Reactive ion etching of GaN/InGaN using BCl3 plasma

Reactive ion etching (RIE) of GaN and InGaN using BCl3 plasma under a high self-bias voltage was carried out. The effects of rf plasma power, chamber pressure and BCl3 flow rate on the etch rate were investigated. An etch rate as high as 132 nm min−1 for GaN was obtained under an rf power of 200 W, a BCl3 flow rate of 2 sccm and a pressure of 25 mTorr. The root-mean-square roughness of the etched surface was between 2.5 and 3 nm as determined by atomic force microscopy. It was also found that the etch rate for InGaN under the same conditions was slightly higher than those for GaN. Photoluminescence measurements revealed that the damage due to RIE could be recovered significantly by a short-time thermal annealing process.