Reactive ion etching of GaN layers using

Abstract

The characteristics of reactive ion etching of gallium nitride layers, using etching gas are investigated. The GaN etch rate is examined by varying the bias voltage and the flow rate of . For bias voltages in the range of 250 V to 400 V, the etch rate is found to increase with voltage, attaining a maximum rate of at 400 V. The rate also increases with increasing flow. The addition of an inert gas, Ar, or of a reactive gas, , is found to barely affect the etch rate. Surface morphology after etching is checked by atomic force microscopy and scanning electron microscopy, which show that the smoothness of the etched surface is comparable to that of the unetched, and the etched sidewall forms an angle of to the surface normal.