Investigation of the Two-Way Injection Slurry-Supply Method for the Cu CMP Process

The effect of the two-way injection method during a copper chemical mechanical planarization (CMP) process was investigated. The two-way slurry-injection method has the advantage of not only preventing the degradation of the slurry, but also shortening the process time because the mixing process of the slurry and H2O2 is not required. Compared to the conventional method, the two-way injection method has an equivalent level of less than 9% in material removal rate. In particular, when injecting near the center of the pad, the influence according to the positions and flow rates of the two nozzles is also insignificant, so it deserves to be studied as a slurry-supply method.