Magnetic flux concentrator for out-of-plane magnetic field concentration

Abstract

SOLUTION: A structure (100) includes a substrate (110) including a surface. The structure (100) also includes a horizontal-type Hall sensor (120) disposed in the substrate (110) and below a surface of the substrate (110). The structure (100) further includes a protective overcoat layer (140) disposed over the surface of the substrate (110) and a spherical magnetic concentrator (134) disposed over the protective overcoat layer (140). Instead of the spherical magnetic concentrator (134) or in addition to the spherical magnetic concentrator (134), the structure (100) may include an embedded magnetic concentrator (132) disposed in the substrate (110) and below the horizontal Hall sensor (120).SELECTED DRAWING: Figure 1

Description

[Background technology]

[0001] Two-dimensional (2D) speed and direction sensors use both horizontal and vertical Hall sensors. Hall sensors are used to measure the magnitude of a magnetic field. Their output voltage is directly proportional to the strength of the magnetic field across the Hall sensor. Hall sensors can be used for proximity sensing, position, speed detection, and current sensing applications. 2D pulse encoders also use horizontal Hall sensors, but with sensitivity-enhancing magnetic concentrators formed through package-level deposition, for example, via pick-and-place of magnetic concentrator disks. Because the magnetic concentrators are disk-shaped, the magnetic field strength near the Hall sensor is weak, resulting in low structural sensitivity. Summary of the Invention

[0002] In at least one example, a structure includes a substrate including a surface, the structure includes a horizontal Hall sensor disposed within the substrate and below the surface of the substrate, the structure further includes a protective overcoat layer disposed above the surface of the substrate, and a spherical magnetic concentrator disposed above the protective overcoat layer.

[0003] In another example, a structure includes a substrate including a surface, the structure also includes a horizontal Hall sensor disposed within the substrate and below the surface of the substrate, and the structure further includes an embedded magnetic concentrator disposed within the substrate and below the horizontal Hall sensor.

[0004] In yet another example, a method of forming a structure includes forming a substrate including a surface, disposing a horizontal Hall sensor in the substrate and below the surface of the substrate, forming a protective overcoat layer above the surface of the substrate, and placing a spherical magnetic concentrator above the protective overcoat layer.

[0005] In yet another example, a method of forming a structure includes forming a substrate including a surface, disposing a horizontal Hall sensor in the substrate and below the surface of the substrate, and forming an embedded magnetic concentrator in the substrate and below the horizontal Hall sensor. [Brief explanation of the drawings]

[0006] Reference will now be made to the accompanying drawings for a detailed description of various examples.

[0007] [Figure 1] 1 is a cross-sectional schematic side view of a structure including a substrate, a horizontal Hall sensor, an interlevel dielectric oxide layer, a protective overcoat layer, a buried magnetic concentrator, and a spherical-shaped magnetic concentrator.

[0008] [Figure 2] 1 is a cross-sectional schematic side view of a structure including a substrate, a lateral Hall sensor, an interlevel dielectric oxide layer, a protective overcoat layer, an embedded magnetic concentrator, and a patterned magnetic concentrator.

[0009] [Figure 3] FIG. 1 is a top perspective view of a structure including a spherical magnetic concentrator disposed above a protective overcoat layer.

[0010] [Figure 4] 1A is a bottom perspective view of a structure including a cylindrical or rod-shaped embedded magnetic concentrator positioned within a substrate and below a horizontal Hall sensor (relative to the orientation of FIG. 1). FIG.

[0011] [Figure 5] 1 is a bottom perspective view of a structure including a pyramidal-shaped embedded magnetic concentrator disposed within a substrate, where the pyramidal-shaped embedded magnetic concentrator is disposed below the horizontal Hall sensor relative to the orientation of FIG. 1 (i.e., by replacing the rod-shaped embedded magnetic concentrator shown in FIG. 1 with the pyramidal-shaped embedded magnetic concentrator).

[0012] [Figure 6] 1 is a bottom perspective view of a structure including a cylindrically-conical embedded magnetic concentrator disposed within a substrate, with respect to the orientation of FIG. 1 (i.e., by replacing the rod-shaped embedded magnetic concentrator shown in FIG. 1 with the cylindrically-conical embedded magnetic concentrator), the cylindrically-conical embedded magnetic concentrator being disposed below the horizontal Hall sensor.

[0013] [Figure 7] 1 is a top perspective view of a structure including a patterned magnetic concentrator disposed beneath a protective overcoat layer, the protective overcoat layer not shown.

[0014] [Figure 8] FIG. 1 is a schematic top perspective view of a structure including an array of spherically shaped magnetic concentrators disposed above a protective overcoat layer.

[0015] [Figure 9] FIG. 1 is a schematic top perspective view of a structure including an array of bar-shaped embedded magnetic concentrators disposed within a substrate.

[0016] [Figure 10A] FIG. 1 is a schematic top perspective view of a structure including an array of bar-shaped embedded magnetic concentrators disposed in a substrate and a patterned magnetic concentrator disposed above the array of bar-shaped embedded magnetic concentrators.

[0017] [Figure 10B] FIG. 10B is a top schematic view of the structure shown in FIG. 10A. DETAILED DESCRIPTION OF THE INVENTION

[0018] An aspect of the present description is to improve the sensitivity of Hall sensors using a combination of a magnetic concentrator and at least one horizontal Hall sensor. Hall sensors are devices used to measure the magnitude of magnetic fields. Their output voltage is directly proportional to the strength of the magnetic field across the Hall sensor. Hall sensors are used for proximity sensing, position, speed detection, direction detection, rotation detection, and current sensing applications. Hall sensors can be used in magnetic switches or rotary switches or shifters, where the Hall sensors measure changes in direction or rotation of such switches or shifters.

[0019] A horizontal Hall sensor has a longitudinal axis that is horizontal and parallel to the flat upper surface of the substrate, which also extends horizontally. Similarly, a vertical Hall sensor has a longitudinal axis that is vertical and perpendicular to the flat upper horizontal surface of the substrate. A horizontal Hall sensor measures a vertical magnetic field, and conversely, a vertical Hall sensor measures a horizontal magnetic field. The use of the terms "horizontal" and "vertical" should not be construed as being limited to reference only to the Earth's surface. Such use should be interpreted relative to elements of the structure. For example, the structure in FIG. 1 could be rotated, e.g., 90 degrees. Even when rotated in this manner, the horizontal Hall sensor 120 would still be considered a "horizontal Hall sensor" and would still measure a vertical magnetic field. Other terms, such as "top," "bottom," "upper," and "lower," should be interpreted similarly.

[0020] In one example, FIG. 1 shows a cross-sectional schematic side view of a structure 100 including a substrate 110, a horizontal Hall sensor 120, an interlevel dielectric oxide layer 125, an embedded magnetic concentrator 132, a protective overcoat layer 140, and a spherical magnetic concentrator 134. As shown in FIG. 1, a magnetic field is applied out-of-plane (i.e., vertically). The substrate 110 may include Si, glass, ceramic, etc. Below the surface of the substrate 110 is the horizontal Hall sensor 120. The horizontal Hall sensor 120 is electrically connected to circuitry (not shown) so that the Hall sensor 120 can measure the magnetic field. Circuit elements may be integrated on the substrate 110, for example, within the interlevel dielectric oxide layer 125. The interlevel dielectric oxide layer 125 includes metal routing for the Hall sensor and associated integrated circuitry. Alternatively, the circuit elements may be located remotely (e.g., on a separate substrate). 1 illustrates the use of both embedded magnetic concentrators 132 and spherical magnetic concentrators 134, either magnetic concentrator may be used alone. When both magnetic concentrators are used, the magnetic field focusing effect is further amplified / magnified than when only one of the magnetic concentrators is used.

[0021] During wafer processing, before the protective overcoat layer 140 is formed, the buried magnetic concentrators 132 are formed, for example, by an etching process (such as a through-silicon via (TSV)) through the bottom surface of the substrate 110 where a via or hole is formed, followed by a deposition process to fill the etched / via area, such as by sputtering or spraying a ferromagnetic material (e.g., NiFe). The fill material (i.e., the material of the resulting buried magnetic concentrators 132) is described below.

[0022] The embedded magnetic concentrator 132 is bar-shaped and includes a ferromagnetic material such as NiFe (e.g., with a horizontal thickness (diameter) of 10 μm to 100 μm and a vertical height of 60 μm to 800 μm). The top surface of the embedded magnetic concentrator 132 is spaced below the Hall sensor 120 by a distance in the range of 10 μm to 100 μm, while the bottom surface of the embedded magnetic concentrator 132 extends to the bottom surface of the substrate 110.

[0023] By locating the embedded magnetic concentrator 132 below the Hall sensor 120, a magnetic field applied substantially perpendicularly from above the Hall sensor 120 strikes the surface of the Hall sensor 120 perpendicularly and is concentrated at the Hall sensor 120, thereby providing amplification / boosting of the magnetic field before it reaches the Hall sensor 120. The Hall sensor 120 receives the amplified magnetic field. In other words, having the embedded magnetic concentrator 132 below the Hall sensor 120 keeps the magnetic field concentrated as it exits the bottom of the Hall sensor 120 and before it exits the bottom surface of the substrate 110.

[0024] In one example, a spherical magnetic concentrator 134 may be included in the structure 100 of FIG. 1. The spherical magnetic concentrator 134 may be formed by pick-and-place or other deposition process. The spherical magnetic concentrator 134 includes a ferromagnetic material, such as NiFe, and is formed with a diameter in the range of 30 μm to 450 μm. The bottom surface of the spherical magnetic concentrator 134 is spaced above the horizontal Hall sensor 120 by a distance in the range of 4 μm to 50 μm.

[0025] The spherical-shaped magnetic concentrators 134 are placed above a protective overcoat layer 140, optionally in a layer of, for example, polyamide (which may be 10-30 μm thick). If used, a polyamide layer (not shown) is formed over the protective overcoat layer 140. The spherical-shaped magnetic concentrators 134 may be formed within the polyamide layer, or alternatively, may be formed above the polyamide layer. Polyamide has good mechanical elongation and tensile strength, which aids bonding, temperature stability, and mechanical stability of the die, making the die less susceptible to pressure / stress changes from the mold compound.

[0026] By placing the spherical magnetic concentrator 134 above the Hall sensor 120, and due to its spherical shape, a magnetic field applied substantially perpendicularly from above the spherical magnetic concentrator 134 strikes the surface of the Hall sensor 120 perpendicularly and is concentrated at the Hall sensor 120, thereby providing amplification / boosting of the magnetic field before it reaches the Hall sensor 120. The Hall sensor 120 receives the amplified magnetic field.

[0027] In one implementation, protective overcoat layer 140 is a layer of SiON or other dielectric material (eg, 2.8 μm thick), although other thicknesses may alternatively be used.

[0028] In one example, Figure 2 shows a cross-sectional schematic side view of a structure 200 including a substrate 210, a horizontal Hall sensor, an interlevel dielectric oxide layer 225, a protective overcoat layer 240, and patterned magnetic concentrators 230, 231. As shown in Figure 2, a magnetic field is applied in-plane (i.e., horizontally). The buried magnetic concentrator 232 can be the same as the buried magnetic concentrator 132 used in Figure 1. In addition to the buried magnetic concentrator 232, either or both of the patterned magnetic concentrators 230, 231 can be used.

[0029] Patterned magnetic concentrator 230 (i.e., formed below protective overcoat layer 240) may be of the type (e.g., including multiple sizes, shapes, and / or layers of magnetic material) disclosed in co-pending U.S. application Ser. No. 16 / 521,053, filed July 24, 2019 (the '053 application). Neighboring layers of the magnetic concentrator in the '053 application may also be used in this example. Patterned magnetic concentrator 230 may be formed using any of the processes described for forming magnetic concentrators in the '053 application. Additional horizontal Hall sensors may be located below patterned magnetic concentrator 230 (i.e., within substrate 210), similar to those disclosed in the '053 application. [Patent Document 1] U.S. Application No. 16 / 521,053

[0030] As an alternative to, or in addition to, patterned magnetic concentrator 230, patterned magnetic concentrator 231 may be used. Although patterned magnetic concentrator 231 is formed above protective overcoat layer 240, patterned magnetic concentrator 231 may be of the type disclosed in the '053 application (e.g., including multiple sizes, shapes, and / or layers of magnetic material). Neighboring layers of the magnetic concentrator in the '053 application may also be used in this example. Patterned magnetic concentrator 231 may be formed using any of the processes described for forming magnetic concentrators in the '053 application. Additional horizontal Hall sensors may be placed below patterned magnetic concentrator 231 (i.e., within substrate 210), similar to those disclosed in the '053 application.

[0031] As also disclosed in the '053 application, as a result of using one or both of the patterned magnetic concentrators 230, 231, the input magnetic field is redirected or transformed from horizontal to vertical.

[0032] When a combination of embedded magnetic concentrator 232 and either or both of patterned magnetic concentrators 230, 231 is used, the concentrating effect of the magnetic field is further amplified / magnified before it reaches the Hall sensor than when any one of the magnetic concentrators is used alone.

[0033] In one example, FIG. 3 shows a top perspective view of a structure 300 including a substrate 310 and a spherical magnetic concentrator 334 disposed above a protective overcoat layer 340. For simplicity, the horizontal Hall sensor and remaining layers are not shown. The spherical magnetic concentrator 334 may have a diameter ranging from 30 μm to 450 μm, for example. The substrate 310 may have a width ranging from 0.7 mm to 2 mm and a depth / thickness ranging from 60 to 800 μm. The Hall sensor may have a thickness (i.e., the depth of the hole well) ranging from 1 to 3 μm and may be spaced a distance of 3 to 5 μm from the top surface of the substrate 310. The protective overcoat layer (not shown) may have any thickness.

[0034] In one example, Figure 4 shows a bottom perspective view of a structure 400 including a bar-shaped embedded magnetic concentrator 432 located within a substrate 410 and below a horizontal Hall sensor (relative to the orientation of Figure 1). A protective overcoat layer 440 is shown. For simplicity, the horizontal Hall sensor and remaining layers are not shown.

[0035] In one example, FIG. 5 shows a bottom perspective view of a structure 500 including a pyramidal-shaped embedded magnetic concentrator 532 disposed within a substrate 510. Relative to the orientation of FIG. 1 (i.e., by replacing the bar-shaped embedded magnetic concentrator shown in FIG. 1 with a pyramidal-shaped embedded magnetic concentrator), the pyramidal-shaped embedded magnetic concentrator 532 is disposed below a horizontal Hall sensor (not shown). A protective overcoat layer 540 is shown. For simplicity, the horizontal Hall sensor and remaining layers are not shown. The pyramidal-shaped embedded magnetic concentrator 532 may be hollow or filled. In either scenario, the pyramidal-shaped embedded magnetic concentrator 532 and / or its filler material comprise a ferromagnetic material such as NiFe. The pyramidal-shaped embedded magnetic concentrator 532 may have a horizontal width of 10 μm to 100 μm and a vertical height of 60 μm to 800 μm. The apex of the pyramidal-shaped embedded magnetic concentrator 532 is spaced below the Hall sensor by a distance ranging from 10 μm to 100 μm, while the bottom surface (i.e., base) of the pyramidal-shaped embedded magnetic concentrator 532 extends to the bottom surface of the substrate 510. The pyramidal-shaped embedded magnetic concentrators 532 are formed in the substrate 510 (e.g., by wet etching). The above dimensions and spacing for the pyramidal-shaped embedded magnetic concentrators 532 may be limited by the angle of etching: e.g., 54.7 degrees for (100) and (111) surface wafers.

[0036] In one example, FIG. 6 shows a bottom perspective view of a structure 600 including a cylindrically-conical embedded magnetic concentrator 632 disposed within a substrate 610. Relative to the orientation of FIG. 1 (i.e., by replacing the bar-shaped embedded magnetic concentrator shown in FIG. 1 with a cylindrically-conical embedded magnetic concentrator), the cylindrically-conical embedded magnetic concentrator 632 is disposed below a horizontal Hall sensor (not shown). A protective overcoat layer 640 is shown. For simplicity, the horizontal Hall sensor and remaining layers are not shown. The cylindrically-conical embedded magnetic concentrator 632 may be hollow or filled. In either scenario, the cylindrically-conical embedded magnetic concentrator 632 and / or its filler material comprise a ferromagnetic material such as NiFe. The cylindrically-conical embedded magnetic concentrator 632 may have a horizontal diameter of 10 μm to 100 μm and a vertical height of 60 μm to 800 μm. The apex of the cylindrically-conical embedded magnetic concentrator 632 is spaced below the Hall sensor by a distance ranging from 10 μm to 100 μm, while the bottom surface of the cylindrically-conical embedded magnetic concentrator 632 extends to the bottom surface of the substrate 610. The cylindrically-conical embedded magnetic concentrator 632 may be formed in a manner similar to the pyramidal embedded magnetic concentrator 532 described above. The above dimensions and spacing for the cylindrically-conical embedded magnetic concentrator 632 may be limited by the etch angle, e.g., 54.7 degrees for (100) and (111) wafers.

[0037] 7 shows a top perspective view of a structure 700 including a patterned magnetic concentrator 730 disposed below a protective overcoat layer (not shown). A substrate 710 and an interlevel dielectric oxide layer 725 are shown. For simplicity, the horizontal Hall sensor and remaining layers are not shown. In this example, an additional horizontal Hall sensor may be placed below the patterned magnetic concentrator 730 (i.e., within the substrate 710), similar to that disclosed in the '053 application.

[0038] Various patterned shapes and locations of the magnetic concentrator enable greater structural sensitivity by enhancing / amplifying the magnetic field near the area of ​​the Hall sensor. While different magnetic concentrator shapes provide different magnetic field outputs, they also enhance the magnetic field by concentrating such output near the Hall sensor. Table 1 below shows the enhancement / amplification / concentration of the magnetic field from various exemplary shaped magnetic concentrators at the locations described in the above embodiments, resulting from, for example, an applied vertical magnetic flux of 1 mT (i.e., out-of-plane for sphere-, pyramidal-, and bar-shaped magnetic concentrators) or an applied horizontal magnetic flux of 1 mT (i.e., in-plane for patterned, pyramidal, and bar-shaped magnetic concentrators). For example, when a vertical magnetic flux of 1 mT is applied to a spherical-shaped magnetic concentrator (having a diameter of 150 μm), the vertical magnetic field output can be amplified by a factor of 2.8. As shown in Table 1, the pyramidal-shaped magnetic concentrator concentrates the magnetic field more than magnetic concentrators of other shapes. The apex of the pyramid is near or adjacent to the Hall sensor from below, concentrating the magnetic field at the apex. Because the vertex includes a point at or near the Hall sensor, the highly concentrated magnetic field experienced by the vertex is input to the Hall sensor. The magnetic flux enhancement listed in Table 1 assumes each associated magnetic concentrator acting alone. However, when magnetic concentrators are combined (e.g., a ball and rod), a cumulative magnetic flux enhancement is achieved. [Table 1]

[0039] 8 shows a schematic top perspective view of a structure 800 including a substrate 810 and an array of spherically shaped magnetic concentrators 834 disposed above a protective overcoat layer 840. For simplicity, the horizontal Hall sensors (disposed below each spherically shaped magnetic concentrator 834) and the remaining layers are not shown.

[0040] 9 shows a schematic top perspective view of a structure 900 including an array of bar-shaped embedded magnetic concentrators 932 disposed below horizontal Hall sensors within a substrate 910. For simplicity, the horizontal Hall sensors (which are each disposed above the bar-shaped embedded magnetic concentrators 932) and the remaining layers are not shown.

[0041] In one example, FIG. 10A shows a schematic top perspective view of a structure 1000 including an array of bar-shaped embedded magnetic concentrators 1032 disposed within a substrate 1010 below horizontal Hall sensors and a patterned magnetic concentrator 1030 disposed above the array of bar-shaped embedded magnetic concentrators 1032. For simplicity, the horizontal Hall sensors (each disposed above the bar-shaped embedded magnetic concentrators 1032) and the remaining layers are not shown. In this example, an additional horizontal Hall sensor can be placed below the patterned magnetic concentrators 1030 (i.e., within the substrate 1010), similar to that disclosed in the '053 application. In this manner, Hall sensors are both above the bars and below the tips of the patterned magnetic concentrators 1030. FIG. 10B is a schematic top view of the structure 1000 shown in FIG. 10A. Another example configuration has the bar-shaped embedded magnetic concentrators 1032 disposed below the Hall sensors, which are below the tips of the patterned magnetic concentrators 1030. Also, with multiple Hall sensors, this configuration can detect magnetic fields applied in all directions (x, y, z).

[0042] Referring again to Figure 1, when a magnetic field (B) is applied vertically from above, the spherical magnetic concentrator 134 concentrates the magnetic field. The structures in Figures 3-6, 8, and 9 are designed to use a vertically applied input magnetic field as in Figure 1. Importantly, with this configuration, a vertical Hall sensor (which measures a magnetic field applied horizontally from the side) is not required for this structure.

[0043] Referring again to FIG. 2, when a magnetic field (B) is applied horizontally from the side, the patterned magnetic concentrator 230 concentrates the magnetic field. This concentration occurs at the tip of the patterned magnetic concentrator 230, causing the magnetic field to bend and change direction from horizontal to vertical. This conversion causes the horizontally applied magnetic field (B) to arc and bend into a vertical field as the field enters the substrate 210. In other words, an input magnetic field in the in-plane (xy) direction is converted into an output magnetic field in the out-of-plane (z) direction. The patterned magnetic concentrator 231 above the protective overcoat layer 240 functions similarly to the patterned magnetic concentrator 230, i.e., converting an input magnetic field in the in-plane (xy) direction into an output magnetic field in the out-of-plane (z) direction. The horizontal Hall sensor 220 is positioned in the vertical magnetic field to maximize its measurement of the magnetic field in the z direction. The structures in FIGS. 7, 10A, and 10B are designed to use a horizontally applied input magnetic field as in FIG. 2. Importantly, due to this configuration, vertical Hall sensors (which measure magnetic fields applied horizontally from the side) are not required in this structure.

[0044] Referring again to Figure 1 and Table 1 above, an applied magnetic field of 1 mT in the z direction results in a maximum output of 14 mT in the z direction. A sensitivity enhancement / amplification / concentration of up to 6.2 times (a combination of 2.8 times for the sphere and 3.4 times for the rod according to Table 1, assuming a 10 μm separation from the rod end to the Hall sensor) of the magnetic field can be achieved with this structure.

[0045] 2 and Table 1 above, an applied magnetic field of 1 mT in the x-direction results in a maximum output of 14 mT in the z-direction. A sensitivity enhancement / amplification / concentration of up to 10.4 times (a combination of 7 times for the sputtered patterned magnetic concentrator 230 and 3.4 times for the rod according to Table 1, assuming a 10 μm separation from the rod end to the Hall sensor) of the magnetic field can be achieved with this structure.

[0046] Although the Hall sensors are shown as rectangular in shape from a top view, they may be other shapes, such as a cross. Also, any single Hall sensor may alternatively be replaced with an array of Hall sensors (i.e., two or more Hall sensors). Arrays can be made by cross-connecting two or four sensors together in a given array. The purpose of an array is to reduce offset and resistance. Offset negatively impacts sensor accuracy, and resistance introduces thermal noise and sets voltage headroom.

[0047] The magnetic concentrators in any of the above examples may be used alone or in combination with at least one magnetic concentrator from another example, the use of additional magnetic concentrators providing an additional increase in magnetic field power.

[0048] In any of the above examples, using only horizontal Hall sensors reduces the degree of possible mismatch between the Hall sensors in terms of calibration, whereas using both horizontal and vertical Hall sensors requires additional or extensive calibration, thereby adding significant complexity and time to wafer fabrication and packaging.

[0049] Referring again to at least FIGS. 1 and 8, in at least one example, a structure includes a substrate including a surface. The structure also includes horizontal Hall sensors within the substrate and disposed below the surface of the substrate. The structure further includes a protective overcoat layer disposed above the surface of the substrate and spherical magnetic concentrators disposed above the protective overcoat layer. The spherical magnetic concentrators are disposed above the horizontal Hall sensors. The structure may further include an array of horizontal Hall sensors within the substrate and disposed below the surface of the substrate and an array of spherical magnetic concentrators disposed above the protective overcoat layer. The spherical magnetic concentrators are each disposed above the horizontal Hall sensors.

[0050] In another example, a method for forming a structure includes forming a substrate including a surface, disposing horizontal Hall sensors within the substrate and below the surface of the substrate, forming a protective overcoat layer above the surface of the substrate, and disposing spherical magnetic concentrators above the protective overcoat layer. The disposing step includes disposing the spherical magnetic concentrators above the horizontal Hall sensors. The method further includes disposing an array of horizontal Hall sensors within the substrate below the surface of the substrate and disposing the array of spherical magnetic concentrators above the protective overcoat layer. The disposing the array of spherical magnetic concentrators above the protective overcoat layer includes disposing the spherical magnetic concentrators respectively above the horizontal Hall sensors.

[0051] Referring again to at least FIGS. 1 , 2 , and 9 , in another example, a structure includes a substrate including a surface. The structure also includes a horizontal Hall sensor disposed within the substrate and below the surface of the substrate. The structure further includes an embedded magnetic concentrator disposed within the substrate and below the horizontal Hall sensor. The embedded magnetic concentrator may include a shape selected from the group consisting of a rod, a pyramid, a cylinder, and combinations thereof. The structure may further include an array of horizontal Hall sensors disposed within the substrate and below the surface of the substrate and an array of embedded magnetic concentrators disposed within the substrate, each embedded magnetic concentrator disposed below the horizontal Hall sensor.

[0052] The structure may further include a protective overcoat layer disposed above the surface of the substrate and a spherical magnetic concentrator disposed above the protective overcoat layer and above the horizontal Hall sensors. The structure may further include an array of horizontal Hall sensors disposed within the substrate and below the surface of the substrate and an array of spherical magnetic concentrators disposed above the protective overcoat layer, the spherical magnetic concentrators each disposed above the horizontal Hall sensors.

[0053] The structure may further include a protective overcoat layer disposed above the surface of the substrate, and a patterned magnetic concentrator disposed above the surface of the substrate and below the protective overcoat layer. The structure may further include an array of horizontal Hall sensors disposed in the substrate and below the surface of the substrate, and an array of embedded magnetic concentrators disposed in the substrate, each embedded magnetic concentrator disposed below the horizontal Hall sensors.

[0054] In another example, a method of forming a structure includes forming a substrate including a surface, disposing horizontal Hall sensors in the substrate below the surface of the substrate, and forming embedded magnetic concentrators in the substrate below the horizontal Hall sensors. The embedded magnetic concentrators may include a shape selected from the group consisting of a rod, a pyramid, a cylinder, and combinations thereof. The method may further include disposing an array of horizontal Hall sensors in the substrate below the surface of the substrate and forming the array of embedded magnetic concentrators in the substrate, wherein forming the array of embedded magnetic concentrators in the substrate includes disposing each embedded magnetic concentrator below the horizontal Hall sensors.

[0055] The method may further include forming a protective overcoat layer above the surface of the substrate and disposing spherical magnetic concentrators above the protective overcoat layer and above the horizontal Hall sensors. The method may further include disposing an array of horizontal Hall sensors within the substrate and below the surface of the substrate and disposing an array of spherical magnetic concentrators above the protective overcoat layer, wherein disposing the array of spherical magnetic concentrators above the protective overcoat layer includes disposing the spherical magnetic concentrators respectively above the horizontal Hall sensors.

[0056] The method may further include forming a protective overcoat layer above the surface of the substrate and forming a patterned magnetic concentrator above the surface of the substrate and below the protective overcoat layer. The method may further include disposing an array of horizontal Hall sensors in the substrate below the surface of the substrate and forming an array of embedded magnetic concentrators in the substrate, wherein forming the array of embedded magnetic concentrators in the substrate includes disposing the embedded magnetic concentrators respectively below the horizontal Hall sensors.

[0057] Any particular magnetic concentrators described in the above examples (i.e., their types and locations) may be used in combination with any or all of the other mentioned types (and locations) of magnetic concentrators in the above examples. For example, patterned magnetic concentrator 230 may be used in combination with pyramidal-shaped embedded magnetic concentrator 532.

[0058] In this description, the term "couple" means an indirect or direct wired or wireless connection. Thus, when a first device couples to a second device, such connection may be through a direct connection or through an indirect connection via other devices and connections. The phrase "based on" means "based at least in part on." Thus, if X is based on Y, X may be a function of Y and any number of other factors.

[0059] Modifications in the described embodiments are possible, and other embodiments are possible, within the scope of the claims.

Claims

1. A structure comprising: a substrate including a surface; a horizontal Hall sensor disposed within the substrate and below the surface of the substrate; a protective overcoat layer disposed over the surface of the substrate; a spherical magnetic concentrator disposed above the protective overcoat layer; Including, structure.

2. 10. The structure of claim 1, A structure in which the spherical magnetic concentrator is disposed above the horizontal Hall sensor.

3. 10. The structure of claim 1, further comprising: A structure including an array of horizontal Hall sensors disposed within the substrate and below the surface of the substrate, and an array of spherical magnetic concentrators disposed above the protective overcoat layer.

4. 4. The structure of claim 3, A structure in which the spherical magnetic concentrators are each disposed above the horizontal Hall sensors.

5. A structure comprising: a substrate including a surface; a horizontal Hall sensor disposed within the substrate and below the surface of the substrate; an embedded magnetic concentrator disposed within the substrate and below the horizontal Hall sensor; Including, structure.

6. 6. The structure of claim 5, A structure wherein the embedded magnetic concentrator comprises a shape selected from the group consisting of a rod, a pyramid, a cylinder, and combinations thereof.

7. 6. The structure of claim 5, The structure further includes an array of horizontal Hall sensors disposed within the substrate and below the surface of the substrate, and an array of embedded magnetic concentrators disposed within the substrate, each embedded magnetic concentrator being disposed below the horizontal Hall sensors.

8. 6. The structure of claim 5, further comprising: a protective overcoat layer disposed over the surface of the substrate; a spherical magnetic concentrator disposed above the protective overcoat layer and above the horizontal Hall sensor; Including, structure.

9. 9. The structure of claim 8, The structure further includes an array of horizontal Hall sensors within the substrate and disposed below the surface of the substrate, and an array of spherical magnetic concentrators disposed above the protective overcoat layer, each of the spherical magnetic concentrators being disposed above one of the horizontal Hall sensors.

10. 6. The structure of claim 5, further comprising: a protective overcoat layer disposed over the surface of the substrate; a patterned magnetic concentrator disposed above the surface of the substrate and below the protective overcoat layer; Including, structure.

11. 11. The structure of claim 10, The structure further includes an array of horizontal Hall sensors disposed within the substrate and below the surface of the substrate, and an array of embedded magnetic concentrators disposed within the substrate, each embedded magnetic concentrator being disposed below the horizontal Hall sensors.

12. 1. A method of forming a structure, comprising: forming a substrate including a surface; disposing a horizontal Hall sensor within the substrate and below the surface of the substrate; forming a protective overcoat layer over the surface of the substrate; placing a spherical magnetic concentrator above said protective overcoat layer; A method comprising:

13. 13. The method of claim 12, The method, wherein the placing step includes placing the spherical magnetic concentrator above the horizontal Hall sensor.

14. 13. The method of claim 12, further comprising: The method includes disposing an array of horizontal Hall sensors within the substrate below the surface of the substrate, and placing an array of spherical magnetic concentrators above the protective overcoat layer.

15. 15. The method of claim 14, The method, wherein the step of placing the array of spherical magnetic concentrators above the protective overcoat layer includes positioning each of the spherical magnetic concentrators above the horizontal Hall sensor.

16. 1. A method of forming a structure, comprising: forming a substrate including a surface; disposing a horizontal Hall sensor within the substrate and below the surface of the substrate; forming an embedded magnetic concentrator within the substrate and below the horizontal Hall sensor; A method comprising:

17. 17. The method of claim 16, The method, wherein the embedded magnetic concentrator comprises a shape selected from the group consisting of a rod, a pyramid, a cylinder, and combinations thereof.

18. 17. The method of claim 16, The method further includes disposing an array of horizontal Hall sensors in the substrate below the surface of the substrate, and forming an array of embedded magnetic concentrators in the substrate, wherein forming the array of embedded magnetic concentrators in the substrate includes disposing each embedded magnetic concentrator below the horizontal Hall sensors.

19. 17. The method of claim 16, further comprising: forming a protective overcoat layer over the surface of the substrate; placing a spherical magnetic concentrator above the protective overcoat layer and above the horizontal Hall sensor; A method comprising:

20. 20. The method of claim 19, the method further comprising: disposing an array of horizontal Hall sensors within the substrate below the surface of the substrate; and disposing an array of spherical magnetic concentrators above the protective overcoat layer, wherein disposing the array of spherical magnetic concentrators above the protective overcoat layer comprises disposing the spherical magnetic concentrators respectively above the horizontal Hall sensors.

21. 17. The method of claim 16, further comprising: forming a protective overcoat layer over the surface of the substrate; forming a patterned magnetic concentrator above the surface of the substrate and below the protective overcoat layer; A method comprising:

22. 22. The method of claim 21, The method further includes disposing an array of horizontal Hall sensors in the substrate below the surface of the substrate, and forming an array of embedded magnetic concentrators in the substrate, wherein forming the array of embedded magnetic concentrators in the substrate includes disposing each embedded magnetic concentrator below the horizontal Hall sensors.

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