JP5297442B2 - Magnetic sensor - Google Patents

Description

  The present invention relates to a magnetic sensor including a magnetoresistive element and a soft magnetic material.

  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.

  For example, as shown in Patent Document 1, in a magnetic sensor including a magnetoresistive effect element and a soft magnetic body, by providing the soft magnetic body, the detection accuracy with respect to the detection magnetic field from the sensitivity axis direction is improved, and the sensitivity axis It is said that the magnetic shielding effect against a disturbance magnetic field orthogonal to the direction can be improved ([0062] column).

  However, as shown in FIG. 1 of Patent Document 1, it is necessary to provide three chips, that is, an X magnetic field detection unit, a Y magnetic field detection unit, and a Z magnetic field detection unit, and the miniaturization of the magnetic sensor cannot be effectively promoted. .

  Patent Document 2 discloses a structure of a magnetic sensor that can detect a vertical magnetic field, but does not describe anything about a horizontal magnetic field detection structure.

WO2010 / 010872 JP 2003-149212 A

  Accordingly, the present invention is to solve the above-described conventional problems, and in particular, to provide a magnetic sensor capable of detecting a plurality of axes of external magnetic fields with a smaller number of chips than in the past.

The magnetic sensor in the present invention is
A plurality of magnetoresistive effect elements that exhibit a magnetoresistive effect formed by laminating a magnetic layer and a nonmagnetic layer, and a soft magnetic material provided in a non-contact position via each magnetoresistive effect element and an insulating layer Have
Husband in plan view on both sides of the first horizontal direction of the soft magnetic material s, the fixed magnetization direction of the pinned magnetic layer, the first of said magnetoresistive element oriented in the horizontal direction are disposed, wherein The first magnetoresistive element and the second magnetoresistive element, which are disposed on the same side surface of the soft magnetic body and whose fixed magnetization directions are opposite to each other, the first magnetoresistive element and the second magnetoresistive element A third magnetoresistive element disposed on the side surface of the soft magnetic material opposite to the magnetoresistive element, and having the same fixed magnetization direction as the first magnetoresistive element,
The second magnetoresistive element and the third magnetoresistive element form a first bridge circuit capable of detecting a horizontal magnetic field from the first horizontal direction,
The first magnetoresistive effect element and the third magnetoresistive effect element constitute a second bridge circuit capable of detecting a vertical magnetic field from the thickness direction of the soft magnetic material. Is.

  Accordingly, at least the external magnetic field from the first horizontal direction can be detected, and the disturbance magnetic field resistance can be enhanced. If this chip configuration is used, it is possible to detect a multi-axis external magnetic field with a smaller number of chips than in the prior art. Specifically, a magnetic sensor capable of three-axis detection can be configured with a one-chip or two-chip configuration.

  In the present invention, two chips having the soft magnetic material, the first magnetoresistive effect element, the second magnetoresistive effect element, and the third magnetoresistive effect element are prepared, and one of the chips is prepared. The first magnetic field can be detected by rotating a 90 ° direction so that the fixed magnetization direction of each magnetoresistive element is directed to a second horizontal direction orthogonal to the first horizontal direction, and a horizontal magnetic field from the first horizontal direction can be detected. It is preferable that a third bridge circuit capable of detecting a horizontal magnetic field from the second horizontal direction is configured together with the second bridge circuit capable of detecting a vertical magnetic field. Accordingly, the first bridge circuit capable of detecting the horizontal magnetic field from the first horizontal direction, the second bridge circuit capable of detecting the vertical magnetic field, and the second horizontal direction with a simple configuration and two chips. A third bridge circuit capable of detecting the horizontal magnetic field can be configured.

Or the magnetic sensor in this invention is
A plurality of magnetoresistive elements that exhibit a magnetoresistive effect formed by laminating a magnetic layer and a nonmagnetic layer, and a soft magnetic material provided in a non-contact position via each magnetoresistive element and an insulating layer Have
The magnetoresistive effect element in which the pinned magnetization direction of the pinned magnetic layer is oriented in the first horizontal direction on each side in the first horizontal direction of the soft magnetic body in a plan view,
Within one chip,
The fixed magnetic layers of the magnetoresistive elements arranged on both sides of the first soft magnetic body in the first horizontal direction are fixedly magnetized in opposite directions to detect a horizontal magnetic field from the first horizontal direction. A possible bridge circuit is configured,
A second soft magnetic body different from the first soft magnetic body is provided, and both sides in the second horizontal direction orthogonal to the first horizontal direction of the second soft magnetic body in plan view The magnetoresistive effect element having the fixed magnetization direction of the fixed magnetic layer oriented in the second horizontal direction is disposed on both sides of the second soft magnetic body in the second horizontal direction. A pinned magnetic layer of each magnetoresistive effect element is fixedly magnetized in opposite directions to form a bridge circuit capable of detecting a horizontal magnetic field from the second horizontal direction,
A third soft magnetic body different from the first soft magnetic body and the second soft magnetic body is provided, and the fixed magnetic layer is in the same direction on both sides of the third soft magnetic body in plan view. is arranged fixed magnetized each magnetoresistive element to one in which the third detectable bridge circuit vertical magnetic field from the thickness direction of the soft magnetic material is characterized by being composed.

In the present invention, the magnetoresistive effect element has a laminated structure in which the pinned magnetic layer and the free magnetic layer are laminated via a nonmagnetic material layer,
In the pinned magnetic layer, a first magnetic layer and a second magnetic layer in contact with the nonmagnetic material layer are laminated via a nonmagnetic intermediate layer, and the first magnetic layer and the second magnetic layer are antiparallel. A self-pinning type in which magnetization is fixed is preferable. In the self-pinning type magnetoresistive effect element, the first magnetic layer and the second magnetic layer constituting the pinned magnetic layer can be pinned in an antiparallel manner without using an antiferromagnetic layer and without performing a heat treatment in a magnetic field. Accordingly, it is possible to appropriately form the magnetoresistive elements having different fixed magnetization directions in the same chip.

  According to the magnetic sensor of the present invention, it is possible to detect a multi-axis external magnetic field with a smaller number of chips than in the prior art.

FIG. 1A is a plan view showing the basic configuration of the magnetic sensor in the first embodiment, and FIG. 1B is a partial longitudinal section taken along the line AA shown in FIG. FIG. 1C is a circuit diagram of the magnetic sensor. FIG. 2 is a plan view showing the entire magnetic sensor in the present embodiment. FIG. 3 is a plan view of the magnetic sensor according to the second embodiment. FIG. 4 is an enlarged plan view of each magnetoresistive element. FIG. 5 is a partially enlarged longitudinal sectional view of the element portion shown in FIG. 4 cut along the line BB and viewed from the arrow direction.

  FIG. 1A is a plan view showing the basic configuration of the magnetic sensor in the first embodiment, and FIG. 1B is a partial longitudinal section taken along the line AA shown in FIG. FIG. 1C is a circuit diagram of the magnetic sensor. In FIG. 1B, the magnetoresistive element S1 that is originally hidden behind the insulating layer 4 and is not visible is shown through. FIG. 2 is a plan view showing the entire magnetic sensor in the present embodiment, and FIG. 3 is a plan view of the magnetic sensor in the second embodiment. FIG. 4 is an enlarged plan view of each magnetoresistive effect element, and FIG. 5 is a partially enlarged longitudinal sectional view of the element portion shown in FIG. 4 cut along the line BB and viewed from the direction of the arrow.

  A magnetic sensor 1 having a magnetoresistive effect element according to the present embodiment shown in FIG. 1 is used for multi-axis magnetic field detection, and is not particularly limited in use, but for example, geomagnetism mounted on a mobile device such as a mobile phone. Configured as a sensor.

  The X-axis direction and the Y-axis direction shown in each figure indicate two directions orthogonal to each other in the horizontal plane, and the Z-axis direction indicates a direction orthogonal to the horizontal plane. One of the X1-X2 direction and the Y1-Y2 direction is the “first horizontal direction”, and the other is the “second horizontal direction”. In this embodiment, the X1-X2 direction is referred to as the “first horizontal direction”. The Y1-Y2 direction will be described as a “second horizontal direction”.

  As shown in FIGS. 1A and 1B, the magnetic sensor 1 includes a plurality of magnetoresistive elements S1 to S3 formed on a substrate 2 and a soft magnetic body 3. The

  As shown in FIG. 1B, the magnetoresistive elements S1 to S3 are formed on a substrate 2 made of silicon or the like via an insulating layer (not shown).

  As shown in FIG. 4, the magnetoresistive effect element S (GMR element) includes a plurality of element portions 10 formed extending in the Y1-Y2 direction at intervals in the X1-X2 direction, and between the element portions 10. And a conductive connecting portion 13 for connecting the two. As shown in FIG. 4, the magnetoresistive effect element S is formed in a meander shape. The conductive connection portion 13 can be a permanent magnet layer (hard bias layer). Alternatively, a permanent magnet layer (not shown in FIG. 4) can be arranged. The configuration of the magnetoresistive effect element S shown in FIG. 4 is an example, and does not limit the arrangement of the element portion 10, the permanent magnet layer, and the connection portion.

  As shown in FIG. 5, the element unit 10 is formed by laminating, for example, a nonmagnetic underlayer 60, a pinned magnetic layer 61, a nonmagnetic layer 62, a free magnetic layer 63, and a protective layer 64 from the bottom. Each layer constituting the first element unit 9 is formed by sputtering, for example.

  In the embodiment shown in FIG. 5, the pinned magnetic layer 61 is a laminated ferrimagnetic layer made up of a first magnetic layer 61a, a second magnetic layer 61b, and a nonmagnetic intermediate layer 61c interposed between the first magnetic layer 61a and the second magnetic layer 61b. It is a 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). In the present embodiment, the magnetoresistive effect element S can be a TMR element, and in such a case, the nonmagnetic layer 62 is an insulating layer. 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 the first magnetic layer 61a and the second magnetic layer 61b have a self-pinned structure in which the magnetization is fixed antiparallel. However, the antiferromagnetic layer is formed in contact with the pinned magnetic layer, and an exchange coupling magnetic field Hex is generated between the antiferromagnetic layer and the pinned magnetic layer by heat treatment in a magnetic field, thereby magnetizing the pinned magnetic layer in a predetermined direction. It may be a fixed structure. For example, in the self-pinned structure 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.

  In this embodiment, the fixed magnetization direction (P1; sensitivity axis direction) of the second magnetic layer 61b is the X1 direction. This fixed magnetization direction (P 1) is the fixed magnetization direction of the fixed magnetic layer 61.

  As will be described later, in the present embodiment, the fixed magnetization direction P1 of all the magnetoresistive elements S is not reversed in the same direction but partly inverted by 180 degrees (FIG. 1A). The self-pinning structure can be effectively obtained. However, even in a configuration using an antiferromagnetic layer, for example, one magnetoresistive element S is antiferromagnetic layer / pinned magnetic layer [first magnetic layer / nonmagnetic intermediate layer / second magnetic layer]. The other magnetoresistive element S is an antiferromagnetic layer / pinned magnetic layer [first magnetic layer / nonmagnetic intermediate layer / second magnetic layer / nonmagnetic intermediate layer / third magnetic layer]. By applying the same heat treatment in the magnetic field to these magnetoresistive effect elements S, the fixed magnetization direction P1 of the second magnetic layer that defines the fixed magnetization direction of one magnetoresistive effect element S and the other magnetoresistance The fixed magnetization direction P1 of the third magnetic layer that defines the fixed magnetization direction of the effect element S can be reversed.

  As shown in FIG. 1B, an insulating layer 4 is formed from the magnetoresistive elements S1 to S3 to the substrate 2. The upper surface 4a of the insulating layer 4 is formed on a planarized surface using a CMP technique or the like.

  As shown in FIG. 1B, the soft magnetic body 3 is formed on the upper surface 4 a of the insulating layer 4. As shown in FIG. 1A, the soft magnetic body 3 is formed in a shape extending longer along Y1-Y2 than the width dimension of X1-X2. Further, as shown in FIG. 1B, the film thickness T2 is formed larger than the width dimension T1 in X1-X2 of the soft magnetic body 3. T2 / T1 is about 1.5-4.

  Since the insulating layer 4 is interposed between the magnetoresistive elements S1 to S3 and the soft magnetic body 3 shown in FIG. 1B, the magnetoresistive elements S1 to S3 and the soft magnetic body 3 are non-existent. Contact. In FIG. 1A (the same applies to FIGS. 2 and 3), the insulating layer 4 is not shown, and the positional relationship between the soft magnetic body 3 and the magnetoresistive elements S1 to S3 is shown.

  As shown in FIGS. 1A and 1B, the first magnetoresistive element S1 and the second magnetoresistive element S2 are both arranged on the X1 side surface 3a side of the soft magnetic body 3. A predetermined interval is provided in the Y1-Y2 direction between the first magnetoresistive element S1 and the second magnetoresistive element S2. As shown in FIG. 1B, the magnetoresistive elements S1 and S2 enter slightly below the soft magnetic body 3 from the X1 side surface 3a of the soft magnetic body 3, but the magnetoresistive elements S1 and S2 The X2 side surface and the X1 side surface 3a of the soft magnetic body 3 may coincide with each other in the Z1-Z2 direction, or the X2 side surface of each magnetoresistive element S1, S2 is from the X1 side surface 3a of the soft magnetic body 3. It may be located slightly away from the X1 side.

  The arrow P1 shown in the first magnetoresistive element S1 and the second magnetoresistive element S2 shown in FIG. 1A indicates the fixed magnetization direction (second magnetic layer 61b) of the fixed magnetic layer 61 described in FIG. Fixed magnetization direction; sensitivity axis direction). As shown in FIG. 1A, the fixed magnetization direction P1 of the first magnetoresistive element S1 and the second magnetoresistive element S2 is opposite.

  On the other hand, the third magnetoresistance effect element S3 is arranged on the X2 side surface 3b side of the soft magnetic body 3. The position of the third magnetoresistive element S3 in the Y1-Y2 direction is within the interval in the Y1-Y2 direction between the first magnetoresistive element S1 and the second magnetoresistive element S2. However, the present invention is not limited to this. However, as shown in FIG. 1A, the arrangement of the third magnetoresistance effect element S3 is shifted in the Y1-Y2 direction with respect to both the first magnetoresistance effect element S1 and the second magnetoresistance effect element S2. By setting the position, it is possible to appropriately secure a wiring pattern routing space in each of the magnetoresistive elements S1 to S3.

  As shown in FIG. 1B, the third magnetoresistive element S3 is slightly below the soft magnetic body 3 than the X2 side surface 3b of the soft magnetic body 3, but the third magnetoresistive element S3. The X1 side surface of the soft magnetic body 3 and the X2 side surface 3b of the soft magnetic body 3 may coincide with each other in the Z1-Z2 direction, or the X1 side surface of the third magnetoresistive element S3 is the X2 side surface 3b of the soft magnetic body 3 It may be located slightly further away from the X2 side.

  Each magnetic field applied to the soft magnetic body 3 so that horizontal magnetic field components H4 and H5 appropriately enter the magnetoresistive elements S1 and S3 when a vertical magnetic field H3 (described later) passes through the soft magnetic body 3 and leaks from the lower surface. The positions of the resistance effect elements S1 and S3 are determined.

  As shown in FIG. 1A, the fixed magnetization direction P1 of the fixed magnetic layer in the third magnetoresistive element S3 is the same as that of the first magnetoresistive element S1.

  In FIG. 1A, each of the magnetoresistive elements S1 to S3 is arranged one by one. For example, two soft magnetoresistive elements S1 and second magnetoresistive elements S1 are provided. Two magnetoresistive elements S2 and four third magnetoresistive elements S3 are arranged.

  As shown in FIG. 1C, the two second magnetoresistive effect elements S2 and the two third magnetoresistive effect elements S3 constitute the first bridge circuit 11, and the two first magnetoresistive effect elements S3. The second bridge circuit 12 is composed of the magnetoresistive element S1 and the two third magnetoresistive elements S3.

  The first bridge circuit 11 shown in FIG. 1C is for detecting a horizontal magnetic field H1 from the X1-X2 direction shown in FIG. In the absence of a magnetic field, the free magnetic layer 63 shown in FIG. 5 is oriented in the Y1-Y2 direction. The magnetization control of the free magnetic layer 63 can be performed by a bias magnetic field or a shape anisotropy by a permanent magnet layer.

  When the horizontal magnetic field H1 acts, the magnetization direction of the free magnetic layer 63 changes in the direction of the horizontal magnetic field H1. Since the horizontal magnetic field H1 acts in the X1 direction as shown in FIG. 1A, each of the second magnetoresistive effect element S2 and the third magnetoresistive effect element S3 constituting the first bridge circuit 11 is provided. The magnetization direction of the free magnetic layer 63 also faces the X1 direction. At this time, since the fixed magnetization direction P1 of the second magnetoresistive element S2 is the X2 direction, the electrical resistance value of the second magnetoresistive element S2 increases from the non-magnetic field state, while the third magnetoresistive effect Since the fixed magnetization direction P1 of the element S3 is the X1 direction, the electric resistance value of the third magnetoresistive element S3 is reduced from the no magnetic field state. As a result, the midpoint potential of the output terminals V1, V2 varies, and an output can be obtained.

  The soft magnetic body 3 exhibits a magnetic shielding effect with respect to the horizontal magnetic field H2 from the Y1-Y2 direction orthogonal to the horizontal magnetic field H1 in the X1-X2 direction in the horizontal plane, and the horizontal magnetic field H2 is a magnetoresistive effect element. It is possible to attenuate the magnetic field flowing into S2 and S3. Even if the horizontal magnetic field H2 acts, the electric resistance values of the magnetoresistive elements S2 and S3 all have the same value, so that output fluctuation does not occur in the first bridge circuit 11 shown in FIG. . Further, as shown in FIG. 1B, when the vertical magnetic field H3 from the Z1-Z2 direction is applied, the second magnetoresistance effect element S2 located on the X1 side surface 3a side of the soft magnetic body 3 is moved in the X1 direction. The horizontal magnetic field component H4 acts on the third magnetoresistive element S3 located on the X2 side surface 3b side of the soft magnetic body 3, and the horizontal magnetic field component H5 in the X2 direction acts.

  For this reason, since each fixed magnetization direction P1 of the 2nd magnetoresistive effect element S2 and 3rd magnetoresistive effect element S3 and the magnetization direction of each free magnetic layer become antiparallel, an electrical resistance value is a no-magnetic-field state However, since the second magnetoresistive element S2 and the third magnetoresistive element S3 have the same electric resistance value, the output fluctuation occurs in the first bridge circuit 11 shown in FIG. Does not occur.

  Therefore, the first bridge circuit 11 detects the horizontal magnetic field (component) H1 from the X1-X2 direction, but does not detect the external magnetic field component from the other directions, and thus the disturbance magnetic field to the first bridge circuit 11 is detected. Can increase resistance.

  The second bridge circuit 12 shown in FIG. 1C is for detecting the vertical magnetic field H3 shown in FIG. When the vertical magnetic field H3 is guided from the upper surface of the soft magnetic body 3 to the lower surface, a part of the vertical magnetic field H3 leaks from the lower surface of the soft magnetic body 3 and the horizontal magnetic field component H4 in the X1 direction and horizontal in the X2 direction. It is converted into a magnetic field component H5.

  As shown in FIG. 1B, a horizontal magnetic field component H4 in the X1 direction acts on the first magnetoresistive element S1 disposed on the X1 side surface 3a side of the soft magnetic body 3, and the soft magnetic body 3 A horizontal magnetic field component H5 in the X2 direction acts on the third magnetoresistance effect element S3 disposed on the X2 side surface 3b side. Since the fixed magnetization direction P1 of the first magnetoresistive element S1 is the X1 direction, the electrical resistance value of the first magnetoresistive element S1 is changed from the no magnetic field state by receiving the horizontal magnetic field component H4 in the X1 direction. Get smaller. On the other hand, the fixed magnetization direction P1 of the third magnetoresistive effect element S3 is also the X1 direction. However, the third magnetic resistance effect element S3 is affected by the horizontal magnetic field component H5 in the X2 direction, so that the third magnetic The electrical resistance value of the resistive element S3 increases from the no magnetic field state. As a result, the midpoint potential of the output terminals V3 and V4 varies and an output can be obtained.

  In addition, when the horizontal magnetic field H1 in the X1 direction is applied, the first magnetoresistive element S1 and the third magnetoresistive element S3 both have the same electric resistance value. No output fluctuation occurs in the second bridge circuit 12. Similarly, when a horizontal magnetic field H2 in the Y1 direction is applied, both the first magnetoresistive element S1 and the third magnetoresistive element S3 have the same electric resistance value, and therefore, as shown in FIG. No output fluctuation occurs in the second bridge circuit 12.

  Therefore, the second bridge circuit 12 detects the vertical magnetic field (component) H3, but does not detect the external magnetic field component from the other direction, so that the disturbance magnetic field resistance to the second bridge circuit 12 can be enhanced.

  FIG. 2 shows a first bridge circuit 11 that detects a horizontal magnetic field H1 in the X1-X2 direction with two chips 15, 16 based on the basic configuration of the magnetic sensor 1 shown in FIG. In addition to the second bridge circuit 12 that detects the horizontal magnetic field H2, a third bridge circuit that detects the horizontal magnetic field H2 in the Y1-Y2 direction can be configured. Thus, a magnetic sensor capable of three-axis detection can be formed.

  As shown in FIG. 2, the first chip 15 includes a soft magnetic body 3 extending in the Y1-Y2 direction and magnetoresistive elements S1 to S3 disposed on both sides of the soft magnetic body 3 in the X1-X2 direction. And is configured. As shown in FIG. 2, the first chip 15 has one first magnetoresistive element S1, two second magnetoresistive elements S2, and three third magnetoresistive elements S3. Has been. The film configuration of each of the magnetoresistive elements S1 to S3 and the formation position with respect to the soft magnetic body 3 are as shown in FIG. 1, FIG. 4, and FIG.

  Another second chip 16 having the same configuration as the first chip 15 shown in FIG. 2 is formed, and the second chip 16 is arranged in a state rotated by 90 degrees with respect to the first chip 15. As a result, the fixed magnetization direction P1 (sensitivity axis direction) of each of the magnetoresistive elements S1 to S3 arranged on the second chip 16 faces the Y1-Y2 direction.

  A second magnetic field effect element S2 and two third magnetoresistance effect elements S3 provided on the first chip 15 shown in FIG. 2 can detect a horizontal magnetic field in the X1-X2 direction. 1 bridge circuit 11 and two second magnetoresistive elements S2 and two third magnetoresistive elements S3 provided on the second chip 16 shown in FIG. A third bridge circuit capable of detecting a horizontal magnetic field in the Y2 direction is configured, and the first magnetoresistive element S1, the third magnetoresistive element S3, and the second chip remaining in the first chip 15 are provided. The second bridge circuit 12 capable of detecting the vertical magnetic field can be configured by the remaining first magnetoresistive element S1 and third magnetoresistive element S3.

  As shown in FIG. 3, a magnetic sensor capable of three-axis detection with one chip 17 can be configured.

  In FIG. 3, two magnetoresistive elements S4 to S7 are disposed on both sides of the first soft magnetic body 18 extending in the Y1-Y2 direction in the X1-X2 direction. The thick arrows shown in the magnetoresistive elements S4 to S7 indicate the fixed magnetization direction (sensitivity axis direction) P1, and the thin arrows indicate the bias direction HB from the permanent magnet layer. The fixed magnetization direction P1 is the X1-X2 direction, and the bias direction HB is the Y1-Y2 direction.

  As shown in FIG. 3, the magnetoresistive effect element S4 and the magnetoresistive effect element S6 disposed on the X1 plane side of the first soft magnetic body 18 have the same fixed magnetization direction P1 but opposite bias directions HB. It has become a direction. Further, the magnetoresistive effect element S5 and the magnetoresistive effect element S7 arranged on the X2 side surface side of the first soft magnetic body 18 have the same fixed magnetization direction P1 and are opposite to the magnetoresistive effect elements S4 and S6. It has become. The bias directions HB of the magnetoresistive effect element S5 and the magnetoresistive effect element S7 are opposite to each other. These magnetoresistive elements S4 to S7 constitute a bridge circuit for X-axis detection. That is, when an external magnetic field acts in the X1-X2 direction, an output is generated because there is a difference in electrical resistance value between the magnetoresistive effect element S4 and the magnetoresistive effect element S6, and the magnetoresistive effect element S5 and the magnetoresistive effect element S7. It becomes possible to obtain. On the other hand, output fluctuation does not occur when a horizontal magnetic field acts in the Y1-Y2 direction and when a vertical magnetic field acts.

  In FIG. 3, two magnetoresistive elements S12 to S15 are arranged on each side of the second soft magnetic body 20 extending in the X1-X2 direction in the Y1-Y2 direction. The thick arrows shown in the magnetoresistive elements S12 to S15 indicate the fixed magnetization direction (sensitivity axis direction) P1, and the thin arrows indicate the bias direction HB from the permanent magnet layer. The fixed magnetization direction is the Y1-Y2 direction, and the bias direction HB is the X1-X2 direction.

  As shown in FIG. 3, the magnetoresistive effect element S12 and the magnetoresistive effect element S14 disposed on the Y1 side surface side of the second soft magnetic body 20 have the same fixed magnetization direction P1 but the opposite bias direction HB. It has become a direction. Further, the magnetoresistive effect element S13 and the magnetoresistive effect element S15 disposed on the Y2 side surface side of the third soft magnetic body 20 have the same fixed magnetization direction P1 and are opposite to the magnetoresistive effect elements S12 and S14. It has become. The bias directions HB of the magnetoresistive effect element S13 and the magnetoresistive effect element S15 are opposite to each other. These magnetoresistive elements S12 to S15 constitute a bridge circuit for Y-axis detection. That is, when an external magnetic field acts in the Y1-Y2 direction, an output is generated because there is a difference in electrical resistance value between the magnetoresistive effect element S12 and the magnetoresistive effect element S14, and the magnetoresistive effect element S13 and the magnetoresistive effect element S15. It becomes possible to obtain. On the other hand, output fluctuation does not occur when a horizontal magnetic field acts in the X1-X2 direction and when a vertical magnetic field acts.

  In FIG. 3, two magnetoresistive elements S8 to S11 are arranged on each side of the third soft magnetic body 19 extending in the Y1-Y2 direction in the X1-X2 direction. The thick arrows shown in the magnetoresistive elements S8 to S11 indicate the fixed magnetization direction (sensitivity axis direction) P1, and the thin arrows indicate the bias direction HB from the permanent magnet layer. The fixed magnetization direction is the X1-X2 direction, and the bias direction HB is the Y1-Y2 direction.

  As shown in FIG. 3, the fixed magnetization directions P1 of the magnetoresistive elements S8 to S11 arranged on both sides in the X1-X2 direction of the third soft magnetic body 19 are all the same direction. The bias direction HB of the magnetoresistive effect element S8 and the magnetoresistive effect element S9 is the same direction, but the bias direction HB of the magnetoresistive effect element S10 and the magnetoresistive effect element S11 is relative to the magnetoresistive effect elements S8 and S9. The opposite direction. These magnetoresistive elements S8 to S11 constitute a bridge circuit for Z-axis detection. That is, when a vertical magnetic field from the Z direction acts, a difference is produced in the electric resistance value between the magnetoresistive effect element S8 and the magnetoresistive effect element S10, and the magnetoresistive effect element S9 and the magnetoresistive effect element S11, thereby obtaining an output. It becomes possible. On the other hand, output fluctuation does not occur when a horizontal magnetic field acts in the X1-X2 direction and the Y1-Y2 direction.

  The bridge circuit for Z-axis detection shown in FIG. 3 is different from FIG. 3 if the fixed magnetization directions P1 of the magnetoresistive elements S8 to S11 arranged on both sides of the soft magnetic body 19 are all controlled to be the same direction. It can also be. For example, the soft magnetic body 19 and the magnetoresistive elements S8 to S11 may be arranged by being rotated 90 degrees from the state of FIG. 3, or may be arranged obliquely with respect to both the X direction and the Y direction. . However, it is preferable to align in the X direction or the Y direction because the number of film formation can be reduced.

  2 and 3, each of the magnetoresistive elements S1 to S15 has the self-pin structure shown in FIG. 5, and therefore, the antiferromagnetic layer is not used, and thus the pinned magnetic layer is configured without performing heat treatment in a magnetic field. The magnetization of the first magnetic layer 61a and the second magnetic layer 61b can be antiparallel. Therefore, it is possible to appropriately form a plurality of magnetoresistive elements S1 to S15 having different fixed magnetization directions in the same chip.

  In the configuration of FIG. 3, a total of eight film formations are required depending on the fixed magnetization direction P1 and the bias direction HB of each of the magnetoresistive effect elements S4 to S15, but the bias direction HB for the magnetoresistive effect elements S4 and S6, the magnetoresistive effect element By making the bias direction HB for S5, S7, and S8 to S11, the bias direction HB for the magnetoresistive effect elements S12 and S14, and the bias direction HB for the magnetoresistive effect elements S13 and S15, unified, the film formation is performed four times in total. It can be reduced to the number of times.

H1, H2, H4, H5 Horizontal magnetic field (component)
H3 Perpendicular magnetic field P1 Fixed magnetization direction (sensitivity axis direction)
S, S1 to S15 Magnetoresistive element 1 Magnetic sensor 2 Substrate 3, 18 to 20 Soft magnetic material 4 Insulating layer 10 Element part 11, 12 Bridge circuit 15, 16, 17 Chip 61 Fixed magnetic layer 61a, 61b Magnetic layer 61c Non Magnetic intermediate layer 63 Free magnetic layer

Claims (4)

A plurality of magnetoresistive effect elements that exhibit a magnetoresistive effect formed by laminating a magnetic layer and a nonmagnetic layer, and a soft magnetic material provided in a non-contact position via each magnetoresistive effect element and an insulating layer Have
Husband in plan view on both sides of the first horizontal direction of the soft magnetic material s, the fixed magnetization direction of the pinned magnetic layer, the first of said magnetoresistive element oriented in the horizontal direction are disposed, wherein The first magnetoresistive element and the second magnetoresistive element, which are disposed on the same side surface of the soft magnetic body and whose fixed magnetization directions are opposite to each other, the first magnetoresistive element and the second magnetoresistive element A third magnetoresistive element disposed on the side surface of the soft magnetic material opposite to the magnetoresistive element, and having the same fixed magnetization direction as the first magnetoresistive element,
The second magnetoresistive element and the third magnetoresistive element form a first bridge circuit capable of detecting a horizontal magnetic field from the first horizontal direction,
The first magnetoresistive effect element and the third magnetoresistive effect element constitute a second bridge circuit capable of detecting a vertical magnetic field from the thickness direction of the soft magnetic material. Magnetic sensor. Two chips having the soft magnetic material, the first magnetoresistive element, the second magnetoresistive element, and the third magnetoresistive element are prepared, and one of the chips is rotated by 90 degrees. The first bridge circuit capable of detecting a horizontal magnetic field from the first horizontal direction with the fixed magnetization direction of each magnetoresistive element oriented in a second horizontal direction orthogonal to the first horizontal direction; with detectable second bridge circuit perpendicular magnetic field, the magnetic sensor according to claim 1, wherein configuring the third bridge circuit capable of detecting the horizontal magnetic field from the second horizontal direction. A plurality of magnetoresistive elements that exhibit a magnetoresistive effect formed by laminating a magnetic layer and a nonmagnetic layer, and a soft magnetic material provided in a non-contact position via each magnetoresistive element and an insulating layer Have
The magnetoresistive effect element in which the pinned magnetization direction of the pinned magnetic layer is oriented in the first horizontal direction on each side in the first horizontal direction of the soft magnetic body in a plan view,
Within one chip,
The fixed magnetic layers of the magnetoresistive elements arranged on both sides of the first soft magnetic body in the first horizontal direction are fixedly magnetized in opposite directions to detect a horizontal magnetic field from the first horizontal direction. A possible bridge circuit is configured,
A second soft magnetic body different from the first soft magnetic body is provided, and both sides in the second horizontal direction orthogonal to the first horizontal direction of the second soft magnetic body in plan view The magnetoresistive effect element having the fixed magnetization direction of the fixed magnetic layer oriented in the second horizontal direction is disposed on both sides of the second soft magnetic body in the second horizontal direction. A pinned magnetic layer of each magnetoresistive effect element is fixedly magnetized in opposite directions to form a bridge circuit capable of detecting a horizontal magnetic field from the second horizontal direction,
A third soft magnetic body different from the first soft magnetic body and the second soft magnetic body is provided, and the fixed magnetic layer is in the same direction on both sides of the third soft magnetic body in plan view. magnetic sensor is located each magnetoresistive element fixed magnetization, the third detectable bridge circuit vertical magnetic field from the thickness direction of the soft magnetic material, characterized in that it is configured. The magnetoresistive effect element includes a laminated structure in which the pinned magnetic layer and the free magnetic layer are laminated via a nonmagnetic material layer,
In the pinned magnetic layer, a first magnetic layer and a second magnetic layer in contact with the nonmagnetic material layer are laminated via a nonmagnetic intermediate layer, and the first magnetic layer and the second magnetic layer are antiparallel. the magnetic sensor according to any one of claims 1 is a self-pinned type magnetized fixed 3.

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