HI-ERDA, Micro-Raman and HRXRD studies of buried silicon oxynitride layers synthesized by dual ion implantation

Silicon oxynitride (SixOyNz) buried insulating layers were synthesized by dual implantation of nitrogen (14N+) and oxygen (16O+) ions sequentially into single crystal silicon in the ratio 1:1 at 150 keV to ion-fluences ranging from 1 × 1017 to 5 × 1017 cm−2. Heavy ion elastic recoil analysis (HI-ERDA) studies of as implanted samples show Gaussian like distributions of nitrogen and oxygen. After annealing at 800 °C, both the nitrogen and oxygen distributions appear as flat plateau like regions near projected range showing the formation of a continuous buried oxynitride layer. Micro-Raman study of as implanted samples shows a broad peak at 480 cm−1 for all fluences. It signifies a complete amorphization of silicon due to high fluence implantation. The annealing at 800 °C results in the reduction of the intensity of the broad peak observed at 480 cm−1 and also gives rise to an additional peak at 517 cm−1. It shows partial recrystallization of damaged silicon due to annealing. The X-ray rocking curves studies from high-resolution X-ray diffraction (HRXRD) of the samples implanted with different fluences have also further confirmed partial recrystallization of damaged silicon on annealing.