Individual Roles of Atoms and Ions during Hydrogen Plasma Passivation of Surface Defects on GaN Created by Plasma Etching

In the recovery of photoluminescence intensities for band-edge emissions at around 3.47 eV in the case of gallium nitride (GaN), we have studied the individual roles of hydrogen atoms (H) and hydrogen ions (H n +). Surface defects such as nitrogen vacancies created by plasma etching were passivated by H termination. By utilizing hydrogen plasmas, we clarified the recovery efficiency by optical and stoichiometrical improvements with respect to the balance between the fluxes of H and H n +. By deflecting H n + by applying an electric field, the efficiency was improved using an identical H dosage, since the simultaneous irradiation of the energetic H n + promoted the desorption of the formed passivated Ga–H bonds.