Application of high energy resolved X-ray emission spectroscopy for monitoring of silicide formation in Co/SiO2/Si system

High-energy resolved X-ray emission spectroscopy was used to study the influence of oxide thickness on the thermally-induced CoSi2-formation in the Co/SiO2/Si system. The Si L(2,3) X-ray emission spectra have shown different fine structure dependent on the thickness of the buried oxide layer, the annealing temperature and the time of annealing. A full analysis of silicidation is undertaken on the basis of comparison of the spectra of the samples under investigation with those of reference samples of c-Si, SiO2 and CoSi2. It is found that silicidation in this system, with formation of CoSi2, starts at annealing temperatures above 900 deg C. Annealing at 11O deg C for 1 0 s was required for formation of the CoSi2 phase in the Co/SiO2/Si system with a 3-nm thick layer of SiO2. It is shown that increasing annealing time from 1 0 to 45 s leads to formation of CoSi2 for thicker (about 1 0 n m) layers of SiO2.