Polishing pad, and method and apparatus for polishing

• US 20030003857A1
• Filed: 06/21/2002
• Published: 01/02/2003
• Est. Priority Date: 12/22/1999
• Status: Active Grant

• Current Assignee: Toray Industries Incorporated
• Original Assignee: Toray Industries Incorporated
• Inventors: Ohta, Masami, Shimagaki, Masaaki, Minamiguchi, Hisashi
• Granted Patent: US 6,953,388 B2
• Time in Patent Office: Days
• US Class Current: 451/534
• CPC Class Codes: B24B 37/26 characterised by the shape of the lapping pad surface, e.g. grooved
• CPC Class Codes: B24B 57/02 for feeding of fluid, sprayed, pulverised, or liquefied grinding, polishing or lapping agents
• CPC Class Codes: B24D 11/001 Manufacture of flexible abrasive materials
• CPC Class Codes: B24D 3/28 Resins or natural or synthetic macromolecular compounds B24D3/22 takes precedence

Abstract

A polishing pad characterized by having a mechanism for supplying water to the plane of the polishing pad in contact with the article to be polished, in particular, in case the mechanism comprises a domain structure having an area of 1×10⁻⁶ m² or smaller, reduces the generation of scratches and the dust adhesion on the surface of the article to be polished, while increasing polishing rate at low dishing and erosion; hence, the product is applicable to the field of surface polishing of semiconductor thin films.

Claims

1. A polishing pad characterized by that it comprises a mechanism for supplying water to the plane of the polishing pad in contact with the article to be polished.

2. A polishing pad as claimed in claim 1, wherein the mechanism for supplying water is characterized by that it comprises a domain structure having an area of 1×

10<sup>−

6</sup> m² or smaller.

3. A polishing pad as claimed in claim 1 or 2 above, wherein the mechanism for supplying water is characterized in that it is hydrophilic, and that it has a complex structure comprising a substantially water-insoluble polymer and a resin matrix.

4. A polishing pad as claimed in claim 3 above, wherein the polymer substantially insoluble to water is characterized in that it comprises particles and/or fibrous material having a water absorptivity of 5000% or lower.

5. A polishing pad as claimed in claim 4 above, wherein said particles and/or fibrous material are characterized in that they are mixed in such a manner to account for 4 wt. % or higher but not higher than 60 wt. %.

6. A polishing pad as claimed in claim 3 above, wherein the hydrophilic polymer substantially insoluble to water is characterized in that it is a sheet-like material, and comprises a laminate of a complex structure with an organic polymer matrix.

7. A polishing pad as claimed in claim 6 above, wherein the sheet-like material is characterized in that it comprises at least one of non-woven-like, textile-like, woven-like, felt-like, porous membrane-like, film-like, and sponge-like sheet.

8. A polishing pad as claimed in claim 6 or 7 above, wherein the layers constituting the laminate are characterized in that each has a thickness of 1 μ

m or more.

9. A polishing pad as claimed in claims 6 to 8 above, wherein the pad is characterized in that the resin content and/or the type of the resin of the resin matrix differs from layer to layer.

10. A polishing pad as claimed in claims 6 to 9 above, wherein the pad is characterized in that the thickness and/or the type of the sheet-like material differs from layer to layer.

11. A polishing pad as claimed in claims 6 to 10 above, wherein it is characterized in that the sheet-like material accounts for 3 wt. % or more.

12. A polishing pad as claimed in claim 3 above, wherein the hydrophilic polymer substantially insoluble to water is characterized in that it comprises a fibrous material having an aspect ratio of 5 or higher and/or particles formed from the composite thereof.

13. A polishing pad as claimed in claims 3 to 12 above, wherein the hydrophilic polymer substantially insoluble to water is characterized in that it has nominal water content of 3% or higher.

14. A polishing pad as claimed in claims 3 to 13 above, wherein it is characterized in that, on taking the centerline average roughness Ra of a single silicon wafer having provided with an oxide film after polishing, the difference in value of Ra falls in a range of 0.2 μ

m or less with respect to the surface roughness profile generated by dressing before polishing taken as the standard.

15. A polishing pad as claimed in claims 3 to 13 above, wherein the hydrophilic polymer substantially insoluble to water is characterized in that it is mixed in such a manner substantially free from interstices.

16. A polishing pad as claimed in claims 1 to 15 above, wherein the matrix constituting the pad is characterized in that it is made of a thermosetting resin.

17. A polishing pad as claimed in claims 3 to 16 above, wherein the pad is characterized in that it has interstices in addition to the hydrophilic polymer substantially insoluble to water.

18. A polishing pad as claimed in claims 1 to 17 above, wherein the pad is characterized in that it comprises inorganic fine particles.

19. A polishing pad as claimed in claim 18 above, wherein the pad is characterized in that it comprises organic-inorganic nanocomposite and/or barium carbonate particles.

20. A polishing pad as claimed in claim 1 to 19 above, wherein the organic-inorganic nanocomposite is characterized in that it is at least one selected from a combination of a phenolic resin and silica particles, a combination of an epoxy resin and silica particles, and a combination of a polyamide resin and silica particles.

21. A polishing pad as claimed in claims 1 to 20 above, wherein the pad is characterized in that it further comprises a water-soluble substance.

22. A polishing pad as claimed in claim 21 above, wherein the pad is characterized in that the water-soluble substance accounts for 0.01 wt % to 10 wt %.

23. A polishing pad as claimed in claims 1 to 22 above, wherein the pad is characterized in that it yields a D hardness of 65 or higher.

24. A polishing pad as claimed in claims 1 to 23 above, wherein the pad is characterized in that it yields a flexural modulus of elasticity of 0.5 GPa or higher but not higher than 100 GPa.

25. A polishing pad as claimed in claims 1 to 24 above, wherein the pad is characterized in that it yields a one-hour water absorptivity of 0.8% or higher but not higher than 15%.

26. A polishing pad as claimed in claims 1 to 25 above, wherein the pad is characterized in that the water absorption rate within 5 minutes from contact with water is 3%/hr or higher.

27. A polishing apparatus characterized in that it used a polishing pad claimed in one of claims 1 to 26.

28. A polishing method characterized in that it used a polishing pad claimed in one of claims 1 to 26.

29. A method for producing a semiconductor wafer or a semiconductor chip, characterized in that processing is carried out by using a polishing pad claimed in one of claims 1 to 26.