Worst-Case Proton Contribution to the Direct Ionization SEU Rate

Low energy protons can induce Single Event Upsets in highly integrated memories. The direct ionization phenomenon has been observed for technology nodes lower than 90 nm. The Single Event Upset rate calculation is usually performed with an isotropic shielding of 1 g.cm
^-2
. Considering the direct ionization, low energy proton fluxes can be significantly impacted by the shielding or the altitude considered for the mission. The purpose of this study was to assess the impact of the radiative and mechanical environments on the calculated in-orbit rates.