Composition and thickness of submicron metal coatings and multilayers on Si determined by EPMA

Abstract

Abstract Electron probe micro‐analysis is applied to the determination of thin films (20–200 nm) deposited on a known substrate. Bulk standards are used for calibration and data reduction is based on the computation of Φ( pz ) depth distribution functions. The Φ( pz ) model of Pouchou and Pichoir and the Gaussian Φ( pz ) expression of Packwood and Brown are compared by investigating Cu and Au films on various substrates. Particular refinements, mainly by introducing an effective atomic number, are discussed in respect of double layers and a large difference between the atomic number of the film(s) and that of the substrate. Mass thickness and composition of single layers as well as double layers can be determined with an accuracy of at least 5% relative. This was estimated in comparison with chemical analysis and Rutherford backscattering spectroscopy of alloys on Si applied to magneto‐optic recording.