JP2002100011A - Magnetoresistance effect type magnetic head and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reliably ensure an insulating property due to an intershield gap while effectively preventing electromigration by suppressing the temperature rise of an MR (magnetoresistance) element. SOLUTION: The intershield gap 4 comprises upper and lower insulating films 11, 12 including positions which overlap at least an MR element 5 in the laminating direction and a rear insulating film 13 formed in such a way that it comes in contact with at least one of a pair of magnetic shield layers 2, 3 and an end of the MR element 5 on the side (position at which depth becomes zero) distant from the face 1a of the element 5 opposite to a medium. A material having a higher heat conductivity than Al2O3, SiO2 or the like used for the upper and lower insulating films 11, 12, e.g. one or more insulating materials selected from AlN, SiC and DLC(diamond-like carbon) are used as the material of the rear insulating film 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetoresistance effect type magnetic head for reading a magnetic signal recorded on a magnetic recording medium by utilizing a magnetoresistance effect.

[0002]

2. Description of the Related Art In recent years, in the field of magnetic recording, the recording density has been actively increased, and instead of a bulk head as a magnetic head suitable for such a high density recording,
Thin film heads are becoming widely used. Thin-film head is a manufacturing technology in the field of semiconductor integrated circuits,
Specifically, since it is manufactured using a film forming technique such as evaporation or sputtering, photolithography, or a photolithography technique such as etching, a fine shape can be accurately formed.
In addition, there is an advantage that mass production is possible. Thin film heads having such advantages are currently the mainstream as magnetic heads in high-density recording / reproducing systems such as hard disk drives.

As such a thin film head, a magnetoresistive effect type magnetic head (hereinafter referred to as an MR head) for reading a signal utilizing a magnetoresistive effect is generally used as a reproducing head element in a hard disk drive. It is being used for

In this MR head, the track width is determined by the width of the MR element to be formed as a thin film, so that it is easy to make the track narrower and the reproducing sensitivity is higher than that of an inductive head using a winding. Further, since there is no influence of inductance, it has a feature that signal transfer at a high frequency is possible.

Here, a configuration example of an MR head generally used as a reproducing head element in a conventional hard disk drive will be described with reference to FIGS. 14 and 15. FIG.

The MR head 100 is mounted on a flying slider that flies above a magnetic disk that rotates at a high speed, and reads a magnetic signal recorded on the magnetic disk. In general, in a hard disk drive, a composite magnetic head in which an inductive thin film head as a recording head element is formed on the MR head 100 is used, but here, the inductive thin film head will be described. Is omitted.

The MR head 100 is formed on a substrate serving as a flying slider with an underlayer interposed therebetween. A lower insulating film 104 and an upper insulating film 104 are provided between a lower magnetic shield layer 102 and an upper magnetic shield layer 103 made of a soft magnetic film. An inter-shield gap composed of an insulating film 105 is provided, and an MR element 101 exhibiting a magnetoresistance effect is embedded in the inter-shield gap.

The MR element 101 changes its resistance value in response to a change in an external magnetic field. One end of the MR element 101 has an air bearing surface (ABS) of a flying slider.
The MR head 100 is provided on one end face (medium facing surface) side of the MR head 100 so as to face the outside. MR
The element 101 has an AMR exhibiting an anisotropic magnetoresistance effect.
(Anistropic Magneto-Resistive) elements and GMR (Giant Magneto-Resistive) elements exhibiting a giant magnetoresistive effect. In recent years, GMRs with higher reproduction sensitivity have been obtained.
Elements are mainly used.

As a structure of the GMR element, for example, a structure called a spin valve has been proposed, and the GMR element having the spin valve structure has been widely used as the MR element 101. Here, the MR element 1
An example in which a GMR element having a spin valve structure is used as 01 will be described.

In this GMR element having a spin valve structure, a first ferromagnetic film (free layer), a non-magnetic conductive film, a second ferromagnetic film (pin layer), and an antiferromagnetic film are sequentially laminated. The magnetization direction of the pinned layer is fixed by the bias magnetic field from the antiferromagnetic film, and the magnetization direction of the free layer rotates according to the signal magnetic field. In such a GMR element having a spin valve structure, Barkhausen noise caused by the movement of the domain wall of the free layer poses a problem. Then, M
In the R head 100, this GMR element (MR element 10
A pair of bias layers 106 and 107 for suppressing Barkhausen noise are provided at both ends of 1).

In the MR head 100, a pair of electrode layers 108 and 107 are formed on the pair of bias layers 106 and 107.
109 are formed, and these electrode layers 108 and 109 are formed.
By supplying a sense current to the MR element 101 via the interface, a change in the resistance value of the MR element 101 can be detected as a voltage change.

The MR head 100 configured as described above
Is formed on the end surface of the flying slider so that the medium facing surface is located on the air lubrication surface side of the flying slider. In the MR head 100, the resistance value of the MR element 101 changes according to the signal magnetic field from the magnetic disk by supplying a sense current to the MR element 101 with the flying slider flying above the magnetic disk. Will do. Then, a change in the resistance value of the MR element 101 in accordance with the signal magnetic field from the magnetic disk is detected as a voltage change via the electrode layers 108 and 109.

Incidentally, in such an MR head 100, it is desired to further improve the reproduction sensitivity in order to cope with a further increase in the recording density. In order to improve the reproduction sensitivity, it is effective to increase the current density of the sense current supplied to the MR element 101 via the electrode layers 108 and 109. The amount of heat generated increases, and the temperature of the MR element 101 rises. Then, when the temperature of the MR element 101 rises, electromigration, which is element destruction due to heat generation and current, occurs, and there is a problem that the reliability of the MR head 100 is reduced.

As a method for solving such a problem, JP-A-5-205224 and JP-A-11-15431 are known.
In Japanese Patent Application Publication No. 0-104, etc., the lower insulating film 104 and the upper insulating film 105 constituting the gap between the shields are made of AlN or SiC having a higher thermal conductivity than Al ₂ O ₃ or SiO ₂ generally used so far. And a technique using an insulating material such as DLC (diamond-like carbon).

If such an insulating material having a high thermal conductivity is used for the lower insulating film 104 and the upper insulating film 105, the heat generated in the MR element 101 causes the lower insulating film 1
04 and the upper insulating film 105 are efficiently transmitted and diffused through the lower insulating film 104 and the upper insulating film 105, thereby suppressing the temperature rise of the MR element 101 and effectively preventing the occurrence of electromigration. It becomes possible.

[0016]

By the way, the high recording density of a magnetic disk used as a recording medium in a hard disk drive is realized mainly by narrowing the recording track and improving the recording linear density. . In order to cope with the improvement in the recording linear density of the magnetic disk, the gap between the shields of the MR head 100 is being narrowed.

As described above, when the gap between the shields is narrowed, in the MR head 100, it is important to ensure the insulating property of the lower insulating film 104 and the upper insulating film 105 constituting the gap between the shields. . That is, if insulation failure occurs between the lower magnetic shield layer 102 or the upper magnetic shield layer 103 and the MR element 101,
Since the element destruction of the MR element 101 is caused, it is important to ensure insulation by the lower insulating film 104 and the upper insulating film 105 even when the gap between the shields is narrowed.

However, in order to suppress the temperature rise of the MR element 101, the lower insulating film 104 and the upper insulating film 10
In the case where an insulating material having a high thermal conductivity such as AlN, SiC, DLC (diamond-like carbon), or the like described above is used, the insulating material may be Al ₂ O ₃ or SiO ₂ which has been generally used in the past. Since the withstand voltage is low as compared with the above, there is a problem that it is difficult to secure insulation when the gap between the shields is narrowed.

The present invention has been made in view of the above-described conventional circumstances, and suppresses the temperature rise of the MR element to effectively prevent the occurrence of electromigration while maintaining the gap between the shields. An object of the present invention is to provide a magnetoresistive magnetic head capable of ensuring insulation and effectively coping with high density, and a method of manufacturing the same.

[0020]

In the magnetoresistive head according to the present invention, a pair of upper and lower magnetic shield layers are laminated via a gap between the shields, and a magnetoresistive element which exhibits a magnetoresistive effect is provided. In the magnetoresistive head having a structure disposed in the gap between the shields such that one end is exposed from a medium facing surface of the magnetoresistive head facing the magnetic recording medium, the gap between the shields is preferably An upper insulating film and a lower insulating film formed so as to include at least a position overlapping the magnetoresistive element in the stacking direction, at least one of the pair of magnetic shield layers, and the medium facing surface of the magnetoresistive element. And a rear insulating film formed so as to be in contact with the other end on the side separated from the upper insulating film and the lower insulating film. It is characterized by comprising a higher insulating material having a thermal conductivity compared.

In this magneto-resistance effect type magnetic head, heat generated in the magneto-resistance effect element is converted into an insulating material having a high thermal conductivity, specifically, for example, any one of AlN, SiC, DLC (diamond-like carbon). The light is efficiently transmitted to one or more types of rear insulating films, and is diffused through the rear insulating films. Insulation between the pair of upper and lower magnetic shield layers and the magnetoresistive element is ensured by the upper insulating film and the lower insulating film.

Further, in the method of manufacturing a magnetoresistive head according to the present invention, a pair of upper and lower magnetic shield layers are laminated via a gap between shields, and a magnetoresistive element exhibiting a magnetoresistive effect is provided at one end. A magnetic head for manufacturing a magnetoresistive head having a structure disposed in the gap between the shields by a thin film process so that a portion is exposed from a medium facing surface of the magnetoresistive head facing the magnetic recording medium. A method of manufacturing a resistance effect type magnetic head, comprising: sequentially forming a lower insulating film constituting the gap between shields and a magnetoresistive effect film which finally becomes the magnetoresistive effect element on a lower magnetic shield layer. After forming, or after forming an upper insulating film constituting the gap between the shields on the magnetoresistive effect film, etching using a resist pattern is performed. Forming a part of the magnetoresistive film except for a part of the magnetoresistive film on the medium facing surface side to form the magnetoresistive device, and a portion where the magnetoresistive film is removed by the etching. Forming an insulating material having a higher thermal conductivity than the upper insulating film and the lower insulating film to form a rear insulating film forming the gap between the shields together with the upper insulating film and the lower insulating film; It is characterized by having.

According to the method of manufacturing the magnetoresistive head, the upper insulating film and the lower insulating film are formed such that the gap between the shields includes at least a position overlapping the magnetoresistive element in the stacking direction. And a rear insulating film formed so as to be in contact with at least one of the magnetic shield layers and the other end of the magnetoresistive effect element which is separated from the medium facing surface, wherein the rear insulating film comprises an upper insulating film and a lower insulating film. It is possible to appropriately manufacture a magnetoresistance effect type magnetic head made of an insulating material having a higher thermal conductivity than a film.

According to the method of manufacturing a magneto-resistance effect type magnetic head, the rear insulating film is formed after performing the etching using the resist pattern.
The rear insulating film is formed using an insulating material having a property of being easily dissolved in an alkaline aqueous solution used for forming a resist pattern, specifically, for example, one or more of AlN, SiC, and DLC (diamond-like carbon). Even in this case, corrosion of the rear insulating film can be prevented beforehand, and a highly reliable magnetoresistive head can be manufactured.

In the magnetoresistive head manufactured by this method, no step is formed in the upper insulating film at the other end of the magnetoresistive head.
Better insulation can be ensured.

[0026]

Embodiments of the present invention will be described below in detail with reference to the drawings. Here, a magnetoresistive head (hereinafter referred to as an MR head) used as a reproducing head element in a hard disk drive.
Will be described. When an MR head is used as a reproducing head element in a hard disk drive, it is usually configured as a composite magnetic head in which an inductive thin film head as a recording head element is formed on the MR head. Here, description of the inductive type thin film head is omitted.

The drawings used in the following description schematically show the structure of each part in order to easily illustrate the features of the present invention, and the shapes, dimensional ratios, etc. of the parts are the same as actual ones. Not necessarily. In the following, the configuration and material of each thin film constituting the MR head will be described with specific examples. However, the MR head according to the present invention is not limited to the examples described below, The configuration, material, and the like of each thin film may be appropriately selected depending on the purpose and performance.

FIG. 1 shows an example of an MR head to which the present invention is applied.
And FIG. MR head 1 shown in FIGS. 1 and 2
Is mounted on a flying slider that levitates on a magnetic disk that rotates at a high speed, and reads a magnetic signal recorded on the magnetic disk. A substrate serving as a flying slider, specifically, for example, Altic (Al ₂₎ the O ₃ -TiC) on a substrate made of a hard material, such as, through the base layer, the MR
Each thin film constituting the head 1 is sequentially laminated.

In the MR head 1, an inter-shield gap 4 is provided between the lower magnetic shield layer 2 and the upper magnetic shield layer 3, and a magneto-resistance effect element (hereinafter referred to as an MR element) is provided in the inter-shield gap 4. .), Which is a so-called shield type MR head in which 5 is embedded.

The lower magnetic shield layer 2 and the upper magnetic shield layer 3 are formed of a soft magnetic material such as Sendust (Fe-Al-Si alloy), Fe-Si-Ru-Ga alloy, Fe-Ta-N alloy. Have been. The MR head 1 has a structure in which the lower magnetic shield layer 2 and the upper magnetic shield layer 3 sandwich the gap 4 between the shields in which the MR elements 5 are provided, thereby shielding the magnetic field outside the reproduction target from the magnetic field. It is prevented from being led to the element 5. That is, in the MR head 1, the magnetic field outside the reproduction target is guided to the lower magnetic shield layer 2 and the upper magnetic shield layer 3, and only the signal magnetic field to be reproduced is guided to the MR element 5. Thereby, in the MR head 1, the frequency characteristics and the reading resolution of the MR element 5 are improved.

The resistance of the MR element 5 changes in accordance with the change in the external magnetic field. One end of the MR element 5 faces the outside from an air bearing surface (ABS) of the flying slider. The MR head 1 is provided on one end surface (medium facing surface) 1a side. Here, G of a spin valve structure showing a giant magnetoresistance effect is used.
An example in which an MR (Giant Magneto-Resistive) element is used as the MR element 5 will be described. A GMR element having another structure or an AMR (Anistropic Magnet) exhibiting an anisotropic magnetoresistance effect will be described.
A neto-Resistive element may be used as the MR element 5.

The MR element 5 (a GMR element having a spin valve structure) is a first element made of, for example, a Ni—Fe alloy, Co, a Co—Fe alloy, a Co—Ni alloy, a Ni—Fe—Co alloy, or the like. A ferromagnetic film (free layer), a nonmagnetic conductive layer made of, for example, Cu or the like, and a Ni—Fe alloy or C
o, Co-Fe alloy, Co-Ni alloy, Ni-Fe
-A second ferromagnetic film (pin layer) made of a Co-based alloy or the like;
For example, an antiferromagnetic film made of a Pt—Mn alloy or the like is sequentially laminated, the magnetization direction of the pinned layer is fixed by a bias magnetic field from the antiferromagnetic film, and the magnetization direction of the free layer is rotated according to the signal magnetic field. It is supposed to.

At both ends of the MR element 5 in the track width direction, a pair of bias layers 6 and 7 for suppressing Barkhausen noise are provided. The pair of bias layers 6 and 7 are made of a Co—Pt alloy or a Co—Pt alloy, respectively.
It is made of a hard magnetic material such as a Cr-Pt alloy and is formed so as to be magnetically and electrically connected to both ends in the track width direction of the MR element 5. The pair of bias layers 6 and 7 have a function of applying a bias magnetic field to the free layer of the MR element 5 and converting the magnetic domain of the free layer into a single magnetic domain to suppress Barkhausen noise.

On the pair of bias layers 6 and 7, M
A pair of electrode layers 8 and 9 for supplying a sense current to the R element 5 are provided. The pair of electrode layers 8 and 9 are made of, for example, a conductive metal material such as Cr, Ta, or Cu, and are formed so as to be electrically connected to the MR element 5. The MR head 1 includes a pair of these electrode layers 8,
9 to supply a sense current to the MR element 5 via
A change in resistance according to the signal magnetic field of the MR element 5 can be detected as a change in voltage.

The pair of electrode layers 8 and 9 correspond to FIG.
As shown in (1), it may be formed so as to overlap on the MR element 5. When the pair of electrode layers 8 and 9 are formed on the MR element 5 so as to overlap with each other, the sense current from the pair of electrode layers 8 and 9 increases the electric contact resistance due to the adhesion of foreign matter or the like. Without passing through the interface between the pair of bias layers 6 and 7 and the MR element 5 which may possibly cause the MR element 5, the sense current is supplied to the MR element 5 directly through the overlapped portion. And a more stable reproduction operation can be performed.

The gap 4 between the shields secures insulation between the lower magnetic shield layer 2 and the upper magnetic shield layer 3 and the MR element 5 and transfers heat generated in the MR element 5 to the lower magnetic shield layer 2 and the upper magnetic shield layer. This is for guiding to the shield layer 3 for radiation. In the MR head 1 to which the present invention is applied, the gap 4 between the shields has at least an MR gap.
An upper insulating film 11 and a lower insulating film 12 formed so as to include a position overlapping with the element 5 in the stacking direction, at least one of the lower magnetic shield layer 2 and the upper magnetic shield layer 3 and a medium facing surface of the MR element 5 And a rear insulating film 13 formed so as to be in contact with an end (a position where the depth becomes zero) on the side away from 1a.

The upper insulating film 11 and the lower insulating film 12 are located at positions where a non-magnetic non-conductive material such as Al ₂ O ₃ or SiO ₂ , which can provide relatively high insulating properties, at least overlaps the MR element 5 in the laminating direction. And a thin film is formed. That is, in this MR head 1, the MR element 5
Structure sandwiched between the lower magnetic shield layer 2 and the upper magnetic shield layer 3 via the upper insulating film 11 and the lower insulating film 12 made of Al ₂ O ₃ , SiO _2, or the like from which relatively high insulating properties can be obtained. It has become. Therefore, in the MR head 1, the insulation between the lower magnetic shield layer 2, the upper magnetic shield layer 3, and the MR element 5 is favorably provided by the upper insulating film 11 and the lower insulating film 12 forming the gap 4 between the shields. Will be kept. In particular, Al ₂ O ₃ or S ₂ used as a material of the upper insulating film 11 and the lower insulating film 12 is used.
Since iO _{2 and the} like have a high withstand voltage and can secure sufficient insulation even when the film thickness is reduced, in the MR head 1 to which the present invention is applied, the MR element 5 causes dielectric breakdown or the like. Without the upper insulating film 11 and the lower insulating film 1
2, the gap 4 between the shields can be narrowed and the recording linear density of the magnetic disk can be easily improved.

By the way, Al ₂ O ₃ , SiO _2, etc. used as the material of the upper insulating film 11 and the lower insulating film 12 are as follows:
While having high insulation properties, it has a characteristic of low thermal conductivity. There is a trade-off between these insulating properties and the thermal conductivity, and generally, a material having a higher insulating property tends to have a lower thermal conductivity. Therefore, Al
_{When the} gap 4 between the shields is formed only of a material having a relatively high insulating property such as ₂ O ₃ or SiO ₂ , the lower magnetic shield layer 2 and the upper magnetic shield layer 3 and the MR element 5
However, the function of conducting the heat generated in the MR element 5 to the lower magnetic shield layer 2 and the upper magnetic shield layer 3 and dissipating the heat may not be sufficiently exhibited.

In particular, in the MR head 1, the current density of the sense current supplied to the MR element 5 tends to be increased in order to further improve the reproduction sensitivity in order to cope with the further increase in the recording density. . With the increase in the current density of the sense current, the MR element 5
Tends to increase. Under these circumstances, since the gap 4 between the shields is made of only a material having a low thermal conductivity, the function of guiding the heat generated in the MR element 5 to the lower magnetic shield layer 2 and the upper magnetic shield layer 3 and dissipating the heat is sufficient. Otherwise, the temperature of the MR element 5 will rise excessively, and the MR element 5 will be destroyed by electro-migration.

Therefore, in the MR head 1 to which the present invention is applied, the upper shield film 11 and the lower insulating film 12 formed so that the gap 4 between the shields includes at least the position overlapping the MR element 5 in the stacking direction. A rear insulating film formed so as to be in contact with at least one of the lower magnetic shield layer 2 and the upper magnetic shield layer 3 and the end (position where the depth becomes zero) of the MR element 5 on the side away from the medium facing surface. 13 and the material of the rear insulating film 13 is Al ₂ used for the upper insulating film 11 and the lower insulating film 12.
A material having a higher thermal conductivity than O ₃ or SiO ₂ , for example,
At least one kind of insulating material of AlN, SiC, and DLC (diamond-like carbon) is used.

Specifically, in the MR head 1, for example,
As shown in FIGS. 1 and 2, a position overlapping with the MR element 5 provided on the medium facing surface 1 a side of the MR head 1 in the laminating direction, that is, immediately above and immediately below the MR element 5,
_An upper insulating film 11 and a lower insulating film 12 made of ₂ O ₃ , SiO _2, or the like are provided, and the lower magnetic shield layer 2 and the upper magnetic shield layer 3 are located on the side of the MR element 5 farther from the medium facing surface 1 a. And AlN, SiC, D, so as to be in contact with the end of the MR element 5 on the side away from the medium facing surface 1a.
A rear insulating film 13 made of at least one of LC (diamond-like carbon) is provided, and these films constitute the gap 4 between the shields.

As described above, in the MR head 1 to which the present invention is applied, as a material of each film constituting the gap 4 between the shields, an insulating material having different characteristics depending on the formation position of each film and its required function. Is used to secure insulation between the lower magnetic shield layer 2 and the upper magnetic shield layer 3 and the MR element 5 in the gap 4 between the shields, and the heat generated in the MR element 5 is transferred to the lower magnetic shield layer 2. In addition, both the function and the function of conducting the radiation to the upper magnetic shield layer 3 and dispersing them are more reliably exerted. That is,
In this MR head 1, immediately above and immediately below the MR element 5 for which insulation between the lower magnetic shield layer 2 and the upper magnetic shield layer 3 and the MR element 5 is required to be ensured, Table 1
As shown in the figure, Al ₂ O ₃
And the upper insulating film 11 and the lower insulating film 1 made of SiO ₂ or the like
2 is arranged. Then, as shown in Table 1, the portion on the side more distant from the medium facing surface 1a than the MR element 5 where the volume as an insulating film can be secured, as shown in Table 1, compared with Al ₂ O ₃ or SiO _2. A with high conductivity
1N, SiC, DLC (diamond-like carbon)
A rear insulating film 13 made of at least one of the following:
The heat generated in the MR element 5 is more effectively conducted to the lower magnetic shield layer 2 and the upper magnetic shield layer 3 so as to suppress the temperature rise of the MR element 5 and prevent the occurrence of electromigration.

[0043]

[Table 1]

Actually, the MR head 1 to which the present invention is applied, which has the rear insulating film 13 made of AlN, and the conventional MR head, in which the gap 4 between the shields is formed only by Al ₂ O ₃ , are manufactured. When the resistance of the MR element was measured while changing the value of the sense current supplied to the MR head, the result shown in FIG. 4 was obtained. here,
The reason for measuring the resistance value of the MR element is that the resistance value of the MR element generally rises due to the temperature rise, so that the element temperature of the MR element can be indirectly measured by measuring the resistance value of the MR element. It is.

From the results shown in FIG. 4, in the MR head 1 to which the present invention is applied, using a material having a high thermal conductivity such as AlN, the magnetic head 1 on the side more distant from the medium facing surface 1a than the MR element 5 By forming the rear insulating film 13 in a portion where a volume as an insulating film can be secured, the temperature rise of the MR element 5 is reduced as compared with the conventional MR head in which the gap 4 between the shields is formed only by Al ₂ O _3. As a result, it was confirmed that the effect of preventing the occurrence of electromigration was obtained.

Incidentally, the MR head 1 to which the present invention is applied
The AlN or SiC used for the rear insulating film 13
As shown in Table 1, the insulating material such as Al ₂ O ₃ or S ₂ used for the upper insulating film 11 and the lower insulating film 12 is used.
The internal stress is much larger than that of iO ₂ or the like. If an insulating film is formed by forming a material having a large internal stress at a position overlapping with the MR element 5 in the laminating direction, there is a disadvantage that the insulating film is easily peeled off. However, in the MR head 1 to which the present invention is applied, the upper insulating film 1 formed at a position overlapping the MR element 5 in the laminating direction.
Since Al ₂ O ₃ , SiO _2, or the like having relatively small internal stress is used as the material of the lower magnetic film 1 and the lower insulating film 12, the lower magnetic shield layer 2 and the upper magnetic layer 2 can be formed without causing such inconvenience. The insulation between the shield layer 3 and the MR element 5 can be more reliably maintained.

In the MR head 1 to which the present invention is applied, as shown in FIG. 5, the upper insulating film 11 is formed on the rear insulating film 13 at a position separated from the medium facing surface 1a from immediately above the MR element 5. And the rear insulating film 13 is formed
It may be formed so as to contact only the lower magnetic shield layer 2 of the pair of upper and lower magnetic shield layers 2 and 3.
As shown in FIG. 6, the lower insulating film 12 is formed from directly below the MR element 5 to below the rear insulating film 13 at a position separated from the medium facing surface 1a.
It may be formed so as to contact only the upper magnetic shield layer 3 of the pair of upper and lower magnetic shield layers 2 and 3.
In these cases, the heat dissipation effect is slightly inferior to the above-described example in which the rear insulating film 13 contacts both the lower magnetic shield layer 2 and the upper magnetic shield layer 3, but the effect is almost the same as the above-described example. Obtainable.

Next, a method of manufacturing the MR head 1 according to the present invention configured as described above will be described. Incidentally, the MR head 1 is usually formed on a substrate serving as a flying slider in batches for a plurality of MR heads, and the substrate on which the plurality of MR heads are formed is cut, so that the individual MR heads 1 are finally formed as individual heads. Although completed, only a portion corresponding to one MR head 1 is illustrated and described here.

When manufacturing the MR head 1 to which the present invention is applied, first, a substrate (not shown) made of, for example, AlTiC (Al ₂ O ₃ —TiC) is placed on a substrate (not shown) made of Al ₂ O ₃ or the like via a base film made of Al ₂ O ₃ or the like. A lower magnetic shield layer 2 made of a soft magnetic material such as Sendust (Fe-Al-Si alloy);
For example, a lower insulating film 11 made of an insulating material such as Al ₂ O ₃ is formed as a thin film by sputtering or the like. Then, as shown in FIG. 7, a first ferromagnetic film (free layer) made of, for example, a Ni—Fe alloy and a nonmagnetic conductive layer made of, for example, Cu, are formed over the entire surface of the lower insulating film 11. And a second ferromagnetic film (pinned layer) made of, for example, a Ni—Fe alloy, and an antiferromagnetic film made of, for example, a Pt—Mn alloy, which are sequentially formed into thin films by sputtering or the like. 5 is formed.

Next, a lift-off pattern is formed on the MR film 20 using a resist material, and etching such as ion milling is performed using the lift-off pattern as a mask, so that the MR element 5 is located outside both ends in the track direction. The MR film 20, that is, the MR film 20 that is not required for the MR element 5 is removed. And MR film 2
In a portion where 0 is removed, a pair of bias layers 6 and 7 made of a hard magnetic material such as a Co—Pt alloy, for example, and Cu
A pair of electrode layers 8 and 9 made of a conductive metal material such as are formed as thin films by sputtering or the like. Then, by removing the lift-off pattern using an organic solvent, a pair of bias films 6 and 7 and a pair of electrode layers 8 and 9 are buried on both left and right sides of the MR film 20, as shown in FIG. State.

At this time, the pair of electrode layers 8 and 9
As previously shown in FIG. 3, the M
It may be formed so as to overlap on the R film 20. In order to form the pair of electrode layers 8 and 9 so as to overlap on the MR film 20 which will eventually become the MR element 5, a so-called two-layer resist having an undercut as the lift-off pattern is used. A resist having an inverse tapered shape may be deposited on the upper surface of the MR film 20 by obliquely entering a conductive metal material to be an electrode layer. In addition, the lift-off pattern used for removing the MR film 20 is removed after forming the pair of bias layers 6 and 7, and a slightly smaller lift-off pattern is newly formed. The layers 8 and 9 may be formed.

After burying a pair of bias films 6 and 7 and a pair of electrode layers 8 and 9 on the left and right sides of the MR film 20, respectively, next, as shown in FIG. A over the entire surface on the pair of electrode layers 8 and 9 on both sides,
An upper insulating film 12 made of an insulating material such as l ₂ O ₃ is formed as a thin film by sputtering or the like.

Next, as shown in FIG.
2, a lift-off pattern 30 having a substantially U-shape in plan view is formed by a resist material.
0 is used as a mask to perform an etching process such as ion milling, and the MR film 2 at a position separated from the medium facing surface 1a.
0, that is, the MR film 2 not required as the MR element 5
0 and a pair of bias layers 6 and 7 and a pair of electrode layers 8 and 9
, And the upper insulating film 12 located immediately above them is removed. Thus, the element height (depth) of the MR element 5 in the direction approaching to and away from the medium facing surface 1a is defined.

At this time, if necessary, the removed MR film 20 and the pair of bias layers 6 and 7 and the pair of electrode layers 8 and 9 are removed.
May be removed at the same time, the lower insulating film 13 located directly below a part of the substrate and separated from the medium facing surface 1a. As described above, when the lower insulating film 13 on the side separated from the medium facing surface 1a is also removed at the same time, finally, FIG.
As shown in FIG. 2, the MR head 1 having a structure in which the rear insulating film 13 contacts both the lower magnetic shield layer 2 and the upper magnetic shield layer 3 is manufactured. On the other hand, when the lower insulating film 13 is not removed, the rear insulating film 13 finally contacts only the upper magnetic shield layer 3 of the pair of upper and lower magnetic shield layers 2 and 3 as shown in FIG. The MR head 1 having the structure described above is manufactured.

Next, a material such as AlN, for example, Al used as a material of the upper insulating film 11 and the lower insulating film 12 is filled in the recess formed on the side separated from the medium facing surface 1a by the above-described etching process. _An insulating material having a higher thermal conductivity than ₂ O ₃ or the like is formed by sputtering or the like, and the rear insulating film 13 is formed. Then, by removing the lift-off pattern 30 using an organic solvent, as shown in FIG. 11, the upper insulating film 11 and the lower insulating film 12 are shielded together with the upper insulating film 11 and the lower insulating film 12 in the recess formed on the side separated from the medium facing surface 1a. The rear insulating film 13 forming the gap 4 is buried.

After the rear insulating film 13 is buried in the concave portion formed on the side away from the medium facing surface 1a, next, FIG.
As shown in FIG. 2, over the entire surface of the rear insulating film 13 and the remaining upper insulating film 12, for example, sendust (Fe-Al
An upper magnetic shield layer 3 made of a soft magnetic material such as -Si alloy) is formed as a thin film by sputtering or the like. Thus, the MR head 1 having the structure shown in FIGS. 1 and 2 or the MR head 1 having the structure shown in FIG. 6 is completed.

As described above, when the pair of electrode layers 8 and 9 are formed so as to overlap on the MR film 20 which will eventually become the MR element 5, the MR film 2
The lift-off pattern used to remove the 0 is removed after forming the pair of bias layers 6 and 7, and a slightly smaller lift-off pattern is newly formed, and the lift-off pattern is used as a mask to form the pair of electrode layers 8 and 9. When forming the pair of electrode layers 8 and 9, M
It is necessary to perform an etching process for defining the depth of the R element 5.

In this case, at the stage where the pair of bias layers 6 and 7 are buried in the portion where the MR film 20 has been removed by the first etching process, the above-described lift-off pattern 30 having a substantially U-shaped plane is formed. Then, etching is performed using the lift-off pattern 30 as a mask to control the depth of the MR element 5. Then, in the recess formed on the side separated from the medium facing surface 1a by this etching process, for example, AlN or the like is formed by sputtering or the like to form the rear insulating film 13. afterwards,
A pair of electrode layers 8 and 9 are finally formed so as to overlap on the MR element 5, and an insulating material such as Al ₂ O ₃ is formed over the entire surface of the MR element 5 and the pair of electrode layers 8 and 9. An upper insulating film 12 made of a material is formed as a thin film by sputtering or the like. Finally, the upper magnetic shield layer 3 is formed as a thin film over the entire surface of the upper insulating film 12 by sputtering or the like. Thereby, as shown in FIG. 5, the MR head 1 having a structure in which the rear insulating film 13 contacts only the lower magnetic shield layer 2 of the pair of upper and lower magnetic shield layers 2 and 3 is completed.

If the MR head 1 is manufactured by the above-described method, the upper insulating film 11 and the lower insulating film 11 are formed so that the gap 4 between the shields at least includes the position overlapping the MR element 5 in the stacking direction. The film 12 is formed so as to be in contact with at least one of the lower magnetic shield layer 2 and the upper magnetic shield layer 3 and the end (position where the depth becomes zero) of the MR element 5 on the side separated from the medium facing surface. And the rear insulating film 13 to which the present invention is applied.
The R head 1 can be manufactured appropriately.

Further, according to the above-described method, after the etching is performed using the lift-off pattern 30 to control the depth of the MR element 5, the rear insulating film 13 made of AlN or the like is formed. Therefore, it is possible to prevent the disadvantage that the rear insulating film 13 is corroded during the manufacturing process. That is, the insulating material such as AlN used for the rear insulating film 13 has a property of easily dissolving in the alkaline aqueous solution used for forming the lift-off pattern 30, and is formed by etching using the lift-off pattern 30 after forming the rear insulating film 13. When the depth control of the MR element 5 is performed, there is a problem that the rear insulating film 13 is dissolved in an alkaline aqueous solution and corroded, and the reliability of the completed MR head 1 is reduced. However, if the MR head 1 is manufactured by the above-described method, such a problem can be prevented beforehand and the highly reliable MR head 1 can be manufactured.

Further, according to the above-described method, since a large step is not formed in each insulating film forming the gap 4 between the shields, the MR manufactured by this method is not used.
The gap 4 between the shields of the head 1 can have very good insulation. That is, FIG. 14 and FIG.
In the MR head having the conventional structure shown in FIG.
A relatively large step is formed in the upper insulating film 105 on the end (position where the depth becomes zero) on the side away from the medium facing surface. For this reason, the thickness of the upper insulating film 105 in the portion where the step is formed is locally reduced, and good insulating properties may not be secured in some cases. On the other hand, in the MR head 1 manufactured by the above-described method, a large step is not formed in each insulating film constituting the gap 4 between the shields.
Can have very good insulation properties.

Actually, in the MR head 1 having the structure as shown in FIG. 5, the states of the upper surface of the MR element 5 and the upper surface of the rear insulating film 13 are determined by using an atomic force microscope (AFM).
FIG. 13 shows a cross-sectional profile of the measurement result using an icroscope). From FIG. 13, in the MR head 1 having the structure as shown in FIG. 5, the upper surface of the MR element 5 and the upper surface of the rear insulating film 13 form the same plane with almost no step. It can be understood that a large step is not formed in the upper insulating film 11 formed from the upper surface of the upper insulating film 11 to the upper surface of the rear insulating film 13.

[0063]

According to the magnetoresistive head according to the present invention, the upper insulating film and the lower insulating film constituting the gap between the shields provide insulation between the pair of upper and lower magnetic shield layers and the magnetoresistive element. The heat generated in the magnetoresistive element is effectively transmitted to the magnetic shield layer by the rear insulating film that forms the gap between the shields together with the upper insulating film and the lower insulating film while maintaining good performance. Therefore, the insulation required for the gap between the shields can be ensured and the function of suppressing the temperature rise of the magnetoresistive element can be compatible.

Therefore, in the magnetoresistive head according to the present invention, the gap between the shields can be reduced and the sense current can be increased without causing problems such as electrostatic breakdown and electromigration of the magnetoresistive element. It is possible to increase the density, and it is possible to appropriately cope with the increase in the recording density.

Further, according to the method of manufacturing a magnetoresistive head according to the present invention, a magnetic head having both a function of ensuring insulation required for a gap between shields and a function of suppressing a temperature rise of the magnetoresistive element is achieved. The resistance effect type magnetic head can be manufactured appropriately.

According to the method of manufacturing a magneto-resistance effect type magnetic head according to the present invention, the rear insulating film made of an insulating material which is easily soluble in an alkaline aqueous solution such as AlN is corroded during the manufacturing process. Inconveniences can be prevented beforehand and a highly reliable magnetoresistive head can be manufactured.

Further, according to the method of manufacturing a magnetoresistive head according to the present invention, since a large step is not formed in each insulating film constituting the gap between the shields, the insulating property of the gap between the shields is reduced. Can be further improved.

[Brief description of the drawings]

FIG. 1 is a perspective view schematically showing an MR head to which the present invention is applied.

FIG. 2 is a longitudinal sectional view of the MR head taken along a line X1-X2 in FIG. 1;

FIG. 3 is a perspective view showing a state where a pair of electrode layers are formed so as to overlap on an MR element.

FIG. 4 shows a current value of a sense current supplied to an MR head and M.
FIG. 4 is a diagram illustrating a relationship with a resistance value of an R element.

FIG. 5 is a view showing another example of the MR head to which the present invention is applied, and is a longitudinal sectional view of an MR head having a structure in which a rear insulating film contacts only a lower magnetic shield layer of a pair of upper and lower magnetic shield layers. is there.

FIG. 6 is a view showing still another example of an MR head to which the present invention is applied, and is a longitudinal sectional view of an MR head having a structure in which a rear insulating film contacts only an upper magnetic shield layer of a pair of upper and lower magnetic shield layers. It is.

FIG. 7 is a diagram for explaining a method of manufacturing an MR head to which the present invention is applied, and is a perspective view showing a state in which a lower magnetic shield layer, a lower insulating film, and an MR film are laminated on a substrate.

FIG. 8 is a diagram for explaining a method of manufacturing an MR head to which the present invention is applied, in which the left and right ends of the MR film are removed by etching, and a pair of bias layers and a pair of electrode layers are provided at portions where the MR film has been removed; FIG. 6 is a perspective view showing a state in which are embedded.

FIG. 9 is a diagram for explaining a method of manufacturing an MR head to which the present invention is applied, and is a perspective view showing a state in which an upper insulating film is formed over the entire surface of the MR film and a pair of electrode layers.

FIG. 10 is a diagram for explaining a method of manufacturing an MR head to which the present invention is applied, in which a lift-off pattern is formed on an upper insulating film, and the lift-off pattern is used as a mask to perform etching on the side separated from the medium facing surface. FIG. 9 is a perspective view showing a state in which the MR film has been removed and depth control of the MR element has been performed.

FIG. 11 is a diagram for explaining a method of manufacturing an MR head to which the present invention is applied, in which a rear insulating film is buried in a concave portion formed on a side away from the medium facing surface by etching for controlling the depth of the MR element; It is a perspective view showing the situation where it was done.

FIG. 12 is a diagram for explaining the method of manufacturing the MR head to which the present invention is applied, and is a perspective view showing a state in which an upper magnetic shield layer is formed over the entire surface of the rear insulating film and the remaining upper insulating film. It is.

FIG. 13 shows the state of the upper surface of the MR element and the upper surface of the rear insulating film using an atomic force microscope in an MR head having a structure in which the rear insulating film contacts only the lower magnetic shield layer of the pair of upper and lower magnetic shield layers. It is a figure showing the section profile obtained by measurement.

FIG. 14 is a perspective view schematically showing an example of a conventional MR head.

FIG. 15 is a longitudinal sectional view of the conventional MR head, and is a sectional view taken along line Y1-Y2 in FIG.

[Explanation of symbols]

Reference Signs List 1 MR head, 2 Lower magnetic shield layer, 3 Upper magnetic shield layer, 4 Shield gap, 5 M
R element, 11 upper insulating film, 12 lower insulating film,
13 Back insulation film, 20 MR film, 30 Lift-off pattern

Claims (4)

[Claims] An upper and lower pair of magnetic shield layers are laminated via a gap between shields, and a magnetoresistive element which exhibits a magnetoresistive effect has one end facing a magnetic recording medium of the magnetoresistive magnetic head. In the magnetoresistive magnetic head having a structure disposed in the gap between the shields so as to be exposed from the medium facing surface, the gap between the shields includes a position overlapping at least the magnetoresistive element in the stacking direction. The upper insulating film and the lower insulating film formed as described above are formed so as to contact at least one of the pair of magnetic shield layers and the other end of the magnetoresistive element on the side separated from the medium facing surface. A rear insulating film, wherein the rear insulating film is made of an insulating material having a higher thermal conductivity than the upper insulating film and the lower insulating film. Gas-resistance effect type magnetic head. 2. The method according to claim 1, wherein the rear insulating film is made of AlN, SiC, D
2. The magnetoresistive head according to claim 1, wherein the magnetic head is made of at least one of LC (diamond-like carbon). 3. A pair of upper and lower magnetic shield layers are stacked via a gap between shields, and a magnetoresistive element which exhibits a magnetoresistive effect has one end facing a magnetic recording medium of the magnetoresistive magnetic head. A method of manufacturing a magnetoresistive magnetic head having a structure disposed in the gap between the shields so as to be exposed from the medium facing surface by a thin film process, comprising: After sequentially forming a lower insulating film constituting the gap between the shields and a magnetoresistive effect film which will eventually become the magnetoresistive effect element on the layer, or further forming the inter-shield gap on the magnetoresistive effect film. After the upper insulating film forming the gap is formed, etching using a resist pattern is performed to form one of the magnetoresistive effect films on the medium facing surface side. Forming the magnetoresistive element by removing the portions except for the above, and insulating the portion having the magnetoresistive effect film removed by the etching with higher thermal conductivity than the upper insulating film and the lower insulating film. Forming a material, and forming a rear insulating film that forms the inter-shield gap together with the upper insulating film and the lower insulating film. 4. The magnetoresistive device according to claim 3, wherein an insulating material made of at least one of AlN, SiC and DLC (diamond-like carbon) is formed to form the rear insulating film. Manufacturing method of effect type magnetic head.