Non-contact electrical detection of intrinsic local charge and internal electric field at nanointerfaces

A nanoscale non-contact electrical measurement has been developed based on Auger electron spectroscopy. This approach used the specialty of an Auger electron, which is self-generated and free from external influences, to overcome the technical limitations of conventional measurements. The detection of the intrinsic local charge and internal electric field for nanostructured materials was achieved with a resolution below 10 nm. As an example, the electrical properties at the GaN/AlGaN/GaN nanointerfaces were characterized. The concentration of the intrinsic polarization sheet charges embedded in GaN/AlGaN nanointerfacial layers were accurately detected to be -4.4 e nm-2. The mapping of the internal electric field across the nanointerface revealed the actual energy-band configuration at the early stage of the formation of a two-dimensional electron gas.