Low temperature fast growth of nanocrystalline silicon films by rf-PECVD from SiH4/H2 gases:: microstructural characterization

Hydrogenated nanocrystalline silicon thin films were deposited at a high rate of 0.8 nm s(-1) by conventional (13.56 MHz) plasma enhanced chemical vapour deposition from SHi(4)/H-2 gas mixture at a low temperature of 200 degrees C. The effects of hydrogen dilution, radio frequency power density, substrate temperature and deposition pressure on the crystalline volume fraction and the deposition rate of films were systematically investigated. The results show that the high hydrogen dilution and the substrate temperature are favourable for improving the crystallinity properties. The high deposition rate requires high power density over 0.7 W cm(-2) in combination with high deposition pressure above several hundreds of Pa to overcome the degradation of film quality.