Etching of GaN by inductively coupled plasma using Cl2/H2

An inductively coupled plasma etching of GaN using Cl-2/H-2 chemistry has been studied. During the etching process, sputter desorption of Ga by energetic ion bombardment was observed by optical emission spectroscopy. The highest etch rate of 5500 Angstrom/min was measured in this study, and this was greater than those for electron cyclotron resonance etching technique using same chemistry. The etch rates were proportional to radio frequency and inductively coupled plasma powers. The root mean square roughness of etched GaN surface was also increased with increasing source power. Furthermore, photoluminescence emission efficiency from etched surface was degraded by increasing the source power, suggesting that the etching damage on the surface was increased with increasing the energetic ion energy.