Creation of Singularity Structures by Time-Domain Control under Nonequilibrium Conditions

2020 Fiscal Year Final Research Report

• Project Area: Materials Science and Advanced Elecronics created by singularity
• Project/Area Number: 16H06414
• 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: The University of Tokyo
• Principal Investigator: FUJIOKA Hiroshi 東京大学, 生産技術研究所, 教授 (50282570)
• Co-Investigator(Kenkyū-buntansha): 徳本 有紀 東京大学, 生産技術研究所, 講師 (20546866)
• Project Period (FY): 2016-06-30 – 2021-03-31
• Keywords: 特異構造 / 結晶工学 / 窒化物半導体

Outline of Final Research Achievements

A new epitaxial growth technique, called a pulsed excitation deposition enabled to introduce high density of singularity structures (point defects) into group III nitride semiconductor thin films by controlling the time domain of raw material supply in a highly excited (non-equilibrium) state. Specifically, the pulsed excitation deposition provided higher doping capability of substitutional impurity atoms such as Si, Ge, and Mg into the nitride semiconductor thin films with better reproducibility than nearly thermal-equilibrium conventional epitaxial growth techniques. Such a high-density singularity structures in group III nitride thin films yielded new insight and opportunity to develop a novel vertical p-type GaN Schottky barrier diodes and integrated dual color micro-LEDs.

Free Research Field

理工系 / 無機工業材料 / 無機工業化学 / 機能材料・デバイス

Academic Significance and Societal Importance of the Research Achievements

本研究は、窒化物半導体薄膜内への熱力学的平衡状態を超えた高濃度特異点導入（点欠陥）を可能とするプラズマ変調技術を開発し、非平衡化学反応を積極的に結晶成長学に展開した点で学術的意義が大きい。この点欠陥導入時には、プラズマ中の高エネルギー粒子の照射による欠陥準位の疑フェルミレベルのコントロールが可能であることが示唆され、結晶成長技術に新しい展開が開かれたといえる。さらに高濃度特異構造窒化物結晶の機能を半導体パワーデバイスやマイクロLEDディスプレイ技術へと展開することで、産業応用上価値の高い成果を得たと考えられる。