New Polish Chemistry and Process for Improved Fixed Abrasive CMP Performance

Fixed abrasive chemical mechanical planarization (CMP) has demonstrated excellent polish planarity with low dishing for direct-polish shallow trench isolation (STI) applications. However, the standard process exhibits a removal fast band near the wafer periphery that degrades polish performance. A new polish chemistry has been developed that dramatically increases the oxide removal rate for a given polish pressure, enabling the use of lower pressure processes. Low pressure polishing improves nitride polish performance and provides a larger CMP process window than is achievable using the baseline process.