Deposition of LiCoO2

• US 20060134522A1
• Filed: 12/07/2005
• Published: 06/22/2006
• Est. Priority Date: 12/08/2004
• Status: Active Grant

• Current Assignee: Demaray LLC
• Original Assignee: Demaray LLC
• Inventors: Zhang, Hongmei, Shao, May, Demaray, Richard E.
• Granted Patent: US 8,636,876 B2
• Time in Patent Office: Days
• US Class Current: 429/231.300
• CPC Class Codes: C23C 14/08 Oxides C23C14/10 takes precedence
• CPC Class Codes: C23C 14/35 by application of a magnetic field, e.g. magnetron sputtering C23C14/3457 takes precedence
• CPC Class Codes: C23C 14/5806 Thermal treatment
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/0562 Solid materials
• CPC Class Codes: H01M 10/0585 of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators
• CPC Class Codes: H01M 2004/028 Positive electrodes
• CPC Class Codes: H01M 2300/002 Inorganic electrolyte
• CPC Class Codes: H01M 2300/0071 Oxides
• CPC Class Codes: H01M 4/0423 Physical vapour deposition
• CPC Class Codes: H01M 4/0426 Sputtering
• CPC Class Codes: H01M 4/0428 Chemical vapour deposition
• CPC Class Codes: H01M 4/0471 involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis
• CPC Class Codes: H01M 4/131 Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
• CPC Class Codes: H01M 4/1391 of electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
• CPC Class Codes: H01M 4/525 of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
• CPC Class Codes: H01M 4/66 Selection of materials
• CPC Class Codes: H01M 4/661 Metal or alloys, e.g. alloy coatings H01M4/669 take precedence
• CPC Class Codes: H01M 4/667 in the form of layers, e.g. coatings
• CPC Class Codes: H01M 6/185 with oxides, hydroxides or oxysalts as solid electrolytes
• CPC Class Codes: H01M 6/188 : Processes of manufacture
• CPC Class Codes: H01M 6/46 : of flat cells
• CPC Class Codes: Y02E 60/10 : Energy storage using batteries
• CPC Class Codes: Y02P 70/50 : Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y10T 29/49115 : including coating or impregnating

Abstract

In accordance with the present invention, deposition of LiCoO₂ layers in a pulsed-dc physical vapor deposition process is presented. Such a deposition can provide a low-temperature, high deposition rate deposition of a crystalline layer of LiCoO₂ with a desired <101> or <003> orientation. Some embodiments of the deposition addresses the need for high rate deposition of LiCoO₂ films, which can be utilized as the cathode layer in a solid state rechargeable Li battery. Embodiments of the process according to the present invention can eliminate the high temperature (>700° C.) anneal step that is conventionally needed to crystallize the LiCoO₂ layer. Some embodiments of the process can improve a battery utilizing the LiCoO₂ layer by utilizing a rapid thermal anneal process with short ramp rates.

Claims

1. A method of depositing a LiCoO₂ layer, comprising:

placing a substrate in a reactor;

flowing a gaseous mixture including argon and oxygen through the reactor; and

applying pulsed DC power to a target formed of LiCoO₂ positioned opposite the substrate,

wherein a crystalline layer of LiCoO₂ is deposited over the substrate.

2. The method of claim 1, further including applying an RF bias to the substrate.

3. The method of claim 1, wherein the crystalline layer is <

101>

oriented.

4. The method of claim 1, wherein the crystalline layer is <

003>

oriented.

5. The method of claim 1, wherein a grain size of the crystalline layer is between about 750 Å

and about 1700 Å

.

6. The method of claim 1 wherein the substrate is a material chosen from a set comprised of silicon, polymers, glasses, ceramics, and metals.

7. The method of claim 1, further including preheating the substrate to a temperature of about 200°

C.

8. The method of claim 1, wherein the substrate is a low temperature substrate.

9. The method of claim 8, wherein the low temperature substrate is one of a set of substrates including glass, plastic, and metal foil.

10. The method of claim 1, further including depositing an oxide layer on the substrate.

11. The method of claim 10, wherein the oxide layer is a silicon dioxide layer.

12. The method of claim 3, wherein the crystalline layer is deposited at a rate of greater than 1 μ

m per hour.

13. The method of claim 1 wherein the target is a ceramic LiCoO₂ sputter target with a resistance measured across about 4 cm of surface of less than about 500 kΩ

.

14. The method of claim 1, further including depositing a metal layer on the substrate.

15. The method of claim 14, wherein the metal layer is iridium.

16. The method of claim 14, wherein the metal layer is platinum.

17. The method of claim 1, further including annealing the crystalline layer with a low thermal budget.

18. The method of claim 17, wherein annealing the crystalline layer includes annealing to 700°

C. in a rapid thermal anneal process for a period of time less than about 10 minutes.

19. The method of claim 14, further including annealing the LiCoO₂ layer at a temperature of less than or equal to about 500°

C.

20. The method of claim 14, further including annealing the LiCoO₂ layer at a temperature of less than or equal to about 400°

C.

21. A battery structure, comprising:

a crystalline LiCoO₂ layer deposited over a low-temperature substrate.

22. The structure of claim 21, further including a conducting layer deposited between the crystalline LiCoO₂ layer and the low-temperature substrate.

23. The structure of claim 22, wherein the conducting layer is an iridium layer.

24. The structure of claim 22, wherein the conducting layer is a platinum layer.

25. The structure of claim 21, further including a LiPON layer deposited over the LiCoO₂ layer.

26. The structure of claim 21, further including a second conducting layer deposited over the LiCoO₂ layer.

27. A stacked battery structure, comprising:

one or more battery stacks deposited on a thin substrate, wherein each battery stack comprises;

a conducting layer,

a LiCoO₂ layer deposited as a crystalline layer over the conducting layer,

a LiPON layer deposited over the crystalline LiCoO₂ layer,

an anode layer deposited over the LiPON layer; and

a top conducting layer deposited over the one or more battery stacks.

28. The stacked battery structure of claim 27, wherein the battery stacks form a parallel stacked battery structure.

29. The stacked battery structure of claim 27, wherein the battery stacks form a series stacked battery structure.

30. The stacked battery structure of claim 27, wherein the conducting layer is a metal layer deposited on a substrate.

31. The stacked battery structure of claim 30, wherein the metal layer is an iridium layer.

32. The stacked battery structure of claim 30, wherein the metal layer is a platinum layer.

33. The stacked battery structure of claim 30, wherein the substrate is a low temperature substrate.

34. The stacked battery structure of claim 27, wherein the conducting layer is a metallic foil.

35. The stacked battery structure of claim 34, wherein the metallic foil is formed of a metal from a group consisting of copper, gold, platinum, aluminum, stainless steel and other nickel or cobalt based super alloy.

36. A method of producing a battery, comprising:

loading a substrate into a cluster tool;

depositing a crystalline LiCoO₂ layer over a conducting layer in a chamber of the cluster tool with a pulsed-dc PVD process.

37. The method of claim 36, wherein depositing a crystalline LiCoO₂ layer includes depositing crystalline LiCoO₂ through a mask.

38. The method of claim 36, further including

depositing a conducting layer on the substrate.

39. The method of claim 36, further including depositing a LiPON layer over the LiCoO₂ layer.

40. The method of claim 39, further including deposition an anode over the LiPON layer.

41. The method of claim 40, further including depositing a conducting layer over the anode.

42. The method of claim 36, wherein the conducting layer is an iridium layer.

43. A fixture for holding a thin substrate, comprising:

a top portion; and

a bottom portion, wherein

the thin substrate is held when the top portion is attached to the bottom portion.