Nature of Radiation Defects in Silicon Single Crystals

Abstract

Floating zone Silicon single crystals containing phosphorus were irradiated with Co 60 γ-rays or electrons of 2 Mev at room temperature. Temperature dependence of Hall coefficient after irradiation showed the presence of two net acceptor levels, 0.17 ev and 0.38 ev below the conduction band. The introduction rate of the deep level increased with increasing phosphorus concentration, while that of the shallow level slightly decreased with increasing phosphorus concentration. The activation energy for the annealing of the 0.38 ev level was found to be 0.94 ev in the temperature range, 120–180°C. All of the results obtained can be successfully explained, if Watkins' model was adopted.