Large-Area In-Situ Oxide, GaN Interlayer-Based Vertical Trench MOSFET (OG-FET)

We present a large-area in-situ oxide, GaN interlayer-based vertical trench MOSFET (OG-FET) with a metal organic chemical vapor deposition regrown 10-nm unintentional-doped-GaN interlayer as the channel and 50-nm in-situ Al-2 O-3 as the gate dielectric. The threshold voltage of the device on bulk GaN substrate was 1 V measured at I-on/I-off = 10(7). The OG-FET with an area scaled to 0.2 mm(2) demonstrated a breakdown voltage (V-BR) of 320 V and an on-state resistance (R-on) of 3.8 Omega (specific on-state resistance: R-on,R-sp = 7.6 m Omega center dot cm(2)). For the single unit cell OG-FET from the same sample, VBR was as high as 700 V (measured at V-GS = -10 V), corresponding to a breakdown electric field of 1.4 MV/cm and Ron, sp of 0.98 m Omega center dot cm2. On our control sample, which was grown on sapphire substrate, a 1-A current was measured as well. These results show the potential of the OG-FET in power conversion applications.