ADDITIVES TO IMPROVE PARTICLE DISPERSION FOR CMP SLURRY
The invention provides a chemical-mechanical polishing composition comprising (a) about 0.05 wt. % to about 10 wt. % of an abrasive; (b) a dispersant, wherein the dispersant is a linear or branched C 2 -C 10 alkylenediol; and (c) water, wherein the chemical-mechanical polishing composition has a pH of about 2 to about 6. The invention also provides a method of chemically-mechanically polishing a substrate by contacting the substrate with the inventive chemical-mechanical polishing composition.
1 . A chemical-mechanical polishing composition comprising:
(a) about 0.05 wt. % to about 10 wt. % of an abrasive;
(b) a dispersant, wherein the dispersant is a linear or branched C 2 -C 10 alkylenediol; and
(c) water,
wherein the chemical-mechanical polishing composition has a pH of about 1 to about 7.
2 . The chemical-mechanical polishing composition of claim 1 , wherein the composition comprises about 2 wt. % to about 5 wt. % of the abrasive.
3 . The chemical-mechanical polishing composition of claim 1 , wherein the abrasive is selected from treated alumina, colloidal silica, fumed silica, surface-modified silica, and combinations thereof.
4 . The chemical-mechanical polishing composition of claim 1 , wherein the abrasive is colloidal silica.
5 . The chemical-mechanical polishing composition of claim 4 , wherein the colloidal silica has a mean particle size of about 10 nm to about 100 nm.
6 . The chemical-mechanical polishing composition of claim 1 , wherein the composition comprises about 0.5 wt. % to about 20 wt. % of the dispersant.
7 . The chemical-mechanical polishing composition of claim 1 , wherein the chemical-mechanical polishing composition has a pH of about 2 to about 5.
8 . The chemical-mechanical polishing composition of claim 1 , wherein the dispersant is a linear or branched C 2 -C 7 alkylenediol.
9 . The chemical-mechanical polishing composition of claim 1 , wherein the dispersant is selected from 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, and combinations thereof.
10 . The chemical-mechanical polishing composition of claim 1 , wherein the dispersant is 1,4-butanediol.
11 . The chemical-mechanical polishing composition of claim 1 , wherein the dispersant is a linear C 2 -C 10 alkylenediol.
12 . A method of chemically-mechanically polishing a substrate comprising:
(i) providing a substrate;
(ii) providing a polishing pad;
(iii) providing a chemical-mechanical polishing composition comprising:
(a) about 0.05 wt. % to about 10 wt. % of an abrasive;
(b) a dispersant, wherein the dispersant is a linear or branched C 2 -C 10 alkylenediol; and
(c) water,
wherein the chemical-mechanical polishing composition has a pH of about 2 to about 6;
(iv) contacting the substrate with the polishing pad and the chemical-mechanical polishing composition; and
(v) moving the polishing pad and the chemical-mechanical polishing composition relative to the substrate to abrade at least a portion of a surface of the substrate to polish the substrate.
13 . The method of claim 12 , wherein the composition comprises about 1 wt. % to about 5 wt. % of the abrasive.
14 . The method of claim 12 , wherein the abrasive is selected from treated alumina, colloidal silica, fumed silica, surface-modified silica, and combinations thereof.
15 . The method of claim 12 , wherein the abrasive is colloidal silica.
16 . The method of claim 15 , wherein the colloidal silica has a mean particle size of about 10 nm to about 100 nm.
17 . The method of claim 12 , wherein the composition comprises about 0.5 wt. % to about 20 wt. % of the dispersant.
18 . The method of claim 12 , wherein the chemical-mechanical polishing composition has a pH of about 2 to about 5.
19 . The method of claim 12 , wherein the dispersant is a linear or branched C 2 -C 7 alkylenediol.
20 . The method of claim 12 , wherein the dispersant is selected from 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, and combinations thereof.
21 . The method of claim 12 , wherein the dispersant is 1,4-butanediol.
22 . The method of claim 12 , wherein the substrate comprises a tungsten layer on a surface of the substrate, and wherein at least a portion of the tungsten layer is abraded to polish the substrate.