Wide-Range Threshold Voltage Tunable β-Ga₂O₃FETs With a Sputtered AlScN Ferroelectric Gate Dielectric

In this study, we demonstrate a
$\beta $
-Ga2O3 ferroelectric field-effect transistor (Fe-FET) using a sputtered aluminum scandium nitride (AlScN) gate dielectric. The device exhibits a steep subthreshold swing as low as 56 mV/dec with a high on/off ratio of
$\sim 10^{\mathbf {{8}}}$
and on-resistances of 201 and
$185~\Omega \cdot $
mm for the polarization states. Furthermore, wide threshold voltage modulation from -23.4 to 3.5 V is achieved via gate pulses. Finally, retention and endurance tests show stable depletion (D-) and enhancement (E-) mode switching for up to 10,000 cycles. These results suggest the potential of the proposed
$\beta $
-Ga2O3 Fe-FET with AlScN gate structure for monolithic integration of
$\beta $
-Ga2O3 NMOS logic circuits.