Advanced FD system for COC reduction and quality improvement by using pad height sensor for CMP process

We present an advanced FD system that reduces cost of consumables (COC) and improves quality of Cu-CMP process. By applying a pad height sensor, the lifetime of the polishing pad is precisely extracted. This changes the pad replacement maintenance from time-based to wear-based, resulting in 10% longer pad lifetime. In addition, by monitoring these electric currents of both the polishing head and the polishing table, the pad lifetime is extended up to 10% from wear-based. Then the lifetime is totally 20% improved from the current maintenance period. The pad height sensor also provides the cutting rate of the pad that can predict an unexpected drop in quality due to micro scratches.