JP4614061B2 - Magnetic sensor using giant magnetoresistive element and method of manufacturing the same - Google Patents

Description

  The present invention relates to a magnetic sensor including a giant magnetoresistive element and a method for manufacturing the same.

  A conventionally known giant magnetoresistive element includes a pinned layer and a pinned layer for pinning the magnetization direction of the pinned layer, and a free layer whose magnetization direction changes according to an external magnetic field. The spin valve film includes a spacer layer made of a nonmagnetic conductor and disposed between the pinned layer and the free layer. Since the pinned layer of the fixed layer includes only a single ferromagnetic film (for example, a CoFe layer), it is hereinafter referred to as a “single film fixed layer” for convenience. In addition, the giant magnetoresistive effect element having such a single film fixed layer is referred to as “normal GMR element” in this specification.

  The resistance value of this normal GMR element changes according to the angle formed by the magnetization direction of the pinned layer and the magnetization direction of the free layer. That is, the resistance value of the element changes according to the component along the direction of magnetization of the pinned layer of the external magnetic field. Therefore, the magnetic detection direction of the element is a direction along the direction of the fixed magnetization of the pinned layer (actually, an antiparallel direction to the direction of the fixed magnetization of the pinned layer). The magnetization of the pinned layer is, for example, by laminating an antiferromagnetic film serving as a pinning layer on a ferromagnetic film serving as a pinned layer, and applying the magnetic field in a predetermined direction to the stacked film while keeping the film at a high temperature. It is fixed in the predetermined direction by performing heat treatment in a magnetic field.

  By the way, as shown in FIG. 45A, a magnetic sensor using such a normal GMR element has two normal GMR elements 101 and 102 having a predetermined magnetic detection direction and the predetermined magnetic detection direction. Two normal GMR elements 103 and 104 different from the direction by 180 degrees are provided, and these elements are connected by a full bridge to extract the potential difference at the illustrated location as an output V. FIG. 45B shows an output V with respect to the external magnetic field H in the magnetic detection direction of the magnetic sensor shown in FIG.

By this bridge connection, the conventional magnetic sensor can obtain a large output even for a minute magnetic field. Moreover, since the temperature of each element changes similarly, the resistance value of each element also changes similarly. That is, for example, when the temperature of one element rises, the temperature of the other elements also rises in the same manner, so that the resistance value of each element similarly changes. Therefore, since the output V is not easily affected by changes in the element temperature, the magnetic sensor can accurately detect an external magnetic field even when the element temperature changes (see, for example, Patent Document 1).
JP 2004-163419 A

  On the other hand, since the magnetization direction of the pinned layer that determines the magnetic detection direction coincides with the magnetic field applied to the layer serving as the fixed layer in the heat treatment in the magnetic field, a plurality of normal GMRs whose magnetic detection directions used for the bridge connection differ from each other by 180 degrees. In order to form an element, magnetic fields whose directions are different by 180 degrees must be applied to a substrate on which a plurality of films to be normal GMR elements are formed. Furthermore, a magnetic sensor that can detect magnetic field components in two orthogonal axes (for example, the X-axis and the Y-axis) respectively has an X-axis positive direction, a Y-axis positive direction, an X-axis negative direction, and a Y-axis negative direction. Since a normal GMR element having a magnetic detection direction in each direction must be provided on a minute substrate, a magnetic field in these four directions is applied to a substrate on which a plurality of films that become normal GMR elements are formed in a heat treatment in a magnetic field. Must. However, it is not easy to generate such magnetic fields having different directions in a narrow range.

  Therefore, the above patent document discloses a technique for manufacturing such a magnetic sensor by employing a sensor structure and a magnet array described below. That is, first, as shown in FIG. 46 which is a plan view, two (total 8) films to be normal GMR elements 101 to 108 are formed in the vicinity of each side of the substantially square substrate 100a.

  The magnet array is an array of square pole permanent magnets arranged in a square lattice pattern. In the permanent magnet, all of the end faces of the plurality of permanent magnets are substantially on the same plane, and the polarities of the magnetic poles formed on the end faces of the two permanent magnets adjacent to each other with the shortest distance are different. Has been placed. FIG. 47 is a perspective view of a part of the permanent magnet 110 of the magnet array. As understood from FIG. 47, four directions of magnetic fields from the north pole to the south pole are generated in the upper part of the magnet array.

  Then, when performing heat treatment in a magnetic field, the substrate 100a on which the film to be the normal GMR film is formed is disposed on the magnet array. As a result, as shown in FIG. 48, the four-direction magnetic field generated in the upper part of the magnet array is applied to the film that normally becomes a GMR element as the magnetic field of the heat treatment in the magnetic field. Thus, the magnetic sensor 100 shown in FIG. 46 is manufactured.

  In this magnetic sensor 100, normal GMR elements 101 to 104 are elements for detecting a magnetic field component in the X-axis direction. Usually, the fixed magnetization direction of each pinned layer of the GMR elements 101 and 102 is the negative X-axis direction. Usually, the fixed magnetization direction of each pinned layer of the GMR elements 103 and 104 is the positive direction of the X axis. Normally, the GMR elements 101 to 104 are X-axis magnetic sensors that detect a magnetic field in the X-axis direction by being connected in a full bridge as shown in FIG.

  Usually, the GMR elements 105 to 108 are elements for detecting a magnetic field component in the Y-axis direction. Usually, the fixed magnetization direction of each pinned layer of the GMR elements 105 and 106 is the Y-axis positive direction. Usually, the fixed magnetization direction of each pinned layer of the GMR elements 107 and 108 is the Y-axis negative direction. Similarly to the normal GMR elements 101 to 104, the normal GMR elements 105 to 108 are full-bridge connected and serve as Y axis magnetic sensors for detecting a magnetic field in the Y axis direction.

  However, in such a magnetic sensor, a GMR element is usually disposed in the vicinity of each side of the substrate 100a, so that there is a problem that the magnetic sensor (chip) cannot be sufficiently reduced in size.

  Further, if the distance between the plurality of normal GMR elements is large, when the resin covering the substrate 100a, the substrate 100a, etc. is deformed by heat or stress applied from the outside, different stresses are applied to the plurality of normal GMR elements. Usually, the GMR elements are deformed to be different from each other. Therefore, since the resistance value of each normal GMR element changes variously, in the magnetic sensor having a circuit in which the normal GMR elements are bridge-connected, the balance of the bridge circuit is lost. As a result, such a magnetic sensor has a problem that it cannot detect a magnetic field with high accuracy.

  Further, in the above magnetic sensor, since the distance between the GMR elements is usually increased, there is a problem that the length of the wiring for full-bridge connection between them becomes long and the loss due to the resistance of the wiring becomes large. .

  The magnetic sensor of the present invention is a sensor comprising a single giant pinned layer first giant magnetoresistive element and a multiple-layer laminated pinned layer giant giant magnetoresistive element on a single substrate.

The first giant magnetoresistive element is:
The ferromagnetic film is composed of a single ferromagnetic film and a pinning layer, and the magnetization direction of the ferromagnetic film is fixed in the first direction (for example, the positive direction of the X axis) by the pinning layer so that the ferromagnetic film is a pinned layer. A fixed layer comprising
A free layer whose direction of magnetization changes according to an external magnetic field;
A spacer layer made of a non-magnetic conductor disposed between the pinned layer and the free layer;
A single-layer fixed-layer spin-valve film.

The second giant magnetoresistive element is:
The second ferromagnetic film comprises a first ferromagnetic film, an exchange coupling film in contact with the first ferromagnetic film, a second ferromagnetic film in contact with the exchange coupling film, and a pinning layer in contact with the second ferromagnetic film. The magnetization direction of the body film is fixed by the pinning layer, and the second ferromagnetic film and the first ferromagnetic film are exchange-coupled through the exchange coupling film, whereby the first ferromagnetic film A fixed layer constituting a pinned layer in which the magnetization direction is fixed in a second direction (for example, the negative X-axis direction);
A free layer whose direction of magnetization changes according to an external magnetic field;
A spacer layer made of a non-magnetic conductor disposed between the pinned layer and the free layer;
A multi-layered laminated fixed layer spin valve film.

  Then, the fixed magnetization direction of the pinned layer of the first giant magnetoresistive element (ie, the first direction) and the fixed magnetization direction of the pinned layer of the second giant magnetoresistive element (ie, the first direction) , The second orientation) is 180 degrees different (antiparallel).

  By the way, a film to be the first giant magnetoresistive element of the single film fixed layer and a film to be the second giant magnetoresistive element of the multiphase film fixed layer are formed on the substrate, and these films are formed. When a magnetic field heat treatment is applied in which a magnetic field in the same direction is applied at a high temperature, the magnetization of the ferromagnetic film serving as the pinned layer of the film serving as the first giant magnetoresistance effect element and the second giant magnetoresistance effect The magnetization of the second ferromagnetic film of the film serving as the element is fixed in the same direction. Further, since the first ferromagnetic film serving as the pinned layer of the film serving as the second giant magnetoresistive element is exchange coupled with the second ferromagnetic film via the exchange coupling film, the magnetization of the first ferromagnetic film Is fixed in a direction that is 180 degrees different from the magnetization direction of the second ferromagnetic film. As a result, the magnetization direction of the pinned layer (ferromagnetic film) of the first giant magnetoresistive element and the magnetization direction of the pinned layer (first ferromagnetic film) of the second giant magnetoresistive element are 180 degrees. Fixed to be different.

  On the other hand, each of the first giant magnetoresistive element and the second giant magnetoresistive element has a magnetic detection direction in a direction that is 180 degrees different from the fixed magnetization direction of the pinned layer. In other words, in any element, the magnetic detection direction is antiparallel to the fixed magnetization direction of the pinned layer. As a result, the magnetic detection directions of these elements are 180 degrees different from each other (see FIG. 14).

  From the above, in the magnetic sensor according to the present invention, as in the conventional magnetic sensor, the two giant magnetoresistive effect elements can be applied with a magnetic field having a direction different by 180 degrees. It is not required to make the distance between the magnetoresistive elements large. That is, in the magnetic sensor according to the present invention, a film to be the first giant magnetoresistive effect element and a film to be the second giant magnetoresistive effect element are formed on a substrate, and these elements have the same orientation. It can be easily manufactured by performing the above-mentioned heat treatment in a magnetic field that applies a magnetic field. Therefore, according to the present invention, the distance between two giant magnetoresistive elements having a magnetic detection direction different by 180 degrees (the distance between the first giant magnetoresistive element and the second giant magnetoresistive element) can be set small. As a result, a very small magnetic sensor is provided.

  In the magnetic sensor of one aspect of the present invention, the first giant magnetoresistive effect element and the second giant magnetoresistive effect element are bridge-connected to form a circuit, and the first magnetic field applied to the magnetic sensor. The output value based on the potential at a predetermined point in the circuit where the potential monotonously increases or monotonously decreases as the magnitude of the component in the direction increases can be configured.

  The circuit formed by such bridge connection includes a herb bridge circuit and a full bridge circuit. In addition to the first giant magnetoresistive element and the second giant magnetoresistive element, the element constituting this circuit may include a fixed resistor.

  The magnetic sensor of the above aspect can include a full bridge circuit including two each of the first giant magnetoresistive effect element and the second giant magnetoresistive effect element and connecting these elements.

That is, such a magnetic sensor is
One end of one first giant magnetoresistive effect element of the first giant magnetoresistive effect element is connected to one end of one second giant magnetoresistive effect element of the second giant magnetoresistive effect element. Constituting a first circuit element;
A first potential is applied to the other end of the first giant magnetoresistive element of the first circuit element, and a second potential different from the first potential is applied to the other end of the second giant magnetoresistive element of the first circuit element. It is configured to apply two potentials.

In addition, the magnetic sensor
One end of another first giant magnetoresistive effect element of the first giant magnetoresistive effect element and one end of another second giant magnetoresistive effect element of the second giant magnetoresistive effect element To configure the second circuit element,
Applying the first potential to the other end of the second giant magnetoresistive element of the second circuit element and applying the second potential to the other end of the first giant magnetoresistive element of the second circuit element Configured to do.

And the magnetic sensor
A potential at a connection point between one end of the first giant magnetoresistive element of the first circuit element and one end of the second giant magnetoresistive element of the first circuit element; and the first of the second circuit element A potential difference between a connection portion between one end of the giant magnetoresistive effect element and one end of the second giant magnetoresistive effect element of the second circuit element is output as an output value.

  The magnetic sensor of the above aspect requires two giant magnetoresistive elements each having a magnetic detection direction different from each other by 180 degrees. On the other hand, as described above, the first giant magnetoresistive element and the second giant magnetoresistive element whose magnetic detection directions are different from each other by 180 degrees can be easily formed in a minute region on one substrate. Therefore, it is easy to form the two first giant magnetoresistive elements and the two second giant magnetoresistive elements in a minute region on the substrate. Therefore, according to the above aspect, it is possible to provide a small-sized magnetic sensor that includes the full bridge circuit and has good temperature characteristics.

  In addition, since these giant magnetoresistive elements can be formed in a minute region on a single substrate, even when the resin covering the substrate and the substrate is deformed by heat or external stress, the above-mentioned Uniform stress (for example, substantially the same tensile stress or substantially the same compressive stress) is applied to the giant magnetoresistive element. Therefore, since the resistance values of the giant magnetoresistive elements increase or decrease in the same manner, the possibility that the balance of the full bridge circuit is lost is reduced. As a result, the magnetic sensor of the above aspect can detect the magnetic field with high accuracy.

In addition to the first giant magnetoresistive element and the second giant magnetoresistive element, the magnetic sensor according to another aspect of the present invention includes:
A spin-valve film having a single-layer pinned layer that is formed on the substrate and is identical to the first giant magnetoresistive element, and the magnetization direction of the ferromagnetic film of the pinned layer is the first direction. A third giant magnetoresistive element fixed in a third direction orthogonal to
A spin-valve film of a multi-layer stacked pinned layer that is formed on the substrate and is the same as the second giant magnetoresistive element, and the magnetization direction of the first ferromagnetic film of the pinned layer is the third A fourth giant magnetoresistive element fixed in a fourth orientation that is 180 degrees different from the orientation of
Is further provided.

  According to this, a magnetic sensor (hereinafter also referred to as “orthogonal biaxial direction detection type magnetic sensor”) capable of detecting a magnetic field component (magnetism) along two orthogonal biaxial directions is provided. Further, according to the above aspect, the third giant magnetoresistive effect element and the fourth giant magnetoresistive effect element can be easily placed in a minute region on the substrate in the same manner as the first giant magnetoresistive effect element and the second giant magnetoresistive effect element. Therefore, a small orthogonal two-axis direction detection type magnetic sensor can be easily provided.

Furthermore, the magnetic sensor of the above aspect is
A circuit is formed by bridge-connecting the first giant magnetoresistive element and the second giant magnetoresistive element, and the potential increases as the magnitude of the component in the first direction of the magnetic field applied to the magnetic sensor increases. Output as a first output value a value based on the potential of a predetermined point in the same circuit where monotonically increases or decreases monotonously,
A circuit is formed by bridge-connecting the third giant magnetoresistive element and the fourth giant magnetoresistive element, and the potential increases as the magnitude of the component in the third direction of the magnetic field applied to the magnetic sensor increases. Can be configured to output as the second output value a value based on the potential at a predetermined point in the circuit where the value monotonously increases or decreases monotonously.

  The circuit formed by such bridge connection includes a herb bridge circuit and a full bridge circuit. Further, the circuit including the first giant magnetoresistive effect element and the second giant magnetoresistive effect element may include a fixed resistor, and the third giant magnetoresistive effect element and the fourth giant magnetoresistive effect element are included in the circuit. The included circuit may include a fixed resistor.

  The magnetic sensor of the above aspect includes a full bridge circuit including the first giant magnetoresistive element and the second giant magnetoresistive element, each of which includes the first and second circuit elements connected to each other. In addition, a full bridge circuit including the third giant magnetoresistive effect element and the fourth giant magnetoresistive effect element, each including two third and fourth circuit elements connected to each other can be included.

  Thereby, an orthogonal two-axis direction detection type magnetic sensor including two full-bridge circuits with good temperature characteristics can be obtained. Further, as described above, it is easy to form the two first giant magnetoresistive elements and the two second giant magnetoresistive elements in a minute region on the substrate. It is also easy to form the two third giant magnetoresistive elements and the two fourth giant magnetoresistive elements in other minute regions on the substrate. Therefore, according to the above aspect, it is possible to provide a small-sized magnetic sensor of an orthogonal two-axis direction detection type including two sets of full bridge circuits having good temperature characteristics.

  Moreover, the giant magnetoresistive effect elements forming a part of one bridge circuit can be formed in a minute region on a single substrate. Therefore, even when the substrate and the resin covering the substrate are deformed, uniform stress is applied to each giant magnetoresistive element forming a part of one bridge circuit. The resistance values of the giant magnetoresistive elements forming the part increase or decrease in the same manner. As a result, the possibility that the balance of each full-bridge circuit will be lost is reduced, so that the magnetic sensor of the above aspect can detect the magnetic field components in the orthogonal biaxial directions with high accuracy.

  A magnetic sensor according to another aspect of the present invention forms a giant magnetoresistive effect element composed of four single-film fixed-layer spin-valve films on a substrate, and the direction in which these elements are fully bridged is defined as a magnetic detection direction. And forming a giant magnetoresistive effect element composed of four multi-layered laminated fixed layer spin valve films on the same substrate, and connecting them in a full-bridge manner to make the certain direction a magnetic detection direction. The sensor is provided with a circuit, and by using the outputs of these two circuits, it is possible to obtain an output value in which the influence of stress applied to each element is eliminated as much as possible.

For ease of understanding, the magnetic sensor will be described in more detail in comparison with FIGS. 30 to 34.
Two first giant magnetoresistive elements (51G, 52G);
Two second giant magnetoresistive elements (61S, 62S);
The two first giant magnetoresistive effect elements and the two second giant magnetoresistive effect elements are sensors formed in a first region in proximity to each other.

Furthermore, this magnetic sensor
The spin valve film of a single-layer fixed layer that is formed on the substrate and is the same as the first giant magnetoresistance effect element, and the magnetization direction of the ferromagnetic film of the fixed layer is the second direction. Two fixed fifth giant magnetoresistive elements (53G, 54G)
It is formed of a spin valve film of a multi-layer stacked fixed layer that is formed on the substrate and is the same as the second giant magnetoresistive element, and the direction of magnetization of the first ferromagnetic film of the fixed layer is the first Two sixth giant magnetoresistance effect elements fixed in the direction (63S, 64S),
The two fifth giant magnetoresistive elements and the two sixth giant magnetoresistive elements are sensors formed in a second region that is close to each other and separated from the first region.

Furthermore, as shown in FIG.
One end of the first giant magnetoresistive effect element (51G) of the first giant magnetoresistive effect element and the fifth giant magnetoresistive effect element of one of the fifth giant magnetoresistive effect elements (53G) Is connected to one end to form a fifth circuit element,
One end of the other first giant magnetoresistance effect element (52G) of the first giant magnetoresistance effect element and the fifth giant of the other one (54G) of the fifth giant magnetoresistance effect element. A sixth circuit element is configured by connecting one end of the magnetoresistive element in series,
A first potential (+ V) is applied to the other end of the first giant magnetoresistive effect element (51G) of the fifth circuit element and the fifth giant magnetoresistive effect element (53G) of the fifth circuit element. Apply a second potential (GND) different from the first potential to the end,
The first potential (+ V) is applied to the other end of the fifth giant magnetoresistive effect element (54G) of the sixth circuit element, and the first giant magnetoresistive effect element (52G) of the sixth circuit element is provided. Apply the second potential (GND) to the other end,
A potential at a connection point (Q10) between one end of the first giant magnetoresistive element (51G) of the fifth circuit element and one end of the fifth giant magnetoresistive element (53G) of the fifth circuit element; A potential at a connection point (Q20) between one end of the first giant magnetoresistive element (52G) of the sixth circuit element and one end of the fifth giant magnetoresistive element (54G) of the sixth circuit element; Is obtained as a normal GMR element output value.

Furthermore, as shown in FIG.
One end of one second giant magnetoresistance effect element (61S) of the second giant magnetoresistance effect elements and one sixth giant magnetoresistance effect element (63S) of the sixth giant magnetoresistance effect elements. Connect one end to form the seventh circuit element,
One end of the other second giant magnetoresistive effect element (62S) of the second giant magnetoresistive effect element and the other sixth giant magnetoresistive effect element of the sixth giant magnetoresistive effect element. (64S) is connected in series to constitute an eighth circuit element,
The first potential (+ V) is applied to the other end of the second giant magnetoresistive element (61S) of the seventh circuit element, and the sixth giant magnetoresistive element (63S) of the seventh circuit element is applied. Apply the second potential (GND) to the other end,
The first potential (+ V) is applied to the other end of the sixth giant magnetoresistive element (64S) of the eighth circuit element and the second giant magnetoresistive element (62S) of the eighth circuit element is applied. Apply the second potential (GND) to the other end,
A potential at a connection point (Q30) between one end of the second giant magnetoresistive element (61S) of the seventh circuit element and one end of the sixth giant magnetoresistive element (63S) of the seventh circuit element; A potential at a connection point (Q40) between one end of the second giant magnetoresistive element (62S) of the eighth circuit element and one end of the sixth giant magnetoresistive element (64S) of the eighth circuit element; Is obtained as the SAF element output value.

And this magnetic sensor, as shown in FIG. 31,
A value based on the normal GMR element output value and the SAF element output value is output. The “value based on the normal GMR element output value and the SAF element output value” may be a difference between the normal GMR element output value and the SAF element output value, or a ratio thereof.

  Here, for convenience of explanation, the positive direction of the direction of the magnetic field to be detected is assumed to be the direction opposite to the first direction. Further, the value obtained by subtracting the potential of the connection point Q20 from the potential of the connection point Q10 is the normal GMR element output value VoxConv, and the value obtained by subtracting the potential of the connection point Q40 from the potential of the connection point Q30 is the SAF element output value VoxSAF. To do. In addition, it is assumed that the magnetic sensor is configured to output a value obtained by subtracting the normal GMR element output value VoxConv from the SAF element output value VoxSAF.

  At this time, as shown in FIG. 32B, as the magnetic field to be detected increases, the normal GMR element output value VoxConv decreases, and as shown in FIG. 33B, the SAF The element output value VoxSAF increases. As a result, as shown in FIG. 34, the output value Vox of the magnetic sensor increases as the magnetic field to be detected increases.

  On the other hand, in the magnetic sensor thus configured, each of the two first giant magnetoresistive elements (51G, 52G) and second giant magnetoresistive elements (61S, 62S) formed in the first region. A uniform stress (for example, substantially the same tensile stress or substantially the same compressive stress) is applied to. Similarly, each of the two fifth giant magnetoresistive elements (53G, 54G) and sixth giant magnetoresistive element (63S, 64S) formed in the second region has a uniform stress (for example, Substantially the same tensile stress or substantially the same compressive stress).

  Therefore, it is assumed that a compressive stress is applied to the element formed in the first region and a tensile stress is applied to the element formed in the second region in a state where the magnetic field to be detected does not change. In this case, the resistance value of each element (51G, 52G, 61S, 62S) in the first region is uniformly reduced, and the resistance value of each element (53G, 54G, 63S, 64S) in the second region is one. Increase. Accordingly, the potential at the connection point Q10 and the connection point Q30 increases, and the potential at the connection point Q20 and the connection point Q40 decreases.

  As a result, since both the SAF element output value VoxSAF and the normal GMR element output value VoxConv rise, the output value of the magnetic sensor, which is the difference between them, hardly changes.

  Next, it is assumed that a tensile stress is applied to the element formed in the first region and a compressive stress is applied to the element formed in the second region. In this case, the resistance value of each element (51G, 52G, 61S, 62S) in the first region uniformly increases, and the resistance value of each element (53G, 54G, 63S, 64S) in the second region is one. Decrease. Accordingly, the potentials at the connection point Q10 and the connection point Q30 are decreased, and the potentials at the connection point Q20 and the connection point Q40 are increased.

  As a result, the SAF element output value VoxSAF and the normal GMR element output value VoxConv both decrease, and the output value of the magnetic sensor hardly changes.

  Further, it is assumed that tensile stress is applied to all elements. In this case, the resistance value of each element in the first region and each element in the second region increases uniformly. Therefore, the potential at the connection points Q10 to Q40 hardly changes. As a result, since the SAF element output value VoxSAF and the normal GMR element output value VoxConv do not change, the output value of the magnetic sensor, which is the difference between them, hardly changes. Similarly, when compressive stress is applied to all the elements, the output values of the magnetic sensor hardly change because the potentials of the connection points Q10 to Q40 hardly change.

  As is clear from the above exemplary explanation, the magnetic sensor of the above aspect can output a constant output value as long as the external magnetic field does not change even when the stress applied to the element changes. As a result, the magnetic sensor of the above aspect can detect the magnetic field with high accuracy.

Another aspect of the present invention is a magnetic sensor.
A plurality of the first giant magnetoresistance effect elements and the same number of the second giant magnetoresistance effect elements as the first giant magnetoresistance effect elements;
The first giant magnetoresistive effect element and the second giant magnetoresistive effect element are alternately arranged along a predetermined direction on the substrate,
The plurality of first giant magnetoresistance effect elements are connected in series to form one giant magnetoresistance effect element, and the plurality of second giant magnetoresistance effect elements are connected in series to form another giant magnetoresistance effect element. Is a magnetic sensor.

  As described above, since the magnetic sensor according to the present invention can be miniaturized, the difference in stress applied to each giant magnetoresistive element on the substrate is small. By the way, there is a high probability that the stress applied to the plurality of elements formed on the substrate along with the deformation of the substrate or the resin gradually changes along the substrate plane. Therefore, as in the above configuration, the first giant magnetoresistive elements and the second giant magnetoresistive elements are alternately arranged along a predetermined direction on the substrate, and the plurality of first giant magnetoresistive elements are arranged. The effect elements are connected in series to form one giant magnetoresistance effect element (first element), and the plurality of second giant magnetoresistance effect elements are connected in series to another giant magnetoresistance effect element (second element). If the (element) is formed, there is a high possibility that stresses having a magnitude close to each other (stress having an average stress value) are applied to the first element and the second element as a whole. Accordingly, since the resistance change amount due to the stress of the first element and the second element is close to each other, for example, when the magnetic sensor is configured to obtain an output value by a circuit in which these elements are bridge-connected, the output value The effect of stress on

Another aspect of the present invention is a magnetic sensor.
The first giant magnetoresistive effect element and the second giant magnetoresistive effect element are each provided in four, the first group consisting of the two first giant magnetoresistive effect elements adjacent to each other, and the other two adjacent to each other. A second group of the first giant magnetoresistive elements, a third group of the two second giant magnetoresistive elements adjacent to each other, and the other two second giant magnetoresistive effects adjacent to each other. A fourth group of elements is formed, and the first group, the third group, the second group, and the fourth group are arranged in a predetermined direction on the substrate, or in a predetermined direction on the substrate. Arranged in the order of group, first group, fourth group and second group; and
Two elements (third element and fourth element) composed only of the first giant magnetoresistive effect element are formed by serially connecting the two first giant magnetoresistive effect elements that are not adjacent to each other, and are not adjacent to each other. In this magnetic sensor, two elements (fifth element and sixth element) composed of only the second giant magnetoresistive effect element are formed by connecting the two second giant magnetoresistive effect elements in series.

  According to this, there is a high possibility that stresses closer to each other are applied to the third to sixth elements. Therefore, the resistance change amounts due to the stresses of the third to sixth elements are close to each other. Therefore, a magnetic sensor configured to obtain an output value by a circuit in which the third to sixth elements are connected by a full bridge can output an output value that further eliminates the influence of stress applied to each element.

On the other hand, as described above, the magnetic sensor according to the present invention is
Forming a film to be the first giant magnetoresistive element and a film to be the second giant magnetoresistive element on a substrate;
A heat treatment step in a magnetic field for fixing the magnetization direction of the pinned layer of each film by applying a magnetic field in the same direction to each formed film at a high temperature;
It can manufacture easily by the manufacturing method containing.

  That is, by this heat treatment in a magnetic field, the magnetization of the pinned layer of the pinned layer of the first giant magnetoresistive element and the pinned layer of the pinned layer of the second giant magnetoresistive element can be easily pinned in directions different by 180 degrees. Therefore, it is possible to easily manufacture two giant magnetoresistive elements whose magnetic detection directions are 180 degrees different from each other on a single substrate.

in this case,
The heat treatment step in the magnetic field includes
A plurality of permanent magnets having a substantially rectangular parallelepiped shape and having a substantially square cross-section perpendicular to one central axis of the rectangular parallelepiped are arranged so that the center of gravity of the end surface having the substantially square shape coincides with the lattice point of the square lattice. And the magnetic field formed by the magnet array arranged so that the polarity of the magnetic poles of the permanent magnets arranged in the same manner is different from the polarity of the magnetic poles of other permanent magnets adjacent to each other at the shortest distance. It is preferably used as a magnetic field during the heat treatment step.

Furthermore, the film forming step includes
A first film forming step of forming one of a film to be the first giant magnetoresistive element and a film to be the second giant magnetoresistive element on the substrate;
A first unnecessary portion removing step of removing an unnecessary portion of the formed one film;
An insulating film forming step of covering the one film from which the unnecessary portion has been removed with an insulating film;
A second film forming step of forming the other film of the film to be the first giant magnetoresistive element and the film to be the second giant magnetoresistive element on the substrate and the insulating film;
A second unnecessary portion removing step of removing an unnecessary portion of the other formed film;
Is preferably included.

  Thereby, the magnetic sensor which formed the 1st giant magnetoresistive effect element and the 2nd giant magnetoresistive effect element on the single substrate can be manufactured easily.

In addition, the film forming step includes
A film serving as the pinning layer of the second giant magnetoresistive effect element, a film serving as the second ferromagnetic film, and a film serving as the exchange coupling film are sequentially stacked on the substrate to form a first preliminary film. A first preliminary film forming step,
The exchange coupling film of the first preliminary film in the portion where the first giant magnetoresistive element is to be formed without removing the first preliminary film in the portion where the second giant magnetoresistive element is to be formed A first exchange coupling membrane removal step of removing all of the membrane to be
The same ferromagnetic film as the second ferromagnetic film is formed on the entire top surface of the film that has undergone the first exchange coupling film removal step, and then the first giant magnetoresistive element and the second A first additional film forming step of forming a film to be a spacer layer and a free layer of the giant magnetoresistive element;
Can be included.

  According to this, a film to be a second giant magnetoresistive element having a first ferromagnetic film and a second ferromagnetic film sandwiching an exchange coupling film on one side is formed, and the other is laminated in two portions. A film to be a first giant magnetoresistive effect element is formed, in which the formed ferromagnetic film is provided in a film to be a fixed layer (film to be a pinned layer). Therefore, also by this method, a magnetic sensor in which the first giant magnetoresistive element and the second giant magnetoresistive element are formed on a single substrate can be easily manufactured.

Furthermore, the film forming step includes
A film to be a free layer of the first giant magnetoresistive element and the second giant magnetoresistive element, a film to be a spacer layer of the first giant magnetoresistive element and the second giant magnetoresistive element, Forming a second preliminary film in which a film to be the first ferromagnetic film of the two giant magnetoresistive effect elements and a film to be the exchange coupling film of the second giant magnetoresistive effect element are sequentially laminated on the substrate; A second preliminary film forming step,
The exchange coupling film of the second preliminary film where the first giant magnetoresistive element is to be formed without removing the second spare film where the second giant magnetoresistive element is to be formed A second exchange coupling membrane removal step of removing all of the membrane to be
The same ferromagnetic material film as the first ferromagnetic material film is formed on the entire top surface of the film that has undergone the second exchange coupling film removal step, and then the first giant magnetoresistive element and the second A second additional film forming step of forming a film to be a pinning layer of the giant magnetoresistive element;
Can be included.

  This also forms a film that becomes the second giant magnetoresistive element having the first ferromagnetic film and the second ferromagnetic film sandwiching the exchange coupling film on one side, and is laminated in two on the other side. The first giant magnetoresistive element and the second giant magnetoresistive element are formed because the film that becomes the first giant magnetoresistive effect element having the ferromagnetic film as the pinned layer (film that becomes the pinned layer) is formed. A magnetic sensor in which an effect element is formed on a single substrate can be easily manufactured.

Embodiments of a magnetic sensor according to the present invention will be described below with reference to the drawings.
<First Embodiment>
(Magnetic sensor structure)
The magnetic sensor 10 according to the first embodiment of the present invention shown in a plan view in FIG. 1 includes a single substrate (monolithic chip) 10a and a total of eight giant magnetoresistive elements 11 to 14, 21 to 24. And. The magnetic sensor 10 is referred to as “N type magnetic sensor 10” for convenience.

  The substrate 10a is made of silicon. The substrate 10a has a rectangular shape (substantially square shape) having sides along the X axis and the Y axis orthogonal to each other in plan view, and has a small thickness in the Z axis direction orthogonal to the X axis and the Y axis. It is.

  The giant magnetoresistive elements 11, 12, 21 and 22 are the normal GMR elements described above. The giant magnetoresistive elements 13, 14, 23, and 24 are elements composed of a synthetic spin valve film including a multi-layer laminated fixed layer (to be described later) (hereinafter referred to as “SAF element” for convenience).

  In the present embodiment, the giant magnetoresistive elements 11, 12, 13 and 14 are also referred to as first, second, third and fourth X-axis magnetic sensing elements, respectively, and the giant magnetoresistive elements 21, 22, 23 and 24 are used. Are also referred to as first, second, third and fourth Y-axis magnetic sensing elements, respectively. Also, the normal GMR elements 11 and 12 are the first giant magnetoresistive effect element, the SAF elements 13 and 14 are the second giant magnetoresistive effect element, and the normal GMR elements 21 and 22 are the third giant magnetoresistive effect element, the SAF element 23, 24 is also referred to as a fourth giant magnetoresistive element.

  Normally, the GMR elements 11, 12, 21, and 22 have substantially the same structure except for the difference in arrangement on the substrate 10a. Therefore, the structure of the normal GMR element 11 will be described below using the typical GMR element 11 as a representative example.

  As shown in FIG. 3 which is a schematic sectional view in which the normal GMR element 11 is cut along a plane along line 1-1 of FIG. 2 and FIG. In this example, there are six narrow strip portions 11a1 to 11a6, a plurality (seven in this example) of bias magnet films 11b1 to 11b7, and a pair of terminal portions 11c1 and 11c2.

  Each of the narrow strip portions 11a1 to 11a6 has a longitudinal direction in the Y-axis direction. The end on the Y axis negative direction side of the narrow strip portion 11a1 located closest to the X axis positive direction side is formed on the bias magnet film 11b1. The bias magnet film 11b1 is connected to the connection portion 11c1. The end of the narrow strip portion 11a1 on the Y axis positive direction side is formed on the bias magnet film 11b2.

  The narrow strip portion 11a2 is disposed adjacent to the narrow strip portion 11a1 on the X axis negative side of the narrow strip portion 11a1. One end of the narrow strip portion 11a2 is formed on the bias magnet film 11b2, and is connected to the narrow strip portion 11a1 on the bias magnet film 11b2. The other end of the narrow strip portion 11a2 is formed on the bias magnet film 11b3.

  The narrow strip portion 11a3 is disposed adjacent to the narrow strip portion 11a2 on the X-axis negative side of the narrow strip portion 11a2. One end of the narrow strip portion 11a3 is formed on the bias magnet film 11b3 and is connected to the narrow strip portion 11a2 on the bias magnet film 11b3. The other end of the narrow strip portion 11a3 is formed on the bias magnet film 11b4.

  The narrow strip portion 11a4 is disposed adjacent to the narrow strip portion 11a3 on the X-axis negative side of the narrow strip portion 11a3. One end of the narrow strip portion 11a4 is formed on the bias magnet film 11b4 and is connected to the narrow strip portion 11a3 on the bias magnet film 11b4. The other end of the narrow strip portion 11a4 is formed on the bias magnet film 11b5.

  The narrow strip portion 11a5 is disposed adjacent to the narrow strip portion 11a4 on the X-axis negative side of the narrow strip portion 11a4. One end of the narrow strip portion 11a5 is formed on the bias magnet film 11b5 and is connected to the narrow strip portion 11a4 on the bias magnet film 11b5. The other end of the narrow strip portion 11a5 is formed on the bias magnet film 11b6.

  The narrow strip portion 11a6 is disposed adjacent to the narrow strip portion 11a5 on the X axis negative side of the narrow strip portion 11a5. One end of the narrow strip portion 11a6 is formed on the bias magnet film 11b6 and is connected to the narrow strip portion 11a5 on the bias magnet film 11b6. The other end of the narrow strip portion 11a6 is formed on the bias magnet film 11b7. The bias magnet film 11b7 is connected to the connection portion 11c2. Thus, the normal GMR element 11 is an element in which a plurality of narrow strips are arranged in a zigzag shape and connected in series.

Each of the narrow strip portions 11a1 to 11a6 is made of a normal spin valve film whose film configuration is shown in FIG. This spin valve film is formed on the free layer F formed on the substrate 10a, the spacer layer S formed on the free layer F, the fixed layer P formed on the spacer layer S, and the fixed layer P. The protective layer (capping layer) C is formed. In practice, an insulating / wiring layer made of SiO ₂ or SiN (not shown) is formed between the upper surface of the substrate 10a and the free layer F.

  The free layer F is a layer whose magnetization direction changes in accordance with the direction of the external magnetic field. The free layer F includes a CoZrNb amorphous magnetic layer formed directly on the substrate 10a, a NiFe magnetic layer formed on the CoZrNb amorphous magnetic layer, and a CoFe magnetic layer formed on the NiFe magnetic layer. Yes. These constitute a soft ferromagnetic film.

  Since each of the narrow strip portions 11a1 to 11a6 has a longitudinal direction, the free layer F has a shape having a longitudinal direction along the Y-axis direction. Therefore, the direction of magnetization of the free layer F when the external magnetic field is not applied to the free layer F (hereinafter referred to as “the direction of magnetization in the initial state”) depends on the shape anisotropy. It is the longitudinal direction (normally the Y-axis positive direction in the case of the GMR element 11).

  The spacer layer S is a film made of a nonmagnetic conductor (Cu in this example).

  The fixed layer (fixed layer, fixed magnetization layer) P is a single film in which a CoFe magnetic layer Pd, which is a ferromagnetic film, and an antiferromagnetic film Pi formed of a PtMn alloy containing 45 to 55 mol% of Pt are stacked. It is a fixed layer. The CoFe magnetic layer Pd constitutes a pinned layer Pd in which the direction of magnetization (magnetization vector) is pinned (fixed) in the positive direction of the X-axis by being back-coupled to the antiferromagnetic film Pi constituting the pinning layer in an exchange coupling manner. is doing. The magnetization direction of the CoFe magnetic layer Pd is the fixed magnetization direction of the pinned layer of each normal GMR element.

  The protective layer C is made of titanium (Ti) or tantalum (Ta).

  Referring to FIGS. 2 and 3 again, the bias magnet films 11b1 to 11b7 are made of a hard ferromagnetic material such as CoCrPt and have a high coercive force and a high squareness ratio. Magnet film). The bias magnet films 11b1 to 11b7 are magnetically coupled to the free layer F formed immediately above each of the bias magnet films 11b1 to 11b7, and the longitudinal direction of the free layer F relative to the free layer F (in the case of the normal GMR element 11, the Y-axis positive Direction)).

  With the above configuration, the resistance value of the normal GMR element 11 is acquired from the connection portion 11c1 and the connection portion 11c2 as the sum of the resistance values of the narrow strip portions 11a1 to 11a6. As a result, the normal GMR element 11 has the fixed magnetization direction of the CoFe magnetic layer Pd of the fixed layer P in the range of −Hc to + Hc, as shown in FIGS. 4B and 4C. In this case, a resistance value that changes with respect to the external magnetic field H that changes along the X-axis positive direction (resistance value that decreases as the magnitude of the external magnetic field in the X-axis positive direction increases) is shown. ing. In other words, the magnetic detection direction of the normal GMR element 11 is an antiparallel direction (a direction different by 180 degrees) from the fixed magnetization direction of the CoFe magnetic layer Pd of the fixed layer P adjacent to the spacer layer S. Note that the normal GMR element 11 exhibits a substantially constant resistance value with respect to an external magnetic field that changes along the Y axis.

  On the other hand, the SAF elements 13, 14, 23, and 24 have substantially the same structure except that the arrangement on the substrate 10a is different. Therefore, the structure of the SAF element 13 will be described below using the SAF element 13 as a representative example.

The SAF element 13 has the same structure as the normal GMR element 11 except for the film configuration of the spin valve film.
The SAF element 13 is made of a synthetic spin valve film shown in FIG. This synthetic spin valve film includes a free layer F formed on the substrate 10a, a spacer layer S formed on the free layer F, a fixed layer P ′ and a fixed layer P ′ formed on the spacer layer S. And a protective layer (capping layer) C formed on the substrate.

  The free layer F, spacer layer S, and protective layer C of the synthetic spin valve film have the same configuration as that of the normal spin valve film shown in FIG. That is, the synthetic spin valve film is different from the fixed layer P of a normal spin valve film only in the fixed layer P ′.

  The fixed layer P ′ is laminated on the first ferromagnetic film P1 made of CoFe, the exchange coupling film Ex made of Ru laminated on the first ferromagnetic film P1, and the exchange coupling film Ex. A second ferromagnetic film P2 made of CoFe, and an exchange bias film (antiferromagnetic film) Eb made of a PtMn alloy that is laminated on the second ferromagnetic film P2 and contains 45 to 55 mol% of Pt. It is a multi-layer laminated fixed layer that is superposed.

  The exchange coupling film Ex is sandwiched between the first ferromagnetic film P1 and the second ferromagnetic film P2. The first ferromagnetic film P1 forms a pinned layer that is fixed so that the direction of magnetization does not change with respect to the change of the external magnetic field in cooperation with the exchange coupling film Ex and the second ferromagnetic film P2. Yes. The exchange bias film Eb constitutes a pinning layer that fixes the magnetization direction of the first ferromagnetic film P1, which is a pinned layer, via the second ferromagnetic film P2 and the exchange coupling film Ex. The first ferromagnetic film P1, the exchange coupling film Ex, and the second ferromagnetic film P2 can also be called a pinned layer.

  The exchange bias film Eb exchange-couples with the second ferromagnetic film P2, and fixes the direction of magnetization (magnetization vector) of the second ferromagnetic film P2 in the positive X-axis direction. The first ferromagnetic film P1 and the second ferromagnetic film P2 are exchange coupled with each other via the exchange coupling film Ex. At this time, as indicated by an arrow in FIG. 5B, the magnetization direction of the first ferromagnetic film P1 and the magnetization direction of the second ferromagnetic film P2 are antiparallel. As a result, the magnetization direction of the first ferromagnetic film P1 is fixed in the negative X-axis direction.

  In the SAF element 13 configured as described above, as shown in FIG. 5C, the first ferromagnetic film P1 (pinned layer) in the fixed layer P ′ is fixed in the range of −Hc to + Hc. A resistance value that changes with respect to the external magnetic field H that changes along the direction of magnetization (a resistance value that increases as the magnitude of the external magnetic field H in the positive direction of the X axis increases) is shown. In other words, the magnetic detection direction of the SAF element 13 is antiparallel to the fixed magnetization direction of the first magnetic layer P1 of the fixed layer P ′ adjacent to the spacer layer S. The SAF element 13 exhibits a substantially constant resistance value against an external magnetic field that changes along the Y axis.

  Referring again to FIG. 1, the normal GMR element 11 is formed in the vicinity of the X-axis positive direction end portion at a position approximately above the center of the substrate 10 a in the Y-axis direction. Usually, the magnetic detection direction of the GMR element 11 is the negative X-axis direction. Usually, the GMR element 12 is formed in the vicinity of the end in the X-axis positive direction below the central portion of the substrate 10a in the Y-axis direction. Usually, the magnetic detection direction of the GMR element 12 is the negative X-axis direction.

  The SAF element 13 is formed at a position away from the normal GMR element 11 in the X-axis negative direction by a slight distance above the substantially central portion of the substrate 10a in the Y-axis direction. The magnetic detection direction of the SAF element 13 is the X-axis positive direction. The SAF element 14 is formed at a position that is separated from the GMR element 12 by a slight distance in the negative direction of the X axis, generally below the center of the substrate 10a in the Y axis direction. The magnetic detection direction of the SAF element 14 is the X-axis positive direction.

  As described above, the elements 11 to 14 are formed at positions close to each other (in the first minute region) in the vicinity of the X-axis positive direction end on the substrate 10a.

  Usually, the GMR element 21 is formed in the vicinity of the Y-axis positive direction end on the left side of the substantially central portion of the substrate 10a in the X-axis direction. Usually, the magnetic detection direction of the GMR element 21 is the negative Y-axis direction. Normally, the GMR element 22 is formed in the vicinity of the Y-axis positive direction end on the right side of the central portion of the substrate 10a in the X-axis direction. Normally, the magnetic detection direction of the GMR element 22 is the negative Y-axis direction.

  The SAF element 23 is formed at a position left in the negative direction of the Y axis by a slight distance from the normal GMR element 21 on the left side of the substantially central portion of the substrate 10a in the X axis direction. The magnetic detection direction of the SAF element 23 is the positive Y-axis direction. The SAF element 24 is formed at a position slightly away from the normal GMR element 22 in the Y-axis negative direction on the right side of the central portion of the substrate 10a in the X-axis direction. The magnetic detection direction of the SAF element 24 is the Y axis positive direction.

  As described above, the elements 21 to 24 are formed in positions close to each other in the vicinity of the Y-axis positive direction end on the substrate 10a (in the second minute region separated from the first minute region by a predetermined distance).

  The magnetic sensor 10 includes an X-axis magnetic sensor composed of elements 11 to 14 (magnetic sensor having the X-axis direction as a magnetic field detection direction) and a Y-axis magnetic sensor composed of elements 21 to 24 (magnetism having the Y-axis direction as a magnetic field detection direction). Sensor).

  As shown in an equivalent circuit in FIG. 6A, the X-axis magnetic sensor is configured by connecting the elements 11 to 14 through a full-bridge connection via conductors not shown in FIG. In FIG. 6A, the graphs shown at the positions adjacent to each of the elements 11 to 14 are the characteristics of the elements adjacent to the respective graphs (external magnetic fields whose sizes change along the X axis (external (X-axis positive direction component of magnetic field H) Change in resistance value R with respect to Hx). In addition, the symbol “Conv” is attached to the normal GMR element after each symbol, and the symbol “SAF” is attached to the SAF element.

  The X-axis magnetic sensor will be specifically described. Usually, one end of the GMR element 11 and one end of the SAF element 113 are connected to constitute a first circuit element. Usually, a first potential (a constant voltage given by a constant voltage source not shown) + V is applied to the other end of the GMR element 11. The other end of the SAF element 13 is grounded (connected to GND). That is, a second potential different from the first potential is applied to the other end of the SAF element 13.

  Further, one end of the normal GMR element 12 and one end of the SAF element 14 are connected to form a second circuit element. A first potential + V is applied to the other end of the SAF element 14. Usually, the other end of the GMR element 12 is grounded (connected to GND). That is, the second potential different from the first potential is applied to the other end of the normal GMR element 12.

  A potential difference Vox () between the potential VQ1 of the connection point Q1 between one end of the normal GMR element 11 and one end of the SAF element 13 and the potential VQ2 of the connection point Q2 between one end of the normal GMR element 12 and one end of the SAF element 14 is obtained. = VQ2-VQ1) is taken out as the sensor output value (first output value). As a result, as shown in FIG. 6B, the X-axis magnetic sensor outputs a voltage Vox that is substantially proportional to the external magnetic field Hx and decreases as the external magnetic field Hx increases.

  As shown in an equivalent circuit in FIG. 7A, the Y-axis magnetic sensor is configured by connecting the elements 21 to 24 through a full-bridge connection that is not shown in FIG. In FIG. 7A, the graphs shown at positions adjacent to each of the elements 21 to 24 are the characteristics of the elements adjacent to the respective graphs (external magnetic field H (the magnitude of which changes along the Y axis). (Y-axis positive direction component of external magnetic field) (change in resistance value R with respect to Hy).

  More specifically describing the Y-axis magnetic sensor, one end of the GMR element 21 and one end of the SAF element 23 are usually connected to constitute a third circuit element. Usually, the first potential + V is applied to the other end of the GMR element 21. The other end of the SAF element 23 is grounded (connected to GND). That is, a second potential different from the first potential is applied to the other end of the SAF element 23.

  Further, one end of the normal GMR element 22 and one end of the SAF element 24 are connected to constitute a fourth circuit element. A first potential + V is applied to the other end of the SAF element 24. Usually, the other end of the GMR element 22 is grounded (connected to GND). That is, the second potential different from the first potential is applied to the other end of the normal GMR element 22.

  A potential difference Voy between the potential VQ3 of the connection point Q3 between one end of the normal GMR element 21 and one end of the SAF element 23 and the potential VQ4 of the connection point Q4 between one end of the normal GMR element 22 and one end of the SAF element 24 is obtained. = VQ3−VQ4) is taken out as the output value (second output value) of the sensor. As a result, as shown in FIG. 7B, the Y-axis magnetic sensor outputs a voltage Voy that is substantially proportional to the external magnetic field Hy that changes along the Y-axis and increases as the external magnetic field Hy increases. It is like that.

(Method of fixing the magnetization of the pinned layer of the magnetic sensor 10)
Next, a method for fixing the magnetization of each pinned layer of the elements 11 to 14 and 21 to 24 will be described. First, as shown in FIG. 8 which is a plan view, a plurality of films M constituting the elements 11 to 14 and 21 to 24 are formed in an island shape on a substrate 10a-1 to be a substrate 10a later. These films M are formed when the substrate 10a-1 is cut along the cutting line CL shown by the chain line in FIG. 8 in a subsequent cutting step and divided into the individual magnetic sensors 10 shown in FIG. 11 to 14 and 21 to 24 are formed so as to be arranged at respective positions on the substrate 10a shown in FIG. A method for forming the film M will be described later.

  Next, the magnet array 30 shown in FIGS. 9 and 10 is prepared. FIG. 9 is a plan view of the magnet array 30. FIG. 10 is a cross-sectional view of the magnet array 30 obtained by cutting the magnet array 30 along a plane along line 2-2 in FIG. The magnet array 30 includes a plurality of permanent magnets (permanent bar magnets) 31... 31 each having a rectangular parallelepiped shape and a plate 32 made of transparent quartz glass. The permanent magnets 31... 31 are arranged in a square lattice shape, and each upper surface is fixed to the lower surface of the plate 32. The permanent magnets 31... 31 are arranged so that the polarities of the adjacent magnetic poles are different at the shortest distance on the plane including the end faces of the permanent magnets 31.

  That is, the magnet array 30 includes a plurality of permanent magnets 31 having a substantially rectangular parallelepiped shape and a cross-sectional shape orthogonal to one central axis of the rectangular parallelepiped. The center of gravity of an end surface having the substantially square shape is a square lattice. The magnetic poles of the permanent magnets 31 are arranged so as to coincide with the lattice points, and are arranged and configured so that the polarities of the permanent magnets 31 arranged in the same manner are different from the polarities of the other permanent magnets 31 adjacent to each other with a shortest distance. Magnet array.

  FIG. 11 is a perspective view of the permanent magnet showing a state in which only five of the permanent magnets 31... 31 are taken out. As is clear from this figure, the direction of the end faces of the permanent magnets 31... 31 (end faces on which the magnetic poles are formed) is different by 90 ° from one N pole to the S pole adjacent to the N pole at the shortest distance. A magnetic field is formed. In the present embodiment, this magnetic field is used as a magnetic field for fixing the magnetization directions of the pinned layers of the elements 11 to 14 and 21 to 24.

  Next, the substrate 10 a-1 on which the film M is formed is disposed on the magnet array 30. At this time, as shown in the plan view of FIG. 12, the two sides where the square film M formed when the substrate 10a-1 is cut along the cutting line CL are not formed adjacent to each other and the two sides are formed. The substrate 10a-1 and the magnet array 30 are relatively arranged so that the intersection points coincide with the two cutting lines CL and the intersections of the two cutting lines CL, respectively. As a result, as indicated by arrows in FIGS. 11 and 12, a magnetic field in a direction orthogonal to the longitudinal direction of the narrow strip portion of each film M is applied to each film M.

  Then, the substrate 10a-1 and the magnet array 30 in this state are heated to 250 ° C. to 280 ° C. in a vacuum, and then heat treatment in a magnetic field is performed for about 4 hours. As a result, the magnetization direction of the fixed layer P (pinned layer Pd) and the magnetization direction of the fixed layer P ′ (pinned layer P1) are fixed.

  By the way, as shown in FIG. 13, when an ordinary GMR element whose magnetic detection directions are antiparallel to each other (180 degrees different) is formed at a position close to each other, one film M1 that becomes the ordinary GMR element is formed. The direction of the magnetic field applied during the heat treatment in the magnetic field and the direction of the magnetic field applied during the heat treatment in the magnetic field to the other film M2 that is normally a GMR element must be antiparallel to each other. However, it is generally difficult to generate an antiparallel magnetic field having a large size in such a small region. For this reason, conventionally, the distance between two normal GMR elements is increased, and magnetic fields (or magnets) having different orientations of 180 degrees from one N pole of the magnet array 30 to two S poles adjacent to the N pole. A magnetic field having a 180-degree orientation difference from two south poles adjacent to the south pole to the south pole from one south pole of the array 30 is applied.

  On the other hand, as shown in FIG. 14, when a film M3, which is a normal GMR element, and a film M4, which is a SAF element, are formed close to each other, and a magnetic field in the same direction is applied in a magnetic field heat treatment, magnetic detection Giant magnetoresistive elements having directions antiparallel to each other are obtained. This is because the magnetization directions of the pinned layer Pd (CoFe magnetic layer) of the pinned layer P of the film normally serving as the GMR element and the second ferromagnetic film P2 of the pinned layer P ′ of the film serving as the SAF element coincide with each other. This is because the magnetization direction of the first ferromagnetic film P1 in the layer P ′ is antiparallel to the magnetization direction of the second ferromagnetic film P2.

  Therefore, according to this method, it is possible to form two or more giant magnetoresistance effect elements whose magnetic detection directions are different from each other by 180 degrees in an extremely narrow region.

  Actually, after performing the heat treatment in the magnetic field as described above, necessary processing such as magnetization of the bias magnet film or the like is performed, and the substrate 10a-1 is cut along the cutting line CL shown in FIG. . Thereby, a large number of the magnetic sensors 10 shown in FIG. 1 and the magnetic sensors 40 shown in FIG. 15 are manufactured simultaneously.

  This magnetic sensor 40 is referred to as “S-type magnetic sensor 40” for convenience. Here, the magnetic sensor 40 will be described. The magnetic sensor 40 includes giant magnetoresistive elements 41 to 44 and 51 to 54. The elements 41, 42, 51 and 52 are usually GMR elements, and the elements 43, 44, 53 and 54 are SAF elements. The direction of magnetization in the initial state of the free layer of these elements and the direction of magnetization of the pinned layer (the ferromagnetic film in contact with the spacer layer) (thus, the direction antiparallel to the magnetic detection direction) are shown in FIG. As shown.

  The elements 41, 42, 43, and 44 are respectively referred to as first, second, third, and fourth X-axis magnetic sensing elements, and are full-bridge connected in the same manner as the elements 11, 12, 13, and 44 of the magnetic sensor 10. Thus, an X-axis magnetic sensor is configured. Similarly, the elements 51, 52, 53, and 54 are referred to as first, second, third, and fourth Y-axis magnetic sensing elements, respectively, and are in full bridge connection like the elements 21, 22, 23, and 24 of the magnetic sensor 10. Thus, a Y-axis magnetic sensor is configured.

(First manufacturing method of membrane M)
Next, a first manufacturing method (film forming process) of the above-described film M (a film that normally becomes a GMR element and a film that becomes a SAF element) will be described.

  Step 1: First, as shown in FIG. 16A, a substrate 10a is prepared. An insulating / wiring layer including the wiring 10a1 for bridge connection and the insulating layer 10a2 covering the wiring 10a1 is formed on the substrate 10a. A connection hole called a VIA hole is formed in the insulating layer 10a2. A part of the wiring 10a1 is exposed to the outside through the VIA hole.

Step 2: As shown in FIG. 16B, a film made of CoCrPt to be the bias magnet film 10b is formed on the upper surface of the substrate 10a by sputtering.
Step 3: As shown in FIG. 16C, a resist R1 is formed on the upper surface of the bias magnet film 10b, and the resist R1 is cut into a pattern that covers only a necessary portion of the bias magnet film 10b. That is, a resist mask made of the resist R1 is formed.

Step 4: As shown in FIG. 17A, unnecessary portions of the bias magnet film 10b are removed by ion milling.
Step 5: As shown in FIG. 17B, the resist R1 is removed.
Step 6: As shown in FIG. 17C, the film 10c shown in FIG. 4A to be a normal GMR element is formed on the upper surface.

Step 7: As shown in FIG. 18A, a resist R2 is formed on the upper surface, and the resist R2 is cut into a pattern that covers only a necessary portion of the film 10c that normally becomes a GMR element. That is, a resist mask made of the resist R2 is formed.
Step 8: As shown in FIG. 18B, unnecessary portions of the film 10c that normally becomes a GMR element are removed by ion milling.
Step 9: As shown in FIG. 18C, the resist R2 is removed.

Step 10: As shown in FIG. 19A, an interlayer insulating film INS1 made of SiN is formed on the upper surface by CVD. The interlayer insulating film INS1 may be SiO ₂ .
Step 11: As shown in FIG. 19B, a resist R3 is formed on the upper surface, and the resist R3 is cut into a pattern that covers only a portion that will later become a normal GMR element. That is, a resist mask made of the resist R3 is formed.
Step 12: As shown in FIG. 19C, unnecessary portions of the interlayer insulating film INS1 are removed by ion milling.

Step 13: As shown in FIG. 20A, the resist R3 is removed.
Step 14: As shown in FIG. 20B, the film 10d shown in FIG. 5A to be the SAF element is formed on the upper surface.
Step 15: As shown in FIG. 20C, a resist R4 is formed on the upper surface, and the resist R4 is cut into a pattern covering only a necessary portion of the film 10d to be the SAF element. That is, a resist mask is formed from the resist R4.

Step 16: As shown in FIG. 21A, unnecessary portions of the film 10d to be the SAF element are removed by ion milling.
Step 17: As shown in FIG. 21B, the resist R4 is removed.
As described above, a film that will be a normal GMR element is formed on the left side of the sheet of FIG. 21B, and a film that will be a SAF element is formed on the right side. Thereafter, the above-described heat treatment in a magnetic field is performed.

  In the above method, the film that becomes the normal GMR element is formed first, and then the film that becomes the SAF element is formed. However, the film that becomes the SAF element is formed first, and then the normal GMR element is formed. A film may be formed.

Thus, the first manufacturing method is
First film formation in which one of a film to be a first giant magnetoresistance effect element (usually GMR element) and a film to be a second giant magnetoresistance effect element (SAF element) is formed on a single substrate Process (step 6);
A first unnecessary portion removing step (steps 7 to 9) for removing an unnecessary portion of the one formed film;
An insulating film forming step (steps 10 to 13) for covering the one film from which the unnecessary portion has been removed with an insulating film;
A second film forming step of forming the other film of the film to be the first giant magnetoresistive element and the film to be the second giant magnetoresistive element on the substrate and the insulating film (step 14); )When,
A second unnecessary portion removing step (steps 15 to 17) for removing an unnecessary portion of the other formed film;
The film formation process provided with this is included.
Thereby, a film that normally becomes a GMR element and a film that becomes a SAF element are continuously formed on a single substrate.

(Second manufacturing method of membrane M)
Next, the second manufacturing method of the above-described film M will be described. The film formed by the second manufacturing method is a film in which the fixed layers P and P ′ are disposed on the substrate, and the spacer layer S and the free layer F are formed thereon. Such a film is also called a bottom spin valve film.

Step 1: First, the substrate 10a shown in FIG. 22A is prepared. This substrate has the same structure as the substrate 10a shown in FIG.
Step 2: As shown in FIG. 22B, a film made of CoCrPt to be the bias magnet film 10b is formed on the upper surface of the substrate 10a by sputtering.
Step 3: As shown in FIG. 22C, a resist R1 is formed on the upper surface of the film to be the bias magnet film 10b, and the resist R1 is cut into a pattern covering only a necessary portion of the bias magnet film 10b. That is, a resist mask made of the resist R1 is formed.

Step 4: As shown in FIG. 23A, unnecessary portions of the bias magnet film 10b are removed by ion milling.
Step 5: As shown in FIG. 23B, the resist R1 is removed. The steps up to step 5 are the same as the steps up to step 5 of the first manufacturing method described above.
Step 6: As shown in FIG. 24A, a PtMn film, a CoFe film, and a Ru film are sequentially formed (laminated). That is, a part of the film to be the SAF element (hereinafter also referred to as “SAF first laminated film”) is formed. FIG. 24B is an enlarged view of the first laminated film for SAF.

  Step 7: As shown in FIG. 25A, a resist R5 is formed on the upper surface, and the resist R5 covers a portion of the first laminated film for SAF necessary for forming the SAF element and its periphery. Cut into patterns. That is, a resist mask made of the resist R5 is formed. FIG. 25B is an enlarged view showing the vicinity of the end of the resist R5.

Step 8: As shown in FIG. 26A, unnecessary Ru film is removed by ion milling, and part of the CoFe film is removed. FIG. 26B is an enlarged view of the film that has been subjected to ion milling.
Step 9: As shown in FIG. 26C, the resist R5 is removed.

  Step 10: As shown in FIG. 27A, a CoFe film, a film made of a spacer layer made of Cu, and a film made a free layer made of a CoFe film, a NiFe film, and a CoZrNb film are formed on the upper surface. Laminate in order. FIG. 27B is an enlarged view of the film thus formed. At this stage, the above-described heat treatment in a magnetic field is performed.

Step 11: As shown in FIG. 28A, a resist R6 is formed on the upper surface, and the resist R6 is a pattern that covers only a necessary portion corresponding to a film that normally becomes a GMR element and a film that becomes a SAF element. Cut into. That is, a resist mask made of the resist R6 is formed.
Step 12: As shown in FIG. 28B, unnecessary film portions are removed by ion milling.
Step 13: As shown in FIG. 28C, the resist R6 is removed.
As a result, a film that will be a SAF element is formed on the left side of the sheet of FIG. 28C, and a film that will be a normal GMR element is formed on the right side.

Thus, the second manufacturing method is
A film serving as the pinning layer, a film serving as the second ferromagnetic film, and a film serving as the exchange coupling film of the second giant magnetoresistive effect element (SAF element) are sequentially stacked on the substrate. A first preliminary film forming step (step 6) for forming a film (first laminated film for SAF);
The first preliminary film of the portion where the first giant magnetoresistive element (usually GMR element) is to be formed without removing the first preliminary film of the portion where the second giant magnetoresistive element is to be formed. A first exchange coupling membrane removal step (steps 7 to 9) for removing all of the membrane to be the exchange coupling membrane;
The same ferromagnetic film as the second ferromagnetic film is formed on the entire top surface of the film that has undergone the first exchange coupling film removal step, and then the first giant magnetoresistive element and the second A first additional film forming step (step 10) for forming a film serving as a spacer layer and a free layer of the giant magnetoresistive element;
The film formation process provided with this is included.
Thereby, a film that normally becomes a GMR element and a film that becomes a SAF element are continuously formed on a single substrate.

(Third manufacturing method of the film M)
Next, the third manufacturing method of the above-described film M will be briefly described with reference to FIG. The film formed by the third manufacturing method is the same film as the film formed by the first manufacturing method, and the free layer F is disposed on the substrate, and the spacer layer S and the fixed layers P and P ′. Is a film formed thereon. Such a film is also referred to as a top spin valve film.

  Step 1; First, as shown in Step 1 of FIG. 29, a film (as a free layer F) is formed on the substrate 10a on which the bias magnet film 10b is formed by executing up to Step 5 of the first manufacturing method. (CoZrNb film, NiFe film, and CoFe film), a film that becomes the spacer layer S, a CoFe film, and a Ru film are sequentially stacked.

Step 2: Next, as shown in Step 2 of FIG. 29, a resist is formed on the portion where the SAF element is to be formed, and unnecessary portions of the Ru film and the CoFe film immediately below the Ru film are formed by ion milling. Remove the top.
Step 3: Next, the resist is removed.
Step 4: Next, as shown in Step 4 of FIG. 29, a CoFe film, a PtMn film, and a Ta film are sequentially laminated. As a result, a film that becomes the fixed layer P ′ of the film that becomes the SAF element is formed in the portion where the Ru film remains, and a fixed layer P of the film that usually becomes the GMR element is formed in the portion where the Ru film does not remain. A film is formed.

Step 5: Next, the above-described heat treatment in a magnetic field is performed to fix the magnetization direction of the pinned layer of the fixed layer P and the magnetization direction of the pinned layer of the fixed layer P ′.
Step 6: Finally, a normal GMR element and a SAF element are formed by performing a patterning process similar to the steps shown in FIGS.

Thus, the third manufacturing method is
Films to be free layers of the first giant magnetoresistance effect element (usually GMR element) and the second giant magnetoresistance effect element (SAF element), spacers of the first giant magnetoresistance effect element and the second giant magnetoresistance effect element A film to be a layer, a CoFe film to be the first ferromagnetic film of the second giant magnetoresistive effect element, and a film to be the exchange coupling film of the second giant magnetoresistive effect element are sequentially laminated on the substrate. A second preliminary film forming step (step 1) for forming the second preliminary film,
The exchange coupling film of the second preliminary film where the first giant magnetoresistive element is to be formed without removing the second spare film where the second giant magnetoresistive element is to be formed A second exchange coupling film removal step (steps 2 and 3) for removing all of the film to be
The same ferromagnetic film (CoFe film) as the first ferromagnetic film is formed on the entire top surface of the film that has undergone the second exchange coupling film removal step, and then the first giant magnetoresistive element And a second additional film forming step (step 4) for forming a film to be a pinning layer of the second giant magnetoresistive element,
The film formation process provided with this is included.
Thereby, a film that normally becomes a GMR element and a film that becomes a SAF element are continuously formed on a single substrate.

  As described above, since the magnetic sensor 10 has a structure including a normal GMR element and a SAF element on a single substrate, a magnetic field in a single direction is formed after the films to be these elements are formed at close positions. By adding, an element having a magnetic detection direction different by 180 degrees can be provided in a minute region. Therefore, the magnetic sensor 10 is a very small magnetic sensor.

  On the other hand, in the magnetic sensor 10, the giant magnetoresistive effect elements 11 to 14 and 21 to 24 are formed on the substrate 10a and covered with a resin or the like. Therefore, when the substrate 10a, the resin, or the like is deformed by heat or externally applied stress, the giant magnetoresistive elements 11 to 14, 21 to 24 are also deformed by heat or stress, and the resistance value changes. As a result, in the magnetic sensor in which the giant magnetoresistive effect element is bridge-connected like the magnetic sensor 10, the lance of the bridge circuit is broken and the output value changes due to the stress. Therefore, such a magnetic sensor has a problem that the magnitude of the external magnetic field cannot be accurately detected.

  However, in the magnetic sensor 10, the giant magnetoresistive elements 11 to 14 (or giant magnetoresistive elements 21 to 24) forming one full bridge circuit are formed in a minute region on the substrate 10a. Therefore, uniform stress (for example, substantially the same tensile stress or substantially the same compressive stress) is applied to these elements. Therefore, since the resistance values of the giant magnetoresistive elements increase or decrease in the same manner, the possibility that the balance of the bridge circuit is lost is reduced. As a result, the magnetic sensor 10 can detect the magnetic field with high accuracy.

<Second Embodiment>
Next, a magnetic sensor according to a second embodiment of the invention will be described. As shown in FIG. 30, the magnetic sensor 50 includes a single substrate 50a, normal GMR elements 51G to 54G, SAF elements 61S to 64S, normal GMR elements 71G to 74G, and SAF elements 81S to 84S.

  The substrate 50a is a thin plate made of silicon having the same shape as the substrate 10a.

  Each of the normal GMR elements 51G to 54G and the normal GMR elements 71G to 74G has the same structure as the normal GMR element 11 described above. Each of the SAF elements 61S to 64S and the SAF elements 81S to 84S has the same structure as the SAF element 13 described above. In addition, these elements exhibit the same resistance value when a magnetic field of the same magnitude is applied in the respective magnetic detection directions, and each resistance value when subjected to stress of the same direction and magnitude. The film thickness and the like constituting the spin valve film are adjusted so as to change by the same amount.

  In this embodiment, the normal GMR elements 51G and 52G are the first giant magnetoresistive effect element, the SAF elements 61S and 62S are the second giant magnetoresistive effect element, and the normal GMR elements 53G and 54G are the fifth giant magnetoresistive effect element. The SAF elements 63S and 64S are also referred to as sixth giant magnetoresistance effect elements.

  The positions of these elements on the substrate 50a, the fixed magnetization directions of the pinned layers Pd of the fixed layers P of the normal GMR elements 51G to 54G and 71G to 74G, and the fixed layers P ′ of the SAF elements 61S to 64S and 81S to 84S The fixed magnetization direction and the magnetic detection direction of the first ferromagnetic film P1 that is the pinned layer are as shown in FIG. 30 and Tables 1 to 4 below.

  Note that the SAF element 61S and the SAF element 62S are disposed at positions separated from the normal GMR element 51G and the normal GMR element 52G in the X-axis positive direction by a slight distance. Similarly, the SAF element 63S and the SAF element 64S are disposed at positions separated from the normal GMR element 53G and the normal GMR element 54G by a slight distance in the negative direction of the X axis.

  Note that the SAF element 81S and the SAF element 82S are disposed at positions separated from the normal GMR element 71G and the normal GMR element 72G in the Y-axis negative direction by a slight distance. Similarly, the SAF element 83S and the SAF element 84S are disposed at positions separated from the normal GMR element 73G and the normal GMR element 74G in the Y-axis positive direction by a slight distance.

  Further, the normal GMR elements 51G and 52G (first giant magnetoresistive effect element) and the SAF elements 61S and 62S (second giant magnetoresistive effect element) are close to each other, and are a first region (one narrow region). It is formed in the X-axis negative direction end region of the substrate 50a. Therefore, these elements are disposed at positions that are subjected to deformation caused by substantially the same stress.

  Similarly, the normal GMR elements 53G and 54G (fifth giant magnetoresistive effect element) and the SAF elements 63S and 64S (sixth giant magnetoresistive effect element) are close to each other and are one narrow region, It is formed in a second region (the end region in the X-axis positive direction of the substrate 50a) that is separated from one region. Therefore, these elements are disposed at positions that are subjected to deformation caused by substantially the same stress.

  Furthermore, the normal GMR element 71G, the normal GMR element 72G, the SAF element 81S, and the SAF element 82S are close to each other, and are formed in a third narrow area (the Y-axis positive end area of the substrate 50a). Has been. Therefore, these elements are disposed at positions that are subjected to deformation by the same stress.

  Similarly, the normal GMR element 73G, the normal GMR element 74G, the SAF element 83S, and the SAF element 84S are close to each other, and are a fourth region (a Y-axis of the substrate 50a) that is one narrow region and separated from the third region. Negative end region). Therefore, these elements are disposed at positions that are subjected to deformation by the same stress.

  As shown in FIG. 31, the magnetic sensor 50 includes an X-axis magnetic sensor 50X including a first X-axis magnetic sensor 50X1, a second X-axis magnetic sensor 50X2, and a difference circuit 50Xdif.

  In the first X-axis magnetic sensor 50X1, as shown in an equivalent circuit in FIG. 32A, the four normal GMR elements 51G to 54G are connected by a full bridge via conductors not shown in FIG. It is configured.

  More specifically, regarding the first X-axis magnetic sensor 50X1, one end of the normal GMR element 51G and one end of the normal GMR element 53G are connected to constitute a fifth circuit element. Usually, a first potential (a constant voltage applied by a constant voltage source not shown) + V is applied to the other end of the GMR element 51G. Usually, the other end of the GMR element 53G is grounded (connected to GND). That is, the second potential different from the first potential is applied to the other end of the normal GMR element 53G.

  Further, one end of the normal GMR element 54G and one end of the normal GMR element 52G are connected to constitute a sixth circuit element. Usually, the first potential + V is applied to the other end of the GMR element 54G. Usually, the other end of the GMR element 52G is grounded (connected to GND). That is, the second potential different from the first potential is applied to the other end of the normal GMR element 52G.

  The potential difference between the potential VQ10 at the connection point Q10 between one end of the normal GMR element 51G and one end of the normal GMR element 53G and the potential VQ20 at the connection point Q20 between one end of the normal GMR element 54G and one end of the normal GMR element 52G. VoxConv (= VQ10−VQ20) is taken out as the output value of the sensor (normal GMR element output value, normal GMR element X-axis output value).

  In FIG. 32A, the graphs shown at positions adjacent to each of the normal GMR elements 51G to 54G show the characteristics of the elements adjacent to each graph. In these graphs, a solid line, a broken line, and a two-dot chain line are obtained when each normal GMR element is not subjected to stress, when each normal GMR element is subjected to tensile stress, and when each normal GMR element is subjected to compressive stress. Changes in the resistance value R with respect to the external magnetic field Hx are shown.

  Therefore, the output VoxConv of the first X-axis magnetic sensor 50X1 is generally proportional to the external magnetic field Hx as indicated by the solid line in FIG. 32B when no stress is applied to the GMR elements 51G to 54G. The smaller the external magnetic field Hx, the smaller.

  The second X-axis magnetic sensor 50X2 is configured by a full bridge connection of four SAF elements 61S to 61S via conductors not shown in FIG. 30, as shown in an equivalent circuit in FIG. Has been.

  More specifically, regarding the second X-axis magnetic sensor 50X2, one end of the SAF element 61S and one end of the SAF element 63S are connected to constitute a seventh circuit element. A first potential + V is applied to the other end of the SAF element 61S. The other end of the SAF element 63S is grounded (connected to GND). That is, a second potential different from the first potential is applied to the other end of the SAF element 63S.

  Furthermore, one end of the SAF element 64S and one end of the SAF element 62S are connected to constitute an eighth circuit element. A first potential + V is applied to the other end of the SAF element 64S. The other end of the SAF element 62S is grounded (connected to GND). That is, a second potential different from the first potential is applied to the other end of the SAF element 62S.

  Then, the potential difference VoxSAF (= VQ30) between the potential VQ30 at the connection point Q30 between one end of the SAF element 61S and one end of the SAF element 63S and the potential VQ40 at the connection point Q40 between one end of the SAF element 64S and one end of the SAF element 62S. -VQ40) is taken out as the sensor output value (SAF element output value, SAF element X-axis output value).

  In FIG. 33A, the graphs shown at positions adjacent to each of the SAF elements 61S to 64S indicate the characteristics of the elements adjacent to each graph. In these graphs, the solid line, the broken line, and the two-dot chain line indicate the external magnetic field Hx when each SAF element is not subjected to stress, when each SAF element is subjected to tensile stress, and when each SAF element is subjected to compressive stress. The change of the resistance value R with respect to is shown, respectively.

  Therefore, the output VoxSAF of the second X-axis magnetic sensor 50X2 is substantially proportional to the external magnetic field Hx as shown by the solid line in FIG. 33B when no stress is applied to the SAF elements 61S to 64S. The larger the magnetic field Hx, the larger the magnetic field Hx.

  As shown in FIG. 31, the difference circuit 50Xdif subtracts the output VoxConv of the first X-axis magnetic sensor 50X1 from the output VoxSAF of the second X-axis magnetic sensor 50X2, and the subtraction result is the output value Vox of the X-axis magnetic sensor 50X. Is output as a circuit. As a result, the output Vox of the magnetic sensor 50 is substantially proportional to the external magnetic field Hx as shown in FIG. 34, and increases as the external magnetic field Hx increases.

  Further, the magnetic sensor 50 includes a Y-axis magnetic sensor 50Y as shown in FIG. The Y-axis magnetic sensor 50Y includes a first Y-axis magnetic sensor 50Y1, a second Y-axis magnetic sensor 50Y2, and a difference circuit 50Ydif.

  The first Y-axis magnetic sensor 50Y1, as shown in an equivalent circuit in FIG. 36A, is obtained by connecting the four normal GMR elements 71G to 74G through a full-bridge connection that is not shown in FIG. It is configured.

  More specifically, regarding the first Y-axis magnetic sensor 50Y1, the ninth circuit element is configured by connecting one end of the normal GMR element 71G and one end of the normal GMR element 73G. Usually, the first potential + V is applied to the other end of the GMR element 71G. Usually, the other end of the GMR element 73G is grounded (connected to GND). That is, the second potential different from the first potential is applied to the other end of the normal GMR element 73G.

  Further, one end of the normal GMR element 74G and one end of the normal GMR element 72G are connected to constitute a tenth circuit element. Usually, the first potential + V is applied to the other end of the GMR element 74G. Usually, the other end of the GMR element 72G is grounded (connected to GND). That is, the second potential different from the first potential is applied to the other end of the normal GMR element 72G.

  The potential difference between the potential VQ50 at the connection point Q50 between one end of the normal GMR element 71G and one end of the normal GMR element 73G and the potential VQ60 at the connection point Q60 between one end of the normal GMR element 74G and one end of the normal GMR element 72G. VoyConv (= VQ50−VQ60) is taken out as an output value of the sensor (normal GMR element output value, normal GMR element Y-axis output value).

  In FIG. 36A, the graphs shown at positions adjacent to each of the normal GMR elements 71G to 74G indicate the characteristics of the elements adjacent to each graph. In these graphs, a solid line, a broken line, and a two-dot chain line are obtained when each normal GMR element is not subjected to stress, when each normal GMR element is subjected to tensile stress, and when each normal GMR element is subjected to compressive stress. The change of the resistance value R with respect to the external magnetic field Hy is shown, respectively.

  Accordingly, the output VoyConv of the first Y-axis magnetic sensor 50Y1 is generally proportional to the external magnetic field Hy as indicated by the solid line in FIG. 36B when no stress is applied to the normal GMR elements 71G to 74G. The larger the external magnetic field Hy, the larger the external magnetic field Hy.

  The second Y-axis magnetic sensor 50Y2 is configured by full-bridge connection of four SAF elements 81S to 84S via conductors not shown in FIG. 30, as shown in an equivalent circuit in FIG. Has been.

  To describe the second Y-axis magnetic sensor 50Y2 more specifically, an eleventh circuit element is configured by connecting one end of the SAF element 81S and one end of the SAF element 83S. A first potential + V is applied to the other end of the SAF element 81S. The other end of the SAF element 83S is grounded (connected to GND). That is, a second potential different from the first potential is applied to the other end of the SAF element 83S.

  Furthermore, one end of the SAF element 84S and one end of the SAF element 82S are connected to constitute a twelfth circuit element. A first potential + V is applied to the other end of the SAF element 84S. The other end of the SAF element 82S is grounded (connected to GND). That is, a second potential different from the first potential is applied to the other end of the SAF element 82S.

  Then, the potential difference VoySAF (= VQ70) between the potential VQ70 at the connection point Q70 between one end of the SAF element 81S and one end of the SAF element 83S and the potential VQ80 at the connection point Q80 between one end of the SAF element 84S and one end of the SAF element 82S. -VQ80) is taken out as the sensor output value (SAF element output value, SAF element Y-axis output value).

  In FIG. 37A, graphs shown at positions adjacent to each of the SAF elements 81S to 84S indicate the characteristics of the elements adjacent to each graph. In these graphs, a solid line, a broken line, and a two-dot chain line indicate the external magnetic field Hy when each SAF element is not subjected to stress, when each SAF element is subjected to tensile stress, and when each SAF element is subjected to compressive stress. The change of the resistance value R with respect to is shown, respectively.

  Therefore, the output VoySAF of the second Y-axis magnetic sensor 50Y2 is substantially proportional to the external magnetic field Hy as shown by the solid line in FIG. 37B when no stress is applied to the SAF elements 81S to 84S. The smaller the magnetic field Hy, the smaller.

  As shown in FIG. 35, the difference circuit 50Ydif subtracts the output VoySAF of the second Y-axis magnetic sensor 50Y2 from the output VoyConv of the first Y-axis magnetic sensor 50Y1, and the subtraction result is the output value Voy of the Y-axis magnetic sensor 50Y. Is output as a circuit. Thereby, as shown in FIG. 38, the output Voy of the magnetic sensor 50 is substantially proportional to the external magnetic field Hy and decreases as the external magnetic field Hy increases.

  Next, the operation of the magnetic sensor 50 configured as described above will be described separately. The X-axis magnetic sensor 50X and the Y-axis magnetic sensor 50Y operate similarly except that the magnetic field detection directions are different by 90 degrees. Accordingly, the operation of the X-axis magnetic sensor 50X will be described below.

(1) When no stress is applied to the normal GMR elements 51G to 54G and the SAF elements 61S to 64S.
At this time, the X-axis magnetic sensor 50X outputs the voltage Vox that increases as the external magnetic field Hx increases as described above.

(2) Tensile stress is applied to the elements in the first region (normal GMR element 51G, normal GMR element 52G, SAF element 61S and SAF element 62S), and the elements in the second region (normal GMR element 53G, normal GMR element 54G). , SAF element 63S and SAF element 64S) are subjected to compressive stress.

  In this case, the resistance values of the normal GMR element 51G and the normal GMR element 52G both increase by a substantially constant value regardless of the magnitude of the external magnetic field Hx (see the broken lines in the graph corresponding to the elements 51G and 52G in FIG. 32). ). Further, the resistance values of the normal GMR element 53G and the normal GMR element 54G are both reduced by the same substantially constant value regardless of the magnitude of the external magnetic field Hx (the two-dot chain line in the graph corresponding to the elements 53G and 54G in FIG. reference.). As a result, the output VoxConv of the first X-axis magnetic sensor 50X1 decreases by a constant value regardless of the magnitude of the external magnetic field Hx, as indicated by the alternate long and short dash line in FIG.

  On the other hand, the resistance values of the SAF element 61S and the SAF element 62S both increase by a constant value regardless of the magnitude of the external magnetic field Hx (see the broken lines in the graph corresponding to the elements 61S and 62S in FIG. 33). In addition, the resistance values of the SAF element 63S and the SAF element 64S both decrease by a constant value regardless of the magnitude of the external magnetic field Hx (see the two-dot chain line in the graph corresponding to the elements 63S and 64S in FIG. 33). As a result, the output VoxSAF of the second X-axis magnetic sensor 50X2 decreases by a constant value regardless of the magnitude of the external magnetic field Hx, as indicated by the alternate long and short dash line in FIG. Therefore, in this case, both the output VoxConv and the output VoxSAF are decreased by a certain value, so that the output Vox of the X-axis magnetic sensor 50X, which is the difference between them, does not change.

(3) Compressive stress is applied to the elements in the first region (normal GMR element 51G, normal GMR element 52G, SAF element 61S and SAF element 62S), and the elements in the second region (normal GMR element 53G, normal GMR element 54G) , SAF element 63S and SAF element 64S) when tensile stress is applied.

  In this case, the resistance values of the normal GMR element 51G and the normal GMR element 52G are both reduced by a substantially constant value regardless of the magnitude of the external magnetic field Hx (the two-dot chain line in the graph corresponding to the elements 51G and 52G in FIG. reference.). Further, the resistance values of the normal GMR element 53G and the normal GMR element 54G increase by the same substantially constant value regardless of the magnitude of the external magnetic field Hx (see the broken lines in the graph corresponding to the elements 53G and 54G in FIG. 32). ). As a result, the output VoxConv of the first X-axis magnetic sensor 50X1 increases by a constant value regardless of the magnitude of the external magnetic field Hx, as indicated by a broken line in FIG.

  On the other hand, the resistance values of the SAF element 61S and the SAF element 62S both decrease by a constant value regardless of the magnitude of the external magnetic field Hx (see the two-dot chain line in the graph corresponding to the elements 61S and 62S in FIG. 33). Further, the resistance values of the SAF element 63S and the SAF element 64S both increase by a constant value regardless of the magnitude of the external magnetic field Hx (see the broken lines in the graph corresponding to the elements 63S and 64S in FIG. 33). As a result, the output VoxSAF of the second X-axis magnetic sensor 50X2 increases by a constant value regardless of the magnitude of the external magnetic field Hx, as indicated by a broken line in FIG. Therefore, in this case, since both the output VoxConv and the output VoxSAF increase by a certain value, the output Vox of the X-axis magnetic sensor 50X, which is the difference between them, does not change.

(4) When compressive stress is applied to all the elements in the first region and the elements in the second region.
In this case, the resistance values of all elements are reduced by a certain amount. Therefore, the output VoxConv and the output VoxSAF do not change. As a result, the output Vox of the X-axis magnetic sensor 50X does not change.

(5) When tensile stress is applied to all the elements in the first region and the elements in the second region.
In this case, the resistance values of all the elements are increased by a certain amount. Therefore, the output VoxConv and the output VoxSAF do not change. As a result, the output Vox of the X-axis magnetic sensor 50X does not change.

  As described above, the magnetic sensor 50 according to the second embodiment can output a constant output value as long as the external magnetic field does not change even when the stress applied to each element changes. As a result, the magnetic sensor 50 can detect the magnetic field with high accuracy.

<Third Embodiment>
The magnetic sensor according to the third embodiment includes one normal GMR element (for example, normal GMR element 11) and one SAF element (for example, SAF element) adjacent to each other of the magnetic sensor 10 illustrated in FIG. 1 according to the first embodiment. It differs from the magnetic sensor 10 only in that the element group consisting of the elements 13) is replaced with one of the element groups shown in FIGS. Therefore, hereinafter, this difference will be mainly described.

  That is, in the magnetic sensor according to the third embodiment, the first element group including the normal GMR element 11 and the SAF element 13 of the magnetic sensor 10 according to the first embodiment is replaced with the element group 91 shown in FIG. The The element group 91 is formed in a portion where the first element group including the normal GMR element 11 and the SAF element 13 is formed on the substrate 10a shown in FIG.

  The element group 91 includes four normal GMR elements 91g1 to 91g4 and four SAF elements 91s1 to 91s4. The shapes of the normal GMR elements 91g1 to 91g4 and the SAF elements 91s1 to 91s4 in plan view are the same narrow band shape. The longitudinal direction of each element is along the Y axis. These elements are arranged in the normal GMR element 91g1, the SAF element 91s1, the normal GMR element 91g2, the SAF element 91s2, the normal GMR element 91g3, the SAF element 91s3, from the X axis positive direction end of the substrate 10a in the X axis negative direction. Usually, the GMR element 91g4 and the SAF element 91s4 are arranged in this order. That is, in the element group 91, normal GMR elements (first giant magnetoresistive elements) and SAF elements (second giant magnetoresistive elements) alternate along a predetermined direction (X-axis negative direction) on the substrate 10a. Is arranged.

  The film configurations of the normal GMR elements 91g1 to 91g4 are the same as those of the spin valve film shown in FIG. Usually, the fixed magnetization direction of the pinned layer Pd of each fixed layer P of the GMR elements 91g1 to 91g4 is the X axis positive direction, and the magnetization direction of each free layer F in the initial state is the Y axis positive direction. .

  The end of the normal GMR element 91g1 in the Y-axis negative direction is connected to the terminal portion 91a. The end of the normal GMR element 91g1 in the Y-axis positive direction is connected to the end of the normal GMR element 91g2 in the Y-axis positive direction. The Y-axis negative direction end portion of the normal GMR element 91g2 is connected to the Y-axis negative direction end portion of the normal GMR element 91g3. The end of the normal GMR element 91g3 in the Y-axis positive direction is connected to the end of the normal GMR element 91g4 in the Y-axis positive direction. Normally, the Y-axis negative direction end portion of the GMR element 91g4 is connected to the terminal portion 91b.

  Thereby, the sum of the resistance values of the normal GMR elements 91g1 to 91g4 is extracted from the terminal portion 91a and the terminal portion 91b instead of the resistance value of the normal GMR element 11 of the magnetic sensor 10. The sum of the resistance values of the normal GMR elements 91g1 to 91g4 changes in the same manner as the normal GMR element 11. In other words, the normal GMR elements 91g1 to 91g4 constitute the changed normal GMR element 11. That is, a plurality of normal GMR elements 91g1 to 91g4 are connected in series to form one giant magnetoresistive element (first element).

  Each of the four SAF elements 91s1 to 91s4 has the same film configuration as that of the synthetic spin valve film shown in FIG. The pinned layer (first magnetic layer P1) of the pinned layer P ′ of each of the SAF elements 91s1 to 91s4 has a fixed magnetization direction in the X-axis negative direction. The direction is the Y axis positive direction.

  The Y-axis negative direction end portion of the SAF element 91s1 is connected to the terminal portion 91c. The Y-axis positive direction end of the SAF element 91s1 is connected to the Y-axis positive direction end of the SAF element 91s2. The Y-axis negative direction end portion of the SAF element 91s2 is connected to the Y-axis negative direction end portion of the SAF element 91s3. The Y-axis positive direction end portion of the SAF element 91s3 is connected to the Y-axis positive direction end portion of the SAF element 91s4. The Y-axis negative direction end portion of the SAF element 91s4 is connected to the terminal portion 91d.

  As a result, the sum of the resistance values of the SAF elements 91s1 to 91s4 is extracted from the terminal portion 91c and the terminal portion 91d instead of the resistance value of the SAF element 13 of the magnetic sensor 10. The sum of the resistance values of the SAF elements 91s1 to 91s4 changes in the same manner as the SAF element 13. In other words, the SAF elements 91s1 to 91s4 constitute the changed SAF element 13. That is, a plurality of SAF elements 91s1 to 91s4 are connected in series to form another giant magnetoresistive element (second element).

  A bias magnetic field having the same direction as the magnetization direction in the initial state of each free layer F is applied to each free layer F at both ends of the normal GMR elements 91g1 to 91g4 and the SAF elements 91s1 to 91s4. A bias magnet film (not shown in FIG. 39) is formed.

  In the magnetic sensor according to the third embodiment, the second element group including the normal GMR element 12 and the SAF element 14 of the magnetic sensor 10 according to the first embodiment has the same configuration as the element group 91 shown in FIG. It is replaced with the element group. This element group is formed in a portion where the second element group composed of the normal GMR element 12 and the SAF element 14 is formed on the substrate 10a shown in FIG. Thus, in the magnetic sensor according to the third embodiment, the changed normal GMR element 12 and the changed SAF element 14 are formed at the position where the second element group of the magnetic sensor 10 is formed. .

  Furthermore, in the magnetic sensor according to the third embodiment, the third element group including the normal GMR element 21 and the SAF element 23 of the magnetic sensor 10 according to the first embodiment is replaced with an element group 92 shown in FIG. . The element group 92 is formed in a portion where the third element group including the normal GMR element 21 and the SAF element 23 is formed on the substrate 10a shown in FIG.

  As shown in FIG. 40, the element group 92 has the same configuration as the element group 91 shown in FIG. That is, the element group 92 includes normal GMR elements 92g1 to 92g4 and SAF elements 92s1 to 92s4. Each of these elements has a narrow band shape in plan view. FIG. 40 shows the longitudinal direction of each element of the element group 92, the magnetization direction in the initial state of the free layer F, the fixed magnetization direction of the pinned layers of the fixed layers P and P ′, and the connection relationship of the elements. That's right. As described above, in the magnetic sensor according to the third embodiment, the element group 92 is formed at the position where the third element group of the magnetic sensor 10 is formed, and the changed normal GMR element 21 and the changed GMR element 21 are changed. A SAF element 23 is formed.

  In the magnetic sensor according to the third embodiment, the fourth element group including the normal GMR element 22 and the SAF element 24 of the magnetic sensor 10 according to the first embodiment has the same configuration as the element group 92 shown in FIG. It is replaced with the element group. This element group is formed in a portion where the fourth element group including the normal GMR element 22 and the SAF element 24 is formed on the substrate 10a shown in FIG. Thus, in the magnetic sensor according to the third embodiment, the changed normal GMR element 22 and the changed SAF element 24 are formed at the position where the fourth element group of the magnetic sensor 10 is formed. .

  Also in the magnetic sensor according to the third embodiment, the changed normal GMR elements 11, 12, 21, 22 and the changed SAF elements 13, 14, 23, 24 are full-bridge connected in the same manner as the magnetic sensor 10. The X-axis magnetic sensor and the Y-axis magnetic sensor are configured.

  By the way, as described above, in a sensor provided with a plurality of giant magnetoresistive elements on a single substrate, the same giant magnetoresistive elements are formed by deformation of the resin covering the substrate and the giant magnetoresistive elements. Stress is applied. The probability that the stress gradually changes along the substrate plane is high.

  Therefore, as in the magnetic sensor according to the third embodiment, normal GMR elements and SAF elements are alternately arranged along a predetermined direction (in this example, the X-axis direction or the Y-axis direction) on the substrate 10a. When the plurality of normal GMR elements are connected in series to form one first element, and the plurality of SAF elements are connected in series to form the second element, the first element and the second element have There is a high possibility that stresses close to each other are applied. Therefore, the amount of resistance change due to the stress of the first element and the second element becomes a value close to each other.

  Thereby, the X-axis magnetic sensor and the Y-axis magnetic sensor that obtain an output value by a circuit in which these elements are bridge-connected can output an output value in which the influence of stress applied to the element is reduced. As a result, the magnetic sensor according to the third embodiment can eliminate the influence of the stress applied to the element on the output value, as compared with the magnetic sensor 10 according to the first embodiment, and can detect the magnetic field with higher accuracy. be able to.

  In the magnetic sensor (element group 91, element group 92) according to the third embodiment, the arrangement order of elements may be changed. That is, the SAF element 91s1, the normal GMR element 91g1, the SAF element 91s2, the normal GMR element 91g2, the SAF element 91s3, the normal GMR element 91g3, and the SAF from the X axis positive direction end of the substrate 10a toward the X axis negative direction. The elements 91s4 and the normal GMR element 91g4 may be arranged in this order. Further, the SAF element 92s1, the normal GMR element 92g1, the SAF element 92s2, the normal GMR element 92g2, the SAF element 92s3, the normal GMR element 92g3, and the SAF element 92s4 from the Y axis positive direction end of the substrate 10a toward the Y axis negative direction. The normal GMR elements 92g4 may be arranged in this order.

  Furthermore, the element group shown in FIGS. 39 and 40 may be applied to the magnetic sensor 50 shown in FIG.

<Fourth embodiment>
A magnetic sensor 95 according to the fourth embodiment of the present invention shown in a plan view in FIG. 41 includes a single substrate 95a similar to the substrate 10a, an X-axis direction magnetic detection element group 96, and a Y-axis direction magnetic detection element. Group 97. The X-axis direction magnetic detection element group 96 is formed in the Y-axis direction substantially central portion of the substrate 95a and in the vicinity of the X-axis positive direction end. The Y-axis direction magnetic detection element group 97 is formed in the X-axis direction substantially central portion and near the Y-axis positive direction end portion of the substrate 95a.

  As shown in FIG. 42, the X-axis direction magnetic detection element group 96 includes four normal GMR elements 96g1 to 96g4 and four SAF elements 96s1 to 96s4. The shapes of the normal GMR elements 96g1 to 96g4 and the SAF elements 96s1 to 96s4 in plan view are the same narrow band shape. The longitudinal direction of each element is along the Y axis. These elements are the normal GMR element 96g1, the normal GMR element 96g2, the SAF element 96s1, the SAF element 96s2, the normal GMR element 96g3, and the normal GMR element 96g4 from the X axis positive direction end of the substrate 95a toward the X axis negative direction. , SAF element 96s3 and SAF element 96s4 are arranged in this order.

  Each film configuration of the normal GMR elements 96g1 to 96g4 is the same as the spin valve film shown in FIG. Usually, the fixed magnetization direction of the pinned layer Pd of each fixed layer P of the GMR elements 96g1 to 96g4 is the X-axis positive direction, and the magnetization direction of each free layer F in the initial state is the Y-axis positive direction. .

  Usually, the Y-axis negative direction end portion of the GMR element 96g1 is connected to the terminal portion 96a1. The end of the normal GMR element 96g1 in the Y-axis positive direction is connected to the end of the normal GMR element 96g3 in the Y-axis positive direction. Usually, the Y-axis negative direction end portion of the GMR element 96g3 is connected to the terminal portion 96a2.

  Thereby, the sum of the resistance value of the normal GMR element 96g1 and the resistance value of the normal GMR element 96g3 is extracted from the terminal portion 96a1 and the terminal portion 96a2. This resistance value changes similarly to the normal GMR element 11 of the magnetic sensor 10. In other words, the normal GMR element 96g1 and the normal GMR element 96g3 constitute a modified normal GMR element 11.

  On the other hand, the end of the normal GMR element 96g2 in the negative Y-axis direction is connected to the terminal portion 96b1. The end of the normal GMR element 96g2 in the Y-axis positive direction is connected to the end of the normal GMR element 96g4 in the Y-axis positive direction. Normally, the Y-axis negative direction end of the GMR element 96g4 is connected to the terminal portion 96b2.

  Thereby, the sum of the resistance value of the normal GMR element 96g2 and the resistance value of the normal GMR element 96g4 is extracted from the terminal portion 96b1 and the terminal portion 96b2. This resistance value changes similarly to the normal GMR element 12 of the magnetic sensor 10. In other words, the normal GMR element 96g2 and the normal GMR element 96g4 constitute a modified normal GMR element 12.

  The respective film configurations of the SAF elements 96s1 to 96s4 are the same as those of the synthetic spin valve film shown in FIG. The pinned layer (first magnetic layer P1) of the pinned layer P ′ of each of the SAF elements 96s1 to 96s4 has a fixed magnetization direction in the X-axis negative direction. The direction is the Y axis positive direction.

  The Y-axis negative direction end of the SAF element 96s1 is connected to the terminal portion 96c1. The Y-axis positive direction end portion of the SAF element 96s1 is connected to the Y-axis positive direction end portion of the SAF element 96s3. The Y-axis negative direction end portion of the SAF element 96s3 is connected to the terminal portion 96c2.

  As a result, the sum of the resistance value of the SAF element 96s1 and the resistance value of the SAF element 96s3 is extracted from the terminal portion 96c1 and the terminal portion 96c2. This resistance value changes similarly to the SAF element 13 of the magnetic sensor 10. In other words, the SAF element 96s1 and the SAF element 96s3 constitute the changed SAF element 13.

  On the other hand, the Y-axis negative direction end portion of the SAF element 96s2 is connected to the terminal portion 96d1. The Y axis positive direction end portion of the SAF element 96s2 is connected to the Y axis positive direction end portion of the SAF element 96s4. The end of the SAF element 96s4 in the negative Y-axis direction is connected to the terminal portion 96d2.

  Thereby, the sum of the resistance value of the SAF element 96s2 and the resistance value of the SAF element 96s4 is extracted from the terminal portion 96d1 and the terminal portion 96d2. This resistance value changes similarly to the SAF element 14 of the magnetic sensor 10. In other words, the SAF element 96s2 and the SAF element 96s4 constitute the modified SAF element 14.

  A bias magnetic field having the same direction as the magnetization direction in the initial state of each free layer F is applied to each free layer F at both ends of the normal GMR elements 96g1 to 96g4 and the SAF elements 96s1 to 96s4. A bias magnet film (not shown in FIG. 42) is formed.

  The modified normal GMR elements 11 and 12 and the modified SAF elements 13 and 14 described above are full-bridge connected in the same manner as the ordinary GMR elements 11 and 12 and the SAF elements 13 and 14 of the magnetic sensor 10, and the X-axis magnetic sensor. Is configured.

  As shown in FIG. 43, the Y-axis direction magnetic detection element group 97 has the same configuration as the X-axis direction magnetic detection element group 96 shown in FIG. That is, the Y-axis direction magnetic detection element group 97 includes normal GMR elements 97g1 to 97g4 and SAF elements 97s1 to 97s4. Each of these elements has a narrow band shape in plan view. The longitudinal direction of each element of the Y-axis direction magnetic detection element group 97, the magnetization direction in the initial state of the free layer F, the fixed magnetization direction of the pinned layers of the fixed layers P and P ′, and the connection relationship of the elements are as follows: This is as shown in FIG.

  Therefore, the normal GMR element 97g1 and the normal GMR element 97g3 constitute a modified normal GMR element 21, and the normal GMR element 97g2 and the normal GMR element 97g4 constitute a modified normal GMR element 22. Similarly, the SAF element 97s1 and the SAF element 97s3 constitute a modified SAF element 23, and the SAF element 97s2 and the SAF element 97s4 constitute a modified SAF element 24.

  The modified normal GMR elements 21 and 22 and the modified SAF elements 23 and 24 described above are full-bridge connected in the same manner as the normal GMR elements 21 and 22 and the SAF elements 23 and 24 of the magnetic sensor 10, and the Y axis It constitutes a magnetic sensor.

  The magnetic sensor 95 according to the fourth embodiment configured as described above includes, for example, four normal GMR elements and four SAF elements each when paying attention to the X-axis magnetic sensor, and includes two normal GMR elements adjacent to each other. The first group (normal GMR elements 96g1 and 96g2), the second group consisting of two other normal GMR elements adjacent to each other (normal GMR elements 96g3 and 96g4), and the third group consisting of two adjacent SAF elements. (SAF elements 96s1, 96s2) and a fourth group (SAF elements 96s3, 96s4) composed of two other adjacent SAF elements are formed, and the fourth group along the predetermined direction (X-axis negative direction) on the substrate 10a is formed. The order of the first group, the third group, the second group, and the fourth group (or the order of the third group, the first group, the fourth group, and the second group along a predetermined direction on the substrate may be used. )) Is the difference.

  Further, the X-axis magnetic sensor of the magnetic sensor 95 is composed of two normal GMR elements that are not adjacent to each other (normal GMR elements 96g1 and 96g3 and normal GMR elements 96g2 and 96g4) connected in series. 2 elements (third element and fourth element) are formed, and two SAF elements (SAF elements 96s1 and 96s3 and SAF elements 96s2 and 96s4) that are not adjacent to each other are connected in series to form only the SAF element. This is a magnetic sensor formed by forming two elements (fifth element and sixth element).

  According to this, there is a high possibility that stresses closer to each other are applied to each of the third to sixth elements. Therefore, the resistance change amounts due to the stresses of the third to sixth elements are close to each other. Therefore, the X-axis magnetic sensor of the magnetic sensor 95 that obtains an output value by a circuit in which the third to sixth elements are connected by a full bridge can output an output value that further eliminates the influence of stress applied to each element.

  As described above, the magnetic sensor according to each embodiment of the present invention is a small-sized magnetic sensor that minimizes the influence of the stress received by the element on the output value. In addition, this invention is not limited to said each embodiment, A various modification can be employ | adopted within the scope of the present invention.

  For example, as shown in FIG. 44A, the SAF element 14 and the normal GMR element 12 may be half-bridge connected, and the potential at the connection point T1 between these elements may be the output value Vox of the X-axis magnetic sensor. . Further, as shown in FIG. 44B, a full bridge circuit is configured including fixed resistors 98 and 99, and the potential difference between the potential at the connection point T2 and the potential at the connection point T3 is output from the X-axis magnetic sensor. It may be the value Vox.

  Further, for example, in the circuit shown in FIG. 6, a fixed resistor is connected in series between the SAF element 13 and the connection location Q1, and another fixed resistance is connected in series between the SAF element 14 and the connection location Q2. May be.

  Moreover, although each said embodiment was an orthogonal biaxial direction detection type magnetic sensor, the uniaxial direction detection type magnetic sensor provided only with the X-axis magnetic sensor may be sufficient.

It is a top view of the magnetic sensor (N type) concerning a 1st embodiment of the present invention. FIG. 2 is an enlarged plan view of the normal GMR element shown in FIG. 1. It is the schematic sectional drawing which cut | disconnected the normal GMR element in the plane in alignment with the 1-1 line | wire of FIG. 4A is a diagram showing a film configuration of the normal GMR element shown in FIG. 1, FIG. 4B is a conceptual perspective view of the normal GMR element shown in FIG. 1, and FIG. FIG. 3 is a graph showing a change in resistance value of the normal GMR element shown in FIG. 1 with respect to an external magnetic field. 5A is a diagram showing a film configuration of the SAF element shown in FIG. 1, FIG. 5B is a conceptual perspective view of the SAF element shown in FIG. 1, and FIG. 3 is a graph showing a change in resistance value with respect to an external magnetic field of the SAF element shown in FIG. 6A is an equivalent circuit diagram of the X-axis magnetic sensor provided in the magnetic sensor shown in FIG. 1, and FIG. 6B is an output of the X-axis magnetic sensor with respect to the X-axis positive direction component of the external magnetic field. It is the graph which showed change of. 7A is an equivalent circuit diagram of the Y-axis magnetic sensor provided in the magnetic sensor shown in FIG. 1, and FIG. 7B is an output of the Y-axis magnetic sensor with respect to the Y-axis positive direction component of the external magnetic field. It is the graph which showed change of. FIG. 2 is a partial plan view of a wafer (substrate) for manufacturing the magnetic sensor shown in FIG. 1. It is a top view of the magnet array used when fixing the direction of magnetization of the pinned layer of the magnetic sensor shown in FIG. It is sectional drawing of the same magnet array which cut | disconnected the magnet array in the plane along the 2-2 line of FIG. FIG. 10 is a perspective view of the permanent magnet showing a state where only five permanent magnets of the magnet array shown in FIG. 9 are taken out. FIG. 2 is a partial plan view of a magnet array and a wafer showing a method of fixing the magnetization direction of the pinned layer of the normal GMR element and SAF element of the magnetic sensor shown in FIG. 1. It is the figure which showed the relationship between the magnetic field direction at the time of the heat processing in a magnetic field of a normal GMR element, and the characteristic of the element obtained. It is the figure which showed the relationship between the magnetic field direction at the time of the heat processing in a magnetic field of a normal GMR element and a SAF element, and the characteristic of the element obtained. It is a top view of the magnetic sensor (S type) concerning a 1st embodiment of the present invention. It is the figure which showed one process in the 1st manufacturing method for forming each film | membrane used as the normal GMR element and SAF element with which the magnetic sensor shown in FIG. 1 is provided on a board | substrate. It is the figure which showed the process following FIG. 16 in a 1st manufacturing method. It is the figure which showed the process of following the FIG. 17 in a 1st manufacturing method. It is the figure which showed the process following FIG. 18 in a 1st manufacturing method. FIG. 20 is a diagram showing a step following the step in FIG. 19 in the first manufacturing method. It is the figure which showed the process following FIG. 20 in a 1st manufacturing method. It is the figure which showed the process in the 2nd manufacturing method for forming each film | membrane used as the normal GMR element and SAF element with which the magnetic sensor shown in FIG. 1 is provided on a board | substrate. It is the figure which showed the process following FIG. 22 in a 2nd manufacturing method. It is the figure which showed the process following FIG. 23 in the 2nd manufacturing method. It is the figure which showed the process following FIG. 24 in the 2nd manufacturing method. FIG. 26 is a diagram showing a step following the step in FIG. 25 in the second manufacturing method. It is the figure which showed the process following FIG. 26 in the 2nd manufacturing method. FIG. 28 is a diagram showing a step following the step in FIG. 27 in the second manufacturing method. It is the figure which showed the 3rd manufacturing method for forming each film | membrane used as the normal GMR element and SAF element with which the magnetic sensor shown in FIG. 1 is provided on a board | substrate. It is a top view of the magnetic sensor which concerns on 2nd Embodiment of this invention. It is the block diagram which showed the circuit structure of the X-axis magnetic sensor with which the magnetic sensor shown in FIG. 30 is provided. 32A is an equivalent circuit diagram of the first X-axis magnetic sensor provided in the magnetic sensor shown in FIG. 30, and FIG. 32B is the first X-axis magnetic sensor for the X-axis positive direction component of the external magnetic field. It is the graph which showed the change of output. 33A is an equivalent circuit diagram of the second X-axis magnetic sensor provided in the magnetic sensor shown in FIG. 30, and FIG. 33B is the second X-axis magnetic sensor for the X-axis positive direction component of the external magnetic field. It is the graph which showed the change of output. FIG. 31 is a graph showing changes in the output of the X-axis magnetic sensor included in the magnetic sensor shown in FIG. 30 with respect to the X-axis positive direction component of the external magnetic field. It is the block diagram which showed the circuit structure of the Y-axis magnetic sensor with which the magnetic sensor shown in FIG. 30 is provided. 36A is an equivalent circuit diagram of the first Y-axis magnetic sensor provided in the magnetic sensor shown in FIG. 30, and FIG. 36B is the first Y-axis magnetic sensor for the Y-axis positive direction component of the external magnetic field. It is the graph which showed the change of output. 37A is an equivalent circuit diagram of the second Y-axis magnetic sensor included in the magnetic sensor shown in FIG. 30, and FIG. 37B is the second Y-axis magnetic sensor for the Y-axis positive direction component of the external magnetic field. It is the graph which showed the change of output. FIG. 31 is a graph showing changes in the output of the Y-axis magnetic sensor included in the magnetic sensor shown in FIG. 30 with respect to the Y-axis positive direction component of the external magnetic field. It is a top view of one element group of the magnetic sensor which concerns on 3rd Embodiment of this invention. It is a top view of other element groups of the magnetic sensor concerning a 3rd embodiment of the present invention. It is a top view of the magnetic sensor which concerns on 4th Embodiment of this invention. It is a top view of the X-axis direction magnetic detection element group of the magnetic sensor shown in FIG. It is a top view of the Y-axis direction magnetic detection element group of the magnetic sensor shown in FIG. 44A is an equivalent circuit diagram of a magnetic sensor according to a modification of the present invention, and FIG. 44B is an equivalent circuit diagram of a magnetic sensor according to another modification of the present invention. FIG. 45A is an equivalent circuit diagram of a conventional magnetic sensor, and FIG. 45B is a graph showing a change in output with respect to an external magnetic field of the conventional magnetic sensor. It is a top view of the conventional magnetic sensor. It is a perspective view of the permanent magnet showing a state where only five permanent magnets of a magnet array used for fixing the magnetization direction of the fixed layer of the conventional magnetic sensor are taken out. FIG. 48 is a plan view showing the positional relationship between the magnet array shown in FIG. 47 and the wafer when the magnetization direction of the fixed layer is fixed.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Magnetic sensor 11, 12, 21, 22 ... Normal GMR element, 13, 14, 23, 24 ... SAF element, 11a1-11a6 ... Narrow strip part, 30 ... Magnet array, 31 ... Permanent magnet, 40 ... Magnetic Sensor, 41, 42, 51, 52 ... Normal GMR element, 43, 44, 53, 54 ... SAF element, 50 ... Magnetic sensor, 51G-54G, 71G-74G ... Normal GMR element, 61S-64G, 81S-84S ... SAF element, 91g1-91g4 ... normal GMR element, 91s1-91s4 ... SAF element, 95 ... magnetic sensor, 96 ... X-axis direction magnetic detection element group, 96g1-96g4 ... normal GMR element, 96s1-96s4 ... SAF element, Eb ... Exchange bias film, Ex ... exchange coupling film, F ... free layer, P, P '... fixed layer, P1 ... pinned layer (first ferromagnetic film), P2 ... first 2 Ferromagnetic film, Pd ... pinned layer, S ... spacer layer.

Claims (14)

A single substrate,
The ferromagnetic film is formed on the substrate and includes a single ferromagnetic film and a pinning layer, and the magnetization direction of the ferromagnetic film is fixed in the first direction by the pinning layer so that the ferromagnetic film is pinned. A fixed layer constituting the layer, a free layer whose magnetization direction changes according to an external magnetic field, and a spacer layer made of a non-magnetic conductor disposed between the pinned layer and the free layer. A first giant magnetoresistive element comprising a single-layer pinned spin valve film;
Formed on the substrate and in contact with the first ferromagnetic film, the exchange coupling film in contact with the first ferromagnetic film, the second ferromagnetic film in contact with the exchange coupling film, and the second ferromagnetic film The direction of magnetization of the second ferromagnetic film made of a pinning layer is fixed by the pinning layer, and the second ferromagnetic film and the first ferromagnetic film are exchange coupled via the exchange coupling film. The magnetization direction of the first ferromagnetic film changes in accordance with the external magnetic field and the fixed layer constituting the pinned layer fixed in a second direction that is 180 degrees different from the first direction. And a second giant magnetoresistive element comprising a multi-layer laminated fixed layer spin-valve film comprising: a free layer, and a spacer layer made of a nonmagnetic conductor disposed between the pinned layer and the free layer When,
A magnetic sensor comprising: The magnetic sensor according to claim 1,
A circuit is formed by bridge-connecting the first giant magnetoresistive element and the second giant magnetoresistive element, and the potential increases as the magnitude of the component in the first direction of the magnetic field applied to the magnetic sensor increases. A magnetic sensor configured to output an output value based on a potential at a predetermined point in the same circuit in which monotonically increases or decreases monotonously. The magnetic sensor according to claim 1,
Two each of the first giant magnetoresistance effect element and the second giant magnetoresistance effect element,
One end of one first giant magnetoresistive effect element of the first giant magnetoresistive effect element is connected to one end of one second giant magnetoresistive effect element of the second giant magnetoresistive effect element. Constituting a first circuit element;
One end of another first giant magnetoresistive effect element of the first giant magnetoresistive effect element and one end of another second giant magnetoresistive effect element of the second giant magnetoresistive effect element To configure the second circuit element,
A first potential is applied to the other end of the first giant magnetoresistive element of the first circuit element, and a second potential different from the first potential is applied to the other end of the second giant magnetoresistive element of the first circuit element. 2 potentials applied,
Applying the first potential to the other end of the second giant magnetoresistive element of the second circuit element and applying the second potential to the other end of the first giant magnetoresistive element of the second circuit element And
A potential at a connection point between one end of the first giant magnetoresistive element of the first circuit element and one end of the second giant magnetoresistive element of the first circuit element; and the first of the second circuit element A magnetic sensor configured to output, as an output value, a potential difference between a connection portion between one end of the giant magnetoresistive effect element and one end of the second giant magnetoresistive effect element of the second circuit element. The magnetic sensor according to claim 1,
A spin-valve film having a single-layer pinned layer that is formed on the substrate and is identical to the first giant magnetoresistive element, and the magnetization direction of the ferromagnetic film of the pinned layer is the first direction. A third giant magnetoresistive element fixed in a third direction orthogonal to
A spin-valve film of a multi-layer stacked pinned layer that is formed on the substrate and is the same as the second giant magnetoresistive element, and the magnetization direction of the first ferromagnetic film of the pinned layer is the third A fourth giant magnetoresistive element fixed in a fourth orientation that is 180 degrees different from the orientation of
A magnetic sensor further comprising: The magnetic sensor according to claim 4,
A circuit is formed by bridge-connecting the first giant magnetoresistive element and the second giant magnetoresistive element, and the potential increases as the magnitude of the component in the first direction of the magnetic field applied to the magnetic sensor increases. Output as a first output value a value based on the potential of a predetermined point in the same circuit where monotonically increases or decreases monotonously,
A circuit is formed by bridge-connecting the third giant magnetoresistive element and the fourth giant magnetoresistive element, and the potential increases as the magnitude of the component in the third direction of the magnetic field applied to the magnetic sensor increases. A magnetic sensor configured to output, as a second output value, a value based on a potential at a predetermined point in the same circuit where monotone increases or decreases monotonously. The magnetic sensor according to claim 4,
Two each of the first giant magnetoresistance effect element, the second giant magnetoresistance effect element, the third giant magnetoresistance effect element, and the fourth giant magnetoresistance effect element,
One end of one first giant magnetoresistive effect element of the first giant magnetoresistive effect element is connected to one end of one second giant magnetoresistive effect element of the second giant magnetoresistive effect element. Constituting a first circuit element;
One end of another first giant magnetoresistive effect element of the first giant magnetoresistive effect element and one end of another second giant magnetoresistive effect element of the second giant magnetoresistive effect element To configure the second circuit element,
A first potential is applied to the other end of the first giant magnetoresistive element of the first circuit element, and a second potential different from the first potential is applied to the other end of the second giant magnetoresistive element of the first circuit element. 2 potentials applied,
Applying the first potential to the other end of the second giant magnetoresistive element of the second circuit element and applying the second potential to the other end of the first giant magnetoresistive element of the second circuit element And
A potential at a connection point between one end of the first giant magnetoresistive element of the first circuit element and one end of the second giant magnetoresistive element of the first circuit element; and the first of the second circuit element A potential difference between one end of the giant magnetoresistive effect element and the potential of the second circuit element connected to one end of the second giant magnetoresistive effect element is output as a first output value;
One end of one third giant magnetoresistive effect element of the third giant magnetoresistive effect element is connected to one end of one fourth giant magnetoresistive effect element of the fourth giant magnetoresistive effect element. Configure the third circuit element,
One end of another third giant magnetoresistive effect element of the third giant magnetoresistive effect element and one end of another fourth giant magnetoresistive effect element of the fourth giant magnetoresistive effect element To configure the fourth circuit element,
Applying the first potential to the other end of the third giant magnetoresistive element of the third circuit element and applying the second potential to the other end of the fourth giant magnetoresistive element of the third circuit element And
Applying the first potential to the other end of the fourth giant magnetoresistive element of the fourth circuit element and applying the second potential to the other end of the third giant magnetoresistive element of the fourth circuit element And
A potential at a connection point between one end of the third giant magnetoresistive element of the third circuit element and one end of the fourth giant magnetoresistive element of the third circuit element; and the third of the fourth circuit element A magnetic sensor configured to output, as a second output value, a potential difference between a connection point between one end of the giant magnetoresistance effect element and one end of the fourth giant magnetoresistance effect element of the fourth circuit element. The magnetic sensor according to claim 1,
Two first giant magnetoresistive elements are provided,
Two second giant magnetoresistive elements,
The two first giant magnetoresistive elements and the two second giant magnetoresistive elements are formed in the first region adjacent to each other;
The spin valve film of a single-layer fixed layer that is formed on the substrate and is the same as the first giant magnetoresistance effect element, and the magnetization direction of the ferromagnetic film of the fixed layer is the second direction. 2 fixed fifth giant magnetoresistive elements,
It is formed of a spin valve film of a multi-layer stacked fixed layer that is formed on the substrate and is the same as the second giant magnetoresistive element, and the direction of magnetization of the first ferromagnetic film of the fixed layer is the first It has two sixth giant magnetoresistive effect elements fixed in the direction,
The two fifth giant magnetoresistive effect elements and the two sixth giant magnetoresistive effect elements are formed in a second region adjacent to and spaced apart from the first region;
One end of one of the first giant magnetoresistive elements is connected to one end of a fifth giant magnetoresistive element of the fifth giant magnetoresistive elements. Constituting a fifth circuit element,
One end of another first giant magnetoresistive effect element of the first giant magnetoresistive effect element and one end of another fifth giant magnetoresistive effect element of the fifth giant magnetoresistive effect element Are connected in series to form a sixth circuit element,
A first potential is applied to the other end of the first giant magnetoresistive effect element of the fifth circuit element, and a second potential different from the first potential is applied to the other end of the fifth giant magnetoresistive effect element of the fifth circuit element. 2 potentials applied,
Applying the first potential to the other end of the fifth giant magnetoresistive element of the sixth circuit element and applying the second potential to the other end of the first giant magnetoresistive element of the sixth circuit element And
A potential at a connection point between one end of the first giant magnetoresistive effect element of the fifth circuit element and one end of the fifth giant magnetoresistive effect element of the fifth circuit element; and the first of the sixth circuit element A potential difference between a connection point between one end of the giant magnetoresistive effect element and one end of the fifth giant magnetoresistive effect element of the sixth circuit element is obtained as a normal GMR element output value,
and,
One end of the second giant magnetoresistive effect element of the second giant magnetoresistive effect element is connected to one end of the sixth giant magnetoresistive effect element of the sixth giant magnetoresistive effect element. Configure the seventh circuit element,
One end of another second giant magnetoresistive effect element of the second giant magnetoresistive effect element and one end of another sixth giant magnetoresistive effect element of the sixth giant magnetoresistive effect element Are connected in series to form an eighth circuit element,
Applying the first potential to the other end of the second giant magnetoresistive element of the seventh circuit element and applying the second potential to the other end of the sixth giant magnetoresistive element of the seventh circuit element And
Applying the first potential to the other end of the sixth giant magnetoresistive element of the eighth circuit element and applying the second potential to the other end of the second giant magnetoresistive element of the eighth circuit element And
A potential at a connection point between one end of the second giant magnetoresistive element of the seventh circuit element and one end of the sixth giant magnetoresistive element of the seventh circuit element; and the second of the eighth circuit element Obtaining the potential difference between the one end of the giant magnetoresistive effect element and the potential of the connection point between the end of the sixth giant magnetoresistive effect element of the eighth circuit element as the SAF element output value;
A magnetic sensor configured to output a value based on the normal GMR element output value and the SAF element output value. The magnetic sensor according to claim 1,
A plurality of the first giant magnetoresistance effect elements and the same number of the second giant magnetoresistance effect elements as the first giant magnetoresistance effect elements;
The first giant magnetoresistive effect element and the second giant magnetoresistive effect element are alternately arranged along a predetermined direction on the substrate,
The plurality of first giant magnetoresistance effect elements are connected in series to form one giant magnetoresistance effect element, and the plurality of second giant magnetoresistance effect elements are connected in series to form another giant magnetoresistance effect element. A magnetic sensor formed of The magnetic sensor according to claim 1,
The first giant magnetoresistive effect element and the second giant magnetoresistive effect element are each provided in four, the first group consisting of the two first giant magnetoresistive effect elements adjacent to each other, and the other two adjacent to each other. A second group of the first giant magnetoresistive elements, a third group of the two second giant magnetoresistive elements adjacent to each other, and the other two second giant magnetoresistive effects adjacent to each other. A fourth group of elements is formed, and the first group, the third group, the second group, and the fourth group are arranged in a predetermined direction on the substrate, or in a predetermined direction on the substrate. Arranged in the order of group, first group, fourth group and second group; and
Two elements made only of the first giant magnetoresistive effect element are formed by serially connecting the two first giant magnetoresistive effect elements that are not adjacent to each other, and the two second giant magnetoresistive elements that are not adjacent to each other are formed. A magnetic sensor formed by connecting two effect elements in series to form two elements consisting of only the second giant magnetoresistive effect element. A single substrate,
The ferromagnetic film is formed on the substrate and includes a single ferromagnetic film and a pinning layer, and the magnetization direction of the ferromagnetic film is fixed in the first direction by the pinning layer so that the ferromagnetic film is pinned. A fixed layer constituting the layer, a free layer whose magnetization direction changes according to an external magnetic field, and a spacer layer made of a non-magnetic conductor disposed between the pinned layer and the free layer. A first giant magnetoresistive element comprising a single-layer pinned spin valve film;
Formed on the substrate and in contact with the first ferromagnetic film, the exchange coupling film in contact with the first ferromagnetic film, the second ferromagnetic film in contact with the exchange coupling film, and the second ferromagnetic film The direction of magnetization of the second ferromagnetic film made of a pinning layer is fixed by the pinning layer, and the second ferromagnetic film and the first ferromagnetic film are exchange coupled via the exchange coupling film. The magnetization direction of the first ferromagnetic film changes in accordance with the external magnetic field and the fixed layer constituting the pinned layer fixed in a second direction that is 180 degrees different from the first direction. And a second giant magnetoresistive element comprising a multi-layer laminated fixed layer spin-valve film comprising: a free layer, and a spacer layer made of a nonmagnetic conductor disposed between the pinned layer and the free layer When,
A method of manufacturing a magnetic sensor comprising:
Forming a film to be the first giant magnetoresistive element and a film to be the second giant magnetoresistive element on the substrate;
A heat treatment step in a magnetic field for fixing the magnetization direction of the pinned layer of each film by applying a magnetic field in the same direction to each formed film at a high temperature;
A method for manufacturing a magnetic sensor comprising: In the manufacturing method of the magnetic sensor according to claim 10,
The heat treatment step in the magnetic field includes
A plurality of permanent magnets having a substantially rectangular parallelepiped shape and having a substantially square cross-section perpendicular to one central axis of the rectangular parallelepiped are arranged so that the center of gravity of the end surface having the substantially square shape coincides with the lattice point of the square lattice. And the magnetic field formed by the magnet array arranged so that the polarity of the magnetic poles of the permanent magnets arranged in the same manner is different from the polarity of the magnetic poles of other permanent magnets adjacent to each other at the shortest distance. A method of manufacturing a magnetic sensor used as a magnetic field during a heat treatment process. In the manufacturing method of the magnetic sensor of Claim 10 or Claim 11,
The film forming step includes
A first film forming step of forming one of a film to be the first giant magnetoresistive element and a film to be the second giant magnetoresistive element on the substrate;
A first unnecessary portion removing step of removing an unnecessary portion of the formed one film;
An insulating film forming step of covering the one film from which the unnecessary portion has been removed with an insulating film;
A second film forming step of forming the other film of the film to be the first giant magnetoresistive element and the film to be the second giant magnetoresistive element on the substrate and the insulating film;
A second unnecessary portion removing step of removing an unnecessary portion of the other formed film;
A method for manufacturing a magnetic sensor comprising: In the manufacturing method of the magnetic sensor of Claim 10 or Claim 11,
The film forming step includes
A film serving as the pinning layer of the second giant magnetoresistive effect element, a film serving as the second ferromagnetic film, and a film serving as the exchange coupling film are sequentially stacked on the substrate to form a first preliminary film. A first preliminary film forming step,
The exchange coupling film of the first preliminary film in the portion where the first giant magnetoresistive element is to be formed without removing the first preliminary film in the portion where the second giant magnetoresistive element is to be formed A first exchange coupling membrane removal step of removing all of the membrane to be
The same ferromagnetic film as the second ferromagnetic film is formed on the entire top surface of the film that has undergone the first exchange coupling film removal step, and then the first giant magnetoresistive element and the second A first additional film forming step of forming a film to be a spacer layer and a free layer of the giant magnetoresistive element;
A method for manufacturing a magnetic sensor comprising: In the manufacturing method of the magnetic sensor of Claim 10 or Claim 11,
The film forming step includes
A film to be a free layer of the first giant magnetoresistive element and the second giant magnetoresistive element, a film to be a spacer layer of the first giant magnetoresistive element and the second giant magnetoresistive element, Forming a second preliminary film in which a film to be the first ferromagnetic film of the two giant magnetoresistive effect elements and a film to be the exchange coupling film of the second giant magnetoresistive effect element are sequentially laminated on the substrate; A second preliminary film forming step,
The exchange coupling film of the second preliminary film where the first giant magnetoresistive element is to be formed without removing the second spare film where the second giant magnetoresistive element is to be formed A second exchange coupling membrane removal step of removing all of the membrane to be
The same ferromagnetic material film as the first ferromagnetic material film is formed on the entire top surface of the film that has undergone the second exchange coupling film removal step, and then the first giant magnetoresistive element and the second A second additional film forming step of forming a film to be a pinning layer of the giant magnetoresistive element;
A method for manufacturing a magnetic sensor comprising:

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