This work investigates inductively coupled plasma (ICP) etching processes o
f GaN. Etching behaviors are also characterized by varying the ICP power, C
l-2/Ar or Cl-2/N-2 mixing ratio, radio-frequency (rf) power, and chamber pr
essure. Experimental results indicate that the etching profiles are highly
anisotropic over the range of etching conditions. Maximum etching rates of
8200 Angstrom/min in Cl-2/Ar plasma and 8330 Angstrom/min in Cl-2/N-2 plasm
a are obtained as well. In addition, pressure, ICP power, Cl-2/Ar(N-2) flow
ratio and rf power significantly influence etching rate and surface morpho
logy. In particular, dc bias heavily influences the etching rates, suggesti
ng that the ion-bombardment effect is an important factor of these etching
processes. (C) 1999 American Institute of Physics. [S0021-8979(99)03903-1].