3000-V 4.3-$\hbox{m}\Omega \cdot \hbox{cm}^{2}$ InAlN/GaN MOSHEMTs With AlGaN Back Barrier

Abstract

This letter reports the fabrication of InAlN/GaN high-electron mobility transistors (HEMTs) with a three-terminal off-state breakdown voltage (BV) of 3000 V and a low specific on-resistance of 4.25 mΩ·cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . To reduce the drain-to-source leakage current in these devices, an AlGaN back barrier has been used. The gate leakage current in these devices is in the ~10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-10</sup> A/mm range owing to the use of a SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> gate dielectric. This current level is more than six orders of magnitude lower than in Schottky-barrier HEMTs. The combination of an AlGaN back barrier, the high charge sheet density of InAlN/GaN HEMTs, and the low leakage due to the gate-dielectric layer allows for a figure-of-merit BV <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> / <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">R</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ON,SP</sub> of ~2.1 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">9</sup> V <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ·Ω <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> ·cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-2</sup> .