Over 12000 A/cm 2 and 3.2 mΩ cm 2 Miniaturized Vertical-Type Two-Dimensional Hole Gas Diamond MOSFET

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 Al2O3insulator 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/cm2at VDS= -50 V and the specific on-resistance of RON= 3.2 mcm2at VDS= -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.