Auger electron and IR spectroscopic studies of SOI structure formed by oxygen and nitrogen implantation

Abstract

The chemical composition and structure of silicon on insulator (SOI) formed by the combination of O+ (200 keV, 1.8*1018 cm-2) and N+ (180 keV, 4*1017 cm-2) implanted into silicon has been investigated by Auger electron, IR absorption and reflection spectroscopic measurements. After annealing at 1200 degrees C for 2 h, the in-depth composition profiles of the SOI structure show that the nitrogen segregates to the wings of the buried silicon oxide layer where it forms an oxynitride. The characteristic Auger spectrum for the buried oxide layer identified a chemical state of silicon whose major transition at 85 eV is different from that of bulk silicon or silicon in SiO2 and the ratio of the amplitude of the Si peak at 85 eV to the Si peak at 76 eV remains unchanged in the buried oxide layer. Infrared (IR) absorption and reflection spectra in the wavenumber range 800-5000 cm-1 were measured for the SOI structure. Interference fringes were observed in the IR spectra. By detailed theoretical analysis and computer simulation of the IR reflection interference spectra, refractive index profiles of SOI structure were obtained.