Control of HVPE grown GaN nanostruturing by anodization

Abstract

In this paper, results of a systematic study of morphologies obtained with anodization in HNO3, HCl, and NaCl solutions are presented. It is shown that complex pyramidal structures composed by regions with modulated porosity parallel to the pyramid surface, with pores oriented perpendicular to the wafer surface, or with arrays of nanowires are produced near the N-wafer surface, depending on the applied anodization voltage and the used electrolyte. The thickness of the pore walls is controlled by the applied voltage. Porous matrices with the depth up to 50 µm have been demonstrated.