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HL: Fachverband Halbleiterphysik
HL 25: Poster 1
HL 25.55: Poster
Mittwoch, 7. September 2022, 18:00–20:00, P2
Influence of the probe-to-semiconductor contact on the electrical characterization of nanowire structures — •Juliane Koch1, Lisa Liborius2, Peter Kleinschmidt1, Nils Weimann2, Werner Prost2, and Thomas Hannappel1 — 1Fundamentals of energy materials, Ilmenau University of Technology, Germany — 2Components for high frequency Electronics (BHE), University of Duisburg-Essen, Germany
For the purpose of well-defined III-V semiconductor junctions, various sophisticated tip-based methods such as multi-tip scanning tunnelling microscopy (MTSTM) can be employed to study the electrical behaviour with high spatial resolution. We investigated a variety of upright, freestanding GaAs-based axial as well as co-axial nanowires on the growth substrates covered with native oxide. Based on our studies with MTSTM, we demonstrate that in tip-based measurement methods, the probe-to-semiconductor contact is essential for interpreting the properties of the sample. Our investigation reveals charging currents at the interface between the measuring tip and the semiconductor via the native insulating oxide, which acts as a MIS-capacitor in the operating voltage range. All the samples investigated displayed a strong dependency of the overall electrical behaviour on the condition of the tip-to-semiconductor contact. We analyse in detail the observed I-V characteristics and propose a strategy to achieve an optimized measuring tip-to-semiconductor junction which minimizes the influence of the native oxide layer on the overall electrical measurements.