Thermal Stability of Schottky Contacts and Rearrangement of Defects in β‐Ga2O3 Crystals
Abstract The thermal stability of different Schottky contacts (Au, Pt, and Ni) on (100) β‐Ga2O3 single crystals grown by the Czochralski method is investigated. Besides the examination of the Schottky barrier parameters, contact‐dependent defect levels are investigated by deep‐level transient spectr...
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Wiley-VCH
2025-01-01
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| Series: | Advanced Electronic Materials |
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| Online Access: | https://doi.org/10.1002/aelm.202300428 |
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| author | Palvan Seyidov Joel B. Varley Ymir Kalmann Frodason Detlef Klimm Lasse Vines Zbigniew Galazka Ta‐Shun Chou Andreas Popp Klaus Irmscher Andreas Fiedler |
| author_facet | Palvan Seyidov Joel B. Varley Ymir Kalmann Frodason Detlef Klimm Lasse Vines Zbigniew Galazka Ta‐Shun Chou Andreas Popp Klaus Irmscher Andreas Fiedler |
| author_sort | Palvan Seyidov |
| collection | DOAJ |
| description | Abstract The thermal stability of different Schottky contacts (Au, Pt, and Ni) on (100) β‐Ga2O3 single crystals grown by the Czochralski method is investigated. Besides the examination of the Schottky barrier parameters, contact‐dependent defect levels are investigated by deep‐level transient spectroscopy (DLTS) in a 100–650 K (ramp‐up) and 650–100 K (ramp‐down) temperature cycle. Several defect levels are detected below the conduction band minimum at 0.41, 0.60, 0.77, 0.96, and 1.17 eV. In the temperature ramp‐down DLTS, the 1.17 eV level disappears, and the 0.60 eV level appears for all Schottky contacts. DFT calculations suggest that rearrangement and dissociation of a single hydrogen from a doubly‐hydrogenated Ga─O divacancy complex occurs during the temperature sweep under bias. The trap level at 0.96 eV only appears after the thermal load for the Ni contact, in contrast to Au and Pt, where it is present without a thermal budget. Temperature‐dependent leakage current (at −4 V) measurements indicate oxidation of Ni, and further thermodynamic analysis suggests alloying of Au‐Ga atoms at the Au/β‐Ga2O3 interface. These studies provide insight into the behavior induced by these common Schottky contacts and the alteration associated with temperature cycling. |
| format | Article |
| id | doaj-art-ed1152d872c445889ec109cf681cbd47 |
| institution | Kabale University |
| issn | 2199-160X |
| language | English |
| publishDate | 2025-01-01 |
| publisher | Wiley-VCH |
| record_format | Article |
| series | Advanced Electronic Materials |
| spelling | doaj-art-ed1152d872c445889ec109cf681cbd472025-01-10T13:40:16ZengWiley-VCHAdvanced Electronic Materials2199-160X2025-01-01111n/an/a10.1002/aelm.202300428Thermal Stability of Schottky Contacts and Rearrangement of Defects in β‐Ga2O3 CrystalsPalvan Seyidov0Joel B. Varley1Ymir Kalmann Frodason2Detlef Klimm3Lasse Vines4Zbigniew Galazka5Ta‐Shun Chou6Andreas Popp7Klaus Irmscher8Andreas Fiedler9Leibniz‐Institut für Kristallzüchtung 12489 Berlin GermanyLawrence Livermore National Laboratory Livermore CA 94550 USADepartment of Physics/Centre for Materials Science and Nanotechnology University of Oslo Oslo N‐0316 NorwayLeibniz‐Institut für Kristallzüchtung 12489 Berlin GermanyDepartment of Physics/Centre for Materials Science and Nanotechnology University of Oslo Oslo N‐0316 NorwayLeibniz‐Institut für Kristallzüchtung 12489 Berlin GermanyLeibniz‐Institut für Kristallzüchtung 12489 Berlin GermanyLeibniz‐Institut für Kristallzüchtung 12489 Berlin GermanyLeibniz‐Institut für Kristallzüchtung 12489 Berlin GermanyLeibniz‐Institut für Kristallzüchtung 12489 Berlin GermanyAbstract The thermal stability of different Schottky contacts (Au, Pt, and Ni) on (100) β‐Ga2O3 single crystals grown by the Czochralski method is investigated. Besides the examination of the Schottky barrier parameters, contact‐dependent defect levels are investigated by deep‐level transient spectroscopy (DLTS) in a 100–650 K (ramp‐up) and 650–100 K (ramp‐down) temperature cycle. Several defect levels are detected below the conduction band minimum at 0.41, 0.60, 0.77, 0.96, and 1.17 eV. In the temperature ramp‐down DLTS, the 1.17 eV level disappears, and the 0.60 eV level appears for all Schottky contacts. DFT calculations suggest that rearrangement and dissociation of a single hydrogen from a doubly‐hydrogenated Ga─O divacancy complex occurs during the temperature sweep under bias. The trap level at 0.96 eV only appears after the thermal load for the Ni contact, in contrast to Au and Pt, where it is present without a thermal budget. Temperature‐dependent leakage current (at −4 V) measurements indicate oxidation of Ni, and further thermodynamic analysis suggests alloying of Au‐Ga atoms at the Au/β‐Ga2O3 interface. These studies provide insight into the behavior induced by these common Schottky contacts and the alteration associated with temperature cycling.https://doi.org/10.1002/aelm.202300428defectsDFTgallium oxideSchottky contactthermal stability |
| spellingShingle | Palvan Seyidov Joel B. Varley Ymir Kalmann Frodason Detlef Klimm Lasse Vines Zbigniew Galazka Ta‐Shun Chou Andreas Popp Klaus Irmscher Andreas Fiedler Thermal Stability of Schottky Contacts and Rearrangement of Defects in β‐Ga2O3 Crystals Advanced Electronic Materials defects DFT gallium oxide Schottky contact thermal stability |
| title | Thermal Stability of Schottky Contacts and Rearrangement of Defects in β‐Ga2O3 Crystals |
| title_full | Thermal Stability of Schottky Contacts and Rearrangement of Defects in β‐Ga2O3 Crystals |
| title_fullStr | Thermal Stability of Schottky Contacts and Rearrangement of Defects in β‐Ga2O3 Crystals |
| title_full_unstemmed | Thermal Stability of Schottky Contacts and Rearrangement of Defects in β‐Ga2O3 Crystals |
| title_short | Thermal Stability of Schottky Contacts and Rearrangement of Defects in β‐Ga2O3 Crystals |
| title_sort | thermal stability of schottky contacts and rearrangement of defects in β ga2o3 crystals |
| topic | defects DFT gallium oxide Schottky contact thermal stability |
| url | https://doi.org/10.1002/aelm.202300428 |
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