High performance Ga2O3 metal-oxide-semiconductor field-effect transistors on an AlN/Si substrate

Abstract

We propose and demonstrate Ga2O3 metal-oxide-semiconductor field-effect transistors (MOSFETs) on a high thermal conductivity AlN/Si substrate to improve the heat dissipation capability and keep their cost-effectiveness. Owing to the optimized source/drain contact and Al2O3/Ga2O3 interface, a drain current of 580 mA/mm and peak intrinsic transconductance Gm,int of 35.5 mS/mm were achieved, which are among the highest for all the reported top-gate Ga2O3 MOSFETs. A peak mobility of 82.9 cm2/Vs, a high saturation velocity vsat of 1.1× 107 cm/s, and a low interface trap density of 1.1× 1012 cm-2 eV-1 are also obtained. Pulse measurement reveals the good heat dissipation capability of the AlN/Si substrate. A three terminal off-state breakdown voltage Vbr of 118 V, a small specific on resistance Ron,sp of 1.44 m ?cm2, and power figure-of-merit of 9.7 MW/cm2 are achieved in a device with LGD of 1.14 ?m. These excellent results indicate the great potential of Ga2O3 MOSFETs on AlN/Si substrate for future power electronics applications. © 2019 IEEE.