Cu Post CMP Cleaner Development Utilizing AI System

CMP (Chemical Mechanical Polishing) is a process that is widely used in the manufacturing of semiconductors, particularly for the BEOL (Back End Of Line) process which involves multi-level interconnections. Copper (Cu) is commonly used as the wiring metal in the BEOL process. Cu CMP plays a crucial role in achieving the necessary planarization of the BEOL layer for effective alignment of multiple layers. In recent times, Cu CMP has gained significance in 3D integration schemes such as hybrid bonding and TSV (Through Silicon Via). For the Cu slurry in the CMP process, 1H-Benzotriazole (BTA) is known to be an effective Cu corrosion inhibitor that helps in achieving better planarization. However, the use of BTA is often associated with the formation of organic residue in the CMP process. Therefore, a specialized chemical for post CMP (pCMP) cleaning is required to remove any residue of BTA. On this occasion, we conducted a special exploration of additives using an AI system to achieve selective removal of BTA specifically from Cu surfaces. The system classified a large number of parameters and identified specific parameters for BTA removal and Cu compatibility. Following regression analysis using these parameters, we observed a strong correlation with actual experimental results. In conclusion, our Cu pCMP cleaner, which includes a special additive designed by the AI system, exhibited commendable cleaning performance.