Process For Wafer Bonding

The present disclosure provide a method of manufacturing a microelectronic device. The method includes forming a top metal layer on a first substrate, in which the top metal layer has a plurality of interconnect features and a first dummy feature; forming a first dielectric layer over the top metal layer; etching the first dielectric layer in a target region substantially vertically aligned to the plurality of interconnect features and the first dummy feature of the top metal layer; performing a chemical mechanical polishing (CMP) process over the first dielectric layer; and thereafter bonding the first substrate to a second substrate.