Process temperature and resistance reduction for solid-phase deposition of multi-layer graphene by current application

2022 Fiscal Year Final Research Report

• Project/Area Number: 18K04289
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 21060:Electron device and electronic equipment-related
• Research Institution: Shibaura Institute of Technology
• Principal Investigator: Ueno Kazuyoshi 芝浦工業大学, 工学部, 教授 (10433765)
• Project Period (FY): 2018-04-01 – 2023-03-31
• Keywords: 多層グラフェン / 固相析出 / 電流作用 / 低温化 / ドーピング / 低抵抗化 / 配線 / エレクトロマイグレーション

Outline of Final Research Achievements

Multilayer graphene (MLG) is attracting attention as a candidate for integrated circuit interconnect materials to replace copper due to the possibility of a fine line width of several tens of nanometers or less with lower resistance than copper and high current endurance. However, the issues are how to form a film at a temperature lower than 400 degree C and how to reduce the resistance.In this research, in the solid-phase deposition method, which enables direct film formation on the device wafers, current was applied as an energy source other than temperature, and MLG formation was realized at 400°C or less, which is applicable to the interconnect process.In addition, by optimizing the heating rate and film thickness, optimization was performed to achieve both crystallinity and flatness leading to a lower resistance. In addition, as an effective doping method, the intercalation process of molybdenum pentachloride was investigated to reduce the resistance of MLG.

Free Research Field

集積回路配線プロセス

Academic Significance and Societal Importance of the Research Achievements

本研究では、多層グラフェン（MLG）の固相析出において電流の作用によってMLG形成反応が促進されることを初めて実験的に明らかにした。電流によるエレクトロマイグレーションのような原子の拡散促進作用は知られているが、それが固体の析出や結晶化に影響を及ぼすことがわかったことで、今後、電流の作用による化学反応や構造制御の可能性を示すものとして意義があると考えられる。また、インターカレーションドーピングにおいて、MLGの結晶性の向上が重要であることを明らかにしたことや、ひずみによる欠陥発生の問題など、MLGの実用化に向けた課題が明らかになったと考えられる。