Development of crystal-grain enlarging process for ultra-fine Cu wiring by strain-energy driving

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K06793
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Material processing/Microstructural control engineering
• Research Institution: Ibaraki University
• Principal Investigator: SASAJIMA Yasushi 茨城大学, 理工学研究科(工学野), 教授 (80187137)
• Research Collaborator: ONUKI Jin
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 超微細銅配線 / 粒径粗大化 / 不純物効果 / フェーズフィールド法 / 計算機実験

Outline of Final Research Achievements

It is essential to enlarge Cu-polycrystal grains uniformly for high-reliable ultra-fine Cu wiring. In the present study, we performed computer experiments by the phase field method to examine the pinning effect and performed actual experiment to access the impurity reducing process. In addition, it is computed whether the further enlargement of Cu grain can be expected when the external process is applied to the system.
The computer experiment of grain growth found the prohibition of crystal grains by the impurity pinning effect. The results showed good accordance with the observation by electron microscopy. The actual experiment by reducing impurities produced Cu wiring with large and uniform Cu grains and reduced the resistivity of the wire drastically. In addition, our computer experiment showed that it can be expected to enlarge the grain radius further by applying external stress to the wire under annealing.

Free Research Field

工学(材料工学)

Academic Significance and Societal Importance of the Research Achievements

不純物低減によって粒成長の阻害要因を取り除くことで、極細配線中の銅多結晶粒を一様に粗大化でき、配線抵抗を著しく低減することに成功した。これにより、銅配線の飛躍的な信頼性向上の実現の道を開いた。今後のLSI産業への応用展開が期待できる。