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Formation of thermally grown SiO2/GaN interface
| Title: | Formation of thermally grown SiO2/GaN interface |
| Authors: | Akazawa, Masamichi Browse this author →KAKEN DB | | Kitawaki, Yuya Browse this author |
| Issue Date: | 13-Aug-2021 |
| Publisher: | American Institute of Physics (AIP) |
| Journal Title: | AIP Advances |
| Volume: | 11 |
| Issue: | 8 |
| Start Page: | 085020 |
| Publisher DOI: | 10.1063/5.0060821 |
| Abstract: | An attempt was made to form a thermally grown SiO2/GaN interface. A Si layer deposited on the c-plane GaN surface was oxidized in an O-2 atmosphere to form a SiO2 layer. The formation of SiO2 with a bandgap of 8.6 eV was confirmed by x-ray photoelectron spectroscopy. Metal-oxide-semiconductor diodes were fabricated and tested to characterize the interface by electrical measurements. The capacitance-voltage (C-V) characteristics measured at 1 MHz showed that a longer oxidation time resulted in a steeper slope. However, it was unavoidable that a bump in a C-V curve appeared after a long oxidation time. The electron trap distributions derived from C-V curves exhibited a discrete-level trap at 0.7 eV from the conduction band edge. This discrete-level trap was an acceptor-like trap that can be assigned to a Ga vacancy. An insufficient oxidation led to a high leakage current owing to the asperities of the residual polycrystalline Si layer. Although the leakage current was improved by extending the oxidation time, an excessively long oxidation time resulted in a slight increase in the leakage current. We cannot deny the possibility of the diffusion of Ga atoms into SiO2 during oxidation. Moreover, the cross-sectional transmission electron microscopy and energy-dispersive x-ray spectroscopy of a sample formed with an excessively long oxidation time indicated the formation of a Ga oxide interlayer without a severe disorder. Most possibly, the formation of the Ga oxide interlayer by excess oxidation improved the interface properties. |
| Rights: | This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in AIP Advances and may be found at https://aip.scitation.org/doi/10.1063/5.0060821. |
| Type: | article |
| URI: | http://hdl.handle.net/2115/82684 |
| Appears in Collections: | 量子集積エレクトロニクス研究センター (Research Center for Integrated Quantum Electronics) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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