Edge bead removal inspection by reflectometry

摘要

A method and apparatus for enhancing image contrast between resist-covered and bare silicon regions of a wafer, applicable to Edge Bead Removal inspection. The wafer is illuminated separately by s-polarized light and p-polarized light impinging at near the Brewster angle of silicon or resist, and an image difference between the reflected s-polarized light and the reflected p-polarized light is derived.