Regensburg 2013 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 66: GaN: Preparation and characterization of rods and wires

HL 66.10: Vortrag

Mittwoch, 13. März 2013, 19:15–19:30, H15

Electrical characterization of doped single GaN nanowires: A comparison of Si- and Ge-doping — •Markus Schäfer, Christian Länger, Marius Günther, Pascal Hille, Jörg Schörmann, Jörg Teubert, and Martin Eickhoff — I. Physikalisches Institut, Justus-Liebig-Universität Gießen, Germany

We present a comparison of the impact of Si- and Ge-doping on the electrical properties of GaN nanowires (NWs). While Si is well established as a shallow donor in GaN thin films, a systematic study of its effect on the electrical properties of NWs has not been reported and no report on Ge-doping of GaN NWs exists. Here, GaN NWs doped with different concentrations of Si and Ge were grown by plasma assisted molecular beam epitaxy on Si(111) substrates. Single NW conductivity measurements were carried out in four point geometry realized by electron beam lithography processing. A linear increase of the conductivity with increasing Ge-flux was observed. The results are correlated to time-of-flight secondary ion mass spectrometry, revealing a constant doping profile and an estimate for the Ge-concentration. These results are compared to Si-doped NWs. Contact resistances and the effect of Si-doping of n.i.d. GaN NWs due to diffusion from the Si substrate are also discussed.