Hot-wire CVD of Ge nanoparticles on Si-etched silicon dioxide

Germanium nanoparticles are grown on SiO2 by hot-wire chemical vapor deposition of GeH4. Etching of the silica surface by low doses of SiHx (x=1, 2, 3) prior to Ge deposition is found to increase the nanoparticle density by up to an order of magnitude. This result is attributed to the creation of defects during the etching reaction in proportion to the SiHx flux that serve as nucleation sites for Ge particles. Mean particle sizes of ∼5 nm and areal densities over 1×1012 cm−2 are obtained using these techniques.