Accumulation and Suppression of Radiation-Induced Charge in MOS Structures

It is shown that when a MOS (metal–oxide–semiconductor) structure is simultaneously exposed to radiation and the high-field injection of electrons, part of the radiation-induced positive charge can be suppressed when interacting with injected electrons, and the density of surface states can increase. These phenomena must be taken into account during the operation of MOS radiation sensors in high-field charge injection modes. High-field injection modes used for postradiation suppression of positive charge in MOS sensors are analyzed. It is established that to annihilate one hole (radiation-induced positive charge), it is necessary to inject (0.5–2) × 10⁴ electrons into the gate dielectric; the magnitude of the electric field has almost no effect on the process of suppression of the radiation-induced charge.