JP2013002856A - Magnetic sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic sensor with improved resistance to a strong magnetic field.SOLUTION: A magnetic sensor includes connected element assemblies 17, 18, 52, and 53. In each of the connected element assemblies, the respective bias layers are arranged such that the directions of bias magnetic fields B1 and B2 supplied to element parts are opposite between neighboring element parts, and the element part having the bias layers with a large area overlapped with the soft magnetic material in a plane view at both sides and the element part having the bias layers with no overlapped area at both sides are arranged. P1 and P2 represent sensitivity axis directions. The magnetic sensor includes a magnetoresistance element composed of the first connected element assembly 17 and the second connected element assembly 18 which are serially connected and a second magnetoresistance element composed of the third connected element assembly 52 and the fourth connected element assembly 53 which are serially connected.

Description

  The present invention relates to a magnetic sensor excellent in strong magnetic field resistance.

  A magnetic sensor using a magnetoresistive effect element can be used as a geomagnetic sensor that detects geomagnetism incorporated in a portable device such as a mobile phone.

  However, in a magnetic sensor having a bias layer for supplying a bias magnetic field to the element portion, when a very strong magnetic field is applied from the outside, there is a problem that the output (midpoint potential difference) fluctuates after removal of the applied magnetic field. This is because the magnetization of the bias layer is easily broken or fluctuated by the action of the strong magnetic field.

JP 7-325138 A JP-A-9-105630 JP-A-7-324933 JP-A-7-324934

  Therefore, the present invention is to solve the above-described conventional problems, and an object thereof is to provide a magnetic sensor with improved strong magnetic field resistance.

The magnetic sensor in the present invention is
A plurality of element portions exhibiting a magnetoresistive effect formed by laminating a magnetic layer and a nonmagnetic layer;
Bias layers disposed on both sides of each element portion in the X1-X2 direction;
Each element portion is disposed on both sides of the Y1-Y2 direction orthogonal to the X1-X2 direction, and each element portion and each bias layer has a non-contact soft magnetic material,
The sensitivity axis direction of each element unit is the Y1-Y2 direction,
The magnetization direction of each bias layer is the Y1-Y2 direction, and each bias layer is configured so that a bias magnetic field in the X1-X2 direction is supplied from each bias layer to each element unit.
Each soft magnetic material disposed on both sides of each element portion in the Y1-Y2 direction converts the external magnetic field into a substantially Y1-Y2 direction when an external magnetic field from the X1-X2 direction is applied. It is configured so that it can be supplied to the element part,
The plurality of element portions are arranged at an interval in the X1-X2 direction, and the bias layers connected to the adjacent element portions in the X1-X2 direction are connected by a conductive layer so that the elements are connected in series. Make up the body,
A first element connecting body, a second element connecting body, a third element connecting body, and a fourth element connecting body;
The first element connecting body and the fourth element connecting body have the same arrangement of the element portion, the bias layer, the soft magnetic body, and the conductive layer,
The second element connecting body and the third element connecting body include the first element connecting body and the fourth element connecting body, the element portion, the bias layer, and the conductive layer. Although the arrangement is the same, the soft magnetic body is inverted by 180 degrees with respect to the soft magnetic bodies constituting the first element connecting body and the fourth element connecting body with the X1-X2 direction as the rotation axis. The line
In each element connection body, each bias layer is disposed so that the direction of the bias magnetic field supplied to the element part is opposite to that of the adjacent element part, and The element portion in which the bias layer having a large overlap area is arranged on both sides and the element portion in which the bias layer having a small overlap area or the overlap area is arranged on both sides are alternately arranged,
The conversion directions of the external magnetic field in the first element connecting body and the fourth element connecting body are the same, and in the second element connecting body and the third element connecting body. A direction opposite to the conversion direction of the external magnetic field,
The sensitivity axis directions of the first element connecting body and the third element connecting body are the same, and the sensitivity of the second element connecting body and the fourth element connecting body is the same. It is the opposite direction to the axial direction,
A first magnetoresistive element in which the first element connecting body and the second element connecting body are connected in series; the third element connecting body; and the fourth element connecting body. And the second magnetoresistive effect element connected in series with each other are connected in series via the output section. Thereby, strong magnetic field tolerance can be improved.

In the present invention, the first magnetoresistive effect element is connected to an input section, and the second magnetoresistive effect element is connected to the ground, and the first magnetoresistive effect element and the second magnetoresistive effect element are connected to each other. Are connected in series via the first output unit,
A fourth magnetoresistive element in which the first element connection body and the second element connection body are connected in series; the third element connection body; and the fourth element connection body. Are connected in series via a second output unit, and the third magnetoresistive element is connected to the input unit and the fourth magnetoresistive element is connected to the third magnetoresistive element connected in series. It is preferable that an effect element is connected to the ground to constitute a bridge circuit.

  In the present invention, each element continuous body includes a portion in which an antiferromagnetic layer and a pinned magnetic layer are laminated, and each of the first element continuous body and the fourth element continuous body is configured. The pinned magnetic layer of the element portion and the pinned magnetic layer of each element portion constituting the second element connecting body and the third element connecting body have different laminated structures, and the first element connecting body is different. The fixed magnetization direction of the fixed magnetic layer of the structure and the fourth element connection body and the fixed magnetization direction of the fixed magnetic layer of the second element connection body and the third element connection body It is preferable that the direction is reversed.

  Alternatively, in the present invention, the pinned magnetic layer of each element part constituting the first element connecting body and the fourth element connecting body, and the second element connecting body and the third element connecting body. The pinned magnetic layer of each element part constituting the structure is a self-pinned type having the same laminated structure, and the fixed magnetization direction of the pinned magnetic layer of the first element linked body and the fourth element linked body It is preferable that the fixed magnetization direction of the fixed magnetic layer of the second element connection body and the third element connection body is opposite to that of the second element connection body.

  According to the magnetic sensor of the present invention, strong magnetic field resistance can be improved.

Schematic (plan view) of the magnetic sensor in the present embodiment, (A)-(d) is a top view which shows each structure of the 1st element connection body in this embodiment-the 4th element connection body, (A) is the partial enlarged plan view which expanded and showed a part of 1st element continuous connection body and the 4th element continuous connection body, (b) is the 2nd element continuous connection body, and the 1st 3 is a partially enlarged plan view showing a part of the element continuous body 3 in an enlarged manner, FIG. 1 is a partially enlarged plan view of a magnetic sensor showing an enlarged portion IV in FIG. 1; (A) is a partially enlarged longitudinal sectional view of the first element portion cut in the height direction, (b) is a partially enlarged longitudinal sectional view of the second element portion cut in the height direction, 5 is a structure of an element part different from FIG. 5, (a) is a partially enlarged longitudinal sectional view in which the first element part is cut in the height direction, and (b) is a cut in the second element part in the height direction. Partial enlarged longitudinal sectional view, FIG. 2A is a partially enlarged longitudinal sectional view of the magnetic sensor cut along the line AA in FIG. Schematic diagram (plan view) of a magnetic sensor in a comparative example, (A) and (b) are top views which show the structure of the element continuous body which comprises the magnetic sensor of a comparative example.

  FIG. 1 is a schematic diagram (plan view) of a magnetic sensor according to the present embodiment, and FIGS. 2A to 2D are diagrams illustrating first to fourth element connection bodies according to the present embodiment. FIG. 3A is a plan view showing the structure, FIG. 3A is a partially enlarged plan view showing a part of the first element connecting body and the fourth element connecting body, and FIG. FIG. 4 is a partially enlarged plan view showing a part of the second element connecting body and the third element connecting body in an enlarged manner, and FIG. 4 is a partially enlarged view of the magnetic sensor showing the part IV in FIG. FIG. 5A is a partially enlarged longitudinal sectional view in which the first element portion is cut in the height direction, and FIG. 5B is a partially enlarged longitudinal section in which the second element portion is cut in the height direction. 6 is a structure of the element part different from FIG. 5, FIG. 6A is a partially enlarged longitudinal sectional view of the first element part cut in the height direction, and FIG. Second element part in height direction Cut partially enlarged longitudinal sectional view, FIG. 7 is a partial enlarged vertical sectional view of a magnetic sensor as viewed from an arrow direction taken along the line A-A of FIG. 2 (a), a.

  The magnetic sensor S provided with the magnetoresistive effect element in the present embodiment is configured as a geomagnetic sensor mounted on a mobile device such as a mobile phone.

  The X1-X2 direction and the Y1-Y2 direction shown in each figure indicate two directions orthogonal to each other in the horizontal plane, and the Z direction indicates a direction orthogonal to the horizontal plane.

  As shown in FIG. 1, the magnetic sensor S has a magnetoresistive element forming region 13 divided into four regions from the center 13a by the X1-X2 direction and the Y1-Y2 direction. A magnetoresistive effect element 1, a second magnetoresistive effect element 2, a third magnetoresistive effect element 3, and a fourth magnetoresistive effect element 4 are formed. As will be described later, each of the magnetoresistive effect elements 1 to 4 is formed in a meander shape by connecting an element portion, a bias layer, and a conductive layer. In FIG. The figure is omitted.

  As shown in FIG. 1, the first magnetoresistive element 1 and the third magnetoresistive element 3 are connected to an input terminal (Vdd) 5. The second magnetoresistive effect element 2 and the fourth magnetoresistive effect element 4 are connected to a ground terminal (GND) 6. A first output terminal (V 1) 7 is connected between the first magnetoresistive element 1 and the second magnetoresistive element 2. A second output terminal (V 2) 8 is connected between the third magnetoresistive element 3 and the fourth magnetoresistive element 4. As described above, the first magnetoresistive element 1, the second magnetoresistive element 2, the third magnetoresistive element 3, and the fourth magnetoresistive element 4 form a bridge circuit.

  Each of the magnetoresistive effect elements 1 to 4 includes a plurality of element portions, a bias layer (permanent magnet layer) connected to both sides of each element portion, and a plurality of soft magnetic bodies that are not in contact with each element portion and each bias layer. And an element connecting body having a conductive layer connecting the bias layers.

  In the present embodiment, the element connection body includes a first element connection body, a second element connection body, a third element connection body, and a fourth element connection body.

  Hereinafter, the structure of the first element connecting body will be mainly described, and the second element connecting body, the third element connecting body, and the fourth element connecting body will be described. Different parts will be described.

(About the structure of the first element continuous body)
FIG. 2A shows a plan view of the first element connecting body 17. 2, 3, and 4 are all perspective views of the insulating layer 22 shown in FIG. 7.

  As shown in FIG. 2A, a pair of bias layers 10 are arranged on both sides in the X1-X2 direction of each first element portion 9 constituting the first element connection body 17. Each bias layer (permanent magnet layer) 10 is formed of CoPt, CoPtCr, or the like.

  As shown in FIG. 7, each element unit 9 is formed on an insulating base layer 19 on the surface of the substrate 15. As shown in FIG. 7, an insulating layer 22 is formed on the element portion 9 and the bias layer 10, and each soft magnetic body 12 is formed on the planarized insulating layer 22. The bias layer 10 may be formed on the insulating base layer 19 similarly to the element portion 9, but is not limited thereto.

  As shown in FIG. 2A, the first element portion 9 is further divided into a first element portion 9A and a first element portion 9B in which the directions of the bias magnetic fields B1 and B2 are opposite directions.

  As shown in FIG. 2A, the first bias layer 10A is connected to the X1 side of the first element portion 9A, and the second bias layer 10B is connected to the X2 side. Each of the bias layers 10A and 10B is formed in a substantially triangular shape, and the first bias layer 10A and the second bias layer 10B are inverted from each other by 180 °.

  As shown in FIG. 2A, the second bias layer 10B is connected to the X1 side of the first element portion 9B, and the first bias layer 10A is connected to the X2 side. As described above, the arrangement of the bias layers 10A and 10B connected to the first element unit 9B is opposite to the arrangement of the bias layers 10A and 10B with respect to the first element unit 9A.

  Therefore, when each bias layer 10 is magnetized, for example, in the Y2 direction, a bias magnetic field of approximately X1-X2 direction is generated between the bias layers 10, and the first element portion 9A has a first magnetic field facing in the X1 direction. One bias magnetic field B1 acts, and a second bias magnetic field B2 directed in the X2 direction acts on the first element portion 9B. Note that the magnetization directions of all the bias layers 10 shown in FIGS. 2A to 2D are all the same direction.

  As shown in FIG. 2A, the first bias layer 10A and the second bias layer 10B are inclined with respect to both the X1-X2 direction and the Y1-Y2 direction on the side surfaces in contact with the element portions 9, respectively. An inclined surface 20 is formed. The side surface opposite to the inclined surface 20 is also an inclined surface 21. By making the side surface of each bias layer 10 in contact with the element portion 9 the inclined surface 20, the bias magnetic field B1 from the direction perpendicular to the magnetization direction (Y1-Y2) of each bias layer 10 is made to each element portion 9. , B2 can be appropriately supplied. The inclined surface 21 on the opposite side is not always necessary. That is, instead of the inclined surface 21, it may be a side surface extending linearly in the Y1-Y2 direction, for example. However, if the opposite side is also the inclined surface 21, the first bias layer 10A can have the same shape with respect to both the first element portion 9A and the first element portion 9B, and the second bias layer 10A can have the same shape. The layer 10B may have a shape obtained by rotating the first bias layer 10A by 180 °. For this reason, the shape of the bias layer 10 can be made into two patterns. Therefore, the mask pattern used in the manufacturing process for forming the bias layer 10 is simple and suitable. If the opposite side is also the inclined surface 21, the shape of each bias layer 10 can be made smaller.

  As shown in FIG. 2A, the bias layers 10 connected to the adjacent element portions 9 are electrically connected via the conductive layer 16, and thereby the first element extending in the X1-X2 direction. A continuous body 17 is formed. The conductive layer 16 is made of a nonmagnetic conductive material, and is formed of a nonmagnetic conductive material such as Al, Cu, or Ti.

  As shown in FIG. 2A, each soft magnetic body 12 provided in the first element connecting body 17 is Y1 in a plan view with respect to one element portion 9 adjacent in the X1-X2 direction. Y1 side end portion 12a facing the other side, Y2 side end portion 12b facing the Y2 side in plan view with respect to the other element portion 9, and a connection connecting the Y1 side end portion 12a and the Y2 side end portion 12b And a portion 12c. The Y1 side end portion 12a, the Y2 side end portion 12b, and the connection portion 12c are integrally formed. As shown in FIG. 7, each Y1 side end portion 12a and Y2 side end portion 12b of the soft magnetic body 12 is not in contact with the first element portion 9, and the soft magnetic body 12 and the first element portion 9 are not in contact with each other. An external magnetic field H2 acts between them.

  As shown in FIG. 2A, the Y1 side end portion 12a and the Y2 side end portion 12b are formed extending in parallel to the X1-X2 direction, but the connecting portion 12c is formed in the X1-X2 direction and the Y1-Y2 direction. It is formed in an oblique direction with respect to both directions.

  As shown in FIG. 2, all the soft magnetic bodies 12 formed in the first element continuous body 17 are formed in the same shape.

  The sensitivity axis direction (P1) of the first element portion 9 constituting the first element connecting body 17 shown in FIG. 2A is the Y2 direction.

  FIG. 3A is a partially enlarged plan view in which a part of the first element connecting body 17 in FIG. As shown in FIG. 3 (a), when the external magnetic field H1 acts in the X2 direction, the external magnetic field H1 passes through the soft magnetic body 12 and between the soft magnetic bodies 12 and 12, and FIG. The magnetic path M1 of the arrow shown in FIG. At this time, as shown in FIG. 3 (a), the Y2 side end portion 12b of the soft magnetic body 12 located on the Y2 side with respect to each element portion 9 and the soft portion located on the Y1 side with respect to each element portion 9. An external magnetic field H2 in a substantially Y1 direction leaks between the Y1 side end portions 12a of the magnetic body 12, and this external magnetic field H2 acts on the element portion 9 (see also FIG. 7).

  Thus, the external magnetic field H1 in the X2 direction is converted into the Y1 direction by the soft magnetic body 12 and acts on the element portion 9.

  As described above, since the sensitivity axis direction (P1) of each first element unit 9 is the Y2 direction, the electric resistance value is obtained when the external magnetic field H2 in the Y1 direction acts on each first element unit 9. Increase.

(About the structure of the second element connection body)
FIG. 2B is a plan view of the second element connecting body 18. Unlike the first element connecting body 17, the second element connecting body 18 in FIG. 2B includes a second element portion 50 whose sensitivity axis direction (P2) is in the Y1 direction. The arrangement of the second element portion 50, the bias layer 10, and the conductive layer 16 is the same as that of the first element connecting body 17, but the soft magnetic body 51 constituting the second element connecting body 18 is FIG. 2A shows a shape in which the soft magnetic body 12 constituting the first element connecting body 17 shown in FIG. 2A is inverted 180 degrees about the X1-X2 direction as a rotation axis. Therefore, as shown in FIG. 3B, when the external magnetic field H1 acts in the X2 direction, a magnetic path M2 indicated by an arrow shown in FIG. 3B is formed in the soft magnetic body 51. Y1 side end portion 51a of the soft magnetic body 51 located on the Y2 side with respect to the second element portion 50, and Y2 side end portion 51b of the soft magnetic body 51 located on the Y2 side with respect to each second element portion 50. In the meantime, the external magnetic field H3 in the substantially Y2 direction leaks, and this external magnetic field H3 acts on the second element unit 50.

  Thus, the external magnetic field H1 in the X2 direction is converted into the Y2 direction by the soft magnetic body 51 and acts on the second element unit 50.

  As described above, since the sensitivity axis direction (P2) of each second element unit 50 is the Y1 direction, the electric resistance value is obtained when the external magnetic field H3 in the Y2 direction acts on each second element unit 50. Increase.

(About the structure of the third element connection body)
FIG. 2C is a plan view of the third element connecting body 52. Similar to the first element connecting body 17, the third element connecting body 52 in FIG. 2C includes the first element portion 9 in which the sensitivity axis direction (P1) is directed in the Y2 direction. Furthermore, the arrangement of the first element portion 9, the bias layer 10, and the conductive layer 16 is the same as that of the first element connection body 17.

  The soft magnetic body 51 constituting the third element connection body 52 is the same as the second element connection body 18 shown in FIG. That is, it is a shape obtained by inverting the soft magnetic body 12 constituting the first element connecting body 17 180 degrees about the X1-X2 direction as the rotation axis. Accordingly, also in the third element connecting body 52, when the external magnetic field H1 acts in the X2 direction, the external magnetic field H3 in the Y2 direction acts on each first element portion 9 as in FIG. 3B. .

  Here, since the sensitivity axis direction (PIN) of the first element portion 9 constituting the third element connecting body 52 is the Y2 direction, an external magnetic field H3 in the Y2 direction acts on each first element portion 9. As a result, the electric resistance value decreases.

(About the structure of the fourth element continuous body)
FIG. 2D is a plan view of the fourth element connecting body 53. The fourth element connecting body 53 in FIG. 2D includes the second element portion 50 in which the sensitivity axis direction (P2) is in the Y1 direction, like the second element connecting body 18. Further, the arrangement of the second element unit 50, the bias layer 10, and the conductive layer 16 is the same as that of the first element connection body 17.

  The soft magnetic body 12 constituting the fourth element continuous body 53 is the same as the first element continuous body 17 shown in FIG. Therefore, in the fourth element connecting body 53, as in FIG. 3A, when the external magnetic field H1 acts in the X2 direction, the external magnetic field H2 in the Y1 direction acts on each second element portion 50.

  Here, since the sensitivity axis direction (P2) of the second element unit 50 constituting the fourth element connection body 53 is the Y1 direction, an external magnetic field H2 in the Y1 direction acts on each second element unit 50. As a result, the electric resistance value decreases.

  As described above, if the external magnetic field H1 acts in the X2 direction, the first element connecting body 17 and the second element connecting body 18 increase the electrical resistance value, and the third element connecting body 52. In the fourth element connecting body 53, the electrical resistance value decreases. On the other hand, if the external magnetic field acts in the X1 direction, the first element connecting body 17 and the second element connecting body 18 reduce the electrical resistance value, and the third element connecting body 52 and the fourth element connecting body 52 In the element continuous body 53, the electrical resistance value increases.

  FIG. 4 is a partially enlarged plan view of the magnetic sensor in which the portion IV shown in FIG. 1 is enlarged. As shown in FIG. 4, a plurality of first element connection bodies 17 are arranged side by side in the Y1-Y2 direction, and the X1 side ends of the first element connection bodies 17 are arranged between each other. Alternatively, the end portions on the X2 side are electrically connected via the connection conductive layer 23 to form a meander shape.

  Similarly, the second element connecting body 18, the third element connecting body 52, and the fourth element connecting body 53 are also formed in a meander shape.

  As shown in FIG. 4, among the soft magnetic bodies 12 constituting the first element connecting body 17 and the soft magnetic bodies 51 constituting the third element connecting body 52, the adjacent soft magnetic bodies 12 and The soft magnetic body 51 is integrally formed.

(Relationship between each magnetoresistive effect element 1 to 4 and each element connection body 17, 18, 52, 53)
Next, the relationship between each magnetoresistive effect element 1-4 and each element connection body 17, 18, 52, 53 is demonstrated.

  As shown in FIG. 1, each of the magnetoresistive effect elements 1 to 4 is divided into two regions, and the first region 1 a constituting the first magnetoresistive effect element 1 includes the region shown in FIG. a) a meander-shaped first element connecting body 17 shown in FIG. 4 is arranged, and the second region 1b has a meander-shaped second element connecting body 17 shown in FIG. 2 (b) and FIG. A structure 18 is arranged.

  And the 1st element connection body 17 and the 2nd element connection body 18 are connected in series, and the 1st magnetoresistive effect element 1 is comprised.

  In addition, in the first region 2a constituting the second magnetoresistive element 2, the meander-shaped third element connecting body 52 shown in FIGS. 2C and 4 is disposed, In the region 2b, a meander-shaped fourth element connecting body 53 shown in FIGS. 2D and 4 is arranged.

  And the 3rd element connection body 52 and the 4th element connection body 53 are connected in series, and the 2nd magnetoresistive effect element 2 is comprised.

  Further, in the first region 3a constituting the third magnetoresistive effect element 3, the meander-shaped third element connecting body 52 shown in FIG. 2C and FIG. 4 is arranged. In the region 3b, a meander-shaped fourth element connecting body 53 shown in FIGS. 2D and 4 is arranged.

  And the 3rd element connection body 52 and the 4th element connection body 53 are connected in series, and the 3rd magnetoresistive effect element 3 is comprised.

  Further, in the first region 4a constituting the fourth magnetoresistive effect element 3, the meander-shaped first element connecting body 17 shown in FIG. 2A and FIG. In the region 4b, a meander-shaped second element connecting body 18 shown in FIGS. 2B and 4 is arranged.

  The first element connection body 17 and the second element connection body 18 are connected in series to form the fourth magnetoresistive element 4.

(About the structure of the 1st element part 9 and the 2nd element part 50)
FIG. 5A shows a laminated structure of the first element portion 9, and FIG. 5B shows a laminated structure of the second element portion 50.

  As shown in FIG. 5A, the first element portion 9 is formed by, for example, laminating a nonmagnetic underlayer 60, a pinned magnetic layer 61, a nonmagnetic layer 62, a free magnetic layer 63, and a protective layer 64 in this order from the bottom. A film is formed. Each layer constituting the first element unit 9 is formed by sputtering, for example.

  In the embodiment shown in FIG. 5A, the pinned magnetic layer 61 includes a first magnetic layer 61a and a second magnetic layer 61b, and a nonmagnetic intermediate layer 61c interposed between the first magnetic layer 61a and the second magnetic layer 61b. The laminated ferri structure. Each of the magnetic layers 61a and 61b is formed of a soft magnetic material such as a CoFe alloy (cobalt-iron alloy). The nonmagnetic intermediate layer 61c is made of Ru or the like. The nonmagnetic layer 62 is formed of a nonmagnetic material such as Cu (copper). The free magnetic layer 63 is made of a soft magnetic material such as a NiFe alloy (nickel-iron alloy). The protective layer 64 is Ta (tantalum) or the like.

  In the present embodiment, the pinned magnetic layer 61 has a laminated ferrimagnetic structure, and is a self-pinning type in which the first magnetic layer 61a and the second magnetic layer 61b are magnetization-fixed antiparallel. In the self-pinning type shown in FIG. 5A, the magnetic layers 61a and 61c constituting the pinned magnetic layer 61 are fixed by magnetization without using an antiferromagnetic layer, and thus without performing heat treatment in a magnetic field. The magnetization fixing force of each of the magnetic layers 61a and 61b only needs to be large enough to prevent magnetization fluctuation even when an external magnetic field is applied.

  As shown in FIG. 5A, the fixed magnetization direction (P1; sensitivity axis direction) of the second magnetic layer 61b constituting the first element unit 9 is the Y2 direction. This fixed magnetization direction (P 1) is the fixed magnetization direction of the fixed magnetic layer 61.

  On the other hand, the second element portion 50 shown in FIG. 5B has a laminated structure in which a nonmagnetic underlayer 60, a fixed magnetic layer 61, a nonmagnetic layer 62, a free magnetic layer 63, and a protective layer 64 are laminated in this order from the bottom. Yes, the same as the first element portion 9. That is, the pinned magnetic layer 61 of the second element unit 50 is also a self-pinned type.

  However, unlike the first element portion 9, the fixed magnetization direction (P2; sensitivity axis direction) of the second magnetic layer 61b is the Y1 direction.

  By making the pinned magnetic layer 61 self-pinned, the heat treatment in a magnetic field is not necessary as described above, and the first element portion 9 and the second element portion 50 shown in FIGS. 5A and 5B are the same. Even in a laminated structure, the sensitivity axis direction can be made antiparallel by changing the magnetic field direction during film formation.

  Alternatively, as shown in FIGS. 6A and 6B, the first element portion 9 and the second element portion 50 are respectively arranged from below with a nonmagnetic underlayer 60, an antiferromagnetic layer 65, a fixed magnetic layer 66, The nonmagnetic layer 62, the free magnetic layer 63, and the protective layer 64 are laminated in this order. In FIG. 7, an exchange coupling magnetic field (Hex) is generated between the antiferromagnetic layer 65 and the pinned magnetic layer 66 by heat treatment in a magnetic field, and the pinned magnetic layer 66 is pinned and magnetized.

  In the first element portion 9 shown in FIG. 6A, the pinned magnetic layer 66 has a laminated ferrimagnetic structure in which magnetic layers 66a, 66b, 66c and nonmagnetic intermediate layers 66d, 66e are alternately laminated, Three layers 66a, 66b, and 66c are provided. On the other hand, in the second element portion 50 shown in FIG. 6B, the pinned magnetic layer 66 has a laminated ferrimagnetic structure in which magnetic layers 66a and 66b and nonmagnetic intermediate layers 66d are alternately laminated, and the magnetic layer 66a. , 66b are provided in two layers.

  It is possible to simultaneously perform heat treatment in a magnetic field on the first element portion 9 and the second element portion 50 shown in FIG. The magnetic layers 66a, 66b, 66c constituting the first element unit 9 are fixedly magnetized antiparallel to each other, and as shown in FIG. 6A, the magnetic layer 66c in contact with the nonmagnetic layer 62 is magnetized in the Y2 direction. The Y2 direction is the sensitivity axis direction. As shown in FIG. 6B, the magnetic layer 66b in contact with the nonmagnetic layer 62 of the second element unit 50 is fixed in magnetization in the Y1 direction, and the Y1 direction is the sensitivity axis direction. Thus, the sensitivity axis direction can be made antiparallel by changing the number of magnetic layers of the laminated ferrimagnetic structure between the first element portion 9 and the second element portion 50.

(About strong magnetic field resistance in the magnetic sensor of the comparative example)
First, the strong magnetic field resistance of the magnetic sensor of the comparative example shown in FIG. 8 will be described. The magnetic sensor of FIG. 8 is provided with four magnetoresistive effect elements 71 to 74, and each magnetoresistive effect element 71 to 74 constitutes a bridge circuit. In FIG. 8, the same reference numerals as those in FIG. 1 denote the same layers (members).

  The element connecting body 75 shown in FIG. 9A has the same configuration as, for example, the first element connecting body 17 shown in FIG. 9B has the same configuration as the third element connecting body 52 shown in FIG. 2C, for example. Therefore, the sensitivity axis directions of the element connecting bodies 75 and 76 shown in FIGS. 9A and 9B are the same Y2 direction. At this time, assuming that the external magnetic field H1 in the X2 direction acts, in the element connecting body 75, as shown in FIG. 3A, the external magnetic field H2 in the Y1 direction acts on each element portion 77, In the continuous body 76, as shown in FIG. 3B, the external magnetic field H3 in the Y2 direction acts on each element portion 77. Therefore, the electrical resistance value increases in the element continuous body 75, and the electrical resistance value decreases in the element continuous body 76.

  In the first magnetoresistive element 71 and the fourth magnetoresistive element 74 shown in FIG. 8, the element connecting body 75 is formed in a meander shape, and the second magnetoresistive element 72 and the third magnetoresistive element 72 In the magnetoresistive effect element 73, the element connecting body 76 is formed in a meander shape. Therefore, if the electrical resistance values of the first magnetoresistive effect element 71 and the fourth magnetoresistive effect element 74 are increased, the electrical resistance values of the second magnetoresistive effect element 72 and the third magnetoresistive effect element 73 are increased. Decrease.

  As shown in FIGS. 9A and 9B, the arrangement of the bias layers 10 arranged on both sides in the X1-X2 direction of the element portion 77 is reversed 180 degrees between the adjacent element portions 77. As a result, the directions of the bias magnetic fields B1 and B2 acting on the adjacent element portions 77 are opposite to each other. The arrangement of the bias layer 10 is a characteristic part of the present embodiment, whereby when the external magnetic field H1 acts and the sensitivity of each element section 77 changes, the element sections 77 adjacent in the X1-X2 direction. The sensitivity shift directions are opposite to each other, so that the sensitivity variation as a whole can be reduced by canceling the sensitivity change.

  However, when a strong magnetic field is applied, the magnetic sensor provided with the element continuous bodies 75 and 76 of FIG.

  The bias layers 10A and 10B disposed on both sides of the element portion 77a constituting the element continuous body 75 shown in FIG. 9A have a large overlapping area a1 with the soft magnetic body 12, while both sides of the element portion 77b. In the bias layers 10A and 10B arranged in (1), the overlapping area a2 with the soft magnetic body 12 is zero (or the overlapping area a2 is smaller than a1 even if they overlap). As described above, there is a problem that the overlapping areas a1 and a2 with the soft magnetic body 12 are changed between the bias layers 10A and 10B connected to the adjacent element portions 77a and 77b.

  When the external magnetic field H1 acts from the X2 direction, the bias layer 10 magnetized in the Y2 direction is affected. At this time, the bias layers 10A and 10B having a larger overlapping area a1 with the soft magnetic body 12 are affected by the external magnetic field H1. As shown in FIG. 9A, the bias magnetic field B1 supplied from the bias layers 10A and 10B to the element portion 77a is in the X1 direction and is opposite to the direction of the external magnetic field H1, Due to the action of the strong magnetic field, the magnetized state and the bias magnetic field B1 are disturbed to affect the bias magnetic field B1, and the electric resistance value of the element connecting body 75 when the strong magnetic field is removed is appropriately returned to the initial state. It will disappear.

  On the other hand, in the case of FIG. 9B, the overlap area a2 with the soft magnetic body 51 in the bias layers 10A and 10B arranged on both sides of the element portion 77b is increased, contrary to FIG. 9A. On the other hand, the bias layers 10A and 10B arranged on both sides of the element portion 77a do not overlap the soft magnetic body 51 (or even if they overlap, the overlapping area a1 is smaller than a2).

  At this time, in FIG. 9B, the direction of the bias magnetic field B2 from the bias layers 10A and 10B having a large overlapping area a2 with the soft magnetic body 51 to the element portion 77b coincides with the direction of the external magnetic field H1, and the external magnetic field H1. Since the bias magnetic field B2 is assisted at this time, the bias magnetic field B1 does not become weak and does not easily affect the electric resistance value of the element continuous body 76 when the strong magnetic field is removed.

  Therefore, after the strong magnetic field acts and the strong magnetic field is removed, the electric resistance value changes between the element connecting body 75 and the element connecting body 76, and accordingly, the first magnetoresistance effect element 71 and the The four magnetoresistive effect elements 74 are each formed by one kind of element connecting body 75, and the second magnetoresistive effect element 72 and the third magnetoresistive effect element 73 are each one kind of element connecting body 76. In the comparative example formed in (1), there was a problem that the amount of change in the midpoint potential when the strong magnetic field was removed increased.

(About strong magnetic field tolerance in the magnetic sensor of this embodiment)
Characteristic portions of the magnetic sensor in the present embodiment are as follows.
(1) In the first magnetoresistive element 1 and the fourth magnetoresistive element 4, the first element connecting body 17 and the second element connecting body 18 are directly connected to each other. The magnetoresistive effect element 2 and the third magnetoresistive effect element 3 are configured by directly connecting a third element connecting body 52 and a fourth element connecting body 53.

(2) As shown in FIGS. 2A and 2D, the first element connecting body 17 and the second element connection constituting the first magnetoresistive effect element 1 and the fourth magnetoresistive effect element 4 are provided. The arrangement of the element part, the bias layer 10 and the conductive layer 16 is the same as that of the structure 18, but the arrangement of the soft magnetic bodies 12 and 51 is inverted 180 degrees about the X1-X2 direction as the rotation axis. ing. In addition, the sensitivity axis direction (P1) of the first element unit 9 constituting the first element connecting body 17 and the sensitivity axis direction of the second element unit 50 constituting the second element connecting body 18 ( The direction is opposite to P2).

  Therefore, when the external magnetic field H1 acts from the X2 direction, the first element connecting body 17 is in the state of FIG. 3A, and the electrical resistance value is increased, and the second element connecting body 18 is in FIG. The electrical resistance value increases in the state of a). Therefore, when the external magnetic field H1 acts from the X2 direction, the electric resistance values of the entire first magnetoresistive element 1 and the entire fourth magnetoresistive element 4 increase.

(3) As shown in FIG. 3A, the overlapping area of the bias layers 10A and 10B arranged on both sides of the first element portion 9A constituting the first element connecting body 17 with the soft magnetic body 12 On the other hand, the overlapping area a2 of the bias layer 10B disposed on both sides of the first element portion 9B with the soft magnetic body 12 is zero (or even if overlapping, the overlapping area a2 is smaller than a1). Become).

  On the other hand, as shown in FIG. 3B, the overlapping area a2 of the bias layers 10A, 10B disposed on both sides of the second element portion 50B constituting the second element connecting body 18 with the soft magnetic body 51 On the other hand, the overlapping area a1 of the bias layer 10A disposed on both sides of the second element portion 50A with the soft magnetic body 12 is zero (or even if overlapping, the overlapping area a1 is smaller than a2). ).

  At this time, in the first element connecting body 17 in FIG. 3A, the bias magnetic field B1 acting on the first element portion 9A having a large overlapping area a1 with the soft magnetic body 12 is in the X1 direction. Even if the strong magnetic field is removed due to the influence of the external magnetic field H1 in the X2 direction, the electric resistance value of the first element connecting body 17 varies with difficulty in returning to the initial state.

  On the other hand, in the second element connecting body 18 in FIG. 3B, the bias magnetic field B2 acting on the first element portion 50B having a large overlapping area a2 with the soft magnetic body 12 is the same X2 as the external magnetic field H1. Since it is a direction, it is not influenced (or hardly affected) by the external magnetic field H1.

(4) As shown in FIGS. 2C and 2D, the third element connecting body 52 and the fourth element connection constituting the second magnetoresistive effect element 2 and the third magnetoresistive effect element 3 are provided. In the structure 53, the arrangement of the element portion, the bias layer 10, and the conductive layer 16 is the same, but the arrangement of the soft magnetic bodies 12, 51 is inverted 180 degrees about the X1-X2 direction as the rotation axis. ing. In addition, the sensitivity axis direction (P1) of the first element unit 9 constituting the third element connecting body 52 and the sensitivity axis direction of the second element part 50 constituting the fourth element connecting body 53 ( The direction is opposite to P2).

  Further, the third element connecting body 52 is the same as the second element connecting body 18 in the arrangement of the element portion, the bias layer 10, the conductive layer 16, and the soft magnetic body 51, and the fourth element connecting body 52 is provided. In the body 53, the arrangement of the element portion, the bias layer 10, the conductive layer 16, and the soft magnetic body 12 is the same as that of the first element continuous body 17.

  Here, when the external magnetic field H1 acts from the X2 direction, the third element connecting body 52 is in the state shown in FIG. 3B, and the electric resistance value is reduced, while the fourth element connecting body 53 is shown in FIG. In the state a), the electric resistance value decreases. Therefore, when the external magnetic field H1 acts from the X2 direction, the electric resistance values of the entire second magnetoresistive element 2 and the entire third magnetoresistive element 3 are decreased.

(5) The overlapping areas a1 and a2 of the bias layers 10A and 10B with the soft magnetic bodies 12 and 51 are as described above. Therefore, in the fourth element connection body 53 in FIG. The bias magnetic field B1 acting on the second element portion 50A having a large overlapping area a1 with the soft magnetic body 12 is in the X1 direction. The electric resistance value of the first element continuous body 17 varies with difficulty in returning to the initial state.

  On the other hand, in the third element connecting body 52 in FIG. 3B, the bias magnetic field B2 acting on the first element portion 9B having a large overlapping area a2 with the soft magnetic body 12 is the same as the external magnetic field H1 X2. Since it is a direction, it is not influenced (or hardly affected) by the external magnetic field H1.

(6) Thus, in this embodiment, when receiving the external magnetic field H1 from the X2 direction, the first magnetoresistance effect element 1 (fourth magnetoresistance effect element 4) connected in series and the second In the magnetoresistive effect element 2 (third magnetoresistive effect element 3), the first element connecting body 17 or the fourth element connecting body in which the electric resistance value fluctuates from the initial state by the action of a strong magnetic field. 53.

  Note that when a strong magnetic field acts in the X1 direction, the electrical resistance values of the second element connecting body 18 and the third element connecting body 52 tend to fluctuate from the initial state, but the first connected in series. In the first magnetoresistive effect element 1 (fourth magnetoresistive effect element 4) and the second magnetoresistive effect element 2 (third magnetoresistive effect element 3), the second element connecting body 18 is provided. Alternatively, the third element connecting body 52 is included.

  As described above, since each of the magnetoresistive effect elements 1 to 4 is provided with the element continuous body in which the electrical resistance value is likely to vary due to the influence of the strong magnetic field, the first magnetoresistive effect elements connected in series are provided. 1 (fourth magnetoresistive effect element 4) and second magnetoresistive effect element 2 (third magnetoresistive effect element 3) can cancel the fluctuation amount (ΔR) of the electric resistance value. The potential fluctuation can be effectively reduced as compared with the configuration of the comparative example. Therefore, a magnetic sensor excellent in strong magnetic field resistance can be obtained.

B1, B2 Bias magnetic field H1, H2, H3 External magnetic field M1, M2 Magnetic path P1, P2 Sensitivity axis direction a1, a2 Overlapping area 1-4 Magnetoresistive effect element 9, 9A, 9B First element part 10, 10A, 10B Bias layer 12 Soft magnetic bodies 12a, 12b End 16 Conductive layer 17 First element connecting body 18 Second element connecting bodies 50, 50A, 50B Second element section 51 Soft magnetic body 52 Third element connecting Structure 53 Fourth element connection structure 61, 66 Pinned magnetic layers 61a, 61b, 66a, 66b, 66c Magnetic layer 63 Free magnetic layer

Claims (4)

A plurality of element portions exhibiting a magnetoresistive effect formed by laminating a magnetic layer and a nonmagnetic layer;
Bias layers disposed on both sides of each element portion in the X1-X2 direction;
Each element portion is disposed on both sides of the Y1-Y2 direction orthogonal to the X1-X2 direction, and each element portion and each bias layer has a non-contact soft magnetic material,
The sensitivity axis direction of each element unit is the Y1-Y2 direction,
The magnetization direction of each bias layer is the Y1-Y2 direction, and each bias layer is configured so that a bias magnetic field in the X1-X2 direction is supplied from each bias layer to each element unit.
Each soft magnetic material disposed on both sides of each element portion in the Y1-Y2 direction converts the external magnetic field into a substantially Y1-Y2 direction when an external magnetic field from the X1-X2 direction is applied. It is configured so that it can be supplied to the element part,
The plurality of element portions are arranged at an interval in the X1-X2 direction, and the bias layers connected to the adjacent element portions in the X1-X2 direction are connected by a conductive layer so that the elements are connected in series. Make up the body,
A first element connecting body, a second element connecting body, a third element connecting body, and a fourth element connecting body;
The first element connecting body and the fourth element connecting body have the same arrangement of the element portion, the bias layer, the soft magnetic body, and the conductive layer,
The second element connecting body and the third element connecting body include the first element connecting body and the fourth element connecting body, the element portion, the bias layer, and the conductive layer. Although the arrangement is the same, the soft magnetic body is inverted by 180 degrees with respect to the soft magnetic bodies constituting the first element connecting body and the fourth element connecting body with the X1-X2 direction as the rotation axis. The line
In each element connection body, each bias layer is disposed so that the direction of the bias magnetic field supplied to the element part is opposite to that of the adjacent element part, and The element portion in which the bias layer having a large overlap area is arranged on both sides and the element portion in which the bias layer having a small overlap area or the overlap area is arranged on both sides are alternately arranged,
The conversion directions of the external magnetic field in the first element connecting body and the fourth element connecting body are the same, and in the second element connecting body and the third element connecting body. A direction opposite to the conversion direction of the external magnetic field,
The sensitivity axis directions of the first element connecting body and the third element connecting body are the same, and the sensitivity of the second element connecting body and the fourth element connecting body is the same. It is the opposite direction to the axial direction,
A first magnetoresistive element in which the first element connecting body and the second element connecting body are connected in series; the third element connecting body; and the fourth element connecting body. And a second magnetoresistive element connected in series with each other in series via an output unit. The first magnetoresistive element is connected to an input unit, the second magnetoresistive element is connected to a ground, and the first magnetoresistive element and the second magnetoresistive element are connected between the first magnetoresistive element and the first magnetoresistive element. Are connected in series via the output of
A fourth magnetoresistive element in which the first element connection body and the second element connection body are connected in series; the third element connection body; and the fourth element connection body. Are connected in series via a second output unit, and the third magnetoresistive element is connected to the input unit and the fourth magnetoresistive element is connected to the third magnetoresistive element connected in series. The magnetic sensor according to claim 1, wherein an effect element is connected to the ground to constitute a bridge circuit.   Each element connection body includes a portion in which an antiferromagnetic layer and a pinned magnetic layer are stacked, and the fixed portions of the element portions constituting the first element connection body and the fourth element connection body are provided. The magnetic layer and the pinned magnetic layer of each element portion constituting the second element connecting body and the third element connecting body are different in the laminated structure, and the first element connecting body and the first element connecting body The fixed magnetization direction of the fixed magnetic layer of the element connection body 4 is opposite to the fixed magnetization direction of the fixed magnetic layer of the second element connection body and the third element connection body. The magnetic sensor according to claim 1 or 2.   The pinned magnetic layer of each element part constituting the first element connecting body and the fourth element connecting body, and the second element connecting body and the third element connecting body are configured. The pinned magnetic layer of each element part is a self-pinning type having the same laminated structure, and the pinned magnetization direction of the pinned magnetic layer of the first element connecting body and the fourth element connecting body, and the second The magnetic sensor according to claim 1, wherein the fixed magnetization direction of the pinned magnetic layer of the element continuous body and the third element continuous body is opposite to the fixed magnetic layer.

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