Wide-Range Threshold Voltage Tunable β-Ga₂O₃FETs With a Sputtered AlScN Ferroelectric Gate Dielectric
S. Y. Oh, Seokgi Kim, Gyuhyung Lee, Ji‐Hyeon Park, Dae‐Woo Jeon, Sungkyu Kim, Geonwook Yoo
Abstract
In this study, we demonstrate a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula>-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 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sim 10^{\mathbf {{8}}}$ </tex-math></inline-formula> and on-resistances of 201 and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$185~\Omega \cdot $ </tex-math></inline-formula>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 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula>-Ga2O3 Fe-FET with AlScN gate structure for monolithic integration of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\beta $ </tex-math></inline-formula>-Ga2O3 NMOS logic circuits.