Nitrided valve metal material and method of making same
View Patent ↗Valve metal material, including a valve metal, a nitride layer located on the valve metal, and an oxide layer located on the nitride layer is described. Methods of forming such a valve metal material are also described. The method includes forming an oxide layer onto the valve metal and then forming a nitride layer between the oxide layer and the valve metal.
1. A valve metal material comprising:
a valve metal formed from powder;
a nitride layer located on said valve metal; and
an oxide layer located on said nitride layer.
2. The valve metal material of claim 1 , wherein said valve metal comprises tantalum, said nitride layer comprises tantalum nitride, and said oxide layer comprises tantalum pentoxide.
3. The valve metal material of claim 2 , wherein said valve metal is an anode or a pressed body or a sintered body.
4. A capacitor comprising the valve metal material of claim 3 .
5. A capacitor comprising the valve metal material of claim 2 .
6. The valve metal material of claim 1 , wherein said valve metal comprises niobium, said nitride layer comprises niobium nitride, and said oxide layer comprises niobium pentoxide.
7. The valve metal material of claim 6 , wherein said valve metal is an anode or a pressed body or a sintered body.
8. A capacitor comprising the valve metal material of claim 7 .
9. A capacitor comprising the valve metal material of claim 6 .
10. The valve metal material of claim 1 , wherein said valve metal material is a pressed body of said valve metal.
11. A capacitor comprising the valve metal material of claim 10 .
12. The valve metal material of claim 1 , wherein said valve metal is an anode.
13. A capacitor comprising the valve metal material of claim 12 .
14. The valve metal material of claim 1 , wherein said valve metal is a sintered body.
15. A capacitor comprising the valve metal material of claim 14 .
16. The valve metal material of claim 1 , wherein said nitride layer is a plasma nitrided layer.
17. A capacitor comprising the valve metal material of claim 16 .
18. The valve metal material of claim 1 , wherein said nitride layer is at least about 0.1 nm thick.
19. A capacitor comprising the valve metal material of claim 18 .
20. The valve metal material of claim 1 , wherein said nitride layer is from about 0.5 to about 10 nm thick.
21. A capacitor comprising the valve metal material of claim 20 .
22. The valve metal material of claim 1 , wherein said oxide layer is an anodized oxide layer.
23. A capacitor comprising the valve metal material of claim 22 .
24. The valve metal material of claim 1 , wherein said oxide layer comprises a dielectric layer.
25. A capacitor comprising the valve metal material of claim 24 .
26. The valve metal material of claim 1 , wherein said valve metal is tantalum.
27. A capacitor comprising the valve metal material of claim 26 .
28. The valve metal material of claim 1 , wherein said valve metal is niobium.
29. A capacitor comprising the valve metal material of claim 28 .
30. The valve metal material of claim 1 , wherein said valve metal is a tantalum alloy or a niobium alloy.
31. A capacitor comprising the valve metal material of claim 30 .
32. A capacitor comprising the valve metal material of claim 1 .
33. A method of forming a valve metal material comprising a valve metal formed from powder, a nitride layer located on said valve metal, and an oxide layer located on said nitride layer, said method comprising:
(a) forming said oxide layer onto said valve metal; and
(b) forming said nitride layer between said oxide layer and said valve metal.
34. The method of claim 33 , wherein said valve metal comprises tantalum, said oxide layer comprises tantalum pentoxide, and said nitride layer comprises tantalum nitride.
35. The method of claim 33 , wherein said valve metal comprises niobium, said oxide layer comprises niobium pentoxide, and said nitride layer comprises niobium nitride.
36. The method of claim 33 , wherein said valve metal material is a pressed body of said valve metal.
37. The method of claim 33 , wherein said valve metal is an anode.
38. The method of claim 33 , wherein said valve metal is a sintered body.
39. The method of claim 33 , wherein step (a) comprises anodizing said valve metal.
40. The method of claim 33 , wherein said oxide layer comprises a dielectric layer.
41. The method of claim 33 , wherein step (b) comprises plasma nitriding said valve metal having said oxide layer.
42. The method of claim 41 , wherein said plasma nitriding is in the presence of a plasma comprising a nitrogen source.
43. The method of claim 41 , wherein said plasma nitriding is in the presence of a plasma comprising a nitrogen gas.
44. The method of claim 33 , wherein said nitride layer is formed to a thickness of at least about 0.1 nm.
45. The method of claim 33 , wherein said nitride layer is formed to a thickness of from about 0.5 to about 10 nm.