US Patent 9960129 Hybrid bonding mechanisms for semiconductor wafers

A method of forming a hybrid bonding structure includes depositing an etch stop layer over surface of a substrate, wherein the substrate comprises a conductive structure, and the etch stop layer contacts the conductive structure. The method further includes depositing a dielectric material over the etch stop layer. The method further includes depositing a first diffusion barrier layer over the dielectric material. The method further includes forming an opening extending through the etch stop layer, the dielectric material and the diffusion barrier layer. The method further includes lining the opening with a second diffusion barrier layer. The method further includes depositing a conductive pad on the second diffusion barrier layer in the opening, wherein a surface of the first diffusion barrier layer is aligned with a surface of the conductive pad.