High energy radiation produces defect complexes in semiconductor materials which reduce minority carrier lifetime, change majority carrier density, and reduce mobility. Most of the experimental data on semiconductors and semiconductor devices has been taken using high energy neutrons. Recent research has shown that this data can be extrapolated to other high energy radiation such as protons, electrons, alpha particles and gamma rays by normalizing to the energy going into atomic processes. Minority carrier lifetime is the most sensitive electronic property of silicon in the neutron environment. The degradation of minority carrier lifetime results in changes in semiconductor device properties such as current gain, storage time, saturation voltage and sink current. Carrier removal is the next most important characteristic of displacement damage and it causes a decrease in carrier mobility and an increase in resistivity. The dependence of these basic semiconductor properties on neutron fluence is introduced into device models such as SPICE and the resulting radiation inclusive model permits quantitative determination of device parameters as a function of neutron fluence.
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