Systems and methods for locally reducing oxides

Patent metadata

Field	Value
Publication number	US-9818535-B2
Application number	US-201514592152-A
Country	US
Kind code	B2
Filing date	Jan 8, 2015
Priority date	Jan 8, 2014
Publication date	Nov 14, 2017
Grant date	Nov 14, 2017

Abstract

In the systems and methods for synthesizing a thin film with desired properties (e.g. magnetic, conductivity, photocatalyst, etc.), a metal oxide film may be deposited on a substrate. The metal oxide film may be achieved utilizing any suitable method. A reducing agent may be deposited before, after or both before and after the metal oxide layer. Oxygen may be removed or liberated from the deposited metal oxide film by low temperature local or global annealing. As a result of the annealing to remove oxygen, one or more portions of the metal oxide may be transformed into materials with desired properties. As a nonlimiting example, a metal oxide film may be treated to provide a magnetic multilayer film that is suitable for bit patterned media.

First claim

What is claimed is:

1. A method for reducing a metal oxide layer, the method comprising:
depositing a metal oxide layer on a substrate;
depositing a reducing agent on the substrate to aid removal of oxygen from the metal oxide layer; and
annealing the substrate to remove oxygen from the metal oxide layer, wherein the annealing step comprises heating localized areas to pattern the metal oxide layer thereby resulting in the metal oxide layer providing one or more patterned islands with oxygen removed, wherein further the metal oxide layer is a cobalt oxide, CoO, CoOPd, CoOPt, Fe 2 O 3 , Fe 3 O 4 , iron oxide, TiO 2 , tin oxide, manganese oxide, chromium oxide, nickel oxide, silver oxide, or molybdenum oxide, and the annealing results in a change in magnetism, conductivity, photocatalyst, or refractive index properties of the metal oxide layer.

2. The method of claim 1 , wherein the metal oxide layer is a patterned layer.

3. The method of claim 1 , wherein the reducing agent is deposited before, after, or both before and after the metal oxide layer.

4. The method of claim 1 , wherein the reducing agent is Ta, Al, Mg, Ca, Zr, Zn, Ti, Si, or C.

5. The method of claim 1 , wherein an annealing time is equal to or between 0.1 nanoseconds to 24 hours.

6. The method of claim 1 , wherein an annealing time is 5 minutes or greater.

7. The method of claim 1 , wherein an annealing temperature is equal to or greater than 100° C.

8. The method of claim 1 , wherein an annealing temperature is equal to or between 100-1000° C.

9. The method of claim 1 , wherein an annealing temperature is equal to or between 100° C. to 500° C.

10. The method of claim 1 wherein the metal oxide layer is a cobalt oxide, CoO, CoOPd, CoOPt, iron oxide, Fe 2 O 3 , Fe 3 O 4 , or nickel oxide.

11. The method of claim 1 , wherein the substrate and the annealed metal oxide layer are bit patterned media (BPM).

12. The method of claim 11 , wherein the BPM has a defect density of 15% or less variation in switching properties.

13. The method of claim 11 , wherein the BPM has a defect density of 10% or less variation in switching properties.

14. The method of claim 11 , wherein the BPM has a defect density of 5% or less variation in switching properties.

15. The method of claim 1 , wherein the annealing results in a change in magnetism, photocatalyst, or refractive index properties of the metal oxide layer.

16. A method for forming bit pattern media (BPM), the method comprising:
depositing a media layer comprising a metal oxide on a substrate, wherein the metal oxide demonstrates magnetic properties when oxygen is removed;
depositing a reducing agent on the media layer to aid removal of oxygen; and
locally annealing the media layer, wherein the local annealing heats a plurality of regions of the media layer and the plurality of regions form a matrix of magnetic islands.

17. The method of claim 16 , wherein the metal oxide is a cobalt oxide, CoO, CoOPd, CoOPt, iron oxide, Fe 2 O 3 , Fe 3 O 4 , or nickel oxide.

18. The method of claim 16 , wherein a second reducing agent is deposited before, after or both before and after the media layer.

19. The method of claim 16 , wherein the reducing agent is Ta, Al, Mg, Ca, Zr, Zn, Ti, Si, or C.

20. The method of claim 16 , wherein an annealing time is equal to or between 0.1 nanoseconds to 24 hours.

21. The method of claim 16 , wherein an annealing temperature is equal to or greater than 100° C.

22. The method of claim 16 , wherein the BPM has a defect density of 15% or less variation in switching properties.

Assignees

• Litvinov Dmitri
• Chang Long
• Univ Houston System

Inventors

• Litvinov Dmitri
• Chang Long

Classifications

• C23C14/5806

  Thermal treatment · CPC title

• H01F10/16

  containing cobalt ({H01F10/126} , H01F10/13 take precedence) · CPC title

• C23C14/5846

  Reactive treatment · CPC title

• C23C14/0036

  Reactive sputtering · CPC title

• H01F10/14

  containing iron or nickel ({H01F10/126} , H01F10/13, H01F10/16 take precedence) · CPC title