Investigation of the role of pre-existing oxide in the initial degradation mechanism in AlGaN/GaN HEMTs under ON-state stress

The role of pre-existing oxide in the initial degradation mechanism of AlGaN/GaN high electron mobility transistors during ON-state stressing was systematically studied. The pre-existing oxide was revealed to exist as an amorphous oxide layer consisting primarily of Ni and Ga oxides with a small amo...

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Bibliographic Details
Main Authors: Tan, H. T., Gao, Y., Syaranamual, G. J., Sasangka, W. A., Foo, Siew Chuen, Lee, K. H., Arulkumaran, Subramaniam, Ng, Geok Ing, Thompson, C. V., Gan, Chee Lip
Other Authors: School of Materials Science and Engineering
Format: Article
Language:English
Published: 2024
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Online Access:https://hdl.handle.net/10356/173086
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Institution: Nanyang Technological University
Language: English
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Summary:The role of pre-existing oxide in the initial degradation mechanism of AlGaN/GaN high electron mobility transistors during ON-state stressing was systematically studied. The pre-existing oxide was revealed to exist as an amorphous oxide layer consisting primarily of Ni and Ga oxides with a small amount of Al oxide at the GaN-cap/Ni-gate interface. Through an ON-state stressing experiment carried out in vacuum that excluded the influence of atmospheric oxygen, we discovered that the pre-existing interfacial oxide participated in an electrochemical reaction, accounting for the initial degradation in AlGaN/GaN HEMTs. The thickening of the oxide layer at the gate edge reduces the effective gate length of the device, thereby causing a decrease in the drain saturation current.