A parametric investigation on the ability to use dry etching to form conical field emitter type structures in AlN and GaN was conducted using an inductively coupled plasma reactive ion etcher. Etched structures viewed with a scanning electron microscope demonstrate that an array of conical and wedge shaped structures, both with tip radius of curvatures less than 100 nm, can be manufactured by etching AlN and GaN using a photoresist mask. The etch gases investigated include Cl-2, BCl3, SF6, HBr, and Ar. We also discuss the etch rates and sidewall profiles that result from using higher gas flows (up to 45 sccm) and higher discharge pressures (up to 24 mTorr) than previously reported in the literature.