Stabilized Negative Capacitance in In2Se3-Based 2D Ferroelectric Transistors.

Abstract

Ferroelectric materials with a negative capacitance (NC) effect, incorporated with a dielectric layer, hold great potential for low-power electronics. However, integrating an NC layer into ultrathin silicon-based electronics still faces critical challenges, including thickness scalability and fatigue reliability concerns. Here, we report two-dimensional (2D) negative capacitance field-effect transistors (NC-FETs) that utilize ferroelectric α-indium selenide (α-In2Se3) and hafnium oxide (HfO2) in the gate dielectric, with a molybdenum disulfide (MoS2) channel. Optimized oxide capacitance matching enables steep-slope switching with a minimum subthreshold swing (SS) of 28.8 mV decade-1 and an on/off ratio of ∼107, via internal ferroelectric voltage amplification. The experimentally measured NC effect and oxide passivation not only enhance device performance but also yield robust long-term stability. Furthermore, a depletion-load inverter built from these NC-FETs demonstrates clear logic functionality and ultralow power consumption, surpassing the Boltzmann limit for switching steepness and paving the way for high-performance and long endurance electronics.