Radiation Resistant MNOS Memories

Three types of memory transistor structures were subjected to gamma, neutron and electron radiation. The survival of stored information as a function of total dose and dose rate was recorded, and in addition, the effect of radiation on the overall writing and storage characteristics of the devices was studied. The results indicate that the threshold voltage vs applied voltage characteristics of the transistors are essentially unchanged up to total doses of 108 rads. A specific bit of stored information will survive 106 rads. The expected insensitivity of stored information to photocurrents during high intensity radiation spikes was proved by experiment.