Optical properties fo thin CVD-tungsten oxide films by spectroscopic elipsometry

摘要

The physical compostion and optical constants of CVD-tungsten oxide films deposited onto Si substrtes by W(CO)_6 pyrolysis at k200, 300 and 400 deg C has been obtained by ellipsometric measurements made in he spectral range of 0.35-0.7 μm. It has been found that films formed at temeprautres lower than 400 deg C are amorphous, while WO_3 deposition at 400 deg C yields a polycrystalline strucutre. A two-layer model describes the experimental data well. In all cases a consiserably thick and rough surface laeyr is observed, the compositon of whcih differes from that of the bulk film.