Growth kinetics of nanocrystalline silicon from SiH2Cl2 by plasma-enhanced chemical vapor deposition

Abstract We demonstrate some specific features of hydrogenated chlorinated crystalline silicon with nanometer sized crystallites (nc-Si:H(Cl)) film fabricated from a H2-diluted dichlorosilane, SiH2Cl2 by radio frequency (RF) plasma-enhanced chemical vapor deposition (PECVD). Contrary to the conventional SiH4 based nc-Si:H growth, the crystallization occured from the initial growth stage on glass without incubation of an amorphous layer. Best crystallinity was obtained at substrate temperature, Ts of 200°C with a 10–20 nm-sized c-Si particles. The crystallinity increased with an increase in the pressure to ∼525 mTorr in the flow rate of SiH2Cl2, Fr(SiH2Cl2):Fr(H2)=3:100 (sccm) condition. In addition, the SiH2Cl2 based nc-Si:H(Cl) film had smaller optical absorption in the visible range than that of the SiH4 based nc-Si:H. The growth mechanism is discussed to better comprehend some specific features in terms of the gas phase and surface reactions in comparison with that in SiH4 and H2 system.