Particles, Residues, and Trace Metals

FIGURE 17.48 Pictures of watermark and organic residues. The top left picture is an optical image of watermark. The other pictures are SEM images of organic contamination of filled area and patterned area. 

FIGURE 17.49 The left image shows a 300-mm blanket wafer with massive delamination of the porous low-k film during CMP when using only 1 psi and 40 rpm. The same CMP process condition has been used on the patterned wafer in the right picture. As the picture shows, the same film behaves much better when patterned with copper structures. Only small areas of the patterned wafer present signs of delamination. 

FIGURE 17.51 The delamination occurs at the early stage of copper CMP, only after a few seconds of CMP. In the present integration scheme, the delamination occurs at the low-k interface and the low-1 capping material. The copper structure stops the cap material delamination until the end of the CMP as shown in the right image. 

FIGURE 17.52 This picture shows that a scratch on a porous low-1 with a cap results in the delamination of the cap film. The fragments of the cap material create scratches and more delamination. The porous low-1 material mostly remains but it is scratched down to the bottom in some places. 

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