The Modulation Effect of LPCVD-Si x N y Stoichiometry on 2-DEG Characteristic of UTB AlGaN/GaN Heterostructure.
In: IEEE Transactions on Electron Devices, Jg. 69 (2022-09-01), Heft 9, S. 4828-4834
academicJournal
Zugriff:
In this work, the impact of low-pressure chemical vapor deposition (LPCVD)-SixNy stoichiometry on 2-D electron gas (2-DEG) transport characteristics of the AlGaN (3.9 nm)/GaN heterostructure and the underlying mechanism of increased 2-DEG density are studied, which reveals a new perspective of improving AlGaN/GaN performance by dielectric engineering. Among the AlGaN/GaN passivated by the LPCVD-SixNy with tailored stoichiometry, the 2-DEG density and mobility in the Si-rich sample were significantly improved by 25% and 16.3% compared with the N-rich sample, respectively. Accordingly, 30% reduction in sheet resistance of AlGaN/GaN heterostructure is obtained. The potentially strained-induced enhancement of piezoelectric polarization and corresponding 2-DEG variation by the SixNy passivation layer was excluded by the negligible change in Raman spectra among the different samples. Alternatively, the X-ray photoelectron spectroscopy (XPS) showed that the varied stoichiometry of the SixNy enables a discernible modulation effect of heterostructure energy-band. The reduced surface potential in the sample passivated by Si-rich SixNy attributes to the pronounced Ga dangling bonds (DBs) at the LPCVD-SixNy/AlGaN interfaces, which provides the near-conduction band (NCB) states and leads to enhanced 2-DEG accumulation. [ABSTRACT FROM AUTHOR]
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Titel: |
The Modulation Effect of LPCVD-Si x N y Stoichiometry on 2-DEG Characteristic of UTB AlGaN/GaN Heterostructure.
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Autor/in / Beteiligte Person: | Zhu, Liyang ; Zhou, Qi ; Chen, Kuangli ; Gao, Wei ; Cai, Yong ; Cheng, Kai ; Li, Zhaoji ; Zhang, Bo |
Zeitschrift: | IEEE Transactions on Electron Devices, Jg. 69 (2022-09-01), Heft 9, S. 4828-4834 |
Veröffentlichung: | 2022 |
Medientyp: | academicJournal |
ISSN: | 0018-9383 (print) |
DOI: | 10.1109/TED.2022.3188609 |
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