Shape Feature Extraction for IC Wafer Circuit

IC wafer image is composed of basic shape, mainly including lines, rectangles, rounds and ellipses. Firstly, this paper analyzes the shape of IC circuit image by the geometry of basic shape. When the images are moved and rotated, the moment has the same feature. Therefore, we can calculate the moment, the barycentric coordinate points and barycentric moment which are invariant in the same image. Secondly, this paper analyzes the theory of Hough transform and extracts the lines and rounds in the IC circuit image by modified Hough transform. Finally, the pads which are the rounds are detected, and the boundary which is the lines is detected. We can count the number of the lines and pads, and calculate the start and end of the lines, the center and radius of the pads. The experimental results demonstrate the modified Hough transform can effectively and accurately detect the rounds and lines in the IC wafer image.