Kinetics of nucleation and growth of Si on SiO₂ in very low pressure SiH₄ chemical vapor deposition

Abstract

The initial growth kinetics for SiH4 chemical vapor deposition of Si on SiO2 at low temperature (500-600°C) have been revealed using rapid thermal UHV-CVD, together with in situ H2 thermal desorption spectroscopy to titrate the amount of exposed Si surface. In the few mTorr pressure range, the reaction is heterogeneous, i.e., dominated by surface reaction. Below ∼0.7 monolayer Si coverage, the growth kinetics is rapid (∼t4), indicating spontaneous generation of new nuclei, while at higher coverage Si island growth dominates.