Oxygen diffusion in β-Ga2O3 single crystals at high temperatures

Monoclinic gallium oxide (beta-Ga2O3) is an ultra-wide bandgap semiconductor with importance in various technological areas. We investigated oxygen tracer self-diffusion in (100) oriented beta-Ga2O3 single crystals at high temperatures between 1200 & DEG;C and 1600 & DEG;C. Isotope enriched O-18(2) gas was used as a tracer source. The isotope exchanged samples were analyzed by secondary ion mass spectrometry in depth profile mode. The diffusivities can be described by the Arrhenius law with an activation enthalpy of (3.2 & PLUSMN; 0.4) eV. Possible diffusion mechanisms are discussed using defect equilibria and density functional theory calculations as found in the literature. As a result, oxygen interstitials are more likely than vacancies as defects governing diffusion.

Automated summary

The study investigated oxygen tracer self-diffusion in monoclinic gallium oxide single crystals at high temperatures using O-18(2) gas as a tracer source. The diffusivities follow the Arrhenius law with an activation enthalpy of (3.2±0.4) eV. Oxygen interstitials are suggested to be more dominant than vacancies in governing diffusion.