Retaining Ring Wear Study with Ceria Slurry in Chemical Mechanical Planarization

Retaining ring in CMP polisher is a consumable and could contribute significantly to overall cost of ownership. Longer retaining ring life is desirable. Thereafter, we carried out a study of retaining ring wear rate regarding to retaining ring materials and ceria slurries and abrasives. We find the type of retaining ring materials can show significant impact on the retaining ring wear rate, in which PET type of retaining ring is up to 2.5 times lower wear rate than PPS. Ceria abrasive type and size can impact retaining ring wear rate as well. Adding dispersants to ceria particles can greatly reduce retaining wear rates than bare particles.