Development of slurry concentration adjustable tungsten chemical mechanical planarization process

Understanding the interaction of slurry component and concentration with polishing condition is necessary for developing a tightly controlled chemical mechanical planarization (CMP) process. This paper investigates the impacts of flowrate and concentration variation of tungsten CMP slurry. The slurry concentration adjustable tungsten CMP process is described. Finally, physical characterization and electrical results are presented. We demonstrate that the new process yields a significant improvement on the oxide erosion and a remarkable reduction in the cost of consumables.