Research Status of Copper Film Slurries for Through-Silicon Via Process

The process of planar devices is approaching its physical limit, and through-silicon via (TSV) technology is the core of 3D integration technology that breaks Moore's law and has a competitive advantage. Chemical mechanical polishing (CMP) is a key process for removing excess copper in the TSV process. The composition of TSV copper film slurry is very important for achieving TSV wafer planarization. At the same time, as the slurry is a disposable product, the cost of copper polishing is relatively high, so the research and development of TSV copper film slurry has become a hot topic. This article reviews the research progress of TSV copper slurries both domestically and internationally from the perspective of improving the surface quality and polishing rate of copper polishing, as well as regulating the removal rate selection ratio of copper and barrier layer materials. It also predicts the future development direction of TSV copper film slurries. It is believed that TSV copper film slurries should be developed based on faster copper polishing rates, controllable copper and barrier layer polishing rate selection ratios, higher polishing quality, lower costs, and lower pollution with less environmental impact.