JP2000180207A - Magnetic sensor - Google Patents

Abstract

(57) Abstract: Provided is a magnetic sensor capable of generating a differential output with a simple configuration by generating a resistance value difference with respect to a signal magnetic field without applying a bias magnetic field. A magnetic sensor includes a substrate, and a giant magnetoresistive element formed on the substrate and having a resistance that changes with respect to a signal magnetic field applied substantially parallel to the surface of the substrate. The giant magnetoresistive element 3 includes a magnetic layer 15 and a non-magnetic layer 17.
Are connected in series to a first giant magnetoresistive element 3a whose resistance changes with respect to a change in the signal magnetic field 9 applied to the artificial lattice film alternately laminated, and the first giant magnetoresistive element 3a, The second resistance value does not change in response to a change in the signal magnetic field 9 applied to the artificial lattice film in which the magnetic layer 15 and the nonmagnetic layer 17a having different thicknesses with respect to the thickness of the nonmagnetic layer 17 are alternately stacked. A giant magnetoresistive element 3b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic sensor having a high sensitivity and a simple structure for detecting rotation or the like of an object to be detected by utilizing the magnetoresistive effect of a magnetoresistive element. Resistive element GMR (giant magnetoresista
nce).

[0002]

2. Description of the Related Art Since a resistance value of a magnetoresistive element changes in accordance with a change in a magnetic field, it is used as a magnetic sensor for detecting rotation of a gear. In this magnetic sensor, the magnetic field of the bias magnet changes due to rotation of a gear or the like, and the change in the magnetic field is extracted as a change in resistance (voltage output) from the connection point of the two magnetoresistive elements connected in series.

When a voltage output of the magnetoresistive element is supplied to a signal processing circuit, the signal processing circuit outputs a pulse corresponding to the number of rotations of the gear. Therefore, the number of rotations of the gear can be detected by counting the number of pulses.

The above-described conventional magnetoresistive element is generally a ferromagnetic magnetoresistive element made of Ni—Fe, Ni—Co, or the like, and has magnetic anisotropy. Therefore, as shown in FIG. 8, a first magnetoresistive element 103a provided between the electrodes 107a and 107b and a second magnetoresistive element 103 provided between the electrodes 107b and 107c.
The ferromagnetic magnetoresistive element 103 made of b is used.
First magnetoresistive element 103a and second magnetoresistive element 10
3b, the electrode patterns are arranged orthogonal to each other, and a signal magnetic field 109 is applied.

In this case, as shown in FIG. 9, only the resistance value of the first magnetoresistive element 103a changes according to the fluctuation of the signal magnetic field 109. Therefore, the first magnetoresistive element 10
A differential output can be obtained from the electrode 107b, which is the midpoint electrode, based on the difference between the resistance value of the resistance 3a and the resistance value of the second magnetoresistance element 103b.

However, the conventional ferromagnetic magnetoresistive element 10
In the case of No. 3, since the rate of change in the magnetoresistance representing the change in the resistance value with respect to the signal magnetic field is as small as several percent, the differential output is considerably reduced. Therefore, in order to increase the differential output by using the ferromagnetic magnetoresistive element 103, a peripheral circuit must be provided, and the peripheral circuit has made the magnetic sensor a complicated circuit.

On the other hand, a giant magnetoresistive element comprising a multilayer film is described, for example, in Japanese Patent Application Laid-Open No. Hei 8-32141. The giant magnetoresistive element described in this publication is
It has a laminated structure including a first magnetic layer, a second magnetic layer, and an intermediate nonmagnetic layer formed therebetween, and the magnetoresistance change rate is as large as several tens%. Therefore, the peripheral circuit in the magnetic sensor can be simplified as compared with the conventional ferromagnetic magnetoresistive element.

However, unlike a ferromagnetic magnetoresistive element, a giant magnetoresistive element is isotropic with respect to a signal magnetic field. For this reason, even if an electrode pattern as shown in FIG. 8 is formed with this giant magnetoresistive element, the respective resistance values of the first giant magnetoresistive element 113a and the second giant magnetoresistive element 113b are as shown in FIG. As shown in FIG. 7, the values change with substantially the same value with respect to the signal magnetic field. For this reason, it is not possible to take out a differential output that causes a resistance value difference.

That is, although the giant magnetoresistive element 113 has a large magnetoresistance change rate, it has a problem that a differential output cannot be obtained because it is isotropic. One example of solving this problem is disclosed in, for example, JP-A-8-2014.
A magnetic sensor described in Japanese Patent Publication No. 92-92 is known.

As shown in FIG. 11, the magnetic sensor described in Japanese Patent Application Laid-Open No. Hei 8-201492 has a resistor pattern (giant giant) using an artificial lattice film in which ferromagnetic layers and non-ferromagnetic layers are alternately stacked. The magnetoresistive elements 113a and 113b are connected in series in the same direction in parallel on the same substrate, reverse biases 121 and 122 are applied to the resistor patterns 113a and 113b, and a signal magnetic field 119 is applied.

According to this magnetic sensor, each of the resistor patterns 103a and 103b has a characteristic of magnetoresistance change as shown by a waveform 126 in FIG. 12A and a waveform 127 in FIG. 12B. When a signal magnetic field 119 having one cycle λ is applied to the substrate, a waveform 130 (resistor pattern 113a) in FIG. 12A and a waveform 131 in FIG.
A resistance value change like (resistor pattern 113b) occurs. The differential output is obtained as an output shown by a waveform 132 in FIG. In other words, even with an isotropic giant magnetoresistive element, a differential value can be obtained by generating a resistance value difference due to a signal magnetic field.

[0012]

However, in the magnetic sensor described in Japanese Patent Application Laid-Open No. 8-201492, a magnetic sensor using a giant magnetoresistive element having isotropic property is realized. However, it was difficult to control the bias magnetic field in the minute area. Further, since a bias magnetic field is applied using a bias magnet or the like, the structure of the magnetic sensor has been complicated.

An object of the present invention is to provide a magnetic sensor capable of generating a resistance value difference with respect to a signal magnetic field without applying a bias magnetic field and capable of extracting a differential output with a simple configuration. Make it an issue.

[0014]

The present invention has the following arrangement to solve the above problems. The magnetic sensor according to claim 1 includes a substrate, and magnetoresistive means formed on the substrate and having a resistance value that changes with respect to a signal magnetic field applied substantially in parallel to the surface of the substrate, wherein the magnetoresistive means comprises: A first artificial lattice film in which magnetic layers and first nonmagnetic layers are alternately stacked, and the resistance value changes with respect to a change in the signal magnetic field applied to the first artificial lattice film. A first magneto-resistance element and a second non-magnetic layer connected in series to the first magneto-resistance element and having a different thickness from the thickness of the magnetic layer and the first non-magnetic layer; A second artificial lattice film,
A second magnetoresistive element whose resistance does not change in response to a change in the signal magnetic field applied to the second artificial lattice film.

According to the first aspect of the present invention, the first magnetoresistive element has the first artificial lattice film in which the magnetic layers and the first nonmagnetic layers are alternately stacked, The resistance value changes with a change in the signal magnetic field applied to the lattice film. On the other hand, the second magnetoresistance element connected in series to the first magnetoresistance element has a magnetic layer and a second nonmagnetic layer having a thickness different from the thickness of the first nonmagnetic layer, which are alternately stacked. And the resistance value does not change in response to a change in the signal magnetic field applied to the second artificial lattice film.

Therefore, the first magneto-resistive element acts as a variable resistor, the second magneto-resistive element acts as a fixed resistor, and a midpoint voltage is extracted from the midpoint between the first and second magneto-resistive elements. In addition, a difference in resistance value can be generated with respect to a signal magnetic field without applying a bias magnetic field, and a differential output can be obtained with a simple configuration.

According to a second aspect of the present invention, the magnetoresistive means has the second artificial lattice film, and has a resistance value against a change in the signal magnetic field applied to the second artificial lattice film. A third magnetoresistive element that does not change; and a third magnetoresistive element that is connected in series to the third magnetoresistive element, has the first artificial lattice film, and receives a change in the signal magnetic field applied to the first artificial lattice film. A fourth magnetoresistive element whose resistance value changes
One end of the magnetoresistive element is connected to one end of the third magnetoresistive element, and one end of the second magnetoresistive element is connected to the fourth magnetoresistive element.
Is connected to one end of the magnetoresistive element to form a full bridge configuration.

According to the second aspect of the present invention, since the first to fourth magnetoresistive elements form a full bridge configuration, a larger differential output can be obtained than in the half bridge configuration.

According to a third aspect of the present invention, when the rate of change in magnetoresistance representing the change in the resistance value with respect to the signal magnetic field changes according to the thickness of the nonmagnetic layer and has a maximum value and a minimum value, The thickness of the non-magnetic layer is set to a thickness at which the magnetoresistance change rate becomes the maximum value, and the thickness of the second nonmagnetic layer is set when the magnetoresistance change rate becomes substantially the minimum value. The thickness is set to be.

According to the third aspect of the invention, the thickness of the first non-magnetic layer is set to a thickness at which the rate of change in magnetoresistance reaches a maximum value, and the thickness of the second non-magnetic layer is set to Since the change rate is set to a thickness at which the change rate becomes substantially the minimum value, a difference in resistance between the first magnetoresistive element and the second magnetoresistive element with respect to signal magnetism can be generated, and You can extract the output.

According to a fourth aspect of the present invention, when the rate of change in magnetoresistance representing the change in the resistance value with respect to the signal magnetic field changes in accordance with the thickness of the nonmagnetic layer and has a plurality of maximum values and a plurality of minimum values, The thickness of the first non-magnetic layer is set to a thickness at which the rate of change in magnetoresistance becomes one of the plurality of local maximums, and the thickness of the second non-magnetic layer is: The thickness is set to a value at which the rate of change in magnetoresistance becomes a minimum value of the plurality of minimum values.

According to the fourth aspect of the present invention, the thickness of the first nonmagnetic layer is such that the rate of change in magnetoresistance is one of a plurality of local maximum values.
Since the thickness of the second non-magnetic layer is set to the thickness at which the rate of change in magnetoresistance becomes the minimum value of a plurality of minimum values, the thickness of the second nonmagnetic layer is As a result, a resistance difference between the first and second magnetoresistive elements can be generated, and a differential output can be obtained.

According to a fifth aspect of the present invention, the thickness of the first nonmagnetic layer is set to a thickness at which the rate of change in magnetoresistance reaches a second peak value, and the thickness of the second nonmagnetic layer is: It is characterized in that the magnetoresistance change rate is set to a thickness between the first peak value and the second peak value.

According to the fifth aspect of the present invention, the thickness of the first non-magnetic layer is set to a thickness at which the rate of change in magnetoresistance reaches the second peak value, and the thickness of the second non-magnetic layer is magnetic. By setting the resistance change rate to a thickness between the first peak value and the second peak value, a differential output can be efficiently taken out.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the magnetic sensor according to the present invention will be described in detail with reference to the drawings. FIG. 1A is a configuration diagram of the magnetic sensor according to the embodiment.

The magnetic sensor shown in FIG.
And a giant magnetoresistive element 3 formed on the substrate 1. In the embodiment, the giant magnetoresistive element 3 is, for example, a magnetic sensor using a giant magnetoresistive element made of an exchange-coupled artificial lattice film such as a [NiFeCo / Cu] or [CoFe / Cu] multilayer film. Target.

The giant magnetoresistive element 3 includes a first giant magnetoresistive element 3a having a comb-shaped electrode pattern 5a and a comb-shaped electrode pattern 5b connected in series to the first giant magnetoresistive element 3a. And a second giant magnetoresistive element 3b. This half-bridge configuration is employed for temperature compensation. A signal magnetic field 9 is applied to the giant magnetoresistive element 3 substantially in parallel with the surface of the substrate 1, and the magnetoresistive element 3 changes its resistance by a change in the signal magnetic field 9.

The electrode 7a is connected to one end of the electrode pattern 5a, the electrode 7c is connected to one end of the electrode pattern 5b, and the electrode 7b is connected to the midpoint between the electrode pattern 5a and the electrode pattern 5b.

The giant magnetoresistive element 3 is obtained from an exchange-coupled artificial lattice film. FIG. 1B is a structural diagram of an exchange-coupled artificial lattice film in the first giant magnetoresistance element. FIG.
(C) is a structural diagram of the exchange-coupled artificial lattice film in the second giant magnetoresistance element.

The exchange-coupled artificial lattice film in the first giant magnetoresistive element 3a shown in FIG. 1B is composed of a substrate 1, a buffer layer 13 laminated on the substrate 1, and It has a laminated magnetic layer 15 and a non-magnetic layer 17 (first non-magnetic layer) laminated on the magnetic layer 15, and the magnetic layer 15 and the non-magnetic layer 17 are alternately laminated. Is done.

The exchange-coupled artificial lattice film in the second giant magnetoresistive element 3b shown in FIG. 1C is composed of a substrate 1, a buffer layer 13 laminated on the substrate 1, and a A magnetic layer having a thickness different from the thickness of the first non-magnetic layer laminated on the magnetic layer; 15 and the nonmagnetic layer 17a are alternately laminated. Note that the buffer layer 13 may or may not be provided.

The substrate 1 is a silicon substrate to which an insulating film has been added. Buffer layer 13 has a thickness of about 50 to 150 °. The magnetic layer 15 is made of NiFeCo, CoFe, or the like, and the thickness of the magnetic layer 15 is about 10 to 20 °. The non-magnetic layer 17 is made of Cu or the like. Magnetic layer 15 and non-magnetic layer 1
7, and the number of layers of the magnetic layer 15 and the nonmagnetic layer 17a are:
When [magnetic layer / nonmagnetic layer] is one cycle, 10 to 60
About a cycle.

FIG. 3 shows the relationship between the magnetoresistance ratio of a general exchange-coupling type artificial lattice film and the thickness of the nonmagnetic layer. As can be seen from FIG. 3, the rate of change in magnetoresistance of the exchange-coupled artificial lattice film depends on the thickness of the nonmagnetic layer, and reaches the first peak value when the thickness of the nonmagnetic layer is about 9 °, and about 21 °. It becomes the second peak value. When the thickness of the nonmagnetic layer is about 11 ° to 19 ° between the first peak value and the second peak value, the rate of change in magnetoresistance is several percent or less.

FIG. 2 is a circuit diagram of a giant magnetoresistive element having a half-bridge structure. The power supply voltage V _DD is supplied to the electrode 7a, and the electrode 7c is grounded. As the first giant magnetoresistive element 3a, an artificial lattice film in which the thickness of the nonmagnetic layer 17 is set so that the magnetoresistance ratio has a peak value (first peak value or second peak value) shown in FIG. 3 is used. Thus, a change in magnetoresistance occurs with respect to the signal magnetic field 9.

The second giant magnetoresistance element 3b uses an artificial lattice film in which the thickness of the nonmagnetic layer 17a is set so that the rate of change in magnetoresistance does not have a peak value but has a substantially minimum value as shown in FIG. A change in magnetoresistance with respect to the magnetic field 9 does not occur. A differential output is extracted from an electrode 7b which is a midpoint terminal between the first giant magnetoresistive element 3a and the second giant magnetoresistive element 3b.

That is, the embodiment is characterized in that an element which does not cause a change in magnetoresistance in response to a change in the signal magnetic field 9 is realized by a simple element utilizing the nonmagnetic layer dependence of the giant magnetoresistance element 3. And

Next, the operation of the magnetic sensor of the embodiment configured as described above will be described with reference to the drawings. A signal magnetic field 9 is applied to the respective exchange-coupled artificial lattice films of the first giant magnetoresistive element 3a and the second giant magnetoresistive element 3b.

At this time, the first giant magnetoresistive element 3a
Means that the non-magnetic layer 1
Since an artificial lattice film with a thickness of 7 is used,
A magnetoresistance change occurs in the signal magnetic field 9.

On the other hand, the second giant magnetoresistive element 3b uses an artificial lattice film in which the thickness of the nonmagnetic layer 17a is set so that the rate of change in magnetoresistance takes a substantially minimum value. On the other hand, there is almost no change in magnetoresistance.

That is, since the first giant magnetoresistive element 3a whose magnetoresistance changes with respect to the signal magnetic field 9 and the second giant magnetoresistance element 3b whose magnetoresistance does not substantially change are used, the circuit is A resistance value difference occurs in the giant magnetoresistive element 3 constituting the first giant magnetoresistive element 3a and the second giant magnetoresistive element 3a.
A differential output is taken out from the electrode 7b which is a midpoint terminal with the giant magnetoresistive element 3b.

As described above, according to the magnetic sensor of the embodiment, by using the giant magnetoresistive element 3 composed of a multilayer film in the sensing part of the magnetic sensor, it is larger than the conventional ferromagnetic magnetoresistive element. You can get the output.

By utilizing the non-magnetic layer thickness dependency of the magnetoresistance change rate, a differential output can be obtained from the giant magnetoresistance element 3 having isotropic magnetoresistance element characteristics. That is, an exchange-coupled artificial lattice film whose nonmagnetic layer thickness is different by several Å is used for the giant magnetoresistive element 3 constituting the circuit.

This exchange-coupled artificial lattice film is characterized in that a difference in thickness of the nonmagnetic layer of several Å has a remarkable effect on the magnetoresistance ratio. By utilizing this feature, the isotropic giant magnetoresistive element 3 can generate a resistance value difference with respect to a signal magnetic field without applying a bias magnetic field and without a magnetic shield. You can extract the output.

The present applicant has made a prototype of the giant magnetoresistive element 3 of the embodiment. The giant magnetoresistive element 3 is an exchange-coupled artificial lattice film using NiFeCo for the buffer layer 13 and the magnetic layer 15 and Cu for the nonmagnetic layers 17 and 17a. Substrate 1 is made of a Si / SiO _2. The buffer layer thickness was 50 °, the magnetic layer thickness was 15 °, and the nonmagnetic layer thickness was t _CU . The lamination cycle number n was set to 20.

The first giant magnetoresistive element 3a, the non-magnetic layer thickness t _CU is made from an artificial lattice film of 21 Å (the second peak). The second giant magnetoresistive element 3b was formed from an artificial lattice film having a nonmagnetic layer thickness t _CU of 19 °.

FIG. 4 shows the relationship between the magnetoresistance change rate of the first giant magnetoresistance element 3a and the second giant magnetoresistance element 3b and the signal magnetic field. First giant magnetoresistive element 3a
Is about 9%, while the magnetoresistance change of the second giant magnetoresistive element 3b is 1% or less.

The characteristics of the first giant magnetoresistive element 3a and the second giant magnetoresistive element 3b other than the magnetoresistance ratio characteristics are the same. For example, the resistivity of the first giant magnetoresistive element 3a and the second giant magnetoresistive element 3b is about 2.17 × 10 ⁻⁷ Ω · m, and the same applies to the material composition and manufacturing history. It is. Therefore, there is no difference in basic characteristics such as the temperature characteristics of the giant magnetoresistive element 3.
That is, in the embodiment, the characteristic of the exchange-coupling type artificial lattice film that the presence or absence of a change in the magnetoresistance occurs only by a difference in the thickness of the nonmagnetic layer by a few Å.

In the above-described embodiment, the giant magnetoresistive element 3 having a half-bridge configuration including the first giant magnetoresistive element 3a and the second giant magnetoresistive element 3b has been described.

The present invention is not limited to the giant magnetoresistive element 3 described above, but can be applied to, for example, a giant magnetoresistive element having a full bridge configuration. FIG. 5 is a configuration diagram of a giant magnetoresistive element having a full bridge configuration.
FIG. 6 is a circuit diagram of a giant magnetoresistive element having a full bridge configuration.

The giant magnetoresistive element of the full bridge configuration shown in FIG. 5 has one end connected to the electrode 7a and the other end connected to the electrode 7b, and the first giant magnetoresistive element whose resistance value changes with a change in the signal magnetic field 9. A magnetoresistive element 3a1, a second giant magnetoresistive element 3b whose one end is connected to the electrode 7b and the other end is connected to the electrode 7c, and whose resistance value does not change in response to a change in the signal magnetic field 9;
1, a third giant magnetoresistive element 3b2 whose one end is connected to the electrode 7a and the other end is connected to the electrode 7d and whose resistance value does not change in response to a change in the signal magnetic field 9, and one end which is connected to the electrode 7d. A fourth giant magnetoresistive element 3a2 whose end is connected to the electrode 7c and whose resistance value changes with a change in the signal magnetic field 9;

A power supply terminal is connected to the electrode 7a.
The electrode 7c is grounded, and a differential output (OUT1, OUT2) is extracted from the electrode 7b and the electrode 7d.

As described above, the first giant magnetoresistive element 3a
By using a giant magnetoresistive element having a full bridge configuration including the first to fourth giant magnetoresistive elements 3b2, a differential output larger than the differential output of the giant magnetoresistive element having a half bridge configuration can be obtained.

Note that the present invention is not limited to the magnetic sensors of the above embodiments. In the embodiment, the entire length of the electrode pattern of each giant magnetoresistive element is arranged so as to be substantially orthogonal to the signal magnetic field 9. For example, as shown in FIG. Electrode pattern 5a of second giant magnetoresistive element 3a and second giant magnetoresistive element 3
The electrode pattern 5c may be arranged so as to be substantially orthogonal to the electrode pattern 5c.

For example, as shown in FIG.
The electrode pattern 5d of the first giant magnetoresistive element 3d and the second
May be arranged substantially parallel to the electrode pattern 5c of the giant magnetoresistive element 3c, and the signal magnetic field 9 may be applied substantially parallel to the longitudinal direction of the electrode pattern.

Further, each electrode pattern may be arranged at a predetermined angle (for example, 45 °) with respect to the signal magnetic field. This is because the giant magnetoresistive element of the embodiment has isotropic properties. In addition, it goes without saying that various modifications can be made without departing from the technical idea of the present invention.

[0056]

According to the first aspect of the present invention, the first magnetoresistive element has the first artificial lattice film in which the magnetic layers and the first nonmagnetic layers are alternately laminated. The resistance value changes with a change in the signal magnetic field applied to the artificial lattice film. The second magnetoresistive element has a second artificial lattice film in which magnetic layers and second nonmagnetic layers having different thicknesses with respect to the thickness of the first nonmagnetic layer are alternately laminated. The resistance value does not change in response to a change in the signal magnetic field applied to the artificial lattice film.

For this reason, the midpoint voltage is taken out from the midpoint of the first and second magnetoresistance elements, so that a resistance value difference can be generated with respect to the signal magnetic field without applying a bias magnetic field. Moreover, a differential output can be obtained with a simple configuration.

According to the second aspect of the present invention, since the first to fourth magnetoresistive elements form a full bridge configuration, a larger differential output can be obtained than in the half bridge configuration.

According to the third aspect of the invention, the thickness of the first non-magnetic layer is set to a thickness at which the rate of change in magnetoresistance reaches a maximum value, and the thickness of the second non-magnetic layer is set to Since the change rate is set to a thickness at which the change rate becomes substantially the minimum value, a difference in resistance between the first magnetoresistive element and the second magnetoresistive element with respect to signal magnetism can be generated, and You can extract the output.

According to the fourth aspect of the present invention, the thickness of the first nonmagnetic layer is such that the rate of change in magnetoresistance is one of a plurality of maximum values.
Since the thickness of the second non-magnetic layer is set to the thickness at which the rate of change in magnetoresistance becomes a minimum value of a plurality of minimum values, the thickness of the second non-magnetic layer is As a result, a resistance difference between the first and second magnetoresistive elements can be generated, and a differential output can be obtained.

According to the fifth aspect of the present invention, the thickness of the first nonmagnetic layer is set to a thickness at which the rate of change in magnetoresistance reaches the second peak value, and the thickness of the second nonmagnetic layer is set to By setting the rate of change to a thickness between the first peak value and the second peak value, differential output can be efficiently taken out.

[Brief description of the drawings]

FIG. 1A is a configuration diagram of a magnetic sensor according to an embodiment,
(B) is a structural diagram of an exchange-coupling type artificial lattice film in the first giant magnetoresistance element, and (c) is a structural diagram of an exchange-coupling type artificial lattice film in the second giant magnetoresistance element.

FIG. 2 is a circuit diagram of a giant magnetoresistive element having a half-bridge configuration.

FIG. 3 is a diagram showing a relationship between a magnetoresistance change rate of a general exchange-coupling type artificial lattice film and a nonmagnetic layer thickness.

FIG. 4 is a diagram illustrating a relationship between a magnetoresistance change rate of a first giant magnetoresistive element and a second giant magnetoresistive element and a signal magnetic field;

FIG. 5 is a configuration diagram of a giant magnetoresistive element having a full bridge configuration.

FIG. 6 is a circuit diagram of a giant magnetoresistive element having a full bridge configuration.

FIG. 7 is a diagram illustrating another configuration example of the giant magnetoresistive element having the half bridge configuration according to the embodiment;

FIG. 8 is a configuration diagram of a conventional magnetic sensor using a magnetoresistive element having anisotropy.

FIG. 9 is a diagram showing a change in resistance value with respect to a signal magnetic field of a conventional magnetoresistive element having anisotropy.

FIG. 10 is a diagram showing a change in resistance value of a conventional isotropic magnetoresistive element with respect to a signal magnetic field.

FIG. 11 is a diagram illustrating an example of a conventional magnetic sensor using a magnetoresistive element having isotropic properties.

12 is a diagram showing a change in magnetoresistance of the magnetic sensor shown in FIG. 11 with respect to a magnetic field.

13 is a diagram showing an output with respect to a signal magnetic field of the magnetic sensor shown in FIG.

[Explanation of symbols]

 Reference Signs List 1 substrate 3 giant magnetoresistive element 3a first giant magnetoresistive element 3b second giant magnetoresistive element 5a-5b electrode pattern 7a-7c electrode 9 signal magnetic field 13 buffer layer 15 magnetic layer 17, 17a nonmagnetic layer

Claims (5)

[Claims] 1. A magnetic head comprising: a substrate; and a magnetoresistive means formed on the substrate and having a resistance value changed with respect to a signal magnetic field applied substantially parallel to a surface of the substrate, wherein the magnetoresistive means comprises a magnetic layer. And a first non-magnetic layer alternately laminated with a first artificial lattice film, wherein the first artificial lattice film has a resistance value that changes with a change in the signal magnetic field applied to the first artificial lattice film. A magneto-resistive element, a second non-magnetic layer having a thickness different from the thickness of the magnetic layer and the first non-magnetic layer, which is connected in series to the first magneto-resistive element; And a second magnetoresistive element having a resistance value that does not change in response to a change in the signal magnetic field applied to the second artificial lattice film. 2. The third magnetoresistive means having the second artificial lattice film, wherein the resistance value does not change in response to a change in the signal magnetic field applied to the second artificial lattice film. An element, which is connected in series to the third magnetoresistive element, has the first artificial lattice film, and has a resistance value that changes with respect to a change in the signal magnetic field applied to the first artificial lattice film. And one end of the first magnetoresistive element and one end of the third magnetoresistive element, and one end of the second magnetoresistive element and the fourth magnetoresistive element. 2. The magnetic sensor according to claim 1, wherein one end of the magnetic sensor is connected to form a full bridge configuration. 3. The method according to claim 1, wherein the change rate of the magnetoresistance representing the change in the resistance value with respect to the signal magnetic field changes according to the thickness of the nonmagnetic layer and has a maximum value and a minimum value. The thickness is set to a thickness when the magnetoresistance change rate reaches the local maximum value, and the thickness of the second nonmagnetic layer is set to a thickness when the magnetoresistance change rate becomes approximately the local minimum value. The magnetic sensor according to claim 1 or 2, wherein 4. The method according to claim 1, wherein the change rate of the magnetoresistance representing the change in the resistance value with respect to the signal magnetic field changes according to the thickness of the nonmagnetic layer and has a plurality of maximum values and a plurality of minimum values. The thickness of the nonmagnetic layer is set to a thickness at which the magnetoresistance change rate becomes one of the plurality of local maximum values, and the thickness of the second nonmagnetic layer is the magnetic resistance change rate. 3. The magnetic sensor according to claim 1, wherein the thickness is set to a thickness at which the minimum value of the plurality of minimum values is obtained. 5. The thickness of the first nonmagnetic layer is set to a thickness at which the rate of change in magnetoresistance reaches a second peak value,
5. The magnetic sensor according to claim 3, wherein the thickness of the nonmagnetic layer is set to a thickness such that the rate of change in magnetoresistance is between the first peak value and the second peak value. 6.