Abstract
In deep-submicron semiconductor manufacturing, due to tighter budget of the depth of focus in lithography, a global planarization technique is desired. Chemical mechanical planarization (CMP) is the only process to achieve the global planarization. However, the complex dynamic chemical and mechanical effects during CMP impede the establishment of a sound analysis of the process-induced nonuniformity.The study derives a material removal model, which predicts the material removal rate is proportional to the relative velocity between the wafer and the pad by the power between 1/3 to 2/3. Experimental results by the single-head and the planetary-train machines agree with the prediction. The support is also found in independent experimental data.The kinematic analysis is conducted to investigate the effects of the kinematic parameters. When the pad velocity equals to the carrier velocity (or the resulted carrier rotational velocity in the planetary-train machine), the relative velocity remains constant across the wafer called "Absolute Velocity Uniformity". The nonuniformity is analyzed based on the above material removal model and the kinematic study. The experimental results agree with the prediction.