Background: Reactor neutron can induce single event upset (SEU) in Static Random Access Memory (SRAMs). Local metal interconnection is widely used in modern complementary metal oxide semiconductor (CMOS) technology. The most frequently used local materials are some heavy metals

such as tungsten (W) or copper (Cu). These metals could affect the neutron induced SEU in CMOS. Purpose: The relationship between SEU cross section and critical energy (Ec) can be referred by SEU experiments with reactors. Methods: The SEU cross sections with different Ec of a SRAM are simulated and calculated using Geant4 with a reactor neutron spectrum

and SEU induced by 1?14 MeV neutrons are also simulated in structures with and without a tungsten layer. Results: The relationship between SEU cross section σ (in unit: cm2) and Ec (in unit: MeV) is σ=exp[?18.7×Ec?32.3]. In the structure with a tungsten layer

SEU cross sections induced by 1?3 MeV neutrons are increased because a few α particles are created. Conclusion: To reduce neutron SEU cross section

the critical energy of CMOS should be increased as high as possible

and usage of tungsten should be avoided. Abstract