Three-dimensional stacking semiconductor assemblies with near zero bond line thickness

A semiconductor device, comprising:

• a front side;
• a back side opposite the front side;
• a metallization structure at the front side, the metallization structure a plurality of metallization layers;
• a substrate at the back side, the metallization structure being exposed from the back side via a cavity extending through the substrate;
• a metal bump at least partially positioned in the cavity and electrically coupled to the metallization structure, the metal bump extending from the metallization structure past the back side of the device.

A semiconductor device, comprising:

• a front side;
• a back side opposite the front side;
• a metallization structure at the front side, the metallization structure including first, second, and third metallization layers;
• a substrate at the back side, the metallization structure being exposed from the back side via a cavity extending through the substrate;
• a metal bump vertically aligned with the cavity and electrically coupled to the metallization structure, the metal bump extending away from the metallization structure opposite the substrate.