Semiconductor device having hybrid bonding interface, method of manufacturing the semiconductor device, and method of manufacturing semiconductor device assembly

A method of manufacturing a semiconductor device, comprising:

• forming a dielectric layer on a substrate;
• etching the dielectric layer to create a plurality of openings in the dielectric layer;
• applying a sacrificial layer in at least one of the openings to cover at least a portion of the dielectric layer;
• forming at least one first conductive feature in the openings where the sacrificial layer is disposed and a plurality of bases in the openings where the sacrificial layer is not disposed;
• removing the sacrificial layer to form at least one air gap in the dielectric layer;
• and
• forming a plurality of protrusions on the bases.

A method of manufacturing a semiconductor device assembly, comprising:

• providing a pair of semiconductor devices comprising at least one first conductive feature and at least one second conductive feature having complimentary structures;
• aligning the semiconductor devices to cause the first conductive feature of one of the semiconductor devices to be in contact with the second conductive feature of the other semiconductor device;
• and
• performing an annealing process to bond the first conductive feature to the second conductive feature.