Investigation of CMP of Ni in the Preparation Process of Micro-Electro-Mechanical System Devices

CMP (chemical mechanical polish) experiments were carried out by using high purity nickel and home-made slurry. The effects of polishing down force, pH value, H2O2 concentration, chelating agent species and their concentration as well as particle concentration on the material removal rate (MRR) were investigated. The results reveal that MRR can reach 312.3 nm/min under the following conditions: the down force is 13.79 kPa, H2O2 concentration is 0.5% (mass fraction), pH = 3.0, SiO2 concentration is 0.5% and EDTA concentration is 1%, The better surface quality can be obtained under the following conditions: the down force is 13.79 kPa, H2O2 concentration is 1%, pH = 4.0, SiO2 concentration is 1%, EDTA concentration is 1%, and the surface roughness Ra can reach 5 nm.