Dose Dependence of Single Event Upset Rate in MOS dRAMS

The upset sensitivity of MOS dynamic RAMs has been found to decrease as a result of total dose irradiation, both for cobalt-60 gammas and MeV helium ions, up to the point where device failure is imminent. Device failure levels have been compared for cobalt-60 gammas, and MeV helium ions and protons. It has been found that in terms of rad(Si) necessary to cause device failure, cobalt-60 was more effective than protons which were more effective than helium ions.