Quantitative dopant distributions in GaAs nanowires using atom probe tomography

Controllable doping of semiconductor nanowires is critical to realize their proposed applications, however precise and reliable characterization of dopant distributions remains challenging. In this article, we demonstrate an atomic-resolution three-dimensional elemental mapping of pristine semiconductor nanowires on growth substrates by using atom probe tomography to tackle this major challenge. This highly transferrable method is able to analyze the full diameter of a nanowire, with a depth resolution better than 0.17nm thanks to an advanced reconstruction method exploiting the specimen's crystallography, and an enhanced chemical sensitivity of better than 8-fold increase in the signal-to-noise ratio. ► Probing pristine semiconductor NWs from growth substrate has been demonstrated. ► Analyzing the full diameter of a nanowire has been achieved. ► A spatial resolution better than 0.17nm in depth has been obtained for GaAs. ► An enhanced SNR 100:2 has been achieved.