Wireless substrate-like sensor

• US 20060171561A1
• Filed: 03/15/2006
• Published: 08/03/2006
• Est. Priority Date: 02/06/2002
• Status: Active Grant

• Current Assignee: CyberOptics Semiconductor, Inc. (Nordson Corporation)
• Original Assignee: CyberOptics Semiconductor, Inc. (Nordson Corporation)
• Inventors: Gardner, DelRae H., Ramsey, Craig C., Huntzinger, Greg, Lassahn, Jeffrey K.
• Granted Patent: US 7,456,977 B2
• Time in Patent Office: Days
• US Class Current: 382/103
• CPC Class Codes: H01L 21/67259 Position monitoring, e.g. misposition detection or presence detection
• CPC Class Codes: Y10S 414/135 Associated with semiconductor wafer handling

Abstract

A wireless substrate-like sensor is provided to facilitate alignment and calibration of semiconductor processing systems. The wireless substrate-like sensor includes an optical image acquisition system that acquires one or more images of targets placed within the semiconductor processing system. Analysis of images of the targets obtained by the wireless substrate-like sensor provides position and/or orientation information in at least three degrees of freedom. An additional target is affixed to a known location within the semiconductor processing system such that imaging the reference position with the wireless substrate-like sensor allows the measurement and compensation for pick-up errors.

Claims

1. A method for determining position and orientation of a flat target in three dimensions, the method comprising:

providing at least four reference indicia on the target;

digitizing an image of the target;

identifying the at least four reference indicia in the image of the target; and

solving a system of equations representing the indicia for a system of unknowns representative of the position and orientation based upon identification of the at least four reference indicia.

2. The method of claim 1, wherein the reference indicia are shaped circularly.

3. The method of claim 1, wherein digitizing an image of the target is performed with an image acquisition system.

4. The method of claim 3, wherein the image acquisition system includes an area array device.

5. The method of claim 4, wherein the area array device is a Charge Coupled Device (CCD).

6. The method of claim 4, wherein the area array device is a Complementary Metal Oxide Semiconductor (CMOS) image device.

7. The method of claim 4, wherein the image acquisition system is operably coupled to a robot.

8. The method of claim 7, wherein the robot is a material handling robot.

9. The method of claim 7, wherein the image acquisition system is embodied within a substrate-like sensor.

10. The method of claim 1, wherein the at least four reference indicia have high contrast with respect to a background of the target.

11. The method of claim 10, wherein the at least four reference indicia are dark, and the background of the target is light.

12. The method of claim 10, wherein the at least four reference indicia are raised above a surface of the target.

13. The method of claim 1, wherein the target is fixedly attached relative to a processing tool.