Tantalum sputtering target and method of fabrication

• US 20070089815A1
• Filed: 02/10/2005
• Published: 04/26/2007
• Est. Priority Date: 02/10/2005
• Status: Active Grant

• Current Assignee: Global Advanced Metals, USA, Inc. (Global Advanced Metals Pty Ltd.)
• Original Assignee: Global Advanced Metals, USA, Inc. (Global Advanced Metals Pty Ltd.)
• Inventors: Levit, Vladimir, Wickersham, Charles, Alexander, P.
• Granted Patent: US 7,998,287 B2
• Time in Patent Office: Days
• US Class Current: 148/668
• CPC Class Codes: B21B 1/02 for rolling heavy work, e.g. ingots, slabs, blooms, or billets, in which the cross-sectional form is unimportant ; Rolling combined with forging or pressing
• CPC Class Codes: B21H 1/02 discs; disc wheels
• CPC Class Codes: C22C 27/02 Alloys based on vanadium, niobium, or tantalum
• CPC Class Codes: C22F 1/18 High-melting or refractory metals or alloys based thereon
• CPC Class Codes: C23C 14/3414 Metallurgical or chemical aspects of target preparation, e.g. casting, powder metallurgy
• CPC Class Codes: Y10T 428/12243 Disk

Abstract

A process is described for processing metal which includes clock rolling a metal plate until the desired thickness is achieved to form a rolled plate. Sputtering targets and other metal articles are further described.

Claims

1. A process for processing metal comprising clock rolling a metal plate until the desired thickness is achieved to form a rolled plate.

2. The process of claim 1, wherein the metal plate, prior to said clock rolling, is obtained by forging a billet to form said metal plate.

3. The process of claim 1, wherein said metal plate is circular.

4. The process of claim 2, wherein said billet is obtained by extruding or swaging a metal ingot to a desired diameter to form an extruded or swaged ingot and, optionally, cutting said extruded or swaged ingot.

5. The process of claim 4, wherein said metal ingot has a starting diameter of about 7 inches or more and said billet has a diameter of from about 3 inches to about 6 inches.

6. The process of claim 1, further comprising annealing said rolled plate.

7. The process of claim 4, further comprising annealing said extruded or swaged ingot.

8. The process of claim 1, wherein said clock rolling is with a rotation of 100 degrees to 170 degrees after each rolling pass.

9. The process of claim 1, wherein each clock rolling is with a rotation of about 120 degrees after each rolling pass.

10. The process of claim 1, further comprising annealing said rolled plate and wherein no annealing occurs beforehand throughout said process.

11. The process of claim 1, wherein a true strain reduction of at least 3.0 is imparted to the rolled plate during said process.

12. The process of claim 1, wherein a true strain reduction of at least 4.0 is imparted to the rolled plate during said process.

13. The process of claim 1, wherein a true strain reduction of from about 3.0 to about 6.0 is imparted to the rolled plate during said process.

14. The process of claim 4, wherein a true strain imparted to the extruded or swaged ingot is from about 0.5 to about 2.0.

15. The process of claim 4, wherein said billet has a ratio of billet length to billet diameter of about 3 or less.

16. The process of claim 2, wherein said forging is axial forging.

17. The process of claim 16, wherein said axial forging imparts a true strain of from about 0.75 to about 2.0.

18. The process of claim 1, wherein said clock rolling comprises clock rolling on one side of said metal plate and then clock rolling on the opposite side of said metal plate.

19. The process of claim 18, wherein said clock rolling on said one side and said opposite side is the same or about the same with regard to the number of rolling passes.

20. The process of claim 1, wherein said rolling pass imparts a true strain of from about 0.02 to about 0.5.

21. The process of claim 1, wherein said clock rolling imparts a true strain of from about 1.0 to about 2.0.

22. The method of claim 1, comprising at least 3 rolling passes.

23. The method of claim 1, comprising at least 6 rolling passes.

25. The process of claim 4, wherein said ingot has a starting diameter of from about 10 to 14 inches.

26. The process of claim 1, wherein said metal plate is tantalum plate.

27. The process of claim 1, wherein said rolled plate is a sputtering target.

24. A method to reduce or control earing in metal plate comprising clock rolling said metal plate with at least two rolling passes.

28. A process for making a circular metal article comprising processing a metal ingot having a cylindrical shape so that the cylindrical shape is maintained throughout said process.

29. A BCC metal article that deforms isotropically in any direction within the plane of the metal article.

30. The BCC metal article of claim 29, wherein the BCC metal article is a disk.

31. The BCC metal article of claim 29, wherein said BCC metal article is a sputter target disk.

32. The BCC metal article of claim 29, wherein said BCC metal article is a tantalum article.

33. The BCC metal article of claim 29 wherein said BCC metal article is a niobium article.

34. A BCC metal plate comprising an axial symmetrical texture with an axis.

36. The BCC metal plate of claim 34, wherein said axis is a primary axial <

111>

crystallographic texture.

37. The BCC metal plate of claim 34, wherein said axis is a primary axial <

100>

crystallographic texture.

38. The BCC metal plate of claim 34, wherein said BCC metal plate is a tantalum plate.

39. The BCC metal plate of claim 34, wherein said BCC metal plate is a niobium plate.

40. The BCC metal plate of claim 34, wherein said BCC metal plate is a BCC metal sputter target.

41. The BCC metal plate of claim 40, further comprising a backing plate attached to said BCC metal sputter target.

42. The BCC metal plate of claim 40, wherein said BCC metal plate is a tantalum plate.

43. The BCC metal plate of claim 40, wherein said BCC metal plate is a niobium plate.

47. The BBC metal plate of claim 40, wherein said BBC metal plate has at least one of the following characteristics:

a) a purity of at least 95%,

b) an average grain size of 150 microns or less.

35. A BCC metal plate having the pole figures of FIG. 3.

44. A metal article having a primary texture, wherein said metal article has a percent texture banding area of less than 0.5% that is inconsistent or non-uniform with respect to the primary texture present in said metal article.

45. The metal article of claim 44, wherein said metal article is a BCC metal article.

46. The metal article of claim 44, wherein said metal article is a tantalum article, niobium article, or alloys containing tantalum, niobium, or both.

48. The metal article of claim 46, wherein said primary texture is a primary (111) texture.

49. The metal article of claim 48, wherein said percent texture banding area is with respect to (100) texture banding.

50. The metal article of claim 46, wherein said metal article has a uniform mixed (111):

(100) texture.

51. The metal article of claim 46, wherein said metal article is a sputter target blank.

52. The metal article of claim 46, wherein said metal article is a sputter target that is bonded to a backing plate.

53. The metal article of claim 46, wherein said metal article is a plate, billet, rod, or disk.

54. The metal article of claim 46, wherein percent banding area is from 0.1 to less than 0.5%.

55. The metal article of claim 46, wherein percent banding area is from 0.1 to 0.4%.

56. The metal article of claim 46, wherein said percent banding area is from 0.1 to 0.25%.

57. The metal article of claim 46, wherein said metal article is a tantalum article.

58. The metal article of claim 57, wherein said tantalum article is a sputter target blank.

59. The metal article is claim 57, wherein said tantalum article is a sputter target bonded to a backing plate.