Generalized Ellipsometric Method for the Absorbing Substrate Covered with a Transparent-Film System Optical Constants of Silicon at 3655 Å*

Abstract

A new generalized method of determining all optical parameters of the system of an optically absorbing substrate covered by a transparent film is described. This is based on the successful numerical inversion of Drude’s exact ellipsometric equation. The input data of Δ and ψ can be obtained either by the use of different film thicknesses or of one film but with different ambients or multiple angles of incidence, or by any combination of these measurements. The method has been applied to the case of silicon for 3655 Å and the optical constants (n2–ik2) of silicon were found to be n2 = 6.66±0.02 and k2 = 2.22±0.04.