WET CHEMICAL ETCHING OF ALN

Single-crystal AIN grown on Al2O3 is found to be wet etched by AZ400K photoresist developer solution, in which the active component is KOH. The etching is thermally activated with an activation energy of 15.5+/ -0.4 kcal mol(-1), and the etch rate is found to be strongly dependent on the crystalline quality of the AIN. There was no dependence of etc h rate on solution agitation or any crystallographic dependence noted, and the etching is selective over other binary group III nitrides (Ga N, InN) and substrate materials such as Al2O3 and GaAs. (C) 1995 Ameri can Institute of Physics.