Speakers
Description
Radiation-induced single-event upsets (SEUs) in advanced nanoscale memories present a major reliability challenge for CubeSat missions operating in proton-rich space environments. This work investigates SEUs in a realistic 14 nm FinFET (FF) memory array using Geant4 simulations under 1–500 MeV proton irradiation. A 2D array of 83 × 53 FF devices was modeled within a 7 × 7 µm² silicon cell including 23 Cu/SiO₂ BEOL layers, with the drain and fin defined as sensitive volumes. Energy deposition per event was recorded and classified into single-bit upsets (SBU) and multi-bit upsets (DBU, TBU, QBU), and cross-sections were calculated using the single-hit exponential model.
Results show that σSBU dominates the total cross-section, while σDBU is the primary contributor among multi-bit events. Both σSBU and σMBU decrease with increasing proton energy. Shielding analysis for ISS and polar orbits demonstrates that 1 mm aluminum reduces the soft error rate (SER) by approximately three orders of magnitude in ISS orbit and two orders of magnitude in polar orbit.
Interleaving analysis based on centroid radius calculations indicates that a spacing of ~300 nm eliminates most correlated multi-bit errors, significantly reducing DBU, TBU, and QBU occurrence. System-level reliability was evaluated through Uncorrectable Error Rate (UER) heatmaps expressed in FIT/day as a function of memory size and scrub interval. The combined use of shielding, interleaving, SECDED coding, and short scrub intervals substantially reduces FIT/day to levels compatible with CubeSat mission requirements, particularly in ISS orbit, while polar orbit conditions remain more challenging due to higher proton flux.