Semiconductor device and method of manufacturing the same

A semiconductor device comprising:

• a semiconductor structure comprising a semiconductor substrate and a semiconductor element layer;
• a wiring structure under the semiconductor structure;
• a bonding dielectric layer under the wiring structure;
• a connection pad penetrating the bonding dielectric layer from a bottom surface of the bonding dielectric layer in an upward direction and having sidewalls surrounded by the bonding dielectric layer;
• and
• a dummy pad penetrating at least a portion of the bonding dielectric layer from the bottom surface of the bonding dielectric layer in the upward direction and having sidewalls surrounded by the bonding dielectric layer,
• wherein a top surface of the dummy pad is at a vertical level lower than a top surface of the connection pad, and
• wherein the top surface of the dummy pad comprises a plurality of surfaces at different vertical levels.

A semiconductor device comprising a plurality of stacked structures stacked in a vertical direction and comprising a first stacked structure and a second stacked structure disposed on the first stacked structure,

• wherein an upper structure of the first stacked structure comprises:
• a first bonding dielectric layer;
• a first connection pad penetrating the first bonding dielectric layer in a downward direction from a top surface of the first bonding dielectric layer;
• and
• a first dummy pad penetrating at least a portion of the first bonding dielectric layer in the downward direction from the top surface of the first bonding dielectric layer,
• wherein a lower structure of the second stacked structure comprises:
• a second bonding dielectric layer;
• a second connection pad penetrating the second bonding dielectric layer in an upward direction from a bottom surface of the second bonding dielectric layer and disposed on the first connection pad;
• and
• a second dummy pad penetrating at least a portion of the second bonding dielectric layer in the upward direction from the bottom surface of the second bonding dielectric layer and disposed on the first dummy pad,
• wherein at least one of a bottom surface of the first dummy pad and a top surface of the second dummy pad comprises an embossed structure, and
• wherein the embossed structure comprises a plurality of surfaces at different vertical levels.