Transmission electron microscopy and Auger electron spectroscopy of silicon-on-insulator structures prepared by high-dose implantation of nitrogen

Abstract

The effects of substrate temperature and ion dose on silicon-on-insulator structures prepared by nitrogen implantation were characterized by transmission electron microscopy and Auger electron spectroscopy. Substrate temperatures below 200 °C during implantation result in amorphous surface layers that become polycrystalline after annealing. Implantation above 800 °C leaves the surface single crystalline containing a high density of defects. The majority of these defects are removed after annealing. High nitrogen doses (1.6×1018 cm−2 at 150 keV) resulted in two nitride layers separated by a porous region. This porous region may be attributed to the creation of N2 gas. A continuous nitride layer, without a porous region, was formed using a nitrogen dose of 9.4×1017 cm−2. When a nitrogen dose of 4×1017 cm−2 is used, however, it results in a two-phase layer containing amorphous nitride and Si crystallites.