Method for azimuthal alignment in fixed-angle ellipsometry

Abstract

Our objective is to develop a method for azimuthal alignment of the polarizer-analyzer in fixed-angle ellipsometry systems in which measurement of the light intensity in the straight-through mode is not possible. An analytical technique has been developed that allows the determination of the reference positions of the polarizer and analyzer through the use of reflection measurements from a dielectric sample at a single angle of incidence. The method was verified by using both a high-temperature unit and a room-temperature reflectometer system. In these cases the real part of the refractive index of the test sample was inferred with accuracy to within 0.5% and 1.7%, respectively. In addition the sensitivity of the technique to the polarizer-analyzer setting was assessed.