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 <inline-formula> <tex-math notation= LaTeX >$G_{m,int}$ </tex-math></inline-formula> 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/<inline-formula> <tex-math notation= LaTeX >$\\text{V}\\cdot \\text{s}$ </tex-math></inline-formula>, a high saturation velocity <inline-formula> <tex-math notation= LaTeX >$v_{sat}$ </tex-math></inline-formula> of <inline-formula> <tex-math notation= LaTeX >$1.1\\times 10^{7}$ </tex-math></inline-formula> cm/s, and a low interface trap density of <inline-formula> <tex-math notation= LaTeX >$1.1\\times 10^{12}$ </tex-math></inline-formula> cm<inline-formula> <tex-math notation= LaTeX >$^{-2}$ </tex-math></inline-formula>eV<inline-formula> <tex-math notation= LaTeX >$^{-1}$ </tex-math></inline-formula> are also obtained. Pulse measurement reveals the good heat dissipation capability of the AlN/Si substrate. A three terminal off-state breakdown voltage <inline-formula> <tex-math notation= LaTeX >${V} _{br}$ </tex-math></inline-formula> of 118 V, a small specific on resistance <inline-formula> <tex-math notation= LaTeX >$R_{on,sp}$ </tex-math></inline-formula> of 1.44 <inline-formula> <tex-math notation= LaTeX >$\\text{m}\\Omega \\cdot $ </tex-math></inline-formula>cm², and power figure-of-merit of 9.7 MW/cm² are achieved in a device with <inline-formula> <tex-math notation= LaTeX >$L_{GD}$ </tex-math></inline-formula> of <inline-formula> <tex-math notation= LaTeX >$1.14~\\mu \\text{m}$ </tex-math></inline-formula>. These excellent results indicate the great potential of Ga₂O₃ MOSFETs on AlN/Si substrate for future power electronics applications.