FT-IR Based Ellipsometer Using High-Quality Brewster-Angle Polarizers
Simon G. Kaplan, Leonard M. Hanssen
A Fourier transform infrared (FT-IR) spectrometer-based broadband infrared ellipsometer has been developed around a pair of high-quality Brewster angle polarizers. These polarizers consist of four Ge plates in a chevron geometry and have been measured to have extinction ratios of less than 10-5 in the infrared spectral region. The ellipsometer can be used in transmission or reflection mode for angles of incidence of 10 to near grazing (dependent upon sample size). We describe the design and construction of the ellipsometer and initial testing of the system using measurements on Si wafers from 2 mm to 12 mm wavelength.