Formation of Ultra-High-Resistance Au/Ti/p-GaN Junctions and the Applications in AlGaN/GaN HEMTs

• Published in: arXiv.org
• Main Authors: Zhou, Guangnan, Jiang, Yang, Yang, Gaiying, Wang, Qing, Fan, Mengya, Jiang, Lingli, Yu, Hongyu, Xia, Guangrui
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 05.02.2021
• Subjects: Aluminum gallium nitrides; Annealing; Anodes; Gallium nitrides; Graphene; Hall effect; Physics - Materials Science; Threshold voltage
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2102.03418

We report a dramatic current reduction, or a resistance increase, by a few orders of magnitude of two common-anode Au/Ti/pGaN Schottky junctions annealed within a certain annealing condition window (600 - 700 oC, 1 - 4 min). Results from similar common-anode Schottky junctions made of Au/p-GaN, Al/Ti/p-GaN and Au/Ti/graphene/p-GaN junctions demonstrated that all the three layers (Au, Ti and p-GaN) are essential for the increased resistance. Raman characterization of the p-GaN showed a decrease of the Mg-N bonding, i.e., the deactivation of Mg, which is consistent with the Hall measurement results. Moreover, this high-resistance junction structure was employed in p-GaN gate AlGaN/GaN HEMTs. It was shown to be an effective gate technology that was capable to boost the gate breakdown voltage from 9.9 V to 13.8 V with a negligible effect on the threshold voltage or the sub-threshold slope.