Cobalt inhibitor combination for improved dishing

Patent metadata

Field	Value
Publication number	US-9528030-B1
Application number	US-201514918756-A
Country	US
Kind code	B1
Filing date	Oct 21, 2015
Priority date	Oct 21, 2015
Publication date	Dec 27, 2016
Grant date	Dec 27, 2016

Abstract

The invention provides a chemical-mechanical polishing composition that contains (a) abrasive particles, (b) an azole compound having an octanol-water log P of about 1 to about 2, (c) a cobalt corrosion inhibitor, wherein the cobalt corrosion inhibitor comprises an anionic head group and a C 8 -C 14 aliphatic tail group, (d) a cobalt accelerator, (e) an oxidizing agent that oxidizes cobalt, and (f) water, wherein the polishing composition has a pH of about 3 to about 8.5. The invention further provides a method of chemically-mechanically polishing a substrate with the inventive chemical-mechanical polishing composition. Typically, the substrate contains cobalt.

First claim

The invention claimed is:

1. A chemical-mechanical polishing composition comprising:
(a) abrasive particles,
(b) an azole compound having an octanol-water log P of about 1 to about 2,
(c) a cobalt corrosion inhibitor, wherein the cobalt corrosion inhibitor comprises an anionic head group and a C 8 -C 14 aliphatic tail group,
(d) a cobalt accelerator,
(e) an oxidizing agent that oxidizes cobalt, and
(f) water,

wherein the polishing composition has a pH of about 3 to about 8.5.

2. The polishing composition of claim 1 , wherein the polishing composition comprises about 0.1 wt. % to about 4 wt. % of abrasive particles.

3. The polishing composition of claim 1 , wherein the azole compound is benzotriazole or 5-phenyltetrazole.

4. The polishing composition of claim 1 , wherein the cobalt corrosion inhibitor has the formula: RCON(CH 3 )COOH wherein R is a C 8 -C 13 aliphatic group.

5. The polishing composition of claim 1 , wherein the cobalt accelerator is selected from a compound having the formula: NR 1 R 2 R 3 wherein R 1 , R 2 , and R 3 are independently selected from hydrogen, carboxyalkyl, substituted carboxyalkyl, hydroxyalkyl, substituted hydroxyalkyl and aminocarbonylalkyl, and wherein none or only one of R 1 , R 2 , and R 3 is hydrogen; dicarboxyheterocycles; heterocyclylalkyl-α-amino acids; N-(amidoalkyl)amino acids; unsubstituted heterocycles; alkyl-substituted heterocycles; substituted-alkyl-substituted heterocycles; N-aminoalkyl-α-amino acids; and combinations thereof.

6. The polishing composition of claim 5 , wherein the cobalt accelerator is selected from iminodiacetic acid, picolinic acid, dipicolinic acid, bicine, [(2-amino-2-oxoethyl)amino]acetic acid, lysine, imidazole, histidine, 2-[bis(2-hydroxyethyl)amino]-2-(hydroxymethyl)-1,3-propanediol, and combinations thereof.

7. The polishing composition of claim 1 , wherein the polishing composition comprises about 10 ppm to about 1000 ppm of the azole compound and about 10 ppm to about 1000 ppm of the cobalt corrosion inhibitor.

8. The polishing composition of claim 1 , wherein the oxidizing agent is hydrogen peroxide.

9. The polishing composition of claim 1 , wherein the polishing composition has a pH of about 7 to about 8.5.

10. A method of chemically mechanically polishing a substrate comprising:
(i) contacting a substrate with a polishing pad and a chemical-mechanical polishing composition comprising:
(a) abrasive particles,
(b) an azole compound having an octanol-water log P of about 1 to about 2,
(c) a cobalt corrosion inhibitor, wherein the cobalt corrosion inhibitor comprises an anionic head group and a C 8 -C 14 aliphatic tail group,
(d) a cobalt accelerator,
(e) an oxidizing agent that oxidizes cobalt, and
(f) water,

wherein the polishing composition has a pH of about 3 to about 8.5,
(ii) moving the polishing pad and the chemical mechanical polishing composition relative to the substrate, and
(iii) abrading at least a portion of the substrate to polish the substrate.

11. The method of claim 10 , wherein the polishing composition comprises about 0.1 wt. % to about 4 wt. % of abrasive particles.

12. The method of claim 10 , wherein the azole compound is benzotriazole or 5-phenyltetrazole.

13. The method of claim 10 , wherein the cobalt corrosion inhibitor has the formula: RCON(CH 3 )COOH wherein R is a C 8 -C 13 aliphatic group.

14. The method of claim 10 , wherein the cobalt accelerator is selected from a compound having the formula: NR 1 R 2 R 3 wherein R 1 , R 2 , and R 3 are independently selected from hydrogen, carboxyalkyl, substituted carboxyalkyl, hydroxyalkyl, substituted hydroxyalkyl and aminocarbonylalkyl, and wherein none or only one of R 1 , R 2 , and R 3 is hydrogen; dicarboxyheterocycles; heterocyclylalkyl-α-amino acids; N-(amidoalkyl)amino acids; unsubstituted heterocycles; alkyl-substituted heterocycles; substituted-alkyl-substituted heterocycles; N-aminoalkyl-α-amino acids; and combinations thereof.

15. The method of claim 14 , wherein the cobalt accelerator is selected from iminodiacetic acid, picolinic acid, dipicolinic acid, bicine, [(2-amino-2-oxoethyl)amino]acetic acid, lysine, imidazole, histidine, 2-[bis(2-hydroxyethyl)amino]-2-(hydroxymethyl)-1,3-propanediol, and combinations thereof.

16. The method of claim 10 , wherein the polishing composition comprises about 10 ppm to about 1000 ppm of the azole compound and about 10 ppm to about 1000 ppm of the cobalt corrosion inhibitor.

17. The method of claim 10 , wherein the oxidizing agent is hydrogen peroxide.

18. The method of claim 10 , wherein the polishing composition has a pH of about 7 to about 8.5.

19. The method of claim 10 , wherein the substrate comprises cobalt, and least a portion of the cobalt is abraded to polish the substrate.

20. The method of claim 19 , wherein the substrate comprises a semiconductor device.

Assignees

• Cabot Microelectronics Corp

Inventors

• Kraft Steven
• Carter Phillip W
• Seabold Jason

Classifications

• H10P52/403

  of conductive or resistive materials · CPC title

• H01L21/3212

  Electricity · mapped topic

• C23F3/04

  Heavy metals · CPC title

• H01L21/7684

  Electricity · mapped topic

• C09G1/02 Primary

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