As-doped Si layers were grown using Molecular Beam Epitaxy (MBE) together with simultaneous Low Energy Ion Implantation (LEII). The influence of growth conditions such as Si-substrate temperature, ion energy and ion dose was investigated using structural and electrical characterization techniques. Below the As solid solubility limit, well defined and 100 % electrically active As-doped layers were grown. Above solid solubility segregation occured, with broadened profiles and less than 100 % activation.