JP2013210335A - Magnetic sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic sensor capable of controlling sensor sensitivity not to be too high and increasing resistance to an external disturbance magnetic field from a direction different fro a detected magnetic field.SOLUTION: A magnetic sensor includes a first soft magnetic member 12a and a second soft magnetic member 12b spaced from each other. A magneto-resistance effect element includes a first element part 11a partially facing the first soft magnetic member in a vertical direction (Z), and a second element part 11b partially facing the second soft magnetic member in the vertical direction. The first element part 11a is disposed on the X2 end 14 side of the first soft magnetic member, and the second element part 11b is disposed on the X1 end 15 side of the second soft magnetic member. The overlapping sizes of the element parts 11a and 11b are the same dimension W1. The sensitivity axis directions P of the element parts are identical, and sensitivity is provided with respect to a detected magnetic field H3. The first element part and the second element part are arranged in series.

Description

  The present invention relates to a magnetic sensor including a magnetoresistive effect element and a soft magnetic material that is not in contact with the magnetoresistive effect element.

FIG. 9 is a partially enlarged plan view showing a part of a conventional magnetic sensor.
Reference numeral 1 denotes a magnetoresistive effect element, and the magnetoresistive effect element 1 is formed on a substrate 2 as shown in FIG. The surface of the magnetoresistive effect element 1 is covered with an insulating layer 3, and a soft magnetic material 4 is formed on the surface of the insulating layer 3. The magnetoresistive element 1 and the soft magnetic body 4 are not in contact with each other.

  Electrodes 5 and 5 are connected to both ends of the magnetoresistive element 1 in the Y1-Y2 direction. The soft magnetic body 4 is divided into a first soft magnetic member 4a and a second soft magnetic member 4b with an interval in the X1-X2 direction.

  In the plan view shown in FIG. 9A (the arrow D from the direction (Z) perpendicular to the surface (surface) formed by the substrate 2), the magnetoresistive element 1 includes the first soft magnetic member 4a and the second soft magnetic member 4a. It is located between the soft magnetic member 4b and substantially at the center in the X1-X2 direction.

  The sensitivity axis direction of the magnetoresistive effect element 1 is a direction parallel to the X1-X2 direction. Therefore, as shown in FIGS. 9A and 9B, the magnetoresistive effect element 1 changes its electric resistance in response to the detection magnetic field H1 directed in the X1-X2 direction.

  On the other hand, a disturbance magnetic field H2 directed in the Y1-Y2 direction shown in FIGS. 9A and 9B passes through the soft magnetic body 4 and is shielded against the magnetoresistive effect element 1.

JP 2009-162499 A JP 2003-294818 A

  In the structure of the conventional magnetic sensor shown in FIG. 9, even if the detection magnetic field H1 is weak as in the case of geomagnetism, the detection magnetic field H1 passes through the soft magnetic body 4 as shown in FIG. 1 is formed. At this time, the magnetic path M1 is generated between the ends of the soft magnetic members 4a and 4b, and the magnetic field strength applied to the magnetoresistive effect element 1 is apparently amplified.

  As a result, the sensor sensitivity (output) becomes too high, and there is a problem that the measurement range for the detected magnetic field H1 becomes very small.

  In the configurations of Patent Documents 1 and 2, similarly to FIG. 9, the magnetic field intensity of the detection magnetic field applied to the magnetoresistive effect element 1 is amplified, and the above-described conventional problems cannot be solved.

  Therefore, the present invention is for solving the above-described conventional problems, and in particular, it can be controlled so that the sensitivity of the sensor does not become too high, and improves the disturbance magnetic field resistance against a disturbance magnetic field from a direction different from the detected magnetic field. An object of the present invention is to provide a magnetic sensor that can perform the above-described operation.

The magnetic sensor in the present invention is
A magnetoresistive effect element that exhibits a magnetoresistive effect formed by laminating a magnetic layer and a nonmagnetic layer on a substrate, and is disposed at a distance from the magnetoresistive effect element in a direction perpendicular to a surface formed by the substrate. Soft magnetic material,
When the two directions perpendicular to the plane formed by the substrate are the X1-X2 direction and the Y1-Y2 direction,
The soft magnetic body includes a first soft magnetic member and a second soft magnetic member that are spaced apart in the X1-X2 direction.
The magnetoresistive element includes a first element portion that is at least partially opposed to the first soft magnetic member in the vertical direction, and a first element portion that is at least partially opposed to the second soft magnetic member in the vertical direction. Having two element parts,
The first element portion is disposed on the X2 end side of the first soft magnetic member, and the second element portion is disposed on the X1 end side of the second soft magnetic member, As viewed in the direction of the arrow, the distance in the X1-X2 direction from the X2 end of the first soft magnetic member to the X1 end of the first element portion, and the first soft magnetic member from the X1 end of the second soft magnetic member to the first The distance in the X1-X2 direction to the X2 end of the two element parts is the same dimension,
The sensitivity element directions of the first element part and the second element part are the same direction as the X1-X2 direction, and the first element part and the second element part are detected magnetic fields from the X1-X2 direction. Is sensitive to
The first element part and the second element part are connected in series.

  In the present invention, the first element part and the second element part having the same sensitivity axis direction are connected in series, and the detection magnetic field from the X1-X2 direction can be detected. At this time, in the present invention, at least a part of the first element part and at least a part of the second element part are respectively opposed to the first soft magnetic member and the second soft magnetic member in the vertical direction. By adopting such a configuration, the strong magnetic field strength generated between the end portions of each soft magnetic member is less likely to affect each element portion, and the magnetic field strength applied to the first element portion and the second element portion is conventionally increased. Can also be attenuated. Therefore, in this invention, it can control so that the sensor sensitivity (output) of a magnetic sensor may not become high too much, and can extend the measurement range of a detection magnetic field.

  In addition, in the present invention, the disturbance magnetic field acting in the Y1-Y2 direction can be shielded by the first soft magnetic member and the second soft magnetic member. Moreover, at least a part of the first element part and at least a part of the second element part are opposed to the first soft magnetic member and the second soft magnetic member in the vertical direction, respectively, so that the shielding effect can be further enhanced. . Furthermore, in the present invention, as viewed from the vertical direction, the width dimension from the X2 end of the first soft magnetic member to the X1 end of the first element portion, and the second dimension from the X1 end of the second soft magnetic member. The width dimension up to the X2 end of the element portion is the same dimension. For this reason, the disturbance magnetic field from a perpendicular direction can be canceled appropriately between the 1st element part and the 2nd element part. As described above, according to the present invention, the sensor sensitivity can be appropriately controlled so as not to be too high, a measurement range wider than that of the conventional sensor can be obtained, and a magnetic sensor having excellent disturbance magnetic field resistance can be obtained.

In the present invention, the X2 end portion of the first element portion and the X2 end portion of the first soft magnetic member coincide with each other in the vertical direction, or the X2 end portion of the first element portion is: It protrudes to the X2 side from the X2 end of the first soft magnetic member,
The X1 end portion of the second element portion and the X1 end portion of the second soft magnetic member coincide with each other in the vertical direction, or the X1 end portion of the second element portion is the second soft portion. It is preferable that the magnetic member protrudes to the X1 side from the X1 end portion. Thereby, both the sensor sensitivity and the measurement range of the detected magnetic field can be appropriately controlled.

In the present invention, the first soft magnetic member and the second soft magnetic member are formed so that the length dimension in the Y1-Y2 direction is longer than the width dimension in the X1-X2 direction.
The first element part and the second element part are preferably formed so that the length dimension in the Y1-Y2 direction is longer than the width dimension in the X1-X2 direction. The shielding effect against the disturbance magnetic field in the Y1-Y2 direction can be enhanced. Moreover, shape anisotropy can be imparted to the first element part and the second element part, and hysteresis and linearity can be effectively improved.

  In the present invention, the length dimension of the first soft magnetic member and the second soft magnetic member in the Y1-Y2 direction is set so that the lengths of the first element portion and the second element portion in the Y1-Y2 direction are the same. Each Y1 side end and each Y2 side end of the first soft magnetic member and the second soft magnetic member are longer than the length dimension, and the Y1 side ends of the first element portion and the second element portion respectively. It is preferable to protrude in the Y1-Y2 direction from the end and each Y2-side end. Thereby, the shielding effect of a soft magnetic body can be improved.

  In the present invention, it is preferable that a bridge circuit is configured by combining the magnetoresistive effect element and the fixed resistance element, or combining the plurality of magnetoresistive effect elements having different sensitivity axis directions.

  Further, in the present invention, a plurality of sets each including the first element portion and the second element portion are stacked, and the X2 end portion of the first soft magnetic member to the X1 end portion of the first element portion are stacked. The distance in the X1-X2 direction and the distance in the X1-X2 direction from the X1 end of the second soft magnetic member to the X2 end of the second element portion may be different for each set. .

  ADVANTAGE OF THE INVENTION According to this invention, it can control moderately so that sensor sensitivity may not become high too much, and while being able to expand the measurement range of a detection magnetic field conventionally, it can be set as the magnetic sensor provided with the disturbance magnetic field outstanding.

FIG. 1A is a partial plan view of the magnetic sensor according to the first embodiment, and FIG. 1B is a cross-sectional view of the magnetic sensor shown in FIG. FIG. 2 (a) and 2 (b) show the same partial vertical cross section as FIG. 1 (b). In particular, FIG. 2 (a) shows a magnetic path in the magnetic sensor when the detection magnetic field H3 is applied. FIG. 2B is an explanatory diagram for explaining a magnetic path in the magnetic sensor when a disturbance magnetic field H5 from the vertical direction is applied. FIG. 3 is a partial plan view of the magnetic sensor according to the second embodiment. FIG. 4 is a partial longitudinal sectional view of a magnetic sensor according to the third embodiment. 5A and 5B are circuit diagrams of the magnetic sensor according to the present embodiment. FIG. 6 shows a partially enlarged longitudinal sectional view of the magnetoresistive effect element. Fig.7 (a)-FIG.7 (e) are graphs which show the relationship between the detection magnetic field and sensor output when the overlap dimension with respect to the soft magnetic body of a 1st element part and a 2nd element part is changed. FIG. 8 is a graph showing the relationship between the overlap dimension and the sensor sensitivity. FIG. 9A is a partial plan view showing a part of a conventional magnetic sensor, and FIG. 9B is a sectional view of the magnetic sensor shown in FIG. It is the fragmentary longitudinal cross-section seen from.

  FIG. 1A is a partial plan view of the magnetic sensor according to the first embodiment, and FIG. 1B is a cross-sectional view of the magnetic sensor shown in FIG. FIG. FIGS. 2 (a) and 2 (b) both show the same partial vertical cross section as FIG. 1 (b), and in particular, FIG. FIG. 2B is an explanatory diagram for explaining a magnetic path in the magnetic sensor when a disturbance magnetic field H5 from the vertical direction is applied. FIG. 3 is a partial plan view of the magnetic sensor according to the second embodiment. FIG. 4 is a partial longitudinal sectional view of a magnetic sensor according to the third embodiment. 5A and 5B are circuit diagrams of the magnetic sensor according to the present embodiment. FIG. 6 shows a partially enlarged longitudinal sectional view of the magnetoresistive effect element.

  The X1-X2 direction and the Y1-Y2 direction shown in each figure indicate two directions orthogonal to the plane formed by the substrate 10, and the Z1-Z2 direction is orthogonal to the plane formed by the substrate 10. The direction to do is shown.

  As shown in FIG. 1, the magnetic sensor S includes a magnetoresistive effect element 11 formed on a substrate 10 such as silicon and a soft magnetic body 12. An insulating layer 13 is provided between the magnetoresistive element 11 and the soft magnetic body 12, and the magnetoresistive element 11 and the soft magnetic body 12 are perpendicular to the surface (surface) formed by the substrate 10 (height direction; Z1-Z2) are spaced apart.

  Although the film thickness of the insulating layer 13 is not specifically limited, For example, it is 0.3 micrometer or more. By interposing the insulating layer 13 between the magnetoresistive effect element 11 and the soft magnetic body 12, electrical insulation between the magnetoresistive effect element 11 and the soft magnetic body 12 can be improved.

  As shown in FIGS. 1A and 1B, the magnetoresistive effect element 11 includes a first element part 11a and a second element part 11b. The first element portion 11a and the second element portion 11b have the same shape, and the element width (width dimension in the X1-X2 direction) of each element portion 11a, 11b is T1, and the element length (in the Y1-Y2 direction). The length dimension) is L1. Each element part 11a, 11b is formed in a strip shape in which the element length L1 is larger than the element width T1.

  The laminated structure of the magnetoresistive effect element will be described with reference to FIG. FIG. 6 corresponds to the laminated structure of both the first element part 11a and the second element part 11b.

  As shown in FIG. 6, the magnetoresistive effect element 11 is laminated on the substrate 10 in order of, for example, a nonmagnetic underlayer 60, a fixed magnetic layer 61, a nonmagnetic layer 62, a free magnetic layer 63, and a protective layer 64 from the bottom. To form a film. Each layer constituting the magnetoresistive element 11 is formed by sputtering, for example.

  In the embodiment shown in FIG. 6, the pinned magnetic layer 61 has an artificial reaction between the first magnetic layer 61a, the second magnetic layer 61b, and the nonmagnetic intermediate layer 61c interposed between the first magnetic layer 61a and the second magnetic layer 61b. Ferromagnetic structure (AAF). Each of the magnetic layers 61a and 61b is formed of a soft magnetic material such as a CoFe 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. The free magnetic layer 63 is made of a soft magnetic material such as a NiFe alloy. The protective layer 64 is Ta or the like.

  In the present embodiment, the pinned magnetic layer 61 has an artificial antiferromagnetic 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. 6, the magnetic layers 61a and 61b 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.

  However, the laminated structure of the magnetoresistive effect element 11 in FIG. 6 is an example. For example, a configuration in which an antiferromagnetic layer, a pinned magnetic layer, a nonmagnetic layer, a free magnetic layer, and a protective layer are stacked in this order from the bottom may be employed. In such a configuration, it is possible to fix the magnetization direction of the pinned magnetic layer by generating an exchange coupling magnetic field (Hex) between the antiferromagnetic layer and the pinned magnetic layer. Alternatively, a laminated structure in which the free magnetic layer 63, the nonmagnetic material layer 62, the pinned magnetic layer 61, and the protective layer 64 are laminated in that order from the bottom may be employed. The pinned magnetic layer 61 can be configured such that the first magnetic layer 61a and the second magnetic layer 61b have the same magnetization magnitude and the magnetization directions are antiparallel.

  The fixed magnetization direction (P; sensitivity axis direction) of the second magnetic layer 61b constituting the magnetoresistive effect element 11 is the X1 direction (see FIGS. 1A, 2 and 6). This fixed magnetization direction (P) is the fixed magnetization direction of the fixed magnetic layer 61. As shown in FIG. 1A and the like, the sensitivity axis directions P of the first element portion 11a and the second element portion 11b are both the same direction. The sensitivity axis direction P of the first element unit 11a and the second element unit 11b may be the X2 direction.

  As shown in FIG. 1A, the soft magnetic body 12 includes a first soft magnetic member 12a and a second soft magnetic member 12b. The first soft magnetic member 12a and the second soft magnetic member 12b have the same shape. Each of the soft magnetic members 12a and 12b has a width dimension T2 in the X1-X2 direction and a length dimension L2 in the Y1-Y2 direction. Each of the soft magnetic members 12a and 12b is formed in a rectangular shape or a strip shape in which the length dimension L2 is larger than the width dimension T2.

  Here, the element width T1 of each element part 11a, 11b is about 0.5-8 micrometers, and element length L1 is about 3-300 micrometers. Moreover, the width dimension T2 of each soft magnetic member 12a, 12b is about 10-50 micrometers, and the length dimension L2 is 1.3 times or more of sensor length L1. Moreover, the thickness dimension of each element part 11a, 11b is about 20-40 nm, and the thickness dimension of each soft-magnetic member 12a, 12b is about 0.5-10 micrometers.

  The soft magnetic body 12 is made of NiFe, CoFe, CoFeSiB, CoZrNb, or the like. The soft magnetic body 12 can be formed by sputtering, vapor deposition, plating, or the like.

  As shown in FIGS. 1A and 1B, the first soft magnetic member 12a is disposed on the X1 side, and the second soft magnetic member 12b is disposed on the X2 side. The first soft magnetic member 12a and the second soft magnetic member 12b are arranged in parallel along the Y1-Y2 direction, and a certain interval T3 in the X1-X2 direction is provided between the soft magnetic members 12a, 12b. .

  As shown in FIGS. 1A and 1B, the first element portion 11a is disposed below the first soft magnetic member 12a and on the X2 end portion 14 side of the first soft magnetic member 12a. As shown in FIG. 1, a part 11a1 of the first element portion 11a faces (overlaps) the first soft magnetic member 12a in the vertical direction. Further, the remaining portion of the first element portion 11a protrudes to the X2 side from the X2 end portion 14 of the first soft magnetic member 12a, and the X2 end portion 30 of the first element portion 11a extends to the first soft magnetic member 12a. It is located on the X2 side from the X2 end portion 14.

  As shown in FIGS. 1A and 1B, the second element portion 11b is disposed below the second soft magnetic member 12b and on the X1 end portion 15 side of the second soft magnetic member 12b. As shown in FIG. 1, the second element portion 11b has a part 11b1 facing (overlapping) the second soft magnetic member 12b in the vertical direction. Further, the remaining portion of the second element portion 11b protrudes from the X1 end portion 15 of the second soft magnetic member 12b to the X1 side, and the X1 end portion 31 of the second element portion 11b extends from the second soft magnetic member 12b. It is located on the X1 side from the X1 end portion 15.

  As shown to Fig.1 (a), the 1st element part 11a and the 2nd element part 11b are arrange | positioned in parallel along the Y1-Y2 direction.

  As shown in FIGS. 1 (a) and 1 (b), the first element portion 11a is seen from the X2 end portion 14 of the first soft magnetic member 12a in plan view (arrow C from the vertical direction (Z1-Z2)). Both the distance in the X1-X2 direction to the X1 end portion 34 and the distance in the X1-X2 direction from the X1 end portion 15 of the second soft magnetic member 12b to the X2 end portion 35 of the second element portion 11b are both The same size W1. The distance W1 is an overlap dimension of the element portions 11a and 11b with respect to the soft magnetic members 12a and 12b, and will be described as an overlap dimension W1 unless otherwise specified.

  As shown in FIG. 1A, the Y1 end portion 16 of the first element portion 11a and the Y1 end portion 16 of the second element portion 11b are electrically connected by a conductive layer 17. Thereby, the 1st element part 11a and the 2nd element part 11b are connected in series.

  As shown in FIG. 1A, conductive layers 19 and 20 are electrically connected to the Y2 end portion 18 of the first element portion 11a and the Y2 end portion 18 of the second element portion 11b, respectively. For example, the conductive layer 19 is connected to an output terminal described later, and the conductive layer 20 is connected to an input terminal or a ground terminal.

  Assume that the detection magnetic field H3 acts in the X2 direction as shown in FIG. The detection magnetic field H3 forms a magnetic path M2 between the first soft magnetic member 12a and the second soft magnetic member 12b. FIG. 2A shows a typical magnetic path M2.

  As shown in FIG. 2A, the magnetic path M2 is a magnetic path M3 that travels substantially linearly between the X2 end 14 of the first soft magnetic member 12a and the X1 end 15 of the second soft magnetic member 12b. In addition, the magnetic path M4 extending in the vertical direction (Z1-Z2) between the X2 end portion 14 of the first soft magnetic member 12a and the X1 end portion 15 of the second soft magnetic member 12b, and the soft magnetic members 12a and 12b It is branched into a magnetic path M5 leaking between the vicinity of the lower surface.

  In this embodiment, as shown in FIG. 2A, a part 11a1 of the first element portion 11a is opposed to the first soft magnetic member 12a in the vertical direction (Z1-X2) (overlapping in plan view). A portion 11b1 of the second element portion 11b is opposed to the second soft magnetic member 12b in the vertical direction (Z1-Z2). That is, part 11a1, 11b1 of each element part 11a, 11b has entered under each soft magnetic member 12a, 12b. For this reason, as shown in the partially enlarged view of FIG. 2A, a magnetic field H5 directed in the X2 direction of the magnetic path M5 acts on each of the element portions 11a and 11b. The first element unit 11a and the second element unit 11b have a sensitivity axis direction P in the X1 direction, and are sensitive to a detection magnetic field from the X1-X2 direction. Here, “sensitivity” means that the magnetization direction of the free magnetic layer 63 varies depending on the magnetic field, and the angle between the magnetization direction of the free magnetic layer 63 and the sensitivity axis direction P (the fixed magnetization direction of the fixed magnetic layer 61) is By fluctuating, it means that the electric resistance value fluctuates. In other words, it refers to a state where the magnetoresistive effect is exhibited. Note that the magnetization direction of the free magnetic layer 63 is in the Y1-Y2 direction in the absence of a magnetic field in which an external magnetic field (detection magnetic field or disturbance magnetic field) does not act. In particular, in the present embodiment, since the element portions 11a and 11b are formed in a shape elongated in the Y1-Y2 direction, anisotropy in the X1-X2 direction when no magnetic field is generated due to the shape anisotropy effect. It can be applied to the free magnetic layer 63. Then, by the action of the detection magnetic field, the magnetization direction of the free magnetic layer 63 varies and the electric resistance value can be changed.

  In FIG. 2A, the electric resistance values of the first element portion 11a and the second element portion 11b both increase, and the magnetoresistive effect formed by connecting the first element portion 11a and the second element portion 11b in series. The electric resistance value of the element 11 is increased.

  For example, as shown in FIG. 5A, a bridge circuit can be configured using two magnetoresistive elements 11 and two fixed resistance elements 22 having the same configuration as in FIG. The fixed resistance element 22 is an element whose electric resistance value does not fluctuate due to the action of an external magnetic field. The material and structure of the fixed resistance element 22 are not particularly limited. Reference numeral 23 shown in FIG. 5A is an input terminal, reference numerals 24 and 25 are output terminals, and reference numeral 26 is a ground terminal.

  With the bridge circuit shown in FIG. 5A, the sensor output can be obtained by changing the electric resistance values of the two magnetoresistive elements 11.

  As described above, the detected magnetic field in the X1-X2 direction can be detected by the magnetoresistive effect element 11 shown in the present embodiment.

  Alternatively, as shown in FIG. 5B, a bridge circuit can be configured using two magnetoresistive elements 11 and two magnetoresistive elements 27. Each magnetoresistive effect element 27 is also provided with a first element portion 27a and a second element portion 27b as in the case of each magnetoresistive effect element 11, and the element portions 27a and 27b are connected in series. However, the sensitivity axis directions of the element portions 27 a and 27 b of the magnetoresistive effect elements 27 are opposite to the sensitivity axis directions of the element portions 11 a and 11 b of the magnetoresistive effect elements 11. This can be realized by turning the fixed magnetization directions of the magnetoresistive effect element 11 and the second magnetic layer of the fixed magnetic layer in the magnetoresistive effect element 27 in opposite directions.

  In the present embodiment, the first element portion 11a and the portions 11a1 and 11b1 of the second element portion 11b are perpendicular to the first soft magnetic member 12a and the second soft magnetic member 12b (height direction; Z1-Z2), respectively. ). Therefore, as shown in FIG. 2A, the first soft magnetic member of the magnetic path M2 formed by the detection magnetic field H3 flowing between the first soft magnetic member 12a and the second soft magnetic member 12b. The influence of the magnetic field H5 in the X2 direction of the magnetic path M5 leaking near the lower surface on the X2 end portion 14 side of 12a and near the lower surface on the X1 end portion 15 side of the second soft magnetic member 12b is affected by the first element portion 11a and the second element. The element part 11b receives. The magnetic field intensity of the magnetic field H5 is weaker than the magnetic field on the magnetic paths M3 and M4 generated between the end portions 14 and 15 of the soft magnetic members 12a and 12b. On the other hand, conventionally, a magnetoresistive effect element is arranged at a position where a magnetic field directed in the X2 direction acts on the magnetic path M4.

  For this reason, in this embodiment, when the detection magnetic field H3 acts in the X2 direction, the apparent magnetic field strength (the strength of the magnetic field H5) of the detection magnetic field H3 applied to the first element portion 11a and the second element portion 11b is set. It can be reduced as compared with the prior art, and can be controlled so that the sensor sensitivity of the magnetic sensor S does not become too high as compared with the prior art. Here, “sensor sensitivity” is defined by, for example, an output (mV) when 1 V is applied per 1 mT.

  When the detection magnetic field H3 acts, when the element portions 11a and 11b are arranged at positions on the magnetic path M5 as in the present embodiment, and when they are arranged at positions on the magnetic path M4 as in the prior art, The intensity of the magnetic field directed to the X2 direction acting on each element part 11a, 11b is different. In other words, the magnetic field strength of the detection magnetic field H3 acting on the element portions 11a and 11b apparently changes depending on the arrangement of the element portions 11a and 11b. When the magnetoresistive element is disposed at the position of the conventional magnetic path M4, the magnetic path M4 is generated between the end portions 14 and 15 of the soft magnetic members 12a and 12b, and the X2 direction acting on the magnetoresistive element is defined. The strength of the magnetic field facing is very strong. That is, conventionally, the apparent magnetic field strength of the detection magnetic field H3 acting on the magnetoresistive effect element is increased. On the other hand, the magnetic field leaks somewhat between the lower surfaces 12a3 and 12b3 of the element portions 12a and 12b, but the magnetic field strength of the magnetic field is sufficiently lower than the magnetic field strength between the end portions 14 and 15. Therefore, when each element part 11a, 11b is arranged at the position of the magnetic path M5, a weak magnetic field H5 directed in the X2 direction is applied to each element part 11a, 11b. Therefore, in this embodiment, each element part 11a, The apparent magnetic field strength of the detection magnetic field H3 acting on 11b can be reduced.

  Thus, by changing the arrangement of the magnetoresistive effect element with respect to the soft magnetic members 12a and 12b, conventionally, the magnetic field strength of the detection magnetic field H3 acting on the magnetoresistive effect element is apparently increased, and thus the output is greatly increased. Thus, the sensor sensitivity is high. On the other hand, in the present embodiment, the magnetic field strength of the detection magnetic field H3 acting on each of the element portions 11a and 11b can be made apparently smaller than that of the prior art, so that the output can be reduced compared to the conventional case and the sensor sensitivity can be lowered.

  The expression “apparently” is used here because the magnetic field strength of the detection magnetic field H3 acting on the element portions 11a and 11b passes through the soft magnetic members 12a and 12b, so that the magnetic field strength of the detection magnetic field H3 itself ( This means that the magnetic field intensity is changed from that before entering the soft magnetic members 12a and 12b.

  The measurement range (detection range) of the detected magnetic field is a range where the output fluctuation of the magnetic sensor S occurs. As the magnetic field strength increases, the output eventually reaches magnetic saturation and does not fluctuate. If the sensor sensitivity of the magnetic sensor S is high, the output will be high even if the detection magnetic field H3 having the same magnetic field strength acts. For this reason, the higher the sensor sensitivity, the smaller the magnetic field intensity (here, the magnetic field intensity is not the apparent magnetic field intensity acting on each of the element portions 11a and 11b, but the magnitude of the detection magnetic field H3 itself). It will not fluctuate. Therefore, the measurement range becomes smaller as the sensor sensitivity is higher.

  In the conventional arrangement of the magnetoresistive effect element and the soft magnetic material, the sensor sensitivity becomes too high and the measurement range becomes very narrow.

  On the other hand, in this embodiment, the arrangement of the element portions 11a and 11b with respect to the soft magnetic members 12a and 12b is changed from the conventional one, and control is performed so that the sensor sensitivity (output) of the magnetic sensor S does not become too high. . For this reason, in this embodiment, the measurement range of a detection magnetic field can be expanded compared with the past.

  In FIG. 2A, the detection magnetic field H3 in the X2 direction has been described, but the same applies when the detection magnetic field H3 in the X1 direction acts.

  In addition, in this embodiment, the disturbance magnetic field H4 (see FIG. 1A) acting in the Y1-Y2 direction can be shielded by the first soft magnetic member 12a and the second soft magnetic member 12b. That is, since the disturbance magnetic field H4 passes through the soft magnetic members 12a and 12b, the influence of the disturbance magnetic field H4 on the element portions 11a and 11b can be reduced. In particular, as shown in FIG. 1A, the length dimension L2 of each soft magnetic member 12a, 12b is made longer than the width dimension T2, and a disturbance magnetic field H4 is generated in each soft magnetic member 12a, 12b as Y1- It is easy to pass through in parallel to the Y2 direction. 1A and 1B, rather than disposing the magnetoresistive element at the approximate center in the interval T3 between the first soft magnetic member 12a and the second soft magnetic member 12b as in the prior art. As shown, by making a part 11a1, 11b1 of each element part 11a, 11b face the first soft magnetic member 12a and the second soft magnetic member 12b in the vertical direction (Z1-Z2; height direction), The shielding effect of each soft magnetic member 12a, 12b can be enhanced. In order to further enhance the shielding effect, it is preferable to narrow the interval T3 in the X1-X2 direction between the first soft magnetic member 12a and the second soft magnetic member 12b shown in FIG. For example, the interval T3 is about 1.5 to 6.0 μm.

  In the present embodiment, the length dimension L2 of the first soft magnetic member 12a and the second soft magnetic member 12b in the Y1-Y2 direction is equal to the length L2 of the first element portion 11a and the second element portion 11b in the Y1-Y2 direction. It is longer than the length dimension L1. The Y1 end portions 12a1 and 12b1 and the Y2 end portions 12a2 and 12b2 of the first soft magnetic member 12a and the second soft magnetic member 12b are the Y1 side ends of the first element portion 11a and the second element portion 11b, respectively. It protrudes in the Y1-Y2 direction from the portions 16 and 16 and the Y2 side end portions 18 and 18. Thus, by forming each soft magnetic member 12a, 12b longer than each element portion 11a, 11, the disturbance magnetic field H4 in the Y1-Y2 direction acts before each element portion 11a, 11b. The soft magnetic members 12a and 12b can be effectively passed through, and a better shielding effect can be obtained.

  Next, the disturbance magnetic field H5 from the vertical direction (height direction; Z1-Z2) will be described with reference to FIG.

  As shown in FIG. 2B, the disturbance magnetic field H5 from the vertical direction passes through the soft magnetic members 12a and 12b and acts on the element portions 11a and 11b arranged below the soft magnetic members 12a and 12b. Magnetic paths M6 and M7 are formed. As shown in FIG. 2B, the magnetic path M6 leaks from the lower surface 12a3 of the first soft magnetic member 12a, and is disposed below the first soft magnetic member 12a and on the X2 end portion 14 side. It acts on the one element part 11a in the substantially X2 direction. On the other hand, as shown in FIG. 2B, the magnetic path M7 leaks from the lower surface 12b3 of the second soft magnetic member 12b, and is disposed below the second soft magnetic member 12b and on the X1 end 15 side. In addition, it acts in a substantially X1 direction with respect to the second element portion 11b.

  As shown in FIG. 2B, the sensitivity axis directions P of the element portions 11a and 11b are both X1 directions. Therefore, when the disturbance magnetic field H5 from the vertical direction acts, a magnetic field in the direction opposite to the sensitivity axis direction P (a magnetic field directed in the X2 direction passing through the magnetic path M6) acts on the first element portion 11a. The electric resistance value of the portion 11a is increased. On the other hand, a magnetic field in the same direction as the sensitivity axis direction P (a magnetic field directed in the X1 direction passing on the magnetic path M7) acts on the second element portion 11b, and the electric resistance value of the second element portion 11b becomes small.

  By the way, in this embodiment, as shown to Fig.1 (a) (b), the overlap dimension with respect to the 1st soft magnetic member 12a of the 1st element part 11a and the 2nd soft magnetic member 12b with respect to the 2nd element part 11b are shown. The overlap dimension is the same size W1. Therefore, as shown in FIG. 2B, when the disturbance magnetic field H5 from the vertical direction (height direction; Z1-Z2) is applied, the reference state (the detection magnetic field and the disturbance magnetic field are not applied) in the first element unit 11a. From the increase in the electrical resistance value from the electrical resistance value of the element portion in the non-magnetic field state and the reference state in the second element portion 11b (the electrical resistance value of the element portion in the non-magnetic field state where no detection magnetic field or disturbance magnetic field acts) The decrease in the electrical resistance value can be made substantially the same. And since the 1st element part 11a and the 2nd element part 11b are connected in series, even if the disturbance magnetic field H5 acts from a perpendicular direction, electrical resistance can be made substantially the same as a no magnetic field state. Thus, in the present embodiment, the disturbance magnetic field H5 from the vertical direction can be canceled between the first element portion 11a and the second element portion 11b.

  As described above, in the present embodiment, the sensor sensitivity can be appropriately controlled, the measurement range of the detected magnetic field can be expanded, and the magnetic sensor S having excellent disturbance magnetic field resistance can be obtained.

  The first element portion 11a and the second element portion 11b are formed such that the length dimension L1 in the Y1-Y2 direction is longer than the width dimension T1 in the X1-X2 direction. Thereby, shape anisotropy can be imparted to the first element portion 11a and the second element portion 11b, and anisotropy directed in the X1-X2 direction can be imparted to the free magnetic layer 63 when there is no magnetic field. Thereby, hysteresis and linearity can be effectively improved.

  The first element portion 11a and the second element portion 11b shown in FIG. 1 have a non-bias structure in which a hard bias layer (permanent magnet layer) is not provided, but a hard bias layer may be provided.

  In the embodiment shown in FIG. 1, the X2 end portion 30 of the first element portion 11a protrudes further to the X2 side than the X2 end portion 14 of the first soft magnetic member 12a. Further, the X1 end portion 31 of the second element portion 11b protrudes further to the X1 side than the X1 end portion 15 of the second soft magnetic member 12b. In the present embodiment, the first element part 11a and the parts 11a1 and 11b1 of the second element part 11b are opposed to the first soft magnetic member 12a and the second soft magnetic member 12b in the vertical direction (height direction), The remaining portion protrudes from the first soft magnetic member 12a and the second soft magnetic member 12b. Thereby, both the sensor sensitivity and the measurement range of the detected magnetic field can be appropriately controlled.

  In FIG. 3, the entire first element portion 11a and the entire second element portion 11b are opposed to the first soft magnetic member 12a and the second soft magnetic member 12b in the vertical direction (height direction). Yes. In FIG. 3, the center line O1 of the element width in the X1-X2 direction of the first element part 11a is shifted to the X2 side from the center line O2 of the magnetic width in the X1-X2 direction of the first soft magnetic member 12a. Yes. Further, the center line O3 of the element width in the X1-X2 direction of the second element part 11b is shifted to the X1 side from the center line O4 of the magnetic width in the X1-X2 direction of the second soft magnetic member 12b. Thereby, the 1st element part 11a is arrange | positioned rather than the X1 end part 32 of the 1st soft-magnetic member 12a at the X2 end part 14 side. The second element portion 11b is disposed closer to the X1 end portion 16 than the X2 end portion 33 of the second soft magnetic member 12b.

  In the embodiment of FIG. 3 as well, the distance in the X1-X2 direction from the X2 end portion 14 of the first soft magnetic member 12a to the X1 end portion 34 of the first element portion 11a as viewed from the vertical direction, The distance in the X1-X2 direction from the X1 end portion 16 of the second soft magnetic member 12b to the X2 end portion 35 of the second element portion 11b is the same dimension W2.

  As shown in FIG. 3, even if each element part 11a, 11b is entirely opposed to the lower side of each soft magnetic member 12a, 12b, the center line O1 of the first element part 11a becomes the center line of the first soft magnetic member 12a. By shifting the center line O3 of the second element portion 11b to the X1 side with respect to the center line O4 of the second soft magnetic member 12b, the detection magnetic field from the X1-X2 direction is appropriately detected. it can. According to this embodiment, sensor sensitivity can be reduced and the measurement range of the detected magnetic field can be expanded.

  Also in the embodiment shown in FIG. 3, the disturbance magnetic field resistance to the disturbance magnetic field in the Y1-Y2 direction is provided, and the disturbance magnetic field from the vertical direction (Z1-Z2 direction) is changed to the first element unit 11a and the second element unit. 11b can be canceled with respect to the disturbance magnetic field from the vertical direction.

  As shown in FIG. 3, when the entire element portions 11a and 11b are opposed to the lower side of the soft magnetic members 12a and 12b, the apparent magnetic field strength acting on the element portions 11a and 11b when the detection magnetic field H3 acts is shown. It can be reduced more than the configuration of 1. However, the entire element portions 11a and 11b are opposed to the lower side of the soft magnetic members 12a and 12b, and the X2 end portion 30 of the first element portion 11a is shifted from the X2 end portion 14 of the first soft magnetic member 12a in the X1 direction. If the X1 end portion 31 of the second element portion 11b is shifted in the X2 direction from the X1 end portion 16 of the second soft magnetic member 12b, the apparent magnetic field strength is excessively lowered and appropriate sensor sensitivity cannot be obtained. Conversely, the detection accuracy may be reduced. Therefore, the X2 end portion 30 of the first element portion 11a is made to coincide with the X2 end portion 14 of the first soft magnetic member 12a in the vertical direction (height direction; Z1-Z2) or as shown in FIG. As described above, the X2 end portion 30 of the first element portion 11a protrudes to the X2 side from the X2 end portion 14 of the first soft magnetic member 12a, and a part 11a1 of the first element portion 11a is allowed to protrude from the first soft magnetic member 11a. It is preferable that they are opposed to each other in the vertical direction (height direction). Similarly, the X1 end portion 31 of the second element portion 11b is made to coincide with the X1 end portion 16 of the second soft magnetic member 12b in the vertical direction (height direction), or as shown in FIG. The X1 end portion 31 of the two element portion 11b protrudes to the X1 side from the X1 end portion 16 of the second soft magnetic member 12b, and a part 11b1 of the second element portion 11b is perpendicular to the second soft magnetic member 12b ( It is preferable that they face each other in the height direction). Thereby, both a sensor sensitivity and a measurement range can be adjusted moderately, and it can be set as the magnetic sensor provided with the outstanding detection accuracy with respect to a detection magnetic field, and disturbance magnetic field tolerance.

  In the present embodiment, the distance (overlap dimension) (dimensions W1 and W2 shown in FIGS. 1 and 3) / element width T1 is preferably in the range of 0.25 to 1.25, and 0.25 to 1 Is more preferable, and it is still more preferable that it exists in the range of 0.5-1. In the present embodiment, a shielding effect can be appropriately obtained by disposing at least a part of the first element portion and the second element portion under the soft magnetic member.

  Further, in the embodiment shown in FIG. 4, two sets of the first element part and the second element part are stacked via the insulating layer 40. And the overlap dimension W3 with respect to each soft magnetic member 12a, 12b of the first element part 41a and the second element part 41b of the first set, and each of the first element part 42a and the second element part 42b of the second set The overlap dimension W4 is different from the soft magnetic members 12a and 12b. The first set of first element part 41a and second element part 41b are connected in series, and the second set of first element part 42a and second element part 42b are connected in series. . The first element part 41a and the second element part 41b in the first set and the first element part 42a and the second element part 42b in the second set shown in FIG. As shown in FIG. 3, the soft magnetic members 12a and 12b may be overlapped in the vertical direction (height direction).

  In the magnetoresistive effect element 41 including the first set of the first element portion 41a and the second element portion 41b, and the magnetoresistive effect element 42 including the second set of the first element portion 42a and the second element portion 42b, the elements Although the structure is the same, the sensitivity can be changed apparently. The magnetoresistive effect element 41 including the first set of the first element portion 41a and the second element portion 41b, and the magnetoresistive effect element 42 including the second set of the first element portion 42a and the second element portion 42b are separately provided. May be incorporated into the same sensor circuit, or may be incorporated into the same sensor circuit. Three or more sets of the first element unit and the second element unit may be stacked. The apparent sensitivity of each set is different.

  The magnetic sensor S in this embodiment can be used as a geomagnetic sensor, for example. In such a case, the detection magnetic field H3 is geomagnetism. The disturbance magnetic fields H4 and H5 are external magnetic fields from a speaker or the like in a portable device incorporating a geomagnetic sensor. However, the magnetic sensor in this embodiment can be applied to uses other than the geomagnetic sensor.

  In the experiment, a plurality of magnetic sensors S shown in FIG. 1 were produced in which the overlap dimensions W1 of the element portions 11a and 11b were different.

  In the experiment, the element width T1 of each element part 11a, 11b was set to 2 μm. The width dimension T2 of each soft magnetic member 12a, 12b was 24 μm.

  In the experiment, the output of the magnetic sensor S when the detection magnetic field H3 from the X1-X2 direction was applied was measured.

  In FIG. 7A, the overlap dimension is 2.5 μm, but the element width T1 of each element portion 11a, 11b is 2 μm, so the state of FIG. All of the element portions 11a and 11b are opposed to the lower sides of the respective soft magnetic members 12a and 12b, and the X2 end portion 30 of the first element portion 11a is on the X1 side with respect to the X2 end portion 14 of the first soft magnetic member 12a. The X1 end portion 31 of the second element portion 11b is in a state of entering 0.5 μm closer to the X2 side than the X1 end portion 15 of the second soft magnetic member 12b.

  In FIG. 7B, the overlap dimension W1 is set to 2.0 μm, but the element width T1 of each element portion 11a, 11b is 2 μm, so that the end portions 30, 31 of each element portion 11a, 11b, The end portions 14 and 15 of the soft magnetic members 12a and 12b are aligned in the vertical direction (height direction).

  7 (c) to 7 (d), as shown in FIG. 1, the portions 11a1 and 11b1 of the element portions 11a and 11b are perpendicular to the soft magnetic members 12a and 12b (height direction). The X2 end 30 of the first element portion 11a protrudes to the X2 side from the X2 end portion 14 of the first soft magnetic member 12a, and the X1 end portion 31 of the second element portion 11b extends to the second soft magnetic portion. It is in a state of protruding from the X1 end 15 of the member 12b to the X1 side.

  In FIG. 7E, the overlap dimension t1 is 0.0 μm, that is, the X1 end portion 34 of the first element portion 11a is perpendicular to the X2 end portion 14 of the first soft magnetic member 12a (height direction). ), And the X2 end portion 35 of the second element portion 11b matches the X1 end portion 15 of the second soft magnetic member 12b in the vertical direction (height direction). In this way, in FIG. 7E, the entire element portions 11a and 11b do not overlap the respective soft magnetic members 12a and 12b in the vertical direction (height direction), which corresponds to a comparative example.

  It can be seen from FIG. 7A to FIG. 7E that the output curve gradually changes steeply.

FIG. 8 is a graph showing the relationship between the overlap size, the sensor sensitivity, and the measurement range obtained from each diagram of FIG.
As shown in FIG. 8, it was found that when the sensor sensitivity is lowered, the measurement range is increased.

  In order to reduce the sensor sensitivity and widen the measurement range as compared with the comparative example (FIG. 7 (e)) in which each element part and each soft magnetic member do not face each other in the vertical direction, at least one element part is required. It has been found that it is necessary to make the portion face each soft magnetic member in the vertical direction.

  When the overlap dimension is 2.5 μm (FIG. 7A), the measurement range is effectively widened, but the sensor sensitivity is considerably lowered, and conversely, the detection accuracy is likely to deteriorate. Therefore, the end portions 30 and 31 of the element portions 11a and 11b and the end portions 14 and 15 of the soft magnetic members 12a and 12b are aligned in the vertical direction (height direction) (FIG. 7B). Alternatively, by making a part of each element portion face each soft magnetic member in the vertical direction, it becomes easy to appropriately adjust both the sensor sensitivity and the measurement range.

H1, H3 Detecting magnetic field H2, H4, H5 Disturbing magnetic field M1-M7 Magnetic path P Sensitivity axial direction S Magnetic sensor W1-W4 Distance (overlap dimension)
1, 11, 27, 41, 42 Magnetoresistive elements 4, 12 Soft magnetic bodies 4a, 12a, 27a, 41a, 42a First soft magnetic members 4b, 12b, 27b, 41b, 42b Second soft magnetic member 10 Substrate 11a 1st element part 11b 2nd element part 14 (2nd soft magnetic member) X2 end part 15 (2nd soft magnetic member) X1 end part 19 and 20 Conductive layer 22 Fixed resistance element 30 (1st element part) X2 end portion 31 (of the second element portion) X1 end portion 32 (of the first soft magnetic member) X1 end portion 33 (of the second soft magnetic member) X2 end portion 34 (of the first element portion) X1 end portion 35 X2 end portion 61 (of the second element portion) pinned magnetic layer 62 nonmagnetic layer 63 free magnetic layer

Claims (6)

A magnetoresistive effect element that exhibits a magnetoresistive effect formed by laminating a magnetic layer and a nonmagnetic layer on a substrate, and is disposed at a distance from the magnetoresistive effect element in a direction perpendicular to a surface formed by the substrate. Soft magnetic material,
When the two directions perpendicular to the plane formed by the substrate are the X1-X2 direction and the Y1-Y2 direction,
The soft magnetic body includes a first soft magnetic member and a second soft magnetic member that are spaced apart in the X1-X2 direction.
The magnetoresistive element includes a first element portion that is at least partially opposed to the first soft magnetic member in the vertical direction, and a first element portion that is at least partially opposed to the second soft magnetic member in the vertical direction. Having two element parts,
The first element portion is disposed on the X2 end side of the first soft magnetic member, and the second element portion is disposed on the X1 end side of the second soft magnetic member, As viewed in the direction of the arrow, the distance in the X1-X2 direction from the X2 end of the first soft magnetic member to the X1 end of the first element portion, and the first soft magnetic member from the X1 end of the second soft magnetic member to the first The distance in the X1-X2 direction to the X2 end of the two element parts is the same dimension,
The sensitivity element directions of the first element part and the second element part are the same direction as the X1-X2 direction, and the first element part and the second element part are detected magnetic fields from the X1-X2 direction. Is sensitive to
The magnetic sensor, wherein the first element part and the second element part are connected in series. The X2 end portion of the first element portion and the X2 end portion of the first soft magnetic member coincide with each other in the vertical direction, or the X2 end portion of the first element portion is the first soft portion. It protrudes to the X2 side from the X2 end of the magnetic member,
The X1 end portion of the second element portion and the X1 end portion of the second soft magnetic member coincide with each other in the vertical direction, or the X1 end portion of the second element portion is the second soft portion. The magnetic sensor according to claim 1, wherein the magnetic sensor protrudes from the X1 end of the magnetic member to the X1 side. The first soft magnetic member and the second soft magnetic member are formed such that the length dimension in the Y1-Y2 direction is longer than the width dimension in the X1-X2 direction.
3. The magnetic sensor according to claim 1, wherein the first element portion and the second element portion are formed such that the length dimension in the Y1-Y2 direction is longer than the width dimension in the X1-X2 direction. .   The length dimension in the Y1-Y2 direction of the first soft magnetic member and the second soft magnetic member is longer than the length dimension in the Y1-Y2 direction of the first element portion and the second element portion. The Y1 side end and the Y2 side end of the first soft magnetic member and the second soft magnetic member are respectively the Y1 side end and Y2 of the first element portion and the second element portion, respectively. The magnetic sensor according to claim 3, wherein the magnetic sensor protrudes in the Y1-Y2 direction from the side end.   The bridge circuit is configured by combining the magnetoresistive effect element and the fixed resistance element, or combining a plurality of the magnetoresistive effect elements having different sensitivity axis directions. The magnetic sensor according to item.   A plurality of pairs of the first element part and the second element part are laminated, and the X1-X2 direction from the X2 end of the first soft magnetic member to the X1 end of the first element part is stacked. The distance in the X1-X2 direction from the X1 end portion of the second soft magnetic member to the X2 end portion of the second element portion is different in each group. The magnetic sensor according to item.

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