Methods of manufacturing large-area sputtering targets by cold spray
In various embodiments, a joined sputtering target is formed by filling at least a portion of a gap between two discrete sputtering-target tiles with a gap-fill material, spray-depositing a spray material to form a partial joint, removing at least a portion of the gap-fill material, and, thereafter, spray-depositing the spray material to join the tiles.
1. A method of forming a joined sputtering target comprising a sputtering material, the method comprising:
disposing two discrete sputtering-target tiles comprising the sputtering material proximate each other to form an interface between the tiles, the interface comprising a gap;
filling at least a portion of the gap with a gap-fill material;
spray-depositing a spray material on at least a portion of the gap-fill material to form a partial joint;
thereafter, removing at least a portion of the gap-fill material from the interface; and
after removal of the at least a portion of the gap-fill material, spray-depositing the spray material on at least a portion of the partial joint to join the tiles and form the joined sputtering target.
2. The method of claim 1 , wherein filling the at least a portion of the gap with the gap-fill material alters a microstructure of at least one of the tiles in a region proximate the interface.
3. The method of claim 2 , further comprising, prior to spray-depositing the spray material on at least a portion of the partial joint, removing at least a portion of the altered-microstructure region.
4. The method of claim 1 , wherein the gap-fill material comprises a weld bead.
5. The method of claim 1 , wherein the gap-fill material comprises a rod shaped to fill at least a portion of the gap.
6. The method of claim 5 , wherein the rod is hollow.
7. The method of claim 1 , wherein the sputtering material comprises a mixture or alloy of at least two constituent materials.
8. The method of claim 7 , wherein the gap-fill material comprises at least one of the constituent materials.
9. The method of claim 7 , wherein the at least two constituent materials comprise Mo and Ti.
10. The method of claim 7 , wherein the spray material comprises at least one of the constituent materials.
11. The method of claim 1 , wherein the spray material comprises the sputtering material.
12. The method of claim 11 , wherein the spray material consists essentially of the sputtering material.
13. The method of claim 1 , wherein the tiles consist essentially of the sputtering material.
14. The method of claim 1 , wherein the gap-fill material comprises the sputtering material.
15. The method of claim 1 , wherein at least a portion of each of the two tiles is substantially planar.
16. The method of claim 1 , wherein at least a portion of each of the two tiles is substantially tubular.
17. The method of claim 1 , wherein the interface comprises at least one recess defined by a beveled surface of at least one of the two tiles.
18. The method of claim 17 , wherein the spray material substantially fills the at least one recess to form a surface substantially coplanar with a surface of at least one of the tiles.
19. The method of claim 17 , wherein the beveled surface is reentrant.
20. The method of claim 17 , wherein at least a portion of the beveled surface is substantially planar and forms an angle of greater than 45° with respect to a normal to a top surface of the joined sputtering target.
21. The method of claim 20 , wherein the angle is selected from the range of 45° to 60°.
22. The method of claim 17 , wherein spray-depositing the spray material on at least a portion of the gap-fill material or spray-depositing the spray material on at least a portion of the partial joint comprises spray-depositing at an angle approximately perpendicular to the beveled surface.
23. The method of claim 22 , wherein spray-depositing the spray material on at least a portion of the gap-fill material or spray-depositing the spray material on at least a portion of the partial joint comprises:
spray-depositing a first portion of the spray material at an angle approximately perpendicular to the beveled surface; and
thereafter, spray-depositing a second portion of the spray material at an angle approximately perpendicular to a top surface of the joined sputtering target.
24. The method of claim 1 , further comprising, after forming the joined sputtering target, annealing the joined sputtering target at a temperature selected from the range of approximately 480° C. to approximately 1425° C.
25. The method of claim 1 , further comprising, after forming the joined sputtering target, disposing the joined sputtering target on a backing plate.
26. The method of claim 1 , further comprising, after forming the joined sputtering target, heat treating the joined sputtering target at least proximate the spray material.
27. The method of claim 1 , wherein at least one of spray-depositing the spray material on at least a portion of the gap-fill material or spray-depositing the spray material on at least a portion of the partial joint comprises a cold-spray technique.