Minimization of Metal Loss during Chemical Mechanical Planerization of Copper-Oxide and Copper- Low K Damascene Structures

摘要

Chemical Mechanical Polishing investigations were made on copper-oxide and copper-low κ damascene structures by using several different formulations of copper and barrier polishing slurries. It is shown that selectivity of copper polishing slurry is a key factor in controlling surface topography and metal loss. High selective copper polishing slurry results in relatively lower topography and lower metal loss compared to low selective copper polishing slurry. Low selective barrier polishing slurry is helpful in correcting some of the topography created during copper polishing step. Comparable metal loss, dishing and erosion values were obtained for copper-low κ wafers and copper-oxide wafers.