JP5298404B2 - Triaxial magnetic sensor and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a triaxial magnetic field sensor in a structure to be constructed in a single chip. <P>SOLUTION: A magnetoresistive effect element is formed by a plurality of magnetoresistive effect element bars connected in series by a bias magnet. The magnetoresistive effect elements 21-24 of the X-axis sensor and the magnetoresistive effect elements 31-34 of the Y-axis sensor are formed on a plane parallel to the surface of the substrate. The magnetization sensitivity direction is vertical with respect to the longitudinal direction of each of the magnetoresistive effect element bars. The magnetization direction of the magnetoresistive effect elements 21-24 of the X-axis sensor orthogonally intersects those of the magnetoresistive effect elements 31-34 of the Y-axis sensor. Furthermore, magnetoresistive effect elements 41-44 of the Z-axis sensor are formed on the inclined surface of a protrusion 15, protruding from the surface of the substrate 11, and its magnetization direction is in the inclined surface. The magnetization sensitivity direction is formed so as to be vertical with respect to the longitudinal direction of the magnetoresistive effect element bar. <P>COPYRIGHT: (C)2007,JPO&amp;INPIT

Description

  The present invention includes an X-axis sensor in which magnetoresistive elements having a plurality of pinned layers are bridge-connected, a Y-axis sensor in which magnetoresistive elements having a plurality of pinned layers are bridge-connected, and a plurality of pinned layers. The present invention relates to a three-axis magnetic sensor including a Z-axis sensor having a magnetoresistive effect element bridge-connected in one substrate, and a method for manufacturing the same.

  Conventionally, giant magnetoresistive elements (GMR elements), magnetic tunnel effect elements (TMR elements), and the like are known as elements used in magnetic sensors. These magnetoresistive elements include a pinned layer whose magnetization direction is pinned (fixed) in a predetermined direction, and a free layer whose magnetization direction changes according to an external magnetic field. A resistance value corresponding to the relative relationship between the direction and the magnetization direction of the free layer is shown as an output. As a magnetic sensor using such a magnetoresistive effect element, for example, Patent Document 1 (Japanese Patent No. 3498737) and Patent Document 2 (Japanese Patent Laid-Open No. 2002-299728) have been proposed.

  In the magnetic sensors proposed in Patent Document 1 and Patent Document 2, the magnetoresistive elements are orthogonal to each other so as to detect magnetic field changes in two orthogonal directions (X-axis direction and Y-axis direction). In order to detect an external magnetic field in a two-dimensional plane by obtaining an output (change in resistance value) of each element by bridging each element as a group of several elements. .

By the way, there is a case where it is necessary to obtain a direction in space, that is, a direction in three dimensions, instead of a two-dimensional plane. In such an application, it is necessary to accurately determine the magnetic direction in three dimensions (X-axis direction, Y-axis direction, and Z-axis direction). However, since such a three-dimensional magnetic sensor capable of obtaining the orientation in three dimensions cannot be manufactured on the same substrate, a thin three-dimensional magnetic sensor has not been obtained at the present time.
Japanese Patent No. 3498737 JP 2002-299728 A

  Therefore, a three-axis magnetic sensor (three-dimensional magnetic sensor) in which two chips are mounted in an inclined manner has been proposed. In this three-axis magnetic sensor, as shown in the top view of FIG. 26A, two chips consisting of a square A chip and a B chip in a plan view are mounted in a package. Then, as shown in the side view of FIG. 26 (b), these two chips are arranged inclined by an angle θ from the horizontal plane. The A chip has an x-axis sensor (ad) and a y1-axis. Sensors (e to h) are built in, and y2 axis sensors (i to l) are built in the B chip. Each sensor is composed of four GMR elements (ad, e to h, i to l), and each GMR element is formed along the side of the chip.

  In this case, as shown in FIG. 27A, the GMR elements a to d are bridge-connected to constitute an x-axis sensor. In addition, as shown in FIG. 27 (b), the GMR elements e to h are bridge-connected to constitute a y1-axis sensor. Further, as shown in FIG. 27 (c), the GMR elements i to l are bridge-connected to form a y2-axis sensor. The sensitivity directions of the GMR elements a to d constituting the x axis sensor are the x axis direction, the sensitivity directions of the GMR elements e to h constituting the y1 axis sensor are the y1 axis direction, and the GMR elements constituting the y2 axis sensor. The sensitivity directions i to l are set in the y2 axis direction.

  Thus, when a magnetic field is applied to the GMR elements constituting each sensor in the direction of the arrow in FIG. 26A, the resistance value decreases in proportion to the magnetic field strength. On the other hand, when a magnetic field is applied in a direction opposite to the arrow direction in FIG. 26A, the resistance value increases in proportion to the magnetic field strength. Here, each GMR element is bridge-connected as shown in FIGS. 27A, 27B, and 27C to form each sensor, and when a predetermined voltage (for example, 3 V) is applied between the power source and the ground, x Sx is output from the axis sensor, Sy1 is output from the y1-axis sensor, and Sy2 is output from the y2-axis sensor.

Based on the obtained output, the magnetic field component Hx in the x-axis direction can be obtained by the following equation (1). Similarly, the magnetic field component Hy in the y-axis direction can be obtained from the following equation (2), and the magnetic field component Hz in the z-axis direction can be obtained from the following equation (3).
Hx = 2kx × Sx (1)
Hy = ky (Sy1-Sy2) / cos θ (2)
Hz = kz (Sy1 + Sy2) / sin θ (3)
However, kx, ky, kz are proportional constants, and if the sensitivity of each sensor is equal, kx = ky = kz.

However, in the above-described three-axis magnetic sensor, since it is necessary to mount two chips consisting of an A chip and a B chip in the package, it is complicated and time-consuming to manufacture this type of sensor. Caused a problem. In addition, since it is necessary to use a special package, this type of sensor is expensive and difficult to downsize.
Accordingly, the present invention has been made to solve such problems, and an object thereof is to provide a three-axis magnetic sensor having a structure that can be easily and easily manufactured in one chip (one substrate). To do.

In order to achieve the above object, a triaxial magnetic sensor of the present invention includes an X-axis sensor in which a plurality of magnetoresistive elements each having a pinned layer are bridge-connected to a single substrate on which an LSI and a wiring layer are formed. A Y-axis sensor in which a plurality of magnetoresistive elements having a pinned layer are bridge-connected, and a Z-axis sensor in which a plurality of magnetoresistive elements having a pinned layer are bridge-connected are formed. The magnetoresistive effect element is formed by connecting one magnetoresistive effect element bar or a plurality of magnetoresistive effect element bars in series, and the magnetoresistive effect element of the X-axis sensor and the magnetoresistive effect element of the Y-axis sensor. Is formed on a plane parallel to the plane of the substrate, the direction of sensitivity of magnetization is perpendicular to the longitudinal direction of each magnetoresistive element bar, and the magnetoresistive element of the X-axis sensor and Y The direction of magnetization of the magnetoresistive effect element of the axis sensor is formed so as to be orthogonal to each other, and the magnetoresistive effect element of the Z axis sensor is opposed to the Z axis perpendicular to the plane of the substrate at the same angle. It is formed on the inclined surface of the protruding protrusion, and the magnetization direction of the pinned layer of the magnetoresistive effect element of the Z-axis sensor is formed in the inclined surface, and the sensitivity direction is Magnetic The magnetoresistive effect element bar is formed so as to intersect the longitudinal direction of the resistance effect element bar, and the longitudinal direction of the magnetoresistive effect element bar coincides with either the X-axis direction or the Y-axis direction of the substrate. Two magnetoresistive effect elements constituted by the formed magnetoresistive effect element bars are arranged adjacent to and parallel to each other, and the center of the square substrate in plan view with these two magnetoresistive effect elements And a full-bridge connection with two nonmagnetic resistors formed at point-symmetrical positions .

  Accordingly, the magnetization directions of the magnetoresistive effect elements of the X-axis sensor, the Y-axis sensor, and the Z-axis sensor are formed so as to intersect each other in the three-dimensional direction, so that the X-axis, Y-axis, Z-axis It is possible to measure an accurate magnetic field in the three-dimensional direction. Since the X-axis sensor, the Y-axis sensor, and the Z-axis sensor are provided in one substrate, it is possible to prevent the occurrence of angular deviation as in a magnetic sensor formed by assembling a plurality of sensors on different substrates. In addition, an increase in size of the sensor can be prevented, and a small three-axis magnetic sensor can be provided. In this case, since the Z-axis sensor is only formed on the slope of the protrusion provided so as to protrude from the plane of the substrate, the Z-axis sensor can be easily and easily manufactured in one substrate. .

Here, in the magnetoresistive effect element, when a plurality of magnetoresistive effect element bars are arranged in parallel and adjacent magnetoresistive effect element bars are connected in series by a bias magnet film, each magnetoresistive effect element bar described later A bias magnetic field can be easily applied to the free layer.
In this case, each magnetoresistive effect element bar constituting the magnetoresistive effect element of the Z axis sensor is formed on a slope formed so as to face each other at the same angle with respect to the Z axis perpendicular to the plane of the substrate. The longitudinal direction of the magnetoresistive effect element bar coincides with either the X-axis direction or the Y-axis direction of the substrate, and the magnetoresistive effect elements formed by the magnetoresistive effect element bars respectively formed on the slopes. When arranged adjacent to each other in parallel, the X-axis component and Y-axis component of the magnetic field sensitivity are canceled in each magnetoresistive effect element, so only the Z-axis component of the magnetic field sensitivity appears. Will be.

In this case, with two magnetoresistive elements to each other composed of magnetoresistive element bars are arranged parallel to one another and adjacent, from the center of the substrate in these two magnetoresistive elements in a plan view If the two non-magnetic resistors formed at the point-symmetrical positions are connected with a full bridge, the size can be further reduced.

In order to manufacture the above-described three-axis magnetic sensor , a plurality of magnetoresistive elements having a pinned layer serving as an X-axis sensor on one substrate on which an LSI or a wiring layer is formed , a Y-axis sensor, a plurality of magnetoresistive elements having a pinned layer composed of a magnetoresistive element forming step of forming a plurality of magnetoresistive elements having a pinned layer serving as a Z-axis sensor, the magneto-resistive element formed on the substrate Rutotomoni a fixation treatment step is heated while applying a magnetic field to fix the magnetization direction of each of the pinned layers of the magnetoresistive elements simultaneously, in the fixing step, a plurality of magnetoresistance the Z-axis sensor Magnetization of each pinned layer of the magnetoresistive effect element by heating while applying a magnetic field of 45 degrees from the vertical direction of the substrate on which each magnetoresistive effect element bar constituting the effect element is formed The orientation may be set to so that be fixed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings as a triaxial magnetic sensor of Example 1, a triaxial magnetic sensor of Example 2, a triaxial magnetic sensor of Example 3, and a triaxial magnetic sensor of Example 4. Although described, the present invention is not limited to these examples, and can be implemented with appropriate modifications within a range that does not change the object of the present invention.

1. Example 1
First, the triaxial magnetic sensor of Example 1 is demonstrated below based on FIGS. FIG. 1 is a schematic configuration diagram schematically showing a triaxial magnetic sensor of Example 1, FIG. 1 (a) is a plan view, and FIG. 1 (b) is an AA cross section of FIG. 1 (a). FIG. FIG. 2 is a diagram schematically showing a schematic configuration of a magnetoresistive effect element used in the triaxial magnetic sensor of the present invention. FIG. 2A shows a connection of a plurality of magnetoresistive effect element (GMR) bars. 2B is a plan view showing a state in which one magnetoresistive effect element is configured, and FIG. 2B is a cross-sectional view schematically showing the AA cross section of FIG. (c) is a figure which shows typically the lamination | stacking state inside FIG.2 (b).

  3 is a diagram schematically showing the pinning direction and sensitivity direction of the three-axis magnetic sensor of FIG. 1, and FIG. 3 (a) is a plan view schematically showing the entire plane, and FIG. 3 (b). FIG. 3 is a perspective view schematically showing an enlarged portion A of FIG. 3A, and FIG. 3C is a perspective view schematically showing an enlarged portion B of FIG. . 4 is a block diagram showing the bridge connection, FIG. 4 (a) is a block diagram showing the bridge connection of the X-axis sensor, and FIG. 4 (b) is a block diagram showing the bridge connection of the Y-axis sensor. FIG. 4C is a block diagram showing the bridge connection of the Z-axis sensor. 5-14 is sectional drawing which shows typically the triaxial magnetic sensor of Example 1 in the middle of manufacture. 15A and 15B are diagrams schematically showing a state of ordering heat treatment (pinning treatment), FIG. 15A is a plan view, and FIG. 15B is a cross-sectional view taken along line AA in FIG. FIG. 15C is a cross-sectional view showing the BB cross section of FIG.

  As shown in FIG. 1, the triaxial magnetic sensor 10 according to the first embodiment has a rectangular shape (here, a short side (longitudinal) and a long side) having sides along the X axis and the Y axis that are orthogonal to each other in a plan view. (Horizontal) ratio (aspect ratio) is 1: 2, the side along the X axis is the long side, and the side along the Y axis is the short side). A substrate 11 made of quartz or silicon having a small thickness in the Z-axis direction orthogonal to the Y-axis is provided. A total of 12 GMR elements each including four X-axis GMR elements 21 to 24, Y-axis GMR elements 31 to 34, and Z-axis GMR elements 41 to 44 are formed on the substrate 11. Twelve pads (not shown) and connection lines (not shown) for connecting each pad and each element are formed. Note that an LSI and a wiring layer are built in the substrate 11, and those using the substrate on which the LSI is built are a digital output magnetic sensor, and only the wiring layer is built. The one using the substrate is an analog output magnetic sensor.

  Here, the X-axis GMR element includes a first X-axis GMR element 21, a second X-axis GMR element 22, a third X-axis GMR element 23, and a fourth X-axis GMR element 24. Then, the left end of the substrate 11 in the X-axis direction (in this case, the left end in FIG. 1A is used as the X-axis reference point, and the right side of the drawing from this reference point is the X-axis positive direction. The opposite direction is defined as the negative X-axis direction (the same applies hereinafter) and the substantially central part (hereinafter referred to as the X-axis central part) of the right end part, and the lower end part in this case (in this case) 1A is the Y-axis reference point, the upper direction in the figure from the reference point is the Y-axis positive direction, and the opposite direction is the Y-axis negative direction. When it is 45 ° with respect to the positive axis direction, it means the direction rotated 45 ° clockwise from the positive X-axis direction. The first X-axis GMR element 21 is disposed above (hereinafter referred to as the Y-axis center), and the second X-axis GMR element 22 is disposed below the first X-axis GMR element 22. Yes. Further, in the vicinity of the left end portion of the X-axis of the substrate 11, the third X-axis GMR element 23 is disposed above the Y-axis central portion, and the fourth X-axis GMR element 24 is disposed below the third X-axis GMR element 24.

  The Y-axis GMR element includes a first Y-axis GMR element 31, a second Y-axis GMR element 32, a third Y-axis GMR element 33, and a fourth Y-axis GMR element 34. The first Y-axis GMR element 31 is arranged in the vicinity of the upper end of the substrate 11 in the Y-axis direction, to the right of the middle part from the X-axis central part to the left-side end of the X-axis. An axial GMR element 32 is arranged. A third Y-axis GMR element 33 is disposed in the vicinity of the lower end of the substrate 11 in the Y-axis direction, to the right of a substantially intermediate portion from the X-axis central portion to the left-side end of the X-axis. A 4Y-axis GMR element 34 is arranged.

  Further, the Z-axis GMR element includes a first Z-axis GMR element 41, a second Z-axis GMR element 42, a third Z-axis GMR element 43, and a fourth Z-axis GMR element 44. The first Z-axis GMR element 41 is located at a substantially intermediate portion from the Y-axis central portion of the substrate 11 to the lower end portion of the Y-axis, and to the left of a substantially intermediate portion from the X-axis central portion to the right end portion of the X-axis. The second Z-axis GMR element 42 is arranged on the right side. Further, the third Z-axis GMR element 43 is arranged at a substantially intermediate portion from the Y-axis center portion of the substrate 11 to the upper end portion of the Y-axis, and to the left of a substantially intermediate portion from the X-axis center portion to the left end portion of the X-axis. The fourth Z-axis GMR element 44 is arranged on the right side.

  Here, each of the GMR elements 21 to 24, 31 to 34, and 41 to 44 includes four GMR bars arranged in parallel and adjacent to each other in a strip shape, and these four GMR bars are magnet films (bias). Magnet films) are connected in series, and a magnet film serving as a terminal portion is connected to these end portions. For example, as shown in FIG. 2 (in FIG. 2, only the first X-axis GMR element 21 is shown, but the other GMR elements have the same configuration), four GMR bars 21a, 21b, 21c and 21d are connected in series by magnet films 21f, 21g, and 21h, and magnet films 21e and 21i serving as terminal portions are connected to these ends.

  In this case, each GMR bar (21a, 21b, 21c, 21d, etc.) of the X-axis GMR elements 21 to 24 is formed on a plane parallel to the surface of the substrate 11, and its longitudinal direction is relative to the X-axis. They are arranged at an angle of 45 °. Further, each GMR bar of the Y-axis GMR elements 31 to 34 is formed on a plane parallel to the surface of the substrate 11, and its longitudinal direction is orthogonal to the longitudinal direction of each GMR bar of the X-axis GMR elements 21 to 24. Are arranged to be. Further, each GMR bar of the Z-axis GMR elements 41 to 44 has one inclined surface (inclination angle) on each inclined surface of the plurality of protrusions (bank portions) 15 having a trapezoidal cross-sectional shape formed on the substrate 11. 1 GMR bar (for example, 43a, 43b, 43c, 43d, or 44a, 44b, 44c, 44d (see FIG. 1B)) is formed. They are arranged so that their longitudinal directions are perpendicular to the X axis and parallel to the Y axis.

  Next, the configuration of the GMR bar will be described with reference to FIG. 2, taking the GMR bar 21b of the first X-axis GMR element 21 as an example. Since the other GMR bars 21a, 21c, and 21d are equal to this, only the GMR bar 21b will be described here. The other X-axis GMR elements 22, 23, 24, Y-axis GMR elements 31, 32, 33, and 34 and Z-axis GMR elements 41, 42, 43, and 44 are also the same, and thus description thereof is omitted.

  Here, the GMR bar 21b of the first X-axis GMR element 21 is spin-shaped as shown in FIG. 2B, which is a schematic cross-sectional view taken along the plane AA in FIG. The valve film SV, and magnet films (bias magnet film; hard ferromagnetic thin film layers) 21g and 21f made of a material having a high coercive force, such as CoCrPt, formed under the both end portions are provided. I have. As shown in FIG. 2C, the spin valve film SV has a free layer (free layer, free magnetic layer) F sequentially stacked on the substrate 11, and a film thickness of 2.4 nm (24 cm). A conductive spacer layer S made of Cu, a pinned layer (pinned layer, fixed magnetic layer) P, and a capping layer C made of titanium (Ti) or tantalum (Ta) having a thickness of 2.5 nm (25 mm). ing.

  The free layer F is a layer whose magnetization direction changes according to the direction of the external magnetic field. The CoZrNb amorphous magnetic layer 21b-1 having a film thickness of 8 nm (80 cm) formed immediately above the substrate 11 and the CoZrNb amorphous magnetic layer are formed. The NiFe magnetic layer 21b-2 having a thickness of 3.3 nm (33 Å) formed on the layer 21b-1 and about 1 to 3 nm (10 to 30 Å) formed on the NiFe magnetic layer 21b-2 It consists of a CoFe layer 21b-3 having a thickness. The CoZrNb amorphous magnetic layer 21b-1 and the NiFe magnetic layer 21b-2 constitute a soft ferromagnetic thin film layer. The CoFe layer 21b-3 is provided to prevent diffusion of Ni in the NiFe layer 21b-2 and Cu21b-4 in the spacer layer S.

  The pinned layer P is a CoFe magnetic layer 21b-5 having a thickness of 2.2 nm (22 Å) and an antiferromagnetic film 21b-6 having a thickness of 24 nm (240 Å) formed from a PtMn alloy containing 45 to 55 mol% of Pt. Are superimposed. The CoFe magnetic layer 21b-5 is pinned in the X-axis direction (in this case, the X-axis negative direction) by being backed by an exchange coupling to the antiferromagnetic film 21b-6. It constitutes a pinned layer to be (fixed). As the antiferromagnetic film, NiMn, IrMn, MnRh, FeMn, or the like can be used in addition to PtMn.

  The bias magnet films 21e, 21f, 21g, 21h, 21i of the first X-axis GMR element 21 described above maintain the uniaxial anisotropy of the free layer F. Direction parallel to the direction (45 ° direction relative to the positive direction of the X-axis (45 ° means 45 ° clockwise in the figure, −45 ° is the direction opposite to the clockwise direction (counterclockwise) ) Means a 45 ° direction; the same applies hereinafter))). The CoFe magnetic layer 21b-5 (the same applies to the other GMR bars 21a, 21c, and 21d) is backed in an exchange-coupled manner to the antiferromagnetic film 21b-6, thereby causing the direction of magnetization (magnetization vector). However, the pinned layer is formed so as to be pinned (fixed) in the X-axis positive direction (the direction of the solid arrow a1 in FIG. 3A). Similarly, the bias magnet film of the second X-axis GMR element 22 applies a bias magnetic field in a direction parallel to the longitudinal direction of each GMR bar (direction of 45 ° with respect to the X-axis positive direction). The pinned layer is formed so that the direction of magnetization (magnetization vector) is pinned (fixed) in the positive X-axis direction (the direction of the solid arrow b1 in FIG. 3A).

  As a result, in the first X-axis GMR element 21 and the second X-axis GMR element 22, the direction of sensitivity of the magnetic field is − with respect to the direction perpendicular to the longitudinal direction of each GMR bar, that is, the positive X-axis direction. When the magnetic field is applied in the direction of 45 ° (in the direction of dotted arrows a2 and b2 in FIG. 3A) and in the directions of dotted arrows a2 and b2 in FIG. 3A, the first X-axis GMR element 21 and the first The resistance value of the 2X axis GMR element 22 decreases in proportion to the magnitude of the magnetic field, and the first X axis GMR element 21 is applied when a magnetic field is applied in the direction opposite to the directions of the dotted arrows a2 and b2 in FIG. The resistance value of the second X-axis GMR element 22 increases in proportion to the magnitude of the magnetic field.

  On the other hand, in the third X-axis GMR element 23 and the fourth X-axis GMR element 24, the bias magnet film is parallel to the longitudinal direction of each GMR bar in a direction opposite to the first X-axis GMR element 21 and the second X-axis GMR element 22 by 180 °. A bias magnetic field is applied in a certain direction (a direction of 45 ° with respect to the negative X-axis direction). The direction of magnetization (magnetization vector) is the negative direction of the X axis (the directions of solid arrows c1 and d1 in FIG. 3A), and the magnetization directions of the pinned layers of the first X axis GMR element 21 and the second X axis GMR element 22 A pinned layer is formed so as to be pinned (fixed) in the direction opposite to 180 °.

  Thereby, the direction of sensitivity of the magnetic field is the direction perpendicular to the longitudinal direction of each GMR bar, that is, the directions of the dotted arrows c2 and d2 in FIG. 3A (first X-axis GMR element 21 and second X-axis GMR element 22). When the magnetic field is applied in the directions of dotted arrows c2 and d2 in FIG. 3A, the resistance values of the third X-axis GMR element 23 and the fourth X-axis GMR element 24 are Decreases in proportion to the magnitude of the magnetic field, and the resistance of the third X-axis GMR element 23 and the fourth X-axis GMR element 24 when a magnetic field is applied in the direction opposite to the dotted arrows c2 and d2 in FIG. The value increases in proportion to the magnitude of the magnetic field.

  In the first Y-axis GMR element 31 and the second Y-axis GMR element 32, the bias magnet film is in a direction parallel to the longitudinal direction of each GMR bar (in the direction of 45 ° with respect to the Y-axis positive direction, that is, the first X A bias magnetic field is applied in a direction in which the bias magnetic fields of the axial GMR element 21 and the second X-axis GMR element 22 are rotated 90 ° counterclockwise. The pinned layer is formed so that the direction of magnetization (magnetization vector) is pinned (fixed) in the positive Y-axis direction (the direction of solid arrows e1 and f1 in FIG. 3A).

  Thereby, the direction of sensitivity of the magnetic field is a direction perpendicular to the longitudinal direction of each GMR bar, that is, a direction of −45 ° with respect to the positive direction of the Y axis (the directions of the dotted arrows e2 and f2 in FIG. 3A). When the magnetic field is applied in the directions of the dotted arrows e2 and f2 in FIG. 3A, the resistance values of the first Y-axis GMR element 31 and the second Y-axis GMR element 32 decrease in proportion to the magnitude of the magnetic field. When a magnetic field is applied in the direction opposite to the dotted arrows e2 and f2 in FIG. 3A, the resistance values of the first Y-axis GMR element 31 and the second Y-axis GMR element 32 are proportional to the magnitude of the magnetic field. Will increase.

  On the other hand, in the third Y-axis GMR element 33 and the fourth Y-axis GMR element 34, the bias magnet film is 180 ° opposite to the first Y-axis GMR element 31 and the second Y-axis GMR element 32 and parallel to the longitudinal direction of each GMR bar. The bias magnetic field is applied in a certain direction (a direction of 45 ° with respect to the negative Y-axis direction). The pinned layer is formed so that the direction of magnetization (magnetization vector) is pinned (fixed) in the negative Y-axis direction (the directions of solid arrows g1 and h1 in FIG. 3A).

  Thereby, the direction of sensitivity of the magnetic field is a direction perpendicular to the longitudinal direction of each GMR bar, that is, a direction of −45 ° with respect to the negative Y-axis direction (in the directions of dotted arrows g2 and h2 in FIG. 3A). When the magnetic field is applied in the directions of dotted arrows g2 and h2 in FIG. 3A, the first Y-axis GMR element 31 and the second Y-axis GMR element 32 are in the direction opposite to the magnetization direction of 180 °. The resistance values of the 3Y-axis GMR element 33 and the fourth Y-axis GMR element 34 decrease in proportion to the magnitude of the magnetic field, and when a magnetic field is applied in the direction opposite to the dotted arrows g2 and h2 in FIG. The resistance values of the third Y-axis GMR element 33 and the fourth Y-axis GMR element 34 increase in proportion to the magnitude of the magnetic field.

  In the first Z-axis GMR element 41 and the second Z-axis GMR element 42, as schematically shown in FIG. 3B, the bias magnet films 41f, 41g, 41h (42f, 42g, 42h) In the direction parallel to the longitudinal direction of the bars 41a, 41b, 41c, 41d (42a, 42b, 42c, 42d), that is, on the plane of each slope (inclination angle is approximately 45 °) of the protrusion (bank portion) 15, A bias magnetic field is applied in a direction in which the longitudinal direction is perpendicular to the X axis and parallel to the Y axis. Then, the direction of magnetization (magnetization vector) is pinned (fixed) in a direction inclined by 45 ° from the positive direction of the Z axis (the direction of the solid arrow i1 (j1) in FIG. 3B) toward the positive direction of the Y axis. Thus, a pinned layer is formed.

  These GMR bars 41a, 41b, 41c, 41d (42a, 42b, 42c, 42d) are connected in series by bias magnet films 41f, 41g, 41h (42f, 42g, 42h). Thereby, the direction of sensitivity of the magnetic field is a direction perpendicular to the longitudinal direction of each GMR bar and has a component in the positive Z-axis direction, and is in the direction of the dotted arrow i2 (j2) in FIG. When the magnetic field is applied in the direction of the dotted arrow i2 (j2) in FIG. 3B, the resistance values of the first Z-axis GMR element 41 and the second Z-axis GMR element 42 are the magnitude of the magnetic field. When the magnetic field is applied in the direction opposite to the dotted arrow i2 (j2) in FIG. 3B, the resistance values of the first Z-axis GMR element 41 and the second Z-axis GMR element 42 are reduced. Will increase in proportion to the size of.

  On the other hand, in the third Z-axis GMR element 43 and the fourth Z-axis GMR element 44, as schematically shown in FIG. 3C, the bias magnet films 43f, 43g, 43h (44f, 44g, 44h) In the direction parallel to the longitudinal direction of the bars 43a, 43b, 43c, 43d (44a, 44b, 44c, 44d), that is, on the plane of each slope (inclination angle is approximately 45 °) of the protrusion (bank portion) 15, A bias magnetic field is applied in a direction in which the longitudinal direction is perpendicular to the X axis and parallel to the Y axis. Then, the direction of magnetization (magnetization vector) is pinned (fixed) in a direction inclined by 45 ° from the negative Z-axis direction (the direction of the solid arrow k1 (l1) in FIG. 3C) toward the positive Y-axis direction. Thus, a pinned layer is formed.

  These GMR bars 43a, 43b, 43c, 43d (44a, 44b, 44c, 44d) are connected in series by bias magnet films 43f, 43g, 43h (44f, 44g, 44h). Thereby, the sensitivity direction of the magnetic field is a direction perpendicular to the longitudinal direction of each GMR bar, and has a component in the negative Z-axis direction, and is in the k2 (l2) direction of the dotted arrow in FIG. When the magnetic field is applied in the direction of the dotted arrow k2 (l2) in FIG. 3C, the resistance values of the third Z-axis GMR element 43 and the fourth Z-axis GMR element 44 are When a magnetic field is applied in the direction opposite to the dotted arrow k2 (l2) in FIG. 3C, the resistance value of the third Z-axis GMR element 43 and the fourth Z-axis GMR element 44 decreases in proportion to the magnitude. It increases in proportion to the magnitude of the magnetic field.

  The X-axis magnetic sensor is configured by full-bridge connection of the first to fourth X-axis GMR elements 21 to 24 as shown in an equivalent circuit in FIG. In FIG. 4A, the arrow indicates the direction of pinned magnetization of the pinned layer of each GMR element 21-24. In such a configuration, the pad 25 and the pad 26 are connected to the positive electrode and the negative electrode of the constant voltage source 29, and the potential Vxin + (3 V in this example) and the potential Vxin− (0 (V) in this example) are applied. The potentials of the pad 27 and the pad 28 are taken out as the potential Vxout + and the potential Vxout-, respectively, and the potential difference (Vxout + −Vxout−) is taken out as the sensor output Vxout.

  The Y-axis magnetic sensor is configured by full-bridge connection of the first to fourth Y-axis GMR elements 31 to 34 as shown in an equivalent circuit in FIG. The pad 35 and the pad 36 are connected to the positive electrode and the negative electrode of the constant voltage source 39, and a potential Vyin + (3 V in this example) and a potential Vyin- (0 (V) in this example) are applied. Is taken out as a sensor output Vyout.

  The Z-axis magnetic sensor is configured by full-bridge connection of the first to fourth Z-axis GMR elements 41 to 44 as shown in an equivalent circuit in FIG. The pad 45 and the pad 46 are connected to the positive electrode and the negative electrode of the constant voltage source 49, and a potential Vzin + (3 V in this example) and a potential Vzin− (0 (V) in this example) are applied. Is extracted as a sensor output Vzout.

  Next, a method for manufacturing a triaxial magnetic sensor having the above-described configuration will be described below based on schematic cross-sectional views in FIGS. 5 to 14, (a) shows a via portion, (b) shows a pad portion, and (c) shows a Z-axis GMR portion. In this case, as described above, as the substrate 11, it is desirable to use a substrate in which an LSI has been fabricated in advance by a CMOS process or a substrate in which only a wiring layer has been fabricated in advance.

In this method of manufacturing a triaxial magnetic sensor, as shown in FIG. 5, first, an interlayer insulating film made of a silicon oxide film or a silicon nitride film on a substrate (quartz substrate or silicon substrate) 11 on which a wiring layer 11a is formed. 11b is applied by SOG method or formed flat by CMP method. Thereafter, as shown in FIG. 6, the interlayer insulating film 11b on the via portion and the pad portion is removed by etching, and openings 11c and 11d are formed. Next, as shown in FIG. 7, an SiO ₂ film (thickness: 1500 mm) 11e and an Si ₃ N ₄ film (thickness: 5000 mm) 11f are formed on these surfaces by plasma CVD.

Next, a resist is applied on these and cut into a pattern that forms openings in the via part and the pad part. Next, as shown in FIG. 8, after removing the Si ₃ N ₄ film 11f on the via portion and the pad portion by etching, the resist is removed. Thereby, openings 11g and 11h are formed on the via part and the pad part, but the SiO ₂ film 11e is left without being etched. In this case, the opening widths of the openings 11g and 11h are made smaller than the opening widths of the openings 11c and 11d. This is to prevent the interlayer insulating film 11b from being exposed in the openings 11c and 11d and preventing moisture from entering the wiring layer and the LSI.

Thereafter, as shown in FIG. 9, a SiO ₂ film (thickness: 5 μm) 11i is formed thereon by plasma CVD. Next, a resist is applied on these to form a resist film (thickness: 5 μm) 11j. Then, a pattern for forming openings in the via portion and the pad portion is cut in the formed resist film (thickness: 5 μm) 11j, and projections for arranging the Z-axis GMR elements 41, 42, 43, 44 ( A pattern for forming the bank portion 15 is cut. After the cutting, a heat treatment is performed at a temperature of 150 ° C. for 10 minutes, so that the corners of the resist 11j are tapered (tapered) as shown in FIG.

Thereafter, the SiO ₂ film (thickness: 5 μm) 11i and the resist film (thickness: 5 μm) 11j are etched at approximately the same ratio, and a thickness of about 5000 mm remains at the maximum thickness portion of the etched SiO ₂ film 11i. Dry etching is performed under various conditions. At this time, the opening size in the via portion and the pad portion of the SiO ₂ film 11i is set not to be larger than the opening size in the via portion and the pad portion of the Si ₃ N ₄ film 11f. After dry etching, the remaining resist is removed. As a result, as shown in FIG. 11, a protrusion (bank portion) 15 made of the SiO ₂ film 11i is formed in the GMR portion.

  Next, a resist is applied on these, and the resist is cut into a pattern for forming an opening in the via portion, and then etched. Thereafter, the remaining resist is removed, thereby forming an opening 11k in the via portion and exposing the uppermost wiring layer 11a of the substrate 11 as shown in FIG. Next, a base film made of Ti or Cr (film thickness is 300 μm) is formed by sputtering.

  Next, a bias magnet film 11m (later, for example, 21e, 21f, 21g, 21h, and 21i shown in FIG. 2A) is formed by sputtering using a hard ferromagnetic material made of a material such as CoCrPt and having a high coercive force. It is formed on the surface of the base film by a vacuum deposition method, an ion plating method or the like. After applying a resist on these and cutting this resist into a bias magnet film pattern, the bias magnet film 11m and the underlying film are etched. Before the etching, in order to appropriately perform the etching on the slope portion of the protrusion (bank portion) 15, it is desirable to perform a heat treatment to reflow the resist and round the corners of the resist end. Thereafter, the remaining resist is removed. Next, a GMR multilayer film 11n (which will later become 21-24, 31-34, 41-44, etc.) forming a GMR element is formed on these surfaces by sputtering.

  As shown in FIG. 2C, the GMR multilayer film 11n has a free layer (free layer, free magnetic layer) F sequentially stacked on the substrate 11, and a film thickness of 2.4 nm (24 cm). A conductive spacer layer S made of Cu, a pinned layer (fixed layer, fixed magnetic layer) P, and a capping layer C made of titanium (Ti) or tantalum (Ta) having a film thickness of 2.5 nm (25 mm). Yes. The free layer F includes a CoZrNb amorphous magnetic layer 21b-1 having a film thickness of 8 nm (80 mm) formed immediately above the substrate 11, a NiFe magnetic layer 21b-2 having a film thickness of 3.3 nm (33 mm), The CoFe layer 21b-3 has a thickness of about 1 to 3 nm (10 to 30 mm). The CoZrNb amorphous magnetic layer 21b-1 and the NiFe magnetic layer 21b-2 constitute a soft ferromagnetic thin film layer. On the other hand, the pinned layer P is formed by superposing a CoFe magnetic layer 21b-5 having a thickness of 2.2 nm (22 Å) and an antiferromagnetic film 21b-6 having a thickness of 24 nm (240 Å).

  Next, a regular magnetizing heat treatment (pinning treatment) is performed by bringing a permanent magnet array close to the obtained laminate, and the magnetization direction of the pinned layer P is fixed. In this case, as shown schematically in FIG. 15, the regularized heat treatment (pinning process) is a permanent bar magnet array arranged in a grid so that the polarities of the upper ends (lower ends) of adjacent permanent bar magnet pieces are different from each other. The (magnet array) is arranged such that the N pole is disposed on the center of the left region from the center of the substrate 11 and the S pole is disposed on the center of the right region from the center of the substrate 11. Place and do.

  As is clear from FIG. 15 (FIG. 15 shows a state in which only six permanent magnet pieces are disposed), the permanent bar magnet disposed on the central portion of the left region from the central portion of the substrate 11. On the lower surface of the piece, magnetic fields having different directions by 90 ° from one N pole to the S pole adjacent to the N pole at the shortest distance are formed. On the other hand, on the lower surface of the permanent bar magnet piece arranged on the right side region from the center of the substrate 11, the direction is 90 ° from one S pole to the N pole adjacent to the S pole at the shortest distance. However, different magnetic fields are formed. A heat treatment is performed to fix the magnetization direction of the pinned layer P (the pinned layer of the pinned layer P) using such a magnetic field. That is, in the state shown in FIG. 15, the substrate 11 and the permanent bar magnet array (magnet array) are fixed, these are heated to 60 ° C. to 290 ° C. in a vacuum, and left in that state for about 4 hours. In the case of PtMn or NiMn, they are ordered (pinned) by this heat treatment in a magnetic field. When using IrMn, MnRh, FeMn, etc., the optimum magnetic field, temperature, time, etc. may be adjusted.

  As a result, as shown in FIG. 3, in the first X-axis GMR element 21 and the second X-axis GMR element 22, the magnetization direction of the pinned layer is fixed in the directions a1 and b1 in FIG. In the axial GMR element 23 and the fourth X-axis GMR element 24, the magnetization direction of the pinned layer is fixed in the c1 and d1 directions in FIG. In the first Y-axis GMR element 31 and the second Y-axis GMR element 32, the magnetization direction of the pinned layer is fixed in the e1 and f1 directions in FIG. 3A, and the third Y-axis GMR element 33 and the fourth Y-axis GMR In the element 34, the magnetization direction of the pinned layer is fixed in the g1 and h1 directions in FIG. Further, in the first Z-axis GMR element 41 and the second Z-axis GMR element 42, the magnetization direction of the pinned layer is fixed in the direction inclined 45 ° from the X axis in the positive direction of the Z axis within the slope of the protrusion (bank) 15. In the third Z-axis GMR element 43 and the fourth Z-axis GMR element 44, the magnetization direction of the pinned layer is fixed in a direction inclined 45 ° from the X axis in the negative Z-axis direction within the slope of the protrusion (bank) 15. Will be.

  Thereafter, a resist is applied on the surface of the GMR multilayer film 11n so as to have an arbitrary thickness, for example, 2 μm in a flat portion, a mask is disposed on the resist surface, and baking and development are performed. Unnecessary resist is removed, and a resist film having the same pattern as the GMR multilayer film 11n obtained later is formed. At that time, the resist is tapered in order to appropriately perform the etching at the projecting portion (bank portion) 15. Thereafter, the portion of the GMR multilayer film 11n not protected by the resist film is removed by ion milling to form the GMR multilayer film 11n in a predetermined shape (for example, a plurality of narrow strips). At that time, both the GMR multilayer film 11n and the bias magnet film 11m remain in the via portion. This is to prevent disconnection at the edge of the via portion.

Next, the resist film is removed, and a Si ₃ N ₄ film 11o having a thickness of 10,000 mm is formed thereon by plasma CVD, and then a polyimide film 11p is formed thereon to form a protective film. did. Next, using the polyimide film 11p on the pad portion as a mask, the Si ₃ N ₄ film 11o on the pad portion is removed by etching to open the pad portion to form each pad and to form a wiring for connecting these pads. Finally, the substrate 11 is cut. As described above, the triaxial magnetic sensor 10 of the first embodiment shown in FIG. 1 is manufactured.

<Modification>
The three-axis magnetic sensor of the first embodiment described above can be modified by adding various modifications to the arrangement relationship of the GMR elements. Hereinafter, a typical modification of the three-axis magnetic sensor according to the first embodiment will be briefly described with reference to FIG. It should be noted that which of the arrangement relationships of the GMR elements of the first embodiment or the arrangement relations of the GMR elements of the following modifications is appropriately selected depending on the LSI circuit or the like formed on the substrate. You just have to do it.

<First Modification>
FIG. 16A is a schematic configuration diagram schematically showing the three-axis magnetic sensor 50a of the first modified example. In the first modified example, the arrangement relation of the Z-axis GMR elements is modified. That is, as shown in FIG. 16A, the first Z-axis GMR element 51i is a substantially intermediate portion from the Y-axis central portion of the substrate 51 to the upper end portion of the Y-axis, and the right-hand end of the X-axis from the X-axis central portion. The second Z-axis GMR element 51j is arranged on the left side of the substantially intermediate part to the right side. Further, the third Z-axis GMR element 51k is positioned at a substantially intermediate portion from the Y-axis central portion of the substrate 51 to the lower end portion of the Y-axis, and to the left of a substantially intermediate portion from the X-axis central portion to the left end portion of the X-axis. The fourth Z-axis GMR element 51l is arranged on the right side. In this case, the X-axis GMR elements 51a to 51d and the Y-axis GMR elements 51e to 51h are the same as the X-axis GMR elements 21 to 24 and the Y-axis GMR elements 31 to 34 of the first embodiment.

<Second modification>
FIG. 16B is a schematic configuration diagram schematically showing a three-axis magnetic sensor 50b according to the second modification. In the second modification, the arrangement relationship of the Y-axis GMR elements is modified. That is, as shown in FIG. 16B, the first Y-axis GMR element 52e is positioned in the vicinity of the upper end of the Y-axis of the substrate 52 to the right of the middle part from the X-axis center to the right-side end of the X-axis. The second Y-axis GMR element 52f is arranged on the left side. Further, the third Y-axis GMR element 52g is disposed in the vicinity of the lower end portion of the Y-axis of the substrate 52 at the right side of the X-axis central portion to the right end portion of the X-axis, and the fourth Y-axis is provided on the left side. An axial GMR element 52h is arranged. In this case, the X-axis GMR elements 52a to 52d and the Z-axis GMR elements 52i to 52l are the same as the X-axis GMR elements 21 to 24 and the Z-axis GMR elements 41 to 44 of the first embodiment described above.

<Third Modification>
FIG. 16C is a schematic configuration diagram schematically showing the three-axis magnetic sensor 50c of the third modification. In the third modification, the arrangement relationship of the X-axis GMR elements is modified. That is, as shown in FIG. 16C, the first X-axis GMR element 53a is disposed near the right end of the X-axis of the substrate 53 and above the Y-axis central portion, and the second X-axis GMR element 53b is disposed below the first X-axis GMR element 53b. I try to arrange it. Further, the third X-axis GMR element 53c is arranged at the X-axis central portion of the substrate 53 above the Y-axis central portion, and below the fourth X-axis GMR element 53d. In this case, the Y-axis GMR elements 53e to 53h and the Z-axis GMR elements 53i to 53l are the same as the Y-axis GMR elements 31 to 34 and the Z-axis GMR elements 41 to 44 of the first embodiment described above.

<Fourth modification>
FIG. 16D is a schematic configuration diagram schematically showing a three-axis magnetic sensor 50d of the fourth modified example. In this fourth modified example, the arrangement relationship between the Y-axis GMR element and the Z-axis GMR element is modified. Added. That is, as shown in FIG. 16D, the first Y-axis GMR element 54e is placed near the upper end of the Y-axis of the substrate 54 and to the right of the middle part from the X-axis center to the left-side end of the X-axis. The second Y-axis GMR element 54f is arranged on the left side. Further, the third Y-axis GMR element 54g is arranged in the vicinity of the upper end portion of the Y-axis of the substrate 54, to the right of the middle part from the X-axis central portion to the right-side end portion of the X-axis, and on the left side, the fourth Y-axis The GMR element 54h is arranged. Further, the first Z-axis GMR element 54i is disposed at a substantially intermediate portion from the Y-axis central portion of the substrate 54 to the upper end portion of the Y-axis, and to the left of a substantially intermediate portion from the X-axis central portion to the right end portion of the X-axis. The second Z-axis GMR element 54j is arranged on the right side. In addition, the third Z-axis GMR element 54k is disposed at a substantially intermediate portion from the Y-axis center portion of the substrate 54 to the lower end portion of the Y-axis, and to the left of a substantially intermediate portion from the X-axis center portion to the left end portion of the X-axis. The fourth Z-axis GMR element 54l is arranged on the right side. In this case, the X-axis GMR elements 54a to 54d are the same as the X-axis GMR elements 21 to 24 of the first embodiment described above.

2. Example 2
Next, the triaxial magnetic sensor of Example 2 will be described below with reference to FIGS. FIG. 17 is a schematic configuration diagram showing the three-axis magnetic sensor of Example 2, FIG. 17 (a) is a plan view, and FIG. 17 (b) is a cross-sectional view showing the AA cross section of FIG. 17 (a). FIG. 18 is a diagram schematically showing the pinning direction and sensitivity direction of the triaxial magnetic sensor of FIG. 17, and FIG. 18 (a) is a plan view schematically showing the entire plane, and FIG. 18 (b). FIG. 18 is a perspective view schematically showing an enlarged portion A of FIG. 18A, and FIG. 18C is a perspective view schematically showing an enlarged portion B of FIG. .

  FIG. 19 is a block diagram showing the bridge connection, FIG. 19 (a) is a block diagram showing the bridge connection of the X-axis sensor, and FIG. 19 (b) is a block diagram showing the bridge connection of the Y-axis sensor. FIG. 19C is a block diagram showing the bridge connection of the Z-axis sensor. FIG. 20 is a diagram schematically showing a state of ordered heat treatment (pinning treatment), FIG. 20 (a) is a plan view, and FIG. 20 (b) is a cross-sectional view taken along line AA in FIG. 20 (a). FIG. 20C is a cross-sectional view showing the BB cross section of FIG.

  As shown in FIG. 17, the triaxial magnetic sensor 60 according to the second embodiment has a rectangular shape (here, a short side (vertical) and a long side) having sides along the X axis and the Y axis that are orthogonal to each other in a plan view. (Horizontal) ratio (aspect ratio) is 1: 1.5, the side along the X-axis is the long side, and the side along the Y-axis is the short side) A substrate 61 made of quartz or silicon having a small thickness in the Z-axis direction orthogonal to the axis and the Y-axis is provided. By using such a substrate 61, it is possible to achieve a smaller size than the triaxial magnetic sensor of the first embodiment.

  On the substrate 61, a total of 12 GMR elements each consisting of four X-axis GMR elements 61a to 61d, Y-axis GMR elements 61e to 61h, and Z-axis GMR elements 61i to 61l, Twelve pads (not shown) and connection lines (not shown) for connecting each pad and each element are formed. In the substrate 61, an LSI and a wiring layer are formed in the same manner as the substrate 11 of the first embodiment described above. A digital output magnetic sensor is used in a substrate using the substrate in which the LSI is formed. In the case of using a substrate on which only a wiring layer is formed, an analog output magnetic sensor is formed.

  Here, the X-axis GMR element includes a first X-axis GMR element 61a, a second X-axis GMR element 61b, a third X-axis GMR element 61c, and a fourth X-axis GMR element 61d. The first X-axis GMR element 61a is disposed above the Y-axis central portion at approximately 2/3 of the substrate 61 from the left end to the right end of the X-axis, and the second X-axis GMR element 61b is disposed below the first X-axis GMR element 61b. Has been. In addition, a third X-axis GMR element 61c is disposed near the left end of the X-axis of the substrate 61 and above the Y-axis center, and a fourth X-axis GMR element 61d is disposed below the third X-axis GMR element 61d.

  The Y-axis GMR element includes a first Y-axis GMR element 61e, a second Y-axis GMR element 61f, a third Y-axis GMR element 61g, and a fourth Y-axis GMR element 61h. The first Y-axis GMR element 61e is disposed in the vicinity of the upper end of the Y-axis of the substrate 61, approximately 1/3 of the X-axis from the left end to the right end of the X-axis, and the second Y on the left. An axis GMR element 61f is arranged. A third Y-axis GMR element 61g is arranged in the vicinity of the lower end of the Y-axis of the substrate 61, approximately 1/3 part to the right from the left-side end of the X-axis to the right-side end. A 4Y-axis GMR element 61h is arranged.

  Further, the Z-axis GMR element includes a first Z-axis GMR element 61i, a second Z-axis GMR element 61j, a third Z-axis GMR element 61k, and a fourth Z-axis GMR element 61l. The first Z-axis GMR element 61i is disposed above the center of the Y-axis at an intermediate portion between approximately 2/3 and the right-hand end of the substrate 61 from the left end to the right end of the X axis. The second Z-axis GMR element 61j is disposed at the center. A third Z-axis GMR element 61k is disposed above the center of the Y axis at an intermediate portion between approximately 1/3 and 2/3 from the left end of the X axis toward the right end of the substrate 61. A fourth Z-axis GMR element 61l is disposed below.

Each of the GMR elements 61a to 61d, 61e to 61h, and 61i to 61l includes four GMR bars arranged in parallel and adjacent to each other in a strip shape, and these four GMR bars are magnet films (bias magnet films). ) In series, and a magnet film serving as a terminal portion is connected to these end portions.
In this case, each GMR bar of the X-axis GMR elements 61a to 61d is formed on a plane parallel to the surface of the substrate 61, and is arranged so that its longitudinal direction is at an angle of 45 ° with respect to the X-axis. ing. The GMR bars of the Y-axis GMR elements 61e to 61h are formed on a plane parallel to the surface of the substrate 61, and the longitudinal direction thereof is orthogonal to the GMR bars of the X-axis GMR elements 61a to 61d. It is arranged.

  Further, each of the GMR bars of the Z-axis GMR elements 61i to 61l has a plurality of trapezoidal cross sections formed on the substrate 61 as shown in FIGS. 17 (b), 18 (b) and 18 (c). One GMR bar (61i-1, 61i-2, 61i-3, 61i-4) on one inclined surface (inclination angle of approximately 45 °) is formed on each inclined surface of the protrusion (bank portion) 65. (61j-1, 61j-2, 61j-3, 61j-4) or 61k-1, 61k-2, 61k-3, 61k-4 (61l-1, 61l-2, 61l-3, 61l-4) )) Is formed, and is arranged so that its longitudinal direction is parallel to the X axis and perpendicular to the Y axis.

 In the triaxial magnetic sensor 60 of the second embodiment, the substrate 61 is 2/3 the size of the substrate 11 of the first embodiment, and the arrangement positions of the Z-axis GMR elements 61i to 61l are different. Although it is different from the triaxial magnetic sensor 10 of Example 1, other configurations are the same as those of the triaxial magnetic sensor 10 of Example 1.

  In this case, in the X-axis GMR elements 61a and 61b, the bias magnet film applies a bias magnetic field in a direction parallel to the longitudinal direction of each GMR bar (a direction of 45 ° with respect to the X-axis positive direction). The pinned layer is formed so that the direction of magnetization (magnetization vector) is pinned (fixed) in the positive direction of the X axis (the directions of solid arrows a1 and b1 in FIG. 18A). In the third X-axis GMR element 61c and the fourth X-axis GMR element 61d, the bias magnet film applies a bias magnetic field in a direction parallel to the longitudinal direction of each GMR bar (45 ° direction with respect to the negative X-axis direction). Giving. The direction of magnetization (magnetization vector) is 180 ° from the direction of magnetization of the first X-axis GMR element 61a and the second X-axis GMR element 61b in the X-axis negative direction (the directions of solid arrows c1 and d1 in FIG. 18A). A pinned layer is formed so as to be pinned (fixed) in the opposite direction.

  Therefore, in the first X-axis GMR element 61a and the second X-axis GMR element 61b, the sensitivity direction of the magnetic field is a direction perpendicular to the longitudinal direction of each GMR bar, that is, −45 ° with respect to the X-axis positive direction. Direction (direction of dotted arrows a2 and b2 in FIG. 18A). On the other hand, in the third X-axis GMR element 61c and the fourth X-axis GMR element 61d, the magnetic field sensitivity direction is −45 ° with respect to the direction perpendicular to the longitudinal direction of each GMR bar, that is, the negative X-axis direction. Direction (direction opposite to the sensitivity direction of the first X-axis GMR element 61a and the second X-axis GMR element 61b in the directions of the dotted arrows c2 and d2 in FIG. 18A).

  In the first Y-axis GMR element 61e and the second Y-axis GMR element 61f, the bias magnet film has a direction parallel to the longitudinal direction of each GMR bar (a direction of 45 ° with respect to the Y-axis positive direction, that is, the X-axis The bias magnetic field is applied in the direction in which the bias magnetic field of the GMR elements 61a to 61b is rotated 90 ° counterclockwise. The pinned layer is formed so that the direction of magnetization (magnetization vector) is pinned (fixed) in the positive Y-axis direction (the directions of solid arrows e1 and f1 in FIG. 18A). On the other hand, in the third Y-axis GMR element 61g and the fourth Y-axis GMR element 61h, the bias magnet film is 180 ° opposite to the first Y-axis GMR element 61e and the second Y-axis GMR element 61f and in the longitudinal direction of each GMR bar. A bias magnetic field is applied in a parallel direction (a direction of 45 ° with respect to the Y-axis negative direction). The pinned layer is formed so that the direction of magnetization (magnetization vector) is pinned (fixed) in the negative Y-axis direction (the directions of solid arrows g1 and h1 in FIG. 18A).

  Therefore, in the first Y-axis GMR element 61e and the second Y-axis GMR element 61f, the magnetic field sensitivity direction is a direction perpendicular to the longitudinal direction of each GMR bar, that is, a direction of −45 ° with respect to the Y-axis positive direction ( This is the direction of the dotted arrows e2 and f2 in FIG. On the other hand, in the third Y-axis GMR element 61g and the fourth Y-axis GMR element 61h, the direction perpendicular to the longitudinal direction of each GMR bar, that is, the direction of −45 ° with respect to the Y-axis negative direction (FIG. ) In the directions of dotted arrows g2 and h2 (the direction of magnetization opposite to the direction of magnetization of the first Y-axis GMR element 61e and the second Y-axis GMR element 61f).

  In the first Z-axis GMR element 61i and the second Z-axis GMR element 61j, as schematically shown in FIG. 18B, the bias magnet films 61i-5, 61i-6, 61i-7 (61j-5, 61j-6, 61j-7) are parallel to the longitudinal direction of each GMR bar 61i-1, 61i-2, 61i-3, 61i-4 (61j-1, 61j-2, 61j-3, 61j-4). A bias magnetic field is applied in a direction that is parallel to the X axis and perpendicular to the Y axis on a flat surface, that is, on the plane of each slope (inclination angle is approximately 45 °) of the protrusion (bank) 65 ing. Then, the direction of magnetization (magnetization vector) is inclined by 45 ° from the Z-axis positive direction toward the X-axis positive direction within each inclined surface of the protrusion (bank portion) 65 (solid arrow i1 in FIG. 18B ( A pinned layer is formed so as to be pinned (fixed) in the direction j1).

  The GMR bars 61i-1, 61i-2, 61i-3, 61i-4 (61j-1, 61j-2, 61j-3, 61j-4) are bias magnet films 61i-5, 61i-6. , 61i-7 (61j-5, 61j-6, 61j-7). Thereby, the direction of sensitivity of the magnetic field is a direction perpendicular to the longitudinal direction of each GMR bar and has a component in the positive Z-axis direction, and is in the direction of the dotted arrow i2 (j2) in FIG. When the magnetic field is applied in the direction of the dotted arrow i2 (j2) in FIG. 18B, the resistance values of the first Z-axis GMR element 61i and the second Z-axis GMR element 61j are the magnitude of the magnetic field. When the magnetic field is applied in the direction opposite to the dotted arrow i2 (j2) in FIG. 18B, the resistance values of the first Z-axis GMR element 61i and the second Z-axis GMR element 61j Will increase in proportion to the size of.

  On the other hand, in the third Z-axis GMR element 61k and the fourth Z-axis GMR element 61l, as schematically shown in FIG. 18C, the bias magnet films 61k-5, 61k-6, 61k-7 (61l-5, 61l-6, 61l-7) are parallel to the longitudinal direction of each GMR bar 61k-1, 61k-2, 61k-3, 61k-4 (61l-1, 61l-2, 61l-3, 61l-4). A bias magnetic field is applied in a direction that is parallel to the X axis and perpendicular to the Y axis on a flat surface, that is, on the plane of each slope (inclination angle is approximately 45 °) of the protrusion (bank) 65 ing. Then, the direction of magnetization (magnetization vector) is inclined by 45 ° from the Z-axis negative direction toward the X-axis positive direction within each slope of the projection (bank) 65 (solid line arrow k1 (FIG. 18C)). The pinned layer is formed so as to be pinned (fixed) in the direction l1).

  These GMR bars 61k-1, 61k-2, 61k-3, 61k-4 (61l-1, 61l-2, 61l-3, 61l-4) are bias magnet films 61k-5, 61k-6. , 61k-7 (61l-5, 61l-6, 61l-7). Thereby, the sensitivity direction of the magnetic field is a direction perpendicular to the longitudinal direction of each GMR bar and has a component in the negative Z-axis direction, and is in the k2 (l2) direction of the dotted arrow in FIG. When the magnetic field is applied in the direction of the dotted arrow k2 (l2) in FIG. 18C, the resistance values of the third Z-axis GMR element 61k and the fourth Z-axis GMR element 61l are When a magnetic field is applied in the direction opposite to the dotted arrow k2 (l2) in FIG. 18C, the resistance value of the third Z-axis GMR element 61k and the fourth Z-axis GMR element 61l decreases in proportion to the magnitude. It increases in proportion to the magnitude of the magnetic field.

  The X-axis magnetic sensor is configured by full-bridge connection of first to fourth X-axis GMR elements 61a to 61d as shown in an equivalent circuit in FIG. In FIG. 19A, arrows indicate the pinned magnetization directions of the pinned layers of the GMR elements 61a to 61d. In such a configuration, the pad 62a and the pad 62b are connected to the positive electrode and the negative electrode of the constant voltage source 62e, and a potential Vxin + (3 V in this example) and a potential Vxin− (0 (V) in this example) are applied. The potentials of the pad 62c and the pad 62d are taken out as the potential Vxout + and the potential Vxout-, respectively, and the potential difference (Vxout + −Vxout−) is taken out as the sensor output Vxout.

  The Y-axis magnetic sensor is configured by full-bridge connection of the first to fourth Y-axis GMR elements 61e to 61h, as shown in an equivalent circuit in FIG. The pad 63a and the pad 63b are connected to the positive electrode and the negative electrode of the constant voltage source 63e, and a potential Vyin + (3 V in this example) and a potential Vyin− (0 (V) in this example) are applied, and the pad 63c and the pad 63d. Is taken out as a sensor output Vyout.

  The Z-axis magnetic sensor is configured by full-bridge connection of the first to fourth Z-axis GMR elements 61i to 61l as shown in an equivalent circuit in FIG. The pad 64a and the pad 64b are connected to the positive electrode and the negative electrode of the constant voltage source 64e, and a potential Vyin + (3 V in this example) and a potential Vyin- (0 (V) in this example) are applied, and the pad 64c and the pad 64d. Is taken out as a sensor output Vyout.

  In addition, since it is substantially the same as the manufacturing method of the triaxial magnetic sensor 10 of Example 1 mentioned above when manufacturing the triaxial magnetic sensor 60 of this Example 2, description about the manufacturing method is abbreviate | omitted. However, the regularizing heat treatment (pinning treatment) will be briefly described below.

  In the regularized heat treatment (pinning process) in manufacturing the triaxial magnetic sensor 60 of the second embodiment, as shown schematically in FIG. 20, the polarities of the upper ends (lower ends) of adjacent permanent bar magnet pieces are mutually different. A permanent bar magnet array (magnet array) arranged in a grid pattern so as to be different is prepared. Using this, the N pole is centered on the point where the line dividing the long side of the substrate 61 by 1/3 with respect to the left edge of the substrate in the drawing intersects with the line dividing the short side of the substrate 61 by 1/2. The S poles are arranged symmetrically in the vertical and horizontal directions around the N pole. The upper and lower S poles and one of the left and right S poles are disposed outside the substrate 61, but the center of the left and right S poles is disposed on the short side of the substrate 61. As a result, as shown in FIG. 18, a magnetic field in the positive X-axis direction is applied to the first X-axis GMR element 61a and the second X-axis GMR element 61b, and in the third X-axis GMR element 61c and the fourth X-axis GMR element 61d, A magnetic field in the negative direction of the X axis is applied.

In addition, a magnetic field in the Y-axis positive direction is applied to the first Y-axis GMR element 61e and the second Y-axis GMR element 61f, and a magnetic field in the Y-axis negative direction is applied to the third Y-axis GMR element 61g and the fourth Y-axis GMR element 61h. It becomes. Further, in the first Z-axis GMR element 61i and the second Z-axis GMR element 61j, a magnetic field in a direction inclined by 45 ° from the positive X-axis direction to the positive Z-axis direction is applied within the slope of the protrusion (bank) 65, In the axial GMR element 61k and the fourth Z-axis GMR element 61l, a magnetic field in a direction inclined by 45 ° from the positive X-axis direction to the negative Z-axis direction is applied within the slope of the protrusion (bank) 65.
20A, 20B, and 20C show an example in which the S pole is on the right short side of the substrate 61. In the substrate adjacent to the right, the S pole is the left short side of the substrate. Placed on top. If this substrate (chip) is rotated 180 degrees, it becomes the same as that obtained in FIGS. 20 (a), (b) and (c). Moreover, in the board | substrate adjacent up and down, a north-pole will be on the right short side of a board | substrate. Since the magnetic field of the substrate (chip) is reversed, the signs of the chip and output described in FIGS. 20A, 20B, and 20C are reversed.

3. Example 3
Next, the triaxial magnetic sensor of Example 3 will be described below with reference to FIGS. FIG. 21 is a schematic configuration diagram illustrating the three-axis magnetic sensor according to the third embodiment. FIG. 21A is a plan view, and FIG. 21B is a cross-sectional view taken along line AA in FIG. FIG. 22 is a diagram schematically showing the pinning direction and sensitivity direction of the three-axis magnetic sensor of FIG. 21, and FIG. 22 (a) is a plan view schematically showing the entire plane, and FIG. 22 (b). FIG. 22 is a perspective view schematically showing an enlarged A part of FIG. 22 (a). FIG. 23 is a block diagram showing the bridge connection, FIG. 23 (a) is a block diagram showing the bridge connection of the X-axis sensor, and FIG. 23 (b) is a block diagram showing the bridge connection of the Y-axis sensor. FIG. 23C is a block diagram showing the bridge connection of the Z-axis sensor. FIG. 24 is a diagram schematically showing a state of ordered heat treatment (pinning treatment), FIG. 24 (a) is a plan view, and FIG. 24 (b) is a cross-sectional view taken along line AA in FIG. 24 (a). FIG.

  As shown in FIG. 21, the triaxial magnetic sensor 70 according to the third embodiment has a square shape having sides along the X axis and the Y axis that are orthogonal to each other in plan view (that is, the substrate 11 according to the first embodiment described above). And a substrate 71 made of a quartz substrate or a silicon substrate having a small thickness in the Z-axis direction perpendicular to the X-axis and the Y-axis. In addition, by using such a board | substrate 71, it becomes possible to achieve further size reduction compared with the triaxial magnetic sensor of Example 1, and the triaxial magnetic sensor of Example 2. FIG.

  A total of ten X-axis GMR elements 71a to 71d and Y-axis GMR elements 71e to 71h formed on the substrate 71 and two Z-axis GMR elements 71i to 71j are formed. GMR element, two nonmagnetic resistors 71k to 71l, a total of twelve pads (not shown) formed on the substrate 71, and connection lines for connecting each pad to each element (not shown) (Not shown). An LSI and a wiring layer are formed in the substrate 71 in the same manner as the substrate 11 in the first embodiment described above. A digital output magnetic sensor is used in a substrate using the substrate in which the LSI is formed. In the case of using a substrate on which only a wiring layer is formed, an analog output magnetic sensor is formed.

  Here, the X-axis GMR element includes a first X-axis GMR element 71a, a second X-axis GMR element 71b, a third X-axis GMR element 71c, and a fourth X-axis GMR element 71d. In the vicinity of the right end of the X axis, the first X axis GMR element 71a is disposed above the Y axis center, and the second X axis GMR element 71b is disposed below the first X axis GMR element 71b. Further, in the vicinity of the left end portion of the X axis, the third X axis GMR element 71c is disposed above the Y axis center, and the fourth X axis GMR element 71d is disposed below the third X axis GMR element 71d.

  The Y-axis GMR element includes a first Y-axis GMR element 71e, a second Y-axis GMR element 71f, a third Y-axis GMR element 71g, and a fourth Y-axis GMR element 71h. A first Y-axis GMR element 71e is arranged on the right side of the X-axis center near the upper end of the Y-axis, and a second Y-axis GMR element 71f is arranged on the left side. In addition, a third Y-axis GMR element 71g is disposed on the right side of the X-axis center near the lower end of the Y-axis, and a fourth Y-axis GMR element 71h is disposed on the left.

  Further, the Z-axis GMR element includes a first Z-axis GMR element 71i and a second Z-axis GMR element 71j, a first nonmagnetic resistor 71k for bridge connection with these, a second nonmagnetic resistor 71l, It is comprised by. The first Z-axis GMR element 71j is arranged on the left side of the X-axis central part and the second Z-axis GMR element 71j is arranged on the right side of the middle part from the Y-axis central part to the upper end of the Y-axis. Yes. In addition, a first nonmagnetic resistor 71k is disposed on the left side of the X-axis central portion at the intermediate portion from the Y-axis central portion to the lower end portion of the Y-axis, and a second nonmagnetic resistor 71l is disposed on the right side thereof. Has been placed.

Each of the GMR elements 71a to 71d, 71e to 71h and 71i and 71j includes four GMR bars arranged in parallel and adjacent to each other in a strip shape, and these four GMR bars are magnet films (bias magnet films). ) In series, and a magnet film serving as a terminal portion is connected to these end portions.
In this case, each GMR bar of the X-axis GMR elements 71a to 71d is formed on a plane parallel to the surface of the substrate 71, and is arranged so that its longitudinal direction is at an angle of 45 ° with respect to the X-axis. ing. Each GMR bar of the Y-axis GMR elements 71e to 71h is formed on a plane parallel to the surface of the substrate 71, and its longitudinal direction intersects with each GMR bar of the X-axis GMR elements 71a to 71d. They are arranged (in this case so as to be orthogonal).

  Further, each GMR bar of the Z-axis GMR elements 71i, 71j has a plurality of protrusions (the cross-sectional shape formed on the substrate 71 having a trapezoidal shape (see FIG. 21B and FIG. 22B)). On each slope of the levee portion) 75, one GMR bar 71i-1, 71i-2, 71i-3, 71i-4 (71j-1) is provided on one slope (the inclination angle is formed to be approximately 45 °). , 71j-2, 71j-3, 71j-4) are arranged so that the longitudinal direction thereof is perpendicular to the X axis and parallel to the Y axis. The nonmagnetic resistors 71k to 71l are formed on a plane parallel to the surface of the substrate 71, and are arranged so that the longitudinal direction thereof is perpendicular to the X axis and parallel to the Y axis. ing.

 In the three-axis magnetic sensor 70 of the third embodiment, the substrate 71 is square and is half the size of the substrate 11 of the first embodiment described above, two Z-axis GMR elements 71i to 71j, 2 Although it is different from the triaxial magnetic sensor 10 of the first embodiment described above in that the nonmagnetic resistors 71k to 71l are provided, the other configurations are the same as those of the triaxial magnetic sensor 10 of the first embodiment described above. Become.

  In this case, in the X-axis GMR elements 71a and 71b, the bias magnet film applies a bias magnetic field in a direction parallel to the longitudinal direction of each GMR bar (a direction of 45 ° with respect to the X-axis positive direction). The pinned layer is formed so that the direction of magnetization (magnetization vector) is pinned (fixed) in the positive direction of the X axis (the directions of solid arrows a1 and b1 in FIG. 17A). In the third X-axis GMR element 71c and the fourth X-axis GMR element 71d, the bias magnet film applies a bias magnetic field in a direction parallel to the longitudinal direction of each GMR bar (45 ° direction with respect to the negative X-axis direction). Giving. The direction of magnetization (magnetization vector) is 180 ° from the direction of magnetization of the first X-axis GMR element 71a and the second X-axis GMR element 71b in the negative direction of the X-axis (in the directions of solid arrows c1 and d1 in FIG. 17A). A pinned layer is formed so as to be pinned (fixed) in the opposite direction.

  Therefore, in the first X-axis GMR element 71a and the second X-axis GMR element 71b, the magnetic field sensitivity direction is −45 ° with respect to the direction perpendicular to the longitudinal direction of each GMR bar, that is, the positive X-axis direction. Direction (indicated by dotted arrows a2 and b2 in FIG. 22A). On the other hand, in the third X-axis GMR element 71c and the fourth X-axis GMR element 71d, the sensitivity direction of the magnetic field is −45 ° with respect to the direction perpendicular to the longitudinal direction of each GMR bar, that is, the negative X-axis direction. Direction (direction opposite to the sensitivity direction of the first X-axis GMR element 71a and the second X-axis GMR element 71b in the directions of the dotted arrows c2 and d2 in FIG. 22A).

  Further, in the first Y-axis GMR element 71e and the second Y-axis GMR element 71f, the bias magnet film is in a direction parallel to the longitudinal direction of each GMR bar (a direction of 45 ° with respect to the Y-axis positive direction, that is, the X-axis The bias magnetic field is applied in the direction in which the bias magnetic field of the GMR elements 71a to 71b is rotated 90 ° counterclockwise. The pinned layer is formed so that the direction of magnetization (magnetization vector) is pinned (fixed) in the positive Y-axis direction (the direction of solid arrows e1 and f1 in FIG. 22A). On the other hand, in the third Y-axis GMR element 71g and the fourth Y-axis GMR element 71h, the bias magnet film is 180 ° opposite to the first Y-axis GMR element 71e and the second Y-axis GMR element 71f and in the longitudinal direction of each GMR bar. A bias magnetic field is applied in a parallel direction (a direction of 45 ° with respect to the Y-axis negative direction). The pinned layer is formed so that the direction of magnetization (magnetization vector) is pinned (fixed) in the negative Y-axis direction (the directions of solid arrows g1 and h1 in FIG. 22A).

  Therefore, in the first Y-axis GMR element 71e and the second Y-axis GMR element 71f, the magnetic field sensitivity direction is a direction perpendicular to the longitudinal direction of each GMR bar, that is, a direction of −45 ° with respect to the Y-axis positive direction ( This is the direction of the dotted arrows e2 and f2 in FIG. On the other hand, in the third Y-axis GMR element 71g and the fourth Y-axis GMR element 71h, the direction perpendicular to the longitudinal direction of each GMR bar, that is, the direction of −45 ° with respect to the Y-axis negative direction (see FIG. ) In the direction of the dotted arrows g2 and h2 (the direction opposite to the magnetization direction of the first Y-axis GMR element 71e and the second Y-axis GMR element 71f).

  Further, in the first Z-axis GMR element 71i and the second Z-axis GMR element 71j, as schematically shown in FIG. 22B, the bias magnet films 71i-5, 71i-6, 71i-7 (71j-5, 71j-6, 71j-7) are parallel to the longitudinal direction of each GMR bar 71i-1, 71i-2, 71i-3, 71i-4 (71j-1, 71j-2, 71j-3, 71j-4). A bias magnetic field is applied in a direction that is perpendicular to the X axis and parallel to the Y axis on a flat surface, that is, on the plane of each slope (inclination angle is approximately 45 °) of the protrusion (bank portion) 75. ing. Then, the direction of magnetization (magnetization vector) is inclined by 45 ° from the negative Z-axis direction with respect to the positive Y-axis direction within each slope of the protrusion (bank portion) 75 (the direction of the solid arrow i1 in FIG. 22B) The pinned layer is formed so as to be pinned (fixed) to the surface.

  These GMR bars 71i-1, 71i-2, 71i-3, 71i-4 (71j-1, 71j-2, 71j-3, 71j-4) are bias magnet films 71i-5, 71i-6. , 71i-7 (71j-5, 71j-6, 71j-7). As a result, the direction of sensitivity of the magnetic field is a direction perpendicular to the longitudinal direction of each GMR bar, ie, the negative Z-axis direction, that is, the direction indicated by the dotted arrow i2 in FIG. When the magnetic field is applied in the direction of the dotted arrow i2 in FIG. 22B, the resistance values of the first Z-axis GMR element 71i and the second Z-axis GMR element 71j decrease in proportion to the magnitude of the magnetic field, When a magnetic field is applied in the direction opposite to the dotted arrow i2 in FIG. 22B, the resistance values of the first Z-axis GMR element 71i and the second Z-axis GMR element 71j increase in proportion to the magnitude of the magnetic field. Become.

  On the other hand, the first nonmagnetic resistor 71k and the second nonmagnetic resistor 71l are formed of a nonmagnetic material such as polysilicon. In the third embodiment, the first nonmagnetic resistor 71k is disposed at the left side of the substantially central portion of the X axis in the Y axis positive direction approximately 1/4 part, and the second nonmagnetic resistor 71l is disposed on the right side thereof. Although arranged, the first nonmagnetic resistor 71k and the second nonmagnetic resistor 71l may be arranged anywhere on the substrate 71.

  As shown in an equivalent circuit in FIG. 23A, the X-axis magnetic sensor is configured by first to fourth X-axis GMR elements 71a to 71d being full-bridge connected. In FIG. 23A, the arrows indicate the directions of pinned magnetization of the pinned layers of the GMR elements 71a to 71d. In such a configuration, the pad 72a and the pad 72b are connected to the positive electrode and the negative electrode of the constant voltage source 72e, and a potential Vxin + (3 V in this example) and a potential Vxin− (0 (V) in this example) are applied. Then, the potentials of the pad 72c and the pad 72d are taken out as the potential Vxout + and the potential Vxout-, respectively, and the potential difference (Vxout + −Vxout−) is taken out as the sensor output Vxout.

  The Y-axis magnetic sensor is configured by full-bridge connection of the first to fourth Y-axis GMR elements 71e to 71h as shown in an equivalent circuit in FIG. The pad 73a and the pad 73b are connected to the positive electrode and the negative electrode of the constant voltage source 73e, and a potential Vyin + (3 V in this example) and a potential Vyin- (0 (V) in this example) are applied, and the pad 73c and the pad 73d are applied. Is taken out as a sensor output Vyout.

  As shown in the equivalent circuit of FIG. 23C, the Z-axis magnetic sensor includes a first Z-axis GMR element 71i, a second Z-axis GMR element 71j, a first nonmagnetic resistor 71k, and a second nonmagnetic resistor 71l. It is configured by full bridge connection. The pad 74a and the pad 74b are connected to the positive electrode and the negative electrode of the constant voltage source 74e, and a potential Vyin + (3 V in this example) and a potential Vyin− (0 (V) in this example) are applied. Is taken out as a sensor output Vyout.

  In manufacturing the three-axis magnetic sensor 70 of the third embodiment, the manufacturing of the three-axis magnetic sensor 10 of the first embodiment described above except that the first nonmagnetic resistor 71k and the second nonmagnetic resistor 71l are manufactured. Since it is almost the same as the method, the description of the manufacturing method is omitted. However, the regularizing heat treatment (pinning treatment) will be briefly described below.

In the regularized heat treatment (pinning process) when manufacturing the triaxial magnetic sensor 70 of the third embodiment, the polarities of the upper ends (lower ends) of the adjacent permanent bar magnet pieces are mutually different, as schematically shown in FIG. A permanent bar magnet array (magnet array) arranged in a grid pattern so as to be different is prepared. Using this, the N pole is arranged on the center of the substrate 71, and the S pole is arranged on the outside of the substrate 71 at positions symmetrical to the top, bottom, left and right with respect to this N pole. To be arranged.
Thereby, as shown in FIG. 22, a magnetic field in the X-axis positive direction is applied to the first X-axis GMR element 71a and the second X-axis GMR element 71b, and in the third X-axis GMR element 71c and the fourth X-axis GMR element 71d, A magnetic field in the negative direction of the X axis is applied. In addition, a magnetic field in the Y-axis positive direction is applied to the first Y-axis GMR element 71e and the second Y-axis GMR element 71f, and a magnetic field in the Y-axis negative direction is applied to the third Y-axis GMR element 71g and the fourth Y-axis GMR element 71h. It becomes. Further, in the first Z-axis GMR element 71i and the second Z-axis GMR element 71j, a direction inclined by 45 ° from the positive Y-axis direction to the negative Z-axis direction on the slope of the protrusion (bank) 75 (the reverse side of the paper surface of FIG. 22). The magnetic field in the direction from) to the table)) is applied.

4). Example 4
Next, the triaxial magnetic sensor of Example 4 will be described below with reference to FIG. FIG. 25 is a plan view showing a schematic configuration of the triaxial magnetic sensor of the fourth embodiment. As shown in FIG. 25, the triaxial magnetic sensor 80 of the fourth embodiment has a rectangular shape (here, a short side (longitudinal) and a long side having sides along the X axis and the Y axis that are orthogonal to each other in plan view). The side (horizontal) ratio (aspect ratio) is 1: 2, the side along the X axis is the long side, and the side along the Y axis is the short side), and the X axis And a substrate 81 made of quartz or silicon having a small thickness in the Z-axis direction orthogonal to the Y-axis.

  On the substrate 81, a total of 12 GMR elements each including four X-axis GMR elements 81a to 81d, Y-axis GMR elements 81e to 81h, and Z-axis GMR elements 81i to 81l, Twelve pads (not shown) and connection lines (not shown) for connecting each pad and each element are formed. In the substrate 81, an LSI and a wiring layer are formed in the same manner as the substrate 11 of the first embodiment described above. A digital output magnetic sensor is used in a substrate using the substrate in which the LSI is formed. In the case of using a substrate on which only a wiring layer is formed, an analog output magnetic sensor is formed.

  Here, the X-axis GMR element is composed of a first X-axis GMR element 81a, a second X-axis GMR element 81b, a third X-axis GMR element 81c, and a fourth X-axis GMR element 81d. The direction is arranged in a direction parallel to the Y axis. A first X-axis GMR element 81a is disposed above the Y-axis central part at the X-axis central part, and a second X-axis GMR element 81b is disposed below the first X-axis GMR element 81b. A third X-axis GMR element 81c is disposed near the left end of the X-axis and above the center of the Y-axis, and a fourth X-axis GMR element 81d is disposed below the third X-axis GMR element 81d.

  The Y-axis GMR element includes a first Y-axis GMR element 81e, a second Y-axis GMR element 81f, a third Y-axis GMR element 81g, and a fourth Y-axis GMR element 81h. The longitudinal direction of each of these GMR elements Are arranged in a direction parallel to the X axis. In the vicinity of the upper end of the Y axis, the first Y axis GMR element 81e is arranged on the right side of the middle part from the center of the X axis to the left end of the X axis, and the second Y axis GMR element 81f is located on the left. Has been placed. A third Y-axis GMR element 81g is arranged near the lower end of the Y-axis and to the right of the middle part from the center of the X-axis to the left end of the X-axis, and on the left side of the fourth Y-axis GMR element 81h. Is arranged.

Further, the Z-axis GMR element includes a first Z-axis GMR element 81i, a second Z-axis GMR element 81j, a third Z-axis GMR element 81k, and a fourth Z-axis GMR element 81l. The longitudinal direction of each of these GMR elements Are arranged in a direction parallel to the Y axis. The first Z-axis GMR element 81i is arranged at the middle part from the Y-axis center part to the lower end part of the Y-axis and to the right of the middle part from the X-axis center part to the right-side end part of the X-axis. A second Z-axis GMR element 81j is arranged on the side. A third Z-axis GMR element 81k is arranged in the middle from the Y-axis center to the upper end of the Y-axis and to the right of the middle from the X-axis center to the left-side end of the X-axis. The fourth Z-axis GMR element 81l is disposed at the end.
Even with such an arrangement, a triaxial magnetic sensor can be constructed in the same manner as the triaxial magnetic sensors of the first, second, and third embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic block diagram which shows typically the triaxial magnetic sensor of Example 1, Fig.1 (a) is a top view, FIG.1 (b) is sectional drawing which shows the AA cross section of Fig.1 (a). . FIG. 2 is a diagram schematically showing a schematic configuration of a magnetoresistive effect element used in a triaxial magnetic sensor of the present invention. FIG. 2A is a diagram showing a magnetoresistive effect element (GMR) bar connected to one magnetoresistive element. It is a top view which shows the state by which the effect element was comprised, FIG.2 (b) is sectional drawing which shows typically the AA cross section of Fig.2 (a), FIG.2 (c) is FIG. It is a figure which shows typically the lamination state inside (b). FIG. 3 is a diagram schematically illustrating a pinning direction and a sensitivity direction of the triaxial magnetic sensor in FIG. 1, FIG. 3A is a plan view schematically illustrating the entire plane, and FIG. FIG. 3A is a perspective view schematically showing an enlarged portion A of FIG. 3A, and FIG. 3C is a perspective view schematically showing an enlarged portion B of FIG. FIG. 4A is a block diagram showing the bridge connection of the X-axis sensor, FIG. 4B is a block diagram showing the bridge connection of the Y-axis sensor, and FIG. c) is a block diagram showing the bridge connection of the Z-axis sensor. It is sectional drawing which shows typically the triaxial magnetic sensor of Example 1 in the middle of manufacture. It is sectional drawing which shows typically the triaxial magnetic sensor of Example 1 in the middle of manufacture. It is sectional drawing which shows typically the triaxial magnetic sensor of Example 1 in the middle of manufacture. It is sectional drawing which shows typically the triaxial magnetic sensor of Example 1 in the middle of manufacture. It is sectional drawing which shows typically the triaxial magnetic sensor of Example 1 in the middle of manufacture. It is sectional drawing which shows typically the triaxial magnetic sensor of Example 1 in the middle of manufacture. It is sectional drawing which shows typically the triaxial magnetic sensor of Example 1 in the middle of manufacture. It is sectional drawing which shows typically the triaxial magnetic sensor of Example 1 in the middle of manufacture. It is sectional drawing which shows typically the triaxial magnetic sensor of Example 1 in the middle of manufacture. It is sectional drawing which shows typically the triaxial magnetic sensor of Example 1 in the middle of manufacture. It is a figure which shows the state of regularization heat processing (pinning process) typically, Fig.15 (a) is a top view, FIG.15 (b) is sectional drawing which shows the AA cross section of Fig.15 (a) FIG.15 (c) is sectional drawing which shows the BB cross section of Fig.15 (a). FIG. 16A is a diagram showing a typical modification of the triaxial magnetic sensor of Example 1, and FIG. 16A is a schematic configuration diagram schematically showing the triaxial magnetic sensor of the first modification, and FIG. ) Is a schematic configuration diagram schematically showing the triaxial magnetic sensor of the second modification, and FIG. 16C is a schematic configuration diagram schematically showing the triaxial magnetic sensor of the third modification. (D) is a schematic block diagram which shows typically the triaxial magnetic sensor of a 4th modification. It is a schematic block diagram which shows the triaxial magnetic sensor of Example 2, Fig.17 (a) is a top view, FIG.17 (b) is sectional drawing which shows the AA cross section of Fig.17 (a). FIG. 18 is a diagram schematically showing a pinning direction and a sensitivity direction of the triaxial magnetic sensor of FIG. 17, FIG. 18 (a) is a plan view schematically showing the entire plane, and FIG. 18 (b) is a diagram showing FIG. FIG. 18C is a perspective view schematically showing an enlarged A part of FIG. 18A, and FIG. 18C is a perspective view schematically showing an enlarged B part of FIG. FIG. 19A is a block diagram showing the bridge connection of the X-axis sensor, FIG. 19B is a block diagram showing the bridge connection of the Y-axis sensor, and FIG. c) is a block diagram showing the bridge connection of the Z-axis sensor. It is a figure which shows the state of regularization heat processing (pinning process) typically, Fig.20 (a) is a top view, FIG.20 (b) is sectional drawing which shows the AA cross section of Fig.20 (a). FIG.20 (c) is sectional drawing which shows the BB cross section of Fig.20 (a). It is a schematic block diagram which shows the triaxial magnetic sensor of Example 3, Fig.21 (a) is a top view, FIG.21 (b) is sectional drawing which shows the AA cross section of Fig.21 (a). FIG. 22 is a diagram schematically showing the pinning direction and sensitivity direction of the triaxial magnetic sensor of FIG. 21, FIG. 22 (a) is a plan view schematically showing the entire plane, and FIG. 22 (b) is FIG. It is a perspective view which expands and shows the A section of (a) typically. FIG. 23A is a block diagram showing the bridge connection of the X-axis sensor, FIG. 23B is a block diagram showing the bridge connection of the Y-axis sensor, and FIG. c) is a block diagram showing the bridge connection of the Z-axis sensor. It is a figure which shows the state of regularization heat processing (pinning process) typically, Fig.24 (a) is a top view, FIG.24 (b) is sectional drawing which shows the AA cross section of Fig.24 (a) It is. 6 is a plan view showing a schematic configuration of a three-axis magnetic sensor of Example 4. FIG. It is a schematic block diagram which shows typically the magnetic sensor of a prior art example, Fig.26 (a) is a top view, FIG.26 (b) is the side view. It is a figure which shows the bridge connection of the magnetic sensor of a prior art example.

Explanation of symbols

10 ... three-axis magnetic sensor of Example 1, 11 ... substrate, 11a ... wiring layer, 11b ... interlayer insulation film, 11c, 11d ... opening, 11e ... SiO ₂ film, 11f ... Si ₃ N ₄ film, 11g, 11h ... opening, 11i ... SiO ₂ film, 11j ... resist film, 11k ... opening, 11m ... bias magnet film, 11n ... GMR multilayer film, 11o ... Si ₃ N ₄ film, 11p ... polyimide film, 15 ... projection (Tsutsumi Part), 21 ... first X-axis GMR element, 21a-21d ... GMR bar, 21e-21i ... bias magnet film, 22 ... second X-axis GMR element, 23 ... third X-axis GMR element, 24 ... fourth X-axis GMR element, 25-28 ... Pad, 29 ... Constant voltage source, 31 ... First Y-axis GMR element, 32 ... Second Y-axis GMR element, 33 ... Third Y-axis GMR element, 34 ... Fourth Y-axis GMR element, 35-38 ... Pad, 39 ... Constant Source: 41 ... first Z-axis GMR element, 42 ... second Z-axis GMR element, 43 ... third Z-axis GMR element, 44 ... fourth Z-axis GMR element, 45-48 ... pad, 49 ... constant voltage source, 50a ... modification 1 triaxial magnetic sensor, 51... Substrate, 51a to 51d, first to fourth X axis GMR elements, 51e to 51h, first to fourth Y axis GMR elements, 51i to 51l, first to fourth Z axis GMR elements, 50b ... Triaxial magnetic sensor of Modification 2 52 ... Substrate 52a-52d ... 1st-4th X-axis GMR element, 52e-52h ... 1st-4th Y-axis GMR element, 52i-52l ... 1st-4th Z Axis GMR element, 50c ... Triaxial magnetic sensor of Modification 3, 53 ... Substrate, 53a-53d ... First to fourth X-axis GMR elements, 53e-53h ... First to fourth Y-axis GMR elements, 53i-53l ... First 1st to 4th Z-axis GMR element, 50d ... Triaxial magnetic sensor of Modification 4 54 ... Substrate 54a to 54d 1st to 4th X-axis GMR element 54e to 54h 1st to 4th Y-axis GMR element 54i to 54l 1st to 4th Z-axis GMR element, 60 ... triaxial magnetic sensor of Example 2, 61 ... substrate, 61a to 61d ... first to fourth X axis GMR elements, 61e to 61h ... first to fourth Y axis GMR elements, 61i to 61l ... first -4th Z-axis GMR element, 62a-62d ... pad, 62e ... constant voltage source, 63a-63d ... pad, 63e ... constant voltage source, 64a-64d ... pad, 64e ... constant voltage source, 65 ... projection (bank) ), 70... Three-axis magnetic sensor of Example 3, 71... Substrate, 71 a to 71 d... First to fourth X axis GMR elements, 71 e to 71 h, first to fourth Y axis GMR elements, 71 i to 71 j. Second Z-axis GMR element, 71k-71l First to second nonmagnetic resistors, 72a to 72d ... Pad, 72e ... Constant voltage source, 73a to 73d ... Pad, 73e ... Constant voltage source, 74a to 74d ... Pad, 74e ... Constant voltage source, 75 ... Protrusion (Bank part), 80 ... triaxial magnetic sensor of Example 4, 81 ... substrate, 81a to 81d ... first to fourth X axis GMR elements, 81e to 81h ... first to fourth Y axis GMR elements, 81i to 81l ... 1st to 4th Z-axis GMR element, 85 ... Projection (bank)

Claims (3)

An X-axis sensor in which a plurality of magnetoresistive effect elements having a pinned layer are bridge-connected to a single substrate on which an LSI or a wiring layer is built, and a plurality of magnetoresistive effect elements having a pinned layer are bridge-connected to each other A triaxial magnetic sensor in which an axial sensor and a Z-axis sensor in which a plurality of magnetoresistive elements having a pinned layer are bridge-connected are formed,
The magnetoresistive effect element is formed by connecting one magnetoresistive effect element bar or a plurality of magnetoresistive effect element bars in series,
The magnetoresistive effect element of the X-axis sensor and the magnetoresistive effect element of the Y-axis sensor are formed on a plane parallel to the plane of the substrate, and the direction of sensitivity thereof is the longitudinal direction of each magnetoresistive element bar. , The magnetization directions of the pinned layers of the magnetoresistive effect element of the X-axis sensor and the magnetoresistive effect element of the Y-axis sensor are perpendicular to each other,
The magnetoresistive effect element of the Z-axis sensor is formed on a slope of a protrusion provided so as to face the Z-axis perpendicular to the plane of the substrate at the same angle, and the Z-axis sensor The magnetization direction of the pinned layer of the magnetoresistive effect element is formed so as to be within the inclined surface, and the sensitivity direction is formed so as to intersect the longitudinal direction of the magnetoresistive effect element bar, The longitudinal direction of the magnetoresistive effect element bar coincides with either the X-axis direction or the Y-axis direction of the substrate, and two magnetoresistive effects each constituted by the magnetoresistive effect bar formed on each of the inclined surfaces. The elements are adjacent and arranged in parallel with each other. These two magnetoresistive elements and the two nonmagnetic resistors formed in a point-symmetrical position from the center of the square substrate in plan view and the full bridge Three-axis magnetic sensor, characterized in that it is continued.   The triaxial according to claim 1, wherein the magnetoresistive effect element includes a plurality of magnetoresistive effect element bars arranged in parallel, and adjacent magnetoresistive effect element bars are connected in series by a bias magnet film. Magnetic sensor. X-axis sensor in which a plurality of magnetoresistive elements having a pinned layer are bridge-connected, a Y-axis sensor in which a plurality of magnetoresistive elements having a pinned layer are bridge-connected, and a plurality of magnetoresistive elements having a pinned layer Is a method of manufacturing a three-axis magnetic sensor comprising a Z-axis sensor bridge-connected in one substrate,
A plurality of magnetoresistive elements serving as an X-axis sensor, a plurality of magnetoresistive elements serving as a Y-axis sensor, and a plurality of magnetoresistive effects serving as a Z-axis sensor on a single substrate on which an LSI or wiring layer is formed A magnetoresistive element forming step of forming an element;
A fixing process step of simultaneously fixing the magnetization directions of the respective pinned layers of the magnetoresistive effect element by heating while applying a magnetic field to each magnetoresistive effect element formed on the substrate, and the fixing process step The magnetoresistive effect element is heated by applying a magnetic field in a direction of 45 degrees from the vertical direction of the substrate on which each magnetoresistive effect element bar constituting the plurality of magnetoresistive effect elements serving as a Z-axis sensor is formed. A method of manufacturing a triaxial magnetic sensor, wherein the magnetization direction of each pinned layer is fixed.

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