Experimental Demonstration of Pattern Influence on DRAM SEU and SEFI Radiation Sensitivities

Thanks to laser and accelerator tests, we investigated the influence of test patterns regarding both SEU and SEFI radiation sensitivities for several DRAM technology nodes, from 210 to 90 nm. Regarding SEUs, we demonstrated that preponderant physical mechanisms vary with technology nodes, so patterns revealing worst-case SEU sensitivity vary as well. Regarding SEFIs, and in particular SEFLUs (Single Event Fuse-Latch Upsets), we shown that the pattern choice has also an influence on their detection rate during accelerator tests due to masking effects. Consequently, non-repetitive patterns, like “Random”, appear the most appropriate to evaluate cutting-edge DRAMs as all Cell-Upset modes are uniformly spread, and all addressing errors are detected.