Method of forming metal wiring line including using a first insulating film as a stopper film

• US 7,091,123 B2
• Filed: 08/30/2002
• Issued: 08/15/2006
• Est. Priority Date: 09/04/2001
• Status: Expired due to Fees

• Current Assignee: Renesas Electronics Corporation
• Original Assignee: NEC Electronics Corporation (Renesas Electronics Corporation)
• Inventors: Inoue, Tomoko, Tsuchiya, Yasuaki, Tonegawa, Takashi
• Primary Examiner(s): NGUYEN, THANH T
• Application Number:
  US10/231,175
• Publication Number:
  US 20030049927A1
• Time in Patent Office: 1,446 Days
• Field of Search: 438/622, 438626-629, 438631-634, 438637-640, 438643-645, 438/648, 438672- 65, 438684-688, 438/692, 438/693
• US Class Current: 438/633
• CPC Class Codes: H01L 21/31053 involving a dielectric removal step
• CPC Class Codes: H01L 21/3212 by chemical mechanical polishing [CMP]
• CPC Class Codes: H01L 21/7684 Smoothing; Planarisation

Abstract

In a method of forming a metal wiring line, a first insulating film is formed directly or indirectly on a semiconductor substrate. A second insulating film is formed on the first insulating film. A wiring line groove is formed to pass through the second insulating film to an inside of the first insulating film. A conductive film is formed to fill the wiring line groove and to cover the second insulating film. The conductive film and the second insulating film are removed by a first CMP polishing process, using the first insulating film as a stopper film, until the first insulating film is exposed.

Claims

1. A method of forming a metal wiring line, comprising:

forming a first insulating film over a semiconductor substrate;

forming a second insulating film on said first insulating film;

forming a wiring line groove to pass through said second insulating film to an inside of said first insulating film;

forming a barrier metal film comprising a first portion formed on an inner surface of said wiring line groove and a second portion formed on said second insulating film;

forming a conductive film to fill said wiring line groove and to cover said barrier metal film;

removing said conductive film by a first CMP polishing process, using a first slurry, until said barrier metal film is exposed; and

removing said first and second portions of said barrier metal film, said conductive film and said second insulating film by a second CMP polishing process using a second slurry which is different from said first slurry, and using said first insulating film as a stopper film, until said first insulating film is exposed,

wherein said second slurry used in said second CMP polishing process comprises abrasive particles and has a polishing selection ratio of a polishing rate of said second insulating film to a polishing rate of said first insulating film of at least 5.

2. The method according to claim 1, wherein said barrier metal film covers an inner surface of said wiring line groove and covers said second insulating film.

3. The method according to claim 1, wherein said polishing selection ratio is at least 10.

4. The method according to claim 1, wherein each of said first slurry and said second slurry comprises abrasive particles, and a diameter of said abrasive particles is in a range of 0.01 μ

m to 1 μ

m.

5. The method according to claim 1, wherein said second slurry comprises colloidal silica.

6. The method according to claim 1, wherein said first insulating film functions as said stopper film in said removing said first and second portions of said barrier metal film, said conductive film and said second insulating film.

7. The method according to claim 1, wherein said first insulating film comprises a dielectric constant lower than that of silicon dioxide.

8. The method according to claim 1, wherein said first insulating film comprises an organic insulating film.

9. The method according to claim 8, wherein a relative dielectric constant of said organic insulating film is in a range of 2.0 to 3.0.

10. The method according to claim 8, wherein said organic insulating film comprises at least one of a hydrocarbon system polymer and an aromatic polymer.

11. The method according to claim 8, wherein said organic insulating film comprises at least one of polyphenylene, poly-allyl-ether, poly-allylene, and benzocyclobutene.

12. The method according to claim 8, wherein said organic insulating film comprises a porous film.

13. The method according to claim 1, wherein said conductive film comprises copper.

14. The method according to claim 1, wherein a diameter of each of said abrasive particles is in a range of 0.02 μ

m to 0.1 μ

m.

15. The method according to claim 1, wherein said first slurry comprises a colloidal silica material.

16. The method according to claim 1, wherein said first CMP polishing process is substantially continuous.

17. The method according to claim 1, wherein said second insulating film is completely removed by said second CMP polishing process.

18. The method according to claim 1, wherein said first slurry comprises abrasive particles, said abrasive particles having diameters within 50% of an average diameter of said diameters.

19. The method according to claim 1, wherein said second insulating film comprises an inorganic insulating film.

20. The method according to claim 1, wherein said second insulating film is removed in a single step.

21. The method according to claim 1, wherein said second insulating film is removed without polishing said first insulating film.

22. The method of forming a metal wiring line according to claim 1, wherein said polishing selection ratio is at least 20:

1.

23. A method of forming a metal wiring line, comprising:

forming an organic insulating film having a dielectric constant lower than that of silicon dioxide over a semiconductor substrate, said organic insulating film comprising a first insulating film;

forming an inorganic insulating film on said first insulating film, said inorganic insulating film comprising a second insulating film;

forming a wiring line groove to pass through said second insulating film to an inside of said first insulating film;

forming a barrier metal film comprising a first portion formed on an inner surface of said wiring line groove and a second portion formed on said second insulating film;

forming a conductive film to fill said wiring line groove and to cover said barrier metal film; and

removing said conductive film by a first CMP polishing process using a first slurry until said barrier metal film is exposed;

removing said first and second portions of said barrier metal film, said conductive film and said second insulating film by a second CMP polishing process using a second slurry and using said first insulating film as a stopper film, until said first insulating film is exposed,

wherein said second slurry comprises a polishing selection ratio of a polishing rate of said second insulating film to a polishing rate of said first insulating film which is at Least 5.

24. The method according to claim 23, wherein first CMP polishing process uses said barrier metal film as a stopper film, and said second CMP polishing process said organic insulating film as a stopper film.

25. The method according to claim 23, wherein said abrasive particles comprise colloidal silica.

26. The method according to claim 23, wherein a relative dielectric constant of said organic insulating film is in a range of 2.0 to 3.0.

27. The method according to claim 23, wherein said organic insulating film comprises at least one of a hydrocarbon system polymer and an aromatic polymer.

28. The method according to claim 23, wherein said organic insulating film comprises at least one of polyphenylene, poly-allyl-ether, poly-allylene, and benzocyclobutene.

29. The method according to claim 23, wherein diameters of said abrasive particles are within 50% of an average diameter of the diameters.

30. The method according to claim 23, wherein said first CMP polishing process is substantially continuous.

31. The method according to claim 23, wherein said second insulating film is completely removed by said second CMP polishing process.

32. The method according to claim 23, wherein said organic insulating film comprises a porous film.

33. The method according to claim 23, wherein said selection ratio is at least 10.

34. The method according to claim 23, wherein said first insulating film is formed on said semiconductor substrate.

35. The method according to claim 23, wherein said first insulating film is indirectly formed on said semiconductor substrate.

36. The method according to claim 23, wherein said second insulating film is removed in a single step.

37. The method according to claim 23, wherein said second insulating film is removed without polishing said first insulating film.

38. The method of forming a metal wiring line according to claim 23, wherein said polishing selection ratio is at least 10:

1.

39. A method of forming a metal wiring line, comprising:

forming a first insulating film on a semiconductor substrate;

forming a second insulating film on said first insulating film;

forming a wiring line groove to pass through said second insulating film to an inside of said first insulating film;

forming a barrier metal film which comprises a first portion formed in said wiring line groove and a second portion formed on said second insulating film;

forming a conductive film on said barrier metal film;

removing said conductive film by a first CMP polishing process, using said barrier metal film as a stopper film, until said barrier metal film is exposed; and

removing said first and second portions of said barrier metal film and said second insulating film by a second CMP polishing process, using said first insulating film as a stopper film, until said first insulating film is exposed,

wherein said first CMP polishing process uses a first slurry and said second CMP process uses a second slurry which is different than said first slurry, and

wherein said first insulating film comprises an organic insulating film and said second slurry comprises silica.