A comparison of AES and RBS analysis of the composition of reactively sputtered TiSix films

By reactive sputtering of Ti in a gas mixture of Ar/SiH4 it is possible to form TiSi2. The influence of rf bias to the target on film composition is investigated. The dependence of partial pressure of SiH4 on film composition TiSix is also demonstrated. A phenomenological description of the physical processes mainly responsible for film composition is outlined. Analysis of the film composition of the TiSix films have been performed by using both Rutherford back scattering (RBS) and quantitative Auger electron spectroscopy (AES). The results obtained from a wide range of stoichiometries show that the composition data obtained from AES analysis deviate from the bulk stoichiometry obtained by RBS analysis. The conclusion is that the surface modification, caused by precleaning the TiSix films prior to AES analysis changes the surface composition significantly. There are, however, other effects which make quantitative AES analyses of the films difficult, i.e., the difference in escape depths for Auger electron...