Large-scale three-dimensional (3-D) device simulations, focused ion microscopy, and broadbeam heavy-ion experiments are used to determine and compare the SEU-sensitive volumes of bulk-Si and SOI CMOS SRAMs. Single-event upset maps and cross-section curves calculated directly from 3-D simulations show excellent agreement with broadbeam cross section curves and microbeam charge collection and upset images for 16 K bulk-Si SRAMs. Charge-collection and single-event upset (SEU) experiments on 64 K and 1 M SOI SRAMs indicate that drain strikes can cause single-event upsets in SOI ICs. 3-D simulations do not predict this result, which appears to be due to anomalous charge collection from the substrate through the buried oxide. This substrate charge-collection mechanism can considerably increase the SEU-sensitive volume of SOI SRAMs, and must be included in single-event models if they are to provide accurate predictions of SOI device response in radiation environments.
Surface micromachined comb drive and microengine fluence thresholds and failure modes were investigated in x-ray, electron, and proton total-dose environments. Very high fluence levels were necessary to induce motion degradation or lockup for normal device biasing or operation. For the abnormal biasing of ungrounded or partially grounded dice, significantly lower fault thresholds were observed, but still in a medium or high fluence range.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.