Removal of dry etch damage in p-type GaN by wet etching of sacrificial oxide layer

摘要

We describe etch-induced damage in p-type GaN caused by an inductively coupled Cl_2/Ar/O_2 plasma and a method for its removal by means of wet etching. When p-GaN was etched by a Cl_2/Ar/O_2 plasma, an oxide layer was formed on the p-GaN surface by the oxygen in the plasma. The electrical properties of the etched p-GaN films deteriorated, as a result of the oxide on the surface, as well as etch-induced damage. However, a HF postwet etching of the dry-etched samples effectively removed the sacrificial oxide layer on the surface that contained the etch-induced defects and damage, resulting in improved characteristics in surface morphology and photoluminescence in the etched p-type GaN.