JP2008153295A - Magnetoresistance effect element, magnetic head, and magnetic storage device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetoresistance effect element capable of reducing the asymmetry of a reproduced waveform even in a fine structure for a high-density recording reproduction. <P>SOLUTION: The magnetoresistance effect element (10) has an antiferromagnetic layer (11) and a first pinned layer (12) fixing the direction of a magnetization by the antiferromagnetic layer. The magnetoresistance effect element (10) further has a reference pinned layer (14) bound with the first pinned layer in an antiferromagnetic manner and running antiparallel with the first pinned layer and a free layer (16) changing the direction of the magnetization to the reference pinned layer by an external magnetic field. A length in the core-width direction of the first pinned layer is longer than that of the reference pinned layer. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a magnetoresistive effect element used for reproduction in a thin film magnetic head.

  The magnetoresistive head (hereinafter also referred to as “MR head”) is a head using a magnetoresistive element (hereinafter also referred to as “MR element”) as a reproducing unit. The MR head is an advantageous magnetic head for increasing the recording density and miniaturization of the magnetic recording apparatus because the reproduction output does not depend on the relative speed between the magnetic recording medium and the magnetic head. In recent years, a composite thin film magnetic head in which an MR head for reproduction and an induction type magnetic recording head for recording are integrated has become the mainstay.

  As an MR element, a spin valve film mainly composed of a free layer, an intermediate layer, a pinned layer, and an antiferromagnetic layer is known, but as shown in FIG. Also known is a laminated ferri-type spin valve film mainly composed of a free layer 106, an intermediate layer 105, a reference pinned layer 104, an intermediate layer 103, a first pinned layer 102, and an antiferromagnetic pinning layer 101 with enhanced magnetic field resistance. It has been.

  In order to obtain a high resistance change as one of the structures aiming at high sensitivity as compared with the structure in which current flows in the in-plane direction of the stack (CIP structure), the direction of current flow is perpendicular to the stack surface of the MR element. A structure (CPP structure) in which current flows in any direction is also employed.

  In the case of an MR head using an MR element, in the case of a laminated ferrimagnetic spin valve film, a resistance change occurs depending on the angle formed by the magnetization of the free layer 106 and the magnetization of the reference pinned layer 104. With this MR head, in order to obtain the highest sensitivity and a reproduced waveform with good vertical asymmetry, when the medium magnetic field does not enter, the magnetization of the free layer 106 is substantially in the core width direction, and the upward direction Alternatively, it is important that the magnetization of the free layer 106 tilts in the element height direction when a downward medium magnetic field is applied.

  By the way, in the MR head using the MR element, when the MR element does not have a single magnetic domain, Barkhausen noise is generated and the reproduction output fluctuates greatly. In order to control the magnetic domain of the MR element, a high coercivity film typified by CoPt or the like, or a laminated film of an antiferromagnetic film and a ferromagnetic film typified by PdPtMn or the like as a magnetic domain control film, the track width direction of the MR element A structure provided on both sides (parallel to the core width direction) or a structure provided by stacking an antiferromagnetic film on the MR element are adopted. This magnetic domain control film is free when there is no medium magnetic field. There is also an effect of matching the magnetization of the layer to some extent in the core width direction.

  On the other hand, in recent years, the bit length and the track width on the medium have been abruptly narrowed along with the increase in the capacity of the magnetic disk device. While the track width becomes narrower, the length of the MR element in the element height direction is regulated by processing such as polishing and is difficult to shorten. For this reason, the aspect ratio of the length in the element height direction with respect to the track width direction of the MR element is increasing, and this causes the magnetization of the free layer 106 to be easily oriented in the element height direction.

  Further, as shown by arrows A and B in FIG. 1, the magnetic field acting on the free layer 106 is a reference pinned layer disposed closer to the magnetic field A from the first pinned layer 102 located at a distant position. Since the magnetic field B from 104 is stronger, a magnetic field in the element height direction is applied to the free layer 106 without a medium magnetic field. This difference magnetic field also causes the magnetization of the free layer 106 to deviate from the core width direction. As shown by the arrow C in FIG. 1, when the magnetic field does not enter and the magnetization of the free layer 106 is oriented in the element height direction, the vertical asymmetry of the reproduction waveform is deteriorated and the reproduction sensitivity is deteriorated. .

In order to solve this problem, the product of the film thickness of the first pinned layer 102 and the saturation magnetic flux density (t _ref × Bs _ref ) compared to the product of the film thickness of the reference pinned layer 104 and the saturation magnetic flux density (t _ref × Bs _ref ) A method of canceling the magnetic fields of the reference pinned layer 104 and the first pinned layer 102 by increasing t ₁ × Bs ₁ ) has been proposed (for example, see Patent Document 1).

In order to realize a low resistance and high sensitivity spin-valve MR element, the length of the free layer in the core width direction is made shorter than the length of the reference pinned layer and the first pinned layer in the core width direction. The structure which performs is known (for example, refer patent document 2).
JP 2006-13430 A JP 2005-167236 A

  However, the method of increasing the (film thickness × saturation magnetic flux density) of the first pinned layer with respect to the (film thickness × saturation magnetic flux density) of the reference pinned layer reduces the MR ratio in material development. Problems arise.

  In order to improve the vertical asymmetry of the reproduced waveform, it is conceivable to reduce the element height with respect to the track width (core width) of the MR element, but as described above, in the element height direction of the MR element. Since the length is limited by processing such as polishing, it is very difficult to process the length smaller than the current state.

  Accordingly, the present invention provides a magnetoresistive effect element capable of aligning the magnetization direction of the free layer when there is no medium magnetic field with the simple processing and using the conventional processing technique in the core width direction, and a manufacturing method thereof. It is an issue to provide.

  In order to solve the above problem, the length in the core width direction of the first pinned layer separated from the free layer is set longer than the length in the core width direction of the reference pinned layer adjacent to the free layer. In the present specification and claims, when the length of the first pinned layer in the core width direction is longer than the length of the upper reference pinned layer in the core width direction, the normal etching process is used. It does not mean the minute length difference due to the taper shape that inevitably occurs, but it means that the length is set differently in the design and that the difference in length appears as a step even in the manufactured product. To do.

Specifically, the magnetoresistive effect element is
(A) an antiferromagnetic layer;
(B) a first pinned layer whose magnetization direction is fixed by the antiferromagnetic layer;
(C) a reference pinned layer antiferromagnetically coupled to the first pinned layer and antiparallel to the first pinned layer;
(D) a free layer in which the direction of magnetization with respect to the reference pinned layer is changed by an external magnetic field,
(E) The length of the first pinned layer in the core width direction is longer than the length of the reference pinned layer in the core width direction.

In a favorable configuration example, a value of ½ of the difference in length in the core width direction between the first pinned layer and the reference pinned layer is in the range of 2 nm to 5 nm.
In another configuration example, a difference in length in the core width direction between the first pinned layer and the reference pinned layer is larger than a difference in length in the core width direction between the reference pinned layer and the free layer.

  Preferably, the length of each of the first pinned layer and the reference pinned layer in the core width direction is determined from the magnetic field from the first pinned layer acting on the free layer and the reference layer acting on the free layer. Is set to a length that cancels out the magnetic field.

In the second aspect, a method for producing a magnetoresistive effect element includes:
(A) a step of laminating an antiferromagnetic film, a first pinned layer, a first intermediate layer, a reference pinned layer, a second intermediate layer, and a free layer in this order;
(B) The length along the track width direction of the storage layer of the first pinned layer is the length along the track width direction of the reference pinned layer on the facing surface where the stacked body faces an arbitrary storage medium. A step of processing the laminate so as to be longer than
including.

  With the above configuration and method, it is possible to improve the vertical asymmetry of the reproduction waveform of the magnetic information read from the recording medium.

  FIG. 2 is a schematic configuration diagram of a magnetoresistive (MR) element according to an embodiment of the present invention. The MR element 10 includes a laminated ferrimagnetic spin valve structure in which an antiferromagnetic film 11, a first pinned layer 12, an intermediate layer 13, a reference pinned layer 14, an intermediate layer 15, and a free layer 16 are stacked in this order. The length of the pinned layer 12 in the core width direction is longer than the length of the reference pinned layer 14 adjacent to the free layer 16 in the core width direction.

  Here, the core width direction means a direction parallel to the track width of the medium on the medium facing surface that faces the magnetic recording medium during reproduction, as shown in FIG. On the other hand, the element height direction refers to the element height in the direction perpendicular to the magnetic recording medium during reproduction. In FIG. 2, a magnetic domain control film such as a hard layer is omitted for convenience of illustration.

  The magnetization directions of the first pinned layer 12 and the reference pinned layer 14 are fixed by the antiferromagnetic layer 11, and the magnetizations of the first pinned layer 12 and the reference pinned layer 14 are antiparallel. As a result, the net magnetization of the first pinned layer 12 and the reference pinned layer 14 is suppressed, the exchange coupling with the antiferromagnetic layer 11 is increased, and the magnetization pinning force is strengthened.

  In the example of FIG. 2, the length of the first pinned layer 12 in the core width direction is 2a larger than the length of the reference pinned layer 14 in the core width direction. By adopting such a configuration, the volume of the first pinned layer 12 is increased as compared with the conventional MR element shown in FIG. That is, the magnetic field B applied from the first pinned layer 12 to the free layer 16 can be increased with respect to the magnetic field A applied from the reference pinned layer 14 to the free layer 16. Can be canceled (cancelled). As a result, the magnetic field in the element height (MRh) direction with respect to the free layer 16 can be reduced, and the free layer 16 can be held substantially in the core width direction when there is no external magnetic field, as indicated by arrow C.

  During reproduction, a sense current is passed in the stacking direction, and the magnetization direction of the free layer 16 with respect to the reference pinned layer 14 changes depending on the direction of the magnetic field from the magnetic medium, and the magnetoresistance changes according to the relative direction. This change in magnetoresistance is detected as a voltage change that occurs across the spin valve. However, since the magnetization direction of the free layer 16 is aligned with the core width direction in the absence of an external magnetic field, the reproduction waveform The vertical asymmetry of the has been improved.

  In this configuration, it is only necessary to adjust the lengths of the first pinned layer 12 and the reference pinned layer 14 in the core width direction so that the effects of the magnetic fields A and B are offset by the free layer 16. The thickness and saturation magnetic flux density of the reference pinned layer 14 can be freely designed. In addition, since a material with the highest MR ratio can be selected, a high reproduction output can be obtained.

  In the example of FIG. 2, the first pinned layer 12 and the antiferromagnetic film 11 have the same length in the core width direction, and the reference pinned layer 14 and the free layer 16 have the same length in the core width direction. There is a difference in the length of the reference pinned layer 14 and the first pinned layer 12 in the core width direction so that the magnetic field B from the reference pinned layer 14 acting on the layer 16 and the magnetic field A from the first pinned layer 12 are canceled out. Since the first pinned layer 12 and the antiferromagnetic film 11 have a length relationship in the core width direction, and the length relationship between the free layer 16 and the reference pinned layer 14 in the core width direction is not particularly limited. . However, the difference in the length in the core width direction between the first pinned layer 12 and the reference pinned layer 14 is preferably larger than the difference in the length in the core width direction between the reference pinned layer 14 and the free layer 16.

FIG. 3 is a graph of simulation results showing the effect of improving the vertical asymmetry of the reproduction waveform by adopting the configuration of FIG. When a half of the difference between the length of the first pinned layer 12 in the core width direction and the length of the reference pinned layer 14 in the core width direction in FIG. It can be seen that the asymmetry is greatly improved.
<Example 1>
FIG. 4 is a schematic perspective view showing a configuration example 1 in which the MR element of the present invention is applied to a CPP structure. In the figure, the X-axis direction is the core width or track width direction, the Y direction is the element height direction, and the XZ plane is the slider ABS (air bearing surface) plane.

  In this example, the length of the first pinned layer 12 in the core width direction is longer than the length of the reference pinned layer 14 in the core width direction, and the core width direction of the antiferromagnetic (pinning) layer 11 and the first pinned layer 12 is And the lengths of the reference pinned layer 14 and the free layer 16 in the core width direction are equal to each other. Magnetic domain control films 17 are provided on both sides along the track width of the laminated portion of the reference pinned layer 14 and the free layer 16.

  5A to 5E are cross-sectional views on the medium facing surface showing the manufacturing steps of the MR element of FIG. First, as shown in FIG. 5A, a shield and / or electrode terminal 18a is formed on a substrate (not shown), and a laminated ferrimagnetic spin valve is formed thereon. That is, the antiferromagnetic film 11, the first pinned layer 12, the intermediate layer 13, the reference pinned layer 14, the intermediate layer 15, and the free layer 16 are sequentially formed by a sputtering method or the like.

  The antiferromagnetic film 11 is, for example, IrMn, PdPtMn, or the like. As the first pinned layer 12, the reference pinned layer 5, and the free layer 7, a single layer or a laminated film such as NiFe or CoFeB is used. The intermediate layer 13 between the first pinned layer 12 and the reference pinned layer 14 is a nonmagnetic coupling layer that magnetically couples the first pinned layer 12 and the reference pinned layer 14 and is, for example, Ru. As the intermediate layer 15 between the reference pinned layer 14 and the free layer 16, an insulating film such as Al2O3 or MgO or a low resistance conductive film such as Cu is used. When an insulating film is used, the MR element is a tunnel junction type GMR element. When a conductive film is used, a CPP-GMR element is obtained. When the shield also serves as the electrode terminal, the shield and / or the electrode terminal 18a is a soft magnetic metal film such as NiFe, and when the shield also does not serve as the electrode terminal, the shield and / or the electrode terminal 18a and a nonmagnetic material such as Cu. It becomes a laminated film of magnetic metal films.

  A resist film is applied on such a laminate and patterned into a desired shape to form a resist mask 21.

  Next, as shown in FIG. 5B, etching is performed using the resist mask 21 until at least most of the reference pinned layer 14 is processed by ion milling or the like. In the example of FIG. 5B (a), the free layer 16, the intermediate layer 15, the reference pinned layer 14, and the intermediate layer 13 are etched until the first pinned layer 12 is exposed. At this time, a part of the reference pinned layer 14 and the intermediate layer 13 may remain as shown in FIG. 5B (b), or one of the first pinned layers 12 as shown in FIG. 5B (c). Even if the portion is etched, the effect of the present invention can be obtained.

Next, as shown in FIG. 5C, an insulating film 23 such as Al2O3 is formed by sputtering, for example, while leaving the resist mask 21 left. In FIG. 5C, illustration of the insulating film 23 deposited on the resist mask 21 is omitted.
Next, as shown in FIG. 5D, the magnetic domain control film 17 and the nonmagnetic insulating film 25 are sequentially formed with the resist mask 21 remaining. Also here, the illustration of the magnetic domain control film 17 and the nonmagnetic insulating film 25 deposited on the resist mask 21 is omitted. As the magnetic domain control film 17, a high coercive force film such as CoCrPt or a laminated film of an antiferromagnetic film such as IrMn or PdPtMn and a soft magnetic film such as NiFe or CoFeB is used. As the nonmagnetic insulating film 25, Al2O3 or the like is used.

Next, as shown in FIG. 5E, the resist 21 is removed by lift-off, and a shield / electrode terminal 18b is formed. Similarly to the shield / electrode terminal 18a, the shield / electrode terminal 18b is a soft magnetic metal film such as NiFe when the shield also serves as an electrode terminal, and the soft magnetic metal such as NiFe when the shield also does not serve as an electrode terminal. It becomes a laminated film of a film and a nonmagnetic metal film such as Cu. In the former case (the shield also serves as an electrode terminal), the soft magnetic metal film is formed by plating or vapor deposition. In the latter case (the shield does not serve as an electrode terminal), the nonmagnetic metal film is formed by plating, vapor deposition, sputtering, or the like.
<Example 2>
FIG. 6 shows another application example of the MR element of the present invention to a CPP structure. 6A is a schematic perspective view, and FIG. 6B is a cross-sectional view at the medium facing surface. In this application example, the configuration is the same as that of FIG. 4 except that the magnetic domain control film 17 is disposed not on both sides of the free layer 16 and the reference pinned layer 14 in the core width direction but on the free layer 16. The magnetic domain control film 17 is magnetized in the track width direction, and the free layer 16 of the MR element is also magnetized in the track width direction by a magnetic field generated therefrom.

  The manufacturing method is substantially the same as that shown in FIGS. 5A to 5E except that the magnetic domain control film 17 is first laminated and deposited. That is, the shield / electrode terminal 18a, the laminated ferrimagnetic spin valve, and the magnetic domain control film 17 are sequentially volumed on a substrate (not shown), and a resist mask having a predetermined shape is formed at a predetermined location. As described above, the laminated ferrimagnetic spin valve is a laminated structure of the antiferromagnetic (pinning) film 11, the first pinned layer 12, the intermediate layer 13 such as Ru, the reference pinned layer 14, the intermediate layer 15, and the free layer 16. . A magnetic domain control film 17, a high coercive force film such as CoCrPt, an antiferromagnetic film such as IrMn, PdPtMn, or the like is used.

Next, as in FIG. 5B, the layers 11 to 16 and the magnetic domain control film 17 constituting the laminated ferrimagnetic spin valve are etched, and the insulating film 23 is formed on the etched surface as in FIG. 5C. The insulating film 23 is formed thicker than FIG. 5C. The insulating film 23 and the magnetic domain control film 17 in FIG. 5D are the same as the insulating film. Finally, similarly to FIG. 5E, the resist mask 21 is removed, and a shield / electrode terminal 18b is formed. The material of each layer is the same as in Application Example 1.
<Example 3>
FIG. 7 is a schematic perspective view showing still another application example in which the MR element of the present invention is applied to a CPP structure. In Application Example 3, the length of the first pinned layer 12 in the core width direction is longer than the length of the reference pinned layer 14 in the core width direction and shorter than the length of the antiferromagnetic film 11 in the core width direction. It is configured. The magnetic domain control film 17 is located on both sides of the free layer 16, the reference pinned layer 14, and the first pinned layer 12 in the core width direction.

  8A to 8F are cross-sectional views on the medium facing surface (ABS surface) showing the manufacturing process of the MR element of FIG. First, in FIG. 8A, a shield / electrode terminal 18a, a laminated ferrimagnetic spin valve, that is, an antiferromagnetic film 11, a first pinned layer 12, an intermediate layer 13 such as Ru, a reference pinned layer 14, An intermediate layer 15 and a free layer 16 are sequentially formed. A resist is applied on the laminated ferri-type spin valve and patterned into a desired shape to form a resist mask 21.

  Next, as shown in FIG. 8B, using the resist mask 21, the free layer 16, the intermediate layer 15, the reference pinned layer 14, the intermediate layer 13, and the first pinned layer 12 are etched by ion milling or the like. In this etching, a part of the first pinned layer 12 may remain, a part or all of the antiferromagnetic film 11 may be etched, or a part of the shield / electrode terminal 18a may be etched. The effect of the present invention can be obtained.

  Next, as shown in FIG. 8C, the resist mask 21 is removed, and a new resist is applied and patterned to form a resist mask 31 that is shorter in the core width direction than the resist mask 21. Using the resist mask 31, the free layer 16, the intermediate layer 15, the reference pinned layer 14, and the intermediate layer 13 are etched by ion milling or the like. Here, the etching of the intermediate layer 13 is not essential, and in the etching, a part of the reference pinned layer 14 may remain or even if a part of the first pinned layer 12 is etched, The effects of the invention can be obtained.

  Next, as shown in FIG. 8D, an insulating film 23 of Al2O3 or the like is formed with the resist mask 31 remaining. The illustration of the insulating film 23 deposited on the resist mask 31 is omitted.

  Next, as shown in FIG. 8E, the magnetic domain control film 17 and the nonmagnetic insulating film 25 are sequentially formed while the resist mask 31 is left.

Next, as shown in FIG. 8F, the resist mask 31 is removed by lift-off, and a shield / electrode terminal 18b is formed. The material of each layer is the same as in Example 1.
<Example 4>
FIG. 9 is a schematic perspective view showing a configuration example in which the MR element of the present invention is applied to a CIP structure. As in the third embodiment, the length of the first pinned layer 12 in the core width direction is longer than the length of the reference pinned layer 14 in the core width direction, and is longer than the length of the antiferromagnetic film 11 in the core width direction. short. Since the direction of current flow is the in-plane direction of the stack, the conductive layers 32 are provided on both sides of the free layer 16, the reference pinned layer 14, and the first pinned layer 12 in the core width direction.

  10A and 10B are cross-sectional views on the medium facing surface showing the manufacturing steps of the MR element of FIG. Similarly to FIGS. 8A to 8C, the resist mask is formed and etching by ion milling or the like is repeated twice so that the length of the first pinned layer 12 in the core width direction is longer than the length of the reference pinned layer 14 in the core width direction. The laminated ferri-type spin valve is processed into a shape that is long and shorter than the length of the antiferromagnetic layer 11 in the core width direction. Thereafter, as shown in FIG. 10A, the nonmagnetic conductive film 32 and the magnetic domain control film 17 are formed on the etching surface while maintaining the resist mask, and the resist mask is removed by lift-off.

  Next, as shown in FIG. 10B, a nonmagnetic insulating film 25 and a shield / electrode terminal 18b are sequentially formed on the entire surface. The material of each layer is the same as in Example 1.

  As described above, the reproducing head using the MR element of the present invention can improve the vertical asymmetry of the reproduced waveform even in a fine element corresponding to a high recording density. As a result, the yield is improved and a reproduction signal can be obtained with high sensitivity.

  FIG. 11 is a plan view showing a main part of a magnetic disk device (magnetic storage device) including a magnetic head in which the MR element of the embodiment of the present invention is applied to a reproducing head. The magnetic disk device 90 includes a magnetic recording medium 93 housed in a housing 91 and a magnetic head 50 that moves on the magnetic recording medium 93 to record and reproduce information. The magnetic head 50 is a composite thin-film magnetic head in which the magnetoresistive effect reproducing element 10 and the inductive magnetic recording element 40 are integrated. In this case, the inductive magnetic recording element 40 is integrally formed by forming a thin film magnetic pole above the MR element, for example, in the Z-axis direction of FIGS.

  The magnetic head 50 is supported at the tip of a suspension 96 extending from the arm 95. The magnetic recording medium 93 is fixed to a hub 92, and rotates when the hub 92 is rotationally driven by a spindle (not shown). The arm 95 is moved in the radial direction of the magnetic recording medium 93 by the actuator 94.

  As shown in FIG. 2, the MR reproducing element 10 of the magnetic head 50 has a length in the core width direction of the first pinned layer 12, that is, the length in the track width direction of the magnetic recording medium 93 in the core width direction of the reference pinned layer 14. The magnetic field from the reference pinned layer 14 that is set longer than the length and acts on the free layer 16 is designed to cancel out the magnetic field from the first pinned layer 12. Therefore, when the magnetic field from the magnetic recording medium 93 does not enter, the magnetization of the free layer 16 is aligned in the core width direction, so that the vertical asymmetry of the reproduced waveform during reproduction is improved satisfactorily.

Finally, the following notes are disclosed for the above explanation.
(Appendix 1) an antiferromagnetic layer;
A first pinned layer whose magnetization direction is fixed by the antiferromagnetic layer;
A reference pinned layer antiferromagnetically coupled to the first pinned layer and antiparallel to the first pinned layer;
A free layer in which the direction of magnetization with respect to the reference pinned layer changes due to an external magnetic field, and the length of the first pinned layer in the core width direction is longer than the length of the reference pinned layer in the core width direction. A magnetoresistive effect element.
(Supplementary note 2) The magnetoresistive effect according to supplementary note 1, wherein a value of ½ of a difference in length in the core width direction between the first pinned layer and the reference pinned layer is in a range of 2 nm to 5 nm. element.
(Supplementary note 3) The difference in length between the first pinned layer and the reference pinned layer in the core width direction is larger than the difference in length between the reference pinned layer and the free layer in the core width direction. The magnetoresistive effect element according to 1.
(Supplementary Note 4) The lengths of the first pinned layer and the reference pinned layer in the core width direction are the magnetic field from the first pinned layer acting on the free layer, and the reference layer acting on the free layer. The magnetoresistive effect element according to claim 1, wherein the magnetoresistive element has a length that cancels out the magnetic field from the magnetic field.
(Additional remark 5) The magnetoresistive effect element of Additional remark 1 characterized by further having a low resistance intermediate | middle layer located between the said free layer and the said reference | standard pinned layer.
(Additional remark 6) The magnetoresistive effect element of Additional remark 1 characterized by further having an intermediate | middle layer which comprises a ferromagnetic tunnel junction located between the said free layer and the said reference | standard pinned layer.
(Supplementary note 7) magnetoresistive element;
The magnetoresistive effect element includes an electrode terminal and / or a shield sandwiching the magnetoresistive effect element,
A first pinned layer in which the direction of magnetization is fixed;
A reference pinned layer in which the direction of magnetization is fixed in a direction antiparallel to the first pinned layer;
A free layer in which the direction of magnetization with respect to the reference pinned layer changes due to an external magnetic field, and the length of the first pinned layer in the core width direction is longer than the length of the reference pinned layer in the core width direction. Characteristic magnetic head.
(Supplementary note 8) The magnetic head according to supplementary note 7, further comprising an inductive recording element provided integrally with the magnetoresistive effect element.
(Additional remark 9) The magnetic head of Additional remark 7 or 8 further provided with the magnetic domain control film which controls the magnetic domain of the said magnetoresistive effect element.
(Supplementary note 10) The magnetic head according to supplementary note 9, wherein the magnetic domain control film is at least one of a high coercive force film and an antiferromagnetic film.
(Supplementary note 11) The magnetic head according to supplementary note 9, wherein the magnetic domain control film is located on both sides of the magnetoresistive element in the core width direction.
(Additional remark 12) The said magnetic domain control film is located on the said free layer of the said magnetoresistive effect element, The magnetic head of Additional remark 9 characterized by the above-mentioned.
(Supplementary note 13) a recording medium;
The magnetic head according to appendix 6 or 7,
A head drive unit for driving the magnetic head with respect to the recording medium;
And the magnetic head detects a magnetic signal of the recording medium.
(Additional remark 14) The process of laminating | stacking an antiferromagnetic film | membrane, a 1st pinned layer, a 1st intermediate | middle layer, a reference | standard pinned layer, a 2nd intermediate | middle layer, and a free layer in this order,
In the facing surface where the stacked body faces an arbitrary storage medium, the length of the first pinned layer along the track width direction of the storage medium is longer than the length of the reference pinned layer along the track width direction. So as to process the laminate,
A method of manufacturing a magnetoresistive effect element comprising:

It is a figure which shows the laminated ferri-type spin valve structure of the conventional MR element. 1 is a schematic perspective view showing a laminated ferri type spin valve structure of an MR element according to an embodiment of the present invention. It is a graph which shows the improvement effect of the up-down asymmetry of the reproduction | regeneration waveform obtained by the structure of FIG. It is a schematic perspective view of the application example 1 to the CPP structure of the MR element of the present invention. FIG. 5 is a first manufacturing process diagram of the MR element of FIG. FIG. 6 is a second manufacturing process diagram of the MR element of FIG. 4. FIG. 6 is a third manufacturing process diagram of the MR element of FIG. 4. FIG. 5 is a fourth manufacturing process diagram of the MR element of FIG. 4. FIG. 6 is a fifth manufacturing process diagram of the MR element of FIG. 4. It is a figure which shows the example 2 of application to the CPP structure of MR element of this invention. It is a figure which shows the example 3 of application to the CPP structure of MR element of this invention. FIG. 8 is a first manufacturing process diagram of the MR element of FIG. 7; FIG. 8 is a second manufacturing process diagram of the MR element of FIG. FIG. 8 is a third manufacturing process diagram of the MR element of FIG. 7; FIG. 8 is a fourth manufacturing process diagram of the MR element of FIG. 7. FIG. 7 is a fifth manufacturing process diagram of the MR element of FIG. FIG. 7 is a sixth manufacturing process diagram of the MR element of FIG. 7; It is a figure which shows the example of application to the CIP structure of MR element of this invention. FIG. 10 is a first manufacturing process diagram of the MR element of FIG. 9; FIG. 10 is a second production process diagram of the MR element of FIG. 9. 1 is a diagram showing a main part of a magnetic disk device including a magnetic head using an MR element according to an embodiment of the present invention.

Explanation of symbols

10 MR element (magnetoresistance effect element)
11 Antiferromagnetic film 12 First pinned layer 14 Reference pinned layer 16 Free layer 17 Magnetic domain control layers 18a and 18b Shield and / or electrode terminal 23 Insulating film 25 Nonmagnetic insulating film 32 Nonmagnetic conductive film 40 Inductive recording element 50 Magnetic Head (Composite type thin film magnetic head)
90 Magnetic disk unit (magnetic storage unit)

Claims (10)

An antiferromagnetic layer,
A first pinned layer whose magnetization direction is fixed by the antiferromagnetic layer;
A reference pinned layer antiferromagnetically coupled to the first pinned layer and antiparallel to the first pinned layer;
A free layer in which the direction of magnetization with respect to the reference pinned layer changes due to an external magnetic field, and the length of the first pinned layer in the core width direction is longer than the length of the reference pinned layer in the core width direction. A magnetoresistive effect element.   2. The magnetoresistive element according to claim 1, wherein a value of ½ of a difference in length in the core width direction between the first pinned layer and the reference pinned layer is in a range of 2 nm to 5 nm.   2. The difference in length in the core width direction between the first pinned layer and the reference pinned layer is greater than the difference in length in the core width direction between the reference pinned layer and the free layer. Magnetoresistive effect element.   The lengths of the first pinned layer and the reference pinned layer in the core width direction are determined by a magnetic field from the first pinned layer acting on the free layer and a magnetic field from the reference layer acting on the free layer, respectively. The magnetoresistive effect element according to claim 1, wherein the magnetoresistive effect element has a length offset. 2. The magnetoresistive element according to claim 1, further comprising a low-resistance intermediate layer positioned between the free layer and the reference pinned layer. The magnetoresistive element according to claim 1, further comprising an intermediate layer that is located between the free layer and the reference pinned layer and forms a ferromagnetic tunnel junction. A magnetoresistive element;
The magnetoresistive effect element includes an electrode terminal and / or a shield sandwiching the magnetoresistive effect element,
A first pinned layer in which the direction of magnetization is fixed;
A reference pinned layer in which the direction of magnetization is fixed in a direction antiparallel to the first pinned layer;
A free layer in which the direction of magnetization with respect to the reference pinned layer changes due to an external magnetic field, and the length of the first pinned layer in the core width direction is longer than the length of the reference pinned layer in the core width direction. Characteristic magnetic head. The magnetic head according to claim 7, further comprising an inductive recording element provided integrally with the magnetoresistive effect element. A recording medium;
A magnetic head according to claim 6 or 7,
A head drive unit for driving the magnetic head with respect to the recording medium;
And the magnetic head detects a magnetic signal of the recording medium. A step of laminating an antiferromagnetic film, a first pinned layer, a first intermediate layer, a reference pinned layer, a second intermediate layer, and a free layer in this order; and
In the facing surface where the stacked body faces an arbitrary storage medium, the length of the first pinned layer along the track width direction of the storage medium is longer than the length of the reference pinned layer along the track width direction. So as to process the laminate,
A method of manufacturing a magnetoresistive effect element comprising:

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