Optical coating for eliminating ghost images in optical metrology tools

Abstract

The present disclosure relates to metrology measurement systems and related methods. In one or more embodiments a measurement system is provided. The measurement system includes a stage operable to retain an object and a light engine disposed above the stage. The light engine includes a light source directed towards the object, a first lens operable to collimate or focus a light from the light source, a reticle tray disposed between the light source and the first lens, and a reticle coupled to a reticle tray. The reticle includes a pattern and an anti-reflective coating disposed on the reticle. The coating is aligned with the pattern.

Dependencies are inferred from the claim text.