Scalability of Capacitive Hardening for Flip-Flops in Advanced Technology Nodes

Capacitive radiation hardening by design (RHBD) techniques to reduce the single-event cross section of flip-flops are shown to be effective at highly scaled technology nodes, especially for the terrestrial environment. Test results for different values of RHBD capacitance for both 40 nm and 28 nm technology node designs show that small values of RHBD capacitance (
$ < 3~\hbox{fF}$
) are effective in reducing the single-event cross section for low LET particles, neutrons, and alpha particles. Reductions of 4x, 2.5x, and 14x respectively were observed for the 28 nm designs for low LET particles, neutrons, and alpha particles, and reductions of 2.4x and 2.1x were observed for the 40 nm designs for low LET particles and alpha particles. Experimental pulse width measurement results for Xenon are used to highlight operating regions where capacitive RHBD techniques are most effective.