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

Abstract

Silicon oxynitride (Si(x)O(y)N(z)) buried insulating layers were synthesized by dual implantation of nitrogen ((14)N(+)) and oxygen ((16)O(+)) ions sequentially into single crystal silicon in the ratio 1:1 at 150 keV to ion-fluences ranging from 1 x 10(17) to 5 x 10(17) 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 degrees 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 degrees 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. (c) 2009