Planarization characteristics of ultra low diluted Ceria (CeO2) based slurry, especially a multi-layered Chemical Mechanical Polishing (CMP) process, have been studied. The multi-layer represents the polished film consists of more than two different materials, so that, more than two different materials are exposed to the polished surface. In this work, ultra low diluted ceria based slurry was introduced to minimize micro-dishing effect of the process such as a storage node contact and a bit line contact in 80nm feature sized DRAM device, which has multi-layer film surfaces. As a result, we can minimize micro dishing of silicon dioxide and polycrystalline silicon at memory cell area, and silicon dioxide dishing at peripheral area.