Gate-Level Mitigation Techniques for Neutron-Induced Soft Error Rate

Neutron-induced single-event upsets have become increasingly problematic in aggressively scaled process technologies due to smaller nodal capacitances and reduced operating voltages. We present a probability-based analysis of neutron strikes on combinational logic chains and investigate techniques to increase circuit robustness in terms of decreasing the probability of upsetting the capturing latch given a particle strike. We show that using a technique of inserting simple cross-coupled inverter pairs on error prone sites, as well as intelligently placing lower Vth devices and readjusting device width, can increase the robustness by nearly 20% thereby increasing the mean time between soft errors by almost 25%. This technique incurs substantially less overhead than traditional redundancy approaches to mitigating soft errors.