Distribution of primary defects in crystals irradiated with megaelectron-volt electrons. Silicon

The results are given of calculations of the spatial distribution of primary radiation defects, representing separated and bound Frenkel pairs in silicon samples irradiated with 0.5 and 1.0 MeV electrons. The actual spectrum of fast electrons is determined allowing for electron energy losses, formation of secondary electrons, and reflection of electrons from the substrate which is important in the case of thin silicon samples. The coordinate dependence of the actual spectrum of electrons gives rise to an inhomogeneous spatial distribution of the defects. The efficiency of introduction of bound Frenkel pairs is at least 2-3 orders of magnitude higher than the efficiency of introduction of free vacancies and interstitial atoms