Measurement and mechanism investigation of negative and positive muon-induced upsets in 65-nm Bulk SRAMs

Irradiation experiments of positive and negative muon were conducted for 65-nm bulk CMOS static random-access memory. The experimental results reveal that parasitic bipolar action (PBA) contributes to negative muon-induced upsets. We observe an increase in single event upset (SEU) cross section at higher operation voltage under negative muon irradiation while positive muon shows an opposite decreasing tendency. Also, the proportion of multiple-cell upset (MCU) events to all the negative muon-induced upset events is up to 66, and more than a 20-bit MCU is observed. Furthermore, Monte Carlo simulation of particle and heavy ion transport code system (PHITS) is performed for explaining the difference in SEU between positive and negative muons. We also discuss the charge threshold that triggers PBA-induced MCU using measurement and simulation results with different momentum muons. The estimated threshold is much larger than the charge that the positive muons can deposit, which well explains that no PBA-induced MCUs are observed under positive muon irradiation.