This paper presents new neutron-induced single event upset (SEU) data on the SRAM devices with the technology nodes from 40 nm to 500 nm due to spallation,reactor,and monoenergetic neutrons.The SEU effect is investigated as a function of incident neutron energy spectrum,technology node,byte pattem and neutron fluence rate.The experimental data show that the SEU effect mainly depends on the incident neutron spectrum and the technology node,and the SEU sensitivity induced by low-energy neutrons significantly increases with the technology downscaling.Monte-Carlo simulations of nuclear interactions with device architecture are utilized for comparing with the experimental results.This simulation approach allows us to investigate the key parameters of the SEU sensitivity,which are determined by the technology node and supply voltage.The simulation shows that the high-energy neutrons have more nuclear reaction channels to generate more secondary particles which lead to the significant enhancement of the SEU cross-sections,and thus revealing thephysical mechanism for SEU sensitivity to the incident neutron spectrum.