Improved Tradeoff Between Subthreshold Swing and Hysteresis for MoS2 Negative-Capacitance FETs by Optimizing Gate-Stack of Hf1−x Zr x O2/Al2O3
| Autor: | Jing-Ping Xu, Lu Liu, Yuqin Xia, Jingjie Wang |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Materials science
business.industry Transistor Capacitance Ferroelectricity Electronic Optical and Magnetic Materials law.invention Hysteresis law Content (measure theory) Optoelectronics Electrical and Electronic Engineering Polarization (electrochemistry) business Layer (electronics) Negative impedance converter |
| Zdroj: | IEEE Transactions on Electron Devices. 68:6546-6550 |
| ISSN: | 1557-9646 0018-9383 |
| DOI: | 10.1109/ted.2021.3118330 |
| Popis: | MoS₂ negative-capacitance field-effect transistors (NCFETs) with a gate-stack of Hf₁₋ₓZrₓO₂/Al₂O₃ are fabricated, and the effects of the Zr content and the thickness of the stacked gate on electrical performance of the devices are investigated. It is found that a large improvement of device performance can be achieved by optimizing these parameters, e.g., using 6-nm Hf $_{0.5}$ Zr $_{0.5}$ O₂ (Zr content of 50%) as a ferroelectric layer and 2-nm Al₂O₃ as a matching layer, the relevant MoS₂ NCFET exhibits the excellent electrical characteristics: a low subthreshold swing (SS) of 31.4 mV/dec, a smaller counterclockwise hysteresis of ~75 mV, and a high on/off current ratio of 3.26 x 10⁶. The involved mechanisms lie in that: 1) an enhanced remnant polarization leads to low SS and 2) changing the thickness of the Hf₁₋ₓZrₓO₂ and Al₂O₃ can adjust the magnitude of ferroelectric capacitance and MOS capacitance to realize a reasonable match between both. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|