Novel Hybrid Bonding Technology Using Ultra-High Density Cu Nano-Pillar for Exascale 2.5D/3D Integration

We propose a novel hybrid bonding technology with a high stacking yield using ultra-high density Cu nanopillar (CNP) for exascale 2.5D/3D integration. To solve the critical issues of a current standard hybrid bonding technology, we developed scaled electrodes with slightly extruded structure and unique adhesive layer of anisotropic conductive film composed of ultra-high density CNP. Test element group (TEG) dies with 7-mm × 23-mm size are bonded to interposer wafer by a new hybrid bonding technology. Scaled electrodes with 3-μm diameter and 6-μm pitch are formed in each TEG chip. We confirmed for the first time that a huge number of electrodes of 4309200 are successfully connected in series with the joining yield of 100% due to the ultra-high density CNP.