Molecular Dynamics Study of Stress-Induced Migration near Al Grain Boundary

• Published in: Nihon Kikai Gakkai ronbunshū. A Vol. 62; no. 595; pp. 853 - 858
• Main Authors: KITAGAWA, Hiroshi, NAKATANI, Akihiro, MAEGAWA, Yukihiro, SAITOH, Ken-ichi, OGATA, Shigenobu
• Format: Journal Article
• Language: Japanese
• Published: The Japan Society of Mechanical Engineers 01.01.1996
• Subjects: Aluminum; Aluminum Conductor; Coalescence; Computational geometry; Computational Mechanics; Computational methods; Computer simulation; diffusion; Effective-Medium Theory; Grain boundaries; Grain Boundary Energy; Grain Boundary Grooving; Grain growth; Mathematical models; Molecular Dynamics; Nucleation; Stress-Induced Migration; Thermal Stress
• ISSN: 0387-5008; 1884-8338
• DOI: 10.1299/kikaia.62.853

Stress-induced migration near the grain boundary in Al thin interconnect is studied by means of an ab initio molecular dynamics simulation formulated on the basis of the effective-medium theory. The consistent grain boundary model is used, whose geometry is characterized by Σ-value. It is shown that besides Σ-value, existence of high-energy sites near the grain-boundary is an important factor which promotes nucleation and growth of voids. In the bulk state, grain boundary decohesion due to coalescence of voids is dominant in the high-boundary-energy case, and growth of a small number of voids leads to breakage of the Al wire with the grain boundary of low energy and high consistency. If there exists a free surface, marked decrease in thickness near the grain boundary occurs and a narrow groove develops in the high-energy case.