Read heads in planar monolithic integrated circuit chips

• US 6,404,191 B2
• Filed: 03/22/2001
• Issued: 06/11/2002
• Est. Priority Date: 08/08/1997
• Status: Expired due to Fees

• Current Assignee: NVE Corporation
• Original Assignee: NVE Corporation
• Inventors: Daughton, James M., Pohm, Arthur V.
• Primary Examiner(s): Metjahic, Safet
• Assistant Examiner(s): SUNDARAM, T R
• Application Number:
  US09/814,637
• Publication Number:
  US 20010017543A1
• Time in Patent Office: 446 Days
• Field of Search: 324/252, 324/207.21, 360/103, 360/104, 360/113
• US Class Current: 324/252
• 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 5/3909 Arrangements using a magnetic tunnel junction
• CPC Class Codes: G11B 5/3948 the sensitive elements being active read-out elements
• CPC Class Codes: G11B 5/3954 the active elements transducing on a single track
• 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: G11B 5/488 Disposition of heads G11B5/49, G11B5/52 take precedence
• CPC Class Codes: G11B 5/59683 for magnetoresistive heads

Abstract

A plurality of magnetic field sensing structures in a monolithic integrated circuit chip structure to provide output signals at outputs thereof of magnetic field changes provided therein from corresponding sources having poled pair structures with a gap space between them with adjacent ones of the magnetic field sensing structures that are interconnected with a circuit formed in the monolithic integrated circuit chip such as an amplifier. The paired pole structures may intersect a surface of the chip perpendicular to the major surfaces thereof or in one of, or a surface parallel to, the major surfaces thereof. A magnetic field generating structure may also be included in the chip.

Claims

1. A plurality of magnetic field sensors in a multiple sensor structure having a substrate, said magnetic field sensors providing at corresponding outputs thereof representations of magnetic field changes provided therein from a corresponding source of such magnetic field changes, said sensor structure comprising:

a plurality of paired pole structures supported on said substrate with each of those pole structures in a said paired pole structure being spaced apart from one another to form a corresponding gap space therebetween and with each of said pole structures comprising a permeable material and having an end thereof substantially in a common surface; and

a plurality of field sensing structures each supported on said substrate adjacent a corresponding paired pole structure with at least a portion thereof positioned away from said common surface, each of said plurality field sensing structures being formed of a plurality of magnetoresistive, anisotropic, ferromagnetic thin-film layers at least two of which are separated from one another by a nonmagnetic layer positioned therebetween.

2. The apparatus of claim 1 wherein said substrate includes a monolithic integrated circuit with circuit interconnections being provided coupling electrical circuits in said monolithic integrated circuit to each of said plurality of field sensing structures.

3. The apparatus of claim 1 wherein said common surface is a surface of said sensor structure substantially perpendicular to a major surface of said substrate on which said plurality of paired pole structures and said plurality of field sensing structures are supported.

4. The apparatus of claim 1 wherein said common surface is a surface of said sensor structure substantially parallel to a major surface of said substrate on which said plurality of paired pole structures and said plurality of field sensing structures are supported.

5. The apparatus of claim 1 wherein each of said plurality of field sensing structures is supported in said gap space of said corresponding paired pole structure and each has said nonmagnetic layer thereof formed of an electrically conductive material and positioned between said two ferromagnetic thin-film layers thereof which each extend to said common surface.

6. The apparatus of claim 1 wherein each of said plurality of field sensing structures has one of said two ferromagnetic thin-film layers thereof extend to said common surface and each has said nonmagnetic layer thereof formed of an electrically insulative material and positioned between said two ferromagnetic thin-film layers thereof.

7. The apparatus of claim 1 wherein said pair of pole structures in a said paired pole structure are relatively closely spaced apart from one another adjacent said common surface but are relatively distantly spaced apart from one another elsewhere along said corresponding field sensing structure.

8. The apparatus of claim 1 further comprising a storing paired pole structure supported on said substrate with each of those pole structures in said storing paired pole structure being spaced apart from one another to form a corresponding storing gap space therebetween and with each of said pole structures comprising a permeable material and having a portion thereof substantially in said common surface, said storing paired pole structure having a coiled electrical conductor provided in said storing gap space away from said common surface supported on a surface parallel to said common surface.

9. The apparatus of claim 2 wherein said electrical circuits contain an electronic signal amplifier.

10. The apparatus of claim 3 wherein at least one of said plurality of field sensing structures has one of said two ferromagnetic thin-film layers thereof extend to said common surface following a straight line path.

11. The apparatus of claim 4 at least one of said plurality of field sensing structures has one of said two ferromagnetic thin-film layers thereof extend to said common surface following a path other than a straight line path.

12. The apparatus of claim 4 at least one of said plurality of field sensing structures has said two ferromagnetic thin-film layers thereof extend to said common surface following a path other than a straight line path.

13. The apparatus of claim 4 wherein at least one of said plurality of paired pole structures can have a selected line in said common surface intersect both of its pole structures so that others of said plurality of paired pole structures each have both of its pole structures intersect such a line.

14. The apparatus of claim 4 wherein at least one of said plurality of paired pole structures can have a selected line in said common surface intersect both of its pole structures so that others of said plurality of paired pole structures each have both of its pole structures laterally offset from such a line.

15. The apparatus of claim 4 wherein at least one of said plurality of paired pole structures can have a selected first line in said common surface intersect both of its pole structures to form a first intersection so that others of said plurality of paired pole structures each have both of its pole structures laterally offset from such a first line, and each of said plurality of paired pole structures can also have a selected correspondence line in said common surface parallel to said selected first line intersect both of its pole structures at least one of which forms an intersection at an angle differing from that in said first intersection.

16. The apparatus of claim 8 wherein said pair of pole structures in a said storing paired pole structure are relatively closely spaced apart from one another adjacent said common surface but are relatively distantly spaced apart from one another elsewhere adjacent said coiled electrical conductor.

17. A plurality of magnetic field sensors in a multiple sensor structure having a substrate, said magnetic field sensors providing at corresponding outputs thereof representations of magnetic field changes provided therein from a corresponding source of such magnetic field changes, said sensor structure comprising:

at least one paired pole structure supported on said substrate with each of those pole structures in said paired pole structure being spaced apart from one another to form a corresponding gap space therebetween and with each of said pole structures comprising a permeable material and having an end thereof substantially in a common surface; and

a plurality of field sensing structures each supported on said substrate adjacent a corresponding paired pole structure with at least a portion thereof positioned away from said common surface, each of said plurality field sensing structures being formed of a plurality of magnetoresistive, anisotropic, ferromagnetic thin-film layers at least two of which are separated from one another by a nonmagnetic layer positioned therebetween.

18. The apparatus of claim 17 wherein said substrate includes a monolithic integrated circuit with circuit interconnections being provided coupling electrical circuits in said monolithic integrated circuit to each of said plurality of field sensing structures.

19. The apparatus of claim 17 wherein said common surface is a surface of said sensor structure substantially perpendicular to a major surface of said substrate on which said plurality of paired pole structures and said plurality of field sensing structures are supported.

20. The apparatus of claim 17 wherein said common surface is a surface of said sensor structure substantially parallel to a major surface of said substrate on which said plurality of paired pole structures and said plurality of field sensing structures are supported.

21. The apparatus of claim 17 wherein said paired pole structure is one of a plurality of such paired pole structures and wherein each of said plurality of field sensing structures is supported in said gap space of said corresponding paired pole structure and each has said nonmagnetic layer thereof formed of an electrically conductive material and positioned between said two ferromagnetic thin-film layers thereof which each extend to said common surface.

22. The apparatus of claim 17 wherein said paired pole structure is one of a plurality of such paired pole structures and wherein each of said plurality of field sensing structures has one of said two ferromagnetic thin-film layers thereof extend to said common surface and each has said nonmagnetic layer thereof formed of an electrically insulative material and positioned between said two ferromagnetic thin-film layers thereof.

23. The apparatus of claim 17 wherein said pair of pole structures in said paired pole structure are relatively closely spaced apart from one another adjacent said common surface but are relatively distantly spaced apart from one another elsewhere along said corresponding field sensing structure.

24. The apparatus of claim 17 further comprising a storing paired pole structure supported on said substrate with each of those pole structures in said storing paired pole structure being spaced apart from one another to form a corresponding storing gap space therebetween and with each of said pole structures comprising a permeable material and having a portion thereof substantially in said common surface, said storing paired pole structure having a coiled electrical conductor provided in said storing gap space away from said common surface supported on a surface parallel to said common surface.

25. The apparatus of claim 18 wherein said electrical circuits contain an electronic signal amplifier.

26. The apparatus of claim 19 wherein at least one of said plurality of field sensing structures has one of said two ferromagnetic thin-film layers thereof extend to said common surface following a straight line path.

27. The apparatus of claim 20 at least one of said plurality of field sensing structures has one of said two ferromagnetic thin-film layers thereof extend to said common surface following a path other than a straight line path.

28. The apparatus of claim 20 at least one of said plurality of field sensing structures has said two ferromagnetic thin-film layers thereof extend to said common surface following a path other than a straight line path.

29. The apparatus of claim 20 wherein at least one of said plurality of paired pole structures can have a selected line in said common surface intersect both of its pole structures so that others of said plurality of paired pole structures each have both of its pole structures intersect such a line.

30. The apparatus of claim 20 wherein at least one of said plurality of paired pole structures can have a selected line in said common surface intersect both of its pole structures so that others of said plurality of paired pole structures each have both of its pole structures laterally offset from such a line.

31. The apparatus of claim 20 wherein at least one of said plurality of paired pole structures can have a selected first line in said common surface intersect both of its pole structures to form a first intersection so that others of said plurality of paired pole structures each have both of its pole structures laterally offset from such a first line, and each of said plurality of paired pole structures can also have a selected correspondence line in said common surface parallel to said selected first line intersect both of its pole structures at least one of which forms an intersection at an angle differing from that in said first intersection.

32. The apparatus of claim 24 wherein said pair of pole structures in a said storing paired pole structure are relatively closely spaced apart from one another adjacent said common surface but are relatively distantly spaced apart from one another elsewhere adjacent said coiled electrical conductor.

33. A method for fabricating a magnetic field sensor in a sensor structure on a substrate, said method comprising:

providing an initial permeable material layer on a surface of said substrate having an opening therein with an angled side formed at an angle with respect to said substrate surface;

providing an initial nonmagnetic material layer supported by said initial permeable material layer including supported by said angled side thereof;

providing a device permeable material layer supported by at least one of said initial nonmagnetic material layer and an electrical interconnection extending therethrough, said device permeable material layer at least in part to be a portion of a magnetic sensing structure;

providing a device nonmagnetic material layer on said device permeable material layer which is at least in part to be a portion of a magnetic sensing structure;

providing a completion permeable material layer on said nonmagnetic material layer which is at least in part to be a portion of a magnetic sensing structure, at least one of said device permeable material layer and said completion permeable material layer also being provided across from said angled side; and

removing portions of at least said initial nonmagnetic material layer and at least one of said device permeable material layer and said completion permeable material layer to form a common surface intersected by such layers which common surface intersects at least a portion of said angled side.

34. The method of claim 33 further providing a subsequent nonmagnetic material layer supported by at least a portion of said completion permeable material layer and thereafter providing an electrically conductive layer on said subsequent nonmagnetic material layer and also across from a portion of said completion permeable material layer.

35. The method of claim 34 wherein said electrically conductive layer is also provided at a location across from a portion of at least one of said device permeable material layer and said completion permeable material layer without also being across from said subsequent nonmagnetic material layer but being across from said angled side.