Development of Alkaline Earth Metal-Mediated Molecular Beam Epitaxy Method and Construction of Novel Group IV Low-Dimensional Structures

2021 Fiscal Year Final Research Report

• Project/Area Number: 18K04883
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 28030:Nanomaterials-related
• Research Institution: The University of Tokyo
• Principal Investigator: Yasutake Yuhsuke 東京大学, 大学院総合文化研究科, 講師 (10526726)
• Co-Investigator(Kenkyū-buntansha): 深津 晋 東京大学, 大学院総合文化研究科, 教授 (60199164)
• Project Period (FY): 2018-04-01 – 2022-03-31
• Keywords: ゲルマニウム / ゲルマナン / 分子線エピタキシー / インターカレート / トランジスタ

Outline of Final Research Achievements

The search for electrical and optical functions of germanium (Ge), a group IV element with high affinity to the silicon platform, has been required. In this study, we have investigated the fabrication and characterization of novel low-dimensional Ge structures by the Ca-mediated molecular beam epitaxy (MBE) method, aiming to enhance Ge functions by constructing novel crystal structures. Through these researches, we have established (1) a method to fabricate chemically modified Ge atomic layer (germanane) structures by topotactic reaction using calcium-mediated Ge molecular beam epitaxy as a core technology, (2) fabrication and operation verification of germanane channel electric double-layer transistors, and (3) optical evaluation method for inter-valley scattering-mediated Ge-based materials. We have explored the functions of novel Ge low-dimensional structures through these studies.

Free Research Field

半導体物性

Academic Significance and Societal Importance of the Research Achievements

次世代電子・光学材料として期待されているゲルマニウム(Ge)のさらなる機能探索として、化学修飾ゲルマニウム原子層(ゲルマナン)構造の作製手法の確立と物性評価を行った。作製したゲルマナン結晶はバルク単結晶に匹敵する優れた電気特性を示し、直接遷移型の光学特性を示した。これらの成果はGeのみならずシリコンを含めたⅣ族材料の高い潜在能力を示し、応用デバイス展開のみならず、新規Ⅳ族低次元に関する学理構築につながるものである。