Chemical-mechanical polishing compositions and methods of making and using the same
View Patent ↗The present invention provides an aqueous CMP slurry composition that includes abrasive particles and from about 0.01% to the limit of solubility in water of a compound according to Formula (I): wherein only one of R 1 , R 2 , R 3 , R 4 and R 5 is a hydroxyl group (—OH), only one of R 1 , R 2 , R 3 , R 4 and R 5 is a methoxy group (—OCH 3 ), and the three of R 1 , R 2 , R 3 , R 4 and R 5 that are not either a hydroxyl group (—OH) or a methoxy group (—OCH 3 ) are hydrogen atoms (—H).
1. An aqueous CMP slurry composition consisting of:
from about 1.0% to about 8.0% by weight of ceria abrasive particles having a mean diameter of from about 20 nm to about 1000 nm;
from about 0.01% by weight to the limit of solubility in water of
vanillic acid;
an amount of nitric acid sufficient to adjust the pH of the CMP slurry composition to from about 2.8 to about 6;
from about 0.1% to 10.0% by weight proline; and
optionally, one or more selected from the group consisting of isopropyl alcohol and a biocide.
2. The aqueous CMP slurry composition according to claim 1 wherein proline is present in an amount of about 0.6% to about 4.0% by weight.
3. The aqueous CMP slurry composition according to claim 1 wherein the CMP slurry composition includes about 0.15% by weight of isopropyl alcohol.
4. The aqueous CMP slurry composition according to claim 1 wherein the aqueous CMP slurry composition has a pH of from about 3.0 to 4.5.
5. The aqueous CMP slurry composition according to claim 1 wherein the ceria abrasive particles have a maximum diameter of less than about 10,000 nm.
6. The aqueous CMP slurry composition according to claim 5 wherein the ceria abrasive particles have a mean diameter of from about 100 nm to about 150 nm.
7. A method for removing silicon dioxide from a surface of a workpiece by chemical-mechanical polishing, the method comprising:
(i) providing an aqueous CMP slurry composition between a polishing pad and the surface of the workpiece, the aqueous CMP slurry composition consisting of:
(a) from about 1.0% to about 8.0% by weight of ceria abrasive particles having a mean diameter of from about 20 nm to about 1000 nm,
(b) from about 0.01% by weight to the limit of solubility in water of
vanillic acid,
(c) an amount of nitric acid sufficient to adjust the pH of the CMP slurry composition to from about 2.8 to about 6,
(d) from about 0.1% to about 10.0% by weight proline, and
(e) optionally, one or more selected from the group consisting of isopropyl alcohol and a biocide; and
(ii) pressing the polishing pad and the surface of the workpiece together with the CMP slurry composition disposed therebetween while the polishing pad and the surface of the workpiece are moving relative to each other to abrade silicon dioxide from the surface.
8. The method according to claim 7 wherein the ceria abrasive particles are dispersed in water prior to chemical-mechanical polishing.
9. The method according to claim 7 wherein the ceria abrasive particles are initially bonded to a polishing pad and become dispersed in water during chemical-mechanical polishing.
10. The method according to claim 7 wherein the silicon dioxide is removed from the surface of the workpiece in ILD or MEMS processing.
11. The method according to claim 7 wherein the aqueous CMP slurry composition includes proline in an amount of about 0.6% to about 4.0% by weight.
12. The method according to claim 11 wherein the silicon dioxide is removed from the surface of the workpiece in STI processing in preference to silicon nitride.
13. The method according to claim 7 wherein the ceria abrasive particles have a maximum diameter of less than about 10,000 nm.
14. The method according to claim 7 wherein the ceria abrasive particles have a mean diameter of from about 100 nm to about 150 nm.