Over 12000 A/cm²and 3.2 m$\Omega$ cm²Miniaturized Vertical-Type Two-Dimensional Hole Gas Diamond MOSFET

Abstract

We present a miniaturized vertical-type twodimensional hole gas (2DHG) diamond metal-oxide-semiconductor field-effect transistor (MOSFET) by adopting a gate-source overlapping structure. We developed a 2-μm-wide trench and disposed a part of the gate electrode to overlap the 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> insulator film on the source electrode to eliminate the space between source and gate electrode. We obtained the maximum drain current density of ID = 12800 A/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> at V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DS</sub> = -50 V and the specific on-resistance of R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ON</sub> = 3.2 mcm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> at V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DS</sub> = -10 V and confirmed their improvement by the miniaturization of devices and reduction of source to gate resistance. In addition, the drain current on/off ratio was 7 orders magnitude even at 200 °C with the formation of a highly concentrated, thick nitrogen-doped layer as the current blocking layer.