Cl2 ‐ Based Dry Etching of GaN and InGaN Using Inductively Coupled Plasma The Effects of Gas Additives

Abstract

The effects of added , Ar, and gases on the etch characteristics of GaN and InGaN were studied using an inductively coupled ‐based plasma. Each added gas had a unique effect on the etch rate, anisotropy, surface roughness, and sidewall morphology. The most anisotropic etch profile was obtained using , but the etched surface showed the roughest morphology and was covered with etch residues, the origins of which were the micromasking of the sputtered dielectric. When gas was added to the plasma, the etch residues were removed and the surface roughness was decreased, even though the etch rate was slightly decreased. The etch rate of GaN by plasmas was saturated above an Ar flow rate of 16 sccm and the surface roughness of the etched GaN was lower, compared with plasmas at low source power. Finally, it was found that the In compound was etched as a result of reaction with . © 2000 The Electrochemical Society. All rights reserved.