Monte-Carlo prediction of single-event characteristics of 65 nm CMOS SRAM under hundreds of MeV/n heavy-ions in space

Single-event performance of 65 nm CMOS SRAM technology was revealed by Monte-Carlo methods, with heavy ions energy ranging from 20 MeV/n to 2 GeV/n. By comparing the energy-deposition spectrums in sensitive volumes (SV) and single event upset (SEU) cross sections, it was found that secondary electrons and nuclear reactions of the 200 MeV/n incident ions have significant impact on the device response. Secondary electrons excited by the energetic space ions can spread beyond the SV of the 65 nm bulk CMOS SRAM and result into partial collection of the ion track. This mechanism causes the constant increase of SEU cross section with ion LET, even deviating from the surface area of the SV by 3.3×. Nuclear reaction can lead to unexpectedly large energy-deposition events in the SV by 10x than the initial LET, which create SEU cross sections in the sub-LET
_th
region, although with lower probability than direct-ionization process by 10
⁴
×~10
⁵
×. Higher ion energy seems to enhance the influence of secondary electrons and nuclear reaction. Moreover, soft error rates of the 65 nm bulk CMOS SRAM technology on GEO were predicted and discussed.