Anodic Dissolution and Selective Etching of Gallium Phosphide

Abstract

Current voltage curves and the effective dissolution valence have been determined for electrodes in solution. At electrode potentials of a few volts the current density for p‐type is a factor of 104 greater than for n‐type electrodes. This difference allows selective removal of p material from p‐n structures. Application of this selective etching to the fabrication of mesa structures for light emitting diodes, and to junction delineation, is discussed. At large current densities, 6 charges are transferred per dissolved molecule in distinction to the 3 transferred charges found previously in alkaline solution at low current densities.