JP2003188228A - Substrate-conveying method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wafer-conveying method for easily determining robot- teaching coordinates, in a wafer carrier on a load port. <P>SOLUTION: A wafer 50 is automatically conveyed from a wafer carrier 541 to a prealignment section 520, and eccentricity errors (ΔX and ΔY) in the wafer 50 are detected by the prealignment section 520 for storing in a storage circuit. The eccentricity errors (ΔX and ΔY)in the wafer 50 are corrected, and the wafer 50 is conveyed to a stage section 530 and further to the wafer carrier 541. In the wafer carrier 541, the teaching coordinates of wafer center coordinates in the wafer carrier 541 are corrected (subtracted), based on the eccentricity errors (ΔX and ΔY), and the corrected value is stored in the storage circuit as the teaching coordinates for new wafer center coordinates in the wafer carrier 541. <P>COPYRIGHT: (C)2003,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate transfer method, for example, a teaching method of a wafer transfer robot of an overlay measuring device. FIG. 4 is a plan view of a conventional superposing apparatus. [0003] This superposition device is a transfer robot 510.
And a pre-alignment unit 520, a stage unit 530, and a load port 540. The transfer robot 510 transfers the wafer 50 to the pre-alignment unit 520 and the stage unit 530, and stores the wafer 50 on the stage unit 530 in the wafer carrier 541 on the load port 540. In the pre-alignment section 520, the wafer 50 is roughly positioned before the wafer 50 is placed on the stage section 530. Conventionally, a wafer 50 is
The robot teaching coordinates for automatically transferring the robot to the stage 20, the stage unit 530, and the like are created as follows. First, the wafer center coordinates of the pre-alignment unit 520, the wafer center coordinates of the stage unit 530, and the wafer center coordinates (design value coordinates) in the wafer carrier 541 on the load port 540 are stored in a storage circuit (not shown) as robot teaching coordinates. Remember. The transfer robot 510 is driven to each of the center coordinates, and each center position is finely adjusted manually using a tool.
Change the robot teaching coordinates. Then, a transfer test of the wafer 50 is performed,
It is visually confirmed that the wafer 50 does not hit the wafer carrier 541, and the changed center coordinates are stored in the storage circuit as robot teaching coordinates, and the teaching ends. Incidentally, the wafer 50 is transferred to the wafer carrier 541.
When a collision occurs, fine adjustment of each center position is performed manually using the above-mentioned tool. Incidentally, in order to determine the coordinates of the center of the wafer in the wafer carrier 541, manual work in the wafer carrier 541 is necessary as described above. However, since only a narrow window is formed in the wafer carrier 541 and the working space is narrow, the center of the wafer carrier 541 while checking the setting of the tool and the position of the robot arm 511 in the wafer carrier 541 is determined. Fine adjustment of the position is very difficult, and there is a problem that it takes time to determine the robot teaching coordinates. The present invention has been made in view of such circumstances, and an object of the present invention is to provide a substrate transfer method that can easily determine a robot teaching coordinate in a substrate carrier on a load port. According to a first aspect of the present invention, there is provided a substrate carrier for holding a substrate, the center coordinates of a substrate in a substrate carrier, and the substrate center of a stage on which the substrate is mounted. A first step of storing coordinates and a substrate center coordinate of a pre-alignment unit for aligning the substrate in a storage unit as teaching coordinates of a robot; and after the first step, teaching of the pre-alignment unit and the stage unit, respectively. Move the robot arm of the robot to the coordinates, fine-tune the position of this robot arm,
A second step of storing the coordinates after the fine adjustment in the storage means as new teaching coordinates, and after the second step, transporting the substrate from the substrate carrier to the pre-alignment unit by the robot arm, A third step of detecting an eccentricity error of the substrate by the alignment unit, storing the eccentricity error in the storage means, and positioning the substrate; and after the third step, a coordinate of a substrate center coordinate in the substrate carrier. And a fourth step of correcting the teaching coordinates based on the eccentric error and storing the corrected value in the storage unit as new teaching coordinates of the center coordinates of the substrate in the substrate carrier. I do. Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a control system of a transfer robot of a wafer transfer apparatus to which a substrate transfer method according to one embodiment of the present invention is applied. The wafer transfer device has the same structure as the conventional superposition device shown in FIG. The transfer robot body 10 is a robot arm 1
1 is provided. As shown in FIG. 1, the transfer robot body 10 includes a control unit 20 such as a personal computer and a robot controller 3.
0, and drives the robot body 10 to move the robot arm 11 to transfer a wafer (substrate). The robot controller 30 is connected to a teaching box 40 as shown in FIG.
The teaching box 40 includes a pre-alignment unit 52.
0 is used to input the wafer center coordinates, the stage center 530 wafer center coordinates, and the wafer center coordinates in the wafer carrier 541 on the load port 540 (see FIG. 4). The robot controller 30 has a rewritable storage circuit (storage means) 31 to which data such as wafer center coordinates are inputted from the teaching box 40 and the control unit 20. The robot 5 is constituted by the robot controller 30 and the transfer robot main body 10. FIG. 2 is a flowchart for explaining a robot teaching method of a wafer transfer method according to an embodiment of the present invention. FIG. 3 is a view for explaining automatic transfer of a wafer. It is shown with an affixed. In FIG. 2, S1 to S7 denote steps of the operation. Points 1, 2 and 3 are the center coordinates of the wafer in the wafer carrier 541, the center coordinates of the wafer of the pre-alignment unit 520, and the center of the stage unit 530, respectively. Shows the wafer center coordinates. First, the coordinates of the center of the wafer in the wafer carrier 541, which are the design value coordinates of points 1, 2 and 3 for transferring the wafer 50 (see FIG. 3), the pre-alignment unit 5
The coordinates of the center of the wafer 20 and the coordinates of the center of the wafer of the stage unit 530 are stored in the teaching box 540 or the control unit 520.
, And stored in the storage circuit 31 as teaching coordinates (S1). Next, the robot arm 511 is moved to the wafer center coordinates of the pre-alignment unit 520, and the wafer center coordinates are finely adjusted manually using a tool, and the coordinates after the fine adjustment are stored as new teaching coordinates in the storage circuit 31. (S2). Next, the robot arm 511 is moved to the wafer center coordinates of the stage section 530, the wafer center coordinates are finely adjusted manually using an adjustment tool, and the coordinates after the fine adjustment are stored in the storage circuit as new teaching coordinates. Remember (S
3). At step 3, the manual teaching ends. After S1 to S3, a wafer transfer test is performed (S4). The wafer 50 is automatically transferred from the wafer carrier 541 to the pre-alignment unit 520 by the robot arm 511, and the pre-alignment unit 520 detects an eccentric error (ΔX, ΔY) of the wafer 50 using a CCD camera. In FIG. 3, a solid line a and a dashed line b indicate the position of the wafer 50 when it is automatically transferred and the position of the corrected wafer 50, respectively. The wafer 50 is conveyed to the stage 530 after correcting the eccentricity error (ΔX, ΔY). At this time, the wafer 50 is received at the wafer center coordinates of the stage section 530. The eccentricity error (ΔX, ΔY) is stored in the storage circuit 31. From the stage section 530 to the load port 540
When the wafer 50 is stored in the upper wafer carrier 541, it is visually confirmed that the wafer 50 does not hit the wafer carrier 541 (S5). When the wafer 50 collides with the wafer carrier 541 (NG), the teaching coordinates of the center coordinates of the wafer in the wafer carrier 541 are corrected (subtracted) based on the eccentric error (ΔX, ΔY) according to a command from the control unit 20. Then, the corrected value is stored in the storage circuit 31 as the teaching coordinates of the new center coordinates of the wafer in the wafer carrier 541 (S6). When the wafer 50 does not hit the wafer carrier 541 (OK), the teaching ends (S7). In FIG. 3, the solid line c and the dashed line d show the automatically corrected position of the wafer 50 and the position of the wafer 50 when the wafer center coordinates are at the design value coordinates. According to this embodiment, the wafer carrier 5
The teaching coordinates of the center coordinates of the wafer in 41 are detected by the pre-alignment unit 520, and are automatically corrected based on the eccentric errors (ΔX, ΔY) of the wafer 50 stored in the storage circuit 31, so that the workability is poor. The fine adjustment operation in the wafer carrier 541 can be omitted, and the teaching coordinates in the wafer carrier 541 can be easily determined as compared with the conventional example. As described above, according to the substrate transfer method of the present invention, difficult fine adjustment work in the substrate carrier can be omitted, and the teaching coordinates in the substrate carrier can be more easily compared with the conventional example. Can be determined.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a control system of a transfer robot of a wafer transfer apparatus to which a wafer transfer method according to an embodiment of the present invention is applied. FIG. 2 is a flowchart illustrating a wafer transfer method according to an embodiment of the present invention. FIG. 3 is a diagram for explaining automatic transfer of a wafer. FIG. 4 is a plan view of a conventional overlapping device. [Description of Signs] 5 Robot 31 Rewriteable storage circuit (storage means) 50 Wafer (substrate) 520 Prealignment unit 530 Stage unit 541 Wafer carrier (substrate carrier)

Claims (1)

Claims: 1. A substrate center coordinate in a substrate carrier for holding a substrate, a substrate center coordinate of a stage on which the substrate is mounted, and a substrate center of a pre-alignment unit for positioning the substrate. A first step of storing coordinates in a storage unit as teaching coordinates of the robot; and after the first step, moving a robot arm of the robot to respective teaching coordinates of the pre-alignment unit and the stage unit. A second step of fine-adjusting the position and storing each coordinate after the fine adjustment in the storage means as new teaching coordinates; and after the second step, the robot arm moves the substrate from the substrate carrier to the pre-alignment unit. The pre-alignment unit detects the eccentricity error of the substrate,
A third step of storing the eccentricity error in the storage means and positioning the substrate; and after the third step, correcting the teaching coordinates of the center coordinates of the substrate in the substrate carrier based on the eccentricity error. And a fourth step of storing the corrected values in the storage unit as new teaching coordinates of the center coordinates of the substrate in the substrate carrier.