JP2002056512A - Method of manufacturing magnetic head, magnetic head, and magnetic disk drive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively fix magnetization to a fixed magnetic layer in a magnetic head having a laminated fixed magnetic layer. SOLUTION: A heating step of heating the magnetic head using a heater for heating the magnetic head from outside, and a current applying step of applying a current to the magnetic head read simultaneously with the heating of the magnetic head in the heating step, The magnetic head is heated by the heat generated when the current applied by the energizing circuit flows through the magnetoresistive film through the lead, and together with the heating from the heating step, the temperature of the magnetization fixed layer is set to the blocking temperature or more, The magnetization of the ferromagnetic layer is fixed by applying current magnetization generated from the magnetoresistive film to the ferromagnetic layer of the magnetization fixed layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method of manufacturing a magneto-resistance effect type magnetic head, a magnetic head, and a magnetic disk drive.

[0002]

2. Description of the Related Art In recent years, the density of magnetic recording has been increasing, and
In D, a system with a high recording density of 10 Gbit / inch2 has been put to practical use, and further higher density is required. As a magnetic head in such a high recording density system, a magnetoresistance effect type magnetic head using a giant magnetoresistance effect (GMR), in which the electric resistance of a magnetic thin film is changed by an external magnetic field from the viewpoint of improving reproduction sensitivity, is used. Used.

A general shield type GMR head (hereinafter, referred to as a GMR head)
FIG. 1 shows one configuration of a shield type GMR head called a magnetic head. In the figure, 1 is Al2O3.
A magnetic shield layer 2 made of a soft magnetic film such as permalloy is formed on the substrate 1. A GMR film 4 (magnetoresistive film) is provided on the magnetic shield layer 2 with an insulating film 3 constituting a reproducing magnetic gap interposed therebetween. A hard magnetic layer 5 made of CoPt or the like and a pair of leads 6 are connected. The GMR film 4, the hard magnetic layer 5, and the pair of leads 6 constitute an abut junction type MR element 7 (magnetoresistive element). On the MR element 7, a magnetic shield layer 9 is formed via an insulating layer 8 constituting a reproducing magnetic gap. Detection of a signal magnetic field in such a general magnetic head is performed, for example, by passing a sense current to a pair of leads 6 and
This is performed by measuring a change in resistance of the GMR film 4 according to a change in the average magnetization direction.

Further, a GMR film 4 of a general magnetic head is used.
Has the basic configuration shown in FIG. That is, the antiferromagnetic layer 11, the magnetization fixed layer 12, the nonmagnetic intermediate layer 13, and the magnetization free layer 14 are sequentially laminated. The antiferromagnetic layer 11 includes PtMn, NiMn, IrMn, FeMn, NiO
And the like. The non-magnetic intermediate layer 13 is C
u is common. The magnetization free layer 14 is made of Co, Ni, F
e or a ferromagnetic material which is an alloy and a laminate thereof are used, and a laminate of NiFe and CoFe is often used.

[0005] The magnetization fixed layer 12 comprises a ferromagnetic layer 12.
a, the exchange coupling layer 12b, and the ferromagnetic layer 12c are sequentially stacked. For the ferromagnetic layers 12a and 12c, the same material as that of the magnetization free layer 14 is used.
Is often used. The exchange coupling layer 12b is made of Ru, Cr, V
Are used. Such a laminated structure of the magnetization fixed layer 12 is designed so that the magnetization of the ferromagnetic layer 12a and the magnetization of the ferromagnetic layer 12c are made antiferromagnetic to each other by the exchange coupling layer 12b. Note that this coupling can be sufficiently obtained only by forming a film. By making the magnetization of the entire magnetization pinned layer 12 close to zero in this way, the operating point of the current bias is easier to design than the conventional magnetization pinned layer having a single-layer film, and the heat resistance such as electrostatic breakdown is improved. ing.

In the above description, the GMR film 4 is described as being laminated in the order of the antiferromagnetic layer 11, the magnetization fixed layer 12, the nonmagnetic intermediate layer 13, and the magnetization free layer 14, but this is not restrictive. , A non-magnetic intermediate layer, a magnetization fixed layer, and an anti-ferromagnetic layer.

Incidentally, as described above, the magnetization fixed layer 12
Is realized in a laminated structure, and the magnetization fixed layer 12
In order to keep the magnetization of the magnetization free layer 14 substantially perpendicular to the magnetization direction, a heat treatment process is required. For example, while applying a magnetic field, induced magnetic anisotropy is given to the magnetic shields 2 and 9 and the magnetization free layer 14 of the GMR film 4 near the blocking temperature (250 ° C.). A magnetic field is directed in a direction in which the magnetization of the magnetic layer 12 is desired to be fixed, and cooling is performed. After heat treatment,
The hard magnetic film 5 is magnetized and a bias magnetic field is applied to the magnetization free layer 14 to suppress the generation of Barkhausen noise in the magnetization free film 14. Here, the blocking temperature refers to a temperature at which the magnetization of the ferromagnetic layer 12a in the antiferromagnetic layer 11 and the magnetization fixed layer 12 is fixed, and the temperature depends on the material, but is from 250 ° C. to 400 ° C. It is about. The exchange coupling in the magnetization fixed layer 12 is hardly affected by the heat treatment.

[0008] However, in the conventional heat treatment method,
From the point of temperature consistency with the resist used in the magnetic head, it is usual to carry out the manufacturing step of the reproducing section of the magnetic head, that is, to perform the operation while the magnetic head is in a wafer state. Therefore, this is an effective method in the case of having a single-layer type magnetization fixed layer.

On the other hand, in the case of the laminated magnetization fixed layer 12, since the exchange coupling layer 12b exists, the exchange coupling layer 1
It is necessary to apply a large magnetic field exceeding the exchange coupling force of 2b, but it is difficult to apply such a large magnetic field while the magnetic head remains in a wafer state. That is, when the magnetic head is in the state of a wafer, it is necessary to apply a uniform and large magnetic field over a wide area of the whole wafer exceeding 3 inches. In this case, a very large electromagnet facility is required. It is difficult to develop a facility that applies a uniform and large magnetic field over such a wide range.

For example, when a Co-based material less than 3 [nm] is used for the ferromagnetic layer 12a and Ru is used for the exchange coupling layer 12b, the magnetization of the ferromagnetic layer 12a is completely applied to the ferromagnetic layer 12a. In order to be parallel to the applied magnetic field, it is necessary to apply a magnetic field that reaches 1185 k [A / m] (≒ 15 k [Oe]).

Further, in the conventional heat treatment, a pattern is formed on the magnetic shield 2 by a photoresist process so that
This is performed after forming the MR4 film. When the GMR film 4 is patterned, a magnetic field from the outside is affected by a demagnetizing field from the shape due to the patterning of the GMR film 4, and the GMR
Since it becomes difficult for a magnetic field to enter the film 4, the above-mentioned 1185
It is necessary to apply a larger magnetic field than k [A / m] (≒ 15 k [Oe]). Further, when the reproducing portion of the magnetic head is subjected to the heat treatment with a small magnetic field having an insufficient value, the magnetization of the magnetization fixed layer 12 may be released from the heat treatment process for the recording portion. is there.

Further, a magnetic field is applied to a magnetic recording head formed on a reproducing portion of a magnetic head, and then divided into a bar by carrying a certain number of magnetic heads. It is possible. In this case, since the range in which the magnetic field needs to be applied is not wide, a large device is not required. However, since an organic material such as a resist is used for the recording portion, it is difficult to heat the recording portion to a temperature exceeding 200 ° C. for heat treatment.

In the above description, the case where the magnetization pinned layer has two ferromagnetic layers has been described. However, a configuration in which three or more ferromagnetic layers are stacked can be considered. When the number of the ferromagnetic layers is three, the ferromagnetic layer, the exchange coupling layer, the ferromagnetic layer, the exchange coupling layer, and the ferromagnetic layer are sequentially stacked. Therefore, since there are two exchange coupling layers, it is necessary to apply an even larger magnetic field to saturate the ferromagnetic layer. As described above, such a large magnetic field is required when the read head is in a wafer state. It is difficult to apply a magnetic field. Further, when the number of ferromagnetic layers of the magnetization fixed layer is four or more, it becomes even more difficult to fix the magnetization of the magnetization fixed layer.
This means that an artificial lattice film (a layer in which n ferromagnetic layers and non-magnetic intermediate layers are alternately laminated to form an n-layer), which is a multilayer structure of a non-magnetic intermediate layer made of Cu or the like instead of an exchange coupling layer, is formed. It is clear that it is difficult to consider a film in which a hard magnetic layer and an antiferromagnetic layer are sequentially laminated on a layer) or a combination of an exchange coupling layer and an artificial lattice film.

Further, US Pat. No. 5,650,887 proposes a system for correcting a deterioration of a pinned layer by applying a pulse to a current supplied to a magnetic head. But,
In this system, no consideration is given to a system using a stacked-type magnetization fixed layer. In the case where the magnetization fixed layer is of a stacked type, a complicated magnetization behavior is shown with respect to an applied current as shown in FIG. 11. Considering the direction of the current magnetic field that accompanies the direction of the current together with the change in the magnetization, it is thought that the magnetization of the magnetization pinned layer shows an indeterminate direction in the process of stopping the current and cooling the magnetic head. Can be Furthermore, if the magnetic head is heated only by the current, the internal current distribution becomes large, and it is difficult to control the current using a pulse.

[0015]

As described above, according to the conventional heat treatment method, it is difficult to effectively fix the magnetization of the magnetization fixed layer to the magnetic head having the stacked magnetization fixed layer. there were. Therefore, in order to take advantage of the excellent characteristics of the stacked magnetic pinned layer, a heat treatment method and a head structure are required instead of the conventional heat treatment method.

Therefore, according to the present invention, in a magnetic head having a stacked-type pinned magnetic layer, the pinning of the magnetization to the pinned magnetic layer can be performed effectively, and the characteristics of the pinned magnetic layer can be brought out. An object of the present invention is to provide a manufacturing method for performing heat treatment, a head structure, and a magnetic disk drive.

[0017]

According to a method of manufacturing a magnetic head of the present invention, there is provided a magnetoresistive film having a magnetization pinned layer having a structure in which a plurality of ferromagnetic layers are stacked, and a method for applying a current to the magnetoresistive film. And a heating step of heating the magnetic head using a heater that externally heats the magnetic head, and simultaneously heating the magnetic head by the heating step. A current applying step of applying a current to the lead using an energizing circuit for applying a current to the lead.In the current applying step, a current applied by the energizing circuit flows through the magnetoresistive film through the lead. The magnetic head is heated by the heat generated at the time, and the magnetization fixed layer is heated to a blocking temperature or higher in combination with external heating in the heating step. Rutotomoni, by applying a current magnetic field generated from the magnetoresistive film on the ferromagnetic layer of the magnetization fixed layer, characterized by fixing the magnetization of the ferromagnetic layer.

Further, the magnetic head of the present invention is a magnetic head having a magnetoresistive film having a pinned layer having a configuration in which a plurality of ferromagnetic layers are stacked, and a lead for applying a current to the magnetoresistive film. The magnetization direction at a position near the center of the ferromagnetic layer in contact with the antiferromagnetic film in the ferromagnetic layer is substantially parallel to the signal magnetic field, and the magnetization direction at a position near the lead of the ferromagnetic layer. Has a tilt of at least 10 degrees or more with respect to the direction of magnetization at the position near the center.

Further, the magnetic disk drive of the present invention has a magnetic head having a magnetoresistive film having a pinned layer having a configuration in which a plurality of ferromagnetic layers are stacked, and a lead for applying a current to the magnetoresistive film. A magnetic disk drive comprising a heater for externally heating the magnetic head, heating the magnetic head using the heater, and simultaneously applying an electric current to the read, and applying the electric current to the magnetic head via the read. By heating the magnetic head with heat generated when flowing through the resistance effect film, the temperature of the magnetization pinned layer is set to be equal to or higher than the blocking temperature together with the heating from the heater, and the current generated from the magnetoresistance effect film By applying a magnetic field to the ferromagnetic layer of the magnetization fixed layer, the magnetization of the ferromagnetic layer is fixed.

According to the above configuration, it is possible to reliably fix the magnetization to the fixed magnetic layer of the magnetic head having the magnetoresistive effect film having the stacked fixed magnetic layer in the reproducing section.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) An embodiment of the present invention will be described below with reference to the drawings. Figure 1
FIG. 2 is a configuration diagram of a reproducing unit of a magnetic head that performs a heat treatment by a first manufacturing method according to the first embodiment of the present invention. 1
Is a substrate made of Al2O3.TiC or the like. On this substrate 1, a magnetic shield 2 made of a soft magnetic film such as permalloy is formed. A GMR film 4 is provided on the magnetic shield 2 via an insulating film 3 constituting a reproducing magnetic gap. Hard magnetic layers made of CoPt or the like are provided at both ends of the GMR film 4 for the purpose of making the magnetization free layer of the GMR film 4 into a single magnetic domain. 5 and a pair of leads 6
Is connected. The GMR film 4, the hard magnetic layer 5, and the pair of leads 6 constitute an abut junction type magnetoresistive element (MR element) 7. On the magnetoresistive element 7, a magnetic shield 9 is formed via an insulating layer 8 constituting a reproducing magnetic gap.

Further, as shown in FIG. 2, the GMR film 4 has a structure in which an antiferromagnetic layer 11, a magnetization fixed layer 12, a nonmagnetic intermediate layer 13, and a magnetization free layer 14 are sequentially laminated. Co90Fe10 for the magnetization free layer 14 or N
Co-based, such as a laminated film in which i80Fe20 is laminated,
An Fe-based soft magnetic material is used.

The pinned layer 12 has a structure in which a ferromagnetic layer 12a, an exchange coupling layer 12b, and a ferromagnetic layer 12c are sequentially stacked. The exchange coupling layer 12b is made of a material such as Ru or Cr that couples the ferromagnetic layer 12a and the ferromagnetic layer 12c antiferromagnetically, so that the magnetizations of the ferromagnetic layer 12a and the ferromagnetic layer 12c are opposite to each other. Designed for This exchange coupling is maintained at a substantially constant value up to around 300 ° C.
Therefore, the entire magnetization of the magnetization fixed layer 12 is designed to be close to zero. In consideration of the distribution of the current magnetic field, of the two ferromagnetic layers 12a and 12c constituting the pinned layer 12,
The magnetization of the ferromagnetic layer 12a in contact with the antiferromagnetic layer 11 may be smaller than the magnetization of the other ferromagnetic layer 12c. The antiferromagnetic layer 11 is made of a Mn-based antiferromagnetic material such as PtMn or IrMn, or an oxide antiferromagnetic material typified by NiO or CoO.
It plays the role of fixing the magnetization of a.

(First Manufacturing Method) Next, a first manufacturing method according to the embodiment of the present invention will be described below. In the first manufacturing method of the present invention, the heat treatment is performed in a state where the shape of the magnetic head is determined. In the heat treatment, the temperature of the magnetic head is reduced by heating the magnetic head from the outside and heating by applying a current to the reproducing portion of the magnetic head (that is, applying a current to the GMR film 4 via the lead 6). 11, the magnetization of the pinned layer 12 is pinned by applying a current magnetic field generated around the current flowing through the nonmagnetic intermediate layer 13 of the GMR 4 to the pinned layer 12 due to the energization. Like that.

Here, the state in which the shape of the magnetic head is determined refers to the state obtained in the next step. After a recording section is formed in the upper layer of the magnetic shield 9 of the reproducing section of the magnetic head of FIG. 1, the recording section is divided into bars on which a fixed number of magnetic heads are mounted by using machining. Then, after adjusting the height of each magnetic head mounted on the wafer in a bar state, the magnetic heads are divided into individual magnetic heads by using machining. Then, each of the divided magnetic heads is attached to a suspension. In the above-described steps, the state in which the wafer is divided into bars and the state in which the magnetic head is in the state of a head gimbal assembly in which the magnetic heads are respectively attached to suspensions are states in which the shape of the magnetic head is determined.

In the first manufacturing method of the present invention, it is possible to perform the heat treatment even in the state of the wafer before being divided into the state of the bar. However, in this case, since a film formed on the wafer is directly processed, there is a high possibility that troubles such as electrostatic destruction and failure of the magnetization fixed layer will occur. On the other hand, when the heat treatment is performed in a state where the shape of the magnetic head is fixed, such troubles such as the electrostatic breakdown and the failure of the magnetization fixed layer are unlikely to occur. Therefore, in the first manufacturing method of the present invention,
The heat treatment is performed on the magnetic head having the determined shape.

(Manufacturing Apparatus) FIG. 3 shows a manufacturing apparatus used in the first manufacturing method of the present invention. In this manufacturing equipment,
It is possible to perform heat treatment on a wafer divided into bars and a head gimbal assembly. FIG. 3 shows an example in which heat treatment is performed on the head gimbal assembly 21.

The manufacturing apparatus of the present invention includes a head gimbal
It has an energizing circuit 22 for energizing the reproducing section of the magnetic head of the assembly 21, and a heater 23 for heating the reproducing section of the magnetic head of the head gimbal assembly 21. Further, it has an electromagnet 24 for applying a magnetic field to the magnetic head of the head gimbal assembly 21. In the manufacturing apparatus, a magnetic field is applied to the magnetic head by the electromagnet 24 so that a change in voltage of the reproducing unit of the magnetic head can be read, and the reproducing characteristics of the reproducing unit of the magnetic head can be evaluated on the spot. It is. Note that an oven or the like may be used as the heater 23.

Hereinafter, a method of performing a heat treatment using this manufacturing apparatus will be described. First, the magnetic head of the head gimbal assembly 21 is heated by the heater 23,
The temperature of the magnetic head is raised to T1. Heater 23
Is at least higher than room temperature and 50 ° C. or higher. In this state, the head gimbal
The reproducing section of the magnetic head of the assembly 21 is supplied with the current Ib. That is, a current Ib flows through the GMR film 4 through the lead 6 of the magnetic head, and the heat generated by the GMR film 4 causes
The magnetic head itself including the film 4 is heated. The current Ib is set to a value larger than the current value when the GMR film 4 of the magnetic head operates normally. For example, the current during normal operation is 5
In the case of [mA], the current Ib is about 8 [mA].

The holding time t of the process for performing the heat treatment of the magnetic head may be a time of one second to several hours. However, if the holding time t is less than 1 second, the magnetic head cannot be sufficiently heated. As described above, after the temperature of the magnetic head is raised to T1, heating is performed by applying a current Ib, so that the temperature T2 of the magnetic head is a function of the amount of the current Ib. Indicated by Therefore, by controlling the amount of the current Ib, the temperature T2 of the magnetic head is set close to the blocking temperature of the antiferromagnetic layer 11.

T2 = T1 + f (Ib) Equation (1)

A current magnetic field generated from a current flowing around the nonmagnetic intermediate layer 13 of the GMR film 4 by applying the current Ib is applied to the magnetization fixed layer 12 to fix the magnetization of the magnetization fixed layer 12. As described above, the temperature T of the magnetic head is controlled by the heating from the heater 23 and the supply of the current Ib from the power supply circuit 22.
2 is raised so as to be near the blocking temperature of the antiferromagnetic layer 11, and the non-magnetic intermediate layer 1
3 can be applied to the magnetization fixed layer 12, whereby the magnetization fixed layer 1 can be applied.
2 can be fixed stably

When the temperature T2 of the magnetic head is set close to the blocking temperature of the antiferromagnetic layer 11, the current magnetic field is changed to the magnetization fixed layer 1
After the heating, the heating of the heater 23 is stopped first, and then the supply of the current Ib is stopped. Here, the reason why the heating of the heater 23 is stopped first is that if the current magnetic field applied to the magnetization fixed layer 12 is weakened before the temperature of the magnetic head decreases,
This is because there is a concern that the fixing of the magnetization becomes unstable. In this way, the heat treatment is performed on the reproducing portion of the magnetic head.

As described above, in a magnetic head having a stacked-type magnetization fixed layer, it is desirable that the current magnetic field applied to the magnetization fixed layer be strong. However, if the value of the current Ib is excessively increased in order to generate a strong current magnetic field, the temperature of the magnetic head excessively increases, and the temperature of the GMR film 4 locally increases excessively. For this reason, GM
Diffusion occurs between the laminated films of the R film 4 or, conversely, the GMR film 4
Insufficient rise in temperature occurs in the magnetization fixed layer 12 of
Problems such as improper fixation of the magnetization at that portion occur, and the performance of the film deteriorates. Therefore, the current I
It is desirable that b is selected to be a minimum value such that the current magnetic field sufficiently affects the magnetization fixed layer 12 of the GMR film 4.

(Appropriate Value of Temperature T1 of Heater) Next, an appropriate value of the temperature T1 when the magnetic head is heated by the heater 23 will be described. Reproducing output Outp of magnetic head
ut (the value of the reproducing operation current is assumed to be constant) can be expressed by a function of the temperature T1 heated by the heater 23 and the current Ib applied to the magnetic head, and the relationship is expressed by the following equation (2). Indicated by

Output = g (T1, Ib) Expression (2)

In order to further explain the relationship expressed by the equation (2), FIG. 4 shows the relationship between the reproduction output of the magnetic head, the heater temperature T applied during manufacturing, and the current Ib. Each graph shows the relationship when the value of the heating temperature T1 of the heater 23 is changed as a parameter. The parameters of the temperature T1 are room temperature, T1 = 100 ° C. (T11), and T1 = 150 ° C. in ascending temperature order.
(T12), T1 = 180 ° C. (T13). Here, at room temperature, the magnetization of the magnetization fixed layer of the magnetic head was not fixed by the manufacturing method of the present invention, but was performed by a conventional method.

As shown in FIG. 4, T1 = 150 ° C.
In the case of (T12), since the value of the reproduction output Output is the highest, the heating temperature T1 of the heater 23 is
It is appropriate that T1 = 150 ° C.

(Magnetization Distribution of Ferromagnetic Layer of Magnetized Pinned Layer) FIG.
FIG. 9 shows the state of the magnetization distribution of the ferromagnetic layer 12a of the magnetization fixed layer 12 on which the magnetization is fixed by the manufacturing method of the present invention, as viewed from the medium facing surface. In the manufacturing method of the present invention, a current is applied to the GMR film 4 to heat the GMR film 4 itself. As can be seen from FIG. 1, the leads 6 are located at both ends of the GMR film 4, that is, located at both ends of the ferromagnetic layer 12a of the magnetization fixed layer 12. For this reason, heat escapes from both ends of the ferromagnetic layer 12a. During the heat treatment, the temperature near the center of the ferromagnetic layer 12a is high, and the temperature near the both ends near the lead 6 is low. A temperature distribution occurs.

Therefore, when the magnetization is fixed by the manufacturing method of the present invention, the heat treatment proceeds because the vicinity of the center of the ferromagnetic layer 12a is sufficiently heated, and the magnetization is fixed substantially in parallel with the medium magnetic field direction. On the other hand, since the vicinity of both ends near the lead 6 is not sufficiently heated, the magnetization fixation near both ends is maintained in a state before the magnetization fixation is performed by the manufacturing process of the present invention. That is, the direction of the magnetization fixed by the heat treatment in the magnetic field during the wafer process is maintained as it is.

As described above, when the magnetization is fixed by the manufacturing method of the present invention, only the center is magnetized almost parallel to the medium magnetic field direction, and both ends are magnetized in the direction not parallel to the medium magnetic field direction. Can be obtained. Accordingly, it is possible to obtain a configuration in which the magnetization measurement sensitivity near the center is high and the magnetization measurement sensitivity near both ends is low in the ferromagnetic layer 12a. As a result of measuring the measurement sensitivity of the magnetization of the ferromagnetic layer 12a with respect to the magnetic layer fixed by the manufacturing method of the present invention, the difference in the measurement sensitivity between the vicinity of the center and the vicinity of both ends indicates the magnetization of the vicinity of the center and the vicinity of both ends. Was found to have a difference of at least 10 degrees.

On the other hand, FIG. 5 shows a ferromagnetic layer 12a formed by a conventional method of fixing magnetization (that is, a method of fixing magnetization by heat treatment in a magnetic field during a wafer process). In the case of the manufacturing method described above, the magnetization is oriented in the same direction in all portions of the ferromagnetic layer 12a, and the angle difference (θ)
There is no. Therefore, in the conventional manufacturing method, the ferromagnetic layer 12
a cannot be configured such that the measurement sensitivity of magnetization near the center is high and the measurement sensitivity of magnetization near both ends is low.

(Second Embodiment) Next, a second manufacturing method according to a second embodiment of the present invention will be described. In the first manufacturing method described above, an external magnetic field was not applied to the magnetic head during the heat treatment, whereas in the second manufacturing method, an external magnetic field was applied to the magnetic head during the heat treatment. That is, in addition to heating the magnetic head of the head gimbal assembly 21 by the heater 23 and energizing the reproducing unit of the magnetic head from the energizing circuit 22,
An external magnetic field is applied to the magnetic head by the electromagnet 24. The direction of the external magnetic field is parallel to the current magnetic field generated by energization. The direction is parallel to the signal magnetic field of the reproducing section of the magnetic head.

Since an external magnetic field is applied to the magnetic head by the electromagnet 24, the current magnetic field can be reduced, so that the value of the current Ib for energizing the reproducing section of the magnetic head can be reduced. Therefore, the current Ib can be supplied in a range where the temperature of the magnetic head rises and the temperature of the GMR film 4 does not locally rise too much.

FIG. 6 shows the relationship between the reproducing output of the magnetic head when an external magnetic field is applied in the second manufacturing method, the heater temperature T applied during manufacturing, and the current Ib.
In order to reduce the value of the current Ib, the temperature rise in the heating by the current Ib is reduced. Therefore, the temperature T1 to be heated by the heater 23 is changed to the optimum value (T1 = 150 ° C.) in the first manufacturing method. It is necessary to set the predetermined value (T14) higher than (T12)).

(Third Embodiment) Next, a third manufacturing method according to a third embodiment of the present invention will be described. In the first manufacturing method, a constant value of the current Ib is applied to the reproducing portion of the magnetic head during the heat treatment. On the other hand, in the third manufacturing method, the current Ib is applied to the reproducing portion of the magnetic head. Before adding the pulse, a pulse of the current Ib1 having a smaller value than the current Ib is further applied. For example, 12 [mA] is added as the current Ib1.

FIG. 7 shows the relationship between the current applied to the reproducing section of the magnetic head and the amount of heat Q generated in the reproducing section of the magnetic head. If the value of the current Ib is too large as described above, the temperature of the magnetic head will be too high,
Since the temperature of the GMR film 4 is too high locally,
The laminated films of the films 4 are diffused, and as a result, the output of the reproducing unit of the magnetic head is reduced. Therefore, the magnetic head is heated for a time (t1) sufficiently shorter than the time when the diffusion occurs so that the stacked films of the GMR film 4 do not diffuse. Here, the time t1 for applying the pulse current Ib1 needs to be 1 second or less at the longest, and is set to 1 microsecond in the present invention.

Since the calorific value Q is delayed with respect to the time when the pulse current Ib1 is added, the magnetic head needs a current Ib to apply a sufficient magnetic field. Further, in the case of the third manufacturing method, unlike the first and second manufacturing methods described above, since the heating required in the end is performed by the current Ib1 which is a pulse, the heating is performed by the current Ib1. It is also possible to stop the heating by the heater 23 at any time later, that is, after the time t1 has elapsed.

(Fourth Embodiment) A fourth embodiment will be described. The invention according to the fourth embodiment relates to an evaluation method for evaluating the reproduction characteristics of a reproduction section of a magnetic head in situ after performing a heat treatment in the above-described first to third manufacturing methods. As an example, FIG. 8 shows the relationship between the current Ib and the temperature T of the heater 23 when heat treatment is performed using the first manufacturing method and thereafter the reproduction characteristics of the reproduction section of the magnetic head are evaluated.

After the magnetic head is heat-treated by setting the temperature of the heater 23 to T1 by the first manufacturing method, when the time reaches t2, the temperature of the heater 23 is lowered to T2. Since the temperature of the heater 23 actually decreases to T2 at the time t3, at this time t3, the current applied to the reproducing portion of the magnetic head by the energizing circuit 22 is set to Ib2, From 24, a magnetic field is applied to the reproducing section of the magnetic head. Then, when a magnetic field is applied from the electromagnet 24 to the reproducing section of the magnetic head, a change in voltage of the reproducing section of the magnetic head is measured by the energizing circuit 22 to measure the reproduction output of the reproducing section of the magnetic head. If the reproduced output does not meet the target value, the magnetic head is again subjected to the heat treatment by the above-described first to third manufacturing methods. Also, based on the measurement result of the reproduction output of the reproducing section of the magnetic head, the condition of the current magnetic field necessary for the subsequent heat treatment can be determined, so that the appropriate current magnetic field condition can be obtained, and this is effective for the subsequent heat treatment. It is.

(Fifth Embodiment) Next, a fifth embodiment of the present invention will be described.
The magnetic head according to the embodiment will be described. FIG.
2 shows the structure of the magnetic head of the present invention. In the magnetic head of the present invention, when viewed from the upper surface of the substrate, a pair of leads 6 'are arranged in a state of being arranged in parallel to the medium magnetic field direction, and the GMR film 4' is located between the leads 6 '. It is in a state where it has been done. By having such a configuration,
The magnetic head of the present invention is designed so that the direction of the current flowing through the GMR film 4 'is substantially parallel to the direction of the medium magnetic field. Therefore, it suffices to apply a current whose magnitude is such that the magnetization of the magnetization fixed layer is directed to the medium magnetic field direction.

On the other hand, in the configuration of a general magnetic head as shown in FIG. 10, a pair of leads 6 are arranged in a direction perpendicular to the direction of the medium magnetic field, and the GMR film 4 is located between them. The direction of the current flowing through the GMR film 4 is orthogonal to the direction of the medium magnetic field. Therefore, it is necessary to direct the magnetization of the magnetization fixed layer to the direction of the current magnetic field (the direction perpendicular to the direction of the medium magnetic field). Therefore, a larger value of current is required than when applied to the magnetic head of the present invention.

The relationship between the current values will be described with reference to FIG. FIG. 11 shows the relationship between the magnetization state in the pinned layer and the value of the current. FIG. 11 shows the magnetization state in the magnetization fixed layer when the current value is gradually increased from the left. The leftmost one is a case where the value of the current is small and the magnetization of the pinned layer due to the current magnetic field of the current is indeterminate. The center shows the state of magnetization of the pinned layer when the value of the current is larger than the case shown on the left, and the magnetization of the pinned layer is in a direction parallel to the medium magnetic field direction. It is fixed. The right side shows the case where the current value is further increased than that shown in the center. In this case, the magnetization of the ferromagnetic layer of the magnetization fixed layer is saturated in the direction of the current magnetic field.

As can be seen from FIG. 11, when the magnetization of the magnetization fixed layer is directed in the direction of the current magnetic field, the value of the current is smaller than when the magnetization is directed in the direction of the medium magnetic field. Therefore, in the magnetic head of the present invention, when the magnetization of the magnetization fixed layer is fixed by the heat treatment, the magnetization is fixed with a current smaller than that required for the general magnetic head shown in FIG. Can be performed.

(Sixth Embodiment) Next, as shown in FIG. 12, a heater 32 is incorporated in a magnetic disk drive 31 to realize the heat treatment in the above-described first to third manufacturing methods. Is possible. Magnetic head 3
In the case of performing the heat treatment on the reproducing unit 3, the magnetic head 33 is moved from the magnetic medium 34 to the position of the heater 32, and then the reproducing unit of the magnetic head 33 is heated by the heater 32 and the reproducing of the magnetic head 32 is performed. This is done by applying current to the part.

Further, similarly to the manufacturing apparatus of FIG. 3, it is possible to incorporate an electromagnet together with the heater 32 in the magnetic disk drive 31. In this case, it is possible to evaluate the reproduction characteristics of the reproduction section of the magnetic head 33 using an electromagnet in the same manner as described in the above-described fourth embodiment.

(Seventh Embodiment) Next, a magnetic head according to a seventh embodiment will be described. The magnetic head according to the seventh embodiment has a configuration in which a magnetic shield 42 is arranged as a base of an MR element 41 and a magnetic shield lead 43 is connected to the magnetic shield 42 as shown in FIG. Features. With this configuration,
By applying an appropriate amount of current to the magnetic shield 42 via the magnetic shield lead 43, the MR of the magnetic head can be reduced.
The element 41 can be heated. Accordingly, there is no need to provide a heater, and the manufacturing apparatus shown in FIG.
In this magnetic disk drive, the heater can be omitted, and the structure is simplified.

(Eighth Embodiment) Next, a method of manufacturing a magnetic head according to an eighth embodiment will be described. The manufacturing method according to the eighth embodiment is a method in which a current is supplied to a recording section of a magnetic head and a reproducing section is heated by using heat generated in the recording section. In this case, as shown in FIG. 14, the current Iw flowing through the recording section of the magnetic head is 70 [m
A], the reproduction output Output of the magnetic head is 1.
The value is about 7 [mVpp], at which time the temperature of the magnetic head becomes about 150 ° C. As described above, instead of heating the reproducing section of the magnetic head with the heater, it is possible to supply the current Iw to the recording section of the magnetic head and heat the reproducing section using the heat generated by the recording section. Therefore, the heater can be omitted in the manufacturing apparatus of FIG. 3 and the magnetic disk apparatus of FIG. 12, and the structure is simplified.

In the first to seventh embodiments, the case where the magnetization fixed layer has two ferromagnetic layers has been described. However, the present invention is not limited to this, and the magnetization fixed layer may have three ferromagnetic layers. You may have the above. When there are three or more ferromagnetic layers,
Since it is necessary to apply a stronger magnetic field than in the case of two layers, the heat treatment in the manufacturing method of the present invention is effective. The layer between the ferromagnetic layers of the magnetization pinned layer is not only an exchange coupling layer, but also an artificial lattice film having a multilayer structure of a nonmagnetic intermediate layer made of Cu or the like (a ferromagnetic layer and a nonmagnetic intermediate layer are alternately formed). A hard magnetic layer on the layer,
The heat treatment in the manufacturing method of the present invention is also effective for a film formed by sequentially stacking antiferromagnetic layers) or a combination of an exchange coupling layer and an artificial lattice film.

[0060]

As described above in detail, according to the present invention, in a magnetic head having a magnetoresistive effect film having a stacked-type pinned magnetic layer in a reproducing section, it is possible to surely fix magnetization to the pinned magnetic layer. As a result, it is possible to provide a stable and high-quality magnetic head and a magnetic disk drive that have the characteristics of the pinned magnetic layer.

[Brief description of the drawings]

FIG. 1 is a diagram showing one configuration of a shield type GMR head.

FIG. 2 is a diagram showing a basic configuration of a GMR film of a shield type GMR head.

FIG. 3 is a view showing an overview of a manufacturing apparatus according to the present invention.

FIG. 4 is a diagram showing a relationship between a reproduction output of the magnetic head according to the first embodiment of the present invention, a heater temperature applied during manufacturing, and a current.

FIG. 5 is a diagram showing a magnetization distribution of a ferromagnetic layer of a magnetization fixed layer.

FIG. 6 is a diagram showing a relationship between a reproduction output of a magnetic head, a heater temperature applied at the time of manufacturing, and a current according to a second embodiment of the present invention.

FIG. 7 is a diagram illustrating a relationship between a current applied to a reproducing unit of a magnetic head and a generated heat amount according to a third embodiment of the present invention.

FIG. 8 is a diagram showing a relationship between a current and a heater temperature when evaluating the reproduction characteristics of a magnetic head according to a fourth embodiment of the present invention.

FIG. 9 is a diagram showing a configuration of a magnetic head according to a fifth embodiment of the present invention.

FIG. 10 is a diagram showing a configuration of a general magnetic head.

FIG. 11 is a diagram showing a magnetization state of a magnetization fixed layer according to a magnitude of a current.

FIG. 12 is a diagram showing a configuration of a magnetic disk drive according to a sixth embodiment of the present invention.

FIG. 13 is a view showing a configuration of a magnetic head according to a seventh embodiment of the present invention.

FIG. 14 is a diagram showing a relationship between a current flowing through a recording section of the magnetic head and a reproduction output of the magnetic head.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Substrate 2, 9, 42 ... Magnetic shield 3, 8 ... Insulating film 4, 4 '... GMR film 5, 5' ... Hard magnetic layer 6, 6 '... Lead 7, 41 ... MR element 11 ... Antiferromagnetic layer DESCRIPTION OF SYMBOLS 12 ... Magnetic pinned layer 12a, 12c ... Ferromagnetic layer 12b ... Exchange coupling layer 13 ... Nonmagnetic intermediate layer 14 ... Magnetic free layer 21 ... Head gimbal assembly 22 ... Electrification circuit 23, 32 ... Heater 24 ... Electromagnet 31 ... Magnetic Disk device 32 Heater 33 Magnetic head 34 Magnetic medium 43 Lead for magnetic shield

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 43/08 H01L 43/12 43/12 G01R 33/06 R

Claims (11)

[Claims] 1. A method of manufacturing a magnetic head, comprising: a magnetoresistive film having a pinned layer having a configuration in which a plurality of ferromagnetic layers are stacked; and a lead for applying a current to the magnetoresistive film. A heating step of heating the magnetic head using a heater that externally heats the magnetic head; and simultaneously applying a current to the lead of the magnetic head by heating the magnetic head in the heating step. In the current applying step, the magnetic head is heated by the heat generated when the current applied by the energizing circuit flows through the magnetoresistive film through the lead. The temperature of the magnetization pinned layer is set to a blocking temperature or higher together with external heating in the step, and the current generated by the magnetoresistive film is reduced. A method of manufacturing a magnetic head, comprising: fixing a magnetization of the ferromagnetic layer by applying a field to the ferromagnetic layer of the magnetization fixed layer. 2. The method according to claim 1, wherein the heating step and the current applying step are performed on the magnetic head in a state in which a shape after performing a process of adjusting a height of the magnetic head is determined. The manufacturing method of the magnetic head described. 3. The method according to claim 2, wherein, after the heating of the magnetic head by the heater in the heating step, the application of the current from the energizing circuit to the lead of the magnetic head is terminated. The method for manufacturing a magnetic head according to claim 1, wherein: 4. A magnetic field applying step of applying the magnetic field to the magnetic head using an electromagnet that generates a magnetic field simultaneously with the application of the current to the read of the magnetic head in the current applying step. The method for manufacturing a magnetic head according to claim 1. 5. The current applying step includes: applying a short-time pulse current to the read; and applying the pulse current in the pulse current applying step, and then applying a value smaller than the pulse current. 2. A method for manufacturing a magnetic head according to claim 1, further comprising a second current applying step of applying a current for a longer time than the pulse current. 6. A reproducing section comprising: a magnetoresistive film having a pinned layer having a configuration in which a plurality of ferromagnetic layers are stacked; and a read section having leads for applying a current to the magnetoresistive film; A method of manufacturing a magnetic head having a formed recording portion, wherein a heating step of heating the magnetic head with heat generated in the recording portion by passing a current through the recording portion; and heating the magnetic head by the heating step At the same time, a current applying step of applying a current to the read using an energizing circuit for applying a current to the read of the magnetic head, wherein in the current applying step, the current applied by the energizing circuit passes through the lead. The magnetic head is heated by the heat generated when flowing through the magnetoresistive film, and the temperature of the magnetization fixed layer is set to be equal to or higher than the blocking temperature together with the heating from the recording unit. A magnetic field fixed to the ferromagnetic layer by applying a current magnetic field generated from the magnetoresistive film to the ferromagnetic layer of the magnetization fixed layer. 7. A magnetoresistive film having a pinned layer having a configuration in which a plurality of ferromagnetic layers are stacked, and a pair of leads for applying a current to the magnetoresistive film substantially in parallel with a medium magnetic field direction. In the method for manufacturing a magnetic head, a heating step of heating the magnetic head using a heater that externally heats the magnetic head; and simultaneously heating the magnetic head in the heating step, applying a current to the read of the magnetic head. A current application step of applying a current to the lead by using an energization circuit to be applied.In the current application step, a current having a value necessary for the magnetization of the magnetization fixed film to be oriented in the medium magnetic field direction is applied by the energization circuit, The magnetic head is heated by heat generated when the current flows through the magnetoresistive film through the lead, and combined with external heating in the heating step. And fixing the magnetization of the ferromagnetic layer by applying a current magnetic field generated from the magnetoresistive film to the ferromagnetic layer of the magnetization fixed layer while keeping the magnetization fixed layer at a blocking temperature or higher. A method for manufacturing a magnetic head. 8. A magnetic head comprising: a magnetoresistive film having a pinned layer having a configuration in which a plurality of ferromagnetic layers are stacked; and a lead for applying a current to the magnetoresistive film, wherein: The direction of magnetization at a position near the center of the ferromagnetic layer in contact with the antiferromagnetic film is substantially parallel to the signal magnetic field, and the direction of magnetization at a position near the lead of the ferromagnetic layer is at a position near the center. A magnetic head having an inclination of at least 10 degrees with respect to the direction of magnetization. 9. A magnetic head comprising: a magnetoresistive film having a pinned layer having a configuration in which a plurality of ferromagnetic layers are stacked; and a pair of leads for applying a current to the magnetoresistive film. Are arranged in parallel with the medium magnetic field direction, and the magnetoresistive film is arranged between the pair of leads, and a current flows through the magnetoresistive film substantially parallel to the medium magnetic field direction. The magnetic head according to claim 8, wherein: 10. A magnetic disk drive comprising a magnetic head having a magnetoresistive film having a pinned layer having a configuration in which a plurality of ferromagnetic layers are stacked, and a lead for applying a current to the magnetoresistive film. A heater for externally heating the magnetic head, heating the magnetic head using the heater, simultaneously applying a current to the lead, and generating a current when the current flows through the magnetoresistive film through the lead; By heating the magnetic head with the heat generated, the temperature of the magnetization fixed layer is set to be equal to or higher than the blocking temperature together with the heating from the heater, and the current magnetic field generated from the magnetoresistive film is reduced by the magnetic fixed layer. A magnetic disk device, wherein the magnetization of the ferromagnetic layer is fixed by adding to the ferromagnetic layer. 11. A magnetic disk drive comprising: a magnetic head having a magnetoresistive film having a pinned layer having a configuration in which a plurality of ferromagnetic layers are stacked; and a lead for applying a current to the magnetoresistive film. The magnetic head further includes: a magnetic shield laminated close to the magnetoresistive effect film; and a magnetic shield lead for applying a current to the magnetic shield, wherein the magnetic shield is provided via the shield lead. Heating the magnetic head with heat generated from the shield by applying a current to the magnetic head at the same time as applying a current to the lead and generating heat when the current flows through the magnetoresistive film through the lead. By heating the magnetic pinned layer together with the heating from the shield, the temperature of the magnetization fixed layer is set to a blocking temperature or higher, and the magnetoresistance effect is increased. By applying a current magnetic field generated from the membrane to the ferromagnetic layer of the magnetization fixed layer, a magnetic disk device characterized by fixing the magnetization of the ferromagnetic layer.