Effect of the Radial Ionization Profile of Proton on SEU Sensitivity of Nanoscale SRAMs

This paper investigates the impact of the radial ionization profile of proton on SEU sensitivity for nanoscale devices. Intrinsic radial track structures of energy deposition of protons (from 0.5 to 2 MeV) in a silicon box with 2 μm of Si over-layer and a 100-nm silicon film were investigated. The orders of magnitude of the radial deposition is around 200 to 300 nm. Approaches based on punctual or average depositions induce a drift increasing for nanoscale volumes. Realistic energy deposition databases were developed thanks to GEANT4 and coupled with MUSCA SEP3 to perform SEU cross sections and SER estimations. Calculations applied to SOI and bulk technologies (65 and 45-nm) were conducted and compared with experimental results. Calculations are consistent with experiments, despite some drifts. Analyses demonstrate the necessity to consider the 3D morphology description in SEE modeling for nanoscale technologies, more particularly for SOI technologies.