Electrical properties, structural properties, and deep trap spectra of thin α-Ga 2 O 3 films grown by halide vapor phase epitaxy on basal plane sapphire substrates

Dae Woo Jeon, Hoki Son, Jonghee Hwang, A. Y. Polyakov, N. B. Smirnov, I. V. Shchemerov, A. V. Chernykh, A. I. Kochkova, S. J. Pearton, In-Hwan Lee

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Abstract

Undoped epitaxial films of α-Ga 2 O 3 were grown on basal plane sapphire substrates by halide vapor phase epitaxy (HVPE) in three different modes: standard HVPE, HVPE with constant flow of Ga and pulsed supply of O 2 (O 2 -control growth regime), and with constant flow of O 2 and pulsed delivery of Ga (Ga-control growth fashion). The best crystalline quality as judged by x-ray symmetric and asymmetric reflection half-widths and by atomic force microscopy morphology profiling was obtained with the O 2 -control deposition, and these results appear to be the best so far reported for α-Ga 2 O 3 films. All grown α-Ga 2 O 3 epilayers were high-resistivity n-type, with the Fermi level pinned near E c − 1 eV deep traps. Photoinduced current transient spectra also showed the existence in standard HVPE samples and samples grown under the O 2 -control pulsed growth conditions of deep hole traps with levels near E v + 1.4 eV whose density was suppressed in the Ga-control pulsed HVPE samples. The levels of the dominant deep traps in these α-Ga 2 O 3 samples are close to the position of dominant electron and hole traps in well documented β-Ga 2 O 3 crystals and films.

Original languageEnglish
Article number121110
JournalAPL Materials
Volume6
Issue number12
DOIs
Publication statusPublished - 2018 Dec 1

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ASJC Scopus subject areas

  • Materials Science(all)
  • Engineering(all)

Cite this

Jeon, D. W., Son, H., Hwang, J., Polyakov, A. Y., Smirnov, N. B., Shchemerov, I. V., Chernykh, A. V., Kochkova, A. I., Pearton, S. J., & Lee, I-H. (2018). Electrical properties, structural properties, and deep trap spectra of thin α-Ga 2 O 3 films grown by halide vapor phase epitaxy on basal plane sapphire substrates APL Materials, 6(12), [121110]. https://doi.org/10.1063/1.5075718