High Mobility 4H-SiC MOSFET

Enhancement mode 4H-SiC MOSFETs with a channel length of 2 μm achieved a room temperature field effect mobility of 125 cm
²
/V·s and a subthreshold slope of 130 mV/dec. The temperature dependence of mobility up to 300 °C indicates that phonon scattering has replaced Coulombic scattering in these devices, which remain enhancement mode with high mobility and an ON/OFF current ratio in excess of 10
⁶
. The fabricated devices utilised a gate stack comprising a 0.7 nm thin thermal SiO
₂
, thereby reducing defects following oxidation, and a 40 nm thick Al
₂
O
₃
formed by atomic layer deposition.