Atomistic simulation of Si oxidation

Since the advent of silicon device technologies, the scaling-down of device sizes has proceeded to within ready of atomic scale lengths. Consequently, it is necessary in some cases to reconsider device fabrication processes in the light of an understanding atomic scale phenomena. Since gate insulating films have been made thinner to such an extent that they are approaching nanometer thickness, a fabrication process for the thin insulating films can be one of good candidates for those considerations among others. We have been conducting theoretical analyses of Si oxidation to understand the mechanism of the early stages of oxygen molecule chemisorption and Si-O bond network formation. Those theoretical analyses require atomic-scale simulations, including electronic structure calculations. We have been, therefore, concentrating on the theoretical study to deal with this problem and to find some new principles inherent in oxidation processes. Then, by applying some of our calculated results, the findings have led to a new idea for the realization of atomically more uniform Si oxidation processes