Nano-crystalline Si1 − xCx:H thin films deposited by PECVD for SiC-on-insulator application

In this work we study the effect of temperature, within low temperature conditions, on the structural properties of amorphous hydrogenated silicon carbide films, deposited by PECVD from appropriate SiH4, CH4, and H2 mixtures. The substrate temperature was varied from 300 to 400 °C. We also analyzed films deposited on silicon and silicon covered with SiO2 capping layer substrates. The Fourier transform infrared spectrometry studies show that films deposited on silicon covered with a SiO2 layer and deposited at 400 °C have a better coordination among Si and C atoms. Raman scattering spectroscopy measurements exhibit C–C bond vibration only for the films deposited at 400 °C, after annealing at 1200 °C. Growth process at 400 °C exhibit a larger deposition rate and the X-ray diffraction results also indicate the formation of H-SiC and β-SiC crystallites, without any thermal annealing. Post-deposition thermal annealing leads to the crystallization of all the amorphous films, apparently in epitaxial orientation with the silicon substrate.