Adhesion and Material Properties Between Polyimide and Passivation Layers for Polymer/Metal Hybrid Bonding in 3-D Integration

This paper investigates polymer/metal hybrid bonding structure using conventional polyimide and modified polyimide-like material. Adhesion properties between bonding material and passivation layer were evaluated by four-point bending method, atomic force microscopy, water contact angle measurement, and X-ray photoelectron spectroscopy. Various annealing temperatures were applied to verify the reliability under thermal stress. The results show that the modified polyimide-like material with the curing temperature below 250 °C has better adhesion than the conventional polyimide. This modified polyimide material can be used in low-temperature hybrid bonding technology for advanced integration.