JP2011091072A - Diagnosis method of semiconductor wafer conveying device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve a device operating rate by detecting a sign of failure during normal operation and optimizing a checkout time without adding a new hardware on a wafer conveying device, especially on an arm part having high risk of failure. <P>SOLUTION: The semiconductor wafer conveying device includes: a robot, which is provided with an arm part having a link mechanism including a belt and pulley and converting rotational movement of a motor into linear movement, and a hand part for holding a wafer, and which conveys the wafer; a motor control part provided with a rotating position detection part for detecting a rotating position of the motor; and a hand part position detection part for detecting passing of the hand part. In the diagnosis method of the semiconductor wafer conveying device, the rotating position when the hand part is detected by the hand part position detection part is recorded and deterioration of the belt is detected based on an amount of change of the rotating position. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a diagnostic method for a semiconductor wafer transfer apparatus.

  The semiconductor wafer transfer apparatus takes out a wafer from a wafer storage container (hereinafter abbreviated as FOUP) supplied from the outside of the apparatus, supplies the semiconductor wafer to the semiconductor manufacturing apparatus, and takes out the wafer discharged from the semiconductor manufacturing apparatus. Store.

  In semiconductor factories, improvement of device operation rate and reduction of maintenance time are important issues for increasing production efficiency. In addition, an unexpected failure of the device affects the schedule of the entire semiconductor factory and causes a reduction in production efficiency.

  In general, a semiconductor wafer transfer apparatus performs wafer transfer by extending and contracting an arm, and the arm is always movable, so that the risk of arm failure is high. As a means to prevent this, it is effective to check the components for wear, deterioration, etc. and repair them in advance. Generally, however, the mechanism of the device is covered with a cover, etc., and cannot be visually checked during normal operation. State.

  Therefore, inspection work such as stopping the apparatus and disassembling the apparatus in some cases is required. In order not to lower the operating rate of the equipment, it is effective to operate the equipment until just before the occurrence of the failure as much as possible, and to take a long inspection cycle. There is only a method for calculating the inspection cycle in consideration of the life and the like, and it is difficult to optimize the inspection cycle. For this reason, the inspection work is wasted, which hinders the improvement of the apparatus operating rate.

  On the other hand, a method of optimizing the inspection time by detecting a sign of failure from the deviation of the arm stop accuracy can be considered. Specifically, a method of photographing with a camera and detecting a positional deviation by image processing, a method of detecting a stop positional deviation by installing an optical sensor or the like at the movement destination of the arm, and the like can be considered.

  However, the occurrence of a deviation at the stop position is already a failure state, and even if this is detected, preventive maintenance is not achieved. In addition, these methods have disadvantages such as requiring new hardware for detecting misregistration and increasing costs, or requiring dedicated operations for detecting misregistration. .

  Patent Document 1 discloses a substrate processing apparatus that performs exposure processing on a substrate to be processed and processing by supplying a resist solution to the substrate to be processed and / or supplying developer to the substrate to be processed. A transfer mechanism disposed between the resist processing apparatus and substantially transferring the target substrate between the exposure processing apparatus and the resist processing apparatus; and a target substrate processed by the exposure processing apparatus. A heating mechanism that performs a heat treatment at a predetermined temperature, a signal that passes signals to and from the exposure processing apparatus and the resist processing apparatus, and is substantially controlled by a control device on the exposure processing apparatus side. A substrate processing apparatus in which the atmospheric pressure in the substrate processing apparatus is set to an atmospheric pressure in the resist processing apparatus and / or an atmospheric pressure lower than an atmospheric pressure in the exposure processing apparatus. There has been disclosed.

  Japanese Patent Application Laid-Open No. 2004-228561 is a transfer device that includes a slide member and a holding member that sucks and holds a wafer on a base that can change direction at least, and transfers a wafer from one object to another. Thus, there is disclosed a wafer transfer apparatus characterized in that a part of the transfer apparatus is provided with detection / detection means for detecting / detecting a positional relationship with each object to which a wafer is transferred.

  In Patent Document 3, a rotary drive member that is rotatably provided around a predetermined rotation axis, a drive source that rotates the rotary drive member, and a rope that is wound around the rotary drive member and on which a driving object is mounted. An extension amount detection device for detecting an extension amount of a striated body of a drive device including a body, which is set in an angular displacement position detection means for detecting an angular displacement position of a rotary drive member, and a movement path of a drive object. An arrangement state detecting means for detecting that the driving object is arranged at the reference position, an angular displacement position at a time when the driving object is arranged at the reference position, and a predetermined period from the present time. In addition, there is disclosed an elongation amount detection apparatus including a calculation unit that compares an angular displacement position in a state in which a driving object is disposed at a reference position at a past time point.

JP 2006-287181 A Japanese Patent Laid-Open No. 2002-9134 JP 2005-233384 A

  In general, the arm of a semiconductor wafer transfer device (hereinafter also referred to as a wafer transfer device or transfer device) is a link mechanism using a belt and a pulley, and the main cause of failure is caused by belt deterioration (elongation). The pulley slips against the belt to run or the belt runs out. The deterioration (elongation) of the belt gradually deteriorates over time and the number of operations. However, the belt stopping accuracy is not affected before the pulley slips against the belt. It was not possible to detect deterioration (elongation).

  An object of the present invention is to detect a sign of failure during normal operation of a semiconductor wafer transfer device, particularly an arm portion with a high risk of failure, to optimize the inspection time, and to improve the operation rate of the device.

  The method for diagnosing a semiconductor wafer transfer apparatus according to the present invention includes a belt and a pulley, and includes an arm portion having a link mechanism for converting the rotational motion of the motor into a linear motion, and a hand portion for gripping the wafer, Semiconductor wafer transfer apparatus including a robot for transferring a wafer, a motor control unit including a rotation position detection unit for detecting the rotation position of the motor, and a hand unit position detection unit for detecting passage of the hand unit The rotation method when the hand unit is detected by the hand unit position detection unit is recorded, and deterioration of the belt is detected based on a change amount of the rotation position. To do.

  According to the present invention, it is possible to grasp the degree of belt degradation, which is the main cause of arm failure, during normal wafer transfer operation.

  In addition, according to the present invention, the inspection time can be optimized, and the production efficiency of the semiconductor factory can be increased by improving the apparatus operating rate.

It is an external appearance perspective view which shows the mini environment system which is one Example of this invention. It is a perspective view which shows the robot installed in the inside of the mini-environment system of FIG. It is a block diagram which shows the sensor, control part, etc. of the mini-environment system of FIG. It is a block diagram which shows the electrical components, control part, etc. of the robot arm of FIG. It is a perspective view which shows FOUP of FIG. It is a schematic sectional drawing which shows the open state of FOUP in the load port of FIG. It is a schematic sectional drawing which shows the closing operation of FOUP in the load port of FIG. It is a schematic sectional drawing which shows the closed state of FOUP in the load port of FIG. It is a schematic sectional drawing which shows the state which the wafer protruded from FOUP of FIG. FIG. 5 is a top view showing a wafer take-out operation by the robot arm of FIG. 4. FIG. 7B is a schematic side view showing a wafer take-out operation by the robot arm of FIG. 7A. FIG. 5 is a top view showing a wafer take-out operation by the robot arm of FIG. 4. FIG. 7B is a schematic side view showing a wafer take-out operation by the robot arm of FIG. 7C. FIG. 7B is a schematic side view showing a wafer take-out operation by the robot arm of FIG. 7C. It is a flowchart which shows the teaching procedure of the robot arm of FIG. It is a schematic block diagram which shows the internal register of the motor control part of FIG. FIG. 4 is a schematic configuration diagram showing a data arrangement of an internal memory in FIG. 3. FIG. 5 is a schematic configuration diagram illustrating a wafer transfer operation by the robot arm of FIG. 4. It is a flowchart which shows the calibration procedure of the robot arm of FIG. It is a graph which shows the process in which the belt of the robot arm of FIG. 4 deteriorates. It is a flowchart which shows the procedure which detects degradation of the belt of the robot arm shown in FIG.

  The present invention relates to a method for diagnosing an arm portion in a wafer transfer apparatus in the semiconductor process field.

  An object of the present invention is to detect a sign of failure during normal operation and optimize the inspection time without adding new hardware to a semiconductor wafer transfer device, particularly an arm portion having a high risk of failure. Thus, the apparatus operating rate is improved.

  In the present invention, paying attention to the fact that the arm extension operation is delayed with respect to the rotation of the drive motor due to belt deterioration (elongation) of the arm portion having a high risk of failure, a sensor for detecting the wafer jump that is a standard component of the wafer transfer device The rotation position of the arm drive motor at the time when the hand attached to the arm passes is measured, and the belt deterioration of the arm is detected based on the amount of change in the rotation position. The measurement of the rotational position may be performed for each transport operation or may be performed once for several to several tens of transport operations.

  Hereinafter, a semiconductor wafer transfer apparatus diagnosis method and a semiconductor wafer transfer apparatus according to an embodiment of the present invention will be described.

  In the diagnostic method of the semiconductor wafer transfer apparatus, it is desirable to record the rotational position for each transfer operation.

  In the method for diagnosing the semiconductor wafer transfer apparatus, it is preferable that a warning is displayed on a display unit or a warning signal is transmitted to a semiconductor manufacturing apparatus which is a host device when the deterioration of the belt is detected.

  In the method for diagnosing the semiconductor wafer transfer device, it is preferable that the time series data of the change amount is stored and used for investigation and analysis.

  The semiconductor wafer transfer device includes a belt and a pulley, and includes an arm unit having a link mechanism for converting the rotational motion of the motor into a linear motion, and a hand unit for gripping the wafer, and a robot for transporting the wafer And a semiconductor wafer transfer device including a motor control unit including a rotation position detection unit for detecting the rotation position of the motor, the hand unit position detection unit for detecting passage of the hand unit, And a recording unit that records the rotational position when the hand unit is detected by the hand unit position detection unit.

  The semiconductor wafer transfer device preferably includes a determination unit that determines that the rotational position has reached a threshold value.

  Whether the semiconductor wafer transfer device stops the operation of the robot immediately when the determination unit determines that the rotational position has reached the threshold value, or performs only the warning and continues the operation of the robot It is desirable to be able to select.

  The semiconductor wafer transfer device is preferably a wafer pop-out sensor installed in the load port by the hand unit position detection unit.

  The semiconductor wafer transfer device is preferably an encoder in which the rotational position detector is connected to the motor.

  Hereinafter, specific embodiments will be described with reference to the drawings.

  FIG. 1 is an external perspective view showing a mini-environment system (hereinafter abbreviated as mini-ene) which is an embodiment of the present invention.

  FIG. 2 is a perspective view showing a robot installed in the mini-environment system of FIG.

  FIG. 3 is a configuration diagram illustrating sensors, a control unit, and the like of the mini-environment system of FIG.

  In the transfer apparatus that supplies the wafer 106 to the semiconductor manufacturing apparatus 100 and discharges the wafer 106 processed or inspected by the semiconductor manufacturing apparatus 100 from the semiconductor manufacturing apparatus 100, the facility for transferring the wafer 106 under a local clean condition is installed in the mini-engine. 101.

  The mini-en 101 includes a connection with the semiconductor manufacturing apparatus 100, a mini-en housing 102, a load port unit 103, a fan filter unit 105 (hereinafter abbreviated as FFU), and a panel 107 (display unit). The robot 200 shown in FIG. 2, the controller 300 shown in FIG. 3, the pre-aligner 311, the external memory 312, and the teaching pendant 313 are included.

  The semiconductor manufacturing apparatus 100 is positioned as an upper apparatus of the mini-en 101, and transmits commands and responses to the mini-en 101 using communication means such as RS-232C and Ethernet (registered trademark) and parallel input / output signals. Processing or inspection of the supplied wafer 106 is performed.

  The mini-en housing 102 covers the outside of the system with a fixed plate (exterior cover), supplies a transfer chamber that is a space isolated from the outside, and has a role of a joint with the load port unit 103, the semiconductor manufacturing apparatus 100, and the like.

  The load port 103 has a fixed base for fixing the FOUP 104 (openable / closable sealed container (wafer storage container)) and a FOUP opening / closing mechanism. The load port 103 is joined to the mini-en housing 102 at a single location or a plurality of locations. The wafer 106 is supplied to the manufacturing apparatus 100 and the mini-en housing 102.

  The panel 107 has a touch panel, a liquid crystal screen, a switch, and the like, and has a display function and an operation function. As will be described later, the panel 107 serves as an assistant for an operator and an interface for external operation. Further, the panel 107 may have a role as a teaching pendant 313 that can be removed depending on the system configuration.

  As shown in FIG. 2, the robot 200 is installed inside the mini-en housing 102. The arms 203 and 204 (also referred to as arm portions) are of a double arm type, and can transfer two wafers 106 at the same time. A travel axis drive unit 201 that travels in the lateral direction (horizontal operation) and a lift axis drive unit that moves the arms 203 and 204 in the up and down direction (up and down operation) by driving the travel axis motor 202 (servo motor). 205, a swing axis drive unit 206 that moves (rotates) the arms 203 and 204 in the rotational direction, and an arm horizontal drive unit 207 and 208 that moves the arms 203 and 204 in the extendable direction (horizontal operation). is doing.

  The arms 203 and 204 of the robot 200 are joined to hands 209 and 210 (also referred to as hand units) as manipulators, respectively, and have a wafer handling mechanism for placing the wafer 106 thereon.

  The wafer handling mechanism of the robot 200 has a function of gripping the back surface of the wafer 106 by vacuum suction, but may be a side surface grasping function of gripping the side surface of the wafer 106.

  The robot 200 moves the wafer 106 to each teaching point in the mini-en housing 102 such as the semiconductor manufacturing apparatus 100, the load port 103, and the pre-aligner 311 (shown in FIG. 3) by the above-described 5-axis drive unit and wafer handling mechanism. Transport.

  The robot 200 may be a single arm type as long as it can transfer the wafer 106.

  In FIG. 3, the pre-aligner 311 is placed on the wafer 106 by the robot 200 before the wafer 106 is supplied to the semiconductor manufacturing apparatus 100, and the notch or orientation flat is aligned in a certain direction by rotating the wafer 106. It has an alignment mechanism that measures the amount of eccentricity.

  The external memory 312 is a portable external auxiliary storage device such as a USB memory, an SD card, a memory stick, or a CF card, and may be arbitrary depending on the system.

  The teaching pendant 313 is a pendant for teaching the transfer position (teaching point) of the wafer 106 in the mini-en housing 102 to the robot 200.

  The controller 300 includes a central processing unit 301, a host device interface 302 (in the drawing, the interface is abbreviated as I / F), an internal memory 303, a robot input / output signal interface 304, various device interfaces 305, and a drive control unit. 320 and a motor control unit 306.

  The central processing unit 301 is connected to the host device interface 302, the internal memory 303, the robot input / output signal interface 304, the various device interfaces 305, the motor control unit 306, and the like via the system bus 309, and receives commands from the semiconductor manufacturing apparatus 100. It has a function of controlling all devices mounted on the mini-en 101 by a command or an external operation from the panel 107 or the teaching pendant 313.

  The central processing unit 301 is a central processing unit (hereinafter abbreviated as “CPU”) having a microprocessor unit (hereinafter abbreviated as “MPU”) and various memories, but is a general personal computer. (Hereinafter abbreviated as “PC”) or a CPU board or the like, which is suitable for the system.

  The host device interface 302 has communication means for communicating with the semiconductor manufacturing apparatus 100 using Ethernet, RS-232C, or the like, and an interface circuit for performing digital or analog input / output signals. It has a function of transmitting command commands, data, input / output signals, and the like between the manufacturing apparatus 100 and the central processing unit 301.

  The internal memory 303 includes a volatile memory, a nonvolatile memory, an interface circuit thereof, a circuit for transferring to the external memory 312 and the like, and is mainly a circuit in which a plurality of large-capacity nonvolatile memories are mounted. It is configured.

  Teaching data 410 (shown in FIG. 4) is stored in the nonvolatile memory of the built-in memory 303.

  FIG. 10 shows the contents of teaching data.

  Hereinafter, the arms 203 and 204 are referred to as a first arm and a second arm, respectively.

  With respect to the FOUP 104, the pre-aligner 311 and the semiconductor manufacturing apparatus 100, the wafer removal standby position 1001 on the traveling axis, the wafer removal standby position 1002 on the pivot axis, the wafer removal standby position 1003 on the lift axis, and the wafer removal standby on the first arm axis, respectively. Position 1004, second arm axis wafer extraction standby position 1005, travel axis wafer extraction position 1006, pivot axis wafer extraction position 1007, lift axis wafer extraction position 1008, first arm axis wafer extraction position 1009, second axis Wafer extraction position 1010 on the arm axis, wafer handling position 1011 on the traveling axis, wafer handling position 1012 on the pivot axis, wafer handling position 1013 on the lift axis, and wafer handling position 10 on the first arm axis 4, and registers store wafer handling position 1015 of the second arm axis.

  The robot input / output signal interface 304 includes interface circuits such as various sensors 335 and electromagnetic valves 336 inside the robot 200 and other devices mounted inside the robot 200.

  The various sensors 335 are a pressure sensor for confirming the vacuum pressure mounted in the robot 200, an origin sensor for each axis, a ± limit sensor, a reflective or transmissive sensor for confirming the presence of a wafer, and the like.

  The various device interfaces 305 have interface circuits for various external peripheral devices such as the load port unit 103, FFU 105, pre-aligner 311, panel 107, external memory 312, teaching pendant 313, etc. Through 309, communication with each device and control of input / output signals are performed.

  The drive control unit 320 includes a servo amplifier 321 that controls the first arm axis motor 331, a servo amplifier 322 that controls the second arm axis motor 332, and a servo amplifier 323 that controls the turning axis motor 333. And a servo amplifier 324 for controlling the lifting axis motor 334 and a servo amplifier 325 for controlling the traveling axis motor 202. Here, the motor is a servo motor. Each servo motor or servo amplifier may be a general-purpose one suitable for the system or mechanism, and may be an AC servo or a DC servo, or a semi-closed loop stepping motor.

  The motor control unit 306 transmits / receives commands and data to / from the central processing unit 301 via the system bus 309 and outputs various output signals according to purposes such as command pulse output for operating an arbitrary axis of the drive control unit 320. 308 and various input signals 307 such as an encoder input of motor rotation position information of each axis, and has a function of controlling the movement of the robot 200. Here, the input signal 307 is an input signal from the drive control unit to the motor control unit, and the output signal 308 is an output signal from the motor control unit to the drive control unit.

  In general, motor motion control includes a position command, a torque command, a speed command, and the like. In this embodiment, a method of controlling the position and speed by command pulses is employed.

  Main output signals 308 from the motor control unit 306 to each servo amplifier are origin search, servo-on, deviation counter clear, alarm clear, command pulse, and the like.

  Main input signals 307 from each servo amplifier to the motor control unit 306 are servo ready, alarm, in-position, encoder value, torque monitor, speed monitor, and the like.

  FIG. 9 shows a data register in the motor control unit 306.

  The motor control unit 306 includes a travel axis drive command pulse register 901, a swing axis drive command pulse register 902, a lift axis drive command pulse register 903, and a first arm axis drive command pulse register 904 as output registers for driving the motor. And a second arm axis drive command pulse register 905, and a travel axis drive encoder value register 906, a swivel axis drive encoder value register 907, a lift axis drive encoder value register 908, a first arm as an input register indicating the rotational position of the motor An axis drive encoder value register 909 and a second arm axis drive encoder value register 910 are mounted.

  Next, taking the first arm 203 as an example, a configuration example of the robot arm and an outline of control will be described with reference to FIG.

  The rotational power of the first arm shaft motor 331 is transmitted to the first pulley 434 via the drive transmission belt 431, and further the first link belt 432, the second pulley 435, the second link belt 433, and the third pulley 436. The first hand 209 is a link mechanism that linearly moves on the arm straight path 401. Here, the various belts described above are formed of an elastic body such as rubber.

  By writing the target position from the central processing unit 301 to the command pulse setting register 407 of the drive control unit 306, the first arm shaft motor 331 rotates via the servo amplifier 321 and the first hand 209 moves linearly. .

  An encoder 438 is mounted on the drive shaft 437 of the first arm shaft motor 331 and is counted by an encoder counter 408 in the drive control unit 306 as an incremental encoder signal via a servo amplifier 321. The arithmetic processing unit 301 can read out and grasp the current position of the first hand 209.

  However, since the encoder 438 is mounted on the drive shaft 437, if a malfunction such as slippage of the pulley relative to the belt or belt breakage occurs in the link mechanism, the central processing unit 301 calculates the current position calculated from the encoder value 408. There is a divergence from the actual current position of the first hand 209, and there is a possibility that the stop accuracy is poor and the worst is an interference accident. Link mechanism failures such as pulley slips and belt breakage with respect to belts often deteriorate (elongate) gradually due to aging and the number of movements, etc. If the deterioration at the initial stage can be found, inspection accuracy can be improved by inspection and repair. Defects and interference accidents can be prevented.

  The hand 209 has suction openings 440 at three locations, and controls the vacuum supply source 441 by the electromagnetic valve 336 to handle the wafer 106 (vacuum suction).

  The vacuum line 442 for vacuum suction is connected to a pressure sensor 443 that outputs a suction ON or suction OFF signal by comparison with a set threshold, and the central processing unit 301 is connected via a robot input / output signal interface 304. The suction state of the wafer 106 is confirmed.

  The controller 300 inputs and outputs signals to and from the pressure sensor 443 and the electromagnetic valve 336 via the robot input / output signal interface 304, and inputs the servo amplifier 321, the command pulse 407, and the encoder 408 via the load port motor control unit 306. Output. In addition, a wafer pop-out signal 409 is transmitted to the central processing unit 301 via various device interfaces 305.

  Next, the FOUP closing operation and the wafer pop-out sensor will be described with reference to FIGS.

  FIG. 5 shows an overview of the FOUP 104.

  The FOUP 104 is a sealed container that stores a wafer, and includes a container body 501 and a lid 502. The lid 502 can be opened and closed by the load port 103 as described above. The container body 501 of the FOUP 104 is provided with a slot 503 (shelf) for placing the wafer 106 thereon.

  An outline of the operation of closing the lid 502 of the FOUP 104 will be described with reference to FIGS.

  6A is a schematic cross-sectional view showing an open state of the FOUP in the load port of FIG.

  6B is a schematic cross-sectional view showing the closing operation of the FOUP in the load port of FIG.

  6C is a schematic cross-sectional view showing a closed state of the FOUP in the load port of FIG.

  FIG. 6D is a schematic cross-sectional view showing a state in which the wafer protrudes from the FOUP of FIG.

  FIG. 6A shows a state where the lid is open.

  The lid 602 is removed from the container body 501 by the lid opening / closing mechanism 603 of the load port, and is held at a position below the opening of the FOUP 104 body so as not to interfere with the first hand 209 and the second hand 210 when the wafer 106 is transferred. ing. In order to close the lid 502, it is necessary to raise the lid opening / closing mechanism 603 of the load port 103 to the same position as the container body 501, and then press the container body 501 to join the lid 502.

  FIG. 6B shows a state where the lid opening / closing mechanism 603 of the load port 103 is raised to the same position as the container main body 501. FIG. 6C shows a state where the lid 502 is closed by pressing the lid 502 against the container body 501.

  However, in the closing operation of the FOUP 104, if the wafer 106 has jumped up and down the upper and lower trajectory of the lid opening / closing mechanism 603 of the load port 103, the wafer 106 interferes with the wafer 106 when the lid opening / closing mechanism 603 of the load port 103 is raised, There is a possibility of damage.

  In order to prevent this, a wafer pop-out sensor 421 that detects a wafer pop-out is generally mounted on the load port 103. As shown in FIG. 4, the signal of the wafer pop-out sensor 421 is reflected in the wafer pop-out sensor status register in the various device interfaces 305 and can be read out by the central processing unit 301.

  FIG. 6D shows a state in which the wafer 106 has jumped up and down on the vertical trajectory of the load port lid opening / closing mechanism 603.

  Next, the wafer transfer operation will be described with reference to FIG.

  In many cases, the mini-en housing 102 is narrower than the movable range of the robot 200, and units may be attached in the mini-en housing 102. There is a risk of an accident. Therefore, a route point (referred to as a teaching point) of the robot 200 is registered so that the wafer 106 moves on the determined trajectory, and the wafer is transferred.

  The main teaching points in the mini-en housing 102 are a wafer take-out waiting position 1101 before taking out or storing the wafer 106 from the FOUP 104, a wafer take-out position 1102 for handling the wafer in the FOUP 104, and taking out or storing the wafer 106 from the pre-aligner. Previous standby position 1103, wafer handling position 1104 for handling the wafer 106 of the pre-aligner 311, standby position 1105 before taking out or storing the wafer 106 from the semiconductor manufacturing apparatus 100, and wafer handling position for handling the wafer of the semiconductor manufacturing apparatus 100 1106.

  In a general wafer transfer sequence of the mini-en 101, the wafer 106 is taken out from the FOUP 104, the wafer 106 is placed on the pre-aligner 311, alignment is performed, and after the alignment is finished, the wafer 106 is taken out from the pre-aligner 311 and stored in the semiconductor manufacturing apparatus 100. To do. Further, the wafer 106 that has been processed by the semiconductor manufacturing apparatus 100 is taken out and stored in the FOUP 104.

  As an example of the wafer take-out operation, an operation of taking out the wafer 106 from the FOUP 104 with the first hand 209 will be described as an example with reference to FIGS.

  FIG. 7A is a top view showing a wafer take-out operation (wafer take-out standby position) by the robot arm of FIG.

  FIG. 7B is a schematic side view showing a wafer take-out operation (wafer take-out position) by the robot arm of FIG. 7A.

  FIG. 7C is a top view showing a wafer take-out operation by the robot arm of FIG.

  FIG. 7D is a schematic side view showing a wafer take-out operation by the robot arm of FIG. 7C.

  FIG. 7E is a schematic side view showing the wafer take-out operation by the robot arm of FIG. 7C.

  First, as shown in FIG. 7A, the travel axis drive unit 201, the lift axis drive unit 205, the pivot axis drive unit 206, and the arm horizontal drive unit 207 of the robot 200 are operated, and the first hand 209 is placed at the wafer 106 take-out standby position. To move.

  The wafer take-off standby position is a state where the center line 710 of the wafer 106 and the first hand 209 coincide with each other and the first arm 203 is contracted. The side view at this time is FIG. 7B. At this time, the wafer 106 is placed on the slot 503 (shelf) of the FOUP 104, and the first hand 209 is located below the wafer 106.

  Next, as shown in FIG. 7C, the arm horizontal driving unit 207 is moved to extend the first arm 203, and the first hand 209 is advanced to the position where the first hand 209 is scooped up from the lower side. The side view at this time is FIG. 7D.

  Next, as shown in FIG. 7E, the lifting / lowering axis drive unit 205 is operated while vacuuming is performed from the suction opening 440 of the first hand 209 by controlling the electromagnetic valve 336 for vacuum suction, and the first hand 209 is moved. The wafer 106 is lifted and handled (vacuum suction).

  Next, a procedure for teaching the wafer take-out standby position and the wafer take-out position in the operation of taking out the wafer 106 from the FOUP 104 with the first hand 209 will be described using the flowchart of FIG.

(Step 800)
Using the teaching pendant 313, the travel axis drive unit 201, the lift axis drive unit 205, the turning axis drive unit 206, and the arm horizontal drive unit 207 of the robot 200 are driven to move the first hand 209 to the wafer take-out standby position.

(Step 810)
An input register indicating a motor rotation position in the motor control unit 306, a travel axis drive encoder value register 906, a swing axis drive encoder value register 907, a lift axis drive encoder value register 908, a first arm axis drive encoder value register 909, and a second The data of the arm axis drive encoder value register 910 (shown in FIG. 9) is read, the wafer removal standby position 1001 of the traveling axis with respect to the FOUP 104, the wafer removal standby position 1002 of the pivot axis, the wafer removal standby position 1003 of the lift axis, and the first It is registered and stored in a wafer take-out standby position 1004 on the arm axis and a wafer take-out standby position 1005 (shown in FIG. 10) on the second arm axis.

(Step 820)
Using the teaching pendant 313, the travel axis drive unit 201, the lift axis drive unit 205, the turning axis drive unit 206, and the arm horizontal drive unit 207 of the robot 200 are driven to move the first hand 209 to the wafer take-out position.

(Step 830)
An input register indicating a motor rotation position in the motor control unit 306, a travel axis drive encoder value register 906, a swing axis drive encoder value register 907, a lift axis drive encoder value register 908, a first arm axis drive encoder value register 909, and a second The data of the arm axis drive encoder value register 910 is read, the wafer extraction position 1006 of the traveling axis with respect to the FOUP 104, the wafer extraction position 1007 of the pivot axis, the wafer extraction position 1008 of the lift axis, the wafer extraction position 1009 of the first arm axis, and the second Each is registered and stored in the wafer take-off standby position 1010 of the arm shaft.

(Step 840)
Using the teaching pendant 313, the lift axis drive unit 205 of the robot 200 is operated from the wafer take-out position, and the hand is raised until the first hand 209 reaches the wafer handling position 704.

(Step 850)
An input register indicating a motor rotation position in the motor control unit 306, a travel axis drive encoder value register 906, a swing axis drive encoder value register 907, a lift axis drive encoder value register 908, a first arm axis drive encoder value register 909, and a second The data of the arm axis drive encoder value register 910 is read, the wafer handling position 1011 of the traveling axis with respect to the FOUP 104, the wafer handling position 1012 of the turning axis, the wafer handling position 1013 of the lift axis, the wafer handling position 1014 of the first arm axis, and the second Each is registered and stored in the wafer handling position 1015 of the arm shaft.

  Next, an arm position deviation detection method in the present embodiment will be described.

  As shown in FIG. 4, in the arm 203, the rotational power of the first arm shaft motor 331 is transmitted to the first pulley 434 via the drive transmission belt 431, and further, the first link belt 432, the second pulley 435, Since the first hand 209 is transmitted to the second link belt 433 and the third pulley 436 so that the first hand 209 moves linearly on the straight arm trajectory 401, slippage of the pulley with respect to the belt is a main cause of the failure. Yes. If slippage of the pulley with respect to the belt occurs, not only the conveyance accuracy is affected, but in the worst case, an interference accident may be caused.

  The slippage of the pulley with respect to the belt is often caused by looseness due to deterioration (elongation) of the belt, and gradually deteriorates due to aging and the number of operations. Predictive maintenance can be achieved by detecting signs.

  However, since the encoder 438 is mounted on the drive shaft 437 and the central processing unit 301 recognizes the position calculated from the encoder value 408 as the position of the first hand 209, the first hand 209 is caused by the slack of the belt. Since it is not possible to recognize that the actual position is different from the position calculated by the central processing unit 301, it is not possible to detect the looseness of the belt.

  In this embodiment, the looseness of the belt is detected by comparing the wafer pop-out sensor light-shielding position by the first hand 209 when the mini-en 101 is installed with the wafer pop-out sensor light-shielding position in the normal wafer transfer sequence.

  FIG. 12 shows a flowchart of wafer pop-out sensor shading position registration (referred to as calibration) by the first hand 209 when the mini-en 101 is installed.

(Step 1200)
The robot 200 is moved to a wafer removal standby position 1101 (wafer removal standby position teaching point).

  At this time, the wafer 106 is not handled by the first hand 209.

(Step 1201)
In order to move the first hand 209 to the wafer removal position 1102 (wafer removal position teaching point), the motor 331 of the first arm 203 is driven.

(Step 1202)
It is monitored whether or not the first hand 209 has reached the wafer removal position 1102.

(Step 1203)
While the first arm 203 is extending, the first hand 209 monitors whether the wafer pop-out sensor 421 is shielded from light.

(Step 1204)
When the first hand 209 shields the wafer pop-up sensor 421, the value of the first arm shaft drive encoder value register 909 is stored in the wafer pop-out sensor light shielding initial position 1021.

(Step 1205)
When the first hand 209 reaches the wafer take-out position 1102 without shielding the wafer pop-out sensor 421, the calibration is not completed normally and the process ends abnormally.

  Next, a method for detecting the displacement of the first arm 203 during the normal wafer transfer of the mini-en 101 using the calibration data will be described with reference to FIG.

  The position deviation detection of the first arm 203 is performed during the first arm 203 extending operation of the operation of taking out the wafer 106 from the FOUP 104, which is the same as the operation at the time of calibration.

  As the first arm 203 is extended from the wafer take-out standby position 1101 to the wafer take-out position 1102, the value of the first arm shaft drive encoder value register 909 indicating the rotational position of the motor is counted up and increased. A wafer pop-out sensor light shielding timing at the time of calibration is shown at 1300. Reference numeral 1301 denotes the wafer pop-out sensor light shielding timing when the link belt of the first arm 203 is loosened.

  When the link belt of the first arm 203 is loosened, when the rotational power of the first arm shaft motor 331 is transmitted to the pulley by the belt, elongation occurs on one side of the belt, and the rotation of the pulley is delayed. The elongation speed of 203 becomes slow.

  As a result, the wafer pop-out sensor light shielding timing 1305 in the case where belt elongation occurs delays light shielding, and the encoder value 1302 of the first arm axis register 909 indicating the motor rotation position at that time is the basis for calibration. Deviation 1306 occurs in encoder value 1020 at the wafer pop-out sensor light shielding initial position. Since this deviation 1306 is somewhat generated even when the belt is not loose, a threshold value 1304 is set as a parameter to determine that the belt is abnormal, and it is determined that the belt is abnormal when the deviation 1306 exceeds the threshold value 1304. .

  Here, a determination unit such as the central processing unit 301 determines that the rotational position of the motor has reached the threshold value.

  In this figure, the rotational position of the first arm shaft motor 331 at the time when the first hand 209 passes the wafer pop-out sensor 421 is measured, and based on the amount of change in the rotational position (corresponding to the deviation 1306). Detect belt degradation.

  The rotation position of the first arm shaft motor 331 when the light shielding of the wafer pop-out sensor 421 due to the passage of the first hand 209 is detected is measured, and an encoder value for detecting belt degradation based on the amount of change in the rotation position is determined. The recording unit for recording may be the external memory 312 or the internal memory 303, or another recording medium.

  A method for detecting the displacement of the first arm 203 during normal wafer transfer will be described in detail with reference to the flowchart of FIG.

(Step 1400)
The robot 200 is moved to the wafer removal standby position teaching point 1101.

  At this time, the wafer 106 is not handled by the first hand 209.

(Step 1401)
In order to move the first hand 209 to the wafer removal position 1102, the motor 331 of the first arm 203 is driven.

(Step 1402)
While the first arm 203 is extending, the first hand 209 monitors whether the wafer pop-out sensor 421 is shielded from light. In this step, the wafer jumping sensor 421 branches to YES when the change point detected from the light projection to the light shielding is detected.

(Step 1403)
When the first hand 209 shields the wafer pop-up sensor 421, the value of the first arm shaft drive encoder value register 909 is stored in the wafer pop-out sensor light-shielding position 1030.

  Further, the recording date and time are added, and the light shielding position of the wafer pop-out sensor is stored in the internal memory 1040 or the external memory 312 in time series. The external memory 312 is a portable external auxiliary storage device as described above, and can be taken out from the mini-en 101 and connected to a personal computer or the like to analyze the time series data.

(Step 1404)
It is monitored whether or not the first hand 209 has reached the wafer removal position 1102.

(Step 1405)
The wafer pop-out sensor light shielding initial position 1021 at the time of calibration is compared with the wafer pop-out sensor light shield position 1030. If there is a difference between a predetermined deviation threshold value 1050 or more due to mechanical characteristics, the first is caused by the belt extension. It is determined that the position shift of the arm 203 has occurred, and the process branches to abnormality detection.

(Step 1406)
This arm misalignment detection is aimed at preventive maintenance by optimizing the inspection time. Even if a misalignment is detected, the operation of the device will continue and only the warning will be issued, and if the warning is issued by stopping the device, whether the operation will be continued or stopped will be stopped when abnormal / The continuation selection parameter 1060 is defined in advance.

(Step 1407)
When the abnormal stop / continuation selection parameter 1060 is continued, the wafer removal operation is continued.

(Step 1408)
A warning is given that the first arm 203 has been displaced, and the first arm 203 is inspected. As a warning method, a warning (abnormality) is displayed on the panel 107 attached to the mini-en 101, and a warning signal (abnormal signal) is transmitted to the semiconductor manufacturing apparatus 100, which is a host device, by communication or a parallel input / output signal. There is a method of (sending), displaying on a display device of a semiconductor manufacturing apparatus, and further reporting to a host computer. Based on this warning signal, the user is urged to check.

  Although the above-described steps (processes) are described using the first hand 209 and the first arm 203, the same operation is performed on the second hand 210 and the second arm 204.

  Thereby, the optimization of the inspection time which is the object of the present invention can be achieved.

  In the above-described embodiment, the passage of the hand portion is detected by the wafer pop-out sensor installed in the load port. However, the present invention is not limited to this, and the optical sensor using the infrared or visible light, the electromagnetic wave, or the ultrasonic wave. You may detect the passage of a hand part using the sensor which utilizes. These sensors will be collectively referred to as a hand part position detection part. The hand portion position detection unit is not necessarily installed in the load port.

  In the above-described embodiment, the rotational position of the motor is detected by the encoder, but the present invention is not limited to this. The encoder is generalized and called a rotational position detector.

  DESCRIPTION OF SYMBOLS 100: Semiconductor manufacturing apparatus, 101: Mini-environment system, 102: Mini-en housing, 103: Load port, 104: FOUP, 105: Fine filter unit, 106: Wafer, 107: Panel, 200: Robot, 201: Travel axis Drive unit, 202: motor for travel axis, 203: first arm, 204: second arm, 205: lifting shaft drive unit, 206: swing axis drive unit, 207: first arm drive unit, 208: second arm drive 209: First hand 210: Second hand 300: Controller 301: Central processing unit 302: Host device interface 303: Internal memory 304: Robot input / output signal interface 305: Various device interfaces 306: Motor control unit, 307: Input signal, 308: Output signal 309: System bus, 311: Pre-aligner, 312: External memory, 313: Teaching pendant, 320: Drive controller, 321: Servo amplifier for first arm axis, 322: Servo amplifier for second arm axis, 323: Rotating axis Servo amplifier, 324: lift axis servo amplifier, 325: travel axis servo amplifier, 331: first arm axis motor, 332: second arm axis motor, 333: swing axis motor, 334: lift axis Motor: 335: Various sensors, 336: Solenoid valve, 401: Straight arm trajectory, 407: Command pulse setting register, 408: Encoder counter, 421: Wafer pop-out sensor, 431: Drive transmission belt, 432: First link belt, 433 : Second link belt, 434: first pulley, 435: second pulley, 43 : Third pulley, 437: drive shaft, 438: encoder, 440: suction opening, 441: vacuum supply source, 442: vacuum line, 443: pressure sensor, 501: container body, 502: lid, 503: slot, 603: Lid opening / closing mechanism, 710: Center line, 1101: Wafer removal standby position, 1102: Wafer removal position, 1103: Standby position, 1104: Wafer handling position, 1105: Standby position, 1106: Wafer handling position, 1300, 1301 : Wafer pop-out sensor light shielding timing, 1302: Encoder value, 1304: Threshold value, 1305: Wafer pop-out sensor light shielding timing, 1306: Deviation.

Claims (9)

  A robot including a belt and a pulley, and an arm having a link mechanism for converting the rotational motion of the motor into a linear motion; and a hand for gripping the wafer; and a rotational position of the motor A method for diagnosing a semiconductor wafer transfer apparatus, comprising: a motor control unit including a rotational position detection unit for detecting a position of the hand unit; and a hand unit position detection unit for detecting passage of the hand unit. A diagnostic method for a semiconductor wafer transfer apparatus, comprising: recording the rotational position when detected by a hand position detection unit; and detecting deterioration of the belt based on a change amount of the rotational position.   2. The diagnostic method for a semiconductor wafer transfer apparatus according to claim 1, wherein the rotation position is recorded for each transfer operation.   3. The semiconductor wafer transfer device according to claim 1, wherein when the belt deterioration is detected, a warning is displayed on the display unit, or a warning signal is transmitted to a semiconductor manufacturing apparatus that is a host device. 4. Diagnostic method.   4. The method for diagnosing a semiconductor wafer transfer apparatus according to claim 1, wherein the time series data of the amount of change is stored and used for investigation and analysis.   A robot including a belt and a pulley, and an arm having a link mechanism for converting the rotational motion of the motor into a linear motion; and a hand for gripping the wafer; and a rotational position of the motor A semiconductor wafer transfer apparatus including a motor control unit including a rotational position detection unit for detecting the hand unit position detection unit for detecting passage of the hand unit, and the hand unit position of the hand unit position And a recording unit for recording the rotational position when detected by the detection unit.   6. The semiconductor wafer transfer apparatus according to claim 5, further comprising a determination unit that determines that the rotational position has reached a threshold value.   When the determination unit determines that the rotational position has reached the threshold value, it is possible to select whether to immediately stop the operation of the robot or to perform only a warning and continue the operation of the robot. The semiconductor wafer conveyance device according to claim 5 or 6, characterized by the above-mentioned.   The semiconductor wafer transfer apparatus according to claim 5, wherein the hand position detection unit is a wafer pop-out sensor installed at a load port.   The semiconductor wafer transfer apparatus according to claim 5, wherein the rotational position detection unit is an encoder connected to the motor.

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