Evolutionary phase diagrams for plasma-enhanced chemical vapor deposition of silicon thin films from hydrogen-diluted silane

Real-time optical studies have been applied to develop phase diagrams that characterize plasma-enhanced chemical vapor deposition (PECVD) of silicon thin films at low temperature (200 °C). The deposition phase diagrams describe regimes over which predominantly amorphous and microcrystalline Si phases are obtained as a function of the accumulated thickness and the hydrogen-to-silane gas flow ratio R=[H2]/[SiH4] in the PECVD process. The diagrams for different substrates provide insights into optimization of amorphous Si materials and solar cells.