the lower side shows the measurement waveform (V) measured at the central FOUP6. out ). Measure the waveform (V) out The four substrates W housed in FOUP6 ​​have four shape patterns (P1, P2, P3, P4). Figure 10 The curve on the upper side represents the reference waveform (V) measured on both sides of the FOUP6 ​​for comparison. ref The reference waveform used for comparison (V) refThe four substrates W housed in FOUP6 ​​also have four shape patterns (P1', P2', P3', P4'). Furthermore, the waveforms measured in FOUP6 ​​on both sides are identical; here, only one measured waveform is represented as the reference waveform (V). ref In addition, the measured waveform and the reference waveform are stored in the storage unit of the control device 5 and read out during diagnosis.

[0073] Control device 5 compares the shape pattern of the measured waveform measured at one FOUP6 ​​with the shape pattern of a reference waveform measured at other FOUP6s. Control device 5 determines the measured waveform (V) at the center of the FOUP6. out Are the shape patterns (P1, P2, P3, P4) in all intervals of the FOUP compared with the reference waveform (V) measured in other FOUPs? ref The shape patterns (P1', P2', P3', P4') in all intervals of the sequence are consistent. Here, the measured waveform (V) measured at the central FOUP6 ​​is consistent. out The shape patterns (P1, P2, P3, P4) in all intervals of the FOUP are compared with the reference waveforms (V) measured in other FOUPs. ref The shape patterns (P1', P2', P3', P4') in all intervals of the measurement are inconsistent. If the measured waveform (V) is compared... out The shape patterns (P1, P2, P3, P4) in all intervals of the spectrum, and the reference waveform (V) used for comparison. ref If the shape pattern (P1', P2', P3', P4') is within all intervals of ), then the waveform (V) is measured. out The entire range of the output value decrease of the shape pattern (P1, P2, P3, P4) is longer than the reference waveform (V) used for comparison. ref The intervals of the shape pattern (P1', P2', P3', P4') Figure 3 (h). The control device 5 can determine that the central FOUP6 ​​is tilted. The diagnostic result of the tilt of FOUP6 ​​is displayed on the display device 40 (refer to h). Figure 7 The monitor of the FOUP6. In this embodiment, the control device 5 is able to diagnose the state of a FOUP6 ​​by using the shape pattern of the measured waveforms measured in multiple FOUP6s.

[0074] Furthermore, in this embodiment, the measured waveform in one FOUP6 ​​within the comparison device is compared with the reference waveform measured in other FOUP6s, but it can also be compared with the reference waveform measured under ideal conditions.

[0075] (Other implementation methods)

[0076] Further, in the first embodiment, as a comparison method, the case where the determination reference waveform and the measurement waveform (the number of wave crests) are compared to determine whether they are identical is described, but for example, the reference waveform can be one shape pattern (for example, only Figure 7 P1') and is repeatedly compared with all of the shape patterns of the measurement waveform (for example, Figure 7 P1 to P4).

[0077] Further, the reference waveform prepared by comparing the value stored in advance in the storage section as the Z position where the substrate W exists with the measurement waveform can be compared.

[0078] Further, as the comparison method of the shape pattern of the measurement waveform and the shape pattern of the reference waveform used for comparison, various methods can be used.

[0079] (a) For example, it can be determined by how much the two waveforms deviate. As a method of calculating how much the two waveforms deviate, a method of calculating based on the deviation at one or a plurality of Z positions, and a method of calculating based on the deviation of the integrated values of the two waveforms at one or a plurality of intervals at the Z position can be given.

[0080] (b) The peak values of the two waveforms can be compared. For example, the V Figure 10 max values, the minimum values of the primary waveforms (for example, ref P1' and P1) can be compared with each other. Further, the peak values on the left and right of the wave valley (the portion of h of ref ) of the V ref max values can be compared. Figure 11

[0081] (c) The value of the horizontal axis when the threshold values of the two waveforms are identical (the ABDE of the waveforms of Figure 11 ) can be used for comparison. The interval between A and B of Figure 11 may be compared. The interval between D and E of Figure 11 may be compared. The interval between the wave valley (corresponding to C of the lower drawing) of Figure 3 V ref and A, B, D, or E can be compared.

[0082] Furthermore, in the above embodiments, the control device 5 diagnoses the tilt of the substrate W and the tilt of the FOUP6, but it can also diagnose the state of the end effector 10. For example, after a temporary interruption of processing in the semiconductor processing equipment due to an operator's mistaken operation of the robot and a collision with the surrounding environment, the state diagnosis of the end effector 10 is performed before the robot (substrate handling device 1) restarts its operation. The state diagnosis of the end effector 10 is performed when the tilt of the FOUP6 ​​has been corrected. The control device 5 compares the shape pattern of the measured waveform measured this time with the shape pattern of the reference waveform used for comparison measured last time when the tilt of the FOUP6 ​​has been corrected. If the shape pattern in all intervals of the measured waveform measured this time is inconsistent with the shape pattern in all intervals of the reference waveform used for comparison measured last time, it can be determined that the end effector 10 is tilted.

[0083] In addition, the control device 5 can also diagnose the lifespan of the optical component. The control device 5 compares the shape and pattern of the measured waveform with the shape and pattern of the previously measured reference waveform. If the output value in all intervals of the measured waveform is lower than the output value in all intervals of the previously measured reference waveform, it can determine that the light-emitting element 16 of the light-emitting section 13 (see reference 16) is at fault. Figure 3 The light intensity and light-receiving element 18 (reference) Figures 1-3 At least one of the light sensitivity of the light-receiving components decreases.

[0084] Furthermore, in this embodiment, the light-receiving element 18 outputs a voltage value that changes continuously according to the amount of light received, but it can also output a current value that changes continuously according to the amount of light received.

[0085] (Third Implementation)

[0086] The substrate handling apparatus according to the third embodiment of the present invention will be described. The basic structure of the substrate handling apparatus of this embodiment is the same as that of the embodiments described above. Figure 12 Since they are the same, the explanation is omitted. Figure 4 The upper layer shows a top view of the end effector 10 in the substrate handling apparatus according to this embodiment. The target is a disk-shaped substrate W. Here, for simplicity, only the end effector 10 and the substrate W are shown. The substrate W is, for example, housed in a FOUP 6 (see reference 6). Figure 12 (a)) The socket. Adjust the end effector 10 and the base plate W to the same level. Figure 12(Reference position in the Z-axis direction). In this embodiment, the control device 5 controls the movement of the arm 2 to scan the substrate W, which is circular when viewed from above, in the horizontal direction (positive direction of the X-axis in the figure) relative to the light B traveling at the front end of the end effector 10. The position of the substrate W in the horizontal direction is measured based on the relative positional relationship between the light B and the substrate W during the movement of the arm 2 and the measurement waveform based on the continuously changing output value in the light receiving part 14, which is different from the above embodiment.

[0087] Figure 12 The graph represents the output waveform of the end effector 10 during operation. The horizontal axis represents the positive direction of the X-axis, and the vertical axis represents the measured waveform output by the light-receiving section 14 of the end effector 10 based on the amount of light received (light intensity). Figure 12 The graph below shows the continuously varying output voltage V at the light-receiving part 14 during the operation of arm 2, based on the relative positional relationship between light B and substrate W. out The measured waveform (analog signal). Figure 12 The upper curve represents the analog signal (output voltage V) shown in the lower curve. out The threshold value is set to convert it into a binary signal V`. out The measured waveform (digital signal).

[0088] In existing mapping sensors, the binary signal V` out ( Figure 12 The value of the upper curve (V') varies depending on whether the light B from the end effector 10 is blocked by the substrate W. Thus, the presence or absence of the substrate W is detected. Here, as a comparative example, the digital signal (V'') using a conventional mapping sensor is compared. out The method for measuring the position of the substrate W in the horizontal direction will be described. Specifically, if the light B of the end effector 10 is positioned relative to the substrate W in the horizontal direction (…),… Figure 12 If the light B of the end effector 10 moves along the positive direction of the X-axis, then the light B of the end effector 10 will be affected by the side surface of the substrate W (and the positive direction of the X-axis). Figure 12 The plane parallel to the Z-axis is blocked. If the light B from the end effector 10 reaches the edge of the substrate W ( Figure 12 From this point onward, the amount of light received (light intensity) in the light-receiving section 14 begins to decrease. As a result, when the amount of light received (light intensity) decreases below a preset threshold, the digital signal (V`)... out The signal transitions from high to low. This is achieved by calculating the digital signal (V`). out The position from high level to low level (value in the positive direction of the X-axis) allows for the measurement of the edge of substrate W. Figure 12 The position of the left edge. However, as Figure 12As shown by the dotted line, the position of the edge of the substrate W measured by the comparative example deviates from the actual position of the edge of the substrate W.

[0089] Subsequently, if the light B of the end effector 10 further moves in the horizontal direction ( Figure 12 As the light B moves along the positive X-axis, the amount of light received (light intensity) in the light-receiving section 14 further decreases. The light B of the end effector 10 further moves horizontally, and after the light B of the end effector 10 passes near the center position C of the substrate W, the amount of light received (light intensity) in the light-receiving section 14 gradually increases. During this period, the digital signal (V` out The signal remains at a low level. Subsequently, if the amount of light received (light intensity) in the light-receiving section 14 increases beyond a preset threshold, the digital signal (V`) will... out The signal transitions from low to high. This is achieved by calculating the digital signal (V`). out The position where the level changes from low to high (the value in the positive direction of the X-axis) allows for the measurement of the edge of the substrate W. Figure 12 The position of the right edge. However, as Figure 12 As shown by the dotted line, the position of the edge of the substrate W measured by the comparative example deviates from the actual position of the edge of the substrate W.

[0090] In addition, by calculating the digital signal (V`) out The center position of the substrate W can be measured by the distance between the position where the voltage level changes from high to low (value in the positive X-axis) and the position where the voltage level changes from low to high (value in the positive X-axis). However, as... Figure 12 As shown by the dotted line, the center position of the substrate W measured by the comparative example deviates from the actual center position C of the substrate W.

[0091] Thus, in the comparative example, the digital signal (V`) transmitted through an existing mapping sensor... out When measuring the position of substrate W in the horizontal direction, due to the threshold setting and hysteresis of the light sensor, the digital signal (V`) out The high and low levels of the signal deviate from the actual position of the substrate W, thus making it impossible to measure the position of the substrate W in the horizontal direction with high accuracy.

[0092] In contrast, in this embodiment, the analog signal V that is continuously varied in the light-receiving section 14 is used... out To measure the position of the substrate W in the horizontal direction. Specifically, if the light B of the end effector 10 is positioned relative to the substrate W in the horizontal direction ( Figure 12 If the light B of the end effector 10 moves along the positive direction of the X-axis, then the light B of the end effector 10 will be affected by the side surface of the substrate W (and the positive direction of the X-axis). Figure 12 The plane parallel to the Z-axis is blocked. If the light B from the end effector 10 reaches the edge of the substrate W (Figure 12 If the light source (on the left side) is affected, then from this moment onward, the amount of light received (the intensity of light) in the light-receiving section 14 begins to decrease. As a result, the analog signal (V...)... out The value begins to decrease from its maximum. This is achieved by calculating the analog signal (V). out Starting from the position where the value decreases (the value in the positive direction of the X-axis), it is possible to measure the edge of the substrate W. Figure 12 The position of the left edge. For example... Figure 12 As shown by the dashed line, compared to the comparative example, the measured position of the edge of the substrate W is a value close to the actual position of the edge of the substrate W.

[0093] Subsequently, if the light B of the end effector 10 further moves in the horizontal direction ( Figure 12 If the light source moves along the positive X-axis, the amount of light received (light intensity) in the light-receiving part 14 gradually decreases. As a result, the analog signal (V...)... out The signal gradually decreases from its maximum value. The light B from the end effector 10 moves further horizontally, and when the light B from the end effector 10 passes near the center position C of the substrate W, the analog signal (V) decreases. out The value becomes minimum. This is achieved by calculating the analog signal (V). out By reaching the position of minimum value (the value in the positive direction of the X-axis), the center position of substrate W can be measured. Compared with the comparative example, the measured center position of substrate W is a value closer to the actual center position C of substrate W. Figure 12 (The line shown by the dashed line).

[0094] Subsequently, if the light B of the end effector 10 further moves in the horizontal direction ( Figure 12 As the light-receiving part 14 moves along the positive X-axis, the amount of light received (light intensity) gradually increases. As a result, the analog signal (V...)... out The light B from the end effector 10 rises slowly. If it passes through the edge of the substrate W... Figure 12 (on the right edge), then the light B of the end effector 10 is no longer blocked by the substrate W, therefore the analog signal (V) out The value reaches its maximum again. This is achieved by calculating the analog signal (V). out When the value reaches its maximum (the value in the positive direction of the X-axis), the edge of the substrate W can be measured. Figure 12 The position of the right edge. Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 Figure 12 As shown by the dashed line, compared to the comparative example, the measured position of the edge of the substrate W is a value close to the actual position of the edge of the substrate W.

[0095] According to this embodiment, based on the analog signal V that continuously changes according to the amount of light received in the light-receiving section 14... outThe measurement waveform of the present embodiment can measure the position of the substrate W in the horizontal direction with higher accuracy than the conventional method (comparative example).

[0096] Furthermore, in the present embodiment, as a target, a disc-shaped substrate W housed in a FOUP is used, and the position of the substrate W in the horizontal direction is measured, but the present embodiment is not limited thereto. For example, the target can be a rod-shaped object.

[0097] Many modifications, other embodiments, of the present application will be apparent to those skilled in the art in view of this specification. Accordingly, the above description should not be construed as limiting, but merely as illustrative.

Claims

1. A substrate handling device, wherein the substrate handling device comprises: a base; a robot arm mounted to the base; an end effector provided at a front end of the robot arm and having a first front end portion and a second front end portion branched into two; a light emitting portion configured to emit light from the first front end portion toward the second front end portion; a light receiving portion configured to convert a detection light into a continuously varying output value according to a light receiving amount of the light traveling in a space between the first and second front end portions and incident to the second front end portion; and a control device that controls an operation of the robot arm, the control device is configured to: control the operation of the robot arm so that an edge of a plurality of substrates housed in a FOUP is scanned by the light traveling at a front end of the end effector, and compare a shape pattern of a measured waveform of the continuously varying output value at the light receiving portion with a shape pattern of a reference waveform for comparison according to a relative positional relationship between the light and the substrates in the operation of the robot arm, and diagnose at least one of a state of the substrates, a state of the FOUP, and a state of the end effector based on a comparison result, wherein the state of the substrates is whether or not a surface of the substrates is inclined, the state of the FOUP is whether or not the FOUP is inclined, the state of the end effector is whether or not the end effector is inclined.

2. The substrate handling device according to claim 1, wherein the control device is configured to: compare the shape pattern in one interval with the shape pattern in another interval in the measured waveform, and determine that a surface of the substrate in the one interval is inclined in a case where the shape pattern in the one interval is not consistent with the shape pattern in the other interval.

3. The substrate handling device according to claim 1, wherein the control device is configured to: compare the shape pattern of the measured waveform measured this time with the shape pattern of the measured waveform for comparison measured last time, and determine that a surface of the substrate in one interval is inclined in a case where the shape pattern in the one interval in the measured waveform measured this time is not consistent with the shape pattern in the one interval in the measured waveform for comparison measured last time.

4. The substrate handling device according to claim 1, wherein the control device is configured to: compare the shape pattern of the measured waveform measured this time with the shape pattern of the measured waveform for comparison measured last time, and determine that the FOUP is inclined in a case where the shape pattern in all intervals in the measured waveform is not consistent with the shape pattern in all intervals in the measured waveform for comparison.

5. The substrate handling device according to claim 1, wherein a plurality of FOUPs are arranged at different positions, the control device is configured to: compare the shape pattern of the measured waveform measured in one FOUP with the shape pattern of the measured waveform for comparison measured in another FOUP, ​ When the shape pattern in all of the sections of the measurement waveform measured this time is not consistent with the shape pattern in all of the sections of the comparison-use measurement waveform measured last time, it is determined that the end effector is tilted.

6. The substrate handling device according to claim 4, wherein the control device is configured to: compare the shape pattern of the measurement waveform measured this time with the shape pattern of the comparison-use measurement waveform measured last time in a state where the tilt of the FOUP is corrected, When the shape pattern in all of the sections of the measurement waveform measured this time is not consistent with the shape pattern in all of the sections of the comparison-use measurement waveform measured last time, it is determined that the end effector is tilted.

7. The substrate handling device according to claim 1, wherein the control device is configured to: compare the shape pattern of the measurement waveform measured this time with the shape pattern of the comparison-use measurement waveform measured last time, When the output value in all of the sections of the measurement waveform measured this time is lower than the output value in all of the sections of the comparison-use measurement waveform measured last time, it is determined that at least one of the intensity of the light from the light emitting section and the light receiving sensitivity of the light receiving section is reduced.

8. The substrate handling device according to any one of claims 1 to 7, wherein a display device that displays the diagnosis result is further provided.

9. A substrate handling device, wherein the substrate handling device is provided with: a base; a robot arm mounted to the base; an end effector provided at a front end of the robot arm and having a first front end section and a second front end section branched into two; a light emitting section configured to emit light from the first front end section toward the second front end section; a light receiving section configured to convert a detected light into a continuously changing output value according to a light receiving amount of the light that travels in a space between the first and second front end sections and is incident on the second front end section; and a control device that controls an operation of the robot arm, the control device is configured to: control the operation of the robot arm in such a manner that the light traveling at the front end of the end effector scans a target in a horizontal direction from an edge of the target to a center of the target with respect to the target, and measure a position of the target in the horizontal direction based on a relative positional relationship between the light and the target in the operation of the robot arm and on a measurement waveform of the continuously changing output value of the light receiving section.

10. The substrate handling device according to claim 9, wherein the position of the target is a position of the center or a position of the edge of the target in the horizontal direction.

11. The substrate handling device according to claim 9 or 10, wherein the target is a disc-shaped substrate housed in a FOUP. ​

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