Smooth GaN surfaces by photoinduced electro-chemical etching

摘要

We have etched n-GaN grown both by plasma assisted MBE and MOCVD in 0.5 M KOH under HeCd-laser illumination (110 mW cm~(-2)) and controlled the photocurrent by an external voltage source. The reproducible etch depths were linear with respect to the charge. The examination of the dissolution potential revealed strong dependence on illumination and current. Thereby, regimes to obtain smoothly etched surfaces were found at low dissolution potentials. Demonstration of the possibilities in photoelectrochemical (PEC) etching are given.