Parasitic bipolar effects on soft errors to prevent simultaneous flips of redundant flip-flops

Parasitic bipolar effects are intentionally used to prevent a simultaneous flip of redundant FFs, which make them more fault-resilient to soft errors. Device simulations reveal that a simultaneous flip of redundant latches is suppressed by storing the opposite values instead of storing the same value due to its asymmetrical structure. The state of latches always becomes a specific value after a particle hit due to the bipolar effects. Spallation neutron irradiation proves that no MCU is observed in the D-FF arrays in which the stored values of latches are equivalent to the specific value. The redundant latch structure storing the opposite values is robust to the simultaneous flip.