Reduction of micro-defects in the inter-metal dielectrics (IMD) chemical mechanical polishing (CMP) for ULSI applications

In this work, we studied the relationship between defect generation and pad count to understand the exact efficiency of the slurry filtration, and to find out the appropriate pad usage. Our experimental results showed that it is impossible to prevent defect-causing particles perfectly through the depth-type filter. Thus, we suggest that it is necessary to optimize flow rate of slurry and to install the high spray bar of de-ionized water (DIW) with high pressure, in order to overcome weak-points of POU depth type filter.