ELECTRON-CYCLOTRON-RESONANCE ETCHING CHARACTERISTICS OF GAN IN SICL4 AR/

Electron cyclotron resonance (ECR) plasma etching characteristics of g allium nitride (GaN) are investigated using low pressure (4-19 mTorr) SiCl4/Ar ECR discharges. The purpose of this effort is to examine the dry etching processes of GaN that do not require hydrogen, which is kn own to cause carrier compensation in GaN. A maximum etching rate of 96 0 Angstrom/min and good surface morphologies are obtained. The etch ra te is found to increase near-linearly with increasing de bias, and a m inimum de bias of 100 V is required to initiate etching. Enhanced etch ing rates are obtained as the fraction of active chemical etchant spec ies (SiCl4) in the discharge is increased. We have also found that the material quality significantly affects the etch rate. The latter decr eases with x-ray rocking curve half-width and increases with defect de nsity. (C) 1996 American Institute of Physics.