Materials and Process Study for Polymer Hybrid Bonding

Low-temperature curable polyimides with minimal device damage have been developed for 3D stacking organic hybrid bonding technology. We confirmed developed polyimides showed significant polishing rates for alkaline slurry. Polyimide-to-polyimide bonding and polyimide/copper hybrid bonding at a low-temperature annealing were successfully demonstrated. Furthermore, polyimide-to-polyimide bonding mechanisms were investigated from the chemical and physical aspects of the material, respectively. Moreover, polymer hybrid bonding with copper protrusion test vehicles was successfully polished with Chemical Mechanical Polishing, which showed good polyimide-to-polyimide and copper-to-copper joints. Finally, it was confirmed that they could maintain insulation reliabilities after accelerated tests.