METHOD FOR ANALYZING DEFLECTION OF THIN FILM

摘要

PURPOSE:To obtain the measured values of the refractive index and the thickness of a thin film with high accuracy by using a sample provided with an absorptive layer having the refractive index higher than the refractive indices of a base plate and the thin film between said plate and film. CONSTITUTION:An absorptive layer 10 having a high refractive index is provided between a base plate 1 and a thin film such as an epitaxial layer 2 on said plate in order to measure exactly the refractive indes and thickness of said thin film to increase the change in the parameter of elliptical polarization with respect to the change in the refractive index n1 and the thickness (d) of the thin film which are unknown and further to eliminate the influence of the light reflected from the rear of the plate 1 so that the refractive index n1 and the thickness (d) can be determined with good accuracy. Refraction light 12 is mostly absorbed in the layer 10 and does not arrive at the boundary 11 between the base plate and the high refractive index layer. Only the upper two layers are therefore required to be considered and there is no need for considering the plate 1 for analysis. Since there is no reflected light from the boundary 11 or the rear 6 of the base plate, the measuring error arising therefrom is eliminated.