Real-time image processing to measure substrate offsets and apply corrections to robot end effector positioning

Abstract

A system includes a substrate support configured to support and rotate a substrate a sensor positioned above the substrate support. Control logic causes the sensor to generate a images of an area of the substrate support and a portion of the substrate in a field of view of the sensor during rotation of the substrate support. Control logic performs edge detection by intensity-thresholding the images to identify a first edge of the substrate and a second edge of the substrate support. Control logic generates data representing a gap distance between the first and second edges and determines, from the data, a magnitude and a direction of an offset between a first center of the substrate support and a second center of the substrate. Control logic converts the offset to coordinates within a coordinate system of a robot and provides the coordinates to the robot.

Images