Growth of microcrystalline silicon films using deuterium dilution

Abstract

The role of atomic hydrogen in microcrystalline silicon formation by plasma enhanced chemical vapor deposition is studied by deuterium dilution, SiH 4/D 2, in comparison with hydrogen dilution. The ratio of SiD* and SiH* emission intensities, SiD*/SiH*, observed in the plasma increases with increasing input power, indicative of increasing number of H–D exchange events. The ratio of deuterium to hydrogen content, D/H, in the film increases with increasing SiD*/SiH* in amorphous phase, while D/H remains constant in microcrystalline films. This implies the difference in hydrogen surface reaction in microcrystalline silicon growth from amorphous silicon growth. The mechanism of these reactions is discussed by investigating temperature dependence of D/H.