Study on the removal rate stability of CMP for ULSI silicon substrate

The polishing process of Si substrate is introduced and its mechanism is analyzed theoretically in this paper. The regularity of removal rate of CMP by using circulation polishing is obtained through experimental study. Then, the stability of removal rate and its influence factors are analyzed systematically. Experiment results show that pH value, polishing temperature and viscosity are the main factors affecting the stability of removal rate. Finally, improving solutions for the removal rate fluctuation are presented.