Novel CMP Material Solution To Enable High Removal Rate Dielectric CMP For Hybrid Bonding Application

Chemical mechanical planarization (CMP) is useful in removing undesired surface topography and surface defects and in forming features on a substrate by removing excess deposited material. However, removal rates by conventional CMP are too low to be useful in advanced packaging technology. On the other hand, a competing technology called back-grinding has some limitations like rough surface finish, mechanical damage to the thin wafer, lack of robust endpoint for the silicon reveal process. A novel CMP slurry and a two-step process has been developed combining the best of the both processes: CMP and back-grinding. The new process can achieve a high removal rate of about 3–4 micron / min for oxide which is about an order of magnitude higher than that obtained with conventional CMP. However, this includes the benefits of conventional CMP like robust endpoint detection and so on. This new process can potentially enable a high removal rate inter-die dielectric removal for hybrid-bonded dies.