Cracking assisted nucleation in chemical vapor deposition of silicon nanoparticles on silicon dioxide

Abstract

Deposition of sub-monolayer silicon on SiO 2/Si(1 0 0) greatly facilitates nucleation in subsequent thermal chemical vapor deposition (CVD) of silicon nanoparticles. Sub-monolayer seeding is accomplished using silicon atoms generated via disilane decomposition over a hot tungsten filament. The hot-wire process is nonselective towards deposition on silicon and SiO 2, is insensitive to surface temperature below 825 K, and gives controlled coverages well below 1 ML. Thermal CVD of nanoparticles at 1×10 −4 Torr disilane and temperatures ranging from 825 to 925 K was studied over SiO 2/Si(1 0 0) surfaces that had been subjected to predeposition of Si or were bare. Seeding of the SiO 2 surface with as little as 0.01 ML is shown to double the nanoparticle density at 825 K, and densities are increased twenty fold at 875 K after seeding the surface with 30% of a monolayer.