The Impact of Delta-Rays on Single-Event Upsets in Highly Scaled SOI SRAMs

Monte-Carlo radiation transport simulations are used to quantify energy deposition from delta-rays in sensitive volumes representative of future SRAM technologies. The results show that single and multiple delta-ray events are capable of depositing sufficient energy to cause SEUs in nonadjacent SRAM cells separated by many micrometers. These results indicate the necessity of considering the variability of the charge track structure when evaluating the single event response of these highly scaled technology nodes. These effects have important implications forradiation hardening techniques that rely upon spatial separation of critical and redundant nodes, and simulation of device and circuit level response to heavy ions with respect to ion track structure.