Tungsten CMP using Fixed Abrasive
Publication Date: 2004-Jul-22
The IP.com Prior Art Database
This paper describes the polishing of tungsten metal using a fixed abrasive polishing pad along with a working fluid. Polishing down forces, polishing speeds of the platen and carrier were varied, and good tungsten removal rates were achieved. Removal rates varied depending on the process conditions. Dishing and erosion of various wafer features were also monitored and good results were achieved. Removal of the underlying Ti and TiN layers was estimated to require less than a minute of additional polishing. Blanket TEOS wafers were polished under the identical process conditions as that of tungsten. Low oxide removal rates under were measured, yielding a high tungsten/oxide removal rate ratio.