abstract |
A method for maintaining the buffer capacity of a polishing slurry during chemical-mechanical wafer polishing, the method comprising circulating the polishing slurry in a chemical-mechanical wafer polishing apparatus, monitoring the pH of the polishing slurry, combining an agent into the polishing slurry to adjust the pH of the polishing slurry and maintaining the pH of the polishing slurry within a predetermined range, thereby maintaining the buffer capacity of the polishing slurry. |