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SJTU Associate Professor Li Published Latest Findings in Nature Communications

April 23, 2020      Author: Department of Micro/Nano Electronics

Recently, Associate Professor Li Xiuyan from Liu Jingquan's team in the Department of Micro/Nano Electronics, School of Electronic Information and Electrical Engineering, SJTU, published a research paper in Nature Communications in cooperation with Professor Akira Toriumi from the University of Tokyo. The paper is titled “Stepwise internal potential jumps caused by multiple-domain polarization flips in metal/ferroelectric/metal/paraelectric/metal stack” and presents their latest findings in this field. Associate Professor Li Xiuyan is the first author and the corresponding author; SJTU is the first completion unit.

This work was supported by JST-CREST (JPMJCR14F2) in Japan, National Natural Science Foundation of China (61904103, 91964110) and Shanghai Science and Technology Innovation Action Program (19ZR1475300, 19JC1416700).

Abstract

Negative capacitance (NC) effects in ferroelectric/paraelectric (FE/PE) stacks have been recently discussed intensively in terms of the steep subthreshold swing (SS) in field-effect transistors (FETs). It is, however, still disputable to stabilize quasi-static-NC effects. In this work, stepwise internal potential jumps in a metal/FE/metal/PE/metal system observed near the coercive voltage of the FE layer are reported through carefully designed DC measurements. The relationship of the internal potential jumps with the steep SS in FETs is also experimentally confirmed by connecting a FE capacitor to a simple metal-oxide-semiconductor FET. On the basis of the experimental results, the observed internal potential jumps are analytically modelled from the viewpoint of bound charge emission associated with each domain flip in a multiple-domain FE layer in a FE/PE stack. This view is different from the original NC concept and should be employed for characterizing FE/PE gate stack FETs.

Link: https://www.nature.com/articles/s41467-020-15753-4