Energy Deposition and Characterization of Single-Event Upset and Latch-Up Cross Sections With 14 MeV and Thermal Neutrons

Single-event latch-up (SEL) cross sections of static random access memory (SRAM) at high energy (100–200 MeV) are generally not reproducible with 14-MeV neutrons, differently to single-event upset (SEU) cross sections. We explain this phenomenon through Monte Carlo simulations, analyzing neutron–silicon interactions and the indirect energy deposition in sensitive volumes (SVs) resembling the two mechanisms, showing that the former approach is not sufficient to explain how the energy is deposited. The SRAMs were characterized in monoenergetic and spallation facilities and their Monte Carlo model was validated using various particle beams. Additionally, the contribution of individual ions to the SEU and SEL cross sections is quantified, demonstrating the distinct impact of these ions in the two mechanisms. For instance, alpha particles play a significant role in triggering SEUs, while they hardly induce SELs. This is related to the energy released by the ion in correlation with its range and the size of the SV. Finally, the models are validated against thermal neutrons, and the SEL sensitivity is also investigated, demonstrating the absence of SEL for devices with a linear energy transfer (LET) threshold above 2 MeV $\,\cdot \, \text {cm}^{2}/\text {mg}$ .