Thin-film stabilization of polar oxide semiconductors and the development of multi-level ferroelectric memory devices

2021 Fiscal Year Final Research Report

• Project/Area Number: 19H02423
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 26020:Inorganic materials and properties-related
• Research Institution: Tohoku University
• Principal Investigator: Fujiwara Kohei 東北大学, 金属材料研究所, 准教授 (50525855)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 酸化物エレクトロニクス / 酸化物半導体 / 強誘電体

Outline of Final Research Achievements

A LiNbO3-type oxide semiconductor, ZnSnO3, holds potential as a new channel material for ferroelectric memory devices because both high-mobility conduction and ferroelectricity can occur in the single ZnSnO3 layer. In this project, fundamental investigations towards the experimental verification of the ferroelectric polarization reversal have been performed. Using X-ray photoemission electron spectroscopy, the valence states of metal cations were identified for ZnSnO3 and MgSnO3 films. By vacuum deposition technique, a new corundum-type conductive oxide, (Cr,Ru)2O3, which is applicable to a bottom electrode layer of a capacitor structure for the polarization reversal experiment, has been synthesized.

Free Research Field

酸化物エレクトロニクス

Academic Significance and Societal Importance of the Research Achievements

合成が困難なためこれまで物性がほとんど明らかにされていないZnSnO3を用いた研究を実施したことで、関連物質の薄膜化研究およびエレクトロニクスへの応用を目指した素子化研究が加速するものと期待される。真空成膜プロセスの高い非平衡性を利用した新物質(Cr,Ru)2O3の開発および異常原子価Ru3+の発見は、酸化物物質の合成に新たなアプローチを提示するものであり、その学術的意義は大きい。