Dressing Behaviors of PCD Conditioners on CMP Polishing Pads
Diamond pad conditioner or dresser can determine the efficiency of chemical mechanical polishing (CMP) processes and the quality of polished wafers. Conventional diamond pad conditioners are made by adhering discrete diamond grits on a flat substrate. The size distribution of diamond grits coupled with the deformation of the substrate often make the tips of diamond grits lying at different heights. Instead of attaching individual diamond grits to a metal substrate, a revolutionary design of pad conditioners is based on carving a structure out of sintered polycrystalline diamond (PCD) matrix. The PCD dresser is manufactured by wire electro discharge machining to form cutting pyramids of a specific size with a designed shape. The dressing characteristics of pad surface textures are studied by comparison with conventional diamond pad conditioner. Experimental results indicate that the PCD dresser can dress asperities of the pad more uniformly than the conventional diamond dresser due to PCD dresser having identically shaped tip and the same height diamond. In addition the cutting rate of PCD dresser for IC1000 pad not only is reduced by about 30% but also it can dress pad more effectively than conventional diamond dresser.
Han Huang, Liangchi Zhang, Jun Wang, Zhengyi Jiang, Libo Zhou, Xipeng Xu and Tsunemoto Kuriyagawa
M.Y. Tsai and J. C. Sung, "Dressing Behaviors of PCD Conditioners on CMP Polishing Pads", Advanced Materials Research, Vols. 76-78, pp. 201-206, 2009