HIGH-PRECISION UV-VISIBLE NEAR-IR STOKES VECTOR SPECTROSCOPY

An ellipsometer utilizing the polarizer-sample-retarder-rotating analy ser configuration measures all four elements of the Stokes vector. Con sequently the ellipsometric parameters PSI and DELTA as well as the po larization transfer factor D of the sample can be measured simultaneou sly as a function of the photon energy E. The measurement of all four elements of the Stokes vector is shown to be well suited for the ellip sometric characterization of non-ideal samples, e.g. laterally inhomog eneous or rough samples, and it may be used to improve the precision o f high lateral resolution (''microspot'') measurements. Formulae for t he error spectra deltaPSI(E), deltaDELTA(E), and deltaD(E) were derive d by analysing the influence of the random errors of the measurement. These error spectra provide the weights in minimization procedures for the determination of the geometrical and strutural sample parameters and result, via the analysis of the hessian matrix, in the errors of t he sample parameters adjusted to the spectra. The effect of systematic alignment errors is discussed and fast Kramers-Kronig-consistent spec tral inversion is shown to be a useful tool for the reduction of syste matic model errors.