Crack-free high composition (>35%) thick (>30 nm) barrier AlGaN/AlN/GaN HEMT on sapphire with record low sheet resistance

• Published in: arXiv.org
• Main Authors: Mukhopadhyay, Swarnav, Liu, Cheng, Chen, Jiahao, Sanyal, Surjava, Bai, Ruixin, Wang, Guangying, Gupta, Chirag, Pasayat, Shubhra
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 03.08.2024
• Subjects: Aluminum gallium nitrides; Aluminum nitride; Barrier layers; Composition; Electron gas; Epitaxial growth; Epitaxial layers; Gallium nitrides; Hall effect; High electron mobility transistors; Optimization; Physics - Applied Physics; Physics - Materials Science; Room temperature; Sapphire; Substrates
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2304.05593

In this article, high composition (>35%) thick (>30 nm) barrier AlGaN/AlN/GaN HEMT structure grown on a sapphire substrate with ultra-low sheet resistivity (<250 \Omega / \Box ) is reported. Optimization of growth conditions, such as reduced growth rate, low carbon incorporation, and thickness optimization of different epitaxial layers allowed to grow a crack-free high composition and thick AlGaN barrier layer HEMT structure. A significantly high two-dimensional electron gas (2DEG) density of 1.46 \times 10^{13} cm^{-2} with a room temperature mobility of 1710 cm^{2}/V.s is obtained by Hall measurement using the Van-Der-Pauw method. These state-of-the-art results show great potential for high-power Ga-polar HEMT design on the sapphire substrate.