Simulation of the Effect of Lattice Defects on the Work of Separating Joined Materials

Abstract

In order to study the strength reliability of interconnections, a generalized model for quantifying the effect of nonequilibrium point crystal defects on the value of the work of the reversible separation of joined materials along the boundary (interface) of their union, generalizing an approach proposed previously by the authors to the description of the mechanism of defect adsorption in the interface area. The developed model makes it possible not to be limited to the situation when the defects of each of the contacting materials are distributed independently in the boundary, over their sublattices, and the transitions of defects between these sublattices are also taken into account, which significantly expands the possibilities of applying the obtained theoretical results. The corresponding system of equations is formulated, which makes it possible to find and study the value of the work of reversible separation as a function of defect concentrations in the vol-umes of materials. In the case when the interstitial impurity atoms are the defects, the problem of the critical impurity concentrations at which the work of reversible separation vanishes and the bonding of the materials becomes thermodynamically unstable is studied in detail by analytical methods; the role of defect transitions between sublattices, in which defects are localized at the interface, is explained. Impurity concentrations are estimated at which the effect of the interface instability can be realized, significantly affecting the reliability characteristics of the interconnections.