600 V/ $1.7~\Omega$ Normally-Off GaN Vertical Trench Metal–Oxide–Semiconductor Field-Effect Transistor

This letter reports a GaN vertical trench metal-oxide-semiconductor field-effect transistor (MOSFET) with normally-off operation. Selective area regrowth of n±GaN source layer was performed to avoid plasma etch damage to the p-GaN body contact region. A metal-organic-chemicalvapor-deposition (MOCVD) grown AlN/SiN dielectric stack was employed as the gate “oxide”. This unique process yielded a 0.5-mm²-active-area transistor with threshold voltage of 4.8 V, blocking voltage of 600 V at gate bias of 0 V, and on-resistance of 1.7 Ω at gate bias of 10 V.