Performance Analysis of an Enhancement Mode Operated AlGaN/GaN MIS-HEMT Device with Ga₂O₃ as a Back Barrier

Rapid technological advancements over the past decade have propelled gallium oxide to the forefront of ultra-wide bandgap semiconductor technologies, owing to its favorable intrinsic material properties. In this work, we propose an enhancement mode-operated recessed gate AlGaN MIS-HEMT device structure with Ga <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> O <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> as a back barrier. Ga <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> O <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> 's wide bandgap reduces trapping states near the semiconductor interface, improving carrier transport and leading to increased saturation current and transconductance. The use of a β-Ga <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> O <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> back-barrier layer in the device creates a potential well that enhances carrier concentration and improves electron mobility, resulting in higher sheet charge density. In this work, we compared a MIS-HEMT device featuring a Ga <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> O <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> back barrier with a conventional MIS-HEMT structure with AlGaN as the back barrier and analyze the DC and RF characteristics. Numerical results of the proposed Al <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.15</inf> Ga <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.85</inf> N/GaN/Ga <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> O <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> obtained from TCAD simulations show that an <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Ids</tex> of 0.84 A/mm, <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">VB D</tex> of 1012 V, R <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ON</inf> of 6.45 ohm.mm, <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">fₜ</tex> of 34 GHz, <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">fₘₐₓ</tex> of 84 GHz, <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">gₘ</tex> of 0.25 S/mm and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">VTH</tex> of 3.02 V is obtained. The results obtained indicate that incorporating Ga <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> O <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> as a back barrier, optimizing layer thickness, and employing a recessed gate structure collectively improve the DC and RF characteristics of the device, rendering it suitable for high-frequency and high-power applications.