Selective-area Growth of Gallium Oxide Nanowires:Synthesis, Characterization, and Device Application

In this paper, we report the selective area synthesis of gallium oxide (Ga₂O₃) nano-wires on gold patterned gallium arsenide (GaAs) substrate which have been treated by ion implantation. The GaAs substrate was first treated with implantation of acetylene (C₂H₂) ions, and then followed by coating the surface with a 2nm thick gold film. After rapid thermal anneal (RTA) at 950degC for 15 seconds, Ga₂O₃ nanowires were found on gold patterned surface. The Ga₂O₃ nanowires with diameters of 50-500nm were examined by Raman spectroscopy, scanning electron microscopy (SEM), and cathodoluminescence (CL). We also measured the I-V behavior for Ga₂O₃ material under the excitation by various laser radiations, hence demonstrating its potential applications as UV sensors. In addition, nano-particles of gold were found at the tip of the nano-wires, suggesting that a vapor-liquid-solid (VLS) mechanism was involved.