Photochemical vapour deposition of hydrogenated amorphous silicon-carbon thin films by using a Xe2∗ excimer lamp

High energy photons (172 nm) provided by a Xe2∗ excimer lamp were applied to deposit a-SiC:H thin films on silicon substrates by irradiating a gas mixture of C2H2, SiH4 and Ar. The photo-CVD system, the processing conditions, film properties and their dependence on the precursor partial pressures and the substrate temperature are presented. Ellipsometric studies revealed that the deposition rate rises gradually with increasing C2H2 partial pressure, but no differences were observed by changing the silane concentrations. Samples deposited in the substrate temperature range between 353 and 523 K exhibit different porosity grade and density. Carbon and hydrogen content followed by IR spectroscopy as a function of precursor gases concentration and substrate temperature is reported.