Three bridge circuits (101, 111, 121), each include magnetoresistive sensors coupled as a Wheatstone bridge (100) to sense a magnetic field (160) in three orthogonal directions (110, 120, 130) that are set with a single pinning material deposition and bulk wafer setting procedure. One of the three bridge circuits (121) includes a first magnetoresistive sensor (141) comprising a first sensing element (122) disposed on a pinned layer (126), the first sensing element (122) having first and second edges and first and second sides, and a first flux guide (132) disposed non-parallel to the first side of the substrate and having an end that is proximate to the first edge and on the first side of the first sensing element (122). An optional second flux guide (136) may be disposed non-parallel to the first side of the substrate and having an end that is proximate to the second edge and the second side of the first sensing element (122).
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0. 43. A ferromagnetic thin-film based magnetic field sensor comprising:
a first plurality of magnetoresistive sensors coupled together, wherein each magnetoresistive sensor of the first plurality of magnetoresistive sensors comprises in an order in a direction:
a reference layer,
an intermediate layer, and
a sensing element; and
one or more flux guides, wherein each flux guide of the one or more flux guides includes a soft ferromagnetic material, wherein the soft ferromagnetic material is a high permeability magnetic material, wherein at least one flux guide of the one or more flux guides is associated with at least one magnetoresistive sensor of the first plurality of magnetoresistive sensors, and wherein (i) the at least one flux guide is in a plane that is above or below the at least one magnetoresistive sensor and parallel to the sensing element of the at least one magnetoresistive sensor, (ii) the at least one flux guide is disposed non-parallel to a first side of the at least one magnetoresistive sensor, and (iii) the at least one flux guide includes an end that is proximate to a first edge and on the first side of the at least one magnetoresistive sensor,
wherein the sensor further includes a plurality of cladded lines, wherein each cladded line is positioned adjacent to a flux guide of the one or more flux guides,
wherein each flux guide of the one or more flux guides includes (i) a first vertical segment, (ii) a second vertical segment, and (iii) a horizontal segment connecting the first and second vertical segments, and wherein a free end of the first vertical segment is flared away from a free end of the second vertical segment, each flux guide having the flared-away free ends at least partially enclosing the cladded line between the two vertical segments, and wherein the first vertical segment, the second vertical segment, and the horizontal segment define an opening, the opening having a width defined by a distance between inner walls of the first and second vertical segments, wherein the width of the opening between the inner walls at the flare-away free ends is larger than the width of the opening between the inner walls at connected ends of the first and second vertical segments, the first and second vertical segments being connected to the horizontal segment at the connected ends.
0. 72. A ferromagnetic thin-film based magnetic field sensor comprising:
a first plurality of magnetoresistive sensors coupled to sense a first magnetic field in a direction orthogonal to a plane of the first plurality of magnetoresistive sensors, wherein each magnetoresistive sensor of the first plurality of magnetoresistive sensors includes a sensing element;
one or more flux guides, wherein each flux guide of the one or more flux guides includes a soft ferromagnetic material, wherein the soft ferromagnetic material is a high permeability magnetic material, wherein at least one flux guide of the one or more flux guides is associated with the sensing element of at least one magnetoresistive sensor of the first plurality of magnetoresistive sensors, and wherein (i) the at least one flux guide is in a plane that is above or below the associated sensing element in the direction and parallel to the associated sensing element, (ii) the at least one flux guide is disposed non-parallel to a first side of the at least one magnetoresistive sensor, and (iii) the at least one flux guide includes an end that is proximate to a first edge of the associated sensing element and on a first side of the associated sensing element; and
a second plurality of magnetoresistive sensors configured to be electrically connected together to sense a second magnetic field orthogonal to the first magnetic field;
wherein each flux guide of the one or more flux guides includes (i) a first vertical segment, (ii) a second vertical segment, and (iii) a horizontal segment connecting the first and second vertical segments, and wherein a free end of the first vertical segment is flared away from a free end of the second vertical segment, each flux guide having the flared-away free ends at least partially enclosing a cladded line between the two vertical segments, and wherein the first vertical segment, the second vertical segment, and the horizontal segment define an opening, the opening having a width defined by a distance between inner walls of the first and second vertical segments, wherein the width of the opening between the inner walls at the flare-away free ends is larger than the width of the opening between the inner walls at connected ends of the first and second vertical segments, the first and second vertical segments being connected to the horizontal segment at the connected ends.
0. 22. A ferromagnetic thin-film based magnetic field sensor comprising:
a first plurality of magnetoresistive sensors coupled to sense a magnetic field in a first direction orthogonal to a plane of the first plurality of magnetoresistive sensors, wherein the first plurality of magnetoresistive sensors includes first, second, third, and fourth magnetoresistive sensors;
the first magnetoresistive sensor comprising:
a first sensing element, and
a first flux guide comprising a first soft ferromagnetic material, wherein the first soft ferromagnetic material is a first high permeability magnetic material, wherein (i) the first flux guide is above or below the first sensing element of the first magnetoresistive sensor in the first direction, (ii) the first flux guide is disposed non-parallel to a first side of the first sensing element, and (iii) the first flux guide includes an end that is proximate to a first edge and on the first side of the first sensing element;
the second magnetoresistive sensor comprising:
a second sensing element, and
a second flux guide comprising a second soft ferromagnetic material, wherein the second soft ferromagnetic material is a second high permeability magnetic material, wherein (i) the second flux guide is above or below the second sensing element of the second magnetoresistive sensor in the first direction, (ii) the second flux guide is disposed non-parallel to a first side of the second sensing element, and (iii) the second flux guide includes an end that is proximate to and on the first side of the second sensing element;
the third magnetoresistive sensor comprising:
a third sensing element, and
a third flux guide comprising a third soft ferromagnetic material, wherein the third soft ferromagnetic material is a third high permeability magnetic material, wherein (i) the third flux guide is above or below the third sensing element of the third magnetoresistive sensor in the first direction, (ii) the third flux guide is disposed non-parallel to a first side of the third sensing element, and (iii) the third flux guide includes an end that is proximate to and on the first side of the third sensing element; and
the fourth magnetoresistive sensor comprising:
a fourth sensing element, and
a fourth flux guide comprising a fourth soft ferromagnetic material, wherein the fourth soft ferromagnetic material is a fourth high permeability magnetic material, wherein (i) the fourth flux guide is above or below the fourth sensing element of the fourth magnetoresistive sensor in the first direction, (ii) the fourth flux guide is disposed non-parallel to a first side of the fourth sensing element, and (iii) the fourth flux guide includes an end that is proximate to and on the first side of the fourth sensing element,
wherein the sensor further includes a plurality of cladded lines, wherein each cladded line is positioned adjacent to one of the first, second, third, and fourth flux guides,
wherein each flux guide of the first, second, third, and fourth flux guides includes (i) a first vertical segment, (ii) a second vertical segment, and (iii) a horizontal segment connecting the first and second vertical segments, wherein a free end of the first vertical segment is flared away from a free end of the second vertical segment, each flux guide having the flared-away free ends at least partially enclosing the cladded line between the two vertical segments, and wherein the first vertical segment, the second vertical segment, and the horizontal segment define an opening, the opening having a width defined by a distance between inner walls of the first and second vertical segments, wherein the width of the opening between the inner walls at the flare-away free ends is larger than the width of the opening between the inner walls at connected ends of the first and second vertical segments, the first and second vertical segments being connected to the horizontal segment at the connected ends.
0. 1. A ferromagnetic thin-film based magnetic field sensor comprising:
a substrate having a planar surface; and
a first magnetoresistive sensor comprising:
a first sensing element having a first side lying parallel to the planar surface of the substrate, the first sensing element having a second side opposed to the first side and having first and second opposed edges; and
a first flux guide comprising a soft ferromagnetic material disposed non-parallel to the first side of the first sensing element and having an end that is proximate to the first edge and the first side of the first sensing element.
0. 2. The ferromagnetic thin-film based magnetic field sensor of
a second flux guide comprising a soft ferromagnetic material disposed non-parallel to the first side of the first sensing element and having an end that is proximate to the second edge and the second side of the first sensing element.
0. 3. The ferromagnetic thin-film based magnetic field sensor of
0. 4. The ferromagnetic thin-film based magnetic field sensor of
0. 5. The ferromagnetic thin-film based magnetic field sensor of
0. 6. The ferromagnetic thin-film based magnetic field sensor of
0. 7. The ferromagnetic thin-film based magnetic field sensor of
0. 8. The ferromagnetic thin-film based magnetic field sensor of
0. 9. The ferromagnetic thin-film based magnetic field sensor of
0. 10. The ferromagnetic thin-film based magnetic field sensor of
0. 11. The ferromagnetic thin-film based magnetic field sensor of
a second magnetoresistive sensor having a second sensing element for detecting a magnetic field in a second direction orthogonal to the first direction; and
a third magnetoresistive sensor having a third sensing element orthogonal to the second sensing element for detecting a magnetic field in a third direction orthogonal to the first and second directions,
wherein the third sensing element is in a plane with the first and second sensing elements.
0. 12. The ferromagnetic thin-film based magnetic field sensor of
0. 13. The ferromagnetic thin-film based magnetic field sensor of
the first magnetoresistive sensor comprising:
a first pinned layer;
a second magnetoresistive sensor comprising:
a second pinned layer; and
a second sensing element formed on the second pinned layer;
a third magnetoresistive sensor comprising:
a third pinned layer; and
a third sensing element formed on the third pinned layer and orthogonal to the second sensing element;
wherein the second and third pinned layers are oriented about 45 degrees to the first pinned layer.
0. 14. The ferromagnetic thin-film based magnetic field sensor of
a second flux guide disposed non-parallel to the first side of the first sensing element and having an end that is proximate to the second edge and the second side of the first sensing element.
0. 15. The ferromagnetic thin-film based magnetic field sensor of
0. 16. A ferromagnetic thin-film magnetic field sensor comprising:
a first bridge circuit comprising first, second, third, and fourth magnetic tunnel junction sensors coupled as a Wheatstone bridge for sensing a magnetic field orthogonal to the plane of the sensors;
the first magnetic tunnel junction sensor comprising:
a first reference layer; and
a first sensing element formed on the first reference layer, the first sensing element having first and second edges and first and second sides; and
a first flux guide comprising a soft ferromagnetic material disposed orthogonal to and spaced from the first edge and the first side of the first sensing element;
the second magnetic tunnel junction sensor comprising:
a second reference layer; and
a second sensing element formed on the second reference layer, the second sensing element having first and second edges and first and second sides; and
a second flux guide comprising a soft ferromagnetic material disposed orthogonal to and spaced from the first edge and the first side of the second sensing element;
the third magnetic tunnel junction sensor comprising:
a third reference layer; and
a third sensing element formed on the third reference layer, the third sensing element having first and second edges and first and second sides; and
a third flux guide comprising a soft ferromagnetic material disposed orthogonal to and spaced from the first edge and the first side of the third sensing element;
the fourth magnetic tunnel junction sensor comprising:
a fourth reference layer; and
a fourth sensing element formed on the fourth reference layer, the fourth sensing element having first and second edges and first and second sides; and
a fourth flux guide disposed orthogonal to and spaced from the first edge and the first side of the fourth sensing element.
0. 17. The ferromagnetic thin-film based magnetic field sensor of
0. 18. The ferromagnetic thin-film based magnetic field sensor of
a second bridge circuit comprising fifth, sixth, seventh, and eighth magnetic tunnel junction sensors coupled as a second Wheatstone bridge for sensing a magnetic field in a second direction orthogonal to the first direction; and
a third bridge circuit comprising, ninth, tenth, eleventh, and twelfth magnetic tunnel junction sensors coupled as a third Wheatstone bridge for sensing a magnetic field in a third direction orthogonal to the first and second directions.
0. 19. The ferromagnetic thin-film based magnetic field sensor of
0. 20. A method of testing the functionality and sensitivity of a response of the Z axis of a ferromagnetic thin-film magnetic field sensor including a substrate having a planar surface, and a first magnetoresistive sensor comprising a sensing element having a first side lying parallel to the planar surface of the substrate, the sensing element having a second side opposed to the first side and having first and second opposed edges, a first flux guide comprising a soft ferromagnetic material disposed non-parallel to the first side of the substrate and having an end that is proximate to the first edge and the first side of the sensing element, and a metal line formed adjacent contiguous to the flux guide, the method comprising:
applying a current through the metal line to provide a magnetic field with a component parallel to the plane of the flux guides.
0. 21. The method of
applying a current pulse through the metal line to reset the flux guide domain structure.
0. 23. The ferromagnetic thin-film based magnetic field sensor of claim 22, wherein each of the first, second, third, and fourth high permeability magnetic materials is the same material.
0. 24. The ferromagnetic thin-film based magnetic field sensor of claim 22, wherein at least one of the first, second, third, and fourth high permeability magnetic materials is nickel iron (NiFe).
0. 25. The ferromagnetic thin-film based magnetic field sensor of claim 22, wherein each of the first, second, third, and fourth high permeability magnetic materials is nickel iron (NiFe).
0. 26. The ferromagnetic thin-film based magnetic field sensor of claim 22, wherein the first plurality of magnetoresistive sensors is connected to form a circuit, and wherein the circuit includes input terminals configured to receive an electrical power and output terminals connected to a voltage meter.
0. 27. The ferromagnetic thin-film based magnetic field sensor of claim 22, wherein the first plurality of magnetoresistive sensors is connected to form a circuit, and wherein the circuit is configured to detect the magnetic field in the first direction.
0. 28. The ferromagnetic thin-film based magnetic field sensor of claim 22, wherein the first plurality of magnetoresistive sensors is connected into a bridge circuit having input terminals and output terminals.
0. 29. The ferromagnetic thin-film based magnetic field sensor of claim 28, wherein the input terminals are configured to receive electrical power and the output terminals are connected to a voltmeter to measure an output signal.
0. 30. The ferromagnetic thin-film based magnetic field sensor of claim 22, wherein the first and second magnetoresistive sensors are connected for differential measurement.
0. 31. The ferromagnetic thin-film based magnetic field sensor of claim 22, wherein the first and second magnetoresistive sensors are connected to, in operation, subtract resistances of the first and second magnetoresistive sensors.
0. 32. The ferromagnetic thin-film based magnetic field sensor of claim 22, wherein the first and second magnetoresistive sensors are connected to, in operation, produce a response when sensing a magnetic field in a second direction orthogonal to the first direction.
0. 33. The ferromagnetic thin-film based magnetic field sensor of claim 22, wherein the first and second magnetoresistive sensors are connected to, in operation, eliminate a magnetic field response in a second direction orthogonal to the first direction.
0. 34. The ferromagnetic thin-film based magnetic field sensor of claim 22, wherein the first and second magnetoresistive sensors are connected to, in operation, double a magnetic field measurement in the first direction.
0. 35. The ferromagnetic thin-film based magnetic field sensor of claim 22, wherein each of the first, second, third, and fourth magnetoresistive sensors is a magnetic tunnel junction sensor.
0. 36. The ferromagnetic thin-film based magnetic field sensor of claim 22, wherein the ferromagnetic thin-film based magnetic field sensor is configured to generate a sensor signal, and wherein the magnetic field in the first direction is determined based on the sensor signal.
0. 37. The ferromagnetic thin-film based magnetic field sensor of claim 22, further comprising:
a second plurality of magnetoresistive sensors configured to be electrically connected together to sense a magnetic field in a second direction orthogonal to the first direction.
0. 38. The ferromagnetic thin-film based magnetic field sensor of claim 22, further comprising:
a second plurality of magnetoresistive sensors configured to be electrically connected together to sense a magnetic field in a second direction orthogonal to the first direction; and
a third plurality of magnetoresistive sensors configured to be electrically connected together to sense a magnetic field in a third direction orthogonal to the first and second directions.
0. 39. The ferromagnetic thin-film based magnetic field sensor of claim 22, wherein the first magnetoresistive sensor further includes a first reference layer, the second magnetoresistive sensor further includes a second reference layer, the third magnetoresistive sensor further includes a third reference layer, and the fourth magnetoresistive sensor further includes a fourth reference layer.
0. 40. The ferromagnetic thin-film based magnetic field sensor of claim 22, wherein at least one of the first, second, third, and fourth flux guides is configured as a bar.
0. 41. The ferromagnetic thin-film based magnetic field sensor of claim 22, wherein the first and third flux guides are above the first and third sensing elements, respectively, and wherein the second and fourth flux guides are below the second and fourth sensing elements, respectively.
0. 42. The ferromagnetic thin-film based magnetic field sensor of claim 22, wherein each of the first, second, third, and fourth sensing elements includes a second side opposite to the first side, and wherein the first and third flux guides are above the first sides of the first and third sensing elements, respectively, and wherein the second and fourth flux guides are below the second sides of the second and fourth sensing elements, respectively.
0. 44. The ferromagnetic thin-film based magnetic field sensor of claim 43, wherein each magnetoresistive sensor of the first plurality of magnetoresistive sensors is a magnetic tunnel junction sensor.
0. 45. The ferromagnetic thin-film based magnetic field sensor of claim 43, wherein the intermediate layer is an insulating dielectric layer.
0. 46. The ferromagnetic thin-film based magnetic field sensor of claim 43, wherein the first plurality of magnetoresistive sensors comprises a first magnetoresistive sensor, a second magnetoresistive sensor, a third magnetoresistive sensor, and a fourth magnetoresistive sensor,
wherein the one or more flux guides comprises a first flux guide, a second flux guide, a third flux guide, and a fourth flux guide, and
wherein the first flux guide is associated with the first magnetoresistive sensor, the second flux guide is associated with the second magnetoresistive sensor, the third flux guide is associated with the third magnetoresistive sensor, and the fourth flux guide is associated with the fourth magnetoresistive sensor.
0. 47. The ferromagnetic thin-film based magnetic field sensor of claim 43, wherein the first plurality of magnetoresistive sensors comprises a first magnetoresistive sensor, a second magnetoresistive sensor, a third magnetoresistive sensor, and a fourth magnetoresistive sensor,
wherein the one or more flux guides comprises a first flux guide, a second flux guide, a third flux guide, and a fourth flux guide, and
wherein the first flux guide is above the first magnetoresistive sensor, the second flux guide is below the second magnetoresistive sensor, the third flux guide is above the third magnetoresistive sensor, and the fourth flux guide is below the fourth magnetoresistive sensor.
0. 48. The ferromagnetic thin-film based magnetic field sensor of claim 43, wherein the first plurality of magnetoresistive sensors comprises a first magnetoresistive sensor, a second magnetoresistive sensor, a third magnetoresistive sensor, and a fourth magnetoresistive sensor, each of the first, second, third, and fourth magnetoresistive sensors including a first side and a second side opposite to the first side,
wherein the one or more flux guides comprises a first flux guide, a second flux guide, a third flux guide, a fourth flux guide, a fifth flux guide, a sixth flux guide, a seventh flux guide, and an eighth flux guide, and
wherein the first flux guide is below the first side of first magnetoresistive sensor, the second flux guide is above the second side of the first magnetoresistive sensor, the third flux guide is above the first side of the second magnetoresistive sensor, the fourth flux guide is below the second side of the second magnetoresistive sensor, the fifth flux guide is below the first side of the third magnetoresistive sensor, the sixth flux guide is above the second side of the third magnetoresistive sensor, the seventh flux guide is above the first side of the fourth magnetoresistive sensor, and the eighth flux guide is below the second side of the fourth magnetoresistive sensor.
0. 49. The ferromagnetic thin-film based magnetic field sensor of claim 43, wherein the high permeability magnetic material is nickel iron (NiFe).
0. 50. The ferromagnetic thin-film based magnetic field sensor of claim 43, wherein the first plurality of magnetoresistive sensors comprises a first magnetoresistive sensor and a second magnetoresistive sensor, and wherein the first and second magnetoresistive sensors are connected for differential measurement.
0. 51. The ferromagnetic thin-film based magnetic field sensor of claim 43, wherein the first plurality of magnetoresistive sensors comprises a first magnetoresistive sensor and a second magnetoresistive sensor, and wherein the first and second magnetoresistive sensors are connected to, in operation, subtract resistances of the first and second magnetoresistive sensors.
0. 52. The ferromagnetic thin-film based magnetic field sensor of claim 43, wherein the first plurality of magnetoresistive sensors comprises a first magnetoresistive sensor and a second magnetoresistive sensor, and wherein the first and second magnetoresistive sensors are connected to, in operation, produce a response when sensing a magnetic field in a second direction orthogonal to the direction.
0. 53. The ferromagnetic thin-film based magnetic field sensor of claim 43, wherein the first plurality of magnetoresistive sensors comprises a first magnetoresistive sensor and a second magnetoresistive sensor, and wherein the first and second magnetoresistive sensors are connected to, in operation, eliminate a magnetic field response in a second direction orthogonal to the direction.
0. 54. The ferromagnetic thin-film based magnetic field sensor of claim 43, wherein the first plurality of magnetoresistive sensors comprises a first magnetoresistive sensor and a second magnetoresistive sensor, and wherein the first and second magnetoresistive sensors are connected to, in operation, double a magnetic field measurement in the direction.
0. 55. The ferromagnetic thin-film based magnetic field sensor of claim 43, further comprising:
a second plurality of magnetoresistive sensors configured to be electrically connected together, wherein the first plurality of magnetoresistive sensors is configured to sense a first magnetic field in the direction, and wherein the second plurality of magnetoresistive sensors is configured to sense a second magnetic field in a second direction orthogonal to the direction.
0. 56. The ferromagnetic thin-film based magnetic field sensor of claim 43, further comprising:
a second plurality of magnetoresistive sensors configured to be electrically connected together; and
a third plurality of magnetoresistive sensors configured to be electrically connected together,
wherein the first plurality of magnetoresistive sensors is configured to sense a first magnetic field in the direction, the second plurality of magnetoresistive sensors is configured to sense a second magnetic field in a second direction orthogonal to the direction, and the third plurality of magnetoresistive sensors is configured to sense a magnetic field in a third direction orthogonal to the direction and the second direction.
0. 57. The ferromagnetic thin-film based magnetic field sensor of claim 43, wherein the first plurality of magnetoresistive sensors is connected to form a circuit, and wherein the circuit is configured to detect a magnetic field in the direction.
0. 58. The ferromagnetic thin-film based magnetic field sensor of claim 43, wherein the first plurality of magnetoresistive sensors is connected to form a circuit, and wherein the circuit includes input terminals configured to receive an electrical power and output terminals connected to a voltage meter.
0. 59. The ferromagnetic thin-film based magnetic field sensor of claim 43, wherein the first plurality of magnetoresistive sensors is connected into a bridge circuit having input terminals and output terminals.
0. 60. The ferromagnetic thin-film based magnetic field sensor of claim 59, wherein the input terminals are configured to receive electrical power and the output terminals are connected to a voltmeter to measure an output signal.
0. 61. The ferromagnetic thin-film based magnetic field sensor of claim 43, wherein the order in the direction includes:
the sensing element of each magnetoresistive sensor of the first plurality of magnetoresistive sensors being formed on or above the associated intermediate layer of each magnetoresistive sensor, and
the intermediate layer of each magnetoresistive sensor of the first plurality of magnetoresistive sensors being formed on or above the associated reference layer of each magnetoresistive sensor.
0. 62. The ferromagnetic thin-film based magnetic field sensor of claim 43, wherein the order in the direction includes:
the reference layer of each magnetoresistive sensor of the first plurality of magnetoresistive sensors being formed on or above the associated intermediate layer of each magnetoresistive sensor, and
the intermediate layer of each magnetoresistive sensor of the first plurality of magnetoresistive sensors being formed on or above the associated sensing element of each magnetoresistive sensor.
0. 63. The ferromagnetic thin-film based magnetic field sensor of claim 43, wherein the reference layer of each magnetoresistive sensor includes a plurality of layers having a combined thickness in a range of 10 to 1000 â„«.
0. 64. The ferromagnetic thin-film based magnetic field sensor of claim 43, wherein the reference layer of each magnetoresistive sensor includes a plurality of layers having a combined thickness in a range of 250 to 350 â„«.
0. 65. The ferromagnetic thin-film based magnetic field sensor of claim 43, wherein the sensing element includes a thickness in a range of 10 to 5000 â„«.
0. 66. The ferromagnetic thin-film based magnetic field sensor of claim 43, wherein the sensing element includes a thickness in a range of 10 to 60 â„«.
0. 67. The ferromagnetic thin-film based magnetic field sensor of claim 43, wherein the ferromagnetic thin-film based magnetic field sensor is configured to generate a sensor signal, and wherein a magnetic field in the direction is determined based on the sensor signal.
0. 68. The ferromagnetic thin-film based magnetic field sensor of claim 43, wherein the reference layer of each magnetoresistive sensor includes:
a ferromagnetic layer; and
an antiferromagnetic layer.
0. 69. The ferromagnetic thin-film based magnetic field sensor of claim 43, wherein the reference layer of each magnetoresistive sensor includes:
a ferromagnetic layer having a thickness in a range of 20 to 80 â„«; and
an antiferromagnetic layer having a thickness of approximately 200 â„«.
0. 70. The ferromagnetic thin-film based magnetic field sensor of claim 43, wherein the reference layer of each magnetoresistive sensor includes:
a ferromagnetic layer; and
an antiferromagnetic layer including iridium-manganese (IrMn) alloy or platinum-manganese (PtMn) alloy.
0. 71. The ferromagnetic thin-film based magnetic field sensor of claim 43, wherein the reference layer of each magnetoresistive sensor includes:
a ferromagnetic layer including a three-layer structure; and
an antiferromagnetic layer.
0. 73. The ferromagnetic thin-film based magnetic field sensor of claim 72, wherein the high permeability magnetic material is nickel iron (NiFe).
0. 74. The ferromagnetic thin-film based magnetic field sensor of claim 72, wherein the first plurality of magnetoresistive sensors is connected to form a circuit, and wherein the circuit includes input terminals configured to receive an electrical power and output terminals connected to a voltage meter.
0. 75. The ferromagnetic thin-film based magnetic field sensor of claim 72, wherein first plurality of magnetoresistive sensors is connected into a bridge circuit having input terminals and output terminals.
0. 76. The ferromagnetic thin-film based magnetic field sensor of claim 75, wherein the input terminals are configured to receive electrical power and the output terminals are connected to a voltmeter to measure an output signal.
0. 77. The ferromagnetic thin-film based magnetic field sensor of claim 72, wherein the sensing element of each magnetoresistive sensor is disposed adjacent to a reference layer, and wherein an intermediate layer is disposed between the sensing element and the reference layer.
0. 78. The ferromagnetic thin-film based magnetic field sensor of claim 72, wherein the sensing element of each magnetoresistive sensor is disposed adjacent to a reference layer, and wherein an insulating dielectric layer is disposed between the sensing element and the reference layer.
0. 79. The ferromagnetic thin-film based magnetic field sensor of claim 72, wherein each magnetoresistive sensor of the first plurality of magnetoresistive sensors is a magnetic tunnel junction sensor.
0. 80. The ferromagnetic thin-film based magnetic field sensor of claim 72, further comprising:
a third plurality of magnetoresistive sensors electrically connected together to sense a third magnetic field orthogonal to the first and second magnetic fields.
0. 81. The ferromagnetic thin-film based magnetic field sensor of claim 72, wherein the first plurality of magnetoresistive sensors is connected together to generate a sensor signal, and wherein the first magnetic field in the direction is determined based on the sensor signal.
0. 82. The ferromagnetic thin-film based magnetic field sensor of claim 72, wherein the first plurality of magnetoresistive sensors comprises a first magnetoresistive sensor, a second magnetoresistive sensor, a third magnetoresistive sensor, and a fourth magnetoresistive sensor,
wherein the one or more flux guides comprises a first flux guide, a second flux guide, a third flux guide, and a fourth flux guide, and
wherein the first flux guide is associated with the first magnetoresistive sensor, the second flux guide is associated with the second magnetoresistive sensor, the third flux guide is associated with the third magnetoresistive sensor, and the fourth flux guide is associated with the fourth magnetoresistive sensor.
0. 83. The ferromagnetic thin-film based magnetic field sensor of claim 72, wherein the first plurality of magnetoresistive sensors comprises a first magnetoresistive sensor, a second magnetoresistive sensor, a third magnetoresistive sensor, and a fourth magnetoresistive sensor,
wherein the one or more flux guides comprises a first flux guide, a second flux guide, a third flux guide, and a fourth flux guide, and
wherein the first flux guide is above the first magnetoresistive sensor, the second flux guide is below the second magnetoresistive sensor, the third flux guide is above the third magnetoresistive sensor, and the fourth flux guide is below the fourth magnetoresistive sensor.
0. 84. The ferromagnetic thin-film based magnetic field sensor of claim 72, wherein the first plurality of magnetoresistive sensors comprises a first magnetoresistive sensor, a second magnetoresistive sensor, a third magnetoresistive sensor, and a fourth magnetoresistive sensor, each of the first, second, third, and fourth magnetoresistive sensors including a first side and a second side opposite to the first side,
wherein the one or more flux guides comprises a first flux guide, a second flux guide, a third flux guide, a fourth flux guide, a fifth flux guide, a sixth flux guide, a seventh flux guide, and an eighth flux guide, and
wherein the first flux guide is below the first side of first magnetoresistive sensor, the second flux guide is above the second side of the first magnetoresistive sensor, the third flux guide is above the first side of the second magnetoresistive sensor, the fourth flux guide is below the second side of the second magnetoresistive sensor, the fifth flux guide is below the first side of the third magnetoresistive sensor, the sixth flux guide is above the second side of the third magnetoresistive sensor, the seventh flux guide is above the first side of the fourth magnetoresistive sensor, and the eighth flux guide is below the second side of the fourth magnetoresistive sensor.
0. 85. The ferromagnetic thin-film based magnetic field sensor of claim 72, wherein the first plurality of magnetoresistive sensors comprises a first magnetoresistive sensor and a second magnetoresistive sensor, and wherein the first and second magnetoresistive sensors are connected for differential measurement.
0. 86. The ferromagnetic thin-film based magnetic field sensor of claim 72, wherein the first plurality of magnetoresistive sensors comprises a first magnetoresistive sensor and a second magnetoresistive sensor, and wherein the first and second magnetoresistive sensors are connected to, in operation, subtract resistances of the first and second magnetoresistive sensors.
0. 87. The ferromagnetic thin-film based magnetic field sensor of claim 72, wherein the first plurality of magnetoresistive sensors comprises a first magnetoresistive sensor and a second magnetoresistive sensor, and wherein the first and second magnetoresistive sensors are connected to, in operation, produce a response when sensing the second magnetic field.
0. 88. The ferromagnetic thin-film based magnetic field sensor of claim 72, wherein the first plurality of magnetoresistive sensors comprises a first magnetoresistive sensor and a second magnetoresistive sensor, and wherein the first and second magnetoresistive sensors are connected to, in operation, eliminate a response generated when sensing the second magnetic field.
0. 89. The ferromagnetic thin-film based magnetic field sensor of claim 72, wherein the first plurality of magnetoresistive sensors comprises a first magnetoresistive sensor and a second magnetoresistive sensor, and wherein the first and second magnetoresistive sensors are connected to, in operation, double a magnetic field measurement when sensing the first magnetic field.
0. 90. The ferromagnetic thin-film based magnetic field sensor of claim 72, wherein each magnetoresistive sensor further includes a reference layer and an intermediate layer disposed between the sensing element and the reference layer.
0. 91. The ferromagnetic thin-film based magnetic field sensor of claim 72, wherein each magnetoresistive sensor further includes a reference layer, and wherein the reference layer includes a plurality of layers having a combined thickness in a range of 10 to 1000 â„«.
0. 92. The ferromagnetic thin-film based magnetic field sensor of claim 72, wherein each magnetoresistive sensor further includes a reference layer, and wherein the reference layer includes a plurality of layers having a combined thickness in a range of 250 to 350 â„«.
0. 93. The ferromagnetic thin-film based magnetic field sensor of claim 72, wherein each magnetoresistive sensor further includes a reference layer, and wherein the reference layer comprises:
a ferromagnetic layer; and
an antiferromagnetic layer.
0. 94. The ferromagnetic thin-film based magnetic field sensor of claim 72, wherein each magnetoresistive sensor further includes a reference layer, and wherein the reference layer comprises:
a ferromagnetic layer having a thickness in a range of 20 to 80 â„«; and
an antiferromagnetic layer having a thickness of approximately 200 â„«.
0. 95. The ferromagnetic thin-film based magnetic field sensor of claim 72, wherein each magnetoresistive sensor further includes a reference layer, and wherein the reference layer comprises:
a ferromagnetic layer; and
an antiferromagnetic layer including iridium-manganese (IrMn) alloy or platinum-manganese (PtMn) alloy.
0. 96. The ferromagnetic thin-film based magnetic field sensor of claim 72, wherein each magnetoresistive sensor further includes a reference layer, and wherein the reference layer comprises:
a ferromagnetic layer including a three-layer structure; and
an antiferromagnetic layer.
0. 97. The ferromagnetic thin-film based magnetic field sensor of claim 72, wherein the sensing element includes a thickness in a range of 10 to 5000 â„«.
0. 98. The ferromagnetic thin-film based magnetic field sensor of claim 72, wherein the sensing element includes a thickness in a range of 10 to 60 â„«.
0. 99. The ferromagnetic thin-film based magnetic field sensor of claim 72, wherein the ferromagnetic thin-film based magnetic field sensor is configured to generate a sensor signal, and wherein the first magnetic field is determined based on the sensor signal.
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One of each of the sense elements 102-105, 112-125, 122-125 and one of each of the pinned layers 106-109, 116-119, 126-129 form a magnetic tunnel junction (MTJ) sensor. For example, for bridge circuit 121, sense element 122 and pinned layer 126 form an MTJ sensor 141. Likewise, sense element 123 and pinned layer 127 form an MTJ sensor 142, sense element 124 and pinned layer 128 form an MTJ sensor 143, and sense element 125 and pinned layer 129 form an MTJ sensor 144.
The pinned layers 106-109, 116-119, and 126-129 may be formed with a single patterned ferromagnetic layer having a magnetization direction (indicated by the arrow) that aligns along the long-axis of the patterned reference layer(s). However, in other embodiments, the pinned reference layer may be implemented with a synthetic anti-ferromagnetic (SAF) layer which is used to align the magnetization of the pinned reference layer along the short axis of the patterned reference layer(s). As will be appreciated, the SAF layer may be implemented in combination with an underlying anti-ferromagnetic pinning layer, though with SAF structures with appropriate geometry and materials that provide sufficiently strong magnetization, the underlying anti-ferromagnetic pinning layer may not be required, thereby providing a simpler fabrication process with cost savings.
The sense elements 102-105, 112-125, 122-125 may be formed with one or more layers of ferromagnetic materials to a thickness in the range 10 to 5000 Å, and in selected embodiments in the range 10 to 60 Å. The upper ferromagnetic materials may be magnetically soft materials, such as NiFe, CoFe, Fe, CFB and the like. In each MTJ sensor, the sense elements 102-105, 112-125, 122-125 function as a sense layer or free magnetic layer because the direction of their magnetization can be deflected by the presence of an external applied field, such as the Earth's magnetic field. As finally formed, sense elements 102-105, 112-125, 122-125 may be formed with a single ferromagnetic layer having a magnetization direction (indicated with the arrows) that aligns along the long-axis of the patterned shapes.
The pinned layers 106-109, 116-119, 126-129 and sense elements 102-105, 112-125, 122-125 may be formed to have different magnetic properties. For example, the pinned layers 106-109, 116-119, 126-129 may be formed with an antiferromagnetic film exchange layer coupled to a ferromagnetic film to form layers with a high coercive force and offset hysteresis curves so that their magnetization direction will be pinned in one direction, and hence substantially unaffected by an externally applied magnetic field. In contrast, the sense elements 102-105, 112-125, 122-125 may be formed with a magnetically soft material to provide different magnetization directions having a comparatively low anisotropy and coercive force so that the magnetization direction of the sense electrode may be altered by an externally applied magnetic field. In selected embodiments, the strength of the pinning field is about two orders of magnitude larger than the anisotropy field of the sense electrodes, although different ratios may be used by adjusting the respective magnetic properties of the electrodes using well known techniques to vary their composition.
The pinned layers 106-109, 116-119, 126-129 in the MTJ sensors are formed to have a shape determined magnetization direction in the plane of the pinned layers 106-109, 116-119, 126-129 (identified by the vector arrows for each sensor bridge labeled “Pinning direction” in
The exemplary embodiments described herein may be fabricated using known lithographic processes as follows. The fabrication of integrated circuits, microelectronic devices, micro electro mechanical devices, microfluidic devices, and photonic devices involves the creation of several layers of materials that interact in some fashion. One or more of these layers may be patterned so various regions of the layer have different electrical or other characteristics, which may be interconnected within the layer or to other layers to create electrical components and circuits. These regions may be created by selectively introducing or removing various materials. The patterns that define such regions are often created by lithographic processes. For example, a layer of photoresist material is applied onto a layer overlying a wafer substrate. A photomask (containing clear and opaque areas) is used to selectively expose this photoresist material by a form of radiation, such as ultraviolet light, electrons, or x-rays. Either the photoresist material exposed to the radiation, or that not exposed to the radiation, is removed by the application of a developer. An etch may then be applied to the layer not protected by the remaining resist, and when the resist is removed, the layer overlying the substrate is patterned. Alternatively, an additive process could also be used, e.g., building a structure using the photoresist as a template.
Referring to
Referring again to
In another exemplary embodiment (shown in
Another exemplary embodiment (see
While various exemplary embodiments have been shown for the flux guides, including the vertical elements 132-139 of
Although the described exemplary embodiments disclosed herein are directed to various sensor structures and methods for making same, the present invention is not necessarily limited to the exemplary embodiments which illustrate inventive aspects of the present invention that are applicable to a wide variety of semiconductor processes and/or devices. Thus, the particular embodiments disclosed above are illustrative only and should not be taken as limitations upon the present invention, as the invention may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. For example, the relative positions of the sense and pinning layers in a sensor structure may be reversed so that the pinning layer is on top and the sense layer is below. Also the sense layers and the pinning layers may be formed with different materials than those disclosed. Moreover, the thickness of the described layers may deviate from the disclosed thickness values. Accordingly, the foregoing description is not intended to limit the invention to the particular form set forth, but on the contrary, is intended to cover such alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims so that those skilled in the art should understand that they can make various changes, substitutions and alterations without departing from the spirit and scope of the invention in its broadest form.
Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments. However, the benefits, advantages, solutions to problems, and any element(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential feature or element of any or all the claims. As used herein, the terms “comprises,” “comprising,” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.
While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment of the invention, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the invention as set forth in the appended claims.
Mather, Phillip, Slaughter, Jon, Rizzo, Nicholas
Patent | Priority | Assignee | Title |
Patent | Priority | Assignee | Title |
10276789, | Mar 31 2010 | Everspin Technologies, Inc. | Methods of manufacturing a magnetic field sensor |
10545196, | Mar 24 2016 | NXP USA, INC | Multiple axis magnetic sensor |
11024799, | Mar 31 2010 | Everspin Technologies, Inc. | Methods of manufacturing a magnetic field sensor |
4566050, | Dec 30 1982 | International Business Machines Corp. (IBM) | Skew insensitive magnetic read head |
5247278, | Nov 26 1991 | Honeywell Inc. | Magnetic field sensing device |
5343143, | Feb 11 1992 | Landis+Gyr LLC | Shielded current sensing device for a watthour meter |
5477143, | Jan 11 1994 | Honeywell Inc. | Sensor with magnetoresistors disposed on a plane which is parallel to and displaced from the magnetic axis of a permanent magnet |
5659499, | Nov 24 1995 | Everspin Technologies, Inc | Magnetic memory and method therefor |
5739988, | Sep 18 1996 | MARIANA HDD B V ; HITACHI GLOBAL STORAGE TECHNOLOGIES NETHERLANDS B V | Spin valve sensor with enhanced magnetoresistance |
5850624, | Oct 18 1995 | The Charles Machine Works, Inc. | Electronic compass |
5893981, | Jun 17 1996 | MARIANA HDD B V ; HITACHI GLOBAL STORAGE TECHNOLOGIES NETHERLANDS B V | Method of making stabilized MR sensor and flux guide joined by contiguous junction |
5930087, | Nov 20 1997 | SAMSUNG ELECTRONICS CO , LTD | Robust recording head for near-contact operation |
5940319, | Aug 31 1998 | Everspin Technologies, Inc | Magnetic random access memory and fabricating method thereof |
6016055, | Feb 02 1995 | Continental Automotive GmbH | Device for increasing the magnetic flux density in the vicinity of a hall sensor cooperating with a magnet wheel |
6023395, | May 29 1998 | International Business Machines Corporation | Magnetic tunnel junction magnetoresistive sensor with in-stack biasing |
6166539, | Oct 30 1996 | Regents of the University of Minnesota | Magnetoresistance sensor having minimal hysteresis problems |
6174737, | Aug 31 1998 | Everspin Technologies, Inc | Magnetic random access memory and fabricating method thereof |
6211090, | Mar 21 2000 | Everspin Technologies, Inc | Method of fabricating flux concentrating layer for use with magnetoresistive random access memories |
6501678, | Jun 18 1999 | Koninklijke Philips Electronics N V | Magnetic systems with irreversible characteristics and a method of manufacturing and repairing and operating such systems |
6545462, | |||
6577124, | Aug 14 1998 | U S PHILIPS CORPORATION | Magnetic field sensor with perpendicular axis sensitivity, comprising a giant magnetoresistance material or a spin tunnel junction |
6721149, | Feb 11 2000 | Western Digital Technologies, INC | Tunneling magnetoresistance spin-valve read sensor with LaNiO3 spacer |
6724584, | Feb 11 1999 | Seagate Technology LLC | Data head and method using a single antiferromagnetic material to pin multiple magnetic layers with differing orientation |
6731108, | Mar 23 2001 | Melexis Tessenderlo NV | Device with a magnetic position encoder |
6784510, | Apr 16 2003 | Everspin Technologies, Inc | Magnetoresistive random access memory device structures |
6875621, | Oct 13 1999 | NVE Corporation | Magnetizable bead detector |
7054114, | Nov 15 2002 | NVE Corporation | Two-axis magnetic field sensor |
7116100, | Mar 21 2005 | HR Textron, Inc. | Position sensing for moveable mechanical systems and associated methods and apparatus |
7126330, | Jun 03 2004 | Honeywell International, Inc. | Integrated three-dimensional magnetic sensing device and method to fabricate an integrated three-dimensional magnetic sensing device |
7235968, | Aug 22 2003 | Melexis Tessenderlo NV | Sensor for detecting the direction of a magnetic field in a plane |
7259556, | Aug 01 2002 | Melexis Tessenderlo NV | Magnetic field sensor and method for operating the magnetic field sensor |
7315470, | Oct 14 2003 | GLOBALFOUNDRIES U S INC | Data storage device and associated method for writing data to, and reading data from an unpatterned magnetic layer |
7358722, | Jun 03 2004 | Honeywell International Inc. | Integrated three-dimensional magnetic sensing device and method to fabricate an integrated three-dimensional magnetic sensing device |
7414396, | Jul 29 2005 | Everspin Technologies, Inc | Sensor with magnetic tunnel junction and moveable magnetic field source |
7505233, | Dec 15 2004 | International Business Machines Corporation | Magnetic sensor |
7509748, | Sep 01 2006 | Seagate Technology LLC | Magnetic MEMS sensors |
7564237, | Oct 23 2007 | Honeywell International Inc. | Integrated 3-axis field sensor and fabrication methods |
7642773, | Feb 23 2006 | MURATA MANUFACTURING CO , LTD | Magnetic sensor, production method thereof, rotation detection device, and position detection device |
7682840, | Nov 06 2002 | IMEC | Magnetic device and method of making the same |
7710113, | Oct 21 2004 | International Business Machines Corporation | Magnetic sensor with offset magnetic field |
7833806, | Jan 30 2009 | Everspin Technologies, Inc.; Everspin Technologies, Inc | Structure and method for fabricating cladded conductive lines in magnetic memories |
7915886, | Jan 29 2007 | Honeywell International Inc. | Magnetic speed, direction, and/or movement extent sensor |
7932571, | Oct 11 2007 | Everspin Technologies, Inc | Magnetic element having reduced current density |
7956604, | Jul 09 2008 | Infineon Technologies, AG | Integrated sensor and magnetic field concentrator devices |
8044494, | Dec 16 2005 | SHENZHEN XINGUODU TECHNOLOGY CO , LTD | Stackable molded packages and methods of making the same |
8093886, | Mar 30 2009 | Hitachi Metals, Ltd | Rotation-angle-detecting apparatus |
8193805, | May 14 2008 | SAE Magnetics (H.K.) Ltd. | Magnetic sensor |
8257596, | Apr 30 2009 | Everspin Technologies, Inc.; Everspin Technologies, Inc | Two-axis magnetic field sensor with substantially orthogonal pinning directions |
8269491, | Feb 27 2008 | Allegro MicroSystems, LLC | DC offset removal for a magnetic field sensor |
8278919, | Aug 11 2010 | The United States of America as represented by the Secretary of the Army; ARMY, UNITED STATES OF AMERICA AS REPRESENTED BY THE SECRETARY OF THE, THE | MEMS oscillating magnetic sensor and method of making |
8390283, | Sep 25 2009 | Everspin Technologies, Inc. | Three axis magnetic field sensor |
8476899, | Mar 11 2010 | ALPS ALPINE CO , LTD | Magnetic sensor and magnetic balance type current sensor including the same |
8518734, | Mar 31 2010 | Everspin Technologies, Inc.; Everspin Technologies, Inc | Process integration of a single chip three axis magnetic field sensor |
9091565, | Nov 22 2010 | Mitsubishi Electric Corporation | Magnetic position detection apparatus |
9269891, | Mar 31 2010 | Everspin Technologies, Inc | Process integration of a single chip three axis magnetic field sensor |
9362491, | Mar 31 2010 | Everspin Technologies, Inc. | Methods of manufacturing a magnetic field sensor |
9525129, | Mar 31 2010 | Everspin Technologies, Inc. | Methods of manufacturing a magnetic field sensor |
9530957, | Dec 02 2009 | ALPS ALPINE CO , LTD | Magnetic sensor |
9553261, | Mar 31 2010 | Everspin Technologies, Inc. | Methods of manufacturing a magnetic field sensor |
9893274, | Mar 31 2010 | Everspin Technologies, Inc. | Methods of manufacturing a magnetic field sensor |
9897667, | Jan 26 2016 | NXP USA, INC | Magnetic field sensor with permanent magnet biasing |
20020131219, | |||
20030035249, | |||
20030048676, | |||
20030148676, | |||
20040137275, | |||
20040137681, | |||
20040164840, | |||
20040207396, | |||
20050013060, | |||
20050036244, | |||
20050270020, | |||
20050275497, | |||
20060022286, | |||
20060087318, | |||
20060103381, | |||
20060126229, | |||
20070190669, | |||
20070209437, | |||
20070217077, | |||
20070217080, | |||
20070230066, | |||
20090052089, | |||
20090115405, | |||
20090243594, | |||
20090279212, | |||
20100072566, | |||
20100148167, | |||
20100181999, | |||
20100213933, | |||
20110062538, | |||
20110074406, | |||
20110304325, | |||
20120200292, | |||
20140138346, | |||
20150177285, | |||
20160104835, | |||
20160260894, | |||
CN101203769, | |||
CN101221849, | |||
CN1726561, | |||
DE10107491, | |||
DE19839446, | |||
EP91000, | |||
EP427171, | |||
EP1054449, | |||
EP2006700, | |||
EP3370072, | |||
FR2420143, | |||
FR2717324, | |||
JP2005197364, | |||
JP2005216390, | |||
JP200550288, | |||
JP2005502888, | |||
JP2006003116, | |||
JP2006267120, | |||
JP2008525789, | |||
JP2009216390, | |||
JP2009276159, | |||
JP765329, | |||
JP8075403, | |||
RE46180, | Sep 25 2009 | Everspin Technologies, Inc. | Three axis magnetic field sensor |
TW200604520, | |||
TW200849684, | |||
TW584735, | |||
WO2008146809, | |||
WO2008148600, | |||
WO2009048018, | |||
WO2009120894, |
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