Planarization process with abrasive polishing slurry that is selective to a planarized surface

摘要

Parameters of an improved planarization process for a semiconductor structure surface are optimized to cause a height reduction rate of the surface that adjusts downward by a factor of at least three once the surface becomes substantially planarized. Localized over-polishing is substantially eliminated by the acquired relative rate of removal for non-planar surfaces over planar surfaces. One embodiment of the improved planarization process comprises the use of a polishing slurry including a plurality of abrasive particles of a size selected that the polishing of a surface having a height causes a surface height reduction rate that drops once the surface becomes planarized. Preferred abrasive particle sizes are about 50 nm in mean diameter or less.