Synthesis of nanocrystalline silicon carbide thin films by HW-CVD using ethane carbon precursor for photo detector application

Hydrogenated nanocrystalline silicon carbide (nc-SiC:H) films were prepared by hot wire chemical vapor deposition (HW-CVD) method using ethane (C₂H₆) as a carbon precursor. The influence of deposition pressure on structural and optical properties was investigated. The formation of nc-SiC:H films was confirmed by low angle x-ray diffraction (XRD), Raman spectroscopy and Fourier transform infrared (FTIR) spectroscopy analysis. An inverse relation between deposition pressure and deposition rate was observed. Optical band gap values, E_Tauc and E₀₄ increases with increase in deposition pressure. In fact, optical band gap values estimated from E₀₄ method was found higher than the E_Tauc values calculated from Tauc´s plot. Finally, at optimized deposition pressure (450 mTorr), a photo detector having configuration glass/nc-SiC:H/Al have been fabricated and its photo response was studied. Further study is required to improve the quality of nc-SiC:H films to make use in photo detectors.