Methods of manufacturing high-strength large-area sputtering targets
View Patent ↗A joined sputtering target comprising a sputtering material is formed by disposing two discrete sputtering-target tiles comprising the sputtering material proximate each other, thereby forming an interface between the tiles, the interface comprising at least one of an interlocking joint therein or a recess in a top surface thereof, and spray-depositing a spray material over at least a portion of the interface, thereby joining the tiles to form the joined sputtering target.
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, thereby forming an interface between the tiles, the interface comprising at least one of an interlocking joint therein or a recess in a top surface thereof;
spray-depositing a spray material over at least a portion of the interface, thereby joining the tiles to form the joined sputtering target, the joined sputtering target having a residual stress after the spray-deposition of the spray material;
after spray-depositing the spray material, annealing the joined sputtering target at an annealing temperature, whereby the residual stress is reduced or substantially eliminated; and
after annealing, attaching the joined sputtering target to a backing plate with a joining compound, at least one of the backing plate or the joining compound having a melting point lower than the annealing temperature.
2. The method of claim 1 , wherein disposing the two tiles proximate each other comprises disposing the two tiles in contact with each other along at least a portion of the interface prior to spray-depositing the spray material.
3. The method of claim 1 , wherein at least a portion of each of the two tiles is substantially planar.
4. The method of claim 1 , wherein (i) each of the two tiles is curved so as to define at least a portion of a tube, and (ii) the backing plate is substantially tubular, the joined sputtering target being disposed on an outer curved surface of the backing plate.
5. The method of claim 1 , wherein the spray material comprises the sputtering material.
6. The method of claim 5 , wherein the spray material consists essentially of the sputtering material.
7. The method of claim 1 , wherein the tiles consist essentially of the sputtering material.
8. The method of claim 1 , wherein the sputtering material comprises a mixture or alloy of at least two constituent materials.
9. The method of claim 8 , wherein the at least two constituent materials comprise Mo and Ti.
10. The method of claim 8 , wherein the spray material comprises at least one of the constituent materials.
11. The method of claim 1 , wherein the interface comprises a recess, and the spray deposition fills at least a portion of the recess with the spray material.
12. The method of claim 1 , wherein the interface comprises a recess defined by a beveled surface of at least one of the two tiles.
13. The method of claim 12 , wherein the beveled surface is reentrant.
14. The method of claim 12 , 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.
15. The method of claim 14 , wherein the angle is selected from the range of 45° to 60°.
16. The method of claim 1 , wherein the annealing temperature is selected from the range of approximately 480° C. to approximately 1425° C.
17. The method of claim 1 , wherein the interface comprises an interlocking joint, the interlocking joint comprising a tongue-in-groove joint, a dovetail joint, a rabbet joint, a finger joint, or a spline joint.
18. The method of claim 1 , wherein the interface comprises a recess, and further comprising, prior to disposing the tiles proximate each other, beveling an edge of at least one of the tiles, the at least one beveled edge forming at least a portion of the recess.
19. The method of claim 1 , wherein spray-depositing the spray material comprises a cold spray technique.
20. The method of claim 1 , further comprising sputtering the joined sputtering target, the spray-deposited spray material substantially preventing particle generation at the interface.
21. The method of claim 1 , wherein the interface defines a plane that is not perpendicular to at least one of a top surface of the joined sputtering target or a bottom surface of the joined sputtering target.
22. The method of claim 1 , wherein the residual stress is compressive.
23. The method of claim 1 , wherein the joining compound has a melting point lower than the annealing temperature.
24. The method of claim 23 , wherein the joining compound comprises In solder.
25. The method of claim 1 , wherein spray-depositing the spray material over at least a portion of the interface comprises (i) spray-depositing a first portion of the spray material onto a top surface of at least one of the two sputtering-target tiles proximate the interface and (ii) spray-depositing a second portion of the spray material onto a bottom surface, opposite the top surface, of at least one of the two sputtering-target tiles proximate the interface.
26. The method of claim 2 , further comprising, prior to disposing the two tiles in contact with each other along at least a portion of the interface, spray-depositing a coating on at least a portion of a surface of at least one of the sputtering-target tiles, the interface comprising at least a portion of the coated surface.
27. The method of claim 26 , wherein (i) the sputtering material comprises a mixture or alloy of at least two constituent materials and (ii) the coating comprises only one of the constituent materials.
28. 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, thereby forming an interface between the tiles, the interface comprising a recess defined by a beveled surface of at least one of the two tiles; and
spray-depositing a spray material over at least a portion of the interface, thereby joining the tiles to form the joined sputtering target,
wherein (i) at least a portion of the beveled surface is neither parallel nor perpendicular to a top or bottom surface of at least one of the two tiles, and (ii) at least a portion of the spray material is spray deposited at a first angle (a) approximately perpendicular to the beveled surface and (b) not perpendicular to a top surface of the joined sputtering target.
29. The method of claim 28 , wherein spray depositing the spray material comprises:
spray depositing a first portion of the spray material at the first angle; and
thereafter, spray depositing a second portion of the spray material at a second angle, different from the first angle, that is approximately perpendicular to the top surface of the joined sputtering target.