Method for characterizing or controlling the production of a thin-layered component using optical methods

Abstract

A method for characterizing or controlling the production of a thin-layered component using optical methods. Acquired signals Sand Sare processed in order to obtain parameters x, ∈ of the deposited layers. The stacking is represented by the product of two Abeles matrices for each direction of polarization s (perpendicular to the incidence plane) and p (parallel to the incidence plane): a known matrix Morepresenting the support and matrix dMrepresenting a thin transparent layer being deposited. The signal variations measured, dSand dS, are inverted to obtain thickness x and dielectric constant ∈ of the thin layer by the following operations: Taylor expansion as a function of variation dx of thickness x of the thin layer of the coefficients of matrix dM; the coefficients of matrix Mare calculated each in the form A(∈)dx+B(∈)dx+C and the relation S=A(∈) dx+B(∈) dx+Cis thereby deduced which connects signals Sand Sto parameters ∈ and dx; dx is eliminated and a master function P(∈)=0 is thereby deduced; the equation is solved and the solutions are selected corresponding to values that are physically plausible in order to measure ∈ and use the ∈ value obtained to determine dx.