Partida-Manzanera, T., Zaidi, Z.H., Roberts, J.W. et al. (6 more authors) (2019) Comparison of atomic layer deposited Al2O3 and (Ta2O5)0.12(Al2O3)0.88 gate dielectrics on the characteristics of GaN-capped AlGaN/GaN metal-oxide-semiconductor high electron mobility transistors. Journal of Applied Physics, 126 (3). 034102. ISSN 0021-8979
Abstract
The current research investigates the potential advantages of replacing Al2O3 with (Ta2O5)0.12(Al2O3)0.88 as a higher dielectric constant (κ) gate dielectric for GaN-based metal-oxide-semiconductor high electron mobility transistors (MOS-HEMTs). The electrical characteristics of GaN-capped AlGaN/GaN MOS-HEMT devices with (Ta2O5)0.12(Al2O3)0.88 as the gate dielectric are compared to devices with Al2O3 gate dielectric and devices without any gate dielectric (Schottky HEMTs). Compared to the Al2O3 MOS-HEMT, the (Ta2O5)0.12(Al2O3)0.88 MOS-HEMT achieves a larger capacitance and a smaller absolute threshold voltage, together with a higher two-dimensional electron gas carrier concentration. This results in a superior improvement of the output characteristics with respect to the Schottky HEMT, with higher maximum and saturation drain current values observed from DC current-voltage measurements. Gate transfer measurements also show a higher transconductance for the (Ta2O5)0.12(Al2O3)0.88 MOS-HEMT. Furthermore, from OFF-state measurements, the (Ta2O5)0.12(Al2O3)0.88 MOS-HEMT shows a larger reduction of the gate leakage current in comparison to the Al2O3 MOS-HEMT. These results demonstrate that the increase in κ of (Ta2O5)0.12(Al2O3)0.88 compared with Al2O3 leads to enhanced device performance when the ternary phase is used as a gate dielectric in the GaN-based MOS-HEMT.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2019 The Authors. This is an author-produced version of a paper subsequently published in Journal of Applied Physics. Uploaded in accordance with the publisher's self-archiving policy. |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Engineering (Sheffield) > Department of Electronic and Electrical Engineering (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 05 Aug 2019 08:35 |
Last Modified: | 05 Aug 2019 09:33 |
Status: | Published |
Publisher: | AIP Publishing |
Refereed: | Yes |
Identification Number: | 10.1063/1.5049220 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:149260 |