Investigations of SiC semiconductor nanoinclusions formed by sequential ion implantation and annealing in thermally oxidized Si

Abstract

The methods of X-ray photoelectron and extended electron energy loss fine structure (EELFS) spectroscopy were used for the investigation of phase composition and structure of SiO2 layer implanted sequentially by Si+ (energy of 100 keV, dose of 7 × 1016 cm -2) and C+ (energy of 50keV, dose of 7 × 10 16 cm-2) ions and postannealed at 1000 or 1100°C (2h). The Si-Si and Si-C bonds in carbide (SiC) nanoinclusions and C-C bonds of sp3 type in carbon inclusions are identified. The concentration of dangling bonds significantly decreases with elevation of annealing temperature. The distribution of SiC nanoinclusions at 1100°C annealing corresponds to the distribution of implanted atoms, whereas sp3-C phase is distributed nearly homogeneously over the implanted layer. The ratio of SiC to sp 3-C quantities is lower when intermediate annealing at 1100°C is provided after Si+ implantation. The local atomic structure near the surface is determined from the EELFS. The experimental results demonstrate the physical basis of white photoluminescence, originating from the SiC nanocrystals, diamond-like carbon particles, matrix, and interfacial defects. Copyright © 2008 John Wiley & Sons, Ltd.