Annealing of Si surface region modified by plasma immersion implantation of nitrogen

Abstract

In the present work, the formation of a nano-scale Si surface layer is studied after high-temperature annealing of Si modified by shallow plasma immersion implantation of nitrogen with fluences of 1016 - 1018 cm−2. The implanted profiles of the atomic (N+) and molecular nitrogen (N2+) are modeled by SRIM for different annealing durations taking into account the diffusion process. The presence of Si-O and Si-N bonds is established by Fourier (FTIR) spectral analysis and spectroscopic ellipsometry (SE). The refractive index value measured at 632.8 nm varies between 1.46 and 1.59, corresponding to a low y/x ratio. The models using VIS and IR ellipsometric data reveal formation of nanostructured SiOxNy layer with Si inclusions.