Dramatic Improvement in the Rectifying Properties of Pd Schottky Contacts on β-Ga₂O₃ During Their High-Temperature Operation
| Autor: | Caixia Hou, Rodrigo M. Gazoni, Martin W. Allen, Roger J. Reeves |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
010302 applied physics
Materials science Band gap Analytical chemistry Schottky diode chemistry.chemical_element Diamond engineering.material 01 natural sciences Electrical contacts Electronic Optical and Magnetic Materials Thermal conductivity chemistry 0103 physical sciences engineering Electrical and Electronic Engineering Gallium Leakage (electronics) Bar (unit) |
| Zdroj: | IEEE Transactions on Electron Devices. 68:1791-1797 |
| ISSN: | 1557-9646 0018-9383 |
| Popis: | $\beta $ -Ga2O3 is a candidate for high-efficiency power electronics and ultraviolet C (UVC) detectors capable of operating in harsh environments. However, electrical contacts that maintain their performance at high temperatures are likely to be important due to the material’s low thermal conductivity. In this study, we report on a dramatic improvement in the rectifying performance of Pd Schottky contacts (SCs) on ( $\bar {2}01$ ) and (010) $\beta $ -Ga2O3 at high temperatures in air. This effect involves a large thermally activated increase in the image-force-corrected barrier height ( $\Phi _{B,IF}$ ) from 1.40 eV at room temperature (RT) to 1.75–2.20 eV, with most of the transition occurring between 250 °C and 450 °C. This improvement is due to the oxidation of the Pd SC layer that creates higher barrier height PdO regions that dominate the high-temperature current transport. In the most oxidized Pd SCs, $\Phi _{B,IF}$ increased to 2.20 eV at 500 °C with leakage currents of $\sim 1\times 10^{-6}$ Acm−2 (−3 V) and rectification ratios (±3 V) of $\sim 10^{7}$ , at 500 °C, similar to the best results for diamond and SiC SCs. Interestingly, very good agreement between the temperature dependence of the built-in voltage of the thermally oxidized Pd SCs and the optical bandgap of $\beta $ -Ga2O3 (approximately −1.3 meV/°C in both cases) was observed between RT and 500 °C. |
| Databáze: | OpenAIRE |
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