The Current Understanding of Charges in the Thermally Oxidized Silicon Structure

Generally accepted facts along with unanswered questions, concerning the four charges, , , , and , associated with the thermally oxidized silicon system are presented and briefly discussed. The discussions and information presented are based on comprehensive investigations carried out in the semiconductor industry over the past ten years. Although reasonably good empirical information concerning charge dependence on device processing is available, much remains to be learned regarding the physical origin of these charges. A simplified model is presented which indicates that most of the charges can be related to silicon bond defects in the thermally oxidized silicon structure.