Effects of thickness on electronic structure of titanium thin films

Effects of thickness on the electronic structure of e-beam evaporated thin titanium films were studied using near-edge X-ray absorption fine structure (NEXAFS) technique at titanium L 2,3 edge in total electron yield (TEY) mode and transmission yield mode. Thickness dependence of L 2,3 branching ratio (BR) of titanium was investigated and it was found that BR below 3·5 nm shows a strong dependence on film thickness. Mean electron escape depth (λ) in titanium, an important parameter for surface applications, was determined to be λ = 2·6 ± 0·1 nm using L 2,3 resonance intensity variation as a function of film thickness. The average L 3 /L 2 white line intensity ratio of titanium was obtained as 0·89 from the ratio of amplitudes of each L 3 and L 2 peaks and 0·66 from the integrated area under each L 3 and L 2 peaks. In addition, a theoretical calculation for pure titanium was presented for comparison with experimental data.