On the new potentials of ellipsometry arising from the null optical circuit. Ellipsometry of real surface structures. 3. Methods for precision determination of ellipsometer phase compensator parameters

The paper offers an approach to precision determination of three complex parameters p, p1, p2 of the phase compensator of the ellipsometer using an instrument alignment procedure combined with invariant relationships for the ellipsometry of anisotropic media. The alignment procedure allows one to express the small parameters p1, p2 in terms of the main phase parameter p. The substitution of the derived expressions for p1, p2 into ellipsometry invariants reduces the respective optimization problem to determination of only one complex parameter ρ (two real values) instead of three complex parameters (six real values) in the old technique. This approach dramatically reduces the influence of experimental errors and inhomogeneity of the reflecting surface used to build specimen invariants.