Super Recovery of Total Dose Damage in MOS Devices

Super recovery of the gate threshold voltage has been observed for several types of commercial NMOS integrated circuits. These devices have characteristic recovery times that are as much as four orders of magnitude shorter than those reported for hardened oxides. Since these fast recovery times are comparable to the irradiation times used in conventional total dose facilities, their failure levels are strongly affected by the dose rate used for testing. An empirical model has been developed that predicts the general features of super recovery, and can be used to calculate the dependence of circuit failure levels on dose rate.