Research on simulation of Cu/SiO2 hybrid bonding process and interface failure mechanism by Finite Element Analysis

Cu/SiO
2
hybrid bonding technology is proposed as a solution for the increasing demand of 3D packaging for higher I/O density and higher bandwidth applications. In this paper, a numerical approach to investigate the stress distribution of fine-pitch die-to-die hybrid bonding (D2D-HB) is proposed. The Finite Element Analysis (FEA) tool is used to build the model of the bonding process of D2D-HB. The influence of design parameters and conditions on the evolution of the stress on the Cu-Cu bonding interface and the dielectric layer interface during the bonding process is investigated. The results show that, the peak pressure on the Cu-Cu interface and the peak tensile force on the SiO
2
-SiO
2
interface can reach up to 85.26 MPa and 183.37 MPa during heating stage, respectively. During cooling stage, the pressure on the Cu-Cu interface changes into tensile force, and the tensile force on the SiO
2
-SiO
2
interface changes into pressure. In addition, the simulation results of the Cu-Cu bonding area are also displayed and discussed. For all the D2D-HB design studied in this research, up to 97.5% of Cu bonding area could be obtained. The simulation results will provide not only theoretical support for hybrid bonding technology.