GaN Nanowire MOSFET with Near-Ideal Subthreshold Slope
Kristine A. Bertness, Wenjun Li, Matthew D. Brubaker, Bryan T. Spann, Patrick Fay
Top-gated GaN nanowire MOSFETs using Al2O3 as gate oxide have been experimentally demonstrated. The fabricated devices exhibit a minimum subthreshold slope of 60 mV/dec, an average subthreshold slope of 68 mV/dec over three decades of drain current, drain-induced barrier lowering of 27 mV/V, an on-current of 98 A/m (normalized by wire diameter), off-current below 10-6 A/m, on/off ratio over 108, and an intrinsic transconductance of 155 S/m. The field-effect channel electron mobility is extracted to be 37 cm2/V-s at 300 K, which is primarily limited by acoustic phonon and impurity scattering. These performance metrics make GaN nanowire MOSFETs a promising candidate for emerging low-power applications such as sensors and RF for the internet of things.