High Performance Ga2O3 Metal-Oxide-Semiconductor Field-Effect Transistors on an AlN/Si Substrate

We propose and demonstrate Ga
₂
O
₃
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 Al
₂
O
₃
/Ga
₂
O
₃
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 Ga
₂
O
₃
MOSFETs. A peak mobility of 82.9 cm
²
/V·s, a high saturation velocity v
_sat
of 1.1 × 10
⁷
cm/s, and a low interface trap density of 1.1 × 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 mΩ·cm
²
, and power figure-of-merit of 9.7 MW/cm
²
are achieved in a device with LGD of 1.14 gym. These excellent results indicate the great potential of Ga
₂
O
₃
MOSFETs on AlN/Si substrate for future power electronics applications.