Ellipsometric Measurements and its Alignment: Using the Intensity Ratio Technique

Using first-order treatment on azimuth errors of the polarizer (P) and analyzer (A) with respect to the plane of incidence (POI), we construct two intensity ratios around a certain configuration, such as P=±π/4 and A=0 as compared to A=π/2. These expressions can be used not only to align the azimuths of the polarizer and analyzer to the POI, but also to obtain the ellipsometric parameter ψ without locating the minimum intensity. BK7 glass and SiO2/Si thin film are ultilized to evaluate this technique.