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

Abstract

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.

SEE Sensitivity Evaluation for Commercial 16 nm SRAM-FPGA

“…Given its high processing power and configuration flexibility, static random-access memory (SRAM)-based field-programmable gate array (FPGA) has become one of the most fascinating devices in astrionics [1][2][3]. However, particle-induced single event effects (SEE) in SRAM-FPGA have shown diversity and complexity in previous studies.…”

“…This was because the basic SRAM architectures were sensitive to single event upset (SEU), single event latch-up (SEL), and single event functional interrupt (SEFI). The corruption of logic values like SEU, disturbance of the functionalities like SEFI, and the thermal damage of circuits like SEL have different effects on the FPGA [1][2][3]. Though SEU is not so destructive as SEL, the occurrence of upset errors in FPGA configure RAMs (CRAMs) may change the internal states of the circuits.…”

“…Though SEU is not so destructive as SEL, the occurrence of upset errors in FPGA configure RAMs (CRAMs) may change the internal states of the circuits. This may propagate to the primary outputs of circuits and produce bit errors, or even cause system failures [3][4][5][6][7]. Thus, some typical radiation-hardened FPGAs have been designed and widely employed in space missions [3,[6][7][8].…”

“…The Xilinx Ultrascale + FPGA has excellent performance and large storage capacity and it is hugely appealing in data handling. However, the SEU influence and FPGA response are more complicated due to their small feature size, high performance, and special charge collection mechanisms in a radiation environment [3]. Apart from the fault injection in the designing procedure, the irradiation results are more direct and effective to characterize the sensitivity of FPGA.…”

“…Moreover, systematic SEE results are essential for the module's potential applications in the radiation environment [11]. Further, FPGA irradiation data will have a guiding significance for logic protections in the design flow and utilization of error mitigation strategies at a system level [1,3].The paper is organized as follows: The device under test (DUT) and testing methods are provided in Section 2. We describe the irradiation parameters and experimental details in Section 3.…”