JPH10198922A - Magnetic sensor and magnetic recording / reproducing apparatus using the same - Google Patents

Abstract

(57) [Problem] To provide a spin valve laminated film having high coupling and high thermal stability and to provide a highly reliable sensor using the same, a magnetic recording device having a high recording density, and high sensitivity and low noise characteristics. Provided is a magneto-resistance effect type recording / reproducing separation head. Kind Code: A1 A magnetic recording / reproducing method in which a fixed layer of a spin-valve type magnetoresistive effect laminated film is made thick, an antiferromagnetic film is made thin, and a magnetoresistive head using a protective film made of NiCr or the like having a thickness of 5 nm or less is mounted. apparatus.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording / reproducing apparatus and a magneto-resistance effect element, and more particularly to a high recording density magnetic recording / reproducing apparatus.

[0002]

2. Description of the Related Art Japanese Patent Application Laid-Open No. 2-61572 describes a laminated film whose electric resistance varies depending on the angle between the magnetizations of ferromagnetic thin films separated by an intermediate layer, a magnetic field sensor and a magnetic recording apparatus using the laminated film. And a description of an iron-manganese alloy thin film.

Proceedings of the 19th Annual Meeting of the Japan Society of Applied Magnetics (1995) pp. 352 shows exchange coupling between a chromium-manganese alloy film and a nickel-iron alloy film.

[0004] Japanese Patent Application No. 7-116894 discloses chromium-
There is a description of a magnetic transducer in which a manganese alloy film and a ferromagnetic material are closely attached.

Japanese Patent Application Laid-Open No. 5-266436 describes a magnetoresistive sensor in which another thin film material is disposed at the interface between the nonmagnetic layer and the ferromagnetic layer separated by the nonmagnetic layer.

JP-A-6-111252 describes a magnetoresistive sensor in which a soft magnetic intermediate layer is attached between a ferromagnetic layer and an antiferromagnetic layer.

Japanese Patent Application Laid-Open No. 7-201016 describes a capping layer in contact with a thin film of an antiferromagnetic material having a thickness of 25 to 200 ° laminated with a thin film of an MR conductive layer.

Japanese Patent Application No. 7-47363 discloses manganese-
There is a description of a spin valve film using an iridium alloy film and a sensor.

Japanese Patent Application No. 7-333015 discloses chromium-
There is a description of a spin valve sensor using a manganese alloy film, and there is a description of the thickness and heat resistance of a fixed layer.

[0010] The pp221 of the abstract of the 1996 Annual Meeting of the Japan Institute of Metals describes exchange coupling between a chromium-aluminum film and a NiFe film.

[0011]

According to the prior art, a magnetic recording device having a sufficiently high recording density, in particular, a magnetoresistive element which acts on a reproducing portion thereof with sufficient sensitivity and output to an external magnetic field, is realized. Furthermore, it was not possible to obtain good characteristics in which noise was sufficiently suppressed, and it was difficult to realize a function as a storage device.

In recent years, it has been known that a magnetoresistance effect, that is, a giant magnetoresistance, of a multilayer film in which ferromagnetic metal layers are stacked via a nonmagnetic metal layer is large. In this case, in the magnetoresistance effect, the electric resistance changes depending on the angle between the magnetizations of the ferromagnetic layers separated by the nonmagnetic layer and the magnetizations. When this giant magnetoresistance effect is used as a magnetoresistance effect element, a structure called a spin valve has been proposed. That is, a ferromagnetic layer having a structure of an antiferromagnetic film / a ferromagnetic layer / a nonmagnetic layer / a soft magnetic layer, and being in close contact with the antiferromagnetic film by an exchange coupling magnetic field generated at an interface between the antiferromagnetic film / the ferromagnetic layer. Is substantially fixed, and an output can be obtained by rotating the magnetization of the other soft magnetic layer by an external magnetic field. The fixed effect is called a fixed bias, and the antiferromagnetic film that produces this effect is called a fixed bias film. A ferromagnetic layer whose magnetization is substantially fixed is referred to as a fixed layer or a ferromagnetic fixed layer.
Similarly, a soft magnetic film whose magnetization is rotated by an external magnetic field is referred to as a free layer or a soft magnetic free layer.

As described above, it is desirable that the magnetic head corresponding to the high recording density has a configuration in which the giant magnetoresistance effect is applied and a spin-valve type magnetoresistance effect laminated film is applied. However, such laminated films are often composed of 1n
It is extremely thin, on the order of m, which often causes difficulties of insufficient heat resistance for application to a magnetic head.
That is, in the magnetoresistive head, when a signal is detected through a current through the magnetoresistive film, a temperature rise occurs. In addition to this, the temperature of the apparatus environment is added. As a result, in the worst case, the magnetic head is required to be continuously driven at a high temperature of 100 ° C. or more for a long time. Further, also in the manufacturing process of the magnetic head, after forming the magnetoresistive film, a heat history such as a hardening process of a photoresist and a manufacturing process of a recording head core or an insulating film must be performed. These thermal effects are
The magnetoresistive film and the magnetic sensor need to have sufficient heat resistance because they cause deterioration such as lowering the resistance change rate of the magnetoresistive film.

The improvement of heat resistance not only has the effect of maintaining high characteristics as a sensor and a medium, and has the effect of improving long-term reliability, but also simplifies the manufacturing process,
This is because a higher temperature manufacturing process can be adopted.

Accordingly, it is an object of the present invention to provide a magnetic recording device having high long-term reliability corresponding to high-density recording and a magnetoresistive element or a magnetic sensor having improved heat resistance in addition to sufficient output and low noise. More specifically, a magnetic sensor consisting of an antiferromagnetic film exhibiting a bias characteristic with an extremely thin thickness, a thick ferromagnetic fixed layer, and a protective film crystallographically connected to the antiferromagnetic film is used. And a magnetic head and a magnetic recording / reproducing apparatus using the same.

[0016]

According to the present invention, a magnetic recording apparatus in which a magnetic sensor using a giant magnetoresistance effect is mounted on a magnetic head is used as means corresponding to a high recording density. As the magnetic sensor, a magnetoresistive effect solidified element composed of a spin valve type giant magnetoresistive film having a laminated structure of a soft magnetic free layer / nonmagnetic conductive layer / ferromagnetic fixed layer / antiferromagnetic film is used.

An object of the present invention is to improve the heat resistance of a magnetoresistive laminated film. As a means to solve the problem,
In the present invention, first, the thickness of the antiferromagnetic film is set to 3 to 9 n.
m is defined as thin. Second, the thickness of the ferromagnetic pinned layer is set to 1.
5 to 10 nm, or more specifically, 3 to 5 n
m. When the ferromagnetic fixed layer is made of a Co—Fe—Ni alloy, the ferromagnetic fixed layer may be excellent in magnetic properties and resistance change rate. Alternatively, the first and second means are combined and the thickness ratio defined by dividing the thickness of the ferromagnetic pinned layer by the thickness of the antiferromagnetic layer is from 0.5 to 1.0. It is specified to be within the range. Alternatively, instead of the thickness of the antiferromagnetic film, the lower limit of the thickness of the antiferromagnetic layer, which is necessary and sufficient for the antiferromagnetic layer to apply an exchange coupling magnetic field to the ferromagnetic fixed layer, is set to a critical value. The thickness may be defined, and the film thickness ratio may be defined using the thickness. The antiferromagnetic film is made of Fe-Mn, MnIr, CrM.
Alloy thin films such as nPt are suitable. In particular, as a third means, the composition of the antiferromagnetic film is changed to Cu, Ag, Au, Pt,
Contains one or more of the noble metals of Pd, Rh, Ru, Ir, Os, and Re, and has a content of 5 at% to 40 at%, especially 10 to 30 at%. . Thereby, heat resistance can be further improved. By adopting such a composition, the average melting point of the antiferromagnetic film rises, making diffusion hard to occur, and the average atomic radius of the antiferromagnetic film is increased. Since the average atomic radius of the fixed layer can be increased by about 2% to 5%, interdiffusion can be prevented. The average atomic radius is defined as follows. The volume per single atom is defined from the density of a single substance composed of a single element and the atomic weight of the element. The atomic diameter is defined assuming that one spherical atom occupies this volume. From the compositions of the antiferromagnetic film and the ferromagnetic film, the average atomic diameter of each film can be obtained using the atomic diameter of each constituent element.

Fourth, the configuration of the magnetoresistive effect laminated film is a soft magnetic free layer / nonmagnetic conductive layer / ferromagnetic pinned layer / antiferromagnetic film /
The protective film or the soft magnetic free layer / non-magnetic conductive layer / ferromagnetic fixed layer / antiferromagnetic film / first protective film / second protective film has a structure of an antiferromagnetic film and a ferromagnetic fixed layer. The stress between them can be relaxed to prevent the destruction due to the introduction of defects, and the diffusion of constituent atoms from the antiferromagnetic film to the ferromagnetic pinned layer and the diffusion of impurity atoms can be reduced. In particular, the composition of the protective film is V, Ti, Cr, Mn, Fe, Co, Ni, C
u, Ag, Au, Pt, Pd, Rh, Ru, Ir, O
s or Re, or an alloy containing these as the main components, and the crystal structure of the protective film is a face-centered cubic, a body-centered cubic structure, or 0 to 5%, which is a distorted structure. By increasing the crystallographic continuity between the ferromagnetic film and the protective film, the effect of improving the heat resistance can be enhanced. When the composition of the protective film is adjusted and the electric resistance is set to 50 to 1000 μΩcm, current loss as the magnetoresistive element is small, and a good output can be obtained.

Fifth, a magnetic head and a magnetic recording / reproducing apparatus having good output can be obtained by mounting a magnetic sensor having improved heat resistance using the above-described means on a magnetic head. By increasing the heat resistance of the magnetic sensor, a high current can be applied to this magnetic head, and long-term reliability can be obtained. Further, in the manufacturing process, a high-temperature process of 200 ° C. to 300 ° C. is adopted, so that a good insulating film, a magnetic core, and the like can be mounted on the magnetic head.

According to the present invention, there is provided a magnetic recording / reproducing apparatus using a magnetoresistive element using such a material and configuration as a reproducing section.
High recording density, that is, recording with a short recording wavelength recorded on a recording medium and narrow recording track width can be realized, sufficient reproduction output can be obtained, and good recording can be maintained.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Films constituting a magnetic laminate, a magnetic recording medium, and a magnetoresistive element of the present invention were produced by a high-frequency magnetron sputtering apparatus as follows. 1mm thick, 3i diameter in an atmosphere of 6mm argon
The following materials were sequentially laminated on an n-th ceramic substrate. Tantalum, nickel-20at% iron alloy, copper, cobalt, chromium-50 as a sputtering target
Each target of at% manganese, manganese, and iron-50 at% manganese was used. On the target, 1
The composition was adjusted by disposing a cm-square chip. For the chip, platinum, nickel, iridium, and aluminum were used.

In the laminated film, plasma is generated in the apparatus by applying high-frequency power to each of the cathodes on which the respective targets are arranged, and shutters arranged for the respective cathodes are opened and closed one by one to sequentially form each layer. did. At the time of film formation, a magnetic field of about 80 Oe was applied in parallel to the substrate using a permanent magnet to impart uniaxial anisotropy and to guide the direction of the exchange coupling magnetic field such as a chromium-manganese film in each direction.

The formation of the device on the substrate was patterned by a photoresist process. Thereafter, the substrate was processed by a slider and mounted on a magnetic recording device.

A specific embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a configuration example of a spin valve film.

On the substrate 50, the underlayer 14, the soft magnetic free layer 1
3, a non-magnetic conductive layer 12, a ferromagnetic pinned layer 15, an anti-ferromagnetic layer 11, and a protective film 30 are continuously laminated. In the drawing, specific constituent elements of each layer and the thickness thereof are Ta5 nm, Ni
Fe 5 nm, Cu 2.5 nm, Co 1.5 nm, MnIr
7 nm and Ta5 nm are shown. Here, the composition of the NiFe film is Ni81-Fe19, and the composition of the MnIr film is Mn
78-Ir22.

FIG. 2 is a diagram showing the exchange coupling magnetic field and the blocking temperature when the thickness of the MnIr film is changed. The thickness of the MnIr film of the film having the configuration shown in FIG. 1 was changed from 3 nm to 22 nm. The blocking temperature is defined as the temperature at which the exchange coupling magnetic field disappears by measuring the temperature dependence of the exchange coupling magnetic field. The exchange coupling magnetic field is small when the thickness of the MnIr film, which is the antiferromagnetic film, is 3 nm, and is almost zero when the thickness is less than 3 nm. When the thickness of the MnIr film is 7 nm or more, the exchange coupling magnetic field is constant. The blocking temperature is low when the MnIr film is 3 nm, but increases with the film thickness, and is constant when the MnIr film is 10 nm or more. Therefore,
The thickness of the MnIr antiferromagnetic film needs to be 3 nm or more.

FIG. 3 is a view showing the heat resistance of a sample in which the thickness of the MnIr film is changed. In FIG. 3A, when the thickness of the MnIr film is 10 nm or more, the resistance change rate decreases by about 1% after the heat treatment, but when the thickness of the MnIr film is 7 nm or less, the decrease is 1% or less. The thinner the thickness, the higher the heat resistance. Similarly, in FIG. 3B, the exchange coupling magnetic field decreases by about 200 Oe after the heat treatment when the thickness of the MnIr film is 10 nm or more. However, the decrease is small when the thickness of the MnIr film is 7 nm or less. When the thickness is 5 nm or less, the exchange coupling magnetic field does not decrease after the heat treatment. As described above, the heat resistance of the spin valve film is higher as the thickness of the MnIr film of the antiferromagnetic film is smaller. Therefore, the results of FIG. 2 and FIG. 3 show that by limiting the thickness of the antiferromagnetic film from 3 nm to 7 nm, both heat resistance and good characteristics can be achieved.

FIG. 4 is a view showing the heat resistance of a sample in which the thickness of the Co fixed layer is changed. FIG. 4A shows that when the thickness of the fixed layer is increased, the resistance change rate after heat treatment becomes closer to the resistance change rate without heat treatment. That is, the heat resistance of the spin valve film can be improved by increasing the thickness of the fixed layer to be greater than 2 nm. FIG. 4 (b) shows the exchange coupling magnetic field. Even if the thickness of the fixed layer is increased, the exchange coupling magnetic field is only inversely proportional to the thickness. I will not do it.

FIG. 5 is a magnetoresistance curve of a spin valve film using an FeMn antiferromagnetic film. FIG. 5A shows the structure of the film. The rate of change of resistance is shown as the height of the magnetoresistance curve, and the rate of change of resistance is 3.0% without the heat treatment in FIG. The exchange coupling magnetic field is 180 Oe
It is. The shift amount of the curve on the low magnetic field curve shown in the left diagram of FIG. 5A is an index indicating the magnetic junction state between the two magnetic layers sandwiching the Cu layer, and this is called an interlayer coupling magnetic field. To In the left diagram of FIG. 5A, the interlayer coupling magnetic field is 8 Oe. FIG. 5 (b) shows the magnetoresistance curve after the heat treatment. The change in the characteristics after the heat treatment is as follows. (1) The rate of change in resistance is reduced to 1.9%, (2) the interlayer coupling magnetic field is reduced to 3 Oe, and (3) the exchange coupling magnetic field is reduced to 130 Oe. Thus, when the antiferromagnetic film is a FeMn film,
Also, the properties of the magnetoresistive film change and deteriorate due to the heat treatment.

FIG. 6 is a diagram showing a change in resistance and a change in interlayer coupling magnetic field when the thickness of the fixed layer is changed. In FIG. 6A, it can be seen that when the thickness of the fixed layer is increased up to 10 nm, the heat resistance of the resistance change rate is improved as in the case of FIG. FIG. 6B also shows that the heat resistance is improved by increasing the thickness of the fixed layer also for the interlayer coupling magnetic field.

FIG. 7 is a diagram showing a change in resistance and a change in interlayer coupling magnetic field when the thickness of the FeMn antiferromagnetic film is changed. In FIG. 7A, the thickness of the FeMn antiferromagnetic film is increased from 6 to 1.
It can be seen that when the thickness is reduced to 0 nm, the heat resistance of the rate of change in resistance is improved as in the case where the fixed layer is thickened.
FIG. 7B also shows that the heat resistance is improved by reducing the thickness of the FeMn antiferromagnetic film in the interlayer coupling magnetic field.

FIG. 8 is a diagram showing the ratio of the thickness of the fixed layer to the antiferromagnetic film, the rate of change in resistance, and the change in the interlayer coupling magnetic field. FIG.
It can be seen that the two data in FIG. 7 and FIG. 8 are on one upward-sloping curve in FIG. That is, by setting the ratio of the thickness of the fixed layer to the thickness of the antiferromagnetic film to 0.5 or more, the resistance change rate and the heat resistance of the interlayer coupling magnetic field can be improved. The greater the thickness ratio, the better the results are shown in FIG. 8, but if this ratio is 1.0, some degree of heat resistance will suffice.

FIG. 9 shows X-ray diffraction curves of the samples without and after the heat treatment. In the drawing, the calculated value of an ideal diffraction curve is indicated by a dotted line. The diffraction curve qualitatively agrees well with the calculated value, indicating that the structure of the thin film sample is good. FIGS. 9 (a) and 9 (b) show the diffraction curves of the samples having different fixed layer thicknesses. In each case, it can be seen that the shapes of the curves do not change before and after the heat treatment. But,
The diffraction intensity, that is, the height of the peak increases after the heat treatment. This change in diffraction intensity is significantly related to the film configuration and heat resistance.

FIG. 10 is a diagram showing the thickness of the fixed layer and the antiferromagnetic film and the X-ray diffraction intensity before and after the heat treatment. FIG. 10 (a)
When the thickness of the fixed layer is increased, the X-ray diffraction intensity increases after the heat treatment. FIG. 10B shows that the X-ray diffraction intensity increases when the FeMn antiferromagnetic film is made thinner.

FIG. 11 is a diagram showing the relationship between the ratio of the thickness of the pinned layer to the thickness of the antiferromagnetic film and the ratio of the X-ray diffraction intensity before and after the heat treatment. In FIG. 11, it can be seen that the results of FIG. 10 are plotted on one curve when the ratio of the thickness and the ratio of the diffraction intensity are arranged.
Therefore, it can be considered that this change in diffraction intensity reflects a certain phenomenon. As shown in FIG. 8, since the thickness ratio between the pinned layer and the antiferromagnetic film is related to heat resistance, it is possible to newly find a relation between heat resistance and a change in X-ray diffraction intensity. it can.

FIG. 12 is a diagram showing the relationship between the ratio of the rate of change in resistance before and after the heat treatment and the ratio of the X-ray diffraction intensity. The ratio between the rate of change in resistance and the ratio between the X-ray diffraction intensities is plotted on one curve, indicating a certain relationship. In other words, the heat resistance of the rate of change of resistance increases as the X-ray diffraction intensity increases before and after the heat treatment. These results suggest that the heat resistance of the spin-valve stacked film is due to the structural change due to the heat treatment. More specifically, the phenomenon that the diffraction intensity increases,
For example, it is possible to obtain the knowledge that this is related to the disappearance or rearrangement of the small-angle grain boundaries of the spin valve laminated film.

FIG. 13 is a diagram showing the relationship between the thickness of the fixed layer and the rate of change in resistance after heat treatment. The description in the figure is the type of antiferromagnetic film / type of fixed layer. The thickness of the antiferromagnetic film is unified with an appropriate value, in this case, the thickness necessary for sufficiently increasing the exchange coupling magnetic field. From FIG. 13, it can be seen that the resistance change rate after the heat treatment in all the configurations increases as the thickness of the fixed layer increases, that is, the heat resistance improves. C
From comparison of the results of rMnPt / NiFe and CrMnPt / Co, it can be seen that the heat resistance is higher when the fixed layer is made of Co or a Co alloy than when it is made of NiFe.
The types of antiferromagnetic films are FeMn and CrM.
It can be seen that the heat resistance is high in the order of nPt and MnIr. This result also suggests that the higher the noble metal content of the antiferromagnetic film, the higher the heat resistance. This is because, for example, by adding a noble metal element having a high melting point, effects such as suppression of diffusion and improvement of strength can be expected.

FIG. 14 shows the relationship between the amount of noble metal in the antiferromagnetic film and the rate of change in resistance after heat treatment. As shown in the figure, the higher the content of the noble metal Pt and Ir, the higher the heat resistance. By setting the content to 5% to 30% or more, the heat resistance of the spin valve laminated film can be improved. We can see that we can do it.

The effect of adding a noble metal can be regarded as an effect of the average atomic diameter. FIG. 15 is a diagram showing the relationship between the average atomic diameter of the antiferromagnetic film and the rate of resistance change after heat treatment. The atomic diameter of each element can be determined from the density and atomic weight of the element alone. The value obtained by averaging the respective atomic diameters of the constituent elements of the antiferromagnetic film with the composition is the average atomic diameter. FIG. 15 shows that the heat resistance can be improved by setting the average atomic diameter to 0.285 nm or more. Extremely increasing the average atomic diameter involves elemental difficulties, so it is better to keep the average atomic diameter within 0.3 or 0.35 nm.

Further, when discussing the heat resistance in terms of the average atomic diameter, comparison with the average atomic diameter of the fixed layer should be considered. That is, as shown in FIGS. 8 and 11, the interaction between the fixed layer and the antiferromagnetic layer strongly influences the result of the heat treatment.

FIG. 16 is a graph showing the relationship between the ratio between the average atomic diameter of the antiferromagnetic film and the average atomic diameter of the fixed layer, and the rate of change in resistance after heat treatment. It can be seen that the heat resistance improves as the average atomic diameter ratio of the antiferromagnetic film / fixed layer increases. However, extremely reducing and increasing the average atomic diameter involves elemental difficulties, so it is better to keep the average atomic diameter ratio within 1.02 to 1.1.

As described above, for example, by increasing the thickness of the fixed layer, the heat resistance of the spin valve laminated film can be improved. Also, simply increasing the thickness may reduce the performance of the device. That is, the magnetic field leaking from the end of the thick fixed layer applies a bias to the free layer, and changes the bias characteristics of the element. Therefore, the present invention realizes a configuration in which the thickness of the film substantially in contact with the antiferromagnetic film is increased and the amount of magnetization is not increased.

FIG. 17 shows a configuration example of a spin valve laminated film using a NiFe protective film. Compared with the configuration of FIG. 1, the tantalum protective film is changed to a NiFe protective film. With such a configuration, the two films in contact with the antiferromagnetic film are the fixed layer 15 and the heat-resistant protective film 31 having the same structure as the fixed layer. A heat resistance improving effect similar to that obtained by increasing the thickness is obtained.

FIG. 18 shows the relationship between the exchange coupling magnetic field and the thickness of the heat-resistant protective film. When the protective film is tantalum, the exchange coupling magnetic field is reduced by about 200 Oe by the heat treatment. When the heat-resistant protective film is made of NiFe, the exchange coupling magnetic field hardly decreases or rather increases when the thickness of the heat-resistant protective film is 1 to 3 nm. When the heat-resistant protective film is 5 nm or more, the exchange coupling magnetic field decreases as in the case of the tantalum protective film. FIG. 19 is a diagram showing the relationship between the heat treatment time and the resistance change rate. It can be seen that the spin valve laminated film using the heat-resistant protective film made of NiFe has a small decrease in the rate of change in resistance even after the heat treatment for 6 hours, indicating that the heat resistance has been improved. In the figure, the exchange coupling magnetic fields of the Cu protective film and the Co ₉₀ Fe ₁₀ protective film after the heat treatment are indicated by Δ and ○, respectively. All values show high heat resistance, and it can be seen that the heat-resistant protective film may be made of Cu, Co alloy or the like in addition to NiFe. In particular, since the same protective effect was obtained with Cu, it is understood that the heat-resistant protective film may be made of a material having no magnetism. Since the protective film is located relatively far from the free layer, it is less likely to exert a magnetic influence on the free layer than the fixed layer. It is clear that there are few. When the heat-resistant protective film is ferromagnetic, its magnetic adverse effect can be eliminated if the direction of the magnetization is perpendicular to the direction of the magnetization of the fixed layer. Further, if the direction of the magnetization is reversed from the direction of the magnetization of the fixed layer, there is an effect of canceling the bias from the fixed layer. Further, Cu, Ni is used as a heat-resistant protective film.
Since Fe and CoFe exhibited good characteristics, it is understood that good heat resistance can be obtained by using a heat-resistant protective film having a face-centered cubic structure. In addition, Cr, Fe, and the like having a body-centered cubic structure have the same atomic diameter as Cu, NiFe, and CoFe, and have a good crystallographic relationship with these materials, for example, a (111) plane having a face-centered cubic structure. Since the epitaxial growth of the (110) plane of the body-centered cubic structure can be easily obtained,
The same effect can be obtained by using a material having a body-centered cubic structure such as r or Fe for the heat-resistant protective film.

Since the heat-resistant protective film is in close contact with the spin-valve laminated film, current flows. Therefore, a spin valve sensor having a higher output can be obtained when the electric resistance of the heat-resistant protective film is higher. For this reason, it is preferable to use a high-resistance protective film such as a NiCr film as the heat-resistant protective film. Alternatively, a thin heat-resistant protective film and a second heat-resistant protective film having high electric resistance may be stacked and used.

FIG. 20 is a structural example of a spin valve laminated film using a heat-resistant protective laminated film. The heat-resistant protective laminated film 34 is formed by laminating a first protective film 32 and a second protective film 33,
To realize a spin valve laminated film having a small amount of flow and having good heat resistance. Even if the second protective film 33 is formed of a material such as a tantalum film, a certain effect can be obtained.

FIG. 21 is a conceptual diagram of a magnetic head equipped with the magnetic sensor of the present invention. Lower shield 8 on base 50
2, lower gap insulating film 83, spin valve magnetoresistive element 11, electrode 40, upper gap insulating film 84, upper shield 81, lower core 84, coil 41, upper core 8
3 is formed. Since the heat resistance of the spin valve magnetoresistive element 11 of the present invention is good, the upper gap insulating film 8
4. In the method of manufacturing the upper shield 81, the lower core 84, the coil 41, the upper core 83, etc., a high-temperature process can be adopted. For example, even if the substrate temperature is set to 100 ° C. when the upper core 83 is formed by sputtering, and the temperature is further increased during film formation, the substrate temperature of the magnetic head of the present invention can be controlled by the spin valve magnetoresistive element. It can be manufactured without exceeding the heat resistance temperature. Similarly, when the lower gap insulating film 83 and the upper gap insulating film 84 are formed by CVD,
Even at 0 to 300 ° C., the magnetic head of the present invention can be manufactured without the substrate temperature exceeding the heat resistance temperature of the spin valve magnetoresistive element. Similarly, with respect to magnetization heat treatment, current resistance, etc., by using the magnetic head of the present invention, higher temperature heat treatment can be realized or more current can be applied.

FIG. 22 is a conceptual diagram of a magnetic recording / reproducing apparatus using the magnetic head of the present invention. A magnetoresistive effect laminated film 10, a magnetic domain control film 41, and an electrode 40 are formed on a base 50 also serving as a head slider 90, and a magnetic head made of these is recorded on a recording track 4 on a disk 95 having a recording medium 91.
4 and reproduction is performed. The head slider 90 floats on the disk 95 and faces the opposing surface 63 to a height of 0.2 .mu. With this mechanism, the magnetoresistive effect laminated film 10 transmits the magnetic signal recorded on the recording medium 91 on the disk 95 to the recording medium 9.
It can be read from one leakage magnetic field 64.

FIG. 23 shows an example of the configuration of a magnetic recording / reproducing apparatus according to the present invention. A disk 95 holding a recording medium 91 for magnetically recording information is rotated by a spindle motor 93,
The actuator 92 guides the head slider 90 onto the track of the disk 95. That is, in the magnetic disk device, the reproducing head and the recording head formed on the head slider 90 relatively move close to a predetermined recording position on the disk 95 by this mechanism, and write and read signals sequentially. The actuator 92 may be a rotary actuator. The recording signal is recorded on the medium by the recording head through the signal processing system 94, and the output of the reproducing head is obtained as a signal through the signal processing system 94. Further, when the reproducing head is moved to a desired recording track, the position on the track is detected using the high-sensitivity output from the reproducing head, and the actuator is controlled.
The positioning of the head slider can be performed. Although one head slider 90 and one disk 95 are shown in this figure, a plurality of these may be used. Also disk 9
5 may have a recording medium on both sides to record information. When information is recorded on both sides of the disk, head sliders 90 are arranged on both sides of the disk.

As a result of testing the magnetic head of the present invention and the magnetic recording / reproducing apparatus equipped with the same with the above-described configuration, the output was sufficient, the noise was low, and the operation reliability was good. .

[0052]

According to the present invention, it is possible to provide a magnetic laminate having a sufficient coupling magnetic field and high thermal stability, and furthermore, a magnetic sensor having a sufficient reproduction output and low noise characteristics and a highly reliable high-density magnetic field. A recording / reproducing device can be obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a configuration example of a spin valve film.

FIG. 2 is a characteristic diagram showing an exchange coupling magnetic field and a blocking temperature when the thickness of a MnIr film is changed.

FIG. 3 is a characteristic diagram showing heat resistance of a sample in which the thickness of a MnIr film is changed.

FIG. 4 is a characteristic diagram showing heat resistance of a sample in which the thickness of a Co fixed layer is changed.

FIG. 5 is a magnetoresistance characteristic diagram of a spin valve film using an FeMn antiferromagnetic film.

FIG. 6 is a characteristic diagram showing a resistance change rate and a change in an interlayer coupling magnetic field when the thickness of a fixed layer is changed.

FIG. 7 is a characteristic diagram showing a change in resistance and a change in interlayer coupling magnetic field when the thickness of the FeMn antiferromagnetic film is changed.

FIG. 8 shows the ratio of the thickness of the fixed layer to the antiferromagnetic film and the rate of resistance change,
FIG. 4 is a characteristic diagram showing a change in an interlayer coupling magnetic field.

FIG. 9 is a characteristic diagram showing X-ray diffraction curves of a sample without heat treatment and after heat treatment.

FIG. 10 is a characteristic diagram showing the thickness of a fixed layer and an antiferromagnetic film and the X-ray diffraction intensity before and after heat treatment.

FIG. 11 is a characteristic diagram showing the relationship between the ratio of the thickness of the fixed layer to the thickness of the antiferromagnetic film and the ratio of the X-ray diffraction intensity before and after the heat treatment.

FIG. 12 is a characteristic diagram showing the relationship between the ratio of the rate of change in resistance before and after the heat treatment and the ratio of the X-ray diffraction intensity.

FIG. 13 is a characteristic diagram showing the relationship between the thickness of a fixed layer and the rate of change in resistance after heat treatment.

FIG. 14 is a characteristic diagram showing the relationship between the amount of noble metal in the antiferromagnetic film and the rate of resistance change after heat treatment.

FIG. 15 is a characteristic diagram showing the relationship between the average atomic diameter of the antiferromagnetic film and the rate of resistance change after heat treatment.

FIG. 16 is a characteristic diagram showing a relationship between the ratio of the average atomic diameter of the antiferromagnetic film to the average atomic diameter of the fixed layer and the rate of change in resistance after heat treatment.

FIG. 17 is an explanatory view of a spin valve laminated film using a NiFe protective film.

FIG. 18 is a characteristic diagram showing a relationship between a heat treatment time and a rate of change in resistance.

FIG. 19 is a characteristic diagram showing the relationship between the exchange coupling magnetic field and the thickness of the heat-resistant protective film.

FIG. 20 is an explanatory diagram of a spin-valve laminated film using a heat-resistant protective laminated film.

FIG. 21 is a perspective view of a magnetic head equipped with the magnetic sensor of the present invention.

FIG. 22 is a perspective view of a magnetic recording / reproducing apparatus using the magnetic head of the present invention.

FIG. 23 is an explanatory view of a magnetic recording / reproducing device of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Magnetoresistance effect film, 40 ... Electric terminal, 42 ... Coil, 50 ... Base, 81 ... Upper shield, 82 ... Lower shield, 83 ... Upper magnetic core, 84 ... Lower magnetic core.

Claims (25)

[Claims] A soft magnetic free layer / nonmagnetic layer / ferromagnetic fixed layer /
An antiferromagnetic layer having a laminated structure, wherein the antiferromagnetic layer has a spin valve film for applying an exchange coupling magnetic field to the ferromagnetic pinned layer, and the soft magnetic free layer is freed according to an external magnetic field. In a magnetic sensor in which the magnetization of the layer rotates and the relative angle with the magnetization of the ferromagnetic fixed layer changes to produce a magnetoresistance effect,
A magnetic sensor, wherein the thickness of the antiferromagnetic layer is 3 nm to 9 nm. 2. A soft magnetic free layer / non-magnetic layer / ferromagnetic fixed layer /
An antiferromagnetic layer having a laminated structure, wherein the antiferromagnetic layer has a spin valve film for applying an exchange coupling magnetic field to the ferromagnetic pinned layer, and the soft magnetic free layer is freed according to an external magnetic field. In a magnetic sensor in which the magnetization of the layer rotates and the relative angle with the magnetization of the ferromagnetic fixed layer changes to produce a magnetoresistance effect,
A magnetic sensor characterized in that said ferromagnetic pinned layer has a thickness of 1.5 nm to 10 nm, particularly 3.0 to 5.0 nm. 3. A soft magnetic free layer / non-magnetic layer / ferromagnetic fixed layer /
An antiferromagnetic layer having a laminated structure, wherein the antiferromagnetic layer has a spin valve film for applying an exchange coupling magnetic field to the ferromagnetic pinned layer, and the soft magnetic free layer is freed according to an external magnetic field. In a magnetic sensor in which the magnetization of the layer rotates and the relative angle with the magnetization of the ferromagnetic fixed layer changes to produce a magnetoresistance effect,
A magnetic sensor, wherein the thickness of the antiferromagnetic layer is 3 nm to 9 nm, and the thickness of the ferromagnetic fixed layer is 1.5 nm to 10 nm. 4. A soft magnetic free layer / non-magnetic layer / ferromagnetic fixed layer /
An antiferromagnetic layer having a laminated structure, wherein the antiferromagnetic layer has a spin valve film for applying an exchange coupling magnetic field to the ferromagnetic pinned layer, and the soft magnetic free layer is freed according to an external magnetic field. In a magnetic sensor in which the magnetization of the layer rotates and the relative angle with the magnetization of the ferromagnetic fixed layer changes to produce a magnetoresistance effect,
A magnetic sensor, wherein a thickness ratio defined by a value obtained by dividing the thickness of the fixed ferromagnetic layer by the thickness of the antiferromagnetic layer is from 0.5 to 1.0. 5. A soft magnetic free layer / non-magnetic layer / ferromagnetic fixed layer /
An antiferromagnetic layer having a laminated structure, wherein the antiferromagnetic layer has a spin valve film for applying an exchange coupling magnetic field to the ferromagnetic pinned layer, and the soft magnetic free layer is freed according to an external magnetic field. In a magnetic sensor in which the magnetization of the layer rotates and the relative angle with the magnetization of the ferromagnetic fixed layer changes to produce a magnetoresistance effect,
When the thickness of the antiferromagnetic layer required for the antiferromagnetic layer to apply an exchange coupling magnetic field to the ferromagnetic fixed layer is defined as a critical thickness, the thickness of the ferromagnetic fixed layer is defined as A film thickness ratio defined by a value divided by a critical thickness of the antiferromagnetic layer is from 0.5 to 1.0. 6. A soft magnetic free layer / non-magnetic layer / ferromagnetic fixed layer /
An antiferromagnetic layer having a laminated structure, wherein the antiferromagnetic layer has a spin valve film for applying an exchange coupling magnetic field to the ferromagnetic pinned layer, and the soft magnetic free layer is freed according to an external magnetic field. In a magnetic sensor in which the magnetization of the layer rotates and the relative angle with the magnetization of the ferromagnetic fixed layer changes to produce a magnetoresistance effect,
The composition of the antiferromagnetic layer is Cu, Ag, Au, Pt, P
It contains any one of d, Rh, Ru, Ir, Os and Re or a plurality of noble metals, and the content thereof is from 5 at% to 40 at%, especially from 10 to 30 at%. A magnetic sensor having a crystal structure having a face-centered cubic structure having a disordered structure, a body-centered cubic structure, or a structure in which these are slightly distorted in the range of 0 to 10% or less. 7. The antiferromagnetic layer has a composition of 70 to 90 atomic% of manganese and 10 to 30 atomic% of a noble metal of iridium, rhodium, ruthenium, osmium or rhenium or a plurality of noble metals. Cubic structure
6. A magnetic sensor according to claim 1, wherein said magnetic sensor has a structure slightly distorted within 0 to 10%. 8. The antiferromagnetic layer comprises 40 to 58 atomic% of chromium, 30 to 48 atomic% of manganese, and one or more of noble metals of platinum, copper, iridium, rhodium, ruthenium, osmium and rhenium. 4 to 2
0 atomic% composition, body-centered cubic or 0-1
A structure having a structure slightly distorted within 0%.
3, 4 or 5 magnetic sensors. 9. An antiferromagnetic layer comprising 40 to 55 atomic% of iron,
50 to 55 atomic% of manganese, or 0 to 10 of noble metals of platinum, copper, iridium, rhodium, ruthenium, osmium, rhenium, or a plurality of noble metals
Atomic% composition, face-centered cubic or 0-10
%, Having a structure slightly distorted within%.
3, 4 or 5 magnetic sensors. 10. The antiferromagnetic layer comprises 60 to 90 atomic% of chromium, 5 to 30 atomic% of aluminum, and platinum.
Copper, iridium, rhodium, ruthenium, osmium,
5 or more noble metals of rhenium
6. The magnetic sensor according to claim 1, wherein the composition is from 25 to 25 atomic% and has a body-centered cubic structure or a structure in which it is slightly distorted within 0 to 10%. 11. The antiferromagnetic layer has an average atomic diameter of the constituent elements of 0.287 nm to 0.2% with respect to the density of the single substance of each element and the value of the atomic diameter defined from the atomic weight.
10. The composition of claim 1, 2, 3, 4, 6, 7, 8, 9, 9.
Or 10 magnetic sensors. 12. The average atomic diameter of the constituent elements of the antiferromagnetic layer and the value of the atomic diameter defined from the density of the single substance of each element and the atomic weight, and the constituent elements of the ferromagnetic film. The ratio of the average atomic diameter to the average atomic diameter (the average atomic diameter of the constituent elements of the antiferromagnetic layer / the average atomic diameter of the constituent elements of the ferromagnetic film) is 1.02 to 1.050. Term 1,
2, 3, 4, 5, 6, 7, 8, 9, 10, or 11 magnetic sensors. 13. The ferromagnetic layer according to claim 1, wherein said ferromagnetic layer comprises 40 to 95 atomic% of cobalt, 5 to 30 atomic% of iron, and 0 to 3 atomic% of nickel.
The composition according to claim 1, which has a composition of 0 atomic% and a face-centered cubic structure.
2,3,4,5,6,7,8,9,10,11 or 1
2 magnetic sensor. 14. A laminated structure of a soft magnetic free layer / nonmagnetic layer / ferromagnetic pinned layer / antiferromagnetic layer / protective layer, wherein the antiferromagnetic layer applies an exchange coupling magnetic field to the ferromagnetic pinned layer. A magnetic sensor having a spin-valve film, wherein the magnetization of the soft magnetic free layer rotates in response to an external magnetic field, and the relative angle with the magnetization of the ferromagnetic fixed layer changes to produce a magnetoresistive effect. 3. The magnetic sensor according to claim 1, wherein the protective layer includes a plurality of constituent elements and has a laminated structure. 15. A laminated structure of a soft magnetic free layer / nonmagnetic layer / ferromagnetic pinned layer / antiferromagnetic layer / protective layer, wherein the antiferromagnetic layer applies an exchange coupling magnetic field to the ferromagnetic pinned layer. A magnetic sensor having a spin-valve film, wherein the magnetization of the soft magnetic free layer rotates in response to an external magnetic field, and the relative angle with the magnetization of the ferromagnetic fixed layer changes to produce a magnetoresistive effect. Wherein the protective layer, or at least a part thereof, is V, T
i, Cr, Mn, Fe, Co, Ni, Cu, Pt, A
g, Au, Pt, Pd, Rh, Ru, Ir, Os, Re
Or a film containing these as a main component. 16. A laminated structure of a soft magnetic free layer / nonmagnetic layer / ferromagnetic pinned layer / antiferromagnetic layer / protective layer, wherein the antiferromagnetic layer applies an exchange coupling magnetic field to the ferromagnetic pinned layer. A magnetic sensor having a spin-valve film, wherein the magnetization of the soft magnetic free layer rotates in response to an external magnetic field, and the relative angle with the magnetization of the ferromagnetic fixed layer changes to produce a magnetoresistive effect. 3. The magnetic sensor according to claim 1, wherein the protective layer is a metal film having a face-centered cubic structure or a body-centered cubic structure. 17. The magnetic sensor according to claim 14, 15 or 16, wherein the protective film or a portion where the protective film is in contact with the antiferromagnetic layer has crystallographic continuity with the antiferromagnetic layer. 18. The method according to claim 14, wherein said protective film is non-magnetic.
15, 16 or 17 magnetic sensors. 19. The protective film has an electric resistivity of 50 to 10
A high electric resistance of 00 μΩcm, wherein the electric resistance is high.
6, 17 or 18 magnetic sensors. 20. A disk having a ferromagnetic recording medium on which a signal is magnetically recorded, and a magnetic field leaking from the recording medium by moving relative to the disk by bringing a sliding surface close to the disk. 20. The magnetic head of a magnetic recording / reproducing apparatus comprising: a magnetic head that detects
A magnetic recording and reproducing apparatus having the magnetic sensor according to any one of the above. 21. A magnetic recording / reproducing apparatus according to claim 20, wherein said magnetic head includes the magnetic sensor according to any one of claims 1 to 19, and an inductive head having a photoresist at least in an inductive coil insulating portion. 22. The magnetic head according to claim 1, wherein the magnetic sensor is subjected to a heat treatment step of 200 ° C. or more and 400 ° C. or less after the formation of the spin valve laminated film in the manufacturing process. Magnetic recording and reproducing device. 23. The magnetic head has a magnetic sensor according to any one of claims 1 to 19 and an inductive head, wherein the core of the inductive head is formed by a sputtering method. 100 ℃ to 3
21. The magnetic recording and reproducing apparatus according to claim 20, manufactured at 00C. 24. The magnetic head according to claim 1, wherein the magnetic head has an insulating film formed by a vacuum film forming method or a CVD method. 21. The magnetic recording / reproducing apparatus according to claim 20, wherein the substrate is manufactured at a substrate temperature of 100 ° C. to 300 ° C. 25. The magnetic head according to claim 1, wherein a current having a density of 30 MA / cm or more is passed through the magnetoresistive effect laminated film portion of the magnetic sensor during a reading operation. Item 21. The magnetic recording and reproducing device according to Item 20.