By Applied Microengineering Ltd.
Hybrid bonding is a combination of direct bonding of dielectric SiO2–SiO2 and thermocompression bonding of Cu-Cu metal, used to form interconnections. Hybrid bonding connects dies in packages via Cu pads that are embedded in the bond interface. It is very widely used in advanced 3D stacking and one of its main advantages is enabling a very low pitch, down to 10µm. This bonding method is an alternative to making vertical connections by microbumps that have limitations on size. Advantages of hybrid bonding: - Very low pitch achievable – higher structure density - Increased power - Extended bandwidth - No need for bumps, eliminates signal losses Disadvantages: - Surface finish and planarization are critical – high CMP requirements - Very tight dimensional process control required, due to Cu expansion Applications: - Advanced 3D device stacking - CMOS image sensor devices
