JP2008098557A - Magnetic sensor element, method of manufacturing the same, magnetic head, magnetic reproducer, and magnetic reproducing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic sensor element which can read a magnetic signal smaller in width than a magnetoresistance element with a high resolution. <P>SOLUTION: A magnetic head 1 of the present embodiment includes a substrate 2, a magnetic sensor element 3 mounted to the substrate 2, and a laser light source element 4 for emitting a light beam to the magnetic sensor element 3. The magnetic sensor element 3 is composed of a magnetic sensing portion 5. In the magnetic sensing portion 5, an insulating film 6, a lower magnetic shield layer 7, and a magnetoresistance element 8 are sequentially stacked on the substrate 2. Further, on each side of the magnetoresistance element 8, a laminated body is formed with an insulating layer 9 disposed between the laminated body and the magnetoresistance element 8. The laminated body is formed by sequentially stacking a heat conductive layer 10 for providing a heat gradient in the film surface direction, that is, in the track width direction (direction along the X axis) and a bias layer 11 for applying a bias magnetic field to the magnetoresistance element 8. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a magnetic sensor element that raises the temperature of a magnetoresistive effect element using light and reproduces recorded information recorded on a magnetic recording medium, and a magnetic head, a magnetic reproducing apparatus, and a magnetic sensor including the magnetic sensor element. Reproduction method.

  As a magnetic sensor element for reading recorded magnetic recording information with high sensitivity as a magnetic recording medium represented by a hard disk increases in density, a magnetoresistive effect element in which the resistance value of the element changes due to a change in an external magnetic field ( A magnetoresistive effect sensor (MR sensor) using an MR element is widely used.

  Among the above MR elements, the giant magnetoresistive effect element (GMR element: Giant magneto-resistive) and the tunnel magnetoresistive effect element (TMR element: Tunneling magneto-resistive) are from several percent to over 200% in some cases. Since a high magnetoresistive effect ratio (MR ratio) can be obtained, application to a magnetic sensor element is actively performed as a magnetoresistive effect element suitable for a highly sensitive magnetoresistive effect sensor.

  FIG. 24 shows a schematic diagram of an example of a conventional magnetoresistive element. A lower electrode layer 308 on a substrate 300, a magnetization fixed layer 303 whose magnetization is fixed in one direction in the plane, a nonmagnetic layer 304, a magnetization free layer 305 whose magnetization direction changes in the film plane by an external magnetic field, an upper electrode A layer 307 is included. The magnetoresistive element shown here operates by applying a voltage between the lower electrode layer 308 and the upper electrode layer 307 to generate a potential difference, and operates by passing a current in a direction perpendicular to the film surface. This is a (Current Perpendicular to Plane) type magnetoresistive element.

The fixed magnetization layer 303 is generally formed to include an antiferromagnetic layer 301 and a ferromagnetic layer 302, and the antiferromagnetic layer 301 uses the exchange coupling force to unite the magnetization of the ferromagnetic layer 302. The apparent coercive force of the ferromagnetic layer 302 is increased by fixing in the direction. Note that an antiferromagnetic material typified by MnPt, MnFe, and MnIr is used for the antiferromagnetic layer 301, and Fe, CoFe, and CoFeB are mainly used for the ferromagnetic layer 302. The substrate 300 is mainly made of a thermally oxidized Si substrate or AlTiC (Al ₂ O ₃ .TiC), and the lower electrode layer 308 and the upper electrode layer 307 are made of a metal containing Cu or Cu, A soft magnetic material such as NiFe is used. The nonmagnetic layer 304 is mainly made of Cu or a metal containing Cu in the GMR element, and Al oxide or Mg oxide is generally used in the TMR element. For the magnetization free layer 305, Fe, CoFe, CoFeB, NiFe, or a laminate of these is used.

  In such a magnetoresistive effect element, the electron transmittance changes depending on the relative angle of magnetization between the magnetization fixed layer 303 and the magnetization free layer 305, and a magnetoresistive effect is generated. The cause of the magnetoresistive effect can be briefly described as follows. Note that the voltage applied between the upper and lower electrode layers may be a direction in which conduction electrons move from the lower electrode layer 308 toward the upper electrode layer 307, or a direction in which the transferred electrons move from the upper electrode layer 307 toward the lower electrode layer 308. However, here, a case where a voltage is applied in a direction in which conduction electrons move from the lower electrode layer 308 toward the upper electrode layer 307 will be described.

  Conduction electrons generated by applying a voltage between the lower electrode layer 308 and the upper electrode layer 307 are composed of two types of electrons having different spin angular motion directions, that is, up-spin electrons and down-spin electrons, and emits the lower electrode layer 308. At the time, it has the same number of up-spin electrons and down-spin electrons.

  When the conduction electrons pass through the fixed magnetization layer 303 having magnetization aligned in one direction, spin-dependent scattering occurs in which the amount of the passing electrons varies depending on the direction of the spin, and there is a difference between the number of up-spin electrons and the number of down-spin electrons. Occurs. Subsequently, when the conduction electrons that have passed through the nonmagnetic layer 304 pass through the magnetization free layer 305, spin-dependent scattering occurs again. At this time, the magnetization direction of the magnetization fixed layer 303 and the magnetization of the magnetization free layer 305 are generated. When the direction is substantially parallel, the amount of scattering in the magnetization free layer 305 is smaller than when the magnetization direction of the magnetization fixed layer 303 and the magnetization direction of the magnetization free layer 305 are substantially antiparallel.

For this reason, the number of conduction electrons that pass through the magnetization free layer 305 varies depending on the magnetization direction of the magnetization free layer 305, and the total number of conduction electrons that reach the upper electrode layer 307 changes, resulting in a change in element resistance. At this time, if the element resistance R _P in the case where the magnetization direction is substantially parallel magnetization direction and the magnetization free layer 305 magnetization fixed layer _303, substantially the element resistance in the case antiparallel and R _AP, the magnetoresistive element MR ratio (magnetoresistive ratio) is defined as _{ΔR / R = (R AP -R} P) / R P.

  When such a magnetoresistive effect element is used as a magnetic sensor element for reading magnetic recording information recorded on a magnetic recording medium, in addition to the above configuration, the magnetization free layer 305 is provided at both ends of the magnetization free layer 305. The bias layer 306 is formed for the purpose of stabilizing (uniaxial) the magnetization of the magnetic recording medium, and the thickness (film thickness) of the magnetization free layer 305 in the vertical direction on the paper surface determines the reproduction resolution in the track length direction and the width in the horizontal direction on the paper surface (magnetic). The width of the film in the film surface direction) determines the reproduction resolution in the track width direction.

The bias layer 306 is mainly made of a ferromagnetic metal such as CoFePt or CoFePtCr. When the bias layer 306 is formed, patterning using photolithography is performed, and a part of the lower electrode layer 308 is cut off. Thereafter, an insulating layer 309 typified by SiO ₂ is formed on the side surface of the element from the magnetization fixed layer 303 to the nonmagnetic material layer 304, and both sides of the magnetization free layer 305 are in direct contact with the magnetization free layer 305 or The bias layer 306 is disposed via a nonmagnetic material. Further, between the lower electrode layer 308 and the magnetization fixed layer 303 and between the upper electrode layer 307 and the magnetization free layer 305, if necessary, the roughness of the film surface is reduced, the adhesion of the film is improved, and In some cases, a buffer layer is formed for the purpose of preventing damage during lithography.

  When the magnetic recording medium to be read by such a magnetic sensor element is a perpendicular magnetic recording medium, the leakage magnetic field from the medium is applied to the magnetoresistive effect element in FIG. Is the medium facing surface.

  Here, Patent Document 1 discloses a technique for suppressing a temperature rise of a magnetoresistive element caused by heat generated when a sense current is passed through the magnetoresistive element in order to operate the magnetic sensor element as described above. Yes. Specifically, silicon or diamond-like carbon, which has excellent thermal conductivity and insulation, is used, and even if the magnetoresistive element generates heat, heat is radiated to the outside through an insulating layer with excellent heat dissipation effect. A technique capable of suppressing the temperature rise of the effect element is disclosed.

JP-A-6-223331

In recent years, with the rapid advancement of information society, the density of magnetic recording media has increased, and studies have been conducted with a view to high-density recording media having a recording density of 1 Tbit / inch ² . The size of the recording bit is as small as 25 nm × 25 nm in theoretical calculation.

  A magnetoresistive element is generally used as a magnetic sensor element for reproducing recorded data. Among these, the width of the magnetoresistive effect element, that is, the horizontal direction on the paper surface in FIG. 24, needs to be processed to the same size as the recording bit or smaller. This is because the magnetoresistive effect element width bears the reproduction resolution in the track width direction. In other words, even if high-density recording can be performed, unless the magnetoresistive effect element width can be processed to the same extent as the recording bit size, there is a problem such as crosstalk, which makes it difficult to reproduce, and advances in miniaturization processing technology. There is a dependent current situation.

  Among them, photolithography is generally used as a technique for miniaturizing a magnetoresistive effect element for reproducing recorded bits of a recording medium recorded at high density, but the current technique has a limit of about 60 nm. Therefore, it is difficult to process to a minute size of 25 nm.

  As a processing technique other than photolithography, there is a fine processing technique using a focused ion beam (FIB) or a high-density electron beam (EB). There is a problem that mass production is difficult because there is a problem that the elements cannot be processed simultaneously. Even if the miniaturization processing technology enables further miniaturization processing of the magnetoresistive effect element, the magnetoresistive effect element width is reduced to reduce the size of the magnetization free layer. It is difficult to realize a magnetized state with uniaxial anisotropy due to problems of magnetic field and thermal fluctuation. In particular, at the processing edge portion, there arises a problem that the magnetization easily forms a closed magnetic path, which greatly hinders the improvement of the reliability of the reproduction signal characteristics and the reproduction resolution. For this reason, it has become difficult to reproduce a high-density recording medium by simply reducing the magnetoresistive element width.

  Therefore, a magnetic sensor element that can read out a magnetic signal having a width narrower than that of the magnetoresistive effect element with high resolution is desired. However, in the above-mentioned Patent Document 1, the temperature of the magnetoresistive effect element is simply used. It is considered that it is only possible to suppress the rise, and that alone cannot provide a magnetic sensor element that can be read with higher resolution.

  Accordingly, an object of the present invention is to provide a magnetic sensor element capable of reading a magnetic signal having a width narrower than that of the magnetoresistive effect element with high resolution.

Means and effects for solving the problems

(1) The magnetic sensor element of the present invention has a nonmagnetic layer, a magnetization free layer and a magnetization fixed layer sandwiching the nonmagnetic layer, and changes the magnetic field sensitivity to an external magnetic field as the temperature changes. A magnetic sensing unit including a magnetoresistive element and a heat exchange heat conductor layer formed along a side surface of the magnetoresistive element;

  According to the configuration of (1) above, when the light beam is irradiated on the magnetic sensing unit, a temperature gradient can be generated in the magnetoresistive effect element included in the magnetic sensing unit. That is, the magnetoresistive effect element is heated, and the thermal conductor layer radiates heat around the side surface of the magnetoresistive effect element to the outside, thereby generating a temperature gradient in the magnetoresistive effect element included in the magnetic sensing unit. Thus, it is possible to realize a high-resolution magnetic sensor capable of reading a recorded magnetic field only at a portion having high magnetic field sensitivity (a portion having the highest temperature and the vicinity thereof) in the magnetoresistive element.

(2) The magnetic sensor element of the above (1) further includes a near-field light generating unit having a linear minute opening formed so that one end of the magnetoresistive element is close to the magnetoresistive element. It is preferable that the opening irradiates the magnetoresistive element with near-field light generated on the one end side by irradiation of light from the other end side.

  According to the configuration of (2) above, the near-field light generated at the minute aperture can be irradiated to the minute region (magnetoresistance effect element) of the magnetic sensing unit, so that heating can be performed around the magnetoresistance effect element, The temperature gradient in the resistance effect element can be further strengthened.

(3) In the magnetic sensor element of the above (1) or (2), the thermal conductor layer is formed of the magnetoresistive effect element in a stacking direction of the nonmagnetic material layer, the magnetization free layer, and the magnetization fixed layer. A pair of layers is preferably formed so as to be symmetrical with respect to the center line and sandwich the magnetoresistive element.

  According to the configuration of (3) above, since the heat radiation effect when generated by the irradiation of the light beam can be strengthened, the magnetoresistive effect element is constituted by a pair of layers from the center of the magnetoresistive effect element. Larger temperature gradients can be generated symmetrically in the respective layer directions of the heat conductor layers to be produced. In addition, since the temperature gradient is generated symmetrically from the center of the magnetoresistive effect element, the sensing point (origin) of the external magnetic field can be the center of the magnetoresistive effect element, so that the magnetic sensor of the magnetic reproducing device It becomes easy to use as a part for the magnetic field, and it becomes easy to design the magnetic reproducing apparatus.

(4) In the magnetic sensor element of (3) above, a pair of bias layers for aligning the magnetization of the magnetization free layer in one direction are positioned symmetrically with respect to the center line, and It is preferable that the magnetic sensing portion is formed so as to be adjacent to each of the heat conductor layers in the stacking direction of the nonmagnetic material layer, the magnetization free layer, and the magnetization fixed layer.

  According to the configuration of (4), the bias layer for aligning the magnetization of the magnetization free layer in one direction and the heat conductor layer having a high heat dissipation effect can be formed together, so that productivity can be improved and a small magnetic A sensor element can be provided.

(5) As another aspect, in the magnetic sensor element of the above (2), the thermal conductor layer has the magnetoresistance in the stacking direction of the nonmagnetic layer, the magnetization free layer, and the magnetization fixed layer. Formed across the magnetic sensing part and the near-field light generating part so as to be symmetrical with respect to the center line of the effect element and so as to sandwich the magnetoresistive effect element and the minute opening at the same time. A pair of layers is preferred.

  According to the configuration of (5) above, since the capacity of the heat conductor layer is increased, heat can be further taken from the magnetoresistive effect element. As a result, the temperature gradient can be made steeper. In addition, since the heat conductor layer of the near-field light generating unit and the heat conductor layer of the magnetic sensing unit can be formed at a time, productivity can be improved and a small magnetic sensor element can be provided.

(6) In the magnetic sensor element of the above (5), the pair of bias layers for aligning the magnetization of the magnetization free layer in one direction are symmetrical with respect to the center line, and Formed across the magnetic sensing unit and the near-field light generating unit so as to be adjacent to each of the heat conductor layers in the stacking direction of the nonmagnetic material layer, the magnetization free layer, and the magnetization fixed layer. Preferably it is.

  According to the configuration of (6) above, since the bias layer of the near-field light generating unit and the bias layer of the magnetic sensing unit can be formed at a time, productivity can be improved and a small magnetic sensor element can be provided.

(7) In the magnetic sensor elements of the above (2), (5), and (6), it is preferable that the near-field light generating unit further includes a metal layer adjacent to the minute opening. Thereby, the near-field light generated at the minute aperture can be enhanced.

(8) In the magnetic sensor elements of the above (2) and (5) to (7), a dielectric layer may be formed in the minute opening. Thereby, the near-field light generated at the minute aperture can be efficiently propagated. In addition, it is possible to provide a magnetic sensor element that can easily form a layer stacked on top of the dielectric layer in the near-field light generating portion.

(9) In the magnetic sensor elements of the above (2) and (5) to (8), one end of the minute opening may be formed adjacent to the magnetoresistive element.

  According to the configuration of (9) above, the near-field light generated at the minute aperture can be directly applied to the magnetoresistive effect element, and the temperature near the center of the magnetoresistive effect element can be higher than the side surface. The temperature gradient in the resistance effect element can be further increased.

(10) In the magnetic sensor elements of the above (1) to (9), the magnetization free layer is at least one element selected from at least one element selected from Gd, Dy, Tb, and Ho, and Fe, Co, and Ni. It is preferable to comprise a kind of element.

  According to the configuration of (10), the absolute value of the coercive force when the coercive force is reduced by temperature change can be reduced, the external magnetic field sensitivity of the magnetoresistive effect element can be increased, and the composition adjustment is used. The temperature can be easily adjusted.

(11) In the magnetic sensor elements of the above (1) to (10), the thermal conductor layer is Au, Ag, Cu, Al, Mg, Mo, W, Si, diamond-like carbon, or these elements It is preferable that it consists of the metal material which has as a main component.

  According to the configuration of (11), the heat dissipation from the magnetoresistive effect element can be further enhanced, and therefore the temperature gradient in the magnetoresistive effect element can be further increased.

(12) Further, the present invention is a method for manufacturing a magnetic sensor element of any one of the magnetic sensor elements of (2) and (5) to (8) above, wherein a magnetization fixed layer and a nonmagnetic material are formed on a substrate. A step of forming a magnetic sensing unit having a magnetoresistive effect element formed by laminating a magnetization free layer, and a step of forming a near-field light generating unit having a minute opening formed by scraping off a part of the magnetoresistive effect element. have.

  According to the configuration of (12) above, the manufacturing process of the near-field light generating unit can be simplified, and a manufacturing method in which the alignment between the minute opening and the magnetoresistive effect element is performed with high accuracy can be provided.

(13) In the method of (12), the method of manufacturing the magnetic sensor element of (5) or (6), wherein the thermal conductor layer is formed across the magnetic sensing unit and the near-field light generating unit. It is preferable to further include a step of: Thereby, compared with the case where a heat conductor layer is produced separately in a magnetic sensing part and a near-field light generation part, a manufacturing process can be simplified.

(14) Preferably, the method for manufacturing a magnetic sensor element according to (13) further includes a step of forming a bias layer across the magnetic sensing portion and the near-field light generating portion. Thereby, compared with the case where a bias layer is produced separately in a magnetic sensing part and a near-field light generation part, a manufacturing process can be simplified.

(15) As another aspect, in the method of (12), the method of manufacturing the magnetic sensor element of (8) further includes a step of embedding and forming a dielectric layer in the minute opening. Is preferred. Thereby, the site | part laminated | stacked on the upper part of the dielectric material layer in a near-field light generation part can be formed easily, and a manufacturing process can be simplified.

(16) A magnetic head according to the present invention includes a slider substrate on which an ABS surface shape is formed, and any one of the magnetic sensor elements (1) to (11) formed on the slider substrate. have. Thereby, since the number of members can be reduced as compared with the case where the slider and the substrate for the magnetic sensor element are separately manufactured, a lightweight magnetic head with a simple manufacturing process can be provided.

(17) In the magnetic head of (16), it is preferable that a laser light source element for irradiating the magnetic sensor element with a light beam is formed on the slider substrate. Thus, by forming the magnetic sensor element and the laser light source element on one substrate, it is possible to improve the light beam irradiation positioning accuracy, improve the light beam irradiation reliability, and improve the productivity. it can.

(18) A magnetic reproducing apparatus of the present invention includes the magnetic head of (16) or (17) and a magnetic recording medium that is magnetically reproduced by the magnetic head. As a result, the magnetic reproducing apparatus capable of reproducing information efficiently while exhibiting the effects of the magnetic head described above can be provided.

(19) Also, the magnetic reproducing method of the present invention uses the magnetic reproducing device of (18) above to raise the temperature of the magnetoresistive element with near-field light and reproduce the recorded information recorded on the magnetic recording medium. It is. Thereby, highly accurate and efficient information reproduction | regeneration is realizable using said magnetic reproduction apparatus.

<First Embodiment>
The magnetic head according to the first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic perspective view showing the main part of the magnetic head according to the first embodiment of the present invention. FIG. 2 is a plan view showing a recording medium facing surface (XZ plane) of the magnetic sensor element in the magnetic head of FIG. 1 and a center point of the recording medium facing surface. FIG. 3 is a cross-sectional view of the magnetoresistive element in the magnetic sensor element of FIG.

  In the magnetic head 1 of this embodiment, as shown in FIG. 1, a substrate 2 as a slider substrate having an ABS surface shape (not shown) on the recording medium facing surface, and a magnetic sensor element 3 mounted on the substrate 2. And a laser light source element 4 for irradiating the magnetic sensor element 3 with a light beam. Here, for convenience of explanation, the following X axis, Y axis, and Z axis are assumed in FIG. That is, the vertical direction of the surface of the substrate 2 is the Z axis, and the upward direction is the positive direction of the Z axis. In addition, the light beam irradiation axis from the laser light source element 4 to the magnetic sensor element 3 is defined as the Y axis, and the depth direction on the paper surface is defined as the Y axis positive direction. Further, an axis parallel to the surface of the substrate 2 and orthogonal to the light beam irradiation direction is taken as an X axis, and a right direction on the paper is taken as a positive X axis direction. Further, the end surfaces (surfaces in front of the paper surface) of the substrate 2 and the magnetic sensor element 3 in FIG. In the following description, unless otherwise indicated, directions may be indicated using the X, Y, and Z axes shown in the drawings.

In order to epitaxially grow the laser light source element 4 on the surface, a group IV semiconductor such as Si, Ge or SiC, GaAs, GaP, InP, AlAs, GaN, AlGaAs, InN, InSb, GaSb, AlN or the like is used. A material such as a III-V group compound semiconductor or a III-VI group compound semiconductor such as ZnTe, ZnSe, ZnS, or ZnO is used. As a modification, when the laser beam source element 4 is not formed on the substrate 2 and the magnetic sensor element 3 is irradiated with a light beam from the outside, in addition to the above materials, AlTiC (Al ₂ O ₃ .TiC) Alternatively, an oxide insulator such as ZnO, Al ₂ O ₃ , SiO ₂ , TiO ₂ , CrO ₂ , or CeO ₂ , a nitride insulator such as SiN, glass, or plastic may be used.

  The magnetic sensor element 3 includes a magnetic sensing unit 5. In the magnetic sensing unit 5, an insulating film 6, a lower magnetic shield layer 7, and a magnetoresistive effect element 8 are sequentially stacked on the substrate 2. Further, a thermal conductor layer 10 for applying a thermal gradient in the film surface direction, that is, the track width direction (direction along the X-axis) is provided on both sides of the magnetoresistive effect element 8 via the insulating layer 9. A laminated body is formed by sequentially laminating a bias layer 11 for applying a bias magnetic field to the magnetoresistive effect element 8. The insulating layer 9 is also formed on the upper surface of the lower magnetic shield layer 7. An upper magnetic shield layer 12 is laminated so as to cover the magnetoresistive effect element 8, the insulating layer 9, and the bias layer 11.

  Here, the lower magnetic shield layer 7 and the upper magnetic shield layer 12 are for canceling a noise magnetic field generated from the periphery of the magnetic recording medium or the magnetic sensor element 3. High magnetic permeability materials are suitable for the upper magnetic shield layer 12 and the lower magnetic shield layer 7. This is because if a space to be magnetically shielded is surrounded by a high permeability material, the magnetic field lines flow along a material having a high relative permeability and a low magnetic resistance, and a magnetic shielding effect is generated. Specifically, it is formed using, for example, NiFe or NiFeTa. The film thickness of the upper magnetic shield layer 12 and the lower magnetic shield layer 7 may be any film thickness that can cancel the magnetic field that becomes a noise source, and is set to, for example, about 500 nm to 3 μm. The upper magnetic shield layer 12 and the lower magnetic shield 5b also serve as an upper electrode and a lower electrode, respectively. For applying a voltage from the outside of the magnetic sensor element 3, the conduction electrons flow in the magnetoresistive effect element 8. It also serves as an electrode layer. Therefore, the insulating film 6 is used to electrically insulate the lower magnetic shield layer 7 from the substrate 2.

  As the magnetoresistive effect element 8, a heat sensitive magnetoresistive effect element whose magnetic field sensitivity with respect to an external magnetic field changes with temperature change is used. In other words, the heat-sensitive magnetoresistive element is a magnetoresistive element having a different magnetic field intensity that can be detected in a low temperature region and a magnetic field intensity that can be detected in a high temperature region. The magnetoresistive effect element senses a leakage magnetic field from a magnetic recording medium by a magnetization free layer included in the magnetoresistive effect element. In the above-described thermosensitive magnetoresistive effect element, a track width direction (see FIG. By providing a temperature distribution in the X direction), a leakage magnetic field from the magnetic recording medium is detected only at a portion (high temperature region) where the magnetic field sensitivity of the magnetization free layer is high. That is, the magnetoresistive effect element can detect a leakage magnetic field from a recording bit narrower than the magnetization free layer with high resolution. Hereinafter, the magnetoresistive effect element 8 which is such a heat-sensitive magnetoresistive effect element will be described.

  The magnetoresistive element 8 has basically the same configuration as that of the prior art except for the magnetization free layer. As shown in FIG. 3, the magnetoresistive effect element 8 is formed by sequentially laminating an antiferromagnetic layer 21 and a ferromagnetic layer 22. The magnetic free layer 25 is formed by sequentially laminating the layer 23, the nonmagnetic layer 24, the in-plane magnetic layer 26, the high magnetic permeability layer 27, and the coercive force change free layer 28 in this order. Among these, the magnetization fixed layer 23 has a magnetization direction in the film plane. The in-plane magnetic layer 26 and the high magnetic permeability layer 27 in the magnetization free layer 25 are formed as necessary and may not be provided.

  The antiferromagnetic layer 21 is produced for the purpose of exchange coupling with the ferromagnetic layer 22 and fixing the ferromagnetic layer 22 (giving unidirectional anisotropy). An alloy exhibiting magnetism, specifically, Mn and at least one element selected from Pt, Ir, Fe, Ru, Cr, Pd, and Ni are used in combination. The film thickness of the antiferromagnetic layer 21 is about 10 to 20 nm. The ferromagnetic layer 22 is given unidirectional anisotropy by exchange coupling with the antiferromagnetic layer 21 and has an apparently higher coercive force in one direction than when the ferromagnetic layer 22 is formed as a single layer. The layer is formed using a ferromagnetic metal such as CoFe, CoFeNi, NiFe, CoFeB, CoPt, or CoFePt. The film thickness of the ferromagnetic layer 22 is about 2 to 10 nm. As a modification, in order to align the orientation of the ferromagnetic layer 22, a material containing NiFe as a seed layer may be stacked on OO.

  The nonmagnetic layer 24 is made of, for example, a metal material with high electrical conductivity such as Al, Cu, Au, Ag, Mg, or an alloy thereof, or an oxide or nitride thereof, and the magnetization fixed layer 23. The magnetic exchange coupling force between the magnetic free layer 25 and the magnetization free layer 25 is interrupted, and the conduction electrons flowing in the direction perpendicular to the film surface pass therethrough. Here, if the nonmagnetic layer 24 is formed using a material having a low electrical resistance, that is, a conductive metal material, the magnetoresistive element becomes a GMR element, and the material having a high electrical resistance, that is, the oxidation of the conductive metal element is performed. If a material or nitride is used, a TMR element is obtained. The film thickness of the nonmagnetic layer 24 is about 1 to 3 nm. Here, as a modification, the nonmagnetic layer 24 is a layer in which an oxide, a nitride, and a conductive metal material are combined such that a cluster of the conductive metal material exists in the oxide or nitride. It does not matter.

  The in-plane magnetic layer 26 has the purpose of increasing the spin polarizability and MR ratio, and when the nonmagnetic material layer 24 is made of oxide or nitride, the coercive force change free layer 28 is oxidized or nitrided to deteriorate the characteristics. For the purpose of preventing this, and / or for the purpose of increasing the detection sensitivity of the coercive force change free layer 28, it is formed. For the in-plane magnetization layer 26, a material having a higher spin polarizability than the coercive force change free layer 28 or a material that is less likely to be oxidized or nitrided than the coercivity change free layer 28 is used. Specifically, for example, it is formed using a material selected from CoFe, CoFeNi, NiFe, NiFeTa, NiFeNb, CoFeB, CoPt, CoFePt, and the like. The film thickness of the in-plane magnetic layer 26 is about 1 to 5 nm.

  The high magnetic permeability layer 27 is formed in contact with the coercive force change free layer 28 for the purpose of increasing the sensitivity to an external magnetic field. The high magnetic permeability layer 27 is made of a soft magnetic material to which NiFe or an additive such as Ta or Nb is added. The film thickness of the high magnetic permeability layer 27 is about 2 to 15 nm.

  The coercive force change free layer 28 is a layer that detects an external magnetic field. In order to increase the detection sensitivity, the coercive force absolute value is small and the permeability is low at the temperature at which the magnetic field is detected (the temperature at which the coercive force is relatively small). Use materials that exhibit significant properties. The film thickness of the coercive force change free layer 28 is about 3 to 20 nm. Since such a coercive force change free layer 28 is used, the magnetization free layer 25 can realize the characteristic that the magnetic field sensitivity changes depending on the temperature. Hereinafter, the coercive force change free layer 28 will be described in detail.

The coercive force change free layer 28 is formed of a ferrimagnetic material having a compensation temperature (T _comp ) at which spontaneous magnetization is 0 and the coercive force is infinite in principle. Specifically, for example, it comprises at least one heavy rare earth metal selected from Gd, Tb, Ho, Dy and at least one 3d transition metal selected from Fe, Co, Ni, more specifically, For example, a coercive force change free layer containing GdCo and GdFeCo is used. The composition is adjusted so that the coercive force in the film surface direction changes between room temperature and a temperature higher than room temperature. Thus, for example, if the compensation temperature (T _comp ) is set near room temperature, the coercive force is large at room temperature, and the coercive force is small at a temperature higher than room temperature. Thereby, the magnetization free layer 25 having different magnetic field detection sensitivities depending on the temperature, that is, the magnetoresistive effect element 8 having different magnetic field detection sensitivities depending on the temperature can be realized.

  Next, the principle of operation of the coercive force change free layer 28 is shown by taking an alloy of a rare earth metal and a 3d transition metal (rare earth transition metal alloy) as an example.

  An alloy of a heavy rare earth metal and a 3d transition metal is an amorphous metal body that exhibits ferrimagnetism in which the magnetizations of each other are antiparallel, and the difference between the magnetization of the heavy rare earth metal sublattice and the magnetization of the 3d transition metal sublattice is It is known to appear as total magnetization. Since such rare earth transition metal alloys show a decreasing tendency of magnetization in the rare earth metal sublattice and the transition metal sublattice toward the Curie temperature as the temperature rises, the total magnetization (spontaneous magnetization) varies depending on the temperature. Change.

Specifically, the magnetization amount (M _RE ) of the rare earth metal sublattice is lower than the temperature at which the magnetization amount of the rare earth metal sublattice and the magnetization amount of the transition metal sublattice are the same (compensation temperature T _comp ). The total amount of magnetization (M _TOTAL ) exceeds the amount of magnetization (M _TM ) of the lattice, and can be expressed as M _TOTAL = M _RE -M _TM . On the other hand, the magnetization of the transition metal sub-lattice in the compensation temperature _{(T comp)} above the temperature _{(M TM)} exceeds the magnetization of the rare earth metal sublattice of _{(M RE),} the magnetization quantity of the total _{(M TOTAL) is, M TOTAL} = _MTM - _MRE . Further, in the vicinity of the compensation temperature T _comp , the total magnetization amount (spontaneous magnetization amount) becomes 0, so that the external magnetic field is not sensed. For this reason, the coercive force H _c increases and theoretically increases to infinity. It is known.

The temperature (compensation temperature T _comp ) at which the coercive force H _c increases as described above can be adjusted by the composition ratio of the rare earth metal and the transition metal.

The coercive force change free layer 28 of the magnetoresistive element 8 uses the vicinity of the compensation temperature T _comp of the ferrimagnetic material. For example, the composition is adjusted so as to be _{close to the} compensation temperature T _comp at room temperature. According to this, as the temperature rises or falls, the difference between the magnetization amount (M _TM ) of the transition metal sublattice and the magnetization amount (M _RE ) of the rare earth metal sublattice increases (M _TOTAL = _M TM _{-M RE} increases, _M TOTAL _{= M} RE _{-M TM} increases as the temperature decreases), the coercive force changes the free layer 28 is obtained. That is, it is possible to realize a coercive force H _c is very large, the coercive force changes the free layer 28 the coercive force Hc decreases as the temperature increases or temperature decrease at room temperature.

Here, in FIG. 4, as an example of the magnetization free layer 25, an in-plane magnetization layer: Co ₇₀ Fe ₃₀ (1 nm) / high permeability layer: Ni ₈₀ Fe ₂₀ (10 nm) / coercive force change free layer: Gd ₃₉ Co The temperature dependence of the coercive force in the magnetization free layer which consists of a ₆₁ (15 nm) laminated film is shown.

As shown in FIG. 4, the magnetization free layer of this example has a reduced coercive force as the temperature rises, and at a temperature exceeding 120 ° C., it is about 7.96 × 10 ² [A / m] (10 [Oe]). The magnetic free layer 25 exhibits the following coercive force. In general, in order to detect a leakage magnetic field from a magnetic recording medium, it is desirable that the coercive force of the magnetization free layer is, for example, about 7.96 × 10 ² [A / m] (10 [Oe]) or less. In this case, the leakage magnetic field can be detected at about 110 ° C. or higher. Note that the temperature dependence of the coercive force as shown in FIG. 4 can be adjusted by changing the film thickness of the laminated film constituting the magnetization free layer and the composition of the coercive force change free layer (here, GdCo). It is.

  Thus, when using the magnetization free layer 25 whose coercive force monotonously changes with temperature change, the larger the temperature difference generated in the magnetization free layer 25, the larger the coercive force difference generated in the magnetization free layer 25. it can. In other words, the difference in the external magnetic field detection sensitivity generated in the magnetization free layer 25 can be increased. Therefore, if a large temperature gradient can be generated in the track width direction (X direction in FIG. 1) of the magnetization free layer 25, the leakage magnetic field from the magnetic recording medium can be detected only in a part of the region where the coercive force is reduced. Thus, a signal from a magnetic recording medium having a track width smaller than the length of the magnetization free layer 25 in the track width direction can be reproduced with high resolution.

The insulating layer 9 prevents the occurrence of a short circuit due to contact between the thermal conductor layer 10 and the bias layer 11 and the magnetoresistive effect element 8 or contact between the thermal conductor layer 10 and the lower magnetic shield layer 7. It is formed for the purpose. The insulating layer 9 includes an oxide insulator such as ZnO, Al ₂ O ₃ , SiO ₂ , TiO ₂ , CrO ₂ , or CeO ₂ having a high electric resistance value, a nitride insulator such as SiN, or glass or plastic. Is used. The insulating layer 9 is formed with a film thickness of about 2 nm to 10 nm, for example.

  The heat conductor layer 10 is positioned symmetrically with respect to the center line of the magnetoresistive effect element 8 in the stacking direction of the magnetization fixed layer 23, the nonmagnetic material layer 24, and the magnetization free layer 25, and the magnetoresistive effect element 8 is a pair of layers formed so as to sandwich 8. This thermal conductor layer 10 is made of a material having high thermal conductivity, for example, Au (gold), Ag (silver), Cu (copper), Al (aluminum), Mg (magnesium), Mo (molybdenum), W ( Tungsten), Si (silicon), DLC (diamond-like carbon), or a metal material mainly composed of these is used as a single layer or stacked layers. By using such a material having high thermal conductivity for the thermal conductor layer 10, the heat dissipation effect in the X direction (track width direction) of the magnetoresistive effect element 8 is enhanced, and the center of the magnetoresistive effect element 8 in the track width direction is increased. The temperature difference between the part and the both end parts can be further increased.

  The bias layer 11 is positioned symmetrically with respect to the center line of the magnetoresistive effect element 8 in the stacking direction of the magnetization fixed layer 23, the nonmagnetic material layer 24, and the magnetization free layer 25, and The magnetic sensing unit 5 is formed so as to be adjacent to each other in the stacking direction of the magnetization fixed layer 23, the nonmagnetic material layer 24, and the magnetization free layer 25. As shown in FIG. 2, the bias layer 11 is formed by sandwiching the insulating layer 9 on the X-axis direction side wall of the magnetoresistive effect element 8, and the magnetization direction of the magnetization free layer 25 in the magnetoresistive effect element 8 is uniform. And a ferromagnetic material such as CoPt, CoFePt, CoPtB, CoCrPt, and CoCrPtB.

  As shown in FIG. 1, the laser light source element 4 has a rectangular parallelepiped shape that is long in the Y-axis direction. A p-type electrode layer 13 is formed on the upper surface of the laser light source element 4, and an n-type electrode layer 14 is formed on the substrate 2 on the side of the laser light source element 4. As a modification, the n-type electrode layer 14 may be formed on the lower surface side of the substrate 2. The laser light emitted from the laser light source element 4 is emitted in the negative Y-axis direction, with the magnetoresistive effect element 8 formed so as to be the same height as the active layer of the laser light source element 4, The magnetic sensing unit 5 is irradiated.

  Next, a method for manufacturing the magnetic head 1 will be described using an example. FIGS. 5A to 5F are views showing the manufacturing process of the magnetic head 51 in order. Here, a method of forming the laser light source element 4 prior to the formation of the magnetic sensor element 3 will be described, but the laser light source element 4 may naturally be formed after the magnetic sensor element 3 is formed. For the laser light source element 4, a GaAlAs semiconductor laser having a wavelength of about 750 to 850 nm, a GaAlInP semiconductor laser having a wavelength of about 620 to 680 nm, a GaN semiconductor laser having a wavelength of about 405 nm, or the like is used. Here, an example of a method for manufacturing the magnetic head 51 using a GaAlInP semiconductor laser will be described.

  First, the laser light source element 4 is formed on the substrate 2 made of n-type GaAs using an MOCVD apparatus. Although not shown, specifically, n-type GaInP is formed as a buffer layer with a film thickness of 300 nm, followed by an n-type AlGaInP cladding layer with a film thickness of 1 μm, an active layer made of GaInP with a film thickness of 60 nm, and p Each of the type AlGaInP cladding layers is formed with a film thickness of 1.2 μm. A part of the p-type AlGaInP cladding layer is etched to form a striped ridge structure, and then a gap layer made of p-type GaInP with a thickness of 200 nm is formed on the ridge structure. In a region other than the ridge structure, an n-type GaAs block layer having a thickness of 700 nm is formed, and a contact layer made of p-type GaAs is formed thereon. Then, a p-type electrode layer 13 made of Zn / Au is formed on the laser light source element 4, and an n-type electrode layer 14 made of Ge / Au is formed on the substrate 2 made of n-type GaAs (see FIG. (See FIG. 5 (a)). These all use known semiconductor laser structures and manufacturing methods.

  Subsequently, a manufacturing process of the magnetic sensing unit 5 will be described with reference to FIGS. For the formation of the magnetic sensing unit 5, a thin film formation method represented by a sputtering method and a lithography method are used.

First, as an insulating film 6 on the substrate 2, SiO ₂ is formed in a thickness of 50 nm in the Z-axis direction, electrically insulated from the substrate 2 made of n-type GaAs, and then a NiFe lower magnetic shield layer 7 is formed on the substrate with a film thickness of 1 μm in the Z-axis direction (see FIG. 5B). The lower magnetic shield layer 7 is formed on the substrate 2 at a position on the Y axis negative direction side with respect to the laser light source element 4. That is, the lower magnetic shield layer 7 is formed in the direction in which the light beam generated from the laser light source element 4 is irradiated.

Next, the magnetoresistive effect element 8 as shown in FIG. 3 is formed using a sputtering method using a sputtering apparatus and a lithography method. Specifically, first, the adhesion between the lower magnetic shield layer 7 and the magnetization fixed layer 23 is enhanced, and the crystal grain sizes and crystal structures of various layers formed after the magnetization fixed layer 23 and the magnetization fixed layer 23 are increased. For the purpose of controlling the surface roughness, a seed layer (not shown) in which Ta, NiFe, and Cu are laminated to a thickness of 5 nm, 2 nm, and 5 nm, respectively, is formed on the lower magnetic shield layer 7. Subsequently, after forming MnIr with a film thickness of 15 nm as the antiferromagnetic layer 21, CoFe is formed with a film thickness of 3 nm as the ferromagnetic layer 22, and these are used as the magnetization fixed layer 23. Subsequently, after forming Al with a film thickness of 1 nm as the nonmagnetic layer 24, O ₂ gas is introduced into the chamber of the sputtering apparatus, and the Al is exposed to oxygen in an O ₂ atmosphere to be oxidized, and Al oxide is oxidized. A membrane. Then, the magnetization free layer 25 shown in the description of FIG. 4 is formed on the nonmagnetic layer 24. Specifically, Co ₇₀ Fe ₃₀ is formed to a thickness of 1 nm as the in-plane magnetic layer 26, and subsequently Ni ₈₀ Fe ₂₀ is formed to a thickness of 10 nm as the high permeability layer 27. Gd ₃₉ Co ₆₁ is formed with a film thickness of 15 nm as the free layer 28. Further, a buffer layer (not shown) made of Ta for protecting the coercive force change free layer 28 is formed with a thickness of 5 nm on the coercive force change free layer 28, and then the length in the track width direction (X direction). Is etched so as to be 100 nm. The magnetoresistive effect element 8 is formed through these steps (see FIG. 5C). The composition ratios of the in-plane magnetic layer 26, the high magnetic permeability layer 27, and the coercive force change free layer 28 are not limited to those described above, and can be changed as appropriate.

  Subsequently, the insulating layer 9 is laminated and formed on the lower magnetic shield layer 7 and the side surface of the magnetoresistive element 8 with a film thickness of 5 nm by using a sputtering method and a lithography method (see FIG. 5D).

  Then, Ag to be the thermal conductor layer 10 is formed with a film thickness of 30 nm on the insulating layer 9 using a sputtering method, and a CoPtB layer to be the bias layer 11 is formed with a film thickness of 30 nm on the thermal conductor layer 10. Form with. At this time, the thermal conductor layer 10 is formed on the side of the magnetization free layer 25 of the magnetoresistive element 8 (see FIG. 5E). Here, as a modification, when the magnetoresistive element 8 is formed, when the magnetization free layer 25 is formed before the magnetization fixed layer 23, the heat conductor layer 10 is formed before the bias layer 11. That is, the arrangement of the thermal conductor layer 10 and the bias layer 11 in this embodiment is reversed.

Subsequently, a NiFe layer to be the upper magnetic shield layer 12 is formed with a thickness of 1 μm on the bias layer 11, the insulating layer 9, and the magnetoresistive element 8 (see FIG. 5F). Finally, the magnetization fixed layer 23 is fixed by annealing in a magnetic field at 250 ° C. for 1 hour in a magnetic field of about 3.98 × 10 ⁴ [A / m] (500 [Oe]). The magnetic head 1 including the magnetic sensor element 3 and the laser light source element 4 is completed through the above steps.

  Next, the operation of the magnetic head 1 will be described. First, a light beam is emitted from the laser light source element 4 in the Y-axis direction in FIG. 1 and irradiated to the magnetic sensing unit 5 centered on the magnetoresistive effect element 8 to heat the magnetoresistive effect element 8. At this time, the upper magnetic shield 12, the bias layer 11, and particularly the thermal conductor layer 10 formed in the track width direction (X direction) of the magnetoresistive effect element 8 are formed around the magnetoresistive effect element 8. By depriving the heat, particularly the end portion of the magnetoresistive effect element 8 is cooled, and a large temperature gradient is generated in the track width direction (X direction).

  In this way, by creating a temperature difference between the central portion of the magnetization free layer 25 in the track width direction (X-axis direction) and both ends in the track width direction, and increasing the temperature of the central portion, the track of the magnetization free layer 25 In the vicinity of the center in the width direction, the coercive force of the coercive force change free layer 28 is smaller than the leakage magnetic field from the magnetic recording medium, and the leakage magnetic field from the magnetic recording medium is detected. On the other hand, at both ends of the magnetization free layer in the track width direction, since the temperature is lower than the center of the magnetization free layer 25 in the track width direction, the coercive force of the coercive force change free layer 28 is large, and the leakage magnetic field is detected. I will not. That is, the signals of the adjacent tracks are not read at both ends of the magnetization free layer 25 in the track width direction.

  According to the present embodiment, when the magnetic sensing unit 5 is irradiated with a light beam from the laser light source element 4, a temperature gradient can be generated in the magnetoresistive effect element 8 included in the magnetic sensing unit 5. That is, the magnetoresistive effect element 8 is heated, and the heat conductor layer 10 dissipates the heat around the side surface of the magnetoresistive effect element 8 to the outside. A high-resolution magnetic sensor element 3 that generates a temperature gradient and can read a recorded magnetic field only at a location where the magnetic field sensitivity in the magnetoresistive effect element 8 is high (a location where the temperature is highest and the vicinity thereof). Can be realized. That is, it is possible to obtain the magnetic sensor element 3 capable of detecting a signal having a track width smaller than the length of the magnetization free layer 25 in the magnetoresistive effect element 8 in the track width direction. In addition, the magnetic head 1 having such a magnetic sensor element 3 can be provided.

  The thermal conductor layer 10 is positioned symmetrically with respect to the center line of the magnetoresistive effect element 8 in the stacking direction of the magnetization fixed layer 23, the nonmagnetic material layer 24, and the magnetization free layer 25, and the magnetoresistance Since it is a pair of layers formed so as to sandwich the effect element 8, it is possible to enhance the heat radiation effect when it is generated by irradiation of the light beam from the laser light source element 4. Therefore, in the magnetoresistive effect element 8, a larger temperature gradient is generated symmetrically in each layer direction of the heat conductor layer 10 composed of a pair of layers from the center of the magnetoresistive effect element 8. Can do. In addition, since the temperature gradient is generated symmetrically from the center 8a of the magnetoresistive effect element 8, the sensing point (origin) of the external magnetic field can be the center 8a of the magnetoresistive effect element 8. It becomes easy to use as a part for the magnetic sensor of the apparatus, and it becomes easy to design the magnetic reproducing apparatus.

  In addition, the bias layer 11 is symmetric with respect to the center line of the magnetoresistive effect element 8 in the stacking direction of the magnetization fixed layer 23, the nonmagnetic layer 24, and the magnetization free layer 25, and the heat conductor layer. 10 is formed in the magnetic sensing unit 5 so as to be adjacent to each other in the stacking direction of the magnetization fixed layer 23, the nonmagnetic layer 24, and the magnetization free layer 25. As a result, since both the bias layer 11 and the thermal conductor layer 10 can be formed, productivity can be improved and the small magnetic sensor element 3 and the magnetic head 1 can be provided.

  Further, the magnetic head 1 includes the substrate 2 that also serves as the slider having the ABS surface shape, and the magnetic sensor element 3 formed on the substrate 2, so that the slider and the substrate for the magnetic sensor element are provided. The number of members can be reduced as compared with the case where these are manufactured separately. As a result, it is possible to provide a lightweight magnetic head 1 with a simple manufacturing process.

  In the magnetic head 1, a magnetic sensor element 3 and a laser light source element 4 are formed on one substrate 2. As a result, it is possible to provide the magnetic head 1 that can improve the light beam irradiation positioning accuracy, improve the light beam irradiation reliability, and improve the productivity.

  In the present embodiment, as shown in FIG. 1, it is not always necessary to form the laser light source element 4 with the same width as the width in the track direction (width in the X direction).

<Modification of First Embodiment>
Next, a magnetic head according to a modification of the first embodiment of the present invention will be described. FIG. 6 is a schematic perspective view showing the main part of a magnetic head according to a modification of the first embodiment of the present invention. In addition, the code | symbols 32-39 and 42-44 are attached | subjected in order to the part similar to the codes | symbols 2-9 and 12-14 of 1st Embodiment, and the description may be abbreviate | omitted.

  The magnetic head 31 of this modification has a magnetic sensor element 33 in which only the thermal conductor layer 40 is formed instead of the bias layer 11 and the thermal conductor layer 10 in the magnetic sensor element 3 of the first embodiment. This is different from the first embodiment.

  As the manufacturing method of the magnetic head 31 of this modification, the same manufacturing method as that shown in the first embodiment is used. However, the bias layer 11 and the heat conductor layer 10 in the magnetic sensor element 3 of the first embodiment are used. Instead, only the heat conductor layer 10 is formed, which is different from the first embodiment.

  According to this modification, the same operation and effect as in the first embodiment can be obtained except that the operation and effect of the bias layer 11 of the first embodiment cannot be obtained. However, since the portion where the bias layer 11 is formed in the first embodiment is also the thermal conductor layer 40, it is generated by irradiation of the light beam from the laser light source element 4 as compared with the first embodiment. The heat dissipation effect when heat is applied can be strengthened. Therefore, in the magnetoresistive effect element 38, a temperature gradient larger than that in the first embodiment is symmetrical in the direction of each layer of the heat conductor layer 40 composed of a pair of layers from the center of the magnetoresistive effect element 38. Can be generated. As a result, it is possible to obtain the magnetic sensor element 33 capable of detecting a signal having a smaller track width than that of the first embodiment and the magnetic head 31 having the magnetic sensor element 33.

<Second Embodiment>
Next, a magnetic head according to a second embodiment of the invention will be described. FIG. 7 is a schematic perspective view showing the main part of the magnetic head according to the second embodiment of the present invention. 8A is a plan view showing a recording medium facing surface (XZ plane) of the magnetic sensor element in the magnetic head of FIG. 7 and a center point of the recording medium facing surface, and FIG. 8B is a plan view showing FIG. It is a top view at the time of seeing the magnetic sensor element in the magnetic head of this in the positive direction of the Y-axis from the predetermined cross section (boundary surface 68). In addition, the code | symbol 52, 54-56, 58, 63, 64 is attached to the part similar to the code | symbols 2, 4-6, 8, 13, 14 of 1st Embodiment in order, and the description may be abbreviate | omitted. .

  The magnetic head 51 of this embodiment is formed on a substrate 52 between the magnetic sensing unit 55 and the laser light source element 54 so as to be in contact with the magnetic sensing unit 55 and not to contact the laser light source element 54. It differs from 1st Embodiment by the point which has the generation | occurrence | production part 65. FIG. Further, the end surfaces of the substrate 2 and the magnetic sensing unit 55 (the surface in front of the paper surface) in FIG. 7 become the recording medium facing surface.

  The near-field light generating unit 65 includes an insulating film 56 and a lower magnetic shield layer 57 that are continuously formed on the substrate 2 from the magnetic sensing unit 55, a lower metal layer 66 that is formed on the lower magnetic shield layer 7, And a dielectric layer 70 formed in a minute opening 69 on the lower metal layer 66. Then, on each of both side portions of the dielectric layer 70, a laminated body in which the thermal conductor layer 60 and the bias layer 61 are sequentially laminated via the insulating layer 59 continuously formed from the magnetic sensing portion 55, It is formed continuously from the magnetic sensing unit 55. The insulating layer 59 is also formed on the upper surface of the lower magnetic shield layer 7. Further, an upper metal layer 67 is laminated so as to cover the magnetoresistive effect element 58, the insulating layer 59, and the bias layer 61 in the near-field light generating unit 65. On the upper metal layer 67, the upper magnetic shield layer 12 continuously formed from the magnetic sensing unit 55 is laminated.

  The minute opening 69 in which the dielectric layer 70 is formed is formed to have the same height as the active layer of the laser light source element 54. Further, the minute opening 69 is in contact with the magnetoresistive effect element 58 of the magnetic sensing unit 55 at the boundary surface 68. Therefore, the light beam emitted from the laser light source element 54 is irradiated to the magnetoresistive effect element 58 as near-field light through the minute opening 69. At this time, the lengths of the minute openings 69 in the X direction and the Z direction are set to be smaller than the wavelength of the light beam. In this way, it is possible to prevent the magnetoresistive effect element 58 from being irradiated with light beam transmitted light (Far Field light), and only near-field light can be obtained.

  The upper magnetic shield layer 62 and the lower magnetic shield layer 57 are formed for the purpose of canceling out a noise magnetic field generated from the periphery of the magnetic recording medium and the magnetic sensor element 53, and are continuously formed up to the near-field light generating unit 65. Yes. A high magnetic permeability material is used for the upper magnetic shield layer 12 and the lower magnetic shield layer 7. This is because if the space to be magnetically shielded is surrounded by a high magnetic permeability material, the magnetic field lines flow along a material having a high relative magnetic permeability and a low magnetic resistance, and a magnetic shielding effect is generated. Specifically, it is formed using, for example, NiFe or NiFeTa. The film thickness of the upper magnetic shield layer 62 and the lower magnetic shield layer 57 may be any film thickness that can cancel the magnetic field that is a noise source, and is, for example, about 500 nm to 3 μm. Here, the film thickness of the lower magnetic shield layer 57 of the magnetic sensing unit 55 is the sum of the film thickness of the lower magnetic shield layer 57 in the near-field light generating unit 65 and the film thickness of the lower metal layer 66. It forms so that it may become. Further, a light beam from the active layer of the laser light source element 54 is disposed so as to be applied to the dielectric layer 70 formed on the lower metal layer 66.

  The insulating layer 59 is a layer formed continuously from the magnetic sensing unit 55 to the near-field light generating unit 65, and in the magnetic sensing unit 55, the bias layer 61, the thermal conductor layer 60, and the magnetoresistive effect element 58. Or the heat conductor layer 60 and the lower magnetic shield layer 57 are in contact with each other to prevent a current short circuit from occurring. Further, the near-field light generating unit 65 is provided for the purpose of preventing the heat conductor layer 60 and the lower metal layer 66 from coming into contact with each other and causing a current short circuit.

  The thermal conductor layer 60 and the bias layer 61 are the same as the thermal conductor layer 10 and the bias layer 11 in the first embodiment, except that the thermal conductor layer 60 and the bias layer 61 are continuously formed from the magnetic sensing unit 55 to the near-field light generating unit 65. is there.

  The lower metal layer 66 and the upper metal layer 67 are members formed as a part of the near-field light generating unit 65, and generate surface plasmons at the interface with the dielectric layer 70 when the micro aperture 69 is irradiated with the light beam. A layer for propagating and generating high-intensity near-field light on the surface of the magnetoresistive effect element 58 of the magnetic sensing unit 55. The lower metal layer 66 and the upper metal layer 67 are made of a material that can efficiently generate and propagate plasmons with respect to a light beam emitted from a semiconductor laser near the visible light wavelength. Specifically, Au, Ag, Al, or an alloy material mainly composed of these is used. The film thickness of the lower metal layer 66 and the upper metal layer 67 is about 10 nm. When a material mainly composed of Au is used for the lower metal layer 66 and the upper metal layer 67, a semiconductor laser of about 600 nm to 1 μm is used as a light source, and a material mainly composed of Ag and Al is used. Although a short wavelength semiconductor laser of 600 nm or less is used, it is not limited to this.

The dielectric layer 70 is a member formed as a part of the near-field light generating unit 65, and generates and propagates surface plasmons at the interface between the lower metal layer 66 and the upper metal layer 67 during light beam irradiation, This is a layer for generating high-intensity near-field light on the surface of the magnetoresistive effect element 58 of the magnetic sensor element 53. A dielectric material having a low refractive index is selected for the dielectric layer 70 from the viewpoint of efficiently generating and propagating surface plasmons. Specifically, materials such as SiO ₂ , SiN, Al ₂ O ₃ , AlN, MgF ₂ , and MgO are used. The film thickness of the dielectric layer 70 and the length in the track width direction are formed to be equal to or greater than the film thickness of the magnetoresistive effect element 58 and the length in the track width direction.

  As shown in FIG. 7, the laser light source element 54 has a rectangular parallelepiped shape that is long in the Y-axis direction. Laser light emitted from the laser light source element 54 is emitted in the negative Y-axis direction, and is irradiated to the near-field light generating unit 65, more specifically, to the vicinity of the minute opening 69 at the substantially central portion of the near-field light generating unit 65.

  Next, a method for manufacturing the magnetic head 51 will be described using an example. FIGS. 9A to 9G are diagrams sequentially illustrating the manufacturing process of the magnetic head 51. Here, a method of forming the laser light source element 54 prior to the formation of the magnetic sensor element 53 will be described, but the laser light source element 54 may be formed after the magnetic sensor element 53 is formed. As the laser light source element 54, a GaAlAs semiconductor laser having a wavelength of about 750 to 850 nm, a GaAlInP semiconductor laser having a wavelength of about 620 to 680 nm, a GaN semiconductor laser having a wavelength of about 405 nm, or the like can be used. However, here, an example of a method of manufacturing the magnetic head 51 using a GaAlInP-based semiconductor laser will be described.

  First, the laser light source element 54 is formed on the substrate 52 made of n-type GaAs using an MOCVD apparatus. Although not shown, specifically, n-type GaInP is formed as a buffer layer with a film thickness of 300 nm, followed by an n-type AlGaInP cladding layer with a film thickness of 1 μm, an active layer made of GaInP with a film thickness of 60 nm, and p Each of the type AlGaInP cladding layers is formed with a film thickness of 1.2 μm. A part of the p-type AlGaInP cladding layer is etched to form a striped ridge structure, and then a gap layer made of p-type GaInP with a thickness of 200 nm is formed on the ridge structure. In a region other than the ridge structure, an n-type GaAs block layer having a thickness of 700 nm is formed, and a contact layer made of p-type GaAs is formed thereon. Then, the p-type electrode layer 13 made of Zn / Au is formed on the laser light source element 54, and the n-type electrode layer 14 made of Ge / Au is formed on the substrate 52 made of n-type GaAs (see FIG. FIG. 9 (a)). These all use known semiconductor laser structures and manufacturing methods.

  Subsequently, a manufacturing process of the magnetic sensing unit 55 and the near-field light generating unit 65 will be described with reference to FIGS. 9B to 9G. For forming the magnetic sensing unit 55, a thin film forming method represented by a sputtering method and a lithography method are used.

First, as an insulating film 56 on the substrate 52, SiO ₂ is formed in a thickness of 50 nm in the Z-axis direction, electrically insulated from the substrate 52 made of n-type GaAs, and then a NiFe lower magnetic shield layer 57 is formed on the substrate with a thickness of 1 μm in the Z-axis direction (see FIG. 9B). The lower magnetic shield layer 57 is formed on the substrate 52 at a position on the Y axis negative direction side with respect to the laser light source element 54. That is, the lower magnetic shield layer 57 is formed in the direction in which the light beam generated from the laser light source element 54 is irradiated.

  Next, approximately half the surface of the lower magnetic shield layer 57 on the laser light source element 54 side is etched by 50 nm in the Z direction, and the lower metal layer 66 is formed on the etched portion of the lower magnetic shield layer 57 using Au. They are stacked with an axial width of 200 nm and a Z-axis thickness of 50 nm (see FIG. 9C).

  Subsequently, similarly to the first embodiment, a magnetoresistive effect element 58 having the same configuration as that of the magnetoresistive effect element 8 in the first embodiment is formed by using a sputtering method using a sputtering apparatus and a lithography method. Subsequently, the insulating layer 59 is laminated and formed on the lower magnetic shield layer 57 and the side surface of the magnetoresistive effect element 58 with a film thickness of 5 nm by using a sputtering method and a lithography method.

  Then, Ag to be the thermal conductor layer 60 is formed with a film thickness of 30 nm on the insulating layer 59 by using a sputtering method, and a CoPtB layer to be the bias layer 61 is further formed with a film thickness of 30 nm on the thermal conductor layer 60. Form with. At this time, the heat conductor layer 60 is formed on the side of the magnetization free layer (not shown) of the magnetoresistive effect element 58 (see FIG. 9D). Here, as a modification, when the magnetoresistive effect element 58 is formed, when the magnetization free layer is formed before the magnetization fixed layer (not shown) in the magnetoresistive effect element 58, the heat conductor layer 60 is biased. Formed before layer 61. That is, the arrangement of the heat conductor layer 60 and the bias layer 61 in the present embodiment is reversed.

Subsequently, the magnetoresistive effect element 58 formed on the lower metal layer 66 (that is, the magnetoresistive effect element 58 existing on the part side to be the near-field light generating portion 65 later) is etched away and a minute opening is formed. 69 is formed. Further, a dielectric layer 70 made of SiO ₂ is formed in the formed minute opening 69 to fill the minute opening 69. Specifically, the minute opening 69 is formed so that the width in the Z-axis direction is 70 nm, the width in the X-axis direction is 100 nm, and the width in the Y-axis direction is 200 nm (see FIG. 9E).

  Subsequently, the upper metal layer 67 is formed on the dielectric layer 70 and the bias layer 61 formed on the side of the portion that will later become the near-field light generating unit 65 by using Au, and the Y-axis direction width is 200 nm and the Z-axis direction. The layers are stacked with a thickness of 50 nm (see FIG. 9F).

Subsequently, a NiFe layer to be the upper magnetic shield layer 62 is formed with a film thickness of 1 μm (see FIG. 9G). Finally, annealing is performed in a magnetic field at 250 ° C. for 1 hour in a magnetic field of about 3.98 × 10 ⁴ [A / m] (500 [Oe]), and the magnetization fixed layer (see FIG. (Not shown). Through the above steps, the magnetic head 51 including the magnetic sensor element 53 and the laser light source element 54 is completed.

  Next, the operation of the magnetic head 51 will be described. First, a light beam having a polarization component in the Z-axis direction in FIG. 7 is emitted from the laser light source element 54 and is irradiated in the vicinity of the minute aperture 69 formed in the near-field light generating portion. As a result, seepage light that passes through the minute aperture 69 smaller than the wavelength of the light beam is generated, and surface plasmons are generated and propagated at the interface between the dielectric layer 70, the upper metal layer 67, and the lower metal layer 66. The surface of the opening 69 opposite to the light beam incident surface (the surface facing the magnetoresistive effect element 58) is reached, and the magnetoresistive effect element 58 is heated. At this time, strong near-field light is generated near the center in the track width direction of the magnetization free layer, particularly in the magnetoresistive effect element 58, and the center is heated more strongly than the end of the magnetization free layer. In addition, the track width of the upper magnetic shield 62 and the lower magnetic shield layer 57 and the bias layer 61, particularly the magnetoresistive effect element 58 and the dielectric layer 70 formed around the magnetoresistive effect element 58 and in the near-field light generating unit 65. Heat is taken away by the heat conductor layer 60 formed in the direction (X direction), whereby both ends of the magnetoresistive element 58 are cooled, and a large temperature gradient is generated in the track width direction (X axis direction).

  Thus, by creating a temperature difference between the central portion of the magnetization free layer of the magnetoresistive effect element 58 in the track width direction (X-axis direction) and both end portions in the track width direction, Near the center of the magnetization free layer in the track width direction, the coercive force of the coercive force change free layer in the magnetization free layer is smaller than the leakage magnetic field from the magnetic recording medium, and the leakage magnetic field from the magnetic recording medium is detected. On the other hand, at both ends of the magnetization free layer in the track width direction, since the temperature is lower than the center of the magnetization free layer in the track width direction, the coercivity of the coercive force change free layer in the magnetization free layer is large, Magnetization reversal due to the leakage magnetic field does not occur, and the leakage magnetic field is not detected. That is, the signal of the adjacent track is not read at both ends of the magnetization free layer in the track width direction.

  According to this embodiment, the same effect as that of the first embodiment can be obtained. Further, the magnetic sensor element 53 having a larger temperature gradient in the magnetization free layer of the magnetoresistive effect element 58 than that of the first embodiment can be provided, and the magnetic head 51 having the magnetic sensor element 53 can be provided.

  In addition, since the heat sensing layer 55 and the near-field light generating unit 65 are continuously formed like the heat conductor layer 60 and the bias layer 61 at a time, the magnetic sensor element 53 that can be manufactured with a simple manufacturing process. And a manufacturing method thereof. Furthermore, it is possible to provide a method of manufacturing the magnetic sensor element 53 that can align the minute opening 69 and the magnetoresistive effect element 58 with high accuracy.

  In addition, the presence of the minute aperture 69 eliminates the need for highly precise positioning control of the light beam irradiation from the laser light source element 54 to the magnetoresistive effect element 58, and irradiates the minute region of the magnetoresistive effect element 58 with the light beam. Can be easily done.

  In the present embodiment, the light beam from the laser light source element 54 may have a polarization component in the Z-axis direction. In this way, plasmon enhancement occurs in the upper metal layer 67 and the lower metal layer 66 that sandwich the dielectric layer 70 in the Z-axis direction. As a result, the near-field light intensity distribution in the track width direction (X-axis direction) in the minute opening 69 on the surface (boundary surface 68) where the minute opening 69 is in contact with the magnetoresistive effect element 58 shows the X of the magnetoresistive effect element 58. Compared with both axial end portions, the distribution is stronger in the vicinity of the central portion, and the central portion in the track width direction of the magnetoresistive effect element 58 can be heated more strongly.

  Further, the light beam from the laser light source element 54 may be linearly polarized light having only a polarization component in the Z direction. This can be realized by forming a polarizer on the light beam optical path between the laser light source element 54 and the magnetic sensor element 53 shown in FIG.

  In the present embodiment, the width in the track direction (X direction width) of the magnetic sensing unit 55 and the near-field light generating unit 65 is not necessarily the same as the width of the laser light source element 54 in the track direction (X direction width). There is no need to form.

<Modification of Second Embodiment>
Next, a magnetic head according to a modification of the second embodiment of the present invention will be described. FIG. 10 is a schematic perspective view showing the main part of a magnetic head according to a modification of the second embodiment of the present invention. In addition, the code | symbol 72, 74-76, 78, 82-84 is attached in order to the part similar to the code | symbol 2, 4-6, 8, 12-14 of 1st Embodiment, and the code | symbol of 2nd Embodiment. The same parts as 66 to 68 are denoted by reference numerals 86 to 88 in order, and the description thereof may be omitted.

  The magnetic head 71 of this modification has a magnetic sensor element 73 in which only the thermal conductor layer 80 is formed instead of the bias layer 61 and the thermal conductor layer 60 in the magnetic sensor element 53 of the second embodiment. This is different from the second embodiment.

  As the manufacturing method of the magnetic head 71, the same manufacturing method as that shown in the second embodiment is used. However, instead of the bias layer 61 and the thermal conductor layer 60 in the magnetic sensor element 53 of the second embodiment, a thermal head is used. The point which forms only the conductor layer 80 differs from 2nd Embodiment.

  According to this modification, the same operation and effect as in the second embodiment can be obtained except that the operation and effect of the bias layer 61 of the second embodiment cannot be obtained. However, since the portion where the bias layer 61 in the second embodiment is formed is also the thermal conductor layer 80, it is generated by irradiation of the light beam from the laser light source element 74 as compared with the second embodiment. The heat dissipation effect when heat is applied can be strengthened. Therefore, in the magnetoresistive effect element 78, a temperature gradient larger than that of the second embodiment is symmetrical in the direction of each layer of the heat conductor layer 80 composed of a pair of layers from the center of the magnetoresistive effect element 78. Can be generated. As a result, it is possible to obtain a magnetic sensor element 73 capable of detecting a signal with a track width smaller than that of the second embodiment and a magnetic head 71 having the magnetic sensor element 73.

<Third Embodiment>
Next, a magnetic head according to a third embodiment of the invention will be described. FIG. 11 is a schematic perspective view showing the main part of the magnetic head according to the second embodiment of the present invention. 12A is a plan view showing the recording medium facing surface (XZ plane) of the magnetic sensor element in the magnetic head of FIG. 11 and the center point of this recording medium facing surface, and FIG. FIG. 6 is a plan view of the magnetic sensor element of the magnetic head when viewed from a predetermined cross section (boundary surface 107) in the positive direction of the Y axis. In addition, the code | symbol 92 and 94-104 are attached | subjected in order to the part similar to the code | symbols 2 and 4-14 of 1st Embodiment, and the description may be abbreviate | omitted.

  The magnetic head 91 of the present embodiment has a near-field light composed of a metal layer 106 having a minute opening 108 in which a dielectric layer 109 is embedded in a substantially central portion, instead of the near-field light generating unit 65 of the second embodiment. The second embodiment is different from the second embodiment in that the generator 105 is provided.

  In the manufacturing method of the magnetic head 91, the manufacturing method of the magnetic sensing unit 95 is the same as the manufacturing method shown in the first embodiment, but the manufacturing method of the near-field light generating unit 105 is different as follows. . That is, although not shown, after the magnetic sensing portion 95 is formed, an Au metal layer is formed on the substrate with a thickness of 1 μm in the Z-axis direction. The metal layer is formed on the substrate 2 between the laser light source element 94 and the magnetic sensing unit 95 so as to be in contact with the magnetic sensing unit 95.

Subsequently, an SiO ₂ film having a thickness of 70 nm is formed on the metal layer having a thickness of 1 μm as the dielectric layer 109. At this time, the dielectric layer 109 and the magnetoresistive effect element 98 are formed in contact with each other.

  Then, the dielectric layer 109 is etched so that the length in the track width direction (X direction) is 100 nm. On the dielectric layer 109 and the above-mentioned metal layer having a thickness of 1 μm, Au is further added. The near-field light generating part 105 is completed by laminating a metal layer with a thickness of 1 μm in the Z-axis direction and combining with the previously formed Au metal layer to form the metal layer 106.

  By forming the near-field light generating part 105 as described above, the minute opening 69 is formed so that the width in the Z-axis direction is 70 nm, the width in the X-axis direction is 100 nm, and the width in the Y-axis direction is 200 nm. The

  Note that Ag, Al, or an alloy material mainly composed of these may be used for the metal layer 106.

  According to this embodiment, there exists an effect | action and effect similar to 2nd Embodiment. In addition, since the near-field light generating unit 105 is formed of the metal layer 106 mainly composed of Au, Ag, or Al and having a high thermal conductivity, a further heat dissipation effect can be obtained as compared with the second embodiment. Yes. As a result, particularly the end portion of the magnetoresistive effect element 98 is cooled, and a large temperature gradient can be generated in the track width direction (X direction), so that a signal with a smaller track width than in the second embodiment can be detected. A magnetic sensor element 93 can be obtained. In addition, a magnetic head 91 having such a magnetic sensor element 93 can be provided.

<Modification of Third Embodiment>
Next, a magnetic head according to a modification of the third embodiment of the present invention will be described. FIG. 13 is a schematic perspective view showing the main part of a magnetic head according to a modification of the third embodiment of the present invention. In addition, the code | symbol 112,114-119,122-124 is attached in order to the part similar to the code | symbol 2, 4-9, 12-14 of 1st Embodiment, and code | symbol 106,107 of 3rd Embodiment and Similar parts may be sequentially denoted by reference numerals 126 and 127, and the description thereof may be omitted.

  The magnetic head 111 of this modification has a magnetic sensor element 113 in which only the thermal conductor layer 120 is formed instead of the bias layer 101 and the thermal conductor layer 100 in the magnetic sensor element 93 of the third embodiment. This is different from the third embodiment.

  As the manufacturing method of the magnetic head 111, the same manufacturing method as that shown in the third embodiment is used. However, instead of the bias layer 101 and the heat conductor layer 100 in the magnetic sensor element 93 of the third embodiment, a thermal head is used. The point which forms only the conductor layer 120 differs from 2nd Embodiment.

  According to this modification, the same operation and effect as in the third embodiment can be obtained except that the operation and effect of the bias layer 101 of the third embodiment cannot be obtained. However, since the portion where the bias layer 101 is formed in the third embodiment is also the thermal conductor layer 120, it is generated by irradiation of the light beam from the laser light source element 114 as compared with the third embodiment. The heat dissipation effect when heat is applied can be strengthened. Therefore, in the magnetoresistive effect element 118, a temperature gradient larger than that in the third embodiment is symmetrical in the direction of each layer of the heat conductor layer 120 composed of a pair of layers from the center of the magnetoresistive effect element 118. Can be generated. As a result, it is possible to obtain the magnetic sensor element 113 capable of detecting a signal having a smaller track width than that of the third embodiment and the magnetic head 111 having the magnetic sensor element 113.

<Fourth embodiment>
Next, a magnetic reproducing apparatus according to the fourth embodiment of the present invention will be described. FIG. 14 is a schematic configuration diagram of a magnetic reproducing apparatus according to the fourth embodiment of the present invention.

  The magnetic reproducing apparatus 200 according to the present embodiment rotationally drives a magnetic head 201, a disk-shaped magnetic recording medium 202, and a magnetic recording medium 202 that are composed of magnetic sensor elements having the same configuration as any one of the above-described embodiments and modifications. A spindle 203 for supporting the magnetic head 201, a suspension arm 204 for supporting and fixing the magnetic head 201, a voice coil motor 205 for driving the suspension arm 204 on the magnetic recording medium 202, and a control circuit 206 for controlling them. The control circuit 206 includes a rotation drive control device 207 that controls the rotation drive of the spindle 203, a signal processing device 208 that exchanges signals with the magnetic head 201, and an output control that controls the output of the light source formed on the magnetic head 201. A device 209 and a memory device 210 for storing the read information are included. Each component of the magnetic reproducing device 200 is a configuration used for a known hard disk except for the magnetic head 201.

  The magnetic head 201 has an ABS surface shape (not shown) on the magnetic recording medium 202 side of the substrate. The ABS surface is formed by rotating the magnetic recording medium 202 by rotating the spindle 203 to generate an air flow, and the magnetic head 201 and the magnetic recording medium when the magnetic head 201 floats on the magnetic recording medium 202. In order to control the air flow to and from 202 and adjust the flying height of the magnetic head 201 to about 5 to 10 nm, it is formed in a convex shape on the surface facing the magnetic recording medium 202, and is a conventional hard disk. It is generally used in a slider of a magnetic head used in the apparatus. Here, the rotation speed of the spindle 203 is not particularly limited as long as the rotation speed can stably perform recording and reproduction. For example, a rotation speed of 1800 rpm to 7200 rpm can be used.

  On the magnetic recording medium 202, for example, a recording layer of CoCrPt, CoCrPtB, FePt, CoPt, CoPd, or a ferrimagnetic material typified by TbFeCo or DyFeCo is formed as a recording layer on a disk-shaped glass substrate. Those formed with a thickness of 20 to 50 nm can be used. A soft magnetic backing layer typified by NiFe may be formed between the recording layer and the disk-shaped glass substrate. On the recording layer of the magnetic recording medium 202, for the purpose of protecting the recording layer, a C film is formed with a film thickness of, for example, about 5 nm, and a lubricant is applied and formed with a film thickness of, for example, 1 nm.

  Next, the operation of the magnetic reproducing apparatus 200 according to the fourth embodiment of the present invention will be described. When the power is turned on, the magnetic head 201 floats on the magnetic recording medium 202 with a flying height of about 5 to 10 nm by an air flow generated as the spindle 203 rotates. Subsequently, the laser light source element of the magnetic head 201 is energized to generate a light beam, which is irradiated to the magnetic sensor element of the magnetic head 201. As a result, as shown in the above-described embodiment, a steep temperature gradient in the track width direction (X-axis direction) on the surface of the magnetization free layer facing the magnetic recording medium 202 included in the magnetoresistive effect element of the magnetic sensor element. Can be formed. At this time, in the output control device 209 included in the control circuit 206, the output of the light source is set so that the coercive force in the high temperature region in the magnetization free layer is small enough to detect the leakage magnetic field from the magnetic recording medium 202. adjust. As an adjustment method, the output of the laser light source is adjusted while performing a test read in the test writing area of the recording medium. As a result, the leakage magnetic field from the recorded magnetic bit of the magnetic recording medium 202 can be read at a location where the local magnetic field sensitivity of the magnetization free layer of the magnetoresistive effect element is high. This is converted into an electrical signal and the recorded information is read out.

  According to this embodiment, the magnetic recording effected by the magnetic sensor element of any one of the above-described embodiments and modifications, and recorded on the magnetic recording medium by generating a temperature gradient in the magnetoresistive effect element A magnetic reproducing apparatus capable of reproducing bits with high resolution can be provided.

  Next, the present invention will be described using examples and comparative examples.

(Example 1)
A thermal conductivity simulation, which will be described later, is performed on the temperature distribution when a magnetic beam having a wavelength of 680 nm is irradiated onto the magnetic sensor element having the same configuration as the magnetic sensor element 3 described in the method for manufacturing the magnetic head 1 of the first embodiment. The temperature change in the track width direction (X-axis direction) on the magnetic recording medium facing surface of the magnetization free layer included in the magnetoresistive effect element of the magnetic sensor element was verified. Further, as a comparative example, the magnetic sensor element 133 in the magnetic head 131 shown in FIG. The magnetic head 131 according to the comparative example is a magnetic sensor element 133 in which only the bias layer 141 is formed without forming the thermal conductor layer 10 in the magnetic sensor element 3 of the magnetic head 1 of the first embodiment. This is different from the first embodiment. Moreover, the code | symbol 132, 134-144 is attached | subjected in order to the part similar to the code | symbol 2, 4-9, 12-14 of 1st Embodiment, and the description is abbreviate | omitted.

Specifically, the thermal conductivity simulation was performed as follows. That is, the intensity distribution of the light beam applied to the magnetic sensor element was a Gaussian distribution, and the light beam spot diameter was 680 nm. At this time, the amount of heat (wattage) incident on each part of the magnetic sensor element was determined based on the Gaussian distribution so that the spot diameter was 680 nm and the peak intensity was 1 / e ² times. In Example 1 and the comparative example, the simulation was performed by adjusting the incident intensity of the light beam so that the temperatures at the centers of the magnetization free layers (X = 0 in the figure) are equal to each other.

  The simulation results described above are shown in FIG. Here, the horizontal axis X of the graph in FIG. 16 indicates the position in the positive direction of the X-axis with the center position of the magnetoresistive effect element facing surface of the magnetic recording medium being 0 (origin). Since each magnetic sensor element is symmetrical with respect to the center position in the X-axis direction, it goes without saying that a result obtained by horizontally inverting the result in the X-axis positive direction with respect to the X-axis negative direction can be obtained.

  FIG. 16 shows that the temperature gradient in the track width direction (X-axis direction) in the magnetoresistive effect element in the medium facing surface is steeper in Example 1 than in the comparative example. Specifically, in the comparative example, the temperature difference is 9 ° C. between the track width center (X = 0) of the magnetization free layer and the end portion in the track width direction (X = 50). Then, a temperature difference of 11.5 ° C. is obtained. Therefore, it was confirmed that the temperature difference between the central portion and the end portion of the magnetoresistive effect element in this example could be larger than that in the comparative example.

In the present embodiment, the simulation was performed using the magnetization free layer having the characteristics shown in FIG. 4, but an external magnetic field of about 7.96 × 10 ² [A / m] (10 [Oe]) is detected. The track width was found to be 85 nm in Example 1 compared to 100 nm in the comparative example.

(Example 2)
Next, a magnetic sensor element having the same configuration as that of the example of the magnetic sensor element 33 described in the method of manufacturing the magnetic head 31 according to the modification of the first embodiment (the thermal conductor layer is formed of Ag) and Example 1 will be described. A similar heat conduction simulation was performed. The result is shown in FIG. The conditions for the heat conduction simulation are the same as those in the first embodiment.

  As can be seen from FIG. 17, in this example, the temperature gradient in the track width direction (X-axis positive direction) in the magnetoresistive effect element on the recording medium facing surface is larger than that in Example 1. Specifically, the temperature difference between the central portion (X = 0) and the end portion (X = 50) in the track width direction (X-axis positive direction) was 13 ° C. Therefore, it was confirmed that the temperature difference between the central portion and the end portion of the magnetoresistive effect element can be made larger than that of the comparative example and the first embodiment.

(Example 3)
Next, the temperature distribution when a light beam having a wavelength of 680 nm is irradiated onto a magnetic sensor element having the same configuration as the example of the magnetic sensor element 53 described in the method of manufacturing the magnetic head 51 of the second embodiment will be described later. A rate simulation was performed to verify the temperature change in the track width direction (X-axis direction) on the magnetic recording medium facing surface of the magnetization free layer included in the magnetoresistive effect element of the magnetic sensor element.

  Specifically, the thermal conductivity simulation was performed as follows. That is, the intensity distribution of the light beam applied to the magnetic sensor element was a Gaussian distribution, and the light beam spot diameter was 680 nm. In the present embodiment, the FDTD (Finite Difference Time Domain) method is used in advance to determine the electric field intensity when the near-field light generating unit (more specifically, the minute aperture of the near-field light generating unit) is irradiated with the light beam having a wavelength of 680 nm. The amount of heat (wattage) incident on each part of the magnetic sensor element of this example was determined based on the result of the simulation.

  The simulation results described above are shown in FIG. From FIG. 18, in Example 3, the temperature gradient in the track width direction (X-axis direction) in the magnetoresistive effect element on the recording medium facing surface is steeper than in Comparative Example and Example 1. Recognize. Specifically, in the comparative example and Example 1, the temperatures of 9 ° C. and 11.5 ° C. are respectively obtained at the track width center (X = 0) and the track width direction end (X = 50) of the magnetization free layer. In contrast to the difference, in Example 3, a temperature difference of 18 ° C. is obtained. Therefore, in the magnetic sensor element of the present example, it was confirmed that the temperature gradient in the magnetoresistive effect element was steeper than in the comparative example and Example 1.

In the present embodiment, the simulation was performed using the magnetization free layer having the characteristics shown in FIG. 4, but an external magnetic field of about 7.96 × 10 ² [A / m] (10 [Oe]) is detected. The track width was found to be 65 nm in Example 3 compared to 100 nm and 85 nm in Comparative Example and Example 1, respectively.

Example 4
Next, a magnetic sensor element having the same configuration as the example of the magnetic sensor element 73 described in the method of manufacturing the magnetic head 71 according to the modification of the second embodiment (the thermal conductor layer is formed of Ag) and Example 3 will be described. A similar heat conduction simulation was performed. The result is shown in FIG. The conditions for the heat conduction simulation are the same as in the third embodiment.

  From FIG. 19, in this example, not only the comparative example and Example 2, but also the temperature gradient in the track width direction (X-axis positive direction) in the magnetoresistive effect element on the recording medium facing surface compared to Example 3. You can see that it is getting bigger. Specifically, in this example, the temperature difference between the central portion (X = 0) and the end portion (X = 50) in the track width direction (X-axis positive direction) was 20.5 ° C. Therefore, it was confirmed that the temperature gradient in the magnetoresistive effect element in the magnetic sensor element of this example becomes steeper than in Example 3.

In the present embodiment, the simulation was performed using the magnetization free layer having the characteristics shown in FIG. 4, but an external magnetic field of about 7.96 × 10 ² [A / m] (10 [Oe]) is detected. It was found that the track width was 60 nm.

(Example 5)
Next, the temperature distribution when a light beam having a wavelength of 680 nm is irradiated onto a magnetic sensor element having the same configuration as the example of the magnetic sensor element 93 described in the method of manufacturing the magnetic head 91 according to the third embodiment will be described later. A rate simulation was performed to verify the temperature change in the track width direction (X-axis direction) on the magnetic recording medium facing surface of the magnetization free layer included in the magnetoresistive effect element of the magnetic sensor element. The result is shown in FIG. The conditions for the heat conduction simulation are the same as in the third embodiment.

  As can be seen from FIG. 20, in this example, the temperature gradient in the track width direction (X-axis direction) on the magnetic recording medium facing surface is steeper than in the comparative example, example 1, and example 3. Specifically, in the comparative example, Example 1, and Example 3, the track width center (X = 0) and the track width direction end (X = 50) of the magnetization free layer are 9 ° C. and 11.1 respectively. In contrast to the temperature difference of 5 ° C. and 18 ° C., in Example 5, a temperature difference of 26 ° C. is obtained. Therefore, in the magnetic sensor element of the present example, it was confirmed that the temperature gradient in the magnetoresistive effect element was steeper than in the comparative example, example 1 and example 3.

In the present embodiment, the simulation was performed using the magnetization free layer having the characteristics shown in FIG. 4, but an external magnetic field of about 7.96 × 10 ² [A / m] (10 [Oe]) is detected. It was found that the track width was 53 nm.

(Example 6)
Next, with respect to a magnetic sensor element having the same configuration as the example of the magnetic sensor element 113 described in the method of manufacturing the magnetic head 111 according to the modification of the second embodiment (the thermal conductor layer is formed of Ag), Example 5 and A similar heat conduction simulation was performed. The result is shown in FIG. The conditions for the heat conduction simulation are the same as those in the fifth embodiment.

  FIG. 21 shows that the temperature gradient in the track width direction (X-axis direction) on the surface facing the magnetic recording medium is steeper in this example than in the comparative example and Examples 2, 4, and 5. Specifically, in this example, the temperature difference between the central portion (X = 0) and the end portion (X = 50) in the track width direction (X-axis positive direction) was 29 ° C. Therefore, in the magnetic sensor element of this example, it was confirmed that the temperature gradient in the magnetoresistive effect element was steeper than in the comparative example and Examples 2, 4 and 5.

In the present embodiment, the simulation was performed using the magnetization free layer having the characteristics shown in FIG. 4, but an external magnetic field of about 7.96 × 10 ² [A / m] (10 [Oe]) is detected. It was found that the track width was 49 nm.

  From each of the above examples, it was confirmed that the temperature difference between the central portion and the end portion of the magnetoresistive element can be made larger than that of the comparative example due to the presence of each thermal conductor layer. Therefore, it can be seen from this result that according to the present invention, a magnetic sensor element capable of detecting a signal having a track width smaller than the length in the track width direction of the magnetization free layer in the magnetoresistive effect element can be provided. It was also found that a magnetic sensor element capable of detecting a signal with a smaller track width can be provided by the near-field light generator.

  The present invention can be changed in design without departing from the scope of the claims, and is not limited to the above-described embodiments and examples. For example, in each of the above-described embodiments, a configuration in which a laminated body of a bias layer and a thermal conductor layer is used is used, but a configuration in which the bias layer and the thermal conductor layer are repeatedly formed in multiple layers may be used. In addition, instead of the laminate of the bias layer and the thermal conductor layer, only the bias layer to which the same component as the material constituting the thermal conductor layer is added is formed to increase the thermal conductivity, or the bias layer It is also possible to form only the heat conductor layer to which the same component as the material constituting the material is added, and to give the effect of the bias layer to the heat conductor layer.

  In addition, in the second embodiment, the modification thereof, and the third embodiment, the magnetic sensor element having a minute opening is formed with a dielectric layer so as to fill the minute opening. It may not be formed, and may be a minute aperture formed of a space smaller than the wavelength of the irradiated light. In this case, in the minute opening, the magnetic sensor element is formed before the formation of the laser light source element, and the manufacturing process of the present embodiment described above is performed except that the magnetoresistive effect element is not etched. The magnetic sensor element can be formed by the above method, and the substantially central portion of the near-field light generating portion (the portion facing the magnetoresistive effect element) can be formed by etching with FIB in the Y-axis direction.

  Further, in each of the above-described embodiments and modifications, a recording element for recording on a magnetic recording medium may be formed by stacking with a magnetic sensor element so that the magnetic head can be used for recording.

  In addition, in the second and third embodiments and their modifications, the gap between the magnetic sensor element and the laser light source element may be filled with a dielectric. Further, the dielectric may have an optical waveguide that guides laser light to the minute aperture.

  Further, in each of the above-described embodiments and modifications, the laser light source element is not necessarily formed on the same substrate as the magnetic sensor element. For example, in a magnetic reproducing apparatus, a laser light source element may be formed on a suspension arm that supports a magnetic head, and an optical waveguide may be used, or a light beam may be drawn and irradiated onto the magnetic sensor element using an objective lens. Absent.

  In each of the above-described embodiments and modifications, a lubricant may be applied or formed on the surface of the magnetic head that faces the magnetic recording medium in order to prevent damage due to contact with the magnetic recording medium. Absent.

1 is a schematic perspective view showing a main part of a magnetic head according to a first embodiment of the invention. FIG. 2 is a plan view showing a recording medium facing surface (XZ plane) of a magnetic sensor element in the magnetic head of FIG. 1 and a center point of the recording medium facing surface. It is sectional drawing of the XZ plane of the magnetoresistive effect element in the magnetic sensor element of FIG. It is a graph which shows the temperature dependence of the coercive force about an example of the magnetization free layer in the magnetoresistive effect element of FIG. FIG. 2 is a schematic perspective view illustrating a manufacturing process of the magnetic head of FIG. 1, illustrating a state after a laser light source element, a p-type electrode layer, and an n-type electrode layer are formed on a substrate. FIG. 6 is a schematic perspective view showing a state after an insulating film and a lower magnetic shield layer are sequentially laminated on the substrate of FIG. FIG. 6 is a schematic perspective view showing a state in which a magnetoresistive element is formed on the lower magnetic shield layer of FIG. FIG. 6 is a schematic perspective view showing a state after an insulating layer is laminated and formed on the lower magnetic shield layer 7 and the side surface of the magnetoresistive effect element 8 in FIG. FIG. 6 is a schematic perspective view showing a state after a thermal conductor layer and a bias layer are sequentially laminated on the insulating layer 9 of FIG. FIG. 6 is a schematic perspective view showing a state after an upper magnetic shield layer is stacked on the bias layer, the insulating layer, and the magnetoresistive effect element in FIG. It is a perspective schematic diagram showing the principal part of the magnetic head concerning the modification of a 1st embodiment of the present invention. It is a perspective schematic diagram showing the principal part of the magnetic head concerning a 2nd embodiment of the present invention. 7A is a plan view showing a recording medium facing surface (XZ plane) of the magnetic sensor element in the magnetic head of FIG. 7 and the center point of the recording medium facing surface, and FIG. 7B is a plan view of the magnetic head of FIG. It is a top view at the time of seeing a magnetic sensor element from the predetermined section in the positive direction of the Y axis. FIG. 8 is a schematic perspective view illustrating a manufacturing process of the magnetic head of FIG. 7, illustrating a state after a laser light source element, a p-type electrode layer, and an n-type electrode layer are formed on a substrate. FIG. 10 is a schematic perspective view illustrating a state after an insulating film and a lower magnetic shield layer are sequentially stacked on the substrate of FIG. FIG. 10 is a schematic perspective view showing a state after a part of the lower magnetic shield layer in FIG. 9B is etched in the Z direction and a lower metal layer is laminated on the etched part. FIG. 10 is a schematic perspective view showing a state after a magnetoresistive effect element, an insulating layer, a heat conductor layer, and a bias layer are formed on the lower magnetic shield layer and the lower metal layer of FIG. FIG. 10 is a schematic perspective view showing a state after a part of the magnetoresistive effect element in FIG. 9D is etched and a dielectric layer is formed in the etched part. FIG. 10 is a schematic perspective view showing a state after an upper metal layer is laminated so as to cover the dielectric layer, the insulating layer, and the bias layer in FIG. FIG. 9F is a schematic perspective view showing a state after the upper magnetic shield layer is laminated on a part of the upper metal layer, the magnetoresistive effect element, the insulating layer not covered with the upper metal layer, and the bias layer in FIG. FIG. It is a perspective schematic diagram showing the principal part of the magnetic head concerning the modification of a 2nd embodiment of the present invention. It is a perspective schematic diagram showing the principal part of the magnetic head concerning a 3rd embodiment of the present invention. 11A is a plan view showing a recording medium facing surface (XZ plane) of the magnetic sensor element in the magnetic head of FIG. 11 and the center point of the recording medium facing surface, and FIG. 11B is a plan view of the magnetic head of FIG. It is a top view at the time of seeing a magnetic sensor element from the predetermined section in the positive direction of the Y axis. It is a perspective schematic diagram showing the principal part of the magnetic head concerning the modification of a 3rd embodiment of the present invention. It is a model block diagram of the magnetic reproducing apparatus which concerns on 4th Embodiment of this invention. It is a perspective schematic diagram which shows the principal part of the magnetic head which concerns on a comparative example. It is a graph which shows the simulation result which concerns on Example 1 of this invention. It is a graph which shows the simulation result which concerns on Example 2 of this invention. It is a graph which shows the simulation result which concerns on Example 3 of this invention. It is a graph which shows the simulation result which concerns on Example 4 of this invention. It is a graph which shows the simulation result which concerns on Example 5 of this invention. It is a graph which shows the simulation result which concerns on Example 6 of this invention. It is a schematic cross section which shows the structure of the conventional magnetoresistive effect element.

Explanation of symbols

1, 31, 51, 71, 91, 111, 201 Magnetic head 2, 32, 52, 72, 92, 112, 300 Substrate 3, 33, 53, 73, 93, 113 Magnetic sensor element 4, 34, 54, 74 , 94, 114 Laser light source element 5, 35, 55, 75, 95, 115 Magnetic sensing part 6, 36, 56, 76, 96, 116 Insulating film 7, 37, 57, 77, 97, 117 Lower magnetic shield layer 8 , 38, 58, 78, 98, 118 Magnetoresistive element 8a, 58a, 98a (Magnetic sensor element) center 9, 39, 59, 79, 99, 119, 309 Insulating layer 10, 40, 60, 80, 100 , 120 Thermal conductor layer 11, 61, 101 Bias layer 12, 42, 62, 82, 102, 122 Upper magnetic shield layer 13, 43, 63, 83, 103, 123 p Electrode layers 14, 44, 64, 84, 104, 124 N-type electrode layers 21, 301 Antiferromagnetic layers 22, 302 Ferromagnetic layers 23, 303 Magnetization fixed layers 24, 304 Nonmagnetic layers 25, 305 Magnetization free layers 26 In-plane magnetic layer 27 High magnetic permeability layer 28 Coercive force change free layer 65 Near-field light generating portion 66 Lower metal layer 67 Upper metal layers 68, 107, 127 Boundary surfaces 69, 108 Micro openings 70, 109 Dielectric layer 106 Metal layer 200 Magnetic reproducing device 202 Magnetic recording medium 203 Spindle 204 Suspension arm 205 Voice coil motor 206 Control circuit 207 Rotation drive control device 208 Signal processing device 209 Output control device 210 Memory device 306 Bias layer 307 Upper electrode layer 308 Lower electrode layer

Claims (19)

  A magnetoresistive effect element having a nonmagnetic layer, a magnetization free layer and a magnetization fixed layer sandwiching the nonmagnetic layer, and having a magnetic field sensitivity that changes to an external magnetic field with a temperature change, and the magnetoresistive effect element A magnetic sensor element comprising a magnetic sensing part including a heat exchange heat conductor layer formed along a side surface of the magnetic sensor element. Further comprising a near-field light generating part having a linear minute opening formed so that one end of the magnetoresistive element is close to the magnetoresistive element,
2. The magnetic sensor according to claim 1, wherein the minute opening irradiates the magnetoresistive element with near-field light generated on the one end side by irradiation of light from the other end side. element.   The magnetoresistive effect is such that the thermal conductor layer is symmetric with respect to the center line of the magnetoresistive effect element in the stacking direction of the nonmagnetic material layer, the magnetization free layer, and the magnetization fixed layer. 3. The magnetic sensor element according to claim 1, wherein the magnetic sensor element is a pair of layers formed so as to sandwich the element.   The pair of bias layers for aligning the magnetization of the magnetization free layer in one direction are symmetrical with respect to the center line, and the non-magnetic layer with respect to each of the thermal conductor layers The magnetic sensor element according to claim 3, wherein the magnetic sensing element is formed in the magnetic sensing portion so as to be adjacent to each other in the stacking direction of the magnetization free layer and the magnetization fixed layer.   The magnetoresistive effect is such that the thermal conductor layer is symmetric with respect to the center line of the magnetoresistive effect element in the stacking direction of the nonmagnetic material layer, the magnetization free layer, and the magnetization fixed layer. 3. The magnetic sensor element according to claim 2, wherein the magnetic sensor element is a pair of layers formed across the magnetic sensing part and the near-field light generating part so as to sandwich the element and the minute opening at the same time.   The pair of bias layers for aligning the magnetization of the magnetization free layer in one direction are symmetrical with respect to the center line, and the non-magnetic layer with respect to each of the thermal conductor layers 6. The magnetic sensor according to claim 5, wherein the magnetic sensor is formed across the magnetic sensing unit and the near-field light generating unit so as to be adjacent to each other in the stacking direction of the magnetization free layer and the magnetization fixed layer. element.   The magnetic sensor element according to claim 2, wherein the near-field light generating unit further includes a metal layer adjacent to the minute opening.   The magnetic sensor element according to claim 2, wherein a dielectric layer is formed in the minute opening.   The magnetic sensor element according to claim 2, wherein one end of the minute opening is formed adjacent to the magnetoresistive element.   10. The magnetization free layer comprises at least one element selected from Gd, Dy, Tb, and Ho and at least one element selected from Fe, Co, and Ni. The magnetic sensor element according to any one of the above.   11. The heat conductor layer is made of Au, Ag, Cu, Al, Mg, Mo, W, Si, diamond-like carbon, or a metal material mainly composed of these elements. The magnetic sensor element according to any one of the above. It is a manufacturing method of the magnetic sensor element according to any one of claims 2 and 5-8,
Forming a magnetic sensing unit having a magnetoresistive effect element formed by laminating a magnetization fixed layer, a non-magnetic material, and a magnetization free layer on a substrate; and a minute opening formed by scraping a part of the magnetoresistive effect element And a step of forming a near-field light generating part. A method of manufacturing a magnetic sensor element according to claim 5 or 6,
13. The method of manufacturing a magnetic sensor element according to claim 12, further comprising a step of forming a thermal conductor layer across the magnetic sensing part and the near-field light generating part.   The method of manufacturing a magnetic sensor element according to claim 13, further comprising a step of forming a bias layer across the magnetic sensing unit and the near-field light generating unit. A method of manufacturing a magnetic sensor element according to claim 8,
13. The method of manufacturing a magnetic sensor element according to claim 12, further comprising a step of embedding and forming a dielectric layer in the minute opening.   A magnetic head comprising: a slider substrate on which an ABS surface shape is formed; and the magnetic sensor element according to claim 1 formed on the slider substrate. .   The magnetic head according to claim 16, wherein a laser light source element for irradiating the magnetic sensor element with a light beam is formed on the slider substrate.   18. A magnetic reproducing apparatus comprising: the magnetic head according to claim 16; and a magnetic recording medium that is magnetically reproduced by the magnetic head.   19. A magnetic reproducing method using the magnetic reproducing apparatus according to claim 18, wherein the magnetoresistive element is heated with near-field light to reproduce recorded information recorded on the magnetic recording medium.

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