A High Throughput Two-Stage Die-to-Wafer Thermal Compression Bonding Scheme for Heterogeneous Integration

In this work, we demonstrate for the first time a two-stage high throughput fine-pitch die-to-wafer Copper-Copper (Cu) thermal compression bonding (TCB) technique, which has a throughput of$> 300$units-per-hour (UPH), with the potential to increase the throughput to 1100 UPH. We have optimized the bonding for high throughput, high overlay accuracy and low contact resistance with a die-to-substrate bump pitch of ≤ 10μmextendible to~7μmpitch. The average shear force per2 × 2 mm²die after high throughput TCB is$> 110$N.

The average specific contact resistance of the Cu-Cu contact is1.24 × 10^-9Ω·cm², comparable to the lowest reported in Cu/SiO2 hybrid bonding. The simplicity of TCB compared to hybrid bonding (HB) makes it a preferred approach for heterogeneous integration for 3D stacking, interposers, and the Silicon Interconnect Fabric (Si-IF) down to ~7 \mumbonding pitches.