Pulsed E-/D-Mode Switchable GaN HEMTs With a Ferroelectric AlScN Gate Dielectric

In this study, we demonstrate ferroelectric GaN high-electron mobility transistors (HEMTs) with a sputtered AlScN gate dielectric, exhibiting a large memory window of ~ 14.6 V and a high on/off ratio of $\sim ~10^{{8}}$ . The strong polarization of AlScN layer contributes to the remarkably large threshold voltage ( $\text{V}_{\text {th}}{)}$ tuning range with counterclockwise hysteresis depending on voltage sweep ranges and pulsed parameters. Moreover, a recessed-gate structure enables the pulsed enhancement and depletion mode switching. The reconfigurable Vth via pulse modulation further allows feasibility of NOR logic gate with the single ferroelectric GaN HEMT.