Dry etch damage in n -type GaN and its recovery by treatment with an N2 plasma

We report on etch-induced damage in n-type GaN caused by an inductively coupled plasma, and damage recovery by means of treatment with an N2 plasma. As the plasma dc bias was increased by increasing the rf table power during etching, the optical and electrical properties of the etched GaN films deteriorated as the result of etch-induced damage. However, an N2 plasma treatment for the etched samples effectively removed the etch-induced defects and damage on the surface, leading to improved surface morphology, photoluminescence, and ohmic contact in n-type GaN.