Giant magnetoresistive (GMR) sensor element with enhanced magnetoresistive (MR) coefficient

• US 6,292,336 B1
• Filed: 09/30/1999
• Issued: 09/18/2001
• Est. Priority Date: 09/30/1999
• Status: Expired due to Fees

• Current Assignee: Headway Technologies Incorporated
• Original Assignee: Headway Technologies Incorporated
• Inventors: Chen, Mao-Min, Tong, Ru-Ying, Ju, Kochan, Horng, Cheng T., Chang, Jei-Wei, Liao, Simon H.
• Primary Examiner(s): Tupper, Robert S.
• Assistant Examiner(s): Watko, Julie Anne
• Application Number:
  US09/408,703
• Time in Patent Office: 719 Days
• Field of Search: 360/324.1, 360/324.12, 360/316, 360/324, 360/313, 360/324.11, 360/110, 360/FOR.213
• US Class Current: 360/324.12
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: B82Y 25/00 Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance
• CPC Class Codes: G01R 33/093 using multilayer structures, e.g. giant magnetoresistance sensors thin magnetic films H01F10/00
• CPC Class Codes: G11B 2005/3996 large or giant magnetoresistive effects [GMR], e.g. as generated in spin-valve [SV] devices
• CPC Class Codes: G11B 5/3903 using magnetic thin film layers or their effects, the films being part of integrated structures
• CPC Class Codes: G11B 5/3967 Composite structural arrangements of transducers, e.g. inductive write and magnetoresistive read G11B5/3906 takes precedence
• CPC Class Codes: H01F 10/3268 the exchange coupling being asymmetric, e.g. by use of additional pinning, by using antiferromagnetic or ferromagnetic coupling interface, i.e. so-called spin-valve [SV] structure, e.g. NiFe/Cu/NiFe/FeMn

Abstract

A method for forming a giant magnetoresistive (GMR) sensor element, and a giant magnetoresistive (GMR) sensor element formed in accord with the method. In accord with the method, there is first provided a substrate. There is then formed over the substrate a seed layer formed of a magnetoresistive (MR) resistivity sensitivity enhancing material selected from the group consisting or nickel-chromium alloys and nickel-iron-chromium alloys. There is then formed over the seed layer a nickel oxide material layer. Finally, there is then formed over the nickel oxide material layer a free ferromagnetic layer separated from a pinned ferromagnetic layer in turn formed thereover by a non-magnetic conductor spacer layer, where the pinned ferromagnetic layer in turn has a pinning material layer formed thereover. The method contemplates a giant magnetoresistive (GMR) sensor element formed in accord with the method. The nickel oxide material layer provides the giant magnetoresistive (GMR) sensor element with an enhanced magnetoresistive (MR) resistivity sensitivity.

Claims

1. A method for forming a fiant magnetoresistive (GMR) sensor element with an enhanced magnetoresistive coefficient comprising:

providing a substrate;

forming over the substrate a double-layer said double layer comprising a first material layr selected from the group of magnetoresistive (MR) resistivity sensitivity enhancing material consisting of nickel-chromium alloys and nickel-iron-chromium alloys and said double-layer seed layer further comprising a second material layer, said material layer being a thin, non-magnetic dielectric nickel oxide material layer that additionally enhances magnetoresistive (MR) resistivity sensitivity;

2. The method of claim 1 wherein the giant magnetoresistive (GMR) sensor element is selected from the group consisting of simple spin valve magnetoresistive (SVMR) sensor elements, synthetic antiferromagnetically biased giant magnetoresistive (GMR) sensor elements, simple spin filter giant magnetoresistive (GMR) sensor elements and spin filter synthetic antiferromagnetically biased giant magnetoresistive (GMR) sensor elements.

3. The method of claim 1 wherein the nickel oxide material layer, which is the second material layer of said double-layer seed layer, is formed to a thickness of from about 5 to about 15 angstroms as a non-magnetic dielectric nickel oxide material layer.

4. The method of claim 1 wherein the free ferromagnetic material layer and the pinned ferromagnetic material layer are each formed of a ferromagnetic material selected from the group consisting of nickel, iron and cobalt ferromagnetic materials, alloys thereof, laminates thereof and laminates of alloys thereof.

5. A giant magnetoresistive (GMR) sensor element with an enhanced magnetoresistive coefficient comprising:

a substrate;

a double-layer seed layer formed over the substrate, said double layer comprising a first material layer selected from the group of magnetoresistive (MR) resistivity sensitivity enhancing material consisting of nickel-chromium alloys and nickel-iron-chromium alloys and said double-layer seed layer further comprising a second material layer, said material layer being a thin, non-magnetic dielectric nickel oxide material layer that additionally enhances magnetoresistive (MR) resistivity sensitivity;

a free ferromagnetic layer formed over the double-layer seed layer;

a non-magnetic conductor spacer layer formed over the free ferromagnetic layer;

a pinned ferromagnetic layer formed over the non-magnetic conductor spacer layer; and

a pinning material layer formed over the pinned ferromagnetic layer.

6. The giant magnetoresistive (GMR) sensor element of claim 5 wherein the giant magnetoresistive (GMR) sensor element is selected from the group consisting of simple spin valve magnetoresistive (SVMR) sensor elements, synthetic antiferromagnetically biased giant magnetoresistive (GMR) sensor elements, simple spin filter giant magnetoresistive (GMR) sensor elements and spin filter synthetic antiferromagnetically biased giant magnetoresistive (GMR) sensor elements.

7. The giant magneteresistive (GMR) sensor element of claim 5 wherein the nickel oxide material layer, which is the second material layer of said double-layer seed layer, is formed to a thickness of from about 5 to about 15 angstroms as a non-magnetic dielectric nickel oxide material layer.

8. The giant magnetoresistive (GMR) sensor element of claim 5 wherein the free ferromagnetic material layer and the pinned ferromagnetic material layer are each formed of a ferromagnetic material selected from the group consisting of nickel, iron and cobalt ferromagnetic materials, alloys thereof, laminates thereof and laminates of alloys thereof.

9. A magnetoresistive (MR) head having incorporated therein a giant magnetoresistive (GMR) sensor element in accord with claim 5.

10. The magnetoresistive (MR) head of claim 9 wherein the magnetoresistive (MR) head is selected from the group consisting of magnetoresistive (MR) read only magnetic heads, merged inductive write magnetoresistive (MR) read magnetic heads and non-merged inductive write magnetoresistive (MR) read magnetic heads.

11. A magnetic data storage enclosure having incorporated therein a magnetoresistive (MR) head in accord with claim 9.

12. A method for forming a spin valve magnetoresistive (SVMR) sensor element with an enhanced magnetoresistive coefficient comprising:

providing a substrate;

forming over the substrate a double-layer seed layer, said double layer comprising a first material layer selected from the group of magnetoresistive (MR) resistivity sensitivity enhancing material consisting of nickel-chromium alloys and nickel-iron-chromium alloys and said double-layer seed layer further comprising a second material layer, said material layer being a thin, non-magnetic dielectric nickel oxide material layer that additionally enhances magnetoresistive (MR) resistivity sensitivity;

forming over the double-layer seedlayer a free ferromagnetic layer;

forming over the free ferromagnetic layer a non-magnetic conductor spacer layer;

forming over the non-magnetic conductor spacer layer a pinned ferromagnetic layer; and

forming over the pinned ferromagnetic layer a pinning material layer.

13. The method of claim 12 wherein the nickel oxide material layer, which is the second material layer of said double-layer seed layer, is formed to a thickness of from about 5 to about 15 angstroms as a non-magnetic dielectric nickel oxide material layer.

14. The method of claim 12 wherein the free ferromagnetic layer and the pinned ferromagnetic layer are each formed of a ferromagnetic material selected from the group consisting of nickel, iron and cobalt ferromagnetic materials, alloys thereof, laminates thereof and laminates of alloys thereof.

15. A spin valve magnetoresistive (SVMR) sensor element with an enhanced magnetoresistive coefficient comprising:

a substrate;

a double-layer seed layer formed over the substrate, said double layer comprising a first material layer selected from the group of magnetoresistive (MR) resistivity sensitivity enhancing material consisting of nickelchromium alloys and nickel-iron-chromium alloys and said double-layer seed layer further comprising a second material layer, said material layer being a thin, non-magnetic dielectric nickel oxide material layer that additionally enhances magnetoresistive (MR) resistivity sensitivity;

a free ferromagnetic layer formed over the double-layer seed layer;

a non-magnetic conductor spacer layer formed over the free ferromagnetic layer;

a pinned ferromagnetic layer formed over the non-magnetic conductor spacer layer; and

a pinning material layer formed over the pinned ferromagnetic layer.

16. The spin valve magnetoresistive (SVMR) sensor element of claim 15 wherein the nickel oxide material layer, which is the second material layer of said double-layer seed layer, is formed to a thickness of from about 5 to about 15 angstroms as a non-magnetic dielectric nickel oxide material layer.

17. The spin-valve magnetoresistive (SVMR) sensor element of claim 15 wherein the free ferromagnetic layer and the pinned ferromagnetic layer are each formed of a ferromagnetic material selected from the group consisting of nickel, iron and cobalt ferromagnetic materials, alloys thereof, laminates thereof and laminates of alloys thereof.

18. A magnetoresistive (MR) head having incorporated therein a spin-valve magnetoresistive (SVMR) sensor element in accord with claim 15.

19. The magnetoresistive (MR) head of claim 18 wherein the magnetoresistive (MR) head is selected from the group consisting of magnetoresistive (MR) read only magnetic heads, merged inductive write magnetoresistive (MR) read magnetic heads and non-merged inductive write magnetoresistive (MR) read magnetic heads.

20. A magnetic data storage enclosure having incorporated therein a magnetoresistive (MR) head in accord with claim 18.