Comparison of atomic layer deposited Al<sub>2</sub>O<sub>3</sub> and (Ta<sub>2</sub>O<sub>5</sub>)<sub>0.12</sub>(Al<sub>2</sub>O<sub>3</sub>)<sub>0.88</sub> gate dielectrics on the characteristics of GaN-capped AlGaN/GaN metal-oxide-semiconductor high electron mobility transistors


Partida-Manzanera, T, Zaidi, ZH, Roberts, JW, Dolmanan, SB, Lee, KB, Houston, PA, Chalker, PR ORCID: 0000-0002-2295-6332, Tripathy, S and Potter, RJ ORCID: 0000-0003-0896-4536 (2019) Comparison of atomic layer deposited Al<sub>2</sub>O<sub>3</sub> and (Ta<sub>2</sub>O<sub>5</sub>)<sub>0.12</sub>(Al<sub>2</sub>O<sub>3</sub>)<sub>0.88</sub> gate dielectrics on the characteristics of GaN-capped AlGaN/GaN metal-oxide-semiconductor high electron mobility transistors. JOURNAL OF APPLIED PHYSICS, 126 (3). 034102-034102.

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Abstract

<jats:p>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.</jats:p>

Item Type: Article
Depositing User: Symplectic Admin
Date Deposited: 25 Jul 2019 15:33
Last Modified: 14 Oct 2023 08:57
DOI: 10.1063/1.5049220
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3050336
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