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 $G_{m,int}$ 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/ $\text{V}\cdot \text{s}$ , a high saturation velocity $v_{sat}$ of $1.1\times 10^{7}$ cm/s, and a low interface trap density of $1.1\times 10^{12}$ 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 ${V} _{br}$ of 118 V, a small specific on resistance $R_{on,sp}$ of 1.44 $\text{m}\Omega \cdot $ cm2, and power figure-of-merit of 9.7 MW/cm2 are achieved in a device with $L_{GD}$ of $1.14~\mu \text{m}$ . These excellent results indicate the great potential of Ga2O3 MOSFETs on AlN/Si substrate for future power electronics applications.