Role of F on the electrical activation of As in Ge

Fluorine is known to strongly influence the dopant diffusion and electrical activation in Si. Similar effects might be exploited in Ge for optimizing its application in microelectronics. The role of F on the electrical activation of As in Ge after thermal treatments is elucidated. We have found that F, enriching the Ge matrix with vacancies strongly affects the electrical response of As-doped junctions. We also demonstrated that the F-interstitials clusters, formed next to the end-of-range region, have an acceptor-like behavior. These phenomena are characterized by chemical and electrical profiling analyses and by positron annihilation lifetime spectrometry.