The Contribution of Low-Energy Protons to the Total On-Orbit SEU Rate

Direct Ionization Impact on Accelerator Mixed-Field Soft-Error Rate

“…Even if lower critical charges are considered, a safety margin of a factor 5 with respect to the traditional qualification would be sufficient to account for possible low-energy direct ionization effects in the accelerator mixed-field environment. This conclusion is compatible with that derived in [4] for space applications, which is also consistent with the similarity between the LEO and the mixed-field proton spectra (including the lowenergy range) and the mixed-field dominance of proton direct ionization with respect to other charged particles such as electrons, positrons, and positive and negative muons and pions. Moreover, the factor 5 is found to be even more conservative when considering technologies with smaller sensitive volumes, which is a relevant result for scaling trends.…”

“…One of the applications and environments for which lowenergy protons can potentially have a sizeable impact on the SER is the trapped proton belts for low-earth orbit (LEO) applications as well as a solar flare environment. A detailed RHA study was carried out to evaluate the possible SER impact of low-energy protons [4], not considered in standard proton qualification and SER prediction approaches. The outcome of such a study, based on a broad range of experimental low-energy proton data and space radiation environment conditions, was that, as opposed to requiring a systematic lowenergy proton qualification, a safety margin of a factor 5 with respect to the SER derived from the standard qualification (i.e., using the proton SEU cross section in the 20-200-MeV range, as per, e.g., the ESCC 25100 specification) should be applied.…”

Single Event Upsets Induced by Direct Ionization from Low-Energy Protons in Floating Gate Cells

“…Remarkably, these differences in the travelled paths may lead to protons reaching the active area with LET values that may differ up to 50%. This highlights that care is needed when evaluating SEU from proton direct ionization and predicting the corresponding error rate in space, as already shown in recent papers [3]- [5]. When possible, the physical removal of layers above the sensitive region would be of course the ideal solution [4], but also simulations can greatly help to gain insight into energy loss in the overlayers, if details on the die stack are available.…”

“…The threshold LET for heavy-ion induced upsets in CMOS technology is decreasing as the device dimensions are scaled down and bit flips from proton direct ionization have been reported on 65-nm SOI latches and SRAM cells for the first time in 2007 by IBM researchers [1], [2]. Today the effects of low-energy protons are a hot topic: the importance of these particles as a potentially relevant source of errors in space has been recently highlighted [3] and the criticalities of the related testing have been discussed in literature [4], [5].…”

Hardness Assurance for Low-Energy Proton-Induced Single-Event Effects: Final report for LDRD Project 173134

“…Results show that grazing angles are the worst case for LEP-induced SEUs in these SOI circuits. (A different LEP angular response was seen for bulk Si circuits in [3].) Angular scattering is shown to affect the measured LEP cross sections to a small degree, even in these circuits with very thin intervening materials.…”