Patent ID: 7167241

Claim:
A method of determining dielectric function and layer thicknesses of a thin metal film deposited onto a substrate using simultaneous in-situ transmission spectroscopic ellipsometric (SE) and transmission intensity (T) measurements to break correlation between thickness and optical constants of very thin absorbing films, comprising the steps of: practicing steps a, b and c, said steps a, b and c being: a) providing a system for depositing metal onto a substrate and a substrate; b) providing a system for directing electromagnetic radiation toward said substrate at an oblique angle of incidence; c) proposing a mathematical model for said substrate as metal is deposited thereonto which comprises at least dielectric function defining parameters and thickness; d) during deposition of metal onto said substrate monitoring ellipsometric and intensity characterizing electromagnetic radiation which transmits through said substrate and enters a detector; e) performing a plurality of time sequenced mathematical regressions to evaluate said dielectric function defining parameters and thickness using the detector output for both received ellipsometric and intensity characterizing electromagnetic radiation.