Impact of Low-Energy Proton Induced Upsets on Test Methods and Rate Predictions

Direct ionization from low energy protons is shown to cause upsets in a 65-nm bulk CMOS SRAM, consistent with results reported for other deep submicron technologies. The experimental data are used to calibrate a Monte Carlo rate prediction model, which is used to evaluate the importance of this upset mechanism in typical space environments. For the ISS orbit and a geosynchronous (worst day) orbit, direct ionization from protons is a major contributor to the total error rate, but for a geosynchronous (solar min) orbit, the proton flux is too low to cause a significant number of events. The implications of these results for hardness assurance are discussed.