A study on the optimization of a CMP system design for lowering of bull's eye effects

Bull's eye effects 를 줄이기 위한 CMP system의 최적화 설계에 관한 연구

A CMP system is newly proposed and analyzed by a home-made computer progarm. The proposed system is possibly to lower bull's eye effects such that the planarity of a wafer surface using a CMP system can be drasitcally improved. The optimum conditions for a design of the proposed system are verified using the home-made simulation program. For the proposed CMP system with a 12" diameter of platen, the optimum design conditons are the 0.09", 0.10", 0.12", and 0.14", clearance from the platern edge for wafer diameters of 5", 6", 8", and 12", respectively. These clear distance such as 0.09", 0.10", 0.12", and 0.14" are optimum lengths of the sample wafers extended ffrom the platen edge. In other words, shorter orbital lengths result in lowering of Bull's eye effects.