JP2017139261A - Device and method for substrate transfer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique capable of detecting an abnormality of a substrate transfer device which includes a holding unit for holding a substrate and moving up and down to transfer the substrate to/from a loading unit.SOLUTION: A substrate transfer device includes: a lifting mechanism which moves the substrate holding unit up and down in the middle of a substrate holding unit moving up and down between a first height position and a second height position, to enable the transfer of the substrate to/from the loading unit; a suction route, connected to a suction hole, in which pressure is changed by a changeover between a state, in which the substrate is held by the substrate holding unit, and a state in which the substrate is not held by the substrate holding unit; a pressure sensor which acquires time series data of the pressure of the suction route while the substrate holding unit moves up and down between the first and second height positions; and a detector unit which, based on the time series data, acquires information of a transfer height position in which the substrate is transferred.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a substrate transfer apparatus and a substrate transfer method for moving a substrate up and down.

  In a semiconductor manufacturing apparatus for manufacturing a semiconductor device, a plurality of modules on which a semiconductor wafer (hereinafter referred to as a wafer) as a substrate is placed are provided, and a substrate transfer device is incorporated as a substrate transfer mechanism. Wafers are transferred between modules. Modules include processing modules that perform processing on wafers and delivery modules in which wafers are temporarily placed to mediate delivery between processing modules. These modules are transferred to the wafers in a predetermined order. A predetermined series of processing is performed.

  The substrate transport mechanism includes a wafer holder that can be raised and lowered. The holding unit is lifted with respect to the module to receive the wafer from the module, and the holding unit is lowered with respect to the module to place the wafer on the module. As shown in Patent Document 1, a suction hole for sucking a wafer may be provided in the holding unit. In order to move the holding unit up and down in this way, the substrate transport mechanism is provided with a drive mechanism including, for example, a motor and a belt driven by the motor.

  However, there may be an abnormality in which the actual height of the holding portion gradually shifts with respect to the set height of the holding portion due to factors such as belt deviation of the drive mechanism and belt tension reduction. In addition, a misalignment between the positions of the respective parts of the substrate transport mechanism may cause a deviation between the setting height of the holding part and the actual height of the holding part. If this height deviation is large, there is a possibility that unintentional contact of the holding part will occur with respect to the structure or wafer in the apparatus.

  In Patent Document 1, a pressure sensor provided in an exhaust pipe connected to a suction hole of a holding unit is configured to perform on / off output. That is, it is configured to output a digital signal indicating whether the pressure in the exhaust pipe exceeds or does not exceed a predetermined threshold value. When the holding unit is raised to receive the wafer from the module, the signal output is switched when the wafer is held from the state of not holding the wafer. By monitoring this signal, the holding unit removes the wafer. It has been shown that the receiving height can be detected. It is conceivable to detect the abnormality by detecting the height at which the wafer is received.

JP 2014-36175 A

By the way, the downstream side of the exhaust pipe connected to the holding unit is connected to an exhaust path provided in the semiconductor manufacturing apparatus via a regulator, for example. As the utility supplied to the semiconductor manufacturing apparatus fluctuates or becomes insufficient, the exhaust flow rate in the exhaust passage fluctuates, and the pressure in the exhaust pipe connected to the holding unit may deviate from the set range. is there. In addition, the pressure in the exhaust pipe may deviate from the set range due to the adjustment of the regulator by the worker. Furthermore, when a plurality of holding units are provided in the apparatus, it is conceivable to connect a plurality of exhaust pipes provided in each holding unit to a common regulator. With such a configuration, one holding unit holds the wafer. Depending on whether or not, the pressure in the exhaust pipe of the other holding part changes. If the pressure in the exhaust pipe deviates or changes from the setting as described above, there may be a difference between the output switching timing from the pressure sensor and the timing at which the holding unit receives the wafer. May not be detected with high accuracy.

  The present invention has been made based on such circumstances, and an object of the present invention is to provide an abnormality of a substrate transport apparatus including a holding unit that holds the substrate and transfers the substrate to the mounting unit by moving up and down. It is providing the technique which can detect this with high precision.

The substrate processing apparatus of the present invention includes a substrate holding portion having a suction hole for sucking and holding the back surface of the substrate by suction,
The substrate holding part has a first height position and a second height between the substrate holding part and a mounting part that supports an outer region of the area held by the substrate holding part on the back surface of the substrate. An elevating mechanism that elevates and lowers the substrate holding part so that the substrate is transferred in the middle of moving up and down between the positions;
A suction path that is connected to the suction hole and changes pressure by switching between a state in which the substrate is held by the substrate holding unit and a state in which the substrate is not held by the substrate holding unit;
The pressure provided in the suction path in order to acquire time-series data of the pressure in the suction path while the substrate holding part moves up and down between the first height position and the second height position. A sensor,
Based on the time-series data, a detection unit that acquires information on a delivery height position where the delivery of the substrate has been performed;
It is provided with.

The substrate processing method of the present invention includes a step of sucking and holding the substrate on the substrate holding unit by sucking the back surface of the substrate through a suction hole provided in the substrate holding unit;
Delivering the substrate between the substrate holding unit and a mounting unit that supports an outer region of the region held by the substrate holding unit on the back surface of the substrate;
Elevating and lowering the substrate holding portion by an elevating mechanism so that the substrate is transferred while the substrate holding portion moves up and down between a first height position and a second height position;
Switching between a state in which the substrate is held by the substrate holding unit and a state in which the substrate is not held by the substrate holding unit, and changing a pressure of a suction path connected to the suction hole;
Time-sequential data of the pressure in the suction path while the substrate holder is moving between the first height position and the second height position by the pressure sensor provided in the suction path. A process of acquiring;
Based on the time-series data, obtaining information on the height position where the substrate has been delivered; and
It is provided with.

  According to the present invention, with respect to the pressure of the exhaust path connected to the suction hole of the substrate holding part, the substrate is provided between the first height position and the second height position in order to deliver the substrate to the mounting part. Time series data of the pressure of the suction path connected to the suction hole of the substrate of the substrate holding unit while the holding unit is moved up and down is acquired, and information on the height at which the substrate was transferred based on this time series data To get. Since the time series data reflects changes in the pressure in the suction path, the accuracy of the information on the height at which the acquired substrate was transferred is high, and therefore whether or not an abnormality has occurred in the substrate transfer device. Can be detected with high accuracy.

It is a perspective view of the conveyance arm provided in the said coating and developing apparatus. It is a top view of the fork of the transfer arm. It is a vertical front view of the fork. It is a block diagram of the control part provided in the said application | coating and developing apparatus. It is explanatory drawing which showed delivery of the wafer with respect to the delivery module by a conveyance arm. It is explanatory drawing which showed delivery of the wafer with respect to the delivery module by a conveyance arm. It is a vertical side view of the said roughening process module. It is explanatory drawing which showed delivery of the wafer with respect to the delivery module by a conveyance arm. It is explanatory drawing which showed delivery of the wafer with respect to the delivery module by a conveyance arm. It is explanatory drawing which showed delivery of the wafer with respect to the delivery module by a conveyance arm. It is explanatory drawing which shows the height of the said fork. It is a graph which shows an example of the time series data of the pressure in an exhaust pipe acquired by the pressure sensor provided in the fork. It is a graph which shows an example of the said time series data by which the arithmetic process was carried out. It is a graph which shows an example of the said time series data by which the arithmetic process was carried out. It is a graph which shows transition of the encoder value output from the motor which drives the said fork. It is a flowchart which shows the procedure of the abnormality detection of the said conveyance arm performed by the said control part, and the handling operation of abnormality. It is a graph for showing the correction timing of the fork height which is the coping operation. It is a schematic diagram which shows the height of the said fork. 2 is a plan view of the coating and developing apparatus. FIG. It is a perspective view of the coating and developing apparatus. It is a vertical side view of the coating and developing apparatus. It is a longitudinal section schematic diagram of a heating module to which the present invention is applied. It is a graph which shows the result of an evaluation test. It is a graph which shows the result of a comparative test. It is a graph which shows the result of an evaluation test. It is a graph which shows the result of a comparative test.

  FIG. 1 is a perspective view of a unit block E3 constituting a processing block D2 provided in a coating and developing apparatus 1 described later. In the unit block E3, a transfer path 11 for the wafer W extending in the front-rear direction is provided, and delivery modules TRS3 and TRS31 are provided on the front side and the rear side of the transfer path 11, respectively. The delivery module TRS3 is a module for loading the wafer W into the unit block E3, and the delivery module TRS31 is a module for carrying out the wafer W from the unit block E3. A place where the wafer W is placed by the wafer W transfer mechanism is referred to as a module. The transfer modules TRS3 and TRS31 that form the mounting portion for the wafer W are each provided with a horizontal plate 12 and three pins 13 projecting vertically on the horizontal plate 12, and the rear surface of the wafer W is placed on the pins 13. The central part is supported horizontally.

A resist film forming module 14 for applying a resist to the wafer W to form a resist film is provided on the right side of the transfer path 11 when viewed from the front to the rear. A number of heating modules 15 are provided along the front-rear direction. The transport path 11 is provided with a transport arm F3 which is a substrate transport mechanism constituting a substrate transport device incorporated in the coating and developing apparatus 1, and the transport arm F3 is provided with a delivery module TRS3 → a resist film forming module 14 → The wafer W is transferred in the order of the heating module 15 → the delivery module TRS31.

The transfer arm F3 will be further described. In the figure, reference numeral 21 denotes an upright frame, which moves along the length direction of the transfer path 11 by a horizontal movement mechanism 22 provided below the heating module 15. In the figure, reference numeral 23 denotes a lifting platform which moves up and down a region surrounded by the frame 21 by the frame 21. In the figure, reference numeral 24 denotes a turntable provided on the lift table 23, which rotates around the vertical axis. Two forks 25 serving as wafer W holding bodies are provided on the turntable 24 in the vertical direction, and are configured to be able to advance and retreat independently between a forward position and a reverse position on the turntable 24. . As will be exemplified later, when the elevating platform 23 is moved up and down so that the wafer W can be transferred to and from the module by the fork 25, the fork 25 moves to the advanced position, and when such raising and lowering is not performed, the retracted position is reached. Move to.

The two forks 25 which are substrate holding portions are configured in the same manner, and one of the two forks will be described with reference to the plan view of FIG. The fork 25 is configured as a frame that surrounds the side periphery of the wafer W, with two protrusions extending in an arc from the base in the forward direction of the fork 25. Further, the fork 25 includes four claw portions 26 protruding toward the center of the region (wafer holding region) surrounded by the fork 25, and the claw portions 26 are spaced from each other in the circumferential direction of the wafer holding region. Arranged. A suction hole 27 is opened above each claw portion 26, and the peripheral edge of the back surface of the wafer W is sucked and held on the claw portion 26 so as to close the suction hole 27. The pins 13 of the transfer modules TRS3 and TRS31 support the outer region of the region held by the claw portion 26 on the back surface of the wafer W so that the wafer W can be transferred to and from the fork 25.

If the description continues with reference to the longitudinal front view of the fork 25 in FIG. 3, the fork 25 is formed with an exhaust passage 28 connected to the suction hole 27 of each claw portion 26, for example, upstream of the exhaust passage 28. The sides merge and communicate with each other in an exhaust pipe 29 that forms a suction path connected to the fork 25. A solenoid valve V <b> 1 is interposed in the exhaust pipe 29. An exhaust pressure sensor (pressure sensor) 31 is provided on the upstream side of the valve V1 of the exhaust pipe 29 forming the exhaust path, and an analog signal corresponding to the pressure (exhaust pressure) in the exhaust pipe 29 is output. . The downstream side of the valve V1 of the exhaust pipe 29 is connected to an exhaust mechanism 33 that performs, for example, regular exhaust via an exhaust passage 28 and a regulator 32 for adjusting the pressure in the exhaust pipe 29, such as an exhaust blower or a pump. It is connected.

The regulator 32 and the exhaust mechanism 33 are shared by the two forks 25, for example. Specifically, the exhaust pipes 29 connected to the forks 25 merge on the downstream side of the valve V1 and are connected to the regulator 32 described above. Regarding the valve V1 of each fork 25, the time period from immediately before the fork 25 receives the wafer W from an arbitrary module to immediately after the wafer W is placed (sent out) on the subsequent module is open. Opening and closing is controlled so as to close in the time zone. That is, suction from the suction hole 27 is performed from immediately before the fork 25 holds the wafer W to immediately after the fork 25 is released. Accordingly, the exhaust pressure sensor 31 detects when the fork 25 receives the wafer W from the module and the suction hole 27 is closed and when the fork 25 sends the wafer W to the module and the suction hole 27 is opened. The exhaust pressure changes.

  The output signal from the exhaust pressure sensor 31 is converted into a digital signal via a converter (not shown) and transmitted to the control unit 4 which is a computer provided in the coating and developing apparatus 1 shown in FIG. Here, the frame 21 of the transfer arm F3 will be described in more detail with reference to FIG. 4. The frame 21 includes an elevating mechanism including a motor 42, a pulley, and a motor 42 and a belt wound around the pulley. ing. Illustration of pulleys and belts is omitted. The above-mentioned lifting platform 23 is locked to the belt, and the belt is driven by the rotation of the motor 42 so that the lifting platform 23 is moved up and down.

The rotation of the motor 42 is controlled by a control signal output from the control unit 4. Further, the motor 42 includes an encoder 43, and a number of pulses (encoder values) corresponding to the rotation amount of the motor 42 is output to the control unit 4 as a signal corresponding to the height position of each fork 25. . The amount of displacement of the encoder value corresponds to the amount of displacement of the height of the lift 23, that is, the amount of displacement of the height of the fork 25. Further, an encoder value when the fork 25 receives the wafer W to the module and an encoder value when the fork 25 sends (places) the wafer W to the module are set for each module, and control is described later. These encoder value set values are stored in the memory of the unit 4 as reception set values and send set values, respectively. When the wafer W is transferred to the module, the height of the lift 23, that is, the height of the fork 25 is controlled based on the receiving setting value and the sending setting value set for the module.

  Specifically, FIG. 5 is a schematic diagram showing that the upper fork of the two forks 25 is used for receiving the wafer W from the transfer module TRS3 and sending the wafer W to the transfer module TRS31. This will be described with reference to FIG. Hereinafter, when the fork 25 is simply described, the upper fork 25 is indicated. 5 to 10 and FIG. 11 described later, the claw portion 26 is shown on the upper side of the fork 25 for convenience of illustration. In the example shown in FIGS. 5 to 10, it is assumed that there is no deviation between the actual height of the fork 25 described in the background art item and the height of the fork 25 in the setting.

  First, reception of the wafer W from the transfer module TRS3 will be described. In parallel with the reception of the wafer W, the control unit 4 acquires data from the exhaust pressure sensor 31. The acquisition of this data will be described later. First, the fork 25 is positioned at a height (referred to as a reception preparation height) at which an encoder value shifted by a predetermined amount with respect to the reception set value of the delivery module TRS3 is output from the motor 42. In FIG. 6, the predetermined amount is indicated as -A1. Thereafter, the fork 25 moves on the rotary table 24 from the retracted position to the advanced position, the elevator table 23 rises, and the valve V1 provided in the exhaust pipe 29 of the fork 25 opens to suck the claw portion 26. Suction from the hole 27 is performed.

  During this ascent, the wafer W is attracted and held on the claw 26 of the fork 25 (FIG. 7). In other words, the claw 26 comes into contact with the back surface of the wafer W placed on the pins 13 of the delivery module TRS3, and the fork 25 receives the wafer W from the module TRS3. Thus, the height of the fork 25 when receiving the wafer W from the module is defined as the receiving height. When the fork 25 continues to rise, the wafer W is lifted from the pins 13, and when the output encoder value deviates from the acceptance setting value of the delivery module TRS3 by a predetermined amount, the fork 25 stops raising. In FIG. 8, this predetermined amount is set to + A2. The height at which the fork 25 stops in this way is defined as the receiving end height. Here, since there is no deviation between the actual height of the fork 25 and the height of the set fork 25, when the fork 25 is positioned at the receiving height (delivery height) as shown in FIG. The encoder value to be set becomes the reception set value.

  Next, the delivery of the wafer W to the delivery module TRS31 will be described. The encoder value deviated by a predetermined amount with respect to the delivery setting value of the delivery module TRS31 is set to a height (referred to as a delivery preparation height) output from the motor 42. A fork 25 is located. Subsequently, the fork 25 moves on the turntable 24 from the retracted position to the advanced position. In FIG. 9, the fork 25 moved to this forward position is indicated by a chain line. In FIG. 9, the predetermined amount is represented as + A3.

  Then, the lift 23 is lowered, and the wafer W is delivered to the delivery module TRS31 during the lowering. That is, the wafer W is held on the pins 13 of the delivery module TRS 31, and the wafer W is separated from the claw portion 26 of the fork 25. The fork 25 at this time is indicated by a solid line in FIG. In this way, the height of the fork 25 when the wafer W is delivered to the module is defined as the delivery height. When the fork 25 continues to descend and the output encoder value deviates by a predetermined amount from the delivery setting value of the delivery module TRS31, the fork 25 stops descending, the valve V1 is closed and the suction hole 27 is closed. Is stopped (FIG. 10). In FIG. 10, this predetermined amount is -A4. This stopped height is set as the sending end height. Here, since there is no deviation between the actual height of the fork 25 and the height of the set fork 25, the fork 25 is positioned at the delivery height (delivery height) as shown by the solid line in FIG. The encoder value to be output becomes the transmission set value.

  In this way, the transfer of the wafer W to the module is performed by controlling the height of the fork 25 based on the encoder value output from the motor 42, and the fork 25 is predetermined when the encoder value indicates a predetermined value. It is set to be located at the height of. However, the correspondence between the encoder value and the height of the fork 25 is deviated due to various factors such as belt displacement and tension reduction described in the background section. That is, a deviation occurs between the actual height of the fork 25 and the height of the set fork 25.

  If a deviation occurs in the correspondence between the encoder value and the height of the fork 25 as described above, the height when the fork 25 delivers the wafer W to each module is, for example, uniformly from a preset height. Shift. FIG. 11 specifically shows the fork 25 in a state in which such a shift has not occurred and the fork 25 in a state in which a slip has occurred. More specifically, FIG. 11 shows a state where there is no deviation and a state where there is a deviation when receiving the wafer W from the delivery module TRS3, as described above, at the receiving preparation height, the receiving height, and the receiving end height. As shown, the heights of the forks 25 when the output encoder values are the reception setting value -A1, the reception setting value, and the reception setting value + A2 are shown. The height of the fork 25 when the encoder value becomes the receiving set value −A1, and the height of the fork when the encoder value becomes the receiving set value + A2 correspond to the first height and the second height, respectively.

  As shown in FIG. 11, the height of the fork 25 when each value is output is shifted by Bmm (B is an arbitrary numerical value) in a state where there is no shift and a state where there is a shift. When such a deviation occurs, the encoder value to be output is set to the transmission set value + A3 so that the fork 25 is positioned at the transmission preparation height, the transmission height, and the transmission end height when transmitting to the delivery module TRS31. The height of the fork 25 when the transmission set value and the transmission set value + A are respectively shifted by B mm from the height of the state where there is no shift.

  The control unit 4 is configured to detect an encoder value when the fork 25 is positioned at the receiving height of the delivery module TRS3 based on the output from the exhaust pressure sensor 31, as will be described in detail later. Has been. As described above, the encoder value at the receiving height is set in advance as the receiving setting value. The encoder value of the receiving height is detected by detecting the actual height of the fork 25 and the setting height of the fork 25. This is performed in order to detect the presence or absence of deviation, that is, the presence or absence of abnormality of the transfer arm F3. Then, the control unit 4 corrects the reception setting value and the transmission setting value set for each module so that the deviation is eliminated based on the detection result of the encoder value, or The operation of the transfer arm F3 is stopped.

  Returning to FIG. 4, the structure of the control part 4 which comprises a detection part, a determination part, and a correction mechanism is demonstrated. The control unit 4 includes a processing program 4A, a detection program 4B, and a countermeasure program 4C. The processing program 4A is a program for processing the wafer W by a module that transfers the wafer W between the modules and processes the wafer W. The detection program 4B is a program for detecting an encoder value at the time of receiving the wafer W from the transfer module TRS3 by the fork 25 according to a procedure described later. The countermeasure program 4C is a program for correcting the reception setting value and the transmission setting value described above or stopping the operation of the transfer arm F3 based on the detected encoder value.

The programs 4A to 4C each have a command (step group) so as to be able to perform the processing assigned in this way, and output a control signal to each part of the developing device 1. The operation of each part of the coating and developing apparatus 1 is controlled by this control signal. The programs 4A to 4C are stored and operated in a program storage unit (not shown) provided in the control unit 4 while being stored in a storage medium such as a hard disk, a compact disk, a magnetic optical disk, or a memory card.

  The control unit 4 is provided with a memory 44, which stores reception setting values and transmission setting values for the respective modules. As described above, the height of the fork 25 is controlled based on the receiving setting value and the sending setting value, and the wafer W is transferred to the module. Further, the memory 44 stores the number of times that the reception setting value and the transmission setting value are corrected.

  The controller 4 is provided with a memory 45. The detection of the encoder value of the receiving height of the fork 25 from the transfer module TRS3 is performed, for example, every time the wafer W is received from the transfer module TRS3. In the memory 45, the time when the fork 25 receives the wafer W and the detected encoder value are stored in association with each other.

  Further, the control unit 4 includes an alarm output unit 46. The alarm output unit 46 includes a display unit such as a monitor and an audio output unit such as a speaker. The alarm output unit 46 displays a predetermined sign as an alarm or outputs a predetermined sound. For example, when the operation of the transport arm F3 is stopped as described above, this alarm is output, and the user of the coating and developing apparatus 1 can be notified of the abnormality of the transport arm F3. When such an abnormality is notified, the user performs maintenance of the transfer arm F3.

  Next, a method for detecting the encoder value of the receiving height of the wafer W with respect to the transfer module TRS3 performed by the control unit 4 will be described. As shown in FIG. 6, the fork 25 located at the receiving preparation height rises, and the fork 25 stops rising at the receiving end height as shown in FIG. The output signal from the exhaust pressure sensor 31 up to the point of time is continuously acquired by the control unit 4. That is, time series data indicating the transition of the exhaust pressure in the pipe 31 connected to the fork 25 is acquired.

  Signal acquisition from the exhaust pressure sensor 31 is performed at intervals shorter than 10 milliseconds in order to ensure detection accuracy. In this example, the signals are acquired at intervals of 2.5 milliseconds. Since suction from the suction hole 27 is started as the fork 25 starts to rise, the detected exhaust pressure fluctuates relatively greatly immediately after the fork 25 starts to rise. The acquisition of the signal is started when 100 milliseconds elapse from the hour.

  FIG. 12 is a graph showing an example of the acquired time series data of the exhaust pressure. The horizontal axis of the graph represents the elapsed time since the fork 25 started to rise, and the vertical axis of the graph represents the detected exhaust pressure (unit: kPa). With respect to the time-series data acquired in this way, the change in the exhaust pressure becomes the largest at the timing when the fork 25 receives the wafer W, and thereafter, processing for detecting this timing is performed. For example, in order to remove the data trend and clarify the change in the exhaust pressure, the acquired time series data is 2.5 milliseconds before the one elapsed time from the exhaust pressure acquired in the one elapsed time. The obtained exhaust pressure is subtracted and obtained as a difference value of one elapsed time. The difference value is calculated for each elapsed time when the exhaust pressure data is acquired. In other words, the differential value is acquired every 2.5 milliseconds for the time zone in which the time series data of the exhaust pressure is acquired. The graph of FIG. 13 shows data obtained by performing the calculation in this way. The horizontal axis of the graph in FIG. 13 indicates the elapsed time in the same manner as the horizontal axis of the graph in FIG. 13, and the vertical axis in the graph in FIG. 13 indicates the difference value acquired by the calculation.

  Subsequently, an average value for each acquired difference value is calculated, and a deviation between the difference value and the average value is calculated for each elapsed time. Then, the sum of the deviation in one elapsed time and the deviation for each elapsed time before the one elapsed time is calculated, and is taken as a cumulative sum in one elapsed time. Such a cumulative sum is acquired for each elapsed time when the exhaust pressure data is acquired. FIG. 14 shows a graph showing the cumulative sum. The horizontal axis of the graph of FIG. 14 indicates the elapsed time similarly to the horizontal axis of the graphs of FIGS. 12 and 13, and the vertical axis of the graph of FIG. 14 indicates the calculated cumulative sum. An elapsed time t indicating the maximum value is determined for the cumulative sum calculated in this way. That is, the change in the elapsed time t is the largest in the graph of the time-series data of the exhaust pressure shown in FIG.

  Then, the encoder value at the elapsed time t is specified from the encoder value transition data in the time zone when the time series data is acquired, and is determined as the encoder value of the receiving height of the delivery module TRS3. The graph of FIG. 15 shows transition data of the encoder value. The horizontal axis of the graph of FIG. 15 indicates the elapsed time similarly to the horizontal axis of the graphs of FIGS. 12 to 14, and the vertical axis of the graph indicates the encoder value. The encoder value transition data may be previously stored in the memory of the control unit 4 or may be created by acquiring the encoder value in parallel with the acquisition of the exhaust pressure transition data. . The determined encoder value is stored in the memory 45 in association with the time when the fork 25 starts to rise from the reception preparation height, for example.

  Next, an operation for handling an abnormality in the transfer arm F3 based on the obtained encoder value will be described with reference to the flowchart of FIG. Each time a wafer W is received from the transfer module TRS3, an encoder value of the transfer height of the wafer W in the transfer module TRS3 is calculated and stored in the memory 44 as described with reference to FIGS. 12 to 15 (step S1). When one week elapses from a specific time point, an average value of the encoder values of the received height acquired in the one week is calculated (step S2). The specific time is, for example, the time when the apparatus starts operating or the time when the previous step S2 is executed. Then, a difference value between the calculated average value and the receiving height setting value of the delivery module TRS3 stored in the memory 44 is calculated, and it is determined whether or not the difference value is included in the allowable range (step). S3).

  When it is determined in step S3 that the difference value is not included in the allowable range, it is determined whether or not the number of corrections stored in the memory 45 is equal to or less than the allowable value (step S4). If it is determined that the received set value and the send set value for each module stored in the memory 44 are corrected by an amount corresponding to the difference value calculated in step S3, the stored value is stored in the memory 44. 1 is added to the number of corrections made (step S5).

  If it is determined in step S4 that the number of corrections exceeds the allowable value, the operation of the transfer arm F3 is stopped and an alarm is output from the alarm output unit 46 (step S6). When it is determined that the difference value between the average value of the encoder values calculated in step S3 and the received height setting value stored in the memory 44 is included in the allowable range, the steps after step S1 are performed again. Done. For example, the operation of step S1 is performed by the detection program 4B, and the operations of steps S2 to S6 are performed by the countermeasure program 4C.

  FIG. 17 is a graph showing an example of the transition of the shift amount for each week acquired in step S3. In this example, the deviation amount gradually increases every week, and the deviation amount between the average value of the acquired reception height encoder values and the reception height setting value exceeds the allowable value in the nth week. . In the nth week, the output encoder value is set to the receiving set value −A1, so as to be positioned at the receiving preparation height, the receiving height, and the receiving end height when the wafer W is received from the transfer module TRS3. Each height of the fork 25 when it becomes the reception setting value and the reception setting value + A2 deviates from the respective heights (the respective heights in a state where there is no deviation) as shown in FIG. Similarly, the delivery preparation height, delivery height, and delivery end height when the wafer W is delivered to the delivery module TRS 31 are also shifted from the set heights.

  After the end of operation of the nth week device, before the start of operation of the (n + 1) th device, the correction is performed as described in step S5 above, and the reception setting value and transmission setting value of each module stored in the memory 44 In addition, a correction value (here, D) corresponding to the difference value described in step S3 is added. In the (n + 1) th week, the wafer W is transferred based on the reception setting value and the sending height position corrected in this way.

  Accordingly, when the wafer W is received from the transfer module TRS3, as shown in FIG. 18, the deviation from the set heights for the receiving preparation height and the receiving end height is eliminated, and the encoder value The wafer W is received when becomes the reception set value. That is, the height of the fork 25 is corrected so that the fork 25 is positioned at each height described with reference to FIGS. Similarly, when the wafer W is delivered to the delivery module TRS31, the deviation from each height set for the delivery preparation height and the delivery height is eliminated, and when the encoder value becomes the delivery set value, W is received. That is, the height of the fork 25 is corrected so that the fork 25 is positioned at each height described with reference to FIGS.

  Next, the overall configuration of the coating and developing apparatus 1 will be described with reference to FIGS. 19, 20, and 21 are a plan view, a perspective view, and a schematic longitudinal side view of the coating and developing apparatus 1, respectively. The coating / developing apparatus 1 is provided in an air atmosphere, and is configured by linearly connecting a carrier block D1, a processing block D2, and an interface block D3. An exposure machine D4 is connected to the interface block D3. A carrier C for storing the wafer W is transferred from the outside of the coating and developing apparatus 1 to the carrier block D1, and the carrier block D1 is connected to the carrier C via the mounting table 51, the opening / closing unit 52, and the opening / closing unit 52. And a transfer mechanism 53 for transporting the wafer W from the carrier C.

  The processing block D2 is configured by laminating first to sixth unit blocks E1 to E6 for performing liquid processing on the wafer W in order from the bottom. For convenience of explanation, “BCT” is a process for forming a lower antireflection film on the wafer W, “COT” is a process for forming a resist film on the wafer W, and a process for forming a resist pattern on the exposed wafer W is performed. Sometimes expressed as “DEV”. In this example, as shown in FIG. 20, two BCT layers, COT layers, and DEV layers are stacked from the bottom. In the same unit block, the wafer W is transferred and processed in parallel with each other.

  The unit block E3 is configured as described in FIG. 1, and the delivery modules TRS3 and TRS31 in FIG. 1 are provided on the carrier block D1 side and the interface block D3 side, respectively. The unit block E4 has the same configuration as the unit block E3. The difference between the unit blocks E1, E2, E5, and E6 from the unit blocks E3 and E4 will be described. The unit blocks E1 and E2 include an antireflection film forming module instead of the resist film forming module. In the antireflection film forming module, a chemical solution for forming the antireflection film is supplied to the wafer W.

  The unit blocks E5 and E6 include a developing module instead of the resist film forming module 14. The developing module supplies a developing solution as a chemical solution to the surface of the wafer W, and develops the resist film exposed along a predetermined pattern by the exposure machine D4 to form a resist pattern. Except for such a difference, the unit blocks E1 to E6 are configured in the same manner. In FIG. 21, the transfer arms of the unit blocks E1 to E6 are shown as F1 to F6, and these transfer arms transfer the wafer W independently of each other. For example, the regulator 32 and the exhaust mechanism 33 are shared by the forks 25 of the transfer arms F1 to F6.

  On the carrier block D1 side in the processing block D2, a tower T1 that extends vertically across the unit blocks E1 to E6 and a transfer arm 54 that is a transport mechanism that can be moved up and down to transfer the wafer W to the tower T1. And are provided. The tower T1 is configured by a plurality of modules stacked on each other, and the transfer module provided at each height of the unit blocks E1 to E6 is a wafer between the transfer arms F1 to F6 of the unit blocks E1 to E6. W can be handed over. This delivery module includes the above TRS3.

  The interface block D3 includes towers T2, T3, and T4 that extend vertically across the unit blocks E1 to E6, and interface arms 55 to 57 that are transfer mechanisms that transfer the wafer W to the towers T2 to T4. ing. The interface arm 55 is a transport mechanism that can move up and down to transfer the wafer W to the tower T2 and the tower T3. The interface arm 56 transfers the wafer W to the tower T2 and the tower T4. It is a transport mechanism that can move up and down. The interface arm 57 is a transfer mechanism for delivering the wafer W between the tower T2 and the exposure machine D4.

  The tower T2 includes a delivery module TRS, a buffer module for storing and retaining a plurality of wafers W before exposure processing, a buffer module for storing a plurality of wafers W after exposure processing, and a temperature for adjusting the temperature of the wafers W. Although the adjustment module and the like are stacked on each other, illustration of the buffer module and the temperature adjustment module is omitted here. The delivery module TRS31 is a module included in the tower T2. Although the modules are also provided in the towers T3 and T4, the description is omitted here. Each delivery module TRS is configured in the same manner as the delivery modules TRS3 and TRS31, for example.

  The transfer path and processing of the wafer W in the system including the coating and developing apparatus 1 and the exposure machine D4 will be described. The wafer W is transferred from the carrier C to the transfer module TRS0 of the tower T1 in the processing block D2 by the transfer mechanism 53. The wafer W is transferred from the delivery module TRS0 to the unit blocks E1 and E2 and transferred. For example, when the wafer W is transferred to the unit block E1, among the transfer modules TRS of the tower T1, the transfer module TRS1 corresponding to the unit block E1 (the transfer module capable of transferring the wafer W by the transfer arm F1). The wafer W is transferred from the TRS0. When the wafer W is transferred to the unit block E2, the wafer W is transferred from the TRS0 to the transfer module TRS2 corresponding to the unit block E2 among the transfer modules TRS of the tower T1. Delivery of these wafers W is performed by the delivery arm 54.

  The wafer W thus distributed is transferred in the order of TRS1 (TRS2) → antireflection film forming module → heating module 15 → TRS1 (TRS2), and then transferred to the transfer module TRS3 corresponding to the unit block E3 by the transfer arm 54. Are distributed to the delivery module TRS4 corresponding to the unit block E4.

  The wafers W thus distributed to TRS3 and TRS4 are transferred in the order of TRS3 (TRS4) → resist film forming module 14 → heating module 15 → tower T2 delivery module TRS31 (TRS41). Thereafter, the wafer W is transferred to the exposure machine D4 by the interface arms 55 and 57, and the resist film formed on the surface of the delivery module is exposed along a predetermined pattern.

  The exposed wafer W is transferred between the towers T2 and T4 by the interface arms 57 and 56, and transferred to the transfer modules TRS51 and TRS61 of the tower T2 corresponding to the unit blocks E5 and E6, respectively. Thereafter, the wafer W is transported in the order of the heating module 15 → the developing module, and the resist film is dissolved along the pattern exposed by the exposure machine D4, so that a resist pattern is formed on the wafer W. Thereafter, the wafer W is transferred to the transfer module TRS5 (TRS6) of the tower T1, and then returned to the carrier C via the transfer mechanism 53.

According to this coating and developing apparatus 1, the detection output from the exhaust pressure sensor 31 provided in the exhaust pipe 29 connected to the fork 25 while the fork 25 is raised by the motor 42 to receive the wafer W from the delivery module TRS 3. The control unit 4 acquires the signal, and the time-series data of the exhaust pressure in the exhaust pipe 29 is acquired. Then, based on the time series data, the control unit 4 obtains an encoder value that is information about the height at which the fork 25 receives the wafer W from the transfer module TRS3. The exhaust pressure of the exhaust pipe 29 deviates from the set range due to various factors as described in the background art section, such as a change in the exhaust flow rate by the exhaust mechanism 33 due to fluctuations in the supplied power while the fork 25 is rising. However, since the state of the exhaust pressure change can be understood from the time series data, the acquired encoder value corresponds to the height at which the wafer W is received with high accuracy. Accordingly, an abnormality in the height of the fork 25 can be detected with high accuracy, and it is possible to reliably prevent unintended contact of the fork 25 with respect to the structure in the coating and developing apparatus 1 and the wafer W. . Furthermore, since the height of the fork 25 when the wafer W is delivered to the module is automatically corrected based on the acquired encoder value, the frequency at which the user of the coating / developing apparatus 1 performs maintenance on the transfer arm F3. Therefore, the burden on the user can be reduced.

  By the way, it is not limited to acquiring an encoder value representing the height of the fork 25 based on time series data acquired while the fork 25 is moving up. For example, the fork 25 acquires time-series data of the exhaust pressure during the downward movement from the delivery preparation height described in FIGS. 9 and 10 to the delivery end height in order to send the wafer W to the delivery module TRS31. The time series data may be processed as described with reference to FIGS. 12 to 15, and the encoder value at the inflection point of the graph for the cumulative sum of deviations may be specified as the encoder value at the sending height position. . Then, the height of the fork 25 may be corrected along the flow of FIG. 16 based on the encoder value specified in this way and the delivery height position set for the delivery module TRS31.

  In the above example, the height of the fork 25 is automatically corrected. However, the correction may not be performed in this way. For example, the encoder value at the receiving position acquired in step S1 is displayed on the display unit constituting the control unit. Based on this display, the user of the apparatus determines whether or not there is an abnormality in the encoder value at the receiving position. If it is determined that there is an abnormality, the operation of the transfer arm F3 is manually stopped to perform maintenance. You may do it.

  Further, as described above, the unit blocks E1 to E6 are configured similarly except that different liquid treatments are performed. Accordingly, as with the transfer arm F3, the transfer arms F1, F2, and F4 to F6 are encoder values indicating the receiving height of the wafer W from the transfer module TRS provided corresponding to each transfer arm F according to the flow of FIG. Or the height of the fork 25 may be corrected based on the encoder value. Further, the present invention can also be applied to a transport mechanism provided in a block other than the processing block D2.

  Further, in the above example, the information about the receiving height of the wafer W in the transfer module TRS3 is obtained as encoder value from the encoder value transition data shown in FIG. However, the encoder value is not limited to being acquired as information about the reception height. The height position of the fork that has started to rise from the receiving preparation position corresponds to the elapsed time from the time when the fork started. That is, in the graph of the cumulative sum of deviations in FIG. 14, the elapsed time when the cumulative sum reaches the maximum value corresponds to the receiving height viewed from the receiving preparation position. For example, the received set value and the send set value, which are encoder values stored in the memory 44 of the control unit 4 based on the difference, are compared with a preset reference elapsed time, for example. You may make it correct | amend.

  Further, in the above example, the receiving preparation height (first height) and the receiving end height (second height) of the fork 25 with respect to the delivery module TRS3 are corrected. Thus, it is not restricted to correct | amend each height of the fork 25 with respect to a module. For example, an elevating mechanism for elevating and lowering the delivery module TRS3 is provided, and the delivery module TRS3 has an amount corresponding to the difference between the encoder value at the time of receipt of the wafer W detected at steps S1 to S3 and the acceptance setting value. The height may be corrected to prevent unintended contact between the delivery module TRS3 and the fork 25.

  Further, the present invention is not limited to being applied only to the substrate transfer mechanism that transfers the wafer W between modules. A heating module 6 shown in FIG. 22 is provided, for example, instead of the heating module 15 shown in FIG. 1, and includes a hot plate 61 on which the wafer W is placed and heated, and lift pins 62 that project and sink on the surface of the hot plate 61. The elevating mechanism 63 is provided. The lifting mechanism 63 includes a motor 42 as with the frame 21, and the lifting pins 62 are lifted and lowered by the operation of the motor 42. The lift pins 62 deliver the wafer W between the transfer arm F3 and the hot plate 61. A suction hole 27 is formed at the tip of the elevating pin 62, and an exhaust pressure sensor 31 is provided in the exhaust pipe 29 connected to the suction hole 27. For example, the downstream side of the exhaust pipe 29 is configured similarly to the downstream side of the fork 25 and is connected to the exhaust mechanism 33. When the lift pins 62 push up the wafer W and receive the wafer W from the transfer arm F3, the suction holes 27 are exhausted, and the wafer W is supported by the lift pins 62, whereby the output of the exhaust pressure sensor 31 changes. .

  Similar to the transfer arm F3 described above, the control unit 4 obtains the time series data of the exhaust pressure output from the exhaust pressure sensor 31, so that it is output from the motor 42 when the wafer W is supported by the lift pins 62. It is possible to identify the encoder value to be detected, detect the presence / absence of an abnormality in the height of the lift pin 62, and correct the height of the lift pin 62. That is, the present invention can also be applied to a substrate transport mechanism provided in a module. Further, the lift pins 62 as the substrate holding portion support a region closer to the center than the region supported by the claw portion 26 of the fork 25 on the back surface of the wafer W. That is, the substrate holding part is not limited to supporting the peripheral part of the wafer W.

(Evaluation test)
Subsequently, an evaluation test performed in connection with the present invention will be described. As the evaluation test 1, the wafer W is placed on the transfer module TRS3, and the fork 25 of the transfer arm F3 described in the embodiment of the present invention is disposed below the wafer W by 6 mm. 25 was raised to receive the wafer W. Then, while the fork 25 is raised, the time series data of exhaust pressure and various calculation processes described in FIGS. 12 to 14 are performed, and the maximum value of the cumulative sum of deviations is set as described in the graph of FIG. The time from when the fork 25 starts to rise corresponding to this maximum value until the wafer W is received by the fork 25 (reception detection time), and the rising start position of the fork 25 and the wafer by the fork 25 The distance (movement distance) from the position where W was received was determined.

  Such a test for obtaining the reception detection time and the moving distance was performed a plurality of times. The downstream side of the regulator 32 of the exhaust pipe 29 of the transfer arm F3 used in this test is connected to a pump, and each time a test is performed, the set value of the exhaust pressure of the regulator 32 and the exhaust flow rate of the exhaust pipe 29 by the pump are combined. Changed. That is, the state in the exhaust pipe 29 where the pressure is detected by the exhaust pressure sensor 31 is changed for each test. The set value of the exhaust pressure of the regulator 32 is selected from 65 kPa, 75 kPa, and 83 kPa, and the exhaust flow rate is selected from 2.6 L, 5.5 L, and 6.5 L, and the experiment is performed under 9 patterns of conditions. Went. For the sake of convenience, numbers are assigned to the combinations of the exhaust pressure and the exhaust flow rate. Patterns 1, 2, and 3 are those having an exhaust pressure of 65 kPa and exhaust flow rates of 2.6 L, 5.5 L, and 6.5 L, respectively. Patterns 4, 5, and 6 are those having an exhaust pressure of 75 kPa and an exhaust flow rate of 2.6 L, 5.5 L, and 6.5 L, respectively. Patterns 7, 8, and 9 are those having an exhaust pressure of 83 kPa and exhaust flow rates of 2.6 L, 5.5 L, and 6.5 L, respectively.

  As comparative test 1, instead of the exhaust pressure sensor 31 described above, a transfer arm F3 provided with an exhaust pressure sensor that outputs a digital on / off signal as described in the section of the background art is used. A test was conducted. Therefore, in the comparative test 1, the reception detection time and the moving distance are determined based on the timing at which the on / off signal switches instead of determining based on the maximum value of the cumulative sum in the graph of FIG.

  23 and FIG. 24 show the reception detection time of the evaluation test 1 and the reception detection time (unit: millisecond) of the comparative test 1, respectively. The graphs of FIG. 25 and FIG. The distance and the moving distance (unit: mm) of Comparative Test 1 are shown. In fact, in the evaluation test 1 and the comparative test 1, the patterns 1 to 9 are received a plurality of times, and the maximum value, the minimum value, and the average value are acquired for the reception detection time and the movement distance. Since the difference between the maximum value, the minimum value, and the average value is slight, only the average value is displayed in a plot in the graph.

  As shown in the graphs of FIGS. 23 and 24, in the comparative test 1, the reception detection times vary in the patterns 1-9, but in the evaluation test 1, the reception detection times are uniform in the patterns 1-9. Further, as shown in the graphs of FIGS. 25 and 26, in the comparative test 1, the movement distances vary in the patterns 1 to 9, but in the evaluation test 1, the movement distances are uniform and set to 6 mm. . Therefore, it was confirmed that the transfer arm F3 shown in the embodiment of the invention is not easily affected by the state in the exhaust pipe 29 and can detect the receiving height with high accuracy.

TRS3, TRS31 Delivery module W Wafer 1 Coating and developing device 25 Fork 26 Claw 27 Suction hole 29 Exhaust pipe 31 Exhaust pressure sensor 4 Control unit 43 Motor

Claims (6)

A substrate holding portion having a suction hole for sucking and holding the back surface of the substrate by suction;
The substrate holding part has a first height position and a second height between the substrate holding part and a mounting part that supports an outer region of the area held by the substrate holding part on the back surface of the substrate. An elevating mechanism that elevates and lowers the substrate holding part so that the substrate is transferred in the middle of moving up and down between the positions;
A suction path that is connected to the suction hole and changes pressure by switching between a state in which the substrate is held by the substrate holding unit and a state in which the substrate is not held by the substrate holding unit;
The pressure provided in the suction path in order to acquire time-series data of the pressure in the suction path while the substrate holding part moves up and down between the first height position and the second height position. A sensor,
Based on the time-series data, a detection unit that acquires information on a delivery height position where the delivery of the substrate has been performed;
A substrate transfer device comprising: The elevating mechanism outputs a height signal corresponding to the height position of the substrate holding unit,
The substrate transport apparatus according to claim 1, wherein the detection unit specifies the height signal output when the substrate is transferred as the transfer height information.   Based on the information on the transfer height position, the first height position and the second height position relative to the transfer height position when the substrate holding portion transfers the substrate to the mounting portion. The substrate transfer apparatus according to claim 1, wherein a correction mechanism for correcting the position is provided. A storage unit is provided that stores information on a plurality of the delivery height positions acquired within a preset period and the number of times the correction has been performed,
A determination unit is provided for determining whether or not to perform correction by the correction mechanism based on information on the plurality of delivery height positions stored in the storage unit and the number of times the correction is performed. The substrate transfer apparatus according to claim 3. The substrate holding unit holds a peripheral portion of the substrate,
5. The apparatus according to claim 1, further comprising a moving mechanism configured to move the substrate holding unit in a lateral direction in order to transfer the substrate between a plurality of modules that respectively constitute the substrate mounting unit. The substrate transfer apparatus according to one. Sucking the back surface of the substrate through a suction hole provided in the substrate holding portion to suck and hold the substrate on the substrate holding portion;
Delivering the substrate between the substrate holding unit and a mounting unit that supports an outer region of the region held by the substrate holding unit on the back surface of the substrate;
Elevating and lowering the substrate holding portion by an elevating mechanism so that the substrate is transferred while the substrate holding portion moves up and down between a first height position and a second height position;
Switching between a state in which the substrate is held by the substrate holding unit and a state in which the substrate is not held by the substrate holding unit, and changing a pressure of a suction path connected to the suction hole;
Time-sequential data of the pressure in the suction path while the substrate holder is moving between the first height position and the second height position by the pressure sensor provided in the suction path. A process of acquiring;
Based on the time-series data, obtaining information on the height position where the substrate has been delivered; and
A substrate carrying method comprising:

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