Sputter targets and methods of forming same by rotary axial forging
View Patent ↗A method of making sputter targets using rotary axial forging is described. Other thermomechanical working steps can be used prior to and/or after the forging step. Sputter targets are further described which can have unique grain size and/or crystal structures.
1. A method of forming a sputter target comprising rotary axial forging of an ingot derived preform to the shape and size of said sputter target.
2. The method of claim 1 , wherein said ingot derived preform is a valve metal or refractory metal.
3. The method of claim 1 , wherein said ingot derived preform is a tantalum preform or alloy thereof.
4. The method of claim 1 , wherein said ingot derived preform is a titanium preform or alloy thereof.
5. The method of claim 1 , wherein said ingot derived preform is a niobium preform or alloy thereof.
6. The method of claim 1 , wherein said ingot derived preform is a cobalt, copper, aluminum, gold, or silver preform, or alloys thereof.
7. The method of claim 1 , wherein said ingot derived preform comprises tantalum, niobium, titanium, combinations thereof, or alloys thereof.
8. The method of claim 1 , further comprising thermomechanically working said ingot derived preform prior to said rotary axial forging.
9. The method of claim 1 , further comprising reducing the diameter of said ingot derived preform by working of said preform prior to said rotary axial forging.
10. The method of claim 9 , wherein said reducing in diameter is achieved by forging, rolling, or combinations thereof.
11. The method of claim 9 , wherein said ingot derived preform is reduced in diameter by at least 5%.
12. The method of claim 1 , wherein said ingot derived preform is annealed prior to said rotary axial forging.
13. The method of claim 1 , further comprising annealing said ingot derived preform at a temperature of from about 900° C. to about 1200° C. for a time of from about 60 minutes to about 240 minutes prior to said rotary axial forging step.
14. The method of claim 1 , wherein said rotary axial forging is achieved by rotating the ingot derived preform at a speed of from about 30 rpms to about 300 rpms and wherein said rotary axial forging has an upper platen which rotates at a speed of 30 rpms to about 300 rpms during said rotary axial forging step.
15. The method of claim 1 , wherein said ingot derived preform is a billet, rod, or cylinder.
16. The method of claim 1 , wherein said shape and size of said sputter target is not the finished shape and size of a sputter target and wherein said method further comprises subjecting said sputter target to further thermomechanical working in order to obtain the desired shape and size of a finished sputter target.
17. The method of claim 1 , wherein said method further comprises machining at least one surface of said sputter target.
18. The method of claim 1 , further comprising affixing said sputter target to a backing plate.
19. The method of claim 1 , further comprising affixing at least one interlayer to said sputter target or to said backing plate, or both and then affixing said target, plate, and interlayer together to form a target assembly.
20. The method of claim 1 , further comprising rolling, flattening, milling, grinding, lapping, polishing, or combinations thereof to said ingot derived preform or to said sputter target or to both.
21. The method of claim 1 , wherein said ingot derived preform is cylindrical in shape and has a height that is no more than 3 times the diameter.
22. The method of claim 1 , wherein said ingot derived preform is reduced in diameter by at least 10%.
23. The method of claim 1 , wherein said rotary axial forging occurs in a closed die.
24. The method of claim 23 , wherein said closed die is in the shape of the sputter target.
25. The method of claim 1 , wherein said sputter target has an average grain size of from about 20 to about 100 μm.
26. The method of claim 25 , wherein the sputter target comprises aluminum, copper, tantalum, niobium, titanium, platinum, gold, nickel, iron, vanadium, molybdenum, tungsten, silver, palladium, iridium, zirconium, hafnium or alloys thereof, or combinations thereof.
27. The method of claim 25 , wherein said sputter target is tantalum with purity of at least 99.99%.
28. The method of claim 25 , wherein said sputter target is tantalum with an average crystallographic texture that is primary (111).
29. The method of claim 25 , wherein said sputter target is tantalum with an average crystallographic texture that is primary (110).
30. The method of claim 1 , wherein said rotary axial forging occurs in two or more forging steps of the ingot derived preform.