Recovery of Electrical Properties in 45-MeV-Electron-Irradiatedn-Type Si from 80 to 350°K

Isochronal annealing from 80 to 360°K of defects induced by 45-MeV electrons in floating-zone and pulled $n$-type silicon was studied using electrical properties, namely, conductivity and carrier concentration. The results indicate that the annealing behavior in this temperature range depends on the imperfections present in the samples before irradiation. In particular, oxygen impurities are found to have a pronounced effect on the defect production and annealing process. The total numbers of silicon $A$ centers produced after irradiation at 80°K and measured after anneal to 350°K yield production rates of 0.2 to 0.3 ${\mathrm{cm}}^{-1\mathrm{}}$ which depend only slightly on the impurity concentration of the samples studied (3×${10}^{13}$ to 3×${10}^{15}$ phosphorus atoms/${\mathrm{cm}}^3$). The production rate of $A$ centers by 45-MeV electrons is comparable for 80 and 300°K irradiations; this is different from results found in 1-MeV electron irradiation. The production of $A$ centers in 15°K irradiation is found to be about one-half the value measured in 80°K irradiations. A comparison of the characteristics of defects induced by 45- and 1-4.5-MeV electrons in silicon is given.