[15p-315-1~17] 13.8 化合物及びパワー電子デバイス・プロセス技術

▲ [15p-315-14] Enhancement-mode Ga₂O₃ MOSFETs with Si-Ion-Implanted Source and Drain

〇Wong ManHoi¹、Nakata Yoshiaki¹、Kuramata Akito²、Yamakoshi Shigenobu²、Higashiwaki Masataka¹ (1.NICT、2.Tamura Corp.)

キーワード：Ga2O3, MOSFET, enhancement-mode

Power converters favor normally-off switches for safety and simplified circuit topologies. Enhancement-mode Ga₂O₃ metal-oxide-semiconductor field-effect transistors (MOSFETs) reported to date employ relatively high channel doping intended for maintaining volume current density, which imposes constraints on the device dimensions or architecture to realize positive threshold voltage while limiting conductance in the ungated access regions. This work demonstrates enhancement-mode Ga₂O₃ MOSFETs with an unintentionally-doped Ga₂O₃ channel, whose low background carrier density offers improved design flexibility and reduced process complexity for achieving full channel depletion at a gate bias of 0 V. Low source/drain series resistances were realized by Si-ion implantation. MOSFETs with a channel length of 4 μm delivered a maximum drain current density (I_DS) of 1.4 mA/mm and an I_DS on/off ratio near 10⁶.