Process Technology
Hybrid Bonding From First Principles: Pitch, Yield and Who Is Ready
Hybrid bonding joins two pieces of silicon with no solder at all. Flat dielectric meets flat dielectric, copper pads meet copper pads, and an anneal makes the joint permanent. That removes the bump, and with it the floor on how close connections can sit. Research wafers are now bonded at a 200 nm pitch, while shipping server processors use about 9 µm. That gap of roughly forty-five times is the subject of this post. Wafer-to-wafer and die-to-w…