Process and apparatus for the manufacture of a sputtering target

• US 20060233965A1
• Filed: 02/23/2004
• Published: 10/19/2006
• Est. Priority Date: 02/24/2003
• Status: Active Grant

• Current Assignee: Tekna Plasma Systems Inc.
• Original Assignee: Tekna Plasma Systems Inc.
• Inventors: Jurewicz, Jerzy W., Boulos, Maher I.
• Granted Patent: US 7,964,247 B2
• Time in Patent Office: Days
• US Class Current: 427/446
• CPC Class Codes: C23C 14/3414 Metallurgical or chemical aspects of target preparation, e.g. casting, powder metallurgy
• CPC Class Codes: C23C 4/12 characterised by the method of spraying
• CPC Class Codes: C23C 4/134 Plasma spraying
• CPC Class Codes: C23C 4/185 Separation of the coating from the substrate
• CPC Class Codes: H01J 37/3491 Manufacturing of targets
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft

Abstract

A process for the manufacture of sputtering target comprises the steps of i) providing a substrate; ii) plasma melting of a material selected to form the sputtering target, yielding droplets of molten material; and iii) deposition of the droplets onto the substrate, yielding a sputtering target comprised of the coated layer of the material on the substrate. In some application, it might be preferable that the substrate be a temporary substrate and iv) to join the coated temporary target via its coated layer to a permanent target backing material; and v) to remove the temporary substrate, yielding a sputtering target comprised of the coated layer of the material on the permanent target backing material. The plasma deposition step is carried out at atmospheric pressure or under soft vacuum conditions using, for example, d.c. plasma spraying, d.c. transferred arc deposition or induction plasma spraying. The process is simple and does not require subsequent operation on the resulting target.

Claims

1. A process for the manufacture of a sputtering target comprising:

i) providing a substrate having a coating-receiving surface;

ii) plasma melting in-flight of a target material selected to form the sputtering target in powder form, yielding droplets of molten target material; and

iii) deposition of said droplets onto said coating-receiving surface of said substrate, yielding a sputtering target comprised of a coated layer of said target material on said coating-receiving surface of said substrate.

2. A process as recited in claim 1, wherein said substrate is a used and depleted target.

3. A process as recited in claim 1, wherein said substrate is a temporary substrate;

the process further comprising;

iv) joining said temporary substrate via said coated layer to a permanent target backing material; and

v) removing said temporary substrate, yielding a sputtering target comprised of said coated layer of said target material on said permanent target backing material.

4. A process as recited in claim 3, wherein said temporary substrate includes stress relief features.

5. A process as recited in claim 4, wherein said stress features are in the form of spiral or radial cuts.

6. A process as recited in claim 3, further comprising iii1) performing a heat treatment of said coated layer prior to step iv).

7. A process as recited in claim 3, further comprising iii1) providing said coated layer with stress relieving markings prior to step iv).

8. A process as recited in claim 3, wherein said temporary substrate is pre-coated with a control layer;

whereby, in operation, said control layer allowing for at least one of facilitating the removing of said temporary substrate in step v) and avoiding contamination of said coated layer by preventing diffusion between said temporary substrate and said coated layer.

9. A process as recited in claim 8, wherein said control layer is deposited onto said temporary substrate by sputtering or using a chemical vapor deposition technique.

10. A process as recited in claim 8, wherein said control layer is made of an inert material.

11. A process as recited in claim 3, wherein, in step iv), joining said temporary substrate via said coated layer to a permanent target backing material is done using at least one of soldering or epoxy.

12. A process as recited in claim 3, wherein, in step v), said temporary substrate is mechanically removed.

13. A process as recited in claim 12, wherein in step v), said temporary substrate is mechanically removed by machining and/or etching.

14. A process as recited in claim 1, wherein steps ii) and iii) are performed using a plasma apparatus selected from the group consisting of a direct current (d.c.) plasma jet, a d.c. plasma transfer arc, and a radio frequency (r.f.) induction plasma spraying apparatus.

15. A process as recited in claim 14, wherein said plasma apparatus is operated under atmospheric or vacuum deposition conditions.

16. A process as recited in claim 14, wherein said plasma apparatus is a d.c. plasma transfer arc wherein said substrate acting as the anode.

17. A process as recited in claim 14, wherein said radio frequency (r.f.) induction plasma spraying apparatus includes a Laval contraction/expansion nozzle provided for operation of said r.f induction plasma spraying apparatus under supersonic or hypersonic flow condition.

18. A process as recited in claim 1, wherein said substrate is made of substrate material selected from the group consisting of a refectory metal, a ceramic, and a carbon-based composite material.

19. A process as recited in claim 18, wherein said refectory metal is molybdenum or tungsten.

20. A process as recited in claim 18, wherein said ceramic is selected from the group consisting of silica, alumina, zirconia, silicon nitride, silicon carbide and boron nitride.

21. A process as recited in claim 18, wherein said carbon-based composite material is graphite.

22. A process as recited in claim 1, wherein said substrate is a generally flat disk.

23. An apparatus for the manufacture of a sputtering target comprising:

a plasma torch for melting of a material selected to form the sputtering target, yielding droplets of molten material and for deposition of said droplets onto a coating-receiving surface of a substrate, yielding a sputtering target comprised of a coated layer of said material on said coating-receiving surface of said substrate.

24. An apparatus as recited in claim 23, wherein said plasma torch is selected from the group consisting of a direct current (d.c.) plasma jet, a d.c. plasma transfer arc, and a radio frequency (r.f.) induction plasma spraying apparatus.

25. An apparatus as recited in claim 23, wherein said plasma torch is a d.c. plasma transfer arc;

said substrate acting as the anode.

26. An apparatus as recited in claim 23, wherein said radio frequency (r.f.) induction plasma spraying apparatus includes a Laval contraction/expansion nozzle.

27. An apparatus as recited in claim 23, wherein said plasma torch is of the r.f. induction plasma spraying type and is mounted on top of a vacuum deposition chamber.

28. An apparatus as recited in claim 27, wherein said plasma torch is oriented downwardly and includes an exit nozzle;

said apparatus further comprising a moving support in said vacuum deposition chamber for receiving said substrate and for maintaining said substrate at a fixed distance from said plasma torch