Effectively Suppressed Short-Channel Effects in Small-Size MoS2 Transistors by Introducing Negative-Capacitance Effect Resulted From Ferroelectric HfZrO2 Film

Few-layered molybdenum disulfide (MoS2) negative-capacitance field-effect transistors (NCFETs) with an Al2O3/HfZrO2 (HZO) gate stack and various channel lengths ( ${L}_{\text {CH}}{)}$ were prepared, and the influences of the ${L}_{\text {CH}}$ on device performances including short-channel effects (SCEs) were investigated. The MoS2 NCFETs with an ${L}_{\text {CH}}$ of $0.2~\mu \text{m}$ exhibit excellent subthreshold characteristics: a minimal subthreshold swing (SS) of 28 mV/dec and an average SS of 45% lower than that of the baseline devices with the same ${L}_{\text {CH}}$ , a greatly reduced average drain-induced barrier lowering (DIBL) (50 mV/V) to a quarter of the baseline devices, and a small hysteresis voltage below 80 mV. The relevant mechanisms lie in that the negative-capacitance (NC) effect of HZO results in a low SS, the negative differential resistance (NDR) effect of the NCFETs leads to a suppressed DIBL, and a reasonable capacitance matching between dielectric capacitance and ferroelectric capacitance realizes a small hysteresis. Statistics show excellent consistency and repeatability for the electric performance of the NCFETs, and the relevant results will be of a great significance to suppressing SCEs for ultrashort-channel NCFETs in the future.