电迁移引起的倒装芯片互连失效

Failure of Flip-chip Interconnects Induced by Electromigration

采用倒装芯片组装菊花链器件研究了高电流密度条件下Al互连的失效问题,分析了不同电迁移条件下,由于金属原子的迁移造成的Al互连微结构的变化。在9.7×105A/cm2电流密度强度条件下,钝化窗口位置的Al原子发生电迁移,在电子风力的作用下,Al原子沿电子流方向扩散进入Al互连层下方的焊料中。同时,随着电流加载时间的延长,化学位梯度和内部应力的作用致使焊料成分向Al互连金属扩散,Al互连金属层形成空洞的同时其成分发生变化。

The failure phenomena of Al interconnect under high electric current density was studied by using daisy-chained flip chip package.The change of microstructure of Al interconnects which induced by the migration of metal atom was investigated with the condition of electromigration.The current density of 9.7×105 A/cm2 resulted in the electromigration of Al interconnects near passivation via.The Al atoms were diffused into the solder along the electron flow under the electronic wind force.The solder composition was diffused into Al interconnects by the action of chemical potential energy and internal stress during the current-stressing time.The voids were formed in Al interconnects and its chemical compositions was varied.