Ultraviolet, Vacuum Ultraviolet, and Extreme Ultraviolet Spectroscopic Reflectometry and Ellipsometry

Abstract

This chapter describes various aspects of the application of spectroscopic ellipsometry in the UV range. After a short introduction on the electromagnetic spectrum and the definition of UV, VUV, PUV, and EUV ranges, general features of the optical indices versus wavelength are presented. Specific instrumental problems related to the wavelength range are discussed, in particular the problem of sources, polarizers, and detectors. The optical mounting selected to work in the PUV range is described in detail with the problems of stray light rejection and carbon contamination. Various measurement results at 157nm concerning oxynitrides, antireflective coatings, masks, phase shifters, and photoresists are also presented. Finally, the specific problem of EUV lithography and the associated metrology is introduced.