Heavy-Ion Induced Threshold Voltage Tails in Floating Gate Arrays

We studied heavy-ion effects on floating gate memories, focusing on the generation of tails in the threshold voltage distributions after irradiation. Using both experiments and simulations based on the Geant4 toolkit, we provide new insight, distinguishing two types of events, large events and small events, which are responsible for the secondary peak and the intermediate region in the post-rad threshold distribution, respectively. Both are well correlated with the energy deposited in the FG. Implications for error rate predictions are discussed.