Enhancement-Mode AlGaN/GaN MIS-HEMTs With High V<sub>TH</sub> and High I<sub>Dmax</sub> Using Recessed-Structure With Regrown AlGaN Barrier
Joel T. Asubar, Shinsaku Kawabata, Hirokuni Tokuda, Akio Yamamoto, Masaaki Kuzuhara
Abstract
We report on an Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> /AlGaN/GaN metalinsulator-semiconductor high-electron-mobility transistor (MIS-HEMT) with recessed-gate structure and regrown AlGaN barrier. After analyzing the possibility of obtaining high threshold voltage (V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sub> ) within the framework of Tapajna and Kuzmik model from preliminary experiments using MIS-diode structures, we fabricated a MIS-HEMT with the same materials and structures. The transistor exhibited a highVth value of +2.3 V determined at the drain current criterion of 10 <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">μ</sub> A/mm together with a maximum drain current density (I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Dmax</sub> ) of 425 mA/mm. We believe that the adoption of a technology, i. e., AlGaN regrowth on dryetched GaN surface, previously demonstrated by our group in planar device, is the main key for achieving such desirable performance.