Defectivity Improvement for Fixed Abrasive Based STI CMP in Advanced Logic Technology

Shallow Trench Isolation (STI) CMP using Fixed Abrasives is an efficient process to provide excellent planarity over a broad variety of pattern density and feature widths. Many investigations have helped to improve the Fixed Abrasive based STI CMP process in terms of defectivity, costs, throughput and process stability. However, for continuous shrinking of feature sizes and the enlargement of die sizes, due to the transition to multi-core microprocessor designs, the impact of defects on product yield becomes even more critical. Therefore, further defect reduction is required in advanced logic volume production for the next technology nodes. A new removal rate enhancing chemical provides further options for scratch reduction by shorter Fixed Abrasive (FA) polish times and / or by using a lower down force with the FA polish. The potential for lowering defects by process parameters, polish time and down force will be discussed in this paper.