Efficacy of Transistor Stacking on Flip-Flop SEU Performance at 22-nm FDSOI Node
Zongru Li, Christopher Elash, Chen Jin, Li Chen, Shi-Jie Wen, Rita Fung, Jiesi Xing, Shuting Shi, Zhi Wu Yang, B. L. Bhuva
Abstract
Fully-depleted silicon-on-insulator (FDSOI) technology nodes offer better single-event (SE) performance compared with comparable bulk technologies. However, upsets are still possible at nanoscale feature sizes and additional hardening techniques need to be explored. This article presents the single-event upset (SEU) performance of multiple flip-flop (FF) designs using the stacked-transistor hardening technique at a 22-nm FDSOI technology node. Irradiation results show significant reductions in SEU cross sections for stacked-transistor-based hardened designs compared to a conventional design. Alpha particle exposures showed zero upsets for all D-flip-flop (DFF) designs tested. When exposed to heavy-ions, the stacked-transistor DFF design showed a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$17\times $ </tex-math></inline-formula> improvement over a conventional DFF design at an LET value of 47 MeV-cm2/mg. The stacked-transistor design with the charge-canceling technique showed upsets when particle LET exceeded 93.8 MeV-cm2/mg and at a high angle of incidence. The stacked-transistor design with the interleaving technique showed zero upsets for all test conditions.