Transport system and determination method

Abstract

To provide a transfer system and a method for determining positional misalignment that can prevent problems that may occur in an aligner device due to misalignment of a wafer.SOLUTION: A transfer system includes a robot, sensors (aligner sensor, protrusion detection sensor), and a controller. The robot includes a hand that supports the wafer and transfers it to the aligner device. The sensor detects the position of the wafer while it is supported by the hand before the robot delivers the wafer to the aligner device. The controller determines the positional deviation of the wafer on the basis of the detection value of the sensor.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present application relates primarily to a transfer system that uses a robot to transfer a wafer, and more particularly to a configuration that detects misalignment of a wafer during transfer. [Background technology]

[0002] Patent Document 1 discloses a transfer device for transferring substrates (wafers). The transfer device in Patent Document 1 includes a container, a transfer unit, and an alignment unit. The transfer unit removes the substrate stored in the container and transfers it to the alignment unit. The alignment unit places the substrate on a turntable, rotates it, and uses a sensor to detect the outer edge of the substrate, thereby determining how far away from the center of the turntable the substrate is placed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-211317 Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, if the substrate is significantly misaligned when the transport unit removes it, the substrate may not be placed properly in the alignment unit, or the substrate may collide with surrounding components when being placed in the alignment unit. Alternatively, even if the substrate can be placed in the alignment unit, the operation of rotating the substrate may fail, or the substrate may not be detected by the sensor. The present application has been made in view of the above circumstances, and its main object is to provide a transfer system that can prevent problems that may occur in an aligner device due to misalignment of a wafer. [Means for solving the problem]

[0005] The problem to be solved by the present application is as described above. Next, the means for solving this problem and the effects thereof will be explained.

[0006] According to a first aspect of the present application, there is provided a transfer system having the following configuration. That is, the transfer system includes a robot, a sensor, and a determination unit. The robot has a hand that supports the wafer and transfers it to an aligner device. The sensor detects the position of the wafer while the wafer is supported by the hand before the robot delivers the wafer to the aligner device. The determination unit determines the positional deviation of the wafer based on the detection value of the sensor.

[0007] According to a second aspect of the present application, there is provided the following determination method. That is, in the determination method, a positional misalignment of a wafer is determined while the wafer is being transported. The wafer is supported by a robot hand and transported to an aligner device. Before the robot delivers the wafer to the aligner device, a sensor is used to detect the position of the edge of the wafer while the wafer is supported by the hand. The positional misalignment of the wafer is determined based on the detection value of the sensor.

[0008] This allows the positional deviation of the wafer to be detected before the wafer is placed in the aligner device, thereby making it possible to prevent problems that may occur in the aligner device due to the positional deviation of the wafer. [Effects of the Invention]

[0009] According to the present application, it is possible to provide a transfer system that can prevent problems that may occur in an aligner device due to misalignment of a wafer. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a perspective view of a transport system according to an embodiment of the present application; [Figure 2] FIG. 1 is a block diagram of a transport system. [Figure 3]10 is a flowchart showing a process for determining a positional deviation of a wafer using an aligner sensor. [Figure 4] FIG. 10 is an explanatory diagram showing a situation in which a wafer misalignment is determined using an aligner sensor. [Figure 5] FIG. 10 is an explanatory diagram showing a method for correcting a target position of a wafer based on a positional deviation. [Figure 6] FIG. 10 is an explanatory diagram showing a situation in which the wafer positional deviation is so large that it cannot be detected by the aligner sensor. [Figure 7] 10 is a flowchart showing a process for determining a positional deviation of a wafer using a protrusion detection sensor. [Figure 8] FIG. 10 is an explanatory diagram showing a situation in which a positional deviation of a wafer is determined using a protrusion detection sensor. DETAILED DESCRIPTION OF THE INVENTION

[0011] Next, an embodiment of the present application will be described with reference to the drawings. Fig. 1 is a perspective view showing the configuration of a transport system 100.

[0012] 1 is a system for transporting a wafer 1, which is an object to be transported, in a working space such as a clean room. Specifically, the transport system 100 includes a robot 10 and a controller (determination unit) 19. The robot 10 of this embodiment takes out the wafer 1 stored in a storage unit 30 and transports it to an aligner device 20.

[0013] In this embodiment, the robot 10 is realized by a SCARA type horizontal articulated robot. SCARA is an abbreviation for Selective Compliance Assembly Robot Arm.

[0014] The wafer 1 carried by the robot 10 is a semiconductor wafer. The wafer 1 is formed in the shape of a circular thin plate. The wafer 1 may be a glass wafer instead of a semiconductor wafer.

[0015] As shown in FIG. 1, the robot 10 includes a base 11, an arm 12, and a hand 13.

[0016] The base 11 is fixed to the floor of a factory or the like, but is not limited to this, and the base 11 may be fixed to, for example, an appropriate processing facility.

[0017] 1, the arm 12 is attached to the base 11 via an elevation shaft 14 that is movable in the vertical direction. The arm 12 is rotatable about the elevation shaft 14.

[0018] The arm 12 is a horizontally articulated arm and includes a first arm 12a and a second arm 12b.

[0019] The first arm 12a is a long, slender member that extends horizontally in a straight line. One longitudinal end of the first arm 12a is attached to the upper end of the lift shaft 14. The first arm 12a is supported so as to be rotatable about the axis (vertical axis) of the lift shaft 14. The second arm 12b is attached to the other longitudinal end of the first arm 12a.

[0020] The second arm 12b is a long, slender member that extends horizontally in a straight line. One longitudinal end of the second arm 12b is attached to the tip of the first arm 12a. The second arm 12b is supported so as to be rotatable about an axis (vertical axis) that is parallel to the lift shaft 14.

[0021] The hand 13 is connected to the second arm 12b. The hand 13 is attached to the tip of the second arm 12b. The hand 13 is supported so as to be rotatable about an axis (vertical axis) parallel to the lift shaft 14. The hand 13 is driven to rotate by an appropriate actuator (not shown). This actuator is, for example, an electric motor.

[0022] The hand 13 of this embodiment is a passive grip type hand having a branched structure. The passive grip type is a configuration in which the wafer 1 placed on the hand 13 is not fixed. The tip of the hand 13 is branched into two, and the wafer 1 is placed at a location including the branch.

[0023] The hand 13 is not limited to an edge grip type. The hand 13 may be a suction type. The suction type is a configuration in which the surface of the wafer 1 is suctioned by negative pressure and transported (for example, a Bernoulli chuck). Alternatively, the hand 13 may be an edge grip type. The edge grip type is a configuration in which the wafer 1 is clamped and held using multiple guides provided on the hand 13.

[0024] In this embodiment, one hand 13 is provided on the arm 12. Alternatively, two or more hands 13 may be provided on the arm 12. For example, two hands 13 are provided on the tip of the second arm 12b of the arm 12. The two hands 13 are independently rotatable about a vertical axis. This allows the robot 10 to simultaneously transport, for example, two wafers 1.

[0025] The lifting shaft 14, the first arm 12a, and the second arm 12b are each driven by an actuator 15 shown in the block diagram of Fig. 2. The actuator 15 is, for example, an electric motor.

[0026] Encoders (not shown) that detect the rotational positions of the first arm 12a, the second arm 12b, and the hand 13 are attached to arm joints located between the lifting shaft 14 and the first arm 12a, between the first arm 12a and the second arm 12b, and between the second arm 12b and the hand 13. In addition, an encoder that detects a change in the position of the first arm 12a in the height direction (i.e., the amount of elevation of the lifting shaft 14) is also provided at an appropriate position on the robot 10.

[0027] The controller 19 includes a calculation device such as a CPU and a storage device such as a HDD, SSD, or flash memory. The calculation device controls the robot 10 by executing a program stored in the storage device. Specifically, the controller 19 sends command values ​​to the actuator 15 based on pre-registered work content, the detection results of the encoder, and the like. This causes the robot 10 to carry out the wafer 1 transport work. The controller 19 also controls the aligner device 20 (details will be described later).

[0028] In this embodiment, the controller 19 controls the robot 10 and the aligner device 20. Alternatively, the controller that controls the aligner device 20 and the controller that controls the robot 10 may be separate.

[0029] The aligner device 20 performs alignment by acquiring and adjusting the rotational phase of the wafer 1. The rotational phase is the orientation of the wafer 1 that changes as the wafer 1 rotates. A notch 1a is formed on the outer periphery of the wafer 1. The notch 1a indicates the crystal orientation of the semiconductor. If an orientation flat is formed on the wafer 1 instead of the notch 1a, the aligner device 20 may be configured to detect the orientation flat.

[0030] The aligner device 20 includes a rotating table 21, a motor 22, a mounting member 23, and an aligner sensor 24.

[0031] The turntable 21 is disk-shaped and is arranged to face the vertical direction. The wafer 1 is placed on the turntable 21 by the robot 10. The shape of the turntable 21 is not limited to a disk. The drive force of the motor 22 is transmitted to the turntable 21, causing it to rotate about the vertical direction as its center of rotation.

[0032] The mounting member 23 is fixed to an appropriate position in the factory, for example, to a member supporting the turntable 21 of the aligner device 20, a member supporting the storage unit 30, or the floor of the factory. A part of the aligner sensor 24 is attached to the mounting member 23.

[0033] The aligner sensor 24 is a line sensor and includes a light-projecting unit 24a and a light-receiving unit 24b. The aligner sensor 24 in this embodiment is a transmission-type light intensity detection sensor. Therefore, the light-projecting unit 24a and the light-receiving unit 24b are arranged with a gap between them in the vertical direction (thickness direction of the wafer 1) so as to sandwich the wafer 1. In this embodiment, the light-projecting unit 24a is on the lower side, but the light-projecting unit 24a may also be on the upper side.

[0034] The light-projecting unit 24a emits inspection light toward the light-receiving unit 24b. When the wafer 1 is located between the light-projecting unit 24a and the light-receiving unit 24b, the light-receiving unit 24b receives the inspection light that is partially blocked by the wafer 1. The light-receiving unit 24b transmits a current signal (or a voltage signal converted from the current signal) corresponding to the amount of received inspection light to the controller 19. While the notch 1a is located within the detection range of the aligner sensor 24, the amount of received inspection light increases. Therefore, based on the current signal output by the aligner sensor 24 (light-receiving unit 24b) and the rotational phase of the turntable 21, the controller 19 obtains the rotational phase of the notch 1a of the wafer 1 placed on the turntable 21. Thereafter, the aligner sensor 24, under the control of the controller 19, rotates the wafer 1 (turntable 21) so that the notch 1a faces a predetermined direction, thereby adjusting the rotational phase of the wafer 1.

[0035] The aligner sensor 24 is not limited to a light intensity detection sensor and may be a different sensor. For example, a CCD (Charge Coupled Device) sensor can be used as the aligner sensor 24. The CCD sensor detects the position of the edge of the wafer 1 and transmits the detected position to the controller 19. The edge of the wafer 1 refers to the radial end of the wafer 1 and the area nearby. By analyzing the detection result of the edge of the wafer 1 by the CCD sensor, it is possible to detect whether the notch 1 a is located within the detection range of the CCD sensor. Therefore, similar to when a light intensity detection sensor is used as the aligner sensor 24, the controller 19 can obtain the rotation phase of the notch 1 a of the wafer 1 placed on the turntable 21.

[0036] The accommodation unit 30 is a container that accommodates a plurality of wafers 1 arranged in the thickness direction. A storage space for accommodating the wafers 1 is formed in the accommodation unit 30. A plurality of wafer support portions are formed in the accommodation unit 30 for placing the edges of the wafers 1. The accommodation unit 30 may be a transportable container or a shelf fixed to the floor surface or the like.

[0037] A protrusion detection sensor 31 is attached to the accommodation unit 30. The protrusion detection sensor 31 is a sensor that detects whether or not the wafer 1 accommodated in the accommodation unit 30 protrudes from the accommodation space (whether or not the wafer 1 is located outside the accommodation space). The protrusion detection sensor 31 includes a light-projecting unit 31a and a light-receiving unit 31b. The light-projecting unit 31a and the light-receiving unit 31b are arranged at an interval in the vertical direction (the direction in which the wafers 1 are arranged). The light-projecting unit 31a emits inspection light toward the light-receiving unit 31b. When the wafer 1 is not located between the light-projecting unit 31a and the light-receiving unit 31b, the light-receiving unit 31b receives the inspection light. When the wafer 1 is located between the light-projecting unit 31a and the light-receiving unit 31b, the light-receiving unit 31b does not receive the inspection light. The light-receiving unit 31b transmits a signal indicating whether or not the inspection light has been received to the controller 19.

[0038] The robot 10 positions the hand 13 below the wafer 1 stored in the storage unit 30 and raises the hand 13 to remove and support the wafer 1. If the wafer 1 stored in the storage unit 30 is misaligned, or if the wafer 1 is misaligned when the hand 13 removes the wafer 1, the position of the wafer 1 supported by the hand 13 may be misaligned. In this case, the wafer 1 may not be centered on the turntable 21, potentially resulting in improper alignment. Alternatively, if the wafer 1 is significantly misaligned, the wafer 1 may collide with the mounting member 23. Therefore, in the transfer system 100 of this embodiment, the robot 10 detects the position of the wafer 1 while it is supported by the hand 13 before transferring the wafer 1 to the aligner device 20. The position of the wafer 1 can be detected using the aligner sensor 24 or the protrusion detection sensor 31. This will be described in detail below.

[0039] First, referring to Figures 3 to 6, we will explain the process of transporting the wafer 1 from the storage section 30 to the aligner device 20 while detecting the position of the wafer 1 using the aligner sensor 24 while the wafer 1 is supported by the hand 13.

[0040] The controller 19 uses the hand 13 to remove the wafer 1 accommodated in the accommodation unit 30 (S101). Next, while maintaining the state in which the hand 13 supports the wafer 1, the controller 19 moves the arm 12 to move the wafer 1 to the detection area 91 of the aligner sensor 24 (S102). As shown in FIG. 4, since the detection area 91 of the aligner sensor 24 is located near the turntable 21, the controller 19 moves the center of the hand 13 closer to the center of the turntable 21.

[0041] The light receiving portion 24b of the aligner sensor 24 transmits the above-mentioned current signal to the controller 19 at predetermined time intervals. Therefore, when the edge of the wafer 1 enters the detection area 91, the edge of the wafer 1 is detected multiple times while the wafer 1 is moving. The controller 19 determines whether the aligner sensor 24 has detected the wafer 1 (S103), and if the aligner sensor 24 has detected the wafer 1, calculates the positional deviation of the wafer 1 based on the multiple detection values ​​of the aligner sensor 24 (S104).

[0042] The positional deviation of the wafer 1 is the difference between the current position of the wafer 1 and the specified position of the wafer 1 (the position determined in the teaching of the robot 10, the position of the wafer 1 when the center of the hand 13 and the center of the wafer 1 are aligned). Specifically, the positional deviation is expressed by coordinate values ​​in a plane coordinate system. There are various methods for calculating the positional deviation of the wafer 1, but the following method can be used, for example.

[0043] That is, when the wafer 1 is at a specified position, how the detection value of the aligner sensor 24 changes depending on the position of the hand 13 is measured or estimated, and stored as a reference value. Then, depending on the position of the hand 13, the reference value is compared with the detection value actually detected by the aligner sensor 24. If the position of the wafer 1 is shifted in the front-to-back direction (the up-and-down direction in FIG. 4), the timing at which the aligner sensor 24 starts to detect the edge of the wafer 1 differs from the reference value. For example, if the position of the wafer 1 is forward of the specified position, the aligner sensor 24 detects the edge of the wafer 1 at a timing earlier than the reference value. Therefore, the positional deviation of the wafer 1 in the front-to-back direction can be calculated based on the timing at which the aligner sensor 24 starts to detect the edge of the wafer 1. Furthermore, if the position of the wafer 1 is shifted in the left-to-right direction (the left-to-right direction in FIG. 4), the minimum detection value of the aligner sensor 24 differs from the reference value. For example, if the position of the wafer 1 is shifted to the left of the specified position, the area that the wafer 1 blocks in the detection area 91 becomes smaller, and the minimum detection value of the aligner sensor 24 becomes larger. Therefore, the left-right positional deviation of the wafer 1 can be calculated based on the minimum value of the detection value of the aligner sensor 24. In this way, the controller 19 can calculate the front-rear and left-right positional deviation of the wafer 1.

[0044] Furthermore, when a CCD sensor is used as the aligner sensor 24, the position of the edge of the wafer 1 can be specifically identified based on the detection result of the edge of the wafer 1 by the CCD sensor. Therefore, even when a CCD sensor is used as the aligner sensor 24, the positional deviation of the wafer 1 can be calculated based on the detection value of the aligner sensor 24.

[0045] Next, the controller 19 determines whether the positional deviation of the wafer 1 calculated in step S104 is equal to or less than a tolerance (S105). The tolerance is set, for example, to a value within a range in which the wafer 1 does not collide with the mounting member 23 or the like when the hand 13 places the wafer 1 on the turntable 21. In other words, if the positional deviation of the wafer 1 is equal to or less than the tolerance, the hand 13 can properly perform the task of placing the wafer 1 on the turntable 21. The tolerance may be set separately for the front-rear direction and the left-right direction. Alternatively, the tolerance may be set for the distance from the wafer 1 in a specified position to the actual wafer 1.

[0046] If the positional deviation of the wafer 1 is within the tolerance, the controller 19 corrects the target position based on the positional deviation and places the wafer 1 on the turntable 21 of the aligner device 20 (S106). Specifically, as shown in Fig. 5, the controller 19 places the wafer 1 at a corrected target position obtained by moving the target position in the opposite direction to the positional deviation and by the same length as the positional deviation so as to cancel out the effect of the positional deviation. Thereafter, the controller 19 repeats the processes from step S101 onwards.

[0047] Furthermore, if the positional deviation exceeds the allowable value, the controller 19 corrects the holding position of the wafer 1 by the hand 13 (S109). Specifically, the controller 19 places the wafer 1 in another location (for example, the storage section 30) and then removes the wafer 1 again, thereby correcting the holding position of the wafer 1 by the hand 13. Instead of correcting the holding position of the wafer 1, an error may be reported and the operation may be stopped.

[0048] 6, if the position of the wafer 1 is significantly deviated to the opposite side of the detection area 91, the wafer 1 may not be detected by the detection area 91. In such a situation, the controller 19 performs the following process to prevent a collision between the wafer 1 and the mounting member 23. That is, if the aligner sensor 24 determines in step S103 that it has not detected the wafer 1, the controller 19 moves the hand 13 to move the wafer 1 (S107) and determines whether the hand 13 has reached a limit position (S108). The limit position is a position where a collision between the wafer 1 and the mounting member 23 cannot occur. In other words, if the hand 13 moves forward beyond the limit position, the wafer 1 may come into contact with the mounting member 23. Therefore, if the hand 13 has reached the limit position, the controller 19 determines that the positional deviation of the wafer 1 exceeds the allowable value and corrects the holding position of the wafer 1 as described above (S109). Note that if there is a possibility that the wafer 1 may collide with an object other than the mounting member 23, the limit position is set taking the position of the object into further consideration.

[0049] By carrying out the above process, it is possible to prevent the wafer 1 from colliding with the mounting member 23 or the like, correct the positional deviation of the wafer 1, and continue the work of transporting the wafer 1.

[0050] Next, with reference to Figures 7 and 8, we will explain the process of transporting the wafer 1 from the storage section 30 to the aligner device 20 while detecting the position of the wafer 1 using the protrusion detection sensor 31 while the wafer 1 is supported by the hand 13.

[0051] The controller 19 uses the hand 13 to remove the wafer 1 accommodated in the accommodation unit 30 (S201). Next, the controller 19 moves the hand 13 in a direction away from the accommodation unit 30 (first direction, backward) to a position where the protrusion detection sensor 31 detects the edge of the wafer 1 (S202). Specifically, immediately after the hand 13 is moved in the first direction, the detection area 92 of the protrusion detection sensor 31 overlaps with the wafer 1 (upper left in FIG. 8). Then, as the hand 13 is moved in the first direction, the detection area 92 no longer overlaps with the wafer 1 (upper right in FIG. 8). In other words, the protrusion detection sensor 31 can detect the edge of the wafer 1 based on the transition from a state in which the protrusion detection sensor 31 detects the wafer 1 to a state in which the protrusion detection sensor 31 no longer detects the wafer 1. The position of the hand 13 at this time is referred to as the first position.

[0052] Next, the controller 19 moves the hand 13 a predetermined length in a direction different from the first direction (a second direction, a direction perpendicular to the first direction, specifically either left or right) (S203, from the upper right in FIG. 8 to the lower left in FIG. 8). Next, the controller 19 moves the hand 13 in a third direction (forward, the opposite direction to the first direction) approaching the storage unit 30 until the protrusion detection sensor 31 detects the edge of the wafer 1 again (S204, from the lower left to the lower right in FIG. 8). The position of the hand 13 when the protrusion detection sensor 31 detects the edge of the wafer 1 again is referred to as the second position. The positional deviation of the wafer 1 can also be calculated by the above-mentioned method using another sensor arranged outside the storage unit 30.

[0053] Next, the controller 19 calculates the positional deviation of the wafer 1 based on the position (two positions in this embodiment) of the hand 13 when the protrusion detection sensor 31 detects the edge of the wafer 1 (S205). Specifically, when the wafer 1 is in a specified position, the first position and the second position are stored in advance as a first reference position and a second reference position. Then, the positional deviation of the wafer 1 can be calculated by comparing the first reference position with the actual first position, and the second reference position with the actual second position.

[0054] The subsequent processing is the same as when the aligner sensor 24 is used as the sensor. That is, if it is determined that the positional deviation is equal to or less than the tolerance (S206), the target position is corrected based on the positional deviation, and the wafer 1 is placed on the turntable 21 (S207). On the other hand, if it is determined that the positional deviation exceeds the tolerance (S206), the holding position of the wafer 1 by the hand 13 is corrected (S208).

[0055] As described above, the transfer system 100 of this embodiment includes the robot 10, sensors (the aligner sensor 24, the protrusion detection sensor 31), and the controller 19. The robot 10 has the hand 13 that supports the wafer 1 and transfers it to the aligner device 20. The sensor detects the position of the wafer 1 while the wafer 1 is supported by the hand 13, before the robot 10 delivers the wafer 1 to the aligner device 20. The controller 19 determines the positional deviation of the wafer 1 based on the detection value of the sensor.

[0056] As a result, any misalignment of the wafer 1 is detected before the wafer 1 is placed on the aligner device 20, and problems that may occur in the aligner device 20 due to the misalignment of the wafer 1 can be prevented in advance.

[0057] In the transfer system 100 of this embodiment, the controller 19 determines whether the positional deviation of the wafer 1 is within the allowable value based on the detection value of the sensor. If the controller 19 determines that the positional deviation of the wafer 1 is within the allowable value, the robot 10 continues to transfer the wafer 1 to the aligner device 20.

[0058] This allows the operator to confirm that there is no or only a slight positional deviation of the wafer 1, and then continue the work.

[0059] In the transport system 100 of this embodiment, if the controller 19 determines that the positional deviation of the wafer 1 is within the allowable value, the robot 10 places the wafer 1 at a corrected target position, which is a target position for transporting the wafer 1 that has been corrected based on the positional deviation of the wafer 1.

[0060] This allows the aligner device to perform alignment more accurately.

[0061] In the transfer system 100 of this embodiment, when the controller 19 determines that the positional deviation of the wafer 1 exceeds the allowable value, the robot 10 stops transferring the wafer 1 to the aligner device 20.

[0062] This makes it possible to prevent problems that may occur in the aligner device 20 due to misalignment of the wafer 1.

[0063] In the transfer system 100 of this embodiment, the sensor is an aligner sensor 24 that detects the wafer 1 when the aligner device 20 aligns the wafer 1.

[0064] This makes it possible to detect the positional deviation of the wafer 1 before placing the wafer 1 on the aligner device 20 without adding a new sensor. Also, it is possible to detect the positional deviation of the wafer 1 immediately before placing it on the aligner device 20.

[0065] In the transfer system 100 of this embodiment, the aligner sensor 24 is a light intensity detection sensor including a light projector 24a and a light receiver 24b. The light projector 24a emits inspection light. The light receiver 24b receives the inspection light that is partially blocked by the wafer 1 and outputs a value corresponding to the light intensity. While the hand 13 is moving the wafer 1, the aligner sensor 24 detects the wafer 1 multiple times. Note that the aligner sensor 24 may be configured so that the light receiver 24b receives the inspection light reflected by the wafer 1.

[0066] This allows the light intensity detection sensor to detect misalignment of the wafer 1 before placing the wafer 1 on the aligner device 20. Furthermore, by the aligner sensor 24 detecting the wafer 1 multiple times, the misalignment of the wafer 1 can be detected in detail.

[0067] In the transfer system 100 of this embodiment, the aligner sensor 24 may be a CCD sensor that detects the position of the edge of the wafer 1.

[0068] This allows the positional deviation of the wafer 1 to be detected using the CCD sensor before the wafer 1 is placed on the aligner device 20.

[0069] In the transfer system 100 of this embodiment, the hand 13 takes out the wafer 1 stored in the storage unit 30 and transfers the wafer 1 to the aligner device 20. The sensor is a protrusion detection sensor 31 that detects whether the wafer 1 protrudes from the storage space of the storage unit 30.

[0070] This makes it possible to detect the positional deviation of the wafer 1 without adding a new sensor before the wafer 1 is placed on the aligner device 20. Furthermore, the positional deviation of the wafer 1 can be detected at an early stage.

[0071] In the transfer system 100 of this embodiment, the sensor includes a light-projecting unit 31a and a light-receiving unit 31b, and detects whether the wafer 1 is present between the light-projecting unit 31a and the light-receiving unit 31b based on whether the inspection light projected by the light-projecting unit 31a is received by the light-receiving unit 31b. The controller 19 obtains multiple positions of the hand 13 when the edge of the wafer 1 is detected, and determines the positional deviation of the wafer 1 based on the multiple positions of the hand 13.

[0072] This makes it possible to detect misalignment of the wafer 1 before placing the wafer 1 on the aligner device 20 using a sensor that determines whether or not an object is present between the light projecting unit 31a and the light receiving unit 31b.

[0073] In the transfer system 100 of this embodiment, the hand 13 is of a passive grip type that places the wafer 1 on the hand 13 and transfers it without holding the edge. The hand 13 may also be of a suction type that transfers the wafer 1 by suctioning the surface of the wafer 1 with negative pressure.

[0074] The passive grip type or suction type hand 13 has a simple configuration, but is characterized by the tendency for the wafer 1 to be easily misaligned. By providing the configuration of this embodiment, the tendency for the wafer 1 to be easily misaligned can be improved.

[0075] The preferred embodiment of the present application has been described above, but the above configuration can be modified, for example, as follows.

[0076] The flowcharts shown in the above embodiments are merely examples, and some processes may be omitted, the contents of some processes may be changed, or new processes may be added.

[0077] In the above embodiment, an optical sensor is used as the protrusion detection sensor 31, but the sensor is not limited to an optical sensor and may be, for example, an image sensor.

[0078] Instead of a configuration in which the base 11 is installed on the floor surface of the factory, the base 11 may be installed on the ceiling surface (ceiling-suspended type).

[0079] The functions of the elements disclosed herein can be performed using circuits or processing circuitry, including general-purpose processors, special-purpose processors, integrated circuits, ASICs (Application Specific Integrated Circuits), conventional circuits, and / or combinations thereof, configured or programmed to perform the disclosed functions. A processor is considered a processing circuit or circuitry because it includes transistors and other circuitry. In this disclosure, a circuit, unit, or means is hardware that performs the recited functions or hardware that is programmed to perform the recited functions. The hardware may be hardware disclosed herein or other known hardware that is programmed or configured to perform the recited functions. Where the hardware is a processor, which is considered a type of circuit, the circuit, means, or unit is a combination of hardware and software, and the software is used to configure the hardware and / or processor.

Claims

1. In a transfer system for transferring a wafer, a robot having a hand that supports the wafer and transports it to an aligner device; a sensor for detecting the position of the wafer while the wafer is supported by the hand before the robot transfers the wafer to the aligner device; a determination unit that determines a positional deviation of the wafer based on a detection value of the sensor; A transport system comprising:

2. 2. The transport system according to claim 1, the determining unit determines whether or not the positional deviation of the wafer is equal to or less than a tolerance based on the detection value of the sensor; A transfer system, characterized in that, when the determination unit determines that the positional deviation of the wafer is equal to or less than a tolerance, the robot continues to transfer the wafer to the aligner device.

3. 3. The transport system according to claim 2, When the determination unit determines that the positional misalignment of the wafer is within an allowable value, the robot places the wafer at a corrected target position, which is a target position for transporting the wafer that has been corrected based on the positional misalignment of the wafer.

4. 4. The transport system according to claim 2 or 3, A transfer system, characterized in that, when the determining unit determines that the positional deviation of the wafer exceeds an allowable value, the robot suspends the transfer of the wafer to the aligner device.

5. A transport system according to any one of claims 1 to 4, The transfer system is characterized in that the sensor is an aligner sensor that detects the wafer when the aligner device aligns the wafer.

6. 6. The transport system according to claim 5, The aligner sensor a light projecting unit that projects inspection light; a light receiving unit that receives the inspection light reflected by the wafer or the inspection light that is partially blocked by the wafer and outputs a value corresponding to the amount of light; A light amount detection sensor comprising: a transfer system in which the aligner sensor detects the wafer multiple times while the hand is moving the wafer;

7. 6. The transport system according to claim 5, The transfer system is characterized in that the aligner sensor is a CCD sensor that detects the position of the edge of the wafer.

8. A transport system according to any one of claims 1 to 7, the hand takes out the wafer accommodated in the accommodation unit and transports the wafer to an aligner device; The transfer system is characterized in that the sensor is a protrusion detection sensor that detects whether or not the wafer protrudes from the accommodation space of the accommodation part.

9. A transport system according to any one of claims 1 to 5, the sensor includes a light-projecting unit and a light-receiving unit, and detects whether the wafer is present between the light-projecting unit and the light-receiving unit based on whether the inspection light projected by the light-projecting unit is received by the light-receiving unit; The transfer system is characterized in that the determination unit obtains multiple positions of the hand when the sensor detects the edge of the wafer, and determines the positional misalignment of the wafer based on the multiple positions of the hand.

10. A transport system according to any one of claims 1 to 9, The transfer system is characterized in that the hand is either a passive grip type that places the wafer on the hand and transfers it without holding the edge, or an adsorption type that transfers the wafer by adsorbing the surface of the wafer with negative pressure.

11. A method for determining a positional misalignment of a wafer during wafer transfer, comprising: Using a robot hand, the wafer is supported and transported to an aligner device; before the robot transfers the wafer to the aligner device, the position of the edge of the wafer is detected using a sensor while the wafer is supported by the hand; a determining method for determining the positional deviation of the wafer based on the detection value of the sensor;

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