CMP (chemical mechanical planarization) is a process in which both chemical and mechanical mechanisms act simultaneously to produce the planarized wafer.[1] The wafer edge profile control is the most challenging issue in CMP process. Even much investigation has been tried to eliminate wafer edge profile control, the understanding the origins of the wafer edge profile control during polishing are still needed. Fig1. shows the differences were compared with the single retainer ring and separated retainer ring. Fig2. shows that the separated retainer ring can control wafer edge profile as the result of the simulation. Fig3. is the removed wafer normalize amount as compared with the result of single retainer ring and separated retainer ring. In this study, we examined the better wafer edge profile control was presented by changing the original form of RR(retainer ring) into having two individual pressure controls. Based on experimental and simulation result, it was possible to achieve uniform surface even in the wafer edge area in the case of separated retainer ring by decreasing pad deformation. REFERENCE 1. P. Singer, “Chemical-Mechanical Polishing : A new focus on consumable”, Semiconductor International, pp. 48-53, Feb, 1994. 2. Preston, F. W., “The Theory and Design of Plate Glass Polishing Machine”. Journal of the Society of Glass Technology, 11, p. 214, 1927. 3. Zhao, D., Wang, T., He, Y., and Lu, X., “Effect of Zone Pressure on Wafer Bending and Fluid Lubrication Behavior during Multi-zone CMP Process”, Microelectronic Engineering, 108, p. 33, 2013. 4. Wang, T., Lu, X., Zhao, D., & He, Y., "Contact Stress Non-uniformity of Wafer Surface for Multi-zone Chemical Mechanical Polishing Process." Science China Technological Sciences, 56(8), p.1974, 2013. Figure 1