Sputtering target

• US 5,478,456 A
• Filed: 10/01/1993
• Issued: 12/26/1995
• Est. Priority Date: 10/01/1993
• Status: Expired due to Fees

• Current Assignee: 3M Company
• Original Assignee: 3M Company
• Inventors: Mathers, James P., Hintz, Michael B., Humpal, Kathleen M.
• Primary Examiner(s): Breneman, R. Bruce
• Assistant Examiner(s): MCDONALD, RODNEY GLENN
• Application Number:
  US08/130,367
• Time in Patent Office: 816 Days
• Field of Search: 204/298.12, 204/298.13, 204/192.15, 204/192.16, 204/192.22, 204/192.23, 204/192.26, 204/192.29, 428/694 DE, 428/694 RE, 428/694 WF, 428/694 XS, 501/88, 501/152, 501/98, 264/29.6, 264/41, 264/63, 264/65, 264/501
• US Class Current: 204/192.13
• CPC Class Codes: C04B 35/013 containing carbon C04B35/103 takes precedence
• CPC Class Codes: C04B 35/505 based on yttrium oxide
• CPC Class Codes: C23C 14/08 Oxides C23C14/10 takes precedence
• CPC Class Codes: C23C 14/3414 Metallurgical or chemical aspects of target preparation, e.g. casting, powder metallurgy
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft

Abstract

Electrically conductive sputtering target comprising yttria and amorphous carbon, a method of making the same, and a method of using the same.

Claims

1. An electrically conductive sputtering target comprising (a) at least 35 volume percent yttria, based on the total volume of the target, present as a porous structure having a series of interconnecting channels, and (b) a substantially continuous amorphous carbon coating on internal surfaces of said porous structure such that said target is electrically conductive.

2. The sputtering target of claim 1 comprising at least about 75 percent by weight of said yttria, based on the total weight of said sputtering target.

3. The sputtering target of claim 1 further comprising at least one stabilizer.

4. The sputtering target of claim 1 further comprising silicon carbide as a stabilizer.

5. The sputtering target of claim 1 wherein said silicon carbide is present in an amount no greater than about 30% by volume, based on the total volume of said sputtering target.

6. The sputtering target of claim 1 wherein said amorphous carbon coating has a thickness in the range from about 5 to about 200 Å

.

7. The sputtering target of claim 1 wherein said amorphous carbon is present in the range from about 0.40 to about 2.5% by weight, based upon total weight of said target.

8. The sputtering target of claim 1, having an electrical resistivity no greater than about 3500 ohm-cm.

9. A method of preparing an electrically conductive sputtering target, the method comprising the steps of:

a) providing a green body comprising a sufficient amount of organic binder and a sufficient amount of yttria particles to provide after steps (b) and (c) an electrically conductive sputtering target comprising amorphous carbon and at least 35 volume percent yttria, based on the total volume of the target;

b) pyrolyzing said green body to provide a pyrolyzed product; and

c) firing said pyrolyzed product in a nonoxidizing atmosphere to provide an electrically conductive sputtering target comprising (i) at least 35 volume percent yttria, based on the total volume of the target, present as a porous structure having a series of interconnecting channels, and (ii) a substantially continuous amorphous carbon coating on internal surfaces of said porous structure such that said target is electrically conductive.

10. The method of claim 9, wherein said green body comprises a sufficient amount of said yttria particles to provide after step (b) an electrically conductive sputtering target comprising at least about 75 percent by weight yttria, based on the total weight of said target.

11. The method of claim 10 wherein said firing is conducted at a temperature no greater than about 1650°

C.

12. The method of claim 10 wherein said organic binder is an organic resin selected from the group consisting of phenolic, polyphenylene, polymethylphenylene, coal tar pitch, and combinations thereof.

13. The method of claim 10 wherein said green body further comprises at least one stabilizer.

14. The method of claim 10 wherein said green body further comprises a stabilizer which is silicon carbide.

15. The method of claim 10 wherein said organic binder is present in an amount sufficient to provide after steps (b) and (c) said electrically conductive sputtering target with amorphous carbon in an amount from about 0.40 to about 2.5% by weight, based upon total weight of said target.

16. The method of claim 10 wherein said target has an electrical resistivity no greater than about 3500 ohm-cm.

17. An electrically conductive sputtering target comprising a substantially continuous pore network of yttria and a substantially continuous amorphous carbon coating on internal surfaces of said pore network such that said target is electrically conductive, said target comprising at least 35 volume percent yttria, based on the total volume of said target.

18. The sputtering target of claim 17, comprising at least about 75 percent by weight of said yttria, based on the total weight of said sputtering target.

19. The sputtering target of claim 17 further comprising at least one stabilizer.

20. The sputtering target of claim 17 further comprising silicon carbide as a stabilizer.

21. The sputtering target of claim 20 wherein said silicon carbide is present in an amount no greater than about 30% by volume, based on the total volume of said sputtering target.

22. The sputtering target of claim 17 wherein said amorphous carbon coating has a thickness in the range from about 5 to about 200 Å

.

23. The sputtering target of claim 17 wherein said amorphous carbon is present in the range from about 0.40 to about 2.5% by weight, based upon total weight of said target.