An experimental study of single-event effects induced in commercial SRAMs by neutrons and protons from thermal energies to 500 MeV

Irradiations have been performed, with neutrons and protons over a wide particle energy range, on six different commercial-grade 4-Mbit SRAM parts from the manufacturers Hitachi, Toshiba, Mitsubishi, and Samsung. At energies above 20 MeV, the single-event upset (SEU) cross sections are similar for protons and neutrons. While the proton cross sections fall off rapidly below this energy due to package shielding and Coulomb barrier effects, the neutron cross sections at 14.5 MeV are close to the high energy plateau values. Four of the devices show significant thermal neutron SEU cross sections and in two cases these exceed the high energy plateau values. The most modern of the parts tested is susceptible to latchup from both protons and neutrons but the response is shifted to higher energies compared with SEU.