In situ observations of micromechanical behaviors of intermetallic compounds for structural applications in 3D IC micro joints

For 3D IC application, solder volume in micro joint is much smaller than in the conventional joint. IMCs can easily occupied micro joints and dominate the properties of micro joint. Thus, it is anticipated that IMCs are to be used as structural materials in commercial scale in a few years. However, mechanical property data for reliability modelling are lacking. To characterize mechanical properties of IMCs becomes an urgent issue. In this study, we investigated the micromechanical behaviors of single crystalline IMCs generally formed in micro joints. Testing structures were produced by focused ion beam machining and subsequently tested by picoindenter in SEM which can simultaneously observe the sequence of failure of test structure. Our results are helpful on understanding the fracture modelling of IMCs.