High-Temperature Annealing of Oxidized Silicon Surfaces

Abstract

The densities of fixed charge and trapping centers on thermally oxidized silicon surfaces have been measured by the MOS capacitance technique upon annealing in O2, N2, He, and vacuum at various temperatures from 600° to 1100°C. These surface characteristics are always determined by the conditions of the final high‐temperature process, except for , which will never increase in neutral ambients. In all atmospheres, higher annealing temperatures yield lower values. It was also found that the values are very sensitive toward trace amounts of water in the high‐temperature ambient. They decrease for increasing water vapor pressure. Effects of other impurities were not observed in this study. Based on saturation values and kinetic data a discussion is given of some models for both types of centers.