Film Growth Mechanisms of Amorphous Silicon in Diode and Triode Glow Discharge Systems

Abstract

AbstractBy simulating the growth morphology of plasma-deposited amorphous silicon films on patterned substrates using a Monte-Carlo technique, we find the effective sticking coefficient for the dominating mass transporting species to be quite different depending on the film growth mechanism. The physical-vapor-deposition-like growth regime producing defective materials is associated with species like SiH2 and SiH which have a large effective sticking coefficient, while the chemical-vapor-deposition-like process producing “device quality” materials is linked to species like SiH3 which has a much smaller effective sticking coefficient. In a triode reactor the physical-vapor-deposition-like process is suppressed since species with small effective sticking coefficients are selected. However, the growth rate decreases rapidly as the substrates are moved away from the plasma. There seems to be an incompatibility between good material quality and fast growth rate in the plasma deposition of amorphous silicon in either diode or triode reactors.