Structure and photoluminescent properties of SiC layers on Si, synthesized by pulsed ion-beam treatment

We report the formation of the continuous beta-SiC layers on Si by means of C+ implantation into Si followed by pulsed ion-beam treatment (C+, 300 keV, 50 ns). Transmission electron microscopy and electron diffraction indicate the formation of a polycrystalline beta-SiC layers with a grain size of up to 100 nm. Porous SiC/Si structures were prepared by anodization and were studied by photoluminescence (PL) at room temperature. Three PL bands were observed at 460, 520 and 615 nm and were ascribed to the SiC nanocrystals, C-rich clusters and Si nanocrystals, respectively. The time constant tau = 40 ns was deduced from time-resolved PL measurements. It is close to the value for direct band gap semiconductors and is shorter nearly by 3 orders of magnitude than that for porous Si. (C) 2003 Published by Elsevier Science B.V.