| AVS 60th International Symposium and Exhibition | |
| Scanning Probe Microscopy Focus Topic | Friday Sessions |
| Session SP+AS+EM+GR+MI+NS+SS-FrM |
| Session: | Probing Electronic and Transport Properties |
| Presenter: | B. Voigtlaender, Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, Germany |
| Authors: | B. Voigtlaender, Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, Germany S. Korte, Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, Germany V. Cherepanov, Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, Germany M. Steidl, TU Ilmenau, Germany W. Zhao, TU Ilmenau, Germany P. Kleinschmidt, TU Ilmenau, Germany T. Hannappel, TU Ilmenau, Germany W. Prost, University of Duisburg-Essen, Germany |
| Correspondent: | Click to Email |
III-V semiconductor nanowires are promising building blocks for novel semiconductor devices in future electronic and opto-electronic applications such as solar cells. In this context the distribution of the dopant over the nanowires is of great importance. Resistance profiles of as-grown freestanding GaAs nanowires were measured with a multitip scanning tunneling microscope (STM) used as nanoprober. Four point probe resistance measurements were performed along the nanowire. The dopant induced carrier concentration along the wire was determined from the resistance measurements and geometrical data. It was found that in the high temperature growth region (450°C) the carrier concentration is about one order of magnitude lower than in the low temperature regime (400°C). The NWs exhibit high mechanical elasticity, they can be deformed by the STM tips and revert to their original shape when released. Even extreme bending of a NW did not show a significant influence on its conductivity. These measurements were performed using a multi-tip scanning tunneling microscope (STM) in which four independent STM units are integrated on a diameter of 50 mm, resulting in an unsurpassed mechanical stability, enabling atomic resolution imaging with each tip. The heart of this STM is a new type of piezoelectric coarse approach called KoalaDrive. The coarse positioning of the tips is done under the control of an SEM. This multi-tip instrument is suited to perform electrical measurements such as local potential measurements at the nanoscale.