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

We demonstrate some specific features of hydrogenated chlorinated crystalline silicon with nanometer sized crystallites (nc-Si:H(Cl)) film fabricated from a H-2-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 grass without incubation of an amorphous layer. Best crystallinity was obtained at substrate temperature, T-s of 200 degrees C with a 10-20 nm-sized c-Si particles. The crystallinity increased with an increase in the pressure to similar to 525 mTorr in the flow rate of SiH2Cl2, Fr(SiH2Cl2):Fr(H-2) = 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 HZ system. (C) 2000 Elsevier Science B.V. All rights reserved.