New design of the variable angle infrared spectroscopic ellipsometer usingdouble Fourier transforms

A new type of incidence-angle-variable infrared spectroscopic ellipsometer working in the 2100-10 000 wave number range has been designed and construc ted. For the system, the analyzer and polarizer were driven by two microste pping motors having hollow shafts and rotating synchronously with a speed r atio of 2:1, i.e., A = 2P. The incidence angle can be varied from 30 degree s to 90 degrees with an accuracy of 0.01 degrees. The doubled Fourier trans forms as both functions of the wave number and the azimuthal angles of the polarizer and analyzer were carried out and integrated in the system. Two s ets of ellipsometric parameters measured in the experiment have been used t o test the data self-consistency of the system. In data reduction, the erro r arising from the slight anisotropy of the stray light was corrected. In a pplication, the complex dielectric function of the Au film was measured wit h a data accuracy better that 1% in the entire spectral range. (C) 2000 Ame rican Institute of Physics. [S0034-6748(00)01207-7].