Influence of carrier and doping gases on the chemical vapor deposition of silicon quantum dots

We present a study of the influence of H2 as a carrier gas on the nucleation and growth of silicon quantum dots (Si-QDs) on SiO2 by CVD. Compared with Si-QDs deposition from pure SiH4, the dilution of SiH4 in H2 leads to a strong increase of the deposition time without significant modification of the Si-QDs morphology. The effects of doping gas, phosphine and diborane on Si-QDs nucleation and growth are also investigated. We show that the nucleation of Si-QDs is strongly dependent on the SiO2 substrate surface chemistry. Si–OH groups are identified as nucleation sites for Si-QDs. We study the influence of H2 carrier gas and doping gases on their impact on Si-QDs nucleation.