Process and Design Consideration for Wafer-to-Wafer Hybrid Bonding

In this paper, we evaluate the surface condition with consideration of different process and designed pattern after chemical mechanical polishing (CMP) process in 12-inch platform for high density hybrid bonding application. After the CMP process, the surface topology was carried out by atomic force microscopy (AFM) measurement. We study the impact on the surface topology of the wafer after CMP process, and the results showed that the surface topology including surface roughness and Cu pad dishing/protrusion is dependent on the design of the pad size and spacing and may further make impact on bonding quality, which is needed to be considered carefully.