Stable Fabrication of High Breakdown Voltage Mesa-Structure Vertical GaN p-n Junction Diodes Using Electrochemical Etching

A wet etching has been performed using an electrochemical etching method to fabricate mesa-structure vertical GaN p-n junction diodes. In case of conventional dry etching, the breakdown voltages of the p-n diodes showed scattered values probably due to local concentration of electric field by roughness at the side wall of the mesa. Smooth and damage-free surface have been obtained by the wet etching, which has enabled higher and stable the breakdown voltages.