Fundamental study of IMC grains at low anneal temperature

Abstract

IMC insertion bonding is a technique for low temperature and high throughput die to wafer stacking where a soft solder material like Sn is mechanically inserted to sharp CoSn3 IMC grains. In this paper a low temperature approach is introduced to form the sharp CoSn3 IMCs. It was found that adding a thin layer of Ni in between Co/Sn or adding a thin layer of Co, in between Ni/Sn enables sharp IMC formation at solid state diffusion regtime.