a-SiC:H Films by Remote Hydrogen Microwave Plasma CVD From Ethylsilane Precursors

Amorphous, hydrogenated, silicon carbide (a-SiC:H) films are deposited in the remote hydrogen microwave plasma (RP-CVD) process using diethylsilane as a single-source precursor. The effect of substrate temperature (T-S) on the kinetics of RP-CVD, chemical composition, structure, surface morphology, and properties (density, refractive index, and extinction coefficient) of the resulting a-SiC:H films is investigated. The T-S dependence of film growth rate implies that RP-CVD is an adsorption-controlled process. The increase of T-S from 30 degrees C to 350 degrees C causes the elimination of organic moieties from the film and the formation of a SiC network structure. The relationships between the content of SiC bonds, represented by the relative integrated intensity of the SiC IR band, and the film properties are determined. The number of SiC bonds is found to be a key parameter in the control of the examined film properties. The films deposited at T-S=350 degrees C appear to be very dense materials exhibiting small surface roughness and high refractive index. The results of the present study are compared with those reported for a-SiC:H films produced by RP-CVD from a triethylsilane precursor.