Low temperature growth of β-(AlGa)2O3 films has been realized by oxygen radical assisted pulsed laser deposition.

No abstract

We report on the impacts of oxygen radical ambient for (AlGa)2O3 films grown on sapphire substrates by pulsed laser deposition (PLD). All the films showed a monoclinic crystal structure and high transmittance in the ultraviolet and visible wavelength range. The surface roughness was less than 3 nm for all films, and the surface morphology has changed by applying oxygen radical ambient. The growth rate was faster in oxygen radical ambient compared with conventional oxygen ambient. Oxygen radical ambient has influences on the crystal quality of the (AlGa)2O3 films. The Ga content in β-(AlGa)2O3 films grown with oxygen plasma assistance was higher than that without the oxygen plasma, indicating the suppression of the re-evaporation of Ga related species from the film surface by plasma assistance during the PLD process.

Gallium oxide was deposited on a c-plane sapphire substrate by oxygen plasma-assisted pulsed laser deposition (PLD). An oxygen radical was generated by an inductive coupled plasma source and the effect of radio frequency (RF) power on growth rate was investigated. A film grown with plasma assistance showed 2.7 times faster growth rate. X-ray diffraction and Raman spectroscopy analysis showed β-Ga2O3 films grown with plasma assistance at 500 °C. The roughness of the films decreased when the RF power of plasma treatment increased. Transmittance of these films was at least 80% and showed sharp absorption edge at 250 nm which was consistent with data previously reported.