Title of Paper:Improvement of crystal quality and UV transparence of dielectric Ga2O3 thin films via thermal annealing in N-2 atmosphere

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Date of Publication:2012-02-01

Journal:JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS

Included Journals:EI、SCIE

Volume:23

Issue:2

Page Number:542-545

ISSN No.:0957-4522

Abstract:Ga2O3 thin films were deposited on sapphire (0001) substrates by low-pressure metal organic chemical vapor deposition. The influence of annealing in N-2 atmosphere at the temperature in the range of 800-1,000 A degrees C was investigated by X-ray diffraction and optical transmittance spectra. With an increase of annealing temperature from 800 to 950 A degrees C, the transformation from the initial amorphous film to polycrystalline beta-Ga2O3 thin film was observed, and the transmittance was also improved remarkably. The optical band gap energy of the sample annealed at 950 A degrees C was evaluated as similar to 5 eV. Whereas, after an annealing at 1,000 A degrees C, the crystal quality became worse and the transmittance degraded. The mechanism of annealing in N-2 atmosphere was discussed in view of phase transition.