SKM 2023 – scientific programme
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KFM: Fachverband Kristalline Festkörper und deren Mikrostruktur
KFM 4: Focus: Domains and Domainwalls in (Multi)Ferroic II
KFM 4.8: Talk
Tuesday, March 28, 2023, 12:10–12:30, POT 51
Field Effect Transistor employing the static negative capacitance of a ferroelectric nano-domain nucleus — •Pavel Mokry1, Vit Kosina1, and Tomas Sluka2 — 1Faculty of Mechatronics, Informatics and Interdisciplinary Studies, Technical University of Liberec, Liberec, Czech Republic — 2CREAL SA, Ecublens, Switzerland
Miniaturization of conventional field effect transistors (FETs) approaches the fundamental limits beyond which opening and closing the transistor channel require such a gate voltage swing, which causes an unacceptable increase in heat generation. This problem could be reduced by placing a ferroelectric layer between the FET gate electrode and the channel. In this ferroelectric-semiconductor sandwich structure, the gate voltage can be amplified due to the negative capacitance regime of ferroelectrics. However, the original idea of using a bulk ferroelectric for voltage amplification suffers several difficulties. In this work, we provide phase-field simulations of a system that provides static negative capacitance from a nano-domain nucleus. We model the nucleus of a ferroelectric domain with reversed polarization produced by applying the voltage on a small gate electrode. We show that such a nano-domain nucleus represents a reversible system, which follows a unique path during electrical cycling and inevitably crosses a higher energy state characterized by negative static differential capacitance. Phase-field simulations confirm the robustness of this concept offering conveniently small effective negative capacitance and its compatibility with FET technology.