OBSERVATION OF ELECTRON-TRANSFER IN THE SILICIDATION AND OXIDATION OFMOLYBDENUM BY AES AND EELS

AES and EELS are used to observe valence-band features of molybdenum i n its pure state and after its oxidation and silicidation. The auto-io nization process is exploited in probing the d-band occupancy, as it i s now manifested at higher energies that are accessible to AES and EEL S. The increase in intensity of the auto-ionization feature in oxidize d molybdenum and the decrease in the silicide, relative to clean molyb denum, is interpreted in terms of the change in the empty density of s tates (DOS) above the Fermi level (E(F)). The change in the valence-ba nd-related transitions, like the auto-ionization feature, the MNN Auge r transition and the p-d quasi-atomic transition in the EELS spectra a re used to explain the electron transfer in the ionically bonded oxide and the dominantly covalent silicide.