Impact of Total Ionizing Dose on Low Energy Proton Single Event Upsets in Nanometer SRAM

The impact of the total ionizing dose (TID) on a low energy proton single event upset (SEU) in a 65-nm static random access memory (SRAM) is investigated based on a low energy proton accelerator. The body potential of the P-well is elevated due to charge depletion along the sidewall of shallow trench isolation (STI) induced by TID irradiation. The radiation-induced narrow channel effect causes a decrease in the area and the thickness of the SEU sensitive volume (SV), further resulting in the low energy proton SEU cross section being lowered in 65-nm SRAM with an external independent power supply of the memory array. The impact of the TID on the low energy proton SEU cross section is dependent on test patterns written to the memory array during TID irradiation and SEU testing. The low energy proton SEU cross section is the highest when the complement test pattern is written to the SRAM memory array during TID irradiation and SEU testing compared with the same and half complement patterns.