An all two-dimensional vertical heterostructure graphene/CuInP <sub>2</sub> S <sub>6</sub> /MoS <sub>2</sub> for negative capacitance field effect transistor
Adeel Liaqat, Yiheng Yin, Sabir Hussain, Wen Wen, Juanxia Wu, Yuzheng Guo, Chunhe Dang, Ching‐Hwa Ho, Zheng Liu, Peng Yu, Zhihai Cheng, Liming Xie
Abstract
Abstract As scaling down the size of metal oxide semiconductor field-effect transistors (FETs), power dissipation has become a major challenge. Lowering down the sub-threshold swing (SS) is known as an effective technique to decrease the operating voltage of FETs and hence lower down the power consumption. However, the Boltzmann distribution of electrons (so-called ‘Boltzmann tyranny’) implements a physical limit to the SS value. Use of negative capacitance (NC) effect has enabled a new path to achieve a low SS below the Boltzmann limit (60 mV dec −1 at room temperature). In this work, we have demonstrated a NC-FET from an all two-dimensional (2D) metal ferroelectric semiconductor (MFS) vertical heterostructure: Graphene/CuInP 2 S 6 /MoS 2 . The negative capacitance from the ferroelectric CuInP 2 S 6 has enabled the breaking of the ‘Boltzmann tyranny’. The heterostructure based device has shown steep slopes switching below 60 mV dec −1 (lowest to < 10 mV dec −1 ) over 3 orders of source-drain current, which provides an avenue for all 2D material based steep slope FETs.