STRUCTURAL CHARACTERIZATION OF PURE AND VANADIUM DOPED FILMS OF RF-SPUTTERED SIO2

An investigation of the local atomic structure via compositional analysis, chemical stability and heat treatment of r.f. sputtered silicon dioxide films and r.f. sputtered vanadium-doped silicon dioxide films has been undertaken using a combination of IR spectroscopy, Rutherford backscattering, Auger electron spectroscopy, X-ray photoelectron spectroscopy, electron microprobe analysis and electron spin resonance. The effects of heat treatment in nitrogen on the bulk and interface properties are examined and comparisons made with the well characterized thermal SiO2-Si system. In the case where vanadium is introduced into the films it appears to be incorporated uniformly throughout for both very thin (0.05-mu-m) and thick films (2-mu-m). The presence of vanadium also results in a reduction in the number of E' centres, and heat treatment causes the metal to disperse into the SiO2 network as an ion which is present mainly in the form of V5+, and some lower valence states.