2020 Fiscal Year Final Research Report

Multiscale characterization of singularity structures and behaviors thereof

Planned Research

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Project Area	Materials Science and Advanced Elecronics created by singularity
Project/Area Number	16H06423
Research Category	Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)
Allocation Type	Single-year Grants
Review Section	Science and Engineering
Research Institution	Osaka University
Principal Investigator	SAKAI AKIRA 大阪大学, 基礎工学研究科, 教授 (20314031)
Co-Investigator(Kenkyū-buntansha)	今井康彦公益財団法人高輝度光科学研究センター, 回折・散乱推進室, 主幹研究員 (30416375)
Project Period (FY)	2016-06-30 – 2021-03-31
Keywords	ナノビームX線回折 / 3次元逆格子マッピング / トモグラフィックマッピング解析 / 深さ分解結晶評価 / 転位 / 漏れ電流 / 逆圧電効果 / 時分割ポンプ－プローブ法
Outline of Final Research Achievements	Multi-scale structural analysis and evaluation were performed on crystals and devices of nitride and group IV semiconductors, focusing on the singular structures such as dislocations and nano-voids. The lattice structure was three-dimensionally analyzed with high spatial resolution by using synchrotron radiation nanobeam X-ray diffraction, and the crystallographic effect induced by the singular structure in the buffer layer and the template thick film was clarified. Various microscopy observations clearly revealed the influence of the singularity structure on the current leakage phenomenon related to dislocations and the lattice deformation behavior caused by the piezoelectricity proper to nitride semiconductors. Furthermore, we succeeded in time-resolved analysis of lattice deformation behaviors caused by the inverse piezoelectric effect in the nitride semiconductor device using in-situ X-ray diffraction, and clarified the nanosecond-order dynamics of the singular structure.
Free Research Field	半導体物性工学
Academic Significance and Societal Importance of the Research Achievements	特異構造の物性や機能を結晶やそれを用いたデバイスへ有効活用するには、その結晶学的構造の解明が不可欠である。特に、特異構造がデバイス活性層やその周囲の結晶相に与える歪等の影響を知ることは、結晶の学理に基づいて特異構造を深く理解し、それを基板結晶やデバイスへ応用していくうえで重要である。本研究では3次元マルチスケールをキーワードに、そうした空間的構造の解明に注力した。さらに、結晶のデバイス応用を視点に入れれば、特異構造の時間的挙動に関わる知見も必要となる。本研究では特異構造の時間発展を含めた4次元構造解析にも着手しており、新たな学理構築に寄与するとともに、産業応用の観点から社会的にも意義深い。