Experiment and Simulation of Soft Error Characteristics in 14 nm FinFET and 28 nm SRAMs at 2400m Deep Underground

Real-time soft error rates (SERs) of 14-nm FinFET and 28-nm planar SRAMs were measured at the world’s deepest China Jinping Underground Laboratory (CJPL), located under 2400 m rock overburden, to isolate alpha particle induced upsets from the atmospheric neutron background. Over 862 days of continuous monitoring, 16 upsets were recorded in the 28 nm SRAMs, including 13 single-bit upsets (SBU) and 3 multiple-cell upsets (MCU). The MCU fraction was 18.6% and the maximum multiplicity was seven cells. No upset was observed in the 14 nm FinFET SRAMs, yielding an upper-bound SER of 21 FIT/Mb. By combining the CJPL results with 4300 m high-altitude measurements at Lhasa, the alpha and neutron contributions to the sea-level SER in Beijing were estimated; alpha particles were inferred to make a non-negligible contribution to the total SER. Motivated by the alpha-emission characterization of package-related materials, Monte Carlo simulations were performed using a representative 5.3 MeV alpha source in a simplified package/interconnect model. The simulation SER for the 28 nm device is 188 FIT/Mb, which is close to the measured 161 FIT/Mb (109-245 FIT/Mb), supporting that package-related alpha particles are a plausible origin of the underground soft errors. These results provide benchmark alpha-SER data and guidance for reliability evaluation of advanced ICs.