Surface chemistry dependence of native oxidation formation on silicon nanocrystals

The growth of silicon oxide on bare and SF6-etched silicon nanocrystals (Si-NCs), which were synthesized by an all gas phase approach, was investigated by examining the surface chemistry and optical properties of the NCs over time. Consistent with previous work in the low temperature oxidation of silicon, the oxidation follows the Cabrera-Mott mechanism, and the measured data are well fitted to the Elovich equation. The use of the SF6 plasma is found to reduce the surface Si-H bond density and dramatically increase the monolayer growth rate. This is believed to be due to the much larger volatility of Si-F bonds compared to Si-H bonds on the surface of the NC.