ABSTRACT

Hydrogenated nanostructured silicon (ns-Si:H) thin films have been deposited in a pulsed argon-silane glow discharge. The structural, optical and electrical film properties have been investigated as functions of the plasma duration (T_on) and the deposition temperature (T_s) and compared to those of films deposited under the same plasma conditions but with a continuous wave (CW) plasma. When deposited at room temperature, a T_on increase from 0.1 s to 1 s leads to rougher and more porous films with deteriorated optical and transport properties. The thermal crystallization and the laser crystallization of such films were compared to evidence the correlation between the film structure and the crystallization threshold. At higher deposition temperature, the T_on is chosen just before the α → γ¹ plasma transition. A drastic change appears in the optical and electrical properties of ns-Si:H films above 50°C, when the CW films only show a gradual improvement of their properties with increasing T_s.