Hydrophobic Modification of Diamond Conditioner for Prevention of Particle Adhesion During Oxide CMP

Abstract

Conditioning with a diamond conditioner is a routine practice in the chemical mechanical planarization process to maintain removal rate and uniformity. Electroplated Ni conditioner surfaces can be easily contaminated by polishing residues from the slurry, pad, and by-products during conditioning. In this study, a hydrophobic film was coated onto a Ni conditioner by vapor phase self assembled monolayer (V-SAM) deposition to prevent contamination. The film was deposited in a vacuum chamber at 0.5 Torr and 100°C using a fluorocarbon (FC) precursor. The modification of the Ni surfaces increased the contact angle from 50 to 105°. The adhesion force between the Ni surface and silica particles was approximately 100 nN in a solution of pH 11.2. The precursor coated Ni resulted in a five times lower adhesion force than the uncoated Ni conditioner. The coated conditioner did not attract any slurry residues on its surface, even after conditioning for 20 h with a fumed silica oxide slurry.