JP2001274477A - Magnetoresistive element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetoresistive element where an exchange combined magnetic field Hex is immune to temperature change, with a large MR ratio. SOLUTION: The magnetoresistive element comprises a tight fitting layer 15 where direction of magnetization is fixed, a free layer 19 where the direction of magnetization changes according to external magnetic field, and an intermediate layer 16 held between the tight fitting layer 15 and the free layer 19. Here the tight fitting layer comprises a magnetic film 14 of soft magnetism and a ferro-magnetic film 12 of hard magnetism for fixing magnetization of that magnetic film. A non-magnetic metal layer 13 for suppressing ferro-magnetic interaction between the magnetic film of soft magnetism and the ferro-magnetic film of hard magnetism is inserted between them.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetoresistive element having a fixed layer and a free layer applied to a magnetic head, various sensors, and the like. Related to the element.

[0002]

2. Description of the Related Art A magnetoresistive element (spin-valve GMR element) that obtains a giant magnetoresistance effect by utilizing scattering depending on the spin direction of electrons has been known. As shown in FIG. 7A, this element has a hard magnetic pinned layer 101 having a fixed magnetization direction (the magnetization is fixed),
It has a soft magnetic free layer 102 whose magnetization direction changes in accordance with an external magnetic field, and a conductive spacer layer 103 sandwiched between the fixed layer and the free layer. The fixed layer 101 is made of, for example, an antiferromagnetic film 101a made of FeMn or the like and a CoFe
The magnetization of the magnetic film 101b is fixed (fixed) in a predetermined direction by exchange coupling between the magnetic film 101b and the antiferromagnetic film 101a.
The free layer 102 is made of NiFe or CoFe and NiFe.
Made of a soft magnetic film such as a laminate of
Reference numeral 3 denotes a conductive metal film such as Cu.

On the other hand, as disclosed in Japanese Patent Application Laid-Open No. 10-4227, a magnetoresistive element utilizing a magnetic tunnel effect is used as an element having a larger magnetoresistance change ratio (MR ratio) and a higher sensitivity than the above-mentioned GMR element. (TMR elements) are attracting attention. This element is, as shown in FIG.
A hard magnetic pinned layer 104 having a fixed magnetization direction, a soft magnetic free layer 105 whose magnetization direction changes according to an external magnetic field, and an insulating barrier layer 106 interposed between the pinned layer and the free layer. Consists of The fixing layer 104 is, for example,
An antiferromagnetic film 104a made of FeMn or the like and a soft magnetic film 104b made of CoFe or NiFe or the like, and the magnetization of the magnetic film 104b is fixed in a predetermined direction by exchange coupling between the magnetic film 104b and the antiferromagnetic film 104a. Have been.
The free layer 105 is made of NiFe or CoFe and NiFe.
Made of a soft magnetic film such as a laminate of
Is made of an insulating film such as Al ₂ O ₃ .

As described above, the GMR element and the TMR element are
They are common in that they have free layers 102 and 105 and pinned layers 101 and 104, and whether layers 103 and 106 (hereinafter referred to as “intermediate layers”) sandwiched between these free layers and pinned layers are conductive. The configuration is different in that it is insulative. Further, the resistance value of the above-described GMR element or TMR element changes depending on the relative relationship between the magnetization directions of the fixed layers 101 and 104 and the magnetization directions of the free layers 102 and 105 which change due to an external magnetic field. . That is, the resistance value of the element is
The magnetization directions of the fixed layers 101 and 104 and the free layers 102 and 1
05 are minimum when the magnetization directions are the same, and maximum when the directions are 180 ° different.

Since the external magnetic field is detected based on the resistance value thus changed, in these devices, the magnetization directions of the free layers 102 and 105 easily change according to the external magnetic field, while the fixed layer 101 is changed. , 104 are required to be reliably fixed under the operating temperature condition. For this reason, it is desirable to select a material having a high blocking temperature as the antiferromagnetic films 101a and 104a of the pinned layers 101 and 104, and as shown in FIG. The use of PtMn, which is an ordered alloy, is also being studied.

[0006]

By the way, the fixing layer 10
The above-described Fe is applied to the antiferromagnetic films
Mn (Those that do not need to be heat-treated to form ordered alloys)
And the like, the exchange coupling magnetic field H
ex decreases linearly (approaches 0). The exchange coupling magnetic field Hex is a magnetic field in which the fixed magnetization of the fixed layer is reversed by an external magnetic field. When examining the effect of the decrease in the exchange coupling magnetic field Hex, as shown in FIG. 8A, at room temperature, the resistance value of the element changes from a large value with an increase in the external magnetic field within the change range of the external magnetic field. Since the value decreases stepwise to a small value, it can be detected from the resistance value whether the external magnetic field is larger than a predetermined magnetic field (in this case, “0”). However, high temperatures (180 ° C. in this example)
As shown in FIG. 8B, when a magnetic field larger than a predetermined value is applied in the positive direction within the change range of the external magnetic field, and a magnetic field larger than the predetermined value in the reverse direction (negative direction), as shown in FIG. In both cases, the resistance value of the element becomes small, and there is a problem that these cases cannot be distinguished.

[0007] Such an element is also used to detect whether or not the magnitude of the external magnetic field is greater than the exchange coupling magnetic field Hex. However, the exchange coupling magnetic field Hex changes greatly with an increase in temperature. This means that the magnitude of the magnetic field serving as a detection reference changes, so that there is a problem that the detection accuracy is greatly deteriorated.

On the other hand, when PtMn is used for the antiferromagnetic film 101c of the pinned layer 101 shown in FIG. 7C, a high-temperature annealing process (a process of leaving the film in a high-temperature environment after film formation) is performed. By using PtMn as an ordered alloy, the temperature dependence of the exchange coupling magnetic field Hex is improved. However, since the high-temperature annealing treatment has an adverse effect on other films, there is a problem in that the magnetoresistance ratio of the manufactured element is reduced as a result. Therefore, an object of the present invention is to provide a magnetoresistive element in which the exchange coupling magnetic field Hex is unlikely to change with temperature and has a high magnetoresistance change rate.

[0009]

SUMMARY OF THE INVENTION The structural features of the present invention that achieve the above object include a pinned layer having a fixed magnetization direction, a free layer having a magnetization direction that changes according to an external magnetic field, A magnetoresistive element comprising an intermediate layer sandwiched between the free layer and the fixed layer, wherein the fixed layer includes a soft magnetic magnetic film and a hard magnetic ferromagnetic film that fixes the magnetization of the magnetic film, A non-magnetic metal layer having a thickness that does not lose the ferromagnetic interaction between the soft magnetic magnetic film and the hard magnetic ferromagnetic film is formed of the same soft magnetic magnetic film and the same hard magnetic ferromagnetic film. It has been interposed between the membrane.

In this case, the hard magnetic ferromagnetic film of the pinned layer is preferably made of a ferromagnetic material having a relatively high Curie temperature, for example, CoPtCr. Preferably, Cr is used for the nonmagnetic metal layer. Further, preferably, the thickness of the nonmagnetic metal layer is 0.3 to 1.0 nm (3 to 10 °), and more preferably, 0.5 to 0.8 nm (5 to 8 °). In addition,
The soft magnetic film of the pinned layer may be a ferromagnetic film or a ferromagnetic laminated film, and the intermediate layer may be a conductive material or an insulating material. That is, the present invention is applied to both the GMR element and the TMR element.

In the magnetoresistive element thus configured, a ferromagnetic film instead of an antiferromagnetic film is used as the hard magnetic film of the pinned layer. The exchange coupling between the hard magnetic ferromagnetic film and the soft magnetic magnetic film has a small temperature dependence in a temperature range sufficiently lower than the Curie temperature, and the hard magnetic ferromagnetic film has a high-temperature annealing treatment. Even if the treatment at a high temperature such as that described above is not performed, many Curie temperatures are higher than room temperature. Further, in the above-mentioned magnetoresistive element, the nonmagnetic metal layer interposed between the soft magnetic magnetic film of the fixed layer and the hard magnetic ferromagnetic film of the fixed layer allows the soft magnetic magnetic film and the hard magnetic The magnetization direction of the soft magnetic film and the magnetization direction of the hard magnetic film are simultaneously controlled because the ferromagnetic interaction with the (At once) is avoided.

As a result, the exchange-coupling magnetic field of the pinned layer hardly changes with a change in temperature (in the operating temperature range), and the magnetization direction of the hard magnetic ferromagnetic film is hardly reversed. A magnetoresistive element suitable as an element for detecting a magnetic field is obtained. Further, since high-temperature annealing is not required as in the case of using PtMn for the fixed layer, the step of processing at high temperature can be omitted or reduced, so that the magnetoresistance ratio is maintained at a large value. A magnetoresistive element can be obtained.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a magnetoresistive element according to the present invention will be described with reference to the drawings. FIG.
The magnetoresistive element according to the first embodiment, whose cross section is shown in FIG. 1, is a GMR element utilizing a giant magnetoresistive effect, and includes a substrate 10 made of Si. On the substrate 10, a lower electrode 1 made of Cr which is a non-magnetic conductive material and having a thickness of 10 nm.
1 is formed.

On the lower electrode 11, a hard magnetic ferromagnetic film 12 made of CoPtCr having a relatively high Curie temperature and having a thickness of 25 nm is formed. On the ferromagnetic film 12, a nonmagnetic conductive material made of Cr and having a thickness of 0.7
A non-magnetic metal layer 13 having a thickness of 5 nm is formed on the non-magnetic metal layer 13 and made of soft magnetic Co.
The lower magnetic layer 14 is formed. The ferromagnetic film 12, the non-magnetic metal layer 13, and the lower magnetic layer 14 constitute a pinned layer 15 whose magnetization direction is not expected to change by an external magnetic field. It functions as a fixed magnetic layer (Pin layer) that fixes the magnetization of the lower magnetic layer 14 by ferromagnetic interaction (ferromagnetic coupling). In this sense, the lower magnetic layer 14 is composed of the pinned layer (P
Also referred to as an inner layer.

The nonmagnetic metal layer 13 functions to suppress (reduce) the ferromagnetic interaction between the ferromagnetic film 12 and the lower magnetic layer 14, but not to lose the effect. Specifically, the thickness of the nonmagnetic metal layer 13 of the fixed layer 15 is set to 0.7 nm in the above example, but is preferably 0.3 to 1.0 nm, and more preferably 0.5 to 0. 8
nm.

On the lower magnetic layer 14, a spacer layer 16 is formed as an intermediate layer. This spacer layer 16
Is made of Cu, which is a conductive metal having high electric conductivity, and has a thickness of 3 nm.

On the spacer layer 16, a lower film 17 of 1 nm in thickness made of Co is formed. On the lower film 17, a soft magnetic film 18 of 20 nm in thickness made of NiFe is laminated. I have. These lower film 17 and magnetic film 18
Constitutes a free layer 19 in which the direction of magnetization is expected to easily change according to an external magnetic field.

Next, the operation of the GMR element will be described. In this GMR element, the direction of magnetization of the free layer 19 changes with a change in an external magnetic field created by a magnetic information recording medium (media) or a rotor in which N and S poles are alternately arranged in a ring shape. Since the angle between the direction of magnetization of the free layer 19 and the direction of magnetization of the pinned layer 15 changes,
The resistance value of the spacer layer 16 changes. Specifically, when the magnetization of the free layer 19 and the magnetization of the pinned layer 15 are in the same direction, the resistance value is minimum, and the directions of both magnetizations are 180 °.
If different (in the opposite direction), the same resistance value will be maximum.
In actual use, electrodes are formed on both sides of the element in FIG. 1, and a sense current is supplied to the spacer layer 16 through the electrodes in a direction parallel to the layer surface of the element, thereby forming both ends of the spacer layer 16. A resistance value between the units is detected, and an external magnetic field is detected from the detected resistance value.

Next, the magnetoresistance change rate of the GMR element will be described. FIGS. 2A and 2B show the case where the ambient temperature is room temperature (20 ° C.) and the ambient temperature is 180 ° C., respectively. It is a measurement result of the magnetoresistance change rate with respect to the magnetic field H. The rate of change in magnetoresistance shown on the vertical axis is generally called an MR ratio, and the minimum resistance value exhibited by the element is represented by R
s, when the resistance value of the element when an external magnetic field H is applied to the element is R (H), MR ratio = ((R (H) −R
s) / Rs) × 100%.

In this measurement, the external magnetic field H is set in a direction parallel to the layer surface of the element, and the external magnetic field H is changed from 0 (Oe) to the direction of the fixed magnetization of the fixed layer 15 (hereinafter, this direction). Is referred to as the positive direction, and the direction opposite to the positive direction is referred to as the negative direction.) When the ratio is increased to +300 (Oe), the measurement of the MR ratio is started. Oe), and the external magnetic field H was again changed in the positive direction to +300 (Oe). The element used for this measurement has the above-mentioned film configuration,
The width was 1 mm and the length was 7 mm (the resistance value was 1.8Ω) in plan view, and the sense current was 1 mA in the length direction.

When the environmental temperature is room temperature, as shown in FIG. 2A, the MR ratio of the GMR element is substantially 0 (O
e) It becomes approximately 0% in the above region. At this time, the magnetizations of the fixed layer 15 and the free layer 19 are in the same direction. In the region of approximately −220 to 0 (Oe), the magnetization of the fixed layer 15 maintains the fixed direction, but the magnetization of the free layer 19 is reversed by the external magnetic field H, and the magnetization of the fixed layer 15 is reduced. Because the direction is opposite to the direction, the MR ratio is about 7%
It becomes big. Further, in a region of approximately −220 (Oe) or less (a region larger in the negative direction than −220 (Oe)), the magnetization direction of the lower magnetic layer 14 is also reversed by the external magnetic field H, and the magnetization of the free layer 19 is reduced. It has the same orientation. As a result, the MR ratio becomes substantially 0% again.

When the ambient temperature is 180 ° C., FIG.
As shown in (B), the MR ratio of the GMR element is approximately 0% in a region of approximately 0 (Oe) or more. At this time, the magnetizations of the fixed layer 15 and the free layer 19 are in the same direction. In the region of approximately −160 to 0 (Oe), the magnetization of the pinned layer 15 maintains the fixed direction, but the free layer 19 is inverted by the external magnetic field H.
The ratio is as large as approximately 5%. Further, in a region of approximately −160 (Oe) or less, the magnetization direction of the lower magnetic layer 14 is also inverted by the external magnetic field H, and becomes the same as the magnetization direction of the free layer 19. As a result, the MR ratio becomes substantially 0% again. As described above, the absolute value of the exchange coupling magnetic field Hex is smaller when the ambient temperature is 180 ° C. than when the ambient temperature is room temperature,
Further, it is recognized that the MR ratio slightly decreases.

The solid and broken lines in FIG. 3 show the exchange coupling magnetic field H of the GMR element and the conventional GMR element at various temperatures.
ex indicates the size of each. The conventional GMR element used for this measurement is 5 nm Cr, 10 nm NiF
e, 1 nm Co, 3 nm Cu, 1 nm Co, 10
It is obtained by laminating NiFe of 10 nm and FeMn of 10 nm. As can be understood from FIG.
In the R element, the exchange coupling magnetic field Hex accompanying the temperature rise
Is smaller than that of the conventional GMR element.

As described above, in the first embodiment, the pinned layer 15 comprises the soft magnetic magnetic film 14 and the hard magnetic ferromagnetic film 12 for fixing the magnetization of the magnetic film 14. The non-magnetic metal layer 13 having a thickness that does not lose the ferromagnetic interaction between the magnetic magnetic film 14 and the hard magnetic ferromagnetic film 12 is replaced with the soft magnetic magnetic film 14 and the hard magnetic ferromagnetic film 12. It was interposed between the ferromagnetic film 12. Thereby, the element according to the first embodiment has the exchange coupling magnetic field H
ex does not easily change with temperature change, and no high-temperature treatment is required, the magnetic properties are good, and the element has characteristics suitable for an element for detecting an external magnetic field.

Next, the magnetoresistive element according to the second embodiment whose cross section is shown in FIG. 4 will be described. This element is a TMR element utilizing the magnetic tunnel effect, and oxidizes the silicon surface to form SiO ₂ . Silicon substrate 30 is provided. The substrate 30 can be made of, for example, glass or quartz. On the substrate 30, a lower electrode 3 made of Cr, which is a non-magnetic conductive material, having a thickness of 10 nm.
1 is formed.

On the lower electrode 31, a hard magnetic ferromagnetic film 32 made of CoPtCr and having a thickness of 30 nm is formed. On this ferromagnetic film 32, a 0.7-nm thick non-magnetic metal layer 33 made of Cr, which is a non-magnetic conductive material, is laminated. A lower magnetic layer 34 made of certain NiFe and having a thickness of 5 nm is formed. These ferromagnetic film 32 and non-magnetic metal layer 3
3 and the lower magnetic layer 34 constitute a pinned layer 35 whose magnetization direction is not expected to be changed by an external magnetic field. The ferromagnetic film 32 is formed of the lower magnetic layer 34 serving as a pinned layer. It functions as a fixed magnetization layer that fixes the magnetization. The non-magnetic metal layer 33 functions so as to suppress the ferromagnetic interaction between the ferromagnetic film 32 and the soft magnetic lower magnetic layer 34 within a range in which the ferromagnetic interaction is not lost.

On the lower magnetic layer 34, an insulating layer 36 as an intermediate layer is formed. The insulating layer 36 is made of an insulating material, Al ₂ O ₃ , and has a thickness of 2 nm.

On the insulating layer 36, a film 1 of Co
The lower film 37 is formed with a thickness of 60 nm, and a soft magnetic film 38 made of soft magnetic NiFe and having a thickness of 60 nm is laminated on the lower film 37. The lower film 37 and the magnetic film 38 constitute a free layer 39 in which the direction of magnetization is expected to easily change according to an external magnetic field. On the magnetic film 38, a dummy film 40 made of Mo and having a thickness of 30 nm is formed.

Next, the operation of the TMR element will be described. In this TMR element, the direction of magnetization of the free layer 39 changes with a change in the external magnetic field generated by the magnetic information recording medium, the rotor, and the like. As a result, when the magnetization of the free layer 39 and the magnetization of the pinned layer 35 are in the same direction, the resistance value in the direction perpendicular to the layer surface is minimized, and the directions of both magnetizations are 180 °.
If they are different, the same resistance value becomes maximum. In actual use, a constant current flows from the dummy film 40 to the lower electrode 31 (or in the opposite direction), and a potential difference between the ends of the element in the same current direction is detected. , That is, a change in the external magnetic field.

Next, the magnetoresistance change rate of the TMR element will be described. FIGS. 5A and 5B show the case where the ambient temperature is room temperature (20 ° C.) and the ambient temperature is high (180 ° C.). The measurement results of the magnetoresistance ratio (MR ratio) with respect to the magnetic field H are shown. In this measurement, the external magnetic field H
Is the same as in the case of FIGS. 2A and 2B described above. In addition, this measurement was performed by connecting 1000 TMR elements each having a size of 20 μm in length and 100 μm in width in a plan view in series, and applying a current of 1 mA to them.

As can be seen from FIG. 5, the MR ratio of this element is such that the external magnetic field is substantially zero at both room temperature and 180 ° C.
It becomes approximately 0% in the region of (Oe) or more. In this case, the magnetization direction of the free layer 39 is the same as the fixed magnetization direction of the fixed layer 35. Also, at room temperature, it is approximately -230 to 0
At (Oe), at 180 [deg.] C., the MR ratio becomes approximately 20% at approximately -180 to 0 (Oe). In this case, the free layer 3
The direction of magnetization 9 is opposite to the direction of the fixed magnetization of the pinned layer 35. Further, at room temperature, the temperature is about -230 (Oe) or less, and at 180 ° C, the temperature is about -180 (Oe) or less.
Both ratios are approximately 0%. In this case, the magnetization of the lower magnetic layer 34 is opposite to the direction of the fixed magnetization, and the free layer 3
It is the same as the direction of 9. As described above, the absolute value of the exchange coupling magnetic field Hex is smaller when the ambient temperature is 180 ° C. than when the ambient temperature is room temperature.

The solid and broken lines in FIG. 6 show the exchange coupling magnetic field H between the TMR element and the conventional TMR element at various temperatures.
ex indicates the size of each. The conventional TMR used in this measurement was 10 nm Cr, 50 nm NiF
e, 1 nm Co, 2 nm Al ₂ O ₃ , 1 nm Co,
It is formed by laminating 10 nm of NiFe, 10 nm of FeMn, and 30 nm of Mo. As can be understood from the figure, in the above-mentioned TMR element, the amount of decrease in the exchange coupling magnetic field Hex with an increase in temperature is smaller than that of the conventional TMR element.

As described above, in the second embodiment, the pinned layer 35 is composed of the soft magnetic magnetic film 34 and the hard magnetic ferromagnetic film 32 for fixing the magnetization of the magnetic film 34. The non-magnetic metal layer 33 having a thickness that does not lose the ferromagnetic interaction between the magnetic magnetic film 34 and the hard magnetic ferromagnetic film 32 is formed of the soft magnetic magnetic film 34 and the hard magnetic ferromagnetic film 32. It was interposed between the ferromagnetic film 32. As a result, the TMR element according to the second embodiment has an exchange coupling magnetic field Hex that is unlikely to change with temperature, does not require processing at high temperatures, has good magnetic characteristics, and has an excellent external magnetic field detection capability. The device had characteristics suitable for use as an element.

In the second embodiment, as in the first embodiment, the thickness of the nonmagnetic metal layer 13 of the pinned layer 35 is 0.7 nm, but the thickness is the same as that of the magnetic film 34. It is sufficient that the ferromagnetic interaction with the magnetic film 32 is not lost. Specifically, when the nonmagnetic metal layer 33 is made of Cr, its thickness is preferably 0.3 to 1.0 nm, and more preferably 0.5 to 0.8 nm.

As described above, in the magnetoresistive element according to the embodiment of the present invention, since the exchange coupling magnetic field Hex does not easily change with a change in temperature, an external magnetic field that changes over a wide range is not affected. It can be detected with high accuracy.

Various modifications can be adopted within the scope of the present invention. For example, the fixing layer 1
The nonmagnetic metal layers 13 and 33 of 5, 35 are not limited to Cr but may be Al, Cu, or the like. Further, the non-magnetic metal layers 13 and 33 do not necessarily have to be in the form of a film.
4 may be in a state where non-magnetic metal molecules are discontinuously present. Further, for the pinned layers 15 and 35, a ferromagnetic material having a relatively high Curie temperature (for example, CoTaCr or the like) may be employed in addition to the above-described CoPtCr.

[Brief description of the drawings]

FIG. 1 is a sectional view of a GMR element according to a first embodiment of the present invention.

FIG. 2A shows how the MR ratio of the GMR element shown in FIG. 1 to an external magnetic field at room temperature changes.
(B) is a diagram showing how the MR ratio of the GMR element to an external magnetic field at 180 ° C. changes.

FIG. 3 is a diagram showing a state of a change in an exchange coupling magnetic field Hex with respect to a temperature change of the GMR element shown in FIG.

FIG. 4 is a sectional view of a TMR element according to a second embodiment of the present invention.

FIG. 5A shows how the MR ratio of the TMR element shown in FIG. 4 to an external magnetic field at room temperature changes.
(B) is a diagram showing how the MR ratio of the same TMR element to an external magnetic field at 180 ° C. changes.

6 is a diagram showing a state of a change of an exchange coupling magnetic field Hex with respect to a temperature change of the TMR element shown in FIG.

7 (A) and 7 (C) are cross-sectional views of a conventional GMR element, and FIG. 7 (B) is a cross-sectional view of a conventional TMR element.

FIGS. 8A and 8B are diagrams showing the operation of a conventional magnetoresistive element at an ambient temperature of room temperature and 180 ° C., respectively.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... board | substrate, 11 ... lower electrode, 12 ... ferromagnetic film (hard magnetic film), 13 ... non-magnetic metal layer, 14 ... lower magnetic layer (soft magnetic film), 15 ... pinned layer, 16 ... spacer Layer (intermediate layer), 17: lower layer film, 18: magnetic film, 19: free layer (soft magnetic film), 30: substrate, 31: lower electrode, 3
2: Ferromagnetic film (hard magnetic film), 33: non-magnetic metal layer, 34: lower magnetic layer (soft magnetic film), 35: fixed layer, 36: insulating layer (intermediate layer), 37: lower layer Film, 38: magnetic film, 39: free layer, 40: dummy film.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Masayoshi Yamashita 10-1 Nakazawa-cho, Hamamatsu-shi, Shizuoka F-term in Yamaha Corporation (reference) 5D034 BA05 BA21 CA08 5E049 AA01 AA04 AA07 AA09 BA12 CB02 DB12 DB18

Claims (4)

[Claims] 1. A fixed layer having a fixed magnetization direction, a free layer whose magnetization direction changes according to an external magnetic field, and an intermediate layer sandwiched between the fixed layer and the free layer. In the magnetoresistive element, the fixed layer includes a soft magnetic magnetic film and a hard magnetic ferromagnetic film for fixing the magnetization of the magnetic film, and the soft magnetic magnetic film and the hard magnetic ferromagnetic film. Characterized in that a nonmagnetic metal layer having a thickness that does not lose the ferromagnetic interaction between layers is interposed between the soft magnetic magnetic film and the hard magnetic ferromagnetic film. element. 2. The magnetoresistive element according to claim 1, wherein CoPtCr is used for said hard magnetic ferromagnetic film. 3. The magnetoresistive element according to claim 1, wherein Cr is used for said nonmagnetic metal layer. 4. The method according to claim 1, wherein said nonmagnetic metal layer has a thickness of 0.3 to 1.
4. The magnetoresistive element according to claim 1, wherein the magnetoresistive element has a thickness of 0 nm. 5.