Schottky-MIS Cascode Drain Reverse-Blocking p-GaN Gate Transistor With Significantly Reduced Forward Drop and Ultralow Leakage Current

In this article, we experimentally propose a reverse-blocking (RB) p-GaN gate transistor with the Schottky-MIS cascode drain (CDT) for the significantly reduced forward voltage drop <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${\textit {V}}_{\mathbf {F}}$ </tex-math></inline-formula> and ultralow reverse leakage current <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${I}_{\mathbf {\textit {LEAK}}}$ </tex-math></inline-formula>. At forward bias, electron concentration at the Schottky-MIS cascode drain is higher than that at conventional p-GaN/Ohmic drain. When experiencing reverse bias, the Schottky-MIS cascode drain effectively protects the Schottky contact from the high reverse potential compared to Schottky drain. The fabricated Schottky-MIS CDT presents a superior <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\mathbf {F}}$ </tex-math></inline-formula> - <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${I}_{\mathbf {\textit {LEAK}}}$ </tex-math></inline-formula> relationship including a greatly reduced <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\mathbf {F}}$ </tex-math></inline-formula> of 3.1V as well as an ultralow <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${I}_{\mathbf {\textit {LEAK}}}$ </tex-math></inline-formula> of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${1}\times {10} ^{-{8}}$ </tex-math></inline-formula> A/mm, together with a competitive reverse power figure-of-merit (FOM) of 120MW/cm2. These performances suggest that the proposed Schottky-MIS CDT can be a promising candidate for low-loss RB GaN power transistors and applications requiring a better <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\mathbf {F}}$ </tex-math></inline-formula> - <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${I} _{\mathbf {\textit {LEAK}}}$ </tex-math></inline-formula> trade-off.