Heavy Ion Induced Permanent Damage in MNOS Gate Insulators

Heavy-ion-induced permanent damage in MNOS gate insulators has been investigated using a Cf252 fission source. The electric field and ion LET thresholds for onset of the damage has been characterized. The results are consistent with a thermal runaway mechanism in the silicon nitride layer initiated by a single heavy ion and leading to a permanent high conductivity path through the dielectric layers.