Engineering shallow and deep level defects in κ-Ga2O3 thin films: comparing metal-organic vapour phase epitaxy to molecular beam epitaxy and the effect of annealing treatments
Materials Today Physics, vol. 45, pp. 101463
Abstract
Orthorhombic gallium oxide (κ-Ga2O3) is an ultra-wide bandgap semiconductor with great potential in new generation electronics. Its application is hindered at present by the limited physical understanding of the relationship between synthesis and functional properties. This work discusses the effects of growth method (metal-organic vapour phase epitaxy and molecular beam epitaxy) as well as annealing treatments in different atmospheres (O2, H2) on point defects in κ-Ga2O3 layers epitaxially grown on c-plane sapphire. Comprehensive experimental characterization by X-ray diffraction, photo current- as well as photoluminescence excitation spectroscopy, and X-ray photo electron spectroscopy is combined with first principles calculations of the point defects’ formation and complex-dissociation energies. We demonstrate that for κ-Ga2O3 the concentration of shallow and deep level defects can be sensitively controlled through annealing treatments at temperatures (T = 500 °C) well below the thermal stability threshold of this polymorph. In particular, our results suggest that hydrogen-related defects (e.g., H-interstitials, Ga-vacancies—H complexes) play a key role in this process. While we provide direct exemplary implications of our results for the performances of κ-Ga2O3 based photodetectors, these findings are predicted to impact further application fields of κ-Ga2O3, such as high electron mobility transistors or memory devices.
Authors 21
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Piero Mazzolini corresponding
University of Parma · Institute of Materials for Electronics and Magnetism
Affiliation as printed
Department of Mathematical, Physical and Computer Sciences, University of Parma, Viale delle Scienze 7/A, 43124 Parma, Italy
IMEM-CNR, Viale delle Scienze 37/A, 43124 Parma, Italy
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Lawrence Livermore National Laboratory
Affiliation as printed
Lawrence Livermore National Laboratory, Livermore, United States
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Affiliation as printed
Department of Mathematical, Physical and Computer Sciences, University of Parma, Viale delle Scienze 7/A, 43124 Parma, Italy
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Affiliation as printed
Department of Mathematical, Physical and Computer Sciences, University of Parma, Viale delle Scienze 7/A, 43124 Parma, Italy
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Affiliation as printed
Department of Mathematical, Physical and Computer Sciences, University of Parma, Viale delle Scienze 7/A, 43124 Parma, Italy
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Affiliation as printed
Department of Mathematical, Physical and Computer Sciences, University of Parma, Viale delle Scienze 7/A, 43124 Parma, Italy
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Institute of Materials for Electronics and Magnetism
Affiliation as printed
IMEM-CNR, Viale delle Scienze 37/A, 43124 Parma, Italy
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Institute of Materials for Electronics and Magnetism
Affiliation as printed
IMEM-CNR, Viale delle Scienze 37/A, 43124 Parma, Italy
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Affiliation as printed
Technische Universität Berlin, Institute of Solid State Physics, Hardenbergstr. 36, 10623 Berlin, Germany
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Affiliation as printed
Technische Universität Berlin, Institute of Solid State Physics, Hardenbergstr. 36, 10623 Berlin, Germany
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Affiliation as printed
Technische Universität Berlin, Institute of Solid State Physics, Hardenbergstr. 36, 10623 Berlin, Germany
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Paul Drude Institute for Solid State Electronics · Forschungsverbund Berlin · Technische Universität Berlin
Affiliation as printed
Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e.V., Hausvogteiplatz 5-7, 10117 Berlin, Germany
Technische Universität Berlin, Institute of Solid State Physics, Hardenbergstr. 36, 10623 Berlin, Germany
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Paul Drude Institute for Solid State Electronics · Forschungsverbund Berlin
Affiliation as printed
Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e.V., Hausvogteiplatz 5-7, 10117 Berlin, Germany
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Paul Drude Institute for Solid State Electronics · Forschungsverbund Berlin
Affiliation as printed
Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e.V., Hausvogteiplatz 5-7, 10117 Berlin, Germany
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Affiliation as printed
Institute of Physical Chemistry, RWTH Aachen University, D-52056 Aachen, Germany
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Affiliation as printed
Institute of Physical Chemistry, RWTH Aachen University, D-52056 Aachen, Germany
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Affiliation as printed
Institute of Physical Chemistry, RWTH Aachen University, D-52056 Aachen, Germany
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Affiliation as printed
Institute of Physical Chemistry, RWTH Aachen University, D-52056 Aachen, Germany
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University of Parma · Institute of Materials for Electronics and Magnetism
Affiliation as printed
Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Viale delle Scienze 17/A, 43124 Parma, Italy
IMEM-CNR, Viale delle Scienze 37/A, 43124 Parma, Italy
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Affiliation as printed
Department of Mathematical, Physical and Computer Sciences, University of Parma, Viale delle Scienze 7/A, 43124 Parma, Italy
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Affiliation as printed
Department of Mathematical, Physical and Computer Sciences, University of Parma, Viale delle Scienze 7/A, 43124 Parma, Italy
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