  A nanoscale non-contact electrical measurement has been developed based on
Auger electron spectroscopy. This approach used the speciality of Auger
electron, which is self-generated and free from external influences, to
overcome the technical limitations of conventional measurements. The detections
of the intrinsic local charge and internal electric field for nanostructured
materials were achieved with 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 internal electric field across the nanointerface revealed the
actual energy band configuration at the early stage of the formation of
two-dimensional electron gas.
