Centre National De La Recherche Scientifique

Jobin Yvon S.a.

Dmitri Kouznetsov

Bernard Drevillon

Alfred Hofrichter

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, &#x2208; 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 &#x2208; 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(&#x2208;)dx+B(&#x2208;)dx+C and the relation S=A(&#x2208;) dx+B(&#x2208;) dx+Cis thereby deduced which connects signals Sand Sto parameters &#x2208; and dx; dx is eliminated and a master function P(&#x2208;)=0 is thereby deduced; the equation is solved and the solutions are selected corresponding to values that are physically plausible in order to measure &#x2208; and use the &#x2208; value obtained to determine dx.

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Palaiseau, France

Dmitri Kouznetsov