Methods and structure for hybrid bonding

A semiconductor structure, comprising:

• a base substrate;
• a dielectric layer on a surface of the base substrate and having an exposed top surface;
• a conductive feature partially embedded within the dielectric layer;
• and
• a barrier layer completely covering a top surface of the conductive feature, wherein the barrier layer comprises a selective material that forms only on the conductive feature.

A semiconductor structure, comprising:

• a base substrate;
• a dielectric layer on a surface of the base substrate and having an exposed surface, wherein the dielectric layer comprises a first dielectric material and a second dielectric material, which is different from the first dielectric material, disposed on the first dielectric material, and wherein the second dielectric material forms the exposed surface;
• a conductive feature embedded within the dielectric layer and comprising a top surface;
• and
• a barrier layer completely covering a top surface of the conductive feature.