Surface and in-depth characterization of TiC/C and Ti(C,N) layers by means of AES and Factor Analysis

Magnetron sputtered TiC/C multilayers and Plasma Vapour Deposited Ti(C,N) layers have been investigated by AES. The carbon sensivity factor has been calibrated for the correct composition of a TiC standard sample. Nitrogen has been measured indirectly based on the Ti(L3M23M23)/Ti(L3M23V) peak area ratio in the direct E.N(E) spectrum using Ti, TiC and TiN standard samples. The influence of Tougaard background removal has been tested. As the less accurate method taking the Ti peak-to-peak ratio has been found to give adequately good results. It has been possible to recalculate AES depth profiles, where only peak-to-peak values and no peak areas in the direct spectrum are available. Factor Analysis has been applied to AES depth profiling results. The data matrix in each column contains the linked experimental spectra of the measured elements. Based on the standard spectra the main components of a TiN layer on silicon have been identified by Factor Analysis. The structure of a TiC/C multilayer system has been resolved by the characteristic C(KLL) peak shape in C and TiC. Factor Analysis enables to calculate the individual profiles for Ti, TiC and C.