Characterization of Transient Threshold Voltage Shifts in Enhancement- and Depletion-mode AlGaN/GaN Metal-Insulator-Semiconductor (MIS)-HEMTs

Cui, Miao, Cai, Yutao, Lam, Sang, Liu, Wen, Zhao, Chun, Mitrovic, Ivona Z ORCID: 0000-0003-4816-8905, Taylor, Stephen ORCID: 0000-0002-2144-8459, Chalker, Paul R ORCID: 0000-0002-2295-6332 and Zhao, Cezhou (2018) Characterization of Transient Threshold Voltage Shifts in Enhancement- and Depletion-mode AlGaN/GaN Metal-Insulator-Semiconductor (MIS)-HEMTs. In: 2018 IEEE International Conference on Electron Devices and Solid State Circuits (EDSSC), 2018-6-6 - 2018-6-8.

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Abstract

Both enhancement-and depletion-mode AlGaN/GaN metal-insulator-semiconductor HEMTs were fabricated with Al<inf>2</inf>O<inf>3</inf> as the gate dielectric formed by atomic layer deposition (ALD). With the common problems of threshold voltage hysteresis in AlGaN/GaN MIS-HEMTs, DC I-V and fast transient I-V as well as frequency-dependent C-V measurements were performed to characterize the threshold voltage shifts Δ V<inf>th</inf> and hence to systematically study the underlying mechanism. The experimental results reveal that Δ V<inf>th</inf> can be as high as 1.0 V at V G<inf>max</inf> =5 V in transient I-V measurements despite the much lower values of 0.42 V in static and CV measurements. This has significant implications in using AlGaN/GaN MIS-HEMTs for high voltage switching applications. Besides, multi-frequency C-V measurements show that the primary Δ V<inf>th</inf> is frequency independent but the second onset of voltage shifts (Δ V<inf>2</inf>) shows obvious frequency dependence. These results imply the likely mechanism of slow (deep) Al<inf>2</inf>O<inf>3</inf> interface traps accounting for Δ V<inf>1</inf> hysteresis, and fast (shallow) interface traps accounting for Δ V<inf>2</inf>

Item Type:	Conference Item (Unspecified)
Uncontrolled Keywords:	51 Physical Sciences, 40 Engineering, 4018 Nanotechnology
Depositing User:	Symplectic Admin
Date Deposited:	15 Feb 2019 09:36
Last Modified:	09 Jun 2025 14:36
DOI:	10.1109/edssc.2018.8487160
Related Websites:	Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3032861