<title>Thickness dependence of the optical constants of thin Pt, Au, and Rh films in the soft x-ray region</title>

Abstract

The optical constants, (delta) equals 1 - n and k, of very thin platinum, rhodium, and gold films have been determined from the reflectance data measured in the soft x-ray region of 60 - 900 eV. Five platinum films (63 - 153 angstroms in thickness), five rhodium films (53 - 124 angstroms), and nine gold films (49 - 270 angstroms) were prepared by ion-beam sputtering on BK7 glass substrates. A Debye-Waller factor was applied to the Fresnel reflectance to take into account the reflectance degradation due to the roughness in the surface and the interface in the least-squares curve fitting analysis. The optical constants determined for the platinum and rhodium films show little dependence on the film thickness, while those of the gold films show definite dependence in a thickness range of 70 - 120 angstroms.