Electronic devices that are designed to use the properties of single atoms such as donors ordefects have become a reality with recent demonstrations of donor spectroscopy, singlephoton emission sources, and magnetic imaging using defect centers in diamond. Ionimplantation, an industry standard for atom placement in materials, requiresaugmentation for single ion capability including a method for detecting a single ionarrival. Integrating single ion detection techniques with the single donor deviceconstruction region allows single ion arrival to be assured. Improving detectorsensitivity is linked to improving control over the straggle of the ion as well asproviding more flexibility in lay-out integration with the active region of the singledonor device construction zone by allowing ion sensing at potentially greaterdistances. Using a remotely located passively gated single ion Geiger mode avalanchediode (SIGMA) detector we have demonstrated 100% detection efficiency at a distance of>75 µm from the center of the collecting junction. This detection efficiency is achieved with sensitivity to∼600 or fewer electron–hole pairs produced by the implanted ion. Ion detectors withthis sensitivity and integrated with a thin dielectric, for example a 5 nm gateoxide, using low energy Sb implantation would have an end of range straggle of<2.5 nm.Significant reduction in false count probability is, furthermore, achieved by modifying theion beam set-up to allow for cryogenic operation of the SIGMA detector. Using adetection window of 230 ns at 1 Hz, the probability of a false count was measured as∼10−1 and10−4 for operationtemperatures of ∼300 K and ∼77 K, respectively. Low temperature operation and reduced false, ‘dark’, countsare critical to achieving high confidence in single ion arrival. For the deviceperformance in this work, the confidence is calculated as a probability of>98% for counting one and only one ion for a false count probability of10−4 at an average ion number per gated window of 0.015.