Radiation reliability benefit of area-optimized interleaved flip-flop layout in 28 nm technology

Abstract

In this work, an area-efficient interleaving layout scheme is proposed and tested for radiation reliability. The new layout scheme introduces area reduction opportunities by means of two flip-flops interleaved into one cell, resulting in a lower area compared to the reference FF. At the same time, the scheme efficiently utilizes a naturally occurring phenomenon of charge sharing and increased critical charge for soft error reliability. Two types of interleaving layouts, latch-based and inverter-based, were fabricated at 28 nm technology. The Interleaved Flip-Flops (IFFs) and a reference FF were tested for reliability using 5 MeV alpha particles. The results show strong effectiveness of IFFs against alpha particles.