Hydrogen plasma treatment of β -Ga2O3: Changes in electrical properties and deep trap spectra

A. Y. Polyakov, In-Hwan Lee, N. B. Smirnov, E. B. Yakimov, I. V. Shchemerov, A. V. Chernykh, A. I. Kochkova, A. A. Vasilev, F. Ren, P. H. Carey, S. J. Pearton

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Abstract

The effects of hydrogen plasma treatment of β-Ga2O3 grown by halide vapor phase epitaxy and doped with Si are reported. Samples subjected to H plasma exposure at 330 °C developed a wide (∼2.5 μm-thick) region near the surface, depleted of electrons at room temperature. The thickness of the layer is in reasonable agreement with the estimated hydrogen penetration depth in β-Ga2O3 based on previous deuterium profiling experiments. Admittance spectroscopy and photoinduced current transient spectroscopy measurements place the Fermi level pinning position in the H treated film near Ec-1.05 eV. Annealing at 450 °C decreased the thickness of the depletion layer to 1.3 μm at room temperature and moved the Fermi level pinning position to Ec-0.8 eV. Further annealing at 550 °C almost restored the starting shallow donor concentration and the spectra of deep traps dominated by Ec-0.8 eV and Ec-1.05 eV observed before hydrogen treatment. It is suggested that hydrogen plasma exposure produces surface damage in the near-surface region and passivates or compensates shallow donors.

Original languageEnglish
Article number032101
JournalApplied Physics Letters
Volume115
Issue number3
DOIs
Publication statusPublished - 2019 Jul 15

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ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

Cite this

Polyakov, A. Y., Lee, I-H., Smirnov, N. B., Yakimov, E. B., Shchemerov, I. V., Chernykh, A. V., Kochkova, A. I., Vasilev, A. A., Ren, F., Carey, P. H., & Pearton, S. J. (2019). Hydrogen plasma treatment of β -Ga2O3: Changes in electrical properties and deep trap spectra. Applied Physics Letters, 115(3), [032101]. https://doi.org/10.1063/1.5108790