Supply voltage dependence of single event upset sensitivity in diverse SRAM devices

Experimental evidences are presented showing the variety of supply voltage dependence of single event upset (SEU) sensitivity in diverse SRAM devices. Devices under test (DUTs) from Alliance Memory, ISSI and IDT companies with different technologies were irradiated by several kinds of heavy ions at Heavy ion Research Facility in Lanzhou (HIRFL) cyclotrons. For the Alliance 256 kb SRAM device, SEU cross section increases by more than one order of magnitude as supply voltage decreases from 5.0 V to 3.0 V. SEU data of Alliance 64 kb SRAM also exhibits significant supply voltage dependence. The reduction of critical charge is the predominant factor worsening the device performance. While for the Alliance 8 Mb, ISSI 2 Mb and IDT 256 kb SRAM devices, no obvious trend was observed, which is attributed to the negligible net contribution of competing mechanisms. Those results suggest that the worst-case supply voltage for evaluation of SEU sensitivity depends on the test devices.