Films of Ga2O3 were grown by Halide Vapor Phase Epitaxy (HVPE) on bulk heavily B-doped (001)-oriented diamond substrates using thin interlayers of Al2O3 deposited by HVPE or AlN/AlGaN deposited by metalorganic chemical vapor deposition. The growth with AlN/AlGaN was dominated by the formation of a highly conducting ɛ-phase with poor crystalline quality. For these samples, excessive leakage of Schottky diodes and of the Ga2O3/diamond heterojunction prevented meaningful electrical characterization. The film grown with the Al2O3 interlayer was mainly composed of (-201) β-Ga2O3 with an admixture of the ɛ-phase. The film had a low density of residual shallow donors, 5 × 1015 cm-3, with deep electron traps spectra consisting of the well documented centers for β-Ga2O3 near Ec 0.27, Ec 0.7, and Ec 1 eV, all of which are often ascribed to native defects or their complexes. The electrical properties of heterojunctions were mostly determined by the properties of the Ga2O3 films. Both Schottky diodes and heterojunctions showed measurable photosensitivity for 259 nm wavelength excitation, but very low photocurrent for near-UV (365 nm wavelength excitation).
Bibliographical noteFunding Information:
The work at NUST MISiS was supported in part by the Russian Science Foundation, Grant No. 19-19-00409. The work was performed in part by using the equipment of the Shared-use Equipment Center of the FSBI TISNUM “Research of nanostruc-tured, carbon and superhard materials” and the Shared Use Equipment Center for high-precision measuring in photonics (ckp.vniiofi.ru, VNIIOFI). The work at IMT RAS was supported in part by the State Task No. 075-00355-21-00. The work at UF was sponsored by the Department of Defense, Defense Threat Reduction Agency, Interaction of Ionizing Radiation with Matter University Research Alliance (Award No. HDTRA1-20-2-0002) monitored by J. Calkins and also by NSF DMR 1856662 (James Edgar).
© 2021 Author(s).
ASJC Scopus subject areas
- General Physics and Astronomy