Copper Oxide Direct Bonding of 200mm CMOS Wafers with Five Metal Levels and TSVs: Morphological and Electrical Characterization

We report for the first time complete data on 200mm wafer to wafer aligned copper oxide direct bonding of wafers with five metal levels each with through-silicon-vias (TSVs) as backside connection. Both surface acoustic microscope (SAM) and cross-section scanning electron microscope (X-SEM) images taken across the bonded wafer pairs evidence the good bonding quality of the resulting interface. Kelvin structures and daisy chains with up to 2500 copper to copper bonded pads are shown to be connected successfully and its resistance value to match a target value.