JP2006351884A - Substrate conveyance mechanism and processing system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate conveyance mechanism capable of accurately transferring a substrate without being affected by the influence of variations in the diameter of the substrate due to heat shrinkage and an individual difference and without any conveyance target position deviation. <P>SOLUTION: The substrate conveyance mechanisms 16, 20 for conveying the substrate W comprise conveyance arm sections 50, 56 capable of bend and stretch, and turn; pick sections 52, 58 provided at the tip of the conveyance arm section; a substrate position detection sensor section 54 that is provided at the pick section and detects the position of the substrate when holding the substrate; a center position operation section 72 for obtaining the center position of the substrate, based on the output of the substrate position detection sensor section; an amount-of-deviation operation section 74 for obtaining the amount of deviation between an obtained center position and a predetermined reference center position; and an arm control section 76 for controlling a conveyance arm section so that the amount of deviation can be canceled, when transferring the substrate held by the pick section to the conveyance target position. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a substrate transfer mechanism for transferring a circular substrate such as a semiconductor wafer and a processing system for performing a predetermined process on the substrate.

Generally, as an apparatus for manufacturing a semiconductor device, a variety of processing chambers are combined in order to repeatedly perform a predetermined process on a circular substrate such as a semiconductor wafer. A substrate transport mechanism is provided for automatically transferring the substrate between a cassette for storing a large number of sheets and the chamber. The substrate transport mechanism has a transport arm portion that can be bent and rotated, for example, and the substrate is held in a pick position provided at the tip of the transport arm portion, and the substrate is held at a transport position (transfer). The substrate is moved horizontally to a position) and conveyed to a predetermined position.
In this case, it is necessary not only to avoid interference or collision with other members during the operation of the transfer arm unit, but also to properly hold the substrate placed at a certain place and It is necessary to convey it to a proper position and deliver it to an appropriate place with high accuracy.
For example, as an apparatus for performing predetermined processing on the substrate, each processing chamber has a plurality of processing chambers and a common transfer chamber in which these chambers are connected in common, and a substrate transfer mechanism provided in the common transfer chamber. There is known a processing system in which a substrate is carried in and out.

  In this type of processing system, for example, as disclosed in Patent Document 1, a substrate is formed by detecting a substrate position by providing a light detection sensor near the entrance of a specific processing chamber among the plurality of processing chambers. It is possible to detect whether the position is correctly held on the pick unit, or as disclosed in Patent Document 2, a line sensor is provided in the common transfer chamber and a wing is provided in the transfer arm unit. By detecting the relative positional relationship between this and the substrate, it is detected whether or not the substrate is correctly held on the pick unit with high positional accuracy. When the positional deviation is found here, the operation of the transfer arm unit is controlled so as to cancel out the positional deviation amount.

JP-A-10-223732 JP 2001-338969 A

As described above, according to the conventional substrate misalignment detection apparatus, when the substrate is carried into the processing chamber or when the substrate is unloaded from the processing chamber, the amount of misalignment of the substrate on the pick unit is detected. be able to.
By the way, in order to improve the throughput, the transfer arm unit that holds the substrate transfers the substrate to a desired transfer target position by performing bending and stretching motions at a relatively high speed. In the process of transporting the substrate to the transport target position after detecting the amount, the substrate may be further displaced due to vibration of the transport arm unit or high-speed operation.

In such a case, the conventional substrate displacement detection apparatus as described above has a problem in that correction for canceling out the newly generated displacement amount cannot be performed.
Also, depending on the substrate transport path, the substrate transport path must be detoured so as to pass through the sensor installation position in order to detect the positional deviation of the substrate by the light detection sensor or the line sensor. There is also a problem that it takes time to transport the substrate, and the throughput is reduced accordingly.
Furthermore, the substrate is often heat-treated at a high temperature, and the substrate may be transported at a relatively high temperature. In this case, the diameter of the substrate is also thermally expanded as compared to that at room temperature, and the diameter varies slightly depending on the high temperature. The fluctuation of the substrate diameter due to heat is small as described above and can be ignored in the past. However, as the substrate diameter increases to 200 mm and 300 mm, the fluctuation amount increases accordingly. Further, the diameter of the circular substrate itself is required to have a high dimensional accuracy of ± 0.2 mm in the case of a 300 mm or 200 mm wafer, for example, and the variation of the diameter within the range of ± 0.2 mm must be allowed. .

Under such circumstances, since the high design rule that the positional accuracy of the substrate transfer is within ± 0.2 mm tends to be applied, the variation amount of the wafer diameter due to the above-mentioned heat and individual differences is the substrate transfer position. There was also a problem that the accuracy could be adversely affected.
The present invention has been devised to pay attention to the above problems and to effectively solve them. The object of the present invention is to maintain a high throughput by always accurately and accurately recognizing the amount of displacement of the substrate relative to the pick part without being affected by fluctuations in the diameter of the substrate due to thermal expansion and contraction or individual differences. Another object of the present invention is to provide a substrate transport mechanism capable of accurately transferring a substrate to a transport target position without a positional shift, and a processing system using the same.

According to a first aspect of the present invention, in a substrate transport mechanism for transporting a circular substrate, a transport arm unit that is capable of bending and stretching and a tip of the transport arm unit are provided and the substrate is placed and held. A pick portion for detecting the position of the substrate when the pick portion is provided to hold the substrate, and an output of the substrate based on the output of the substrate position detection sensor portion. A center position calculation unit for obtaining a center position, a deviation amount calculation unit for obtaining a deviation amount between the obtained center position and a predetermined reference center position, and the substrate held in the pick unit as a transfer target position And an arm control unit that controls the transfer arm unit so as to cancel out the shift amount when transferring to the substrate.
In this way, by providing the substrate position detection sensor unit in the pick unit that holds the substrate, the positional deviation amount of the substrate with respect to the pick unit is always affected without being affected by fluctuations in the diameter of the substrate due to thermal expansion and contraction or individual differences. Since it can be accurately recognized, as a result, the throughput can be maintained high, and the substrate can be accurately transferred to the transfer target position without being displaced.

In this case, for example, as defined in claim 2, the deviation amount calculation unit includes a storage unit that stores the reference center position.
For example, as defined in claim 3, the reference center position is preset by a teaching operation.
Further, for example, as defined in claim 4, the substrate position detection sensor unit is arranged at predetermined intervals along a circular trajectory of the substrate to detect two or more lines for detecting the edge position of the substrate. Has a sensor.

For example, as defined in claim 5, three line sensors are provided.
For example, as defined in claim 6, the line sensor comprises a solid-state imaging device.
For example, as defined in claim 7, the line sensor is composed of a plurality of fine mechanical switches arranged in a line.
For example, as defined in claim 8, the line sensor comprises a light quantity measuring element.
For example, as defined in claim 9, the center position calculation unit corrects the detection value from the light quantity measuring element.
For example, as defined in claim 10, the arm control unit determines whether a substrate is supported by the pick unit based on an output of the substrate position detection sensor unit.

  According to an eleventh aspect of the present invention, in a processing system for performing predetermined processing on a circular substrate, a plurality of processing chambers for performing predetermined processing on the substrate and the processing chamber are connected in common. A processing system comprising: a common transfer chamber; any one of the substrate transfer mechanisms provided in the common transfer chamber; and an apparatus control unit that controls the operation of the entire apparatus.

In this case, for example, as defined in claim 12, the common transfer chamber is in a vacuum atmosphere, and a load lock chamber that can be evacuated and returned to atmospheric pressure is connected to the common transfer chamber. .
For example, as defined in claim 13, a loader chamber for carrying the substrate in and out is connected to the load lock chamber, and the loader chamber is defined in any one of claims 1 to 10. A substrate transport mechanism is provided.

According to the substrate transport mechanism and the processing system according to the present invention, the following excellent operational effects can be exhibited.
By providing a substrate position detection sensor unit in the pick unit that holds the substrate, the amount of positional deviation of the substrate with respect to the pick unit is always accurately recognized without being affected by fluctuations in the diameter of the substrate due to thermal expansion and contraction. As a result, the throughput can be maintained high, and the substrate can be accurately transferred to the transfer target position without being displaced.
Further, when three or more line sensors are provided as the substrate position detection sensor unit, even if there is an individual difference in the diameter of the substrate, the center position and the amount of displacement can be accurately obtained.

Hereinafter, an embodiment of a substrate transport mechanism and a processing system according to the present invention will be described in detail with reference to the accompanying drawings.
1 is a schematic configuration diagram showing a processing system using a substrate transfer mechanism according to the present invention, FIG. 2 is a schematic configuration diagram showing a substrate transfer mechanism according to the present invention, FIG. 3 is a plan view showing a pick section, and FIG. FIG. 5 is an explanatory view for obtaining the center position of the substrate, and FIG. 5 is a plan view showing a positional deviation state of the substrate on the pick portion.

First, a cluster tool type processing system will be described with reference to FIG. The processing system 2 includes a processing unit 4 that performs various processes such as a film forming process, a diffusion process, and an etching process on a circular substrate W such as a semiconductor wafer. A transport unit 6 for carrying in and out is continuously provided.
The processing unit 4 includes a common transfer chamber 8 that can be evacuated and four processing chambers 12A to 12D connected via gate valves 10A to 10D, and the same type or different types of processing are performed in each of the chambers 12A to 12D. Is applied to the substrate W. In each of the chambers 12A to 12D, susceptors 14A to 14D for placing the substrate W are provided. Further, in the common transfer chamber 8, there is provided a first substrate transfer mechanism 16 which can be bent and stretched according to the present invention, and transfers the substrate W between the chambers 12A to 12D and between the load lock chambers described later. Is supposed to do. The configuration of the first substrate transport mechanism 16 will be described later.

On the other hand, the transfer unit 6 includes a cassette stage 18 on which a cassette container is placed and a transfer stage 22 that moves a second substrate transfer mechanism 20 for transferring and transferring the substrate W. The cassette stage 18 is provided with a container mounting table 24 on which a plurality of cassette containers 26A to 26D in the illustrated example can be mounted. Each cassette container 26A to 26D can accommodate, for example, a maximum of 25 wafers W placed in multiple stages at an equal pitch.
The transport stage 22 is provided with a guide rail 28 extending along the length direction at the center thereof, and the second substrate transport mechanism 20 is slidably supported on the guide rail 28. For example, a ball screw (not shown) is provided in parallel on the guide rail 28 as a moving mechanism, and the base of the second substrate transport mechanism 20 is fitted to the ball screw. By rotating the drive motor 32 provided, the second substrate transport mechanism 20 moves in the X direction along the guide rail 28.

  The other end of the transfer stage 22 is provided with an orienter 36 as a direction positioning device for positioning the substrate. Further, in the middle of the transfer stage 22, in order to connect with the common transfer chamber 8. Two load lock chambers 38A and 38B that can be evacuated are provided. In each of the load lock chambers 38A and 38B, there are provided substrate mounting tables 40A and 40B on which the substrate W is placed. Gate valves 42A, 42B and 44A, 44B are provided. The overall operation of the processing system 2 is controlled by an apparatus control unit 46 made of, for example, a microcomputer.

  Here, the first substrate transport mechanism 16 has a pair of transport arm portions 50 arranged so as to be opposed to the left and right, and each of the transport arm portions 50 can be bent and stretched around the same rotation axis. Has been made. A bifurcated pick portion 52 for placing and holding the substrate W is provided at the tip of each transfer arm portion 50. The substrate W is placed on the pick portion 52 and transferred. It can be transferred (transferred) to a target position, or the substrate W can be taken out and transferred. By the first substrate transport mechanism 16, the substrate W is transferred between the processing chambers 12A to 12D or between the processing chambers 12A to 12D and the load lock chambers 38A and 38B. Each pick unit 52 is provided with a substrate position detection sensor unit 54 that is a feature of the present invention for detecting the position of the substrate W when the substrate W is held. The configuration of the substrate position detection sensor unit 54 will be described later.

  Further, the second substrate transport mechanism 20 has a pair of transport arm portions 56 that are arranged in two different levels at different heights, and each transport arm portion 56 is centered on the same rotation axis. As a result, it is possible to swivel integrally and to bend and stretch in the same direction. A bifurcated pick part 58 for placing and holding the substrate W is provided at the tip of each transfer arm part 56, and the substrate W is placed on the pick part 58 and transferred. It can be transferred (transferred) to a target position, or the substrate W can be taken out and transferred. By the second substrate transport mechanism 20, the substrate W is transferred between the cassette containers 26 </ b> A to 26 </ b> D, the load lock chambers 38 </ b> A and 38 </ b> B, and the orienter 38. Each pick unit 58 is provided with a substrate position detection sensor unit 60 that is a feature of the present invention for detecting the position of the substrate W when the substrate W is held.

Here, the configurations of the transfer arm unit 50 and the substrate position detection sensor unit 54 of the first substrate transfer mechanism 16 are the same as the configurations of the transfer arm unit 56 and the substrate position detection sensor unit 60 of the second substrate transfer mechanism 20. Since each of them is the same, here, one transfer arm unit 50 of the first substrate transfer mechanism 16 will be described as an example with reference to FIG. 2 and FIG.
As shown in FIG. 2, the transfer arm unit 50 is supported, for example, on a coaxial rotary shaft 62 that has two axes that are coaxially rotatable. The transfer arm unit 50 can bend and extend the transfer arm unit 50 by forward / reverse rotation of the bending / extending motor 64A, and can turn the transfer arm unit 50 by forward / reverse rotation of the turning motor 64B. A bifurcated pick unit 52 is attached to the tip of the transport arm unit 50, and a substrate position detection sensor unit 54 is provided in the pick unit 52. Although not shown, a sensor light source is provided on the ceiling side of the common transfer chamber 8.

Specifically, as shown in FIG. 3, the substrate position detection sensor unit 54 is arranged at predetermined intervals 2 along a circular locus 68 of the substrate W placed on the pick unit 52. It has the above line sensor. In the case of the illustrated example, there are three line sensors 70A, 70B, and 70C. The two line sensors 70A and 70C are provided at the tip of the bifurcated pick portion 52, respectively, and the remaining one line sensor 70B is It is provided at the base of the bifurcated pick part 52.
The length L1 of each of the line sensors 70A to 70C is set to a predetermined length, for example, about 10 mm, and the length direction is provided toward the center P1 of the circular locus 68. The trajectory 68 crosses the approximate center in the length direction of the sensors 70A to 70C. Thereby, when the substrate W is placed on the pick portion 52, each edge position of the substrate W, that is, the position of the outer peripheral end can be detected. That is, as a result, the coordinates of each edge position can be recognized with the center C1 on the pick portion 52 as the center.

As the line sensors 70A to 70C, an individual image pickup device such as a CCD (Charge Coupled Devices), a light receiving device such as a phototransistor or a photo detector, or a plurality of (many) fine mechanical switches arranged in a line. A group or the like can be used, and the detection accuracy thereof is, for example, about ± 50 μm.
Further, the substrate W is formed with notches such as notches or orientation flats indicating the crystal direction, but the line sensors 70A to 70C are provided in correspondence with places where the notches are not located. . In other words, when the substrate W is placed on the pick unit 52, the substrate W is picked in a state in which the notch is oriented so as not to correspond to the line sensors 70A to 70C. The operation is set so as to be placed on 52.

  The first substrate transport mechanism 16 further includes a center position calculation unit 70 for determining the center position of the substrate W placed on the pick unit 52 based on the output of the substrate position detection sensor unit 54, When the substrate W held by the pick unit 52 and the displacement amount calculation unit 74 for obtaining the amount of displacement between the center position obtained in step 1 and the predetermined reference center position are transferred to the transfer target position, the amount of displacement is determined. An arm control unit 76 for controlling the operation of the transfer arm unit 50 so as to cancel is provided. The deviation amount calculation unit 74 has a storage unit 78 for storing the coordinates of the reference center position obtained in advance. Each of these calculation parts 70 and 74, the arm control part 76, and the memory | storage part 78 are comprised by one computer, for example.

The center position calculation unit 70 obtains the coordinates of the center position of the substrate W as described above, and the calculation is performed as follows. As shown in FIG. 3 and FIG. 4, when the coordinates of the edge positions detected by the line sensors 70A to 70C are points P1, P2, and P3, between any two points among the points P1 to P3. Two perpendicular bisectors are drawn, and the intersection of the two perpendicular bisectors is the center position C1. In FIG. 4, the intersection of the perpendicular bisector of the line segment connecting the points P1 and P2 and the vertical bisector of the line segment connecting the points P1 and P3 is obtained as the center position C1. In this case, it is assumed that the substrate W is a perfect circle.
As described above, the method for obtaining the center of the substrate W from the coordinates of the three points can accurately obtain the center position at that time even if the diameter of the substrate W varies due to thermal expansion and contraction.
As shown in FIG. 5, the deviation amount calculation unit 74 obtains a deviation amount ΔZ between the obtained center position C1 and a predetermined reference center position. Here, it is assumed that the reference center position is “C0”.

The arm control unit 76 controls the operation of the transport arm unit 50 so as to cancel out the deviation amount ΔZ when the substrate W is placed. In this case, the shift amount ΔZ is canceled or absorbed by the bending and stretching radius and the rotation angle (polar coordinates) of the transfer arm unit 50.
As described above, each of the line sensors 70A to 70C, the center position calculation unit 70, the deviation amount calculation unit 74, the arm control unit 76, and the storage unit 78 described here includes the other transfer arm unit 50 and the second substrate transfer. Similarly, both the transfer arm portions 56 of the mechanism 20 are provided. Moreover, each position coordinate calculated | required by the said description is recognized by the encoder provided in the motor which is a motive power source, for example.

Next, a method for transporting the substrate W performed using the processing system 2 configured as described above will be described.
First, before actually starting the substrate transfer operation, the reference position serving as the reference for the operation of the first and second substrate transfer mechanisms 16 and 20, that is, the coordinates of the operation start point and the operation end point are taught by the teaching operation. . At the same time, the substrate is appropriately placed on the pick units 52 and 58 of the first and second substrate transport mechanisms 16 and 20 with high positional accuracy by a manual or the like. At this time, the line sensors 70A to 70C are obtained. The center position of the substrate obtained from the detection value is set as the reference center position C0, and the coordinates thereof are stored in the storage unit 78.

Next, a transport process when the substrate is actually transported and subjected to predetermined processing will be schematically described.
First, as shown in FIG. 1, substrates are transferred from cassette containers 26 </ b> A to 26 </ b> D placed on the container placing table 24 of the cassette stage 18 using one of the transfer arm portions 56 of the second substrate transfer mechanism 20. W is taken out and this substrate W is transferred to an orienter 36 provided at the end of the transfer stage 22. The orienter 36 detects the amount of misalignment of the center of the substrate W and the direction of the notch or orientation flat, and corrects the misalignment amount when the transport arm unit 56 holds the substrate W again. Further, the substrate W is held again so that the notch and the orientation flat are oriented in a predetermined direction.
Then, the substrate W is transferred to one of the two load lock chambers 38A, 38B, for example, the load lock chamber 38A, and the transfer arm unit 56 is bent and stretched, whereby the substrate W is transferred to the load lock chamber 38A. Carry in.

The substrate W in the load lock chamber 38A is taken into the common transfer chamber 8 by turning and bending the transfer arm portion 50 of one of the first substrate transfer mechanisms 16 provided in the common transfer chamber 8. After that, it is carried into a predetermined processing chamber among the four processing chambers 12A to 12D and subjected to predetermined processing.
After a plurality of processes are sequentially performed in a predetermined single or other processing chamber, the substrate W follows a path opposite to that described above, and is accommodated in the cassette container via the load lock chamber. Will be returned to.

  Next, when the substrate W is transferred using the first and second substrate transport mechanisms 16 and 20, the operation at the time of transfer is performed after correcting (offset) the positional deviation of the center position of the substrate W. This will be described with reference to FIG. FIG. 6 is a flowchart showing each process when the substrate is conveyed while offsetting the shift amount of the center position of the substrate. Here, as an example, a case where the transfer is performed using the transfer arm unit 50 (see FIG. 2) of the first substrate transfer mechanism 16 will be described.

  First, if the substrate W is placed and held on the pick unit 52 of the transfer arm unit 50, the edge of the substrate W is positioned on each of the line sensors 70A to 70C of the substrate position detection sensor unit 54. The three edge positions P1, P2, and P3 (see FIG. 4) of the substrate W, that is, edge coordinates are detected (S1). Based on the detected three edge positions, the center position calculation unit 70 calculates the center position of the substrate W held by the pick unit 52 (S2). As described above with reference to FIG. 4, for example, if each point of the detected edge position is set to the points P1, P2, and P3 as described above, the center position can be obtained. Two perpendicular bisectors connecting two arbitrary points in P3 are drawn, and the intersection of the two perpendicular bisectors is obtained as the center position C1 of the substrate W.

Next, the deviation amount calculation unit 74 calculates the deviation amount ΔZ (see FIG. 5) between the calculated center position C1 and the reference center position C0 stored in the storage unit 78 in advance (S3). In FIG. 5, the center position of the circular locus 68 is the reference center position C0. Here, the shift amount ΔZ is a vector amount.
Next, the arm control unit 76 calculates and calculates a correction amount for correcting and canceling the calculated deviation amount ΔZ (S4). Here, the position of the pick unit 52 provided at the tip of the transfer arm unit 50 is determined on the polar coordinates by the turning angle (rotation angle) and the arm length (radius) of the transfer arm unit 50, and therefore corresponds to the deviation ΔZ. Thus, the turning angle and the arm length that can cancel each other are calculated as correction amounts.
Then, the arm control unit 76, when transferring the substrate W on the pick unit 50 to the transfer target position, sets the value of the rotation angle and the arm length to the value obtained by adding the correction amounts of the turning angle and the arm length. The substrate W is transferred to the transfer target position by performing the turning operation and the extending operation (S5).

The detection of the edge positions P1 to P3 of the substrate W, the calculation of the center position C1, the calculation of the shift amount, and the calculation of the correction amount that cancels the shift amount are always performed in the process of transporting the substrate W. The deviation amount ΔZ of the center position of the substrate can be recognized in real time.
As described above, since the substrate position detection sensor unit 54 is provided in the pick unit 52, even if the substrate W is displaced with respect to the pick unit 52 due to vibration of the pick unit 52 or the like, the displacement amount is always accurately determined in real time. Thus, it is possible to accurately transfer the substrate to the transfer target position without being displaced.
Even if the diameter of the substrate W fluctuates due to thermal expansion or contraction or the diameter varies due to individual differences of the substrates W, the center position of the substrate W can be recognized in real time without being affected by the influence.
In addition, unlike the conventional device, it is not necessary to bypass the substrate transport path to the position where the misalignment sensor is installed in order to obtain the amount of misalignment of the substrate center. Can be improved.

Further, unlike the conventional apparatus in which the line sensors are installed at a plurality of locations, it is only necessary to provide the sensor at one location, that is, the pick section 52. Therefore, the number of sensors can be reduced, and the cost can be reduced accordingly.
In the case where a light amount measuring element is used as the line sensors 70A to 70C, the deviation amount detection characteristic generally does not change linearly with respect to the light amount. It is better to correct it. FIG. 7 is a diagram showing a schematic graph showing the characteristic correction of such a light quantity measuring element. FIG. 7A shows the relationship between the shift amount of the center position of the substrate and the detected light amount. The linearity is near the center of the characteristic, but the linearity is broken at both ends of the characteristic. Therefore, it is preferable to obtain a linear correction characteristic in advance as shown in FIG.

As shown in FIG. 3, when three or more line sensors are provided for one pick part 52, the center position of the substrate W can be obtained by geometric processing as shown in FIG. When only two line sensors are provided, the diameter (radius) dimension of the substrate W is required as a parameter in order to obtain the center position of the substrate. Such a dimension of the diameter (radius) of the substrate W can be obtained together with, for example, the positional deviation amount obtained by the orienter 36 (see FIG. 1), and the value may be used.
Further, the configuration of the substrate transport mechanisms 16 and 20 is not limited to the configuration described in the present embodiment, and the present invention is a mechanism that transports and transfers a substrate by a turning operation and bending operation of the transport arm portion. Any configuration can be applied, and it can be applied not only to a two-pick type substrate transfer mechanism but also to a single-pick type substrate transfer mechanism.
Further, any material may be used as long as the substrate is circular, and the present invention can be applied to a semiconductor wafer, a glass substrate, a ceramic substrate, and the like.

It is a schematic block diagram which shows the processing system using the board | substrate conveyance mechanism based on this invention. It is a schematic block diagram which shows the board | substrate conveyance mechanism which concerns on this invention. It is a top view which shows a pick part. It is explanatory drawing for calculating | requiring the center position of a board | substrate. It is a top view which shows the position shift state of the board | substrate on a pick part. It is a flowchart which shows each process at the time of conveying offset the amount of deviation | shift of the center position of a board | substrate. It is a figure which shows the schematic graph which shows the characteristic correction | amendment of a light quantity measuring element.

Explanation of symbols

2 Processing System 8 Common Transfer Chamber 12A to 12D Processing Chamber 16 First Substrate Transfer Mechanism 20 Second Substrate Transfer Mechanism 36 Orientor 38A, 38B Load Lock Chamber 50, 56 Transfer Arm Unit 52, 58 Pick Unit 54 Substrate Position Detection Sensor Unit 60 Substrate position detection sensor unit 70A, 70B, 70C Line sensor 72 Center position calculation unit 74 Deviation amount calculation unit 76 Arm control unit 78 Storage unit C0 Center of substrate (reference center position)
C1 Center position of substrate W substrate

Claims (13)

In a substrate transport mechanism that transports a circular substrate,
A transfer arm section which is capable of bending and stretching, and
A pick unit provided at a tip of the transfer arm unit for mounting and holding the substrate;
A substrate position detection sensor unit for detecting the position of the substrate when the substrate is held by being provided in the pick unit;
A center position calculation unit for obtaining a center position of the substrate based on an output of the substrate position detection sensor unit;
A deviation amount calculation unit for obtaining a deviation amount between the obtained center position and a predetermined reference center position;
An arm control unit that controls the transport arm unit so as to cancel the shift amount when the substrate held by the pick unit is transferred to a transport target position;
A substrate transport mechanism comprising:   The substrate transfer mechanism according to claim 1, wherein the shift amount calculation unit includes a storage unit that stores the reference center position.   The substrate transport mechanism according to claim 2, wherein the reference center position is preset by a teaching operation.   2. The substrate position detection sensor unit includes two or more line sensors that are arranged at predetermined intervals along a circular locus of the substrate and detect an edge position of the substrate. 4. The substrate transport mechanism according to any one of items 1 to 3.   The substrate transport mechanism according to claim 4, wherein three line sensors are provided.   6. The substrate transport mechanism according to claim 4, wherein the line sensor is made of a solid-state imaging device.   6. The substrate transport mechanism according to claim 4, wherein the line sensor includes a plurality of fine mechanical switches arranged in a line.   6. The substrate transport mechanism according to claim 4, wherein the line sensor includes a light amount measuring element.   The substrate transport mechanism according to claim 8, wherein the center position calculation unit corrects a detection value from the light amount measurement element.   The substrate transfer according to claim 1, wherein the arm control unit determines whether a substrate is supported by the pick unit based on an output of the substrate position detection sensor unit. mechanism. In a processing system for performing predetermined processing on a circular substrate,
A plurality of processing chambers for performing predetermined processing on the substrate;
A common transfer chamber to which the processing chambers are connected in common;
The substrate transfer mechanism according to any one of claims 1 to 10, provided in the common transfer chamber,
A device control unit for controlling the operation of the entire device;
A processing system comprising:   12. The processing system according to claim 11, wherein the common transfer chamber is in a vacuum atmosphere, and a load lock chamber capable of evacuation and return to atmospheric pressure is connected to the common transfer chamber. The load lock chamber is connected to a loader chamber for carrying the substrate in and out, and the loader chamber is provided with the substrate transport mechanism according to any one of claims 1 to 10. The processing system according to claim 12.

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