Novel Low Thermal Budget Bonding Using Single Wafer Thermal Processing System, Resulting in Excellent Wafer-to-Wafer Hybrid Bonding at sub-0.5um Pitch

We report on a reduced thermal budget for hybrid bonding anneal using a single wafer thermal processing system (TPS). Robust bonding with excellent Cu gap closure and grain growth across the interface was achieved using a single step 300°C 5min TPS anneal, thereby reducing anneal duration by two orders of magnitude compared to the industry standard furnace anneal. The Cu gap closure efficacy with 350°C 5min TPS anneal was further verified electrically through functional 2Mb viachains @ 0.5um pitch with a Rs/link <5 Ohm.