MoS₂transistors gated by ferroelectric HfZrO₂with MoS₂/mica heterojunction interface

Two-dimensional (2D) molybdenum disulfide (MoS₂) field-effect transistor (FET) gated by negative capacitance (NC) is a promising architecture to overcome the thermionic limit and thus reduce device consumption. Here, top-gated MoS₂NCFETs have been prepared by transferring a mica flake on MoS₂channel to form a van der Waals heterojunction interface, together with a ferroelectric HfZrO₂(HZO) deposited on mica. Stable NC effects are demonstrated for MoS₂NCFETs. The MoS₂NCFETs integrated with mica/HZO gate stack provide competitive electrical characteristics when they are applied with a gate voltage sweep-width in the range of 1-3 V and a sweep-rate from 0.01 to 0.2 V s^-1, including steep-slope of sub 60 mV dec^-1in four orders of magnitude of drain current, on/off current ratio over 10⁶, and small hysteresis-width less than 50 mV. Outstanding performance should be ascribed to damage-free properties of mica/MoS₂van der Waals interface and capacitance matching between the HZO ferroelectric and mica dielectric. The results confirm the promising nature of mica/HZO gate stack and potential applications for future electronics.