부산대학교 도서관

In this work, the influence of the most important parameters on stress around hybrid bonding units is explored by 3D finite element modeling approach. The impact of pad shape, size, pitch, density, and array arrangement on the stress distribution is first investigated. The results indicate that the smaller space is harder to release stress and more prone to reliability problems. The dummy pads between electrical pads provide a wide process window for CMP process, but can also add limitations to stress and alignment. The asymmetrical structure enables higher overlay tolerance, which provides some improvement in stress concentration, especially at small pitches. Followingly, the TEM pictures evidence that the optimized bonding interface is free of gaps and voids, demonstrating excellent stress control. These results can provide guidelines for optimizing the hybrid bonding design and process, reducing potential stress threats, and enhancing the thermomechanical reliability of the bonded units.