Single-Event Upset Cross-Section at High Frequencies for RHBD Flip Flop Designs at the 5-nm Bulk FinFET Node

Rapid advancements in semiconductor technologies have enabled circuit operation at gigahertz (GHz) frequencies. However, conventional radiation hardening by design methods may encounter challenges in the GHz frequency domain, leading to increased single-event upset (SEU) rates. In this study, the SEU susceptibility of flip-flop (FF) designs in a 5-nm bulk FinFET technology node, both with and without hardening techniques, operating at frequencies up to 0.7 GHz is assessed. Comprehensive experiments involving heavy-ion and alpha particles were conducted across a wide range of supply voltages and frequencies to investigate the SEU cross-sections. Results demonstrate the relationship between SEU cross-section, operating frequency, and particle linear energy transfer (LET) values for FF designs employing temporal and spatial hardening techniques. Notably, all hardened designs examined in this work exhibit significantly higher SEU cross-sections when operating at 0.7 GHz compared to 2.5 MHz, approaching or surpassing the SEU cross-section of an unhardened conventional D flip-flop. These findings underscore the significance of considering high-frequency and dynamic operational data, as relying solely on static or low-frequency information can lead to a substantial underestimation of SEU cross-sections, thereby elevating failure rates in deployed electronic systems.