JP3277898B2 - Magnetoresistance effect element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetoresistive element using a magnetoresistive effect, which is used for a magnetic sensor, a magnetic head, and the like.

[0002]

2. Description of the Related Art A magnetoresistive element is expected to be capable of forming a thin film head. However, in a conventional magnetoresistive element, a magnetic field change is performed mainly by using only a magnetization reversal mechanism based on movement of a domain wall. In particular, high-sensitivity magnetic field detection in a low magnetic field could not be performed. Recently, a giant magnetoresistance effect (GMR) has been discovered in a multilayer artificial lattice made of iron and chromium, and a technique for applying the effect has been attracting attention. Hereinafter, the following conventional main magnetoresistive elements will be described. (1) Strongly-coupled GMR multilayer device (2) Weakly-coupled GMR multilayer device (3) Non-coupled GMR multilayer device (4) Spin-polarized tunnel device (5) Granular device

(1) A typical structure of a strong coupling type GMR multilayer film element is a multilayer structure in which a ferromagnetic metal film and a non-ferromagnetic film (for example, Cr) having a thickness of several nm are alternately laminated.
Under a strong applied magnetic field, when the spins in the upper and lower ferromagnetic layers separated by Cr are parallel, spin scattering for electrons decreases and the magnetoresistance decreases. Conversely, when the applied magnetic field is weak and the spins of the upper and lower ferromagnetic layers are antiparallel, the magnetoresistance takes a high value. Magnetoresistance has anisotropy, and two cases are considered: a case where a current is caused to flow in parallel to the film to measure the magnetoresistance (CIP) and a case where the current is caused to flow perpendicularly (CPP). Generally CP
P has a higher spin scattering frequency and a higher magnetoresistance ratio than CIP. The magnetoresistance ratio of this device is generally as high as 100% or more at low temperatures, but it is equal to the resistance at 0 Gauss.
It is the value of the resistance ratio at 0000-20000 gauss. Therefore, the magnetoresistance ratio per unit magnetic field is 0.01% /
The sensitivity is not so good at about Gauss. Strong coupling type G
The magnetic saturation characteristic and the magnetic field-resistance ratio (ΔR /
R) The characteristics are shown in FIG. In this case, the magnetoresistance ratio curve has a single peak structure having one peak near the zero magnetic field. As shown, the sensitivity in the low magnetic field region is higher than that in the high magnetic field region, but not yet sufficiently high.

(2) The GMR element of the weak coupling type is similar to the structure of the strong coupling type, but the non-ferromagnetic layer is thicker than that of the strong coupling type, and the interaction between the ferromagnetic layers is weak. Has become. As shown in FIG. 14, the magnetic characteristics in this case show hysteresis characteristics, and the magnetoresistance curve has a double peak characteristic showing a peak at a magnetic field corresponding to two coercive forces.

[0005] (3) The non-coupling type element contains two kinds of magnetic materials having different coercive forces.
m) / Co (3 nm) / Cu (5 nm) / NiFe (3
nm)) NiF having a small coercive force like a × 15 layer structure.
An e (permalloy) layer and a Co layer having a large coercive force are alternately formed of a multilayer laminated film (the number in parentheses is the film thickness).
The MH curve in this case shows a constriction characteristic as shown in FIG. 15 by including the permalloy layer whose magnetization is reversed in the low magnetic field region. The magnetoresistance characteristic of this element reflects a change in the magnetization and causes a large change in resistance in a low magnetic field.

(4) The spin-polarized tunnel element employs a structure in which a ferromagnetic metal layer is separated by a thin insulating film as seen in, for example, Ni-NiO-Co or Ni-NiO-Ni. When utilizing the tunnel magnetoresistance effect, generally, a current is caused to flow in a direction perpendicular to the laminated film structure.
In the case of this element structure, the size in the film surface direction is considerably larger than the film thickness dimension of the element, and the measurement becomes somewhat difficult because the resistance value of the element is low. Also, it is difficult to control the thickness of the insulator film, and the reproducibility of the magnetoresistance is not very good.

(5) The granular element has a structure in which ferromagnetic particles such as iron and cobalt are precipitated in a non-ferromagnetic metal such as silver and copper. In the weak magnetic field region, the magnetization of each particle is oriented in a random direction, and the particle diameter is 10
In the case of about nm or less, a superparamagnetic state is established (the coercive force is very small and the magnetization is almost proportional to the magnetic field).
When a magnetic field of about several thousand gauss is applied, the spins of this element are aligned and the magnetization is saturated. The magnetoresistance ratio is about 8% for Co ₁₆ Cu ₈₄ and the magnetic field sensitivity is 0.001% / Gauss. This sensitivity is one order of magnitude lower than that of a strongly coupled GMR element. In addition, magnetization characteristics such as coercive force are not yet at a stage where they can be sufficiently controlled.

[0008]

As described in the prior art, for example, in a strong (weak) coupling type GMR element,
The vector sum of the magnetic field where the spin of the ferromagnetic material is aligned and the magnetic resistance is minimized and the magnetic moment of the ferromagnetic material are approximately 0
The magnetic field difference at which the magnetic resistance is maximized is about several Tesla, and the magnetic field sensitivity in a low magnetic field region is low. In addition, it has been difficult to precisely control the coercive force, saturation magnetization, and magnetic domain structure of the ferromagnetic particles of these elements to some extent independently of the material parameters. It has been observed in experiments that the above-mentioned granular element has a high coercive force. However, the magnetic field sensitivity is lower than that of the strong (weak) coupled GMR element, and this element also has a strong (weak) coupled GMR element. As in the case of the element, the desired magnetic element has not been realized by controlling the magnetic domain structure and magnetic characteristics. That is, in any of the GMR elements, the magnetic field sensitivity particularly in a low magnetic field is insufficient, and improvement thereof is desired. Further issues include coercive force, saturation magnetization, domain structure, etc.
It is an object of the present invention to control element characteristic parameters closely related to magnetic characteristics to some extent independently of material parameters.

[0009]

Means for Solving the Problems The magnetoresistance effect element according to the present invention for solving the aforementioned problem, is formed to include a magnetic material, the first composed of several first structure double And a first structure formed by including a magnetic material, wherein the first structure has one or more second structures having different coercive forces due to different structures or materials. And a first structure belonging to the first group and a second structure belonging to the second group are electrically connected. In order to solve the above-mentioned problem, another magnetoresistive effect element according to the present invention comprises: a first group formed of one first structure , which is formed by including a magnetic material; One or more second structures, each of which has a different coercive force due to a different structure from the first structure, including a material.
A first group belonging to the first group and a second group belonging to the second group are electrically connected to each other. It is characterized by.

[0010]

When the first structure is constituted by, for example, island regions having a single magnetic domain structure, the direction of magnetization can be easily reversed by a low magnetic field, and the magnetic saturation characteristics can be reduced.
As shown in (a), the coercive force can be kept low, for example, to H1. Further, when the second structure is formed of, for example, a magnetic film thin line in which the direction of magnetization is regulated in one direction, the direction of magnetization is less likely to be reversed than that of the island region of the single magnetic domain structure, and the magnetic saturation characteristic is reduced. As shown in FIG. 1B, the coercive force can be maintained as high as, for example, H2. Therefore, in an element in which the first structure having the magnetic saturation characteristic shown in FIG. 1A and the second structure having the magnetic saturation characteristic shown in FIG. 1B are mixed, an element shown in FIG. Magnetic saturation characteristics. As a result, FIG.
As shown in (b), -H2 to -H1 (or H1
To H2), a large resistance change can be obtained in a magnetic field in the range, and high magnetic measurement sensitivity can be realized.

Here, the coercive force H of the first and second structures is
1, H2 can be set to an appropriate value not only by its planar shape but also by selecting a pitch, a film thickness and a material. Therefore, it is possible to appropriately set the coercive forces H1 and H2 of the two structures and appropriately select a range of the magnetic field intensity that can be detected with high sensitivity. For example, by setting the coercive force H1 of the first structure low, the magnetic field sensitivity at an arbitrary low magnetic field can be improved. By expanding the example in which the magnetoresistive element is formed from two types of structures having different coercive forces, the magnetoresistive element can be formed using n-type structures having different coercive forces. By doing so, it is possible to realize a magnetoresistive element exhibiting high sensitivity in a wide range from a low magnetic field to a high magnetic field.

[0012]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 3A is a plan view showing the first embodiment of the present invention, and FIG.
It is sectional drawing in the AA 'line of (a). An island-shaped region 2 and a thin wire 3 which are magnetic material layers are formed on a substrate 1 having an insulating property or a surface covered with an insulating film. Here, the direction of the magnetic field to be detected is assumed to be the longitudinal direction of the fine wire 3. In this case, the rows of the island-shaped regions 2 and the thin lines 3 are alternately arranged. The island-shaped region and the thin line are electrically connected by the connecting portion 4, whereby the whole is formed as one conductor layer. As shown in FIG. 3B, the region between the island regions 2 and the region between the island regions 2 and the fine lines can be buried with the insulating film 5. The island region 2 and the thin wire 3 may be a GMR multilayer film of a strong coupling type or a weak coupling type, but may be a single-layer ferromagnetic film. When a single-layer ferromagnetic film is used, the direction of magnetization can be made perpendicular to the substrate surface by setting the film thickness to a certain value or more. In the case of using a GMR multilayer film, if the number of times of lamination is increased, the frequency of coincidence / mismatch of spin directions is increased, and a large change in magnetoresistance is obtained as compared with a single-layer ferromagnetic film.

Although the shape of the island-shaped region can be set so as to have a single magnetic domain structure, it may be a multi-domain structure.
It is desirable to set the width of the thin wire 3 so that the direction of magnetization is regulated in the longitudinal direction of the thin wire. A pair of current terminals 6 for supplying a current to the magnetoresistive element and a pair of voltage terminals 7 for detecting a voltage are formed at appropriate positions on the magnetic film. These terminals may be arranged in a straight line so as to sandwich the voltage terminal. Here, when the space between the magnetic films is not buried with the insulating film 5,
The current terminal 6 and the voltage terminal 7 are formed so as to cover the side surfaces of the island region 2 and the thin wire 3 as well.

FIG. 4A is a plan view showing a second embodiment of the present invention, and FIG.
It is sectional drawing in the B 'line. In FIG. 4, the same reference numerals are given to the same parts as the parts in the embodiment of FIG. 3, and the duplicate description will be omitted. The connecting portion 4 for connecting the thin line is omitted. In this case, a conductive layer 8 made of a non-ferromagnetic film is formed so as to cover the entire surface in order to impart conductivity to the whole. In this embodiment, appropriate portions of the conductor layer 8 are used as the current terminal 6 and the voltage terminal 7. In this case, a part of the conductor layer 8 itself can be used as a terminal, but a low resistance metal film such as an Au film may be formed in a terminal formation region of the conductor layer 8.

FIG. 5A is a plan view showing a third embodiment of the present invention. The cross-sectional view taken along the line BB 'in this case is the same as that of the second embodiment, as shown in FIG. 4B. In the first and second embodiments, the arrangement of the island-shaped regions 2 in the row direction and the thin lines 3 are arranged alternately. In the third embodiment, however, the formation region of the island-shaped regions and the thin line 3 are arranged. Are formed separately from each other. As described above, by completely separating the island-shaped region and the fine line, the interaction between the fine line and the island line can be relaxed, and the magnetization reversal can be caused more rapidly (in a low magnetic field region).

FIG. 5B is a plan view showing a fourth embodiment of the present invention. In the present embodiment, constrictions 2a, 3a are intentionally introduced into the island-shaped region 2 and the thin line 3. In the vicinity of the constrictions 2a and 3a, a magnetic pole is formed before and after the constriction because the curvature is large and the density of spin-polarized electrons is high. Therefore, a constriction is placed in the middle of the elongated island.
When inserted, two dipoles exist in one island region. Similarly, when N constrictions are formed in an elongated thin line, N + 1 dipoles are formed in the thin line. This constricted structure is formed by a method of writing the constricted structure directly by electron beam lithography, photolithography, etc., or a method of drawing dots that are appropriately close and exposing them slightly overdose to connect the dots to each other can do.

FIG. 6A is a plan view showing a fifth embodiment of the present invention. In this embodiment, the island-shaped region 2
Is formed in a circular shape. The thin wires 3 running in the direction of the magnetic field H are connected to each other at the connecting portion 3b. In this embodiment, a conductor film is formed at least on the opening of the lattice-shaped magnetic film in order to secure electrical connection between the island regions 2. In this pattern, when a magnetic field is applied as shown in the figure, the coupling portion 3b and the circular island-shaped region 3 which are oriented in the direction perpendicular to the magnetic field both undergo magnetization reversal at a low magnetic field, and the thin line which is oriented parallel to the magnetic field is formed. Only coercive force is large.

FIG. 6B is a plan view showing a sixth embodiment of the present invention. In this embodiment, a large number of fine wires 3 are connected between two large multi-domain island regions 2b.
In general, a thin film (arbitrarily thick) of a ferromagnetic film having a side of several tens of microns or more is divided into multi-domains (multi-domains). In a typical hysteresis loop of this multi-domain structure, the magnetization is rapidly reversed at a low magnetic field as shown in FIG. The coercive force H1 in this case is about 30 Gauss. On the other hand, for example, with a width of 80 nm and a pitch of 400
The coercive force H2 of a thin iron wire of nm is about 800 Gauss [see FIG. 1 (b)].

FIG. 7A is a plan view showing a seventh embodiment of the present invention. In the examples shown in FIGS. 7 and 8,
Although a thin line or a long island region is formed on the same substrate outside the island region, only the short island region is shown in the figure. In the example of FIG. 7A, cylindrical island-shaped regions 2c are arranged on the substrate 1 in a matrix. This island-shaped region can be formed by using an etching method or a lift-off method by forming this pattern or an inverse pattern by lithography, or can be formed by using an oblique deposition method. In the latter case, for example, using a lithography method, a height of 300 nm having an opening having a diameter of 50 nm is used.
A ferromagnetic material is sputtered while forming a resist pattern of a degree and rotating the substrate holder of the sputtering apparatus. In this case the ion beam and the target (eg iron)
The target is set so that the straight line connecting the target and the straight line connecting the target and the substrate holder forms an angle of, for example, 30 degrees. After the sputtering, if lift-off is performed with acetone or the like, a cylindrical island region is completed.

FIG. 7B is a sectional view showing an eighth embodiment of the present invention, in which a hemispherical island region 2 d is arranged on a substrate 1. The planar arrangement of the hemispherical island regions is the same as that shown in FIG. The method of forming the island-shaped region is the same as that of the above-described cylindrical type shown in FIG. 7A, except that the resist film thickness is made lower than that in the case of forming the cylindrical type. That is, for example, a resist film having a thickness of 100 nm having an opening having a diameter of 50 nm is provided, and lift-off is performed after oblique rotation sputtering deposition to form a hemispherical island region.

The arrangement of the island regions can be appropriately selected from FIGS. 8 (a) to 8 (f). (A) is a square lattice, (b) is a rectangular lattice, (c) is a hexagonal lattice, (d) is a diamond lattice, (e) is a one-dimensional lattice, and (f) is a concentric arrangement. The shape of the island region is not a rectangle or a circle, and FIG.
As shown in FIG. Further, the shape may be a star or a regular polygon.

Next, an example in which a pair of current terminals and voltage terminals are formed on the upper and lower surfaces of the magnetic film will be described with reference to FIG. In the examples shown in FIGS. 3 to 5, the current terminal 6 and the voltage terminal are formed only on the upper surface of the magnetic film. That is, it has a so-called CIP structure in which current flows in the plane direction of the element. This structure may be changed to a so-called CPP structure in which a current flows in a direction perpendicular to the element surface. In this case, the lower conductor layer 9 is formed on the substrate 1, and the upper conductor layer 10 is formed on the upper surfaces of the magnetic films (2, 3). Then, a pair of current terminals 6 are provided on the upper and lower conductor layers, and a pair of voltage terminals 7 are provided on the upper and lower conductor layers. In this case, a part of the conductor layers 9 and 10 itself can be used as a terminal, but a low-resistance metal film such as an Au film may be formed in a terminal formation region of the conductor layers 9 and 10. .

The magnetic properties of the island region can be controlled by changing its size. For example, an island having a size of 100 nm × 50 nm (the longitudinal direction is the direction of the magnetic field) is increased to 150 nm × 5
If it is 0 nm, the coercive force of the element will be large. In other words, in order to improve the sensitivity in a low magnetic field as a magnetoresistive element in this size region, the size of the island in the magnetic field direction may be reduced, and in order to increase the sensitivity in a high magnetic field, the size in the magnetic field direction is increased. You just need to increase it. If the pitch of the arrangement patterns of the island regions is the same and the size of the pattern is small enough to prevent magnetic interaction, there is no magnetic coupling between the island regions, and the coercive force of the element decreases. Conversely, if the pitch is the same and the size is increased, the dipole interaction between the island regions becomes stronger, and the coercive force of the element increases.

In the above, one type of island-shaped region and its material have been considered. For example, if N types of rectangular rows are formed, N digital steps can be realized (the coercive force is N). It is possible to realize a magnetoresistive element having high sensitivity not only in a low magnetic field but also in a high magnetic field region. Further, by forming a plurality of types of islands using different materials, a plurality of islands having a coercive force can be realized. Further, different coercive forces may be realized by combinations of materials and sizes.

For example, a small permalloy island region may be provided between large iron island regions. In this case, two lithography processes are required, but since the small island is permalloy, the coercive force (about 10 gauss) of the element is reduced, and the sensitivity is improved as compared with the case where the element is entirely made of iron. Further, in a device in which two kinds of rectangular rows of iron and cobalt were produced and overlaid thereon, when the spins of iron were uniform (H> 100 gauss), the magnetic resistance was minimized, and the spins of both were antiparallel. Low magnetic field region (40 Gauss
When s <H <100 Gauss), the magnetic resistance becomes maximum.

In order to lower the coercive force of the element, it is also effective to apply a heat treatment to the island region. On the other hand, the coercive force of a thin wire or a long island region can be increased up to about 2500 gauss by processing the ferromagnetic material in a needle shape in the direction of the applied magnetic field.

[0027]

Next, embodiments of the present invention will be described with reference to the drawings. [First Embodiment] FIGS. 10 and 11 are a sectional view and a plan view in the order of steps for explaining a first embodiment of the present invention. A silicon oxide film 102 is formed on a silicon substrate 101, and a high-sensitivity resist film (sensitivity: 300 μC / cm ² ) 103 for electron beam exposure is formed on the silicon oxide film 102 to a thickness of 200 nm. A low-sensitivity resist film (sensitivity: 400 μC / cm ² ) 104 was formed to a thickness of 50 nm (FIG. 10A). The reason why the high-sensitivity resist film is used as the lower layer is to form a divergent opening by development after electron beam exposure to facilitate lift-off.

Next, island and fine line patterns were drawn by an electron beam (current: 100 pA, acceleration voltage: 5).
0 keV, basic dose: 400 μC / cm ² ). The drawn rectangular pattern has a size of 50 nm × 50 mm with respect to a 2.5 mm × 1 mm pattern formation region (see FIG. 11A).
nm, and the pitch is 400 nm. The fine line pattern having a width of 50 nm was drawn in the gap between the rectangular rows. After drawing, development was performed for about 30 seconds in a mixed solution of methyl isobutyl ketone and isopropyl alcohol (mixing ratio 1: 1). Thereafter, in order to evaporate the developing solution, baking was performed in nitrogen gas for about 30 minutes (FIG. 10B).

Thereafter, a multilayer film including a ferromagnetic film was formed by ion beam sputtering. In the multilayer structure, a total of 50 layers of iron and chromium were alternately laminated with the respective film thicknesses of 3 nm and 1 nm. Then, when iron is oxidized and converted into iron oxide, the magnetic moment per unit volume at that portion becomes about 1/4 of that of pure iron. (FIG. 10 (c)).

Thereafter, lift-off is performed in acetone,
An island and a thin line were formed [FIG. 10 (d), FIG.
(A)]. Next, a resist film for electron beam exposure having a thickness of 200 nm is formed again on the sample, and a width of 10 mm is formed between the conductor layer forming region and the four terminal forming portion by electron beam lithography.
A resist film having an opening of 0 nm and a size of 500 μm × 500 μm was formed. Next, Pt is sputtered to a thickness of 20 nm, and then lift-off is performed, so that 5
Width 100 having a conductive pattern of 00 μm × 500 μm
A conductor layer 108 having a thickness of μm was formed (FIG. 11B). Next, a resist having a film thickness of 1 μm is applied again on the sample, and development is performed after electron beam exposure, so that 500
An opening of μm × 500 μm was formed. Next, apply gold to thickness 1
A pair of current supply terminals 109 and a pair of voltage detection terminals 110 were formed by sputtering a film of 00 nm and performing lift-off (FIG. 11C).

Measurement and evaluation were performed on the magnetoresistive element of this example manufactured as described above. as a result,
In this device, the rectangular magnetization is reversed in the same direction as the magnetic field in the magnetic field H1 (60 Gauss), and the magnetoresistance reflects a discontinuous jump in the magnetic field H1 (1).
From 00 ohms to 150 ohms, ie MR ratio 50%, magnetic sensitivity 0.83% / Gauss). The magnitude of this jump was proportional to the total volume of the rectangle in the ferromagnetic volume of the entire device. Further, until the magnetization of the fine wire is reversed by applying a magnetic field (up to the magnetic field H2, 120 gauss), the magnetization of the element does not change much and the magnetoresistance is almost constant.
In No. 2, all the spins in the element were aligned in the direction of the magnetic field, and the magnetoresistance dropped sharply (from 150 ohm to 100 ohm).

[Second Embodiment] In the second embodiment, the first
The 50 nm × 50 nm pattern of the island region of
0 nm × 100 nm (100 nm is the direction of the magnetic field). Other than that, it is the same as the first embodiment. In the device manufactured according to this example, the rectangular magnetization was reversed in the same direction as the magnetic field by the magnetic field H1 (65 Gauss), and the magnetoresistance changed from 100 ohms to 150 ohms.

[Third Embodiment] In the third embodiment, the first
The pitch of 400 nm of the island region of the example of Example was set to 200 nm. Other than that, it is the same as the first embodiment. In the device manufactured according to this example, the rectangular magnetization was reversed in the same direction as the magnetic field by the magnetic field H1 (65 Gauss), and the magnetoresistance changed from 100 ohms to 150 ohms.

[Fourth Embodiment] In the fourth embodiment, the first
The 50 nm × 50 nm pattern of the island region of
0 nm x 100 nm (100 nm is the direction of the magnetic field)
The pitch of the island region was set to 200 nm. Other than that, it is the same as the first embodiment. In the device manufactured according to this example, the rectangular magnetization was reversed in the same direction as the magnetic field by the magnetic field H1 (70 Gauss), and the magnetoresistance changed from 100 ohms to 150 ohms.

[Fifth Embodiment] FIG. 12 shows a fifth embodiment of the present invention.
FIG. 6 is a cross-sectional view in the order of steps for explaining the example. A silicon oxide film 102 is formed on a silicon substrate 101, and iron is deposited on the silicon oxide film 102 to a thickness of 20 nm by sputtering.
A film 111 was formed, and Pt was further formed thereon by sputtering to a thickness of 2 nm to form a Pt film 112. A high-resolution resist for electron beam exposure (calixscus arene) is applied thereon to a thickness of 1 μm, and a resist film 113 is formed.
Was formed [FIG. 12 (a)].

Next, island and fine line patterns are drawn by an electron beam (acceleration voltage 50 keV, beam current 100 p
A), development was performed. The drawn rectangular pattern is 2.5
50nm × 1mm for pattern formation area
The pitch is 50 nm and the pitch is 400 nm. The fine line pattern having a width of 50 nm is between rectangular columns [FIG. 12 (b)]. next,
The Pt film and the Fe film were patterned by ion milling using Ar gas (Ar gas pressure: 5 × 10 ⁻⁵ To).
rr, time: about 45 seconds). Ion milling was stopped when Pt and iron were sequentially etched and a silicon substrate appeared. The reason why the resist film was formed thick (1 μm) is to prevent the rectangular pattern of iron from being etched (FIG. 12C). Next, the resist film 113 remaining on the islands and the fine lines was removed with an oxygen plasma washer (FIG. 12D). Thereafter, a conductor layer and terminals were formed in the same manner and in the same pattern as in the first embodiment described with reference to FIG. 11, thereby completing the manufacture of the magnetoresistive element of this embodiment.

[Sixth Embodiment] In the sixth embodiment, the fifth embodiment
The 50 nm × 50 nm pattern of the island region of
0 nm × 100 nm (100 nm is the direction of the magnetic field). Other than that, it is the same as the fifth embodiment.

[Seventh Embodiment] In the seventh embodiment, the fifth embodiment
The pitch of 400 nm of the island region of the example of Example was set to 200 nm. Other than that, it is the same as the fifth embodiment.

[Eighth Embodiment] In the eighth embodiment, the fifth embodiment
The 50 nm × 50 nm pattern of the island region of
0 nm x 100 nm (100 nm is the direction of the magnetic field)
The pitch of the island region was set to 200 nm. Other than that, it is the same as the fifth embodiment.

The preferred embodiment has been described above.
The present invention is not limited to these examples, and can be appropriately changed without changing the gist of the present invention. For example, the multilayer film is made of, for example, Co / Cr, C
A ferromagnetic material such as o / Cu or Fe / Cu and a non-ferromagnetic material may be alternately laminated. Further, in the embodiment, the patterning is performed using the resist for the electron beam exposure, but another type of resist may be used.

[0041]

As described above, the magnetoresistive effect element of the present invention has different shapes, materials, and the like.
Since it has at least two groups of magnetic material layers with different coercive forces and conductively connected them,
The coercive force can be set arbitrarily, and the magnetoresistance ratio at an arbitrary magnetic field can be increased. Therefore, according to the present invention, the magnetic field sensitivity particularly in a low magnetic field region can be improved.

[Brief description of the drawings]

FIG. 1 is an MH characteristic diagram for explaining functions of the present invention.

FIG. 2 is an MH characteristic diagram and a magnetoresistive characteristic diagram for explaining functions of the present invention.

FIG. 3 is a plan view and a cross-sectional view for explaining the first embodiment of the present invention.

FIG. 4 is a plan view and a cross-sectional view illustrating a second embodiment of the present invention.

FIG. 5 is a plan view for explaining third and fourth embodiments of the present invention.

FIG. 6 is a plan view for explaining fifth and sixth embodiments of the present invention.

FIG. 7 is a plan view for explaining a seventh embodiment of the present invention and a cross-sectional view for explaining an eighth embodiment of the present invention.

FIG. 8 is a plan view for explaining the arrangement and shape of an island region used in the present invention.

FIG. 9 is a sectional view for explaining the arrangement of current terminals and voltage terminals in the device of the present invention.

FIG. 10 is a cross-sectional view in the order of steps for explaining the first embodiment of the present invention.

FIG. 11 is a plan view in the order of steps for explaining the first embodiment of the present invention.

FIG. 12 is a cross-sectional view in the order of steps for explaining a fifth embodiment of the present invention.

FIG. 13 is an MH characteristic diagram and a magnetoresistive characteristic diagram of a strong coupling type GMR element.

FIG. 14 is an MH characteristic diagram and a magnetoresistive characteristic diagram of a weakly coupled GMR element.

FIG. 15 is a MH characteristic diagram and a magnetoresistive characteristic diagram of a non-coupled GMR element.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 substrate 2 island-shaped region 2a constricted portion 2b multi-domain island-shaped region 2c cylindrical island-shaped region 2d hemispherical island-shaped region 3 thin wire 3a constricted portion 3b connecting portion 4 connecting portion 5 insulating film 6 current terminal 7 voltage terminal 8 conductor Layer 9 Lower conductor layer 10 Upper conductor layer 101 Silicon substrate 102 Silicon oxide film 103 High-sensitivity resist film 104 Low-sensitivity resist film 105 Multi-layer Fe / Cr film 106 Island region 107 Pattern formation region 108 Conductor layer 109 Current supply terminal 110 voltage detection terminal 111 Fe film 112 Pt film 113 resist film

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) H01L 43/08 G01R 33/09 G11B 5/39 H01F 10/00 JICST file (JOIS)

Claims (9)

(57) [Claims] 1. A first group comprising a plurality of first structures formed including a magnetic material, and a first group formed including a magnetic material, wherein the first group is a structure or A second group comprising one or more second structures having different coercive forces due to different materials; and a first group belonging to the first group and a second group comprising the second group. A magnetoresistance effect element electrically connected to a second structure belonging to the group of. 2. The semiconductor device according to claim 1, further comprising one or more types of structures having different coercive forces from the first structure and the second structure due to a difference in structure or material. And the structures belonging to these groups are also the first and second structures.
2. The magnetoresistive element according to claim 1, wherein said magnetoresistive element is electrically connected to said structure. 3. The magnetoresistive element according to claim 1, wherein the structures belonging to different groups have different thicknesses. 4. The magnetoresistive element according to claim 1, wherein the first structure is an island region having a cylindrical or hemispherical shape. 5. The magnetoresistive element according to claim 1, wherein the second structure is a fine wire in which a narrow portion having a constant width or a narrow width is formed periodically. 6. A second structure is, magnetoresistance effect element according to claim 1, characterized in that the magnetic wire having a direction of easy magnetization and the flame magnetization direction. 7. The magnetoresistive element according to claim 1, wherein the first and second structures are magnetized in a direction perpendicular to a substrate surface. 8. An electrical connection between the respective structures belonging to the first and second groups by connecting the structures by a connecting portion formed of a magnetic film. the magnetoresistive element according to claim 1 Symbol mounting and. 9. An electrical connection between each of the structures belonging to the first and second groups by covering the structures with a conductive film. 2. The magnetoresistance effect element according to 1.