An internal calibration technique for pseudobinary systems by auger electron spectroscopy

Abstract

An internal calibration technique has been developed for the quantitative analysis of pseudobinary systems by means of Auger electron spectroscopy without the need for stan-dards of known composition. This technique has been used for analyzing PbO-In2O3 two-phase films and A1N-A12 O3 , AlAs-GaAs, and GaP-InP solid solutions. The technique is applicable to systems of the type (ACm) (BCn)1-x if the Auger intensities measured for elemens A, B, and C are given by the linear relationships I = xIA **, IB = (l-x)IB *, and IC = xIC ** + (l-x)IC C * where IA ** and IC ** are the inten-sities for pure ACm and IB * and I* are the intensities for pure BCn . To determine whether this criterion is satisfied, a series of Auger measurements is made on regions of dif-ferent composition within a single specimen (e.g., on speci-mens in which a concentration variation exists across the surface or surfaces exposed by repeated sputter-etching of a sample with an in-depth composition gradient), and plots of IA vs IB and IC/IB vs IA/IB are made. If these plots are linear over tne range of compositions investigated, it is assumed that the above linear relationships are valid over the whole range of the pseudobinary system. It is then possible to construct linear calibration plots of IA, IB , and IC vs x for the whole composition range.