Self-stopping polishing composition and method for bulk oxide planarization
The invention provides a chemical-mechanical polishing composition comprising an abrasive, a self-stopping agent, an aqueous carrier, and optionally, a cationic polymer, and provides a method suitable for polishing a substrate.
1. A chemical-mechanical polishing composition comprising:
(a) an abrasive selected from ceria, zirconia, and combinations thereof,
(b) a self-stopping agent selected from a compound of formula (I):
wherein R is selected from the group consisting of hydrogen, alkyl, cycloalkyl, aryl, heterocyclic alkyl, and heterocyclic aryl, each of which may be substituted or unsubstituted;
(c) a cationic polymer, wherein the cationic polymer comprises a quaternary amine,
(d) an aqueous carrier,
wherein the polishing composition has a pH of about 7 to about 9.
2. The polishing composition of claim 1 , wherein the self-stopping agent is selected from hydroxamic acid, acetohydroxamic acid benzhydroxamic acid, salicylhydroxamic acid and combinations thereof.
3. The polishing composition of claim 1 , wherein the cationic polymer is selected from, 2-(dimethylamino)ethyl methacrylate, diallyldimethylammonium, poly(vinylimidazolium), poly(methacryoyloxyethyltrimethylammonium) halide, poly(diallyldimethylammonium)chloride, polyquaternium-2, Polyquaternium-11, Polyquaternium-16, Polyquaternium-46, Polyquaternium-44, Luviquat Supreme, Luviquat Hold, Luviquat UltraCare, Luviquat FC 370, Luviquat FC 550, Luviquat FC 552, Luviquat Excellence, and combinations thereof.
4. The polishing composition of claim 1 , wherein the polishing composition further comprises a rate enhancer.
5. The polishing composition of claim 1 , wherein the self-stopping agent is present in the polishing composition at a concentration of about 1 wt % or less.
6. The polishing composition of claim 1 , wherein the abrasive is ceria.
7. The polishing composition of claim 1 , wherein the abrasive is present in the polishing composition at a concentration of about 0.001 wt. % to about 5 wt. %.
8. A method of chemically-mechanically polishing a substrate comprising:
(i) providing a substrate, wherein the substrate comprises a pattern dielectric layer on a surface of the substrate,
(ii) providing a polishing pad,
(iii) providing the chemical-mechanical polishing composition of claim 1 ,
(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 the pattern dielectric layer on a surface of the substrate to polish the substrate.