100GHz depletion-mode Ga2O3/GaN single nanowire MOSFET by photo-enhanced chemical oxidation method

We reported transport characterization on [112̄0]GaN single nanowire (SNW)-MOSFET laterally- and directionally-grown on (0001) sapphire substrates. The 60nm-dia. Ga
2
O
3
/GaN SNW-MOSFET of 0.1µm gate length was shown to exhibit a saturation current of 160µA, current on/off ratio of 10
⁵
, swing of 85mV/dec, transconductance of 85µS, and unity current gain bandwidth f
t
at 95GHz. From a 3D diffusion and drift model analysis, it is shown that a polarization induced 2D electron gas (2DEG) density of 7×10
¹²
cm
²
with mobility of 1000cm
²
/V-sec confined at the interface of semi-polar {11̄01̄} GaN/Ga
2
O
3
was responsible for the high-speed transport characteristics.