Chemical mechanical planarization: Slurry chemistry, materials, and mechanisms

Abstract

Slurry chemistry, materials, and mechanisms with respect to chemical mechanical planarization (CMP) have been reported. The CMP process has been used to planarize a variety of materials including dielectrics, semiconductors, metals, polymers, and composites. Applications of CMP in microelectronics can be found in all three main areas of semiconductor device manufacturing. CMP involves removal of materials by a unique combination of chemical and abrasive action to achieve highly planar surfaces that are also very smooth. Modern CMP is a highly evolved and sophisticated process technology involving several disciplines. An alternative means is to add components to the conventional silica slurry to enhance the oxide polish rate or suppress the nitride polish rate. The higher polish rate selectivity of the ceria systems has been attributed to the preferential adsorption of poly (acrylic acid) on the silicon nitride layer. The critical properties are significantly altered after CMP, and these materials need to be protected during post-CMP cleaning as well.