Advanced process control applications for advanced CMP process

There are increasing new needs for advanced process control (APC) from chemical mechanical polishing (CMP) process along with the technology nodes advancing to 28nm and below. Besides traditional applications for wafer to wafer and batch to batch thickness variation reduction, and feed-forward based on incoming thickness/depth, the other new needs include within wafer uniformity control based on consumable counts and incoming profile, preventing polishing rate from dropping due to disk and pad deteriorating etc. This paper discusses those APC applications for CMP processes and along with important features which advanced APC software should equip with.