1. Polarization enhanced two-dimensional hole gas in III-nitride heterostructures for cryogenically operated GaN-based p-channel field effect transistors.
- Author
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Wang, Yingjie, Huang, Sen, Jiang, Qimeng, Wang, Xinhua, Ji, Zhongchen, Fan, Jie, Yin, Haibo, Wei, Ke, Liu, Xinyu, Sun, Qian, and Chen, Kevin J.
- Subjects
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FIELD-effect transistors , *MODULATION-doped field-effect transistors , *HETEROSTRUCTURES , *THRESHOLD voltage , *LOGIC devices , *GASES - Abstract
In this work, AlN polarization-enhancement interlayer (AlN-PEL) is adopted to enhance two-dimensional hole gas (2DHG) density in a p-GaN/AlN-PEL(∼2 nm)/AlGaN(<6 nm)/GaN heterostructure, aiming at monolithic integration of p/n-channel field effect transistors (p-FETs) on GaN-on-Si substrate. Owing to the strong built-in polarization of the AlN-PEL, high density 2DHG over 2.3 × 1013 cm−2 with good immunity to thermal freeze out effect is realized. Assisted by a two-step gate trench etching process, enhancement-mode (E-mode) buried-channel GaN p-FETs with temperature independent ON-resistance RON, and ON/OFF current ratio ION/IOFF (>108), have been fabricated. The fabricated p-FETs also deliver thermally stable subthreshold swing as well as threshold voltage Vth, and smaller Vth shift than that of p-FETs without the AlN-PEL, which is primarily due to enhanced 2DHG confinement by the AlN-PEL. The proposed structure is an attractive platform for monolithic integration of GaN-based logic and power devices for cryogenic applications as low as 10 K. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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