A two-layer Ti-O film prepared by using a technique of d.c.reactive sputter deposition with ion beam bombardment is investigated with XPS and AES.The results show that titanium oxides vary along with the depth of the film.There is a Tio2 layer on the surface of the film after the carbon contamination layer is sputtered away.Titanium and carbon enter the silicon substrate and silicon diffuses into the film during Ar+ bombardment

which causes co-existance of titanium oxides with various stoichiometric composition and the fraction of TiO2 first gradually reduces and then increases along with the film depth.Moreover

the mixed layer at the interface of the substrate and the film consists of TiO2

Ti2O3

TiO

partial oxidized SiO2-x and silicon.