Low-energy ion scattering spectroscopy and reflection high-energy electron diffraction of native oxides on GaN(0001)

Abstract

We investigated native oxides on GaN(0001) wafers by low-energy ion scattering spectroscopy (LEIS) and reflection high-energy electron diffraction (RHEED) simultaneously. As a result, azimuthal angle-resolved LEIS revealed that the surface structure of the native oxide with a thickness of ∼1.1 nm showed a low sixfold symmetry. Moreover, the RHEED patterns of native oxides on GaN showed (1 × 1) surface spots, reflecting the same lattice constant of GaN regardless of the glancing angle of the incident beam. The obtained results suggest that native oxides on GaN(0001) could be either ε-Ga2O3, γ-Ga2O3(111), or their mixture, with lattice-matched structures.