High-Quality AlN/Al₂O₃ Dielectric in AlGaN/GaN MIS-HEMTs

In GaN-based power devices, a broader gate voltage swing is required to match practical circuit applications [1]–[3]. In this paper, novel AlGaN/GaN MIS-high electron mobility transistors (HEMTs) with AlN/Al<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> stack layer as dielectric are proposed. The developed MIS-HEMTs exhibit a maximum drain current of 614.7 mA/mm and high ON/OFF ratio of 1.6×l0<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">8</sup>, while associated low ON-resistance of 8.57 <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\Omega \cdot$</tex> mm. Furthermore, small threshold voltage shifts are observed under positive and negative gate bias conditions, specifically less than 0.3 V under <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$V_{\text{GS}}=1\mathrm{V}$</tex> with a stress time of 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sup> seconds and less than 0.1 V under <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$V_{\text{GS}}=-16\mathrm{V}$</tex> with a stress time of 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sup> seconds. This result indicate the <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{AlN}/\text{Al}_{2}\mathrm{O}_{3}$</tex> stack layer realize high-performance MIS-HEMTs.