Application of characteristic secondary ion mass spectra to a depth analysis of copper oxide on copper

Abstract

The study of molecular and cluster ions in secondary ion mass spectrometry has led to the concept of characteristic (fingerprint) spectra for this mode of ionization. Thin films of copper oxide with decreasing oxygen concentration as a function of depth have been investigated. The dependence of all mass peaks as a function of depth can be calculated from the measured values of just one peak by means of a linear superposition of the characteristic mass spectra of copper oxide and copper. Finally it is shown that the concentration of copper and copper oxide as a function of depth can be calculated from any mass peak when using the appropriate fingerprint spectra.