Low-Temperature Epoxy-based Cu/Polymer Hybrid Bonding for 3D IC Packaging with Optimized CMP

In advanced 3DIC packaging, achieving efficient hybrid bonding with low-temperature interconnections is a critical challenge for improving device performance. This work presents a hybrid bonding approach using copper and a novel epoxy-based material. By synthesizing epoxy-based Silicon Oxycarbide (SiOC) polymers, it is possible to reduce the coefficient of thermal expansion (CTE) and minimize the CTE mismatch with Cu. This reduction in stress is an important factor in ensuring the long-term reliability of 3DIC devices. By utilizing this epoxy, the hybrid bonding technology improves the performance of thermal compression bonding by effectively reducing the CTE mismatch, which is a frequent issue in conventional bonding techniques. Furthermore, an optimized Chemical Mechanical Planarization (CMP) process is employed to enable low-temperature bonding, enhancing process control and supporting the formation of high-density interconnections. Experimental results demonstrate the potential of this material system in achieving reliable bonding and improved performance in 3DIC applications. The primary contribution of this work lies in developing a reliable low temperature bonding method, providing a promising solution for the next generation of high-performance 3DIC packaging.