Calculation of Cross Section for Ion-Induced SEU Through Direct Ionization in Nanometric Silicon Devices With Small Critical Energy

The cross section (CS) for energy deposition by ions in 50 nm cubic volume in silicon, which represents the size of sensitive volumes in nanometric devices, was calculated using a fast Monte Carlo code. The results are used to estimate SEU CS in modern devices with small critical energy. It is shown that, for precise evaluation of SEU rate, detailed energy deposition calculations are needed for each ion. The average track structure can be used only for estimating the energy deposition by relatively high LET ions. It is found that the ion-LET is a good parameter for the SEU CS. However, a better metric is the ion inverse-mean-free-path or a reduced LET which is proportional to this value.