Rare-earth pre-alloyed PVD targets for dielectric planar applications

• US 20030175142A1
• Filed: 03/16/2002
• Published: 09/18/2003
• Est. Priority Date: 03/16/2002
• Status: Abandoned Application

• Current Assignee: Symmorphix, Inc. (Demaray LLC)
• Original Assignee: Symmorphix, Inc. (Demaray LLC)
• Inventors: Demerary, Richard E., Milonopoulou, Vassiliki, Mullapudi, Ravi B.
• Application Number:
  US10/101,341
• Publication Number:
  US 20030175142A1
• Time in Patent Office: Days
• US Class Current: 419/49
• CPC Class Codes: B22F 1/00 Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
• CPC Class Codes: B22F 2998/10 Processes characterised by the sequence of their steps
• CPC Class Codes: B22F 2999/00 Aspects linked to processes or compositions used in powder metallurgy
• CPC Class Codes: B22F 3/15 Hot isostatic pressing
• CPC Class Codes: B22F 9/082 atomising using a fluid using centrifugal force B22F9/10
• CPC Class Codes: C04B 2235/3217 Aluminum oxide or oxide forming salts thereof, e.g. bauxite, alpha-alumina
• CPC Class Codes: C04B 2235/3222 Aluminates other than alumino-silicates, e.g. spinel (MgAl2O4)
• CPC Class Codes: C04B 2235/3224 Rare earth oxide or oxide forming salts thereof, e.g. scandium oxide
• CPC Class Codes: C04B 2235/3418 Silicon oxide, silicic acids, or oxide forming salts thereof, e.g. silica sol, fused silica, silica fume, cristobalite, quartz or flint glass constituents C04B2235/36
• CPC Class Codes: C04B 2235/3427 Silicates other than clay, e.g. water glass
• CPC Class Codes: C04B 2235/608 Green bodies or pre-forms with well-defined density
• CPC Class Codes: C04B 2235/72 Products characterised by the absence or the low content of specific components, e.g. alkali metal free alumina ceramics
• CPC Class Codes: C04B 2235/80 Phases present in the sintered or melt-cast ceramic products other than the main phase
• CPC Class Codes: C04B 2235/94 Products characterised by their shape
• CPC Class Codes: C04B 35/18 rich in aluminium oxide
• CPC Class Codes: C04B 35/6261 Milling
• CPC Class Codes: C04B 35/6455 Hot isostatic pressing
• CPC Class Codes: C22C 1/047 comprising intermetallic compounds C22C1/0441 takes precedence
• CPC Class Codes: C23C 14/3414 Metallurgical or chemical aspects of target preparation, e.g. casting, powder metallurgy
• CPC Class Codes: H01L 21/02263 deposition from the gas or vapour phase
• CPC Class Codes: H01L 21/31604 : Deposition from a gas or vapour H01L21/31691, H01L21/31695 take precedence

Abstract

A target material for deposition of rare-earth doped optical materials is described. The rare-earth ions, for example erbium and ytterbium, is prealloyed with host materials. In some embodiments a ceramic target material can be formed by pre-alloying Er₂O₃ and/or Yb₂O₃ with Al₂O₃ and/or SiO₂. In some embodiments, a metal target material can be formed by pre-alloying Er and/or Yb with Al and/or Si. In some embodiments, ceramic or metallic tiles are formed which can be mounted on a backing plate. In some embodiments, an intermetallic mixture can be formed and flame sprayed onto the backing plate.

Claims

1. A method of forming a target for deposition chamber, comprising:

forming a pre-alloyed material with at least one rare-earth ion alloyed with at least one host material;

forming the target from the pre-alloyed material.

2. The method of claim 1, where forming a pre-alloyed material includes

mixing at least one rare-earth oxide material with at least one host oxide to form mixed material;

forming a green billet from the mixed material;

degassing the green billet to form a de-gassed green billet;

pressing the de-gassed green billet at high temperatures to form a billet of the pre-alloyed material.

3. The method of claim 2, wherein pressing the de-gassed green billet at high temperature includes applying a pressure higher than about 20 Kpsi and temperature less than about 1000 C for a time greater than about 1 hour.

4. The method of claim 2 wherein degassing the green billet includes heating the green billet includes heating the green billet to a temperature greater than about 500 C.

5. The method of claim 2, wherein mixing at least one rare-earth oxide material with at least one host oxide includes barrel mixer in relative concentrations such that the rare-earth ions make up less than about 10 cat. % of the mixed material.

6. The method of claim 5, wherein the mixed material includes up to about 37% Al₂O₃, about 57.0% SiO₂ or less, about 2.5% of Er₂O₃ or less, and about 2.5% of Yb₂O₃ or less.

7. The method of claim 6, wherein the mixed material includes about 57.5 cat. % of SiO₂, about 37.5 cat. % of Al₂O₃, about 2.5 cat. % of Er₂O₃, and about 2.5 cat. % of Yb₂O₃.

8. The method of claim 6, wherein the mixed material includes about 54.5 cat. % of SiO₂, about 44.5 cat. % of Al₂O₃, and about 1.0 cat. % of Er₂O₃.

9. The method of claim 6, wherein the mixed material includes about 54.0 cat. % of SiO₂, about 44.6 cat. % of Al₂O₃, about 1.0 cat. % of Er₂O₃, and about 0.4 cat. % of Yb₂O₃.

10. The method of claim 2, wherein forming a green billet includes pressing the mixed material at room temperature.

11. The method of claim 10, wherein pressing placing the mixed material into a form and applying a pressure greater than about 30 Kpsi to the mixed material.

12. The method of claim 2, wherein forming the target includes

cutting and machining the billet to form tiles;

mounting the tiles on a backing plate to form the target.

13. The method of claim 12, wherein mounting the tiles on a backing plate to form the target includes

sputter coating a side of each of a number of tiles to form a diffusion layer;

tinning the diffusion layer with a solder material; and

soldering the tiles to the backing plate.

14. The method of claim 1, wherein forming a pre-alloyed material with at least one rare-earth ion alloyed with at least one host material includes

atomizing at least one rare-earth ion with at least one metal host to form a pre-alloyed powder;

and

mixing the pre-alloyed powder to form mixed powder.

15. The method of claim 14, wherein forming the target from the pre-alloyed material includes flame spraying the mixed powder onto a backing plate.

16. The method of claim 14, wherein atomizing at least one rare-earth ion with at least one metal host includes atomizing preselected proportions of erbium and ytterbium with aluminum.

17. The method of claim 14, further including adding silicon to the pre-alloyed powder before barrel mixing.

18. The method of claim 17, wherein the mixed powder includes up to about 5 cat. % of rare earth ions.

19. The method of claim 18, wherein the mixed power includes up to about 35% of Al, about 65% Si or less, about 1.0% of Er or less and about 1.0% Yb or less.

20. The method of claim 19, wherein the mixed powder includes about 57.4 cat. % of Si, about 41.0 cat. % of Al, about 0.8 cat. % of Er and about 0.8 cat. % of Yb.

21. The method of claim 19, wherein the mixed powder includes about 57.4 cat. % of Si, about 41.0 cat. % of Al, and about 1.5 cat. % of Er.

22. The method of claim 14, wherein forming the pre-alloyed material includes

degassing the mixed powder to form a green billet;

pressing the green billet to form a billet of pre-alloyed material.

23. The method of claim 22, wherein degassing the mixed powder includes heating the powder to a temperature of about 400 C.

24. The method of claim 23, wherein pressing the green billet includes heating the green billet to a temperature higher than about 450 C at a pressure higher than about 15 Kpsi.

25. The method of claim 14, wherein forming the target includes

cutting and machining the billet to form tiles;

and

mounting the tiles on a backing plate to form the target.

26. A target material for a PVD deposition chamber, comprising:

at least one host constituent; and

at least one rare-earth ion pre-alloyed with some or all of the at least one host constituent.

27. The target material of claim 26, wherein the host constituent includes at least one metal oxide.

28. The target material of claim 27, wherein the rare-earth ions make up less than about 10 cat. % of the mixed material.

29. The method of claim 28, wherein the target material includes more than or equal to about 37% Al₂O₃, less than or equal to about 57.0% SiO₂, less than or equal to about 2.5% of Er₂O₃, and less than or equal to about 2.5% of Yb₂O₃.

30. The target material of claim 29, wherein the at least one host constituent includes about 57.5 cat. % Of SiO₂ and about 37.5 cat. % of Al₂O₃ and the at least one rare-earth ion includes about 2.5 cat. % of Er₂O₃, and about 2.5 cat. % of Yb₂O₃.

31. The target material of claim 29, wherein the at least one host constituent includes about 54.5 cat. % Of SiO₂ and about 44.5 cat. % of Al₂O₃ and the at least one rare-earth ion includes about 1.0 cat. % of Er₂O₃.

32. The target material of claim 29, wherein the at least one host constituent includes about 54.0 cat. % Of SiO₂ and about 44.6 cat. % of Al₂O₃ and the at least one rare-earth ion includes about 1.0 cat. % of Er₂O₃ and about 0.4 cat. % of Yb₂O₃.

33. The target material of claim 26, wherein the host constituent includes at least one metal.

34. The target material of claim 33, wherein the rare-earth ions make up about 5 cat % of the mixed material.

35. The method of claim 34, wherein the target includes more than about 35% of Al, less than about 65% Si, less than about 1.0% of Er and less than about 1.0% Yb.

36. The target material of claim 35, wherein the at least one host constituent includes about 57.4 cat. % of Si and about 41.0 cat. % of Al and the at least one rare-earth ions include about 0.8 cat. % of Er and about 0.8 cat. % of Yb.

37. The target material of claim 35, wherein the at least one host constituent includes about 57.4 cat. % of Si and about 41.0 cat. % of Al and the at least one rare-earth ions includes about 1.5 cat. % of Er.

38. A method of forming a target for a PVD chamber, comprising:

melting a mixture containing rare earth ions in an Al₂O₃ crucible;

cooling the mixture;

forming a power from the cooled mixture;

HIPing the powder to form target material; and

forming the target from the target material.

39. The method of claim 38, wherein melting the mixture includes heating with induction heating.

40. The method of claim 38, wherein melting the mixture includes heating with e-beam heating.