In this paper, based on the different etching characteristics between GaN and Ga2O3, large-scale and vertically aligned β-Ga2O3 nanotube (NT) and microtube (MT) arrays were fabricated on the GaN template by a facile and feasible selective etching method. GaN micro-/nanowire arrays were prepared first by inductively coupled plasma (ICP) etching using self-organized or patterning nickel masks as the etching masks, and then the Ga2O3 shell layer converted from GaN was formed by thermal oxidation, resulting in GaN@Ga2O3 micro-/nanowire arrays. After the GaN core of GaN@Ga2O3 micro-/nanowire arrays was removed by ICP etching, hollow Ga2O3 tubes were obtained successfully. The micro-/nanotubes have uniform morphology and controllable size, and the wall thickness can also be controlled with the thermal oxidation conditions. These vertical β-Ga2O3 micro-/nanotube arrays could be used as new materials for novel optoelectronic devices.
Keywords: GaN template; ICP etching; micro-/nanotubes; β-Ga2O3.