Heavy-Ion Induced Single Event Upsets in Advanced 65 nm Radiation Hardened FPGAs

The 65 nm Static Random Access Memory (SRAM) based Field Programmable Gate Array (FPGA) was designed and manufactured, which employed tradeoff radiation hardening techniques in Configuration RAMs (CRAMs), Embedded RAMs (EBRAMs) and flip-flops. This radiation hardened circuits include large-spacing interlock CRAM cells, area saving debugging logics, the redundant flip-flops cells, and error mitigated 6-T EBRAMs. Heavy ion irradiation test result indicates that the hardened CRAMs had a high linear energy transfer threshold of upset ∼18 MeV/(mg/cm 2 ) with an extremely low saturation cross-section of 6.5 × 10 − 13 cm 2 /bit, and 71% of the upsets were single-bit upsets. The combinational use of triple modular redundancy and check code could decline ∼86.5% upset errors. Creme tools were used to predict the CRAM upset rate, which was merely 8.46 × 10 − 15 /bit/day for the worst radiation environment. The effectiveness of radiation tolerance has been verified by the irradiation and prediction results.