Radiation effects on ion-implanted silicon-dioxide films

The effects of radiation on SiO/sub 2/ films implanted with high ion doses are studied. The interface-state buildup is suppressed by the ion-implanted oxide. The amount of suppression depends on the ion dose, the gate bias during irradiation, and the annealing atmosphere. A radiation-hardening technique for field oxide is proposed, using the ion-implanted oxide. Radiation-induced interface-state density is suppressed by one order of magnitude using arsenic implantation. By applying this technique to a conventional bipolar process, current gain reduction is suppressed to within 10% after 10/sup 6/ rad(SiO/sub 2/) irradiation.<
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