High-pressure plasma CVD for high-quality amorphous silicon

The growth rate of device grade amorphous silicon can be increased up to ∼7 Å/s by using high-pressure plasma CVD (∼5 Torr). Control of the electrode gap is important for utilizing high-pressure plasma. The narrowest possible gap, below which plasma becomes unstable, is the best in order to obtain high growth rates from the high-pressure plasma sticking to cathodes. The suppression of higher silane-related radicals is probably responsible for preserving the good quality at the high growth rates because of lower electron temperature in the high pressure and shorter residence time due to the small plasma space.