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 Al2O3 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 Vth and hence to systematically study the underlying mechanism. The experimental results reveal that Δ Vth can be as high as 1.0 V at V Gmax =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 Vth is frequency independent but the second onset of voltage shifts (Δ V2) shows obvious frequency dependence. These results imply the likely mechanism of slow (deep) Al2O3 interface traps accounting for Δ V1 hysteresis, and fast (shallow) interface traps accounting for Δ V2

Item Type: Conference or Workshop Item (Unspecified)
Depositing User: Symplectic Admin
Date Deposited: 15 Feb 2019 09:36
Last Modified: 15 Mar 2024 00:58
DOI: 10.1109/edssc.2018.8487160
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3032861