Preparation of SiNx and composite SiNx-TiN films from alkoxide solutions by liquid injection plasma CVD

Monolithic SiNx and composite SiNx-TiN films were prepared on a Si wafer at 700 degreesC by a plasma chemical vapor deposition technique designed to inject ethanol solution of alkoxides (hexa-methyl-disiloxane and titanium tetra-ethoxide) at a feed rate of 0.05-0.3 ml min(-1) into a thermal Ar/H-2/N-2 plasma. The films were characterized by X-ray diffraction (XRD), Scanning electron microscope (SEM), X-ray photoelectron spectroscopy, electrical resistivity, and Vickers micro-hardness, The silicon nitride was found to be amorphous, designated as SiNx, by XRD. SiNx films obtained at a feed rate of 0,05 ml min(-1) exhibited the composition near Si3N4 with densely packed particles of 0.1 mum in size. In composite SiNx -TiN films, the N content was 30-35 and 40-45 at.% at a Si fraction of 0.1-0.5 and above 0.5, respectively, and the Ti and Si contents changed linearly and complementarily with the solution composition. SEM showed that films are 1-1.5 mum thick, possessing particle size of 300-400 nm at a Si fraction of 0.1, which increases to 1-2 mum at fractions higher than 0.3. The resistivity and microhardness of the monolithic TiN and composite SiNx-TiN films were measured. (C) 2002 Elsevier Science B.V. All rights reserved.