Cu CMP and its challenge for 20nm nodes and beyond

Abstract

The challenges associated with meeting 20nm technology requirements for better Cu CMP process uniformity and lower defectivity have been studied. Required improvements in uniformity were obtained through platen process optimization along with evaluation & selection of specific Cu slurries and pads and their performance reported. The principal factors influencing defect formation, including Cu barrier metallurgy, interconnect pattern density and process queue times were studied. Specific new post CMP clean chemistries were evaluated to assess their capability to suppress defect formation and their performance reported. The trade off between uniformity and defect suppression as a function slurry, pad and post Cu CMP clean chemistry is described. © 2012 Materials Research Society.