Lithium-containing transition metal oxide target

Patent metadata

Field	Value
Publication number	US-10822690-B2
Application number	US-201615558364-A
Country	US
Kind code	B2
Filing date	Mar 17, 2016
Priority date	Mar 18, 2015
Publication date	Nov 3, 2020
Grant date	Nov 3, 2020

Abstract

A process for the formation of an LiM0 2 (e.g., LiCoO 2 ) sputtering target with a bi-modal grain size distribution (as in a hollow cylinder target body) that includes a CIP-based process involving, for example, forming or sourcing an LiMO 2 (e.g., Li—CoO 2 ) powder; dispersion and milling (e.g., wet milling); binder introduction; drying (e.g., spray drying) to form a granulate; CIP processing of the granulate into a molded shape; and a heating cycle for debinding and sintering to form a densified sintered shape. The target body produced is suited for inclusion on a sputtering target assembly (as in a rotary sputtering target assembly with a plurality of cylindrical target bodies attached to a backing support). The invention is inclusive of the resultant target bodies formed under the CIP based process as well as an induction heater based process for attachment (e.g., metal solder bonding) of the low conductivity target body(ies) of LiMO 2 (e.g., LiCoO 2 ) to a common backing support through use of an added conductive wrap or layer provided to the target body and heated with the induction heater during the attachment process.

First claim

The invention claimed is:

1. A lithium-containing transition metal oxide-based cylindrical hollow target body adapted for use in a sputtering target assembly, said cylindrical hollow target body being suitable for bonding on a backing tube so to form said sputtering target assembly, said cylindrical hollow target body having a relative density value ≥90.0%, and wherein said lithium-containing transition metal oxide consists of a metal oxide microstructure that contains a bimodal grain size distribution.

2. The cylindrical hollow target body according to claim 1 , having a relative density value superior or equal to 91.0% and inferior or equal to 99.8%.

3. The cylindrical hollow target body according to claim 1 , having a resistance value ≤5 kΩ cm.

4. The cylindrical hollow target body according to claim 2 , wherein said lithium-containing transition metal oxide has a mean grain diameter superior or equal to 5 μm and inferior or equal to 50 μm.

5. The cylindrical hollow target body according to claim 1 , wherein said lithium-containing transition metal oxide has a mean grain diameter superior or equal to 5 μm and inferior or equal to 20 μm.

6. The cylindrical hollow target body according to claim 5 , wherein each mode of said bi-modal grain size distribution is centered at a mean diameter value inferior to 50 μm.

7. The cylindrical hollow target body according to claim 6 , wherein each mode of said bi-modal grain size distribution is centered at a mean diameter value superior or equal to 5 μm and inferior or equal to 20 μm.

8. The cylindrical hollow target body according to claim 1 , wherein the lithium-containing transition metal oxide has a general formula: LiMO 2 or LiMM′O 2 , wherein M is a transition metal selected from the group consisting of: Ni, Co, Mn, Ti, Al, V, Cr, Y, Sr, Ca, Zr, Zn, Si, Mg, Ga, W, Fe, Cu, La, or at least one combination thereof, and M′ is a dopant selected from the group consisting of: Ti, Al, V, Cr, Y, Sr, Ca, Zr, Zn, Si, Mg, Ga, W, Fe, Cu, La, or at least one combination thereof.

9. The cylindrical hollow target body according to claim 8 , wherein the LiMO 2 or LiMM′O 2 lithium-containing transition metal oxide has a Li/M or Li/(M+M′) atomic ratio superior or equal to 0.90 and inferior or equal to 1.25.

10. The cylindrical hollow target body according to claim 8 , wherein the LiMM′O 2 lithium-containing transition metal oxide has a M′/M atomic ratio superior or equal to 0.001 and inferior or equal to 0.05.

11. The cylindrical hollow target body according to claim 8 , wherein the LiMO 2 lithium-containing transition metal oxide has a general formula: LiC o O 2 .

12. The cylindrical hollow target body according to claim 11 , wherein the Li/Co ratio is equal to 1.00±0.50.

13. The cylindrical hollow target body according to claim 1 , presenting an outer surface and/or an inner surface roughness superior or equal to 0.2 μm and inferior or equal to 3.0 μm.

14. The cylindrical hollow target body according to claim 1 , presenting an outer surface and/or an inner surface roughness equal to 2.5±0.25 μm.

15. The cylindrical hollow target body according to claim 1 , presenting an axial length range superior or equal to 100 mm and inferior or equal to 1000 mm.

16. The cylindrical hollow target body according to claim 1 , presenting an outer diameter superior or equal to 75 mm and inferior or equal to 175 mm, and an inner diameter superior or equal to 50 mm and inferior or equal to 160 mm.

17. The cylindrical hollow target body according to claim 1 , having a purity of at least 99.995% by weight.

18. A process for manufacturing a lithium-containing transition metal oxide-based cylindrical hollow target body, comprising the following steps:
providing a lithium-containing transition metal oxide material;
providing an aqueous solution;
contacting said lithium-containing transition metal oxide material and said aqueous solution under agitation so to form a slurry wherein said lithium-containing transition metal oxide material is dispersed in said aqueous solution;
wet-milling said slurry;
adding under agitation at least one binder in said slurry resulting in a homogenous slurry comprising said at least one binder;
spray-drying said slurry comprising said at least one binder so to form a lithium-containing transition metal oxide-based granulate; and
molding said lithium-containing transition metal oxide-based granulate in a hollow cylindrical-shaped mold under cold isostatic pressure (CIP) conditions so to form a molded body;
heating said molded body so as to remove said at least one binder; and
sintering, after said heating step, said molded body so to obtain the lithium-containing transition metal oxide cylindrical hollow target body consisting in a lithium transition metal oxide microstructure that contains a bimodal grain size distribution.

19. The process according to claim 18 , comprising a first step of machining said cylindrical hollow body so to shape it in an axial length range superior or equal to 100 mm and inferior or equal to 1000 mm, in an outer diameter superior or equal to 75 mm and inferior or equal to 175 mm, and an inner diameter superior or equal to 50 mm and inferior or equal to 160 mm.

20. The process according to claim 18 , comprising a second step of machining said cylindrical hollow body so to shape it in an outer surface and/or an inner surface roughness superior or equal to 0.2 μm and inferior or equal to 3.0 μm.

21. The process according to claim 18 , wherein the step of molding said lithium-containing transition metal oxide-based granulate is done under CIP with a pressure range between 2000 to 4000 bars.

22. The process according to claim 21 , wherein the step of molding is performed at a temperature ranging between 20° C. and 30° C.

23. The process according to claim 18 , wherein the step of wet-milling is performed so to obtain a lithium-containing transition metal oxide-based granulate comprising at least 50% of the total number of granulates with a size between 40 μm and 120 μm.

24. The process according to claim 18 , wherein the step of heating so as to remove said at least one binder is performed at a first temperature superior or equal to 150° C. and inferior or equal to 600° C., and wherein the sintering step is performed at a second temperature that is superior to the first temperature and inferior or equal to 1050° C.

25. The process according to claim 18 , comprising a step of providing a lithium-containing transition metal oxide material under a powder form having median particle size of less than 40 μm.

26. The process according to claim 18 , wherein the wet-milling step is performed so to provide suspending particles powder having a median particle size superior or equal to 0.15 μm and inferior or equal to 2.0 μm.

27. The process according to claim 19 , wherein the wet-milling step is performed so to provide suspending particles powder having a bi-modal particle size distribution wherein a first mode is centered at a first particle size value comprised between 0.1 μm and 0.3 μm, and wherein a second mode is centered at a second particle size value comprised between 1.0 μm and 7.0 μm.

28. The process according to claim 18 , wherein the wet-milling step is performed so to obtain a slurry that has a viscosity superior or equal to 30 cP and inferior or equal to 120 cP.

29. The process

Assignees

• Umicore Nv

Inventors

• Shin Jong-Won

Classifications

• H01J37/3491

  Manufacturing of targets · CPC title

• C23C14/3414 Primary

  Metallurgical or chemical aspects of target preparation, e.g. casting, powder metallurgy · CPC title

• C23C14/3407

  Cathode assembly for sputtering apparatus, e.g. Target · CPC title

• C04B2235/77

  Density · CPC title

• C04B2235/612

  Machining · CPC title