Investigation of Wafer Dicing and Cleaning Processes for Die-to-die Oxide direct Bonding Technology

A feasibility study of die-to-die (D2D) direct bonding with oxide surface is conducted using regular industrial cleanroom tools for wafer processing. The study highlights the influence of different wafer dicing, die handling and cleaning methods on the die surface quality and the quality of D2D bonding. The presented work features particle control as the biggest challenge and current bottleneck in D2D direct oxide bonding. The successful bonding of the known good dies (KGD's) with minimum defects on the bonding surface, sufficiently clean die surface, suitable roughness and sufficiently high hydrophilicity is achieved. Techniques such as stealth dicing for wafer singulation, modified RCA-SC1 (Radio Corporation of America - Standard Clean 1) recipe for cleaning and tuned plasma activation resulted in the successful D2D direct bonding. Thus, the presented work enables various applications to benefit from higher degree of design flexibility provided by D2D direct bonding approach.