Vertical System Integration by Using Inter-Chip Vias and Solid-Liquid Interdiffusion Bonding

A new approach for 3D system integration, called Inter Chip Via-Solid Liquid Interdiffusion (ICV-SLID) is introduced. This is a new chip-to-wafer stacking technology which combines the advantages of the Inter Chip Via (ICV) process and the solid-liquid-interdiffusion technique (SLID) of copper and tin. The fully modular ICV-SLID concept allows the formation of multiple device stacks. A test chip was designed and the total process sequence of the ICV-SLID technology for the realization of a three-layer chip-to-wafer stack was demonstrated. The proposed wafer-level 3D integration concept has the potential for low cost fabrication of multi-layer high-performance 3D-SoCs and is well suited as a replacement for embedded technologies based on monolithic integration.