Comparative SIMS and US-LSNMS analysis of Cu/Ti multilayer thin films

Abstract

Sputtering of Cu/Ti layers was performed by Ar+ions. Analysis of the atomic and molecular composition of the sputtered plume was performed by means of Ultra-short Laser Neutral Mass Spectrometry (US-LSNMS) and Secondary Ion Mass Spectrometry (SIMS). Several ionic masses were observed and systematically studied with respect to the exposure time, laser fluence and target composition. The obtained data for complex layers indicate generally a good agreement between SNMS and SIMS. SIMS is more sensitive for many elements however the mass interferences can limit the analytical applicability. US-LSNMS mass spectra of Cu(Ti) sample have been acquired for different exposure times. In order to determine the effect of different laser ionization energies over the mass distribution of the elements, mass spectra of Cu(Ti) multilayers at several laser ionization energies were acquired. The elements interdiffusion was analyzed also by US-LSNMS, demonstrating the sensitivity, the limits and the future potential of the SNMS method for material characterization.