Stabilized Negative Capacitance in In2Se3-Based 2D Ferroelectric Transistors
Weifan Cai, Guangchao Zhao, Xin Ju, Hong Kuan Ng, Qibin Zeng, Hui Kim Hui, Jiayi Sun, Sheila Sim, Yunxuan Pan, Guoqiang Xu, Huajun Liu, Dongzhi Chi, Diing Shenp Ang, Qing Zhang, Jing WuAbstract
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.