Metrology applications in lithography with variable angle spectroscopic ellipsometry

Abstract

Variable Angle Spectroscopic Ellipsometry is a common characterization technique for thin films used in lithography. These films include single and multiple layers of photoresists, anti-reflective coatings, and photomasks. The optical constants vary under different processing steps such as baking or UV exposure. Ellipsometry provides precise measurements of both the film thickness and optical constants, which are critical to ensure quality devices.