Abstract
This study presents a comprehensive investigation on the properties of negative capacitance field-effect transistors (NCFETs) based on the metal-ferroelectric-insulator-semiconductor (MFIS) structure with HfxZr1−xO2 (HZO, 0.5≤x≤0.9) thin film. The results indicate that the NCFETs exhibit excellent subthreshold swing (SS) values, consistently below 60 mV·decade−1, which is the theoretical physical limit of conventional Si-based field-effect transistors (FETs). The ferroelectric HZO composition significantly influences the longitudinal electric field, electron concentration, and hole concentration within the channel, thereby directly affecting the SS and saturation current. Notably, the MFIS NCFET incorporating an Hf0.5Zr0.5O2 ferroelectric layer exhibited the lowest SS. Moreover, by modifying the dielectric material and channel length, variations in the trends of SS and saturation current were observed. The device with ZrO2 dielectric layer, characterized by the highest dielectric constant, demonstrated the lowest SS of 47.49 mV·decade−1. Furthermore, the SS decreased as the channel length increased from 50 nm to 1000 nm. This research provides theoretical support for the performance optimization of low-power NCFETs and negative capacitance capacitors.