Abstract: A method for etching GaN material comprising configuring the GaN material as an anode in an electrochemical cell where the electrochemical cell is comprised of an anode, a cathode and an electrolyte, and applying a bias across the anode and the cathode to a level which is sufficient to induce etching of the material. The etch rate of the material is controllable by varying the bias level. The cell is additionally illuminated with a preselected level of UV light which provides for uniformity of the etching process. The present method is particularly useful for etching a GaN HBT from n-p-n GaN material.