Tungsten-processing slurry with cationic surfactant and cyclodextrin

Patent metadata

Field	Value
Publication number	US-9771496-B2
Application number	US-201514924997-A
Country	US
Kind code	B2
Filing date	Oct 28, 2015
Priority date	Oct 28, 2015
Publication date	Sep 26, 2017
Grant date	Sep 26, 2017

Abstract

Described are chemical-mechanical polishing compositions (e.g., slurries) and methods of using the slurries for chemical-mechanical polishing (or planarizing) a surface of a substrate that contains tungsten, the compositions containing cationic surfactant and cyclodextrin.

First claim

The invention claimed is:

1. A chemical mechanical polishing composition useful for processing a tungsten-containing surface, comprising:
liquid carrier,
abrasive particles dispersed in the liquid carrier, wherein the abrasive particles are colloidal silica particles having a permanent positive charge in a range from about 6 mV to about 50 mV,
cyclodextrin selected from alpha-, beta-, gamma-cyclodextrin, or a combination thereof, and
cationic surfactant having a cation and a hydrophobic tail that extends from the cation and that includes a chain comprising at least 7 carbon atoms, the cationic surfactant being capable of forming a complex with the cyclodextrin in the slurry.

2. The composition of claim 1 wherein the cationic surfactant has the structure:

wherein:
n is at least 1,
X is P + or N + ,
R 1 is a straight or branched alkyl group, optionally substituted, optionally containing unsaturation, that contains at least 7 carbon atoms,
R 2 , R 3 , and R 4 can independent be selected from:
hydrogen,
a saturated or unsaturated cyclic group that may be substituted or unsubstituted and may optionally include a heteroatom, a charged group, or both, and
a linear or branched alkyl group that may optionally include one or more of unsaturation, a heteroatom, or charged group and
a saturated or unsaturated ring structure formed from two or three of R 2 , R 3 , and R 4 , the ring optionally being substituted.

3. The composition of claim 2 wherein R 1 is a linear alkyl of from 7 to 20 carbon atoms.

4. The composition of claim 2 wherein R 2 is an alkyl group comprising not more than 6 carbon atoms.

5. The composition of claim 2 wherein each of R 3 and R 4 is independently an alkyl having from 1 to 6 carbon atoms.

6. The composition of claim 2 wherein the cationic surfactant is dicationic.

7. The composition of claim 6 wherein the surfactant has the formula:

wherein
R1 is an alkyl group having from 8 to 20 carbon atoms,
each R 3 , R 4 , R 5 , R 6 , and R 7 is independently an alkyl group having from 1 to 5 carbon atoms, and
Z is a divalent linking group having from 1 to 5 carbon atoms.

8. The composition of claim 7 wherein the dicationic surfactant is N,N,N′,N′, N′-pentamethyl-N-tallow-1,3-propanediammonium dichloride.

9. The composition of claim 1 wherein the cationic surfactant has the formula:

wherein:
n is at least 1,
X is P + or N + ,
R 1 is a straight or branched alkyl group, optionally containing unsaturation, that contains at least 7 carbon atoms, and
R 8 , R 9 , R 10 , R 11 , and R 12 can independent be selected from:
hydrogen,
a saturated or unsaturated cyclic group that may be substituted or unsubstituted and may optionally include a heteroatom, a charged group, or both, and
a linear or branched alkyl group that may optionally include one or more of unsaturation, a heteroatom, or charged group.

10. The composition of claim 9 wherein each of R 8 , R 9 , R 11 , and R 12 is hydrogen and R 10 is an unsaturated cyclic group that may be substituted or unsubstituted and may optionally include a heteroatom (e.g., nitrogen), a charged group (e.g., a charged nitrogen heteroatom), or both.

11. The composition of claim 1 comprising from about 0.001 to about 0.5 weight percent of the cationic surfactant based on total weight composition.

12. The composition of claim 1 comprising from about 0.01 to about 2 weight percent of the beta-cyclodextrin based on total weight composition.

13. The composition of claim 1 comprising a cationic surfactant-cyclodextrin complex of the beta-cyclodextrin associated with the cationic surfactant.

14. The composition of claim 13 comprising from about 0.001 to about 0.5 weight percent of the cationic surfactant-beta cyclodextrin complex.

15. The composition of claim 1 wherein 30 percent or more of the silica abrasive particles include three or more aggregated primary particles.

16. The composition according to claim 1 wherein the silica abrasive particles include a cationic compound incorporated into the particles, wherein the cationic compound is a charged nitrogen-containing compound or a charged phosphorous-containing compound.

17. The composition of claim 1 wherein the silica abrasive particles have a permanent positive charge of at least 10 millivolts.

18. The composition of claim 1 wherein the silica abrasive particles have a mean particle size in a range from about 30 to about 70 nanometers.

19. The composition of claim 1 comprising from about 1 to about 4 weight percent abrasive particles.

20. The composition of claim 1 further comprising:
from about 0.001 to about 1 weight percent inhibitor, wherein the inhibitor is an amino alkyl, an amino acid, or a combination thereof, and
from about 0.001 to about 0.5 weight percent catalyst.

21. The composition of claim 20 wherein the catalyst is a soluble iron-containing catalyst.

22. The composition of claim 1 further comprising an oxidizing agent.

Assignees

• Cabot Microelectronics Corp

Inventors

• Dockery Kevin
• Huang Helin
• Fu Lin
• Li Tina

Classifications

• C23F3/04

  Heavy metals · CPC title

• C09G1/02 Primary

  containing abrasives or grinding agents {(abrasives as such C09K3/14; polishing of semi-conductors H10P52/40)} · CPC title

• B24B37/24

  characterised by the composition or properties of the pad materials · CPC title

• C23F3/06

  with acidic solutions · CPC title

• C09K3/1454

  Abrasive powders, suspensions and pastes for polishing · CPC title