JP2007026554A - Laminated body and magneto-resistive head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminated body that is excellent in corrosion resistance by maintaining the strength of exchange coupling magnetic field. <P>SOLUTION: In the laminate 31 in which a first ferromagnetic layer 28, an antiferromagnetic layer 29 for fixing the magnetization of the first ferromagnetic layer 28 and a protective layer 30 are laminated on a base in this order, material of the antiferromagnetic layer 29 is an IrMn alloy containing 85 to 70 at% Mn while film thickness is ≤5nm, and the protective layer 30 is an alloy containing Cr, wherein the content of Cr is ≥30 at%. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a laminated body using an exchange coupling magnetic field and a magnetoresistive head used for reproduction of a hard disk drive device.

  In response to the demand for high sensitivity and high output heads, GMR (Giant Magneto Resistive) heads using spin valve (SV) sensors have been devised (Patent Documents 1 and 2). From the viewpoint of improving output, a structure called a dual spin valve (DSV) sensor in which two conventional SV sensors are stacked has been proposed (Patent Document 3).

  FIG. 13A is a cross-sectional view showing a configuration example of a conventional SV sensor, and FIG. 13B is a cross-sectional view showing a configuration example of a conventional DSV sensor. Here, a case where an SV film and a DSV film are formed over the buffer layer 302 provided over the substrate 301 is shown.

  As shown in FIG. 13A, the SV sensor fixes the magnetization of the free layer 303 for detecting the magnetism of the recording medium, the nonmagnetic intermediate layer 304, the pinned layer 305 of the ferromagnetic layer, and the pinned layer 305. The structure includes an SV film including an antiferromagnetic layer 306. A cap layer 307 serving as a protective layer is provided on the antiferromagnetic layer 306. As shown in FIG. 13B, the DSV film of the DSV sensor has three layers: the nonmagnetic intermediate layer 304, the pinned layer 305, and the antiferromagnetic layer 306 of the SV film shown in FIG. In this configuration, the free layer 303 is provided on the upper side and the lower side, respectively. In FIG. 13B, “a” is attached to the reference numerals of the upper three layers, and “b” is attached to the reference signs of the lower three layers. The stacking order of the three layers is reversed between the upper side and the lower side, and the free layer 303 is sandwiched between the nonmagnetic intermediate layers 304a and 304b.

  As shown in FIGS. 13A and 13B, the nonmagnetic intermediate layers 304, 304a, 304b are made of a conductive material such as Cu, and the antiferromagnetic layers 306, 306a, 306b are made of IrMn alloy or PtMn. An alloy is used. Then, Ta, Ti, or the like has been mainly used as the cap layer 307 on the antiferromagnetic layers 306, 306a provided on the upper side of the pinned layers 305, 305a.

The pinned layers 305, 305a, and 305b may be monolayer pinned layers or synthetic pinned layers as shown in FIG. As shown in FIG. 13C, the synthetic pinned layer has a structure in which an antiferromagnetic coupling layer 309 is sandwiched between ferromagnetic layers 308a and 308b.
Japanese Examined Patent Publication No. 8-21166 JP-A-6-236527 JP 2002-185060 A

  There are two types of IrMn alloys used for the antiferromagnetic layer, those with a Mn content of about 60 to 40 at% and those with a Mn content of about 85 to 70 at%. In the case of an IrMn alloy with a Mn content of about 60 to 40 at%, a heat treatment for changing the IrMn alloy into an antiferromagnetic material is required, so an IrMn alloy with a Mn content of about 85 to 70 at% Has been used. However, in an SV film or a DSV film, if an IrMn alloy containing about 85 to 70 at% of Mn is used for the antiferromagnetic layer provided on the upper side of the pinned layer, the antiferromagnetic layer has poor corrosion resistance and is easily corroded. There was a problem.

  The present invention has been made to solve the above-described problems of the prior art, and provides a laminated body and a magnetoresistive head having excellent corrosion resistance while maintaining the strength of the exchange coupling magnetic field. With the goal.

In order to achieve the above object, a laminate of the present invention comprises a first ferromagnetic layer, an antiferromagnetic layer for fixing the magnetization of the first ferromagnetic layer, and a protective layer stacked in this order on a substrate. In the laminated body,
The antiferromagnetic layer is an IrMn alloy containing 85 to 70 at% of Mn and a film thickness of 5 nm or less.
The protective layer is an alloy containing Cr, and the Cr content is 30 at% or more.

  In the present invention, since IrMn containing a high concentration of Mn provided as an antiferromagnetic layer of the exchange coupling film contains a predetermined amount or more of Cr in the cap layer provided in contact with IrMn, Cr is a cap. It diffuses from the layer to IrMn and improves the corrosion resistance.

On the other hand, the magnetoresistive head of the present invention for achieving the above object is
A magnetoresistive element having the laminate of the present invention;
Provided in the upper and lower layers of the magnetoresistive effect element, a shield layer for shielding magnetism from the outside excluding the recording medium,
It is the structure which has.

  In the present invention, an exchange coupling film having an exchange coupling magnetic field equivalent to or higher than that of the conventional one and excellent in corrosion resistance can be obtained.

The laminate of the present invention has IrMn containing a predetermined amount of Mn as an antiferromagnetic layer of an exchange coupling film, and a protective layer containing a predetermined amount or more of Cr on the antiferromagnetic layer. .
(Embodiment 1)
The configuration of the magnetoresistive head of this embodiment will be described.

  FIG. 1 is a sectional view showing the main part of a magnetoresistive head according to an embodiment of the present invention.

  The magnetoresistive head 1 of the present embodiment includes a reproducing unit 63 having a substrate 61 and an MR (magnetoresistive) element 62 formed on the substrate 61 for reading from a recording medium (not shown), and The recording unit 64 includes an inductive magnetic conversion element for writing, and the bumps 42a to 42d for electrically connecting the reproducing unit 63 and the recording unit 64 to the outside through wirings 41a to 41d.

The substrate 61 is made of Al ₂ O ₃ .TiC (Altic). Altic is superior in wear resistance and lubricity as compared with alumina, but has high conductivity. Therefore, a base layer 65 made of alumina is formed on the upper surface of the substrate 61, and a reproducing unit 63 and a recording unit 64 are laminated thereon.

  A lower shield layer 66 made of a magnetic material such as permalloy (NiFe) is formed on the base layer 65. An MR element 62 is formed on the lower shield layer 66 at the end on the medium facing surface S side with one end thereof exposed to the medium facing surface S. As the MR element 62, various elements using a magnetosensitive film exhibiting a magnetoresistive effect, such as a GMR (giant magnetoresistive effect) element and a TMR (tunnel magnetoresistive effect) element, can be used. On the MR element 62, an upper shield layer 67 made of a magnetic material such as permalloy is formed. The MR element 62 is insulated from the lower shield layer 66 and the upper shield layer 67 by the insulating layer 68a. The lower shield layer 66, the MR element 62, and the upper shield layer 67 constitute a reproducing unit 63. The lower shield layer 66 and the upper shield layer 67 shield the magnetic field from the outside except the recording medium from the reproducing unit 63.

  A lower magnetic pole layer 69 made of a magnetic material such as permalloy or CoNiFe that can be formed by a plating method is formed on the upper shield layer 67 via an insulating layer 68b.

  An upper magnetic pole layer 71 is formed on the lower magnetic pole layer 69 via a recording gap layer 70 for insulation. The recording gap layer 70 is formed at the end on the medium facing surface S side, with one end exposed at the medium facing surface S. That is, the lower magnetic pole layer 69 and the upper magnetic pole layer 71 are opposed to each other through the recording gap layer 70 at one end thereof. As a material of the recording gap layer 70, for example, a nonmagnetic metal material such as Ru or alumina is used. As the material of the upper magnetic pole layer 71, for example, a magnetic material such as permalloy or CoNiFe is used. The lower magnetic pole layer 69 and the upper magnetic pole layer 71 are magnetically connected by the connecting portion 72 at the end away from the medium facing surface S, and form one magnetic circuit as a whole.

  Between the lower magnetic pole layer 69 and the upper magnetic pole layer 71, a coil 73 made of a conductive material such as copper is formed between the medium facing surface S and the connection portion 72. The coil 73 supplies magnetic flux to the lower magnetic pole layer 69 and the upper magnetic pole layer 71, and is formed in two layers so as to circulate around the connection portion 72 so as to form a planar spiral. The coil 73 is insulated from the surroundings by an insulating layer. The number of turns of the coil 73 is arbitrary. In the present embodiment, the two-layer coil 73 is shown. However, the present invention is not limited to this, and it may be one layer or three or more layers.

  The inductive magnetic transducer includes these lower magnetic pole layer 69, upper magnetic pole layer 71, and coil 73.

  The overcoat layer 74 is provided so as to cover the upper magnetic pole layer 71 and protects the above-described structure. As a material of the overcoat layer 74, for example, an insulating material such as alumina is used.

  The MR element 62 is connected to a pair of wiring lines 41a and 41b for outputting signals read by the MR element 62, which are formed at an interval in the depth direction of the drawing. Similarly, a pair of wirings 41c and 41d for inputting a write signal, which are formed at an interval in the depth direction of the drawing, are connected to the coil 73. Bumps 42a to 42d extend from the wirings 41a to 41d in the stacking direction, respectively. The tips of the bumps 42a to 42d are connected to the electrode pads 43a to 43d on the surface of the overcoat layer 74, respectively. In FIG. 1, the bumps 42a to 42d and the electrode pads 43a to 43d are shown side by side in the horizontal direction in the figure, but these are actually formed side by side in the depth direction of the drawing.

The MR element 62 will be described below. Note that 1 Oe = (1 / 4π) × 10 ³ A / m, and 1Å = 0.1 nm. Further, the MR element of this embodiment is a case of a spin valve (SV) sensor.

  FIG. 2 is a cross-sectional view showing a configuration example of the MR element. As shown in FIG. 2, the MR element has a configuration in which a spin valve film 23 and a cap layer 30 serving as a protective layer for the spin valve film 23 are provided on the buffer layer 21. The spin valve film 23 has a configuration in which a free layer 24 for detecting the magnetization of a recording medium, a nonmagnetic intermediate layer 25, and an exchange coupling film 27 are sequentially stacked. In the exchange coupling film 27, an antiferromagnetic layer 29 for fixing the magnetization of the pinned layer 28 is provided on the pinned layer 28 of the ferromagnetic layer. The pinned layer 28 may be the synthetic pinned layer described in FIG. In this embodiment, the antiferromagnetic layer 29 is made of IrMn containing 85 to 70 at% of Mn and has a film thickness of 50 mm or less. The material of the cap layer 30 is an alloy containing Cr. An experiment showing the effect obtained by configuring the laminate 31 having the exchange coupling film 27 and the cap layer 30 as described above will be described below.

  First, an experimental method for evaluating corrosion resistance will be described.

On the alumina provided on the silicon substrate, a cap layer and an antiferromagnetic layer were sequentially formed by a sputtering method, and a sample of Si / Al ₂ O ₃ / cap layer / antiferromagnetic layer was produced. The following levels are provided for the antiferromagnetic layer and the cap layer. Then, these samples were annealed at 270 ° C. for 3 hours. Then, after immersing the sample in pure water for a predetermined time, the sheet resistance of the sample was measured. The resistance increase rate indicating the change in sheet resistance was obtained from the measurement results, and the corrosion resistance of the antiferromagnetic layer was evaluated by the resistance increase rate. Since the sheet resistance tends to increase when corroded, the smaller the resistance increase rate, the better the corrosion resistance. The resistance increase rate is obtained from the equation of resistance increase rate = (Rs−Rs_ini) / Rs_ini × 100 (%), where Rs is the measured sheet resistance value and Rs_ini is the initial value of the sheet resistance before being immersed in pure water. It was.

  FIG. 3 is a table showing experimental levels. The reference level is Sample 1, and in Sample 1, the antiferromagnetic layer is IrMn with a thickness of 40 mm, and the cap layer is NiCr with a chromium content of 40 at%. The thickness of the cap layer is 40 mm. As shown in FIG. 3, a level is set for the IrMn film thickness of the antiferromagnetic layer in samples 1 to 4, a level is set for the Cr content of NiCr in the cap layer in samples 5 to 7, and samples 8 to 11 shows a level of Cr content of the FeCr in the cap layer.

  Moreover, the sample of the comparative example 1 and the comparative example 2 was produced for corrosion resistance evaluation. In Comparative Example 1, the antiferromagnetic layer is IrMn having a thickness of 40 mm, and the cap layer is Ta having a thickness of 40 mm. In Comparative Example 2, the antiferromagnetic layer is 3Cr-21Ir-Mn with a thickness of 40 mm, and the cap layer is Ta with a thickness of 40 mm. In addition, about the IrMn alloy, the content rate of Mn was 78 at%.

  From the results of the above-described experiment, the change in the resistance increase rate with respect to the pure water immersion time, which is the time for immersing the sample in pure water, will be described.

  FIG. 4A is a table showing the relationship between the resistance increase rate and the pure water immersion time, and FIG. 4B is a graph showing the results. Here, it shows about the result of the sample 1 of the level table shown in FIG. 3, and the comparative example 1 as a representative example. The maximum time of pure water immersion time was 30 minutes, and sheet resistance was measured every 5 minutes from 0 to 20 minutes.

  As shown in FIG. 4A, the resistance increase rate of Sample 1 was smaller than that of Comparative Example 1 regardless of the pure water immersion time. After immersion in pure water for 30 minutes, the resistance increase rate of Comparative Example 1 was twice or more that of Sample 1. As shown in FIG. 4B, the resistance increase rate increased with increasing time for immersion in pure water for both Sample 1 and Comparative Example 1. From the results of FIG. 4, it can be seen that Sample 1 has better corrosion resistance than Comparative Example 1.

  FIG. 5A is a table showing the resistance increase rate for each level, and FIG. 5B is a graph showing the result. Here, the case where the sample is immersed in pure water for 30 minutes for all levels is shown.

  As shown in FIG. 5A, in the samples 1 to 4 in which the film thickness level is provided for IrMn of the antiferromagnetic layer, the resistance increase rate increases as the film thickness of IrMn increases. In Sample 5 to Sample 7 in which the level of Cr content in the NiCr of the cap layer is set, the resistance increase rate decreases as the Cr content rate increases. Further, in Sample 8 to Sample 11 in which the level of Cr content in the cap layer FeCr is set, the resistance increase rate decreases as the Cr content rate increases. The resistance increase rate of Comparative Example 1 was 2.1%.

  FIG. 5B is a graph in which the horizontal axis represents the sample level of Sample 1 to Sample 11, and the vertical axis represents the resistance increase rate. In FIG. 5B, a straight line is drawn to the value of the resistance increase rate of Comparative Example 1. If the resistance increase rate is above this straight line, it will be higher than in Comparative Example 1. From the graph of FIG. 5B, it can be seen that Samples 3 to 5 and 8 have a higher resistance increase rate than Comparative Example 1, and the corrosion resistance is deteriorated as compared with Comparative Example 1.

  Next, since an experiment for evaluating the exchange coupling magnetic field was performed, the method will be described. The film thickness (unit: 単 位) is written after the chemical formula.

A film was laminated by sputtering on alumina provided on a silicon substrate, and a sample having the following SV film was produced. Sample: Si / Al ₂ O ₃ // buffer layer (NiCr40 / Ru8) / free layer (CoFe20) / nonmagnetic intermediate layer (Cu20) / pinned layer (CoFe5 / FeCo5 / CoFe5) / antiferromagnetic layer (IrMn) / The configuration of the cap layer 20. The antiferromagnetic layer and the cap layer were provided with the same level as that shown in FIG. 3 except that the thickness of the cap layer was 20 mm. Each sample was annealed at 270 ° C. for 3 hours. Thereafter, the exchange coupling magnetic field Hex of each sample was obtained from the MR curve.

  Next, the measurement result of the exchange coupling magnetic field by the said experiment is demonstrated. FIG. 6 is a table showing measurement results of the exchange coupling magnetic field. The result of the corrosion resistance evaluation shown in FIG. 5 is shown in the rightmost column of FIG.

  As shown in FIG. 6, in Sample 1 to Sample 4 in which the film thickness level is provided for IrMn of the antiferromagnetic layer, the exchange coupling magnetic field decreases as the film thickness of IrMn increases. In samples 5 to 7, the corrosion resistance deteriorates when the Cr content of the cap layer is 20 at%, but not only the corrosion resistance is improved at 30 at% or more, but the exchange coupling magnetic field is larger than that of Comparative Example 1. Similarly to Samples 5 to 7, Samples 8 to 11 also deteriorated the corrosion resistance when the Cr content of the cap layer is 20 at%, but not only the corrosion resistance is improved at 30 at% or more, but the exchange coupling magnetic field is also reduced. It became larger than the comparative example 1. On the other hand, in Comparative Example 2 in which the antiferromagnetic layer is CrIrMn, the corrosion resistance is improved, but the exchange coupling magnetic field Hex is lower than in Comparative Example 1.

  Samples 1, 2, 6, 7, and 9 to 11 are preferable levels from the results of the corrosion resistance evaluation shown in FIGS. 5 and 6 and the measurement results of the exchange coupling magnetic field. Note that when an alloy of IrMn and Cr is used as an antiferromagnetic layer as described above, the exchange coupling magnetic field Hex is reduced, and therefore it is not preferable to use the alloy as an antiferromagnetic layer.

  FIG. 7 shows a graph summarizing the Cr composition ratio of the cap layer with respect to the resistance increase rate of the antiferromagnetic layer. FIGS. 7A and 7B are graphs showing the dependency of the resistance increase rate on the Cr composition ratio, created using the results of FIG. FIG. 7A shows a case where the cap layer is made of NiCr, and FIG. 7B shows a case where the cap layer is made of FeCr. The horizontal axis represents the Cr composition ratio, and the vertical axis represents the resistance increase rate. As shown in FIGS. 7A and 7B, when the Cr composition ratio increases from 20 at% to 30 at%, the resistance increase rate rapidly decreases to about ½. When the Cr composition ratio exceeds 30 at% and approaches 40 at%, the slope of change in the resistance increase rate gradually decreases. When the Cr composition ratio reaches 80 at%, the slope of the change in the resistance increase rate is close to zero. When the cap layer is made of NiCr or FeCr as an alloy containing Cr, the Cr content needs to be 30 at% or more from the result of the corrosion resistance shown in FIG. In addition, the graph shown in FIG. 7 indicates that the Cr content is more preferably 40 at% or more, and most preferably 80 at% or more.

  Further, from the result shown in FIG. 5A, in order to obtain the effect of corrosion resistance, the thickness of IrMn is set to 50 mm or less. If the film thickness of IrMn is thicker than this, the effect of improving the corrosion resistance is lowered. This is because the corrosion resistance is considered to be related to the diffusion of chromium from NiCr or FeCr in the cap layer to IrMn in the antiferromagnetic layer.

  From the above experimental results, when using an exchange coupling film using an antiferromagnetic layer such as IrMn containing about 85-70 at% of Mn, the antiferromagnetic layer has a predetermined thickness and is adjacent to the antiferromagnetic layer. By using an alloy containing Cr as the material of the cap layer provided as described above, the strength of the exchange coupling magnetic field Hex becomes equal to or higher than that of the conventional one, and the effect of improving the corrosion resistance is obtained. When the cap layer is mainly composed of NiCr or FeCr, the Cr content is set to 30 at% or more. The laminated body 31 having the exchange coupling film 27 and the cap layer 30 according to the present embodiment has the above-described configuration, so that the strength of the exchange coupling magnetic field is equal to or higher than that of the conventional one, and the corrosion resistance is improved.

  In addition, although the case where the laminated body 31 of the present embodiment is applied to a spin valve sensor has been described, it may be applied to a dual spin valve sensor, and in this case, the above-described effects can be obtained.

Further, the laminated body 31 of this embodiment may be used for an exchange coupling film and a protective layer of a CIP (Current in Plane) type magnetic head and a CPP (Current Perpendicular to Plane) type magnetic head. And it may be used for a laminated film of a TMR element which is a kind of CPP type magnetic head. Further, it may be used for a hard bias layer that applies a magnetic field in order to stably operate the free layer. Also in these cases, the above-described effects can be obtained.
(Embodiment 2)
This embodiment includes a wafer on which the magnetoresistive head of Embodiment 1 is manufactured, a head gimbal assembly having a slider provided with the magnetoresistive head, a head arm assembly provided with the head gimbal assembly, and the head A hard disk device having a head stack assembly provided with an arm assembly and a slider provided with a magnetoresistive head. Each configuration will be described below.

  A wafer used for manufacturing the magnetoresistive head of Embodiment 1 will be described.

  FIG. 8 is a conceptual plan view of the wafer. The wafer 100 is partitioned into a plurality of thin film magnetic transducer element assemblies 101. The thin film magnetic transducer assembly 101 includes a thin film magnetic transducer 102 in which an MR element and an inductive magnetic transducer are stacked, and serves as a unit of work when polishing the medium facing surface ABS. A cutting margin (not shown) for cutting is provided between the thin film magnetic transducer element assemblies 101 and between the thin film magnetic transducer elements 102.

  Next, a head gimbal assembly and a hard disk device using the magnetoresistive head 1 will be described. First, the slider 210 included in the head gimbal assembly will be described with reference to FIG.

  In the hard disk device, the slider 210 is arranged to face a hard disk that is a disk-shaped recording medium that is driven to rotate. The slider 210 includes a substrate 211 having a substrate, a thin film magnetic transducer 102 and the like. The base body 211 has a substantially hexahedral shape. One of the six surfaces of the substrate 211 faces the hard disk. On this one surface, a medium facing surface ABS is formed. When the hard disk rotates in the z direction in FIG. 9, an air flow passing between the hard disk and the slider 210 causes a lift in the slider 210 in the lower direction in the y direction in FIG. 9. The slider 210 floats from the surface of the hard disk by this lifting force. Note that the x direction in FIG. 9 is the track crossing direction of the hard disk. Near the end of the slider 210 on the air outflow side (lower left end in FIG. 9), a magnetoresistive head 1 using the thin film magnetic transducer 102 as a head element is formed.

  Next, a head gimbal assembly 220 using the magnetoresistive head 1 will be described with reference to FIG. The head gimbal assembly 220 includes a slider 210 and a suspension 221 that elastically supports the slider 210. The suspension 221 includes, for example, a leaf spring-like load beam 222 formed of stainless steel, a flexure 223 that is provided at one end of the load beam 222 and is joined to the slider 210 to give the slider 210 an appropriate degree of freedom. And a base plate 224 provided at the other end of the beam 222. The base plate 224 is attached to an arm 230 of an actuator for moving the slider 210 in the track crossing direction x of the hard disk 262. The actuator includes an arm 230 and a voice coil motor (not shown) that drives the arm 230. In the flexure 223, a portion to which the slider 210 is attached is provided with a gimbal portion (not shown) for keeping the posture of the slider 210 constant.

  The head gimbal assembly 220 is attached to the arm 230 of the actuator. A structure in which the head gimbal assembly 220 is attached to one arm 230 is called a head arm assembly. Further, a head gimbal assembly 220 attached to each arm of a carriage having a plurality of arms is called a head stack assembly.

  FIG. 10 shows an example of the head arm assembly. In this head arm assembly, a head gimbal assembly 220 is attached to one end of the arm 230. A coil 231 that is a part of the voice coil motor is attached to the other end of the arm 230. A bearing portion 233 attached to a shaft 234 for rotatably supporting the arm 230 is provided at an intermediate portion of the arm 230.

  Next, a head stack assembly and a hard disk device using the magnetoresistive head 1 will be described with reference to FIGS. FIG. 11 is an explanatory view showing a main part of the hard disk device, and FIG. 12 is a plan view of the hard disk device. The head stack assembly 250 has a carriage 251 having a plurality of arms 252. A plurality of head gimbal assemblies 220 are attached to the plurality of arms 252 so as to be arranged in the vertical direction at intervals. A coil 253 that is a part of the voice coil motor is attached to the carriage 251 on the opposite side of the arm 252. The head stack assembly 250 is incorporated in a hard disk device. The hard disk device has a plurality of hard disks 262 attached to a spindle motor 261. For each hard disk 262, two sliders 210 are arranged so as to face each other with the hard disk 262 interposed therebetween. Further, the voice coil motor has permanent magnets 263 arranged at positions facing each other with the coil 253 of the head stack assembly 250 interposed therebetween.

  The head stack assembly 250 and the actuator excluding the slider 210 support the slider 210 and position it relative to the hard disk 262.

  In the hard disk device, the slider 210 is moved with respect to the hard disk 262 by moving the slider 210 in the track crossing direction of the hard disk 262 by the actuator. The magnetoresistive head 1 included in the slider 210 records information on the hard disk 262 by a recording head, and reproduces information recorded on the hard disk 262 by a reproducing head using the thin film magnetic transducer 102 as a head element. To do.

It is sectional drawing which shows the principal part of the example of 1 structure of the magnetoresistive head of this embodiment. It is sectional drawing which shows one structural example of MR element of this embodiment. It is a table | surface which shows the experimental level of the laminated body containing an exchange coupling film | membrane. It is the table | surface and graph which show the relationship between the resistance increase rate of the laminated body containing an exchange coupling film, and a pure water immersion time. It is the table | surface and graph which show the resistance increase rate for every level of a laminated body. It is a table | surface which shows the exchange coupling magnetic field and corrosion resistance for every level of a laminated body. It is a graph which shows Cr composition rate dependence of resistance increase rate. It is a top view of the wafer which concerns on manufacture of the magnetoresistive effect type head of this invention. It is a perspective view which shows the slider contained in the head gimbal assembly incorporating the magnetoresistive effect type head of this invention. It is a perspective view which shows the head arm assembly containing the head gimbal assembly incorporating the magnetoresistive effect type head of this invention. It is explanatory drawing which shows the principal part of the hard-disk apparatus incorporating the magnetoresistive head of this invention. It is a top view of the hard disk drive incorporating the magnetoresistive head of the present invention. It is sectional drawing which shows the structural example of the conventional spin valve sensor, a dual spin valve sensor, and a synthetic pinned layer.

Explanation of symbols

1 magnetoresistive head 21 buffer layer 23 spin valve film 24 free layer 25 nonmagnetic intermediate layer 27 exchange coupling film 28 pinned layer 29 antiferromagnetic layer 30 cap layer 31 laminate 62 MR element

Claims (4)

In the laminate in which the first ferromagnetic layer, the antiferromagnetic layer for fixing the magnetization of the first ferromagnetic layer, and the protective layer are laminated in this order on the substrate,
The antiferromagnetic layer is an IrMn alloy containing 85 to 70 at% of Mn and a film thickness of 5 nm or less.
The said protective layer is an alloy containing Cr, and the content rate of Cr is 30 at% or more, The laminated body characterized by the above-mentioned.   The laminate according to claim 1, wherein the Cr-containing alloy contains NiCr or FeCr as a main component. The laminate according to claim 1 or 2,
A second ferromagnetic layer provided on the substrate for reading the magnetization of the recording medium;
A nonmagnetic intermediate layer provided between the first ferromagnetic layer and the second ferromagnetic layer of the laminate;
A laminate having A magnetoresistive element having the laminate according to claim 3;
Provided in the upper and lower layers of the magnetoresistive effect element, a shield layer for shielding magnetism from the outside excluding the recording medium,
A magnetoresistive effect head.

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