WSe2 N‐Type Negative Capacitance Field‐Effect Transistor with Indium Low Schottky Barrier Contact

Abstract

AbstractIn conventional metal‐oxide‐semiconductor field‐effect transistors, the subthreshold slope (SS) is limited by the Boltzmann distribution and the loss of gate control with the miniaturization of integrated circuits being an insurmountable ceiling for the huge demand of low‐power, high‐density electronic devices. Negative capacitance field‐effect transistors (NC‐FETs) may provide a promising solution to break the SS limit, and 2D semiconductors should give a possibility to prolong the miniaturization of the device size for the excellent gate control ability. Here, using indium as source/drain contact and ferroelectric hafnium zirconium oxide as gate dielectric, a WSe2 N‐type NC‐FET is achieved that is of a steep SS as low as 12.7 mV dec−1 and the current on/off ratio up to 109. The indium with low work function results in a pretty small Schottky barrier of 29.9 meV to the N‐type WSe2. An inverter is integrated based on the fabricated NC‐FET and a resistor load, which exhibited a high gain of ≈4.5 at VDD of 1.5 V. This device should complement the previously reported WSe2 P‐type NC‐FETs and offer a possible approach for homogeneously integrated CMOS circuits with ultralow power consumption.