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
A. I. Semenenko, I. A. Semenenko
Institute of Applied Physics NAS, Ukraine, Sumy
The paper offers an approach to precision determination
of three complex parameters ρ, ρ1, ρ2
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
ρ1, ρ2 in terms
of the main phase parameter ρ. The substitution of the derived expressions
for ρ1, ρ2 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.