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.
Bibliographical noteFunding Information:
This work was supported primarily by the MRSEC program of the National Science Foundation under Award Nos. DMR-0212302 and DMR-0819885 by the IGERT Program of the National Science Foundation under Award No. DGE-0114372 and partially by SPAWAR and NSF Grant No. DMI-0556163. This work was also partially supported by the Center for Nanostructure Applications at the University of Minnesota. Portions of this work were carried out in the IT Characterization Facility, which was partially supported through the NSF NNIN program.