SEU Characterization of Three Successive Generations of COTS SRAMs at Ultralow Bias Voltage to 14.2-MeV Neutrons

This paper presents a single event upset (SEU) sensitivity characterization at ultralow bias voltage of three generations of commercial off-the-shelf static random access memories (SRAMs) manufactured in 130-, 90-, and 65-nm CMOS processes. For this purpose, radiation tests with 14.2-MeV neutrons were performed for SRAM power supplies ranging from 0.5 to 3.15 V. The experimental results yielded clear evidences of the SEU sensitivity increase at very low bias voltages. These results have been cross-checked with predictions issued from the modeling tool multiscales single event phenomena predictive platform. Large-scale single event latchups and single event functional interrupts (SEFIs), observed in the 90- and 130-nm SRAMs, respectively, are also presented and discussed.