Semiconductor structure and manufacturing method thereof

A semiconductor structure comprising:

• a first wafer comprising:
• a first dielectric structure that includes a first recessed portion;
• a first conductive structure disposed within the first recessed portion, the first conductive structure having a surface that forms a first concave recessed portion in the first conductive structure;
• and
• a first conductive material disposed within the first concave recessed portion of the first conductive structure,
• wherein the first conductive material has at least one surface that is generally planar;
• and
• a second wafer comprising:
• a second dielectric structure that includes a second recessed portion;
• a second conductive structure disposed within the second recessed portion, the second conductive structure having a surface that forms a second concave recessed portion in the second conductive structure;
• and
• a second conductive material disposed within the second concave recessed portion,
• wherein the second conductive material has at least one surface that is generally planar.

A method of forming a semiconductor structure, comprising:

• depositing a conductive structure within a recessed portion of a dielectric structure;
• polishing a top surface of the semiconductor structure, the polishing forming a concave recessed portion in the conductive structure;
• and
• forming a conductive material within the concave recessed portion to form a substantially planar top surface for the semiconductor structure.