Patent ID: 8017524

Claim:
A chemical-mechanical polishing composition comprising: (a) wet-process silica, (b) about 0.01 wt. % to about 0.5 wt. % of a stabilizer compound selected from the group consisting of R 1 R 2 R 3 R 4 N + X − , R 1 R 2 R 3 R 4 P + X − , R 1 R 2 R 3 S + X − , an imidazolium salt, and a pyridinium salt, wherein each of R 1 , R 2 , R 3 , and R 4 independently is a C 1 -C 6 alkyl,a C 7 -C 12 arylalkyl, or a C 6 -C 10 aryl, (c) about 0.002 wt. % to about 0.2 wt. % of a potassium salt, wherein the potassium salt is potassium hydrogen carbonate, potassium carbonate, or a combination of potassium hydrogen carbonate and potassium carbonate, (d) about 0.002 wt. % to about 0.2 wt. % of a secondary amine compound, (e) water, wherein the polishing composition has a pH of about 9 to about 12.