THEORETICAL-STUDIES ON NITROGEN-OXYGEN COMPLEXES IN SILICON

Semi-empirical PM3 cluster calculations are used to show that stable, electrically active NO complexes may exist in silicon. Based on their relative stability with respect to oxygen and nitrogen pairs, the reta rdation of thermal double donor formation in the presence of nitrogen is explained, but an equilibrium concentration much less than that of NN pairs is predicted. It is also shown that interaction of NO with a single nitrogen atom creates a bistable NNO defect, while encounter wi th an oxygen or an NN pair preserves the electrical activity of the NO centre. The possible role of the NO complex in shallow thermal donor formation is discussed.