Surface and optical analysis of SiCx films prepared by RF-RMS technique

Silicon Carbide thin films have been prepared by RF reactive magnetron sputtering of a silicon target in a mixture of Ar and CH4. Surface analysis was performed by X-ray photoelectron spectroscopy (XPS) to examine the elemental bonding at the surface and in bulk of the material. Optical analysis was carried out by ellipsometry to study the optical constants (n and k) and band gap of the films. Transmission and scanning electron microscopy, FTIR and X-ray diffraction, were employed to supplement our results. The near surface of SiC exposed to atmosphere was primarily composed of SiO2 along with amorphous carbon while the bulk of the material was SiC. At higher plasma power and lower CH4 concentration, the graphitic phase in the surface decreases and the refractive index increases while surface oxide layer remains present.