Growth and characterization of horizontal GaN wires on silicon

Abstract

We report the growth of in-plane GaN wires on silicon by metalorganic chemical vapor deposition. Triangular-shaped GaN microwires with semi-polar sidewalls are observed to grow on top of a GaN/Si template patterned with nano-porous SiO2. With a length-to-thickness ratio ∼200, the GaN wires are well aligned along the three equivalent 〈112̄0〉 directions. Micro-Raman measurements indicate negligible stress and a low defect density inside the wires. Stacking faults were found to be the only defect type in the GaN wire by cross-sectional transmission electron microscopy. The GaN wires exhibited high conductivity, and the resistivity was 20-30 mΩ cm, regardless of the wire thickness. With proper heterostructure and doping design, these highly aligned GaN wires are promising for photonic and electronic applications monolithically integrated on silicon. © 2014 AIP Publishing LLC.