Sample masking in ellipsometer and the like systems including detection of substrate backside reflections

摘要

A system and method of preventing substrate backside reflected components in a beam of electromagnetic radiation caused to reflect from the surface of a sample in an ellipsometer or polarimeter system, involving placing a mask adjacent to the surface of the sample which allows electromagnetic radiation to access the sample over only a limited area, wherein the mask can include detector elements for collecting electromagnetic radiation reflected from the sample backside.