Hall effect devices, memory devices, and hall effect device readout voltage increasing methods

• US 20040251506A1
• Filed: 06/10/2003
• Published: 12/16/2004
• Est. Priority Date: 06/10/2003
• Status: Abandoned Application

• Current Assignee: the united states of america as represented by the secretary of the navy
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Johnson, Mark B., Prinz, Gary A.
• Application Number:
  US10/457,704
• Publication Number:
  US 20040251506A1
• Time in Patent Office: Days
• US Class Current: 257/421
• CPC Class Codes: G11C 11/18 using Hall-effect devices
• CPC Class Codes: H10N 52/00 Hall-effect devices integrated devices or assemblies of multiple devices H10N59/00

Abstract

Hall Effect devices, memory devices, and Hall Effect device readout voltage increasing method. A hall effect device includes a conductive film layer capable an electrical current, a ferromagnetic layer having a configurable orientation and configured to cover a portion of the conductive film layer such that fringe magnetic fields can be generated by an edge portion of the ferromagnetic layer, a high permeability magnetic layer disposed below the conductive film layer. The fringe magnetic fields are drawn toward the high permeability magnetic layer such that the magnetic fields pass though the conductive film layer to enable closure of the magnetic fields.

Claims

1. A Hall Effect device comprising:

a conductive film layer capable of carrying an electrical current;

a ferromagnetic layer having a configurable magnetization orientation and configured to cover a portion of the conductive film layer such that fringe magnetic fields can be generated by an edge portion of the ferromagnetic layer;

a high permeability magnetic layer disposed below the conductive film layer; and

wherein the fringe magnetic fields are drawn towards the high permeability magnetic layer such that the magnetic fields pass through the conductive film layer to enable closure of the magnetic fields.

2. The device of claim 1, wherein the high permeability magnetic layer is disposed on a substrate and configured to increase a magnitude of a perpendicular component of the fringe magnetic fields thereby increasing a read out voltage of the hall effect device.

3. The device of claim 1, wherein the high permeability magnetic layer is formed as a continuous layer to cover a full length of the substrate.

4. The device of claim 1, wherein the high permeability magnetic layer comprises one or more ferromagnetic components on a substrate.

5. The device of claim 2, wherein an electrical signal is generated in response to the fringe magnetic fields acting on the electrical current in the conductive film layer.

6. The device of claim 1, further comprising:

a buffer layer disposed between the high permeability magnetic layer and the conductive film layer, and wherein the high permeability magnetic layer comprises Permalloy.

7. The device of claim 1, wherein the conductive film layer and the ferromagnetic layer are separated by one or more insulating layers.

8. The device of claim 1, wherein the ferromagnetic film is formed in an elliptical shape.

9. A memory device comprising:

a first layer disposed on a second layer capable of carrying an electrical current, the first layer covering a portion of the second layer;

a third layer disposed below the second layer; and

wherein fringe magnetic fields generated at an edge of the first layer are drawn towards the third layer and pass through the second layer, thereby increasing a readout voltage of the memory device.

10. The device of claim 9, wherein the first layer is a ferromagnetic layer.

11. The device of claim 9, wherein the second layer is a conductive film layer.

12. The device of claim 9, wherein the third layer is a high permeability magnetic layer comprising Ni_0.8Fe_0.2 permalloy.

13. The device of claim 9, further comprising:

a buffer layer disposed between the second layer and the third layer.

14. The device of claim 9, wherein the second layer and the first layer are separated by one or more insulating layers.

15. The device of claim 9, wherein the third layer is formed on a substrate as a continuous layer to cover a full length of the substrate.

16. A hall effect device comprising:

a conductive film layer capable of carrying an electrical current;

a ferromagnetic layer having a configurable magnetization orientation and configured to cover a portion of the conductive film layer such that fringe magnetic fields can be generated by an edge portion of the ferromagnetic layer;

one or more ferromagnetic components formed in close proximity to an edge of the ferromagnetic layer; and

wherein the conductive film layer is patterned using a mesa etch such that the one or more ferromagnetic components are located substantially beneath the level of the conductive film layer, and fringe magnetic fields generated from the edge of the ferromagnetic layer are drawn towards the one or more ferromagnetic components such that the magnetic fields pass through the conductive film layer to enable closure of the magnetic fields.

17. The device of claim 16, further comprising:

a buffer layer located between the conductive film layer and the one or more ferromagnetic components.

18. The device of claim 17, wherein the one or more ferromagnetic components are formed in the buffer layer.

19. The device of claim 16, wherein the one or more ferromagnetic components are configured to increase a magnitude of a perpendicular component of the fringe magnetic fields thereby increasing a read out voltage of the hall effect device.

20. The device of claim 16, wherein the ferromagnetic film is formed in an elliptical shape.

21. The device of claim 16, wherein the hall effect device is a memory device.

22. A hall effect device readout voltage increasing method comprising:

forming a conductive film layer capable of carrying an electrical current;

forming a ferromagnetic layer to cover the conductive film layer such that fringe magnetic fields can be generated by an edge portion of the ferromagnetic layer; and

forming a high permeability magnetic layer below the conductive film layer such that the fringe magnetic fields are drawn towards the high permeability magnetic layer and pass through the conductive film layer thereby increasing the readout voltage.

23. The method of claim 22, further comprising:

forming a buffer layer between the conductive film layer and the high permeability magnetic layer.

24. The method of claim 23, further comprising:

forming one or more insulating layer between the conductive film layer and the ferromagnetic layer.

25. The method of claim 23, wherein the high permeability magnetic layer is formed in the buffer layer.

26. The method of claim 22, wherein the high permeability magnetic layer is formed as a continuous layer to cover a full length of a substrate on which the high permeability magnetic layer is formed.

27. The method of claim 22, wherein the high permeability magnetic layer comprises one or more ferromagnetic components on a substrate.

28. The method of claim 27, wherein the conductive film layer is patterned using a mesa etch such that the one or more ferromagnetic components are located substantially beneath the level of the conductive film layer, and fringe magnetic fields generated from the edge of the ferromagnetic layer are drawn towards the one or more ferromagnetic components such that the magnetic fields pass through the condutive film layer to enable closure of the magnetic fields thereby increasing a readout voltage of hall effect device.