HBr-K₂Cr₂O₇-H₂O etching system for indium phosphide

InP surfaces with (100), (111)In and (111)P orientations were etched with HBr-K₂Cr₂O₂-H₂O solutions. Etching could be diffusion-controlled (giving rise to polishing) or purely kinetically controlled (revealing crystallographic defects), depending on the solution composition. These experimental results have been summarized in a ternary diagram which allows a complete surface treatment of indium phosphide: uniform etching for the elimination of process damage, dislocation revealing and identification of polar 〈110〉 crystallographic orientations, elimination of surface oxides and surface preparation prior to further etching studies.