Effect of Preanneal Heat Treatment on Oxygen Precipitation in Epitaxial Silicon

Abstract

AbstractSubstrate wafers used for fabrication of P/P+ epitaxial silicon wafers were preanneal heat treated at 650°C in nitrogen ambients prior to the epitaxial deposition process for various periods up to 300 minutes. Subsequently, epitaxial wafers were subjected to CMOS simulation heat treatments. Postepitaxial nucleation heat treatment at 750°C in nitrogen ambient was also done on some epitaxial wafers. The results shows that preanneal heat treatment can preserve precipitate nuclei from dissolution during the epitaxial deposition process and lead to a high bulk defect density. These results also indicate the effect of the thermal history and spatial location in the grown crystal on the bulk defect formation.