Molecular Dynamics for Single-Ion-Induced Silicon Device Degradation

Highly-scaled silicon devices are susceptible to degradation by a mechanism not seen in earlier technological generations. A single energetic ion, whether at ground level or in space, can knock out atoms across an entire ~5 nm device, possibly causing it to fail catastrophically. This work seeks to model the dynamics of this effect in order to determine device vulnerability. We employ Monte-Carlo methods to simulate the incident high-energy ion's impact on the silicon material, causing silicon atoms to be knocked out, which subsequently knock additional atoms out. After the initially deposited high energy is sufficiently distributed among lower-energy (≲100 eV) atoms, the rest of the simulation is carried out in crystalline silicon using molecular dynamics until thermalized (~5 ps). A damping term is included, which emulates energy loss to electrons. To determine the long-term (~1 s) atomic configuration in the material, we raise the temperature to run accelerated annealing. The net result is defect clusters which are identified and characterized by their electronic properties, including energy levels and capture cross-sections, and their effect on device performance.