氢化纳米硅薄膜中的本征应力

Hydrogenated nanocrystalline silicon (nc-Si:H) film, as a promising photovoltaic material, has been attracted great interests. The intrinsic stress in nc-Si:H films which deposited on crystalline silicon (111) by radio frequency plasma enhanced chemical vapor deposition (RF PECVD) technology was investigated. If the difference of the thermal expansion coefficient of the crystalline Si substrate from that of nc-Si:H film was ignored, [P. Temple-Boyer, E. Scheid, G. Faugere, B. Rousset (1997) Residual stress in silicon films deposited by LPCVD from disilane. Thin Solid Films, vol. 310, pp. 234-237] the intrinsic stress in films indicates as the intrinsic compressive stress and it can be changed with depositing conditions. The structure disordering, hydrogen (or impurity) content and the thickness of grain boundary has a positive correlation with the intrinsic compressive stress, respectively. The intrinsic compressive stress varies with the silane dilution in hydrogen. It is appeared in high silane dilution in hydrogen deposited film can be ascribed to hydrogen incorporation. While the high stress in low silane dilution in hydrogen deposited film can be assigned to structure disordering and slow growing rate. This kind of stress increases with elevating the doping ratio due to dopants incorporation inducing structure disordering. While the intrinsic compressive stress decreases with raising the RF power density owing to structure ordering and hydrogen desorption.