Monte Carlo Simulations: From Neutron to Defects in Bulk Materials

The assessment of neutron-induced displacement effects in electronic components is a subject that combines several aspects. The material of the electronic component channel and the physics of neutron interactions are important elements. Neutron displacement dose test standards for electronics use a combination of production cross sections associated with the average displacement energy induced by secondary ions. These average values are suitable for cumulative dose effects but do not allow us to assess the amplitude and occurrences of displacement events. In this work, we propose a Monte Carlo neutron-to-defect to estimate statistical variations in these occurrences. Geant4 is used for the statistical treatment of neutron transfer in secondary ion populations. The Iradina tool is then run for each event to translate each secondary ion trajectory into a displacement number. This method has been applied to the following four main technologies: Si, GaAs, GaN, and SiC. Several displacement characteristics are given as a function of material and neutron energy. Equivalence factors for the neutron spectra used for testing are proposed.