ORIGIN OF MACROSCOPIC EFFECTS ON HARDENED MOSFET DEVICES FOLLOWING LOW-TEMPERATURE (90 K) IONIZING IRRADIATION

Macroscopic effects are observed on MOS transistors after low temperat ure ionizing irradiation:the dose dependence of the threshold voltage shift and significantly a novel dose rate dependence. The microscopic origin of these effects is thorougly discussed. A quantitative modelin g of the experimental results is made and we find that the subsequent formulation allows a determination of the hole stochastic transport pa rameter alpha in the gate oxide. The threshold voltage shift as a func tion of dose rate can then be predicted.