Atmospheric adsorption effects in hot-wire chemical-vapor-deposition microcrystalline silicon films with different electrode configurations

Hot-wire chemical-vapor-disposition (CVD) thin silicon films are studied by means of dark conductivity, FTIR, hydrogen evolution, and SEM surface characterization. Three types of metastability are observed: (1) long term irreversible degradation due to oxidization processes on the film surface, (2) reversible degradation determined by uncontrolled water and/or oxygen adsorption, and (3) a fast field-switching effect in the film bulk. We propose that this effect is associated with the morphology changes during film growth and an electrical field induced by adsorbed atmospheric components on the film surface. It is found that metastable processes close to the film surface are stronger than in the bulk. (c) 2005 Pleiades Publishing, Inc