CMP COMPOSITIONS SELECTIVE FOR OXIDE AND NITRIDE WITH HIGH REMOVAL RATE AND LOW DEFECTIVITY

• US 20140346140A1
• Filed: 05/21/2013
• Published: 11/27/2014
• Est. Priority Date: 05/21/2013
• Status: Active Grant

• Current Assignee: CMC Materials LLC (Fujifilm Holdings Corporation)
• Original Assignee: Cabot Microelectronics Corporation (Entegris Incorporated)
• Inventors: Dysard, Jeffrey, Dockery, Kevin P., Jia, Renhe
• Granted Patent: US 8,906,252 B1
• Time in Patent Office: Days
• US Class Current: 216/38
• CPC Class Codes: B24B 37/044 characterised by the composition of the lapping agent
• CPC Class Codes: C09G 1/02 containing abrasives or grinding agents abrasives as such C09K3/14; polishing of semi-conductors H01L
• CPC Class Codes: C09G 1/16 on natural or synthetic resins

Abstract

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

wherein X¹ and X², Z¹ and Z², 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 ceria abrasive,

(b) an ionic polymer of formula I;

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

COOH.

3. The polishing composition of claim 2, wherein Z¹ and Z² are both O, and R¹, R², R³, and R⁴ are hydrogen.

4. 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 with a value of 8 or greater.

5. 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.

6. The polishing composition of claim 1, wherein the ceria abrasive is a wet-process ceria abrasive.

7. The polishing composition of claim 6, wherein the wet-process ceria abrasive is present in an amount of about 0.05 wt. % to about 1 wt. % of the polishing composition.

8. The polishing composition of claim 1, wherein the polishing composition further comprises a polyvinyl alcohol.

9. The polishing composition of claim 8, wherein the polyvinyl alcohol has a molecular weight of about 20,000 daltons to about 200,000 daltons.

10. The polishing composition of claim 8, wherein the polyvinyl alcohol is a branched polyvinyl alcohol.

11. 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) a ceria abrasive,

(b) an ionic polymer of formula I;

12. The method of claim 11, wherein X¹ and X² are both —

COOH.

13. The method of claim 12, wherein Z¹ and Z² are both O, and R¹, R², R³, and R⁴ are hydrogen.

14. The method of claim 11, wherein the ionic polymer has a molecular weight of about 500 daltons to about 10,000 daltons, and wherein n is an integer with a value of 8 or greater.

15. The method of claim 11, wherein the ionic polymer is present in an amount of about 0.01 wt. % to about 0.5 wt. % of the polishing composition.

16. The method of claim 11, wherein the ceria abrasive is a wet-process ceria abrasive.

17. The method of claim 16, wherein the wet-process ceria abrasive is present in an amount of about 0.1 wt. % to about 1 wt. % of the polishing composition.

18. The method of claim 11, wherein the polishing composition further comprises a polyvinyl alcohol.

19. The method of claim 18, wherein the polyvinyl alcohol has a molecular weight of about 20,000 daltons to about 200,000 daltons.

20. The method of claim 18, wherein the polyvinyl alcohol is a branched polyvinyl alcohol.

21. The method of claim 11, wherein the substrate comprises silicon oxide, and wherein at least a portion of the silicon oxide is abraded to polish the substrate.

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

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