Construction of precise step terrace structure with high surface atom density and minimized point defect density

2019 Fiscal Year Final Research Report

• Project/Area Number: 17H03378
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Physical properties of metals/Metal-base materials
• Research Institution: Nagoya University
• Principal Investigator: Yamamoto Takahisa 名古屋大学, 工学研究科, 教授 (20220478)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 酸化物結晶 / 原子構造 / STEM / TEM / 結晶表面

Outline of Final Research Achievements

An atomic level flat step terrace structure is required on the surface of the crystal substrate used for film growth. For the construction of this structure, a heat treatment method using surface diffusion on the substrate surface is often used. However, by performing the heat treatment, point defects having a concentration equilibrium with the heat treatment temperature are formed on the outermost surface portion of the substrate, and the atom density of the outermost surface portion may decrease. In this study, we collected basic knowledge about adjustment of oxygen partial pressure during heat treatment and use of ultrapure water as a method to alleviate this decrease in atomic density as much as possible. We also worked on the effect of electric field application as a method of changing the state of the substrate surface.

Free Research Field

セラミック材料学

Academic Significance and Societal Importance of the Research Achievements

結晶最表面部の原子構造に関する研究はこれまでに多数報告されている。その主な内容は、原子構造自体の変化や、組成変化に関するものである。一方、結晶表面のような格子不整合となる領域は点欠陥の生成消滅箇所として作用することが知られている。これまでに、このような点欠陥生成に伴う原子密度の変化という視点からの研究はなされていない。原子密度という観点からの基礎的な知見が得られれば、表面構造の新たな制御方法の確立へと結びつく可能性が考えられる。