Control of Nucleation to Realize High Density Si Nanoparticles on SiO_2 Thin Films

摘要

A non-thermal method to facilitate nucleation for subsequent thermal chemical vapor deposition of Si nanoparticles on SiO_2/Si(001) with high density and uniform size is demonstrated. Submonolayers of Si adatoms are predeposited on SiO_2/Si(001) substrates by hotwire chemical vapor deposition with disilane in an UHV chamber. The nanoparticles are grown with a disilane pressure of 1x10~(-4) Torr at 550癈. The Si nanoparticles density is increased and size distribution is narrowed by predeposition of Si adatoms when compared to thermal growth on bare SiO_2/Si(001). The nanoparticles density can be controlled by the amount of Si adatom predeposition. 1.2xl0~(12) cm~(-2) density and 5.5 nm size are demonstrated on SiO_2/Si(001) under UHV-CVD conditions.