Method and apparatus for inspecting patterned thin films using diffracted beam ellipsometry

摘要

A method and apparatus for inspecting a repeating pattern on an object using an optical inspection system to detect variations in the pattern. The object is illuminated with substantially monochromatic light. A diffracted beam is formed. The diffracted beam has a plurality of polarization components. At least one of the polarization components of the diffracted beam is blocked. Variations in the pattern are detected as light intensity variations in the polarization components that are not blocked.