High-purity wafers were irradiated with MeV electrons at low temperatures and were then investigated by using X-ray diffraction methods. The intensity of the Huang diffuse scattering showed that a high concentration of defects (above 1019/cm3) could be frozen-in at 4K. A large fraction of the defects was stabilized in the form of close Frenkel pairs which were characterized by a nearly perfect cancellation of the long-range displacement fields of the interstitial atom and the vacancy. The absolute size of these displacements, as well as the introduction-rate of the defects (of the order of 3/cm), was considered. The high defect-introduction rates were at variance with the results of electrical and optical investigations, and indicated that these methods detected only a few percent of the total defect concentration which was produced and frozen-in at 4K.

Vacancies and interstitial atoms in e--irradiated germanium P.Ehrhart, H.Zillgen: Journal of Applied Physics, 1999, 85[7], 3503-11