Remote hydrogen microwave plasma chemical vapor deposition from methylsilane precursors. 2. Surface morphology and properties of deposited a-SiC:H films

Amorphous hydrogenated silicon carbide (a-SiC:H) films produced by remote microwave hydrogen plasma chemical vapor deposition from dimethylsilane and trimethylsilane precursors were characterized in terms of their basic useful properties including surface morphology, conformality of coverage, density, refractive index, optical absorption (absorption coefficient and optical bandgap) adhesion to a substrate, and friction coefficient. The effect of substrate temperature (varied in the range T_S = 30–400 °C) on the properties of a-SiC:H films is reported. In view of the scanning electron microscopy and atomic force microscopy examinations the films were found to be morphologically homogeneous materials exhibiting excellent conformality of coverage and small surface roughness, which drop with rising T_S to a small value of 0.9 nm at T_S = 400 °C. The relationships between the film compositional and structural parameters, expressed, respectively, by the atomic ratio Si/C, and the relative integrated intensities of the absorption IR band from the Si-C bonds (controlled by T_S), were determined. Due to their good conformality of coverage, strong adhesion to a substrate, very low friction coefficient, and excellent optical transparency in a wide range of wavelength a-SiC:H films produced from trimethylsilane precursor at high substrate temperature regime (T_S = 300–400 °C) seem to be useful as scratch-resistant protective coatings for optical glass elements and various metal surfaces. - Highlights: • a-SiC:H films were found to exhibit an excellent conformality of coverage. • The effect of structural parameters on the properties of a-SiC:H films is examined. • The increase in the content of Si-carbidic bonds improves a-SiC:H films' properties