Abstract
We present the results from a focused ion beam instrument designed to implant single ions with a view to the fabrication of qubits for quantum technologies. The difficulty of single ion implantation is accurately counting the ion impacts. This has been achieved here through the detection of secondary electrons generated upon each ion impact. We report implantation of single bismuth ions with different charge states into Si, Ge, Cu and Au substrates, and we determine the counting detection efficiency for single ion im- plants and the factors which affect such detection efficiencies. We found that for 50 keV implants of Bi++ ions into silicon we can achieve a 89% detection efficiency, the first quantitative detection efficiency measurement for single ion implants into silicon without implanting through a thick SiO2 film. This level of counting accuracy provides implantation of single impurity ions with a success rate significantly exceeding that achievable by random (Poissonian) implantation.