WO2009084435A1 - Magnetic sensor and magnetic sensor module - Google Patents

Magnetic sensor and magnetic sensor module Download PDF

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Publication number
WO2009084435A1
WO2009084435A1 PCT/JP2008/072921 JP2008072921W WO2009084435A1 WO 2009084435 A1 WO2009084435 A1 WO 2009084435A1 JP 2008072921 W JP2008072921 W JP 2008072921W WO 2009084435 A1 WO2009084435 A1 WO 2009084435A1
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WIPO (PCT)
Prior art keywords
layer
magnetic
magnetic field
permanent magnet
magnetic sensor
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PCT/JP2008/072921
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French (fr)
Japanese (ja)
Inventor
Hiromitsu Sasaki
Hirofumi Fukui
Takashi Hatanai
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Alps Electric Co., Ltd.
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Publication date
Application filed by Alps Electric Co., Ltd. filed Critical Alps Electric Co., Ltd.
Priority to JP2009547997A priority Critical patent/JP5066581B2/en
Publication of WO2009084435A1 publication Critical patent/WO2009084435A1/en

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/02—Measuring direction or magnitude of magnetic fields or magnetic flux
    • G01R33/06—Measuring direction or magnitude of magnetic fields or magnetic flux using galvano-magnetic devices
    • G01R33/09—Magnetoresistive devices
    • G01R33/093—Magnetoresistive devices using multilayer structures, e.g. giant magnetoresistance sensors
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y25/00—Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N50/00—Galvanomagnetic devices
    • H10N50/10—Magnetoresistive devices

Definitions

  • the present invention relates to a magnetic sensor using a magnetoresistive effect element used as a geomagnetic sensor, for example.
  • a magnetic sensor using a magnetoresistive effect element can be used as a geomagnetic sensor for detecting geomagnetism incorporated in a mobile device such as a mobile phone.
  • the magnetoresistive element varies in electric resistance value with respect to the strength of the magnetic field from the sensitivity axis direction.
  • the geomagnetic sensor needs to detect magnetism by splitting it into two or three axes, so the magnetic sensor that detects the strength of the magnetic field of each axis is not sensitive to the other axes. There is a need to. Further, in order to accurately detect the magnetic field strength, a sensor having a linear output with respect to the magnetic field strength is required.
  • Patent Document 1 a plurality of strip-like magnetoresistive films are arranged in parallel to each other, and end portions of each magnetoresistive element are connected by a permanent magnet film to form a zigzag folded shape.
  • a sensor is disclosed.
  • Patent Document 1 does not recognize the conventional problem with respect to the above-described geomagnetic sensor, and naturally does not show means for solving it. JP 2005-183614 A
  • the present invention is to solve the above-described conventional problems, and in particular, can improve the magnetic shielding effect in the direction orthogonal to the sensitivity axis and obtain a stable magnetic sensitivity in the sensitivity axis direction. It is an object of the present invention to provide a magnetic sensor and a magnetic sensor module capable of performing the above.
  • the present invention is a magnetic sensor comprising a magnetoresistive effect element,
  • the magnetoresistive element has a pinned magnetic layer whose magnetization direction is fixed, and a free magnetic layer whose magnetization direction is changed by receiving an external magnetic field laminated on the pinned magnetic layer via a nonmagnetic layer,
  • An element portion oriented in an element width direction in which the fixed magnetization direction of the fixed magnetic layer is a sensitivity axis direction;
  • the element portion and an intermediate permanent magnet layer in an element length direction orthogonal to the element width direction are provided, and an element coupling body is constituted by the element portion and the intermediate permanent magnet layer, and the element coupling body
  • the element length is longer than the element width
  • a soft magnetic body is disposed in non-contact with the element coupling body,
  • the length dimension of the soft magnetic body in the same direction as the element length direction is longer than the element length of the element coupling body, and the soft magnetic body extends from both sides of the element coupling body in the element length direction. It has an
  • the above configuration can improve the magnetic shield effect in the direction perpendicular to the sensitivity axis, and can obtain a stable magnetic sensitivity in the sensitivity axis direction.
  • the element portion, the outer permanent magnet layer, and the intermediate permanent magnet layer in the element coupling body are all electrically connected, and a plurality of element coupling bodies are arranged at intervals in the element width direction.
  • the outer permanent magnet layers provided on both sides of each element unit coupling body are formed in a meander shape electrically connected by a nonmagnetic connection layer, It is preferable that the soft magnetic body is formed in non-contact with each element portion on either side of the element width direction in the element width direction, directly above, or directly below.
  • the meander shape the element resistance can be increased and the power consumption can be reduced. Further, by arranging a soft magnetic material for each element portion, the magnetic shield effect in the direction orthogonal to the sensitivity axis can be improved more appropriately.
  • the nonmagnetic connection layer has an intersecting portion intersecting the soft magnetic material with an insulating film interposed therebetween.
  • the size can be reduced in a plane, and the parasitic resistance due to the wiring length can be reduced.
  • the length of the outer permanent magnetic layer in the element length direction is longer than the length of the intermediate permanent magnetic layer in the element length direction.
  • the intermediate permanent magnetic layer and the outer permanent magnetic layer are formed wider than the element width.
  • the intermediate permanent magnet layer is provided in a recess formed in the film thickness direction of the element portion.
  • the outer permanent magnetic layer is electrically connected through a recess formed in the film thickness direction of the element portion.
  • a nonmagnetic low resistance layer having a resistance value smaller than that of the permanent magnet layer is formed on the upper surface of the intermediate permanent magnet layer and the upper surface of the outer permanent magnet layer.
  • each of the intermediate permanent magnet layer and the outer permanent magnet layer may be formed through an insulating film with respect to the element portion, or may be formed in a form in which it is directly electrically joined. In view of the characteristics and bias magnetic field application characteristics, it is preferable to form the electrode portion directly in electrical contact with the element portion.
  • a magnetic sensor module according to the present invention includes a plurality of the magnetic sensors according to any one of the above, and each magnetoresistive element is configured so that sensitivity axes of at least one pair of the magnetoresistive elements are orthogonal to each other. Is arranged.
  • the magnetic sensor module of the present invention can be used as a geomagnetic sensor.
  • the magnetic sensor of the present invention it is possible to improve the magnetic shield effect in the direction orthogonal to the sensitivity axis and to obtain a stable magnetic sensitivity with respect to the magnetic field from the sensitivity axis direction.
  • FIG. 1A is a plan view showing a portion of the magnetoresistive element of the magnetic sensor according to the first embodiment
  • FIG. 1B is a height direction along the line AA in FIG.
  • FIG. 2 is a plan view showing a part of the magnetoresistive element of the magnetic sensor in the second embodiment
  • FIG. 3 is a DD shown in FIG.
  • FIG. 4 is a partially enlarged cross-sectional view taken along the line in the height direction (Z direction in the drawing) and viewed from the arrow direction
  • FIG. FIG. 6 is a diagram for explaining the relationship between the fixed magnetization direction of the pinned magnetic layer and the magnetization direction of the free magnetic layer of the magnetoresistive effect element, and the electric resistance value
  • FIG. 6 shows the magnetoresistive effect element cut from the film thickness direction.
  • FIG. 7 is a circuit diagram of the magnetic sensor of the present embodiment. That.
  • the magnetic sensor module using the magnetic sensor 1 provided with the magnetoresistive effect element according to the present embodiment is used as a geomagnetic sensor mounted on a mobile device such as a mobile phone.
  • the geomagnetic sensor 1 includes a sensor unit 6 in which magnetoresistive effect elements 2 and 3 and fixed resistance elements 4 and 5 are bridge-connected, and an input terminal electrically connected to the sensor unit 6. 7, an integrated circuit (IC) 11 having a ground terminal 8, a differential amplifier 9, an external output terminal 10, and the like.
  • IC integrated circuit
  • an element coupling body 61 extending in a strip shape in the X direction is configured by the element portion 12 and the intermediate permanent magnet layer 60.
  • the element length L1 of the element coupling body 61 is formed longer than the element width W1.
  • Outer permanent magnet layers 65 are provided on both sides in the X direction of the element coupling body 61 in the drawing.
  • a plurality of the element coupling bodies 61 are arranged in parallel at intervals in the element width direction (Y direction), and the outer permanent magnet layers 65 provided at both ends of each element coupling body 61 are connected by electrode layers 62.
  • meander-shaped magnetoresistive elements 2 and 3 are configured.
  • the electrode layer 62 connected to the input terminal 7, the ground terminal 8, and the output extraction part 14 is connected to one side of the element coupling body 61 in the both ends formed in the meander shape.
  • the electrode layer 62 has a lower resistance than the permanent magnet layers 60 and 65 and is made of a nonmagnetic conductive material such as Al, Ta, or Au.
  • FIG. 6 shows a cut surface cut in the film thickness direction from the direction parallel to the element width W1.
  • the element portion 12 is formed by laminating, for example, an antiferromagnetic layer 33, a pinned magnetic layer 34, a nonmagnetic layer 35, and a free magnetic layer 36 in this order from the bottom, and the surface of the free magnetic layer 36 is a protective layer 37. Covered.
  • the element unit 12 is formed by sputtering, for example.
  • the antiferromagnetic layer 33 is made of an antiferromagnetic material such as an Ir—Mn alloy (iridium-manganese alloy).
  • the pinned magnetic layer 34 is made of a soft magnetic material such as a Co—Fe alloy (cobalt-iron alloy).
  • the nonmagnetic layer 35 is made of Cu (copper) or the like.
  • the free magnetic layer 36 is formed of a soft magnetic material such as a Ni—Fe alloy (nickel-iron alloy).
  • the protective layer 37 is made of Ta (tantalum) or the like.
  • the nonmagnetic layer 35 is a giant magnetoresistive effect element (GMR element) formed of a nonmagnetic conductive material such as Cu, but a tunnel type magnetoresistive effect element formed of an insulating material such as Al 2 O 3. (TMR element) may be used.
  • GMR element giant magnetoresistive effect element
  • TMR element tunnel type magnetoresistive effect element formed of an insulating material such as Al 2 O 3.
  • the stacked configuration of the element unit 12 illustrated in FIG. 6 is an example, and another stacked configuration may be used.
  • the free magnetic layer 36, the nonmagnetic layer 35, the pinned magnetic layer 34, the antiferromagnetic layer 33, and the protective layer 37 may be stacked in this order from the bottom.
  • the magnetization direction of the pinned magnetic layer 34 is fixed by antiferromagnetic coupling between the antiferromagnetic layer 33 and the pinned magnetic layer 34.
  • the pinned magnetization direction (P direction) of the pinned magnetic layer 34 faces the element width direction (Y direction). That is, the fixed magnetization direction (P direction) of the fixed magnetic layer 34 is orthogonal to the longitudinal direction of the element coupling body 61.
  • the magnetization direction (F direction) of the free magnetic layer 36 varies depending on the external magnetic field.
  • a bias magnetic field acts on the element portion 12 from the permanent magnet layers 60 and 65 from the X direction in the figure. Therefore, the magnetization of the free magnetic layer 36 constituting the element unit 12 is directed in the X direction in the figure in the absence of a magnetic field.
  • the external magnetic field Y1 acts from the same direction as the fixed magnetization direction (P direction) of the fixed magnetic layer 34, and the magnetization direction (F direction) of the free magnetic layer 36 faces the external magnetic field Y1 direction. Then, the fixed magnetization direction (P direction) of the fixed magnetic layer 34 and the magnetization direction (F direction) of the free magnetic layer 36 approach each other, and the electric resistance value decreases.
  • the external magnetic field Y2 acts from the direction opposite to the fixed magnetization direction (P direction) of the fixed magnetic layer 34, and the magnetization direction (F direction) of the free magnetic layer 36 changes to the external magnetic field Y2 direction.
  • the fixed magnetization direction (P direction) of the fixed magnetic layer 34 and the magnetization direction (F direction) of the free magnetic layer 36 approach antiparallel, and the electrical resistance value increases.
  • the magnetoresistive elements 2 and 3 are formed on a substrate 16.
  • the magnetoresistive elements 2 and 3 are covered with an insulating layer 17 such as Al 2 O 3 or SiO 2 .
  • the space between the element coupling bodies 61 constituting the magnetoresistive effect elements 2 and 3 is also filled with the insulating layer 17.
  • the insulating layer 17 is formed by sputtering, for example.
  • the upper surface of the insulating layer 17 is formed as a flat surface by using, for example, a CMP technique.
  • the upper surface of the insulating layer 17 may be formed as an uneven surface following the step between the element coupling body 61 and the substrate 16.
  • a soft magnetic body 18 is provided between the element coupling bodies 61 constituting the magnetoresistive effect elements 2 and 3 and outside the element coupling body 61 located on the outermost side.
  • the soft magnetic material 18 is formed into a thin film by sputtering or plating, for example.
  • the soft magnetic body 18 is made of NiFe, CoFe, CoFeSiB, CoZrNb, or the like.
  • the length L2 of the soft magnetic body 18 is longer than the element length L1 of the element coupling body 61.
  • the soft magnetic body 18 has a longitudinal direction ( An extending portion 18a extending in the longitudinal direction from both sides in the (X direction) is provided.
  • the soft magnetic body 18 is formed on the insulating layer 17 between the element portions 12. Although not shown, the soft magnetic body 18 and the space between the soft magnetic bodies 18 are covered with an insulating protective layer.
  • the element width W1 of the element portion 12 constituting the magnetoresistive effect elements 2 and 3 is in the range of 2 to 10 ⁇ m (see FIG. 1A).
  • the element length L5 of the element unit 12 is in the range of 1 to 10 ⁇ m (see FIG. 1A).
  • the film thickness T2 of the element portion 12 is in the range of 200 to 400 mm (see FIG. 1B).
  • the element section 12 has an aspect ratio (element length L5 / element width W1) of 0.1 to 4.
  • the length L3 of the intermediate permanent magnet layer 60 is in the range of 0.5 to 5 ⁇ m (see FIG. 1 (a)).
  • the width W3 of the intermediate permanent magnet layer 13 is in the range of 3 to 12 ⁇ m (see FIG. 1 (a)). W3 is preferably wider than W1.
  • the film thickness of the intermediate permanent magnet layer 13 is in the range of 150 to 1000 mm.
  • the length L4 of the outer permanent magnet layer 65 is in the range of 5 to 10 ⁇ m (see FIG. 1 (a)).
  • the film thickness of the outer permanent magnet layer 15 is preferably equal to the film thickness of the intermediate permanent magnet layer 13.
  • the distance T5 in the element width direction between the element coupling bodies 61 is in the range of 2 to 10 ⁇ m (see FIG. 1A).
  • the length dimension L1 of the element coupling body 61 is in the range of 50 to 200 ⁇ m.
  • the width dimension W2 of the soft magnetic body 18 is in the range of 1 to 6 ⁇ m when used as a geomagnetic sensor (see FIG. 1A).
  • the length L2 of the soft magnetic body 18 is in the range of 80 to 200 ⁇ m (see FIG. 1A).
  • the film thickness T3 of the soft magnetic body 18 is in the range of 0.2 to 1 ⁇ m (see FIG. 1B).
  • a length dimension T8 of the extending portion 18a of the soft magnetic body 18 is 10 ⁇ m or more (see FIG. 1A).
  • the distance T1 between the soft magnetic bodies 18 is 2 to 8 ⁇ m, which is equal to or larger than the width dimension W2 of the soft magnetic body 18 (see FIG. 1B).
  • the distance T4 in the Y direction between the soft magnetic body 18 located adjacent to the element portion 12 is 0 ⁇ T4 ⁇ 3 ⁇ m (see FIG. 1B).
  • a distance T5 in the height direction (Z direction) between the soft magnetic body 18 and the element portion 12 is 0.1 to 1 ⁇ m (see FIG. 1B).
  • the magnetic sensor 1 shown in FIG. 1 is for detecting geomagnetism from a direction parallel to the Y direction (element width direction) shown in the figure. Therefore, the Y direction in the figure is the sensitivity axis direction, and the X direction (element length direction) orthogonal to the Y direction in the figure is the longitudinal direction of the element coupling body 61.
  • the fixed magnetization direction (P direction) of the fixed magnetic layer 34 is directed to the Y direction in the figure, which is the sensitivity axis direction.
  • the element part 12 and the non-contact soft magnetic body 18 are provided.
  • the soft magnetic body 18 has an elongated shape in the element length direction (X direction in the drawing), like the element coupling body 61.
  • the magnetic permeability of the soft magnetic body 18 is larger than the magnetic permeability of the element portion 12.
  • the soft magnetic body 18 extends in the element length direction from both sides in the element length direction (X direction) of each element coupling body 61 constituting the magnetoresistive effect elements 2 and 3.
  • a protruding portion 18a is provided.
  • the element coupling body 61 is constituted by the element portion 12 and the intermediate permanent magnet layer 60.
  • Comparative Example 1 has a soft magnetic body 18.
  • the comparative example 2 has the permanent magnet layers 60 and 65.
  • FIG. 9A shows the intensity H of the magnetic field from the sensitivity axis direction (hereinafter referred to as sensitivity magnetic field) in the structure of Comparative Example 1 described above and the resistance change rate (MR ratio) per unit magnetic field of the magnetoresistive effect element.
  • FIG. 9B is a graph showing the relationship. The intensity H of the magnetic field from the direction orthogonal to the sensitivity axis direction in the structure of Comparative Example 1 (hereinafter referred to as the orthogonal magnetic field) and the unit magnetic field of the magnetoresistive element. It is a graph which shows the relationship with the resistance change rate (MR ratio) per hit.
  • the disturbance magnetic field generated inside the portable device is actually larger than the detected magnetic field, and the value is constant.
  • the linearity does not collapse when a magnetic field from the direction perpendicular to the sensitivity is applied, as well as the wide linearity of “the magnetic field actually detected + the magnetic field generated in the portable device”. Is required.
  • the resistance change in the direction perpendicular to the sensitivity is required to cause no resistance change within the range of “the magnetic field actually detected + the magnetic field generated in the portable device”.
  • the magnetic field region of “the magnetic field actually detected + the magnetic field generated in the portable device” is defined as the “sensitivity region”.
  • Comparative Example 1 Since Comparative Example 1 has the soft magnetic material 18, the magnetic shielding effect against the orthogonal magnetic field is exhibited. For this reason, the intensity of the sensitivity magnetic field in each of the state where the orthogonal magnetic field is not applied, the state where the orthogonal magnetic field is applied from the first direction, and the state where the orthogonal magnetic field is applied from the second direction opposite to the first direction are provided. Even if H is changed, the sensitivity variation in the sensitivity region seems to be small as shown in FIG.
  • the magnetic field range in the sensitivity region is a low magnetic field in which the sensitivity change becomes large with respect to the orthogonal magnetic field when the orthogonal magnetic field in the same range acts. Therefore, if the orthogonal magnetic field fluctuates in a low magnetic field, the sensitivity variation with respect to the sensitive magnetic field increases.
  • Comparative Example 1 has hysteresis in the magnetic sensitivity, but the hysteresis will be described later.
  • FIG. 10A shows the intensity H of the magnetic field from the sensitivity axis direction (hereinafter referred to as sensitivity magnetic field) in the structure of Comparative Example 2 described above and the resistance change rate (MR ratio) per unit magnetic field of the magnetoresistive effect element.
  • FIG. 10B is a graph showing the relationship. The intensity H of the magnetic field from the direction orthogonal to the sensitivity axis direction (hereinafter referred to as the orthogonal magnetic field) in the structure of Comparative Example 2 described above and the unit magnetic field of the magnetoresistive effect element. It is a graph which shows the relationship with the resistance change rate (MR ratio) per hit.
  • Comparative Example 2 does not have a soft magnetic body 18 and thus has no magnetic shielding effect against an orthogonal magnetic field. That is, the orthogonal magnetic field is not shielded but acts on the element portion as it is.
  • the permanent magnet layers 60 and 65 promote the single magnetic domain of the element part 12.
  • the bias magnetic field that acts on the element unit 12 appears to be apparent.
  • the bias magnetic field acting on the element unit 12 is apparently reduced. For this reason, the intensity H of the sensitivity magnetic field is changed in each of a state where the orthogonal magnetic field is not applied, a state where the orthogonal magnetic field is applied in the same direction as the bias magnetic field, and a state where the orthogonal magnetic field is applied in the opposite direction to the bias magnetic field.
  • the MR ratio at this time is examined, as shown in FIG. 10A, the sensitivity variation in the sensitivity region becomes very large.
  • the substantially V-shaped waveform portion whose sensitivity changes is the same magnetic field range as the sensitivity region due to the influence of the bias magnetic field by the permanent magnet layers 60 and 65. Shift slightly from within. Accordingly, even if the orthogonal magnetic field component fluctuates in the low magnetic field range equivalent to the sensitivity region, the sensitivity variation with respect to the sensitive magnetic field does not change as much as the comparative example 1 from the state of FIG. Since the orthogonal magnetic field cannot be shielded, the waveform portion where the sensitivity changes greatly changes compared to FIG. 9B, and therefore the variation in sensitivity with respect to the sensitive magnetic field cannot be reduced as much as in the embodiment described below.
  • FIG. 11A shows the relationship between the intensity H of the magnetic field from the sensitivity axis direction (hereinafter referred to as sensitivity magnetic field) and the resistance change rate (MR ratio) per unit magnetic field of the magnetoresistive effect element in the structure of this embodiment.
  • FIG. 10B shows the strength H of the magnetic field from the direction orthogonal to the sensitivity axis direction in the structure of this embodiment (hereinafter referred to as the orthogonal magnetic field) and the resistance change per unit magnetic field of the magnetoresistive effect element. It is a graph which shows the relationship with a ratio (MR ratio).
  • the soft magnetic body 18 has a magnetic shielding effect against an orthogonal magnetic field.
  • the soft magnetic body 18 in the present embodiment includes the extending portions 18a extending in the element length direction from both sides in the element length direction (X direction) of each element coupling body 61, the orthogonal magnetic field is It is easier to pass through the soft magnetic body 18 more effectively.
  • the permanent magnet layers 60 and 65 promote the formation of a single magnetic domain in the element portion 12. Therefore, the intensity H of the sensitivity magnetic field is changed in each of a state where the orthogonal magnetic field does not act, a state where the orthogonal magnetic field acts in the same direction as the bias magnetic field, and a state where the orthogonal magnetic field acts in the opposite direction to the bias magnetic field.
  • the sensitivity variation in the sensitivity region becomes very small as shown in FIG.
  • the substantially V-shaped waveform portion whose sensitivity changes due to the influence of the bias magnetic field by the permanent magnet layers 60 and 65 is shifted from the same magnetic field range as the sensitivity region.
  • the corrugated portion can be reduced by the magnetic shielding effect by the soft magnetic body 18. Therefore, even if the orthogonal magnetic field (disturbance magnetic field) within the same magnetic field range as the sensitivity region is not constant and fluctuates, the sensitivity variation with respect to the sensitivity magnetic field can be reduced.
  • the bias magnetic field from the permanent magnet layers 60 and 65 acts on the element portion 12 and the element portion 12 is free.
  • the formation of a single magnetic domain in the magnetic layer 36 is promoted. Therefore, the occurrence of hysteresis of the magnetic sensitivity can be reduced as compared with the configuration in which the permanent magnet layers 60 and 65 are not provided as in the comparative example 1 of FIG.
  • the sensitivity change region easily spreads with respect to the orthogonal magnetic field, and a part of hysteresis easily enters the orthogonal magnetic field range in the same magnetic field range as the sensitivity region as shown in FIG. Therefore, disturbance magnetic field resistance (magnetic shield effect) is likely to decrease. Also, hysteresis is likely to occur even with a sensitive magnetic field, and the magnetic field response to the sensitive magnetic field is reduced. Therefore, in order to appropriately supply a bias magnetic field to the entire element unit 12, the aspect ratio of the element unit 12 is preferably small, preferably 3 or less, and more preferably less than 1. As a result, the thickness of the permanent magnetic layer for appropriately supplying a bias magnetic field to the element portion 12 can also be reduced.
  • FIG. 2 is a modification of FIG.
  • the electrode layer 62 that connects between the end portions of the element coupling body 61 is formed in a straight line shape (band shape) in the Y direction. And passes through the lower side of the soft magnetic body 18 through an insulating layer. That is, the electrode layer 62 and the soft magnetic body 18 intersect in the height direction (Z direction in the drawing).
  • the electrode layer 62 of the part which connects the element coupling body 61 is electrically insulated with the soft magnetic body 18, it is not limited to formation in the lower part, You may form in the upper part.
  • the electrode layer 62 is formed so as to bypass the soft magnetic body 18 in a plane, but in FIG. 2, the electrode layer 62 and the soft magnetic body 18 are arranged in the height direction (Z direction in the drawing). Since they intersect, the length dimension of the magnetoresistive elements 2 and 3 in the X direction shown in the figure can be reduced, and the wiring resistance of the electrode layer 62 can also be reduced. Further, the insulation between the electrode layer 62 and the soft magnetic body 18 (the insulation layer 17 shown in FIG. 1B is interposed) is low, and even if a short circuit occurs, the sensor characteristics are not significantly affected.
  • the parasitic resistance can be reduced as compared with the case where the electrode layer 62 is formed with a permanent magnet layer.
  • such a problem does not occur.
  • the antiferromagnetic layer 33, the pinned magnetic layer 34, and the nonmagnetic layer 35 constituting each element unit 12 are not divided at the formation positions of the permanent magnet layers 60 and 65 and are integrated. ing. That is, at the positions where the permanent magnet layers 60 and 65 are formed, the protective layer 37 and the free magnetic layer 36 constituting the element portion 12 are scraped by ion milling or the like to form the concave portion 63. Therefore, the nonmagnetic layer 35 is exposed on the bottom surface 63 a of the recess 63. Note that the recess 63 may be formed by cutting a part of the nonmagnetic layer 35.
  • the permanent magnet layers 60 and 65 are provided in the recess 63. Since the pinned magnetic layer 34 is not divided by the configuration of FIG. 3, the magnetization of the pinned magnetic layer 34 can be stabilized in the Y direction shown in the figure, and the uniaxial anisotropy can be improved. Further, in the configuration in which the permanent magnet layers 60 and 65 are provided between the element portions 12 by dividing the pinned magnetic layer 34 and the antiferromagnetic layer 33, the electrical contact between the permanent magnet layers 60 and 65 and the element portion 12 is different. The parasitic resistance tends to increase because of the side surface, but the parasitic resistance can be reduced by making the electrical contact between the permanent magnet layers 60 and 65 and the element portion 12 planar contact as in this embodiment.
  • a low resistance layer 64 having a resistance value smaller than that of the intermediate permanent magnet layer 60 is formed on the upper surface of the intermediate permanent magnet layer 60.
  • the low resistance layer 64 is preferably formed of a nonmagnetic good conductor such as Au, Al, or Cu.
  • the low resistance layer 64 is formed by sputtering or plating in the same manner as the intermediate permanent magnet layer 60. As shown in FIG. 13, by forming the low resistance layer 64 on the intermediate permanent magnet layer 60, the parasitic resistance can be more effectively reduced.
  • the electrode layer 62 as a low-resistance layer is formed on the outer permanent magnet layer 65 so as to be superposed on the outer permanent magnet layer 65, so that the parasitic resistance component that does not contribute to the magnetoresistance change can be effectively reduced. .
  • the bias magnetic field of the permanent magnetic layer is formed at the center of the element. Since they are integrated, the outer bias magnetic field is weaker than that near the center. Therefore, it is preferable that the element orthogonal direction length of the outer permanent magnet layer 65 is longer than the length of the intermediate permanent magnet layer 60. Further, the same effect can be obtained by making the outer permanent magnet layer 65 thicker than the intermediate permanent magnet layer 60 by dividing the formation process.
  • the magnetic field becomes extremely strong in the vicinity of the corners where the intermediate permanent magnet layer 60 and the outer permanent magnet layer 65 are formed, by making the permanent magnet layer width wider than the element width W1, the portion with the strongest magnetic field strength is used as the element part. It is possible to prevent direct influence, and the margin of pattern formation alignment accuracy can be increased.
  • the number of element portions 12 constituting the magnetoresistive effect elements 2 and 3 may be only one. However, providing a plurality of element portions 12 in a meander shape is preferable because the element resistance can be increased and the power consumption can be reduced.
  • the magnetoresistive effect elements 2 and 3 and the fixed resistance elements 4 and 5 may be provided one by one. However, as shown in FIG. 7, a bridge circuit is formed, and the output obtained from the output extraction unit 14 is supplied to the differential amplifier 9. By using differential output, the output value can be increased and high-precision magnetic field detection can be performed.
  • the soft magnetic body 18 is provided on both sides of the element coupling body 61.
  • the soft magnetic body 18 has an insulating layer directly above or below the element coupling body 61. The structure provided may be sufficient.
  • the magnetic sensor 1 in this embodiment is used as, for example, a geomagnetic sensor (magnetic sensor module) shown in FIG.
  • a sensor unit of a bridge circuit shown in FIG. 7 is provided in each of the X-axis magnetic field detection unit 50, the Y-axis magnetic field detection unit 51, and the Z-axis magnetic field detection unit 52.
  • the fixed magnetization direction (P direction) of the fixed magnetic layer 34 of the element unit 12 of the magnetoresistive effect elements 2 and 3 faces the X direction that is the sensitivity axis
  • the Y-axis magnetic field detection unit In 51 the fixed magnetization direction (P direction) of the pinned magnetic layer 34 of the element portion 12 of the magnetoresistive effect elements 2 and 3 faces the Y direction which is the sensitivity axis
  • the magnetoresistive effect The pinned magnetization direction (P direction) of the pinned magnetic layer 34 of the element portion 12 of the elements 2 and 3 faces the Z direction that is the sensitivity axis.
  • the X-axis magnetic field detection unit 50, the Y-axis magnetic field detection unit 51, the Z-axis magnetic field detection unit 52, and the integrated circuit (ASIC) 54 are all provided on the base 53.
  • the formation surfaces of the magnetoresistive effect elements 2 and 3 of the X-axis magnetic field detection unit 50 and the Y-axis magnetic field detection unit 51 are both XY planes. Is formed on the XZ plane, and the formation surface of the magnetoresistive effect elements 2 and 3 of the Z-axis magnetic field detection unit 52 is the magnetoresistive effect element 2 of the X-axis magnetic field detection unit 50 and the Y-axis magnetic field detection unit 51. , 3 are orthogonal to the formation surface.
  • each detection unit is orthogonal to the sensitivity axis direction.
  • the magnetic field from the direction can be properly magnetically shielded, and the geomagnetism from the direction of the sensitivity axis of each detector can be detected appropriately.
  • a module in which the geomagnetic sensor and the acceleration sensor shown in FIG. 8 are combined may be used.
  • FIG. 1 is a top view which shows the part of the magnetoresistive effect element especially of the magnetic sensor in 1st Embodiment
  • (b) is a height direction (Z direction shown in figure) along the AA line of Fig.1 (a).
  • a partial cross-sectional view as seen from the direction of the arrow The top view which shows the part of especially the magnetoresistive effect element of the magnetic sensor in 2nd Embodiment
  • FIG. 2 is a partially enlarged sectional view taken along the line DD shown in FIG.
  • a partially enlarged plan view showing a part of the element part in the form of a preferable magnetoresistive element The figure for demonstrating the relationship between the fixed magnetization direction of the fixed magnetic layer of a magnetoresistive effect element, the magnetization direction of a free magnetic layer, and an electrical resistance value, Sectional drawing which shows the cut surface at the time of cut
  • FIG. 18 is a graph showing the relationship between the strength H of the magnetic field from the sensitivity axis direction and the resistance change rate (MR ratio) per unit magnetic field of the magnetoresistive effect element in the structure of FIG.
  • the graph which shows the relationship between the intensity
  • (A) is a magnetic field from the sensitivity axis direction in the structure of the comparative example 2 (the structure in which the soft magnetic body 18 shown in FIG. 1A is not provided, but the permanent magnet layers 60 and 65 are provided).
  • a graph showing the relationship between the intensity H and the resistance change rate (MR ratio) per unit magnetic field of the magnetoresistive effect element (b) shows the magnetic field from the direction orthogonal to the sensitivity axis direction in the structure of Comparative Example 2 described above.
  • a graph showing the relationship with the resistance change rate (MR ratio), (b) is the intensity H of the magnetic field from the direction orthogonal to the sensitivity axis direction in the structure of the present embodiment and the unit magnetic field of the magnetoresistive element.
  • a graph showing the relationship with the resistance change rate (MR ratio) of A graph showing the relationship between the strength H of the orthogonal magnetic field and the resistance change rate (MR ratio) per unit magnetic field of the magnetoresistive effect element for explaining that hysteresis occurs due to the aspect ratio of the element portion;

Abstract

It is possible to provide a magnetic sensor and a magnetic sensor module which can improve the magnetic shield effect especially in a direction orthogonally intersecting the sensibility axis while maintaining the stable magnetic sensitivity in the sensibility axis direction. An element unit (12) and an intermediate permanent magnet layer (60) arranged in the element length direction constitute an element-coupled assembly (61). An external permanent magnet layer (65) is arranged at both sides of the element-coupled assembly in the element length direction. A soft magnetic body (18) is arranged in a non-contact position with respect to the element-coupled assembly (61). The soft magnetic body (18) has a length L2 greater than the element-coupled assembly (61). The soft magnetic element unit (18) has an extending portion (18a) extending from both sides of the element length direction of element-coupled assembly (61) in the element length direction.

Description

磁気センサ及び磁気センサモジュールMagnetic sensor and magnetic sensor module
　本発明は、例えば地磁気センサとして使用される磁気抵抗効果素子を用いた磁気センサに関する。 The present invention relates to a magnetic sensor using a magnetoresistive effect element used as a geomagnetic sensor, for example.
　磁気抵抗効果素子を用いた磁気センサは例えば、携帯電話等の携帯機器に組み込まれる地磁気を検知する地磁気センサとして使用できる。磁気抵抗効果素子は感度軸方向からの磁場の強さに対して電気抵抗値が変動する。 A magnetic sensor using a magnetoresistive effect element can be used as a geomagnetic sensor for detecting geomagnetism incorporated in a mobile device such as a mobile phone. The magnetoresistive element varies in electric resistance value with respect to the strength of the magnetic field from the sensitivity axis direction.
　地磁気センサでは、２軸または３軸に分解して磁気を検知する必要があるため、それぞれの軸の磁場の強さを検知する磁気センサは、他の軸に対しては感度を持たないようにする必要がある。また、磁場の強さを正確に検知するため、磁界強度に対してリニアな出力を持つセンサが求められる。 The geomagnetic sensor needs to detect magnetism by splitting it into two or three axes, so the magnetic sensor that detects the strength of the magnetic field of each axis is not sensitive to the other axes. There is a need to. Further, in order to accurately detect the magnetic field strength, a sensor having a linear output with respect to the magnetic field strength is required.
　一方、携帯機器内には地磁気よりも強い磁場を発生する部材、例えばスピーカーなどが搭載されていることが多く、また機器の開閉や、メモリーカードの挿抜などによって機器内の磁場は変動することも多い。そのため、様々な方向から例えば携帯機器内で生じた数Ｏｅ程度の漏洩磁場がかかっても、正確に地磁気を測定できるように制御することが必要である。 On the other hand, members that generate a magnetic field stronger than geomagnetism, such as speakers, are often installed in mobile devices, and the magnetic field in the device may fluctuate due to opening / closing of the device or insertion / extraction of a memory card. Many. Therefore, it is necessary to perform control so that the geomagnetism can be accurately measured even when a leakage magnetic field of about several Oe generated in a portable device is applied from various directions.
　下記の特許文献１に記載された発明では、複数の帯状の磁気抵抗効果膜を互いに平行に配置し、各磁気抵抗効果素子の端部間を永久磁石膜で接続して、つづら折り形状とした磁気センサが開示されている。 In the invention described in the following Patent Document 1, a plurality of strip-like magnetoresistive films are arranged in parallel to each other, and end portions of each magnetoresistive element are connected by a permanent magnet film to form a zigzag folded shape. A sensor is disclosed.
　しかしながら特許文献１には、上記した地磁気センサに対する従来の課題についての認識がなく当然にそれを解決する手段は示されていない。
特開２００５－１８３６１４号公報 However, Patent Document 1 does not recognize the conventional problem with respect to the above-described geomagnetic sensor, and naturally does not show means for solving it.
JP 2005-183614 A
　そこで本発明は、上記従来の課題を解決するためのものであり、特に感度軸に対して直交する方向への磁気シールド効果を向上できるとともに、感度軸方向に対して安定した磁気感度を得ることが可能な磁気センサ及び磁気センサモジュールを提供することを目的とする。 Therefore, the present invention is to solve the above-described conventional problems, and in particular, can improve the magnetic shielding effect in the direction orthogonal to the sensitivity axis and obtain a stable magnetic sensitivity in the sensitivity axis direction. It is an object of the present invention to provide a magnetic sensor and a magnetic sensor module capable of performing the above.
　本発明は、磁気抵抗効果素子を備えた磁気センサであって、
　前記磁気抵抗効果素子は、磁化方向が固定される固定磁性層と、前記固定磁性層に非磁性層を介して積層された外部磁場を受けて磁化方向が変動するフリー磁性層とを有し、前記固定磁性層の固定磁化方向が感度軸方向である素子幅方向に向けられた素子部を備え、
　前記素子部と、前記素子幅方向に直交する素子長さ方向に中間永久磁石層とが設けられており、前記素子部と前記中間永久磁石層とで素子連結体が構成され、前記素子連結体は素子幅に比べて素子長さが長く形成されており、
　軟磁性体が前記素子連結体と非接触にて配置され、
　前記軟磁性体の前記素子長さ方向と同方向への長さ寸法は、前記素子連結体の素子長さより長く、前記軟磁性体は、前記素子連結体の素子長さ方向の両側から前記素子連結体の長さ方向に延出する延出部を備えていることを特徴とするものである。 The present invention is a magnetic sensor comprising a magnetoresistive effect element,
The magnetoresistive element has a pinned magnetic layer whose magnetization direction is fixed, and a free magnetic layer whose magnetization direction is changed by receiving an external magnetic field laminated on the pinned magnetic layer via a nonmagnetic layer, An element portion oriented in an element width direction in which the fixed magnetization direction of the fixed magnetic layer is a sensitivity axis direction;
The element portion and an intermediate permanent magnet layer in an element length direction orthogonal to the element width direction are provided, and an element coupling body is constituted by the element portion and the intermediate permanent magnet layer, and the element coupling body The element length is longer than the element width,
A soft magnetic body is disposed in non-contact with the element coupling body,
The length dimension of the soft magnetic body in the same direction as the element length direction is longer than the element length of the element coupling body, and the soft magnetic body extends from both sides of the element coupling body in the element length direction. It has an extending portion that extends in the length direction of the connecting body.
　上記の構成により、感度軸に対して直交する方向への磁気シールド効果を向上できるとともに、感度軸方向に対して安定した磁気感度を得ることが出来る。 The above configuration can improve the magnetic shield effect in the direction perpendicular to the sensitivity axis, and can obtain a stable magnetic sensitivity in the sensitivity axis direction.
　本発明では、前記素子連結体中の素子部、外側永久磁石層、及び前記中間永久磁石層がすべて電気的に接続されており、素子連結体が複数、素子幅方向に間隔を空けて配置され、各素子部連結体の両側に設けられた外側永久磁石層間が非磁性接続層により電気的に接続されたミアンダ形状で形成されており、
　各素子連結体の素子幅方向の両側方、真上、あるいは真下のいずれかに前記軟磁性体が前記各素子部と非接触で形成されていることが好ましい。ミアンダ形状とすることで素子抵抗を大きくでき消費電力の低減を図ることができる。また各素子部ごとに軟磁性体を配置したことで、感度軸に対して直交する方向への磁気シールド効果をより適切に向上できる。 In the present invention, the element portion, the outer permanent magnet layer, and the intermediate permanent magnet layer in the element coupling body are all electrically connected, and a plurality of element coupling bodies are arranged at intervals in the element width direction. The outer permanent magnet layers provided on both sides of each element unit coupling body are formed in a meander shape electrically connected by a nonmagnetic connection layer,
It is preferable that the soft magnetic body is formed in non-contact with each element portion on either side of the element width direction in the element width direction, directly above, or directly below. By using the meander shape, the element resistance can be increased and the power consumption can be reduced. Further, by arranging a soft magnetic material for each element portion, the magnetic shield effect in the direction orthogonal to the sensitivity axis can be improved more appropriately.
　また、前記非磁性接続層が、上記軟磁性体と絶縁膜を挟んで交差する交差部を有していることが好ましい。平面的に小さくでき、配線長による寄生抵抗を低減できる。 Further, it is preferable that the nonmagnetic connection layer has an intersecting portion intersecting the soft magnetic material with an insulating film interposed therebetween. The size can be reduced in a plane, and the parasitic resistance due to the wiring length can be reduced.
　また本発明では、前記中間永久磁性層の素子長さ方向の長さよりも外側永久磁性層の素子長さ方向の長さが長く形成されていることが好ましい。外側永久磁石層を中間永久磁石層よりも長く形成することで、中央付近より外側のバイアス磁界が弱くなることを防ぐことができる。 In the present invention, it is preferable that the length of the outer permanent magnetic layer in the element length direction is longer than the length of the intermediate permanent magnetic layer in the element length direction. By forming the outer permanent magnet layer longer than the intermediate permanent magnet layer, it is possible to prevent the bias magnetic field outside the vicinity of the center from becoming weak.
　また本発明では、前記中間永久磁性層および、外側永久磁性層の幅が前記素子幅より広く形成されていることが好ましい。これにより永久磁性層パターンの角部近傍でバイアス磁界が極端に強くなっている部分を素子部に直接影響を及ぼさないようにできる。 In the present invention, it is preferable that the intermediate permanent magnetic layer and the outer permanent magnetic layer are formed wider than the element width. As a result, a portion where the bias magnetic field is extremely strong near the corner of the permanent magnetic layer pattern can be prevented from directly affecting the element portion.
　また本発明では、前記中間永久磁石層が、前記素子部の膜厚方向に形成された凹部に設けられていることが好ましい。 In the present invention, it is preferable that the intermediate permanent magnet layer is provided in a recess formed in the film thickness direction of the element portion.
　また本発明では、前記外側永久磁性層が、前記素子部の膜厚方向に形成された凹部を介して電気的に接続されていることが好ましい。 In the present invention, it is preferable that the outer permanent magnetic layer is electrically connected through a recess formed in the film thickness direction of the element portion.
　また本発明では、前記中間永久磁石層の上面及び前記外側永久磁石層の上面には永久磁石層より抵抗値が小さい非磁性低抵抗層が重ねて形成されていることが好ましい。これにより素子抵抗以外の寄生抵抗分を小さくできる。 In the present invention, it is preferable that a nonmagnetic low resistance layer having a resistance value smaller than that of the permanent magnet layer is formed on the upper surface of the intermediate permanent magnet layer and the upper surface of the outer permanent magnet layer. Thereby, the parasitic resistance other than the element resistance can be reduced.
　なお、本発明では、各中間永久磁石層、外側永久磁石層は素子部対して絶縁膜を介して形成されても、直接電気的に接合する形で形成されてもよいが、作成プロセスの簡便性、バイアス磁界印加特性から直接素子部に対して電気的に接合する形で形成することが好ましい。 In the present invention, each of the intermediate permanent magnet layer and the outer permanent magnet layer may be formed through an insulating film with respect to the element portion, or may be formed in a form in which it is directly electrically joined. In view of the characteristics and bias magnetic field application characteristics, it is preferable to form the electrode portion directly in electrical contact with the element portion.
　本発明における磁気センサモジュールは、上記のいずれかに記載の磁気センサを複数有し、少なくとも前記複数の磁気センサのうち一組の磁気抵抗効果素子の感度軸が直交するように各磁気抵抗効果素子が配置されていることを特徴とするものである。例えば、本発明の磁気センサモジュールは地磁気センサとして使用できる。 A magnetic sensor module according to the present invention includes a plurality of the magnetic sensors according to any one of the above, and each magnetoresistive element is configured so that sensitivity axes of at least one pair of the magnetoresistive elements are orthogonal to each other. Is arranged. For example, the magnetic sensor module of the present invention can be used as a geomagnetic sensor.
　本発明の磁気センサによれば、感度軸と直交する方向への磁気シールド効果を向上できるとともに、感度軸方向からの磁場に対して安定した磁気感度を得ることが可能である。 According to the magnetic sensor of the present invention, it is possible to improve the magnetic shield effect in the direction orthogonal to the sensitivity axis and to obtain a stable magnetic sensitivity with respect to the magnetic field from the sensitivity axis direction.
　図１（ａ）は第１実施形態における磁気センサの特に磁気抵抗効果素子の部分を示す平面図、図１（ｂ）は、図１（ａ）のＡ－Ａ線に沿って高さ方向（図示Ｚ方向）に切断し矢印方向から見た部分断面図、図２は第２実施形態における磁気センサの特に磁気抵抗効果素子の部分を示す平面図、図３は、図２に示すＤ－Ｄ線に沿って高さ方向（図示Ｚ方向）に切断し矢印方向から見た部分拡大断面図、図４は好ましい磁気抵抗効果素子の形態の特に素子部の部分を示す部分拡大平面図、図５は、磁気抵抗効果素子の固定磁性層の固定磁化方向及びフリー磁性層の磁化方向と、電気抵抗値との関係を説明するための図、図６は、磁気抵抗効果素子を膜厚方向から切断した際の切断面を示す断面図、図７は、本実施形態の磁気センサの回路図、である。 FIG. 1A is a plan view showing a portion of the magnetoresistive element of the magnetic sensor according to the first embodiment, and FIG. 1B is a height direction along the line AA in FIG. FIG. 2 is a plan view showing a part of the magnetoresistive element of the magnetic sensor in the second embodiment, and FIG. 3 is a DD shown in FIG. FIG. 4 is a partially enlarged cross-sectional view taken along the line in the height direction (Z direction in the drawing) and viewed from the arrow direction, FIG. FIG. 6 is a diagram for explaining the relationship between the fixed magnetization direction of the pinned magnetic layer and the magnetization direction of the free magnetic layer of the magnetoresistive effect element, and the electric resistance value, and FIG. 6 shows the magnetoresistive effect element cut from the film thickness direction. FIG. 7 is a circuit diagram of the magnetic sensor of the present embodiment. That.
　本実施形態における磁気抵抗効果素子を備えた磁気センサ１を用いた磁気センサモジュールは例えば携帯電話等の携帯機器に搭載される地磁気センサとして使用される。 The magnetic sensor module using the magnetic sensor 1 provided with the magnetoresistive effect element according to the present embodiment is used as a geomagnetic sensor mounted on a mobile device such as a mobile phone.
　前記地磁気センサ１は、図７に示すように、磁気抵抗効果素子２，３と固定抵抗素子４，５とがブリッジ接続されてなるセンサ部６と、前記センサ部６と電気接続された入力端子７、グランド端子８、差動増幅器９及び外部出力端子１０等を備えた集積回路（ＩＣ）１１とで構成される。 As shown in FIG. 7, the geomagnetic sensor 1 includes a sensor unit 6 in which magnetoresistive effect elements 2 and 3 and fixed resistance elements 4 and 5 are bridge-connected, and an input terminal electrically connected to the sensor unit 6. 7, an integrated circuit (IC) 11 having a ground terminal 8, a differential amplifier 9, an external output terminal 10, and the like.
　図１に示すように、素子部１２と中間永久磁石層６０とで図示Ｘ方向に帯状に延びる素子連結体６１が構成される。図１に示すように素子連結体６１の素子長さＬ１は、素子幅Ｗ１に比べて長く形成されている。素子連結体６１の図示Ｘ方向の両側には外側永久磁石層６５が設けられる。 As shown in FIG. 1, an element coupling body 61 extending in a strip shape in the X direction is configured by the element portion 12 and the intermediate permanent magnet layer 60. As shown in FIG. 1, the element length L1 of the element coupling body 61 is formed longer than the element width W1. Outer permanent magnet layers 65 are provided on both sides in the X direction of the element coupling body 61 in the drawing.
　前記素子連結体６１は、素子幅方向（Ｙ方向）に間隔を空けて複数本並設され、各素子連結体６１の両端部に設けられた外側永久磁石層６５間が電極層６２にて接続されてミアンダ形状の磁気抵抗効果素子２，３が構成されている。 A plurality of the element coupling bodies 61 are arranged in parallel at intervals in the element width direction (Y direction), and the outer permanent magnet layers 65 provided at both ends of each element coupling body 61 are connected by electrode layers 62. Thus, meander-shaped magnetoresistive elements 2 and 3 are configured.
　ミアンダ形状に形成された両端にある素子連結体６１の一方には入力端子７、グランド端子８、出力取出し部１４（図７参照）に接続される電極層６２が接続されている。前記電極層６２は永久磁石層６０，６５よりも低抵抗であり、Ａｌ、Ｔａ、Ａｕ等の非磁性導電材料で形成される。 The electrode layer 62 connected to the input terminal 7, the ground terminal 8, and the output extraction part 14 (refer FIG. 7) is connected to one side of the element coupling body 61 in the both ends formed in the meander shape. The electrode layer 62 has a lower resistance than the permanent magnet layers 60 and 65 and is made of a nonmagnetic conductive material such as Al, Ta, or Au.
　前記磁気抵抗効果素子２，３を構成する各素子部１２は、全て図６に示す同じ積層構造で構成される。なお図６は、素子幅Ｗ１と平行な方向から膜厚方向に切断した切断面を示している。 All the element portions 12 constituting the magnetoresistive effect elements 2 and 3 have the same laminated structure shown in FIG. FIG. 6 shows a cut surface cut in the film thickness direction from the direction parallel to the element width W1.
　前記素子部１２は、例えば下から反強磁性層３３、固定磁性層３４、非磁性層３５、およびフリー磁性層３６の順に積層されて成膜され、フリー磁性層３６の表面が保護層３７で覆われている。前記素子部１２は例えばスパッタにて形成される。 The element portion 12 is formed by laminating, for example, an antiferromagnetic layer 33, a pinned magnetic layer 34, a nonmagnetic layer 35, and a free magnetic layer 36 in this order from the bottom, and the surface of the free magnetic layer 36 is a protective layer 37. Covered. The element unit 12 is formed by sputtering, for example.
　反強磁性層３３は、Ｉｒ－Ｍｎ合金（イリジウム－マンガン合金）などの反強磁性材料で形成されている。固定磁性層３４はＣｏ－Ｆｅ合金（コバルト－鉄合金）などの軟磁性材料で形成されている。非磁性層３５はＣｕ（銅）などである。フリー磁性層３６は、Ｎｉ－Ｆｅ合金（ニッケル－鉄合金）などの軟磁性材料で形成されている。保護層３７はＴａ（タンタル）などである。上記構成では非磁性層３５がＣｕ等の非磁性導電材料で形成された巨大磁気抵抗効果素子（ＧＭＲ素子）であるが、Ａｌ2Ｏ3等の絶縁材料で形成されたトンネル型磁気抵抗効果素子（ＴＭＲ素子）であってもよい。また図６に示す素子部１２の積層構成は一例であって他の積層構成であってもよい。例えば、下からフリー磁性層３６、非磁性層３５、固定磁性層３４、反強磁性層３３及び保護層３７の順に積層されてもよい。 The antiferromagnetic layer 33 is made of an antiferromagnetic material such as an Ir—Mn alloy (iridium-manganese alloy). The pinned magnetic layer 34 is made of a soft magnetic material such as a Co—Fe alloy (cobalt-iron alloy). The nonmagnetic layer 35 is made of Cu (copper) or the like. The free magnetic layer 36 is formed of a soft magnetic material such as a Ni—Fe alloy (nickel-iron alloy). The protective layer 37 is made of Ta (tantalum) or the like. In the above configuration, the nonmagnetic layer 35 is a giant magnetoresistive effect element (GMR element) formed of a nonmagnetic conductive material such as Cu, but a tunnel type magnetoresistive effect element formed of an insulating material such as Al 2 O 3. (TMR element) may be used. Further, the stacked configuration of the element unit 12 illustrated in FIG. 6 is an example, and another stacked configuration may be used. For example, the free magnetic layer 36, the nonmagnetic layer 35, the pinned magnetic layer 34, the antiferromagnetic layer 33, and the protective layer 37 may be stacked in this order from the bottom.
　素子部１２では、反強磁性層３３と固定磁性層３４との反強磁性結合により、固定磁性層３４の磁化方向が固定されている。図１及び図６に示すように、前記固定磁性層３４の固定磁化方向（Ｐ方向）は、素子幅方向（Ｙ方向）に向いている。すなわち固定磁性層３４の固定磁化方向（Ｐ方向）は、素子連結体６１の長手方向に対して直交している。 In the element unit 12, the magnetization direction of the pinned magnetic layer 34 is fixed by antiferromagnetic coupling between the antiferromagnetic layer 33 and the pinned magnetic layer 34. As shown in FIGS. 1 and 6, the pinned magnetization direction (P direction) of the pinned magnetic layer 34 faces the element width direction (Y direction). That is, the fixed magnetization direction (P direction) of the fixed magnetic layer 34 is orthogonal to the longitudinal direction of the element coupling body 61.
　一方、前記フリー磁性層３６の磁化方向（Ｆ方向）は、外部磁場により変動する。なお、永久磁石層６０，６５から素子部１２には図示Ｘ方向からバイアス磁界が作用している。よって素子部１２を構成するフリー磁性層３６の磁化は無磁場状態では図示Ｘ方向に向けられている。 On the other hand, the magnetization direction (F direction) of the free magnetic layer 36 varies depending on the external magnetic field. A bias magnetic field acts on the element portion 12 from the permanent magnet layers 60 and 65 from the X direction in the figure. Therefore, the magnetization of the free magnetic layer 36 constituting the element unit 12 is directed in the X direction in the figure in the absence of a magnetic field.
　図５に示すように、固定磁性層３４の固定磁化方向（Ｐ方向）と同一方向から外部磁場Ｙ１が作用して前記フリー磁性層３６の磁化方向（Ｆ方向）が前記外部磁場Ｙ１方向に向くと、前記固定磁性層３４の固定磁化方向（Ｐ方向）とフリー磁性層３６の磁化方向（Ｆ方向）とが平行に近づき電気抵抗値が低下する。 As shown in FIG. 5, the external magnetic field Y1 acts from the same direction as the fixed magnetization direction (P direction) of the fixed magnetic layer 34, and the magnetization direction (F direction) of the free magnetic layer 36 faces the external magnetic field Y1 direction. Then, the fixed magnetization direction (P direction) of the fixed magnetic layer 34 and the magnetization direction (F direction) of the free magnetic layer 36 approach each other, and the electric resistance value decreases.
　一方、図５に示すように、固定磁性層３４の固定磁化方向（Ｐ方向）と反対方向から外部磁場Ｙ２が作用して前記フリー磁性層３６の磁化方向（Ｆ方向）が前記外部磁場Ｙ２方向に向くと、前記固定磁性層３４の固定磁化方向（Ｐ方向）とフリー磁性層３６の磁化方向（Ｆ方向）とが反平行に近づき電気抵抗値が増大する。 On the other hand, as shown in FIG. 5, the external magnetic field Y2 acts from the direction opposite to the fixed magnetization direction (P direction) of the fixed magnetic layer 34, and the magnetization direction (F direction) of the free magnetic layer 36 changes to the external magnetic field Y2 direction. , The fixed magnetization direction (P direction) of the fixed magnetic layer 34 and the magnetization direction (F direction) of the free magnetic layer 36 approach antiparallel, and the electrical resistance value increases.
　図１（ｂ）に示すように前記磁気抵抗効果素子２，３は基板１６上に形成される。前記磁気抵抗効果素子２，３上はＡｌ2Ｏ3やＳｉＯ2等の絶縁層１７に覆われる。また前記磁気抵抗効果素子２，３を構成する素子連結体６１間も前記絶縁層１７で埋められる。前記絶縁層１７は例えばスパッタにて形成される。 As shown in FIG. 1B, the magnetoresistive elements 2 and 3 are formed on a substrate 16. The magnetoresistive elements 2 and 3 are covered with an insulating layer 17 such as Al 2 O 3 or SiO 2 . The space between the element coupling bodies 61 constituting the magnetoresistive effect elements 2 and 3 is also filled with the insulating layer 17. The insulating layer 17 is formed by sputtering, for example.
　図１（ｂ）のように前記絶縁層１７の上面は、例えばＣＭＰ技術を用いて平坦面に形成されている。ただし、前記絶縁層１７の上面は、前記素子連結体６１と前記基板１６間の段差に倣って、凹凸面で形成されていてもよい。 As shown in FIG. 1B, the upper surface of the insulating layer 17 is formed as a flat surface by using, for example, a CMP technique. However, the upper surface of the insulating layer 17 may be formed as an uneven surface following the step between the element coupling body 61 and the substrate 16.
　図１に示すように、磁気抵抗効果素子２，３を構成する各素子連結体６１の間、及び最も外側に位置する素子連結体６１の外側に軟磁性体１８が設けられている。前記軟磁性体１８は例えばスパッタやメッキにて薄膜形成される。前記軟磁性体１８は、ＮｉＦｅ、ＣｏＦｅ、ＣｏＦｅＳｉＢやＣｏＺｒＮｂ等で形成される。前記軟磁性体１８の長さ寸法Ｌ２は前記素子連結体６１の素子長さＬ１よりも長く、図１（ａ）に示すように、軟磁性体１８は、前記素子連結体６１の長手方向（Ｘ方向）の両側から前記長手方向に延出する延出部１８ａを備える。 As shown in FIG. 1, a soft magnetic body 18 is provided between the element coupling bodies 61 constituting the magnetoresistive effect elements 2 and 3 and outside the element coupling body 61 located on the outermost side. The soft magnetic material 18 is formed into a thin film by sputtering or plating, for example. The soft magnetic body 18 is made of NiFe, CoFe, CoFeSiB, CoZrNb, or the like. The length L2 of the soft magnetic body 18 is longer than the element length L1 of the element coupling body 61. As shown in FIG. 1A, the soft magnetic body 18 has a longitudinal direction ( An extending portion 18a extending in the longitudinal direction from both sides in the (X direction) is provided.
　図１（ｂ）に示すように、前記軟磁性体１８は、前記素子部１２間にある絶縁層１７上に形成される。また図示しないが前記軟磁性体１８上及び前記軟磁性体１８間は絶縁性の保護層にて覆われている。 As shown in FIG. 1B, the soft magnetic body 18 is formed on the insulating layer 17 between the element portions 12. Although not shown, the soft magnetic body 18 and the space between the soft magnetic bodies 18 are covered with an insulating protective layer.
　各寸法について説明する。
　前記磁気抵抗効果素子２，３を構成する素子部１２の素子幅Ｗ１は、２～１０μｍの範囲内である（図１（ａ）参照）。また前記素子部１２の素子長さＬ５は、１～１０μｍの範囲内である（図１（ａ）参照）。また、前記素子部１２の膜厚Ｔ２は、２００～４００Åの範囲内である（図１（ｂ）参照）。前記素子部１２のアスペクト比（素子長さＬ５／素子幅Ｗ１）は、０．１～４である。 Each dimension will be described.
The element width W1 of the element portion 12 constituting the magnetoresistive effect elements 2 and 3 is in the range of 2 to 10 μm (see FIG. 1A). The element length L5 of the element unit 12 is in the range of 1 to 10 μm (see FIG. 1A). The film thickness T2 of the element portion 12 is in the range of 200 to 400 mm (see FIG. 1B). The element section 12 has an aspect ratio (element length L5 / element width W1) of 0.1 to 4.
　前記中間永久磁石層６０の長さ寸法Ｌ３は、０．５～５μｍの範囲内である（図１（ａ）参照）。また前記中間永久磁石層１３の幅寸法Ｗ３は、３～１２μｍの範囲内である（図１（ａ）参照）。Ｗ３はＷ１より広いことが好ましい。前記中間永久磁石層１３の膜厚は、１５０～１０００Åの範囲内である。 The length L3 of the intermediate permanent magnet layer 60 is in the range of 0.5 to 5 μm (see FIG. 1 (a)). The width W3 of the intermediate permanent magnet layer 13 is in the range of 3 to 12 μm (see FIG. 1 (a)). W3 is preferably wider than W1. The film thickness of the intermediate permanent magnet layer 13 is in the range of 150 to 1000 mm.
　前記外側永久磁石層６５の長さ寸法Ｌ４は、５～１０μｍの範囲内である（図１（ａ）参照）。また、前記外側永久磁石層１５の膜厚は、前記中間永久磁石層１３の膜厚と等しいことが好ましい。 The length L4 of the outer permanent magnet layer 65 is in the range of 5 to 10 μm (see FIG. 1 (a)). The film thickness of the outer permanent magnet layer 15 is preferably equal to the film thickness of the intermediate permanent magnet layer 13.
　各素子連結体６１間の素子幅方向への間隔Ｔ５は、２～１０μｍの範囲内である（図１（ａ）参照）。 The distance T5 in the element width direction between the element coupling bodies 61 is in the range of 2 to 10 μm (see FIG. 1A).
　また前記素子連結体６１の長さ寸法Ｌ１は、５０～２００μｍの範囲内である。
　また前記軟磁性体１８の幅寸法Ｗ２は、この実施形態では、地磁気センサとして使用する場合、１～６μｍの範囲内である（図１（ａ）参照）。また前記軟磁性体１８の長さ寸法Ｌ２は、８０～２００μｍの範囲内である（図１（ａ）参照）。また、前記軟磁性体１８の膜厚Ｔ３は、０．２～１μｍの範囲内である（図１（ｂ）参照）。前記軟磁性体１８の延出部１８ａの長さ寸法Ｔ８は、１０μｍ以上である（図１（ａ）参照）。 The length dimension L1 of the element coupling body 61 is in the range of 50 to 200 μm.
In this embodiment, the width dimension W2 of the soft magnetic body 18 is in the range of 1 to 6 μm when used as a geomagnetic sensor (see FIG. 1A). The length L2 of the soft magnetic body 18 is in the range of 80 to 200 μm (see FIG. 1A). The film thickness T3 of the soft magnetic body 18 is in the range of 0.2 to 1 μm (see FIG. 1B). A length dimension T8 of the extending portion 18a of the soft magnetic body 18 is 10 μm or more (see FIG. 1A).
　図１の実施形態における各軟磁性体１８間の距離（Ｙ方向への距離）Ｔ１は、軟磁性体１８の幅寸法Ｗ２以上で２～８μｍである（図１（ｂ）参照）。また、前記素子部１２と隣接した位置にある軟磁性体１８とのＹ方向への距離Ｔ４は、０＜Ｔ４＜３μｍである（図１（ｂ）参照）。また、前記軟磁性体１８と素子部１２間の高さ方向（Ｚ方向）への距離Ｔ５は、０．１～１μｍである（図１（ｂ）参照）。 In the embodiment of FIG. 1, the distance T1 between the soft magnetic bodies 18 (distance in the Y direction) is 2 to 8 μm, which is equal to or larger than the width dimension W2 of the soft magnetic body 18 (see FIG. 1B). The distance T4 in the Y direction between the soft magnetic body 18 located adjacent to the element portion 12 is 0 <T4 <3 μm (see FIG. 1B). A distance T5 in the height direction (Z direction) between the soft magnetic body 18 and the element portion 12 is 0.1 to 1 μm (see FIG. 1B).
　図１に示す磁気センサ１は、図示Ｙ方向（素子幅方向）と平行な方向からの地磁気を検知するためのものである。よって図示Ｙ方向が感度軸方向であり、図示Ｙ方向に直交するＸ方向（素子長さ方向）が素子連結体６１の長手方向である。固定磁性層３４の固定磁化方向（Ｐ方向）は感度軸方向である図示Ｙ方向に向けられている。 The magnetic sensor 1 shown in FIG. 1 is for detecting geomagnetism from a direction parallel to the Y direction (element width direction) shown in the figure. Therefore, the Y direction in the figure is the sensitivity axis direction, and the X direction (element length direction) orthogonal to the Y direction in the figure is the longitudinal direction of the element coupling body 61. The fixed magnetization direction (P direction) of the fixed magnetic layer 34 is directed to the Y direction in the figure, which is the sensitivity axis direction.
　本実施形態では、前記素子部１２と非接触の軟磁性体１８を設けている。前記軟磁性体１８は、素子連結体６１と同様に、素子長さ方向（図示Ｘ方向）に細長い形状である。なお軟磁性体１８の透磁率は素子部１２の透磁率よりも大きい。 In this embodiment, the element part 12 and the non-contact soft magnetic body 18 are provided. The soft magnetic body 18 has an elongated shape in the element length direction (X direction in the drawing), like the element coupling body 61. The magnetic permeability of the soft magnetic body 18 is larger than the magnetic permeability of the element portion 12.
　さらに本実施形態における前記軟磁性体１８は、前記磁気抵抗効果素子２，３を構成する各素子連結体６１の素子長さ方向（Ｘ方向）の両側から前記素子長さ方向に延出する延出部１８ａを備える。 Further, in the present embodiment, the soft magnetic body 18 extends in the element length direction from both sides in the element length direction (X direction) of each element coupling body 61 constituting the magnetoresistive effect elements 2 and 3. A protruding portion 18a is provided.
　さらに本実施形態では、素子部１２と中間永久磁石層６０とで素子連結体６１を構成している。 Furthermore, in this embodiment, the element coupling body 61 is constituted by the element portion 12 and the intermediate permanent magnet layer 60.
　ここで、図１（ａ）に示す中間永久磁石層６０及び外側永久磁石層６５が無く、中間永久磁石層６０及び外側永久磁石層の部分も素子部１２で形成された構造を比較例１とする。ただし比較例１は軟磁性体１８を有している。 Here, a structure in which the intermediate permanent magnet layer 60 and the outer permanent magnet layer 65 shown in FIG. To do. However, Comparative Example 1 has a soft magnetic body 18.
　また図１（ａ）に示す構造から軟磁性体１８を除去した構造を比較例２とする。ただし比較例２は、永久磁石層６０，６５を有している。 Further, a structure obtained by removing the soft magnetic material 18 from the structure shown in FIG. However, the comparative example 2 has the permanent magnet layers 60 and 65.
　図９（ａ）は、上記した比較例１の構造における感度軸方向からの磁場（以下、感度磁場という）の強度Ｈと磁気抵抗効果素子の単位磁場当たりの抵抗変化率（ＭＲ比）との関係を示すグラフ、図９（ｂ）は、上記した比較例１の構造における感度軸方向に対して直交方向からの磁場（以下、直交磁場と言う）の強度Ｈと磁気抵抗効果素子の単位磁場当たりの抵抗変化率（ＭＲ比）との関係を示すグラフである。 FIG. 9A shows the intensity H of the magnetic field from the sensitivity axis direction (hereinafter referred to as sensitivity magnetic field) in the structure of Comparative Example 1 described above and the resistance change rate (MR ratio) per unit magnetic field of the magnetoresistive effect element. FIG. 9B is a graph showing the relationship. The intensity H of the magnetic field from the direction orthogonal to the sensitivity axis direction in the structure of Comparative Example 1 (hereinafter referred to as the orthogonal magnetic field) and the unit magnetic field of the magnetoresistive element. It is a graph which shows the relationship with the resistance change rate (MR ratio) per hit.
　ここで、微小な磁場（例えば地磁気など）を携帯機器（例えば携帯電話など）で感知する場合、実際には検知する磁場よりも携帯機器内部で発生する外乱磁場の方が大きく、値も一定では無い為、感度方向の抵抗変化は「実際に検知する磁場＋携帯機器内で発生する磁場」分の広範囲な直線性及び、感度直交方向からの磁場が加わったときにその線形性が崩れないことが要求される。また、感度直交方向の抵抗変化は「実際に検知する磁場＋携帯機器内で発生する磁場」の範囲内では抵抗変化が発生しないことが要求される。以降、「実際に検知する磁場＋携帯機器内で発生する磁場」の磁場領域を“感度領域”と定義する。 Here, when a small magnetic field (for example, geomagnetism) is sensed by a portable device (for example, a cellular phone), the disturbance magnetic field generated inside the portable device is actually larger than the detected magnetic field, and the value is constant. Because there is no resistance change in the sensitivity direction, the linearity does not collapse when a magnetic field from the direction perpendicular to the sensitivity is applied, as well as the wide linearity of “the magnetic field actually detected + the magnetic field generated in the portable device”. Is required. In addition, the resistance change in the direction perpendicular to the sensitivity is required to cause no resistance change within the range of “the magnetic field actually detected + the magnetic field generated in the portable device”. Hereinafter, the magnetic field region of “the magnetic field actually detected + the magnetic field generated in the portable device” is defined as the “sensitivity region”.
　比較例１は軟磁性体１８を有するので直交磁場に対する磁気シールド効果が発揮される。このため、直交磁場を作用させない状態、直交磁場を第１方向から作用させた状態、及び直交磁場を第１方向とは逆方向の第２方向から作用させた状態の夫々において、感度磁場の強度Ｈを変化させても、図９（ａ）のように感度領域での感度ばらつきは小さいように見える。 Since Comparative Example 1 has the soft magnetic material 18, the magnetic shielding effect against the orthogonal magnetic field is exhibited. For this reason, the intensity of the sensitivity magnetic field in each of the state where the orthogonal magnetic field is not applied, the state where the orthogonal magnetic field is applied from the first direction, and the state where the orthogonal magnetic field is applied from the second direction opposite to the first direction are provided. Even if H is changed, the sensitivity variation in the sensitivity region seems to be small as shown in FIG.
　しかしながら図９（ｂ）に示すように、感度領域での磁場範囲は、同範囲の直交磁場が作用したときに直交磁場に対して感度変化が大きくなる低磁場である。よって、低磁場内で一定でなく直交磁場が変動作用すると、感度磁場に対する感度ばらつきは大きくなってしまう。 However, as shown in FIG. 9B, the magnetic field range in the sensitivity region is a low magnetic field in which the sensitivity change becomes large with respect to the orthogonal magnetic field when the orthogonal magnetic field in the same range acts. Therefore, if the orthogonal magnetic field fluctuates in a low magnetic field, the sensitivity variation with respect to the sensitive magnetic field increases.
　なお比較例１の構造では磁気感度にヒステリシスを持つがヒステリシスについては後記する。 The structure of Comparative Example 1 has hysteresis in the magnetic sensitivity, but the hysteresis will be described later.
　図１０（ａ）は、上記した比較例２の構造における感度軸方向からの磁場（以下、感度磁場という）の強度Ｈと磁気抵抗効果素子の単位磁場当たりの抵抗変化率（ＭＲ比）との関係を示すグラフ、図１０（ｂ）は、上記した比較例２の構造における感度軸方向に対して直交方向からの磁場（以下、直交磁場と言う）の強度Ｈと磁気抵抗効果素子の単位磁場当たりの抵抗変化率（ＭＲ比）との関係を示すグラフである。 FIG. 10A shows the intensity H of the magnetic field from the sensitivity axis direction (hereinafter referred to as sensitivity magnetic field) in the structure of Comparative Example 2 described above and the resistance change rate (MR ratio) per unit magnetic field of the magnetoresistive effect element. FIG. 10B is a graph showing the relationship. The intensity H of the magnetic field from the direction orthogonal to the sensitivity axis direction (hereinafter referred to as the orthogonal magnetic field) in the structure of Comparative Example 2 described above and the unit magnetic field of the magnetoresistive effect element. It is a graph which shows the relationship with the resistance change rate (MR ratio) per hit.
　比較例２は、比較例１と違って、軟磁性体１８を有さないので直交磁場に対して磁気シールド効果が無い。すなわち直交磁場は、シールドされず、そのまま素子部に作用する。一方、比較例２では素子部１２が永久磁石層６０，６５と交互に設けられるため、永久磁石層６０，６５により素子部１２の単磁区化が促進されている。しかしながら、比較例２の構造では永久磁石層６０，６５から素子部１２に作用するバイアス磁界の方向と、直交磁場の方向とが同方向であると、素子部１２に作用するバイアス磁界が見かけ上大きくなり、一方、素子部１２に作用するバイアス磁界の方向と、直交磁場の方向とが逆方向であると、素子部１２に作用するバイアス磁界が見かけ上小さくなる。このため、直交磁場が作用していない状態、直交磁場がバイアス磁界と同方向に作用する状態、及び、直交磁場がバイアス磁界と逆方向に作用する状態の夫々について感度磁場の強度Ｈを変化させたときのＭＲ比を調べると、図１０（ａ）に示すように、感度領域での感度ばらつきが非常に大きくなる。 Unlike Comparative Example 1, Comparative Example 2 does not have a soft magnetic body 18 and thus has no magnetic shielding effect against an orthogonal magnetic field. That is, the orthogonal magnetic field is not shielded but acts on the element portion as it is. On the other hand, in the comparative example 2, since the element part 12 is alternately provided with the permanent magnet layers 60 and 65, the permanent magnet layers 60 and 65 promote the single magnetic domain of the element part 12. However, in the structure of Comparative Example 2, if the direction of the bias magnetic field that acts on the element unit 12 from the permanent magnet layers 60 and 65 is the same as the direction of the orthogonal magnetic field, the bias magnetic field that acts on the element unit 12 appears to be apparent. On the other hand, if the direction of the bias magnetic field acting on the element unit 12 is opposite to the direction of the orthogonal magnetic field, the bias magnetic field acting on the element unit 12 is apparently reduced. For this reason, the intensity H of the sensitivity magnetic field is changed in each of a state where the orthogonal magnetic field is not applied, a state where the orthogonal magnetic field is applied in the same direction as the bias magnetic field, and a state where the orthogonal magnetic field is applied in the opposite direction to the bias magnetic field. When the MR ratio at this time is examined, as shown in FIG. 10A, the sensitivity variation in the sensitivity region becomes very large.
　その一方で、直交磁場の強度Ｈを変化させたときのＭＲ比を測定すると、感度変化する略Ｖ字の波形部分は、永久磁石層６０，６５によるバイアス磁界の影響で感度領域と同磁場範囲内からややシフトする。よって、直交磁場が一定でなく感度領域と同等の低磁場範囲で直交磁場成分が変動作用しても、感度磁場に対する感度のばらつきは図１０（ａ）の状態から比較例１ほど大きく変化しないが、直交磁場をシールドできないため、感度変化する波形部分は図９（ｂ）に比べて大きく変化し、このため、感度磁場に対する感度のばらつきを次に説明する実施形態ほど小さくはできない。 On the other hand, when the MR ratio when the intensity H of the orthogonal magnetic field is changed is measured, the substantially V-shaped waveform portion whose sensitivity changes is the same magnetic field range as the sensitivity region due to the influence of the bias magnetic field by the permanent magnet layers 60 and 65. Shift slightly from within. Accordingly, even if the orthogonal magnetic field component fluctuates in the low magnetic field range equivalent to the sensitivity region, the sensitivity variation with respect to the sensitive magnetic field does not change as much as the comparative example 1 from the state of FIG. Since the orthogonal magnetic field cannot be shielded, the waveform portion where the sensitivity changes greatly changes compared to FIG. 9B, and therefore the variation in sensitivity with respect to the sensitive magnetic field cannot be reduced as much as in the embodiment described below.
　図１１（ａ）は、本実施形態の構造における感度軸方向からの磁場（以下、感度磁場という）の強度Ｈと磁気抵抗効果素子の単位磁場当たりの抵抗変化率（ＭＲ比）との関係を示すグラフ、図１０（ｂ）は、本実施形態の構造における感度軸方向に対して直交方向からの磁場（以下、直交磁場と言う）の強度Ｈと磁気抵抗効果素子の単位磁場当たりの抵抗変化率（ＭＲ比）との関係を示すグラフである。 FIG. 11A shows the relationship between the intensity H of the magnetic field from the sensitivity axis direction (hereinafter referred to as sensitivity magnetic field) and the resistance change rate (MR ratio) per unit magnetic field of the magnetoresistive effect element in the structure of this embodiment. FIG. 10B shows the strength H of the magnetic field from the direction orthogonal to the sensitivity axis direction in the structure of this embodiment (hereinafter referred to as the orthogonal magnetic field) and the resistance change per unit magnetic field of the magnetoresistive effect element. It is a graph which shows the relationship with a ratio (MR ratio).
　本実施形態では軟磁性体１８により直交磁場に対して磁気シールド効果がある。また本実施形態における前記軟磁性体１８は、各素子連結体６１の素子長さ方向（Ｘ方向）の両側から前記素子長さ方向に延出する延出部１８ａを備えるため、直交磁場は、より効果的に、軟磁性体１８を通過しやすい。また永久磁石層６０，６５により素子部１２の単磁区化が促進される。したがって、直交磁場が作用していない状態、直交磁場がバイアス磁界と同方向に作用する状態、及び、直交磁場がバイアス磁界と逆方向に作用する状態の夫々について感度磁場の強度Ｈを変化させたときのＭＲ比を調べると、図１１（ａ）に示すように、感度領域での感度ばらつきが非常に小さくなる。 In this embodiment, the soft magnetic body 18 has a magnetic shielding effect against an orthogonal magnetic field. In addition, since the soft magnetic body 18 in the present embodiment includes the extending portions 18a extending in the element length direction from both sides in the element length direction (X direction) of each element coupling body 61, the orthogonal magnetic field is It is easier to pass through the soft magnetic body 18 more effectively. Further, the permanent magnet layers 60 and 65 promote the formation of a single magnetic domain in the element portion 12. Therefore, the intensity H of the sensitivity magnetic field is changed in each of a state where the orthogonal magnetic field does not act, a state where the orthogonal magnetic field acts in the same direction as the bias magnetic field, and a state where the orthogonal magnetic field acts in the opposite direction to the bias magnetic field. When the MR ratio at the time is examined, the sensitivity variation in the sensitivity region becomes very small as shown in FIG.
　また図１１（ｂ）に示すように、直交磁場に対しては、永久磁石層６０，６５によるバイアス磁界の影響で感度変化する略Ｖ字の波形部分を感度領域と同磁場範囲内からシフトさせることが出来るとともに、波形部分を、軟磁性体１８による磁気シールド効果により小さくできる。よって、感度領域と同磁場範囲内での直交磁場（外乱磁場）が一定でなく変動作用しても、感度磁場に対する感度のばらつきを小さくできる。 Further, as shown in FIG. 11B, for the orthogonal magnetic field, the substantially V-shaped waveform portion whose sensitivity changes due to the influence of the bias magnetic field by the permanent magnet layers 60 and 65 is shifted from the same magnetic field range as the sensitivity region. In addition, the corrugated portion can be reduced by the magnetic shielding effect by the soft magnetic body 18. Therefore, even if the orthogonal magnetic field (disturbance magnetic field) within the same magnetic field range as the sensitivity region is not constant and fluctuates, the sensitivity variation with respect to the sensitivity magnetic field can be reduced.
　以上により永久磁石層６０，６５及び軟磁性体１８を有する本実施形態では、直交磁場に対する磁気シールド効果を向上できるとともに、感度磁場に対する感度ばらつきを小さくでき安定した磁気感度を得ることが出来る。 As described above, in the present embodiment having the permanent magnet layers 60 and 65 and the soft magnetic body 18, it is possible to improve the magnetic shielding effect against the orthogonal magnetic field and reduce the sensitivity variation with respect to the sensitive magnetic field and obtain a stable magnetic sensitivity.
　ところで本実施形態のように、素子部１２と永久磁石層６０，６５とを交互に配列した構成では、素子部１２に永久磁石層６０，６５からのバイアス磁界が作用し、素子部１２のフリー磁性層３６の単磁区化が促進される。したがって図９の比較例１のように永久磁石層６０，６５を設けない形態に比べて磁気感度のヒステリシスの発生を小さくできる。 By the way, in the configuration in which the element portions 12 and the permanent magnet layers 60 and 65 are alternately arranged as in the present embodiment, the bias magnetic field from the permanent magnet layers 60 and 65 acts on the element portion 12 and the element portion 12 is free. The formation of a single magnetic domain in the magnetic layer 36 is promoted. Therefore, the occurrence of hysteresis of the magnetic sensitivity can be reduced as compared with the configuration in which the permanent magnet layers 60 and 65 are not provided as in the comparative example 1 of FIG.
　しかしながら、永久磁石層６０，６５間に挟まれた部分の素子部１２のアスペクト比（素子長さＬ５／素子幅Ｗ１）（図４参照）が大きくなると、永久磁石層６０，６５からのバイアス磁界を素子部１２の全体に適切に供給できず、素子部１２のフリー磁性層３６の単磁区化を適切に促進できない。このため比較例１よりヒステリシスは小さくなるものの、例えば、図１２のように、直交磁場に対して感度変化する波形部分にヒステリシスが生じやすくなる。よって直交磁場に対して感度変化領域が広がりやすくなり、図１２に示すように感度領域と同磁場範囲の直交磁場範囲内にヒステリシスの一部が入り込みやすくなる。よって外乱磁場耐性（磁気シールド効果）が低下しやすくなる。また感度磁場に対してもヒステリシスは生じやすくなり、感度磁場に対する磁場応答性が低下する。したがって、素子部１２の全体に適切にバイアス磁界を供給するために素子部１２のアスペクト比は小さいことが好ましく、３以下が好適であり、１より小さいことがより好ましい。これにより素子部１２に適切にバイアス磁界を供給するための永久磁性層膜厚も薄くすることができる。 However, when the aspect ratio (element length L5 / element width W1) (see FIG. 4) of the element portion 12 between the permanent magnet layers 60 and 65 is increased, the bias magnetic field from the permanent magnet layers 60 and 65 is increased. Cannot be appropriately supplied to the entire element portion 12, and the single magnetic domain of the free magnetic layer 36 of the element portion 12 cannot be appropriately promoted. For this reason, although the hysteresis is smaller than that in Comparative Example 1, for example, as shown in FIG. 12, the hysteresis is likely to occur in the waveform portion where the sensitivity changes with respect to the orthogonal magnetic field. Therefore, the sensitivity change region easily spreads with respect to the orthogonal magnetic field, and a part of hysteresis easily enters the orthogonal magnetic field range in the same magnetic field range as the sensitivity region as shown in FIG. Therefore, disturbance magnetic field resistance (magnetic shield effect) is likely to decrease. Also, hysteresis is likely to occur even with a sensitive magnetic field, and the magnetic field response to the sensitive magnetic field is reduced. Therefore, in order to appropriately supply a bias magnetic field to the entire element unit 12, the aspect ratio of the element unit 12 is preferably small, preferably 3 or less, and more preferably less than 1. As a result, the thickness of the permanent magnetic layer for appropriately supplying a bias magnetic field to the element portion 12 can also be reduced.
　図２は図１の変形例である。図２に示す実施形態では、磁気抵抗効果素子２，３は、素子連結体６１の端部間を接続する電極層６２が、Ｙ方向に直線状（帯状）で形成され、前記電極層６２が、絶縁層を介し前記軟磁性体１８の下側を通っている。すなわち、電極層６２と軟磁性体１８とが高さ方向（図示Ｚ方向）にて交差している。素子連結体６１を接続する部分の電極層６２は軟磁性体１８と電気的に絶縁されていれば、下部での形成に限定されず、上部に形成されてもよい。 FIG. 2 is a modification of FIG. In the embodiment shown in FIG. 2, in the magnetoresistive effect elements 2 and 3, the electrode layer 62 that connects between the end portions of the element coupling body 61 is formed in a straight line shape (band shape) in the Y direction. And passes through the lower side of the soft magnetic body 18 through an insulating layer. That is, the electrode layer 62 and the soft magnetic body 18 intersect in the height direction (Z direction in the drawing). As long as the electrode layer 62 of the part which connects the element coupling body 61 is electrically insulated with the soft magnetic body 18, it is not limited to formation in the lower part, You may form in the upper part.
　図１では、電極層６２が平面的に軟磁性体１８を迂回するように形成されていたが、図２では、電極層６２と軟磁性体１８とを高さ方向（図示Ｚ方向）にて交差させているため、磁気抵抗効果素子２，３の図示Ｘ方向への長さ寸法を小さくでき、電極層６２の配線抵抗も低減できる。また電極層６２と軟磁性体１８間の絶縁性（図１（ｂ）に示す絶縁層１７が介在している）が低く、仮にショートしたとしても、センサ特性にさほどの影響は無い。また電極層６２を非磁性の良導体で形成することで、電極層６２を永久磁石層で形成する形態に比べて寄生抵抗を低減できるし、永久磁石層で形成するとバイアス磁界の影響が軟磁性体１８に影響しシールド効果が低下するが、本実施形態では、そのような問題も生じない。 In FIG. 1, the electrode layer 62 is formed so as to bypass the soft magnetic body 18 in a plane, but in FIG. 2, the electrode layer 62 and the soft magnetic body 18 are arranged in the height direction (Z direction in the drawing). Since they intersect, the length dimension of the magnetoresistive elements 2 and 3 in the X direction shown in the figure can be reduced, and the wiring resistance of the electrode layer 62 can also be reduced. Further, the insulation between the electrode layer 62 and the soft magnetic body 18 (the insulation layer 17 shown in FIG. 1B is interposed) is low, and even if a short circuit occurs, the sensor characteristics are not significantly affected. Further, by forming the electrode layer 62 with a non-magnetic good conductor, the parasitic resistance can be reduced as compared with the case where the electrode layer 62 is formed with a permanent magnet layer. However, in the present embodiment, such a problem does not occur.
　永久磁石層の好ましい形状について説明する。図３の断面図に示すように、各素子部１２を構成する反強磁性層３３、固定磁性層３４及び非磁性層３５は永久磁石層６０，６５の形成位置で分断されておらず一体化している。すなわち、永久磁石層６０，６５の形成位置では、素子部１２を構成する保護層３７及びフリー磁性層３６がイオンミリング等で削られて凹部６３が形成される。よって凹部６３の底面６３ａには非磁性層３５が露出している。なお非磁性層３５の一部まで削られて凹部６３が形成されてもよい。そして、この凹部６３内に永久磁石層６０，６５が設けられている。図３の構成により固定磁性層３４が分断されないため、固定磁性層３４の磁化を図示Ｙ方向に安定化でき、一軸異方性を向上させることができる。また固定磁性層３４及び反強磁性層３３まで分断して各素子部１２間に永久磁石層６０，６５を設けた構成では、永久磁石層６０，６５と素子部１２との電気的コンタクトは各側面となるため寄生抵抗が大きくなりやすいが、本実施形態のように永久磁石層６０，６５と素子部１２との電気的コンタクトが平面接触となることで寄生抵抗を低減させることが出来る。 The preferable shape of the permanent magnet layer will be described. As shown in the sectional view of FIG. 3, the antiferromagnetic layer 33, the pinned magnetic layer 34, and the nonmagnetic layer 35 constituting each element unit 12 are not divided at the formation positions of the permanent magnet layers 60 and 65 and are integrated. ing. That is, at the positions where the permanent magnet layers 60 and 65 are formed, the protective layer 37 and the free magnetic layer 36 constituting the element portion 12 are scraped by ion milling or the like to form the concave portion 63. Therefore, the nonmagnetic layer 35 is exposed on the bottom surface 63 a of the recess 63. Note that the recess 63 may be formed by cutting a part of the nonmagnetic layer 35. The permanent magnet layers 60 and 65 are provided in the recess 63. Since the pinned magnetic layer 34 is not divided by the configuration of FIG. 3, the magnetization of the pinned magnetic layer 34 can be stabilized in the Y direction shown in the figure, and the uniaxial anisotropy can be improved. Further, in the configuration in which the permanent magnet layers 60 and 65 are provided between the element portions 12 by dividing the pinned magnetic layer 34 and the antiferromagnetic layer 33, the electrical contact between the permanent magnet layers 60 and 65 and the element portion 12 is different. The parasitic resistance tends to increase because of the side surface, but the parasitic resistance can be reduced by making the electrical contact between the permanent magnet layers 60 and 65 and the element portion 12 planar contact as in this embodiment.
　また図１３に示すように中間永久磁石層６０の上面には、中間永久磁石層６０よりも抵抗値が小さい低抵抗層６４が重ねて形成されている。低抵抗層６４はＡｕ、Ａｌ、Ｃｕ等の非磁性の良導体で形成されることが好適である。低抵抗層６４は、中間永久磁石層６０と同様にスパッタあるいはメッキ等で形成される。図１３に示すように中間永久磁石層６０上に低抵抗層６４を重ねて形成することで、より効果的に、寄生抵抗を低減できる。なお外側永久磁石層６５上には上記したように低抵抗層としての電極層６２が重ねられて形成されており、磁気抵抗変化に寄与しない寄生抵抗成分を効果的に低減できる構成となっている。 Further, as shown in FIG. 13, a low resistance layer 64 having a resistance value smaller than that of the intermediate permanent magnet layer 60 is formed on the upper surface of the intermediate permanent magnet layer 60. The low resistance layer 64 is preferably formed of a nonmagnetic good conductor such as Au, Al, or Cu. The low resistance layer 64 is formed by sputtering or plating in the same manner as the intermediate permanent magnet layer 60. As shown in FIG. 13, by forming the low resistance layer 64 on the intermediate permanent magnet layer 60, the parasitic resistance can be more effectively reduced. As described above, the electrode layer 62 as a low-resistance layer is formed on the outer permanent magnet layer 65 so as to be superposed on the outer permanent magnet layer 65, so that the parasitic resistance component that does not contribute to the magnetoresistance change can be effectively reduced. .
　図２、図３において素子部１２と中間永久磁石層６０が素子幅と直交方向に直列に接続されその外側に外側永久磁石層６５が形成される場合、素子中央において永久磁性層のバイアス磁界が積算されるため、外側のバイアス磁界が中央付近と比較すると弱くなる。そのため、外側永久磁石層６５の素子直交方向長さを中間永久磁石層６０長さより長くすることが好ましい。また、形成プロセスを分けることで、外側永久磁石層６５の膜厚を中間永久磁石層６０の膜厚より厚くすることでも同様の効果を得ることが出来る。 2 and 3, when the element portion 12 and the intermediate permanent magnet layer 60 are connected in series in the direction orthogonal to the element width and the outer permanent magnet layer 65 is formed outside thereof, the bias magnetic field of the permanent magnetic layer is formed at the center of the element. Since they are integrated, the outer bias magnetic field is weaker than that near the center. Therefore, it is preferable that the element orthogonal direction length of the outer permanent magnet layer 65 is longer than the length of the intermediate permanent magnet layer 60. Further, the same effect can be obtained by making the outer permanent magnet layer 65 thicker than the intermediate permanent magnet layer 60 by dividing the formation process.
　さらに中間永久磁石層６０および外側永久磁石層６５形成角部近傍では磁界が極端に強くなるため、素子幅Ｗ１よりも永久磁石層幅を広くすることで、磁界強度の最も強い部分を素子部に直接影響しないようにでき、パターン形成の合わせ精度のマージンも上げることが出来る。 Further, since the magnetic field becomes extremely strong in the vicinity of the corners where the intermediate permanent magnet layer 60 and the outer permanent magnet layer 65 are formed, by making the permanent magnet layer width wider than the element width W1, the portion with the strongest magnetic field strength is used as the element part. It is possible to prevent direct influence, and the margin of pattern formation alignment accuracy can be increased.
　磁気抵抗効果素子２，３を構成する素子部１２は一つだけでもよいが、複数設けてミアンダ形状にすることで、素子抵抗を大きくでき消費電力の低減を図ることができ好適である。 The number of element portions 12 constituting the magnetoresistive effect elements 2 and 3 may be only one. However, providing a plurality of element portions 12 in a meander shape is preferable because the element resistance can be increased and the power consumption can be reduced.
　また、磁気抵抗効果素子２，３及び固定抵抗素子４，５は一つずつでもよいが、図７のようにブリッジ回路を構成し、出力取出し部１４から得られた出力を差動増幅器９にて差動出力とすることで、出力値を大きくでき高精度な磁場検知を行うことが出来る。 The magnetoresistive effect elements 2 and 3 and the fixed resistance elements 4 and 5 may be provided one by one. However, as shown in FIG. 7, a bridge circuit is formed, and the output obtained from the output extraction unit 14 is supplied to the differential amplifier 9. By using differential output, the output value can be increased and high-precision magnetic field detection can be performed.
　また、図１，図２では、軟磁性体１８は、素子連結体６１の両側方に設けられていたが、軟磁性体１８は、素子連結体６１の真上、あるいは真下に絶縁層を介して設けられる構造でもよい。 In FIG. 1 and FIG. 2, the soft magnetic body 18 is provided on both sides of the element coupling body 61. However, the soft magnetic body 18 has an insulating layer directly above or below the element coupling body 61. The structure provided may be sufficient.
　固定磁性層３４の固定磁化方向（Ｐ方向）を、同チップ内で変えたり、あるいは、同じ固定磁化方向（Ｐ方向）を備えるチップを２つ用いてフルブリッジの構成とすることも可能である。 It is also possible to change the fixed magnetization direction (P direction) of the fixed magnetic layer 34 within the same chip, or to form a full bridge using two chips having the same fixed magnetization direction (P direction). .
　本実施形態における磁気センサ１は例えば、図８に示す地磁気センサ（磁気センサモジュール）として使用される。Ｘ軸磁場検知部５０、Ｙ軸磁場検知部５１、Ｚ軸磁場検知部５２では、いずれも図７に示すブリッジ回路のセンサ部が設けられている。Ｘ軸磁場検知部５０では磁気抵抗効果素子２，３の素子部１２の固定磁性層３４の固定磁化方向（Ｐ方向）が感度軸であるＸ方向を向いており、また、Ｙ軸磁場検知部５１では磁気抵抗効果素子２，３の素子部１２の固定磁性層３４の固定磁化方向（Ｐ方向）が感度軸であるＹ方向を向いており、さらに、Ｚ軸磁場検知部５２では磁気抵抗効果素子２，３の素子部１２の固定磁性層３４の固定磁化方向（Ｐ方向）が感度軸であるＺ方向を向いている。 The magnetic sensor 1 in this embodiment is used as, for example, a geomagnetic sensor (magnetic sensor module) shown in FIG. In each of the X-axis magnetic field detection unit 50, the Y-axis magnetic field detection unit 51, and the Z-axis magnetic field detection unit 52, a sensor unit of a bridge circuit shown in FIG. 7 is provided. In the X-axis magnetic field detection unit 50, the fixed magnetization direction (P direction) of the fixed magnetic layer 34 of the element unit 12 of the magnetoresistive effect elements 2 and 3 faces the X direction that is the sensitivity axis, and the Y-axis magnetic field detection unit In 51, the fixed magnetization direction (P direction) of the pinned magnetic layer 34 of the element portion 12 of the magnetoresistive effect elements 2 and 3 faces the Y direction which is the sensitivity axis, and in the Z-axis magnetic field detector 52, the magnetoresistive effect The pinned magnetization direction (P direction) of the pinned magnetic layer 34 of the element portion 12 of the elements 2 and 3 faces the Z direction that is the sensitivity axis.
　Ｘ軸磁場検知部５０、Ｙ軸磁場検知部５１、Ｚ軸磁場検知部５２、及び集積回路（ＡＳＩＣ）５４はいずれも基台５３上に設けられる。Ｘ軸磁場検知部５０、及びＹ軸磁場検知部５１の磁気抵抗効果素子２，３の形成面はいずれもＸ－Ｙ平面であるが、Ｚ軸磁場検知部５２の磁気抵抗効果素子２，３の形成面はＸ－Ｚ平面であり、Ｚ軸磁場検知部５２の磁気抵抗効果素子２，３の形成面は、Ｘ軸磁場検知部５０、及びＹ軸磁場検知部５１の磁気抵抗効果素子２，３の形成面に対して直交した関係にある。 The X-axis magnetic field detection unit 50, the Y-axis magnetic field detection unit 51, the Z-axis magnetic field detection unit 52, and the integrated circuit (ASIC) 54 are all provided on the base 53. The formation surfaces of the magnetoresistive effect elements 2 and 3 of the X-axis magnetic field detection unit 50 and the Y-axis magnetic field detection unit 51 are both XY planes. Is formed on the XZ plane, and the formation surface of the magnetoresistive effect elements 2 and 3 of the Z-axis magnetic field detection unit 52 is the magnetoresistive effect element 2 of the X-axis magnetic field detection unit 50 and the Y-axis magnetic field detection unit 51. , 3 are orthogonal to the formation surface.
　本実施形態では感度軸方向と直交する方向に対して磁気シールド効果があり、また感度軸方向に対しては適切な感度を備える。したがって、Ｘ軸磁場検知部５０、Ｙ軸磁場検知部５１、及びＺ軸磁場検知部５２のうち２以上の検知部を基台５３上に設けても、各検知部において、感度軸方向と直交方向からの磁場を適切に磁気シールドできるとともに、各検知部の感度軸方向からの地磁気を適切に検知できる。 In this embodiment, there is a magnetic shielding effect in the direction orthogonal to the sensitivity axis direction, and appropriate sensitivity is provided in the sensitivity axis direction. Therefore, even if two or more detection units among the X-axis magnetic field detection unit 50, the Y-axis magnetic field detection unit 51, and the Z-axis magnetic field detection unit 52 are provided on the base 53, each detection unit is orthogonal to the sensitivity axis direction. The magnetic field from the direction can be properly magnetically shielded, and the geomagnetism from the direction of the sensitivity axis of each detector can be detected appropriately.
　図８の構成以外に、図８に示す地磁気センサと加速度センサ等を組み合わせたモジュールとすることもできる。 8 In addition to the configuration shown in FIG. 8, a module in which the geomagnetic sensor and the acceleration sensor shown in FIG. 8 are combined may be used.
（ａ）は第１実施形態における磁気センサの特に磁気抵抗効果素子の部分を示す平面図、（ｂ）は、図１（ａ）のＡ－Ａ線に沿って高さ方向（図示Ｚ方向）に切断し矢印方向から見た部分断面図、(A) is a top view which shows the part of the magnetoresistive effect element especially of the magnetic sensor in 1st Embodiment, (b) is a height direction (Z direction shown in figure) along the AA line of Fig.1 (a). A partial cross-sectional view as seen from the direction of the arrow 第２実施形態における磁気センサの特に磁気抵抗効果素子の部分を示す平面図、The top view which shows the part of especially the magnetoresistive effect element of the magnetic sensor in 2nd Embodiment, 図２に示すＤ－Ｄ線に沿って高さ方向（図示Ｚ方向）に切断し矢印方向から見た部分拡大断面図、FIG. 2 is a partially enlarged sectional view taken along the line DD shown in FIG. 好ましい磁気抵抗効果素子の形態の特に素子部の部分を示す部分拡大平面図、A partially enlarged plan view showing a part of the element part in the form of a preferable magnetoresistive element, 磁気抵抗効果素子の固定磁性層の固定磁化方向及びフリー磁性層の磁化方向と、電気抵抗値との関係を説明するための図、The figure for demonstrating the relationship between the fixed magnetization direction of the fixed magnetic layer of a magnetoresistive effect element, the magnetization direction of a free magnetic layer, and an electrical resistance value, 磁気抵抗効果素子を膜厚方向から切断した際の切断面を示す断面図、Sectional drawing which shows the cut surface at the time of cut | disconnecting a magnetoresistive effect element from a film thickness direction, 本実施形態の磁気センサの回路図、A circuit diagram of the magnetic sensor of the present embodiment, 本実施形態における地磁気センサモジュールの部分斜視図、The partial perspective view of the geomagnetic sensor module in this embodiment, （ａ）は、比較例１（図１（ａ）に示す永久磁石層６０、６５が形成されておらず永久磁石層６０、６５の部分も素子部１２で形成された構造。ただし軟磁性体１８は設けられている）の構造における感度軸方向からの磁場の強度Ｈと磁気抵抗効果素子の単位磁場当たりの抵抗変化率（ＭＲ比）との関係を示すグラフ、（ｂ）は、上記した比較例１の構造における感度軸方向に対して直交方向からの磁場の強度Ｈと磁気抵抗効果素子の単位磁場当たりの抵抗変化率（ＭＲ比）との関係を示すグラフ、(A) is a structure in which the permanent magnet layers 60 and 65 shown in FIG. 1A are not formed and the portions of the permanent magnet layers 60 and 65 are also formed by the element portion 12 (provided that the soft magnetic material is used). 18 is a graph showing the relationship between the strength H of the magnetic field from the sensitivity axis direction and the resistance change rate (MR ratio) per unit magnetic field of the magnetoresistive effect element in the structure of FIG. The graph which shows the relationship between the intensity | strength H of the magnetic field from the orthogonal direction with respect to the sensitivity-axis direction in the structure of the comparative example 1, and the resistance change rate (MR ratio) per unit magnetic field of a magnetoresistive effect element, （ａ）は、比較例２（図１（ａ）に示す軟磁性体１８が設けられていない構造。ただし永久磁石層６０、６５は設けられている）の構造における感度軸方向からの磁場の強度Ｈと磁気抵抗効果素子の単位磁場当たりの抵抗変化率（ＭＲ比）との関係を示すグラフ、（ｂ）は、上記した比較例２の構造における感度軸方向に対して直交方向からの磁場の強度Ｈと磁気抵抗効果素子の単位磁場当たりの抵抗変化率（ＭＲ比）との関係を示すグラフ、(A) is a magnetic field from the sensitivity axis direction in the structure of the comparative example 2 (the structure in which the soft magnetic body 18 shown in FIG. 1A is not provided, but the permanent magnet layers 60 and 65 are provided). A graph showing the relationship between the intensity H and the resistance change rate (MR ratio) per unit magnetic field of the magnetoresistive effect element, (b) shows the magnetic field from the direction orthogonal to the sensitivity axis direction in the structure of Comparative Example 2 described above. A graph showing the relationship between the strength H of the magnetoresistive effect element and the rate of change in resistance per unit magnetic field (MR ratio) of the magnetoresistive effect element; （ａ）は、本実施形態（永久磁石層６０、６５及び軟磁性体１８の双方が設けられている）の構造における感度軸方向からの磁場の強度Ｈと磁気抵抗効果素子の単位磁場当たりの抵抗変化率（ＭＲ比）との関係を示すグラフ、（ｂ）は、上記した本実施形態の構造における感度軸方向に対して直交方向からの磁場の強度Ｈと磁気抵抗効果素子の単位磁場当たりの抵抗変化率（ＭＲ比）との関係を示すグラフ、(A) shows the intensity H of the magnetic field from the sensitivity axis direction and the unit magnetic field per unit magnetic field of the magnetoresistive effect element in the structure of this embodiment (where both the permanent magnet layers 60 and 65 and the soft magnetic body 18 are provided). A graph showing the relationship with the resistance change rate (MR ratio), (b) is the intensity H of the magnetic field from the direction orthogonal to the sensitivity axis direction in the structure of the present embodiment and the unit magnetic field of the magnetoresistive element. A graph showing the relationship with the resistance change rate (MR ratio) of 素子部のアスペクト比によりヒステリシスが生じることを説明するための直交磁場の強度Ｈと磁気抵抗効果素子の単位磁場当たりの抵抗変化率（ＭＲ比）との関係を示すグラフ、A graph showing the relationship between the strength H of the orthogonal magnetic field and the resistance change rate (MR ratio) per unit magnetic field of the magnetoresistive effect element for explaining that hysteresis occurs due to the aspect ratio of the element portion;
符号の説明Explanation of symbols
１　磁気センサ
２、３　磁気抵抗効果素子
４、５　固定抵抗素子
６　ブリッジ回路
７　入力端子
８　グランド端子
９　差動増幅器
１０　外部出力端子
１１　集積回路
１２　素子部
１４　出力取出し部
１６　基板
１７　絶縁層
１８　軟磁性体
３３　反強磁性層
３４　固定磁性層
３６　フリー磁性層
３７　保護層
５０　Ｘ軸磁場検知部
５１　Ｙ軸磁場検知部
５２　Ｚ軸磁場検知部
６０　中間永久磁石層
６５　外側永久磁石層
６１　素子連結体
６２　電極層
６３　凹部
６４　低抵抗層
Ｌ１　素子長さ
Ｌ２　（軟磁性体の）長さ寸法
Ｗ１　素子幅
Ｗ２　（軟磁性体の）幅寸法 DESCRIPTION OF SYMBOLS 1 Magnetic sensor 2, 3 Magnetoresistance effect element 4, 5 Fixed resistance element 6 Bridge circuit 7 Input terminal 8 Ground terminal 9 Differential amplifier 10 External output terminal 11 Integrated circuit 12 Element part 14 Output extraction part 16 Substrate 17 Insulating layer 18 Soft Magnetic body 33 Antiferromagnetic layer 34 Pinned magnetic layer 36 Free magnetic layer 37 Protective layer 50 X-axis magnetic field detector 51 Y-axis magnetic field detector 52 Z-axis magnetic field detector 60 Intermediate permanent magnet layer 65 Outer permanent magnet layer 61 Element connection body 62 Electrode layer 63 Recess 64 Low resistance layer L1 Element length L2 (Soft magnetic material) length W1 Element width W2 (Soft magnetic material) width

Claims (9)

  1. 　磁気抵抗効果素子を備えた磁気センサであって、
    　前記磁気抵抗効果素子は、磁化方向が固定される固定磁性層と、前記固定磁性層に非磁性層を介して積層された外部磁場を受けて磁化方向が変動するフリー磁性層とを有し、前記固定磁性層の固定磁化方向が感度軸方向である素子幅方向に向けられた素子部を備え、
    　前記素子部と、前記素子幅方向に直交する素子長さ方向に中間永久磁石層とが設けられており、前記素子部と前記中間永久磁石層とで素子連結体が構成され、前記素子連結体は素子幅に比べて素子長さが長く形成されており、
    　軟磁性体が前記素子連結体と非接触にて配置され、
    　前記軟磁性体の前記素子長さ方向と同方向への長さ寸法は、前記素子連結体の素子長さより長く、前記軟磁性体は、前記素子連結体の素子長さ方向の両側から前記素子連結体の素子長さ方向に延出する延出部を備えていることを特徴とする磁気センサ。     A magnetic sensor comprising a magnetoresistive element,
    The magnetoresistive element has a pinned magnetic layer whose magnetization direction is fixed, and a free magnetic layer whose magnetization direction is changed by receiving an external magnetic field laminated on the pinned magnetic layer via a nonmagnetic layer, An element portion oriented in an element width direction in which the fixed magnetization direction of the fixed magnetic layer is a sensitivity axis direction;
    The element portion and an intermediate permanent magnet layer in an element length direction orthogonal to the element width direction are provided, and an element coupling body is constituted by the element portion and the intermediate permanent magnet layer, and the element coupling body The element length is longer than the element width,
    A soft magnetic body is disposed in non-contact with the element coupling body,
    The length dimension of the soft magnetic body in the same direction as the element length direction is longer than the element length of the element coupling body, and the soft magnetic body extends from both sides of the element coupling body in the element length direction. A magnetic sensor comprising an extending portion extending in the element length direction of the coupling body.
  2. 　前記素子連結体中の素子部、外側永久磁石層、及び前記中間永久磁石層がすべて電気的に接続されており、素子連結体が複数、素子幅方向に間隔を空けて配置され、各素子部連結体の両側に設けられた外側永久磁石層間が非磁性接続層により電気的に接続されたミアンダ形状で形成されており、
    　各素子連結体の素子幅方向の両側方、真上、あるいは真下のいずれかに前記軟磁性体が前記各素子部と非接触で形成されている請求項１に記載の磁気センサ。     The element part, the outer permanent magnet layer, and the intermediate permanent magnet layer in the element coupling body are all electrically connected, and a plurality of element coupling bodies are arranged at intervals in the element width direction. The outer permanent magnet layers provided on both sides of the coupling body are formed in a meander shape electrically connected by a nonmagnetic connection layer,
    2. The magnetic sensor according to claim 1, wherein the soft magnetic body is formed in non-contact with each element portion on either side of the element width direction in the element width direction, directly above, or directly below.
  3. 　前記非磁性接続層が、上記軟磁性体と絶縁膜を挟んで交差する交差部を有している請求項１記載の磁気センサ。 2. The magnetic sensor according to claim 1, wherein the nonmagnetic connection layer has an intersecting portion that intersects the soft magnetic material with an insulating film interposed therebetween.
  4. 　前記中間永久磁性層の素子長さ方向の長さよりも外側永久磁性層の素子長さ方向の長さが長く形成されている請求項１記載の磁気センサ。 2. The magnetic sensor according to claim 1, wherein the length of the outer permanent magnetic layer in the element length direction is longer than the length of the intermediate permanent magnetic layer in the element length direction.
  5. 　前記中間永久磁性層および、外側永久磁性層の幅が前記素子幅より広く形成されている請求項１記載の磁気センサ。 The magnetic sensor according to claim 1, wherein the intermediate permanent magnetic layer and the outer permanent magnetic layer are formed wider than the element width.
  6. 　前記中間永久磁石層が、前記素子部の膜厚方向に形成された凹部に設けられている請求項１記載の磁気センサ。 The magnetic sensor according to claim 1, wherein the intermediate permanent magnet layer is provided in a recess formed in a film thickness direction of the element portion.
  7. 　前記外側永久磁性層が、前記素子部の膜厚方向に形成された凹部を介して電気的に接続されている請求項１記載の磁気センサ。 The magnetic sensor according to claim 1, wherein the outer permanent magnetic layer is electrically connected through a recess formed in the film thickness direction of the element portion.
  8. 　前記中間永久磁石層の上面及び前記外側永久磁石層の上面には永久磁石層より抵抗値が小さい非磁性低抵抗層が重ねて形成されている請求項１記載の磁気センサ。 The magnetic sensor according to claim 1, wherein a nonmagnetic low resistance layer having a resistance value smaller than that of the permanent magnet layer is formed on the upper surface of the intermediate permanent magnet layer and the upper surface of the outer permanent magnet layer.
  9. 　請求項１ないし８のいずれかに記載の磁気センサを複数有し、少なくとも前記複数の磁気センサのうち一組の磁気抵抗効果素子の感度軸が直交するように各磁気抵抗効果素子が配置されていることを特徴とする磁気センサモジュール。 9. A plurality of magnetic sensors according to claim 1, wherein each magnetoresistive element is arranged so that sensitivity axes of at least one set of the magnetoresistive elements are orthogonal to each other. A magnetic sensor module.
PCT/JP2008/072921 2007-12-28 2008-12-17 Magnetic sensor and magnetic sensor module WO2009084435A1 (en)

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