On the new potentials of ellipsometry arising from the null optical circuit. Ellipsometry of real surface structures. 17. Metrology of the null ellipsometry. On the features of the experiment by definition of parameters of the phase compensator

Features of experiment by definition of parameters of a nonideal phase compensator were studied. Character of the interzone polarization angles spread caused by an inexact specification of not only the basic phase parameter ρ, but also small parameters ρ1 and ρ2, defining nondiagonal elements of Johns matrix of the compensator, was studied. Procedure of averaging of polarization angles on measuring bands considering nonideal compensator was also studied. The expressions obtained with the use of invariants of ellipsometry and specifying key parameters f and δ of the nonideal compensator were analyzed. Parameters ρ1 and ρ2, entering the invariants, are expressed through the key parameter ρ by the linear relations obtained with the help of adjustment procedures. The analysis of the experimental data obtained on four silicon samples with the hyperfine films SiO2 on them was carried out. The conclusion on significant heterogeneity of the quartz compensator of ellipsometer "LEF-3М-1" working under the zero scheme was made. The important conclusion on the possibility of estimation of heterogeneity of the reflecting surface of samples on the character of interzone spread of polarization angles.