Distortion Simulation for Direct Wafer-to-Wafer Bonding Process

Direct wafer bonding technology is used in a growing number of semiconductor applications to meet device scaling challenges. Tight bonded wafer distortion requirements are needed to ensure high electrical yield and device integration fidelity. This work addresses the requirements through distortion simulation for the wafer bonding process. A physical simulation model is developed to simulate the bond propagation dynamics and post-bond wafer geometry accurately. The results of this simulation model are compared against experimental data. The role of interfacial properties and incoming wafer shapes are examined in detail to reveal the importance of the wafer conditions before the bonding process. The results of this model can help optimize bonder hardware and process controls to improve tool performance further.