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 degrees 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 = [H-2]/[SiH4] in the PECVD process. The diagrams for different substrates provide insights into optimization of amorphous Si materials and solar cells. (C) 1999 American Institute of Physics. [S0003-6951(99)05241-9].