On the carbon incorporation into a-SiC:H films with low carbon content

In this paper we report on carbon incorporation into a-SiC:H films with low carbon content deposited from SiH4:CH4:H2 gaseous mixtures. In the case of films deposited without H2 dilution, carbon incorporation mainly as CH3 groups, was determined. Increasing H2 dilution was found to induce a selective incorporation of radicals that affects the density of C—H bonds, thus reducing the mean number of carbon bonded hydrogen atoms per carbon atom. Our observations allowed the estimation of the oscillator strength for the C—H stretching mode of CH3 groups in undiluted a-SiC:H films, obtaining ΓC—H(CH3)=9×10−23 cm2.