Vibrational spectrum of hydrogenated amorphous SiC films

Abstract

Abstract Infrared absorption spectra are presented of amorphous Si 1− x C x films made by the glow discharge process. Four bands, representing the stretching modes of SiH, CH, and SiC, and the wagging mode of SiCH 3 , were followed over the entire alloy composition range. It is shown that the compositional dependence of these bands varies in a manner predicted by a model in which Si and C atoms are randomly distributed throughout the film without chemical ordering. The bonded hydrogen content in the films is estimated to be of the order of 20 to 30 at%, depending on composition, with the silicon atoms bonding to a single hydrogen and the carbons bonding predominantly as CH 2 and CH 3 groups.