Vertical GaN-based trench gate metal oxide semiconductor field-effect transistors on GaN bulk substrates

Completely vertical trench gate metal oxide semiconductor field-effect transistors (MOSFETs) have been produced using gallium nitride (GaN) for the first time. These MOSFETs exhibited en hancement-mode operation with a threshold voltage of 3.7 V and an on-resistance of 9.3 m Omega center dot cm(2). The channel mobility was estimated to be 131 cm(2)/(V.s) when all the resistances except for that of the channel are considered. Such structures, which satisfy the key words vertical, trench gate, and MOSFET, will enable us to fabricate practical GaN-based power switching devices. (c) 2008 The Japan Society of Applied Physics.