Slurry, polishing liquid set, polishing liquid, method for polishing substrate, and substrate

• US 9,881,802 B2
• Filed: 01/31/2013
• Issued: 01/30/2018
• Est. Priority Date: 11/22/2010
• Status: Active Grant

• Current Assignee: Resonac Corp. (Resonac Holdings Corp.)
• Original Assignee: Hitachi Chemical Company Limited (Resonac Holdings Corp.)
• Inventors: Iwano, Tomohiro
• Primary Examiner(s): Olsen, Kaj K
• Assistant Examiner(s): Christie, Ross J
• Application Number:
  US13/755,024
• Publication Number:
  US 20130137265A1
• Time in Patent Office: 1,825 Days
• Field of Search: None
• 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: C09K 13/12 containing heavy metal salts in an amount of at least 50% of the non-solvent components
• CPC Class Codes: C09K 3/1463 Aqueous liquid suspensions
• 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

Abstract

A polishing liquid includes abrasive grains, an additive and water, wherein the abrasive grains include a tetravalent metal element hydroxide, and produce a liquid phase with a nonvolatile content of 500 ppm or greater when an aqueous dispersion with a content of the abrasive grains adjusted to 1.0 mass % has been centrifuged for 50 minutes at a centrifugal acceleration of 1.59×10⁵ G.

Claims

1. A slurry comprising abrasive grains and water,

the abrasive grains including a hydroxide of tetravalent cerium, and the abrasive grains including a property of producing a liquid phase with a nonvolatile content of 500 ppm or greater when an aqueous dispersion with a content of the abrasive grains adjusted to 1.0 mass % has been centrifuged for 50 minutes at a centrifugal acceleration of 1.59×

10⁵ G.

2. The slurry according to claim 1, wherein the abrasive grains further include a property of producing light transmittance of 50%/cm or greater for light with a wavelength of 500 nm in an aqueous dispersion with a content of the abrasive grains adjusted to 1.0 mass %.

3. The slurry according to claim 1, wherein the hydroxide of tetravalent cerium is obtained by mixing a tetravalent cerium salt and an alkali solution.

4. A polishing liquid set comprising constituent components of a polishing liquid separately stored as a first liquid and a second liquid, so that the first liquid and the second liquid are mixed to form the polishing liquid, wherein the first liquid is the slurry according to claim 1, and the second liquid comprises an additive and water.

5. The polishing liquid set according to claim 4, wherein the additive is at least one selected from the group consisting of vinyl alcohol polymers and derivatives of the vinyl alcohol polymers.

6. The polishing liquid set according to claim 4, wherein a content of the additive is 0.01 mass % or greater based on a total mass of the polishing liquid.

12. A substrate polishing method comprising:

a step of placing a film to be polished, of a substrate which has the film to be polished on its surface, so as to face an abrasive pad, and

a step of polishing at least a portion of the film to be polished while supplying the slurry according to claim 1 between the abrasive pad and the film to be polished.

13. A substrate polishing method comprising:

a step of placing a film to be polished, of a substrate which has the film to be polished on its surface, so as to face an abrasive pad,

a step of mixing the first liquid and the second liquid of the polishing liquid set according to claim 4 to obtain the polishing liquid, and

a step of polishing at least a portion of the film to be polished while supplying the polishing liquid between the abrasive pad and the film to be polished.

14. A substrate polishing method comprising:

a step of placing a film to be polished, of a substrate which has the film to be polished on its surface, so as to face an abrasive pad, and

a step of polishing at least a portion of the film to be polished while respectively supplying both the first liquid and the second liquid of the polishing liquid set according to claim 4 between the abrasive pad and the film to be polished.

16. The polishing method according to claim 12, wherein the film to be polished includes silicon oxide.

17. The polishing method according to claim 13, wherein the film to be polished includes silicon oxide.

18. The polishing method according to claim 14, wherein the film to be polished includes silicon oxide.

20. The polishing method according to claim 12, wherein a surface of the film to be polished has irregularities.

21. The polishing method according to claim 13, wherein a surface of the film to be polished has irregularities.

22. The polishing method according to claim 14, wherein a surface of the film to be polished has irregularities.

24. The slurry according to claim 1, wherein a mean secondary particle size of the abrasive grains is 2-80 nm, and pH of the slurry is 2.0 to 9.0.

7. A polishing liquid comprising abrasive grains, an additive and water,

the abrasive grains including a hydroxide of tetravalent cerium, and the abrasive grains including a property of producing a liquid phase with a nonvolatile content of 500 ppm or greater when an aqueous dispersion with a content of the abrasive grains adjusted to 1.0 mass % has been centrifuged for 50 minutes at a centrifugal acceleration of 1.59×

10⁵ G.

8. The polishing liquid according to claim 7, wherein the abrasive grains further include a property of producing light transmittance of 50%/cm or greater for light with a wavelength of 500 nm in an aqueous dispersion with a content of the abrasive grains adjusted to 1.0 mass %.

9. The polishing liquid according to claim 7, wherein the hydroxide of tetravalent cerium is obtained by mixing a tetravalent cerium salt and an alkali solution.

10. The polishing liquid according to claim 7, wherein the additive is at least one selected from the group consisting of vinyl alcohol polymers and derivatives of the vinyl alcohol polymers.

11. The polishing liquid according to claim 7, wherein a content of the additive is 0.01 mass % or greater based on a total mass of the polishing liquid.

15. A substrate polishing method comprising:

a step of placing a film to be polished, of a substrate which has the film to be polished on its surface, so as to face an abrasive pad, and

a step of polishing at least a portion of the film to be polished while supplying the polishing liquid according to claim 7 between the abrasive pad and the film to be polished.

19. The polishing method according to claim 15, wherein the film to be polished includes silicon oxide.

23. The polishing method according to claim 15, wherein a surface of the film to be polished has irregularities.

25. The polishing liquid according to claim 7, wherein a mean secondary particle size of the abrasive grains is 2-80 nm, and pH of the polishing liquid is 2.0 to 9.0.