Particles, Slurry Residues, and Trace Metal

In most cases, the trace metal left on the wafer surface after W CMP can be removed by a conventional post-CMP cleaning. Under some circumstances, a more aggressive post-W CMP cleaning that etches the oxide surface is needed to completely remove any trace metal left on the patterned wafer surface. 

Unlike copper CMP, it is rare to see delamination during W CMP. For W integration, most of the delamination can be traced to a poor adhesion between the metal and the linar or the liner and the dielectric film. 

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