Thesis Defense

Lithography-free oxide isolation of GaAs nanowires using the VLS growth method.

Wed, 28 Jun 2017 1:00 PM
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Thesis Defense
Lithography-free oxide isolation of GaAs nanowires using the VLS growth method.

David Dvorak
Department of Physics

June 28, 2017 at 1:00pm in SSB 7172

Semiconductor nanowires show significant potential for incorporation into next generation technologies due to their unique electronic, optical and mechanical properties. In order to keep pace with the rapid development of new semiconductor technologies, quick and efficient device prototyping methods are required. In this work, a lithography-free approach for the fabrication of oxide-isolated nanowire devices is developed using a combination of atomic layer deposition and the vapour-liquid-solid method. Axial growth of Al2O3 and Ga2O3-coated GaAs nanowires is restarted using an annealing step which fractures the oxide surrounding the gold nanoparticle. The oxide fracture is observed to depend on the oxide composition and thickness, annealing temperature and nanoparticle radius. The compositional and electronic properties of the regrown nanowires are investigated and a thermal expansion mismatch model is presented to describe the observed results.