Nanoscale Dopant Profiling of Individual Semiconductor Wires by Capacitance-Voltage Measurement

Developing nanoscale electrical characterization techniques adapted to three-dimensional (3D) geometry is essential for optimization of the epitaxial structure and doping process of nano- and microwires. In this paper, we demonstrate the assessment of the depletion width as well as the doping profile at the nanoscale of individual microwire core-shell light-emitting devices by capacitance-voltage measurements. A statistical study carried out on single wires shows the consistency of the doping profile values measured for individual microwires compared to assemblies of hundreds of wires processed on the same sample. The robustness of this method is then demonstrated on four epitaxial structures with different growth and doping conditions. Finally, electron-beam-induced current and secondary electron profiles are used to validate the depletion region width and the position in the core-shell structure.