Effects of Concurrent Irradiation with Ions and Electrons on Accumulation Process of Damage Cascades in Germanium and Silicon.

Abstract

In-situ observation of Ge and Si has been performed under dual-beam irradiation with ions and electrons in the HVEM-accelerator facility at Kyushu University. Damage cascades show up their contrast and increase in number within a few seconds. The cascade contrast features accumulate with ion fluence, eventually leading to saturation. The saturated areal density decreases with increasing electron flux. Based on analyses using kinetic equations, it has been concluded that damage cascades show up their contrast through overlap or help from other damage cascades and that simultaneous electron irradiation eliminates damage cascades through the production of isolated point defects and irradiation-induced migration of point defects.