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. 46. A ferromagnetic thin-film based magnetic field sensor comprising:
a first plurality of magnetoresistive sensors electrically connected into a first circuit, 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
wherein each magnetoresistive sensor further comprises a flux guide (i) adjacent to an associated sensing element and (ii) in a plane that is above or below the associated sensing element in the direction and parallel to the associated sensing element, wherein the flux guide includes a soft ferromagnetic material.
0. 30. A ferromagnetic thin-film based magnetic field sensor comprising:
a first plurality of magnetoresistive sensors electrically connected into a first circuit to sense a first magnetic field orthogonal to a plane of the first plurality of magnetoresistive sensors, 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
wherein each magnetoresistive sensor further comprises a flux guide (i) adjacent to an associated sensing element and (ii) above or below the associated sensing element in the direction, wherein the flux guide comprises a soft ferromagnetic material; and
a second plurality of magnetoresistive sensors electrically connected into a second circuit to sense a second magnetic field orthogonal to the first magnetic field.
0. 55. A ferromagnetic thin-film based magnetic field sensor comprising:
a first plurality of magnetoresistive sensors electrically connected into a first wheatstone bridge circuit 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, and wherein each magnetoresistive sensor further comprises a flux guide (i) adjacent to an associated sensing element and (ii) in a plane that is above or below the associated sensing element in the direction and parallel to the associated sensing element, wherein the flux guide includes a soft ferromagnetic material; and
a second plurality of magnetoresistive sensors electrically connected into a second wheatstone bridge circuit to sense a second magnetic field orthogonal to the first magnetic field.
0. 62. A ferromagnetic thin-film based magnetic field sensor comprising:
a first plurality of magnetoresistive sensors connected in a first bridge circuit 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 sensing element, and
a first flux guide comprising a soft ferromagnetic material, wherein the first flux guide is (i) adjacent to the sensing element of the first magnetoresistive sensor and (ii) above or below the sensing element of the first magnetoresistive sensor in the first direction;
the second magnetoresistive sensor comprising:
a sensing element, and
a second flux guide comprising a soft ferromagnetic material, wherein the second flux guide is (i) adjacent to the sensing element of the second magnetoresistive sensor and (ii) above or below the sensing element of the second magnetoresistive sensor in the first direction;
the third magnetoresistive sensor comprising:
a sensing element, and
a third flux guide comprising a soft ferromagnetic material, wherein the third flux guide is (i) adjacent to the sensing element of the third magnetoresistive sensor and (ii) above or below the sensing element of the third magnetoresistive sensor in the first direction; and
the fourth magnetoresistive sensor comprising:
a sensing element, and
a fourth flux guide comprising a soft ferromagnetic material, wherein the fourth flux guide is (i) adjacent to the sensing element of the fourth magnetoresistive sensor and (ii) above or below the sensing element of the fourth magnetoresistive sensor in the first direction.
0. 22. A ferromagnetic thin-film based magnetic field sensor comprising:
a plurality of magnetoresistive sensors connected in a first circuit to sense a magnetic field orthogonal to a plane of the plurality of magnetoresistive sensors, wherein the plurality of magnetoresistive sensors includes first, second, third, and fourth magnetoresistive sensors;
the first magnetoresistive sensor comprising in an order in a direction:
a reference layer,
an intermediate layer, and
a sensing element, and
wherein the first magnetoresistive sensor further comprises a first flux guide comprising a soft ferromagnetic material, wherein the first flux guide is (i) adjacent to the sensing element of the first magnetoresistive sensor and (ii) above or below the sensing element of the first magnetoresistive sensor in the direction;
the second magnetoresistive sensor comprising in the direction:
a reference layer,
an intermediate layer, and
a sensing element, and
wherein the second magnetoresistive sensor further comprises a second flux guide comprising a soft ferromagnetic material, wherein the second flux guide is (i) adjacent to the sensing element of the second magnetoresistive sensor and (ii) above or below the sensing element of the second magnetoresistive sensor in the direction;
the third magnetoresistive sensor comprising in the direction:
a reference layer,
an intermediate layer, and
a sensing element, and
wherein the third magnetoresistive sensor further comprises a third flux guide comprising a soft ferromagnetic material, wherein the third flux guide is (i) adjacent to the sensing element of the third magnetoresistive sensor and (ii) above or below the sensing element of the third magnetoresistive sensor in the direction; and
the fourth magnetoresistive sensor comprising in the direction:
a reference layer,
an intermediate layer, and
a sensing element, and
wherein the fourth magnetoresistive sensor further comprises a fourth flux guide comprising a soft ferromagnetic material, wherein the fourth flux guide is (i) adjacent to the sensing element of the fourth magnetoresistive sensor and (ii) above or below the sensing element of the fourth magnetoresistive sensor in the direction.
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 the first circuit is a bridge circuit.
0. 24. The ferromagnetic thin-film based magnetic field sensor of claim 22, wherein the plurality of magnetoresistive sensors are connected in the first circuit to provide a differential measurement.
0. 25. 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. 26. The ferromagnetic thin-film based magnetic field sensor of claim 22, wherein each of the first, second, third, and fourth flux guides is a bar comprising a soft ferromagnetic material.
0. 27. The ferromagnetic thin-film based magnetic field sensor of claim 22, wherein the first circuit is electrically coupled to a voltage meter.
0. 28. The ferromagnetic thin-film based magnetic field sensor of claim 22, wherein the first circuit includes input terminals configured to connect to an electrical source.
0. 29. The ferromagnetic thin-film based magnetic field sensor of claim 22, wherein each of the sensing elements of the first, second, third, and fourth magnetoresistive sensors includes a sense axis parallel to the plane of the plurality of magnetoresistive sensors.
0. 31. The ferromagnetic thin-film based magnetic field sensor of claim 30, wherein the first and second circuits are located on or in a single substrate.
0. 32. The ferromagnetic thin-film based magnetic field sensor of claim 30, wherein each magnetoresistive sensor of the first and second pluralities of magnetoresistive sensors is a magnetic tunnel junction sensor.
0. 33. The ferromagnetic thin-film based magnetic field sensor of claim 30, wherein each of the first and second circuits is a bridge circuit.
0. 34. The ferromagnetic thin-film based magnetic field sensor of claim 30, wherein the first circuit is electrically coupled to a voltage meter.
0. 35. The ferromagnetic thin-film based magnetic field sensor of claim 30, wherein each magnetoresistive sensor of the first and second pluralities of magnetoresistive sensors includes a sense axis parallel to the plane of the first plurality of magnetoresistive sensors.
0. 36. The ferromagnetic thin-film based magnetic field sensor of claim 30, wherein the flux guide of each magnetoresistive sensor of the first plurality of magnetoresistive sensors is a bar comprising a soft ferromagnetic material.
0. 37. The ferromagnetic thin-film based magnetic field sensor of claim 30, wherein the reference layer of each magnetoresistive sensor of the first plurality of magnetoresistive sensors includes a first pinning direction, and wherein each magnetoresistive sensor of the second plurality of magnetoresistive sensors includes a reference layer having a second pinning direction orthogonal to the first pinning direction.
0. 38. The ferromagnetic thin-film based magnetic field sensor of claim 30, wherein the first circuit includes input and output terminals, and wherein the magnetic field sensor further includes:
an electrical source electrically coupled to the input terminals, and
a voltage meter electrically coupled to the output terminals.
0. 39. The ferromagnetic thin-film based magnetic field sensor of claim 30, wherein the intermediate layer of each magnetoresistive sensor of the first plurality of magnetoresistive sensors is an insulating dielectric 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 directly above or directly below a portion of the sensing element of the first, second, third, and fourth magnetoresistive sensors, respectively.
0. 41. The ferromagnetic thin-film based magnetic field sensor of claim 22, wherein the order in the direction includes:
the sensing element of each of the first, second, third, and fourth magnetoresistive sensors being formed on or above the intermediate layer of each of the first, second, third, and fourth magnetoresistive sensors, respectively, and
the intermediate layer of each of the first, second, third, and fourth magnetoresistive sensors being formed on or above the reference layer of each of the first, second, third, and fourth magnetoresistive sensors, respectively.
0. 42. The ferromagnetic thin-film based magnetic field sensor of claim 22, wherein the order in the direction includes:
the reference layer of each of the first, second, third, and fourth magnetoresistive sensors being formed on or above the intermediate layer of each of the first, second, third, and fourth magnetoresistive sensors, respectively, and
the intermediate layer of each of the first, second, third, and fourth magnetoresistive sensors being formed on or above the sensing element of each of the first, second, third, and fourth magnetoresistive sensors, respectively.
0. 43. The ferromagnetic thin-film based magnetic field sensor of claim 30, wherein the flux guide is directly above or directly below a portion of the associated sensing element.
0. 44. The ferromagnetic thin-film based magnetic field sensor of claim 30, 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. 45. The ferromagnetic thin-film based magnetic field sensor of claim 30, 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. 47. The ferromagnetic thin-film based magnetic field sensor of claim 46, further comprising:
a second plurality of magnetoresistive sensors electrically connected into a second circuit, wherein the first circuit is configured to sense a first magnetic field orthogonal to a plane of the first plurality of magnetoresistive sensors, and wherein the second circuit is configured to sense a second magnetic field orthogonal to the first magnetic field.
0. 48. The ferromagnetic thin-film based magnetic field sensor of claim 46, wherein the intermediate layer of each magnetoresistive sensor of the first plurality of magnetoresistive sensors is an insulating dielectric layer.
0. 49. The ferromagnetic thin-film based magnetic field sensor of claim 46, wherein each magnetoresistive sensor of the first plurality of magnetoresistive sensors is a magnetic tunnel junction sensor.
0. 50. The ferromagnetic thin-film based magnetic field sensor of claim 46, wherein the first circuit is a wheatstone bridge circuit.
0. 51. The ferromagnetic thin-film based magnetic field sensor of claim 46, wherein the first circuit includes input conductors configured for connection to an electrical source.
0. 52. The ferromagnetic thin-film based magnetic field sensor of claim 46, wherein the first circuit includes output conductors configured for connection to a voltage meter.
0. 53. The ferromagnetic thin-film based magnetic field sensor of claim 46, 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. 54. The ferromagnetic thin-film based magnetic field sensor of claim 46, 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. 56. The ferromagnetic thin-film based magnetic field sensor of claim 55, 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. 57. The ferromagnetic thin-film based magnetic field sensor of claim 55, 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. 58. The ferromagnetic thin-film based magnetic field sensor of claim 55, wherein each magnetoresistive sensor of the first plurality of magnetoresistive sensors is a magnetic tunnel junction sensor.
0. 59. The ferromagnetic thin-film based magnetic field sensor of claim 55, wherein the first circuit includes input conductors configured for connection to an electrical source.
0. 60. The ferromagnetic thin-film based magnetic field sensor of claim 55, wherein the first circuit includes output conductors configured for connection to a voltage meter.
0. 61. The ferromagnetic thin-film based magnetic field sensor of claim 55, further comprising:
a third plurality of magnetoresistive sensors electrically connected into a third wheatstone bridge circuit to sense a third magnetic field orthogonal to the first and second magnetic fields.
0. 63. The ferromagnetic thin-film based magnetic field sensor of claim 62, wherein each of the first, second, third, and fourth magnetoresistive sensors is a magnetic tunnel junction sensor.
0. 64. The ferromagnetic thin-film based magnetic field sensor of claim 62, wherein the first bridge circuit includes output conductors configured for connection to a voltage meter.
0. 65. The ferromagnetic thin-film based magnetic field sensor of claim 62, wherein the first bridge circuit includes input conductors configured for connection to an electrical source.
0. 66. The ferromagnetic thin-film based magnetic field sensor of claim 62, further comprising:
a second plurality of magnetoresistive sensors connected in a second bridge circuit to sense a magnetic field in a second direction orthogonal to the first direction.
0. 67. The ferromagnetic thin-film based magnetic field sensor of claim 62, further comprising:
a second plurality of magnetoresistive sensors connected in a second bridge circuit to sense a magnetic field in a second direction orthogonal to the first direction; and
a third plurality of magnetoresistive sensors connected in a third bridge circuit to sense a magnetic field in a third direction orthogonal to the first and second directions.
0. 68. The ferromagnetic thin-film based magnetic field sensor of claim 22, wherein each of the soft ferromagnetic materials is nickel iron (NiFe).
0. 69. The ferromagnetic thin-film based magnetic field sensor of claim 30, wherein the soft ferromagnetic material is nickel iron (NiFe).
0. 70. The ferromagnetic thin-film based magnetic field sensor of claim 46, wherein the soft ferromagnetic material is nickel iron (NiFe).
0. 71. The ferromagnetic thin-film based magnetic field sensor of claim 55, wherein the soft ferromagnetic material is nickel iron (NiFe).
0. 72. The ferromagnetic thin-film based magnetic field sensor of claim 62, wherein each of the soft ferromagnetic materials is nickel iron (NiFe).
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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 anti-ferromagnetic 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
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