CMP COMPOSITIONS SELECTIVE FOR OXIDE AND NITRIDE WITH IMPROVED DISHING AND PATTERN SELECTIVITY

• US 20180105721A1
• Filed: 10/16/2017
• Published: 04/19/2018
• Est. Priority Date: 10/17/2016
• Status: Active Grant

• Current Assignee: CMC Materials LLC (Fujifilm Holdings Corporation)
• Original Assignee: Cabot Microelectronics Corporation (Entegris Incorporated)
• Inventors: PALLIKKARA KUTTIATOOR, Sudeep, HAMILTON, Charles, DOCKERY, Kevin P.
• Granted Patent: US 10,640,679 B2
• Time in Patent Office: Days
• CPC Class Codes: C09G 1/02 containing abrasives or grinding agents abrasives as such C09K3/14; polishing of semi-conductors H01L
• CPC Class Codes: H01L 21/30625 With simultaneous mechanical treatment, e.g. mechanico-chemical polishing
• CPC Class Codes: H01L 21/31053 involving a dielectric removal step
• CPC Class Codes: H01L 21/3212 by chemical mechanical polishing [CMP]

Abstract

The invention provides a chemical-mechanical polishing composition containing a ceria abrasive, a polyhydroxy aromatic carboxylic acid, an ionic polymer of formula I:

wherein X¹ and X², Z¹ and Z², R¹, R², R³, and R⁴, and n are as defined herein, and water, wherein the polishing composition has a pH of about 1 to about 4.5. The invention further provides a method of chemically-mechanically polishing a substrate with the inventive chemical-mechanical polishing composition. Typically, the substrate contains silicon oxide, silicon nitride, and/or polysilicon.

Claims

1. A chemical-mechanical polishing composition comprising:

(a) a wet-process ceria abrasive,

(b) a polyhydroxy aromatic carboxylic acid,

(c) optionally, an ionic polymer of formula (I);

2. The polishing composition of claim 1, wherein the wet-process ceria abrasive is present in an amount of about 0.05 wt. % to about 1 wt. % of the polishing composition.

3. The polishing composition of claim 1, wherein the polyhydroxy aromatic carboxylic acid is 3,4-dihydroxybenzoic acid or 3,5-dihydroxybenzoic acid.

4. The polishing composition of claim 1, wherein X¹ and X² are both —

COOH.

5. The polishing composition of claim 4, wherein Z¹ and Z² are both O, and R¹, R², R³, and R⁴ are hydrogen.

6. The polishing composition of claim 1, wherein the ionic polymer has a molecular weight of about 500 daltons to about 10,000 daltons, and wherein n is an integer of 8 to 500.

7. The polishing composition of claim 1, wherein the ionic polymer is present in an amount of about 0.01 wt. % to about 0.5 wt. % of the polishing composition.

8. The polishing composition of claim 1, wherein the polishing composition further comprises a polyvinyl alcohol, wherein the polyvinyl alcohol is a branched polyvinyl alcohol having a molecular weight of about 20,000 daltons to about 200,000 daltons.

9. The polishing composition of claim 1, wherein the polishing composition further comprises a polyethylene glycol.

10. A method of chemically-mechanically polishing a substrate comprising:

(i) providing a substrate,

(ii) providing a polishing pad,

(iii) providing a chemical-mechanical polishing composition comprising;

(a) a wet-process ceria abrasive,

(b) a polyhydroxy aromatic carboxylic acid,

(c) an ionic polymer of formula (I);

11. The method of claim 10, wherein the wet-process ceria abrasive is present in an amount of about 0.05 wt. % to about 1 wt. % of the polishing composition.

12. The method of claim 10, wherein the polyhydroxy aromatic carboxylic acid is 3,4-dihydroxybenzoic acid or 3,5-dihydroxybenzoic acid.

13. The method of claim 10, wherein X¹ and X² are both —

COOH.

14. The method of claim 13, wherein Z¹ and Z² are both O, and R¹, R², R³, and R⁴ are hydrogen.

15. The method of claim 10, wherein the ionic polymer has a molecular weight of about 500 daltons to about 10,000 daltons, and wherein n is an integer of 8 to 500.

16. The method of claim 10, wherein the ionic polymer is present in an amount of about 0.01 wt. % to about 0.5 wt. % of the polishing composition.

17. The method of claim 10, wherein the polishing composition further comprises a polyvinyl alcohol, wherein the polyvinyl alcohol is a branched polyvinyl alcohol having a molecular weight of about 20,000 daltons to about 200,000 daltons.

18. The method of claim 10, wherein the polishing composition further comprises a polyethylene glycol.

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

20. The method of claim 19, wherein the substrate further comprises silicon nitride, and wherein at least a portion of the silicon nitride is abraded to polish the substrate.

21. The method of claim 19, wherein the substrate further comprises polysilicon, and wherein at least a portion of the polysilicon is abraded to polish the substrate.

22. A chemical-mechanical polishing composition comprising:

(a) a wet-process ceria abrasive,

(b) a polyhydroxy aromatic carboxylic acid, and

(c) water,

wherein the polishing composition has a pH of about 1 to about 4.5.

23. Composition of claim 22 further comprising one or more non-ionic polymers selected from the group of polyethylene glycols or polyvinyl alcohols

24. A method of chemically-mechanically polishing a substrate comprising:

(i) providing a substrate,

(ii) providing a polishing pad,

(iii) providing the chemical-mechanical polishing composition of claim 22,

(iv) contacting the substrate with the polishing pad and the 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 substrate to polish the substrate.