US Patent 9425155 Wafer bonding process and structure

A semiconductor device and a method of fabricating the same are introduced. In an embodiment, one or more passivation layers are formed over a first substrate. Recesses are formed in the passivation layers and one or more conductive pads are formed in the recesses. One or more barrier layers are formed between the passivation layers and the conductive pads. The conductive pads of the first substrate are aligned to the conductive pads of a second substrate and are bonded using a direct bonding method.