Energy Dependence of Proton-Induced Displacement Damage in Silicon

Calculations of nonionizing energy deposition in silicon as a function of proton energy between 1-1000 MeV have been reviewed, a new calculation made, and the results compared with experimental data. Major observations are the following: 1) Only one of the calculations reported in the literature was found to contain all of the interactions necessary to qualitatively and quantitatively describe the energy dependence over the full energy range. 2) The new calculation agreed well with the single complete calculation using different input data and an approach that differed in detail. 3) The two complete calculations and the experimental data were not found to support the frequently reported "plateau" in damage production or energy loss at proton energies above 10 MeV. 4) An extensive set of experimental solar cell data (1-200 MeV) showed an almost perfect linear dependence of the silicon damage coefficient for diffusion length on nonionizing energy deposition. 5) New measurements of bipolar transistor displacement damage factors were also found to exhibit a similar dependence. 6) Ratios of proton energy loss to neutron energy loss compared well with experimental ratios of displacement damage factors.