Comparative Simulations of Single Event Upsets Induced by Protons and Neutrons in Commercial SRAMs

Simulations of charge deposition by neutrons and protons have been performed for a Hitachi 4-Mbit SUM device and are combined with heavy ion data to predict single event upset cross-sections. Neutron and proton irradiations have also been performed for this device allowing simulations to be compared with experimental results. In addition, these experimental data along with simulations show that neutron and proton cross-sections are similar above 20 MeV but diverge at lower energies. Simulations are very dependent on the quality of the heavy ion data but accuracies of about a factor 3 are obtainable.