Micromechanical and Macroscopic Modelling (MMM)
Effects of Bi segregation on the tensile properties of Cu/Cu3Sn(100) interface
X. Pang, Z.Q. Liu, S.Q. Wang, J.K. Shang.
Microelectronics Reliability, Elsevier Science Ltd., UK, 51, 2330-5, (2011)
The tensile and fracture processes of the ideal and Bi impurity Cu/Cu3Sn(100) interface were investigated by the first-principles calculations. We found the ideal tensile strength of ideal interface is 8.04GPa and the fracture mode is ductile fracture; and the ideal tensile strength of Bi impurity interface is 4.72GPa and the fracture mode is brittle fracture. Detailed comparisons of electronic structures of two interfaces reveal the origin of transformation of fracture mode. Combine with our previous work, we can conclude that Bi not only drops the adhesion of the Cu/Cu3Sn interface, but also reduces the ideal tensile strength and causes interface become brittle.
Keyword(s): ab initio calculations; adhesion; bismuth; copper; copper alloys; density functional theory; fracture; interface phenomena; segregation; tensile strength; tin alloys