Etch Characteristics of GaN using Inductively Coupled Cl2 Plasma Etching

摘要

In this study, the plasma characteristics and GaN etch properties of inductively coupled C12/AI plasmas were investigated It has shown that the results of a study of inductively coupled plasma (ICP) etching of gallium nitride by using C12/AI is possible to meet the requirement (anisotropy, high etch rate and high selectivity), simultaneously. We have investigated the etching rate dependency on the percentage of Argon in the gas mixture, the total pressure and DC voltage We found that using a gas mixture with 20 seem of Ar, the optimum etch rate of GaN was achieved. The etch rate were found to increase with voltage, attaining a maximum rate 2500 A/min at -557V The addition of an inert gas, Ar is found to barely affect the etch rate Surface morphology of the etched samples was verified by scanning election microscopy and atomic force microscopy. It was found that the etched surface was anisotropic and the smoothness of the etched surface is comparable to that of polished wafer.