COMPOSITION AND METHOD FOR DIELECTRIC CMP
A chemical mechanical polishing composition for polishing a substrate having a silicon oxygen material comprises, consists of, or consists essentially of a liquid carrier, cubiform ceria abrasive particles dispersed in the liquid carrier, and a cationic polymer having a charge density of less than about 6 meq/g.
1 . A chemical mechanical polishing composition comprising:
a liquid carrier;
cubiform ceria abrasive particles dispersed in the liquid carrier; and
a cationic polymer having a charge density of less than about 6 milliequivalents per gram (meq/g).
2 . The composition of claim 1 , wherein the cubiform ceria abrasive particles comprise a mixture of cerium oxide and lanthanum oxide.
3 . The composition of claim 1 , wherein the cubiform ceria abrasive particles have a molar ratio of lanthanum to lanthanum plus cerium in a range from about 1 to about 15 percent.
4 . The composition of claim 1 , wherein the cubiform ceria abrasive particles have a BET surface area in a range from about 3 m 2 /g to about 14 m 2 /g.
5 . The composition of claim 1 , wherein the cubiform ceria abrasive particles have an average particle size in a range from about 50 nm to about 500 nm.
6 . The composition of claim 1 , comprising from about 0.001 to about 1 weight percent of the cubiform ceria abrasive particles at point of use.
7 . The composition of claim 1 , wherein the cationic polymer has a charge density of less than about 4 meq/g.
8 . The composition of claim 1 , wherein the cationic polymer comprises at least one of polyquaternium-69, vinyl caprolactam/vp/dimethylaminoethyl methacrylate copolymer, polyquaternium-46, poly(diallyldimethylammonium)-co-N-vinyl pyrrolidone, polyquaternium-28, polyquaternium-44, polyquaternium-11, polyquaternium-68, polyquaternium-39, acrylamidopropyltrimonium chloride/acrylamide copolymer polyquaternium-16, polyquaternium-7, poly(methacryloyloxyethyltrimethylammonium), and succinylated epsilon polylysine.
9 . The composition of claim 1 , comprising from about 10 ppm by weight to about 500 ppm by weight of the cationic polymer at point of use.
10 . The composition of claim 1 , wherein:
the cationic polymer has a charge density in a range from about 3 meq/g to about 6 meq/g; and
the composition comprises from about 10 ppm by weight to about 100 ppm by weight of the cationic polymer at point of use.
11 . The composition of claim 10 , wherein the cationic polymer comprises at least one of poly(diallyldimethylammonium)-co-N-vinyl pyrrolidone, polyquaternium 7, poly(methacryloyloxyethyltrimethylammonium), polyquaternium 16, and succinylated epsilon polylysine.
12 . The composition of claim 1 , wherein:
the cationic polymer has a charge density of less than about 3 meq/g; and
the composition comprises from about 50 ppm by weight to about 300 ppm by weight of the cationic polymer.
13 . The composition of claim 12 , wherein the cationic polymer comprises at least one of poly(diallyldimethylammonium)-co-N-vinyl pyrrolidone, polyquaternium 11, polyquaternium 46, polyquaternium 68, or acrylamidopropyltrimonium chloride/acrylamide copolymer.
14 . The composition of claim 1 , further comprising picolinic acid, acetic acid, 4-hydroxybenzoic acid, or a mixture thereof.
15 . The composition of claim 1 , further comprising acrylic acid, crotonic acid, 2-pentenoic acid, trans-2-hexenoic acid, trans-3-hexenoic acid, 2-hexynoic acid, 2,4-hexadienoic acid, potassium sorbate, trans-2-methyl-2-butenoic acid, 3,3-dimethylacrylic acid, or a mixture thereof.
16 . The composition of claim 1 , further comprising poly(vinylpyrrolidone).
17 . The composition of claim 1 , having a pH in a range from about 3 to about 6 at point of use.
18 . The composition of claim 1 , comprising:
from about 0.001 to about 1 weight percent of the cubiform ceria abrasive particles at point of use; and
from about 0 from about 10 ppm by weight to about 100 ppm by weight of polyquaternium 7, poly(methacryloyloxyethyltrimethylammonium), succinylated epsilon polylysine, or a mixture thereof at point of use.
19 . The composition of claim 18 , having a pH in a range from about 3 to 6 at point of use and further comprising picolinic acid and crotonic acid.
20 . The composition of claim 1 , comprising from about 0.001 to about 1 weight percent of the cubiform ceria abrasive particles at point of use, wherein:
the cubiform ceria abrasive particles comprise a mixture of cerium oxide and lanthanum oxide and have an average particle size in a range from about 50 to about 500 nm; and
the cationic polymer includes polyquaternium 7, succinylated epsilon polylysine, poly(methacryloyloxyethyltrimethylammonium), or a mixture thereof.
21 . The composition of claim 20 , having a pH in a range from about 3 to 6 at point of use and further comprising picolinic acid, crotonic acid, and poly(vinylpyrrolidone).
22 . A method of chemical mechanical polishing a substrate including a silicon oxide dielectric material, the method comprising:
(a) providing a polishing composition comprising a liquid carrier, cubiform ceria abrasive particles dispersed in the liquid carrier, and a cationic polymer having a charge density of less than about 6 meq/g;
(b) contacting the substrate with said provided polishing composition;
(c) moving said polishing composition relative to the substrate; and
(d) abrading the substrate to remove a portion of the silicon oxide dielectric material from the substrate and thereby polish the substrate.
23 . The method of claim 22 , wherein:
a removal rate of the silicon oxide dielectric material is greater than about 4,000 Å/min in (d); and
a removal rate selectivity of the silicon oxide dielectric material to a silicon nitride layer and/or a polysilicon layer is greater than about 40 to 1.
24 . The method of claim 22 , wherein cationic polymer is polyquaternium-7, succinylated polylysine, poly(methacryloyloxyethyltrimethylammonium), or a mixture thereof.
25 . The method of claim 22 , wherein:
the polishing composition comprises from about 0.001 to about 1 weight percent of the cubiform ceria abrasive particles at point of use, and
the cubiform ceria abrasive particles comprise a mixture of cerium oxide and lanthanum oxide and have an average particle size in a range from about 50 to about 500 nm.
26 . The method of claim 22 , wherein the polishing composition further comprises picolinic acid and crotonic acid.