Migration behaviour of selenium implanted into polycrystalline 3C–SiC

Abstract

The migration behaviour of selenium (Se) implanted into polycrystalline SiC was investigated using Rutherford backscattering spectrometry (RBS), scanning electron microscopy (SEM) and Raman spectroscopy. Se ions of 200 keV were implanted into polycrystalline SiC samples to a fluence of 1 × 1016 cm−2 at room temperature. The implanted samples were isochronal annealed in vacuum at two different regimes. Initially, the samples were annealed from 1000 to 1500 °C in steps of 100 °C for 10 h. Another set, at 1300 °C, 1350 °C and 1450 °C for 20 h. Implantation of Se at room temperature amorphized the near-surface region of the SiC substrate. Annealing at 1000 °C already resulted in the recrystallization of the amorphous SiC. The SEM images showed that the polishing marks became less visible after implantation due to the sputtering and swelling effects. These crystallites became larger and more visible with increase in annealing temperature. No diffusion was observed for annealing up to 1200 °C. Slight peak broadening indicating diffusion was observed after annealing at 1300 °C. This broadening increased with increase in annealing temperature. In the second set of annealing, the diffusion coefficients at 1300 and 1350 °C were estimated to be 6.3 × 10−21 and 2.0 × 10−20 m2 s−1, respectively.