An Aqueous Route to Oxygen-Deficient Wake-Up-Free La-Doped HfO2 Ferroelectrics for Negative Capacitance Field Effect Transistors.
ACS Nano
; 17(19): 19076-19086, 2023 Oct 10.
Article
em En
| MEDLINE
| ID: mdl-37772990
ABSTRACT
The crucial role of nanocrystalline morphology in stabilizing the ferroelectric orthorhombic (o)-phase in doped-hafnia films is achieved via chemical solution deposition (CSD) by intentionally retaining carbonaceous impurities to inhibit grain growth. However, in the present study, large-grained (>100 nm) La-doped HfO2 (HLO) films are grown directly on silicon by adopting engineered water-diluted precursors with a minimum carbonaceous load and excellent shelf life. The o-phase stabilization is accomplished through a well-distributed La dopant, which generates uniformly populated oxygen vacancies, eliminating the need for oxygen-scavenging electrodes. These oxygen-deficient HLOs show a maximum remnant polarization of 37.6 µC/cm2 (2Pr) without wake-up and withstand large fields (>6.2 MV/cm). Furthermore, CSD-HLO in series with Al2O3 improves switching of MOSFETs (with an amorphous oxide channel) based on the negative capacitance effect. Thus, uniformly distributed oxygen vacancies serve as a standalone factor in stabilizing the o-phase, enabling efficient wake-up-free ferroelectricity without the need for nanostructuring, capping stresses, or oxygen-reactive electrodes.
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01-internacional
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MEDLINE
Idioma:
En
Revista:
ACS Nano
Ano de publicação:
2023
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Article
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Índia