Metallic thin film thickness determination using electron probe microanalysis

An experimental procedure to determine metallic thin film thicknesses by using electron probe microanalysis (EPMA) is presented. Several mortoelemental films of Al, Ti, Cr, Cu, Nb, Mo and Au with different thicknesses, deposited on an Si substrate, were characterized by Rutherford backscattering spectrometry for thickness measurement. Characteristic x-ray intensities were measured for films, substrate and bulk standards. The ratios of these intensities (k-ratio), were compared with those obtained from Monte Carlo simulations based on the subroutine package PENELOPE, and good agreement was found. The results from simulation and experiments were added to build calibration curves of k-ratio vs thickness for the monoelemental films investigated. A simple analytical function was fitted to these curves and the behavior of its parameters with atomic number was studied. Copyright (C) 2001 John Wiley & Sons, Ltd.