Removal rate simulation of dissolution-type electrochemical mechanical polishing

A new method for simulating the Cu removal rate in electrochemical mechanical polishing (ECMP) based on the dissolution-type polishing mechanism was developed. The effect of a protective layer on the Cu removal rate was considered in this method because the protective layer is a key element in the dissolution-type polishing mechanism. This method was used to simulate the removal rate in a rotary-type ECMP system. The simulations accurately provided the dependence of the Cu removal rate on the aperture ratio. Furthermore, the dependence of the Cu removal rate on the aperture ratio was described with respect to changes in the average protective layer amount with time. Regarding the dependence of the Cu removal rate on the aperture diameter, however, a discrepancy was observed between the simulation and experimental results because this method did not take into account the effect of the aperture diameter on the electrolyte-filling ratio in apertures.