Bias Dependence of Single-Event Upsets in 16 nm FinFET D-Flip-Flops

With fabrication processes migrating from planar devices to FinFETs, the differences in physical structure necessitate evaluating the SEU mechanisms of FinFET-based circuits. Since FinFET-based bi-stable circuits have shown better stability at low supply voltages and hence improved power dissipation, it is also necessary to assess the SEU performance over a range of voltages. In this work, the SEU cross section of FinFET-based D-flip-flops was measured with alpha particles, protons, neutrons, and heavy-ions. Results show a strong exponential increase in the SEU rate with reduction in bias for low-LET particles. Technology Computer Aided Design (TCAD) simulations show that the weak variation of collected charge with supply voltage, combined with the standard bias dependence of critical charge, is responsible for this trend.