Microstructure Simulation and Thermo-Mechanical Behavior Analysis of Copper Filled Through Silicon Vias Using Coupled Phase Field and Finite Element Methods

Abstract

High thermo-mechanical stresses are usually induced in through silicon via (TSV) structures due to the mismatch of coefficients of thermal expansion (CTE) between copper and silicon in Cu filled TSVs, which has brought an increasing concern for the reliability problems during fabrication process and operation of electronic devices. The size, shape and orientation of Cu grains in TSVs and their effects on thermo-mechanical behavior of TSVs can not be ignored, especially with the continuous miniaturization and increasing integration of 3D ICs. In this study, the dynamic evolution characteristics of grain growth in a Cu filled TSV are simulated by a two-dimensional phase field model firstly, and then the thermo-mechanical behavior of the TSV with different grain morphologies under annealing condition is investigated by finite element method (FEM), and finally the interaction effects of grain growth and thermo-mechanical behavior in the TSV during operation of electronic devices are studied.