JP2000187814A - Composite magnetic head and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composite magnetic head of a one-gap structure having a magneto-resistance effect film as a reproducing head in which deterioration in the characteristics of the magneto-resistance effect film due to a recording magnetic field can be suppressed, and to provide the producing method of the head. SOLUTION: A magneto-resistance effect film 12 is disposed in the magnetic gap 3, 7 of the recording head 10. Magnetic domain controlling layers 5 are formed on both ends of the magneto-resistance effect film 12. The magnetic domain controlling layer 5 consists of a first antiferromagnetic layer 51 or a laminated structure of a ferromagnetic layer 52 and the first antiferromagnetic layer 51. Controlling of magnetic domains by the magnetic controlling layers 5 in the magneto-resistance effect film 12 can be stabilized by the first antiferromagnetic layer 51.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite magnetic head comprising a reproducing magnetic head having a magnetoresistive effect film and a winding type magnetic head for recording used in a magnetic disk drive and the like, and a method of manufacturing the same. It is about.

[0002]

2. Description of the Related Art In recent years, in a magnetic recording / reproducing device such as a magnetic disk device, as the recording density increases, a magnetoresistive film using an anisotropic magnetoresistive effect or a giant magnetoresistive effect is applied to a reproducing head. A recording / reproducing head having a structure combined with a linear thin film recording head has been developed.

This recording / reproducing head is composed of a shield type head having a structure in which a magnetoresistive film is sandwiched between shield layers made of a soft magnetic material, and a winding type thin film head using this shield layer as one magnetic core. A so-called two-gap structure is generally used.

However, in this two-gap structure, the recording gap and the reproducing gap are separated, and the recording gap of the recording head and the reproducing gap of the reproducing head are set along the relative movement direction of the recording medium. Thus, the gap is at least separated by the distance (L) that is the sum of the thickness of the shield layer and the gap length.

Therefore, in a magnetic recording / reproducing apparatus, for example, a magnetic disk apparatus, when the track width is small due to the separation between the reproducing head and the recording head, particularly when the track width is small as in the case of high-density recording, as described in detail below, There is a problem in that reproduction is inconvenient.

That is, the recording / reproducing head is formed on a slider end face for scanning the recording surface of a magnetic disk as a recording medium, and floats and moves on the magnetic disk during recording / reproducing, and moves to a predetermined position on the magnetic disk. The recording and reproduction are performed at the position. The slider on which the recording / reproducing head is mounted is usually mounted on a suspension driven to rotate by a voice coil motor. Therefore, the recording / reproducing head on the slider end surface moves on the magnetic disk in an arc shape substantially in the radial direction of the magnetic disk.

At this time, in the recording / reproducing head having the two-gap structure, as described above, since each gap between the recording head and the reproducing head is separated by the distance (L), the rotation of the suspension accompanying the movement of the slider is performed. As a result, each track position operated by the recording head and the reproducing head is shifted (mismatched) by approximately D = L · sin θ (θ is the rotation angle of the suspension).

Usually, the shield layer of the read head is 2
Since a soft magnetic film made of NiFe, FeAlSi, CoZrNb or the like having a thickness of about 5 μm is used, at least a micron-order track scanning shift occurs. Such a scan deviation of the track does not cause a problem in a magnetic disk drive having a sufficiently large track width and a scan deviation of a track of several microns.

However, in a magnetic disk drive that performs high-density recording with a track width on the order of sub-microns, the scanning deviation of the track poses a serious problem for the stability of recording and reproduction.

Further, when the distance from the recording / reproducing head to the center of rotation of the suspension is shortened with the downsizing of the magnetic disk drive, the rotation angle of the suspension is required to move the recording / reproducing head from the outer peripheral portion to the inner peripheral portion of the magnetic disk. It is necessary to set θ to be large, and the scanning deviation of the track further increases. That is, the recording / reproducing head having the above-mentioned two-gap structure has a serious problem in narrowing the track (increasing the recording density) and miniaturizing the magnetic recording / reproducing apparatus.

On the other hand, in order to solve such a problem from the structure of the recording / reproducing head, a magnetoresistive film is disposed as a reproducing head in a magnetic gap of the recording head, and a magnetic core of the recording head is used as a magnetic core of the reproducing head. A so-called one-gap magnetic head having a structure also serving as a shield layer has been proposed.

In the recording / reproducing head having the one-gap structure, the center position of the recording magnetic gap of the recording head and the center position of the reproducing magnetic gap of the reproducing head can be set at substantially the same position. Since the problem of track scanning deviation can be avoided, it is suitable for narrowing tracks and miniaturization, and is advantageous in a magnetic recording / reproducing apparatus that performs high-density recording.

JP-A-7-110920 discloses such a recording / reproducing head having a one-gap structure. In the recording / reproducing head, when the recording magnetic field is applied to the magnetoresistive film, the magnetoresistive film is magnetized. By setting the length to be smaller than the gap depth of the recording head, the control of the magnetic domain in the magnetoresistive film is stabilized.

The conventional one-gap structure recording / reproducing head described in the above publication will be described below. At the time of recording / reproducing, the recording / reproducing head is perpendicular to (perpendicular to) a surface facing the recording medium (hereinafter referred to as an ABS surface).
The cross section in the direction is shown in FIG.

As shown in FIG. 17, the recording / reproducing head includes a lower insulating layer made of Al ₂ O ₃ or SiO ₂ on a substrate 70 made of glass, Si, or an Al ₂ O ₃ —TiC sintered body. 71, Ni serving as a lower magnetic core of the recording head 75 of the recording / reproducing head and a lower shield layer of the reproducing head 76 of the recording / reproducing head.
Lower magnetic layer 7 made of a soft magnetic film of Fe, FeAlSi, etc.
2 are arranged in a predetermined shape.

On the lower magnetic layer 72, a Cu layer covered with an interlayer insulating layer 74 made of Al ₂ O ₃ or SiO ₂ is used.
A conductor winding layer 80 made of a conductive material such as Al or Al is formed. A part of the interlayer insulating layer 74 is
3 to form magnetic gaps 73 and 77.

The recording head 7 is provided on the interlayer insulating layer 74.
5, an upper magnetic layer 78 magnetically coupled to the lower magnetic layer 72 and linked to the conductor winding layer 80 is formed. This upper magnetic layer 7
Numeral 8 is made of a soft magnetic material such as NiFe or CoZrNb, and also serves as an upper magnetic core of the recording head 75 and an upper shield layer of the reproducing head 76.

Further, on the upper magnetic layer 78, Al ₂ O
_A protective layer 79 made of an insulating material such as ₃ or SiO ₂ is formed. On the other hand, in the magnetic gaps 73 and 77,
A reproducing head 76 that is a magnetoresistive film and is covered by the interlayer insulating layer 74 is provided.

FIG. 18 shows a cross section of the reproducing head 76 in the direction perpendicular to the scanning direction of the recording medium on the ABS 83 facing the recording medium. As described above, the reproducing head 76 is disposed between the upper and lower magnetic layers 78 and 72 also serving as the respective magnetic cores of the recording head 75 via the respective magnetic gaps 73 and 77.

The reproducing head 76 includes a magnetoresistive thin film 82 processed into a predetermined stripe shape, magnetic domain control layers 85 provided at both ends of the magnetoresistive thin film 82, and a magnetic domain control layer 85 on each magnetic domain control layer 85. And the electrode layers 86 provided respectively. The magnetic domain control layer 85 is made of a hard magnetic material such as CoPt or CoCrPt for controlling the magnetic domains of the reproducing head 76 and suppressing Barkhausen noise. The electrode layer 86 is made of a conductive material such as Cu or Al in order to detect a resistance change due to the magnetoresistance effect of the magnetoresistance effect thin film 82.

Although the material of the magnetic domain control layer 85 is not particularly considered in the recording / reproducing head having a one-gap structure described in the above-mentioned publication, the recording / reproducing head having a two-gap structure which is currently manufactured in large numbers is used. In the magnetic domain control layer 85, CoPt or C
Generally, a hard magnetic material having a large coercive force (Hc) such as oCrPt is used.

However, in a recording / reproducing head having a one-gap structure, as shown in FIG. 18, a recording magnetic field 81 generated when recording is performed as shown by broken lines in FIG. In the opposing portions of the layers 78, 72, the magnetic flux is generated from the lower magnetic layer 72 to the upper magnetic layer 78 so as to vertically cross the magnetoresistive thin film 82.

However, at the end of the upper magnetic layer 78, the recording magnetic field 81 diagonally crosses the magnetic domain control layer 85 while spreading right and left (outward). That is, a magnetic field having an in-plane component is applied to the magnetic domain control layer 85. Since the direction of the recording magnetic field 81 changes at a high frequency, the in-plane component of the recording magnetic field 81 applied to the magnetic domain control layer 85 repeats inversion accordingly.

FIG. 19 shows an example of an MH curve of a hard magnetic material used for the magnetic domain control layer 85. Once the hard magnetic material is magnetized by applying a magnetic field having a coercive force (Hc) or more in the positive direction, it has residual magnetization (Mr) even when the magnetic field is removed, and a magnetic field of -Hc is applied in the opposite direction. Until a positive magnetic field is generated. The magnetic domain control layer 85 suppresses the generation of magnetic domains in the magnetoresistive thin film 82 when no external magnetic field is applied by the residual magnetization (Mr).

Usually, a hard magnetic material such as CoPt or CoCrPt has a coercive force (Hc) of about 2000 Oersted (Oe). On the other hand, as the recording density of the magnetic recording / reproducing device increases, the coercive force (Hc) of the recording medium also increases. In order to magnetize such a recording medium having a high coercive force, a material having a high saturation magnetic flux density (Bs) of about 2T is required for the upper and lower magnetic layers 78 and 72 as the magnetic core of the recording head 75. ing.

[0026]

When the recording magnetic field 81 near the magnetic gaps 73 and 77 is increased by using such a material having a high saturation magnetic flux density, the above-described magnetic domain control layer 85
The in-plane component of the magnetic field applied to the magnetic field control layer also increases, and the risk that the absolute value of the magnetic field exceeds the coercive force (Hc) of the magnetic domain control layer 85 increases.

For example, as shown in FIG. 19, the in-plane magnetic field ± Hw whose absolute value exceeds the coercive force (Hc) of the magnetic domain control layer 85.
Is applied, the magnetization state of the magnetic domain control layer 85 becomes “a”.
When the point moves to the point and the in-plane magnetic field is removed, the state becomes −Mr ′ remanent magnetization.

That is, the absolute value of the residual magnetization of the magnetic domain control layer 85 is reduced from Mr to Mr 'by the recording magnetic field 81. At this time, as can be seen from FIG.
The in-plane magnetization in the opposite direction is applied to the magnetic domain control layer 85 at each end of No. 6, so that the residual magnetization of the magnetic domain control layer 85 is in the opposite direction. Therefore, the magnetic field applied from the magnetic domain control layer 85 to the magnetoresistive thin film 82 is in the opposite direction, so that the magnetic domain control becomes impossible, and the read head 76 greatly increases the noise during reproduction. Have a point.

Further, in the recording / reproducing head having the one-gap structure, as described above, the reproducing head 76 is exposed in the magnetic gaps 73 and 77 of the recording head 75 on the ABS surface 83 facing the recording medium. When a hard magnetic material is used for the magnetic domain control layer 85, the magnetization recorded on the recording medium is demagnetized or demagnetized by a leakage magnetic field from the hard magnetic material, and the recorded information is transferred from the recording medium. There is also a problem that the risk of disappearing is high.

[0030]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and is directed to a composite magnetic head in which a magnetoresistive film is disposed as a reproducing head in a magnetic gap of a recording head. The magnetic domain control layer disposed at the end of the magnetoresistive film has an antiferromagnetic layer or a laminated structure of a ferromagnetic layer and an antiferromagnetic layer, and the antiferromagnetic layer and the ferromagnetic layer are exchanged. The magnetic domain of the magnetoresistive film is controlled using the coupling magnetic field.

Also, in the present invention, a GMR film having a spin valve structure (Giant MagnetoResis) is used for the magnetoresistive film.
tive) element, the direction of the exchange coupling magnetic field between the fixed magnetization layer (pinned layer) of the GMR film and the pinning layer made of an antiferromagnetic material, and the magnetic domain control layer It is preferable to set the directions of the exchange coupling magnetic fields so as to be substantially perpendicular to each other because the rate of change in resistance of the magnetoresistive film with respect to a change in the direction of the recording magnetic field from the recording medium can be maximized.

Therefore, in the method of manufacturing a composite magnetic head according to the present invention, the blocking temperature of each antiferromagnetic layer used for the pinning layer and the magnetic domain control layer is set to be different from each other, so that the respective exchange coupling magnetic fields are different. Are set so as to be substantially perpendicular to each other by a simple method.

That is, the composite magnetic head according to the first aspect of the present invention has the following features.
A magnetic head for recording is provided, a magnetic head for reproduction is provided with a magnetoresistive film in a magnetic gap of the magnetic head for recording, and a magnetic domain control layer for controlling magnetic domains of the magnetoresistive film, It is characterized by being provided with a first antiferromagnetic layer.

According to the above configuration, since the first antiferromagnetic layer of the magnetic domain control layer and a part of the magnetoresistive film are exchange-coupled, a recording head from the recording magnetic head at the time of recording is used. Even when the magnetic field changes the magnetization state of the magnetoresistive film in the portion exchange-coupled to the first antiferromagnetic layer, the application of the recording magnetic field from the recording magnetic head stops the first antiferromagnetic layer. The magnetization of the magnetoresistive film in a portion exchange-coupled with the ferromagnetic layer is returned to the original magnetization state by the first antiferromagnetic layer.

For this reason, in the above configuration, the control of the magnetic domain in the magnetoresistive film (referred to as a single magnetic domain) by the magnetic domain control layer having the first antiferromagnetic layer can be stabilized. Generation of Barkhausen noise due to destabilization of the control can be avoided.

Therefore, in the above configuration, by providing the first antiferromagnetic layer, the direction of the magnetic domain in the magnetoresistive film according to the change of the external magnetic field, that is, the recording magnetic field from the recording medium can be prevented. Since it is possible to stabilize and further stabilize the reproduction by the reproducing magnetic head having the magnetoresistive effect film, good reproduction characteristics can be exhibited.

In the above configuration, the magnetic domain control layer is
By using the first antiferromagnetic layer, it is not necessary to use a hard magnetic material, so that it is possible to avoid the adverse effect of the hard magnetic material on recorded information on a recording medium.

In the above configuration, the magnetic domain control layer is
Further, it is preferable to have a ferromagnetic layer laminated on the first antiferromagnetic layer. In the above configuration, even if the magnetization state of the ferromagnetic layer stacked on the first antiferromagnetic layer changes due to the recording magnetic field from the recording magnetic head during recording, the recording magnetic head does When the application of the recording magnetic field is stopped, the magnetization of the ferromagnetic layer returns to the original magnetization state by exchange coupling with the first antiferromagnetic layer. Therefore, in the above configuration, the magnetic domains of the magnetoresistive film can be controlled more stably by utilizing the exchange coupling magnetic field of the first antiferromagnetic layer and the ferromagnetic layer.

Further, the magnetoresistive film has a first magnetic layer, a conductive non-magnetic layer, in which the direction of a magnetic domain changes in response to a change in the magnetic field direction of an external magnetic field, and a change in the magnetic field direction of an external magnetic field. It is desirable to have a second magnetic layer in which the direction of the magnetic domain is constant, and a second antiferromagnetic layer for maintaining the direction of the magnetic domain in the second magnetic layer constant.

In the above configuration, the magnetoresistance effect film can exhibit a giant magnetoresistance effect by having the first magnetic layer, the nonmagnetic layer, the second magnetic layer, and the second antiferromagnetic layer. Therefore, the change in the magnetic resistance due to the change in the magnetic field can be set to be larger. Thereby, in the above configuration, even for magnetically recorded information recorded at a higher density,
Since good reproduction characteristics can be provided, it is possible to cope with higher density recording.

Further, it is preferable that the second antiferromagnetic layer and the first antiferromagnetic layer have different blocking temperatures. According to the above configuration, since the blocking temperatures of the first and second antiferromagnetic layers are set to be different from each other, the fixed magnetic layer (pin layer) and the antiferromagnetic layer, which are the second magnetic layers, are set. The direction of the exchange coupling magnetic field with the pinning layer made of and the direction of the exchange coupling magnetic field of the magnetic domain control layer can be set to be substantially perpendicular to each other. Thus, with the above configuration, the reproduction sensitivity of the magnetoresistive film can be increased, and it is possible to cope with even higher density recording.

In addition, at least one of the first and second antiferromagnetic layers desirably changes to antiferromagnetic by heat treatment in a magnetic field. According to the above configuration, the ordering temperature, which is the temperature at which transition to antiferromagnetism, is lower than the blocking temperature of the antiferromagnetic layer which has transitioned to antiferromagnetism. With this configuration, in the above-described configuration, the same effect as the heat treatment at the higher blocking temperature or higher can be obtained by the heat treatment at the ordering temperature lower than the blocking temperature, and thus the damage to the magnetoresistive effect film due to the heat treatment can be reduced.

Each of the first and second antiferromagnetic layers is
An alloy containing Mn and Pt as main components or an alloy containing Mn and Ru as main components is preferable. The Pt composition ratio in the alloy containing Mn and Pt as main components is 4 to 19%.
At% or 32 to 50 at% is desirable. The Ru composition ratio in the alloy containing Mn and Ru as main components is preferably from 4 to 36 at%.

According to the above configuration, the MnPt alloy and the MnRu alloy used for the first and second antiferromagnetic layers can generate a high exchange coupling magnetic field.
Further, since these alloys have better corrosion resistance than FeMn alloys and the like, it is possible to increase the reliability of the exchange coupling film.

Further, in the above configuration, P in the MnPt alloy
t composition ratio is 4 to 19 at% or 32 to 50 at
%, Similarly, the Ru composition ratio in the MnRu alloy is 4 to 36%.
By setting at%, a high exchange coupling magnetic field can be obtained, and the reproducing operation of the magnetoresistive film can be stabilized. Note that this at% is atomic%.

The method of manufacturing a composite magnetic head according to the present invention comprises:
In order to solve the above-mentioned problems, a method for manufacturing a composite magnetic head according to the above, which comprises changing the direction of an applied magnetic field with respect to the antiferromagnetic layer while controlling the blocking temperature of the antiferromagnetic layer. And a step of performing a heat treatment based on the heat treatment.

In the above manufacturing method, a magnetic field is applied in the first direction to each of the first and second antiferromagnetic layers having the respective blocking temperatures Tb ₁ and Tb ₂ satisfying the relationship of Tb ₁ > Tb _2. a step of holding a predetermined time Tb ₁ or more temperature with less than Tb ₁ while applying the magnetic field, and a step of cooling to Tb ₂ or more temperatures less than Tb _1, and the magnetic field in Tb ₂ or more temperature Changing the direction to a second direction substantially perpendicular to the direction of the first magnetic field and holding the same for a predetermined time; and applying Tb while applying a magnetic field in the second direction.
A step of cooling to a temperature of less than ₂ may be included.

Further, in the above manufacturing method, Td> Tb ₂
The relationship (ordering temperature: Td) at which one of the antiferromagnetic layers that changes to antiferromagnetic by heat treatment in a magnetic field changes to antiferromagnetic, and the blocking temperature of the other antiferromagnetic layer, Tb ₂ while applying a magnetic field in the first direction to each of the first and second antiferromagnetic layers including Tb _2.
Holding at a temperature equal to or higher than a predetermined time, and changing the direction of the magnetic field at a temperature equal to or higher than Tb ₂ to a _second direction substantially perpendicular to the direction of the first magnetic field. The method may include a step of holding for a time and a step of cooling to a temperature lower than Tb ₂ while applying the magnetic field in the second direction.

In addition, in the above manufacturing method, Tb ₄ > Tb
₂ > Td, the temperature at which one of the antiferromagnetic material layers that changes to antiferromagnetic by heat treatment in a magnetic field changes to antiferromagnetic (ordering temperature: Td), a blocking temperature Tb ₄ antiferromagnetic layer, relative to the first and second of each antiferromagnetic layer and a blocking temperature Tb ₂ of the other antiferromagnetic layer, a magnetic field in a first direction a step of holding the applied predetermined time Td of temperature or higher while, Tb less than _4, and a step of setting the Tb ₂ or more temperatures, Tb less than _4, and the direction of the magnetic field at Tb ₂ or more temperatures above first The method may include a step of changing the temperature in a _second direction substantially perpendicular to the direction of the magnetic field and holding the same for a predetermined time, and a step of cooling to a temperature lower than Tb ₂ while applying the magnetic field in the second direction.

According to the above method, the direction of the exchange coupling magnetic field between the fixed magnetic layer (pinned layer) as the second magnetic layer and the pinned layer as the second antiferromagnetic layer, and the direction of the magnetic domain control layer. Setting the direction of the exchange coupling magnetic field so as to be substantially perpendicular to each other can be simplified by the above-described heat treatment in consideration of the respective blocking temperatures of the first and second antiferromagnetic layers.

Thus, in the above method, the reproduction sensitivity can be enhanced by the above setting, so that the composite magnetic head having a magnetoresistive film capable of coping with higher density recording and having good reproduction characteristics can be realized. Can be manufactured stably and simply.

[0052]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] A first embodiment of the present invention will be described below. First, FIG.
FIG. 1 is a structural diagram (schematic configuration diagram) showing a composite magnetic head according to the present embodiment. The composite magnetic head, as the head substrate, Al ₂ to Al ₂ O ₃ is formed on the surface O
_On a substrate 1 made of a _3- TiC sintered body, a lower magnetic layer 2 made of, for example, FeAlSi having a thickness of 3 μm is formed as one magnetic core of a recording head 10 and one shield layer of a reproducing head. On the lower magnetic layer 2, a lower gap layer 3 of Al ₂ O ₃ having a thickness of 1000 ° is formed.

Further, on the lower gap layer 3, a magnetic anisotropy (AMR: Anistropic Mag
The magnetoresistive film 12 having netResistive has a thickness of 3
It is provided in a stripe shape (band shape) with a layer made of NiFe of 00 °. The magnetoresistive film 12 has a longitudinal direction substantially perpendicular to the scanning direction of the recording medium, that is, a track width direction, a thickness direction of the magnetoresistive film 12 substantially parallel to the scanning direction, and Magnetoresistance effect film 12
Is the scanning surface of the composite magnetic head
The direction is set to be substantially perpendicular to the surface 13.

A pair of magnetic domain control layers 5 are formed on both ends of the magnetoresistive film 12 in the longitudinal direction in contact with the magnetoresistive film 12, respectively. The magnetic domain control layer 5 controls the generation of magnetic domains in the magnetoresistive effect film 12 (that is, controls the magnetic domain into a single magnetic domain).
First antiferromagnetic layer 5 made of Pt or MnRu
1 or a laminated structure of the first antiferromagnetic layer 51 and a ferromagnetic layer 52 of NiFe or the like having a thickness of 70 °.

On each of these magnetic domain control layers 5, a film thickness of 500
Are formed, respectively. The reproducing head 14 (reproducing magnetic head) of the composite magnetic head has the magnetoresistive film 12, each magnetic domain control layer 5, and each electrode layer 6.

Further, an Al film having a thickness of 1000 Å is formed so as to cover the magnetoresistive effect film 12, the magnetic domain control layer 5 and the electrode layer 6.
_An upper gap layer 7 made of ₂ O ₃ is formed. In the composite type magnetic head of the present invention, before the later-described upper magnetic layer 8 is formed, the magnetic domain control layer 5 is moved in the track width direction (substantially perpendicular to the scanning direction of the recording medium and recorded on the recording medium). (A direction substantially parallel to the ABS 13 which is the scanning surface of the surface)
Preferably, a magnetic field is applied to the substrate and heat treatment is performed at 200 ° C. or higher for a predetermined time.

Further, on the upper gap layer 7, an upper magnetic layer 8 made of, for example, a 3 μm-thick NiFe layer is formed. The upper magnetic layer 8 is in contact with and magnetically coupled to the lower magnetic layer 2 at the rear end (the side opposite to the ABS 13) of the composite magnetic head.

Although not shown, between the lower magnetic layer 2 and the upper magnetic layer 8, a conductor winding layer (not shown) covered with an insulating layer composed of the lower gap layer 3 and the upper gap layer 7 is provided. The lower magnetic layer 2 and the upper magnetic layer 8 are formed so as to cross each other. The lower magnetic layer 2,
The lower gap layer 3, the upper gap layer 7, the upper magnetic layer 8, and the conductor winding layer form a recording head 10 of a composite magnetic head as a recording magnetic head. Further, a protective layer (not shown) made of Al ₂ O ₃ having a thickness of 30 μm is formed on the upper magnetic layer 8.

In the above-described heat treatment for the magnetic domain control layer 5, the direction of the exchange coupling magnetic field of the diamagnetic material used for the magnetic domain control layer 5 is set substantially parallel to the ABS 13 and, for example, in the track width direction. As described below,
In the case of Mn-32 at% to 50 at% Pt, for example, 250
4 to 8 hours at 4 ° C., Mn-4 at% to 19 at% P
If t or Mn-4 at% to 36 at% Ru, a heat treatment at a temperature corresponding to each blocking temperature for 30 minutes to 1 hour is desirable.

This heat treatment is carried out at Mn-32 at% to 50 a.
In t% Pt, which is necessary for the expression of exchange coupling, Mn-
4 at% to 19 at% Pt and Mn-4 at%
36 at% Ru has an effect of aligning the direction of the exchange coupling magnetic field dispersed in one step after the temperature of the composite magnetic head increases in the step after the formation of the magnetic domain control layer 5. In other words, each of the above alloys
The direction of the exchange coupling magnetic field can be controlled by heating in a state where the magnetic field is applied.

The heat treatment may be performed at any stage as long as it is a step subsequent to the step of forming the magnetic domain control layer 5, but preferably, the upper magnetic layer 8 is formed after the formation of the upper gap layer 7. It is appropriate to carry out the process up to the end of the process.

FIG. 2 shows an example of an MH curve of a ferromagnetic material when an antiferromagnetic material and a ferromagnetic material are stacked. As can be seen from the figure, at the interface between the ferromagnetic material and the antiferromagnetic material,
Due to the exchange coupling of the respective magnetic moments, the MH curve of the ferromagnetic material is largely biased in one direction. When the external magnetic field is removed, the MH curve is located at the position indicated by “a” in the curve. have. The bias amount Hex at this time is called an exchange coupling magnetic field, and when an antiferromagnetic material is used for the magnetic domain control layer 5, the direction of the exchange coupling magnetic field is set in the track width direction.

As described above, during recording, the recording magnetic field obliquely crosses the magnetic domain control layer 5, and ± Hw is applied to the in-plane component of the recording magnetic field in FIG. In the MH curve described above, even if the magnetization state has changed to any position on the MH curve due to the recording magnetic field, it always returns to the position “a” when the recording magnetic field is removed, and has the magnetization of Me.

Therefore, unlike the conventional case using a hard magnetic material, the magnitude of the magnetic field in the magnetic domain control layer is prevented from being reduced by the recording magnetic field.
The direction of the remanent magnetization of each of the magnetic domain control layers 5 at both ends of the 2 is also prevented from being reversed. Thus, the magnetic domain control layer 5 according to the present embodiment can stably control the magnetic domains in the magnetoresistive film 12 even when the recording magnetic field is applied.

FIG. 3 shows that the MnPt / MnPt /
The reproducing head after the recording operation of the composite magnetic head (a) according to the present invention manufactured using the NiFe laminated film and the composite magnetic head (b) of the comparative example using CoPt which is a hard magnetic material. 4 shows resistance change characteristics with respect to a magnetic field. In the figure, the horizontal axis represents the magnetic field (H) applied in the depth direction from the ABS of the read head, and the vertical axis represents the resistance (R) of the read head.

As can be seen from FIG. 3B, in the composite type thin film magnetic head (b) using CoPt, the Barkhausen jump 84 occurs due to the movement of the magnetic domain in the magnetoresistive element, and the resistance change characteristic is discontinuous. It has become. When a reproducing operation is performed using the composite type thin film magnetic head (b) having such characteristics, Barkhausen noise is generated in the reproduced output due to discontinuity of the resistance change characteristic due to the Barkhausen jump 84, and the S / N ratio is increased. Greatly deteriorates.

In comparison with the comparative example, as shown in FIG.
In the composite magnetic head (a) using the MnPt / NiFe laminated film, the resistance change characteristics with respect to the magnetic field are continuous, there is no Barkhausen jump, and it is understood that the generation of magnetic domains is suppressed in the magnetoresistive element.

[Second Embodiment] FIG. 4 is an explanatory diagram of an example of a composite magnetic head according to a second embodiment of the present invention. In this composite magnetic head, as shown in FIG. 4, a spin valve film 4 having a giant magnetoresistance effect is provided instead of the magnetoresistance effect film 12 in the first embodiment.

In this composite magnetic head, the magnetic domain control layer 5
At least at the free layer 42 of the spin valve film 4 at both ends of the spin valve film 4 (see FIGS. 5 to 8)
Is formed in contact with. Further, it is desirable that the gap between the respective electrode layers 6 is disposed at a position corresponding to the same position as the gap between the respective magnetic domain control layers 5 or inside the gap between the magnetic domain control layers 5. The same position as above
This is the position translated in the track scanning direction.

The structures of the spin valve film 4, the magnetic domain control layer 5, and the electrode layer 6 can have the structures shown in FIGS. 5 to 8, respectively. That is, referring to FIG. 5, first, the spin valve film 4 is provided on the lower gap layer 3 with the underlayer 41, the free magnetic layer (free layer) 42, the nonmagnetic conductor layer 43, and the fixed magnetic layer (pin). Layer 44, a second antiferromagnetic layer (pinning layer) 45, and a cap layer 46,
Films are sequentially formed.

The underlayer 41 is made of Ta having a thickness of 50 °. The free magnetic layer 42 is made of a 70 ° -thick NiFe
It is a magnetic film made of a laminated film with Co having a thickness of Å. The nonmagnetic conductor layer 43 is a single-layer film of Cu having a thickness of 32 °. The fixed magnetization layer 44 includes Co having a thickness of 10 ° and 30 °.
This is a magnetic film made of a laminated film with NiFe having a thickness of. The second antiferromagnetic layer 45 is made of Mn-10 having a thickness of 200 °.
It is a single-layer film made of at% Pt. The cap layer 46
It is a single-layer film made of Ta having a thickness of 100 °.

In such a spin valve film 4, the ion incidence angle is controlled by using the ion milling method, and at least the free magnetic layer is formed at both ends (cross section parallel to the track width direction) of the spin valve film 4. The region where the 42 is exposed is processed so as to have a substantially trapezoidal shape having a tapered portion (the length along the track scanning direction decreases sequentially from the base layer 41 to the cap layer 46).
The track scanning direction is a direction parallel to the ABS 13 and perpendicular to the track width direction.

Magnetic domain control layers 5 are formed at both ends of the spin valve film 4 thus processed. The magnetic domain control layer 5 is formed by laminating a ferromagnetic layer 52 of NiFe with a thickness of 70 ° and a first antiferromagnetic layer 51 of Mn-47 at% Pt with a thickness of 200 °. is there. The magnetic domain control layer 5 is set so that the first antiferromagnetic layer 51 is in contact with the tapered cross section where the free magnetic layer 42 is exposed.

The electrode layers 6 are formed on the respective magnetic domain control layers 5. The magnetic domain control layers 5 and the electrode layers 6 are formed such that the surface of each electrode layer 6 is flush with the surface of the cap layer 46. As a result, the thickness of each magnetic domain control layer 5 and each electrode layer 6 are sequentially increased toward the center of the spin valve film 4 on the tapered surface of the magnetic domain control layer 5 (both ends in the track width direction of the magnetic domain control layer 5). Has a tapered shape that reduces The center of the spin valve film 4 indicates the center position in the track width direction in the spin valve film 4.

Next, another configuration of the spin valve film 4, the magnetic domain control layer 5, and the electrode layer 6 shown in FIG. 6 will be described. In this configuration, first, each magnetic domain control layer 5 is formed on the lower gap layer 3. The magnetic domain control layer 5 includes a base layer 50, 2 made of Ta having a thickness of 50 °.
It is formed by laminating a first antiferromagnetic layer 51 of Mn-47 at% Pt with a thickness of 00 ° and a ferromagnetic layer 52 of NiFe with a thickness of 100 °.

In each of the magnetic domain control layers 5, their facing surfaces are:
It has a tapered shape in which the distance increases gradually from the lower gap layer 3 side to the surface side of each magnetic domain control layer 5. Such a tapered shape is formed with a gap portion Wd on the lower gap layer 3 side by a lift-off method or an ion milling method using a multilayer resist having an undercut.

A spin valve film 4 is formed on each of the magnetic domain control layers 5 and the lower gap layer 3 as described above. As described above, the spin valve film 4 includes the free magnetic layer 4
2, a nonmagnetic conductor layer 43, a fixed magnetization layer 44, a second antiferromagnetic layer 45, and a cap layer 46 are formed. Such a spin valve film 4 is formed by an ion milling method.
The spin valve film 4 spans the gap Wd of each magnetic domain control layer 5.
Are processed so as to overlap the magnetic domain control layer 5 at both ends.

Each electrode layer 6 is provided on the spin valve film 4 corresponding to each magnetic domain control layer 5 with the same composition and film thickness as described above.
The gap W1 (W1 ≦ Wd) is processed so as to be arranged between the gaps of the magnetic domain control layer 5.

Next, still another configuration of the spin valve film 4, the magnetic domain control layer 5, and the electrode layer 6 shown in FIG. 7 will be described. In this configuration, the spin valve film 4 is formed on the lower gap layer 3 with the same composition and film thickness as those described above, the underlayer 41, the second antiferromagnetic layer 45, the fixed magnetization layer 44, and the nonmagnetic conductive layer. Body layer 43 and free magnetic layer 42
Are stacked in this order. The spin valve film 4 is processed into a predetermined stripe shape by etching such as ion milling.

On both ends of such a spin valve film 4, magnetic domain control layers 5 are respectively formed. The magnetic domain control layer 5 is formed by laminating a ferromagnetic layer 52 of NiFe with a thickness of 70 ° and a first antiferromagnetic layer 51 of Mn-47 at% Pt with a thickness of 200 °. is there. Each magnetic domain control layer 5 is formed by etching or lift-off on both ends of the spin valve film 4, that is, on both ends of the free magnetic layer 42 so as to overlap and have a gap of Wd.

In each of the magnetic domain control layers 5 as described above, it is desirable that the formation site of the magnetic domain control layer 5 be etched for a short time with Ar plasma in the same vacuum immediately before the ferromagnetic layer 52 is formed.

Each electrode layer 6 is formed on the free magnetic layer 42 and each magnetic domain control layer 5 with the above-described composition and film thickness by an ion milling method by a gap W1 (W1 ≦ W1).
Wd).

Next, still another configuration of the spin valve film 4, the magnetic domain control layer 5, and the electrode layer 6 shown in FIG. 8 will be described. In this configuration, on the lower gap layer 3,
A magnetic domain control layer 5 is formed. This magnetic domain control layer 5
Underlayer 41 made of Ta with a thickness of 50 °, first antiferromagnetic layer 5 made of Mn-16 at% Pt with a thickness of 200 °
1, and a ferromagnetic layer 5 made of NiFe having a thickness of 20 °
2 are laminated in this order.

On the ferromagnetic layer 52, the free magnetic layer 42 and the nonmagnetic conductive layer 4 are formed with the same composition and thickness as described above.
3. The pinned magnetic layer 44, the second antiferromagnetic layer 45, and the cap layer 46 are formed in this order to form the spin valve film 4. In the spin valve film 4, the second antiferromagnetic layer 45 is made of a 200-nm thick Mn-47 at% P
The other layers have the same composition and film thickness as those described above.

The magnetic domain control layer 5 and the spin valve film 4 are processed into a predetermined stripe shape by an ion milling method. At both ends of the spin valve film 4 in the track width direction, the same electrode layers 6 as described above are formed with a gap portion W1 between them. As a method for processing each of the electrode layers 6, an ion milling method or a lift-off method is preferably used.

In each of the spin valve films 4 described above, simply forming or forming the spin valve film 4 causes the second antiferromagnetic layer 45 and the first antiferromagnetic layer 51 to correspond to the corresponding ferromagnetic layers. The directions of the exchange couplings are not substantially perpendicular to each other. The temperature rise during the manufacturing process of the composite magnetic head may cause inconveniences such as the directions of the exchange coupling magnetic fields being dispersed and the respective exchange coupling magnetic fields being aligned in the same direction. Furthermore, when an antiferromagnetic material that changes to antiferromagnetic by heat treatment after film formation is used, no exchange coupling magnetic field is generated without heat treatment.

Then, the above-mentioned two second antiferromagnetic layers 45 and the second antiferromagnetic layer 45 are heat-treated.
And the first antiferromagnetic layer 51 and the ferromagnetic layer 5
A method of setting the directions of the exchange coupling magnetic fields between the two in such a manner as to be substantially perpendicular to each other while maintaining their in-plane directions will be described.

FIGS. 9 to 12 are schematic explanatory diagrams for explaining the principle of the behavior of the exchange coupling between the ferromagnetic layer and the antiferromagnetic layer according to the present embodiment with respect to the heat treatment during application of the magnetic field.

First, referring to FIG. 9, a so-called exchange coupling film in which an antiferromagnetic layer 122 and an antiferromagnetic layer 132 are laminated on a ferromagnetic layer 121 and a ferromagnetic layer 131, respectively. However, the blocking temperatures of the antiferromagnetic layer 122 and the antiferromagnetic layer 132 are set to Tb ₁ and Tb ₁ , respectively.
Assuming that ₂ , the blocking temperature of the antiferromagnetic layer 122 is set higher (the relationship of Tb ₁ > Tb ₂ is established).

Here, the blocking temperature is a temperature at which the exchange coupling magnetic field in the exchange coupling film composed of the ferromagnetic layer and the antiferromagnetic layer disappears. The level of the blocking temperature corresponds to the level of the Neel temperature in the antiferromagnetic layer. Hereinafter, the above two exchange coupling membranes (,)
Are simultaneously heat-treated, and the behavior of exchange coupling when the direction of the applied magnetic field is changed during this heat treatment will be described.

1) While applying a magnetic field, each exchange coupling film
To increase the temperature T of each exchange-coupled membrane,
When the temperature T reaches Tb ₁ or more temperature fluctuation generated inside the spin of both the antiferromagnetic layers 122, 132,
The spin will be in a random direction.

At this time, since a uniform magnetic field is applied in the right-to-left direction (the direction along the track width direction) on the paper, the spin in each of the ferromagnetic layers 121 and 131 is heated by heat. No fluctuation occurs (see FIG. 9A).

2) Thereafter, for each exchange coupling membrane,
When the cooling is performed and the temperature T decreases to a temperature lower than Tb ₁ and higher than Tb ₂ , the spin of the antiferromagnetic layer 122 is ferromagnetically coupled at the interface with the ferromagnetic layer 121, and Align in the same direction as the body layer 121. The spins in the antiferromagnetic layer 122 are aligned in a direction in which the spins at the interface are mutually inverted. On the other hand, the spin of the antiferromagnetic layer 132 is in a random direction (see FIG. 9B).

[0094] 3) At this time, the temperature T is less than Tb _1, Tb
_When the direction of the applied magnetic field is rotated by 90 ° at a temperature of ₂ or more (in a direction perpendicular to the paper surface, that is, in a direction perpendicular to the track), the spin of the antiferromagnetic layer 122 is shifted in the direction aligned in 2). While maintaining the fixed state, only the spin of the ferromagnetic layer 121 rotates according to the change in the direction of the magnetic field.

On the other hand, the spin of the antiferromagnetic layer 132 is oriented in a random direction by heat, and only the corresponding spin of the ferromagnetic layer 131 rotates in response to a change in the applied magnetic field [FIG. c)).

The above-mentioned track perpendicular direction is a direction parallel to the film surface of the magnetoresistive film 12 and perpendicular to the track width direction, in other words, in the scanning direction of the recording medium and the track width direction in the composite magnetic head. The direction is perpendicular to each.

4) In this state, further cooling is performed, and when the temperature T becomes lower than Tb ₂ , the spin of the antiferromagnetic layer 132 is shifted in the direction of the spin of the ferromagnetic layer 131 as in 2). They are aligned correspondingly (see FIG. 9D).

5) Thereafter, the temperature T is cooled to room temperature, and the application of the applied magnetic field is stopped.
1. The ferromagnetic layer 131 is a laminated antiferromagnetic layer 12
2. Exchange coupling with the antiferromagnetic layer 132 to generate each exchange coupling magnetic field in a direction perpendicular to each other [FIG.
(E)).

As described above, the exchange coupling films having different blocking temperatures are used, and the direction of the applied magnetic field is changed at an intermediate temperature between the respective blocking temperatures during cooling during the heat treatment, whereby the exchange coupling is performed in a desired direction. A plurality of exchange coupling films having a magnetic field angle can be obtained.

Next, referring to FIG. 10, an anti-ferromagnetic material layer which changes to anti-ferromagnetic by heat treatment in a magnetic field after film formation is formed on one of the exchange coupling films (,). 142, the behavior of exchange coupling in each exchange coupling film (,) when the direction of the magnetic field is changed during the heat treatment will be described.

Here, the temperature at which the antiferromagnetic layer 142 transitions to antiferromagnetism is Td (ordering temperature), the blocking temperature after ordering is Tb ₃ , and the other antiferromagnetic layer of the exchange coupling film. Assuming a blocking temperature Tb _{2 of} 132, Tb
₃ > Td ≧ Tb ₂ so that each antiferromagnetic layer 132
142 is set.

1) After film formation, at room temperature, the antiferromagnetic layer 132 of the exchange-coupling film is exchange-coupled with the adjacent ferromagnetic layer 131, and the spin directions inside the antiferromagnetic layer 132 are respectively Are arranged antiparallel. On the other hand, in the antiferromagnetic layer 142, the spin of the antiferromagnetic layer 142 is oriented in a random (random) direction because it has not transitioned to antiferromagnetism (see FIG. 10A).

2) With respect to each of the exchange coupling films, the temperature T is increased so that Tb ₃ > T ≧ Td, and the same uniform magnetic field (in the horizontal direction on the paper plane, ie, in the track width direction) as described above. ), The antiferromagnetic layer 142
Are transferred to diamagnetism, and the spins are aligned antiparallel with each other in accordance with the magnetization direction of the adjacent ferromagnetic layer 141. On the other hand, in the antiferromagnetic layer 132, the temperature T is T
Since ≧ Tb ₂ , the spin direction is disordered (see FIG. 10B).

3) Thereafter, when the direction of the magnetic field applied at a temperature T between Tb ₃ and Tb ₂ is rotated by 90 ° (in the direction perpendicular to the paper surface, that is, in the direction perpendicular to the track), The spins of the ferromagnetic layer 142 remain fixed in the aligned direction in 2), and only the spins of the ferromagnetic layer 141 rotate according to the change in the direction of the magnetic field. On the other hand, the spin of the antiferromagnetic layer 132 is in a random direction due to heat, and
Only 31 spins rotate in response to the change in the applied magnetic field (see FIG. 10C).

4) Next, in a state where a magnetic field is applied in this direction, cooling is performed until the temperature T becomes lower than Tb ₂ .
The spins of the antiferromagnetic layer 132 are arranged antiparallel to the directions of the spins of the ferromagnetic layer 131 (perpendicular to the paper). Thereafter, when the application of the magnetic field is stopped, the spins of the ferromagnetic layers 131 and 141 are exchange-coupled with the antiferromagnetic layers 132 and 142, respectively, and the ferromagnetic layers 131 and 141 are respectively connected.
41 are fixed so that the magnetization directions are perpendicular to each other (see FIG. 10D).

As described above, by using the antiferromagnetic layer 142 which changes to antiferromagnetic by heat treatment in a magnetic field after film formation, the ordering temperature lower than the blocking temperature of the antiferromagnetic layer 142 is obtained. In the heat treatment, the same effect as that of the heat treatment at or above the above-mentioned blocking temperature, which is higher, can be obtained, so that damage to the spin valve film 4 as the magnetoresistive film by the heat treatment can be reduced.

Next, referring to FIG. 11, an anti-ferromagnetic material layer which changes to anti-ferromagnetic by heat treatment in a magnetic field after film formation is formed on one of the exchange coupling films (,). 152, the behavior of exchange coupling in each exchange coupling film (,) when the direction of the magnetic field is changed during the heat treatment will be described.

Here, the temperature at which the antiferromagnetic layer 152 transitions to antiferromagnetism is Td (ordering temperature), the blocking temperature after ordering is Tb ₄ , and the other antiferromagnetic layer of the exchange coupling film. Assuming a blocking temperature Tb _{2 of} 132, Tb
₄ > Tb ₂ > Td, each antiferromagnetic layer 132,
152 is set.

1) After film formation, at room temperature, the antiferromagnetic layer 132 of the exchange-coupling film is exchange-coupled with the adjacent ferromagnetic layer 131, and the spin directions inside the antiferromagnetic layer 132 are respectively Are arranged antiparallel. On the other hand, in the antiferromagnetic layer 152, the spin of the antiferromagnetic layer 152 is oriented in a random (random) direction because it has not transitioned to antiferromagnetism (see FIG. 11A).

2) For each of the exchange-coupling films, the temperature T is increased to a temperature equal to or higher than the ordering temperature Td of the antiferromagnetic layer 152 and lower than Tb ₂ , and a uniform temperature is obtained in the same manner as described above. If it is held for a predetermined time in a magnetic field, the antiferromagnetic layer 152
Are transferred to antiferromagnetism, and the spin directions are arranged antiparallel in accordance with the magnetization directions of the adjacent ferromagnetic layers 151. On the other hand, in the antiferromagnetic layer 132, Tb ₂ > T ≧ Td
Therefore, the spin directions are aligned antiparallel to each other (see FIG. 11B).

3) Next, when the temperature T is set to Tb ₄ > T ≧ Tb ₂ , the spin of the antiferromagnetic layer 132 becomes disordered by heat. At this time, when the direction of the magnetic field is rotated by 90 ° (in the direction perpendicular to the paper surface, that is, in the direction perpendicular to the track), the spins of the antiferromagnetic layer 152 remain fixed in the aligned direction in 2). At the same time, only the spin of the ferromagnetic layer 151 rotates according to the change in the direction of the magnetic field. On the other hand, the spin of the antiferromagnetic layer 132 is in a random direction due to heat, and only the corresponding spin of the ferromagnetic layer 131 rotates in response to the change in the applied magnetic field [see FIG. ].

4) Next, in a state where a magnetic field is applied in this direction, cooling is performed until the temperature T becomes lower than Tb ₂ .
The spins of the antiferromagnetic layer 132 are arranged antiparallel to the directions of the spins of the ferromagnetic layer 131 (perpendicular to the paper). Thereafter, when the application of the magnetic field to the exchange coupling films is stopped, the spins of the ferromagnetic layers 131 and 151 are exchange-coupled to the antiferromagnetic layers 132 and 152, respectively, and , 151 are fixed so that the magnetization directions are perpendicular to each other (see FIG. 11D). The temperature of 2) and the temperature of 3) are Tb ₄ > T ≧
It is in the range of Tb _2, may be set to the same.

As described above, by using the antiferromagnetic layer 152 which changes to antiferromagnetic by heat treatment in a magnetic field after film formation, the ordering temperature lower than the blocking temperature of the antiferromagnetic layer 152 is obtained. In the heat treatment, the same effect as that of the heat treatment at or above the above-mentioned blocking temperature, which is higher, can be obtained, so that damage to the spin valve film 4 as the magnetoresistive film by the heat treatment can be reduced.

Next, with reference to FIG. 12, the behavior of exchange coupling by other heat treatment in each of the above exchange coupling films (,) will be described. 1) After film formation, at room temperature, the antiferromagnetic layer 132 of the exchange-coupling film is exchange-coupled with the adjacent ferromagnetic layer 131 by an applied magnetic field in the horizontal direction (track width direction) on the paper surface. In the ferromagnetic layer 132, the spin directions are arranged in the anti-parallel direction along the left-right direction. On the other hand, since the antiferromagnetic layer 152 has not transitioned to antiferromagnetism, the spin of the antiferromagnetic layer 152 is oriented in a disordered direction (see FIG. 12A).

2) Each of the exchange-coupling films is heated to a temperature T which is equal to or higher than the regularization temperature Td of the antiferromagnetic layer 152 and lower than the blocking temperature Tb ₂ of the antiferromagnetic layer 132, and is perpendicular to the paper. When a uniform magnetic field is applied in a desired direction (vertical direction of the track) and is maintained for a predetermined time, the antiferromagnetic layer 15
2 are changed to antiferromagnetic, and the spins are arranged in antiparallel with each other in accordance with the magnetization direction of the adjacent ferromagnetic layer 151. At this time, since the magnetic field is applied in a direction perpendicular to the paper, the spins are arranged in a direction perpendicular to the paper.

On the other hand, the magnetic field of the ferromagnetic layer 131 changes along the direction of the applied magnetic field.
Since the temperature T satisfies Tb ₂ > T, the antiferromagnetic layer 1
The directions of the spins 32 are aligned antiparallel along the track width direction (see FIG. 12B).

3) Thereafter, when the temperature T is cooled to room temperature and the application of the magnetic field is stopped, the spin directions of the antiferromagnetic layer 132 are arranged in the horizontal direction (track width direction) on the paper. In the ferromagnetic layer 131, the magnetization is arranged leftward (in the track width direction) by exchange coupling with the antiferromagnetic layer 132.

On the other hand, in the antiferromagnetic layer 152, the spins are arranged in the direction perpendicular to the paper (the track perpendicular direction) by the heat treatment, and the spin direction of the ferromagnetic layer 151 is different from that of the antiferromagnetic layer 152. They are arranged in a direction perpendicular to the paper surface (track vertical direction) by exchange coupling (see FIG. 12C).

Even in such a heat treatment, the exchange coupling directions of the antiferromagnetic layer 132 and the antiferromagnetic layer 152 in each of the exchange coupling films (,) can be set to be substantially perpendicular to each other. it can.

As described above, by using the antiferromagnetic layers 122, 132, 142, and 152 having different blocking temperatures, the direction of the applied magnetic field is changed in a desired direction by changing the direction of the applied magnetic field during the heat treatment. It becomes possible to produce a plurality of exchange coupling films having angles.

Next, a method of controlling the blocking temperature of each of the antiferromagnetic layers 122 will be described. First, FIG.
In an exchange-coupling film that is a laminated film including a ferromagnetic layer made of a NiFe film and an antiferromagnetic material layer made of a MnPt film, a change in Pt composition in the antiferromagnetic material layer made of a MnPt film It is a graph which shows the change of blocking temperature. Here, the blocking temperature is a temperature at which the exchange coupling magnetic field between the ferromagnetic layer and the antiferromagnetic layer disappears.

In FIG. 13, the Pt composition ratio is about 20 at.
% Of the exchange-coupling film using the MnPt film having a Pt composition ratio of about 30 at% to about 50 at%.
% Of MnPt film at 240 ° C.
Heat treatment is performed in a magnetic field for a long time.

From this graph, it can be seen that the blocking temperature of the exchange-coupling film depends on the Pt composition. It can be seen that the value decreases as the value increases. On the other hand, in an exchange-coupling film using a MnPt film having a Pt composition ratio of more than about 30%, the blocking temperature increases discontinuously, and the blocking temperature increases by about 350 regardless of the Pt composition ratio.
It turns out that it is stable at ° C.

FIG. 14 is a graph showing the change in the blocking temperature with respect to the Ru composition ratio of the MnRu film in the exchange-coupling film including the ferromagnetic layer made of the NiFe film and the antiferromagnetic layer made of the MnRu film. It is. The exchange coupling film generates an exchange coupling magnetic field even if heat treatment is omitted.

As shown in this graph, the blocking temperature of the exchange-coupling film increases as the Ru composition ratio of the MnRu film increases, and reaches a maximum value at about 17 at%. If the Ru composition ratio exceeds 17 at%, Ru
It decreases monotonically as the composition ratio increases.

As can be seen from FIGS. 13 and 14, the blocking temperature of the exchange-coupling film varies greatly depending on the material and composition of the antiferromagnetic layer. By controlling the material and composition of the one antiferromagnetic layer 51, the first antiferromagnetic layer 45 and the first antiferromagnetic layer 45 constituting the magnetic domain control layer 5 having different blocking temperatures from each other as a pinning layer. And the antiferromagnetic layer 51 can be manufactured.

FIG. 15 shows the measurement results of the Pt composition ratio dependence of the exchange coupling magnetic field (Hex) in an exchange coupling film using a NiFe film for the ferromagnetic layer and a MnPt film for the antiferromagnetic layer. It is a graph.

As described above, the exchange coupling film used in this measurement has a Pt composition ratio of less than about 30 at%
No heat treatment is applied to the film using the nPt film for the antiferromagnetic material layer, while MnPt having a Pt composition ratio of about 30% to about 50%.
Those using the film were subjected to a heat treatment in a magnetic field at 240 ° C. for 6 hours.

As shown in this graph, in the exchange coupling film using the MnPt film for the antiferromagnetic layer, the exchange coupling magnetic field (H
ex) increases with an increase in the Pt composition ratio, reaches a maximum value at about 8 at%, monotonously decreases, and disappears at about 20 at%.

When the Pt composition ratio is further increased to about 32 at%, the heat treatment causes the exchange coupling magnetic field to be generated again, and to increase to a maximum value (maximum value) at about 45 at%. When the Pt composition ratio is further increased, the exchange coupling magnetic field decreases and disappears again at about 52 at%.

As described above, when forming a magnetoresistive film using a MnPt film, the Pt composition ratio in the MnPt film should be 4 at% to 19 a in order to obtain a good exchange coupling magnetic field.
It can be seen that t% or from 32 at% to 50 at% is appropriate.

FIG. 16 is a graph showing the measurement results of the dependency of the exchange coupling magnetic field on the Ru composition ratio in an exchange coupling film using a NiFe film as the ferromagnetic layer and a MnRu film as the antiferromagnetic layer. It is. As shown in this graph, in this exchange-coupling film, the exchange-coupling magnetic field increases with an increase in the Ru composition, and reaches a maximum value at about 20 at%. Further, in the exchange coupling film, as the Ru composition ratio increases, the exchange coupling magnetic field decreases and disappears at about 40 at%.

From this measurement, when a magnetoresistive film is formed by using an MnRu film as an antiferromagnetic layer, the preferable range of the Ru composition ratio in the MnRu film for obtaining a good exchange coupling magnetic field is 4 at%. It can be understood that the content is 36 at%.

As described above, in order to fabricate the second antiferromagnetic layer 45, the fixed magnetization layer 44, and the magnetic domain control layer 5 having different blocking temperatures from each other while maintaining a good exchange coupling magnetic field. , Pt is desirably controlled in the range of 4 at% to 19 at%, or 32 at% to 50 at%, or the composition of Ru is controlled in the range of 4 at% to 36 at%.

As described above, by appropriately setting the heat treatment method and the material and composition of the antiferromagnetic material, the second antiferromagnetic material layer 45 and the first antiferromagnetic material layer 51 can be formed.
Can be set substantially perpendicular to each other, that is, about 90 °.

That is, the first heat treatment was performed at 250 ° C. for 6 hours while applying a magnetic field of 300 Oe in the track width direction to the intermediate after the film forming step of the composite magnetic head, and then the C., and the direction of the magnetic field applied at 220 ° C. is changed to a track perpendicular direction (perpendicular to the paper) substantially perpendicular to the track width direction,
By performing a second heat treatment for 30 minutes and cooling to room temperature while applying a magnetic field in this direction, a 1-gap type having a high resistance change rate, a suppressed Barkhausen noise, and excellent reproduction characteristics is provided. A composite magnetic head can be manufactured stably.

[Third Embodiment] In the present embodiment, in the composite magnetic head having the structure shown in the second embodiment, the thickness of the second antiferromagnetic material layer 45 is reduced by 200.degree.
A composite magnetic head is manufactured using a magnetoresistance effect film having a structure using a 200-nm-thick Mn-18 at% Ru film with respect to the n-10 at% Pt film and the first antiferromagnetic layer 51. .

After forming the above-mentioned magnetoresistive effect film, while applying a magnetic field of 300 Oe in the track width direction,
After performing the first heat treatment at 0 ° C. for 6 hours, it is cooled to 220 ° C., and the direction of the magnetic field applied at 220 ° C. is set in the track vertical direction substantially perpendicular to the track width direction (direction perpendicular to the paper surface). Then, a second heat treatment for 30 minutes is performed, and the combined magnetic head having the same effect as that of the second embodiment is stably manufactured by cooling to room temperature while applying a magnetic field in this direction. be able to.

As described in the second and third embodiments, even when an antiferromagnetic layer requiring heat treatment after film formation is used to generate an exchange coupling magnetic field, heat treatment is unnecessary. Even when an antiferromagnetic layer is used, a composite magnetic head having similarly good characteristics can be manufactured.

In each of the above embodiments, a material having a higher blocking temperature is used for the second antiferromagnetic layer 45 than for the first antiferromagnetic layer 51. Even if the first antiferromagnetic layer 51 is a composite magnetic head having a structure in which the blocking temperature is higher, the object of the present invention is to perform a heat treatment based on the above-described mechanism for controlling the direction of the exchange coupling magnetic field. Can be manufactured.

In the first to third embodiments, the magnetic domain control layer 5 has a laminated structure of the ferromagnetic layer 52 and the first antiferromagnetic layer 51. The same effect can be obtained when only the antiferromagnetic layer 51 is used as the magnetic domain control layer 5.

In addition, the structures of the spin valve film 4 and the magnetoresistive film 12 described in the first to third embodiments are not limited to the above description.
Any structure can be applied to the composite type magnetic head according to the present invention as long as the directions of the exchange coupling magnetic fields of the first and second antiferromagnetic layers 45 can be set to be perpendicular to each other.

The materials described in the first to third embodiments are not limited to these, and any material having the same effect or function can be used in the present invention.

That is, as the substrate 1, Al ₂ O ₃ −
In addition to the TiC sintered body, glass and Si can be further used. Underlayers 41 and 50, and cap layer 46
In addition to Ta, high melting point materials such as Ti and W (tungsten) and alloys containing these can be used. For the free magnetic layer 42, the fixed magnetic layer 44, and the ferromagnetic layer 52, NiFe, CoFe, Co, or the like, or an alloy or exchange coupling film thereof can be used.

[0145]

As described above, in the composite magnetic head of the present invention, the reproducing magnetic head is provided with the magnetoresistive film in the magnetic gap of the recording magnetic head. This is a configuration in which a magnetic domain control layer for controlling magnetic domains is provided with a first antiferromagnetic layer.

Therefore, in the above configuration, when the application of the recording magnetic field from the recording magnetic head is stopped, the magnetic control layer returns to the original magnetization state by the first antiferromagnetic layer.
The control of the magnetic domain with respect to the magnetoresistive effect film by the magnetic domain control layer having the first antiferromagnetic layer can be stabilized.

In the above configuration, the magnetic domain control layer is
By using the first antiferromagnetic layer, it is not necessary to use a hard magnetic material, so that it is possible to avoid the adverse effect of the hard magnetic material on recorded information on a recording medium.

As a result, in the above configuration, by using the first antiferromagnetic layer for the magnetic domain control layer, it is possible to further stabilize the reproduction by the reproducing magnetic head. It works.

The method of manufacturing a composite magnetic head according to the present invention comprises:
As described above, in the method for manufacturing a composite magnetic head including the magnetic domain control layer having the first antiferromagnetic material layer, the method for changing the direction of the applied magnetic field with respect to the antiferromagnetic material layer is performed. This is a method including a step of performing a heat treatment based on the blocking temperature of the ferromagnetic layer.

Therefore, in the above method, the direction of the exchange coupling magnetic field between the fixed magnetic layer (pinned layer) as the second magnetic layer and the pinned layer made of the antiferromagnetic material layer in the magnetoresistive film, By setting the direction of the exchange coupling magnetic field of the magnetic domain control layer to be substantially perpendicular to each other, by changing the direction of the applied magnetic field, and by performing the heat treatment in consideration of each blocking temperature of each antiferromagnetic layer. It can be simple.

Thus, according to the above method, the reproduction sensitivity can be increased by the above setting, so that a composite magnetic head having a magnetoresistive film capable of coping with higher density recording can be stably and simply manufactured. This has the effect.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a main part of a composite magnetic head according to a first embodiment of the present invention; FIG. 1 (a) is an enlarged front view of a main part showing a magnetoresistive film in the composite magnetic head; FIG. 2B is a front view of a main part of the composite magnetic head.

FIG. 2 is a graph showing MH curves showing states of magnetization when a recording magnetic field is applied from a recording head to a magnetic domain control layer in the magnetoresistive effect film and when no recording magnetic field is applied.

FIG. 3 is a graph showing an effect of a composite magnetic head of the present invention as a result of comparison with a conventional magnetic head;
(A) shows the reproduction output of the composite magnetic head (a) according to the first embodiment, and (b) shows the reproduction output of the composite magnetic head (b) as a comparative example.

FIG. 4 is an explanatory view of a main part of a composite magnetic head according to a second embodiment of the invention.

FIG. 5 is an explanatory diagram showing a configuration of a spin valve film as a magnetoresistive effect film in the composite magnetic head.

FIG. 6 is an explanatory view showing another configuration of the spin valve film.

FIG. 7 is an explanatory view showing still another configuration of the spin valve film.

FIG. 8 is an explanatory view showing still another configuration of the spin valve film.

FIG. 9 is a schematic explanatory view illustrating the principle of the behavior of the exchange coupling between the ferromagnetic layer and the antiferromagnetic layer in the magnetoresistive film with respect to the heat treatment in a magnetic field.

FIG. 10 is a schematic explanatory view illustrating another principle of the behavior of the exchange coupling between the ferromagnetic layer and the antiferromagnetic layer in the magnetoresistive film with respect to the heat treatment in a magnetic field.

FIG. 11 is a schematic explanatory view illustrating the principle of still another behavior with respect to heat treatment in a magnetic field in exchange coupling between a ferromagnetic layer and an antiferromagnetic layer in the magnetoresistive film.

FIG. 12 is a schematic explanatory view illustrating the principle of still another behavior with respect to heat treatment in a magnetic field in exchange coupling between a ferromagnetic layer and an antiferromagnetic layer in the magnetoresistance effect film.

FIG. 13 is a graph showing the dependency of the blocking temperature on the Pt composition ratio in an exchange coupling film composed of a NiFe film and a MnPt film.

FIG. 14 is a graph showing the dependency of the blocking temperature on the Ru composition ratio in an exchange coupling film composed of a NiFe film and a MnRu film.

FIG. 15 is a graph showing a Pt composition ratio dependency of an exchange coupling magnetic field (Hex) in an exchange coupling film including a NiFe film and a MnPt film.

FIG. 16 is a graph showing a Ru composition ratio dependency of an exchange coupling magnetic field (Hex) in an exchange coupling film including a NiFe film and a MnRu film.

FIG. 17 is a schematic sectional view showing a configuration of a conventional one-gap type composite magnetic head.

FIG. 18 is an explanatory diagram showing the configuration of the composite magnetic head from the ABS side.

FIG. 19 is a graph showing an MH curve of a hard magnetic material film used for a magnetic domain control layer in the composite magnetic head.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Lower magnetic layer 3 Lower gap layer 4 Spin valve film 5 Magnetic domain control layer 6 Electrode layer 7 Upper gap layer 8 Upper magnetic layer 10 Recording head 12 Magnetoresistive film 13 ABS surface 45 Second antiferromagnetic layer 51 First antiferromagnetic layer 52 Ferromagnetic layer

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shoji Michishima 22-22, Nagaikecho, Abeno-ku, Osaka-shi, Osaka Inside Sharp Corporation (72) Inventor Hitoshi Isono 22-22, Nagaikecho, Abeno-ku, Osaka-shi, Osaka Inside Sharp Corporation (72) Inventor Takaya Nakabayashi 22-22 Nagaikecho, Abeno-ku, Osaka City, Osaka Prefecture Inside Sharp Corporation (72) Masanori Kyoho 22-22 Nagaikecho, Abeno-ku, Osaka City, Osaka Co., Ltd. F-term (reference) 5D034 BA05 BA15 BB01 BB09 DA07

Claims (12)

[Claims] A magnetic head for recording is provided, and a magnetic head for reproduction is provided in a magnetic gap of the magnetic head for recording with a magnetoresistive film, for controlling a magnetic domain of the magnetoresistive film. The magnetic domain control layer
A composite magnetic head provided with a first antiferromagnetic layer. 2. The composite magnetic head according to claim 1, wherein the magnetic domain control layer further has a ferromagnetic layer laminated on the first antiferromagnetic layer. 3. A magnetoresistive film, comprising: a first magnetic layer in which the direction of a magnetic domain changes in response to a change in the magnetic field direction of an external magnetic field; a conductive non-magnetic layer; A second magnetic layer having a fixed direction, and a second antiferromagnetic layer for maintaining the direction of the magnetic domain of the second magnetic layer constant. 3. The composite magnetic head according to 1 or 2. 4. The composite magnetic head according to claim 3, wherein said first and second antiferromagnetic layers have different blocking temperatures. 5. The method according to claim 3, wherein at least one of the first and second antiferromagnetic layers changes to an antiferromagnetic state by a heat treatment while applying a magnetic field. The composite magnetic head as described in the above. 6. The first and second antiferromagnetic layers include:
6. The composite magnetic head according to claim 1, wherein the composite magnetic head is an alloy mainly containing Mn and Pt or an alloy mainly containing Mn and Ru. 7. The Pt composition ratio in the alloy containing Mn and Pt as main components is 4 to 19 at% or 32 to 50 at%.
%. The composite magnetic head according to claim 6, wherein 8. The composite magnetic head according to claim 6, wherein the Ru composition ratio in the alloy containing Mn and Ru as main components is 4 to 36 at%. 9. The method of manufacturing a composite magnetic head according to claim 1, wherein the direction of the applied magnetic field is changed with respect to the antiferromagnetic layer. A method for manufacturing a composite magnetic head, comprising a step of performing a heat treatment based on a blocking temperature of a layer. 10. The method of manufacturing a composite magnetic head according to claim 4, wherein each of the blocking temperatures Tb _{1 in} a relationship of Tb ₁ > Tb ₂ ,
To first and second respective antiferromagnetic layer comprises Tb _2, respectively, and a step of holding a predetermined time Tb ₁ or more temperature while applying a magnetic field in a first direction, while applying the magnetic field Tb less than _1, and a step of cooling to Tb ₂ or more temperatures less than Tb _1, and is changed to a substantially perpendicular second direction the direction of the magnetic field to the direction of said first magnetic field in Tb ₂ or more temperature A method for manufacturing a composite magnetic head, comprising: a step of holding for a predetermined time; and a step of cooling to a temperature lower than Tb ₂ while applying a magnetic field in the second direction. 11. A method of manufacturing a composite magnetic head according to claim 5, Td of> Tb ₂ the relationship, one of the antiferromagnetic layer to metastasize to antiferromagnetic by heat treatment in the magnetic field temperature of transferring the antiferromagnetic (ordering temperature: Td) and, with respect to the first and second of each antiferromagnetic layer and a blocking temperature Tb ₂ of the other antiferromagnetic layer, a first Holding the magnetic field in the direction at a temperature of Td or more for a predetermined time while applying a magnetic field in the direction; and making the direction of the magnetic field substantially perpendicular to the direction of the first magnetic field at a temperature of Tb ₂ or more. A method for manufacturing a composite magnetic head, comprising: a step of changing to a second direction and holding for a predetermined time; and a step of cooling to a temperature lower than Tb ₂ while applying a magnetic field in the second direction. 12. The method of manufacturing a composite magnetic head according to claim 5, wherein one of the antiferromagnetic materials that changes to antiferromagnetic by a heat treatment in a magnetic field has a relationship of Tb ₄ > Tb ₂ > Td. The temperature at which the body layer transitions to antiferromagnetic (ordering temperature: Td); and the blocking temperature Tb _{4 of the} antiferromagnetic layer which has transitioned to antiferromagnetic.
And a blocking temperature Tb ₂ of the other antiferromagnetic layer, and applying a magnetic field in the first direction to the first and second antiferromagnetic layers at a temperature equal to or higher than the temperature of Td for a predetermined time. a step of holding, Tb less than _4, and a step of setting the Tb ₂ or more temperatures, Tb less than _4, and a substantially vertical direction of the magnetic field to the direction of the first magnetic field at Tb ₂ or more temperature 2. A method for manufacturing a composite magnetic head, comprising: a step of changing the direction to the second direction and holding the same for a predetermined time; and a step of cooling to a temperature lower than Tb ₂ while applying the magnetic field in the second direction.