GaAs MOSFET using InAlP native oxide as gate dielectric

GaAs metal-oxide-semiconductor field-effect transistors (MOSFETs) using wet thermally oxidized InAIP as the gate insulator are reported for the first time. Leakage current measurements show that the 11-nm-thick native oxide grown from an In0.49Al0.51P layer lattice-matched to GaAs has good insulating properties, with a measured leakage current density of 1.39 x 10(-7) mA/mum(2) at 1 V bias. GaAs MOSFETs with InAlP native gate oxide have been fabricated with gate lengths from 7 to 2 pin. Devices with 2-mum-long gates exhibit a peak extrinsic transconductance of 24.2 mS/mm, an intrinsic transconductance of 63.8 mS/mm, a threshold voltage of 0.15 V, and an off-state gate-drain breakdown voltage of 21.2 V Numerical Poisson's equation solutions provide close agreement with the measured sheet resistance and threshold voltage.