A comprehensive physically based predictive model for radiation damage in MOS systems

We have developed a comprehensive physically based predictive model for rad iation damage in MOS devices. The model involves essentially no adjustable parameter first principles calculations of both oxide hole trapping and int erface trap generation. With both oxide positive charges and interface trap generation accounted for, in principle, the model allows calculation of th e threshold voltage shifts from processing parameters. The model is based o n the statistical mechanics of point defects in solids and extensive electr on spin resonance (ESR) measurements of MOS systems. Although we believe th at this model is fundamentally correct and that it captures most of the fun damental physics of the damage phenomena, we emphasize that the treatment i s first order. The model involves some simplifying assumptions and in its p resent form, it applies only to high quality thermally grown oxides. We pre sent the model as a framework for understanding the radiation damage proces s and as a means to explain a very wide variety of apparently unrelated obs ervations long present in the literature. We believe the approach outlined in this paper will eventually allow manufacturers to build in radiation har d reliability with process design.