Development of Aluminum Chemical Mechanical Planarization

The paper describes the development of an aluminum chemical mechanical planarization process that was successfully integrated into the dual damascene technology producing 1 Gb dynamic random access memory chips meeting all yield and sheet resistance requirements. Three of the major problems of chemical mechanical polishing of Al-0.5 Cu alloys, i.e., copper plate-out on titanium liners, array erosion, and slow polish rate were solved by adding Ce 4 + ions to the polishing slurry.