Microstructure analysis of a-SiC:H thin films grown by high-growth-rate PECVD

Hydrogenated amorphous silicon carbide (a-SiC:H) thin films were synthesized by a non-conventional Plasma Enhanced Chemical Vapor Deposition (PECVD) system in which a 350 kHz High Frequency (HF) is coupled to the standard 13.56 MHz Radio Frequency (RF). Varying the methane to silane gas flux rate in a high power regime, a series of a-SiC:H layers were deposited on silicon substrates with a carbon ratio ranging from 0.25 to 0.46. A very high growth rate up to 150 A/s coupled with a very large homogeneity of both thickness and composition (less than 1.5% on 6 in. Si wafers) were achieved. A careful analysis of chemical composition and microstructure of the films was performed combining Infrared and Micro-Raman spectroscopies.