JP4034319B2 - Magnetoresistive head - Google Patents

Description

  The present invention relates to a spin valve magnetoresistive sensor or transducer and a spin valve magnetoresistive head using the sensor.

  In recent years, with the miniaturization and high density of magnetic disk devices, the flying height of the head slider has decreased, and it has been desired to realize extremely low flying or contact recording / reproduction in which the slider contacts the recording medium.

  Further, in the conventional magnetic induction head, when the peripheral speed (relative speed between the head and the medium) decreases due to the reduction in the diameter of the magnetic disk, the reproduction output deteriorates. Therefore, recently, a magnetoresistive head (MR head) that can obtain a large output even at a low peripheral speed without depending on the peripheral speed has been actively developed and has become the mainstream of the magnetic head. At present, magnetic heads utilizing the giant magnetoresistance (GMR) effect are also commercially available.

As the recording density of the magnetic disk drive increases, the recording area of 1 bit decreases and the generated magnetic field decreases. The recording density of magnetic disk devices currently on the market is around 10 Gbit / in ² , but the increase in recording density is about twice as large as the annual rate. For this reason, there is a demand for a magnetoresistive sensor and a magnetoresistive head that can cope with a smaller magnetic field range and can sense a change in a small external magnetic field.

  Currently, spin valve magnetoresistive sensors using the spin valve GMR effect are widely used for magnetic heads. In a magnetoresistive sensor with a spin valve structure, the magnetization direction of the free ferromagnetic layer (free layer) changes due to the signal magnetic field from the recording medium, and the relative angle with the magnetization direction of the pinned ferromagnetic layer (pinned layer) changes. As a result, the resistance of the magnetoresistive sensor changes.

  When this magnetoresistive sensor is used for a magnetic head, the magnetization direction of the pinned layer is fixed to the element height direction of the magnetoresistive element, and the magnetization direction of the free layer when no external magnetic field is applied is It is generally designed in the element width direction orthogonal to each other.

  Thereby, the resistance of the magnetoresistive sensor can be linearly increased or decreased depending on whether the signal magnetic field direction from the magnetic recording medium is parallel or antiparallel to the magnetization direction of the pinned layer. Such linear resistance change facilitates signal processing of the magnetic disk device.

  In a conventional magnetoresistive sensor, a sense current is passed in parallel to the film surface, and a change in resistance due to an external magnetic field is read. In the case of the current flowing in parallel to the GMR film surface (Current in the plane, CIP) structure, the output is reduced when the sense region defined by the pair of electrode terminals is reduced. In the case of a spin valve magnetoresistive sensor having a CIP structure, an insulating film is required between the GMR film and the upper and lower magnetic shields.

  That is, the distance between magnetic shields = GMR film thickness + insulation film thickness × 2. Since the lower limit of the insulating film thickness is currently about 20 nm, the distance between magnetic shields = GMR film thickness difference + about 40 nm.

  When the length of the recording bit on the recording medium becomes short, it becomes difficult to cope with it, and at present, the CIP spin valve magnetoresistive sensor cannot respond to the desire to reduce the distance between the magnetic shields to 40 nm or less.

For these reasons, it is considered that a magnetic head having a CIP structure using the spin valve GMR effect can cope with a recording density of ^{20 to} 40 Gbit / in ² . Even if the latest technology of specular scattering is applied, the recording density of 60 Gbit / in ² is considered to be the upper limit.

As described above, the recording density of the magnetic disk device is rapidly increasing, and in 2002, a recording density of 80 Gbit / in ² is required. When the recording density is 80 Gbit / in ² or more, even the latest CIP spin valve GMR magnetic head using specular scattering is very difficult to cope with in terms of output and distance between magnetic shields.

  For such problems, tunnel MR (TMR), multilayer film CPP (Current perpendicular to the Plane) structures, and the like have been proposed as post spin valves GMR.

  TMR has a structure in which a thin insulating layer is sandwiched between two ferromagnetic layers, and the amount of tunneling current passing through the insulating layer varies depending on the magnetization direction of the two ferromagnetic layers. Since TMR exhibits a very large resistance change and good sensitivity, it is promising as a post spin valve GMR.

  The multilayer CPP structure applies the effect that the resistance change of the GMR film is approximately doubled at room temperature when a current flows perpendicularly to the GMR film surface (in a direction including at least the vertical component) to improve output. It is a thing. In addition, the CPP structure is characterized in that the output is increased when the cross-sectional area of the portion through which the sense current of the GMR film passes is reduced.

  This is a great advantage over CMR GMR. Note that TMR can also be considered as a kind of CPP structure because current passes from one ferromagnetic layer to the other ferromagnetic layer across the insulating layer, and the above-described advantage is also the same. Thus, although it is a promising TMR or multilayer film CPP structure, it has not yet been put into practical use, and both have some problems.

  The following problems are mentioned as problems in the multilayer film CPP structure.

  (1) The element creation process is complicated and requires high precision.

  In order to produce a device having a multilayer CPP structure, it is necessary to repeat processes such as film formation, resist formation, ion milling or reactive ion etching (RIE), and resist stripping at least three times, which is very high when forming a resist. Alignment accuracy is required. In the case of ion milling or reactive ion etching, a technique for stopping the metal layer halfway without processing or etching to the substrate surface is also required.

  (2) Characteristic evaluation is difficult unless the size of the CPP portion is about 1 μm or submicron.

  When the size of the CPP portion is about 3 μm or more, the voltage with respect to the sense current is measured as a negative value due to the influence of the current distribution. Due to this influence, the MR ratio becomes a very large value when the size of the CPP portion is about 3 μm. For this reason, the conventional evaluation standard cannot be applied.

  (3) The characteristics are easily influenced by the quality of the device fabrication process.

  This is also true for the conventional CIP structure GMR, but this tendency is remarkable in the case of the CPP structure. Since the GMR characteristics vary greatly depending on the cross-sectional shape and the state of occurrence of burrs during processing of the GMR film or insulating film, it becomes difficult to identify the cause when a defective product occurs.

  (4) The existence of hysteresis, the magnetic domain control is difficult, and the thickness of the part that senses an external magnetic field is thick.

  In the multilayer CPP structure, hysteresis exists because each magnetic layer is magnetically coupled. In addition, since the number of magnetic layers is large, it is difficult to control the magnetic domain of each magnetic layer. Furthermore, since all the magnetic layers basically sense the external magnetic field and change the magnetization direction, there is a problem that the thickness of the portion that senses the external magnetic field is thick.

  Among the above problems, (1) to (3) can be solved by improving the element structure and improving the processing accuracy. However, the problem (4) is a fundamental problem of the multilayer GMR, and there is no concrete solution at present.

  As the recording density increases, miniaturization of the GMR element advances, and it is expected that it is difficult to produce the GMR element with a high yield in the process of creating the height of the GMR element by direct polishing as in the past.

  Therefore, a flux guide type GMR head that does not require the GMR element height to be directly ground is also known. When the flux guide type GMR head is used in a conventional CIP structure, the flux guide and the GMR element must be insulated in order to prevent a current from flowing to the flux guide.

  Therefore, the flux guide and the GMR element must be sufficiently separated, and the medium magnetic field cannot be sufficiently transferred from the flux guide to the GMR element, so that the reproduction output is lowered.

  Further, when the GMR element portion is processed to be small as in the conventional CPP structure, the region where the magnetization does not move due to the demagnetizing field on the end surface increases, and the reproduction sensitivity decreases.

  The GMR head has a problem that Barkhausen noise is generated when the GMR film does not have a single magnetic domain, and the reproduction output varies greatly. For this reason, a magnetic domain control film is provided to control the magnetic domain of the GMR film.

  As the magnetic domain control film, a hard magnetic film having a high coercive force film is provided, and the magnetization direction of the free layer is controlled in the element width direction by a bias magnetic field generated by the hard magnetic film.

  The strength and distribution of the magnetic field generated by this hard magnetic film strongly depends on the shape of the hard magnetic film formed, but the shape of the hard magnetic film usually formed by a process such as lift-off is affected by the process accuracy and has a stable bias. It is difficult to obtain a magnetic field.

  When the hard magnetic film wraps around the top of the element, a bias magnetic field is partially applied in the opposite direction to the desired magnetization control direction, inducing the occurrence of Barkhausen noise, etc. It may be deteriorated.

  On the other hand, an antiferromagnetic layer as a bias magnetic field application layer is laminated on both ends of the free layer, and exchange coupling that controls the magnetization direction of the free layer using exchange coupling between the free layer and the antiferromagnetic layer There is a magnetic domain control method.

  Since this method uses exchange coupling between magnetic layers, a more stable bias effect can be obtained than a control method using a hard magnetic film magnetic field. When this exchange coupling type magnetic domain control element is formed, a sufficient bias magnetic field can be obtained by continuously forming a free layer and an antiferromagnetic layer as a bias magnetic field application layer.

  However, in order to improve the element sensitivity, it is necessary to extinguish the bias magnetic field of the magnetic layer sensing unit of the free layer. Conventionally, for an antiferromagnetic layer with poor durability such as FeMn, an oxide with a constituent element of the antiferromagnetic layer is formed by reacting with oxygen, and the bias magnetic field of the magnetic field sensing unit is extinguished. It was.

  However, at present, an antiferromagnetic layer such as NiMn, PtMn, PdPtMn, IrMn and the like having higher durability than FeMn is used from the viewpoint of the reliability of the magnetic head. There is a problem that the process of disappearing becomes difficult.

  An object of the present invention is to provide a spin valve magnetoresistive head having a CPP structure having a flux guide capable of mass production with a high yield.

According to one aspect of the present invention, there is provided a magnetoresistive head for reproducing information recorded on a recording medium, wherein the head converts a change in a signal magnetic field leaking from the first electrode terminal and the recording medium into a resistance change. a spin valve magneto-resistive element and provided on the first electrode terminal recedes from the air bearing surface of the one end is exposed to the medium facing surface of the head, the other end plane of the spin valve magnetoresistive element one end and overlap, the first flux guide disposed magnetically coupled, one end overlaps the other end in the plane of the spin valve magneto-resistive element, a second flux guide disposed bound to magnetically When, and a second electrode terminal provided on the spin valve magnetoresistive element, the first electrode terminal, in the film surface of the spin valve magnetoresistive element, from the spin-valve magnetoresistive element Small size, the a first flux guide, electrically isolated or connected the spin valve electrically only via the magnetoresistive element, and said first electrode terminal, said second flux guide, electrical Or electrically connected only via the spin valve magnetoresistive element, and the second electrode terminal has a size larger than that of the spin valve magnetoresistive element in the film surface of the spin valve magnetoresistive element. Small, electrically separated from the first flux guide or electrically connected only via the spin valve magnetoresistive element, and the second electrode terminal is electrically separated from the second flux guide. Alternatively, a magnetoresistive head is provided that is electrically connected only via the spin valve magnetoresistive element.

  Preferably, at least one of the first and second flux guides is in contact with the spin valve magnetoresistive element. More preferably, at least one of the first and second electrode terminals is in contact with a part of the film surface of the spin valve magnetoresistive element, and the one electrode terminal is within the film surface of the spin valve magnetoresistive element. Smaller than the element.

According to another aspect of the present invention, there is provided a spin valve magnetoresistive head that reproduces information recorded on a recording medium by passing an electric current in a direction perpendicular to the film surface, the first magnetic shield, and the first magnetic shield on the first magnetic shield. A spin-valve magnetoresistive element provided on the insulating layer that is retracted from the medium facing surface of the head and converts the change in the signal magnetic field leaking from the recording medium into a resistance change. One end is exposed on the medium facing surface of the head, the other end is overlapped with one end in the surface of the spin valve magnetoresistive element, and is magnetically coupled, and one end is the spin valve magnetism. other end electrically and second flux guides disposed magnetically in contact in the plane of the resistive element, provided on the opposite side to the second flux guide of the spin valve magneto-resistive element, the spin An electrode terminal having a size smaller than the spin-valve magnetoresistive element in the film plane of the valve magnetoresistive element, and a second magnetic shield disposed over the electrode terminal, the second flux guide and the first magnetic A flux path for electrically and magnetically connecting a shield, and the electrode terminal is electrically connected to the first flux guide only electrically or via the spin valve magnetoresistive element. In addition, there is provided a magnetoresistive head characterized in that the electrode terminal is electrically connected to the second flux guide only electrically or through the spin valve magnetoresistive element.

  According to the magnetoresistive head having this configuration, since the first magnetic shield is electrically connected to the spin valve magnetoresistive element via the flux path and the second flux guide, the first magnetic shield is used as one of the electrode terminals. Works.

  Since the spin valve magnetoresistive head of the present invention has a flux guide type and a CPP structure, only the magnetization movement in the central portion of the spin valve magnetoresistive element having the highest sensitivity can be detected by the electrode terminal. Reproduction characteristics can be obtained.

  Further, since the flux guide structure is used, it is not necessary to directly polish the spin valve magnetoresistive element, so that the spin valve magnetoresistive head can be produced with a high yield.

  Hereinafter, a number of embodiments of the present invention will be described in detail with reference to the drawings. In the description of each embodiment, substantially the same components are denoted by the same reference numerals, and description thereof is omitted to avoid duplication.

  Referring to FIG. 1, there is shown a cross-sectional view of a spin valve magnetoresistive sensor having a CPP (currant perpendicular to the plain) structure according to a first embodiment of the present invention.

A lower terminal 4 made of 400 nm Cu and 100 nm Au is formed on the Al ₂ O ₃ —TiC substrate 2. A spin valve giant magnetoresistive film (GMR film) 6 is formed on the lower terminal 4.

A cap layer 8 made of 10 nm Cu and 10 nm Au is formed on the GMR film 6, and an upper terminal 10 made of 300 nm Cu is formed on the cap layer 8. Reference numeral 12 denotes an insulating layer made of SiO ₂ having a thickness of 150 nm.

  The magnetoresistive sensor of the present invention is characterized in that the GMR film 6 has a spin valve structure and further has a CPP structure in which a sense current flows perpendicularly to the film surface.

  The inventor in the CPP spin valve magnetoresistive sensor, a pinned ferromagnetic layer (hereinafter abbreviated as pinned layer), a nonmagnetic intermediate layer (hereinafter abbreviated as intermediate layer) and a free ferromagnetic layer (hereinafter abbreviated as free layer). It was considered that a large resistance change can be obtained by increasing the thickness of each layer to maximize the bulk scattering.

  Even if the antiferromagnetic layer, the underlayer and the surface protective layer (cap layer) are thickened, the resistance change does not increase. When the pinned layer, the intermediate layer, and the free layer are thickened, the following can be considered.

  (1) When the pinned layer is thickened, Hua (strength of coupling between the antiferromagnetic layer and the pinned layer) decreases, and the sensitivity of the free layer decreases due to the leakage magnetic field, making it difficult to adjust the bias point. Therefore, by forming the pinned layer with a laminated ferrimagnetic structure, Hua can be increased and the leakage magnetic field can be reduced.

  (2) When the free layer is thickened, a large amount of external magnetic field is required to change the magnetization direction, so that the sensitivity of the free layer is reduced. Against this, since the free layer has a laminated ferrimagnetic structure, the magnetization direction of the free layer can be changed with a small external magnetic field, so that the sensitivity is increased. When the pinned layer and the free layer are thickened, it is desirable to thicken the intermediate layer in order to cut the magnetic coupling between the pinned layer and the free layer.

  (3) The GMR film has a dual spin valve structure. In this case, not only the pinned layer, the intermediate layer, and the free layer become thick, but also the number of interfaces increases, so that the resistance change due to interface scattering increases, which is effective in improving the resistance change amount.

  It is more effective to apply the above measures (1) to (3) in combination of two or three instead of a single measure.

  In the measures (1) and (2) above, the thickness of the pinned layer and / or the free layer cannot be increased unconditionally. The inventor experimentally determined the optimum value of each layer thickness by setting the material of the pinned layer and the free layer to CoFeB.

  As a result, it has been found that when the pinned layer and / or the free layer is made thicker than the optimum value in the CIP (currant in the plain) structure, the resistance change amount increases.

  That is, one feature of the present invention is that at least one of the free layer and the pinned layer has a layer thickness that is thicker than a layer thickness that provides the largest amount of resistance change when a current is passed in the in-plane direction. That is.

  Preferably, the thickness of the free layer and / or pinned layer is in the range of 3 nm to 12 nm. More preferably, this layer thickness is in the range of 5 nm to 7 nm. Preferably, the thickness of the intermediate layer is in the range of 4 nm to 6 nm.

  In other words, the layer thickness of the free layer and / or pinned layer is in the range of 0.5 to 2.0 times the mean free path of the propagation electrons in the spin direction that are not spin-dependently scattered with respect to the magnetization direction of the layer. Is preferred. More preferably, the thickness of the free layer or the pinned layer is approximately the same as the mean free path of the propagation electrons in the spin direction that are not spin-dependently scattered.

  This is presumably because the difference in electrical resistance between electrons that are not spin-dependently scattered and electrons that are spin-dependently scattered becomes the largest when passing through a layer thickness comparable to the mean free path. Actually, when the thickness exceeds about twice the mean free path, the possibility that the spin of electrons increases will increase, and the resistance change amount is considered to be small.

  When this idea is pushed forward, not only when the free layer and the pinned layer are formed of CoFeB, but also when the free layer and the pinned layer are formed by combining another ferromagnetic material or two or more types of ferromagnetic materials, it depends on the spin. It is possible to optimize the thickness with the mean free path of spin-direction transmission electrons that are not scattered.

  Hereinafter, the film configuration of the spin valve GMR film 6 will be described with reference to FIGS. Referring to FIG. 2, the film configuration of sample (a) is shown. Sample (a) is a CIP optimum layer thickness single spin valve.

  A 5 nm Ta layer 16 is formed on the lower terminal layer 4 by sputtering. All the following layers are also formed by sputtering. A 2 nm NiFe layer 18 is formed on the Ta layer 16, and the Ta layer 16 and a part of the NiFe layer 18 constitute an underlayer.

  A 2 nm CoFbB layer 20 is formed on the NiFe layer 18. A part of the NiFe layer 18 and the CoFeB layer 20 constitute a free layer.

  On the CoFeB layer 20, a 2.8 nm Cu intermediate layer 22 is formed. A 2.5 nm CoFeB pinned layer 24 is formed on the Cu intermediate layer 22.

  A 15 nm PdPtMn antiferromagnetic layer 26 is formed on the CoFeB pinned layer 24. A 5 nm Ta cap layer 28 is formed on the antiferromagnetic layer 26. The cap layer 28 protects the antiferromagnetic layer 26.

  Referring to FIG. 3, the film configuration of the spin valve GMR film of the sample (b) is shown. This sample (b) is a single spin valve in which a pinned layer is a laminated ferri with an optimum CIP layer thickness.

  The sample (b) is different from the sample (a) only in the configuration of the pinned layer, and the other layer configuration is the same as that of the sample (a). That is, in the sample (b), a 2.5 nm CoFeB layer 24 is formed on the Cu intermediate layer 22, a 0.8 nm Ru layer 30 is formed on the CoFeB layer 24, and 1. A 5 nm CoFeB layer 32 is formed. That is, in the sample (b), the laminated Felipind layer is constituted by the two CoFeB layers 24 and 32 separated by the Ru layer 30. In the form of FIG. 2, the free layer and the antiferromagnetic layer are stacked on the underlayer 16 in order, but the stacking order may be reversed.

  Referring to FIG. 4, the film configuration of the spin valve GMR film of sample (c) is shown. Sample (c) is a single spin valve in which the thickness of the pinned layer and the intermediate layer is increased and the pinned layer has a laminated ferri structure.

  The thickness of the Cu intermediate layer 36 is increased to 5 nm, and the laminated ferri-pinned layer is composed of two CoFeB layers 38 and 40 having a thickness of 5 nm and 4 nm separated by the Ru layer 30.

  Further, the resistance change amount corresponding to the layer thickness was measured by changing the layer thickness of the CoFeB free layer 34 between 2 nm and 12 nm.

  Referring to FIG. 5, the film configuration of the spin valve GMR film of the sample (d) is shown. Sample (d) is a dual spin valve with a CIP optimum layer thickness.

  In the sample (d), the underlayer is composed of a 5 nm Ta layer 16 and a 2 nm NiFe layer 18. A 15 nm PdPtMn antiferromagnetic layer 42 is formed on the underlayer.

  A 2.5 nm CoFeB pinned layer 46 is formed on the antiferromagnetic layer 42, and a 2.8 nm Cu intermediate layer 46 is formed on the CoFeB pinned layer 44.

  On the Cu intermediate layer 46, the CoFeB free layer 20, the Cu intermediate layer 22, the CoFeB pinned layer 24, the PdPtMn antiferromagnetic layer 26, and the Ta cap layer 28 are formed as in the sample (a).

  Referring to FIG. 6, the film configuration of the spin valve GMR film of the sample (e) is shown. Sample (e) is a dual spin valve having a CIP optimum layer thickness and two pinned layers having a ferrimagnetic structure.

  That is, a 1.5 nm CoEeB layer 48 is formed on the PdPtMn antiferromagnetic layer 42. A 0.8 nm Ru layer 50 is formed on the CoFeB layer 48, and a 2.5 nm CoFeB layer 52 is formed on the Ru layer 50. The two CoFeB layers 48 and 52 separated by the Ru layer 50 constitute a laminated ferri structure.

  On the Cu intermediate layer 46, a laminated ferri-pinned layer composed of two CoFeB layers 24 and 32 separated by the CoFeB free layer 20, the Cu intermediate layer 22, and the Ru layer 30 similar to the sample (b) is formed. . Further, a PdPtMn antiferromagnetic layer 26 is formed on the laminated ferri-pinned layer, and a Ta cap layer 28 is formed on the antiferromagnetic layer 26.

  Referring to FIG. 7, the film configuration of the spin valve GMR film of the sample (f) is shown. Sample (f) is a dual spin valve in which the thicknesses of the pinned layer and the intermediate layer are increased and two pinned layers are further laminated into a ferrimagnetic structure.

  That is, a 4 nm CoFeB layer 54 is formed on the PdPtMn antiferromagnetic layer 42, a 0.8 nm Ru layer 50 is formed on the CoFeB layer 54, and a 5 nm CoFeB layer 56 is formed on the Ru layer 50. Has been.

  A laminated ferri-pinned layer is constituted by the two CoFeB layers 54 and 56 separated by the Ru layer 50. A 5 nm thick Cu intermediate layer 58 is formed on the CoFeB layer 56.

  On the Cu intermediate layer 58, the free layer 34, the intermediate layer 36, the laminated ferri-pinned layers 38, 30, 40, the antiferromagnetic layer 26, and the cap layer 28 similar to the sample (c) in FIG. 4 are formed.

  Similar to the sample (c), the resistance change amount was measured by changing the thickness of the CoFeB free layer 34 between 2 nm and 12 nm.

  Referring to FIG. 8, the film configuration of the spin valve GMR film of the sample (g) is shown. Sample (g) is similar to sample (f) in FIG. 7 in that the layer thickness of the pinned layer and the intermediate layer is increased, but the free layer is composed of a 2 nm CoFeB layer 60, a 3 nm NiFe layer 62, It differs from the sample (f) in that it is composed of a 2 nm CoFeB layer 64.

  Referring to FIG. 9, the film configuration of the spin valve GMR film of the sample (h) is shown. The sample (h) is similar to the sample (f) shown in FIG. 7, and is different from the sample (f) in that the free layer has a laminated ferri structure.

  That is, a 3 nm CoFeB layer 66 is formed on the Cu intermediate layer 58, a 0.8 nm Ru layer 68 is formed on the CoFeB layer 66, and a 6 nm CoFeB layer 70 is formed on the Ru layer 68. Yes.

  Further, a 0.8 nm Ru layer 72 is formed on the CoFeB layer 70, and a 3 nm CoFeB layer 74 is formed on the Ru layer 72. The three CoFeB layers 66, 70, 74 separated by the Ru layers 68, 72 constitute a laminated ferri structure.

  In each of the dual spin valves of the samples (d) to (h) shown in FIGS. 5 to 9, two pinned layers are arranged on the top and bottom, and only one free layer is arranged in the middle.

  Although not particularly illustrated, a dual spin valve magnetoresistive sensor having the following laminated structure in which two free layers are arranged vertically and only one antiferromagnetic layer is arranged in the middle is also within the scope of the present invention.

  That is, the dual spin valve magnetoresistive sensor includes a first conductor layer, a first free ferromagnetic layer disposed on the first conductor layer, and a first conductor layer disposed on the first free ferromagnetic layer. 1 nonmagnetic intermediate layer, a first pinned ferromagnetic layer disposed on the first nonmagnetic intermediate layer, an antiferromagnetic layer disposed on the first pinned ferromagnetic layer, and the antiferromagnetic layer A second pinned ferromagnetic layer disposed thereon, a second nonmagnetic intermediate layer disposed on the second pinned ferromagnetic layer, and a second free ferromagnetic layer disposed on the second nonmagnetic intermediate layer Including layers.

  Next, with reference to FIGS. 10 (A) to 14 (C) and FIGS. 10 (A ') to 14 (C'), the manufacturing process of the magnetoresistive sensor of the present invention will be described. 10A to 14C are cross-sectional views, and FIGS. 10A to 14C are plan views.

First, as shown in FIG. 10A, a lower terminal layer 4 made of 400 nm Cu and 100 nm Au is formed on an Al ₂ O ₃ —TiC substrate 2 by sputtering.

  Next, the spin valve GMR film 6 shown in any of FIGS. 2 to 9 is formed on the lower terminal layer 4 by sputtering. A cap layer 8 made of 10 nm Cu and 10 nm Au is formed on the spin valve GMR film 6 by sputtering.

  After the cap layer 8 was formed, heat treatment was performed at 280 ° C. for 3 hours while applying a magnetic field of 100 oersted (Oe).

  Next, as shown in FIGS. 10B and 10B ′, a lower terminal layer-shaped resist 76 is formed on the cap layer 8. As shown in FIGS. 10C and 10C ′, when ion milling is performed with Ar ions and the resist 76 is peeled off, the state shown in FIGS. 11A and 11A ′ is obtained.

  Next, as shown in FIGS. 11 (B) and 11 (B ′), a resist 78 is formed on the GMR portion, and as shown in FIGS. 11 (C) and 11 (C ′), ion mill processing is performed. When the resist 78 is peeled, the state shown in FIGS. 12A and 12A ′ is obtained.

Next, as shown in FIGS. 12B and 12B ′, an insulating layer 80 made of 150 nm of SiO _{2 is} formed by sputtering. Next, as shown in FIGS. 12 (C) and 12 (C ′), an insulating layer-shaped resist 82 is formed on the insulating layer 80, and as shown in FIGS. 13 (A) and 13 (A ′), When the reactive ion etching (RIE) process is performed and the resist is removed, the state shown in FIGS. 13B and 13B ′ is obtained.

  Next, as shown in FIG. 13C and FIG. 13C ′, an upper terminal layer 84 made of 300 nm Cu is uniformly formed. As shown in FIGS. 14A and 14A ′, an upper terminal layer shape resist 86 is formed on the upper terminal layer 84, and as shown in FIGS. 14B and 14B ′, When RIE processing is performed and the resist 86 is peeled off, the state shown in FIGS. 14C and 14C 'is obtained, and the CPP spin valve magnetoresistive sensor is completed.

  The resistance measurement by the four-terminal method was performed on the CPP spin valve magnetoresistive sensor thus prepared while applying a magnetic field of ± 500 oersted (Oe).

FIG. 15 shows the change in resistance change ΔR (mΩ) depending on the element size (area, μm ² ) for the sample (f) having a thickness of 7 nm of the CoFeB free layer 34 shown in FIG. The measured data was regressed on a curve of y = A / x, and ΔR at 1 μm ² was calculated to obtain 3.8 mΩμm ² .

Similarly, ΔR at 1 μm ² was calculated for samples (a) to (h), which are shown in FIGS. 16 and 17. Samples (c) and (f) in FIG. 16 show the resistance change ΔR when the thickness of the free layer is 2 nm.

For the single spin-valve GMR film, ΔR at 1 μm ² is about 1.5 times that of sample (a) in sample (b) formed into a laminated ferrimagnetic material. Further, in the sample (c) having a thickened pinned layer and intermediate layer, ΔR at 1 μm ² is about twice.

Further, in the sample (d) in which the sample (a) is made into a dual spin valve, ΔR at 1 μm ² is about double. Further, in the sample (e) obtained by laminating the ferrimagnetic layer, ΔR is larger than that in the sample (d). ΔR is larger than that of the converted sample (e).

In the sample (c) and the sample (f), the thickness of the free layer was changed. The result is shown in FIG. As is apparent from observation of FIG. 17, the single spin valve sample (c) has a free layer thickness of 5 nm, and the dual spin valve sample (f) has a free layer thickness of 7 nm at 1 μm ² . ΔR is the largest.

A large ΔR of 3.4 and 2.8 mΩμm ² was obtained also in the sample (g) and the sample (h) in which the configuration of the free layer was changed from the sample (f).

  From the above experimental results, it can be concluded as follows. When the spin valve GMR film is used in a CPP structure, the resistance change amount ΔR is improved by increasing the thickness of the pinned layer / intermediate layer / free layer by making dual spin valves, stacking ferrimagnetic layers, and pinned layers / intermediate layers / free layers.

  Making dual spin valves, stacking ferrimagnetic layers, and increasing the thickness of the pinned layer / intermediate layer / free layer alone has the effect of improving the resistance change ΔR, but by combining them, the resistance change ΔR can be further increased. It can be greatly improved.

  In the present embodiment, a sample in which the pinned layer and the intermediate layer are thickened without forming a laminated ferrimagnetic material is not particularly shown, but it has been confirmed that ΔR is also improved.

  If the thickness of the free layer or the pinned layer is thicker than the CIP optimum layer thickness, the resistance change ΔR is improved. The layer thickness of the free layer or pinned layer is preferably in the range of 3 nm to 12 nm, and more preferably in the range of 5 nm to 7 nm.

  This optimum layer thickness is equivalent to the mean free path of electrons that are not spin-dependently scattered in the magnetic material CoFeB. A layer thickness equivalent to the mean free path of electrons that do not undergo spin-dependent scattering even when the material of the free layer and the pinned layer is changed is optimal.

  As for the thickness of the Cu intermediate layer, it is necessary to sufficiently block the interlayer coupling between the magnetic layers when the pinned layer or the free layer is thickened. In CIP optimum layer thickness, the thickness of the intermediate layer is around 2.8 nm. However, if the pinned layer or free layer is thickened, it must be thicker than this, in order to sufficiently block the interlayer coupling between the magnetic layers. In the range of 4 nm to 6 nm.

  The above-described CPP spin valve magnetoresistive sensor is mainly used as a magnetoresistive head of a magnetic disk device that is a recording / reproducing device of a computer.

Referring to FIG. 18, a sectional view of a magnetoresistive head 88 according to the second embodiment of the present invention is shown. Reference numeral 90 denotes a first magnetic shield made of, for example, NiFe, and an insulating layer 92 made of, for example, alumina (Al ₂ O ₃ ) is laminated on the first magnetic shield 90. Similarly, 96 and 112 are insulating layers made of alumina or the like.

Lower electrode terminals 94 and 98 are formed on the insulating layer 92 by plating or vapor deposition. 106 is a spin valve magnetoresistive element, such as a spin valve GMR film such as NiFe / Cu / NiFe / IrMn, a laminated ferri spin valve GMR film such as NiFe / Cu / CoFeB / Ru / CoFeB / PdPtMn, and NiFe / Al ₂ O _3. A tunnel junction type MR film (TMR film) such as / NiFe / PdPtMn can be used.

  Reference numeral 102 denotes a first flux guide made of, for example, NiFe. One end of the first flux guide is exposed on the medium facing surface 88a of the head 88, and the other end is disposed so as to overlap one end of the spin valve magnetoresistive element 106.

  The first flux guide 102 is preferably in contact with the spin valve magnetoresistive element 106, but may or may not be electrically conductive as long as it is close enough to be magnetically coupled.

  Reference numeral 104 denotes a second flux guide made of, for example, NiFe, and one end thereof is disposed so as to overlap the other end of the spin valve magnetoresistive element 106. The second flux guide 104 is preferably in contact with the spin valve magnetoresistive element 106, but may or may not be electrically conductive as long as it is close enough to be magnetically coupled.

  A flux path 100 made of, for example, NiFe is formed between the first magnetic shield 90 and the second flux guide 104. The flux path 100 is preferably in contact with the first magnetic shield 90 and the second flux guide 104, but may or may not be electrically conductive as long as it is close enough to be magnetically coupled. .

  An upper electrode terminal 110 is formed on the spin valve magnetoresistive element 106, and a second magnetic shield 114 made of, for example, NiFe is formed in electrical conduction with the upper electrode terminal 110. 26 magnetic shield 114 functions as an electrode terminal.

  The magnetoresistive head 88 of this embodiment has a CPP structure in which current is passed perpendicularly to the film surface of the spin valve magnetoresistive element 106 because the electrodes 94, 98, and 110 are disposed above and below the spin valve magnetoresistive element 106. . Reference numeral 116 denotes a magnetic recording medium having a recording track 118.

  In the spin valve magnetoresistive head 88 of this embodiment, the signal magnetic field leaking from the magnetic recording medium 116 is guided to the spin valve magnetoresistive element 106 through the first flux guide 102. Further, the signal magnetic field from the spin valve magnetoresistive element 106 reaches the first magnetic shield 90 through the second flux guide 104 and the flux path 100.

  Further, the electrode terminals 98 and 110 are in contact with a part of the film surface of the spin valve magnetoresistive element 106, and the electrode terminals 98 and 110 have a smaller size than the spin valve magnetoresistive element 106 in the film surface. Have.

  Therefore, since only the movement of magnetization in the central portion of the spin valve magnetoresistive element 106 having the highest sensitivity is detected by the electrode terminals 98 and 110, a highly sensitive head reproducing characteristic can be obtained.

  Furthermore, since it is a flux guide type structure, it is not necessary to directly polish the spin valve magnetoresistive element 106, so that a spin valve magnetoresistive head can be produced with a high yield.

  Hereinafter, with reference to FIGS. 19A to 21C and FIGS. 19A ′ to 21C ′, a method of manufacturing the spin valve magnetoresistive head 88 will be described. FIGS. 19A to 21C are cross-sectional views in the height direction of the spin valve magnetoresistive element, and FIGS. 19A to 21C are cross-sectional views in the track width direction.

  First, a first magnetic shield 90, an insulating layer 92, and electrode terminals 94 are sequentially formed on a substrate (not shown). Next, as shown in FIGS. 19A and 19A, the electrode terminal 94 is patterned into a desired shape.

  Next, an insulating layer 96 is formed, a resist 97 is formed on the insulating layer 96, and the resist 97 is patterned into a desired shape. Using the resist 97 as a mask, holes are formed in the insulating layer 96 by ion milling or the like, as shown in FIGS.

  Next, as shown in FIG. 19C and FIG. 19C ′, an electrode terminal 98 is formed on the electrode terminal 94 without removing the resist 97. The electrode terminal 94 and the electrode terminal 98 are electrically connected.

  Next, the flux path 100 is formed by making holes in the insulating layers 92 and 96 as shown in FIG. Here, the first magnetic shield 90 and the flux path 100 are preferably in contact with each other, but may or may not be electrically connected as long as they are close enough to be magnetically coupled.

  Next, as shown in FIG. 20A, the first flux guide 102 and the second flux guide 104 are formed by making a hole in the insulating layer 96 in the same manner as the electrode terminal 98 is formed.

  Here, the first flux guide 102 is preferably formed so as not to be in electrical contact with the electrode terminals 94 and 98 and the first magnetic shield 90. The second flux guide 104 is also preferably formed so as not to be in electrical contact with the electrode terminals 94 and 98 and the first magnetic shield 90.

  Further, the second flux guide 104 is preferably in contact with the flux path 100, but may or may not be electrically conductive as long as it is close enough to be magnetically coupled.

  Next, a GMR film 106 as a spin valve magnetoresistive element is formed by sputtering, and a resist 107 is formed on the GMR film 106 and patterned into a desired shape.

  As shown in FIGS. 20B and 20B ′, the spin valve magnetoresistive element 106 is patterned into a desired shape using the resist 107 as a mask.

  Here, the spin valve magnetoresistive element 106 and the first and second flux guides 102 and 104 are arranged so as to overlap part of the film surface. It is desirable that the spin valve magnetoresistive element 106 and the first and second flux guides 102 and 104 are in contact with each other. However, the spin valve magnetoresistive element 106 and the first and second flux guides 102 and 104 may be electrically connected if close enough to be magnetically coupled. Also good.

  Next, as shown in FIG. 20C ′, a magnetic domain control film 108 is formed on both sides of the spin valve magnetoresistive element 106 by sputtering without removing the resist 107. As the magnetic domain control film 108, a high coercive force film such as CoCrPt or an antiferromagnetic film such as PdPtMn can be used.

  Next, the electrode terminals 110 are uniformly formed, a resist 111 is formed on the electrode terminals 110, and the resist is patterned into a desired shape. As shown in FIGS. 21A and 21A ′, the electrode terminal 110 is patterned using the resist 111 as a mask.

  Next, the insulating layer 112 is formed without removing the resist 111, and then the resist 111 is removed as illustrated in FIGS. 21B and 21B ′. Next, as shown in FIG. 21C and FIG. 21C ′, the second magnetic shield 114 is formed on the insulating layer 112 to complete the spin valve magnetoresistive head 88. Here, the electrode terminal 110 and the second magnetic shield 114 are electrically connected.

  The first and second magnetic shields 90 and 114 and the electrode terminal 110 are formed by plating or vapor deposition, and the insulating layers 92, 96 and 112 are formed by sputtering or the like. With the above manufacturing method, a highly sensitive spin valve magnetoresistive head having a flux guide type and a CPP structure can be obtained.

  Referring to FIG. 22, a cross-sectional view of a spin valve magnetoresistive head 88 ′ according to a third embodiment of the present invention is shown. The spin valve magnetoresistive head 88 ′ of this embodiment is similar to the spin valve magnetoresistive head 88 of the second embodiment shown in FIG. 18, but differs in that the electrodes 94 and 98 of the second embodiment are not provided. To do.

  In the spin valve magnetoresistive head 88 ′ of this embodiment, the spin valve magnetoresistive element 106 and the second flux guide 104 are in contact, and the flux path 100 is in contact with the second flux guide 104 and the first magnetic shield 90. Yes.

  Therefore, the first magnetic shield 90 and the spin valve magnetoresistive element 106 are electrically connected via the flux path 100 and the second flux guide 104. Therefore, in the spin valve magnetoresistive head 88 ′ of the present embodiment, the first magnetic shield 90 acts as one electrode terminal. In the third embodiment, the shield 114 also functions as an electrode terminal.

A nonmagnetic film 122 made of Cu, Al ₂ O ₃ or the like is formed between the first flux guide 102 and the second flux guide 104. Reference numeral 120 denotes an insulating layer.

  Hereinafter, with reference to FIGS. 23A to 25B and FIGS. 23A ′ to 25B ′, a method of manufacturing the spin valve magnetoresistive head 88 ′ of the third embodiment will be described. . FIGS. 23A to 25B are cross-sectional views in the height direction of the spin valve magnetoresistive element, and FIGS. 23A to 25B are cross-sectional views in the track width direction.

  A first magnetic shield 90 and an insulating layer 120 are sequentially formed on a substrate (not shown). Next, as shown in FIG. 23A, the flux path 100 is formed by making a hole in the insulating layer 120. Here, the first magnetic shield 90 and the flux path 100 are in contact and are electrically connected.

Next, a nonmagnetic film 122 is formed, a resist 123 is formed on the nonmagnetic film 122, and the resist 123 is patterned into a desired shape. As shown in FIGS. 23B and 23B ′, the nonmagnetic film 122 is patterned using the resist 123 as a mask. As the nonmagnetic film 122, Cu, Al ₂ O ₃ or the like can be used.

  Next, the first flux guide 102 and the second flux guide 104 are formed without removing the resist 123, and patterned again after removing the resist 123, as shown in FIGS. 23C and 23C '. In addition, the first and second flux guides 102 and 104 are formed. Here, the second flux guide 104 is in contact with the flux path 100 and is electrically conductive.

  Next, a spin valve GMR film 106 as a spin valve magnetoresistive element is formed by sputtering or the like, a resist 107 is uniformly formed on the GMR film 106, and this resist 107 is patterned into a desired shape.

  As shown in FIGS. 24A and 24A ′, the GMR film 106 is patterned into a desired shape using the resist 107 as a mask. Here, the spin valve magnetoresistive element (GMR film) 106 and the first and second flux guides 102 and 104 are arranged so as to overlap each other on a part of the film surface.

  The spin valve magnetoresistive element 106 and the first flux guide 102 are preferably in contact with each other, but may not be electrically connected as long as they are close enough to be magnetically coupled. The spin valve magnetoresistive element 106 and the second flux guide 104 are in contact with each other and are electrically connected.

  Next, when the resist 107 is not removed, the magnetic domain control film 108 is formed by sputtering or the like, and when the resist 107 is removed, the spin valve magnetoresistive element 106 is formed on both sides as shown in FIG. A magnetic domain control film 108 is formed. As the magnetic domain control film 108, a high coercive force film such as CoCrBt or an antiferromagnetic film such as PdPtMn can be used.

  Next, the electrode terminal 110 is uniformly formed, and the resist 111 is uniformly formed on the electrode terminal 110, and then the resist 111 is patterned into a desired shape. As shown in FIGS. 24C and 24C ′, the electrode terminal 110 is patterned into a desired shape using the resist 111 as a mask.

  Next, the insulating layer 112 is formed without removing the resist 111, and then the resist 111 is removed, whereby the states shown in FIGS. 25A and 25A 'are obtained.

  Next, as shown in FIG. 25B and FIG. 25B ′, the second magnetic shield 114 is formed on the insulating layer 112, thereby completing the spin valve magnetoresistive head 88 ′. The electrode terminal 110 and the second magnetic shield 114 are in contact with each other and are electrically connected.

  In the spin valve magnetoresistive head 88 ′ of the present embodiment, the first magnetic shield 90 also serves as one electrode terminal, so that a spin valve magnetoresistive head 88 ′ having a CPP structure can be configured.

  Referring to FIG. 26, there is shown the structure of an inversely stacked spin valve GMR film as a spin valve magnetoresistive element. On a Si substrate (not shown), a 5 nm Ta underlayer 130, a 5 nm NiFe buffer layer 132, a 25 nm PdPtMn antiferromagnetic layer 134, and a 2.2 nm CoFeB pinned layer 136 are formed by DC magnetron sputtering.

  A 3.5 nm Cu intermediate layer 138 is formed on the pinned layer 136, and a free layer 140 made of 1.5 nm CoFeB and 2 nm NiFe is formed on the Cu intermediate layer 138.

  On the free layer 140, an antiferromagnetic layer 142 as a bias magnetic field applying layer to the free layer 140 made of 10 nm IrMn and a Ta cap layer 144 of 5 nm were formed.

This sample was ordered at 280 ° C. for 3 hours while applying a magnetic field of 2.5 kOersted (Oe) in a vacuum of 8 × 10 ⁻⁵ Pascal (Pa) or less for ordering PdPtMn, which is an ordered antiferromagnetic material The heat treatment was performed.

Thereafter, this sample was subjected to RIE treatment using SF ₆ gas. The conditions of the RIE process were a process gas pressure of 0.5 Pa, a substrate temperature of 20 ° C., a substrate potential of 1 volt, an antenna power of 100 W, and a bias power of 2 W. Ta of the cap layer 144 is etched with SF ₆ gas.

FIG. 27 shows the relationship between the RIE processing time with SF ₆ gas and various characteristics of the spin valve GMR film. Hua is a bias magnetic field that moves between the free layer and the IrMn antiferromagnetic layer, Hc is the coercivity of the free layer, and Ms is the saturation magnetization of the free layer.

  When observing FIG. 27, the bias magnetic field Hua between the free layer 140 and the IrMn bias magnetic field applying layer 142 disappears after 10 minutes of RIE processing, and the coercive force Hc of the free layer becomes about 8 Oersted (Oe). The value is equivalent to the characteristics of the single layer film.

  On the other hand, the saturation magnetization Ms of the free layer 140 and the MR ratio of the spindle valve GMR film hardly change. Thus, it is understood that the exchange coupling force between the IrMn antiferromagnetic layer (bias magnetic field application layer) 142 and the free layer 140 can be eliminated while maintaining the characteristics of the spin valve GMR film when fluorine is used. .

FIG. 28 shows the relationship between the peak intensity (content) of F, Ir, and Mn when the spin valve GMR film is RIE-treated with SF ₆ and Hua acting on the free layer. The amount of F in the GMR film increases with the processing time, and there is a correlation with the decrease in Hua.

  On the other hand, since the contents of Ir and Mn are hardly changed, it is understood that IrMn remains without being physically etched. When heat treatment at 280 ° C. was performed on a sample that had been subjected to RIE for 20 minutes, the change in F amount was hardly reduced to minus 8%, and it can be said that F was in a stable state because a compound was formed in the GMR film.

  FIG. 29 shows the X-ray diffraction characteristics of the spin valve GMR film before and after the RIE treatment. In the sample before the RIE treatment, an IrMn fcc (111) peak contributing to the expression of Hua is observed when 2θ is around 41 ° C. On the other hand, the peak is not seen in the sample after RIE treatment.

  From this, it can be said that Hua disappeared because the crystallinity of IrMn was disturbed by the formation of fluoride in the GMR film. Moreover, since the peak of fcc (111) of the free layer observed when 2θ is around 44 degrees does not change before and after the RIE process, the RIE process is performed under the above-described conditions, and the free layer 140 is adversely affected. It can be seen that the exchange coupling force between the antiferromagnetic layer 142 and the free layer 140 can be eliminated.

  In other PdPtMn materials, which are antiferromagnetic layers, it has been confirmed that Hua disappears due to fluorine or chlorine. It can be easily analogized that the exchange coupling force of the magnetic field sensing part of the GMR film can be eliminated by fluorine or chlorine.

  The present invention includes the following supplementary notes.

(Appendix 1) A magnetoresistive sensor,
A first conductor layer;
A free ferromagnetic layer disposed on the first conductor layer;
A nonmagnetic interlayer disposed on the free ferromagnetic layer;
A pinned ferromagnetic layer disposed on the nonmagnetic intermediate layer;
An antiferromagnetic layer disposed on the pinned ferromagnetic layer;
A second conductor layer disposed on the antiferromagnetic layer,
At least one of the free ferromagnetic layer and the pinned ferromagnetic layer has a layer thickness that is thicker than a layer thickness at which the greatest resistance change rate or resistance change amount can be obtained when a current flows in the in-plane direction. A magnetoresistive sensor.

  (Supplementary note 2) The thickness of at least one of the free ferromagnetic layer and the pinned ferromagnetic layer is 0.5 to 2 of the mean free path of conduction electrons in the spin direction that is not spin-dependently scattered with respect to the magnetization direction of the layer. The magnetoresistive sensor according to appendix 1, which is in a range of 0 times.

  (Supplementary note 3) The magnetoresistive sensor according to supplementary note 2, wherein a thickness of at least one of the free ferromagnetic layer and the pinned ferromagnetic layer is in a range of 3 nm to 12 nm.

  (Additional remark 4) The magnetoresistive sensor of Additional remark 1 whose said pinned ferromagnetic layer is a laminated ferri structure.

  (Supplementary note 5) The magnetoresistive sensor according to supplementary note 1, wherein the free ferromagnetic layer has a laminated ferrimagnetic structure.

  (Additional remark 6) The magnetoresistive sensor of Additional remark 1 whose layer thickness of the said nonmagnetic intermediate | middle layer is thicker than the layer thickness from which the largest resistance change rate or resistance change amount is obtained when an electric current is sent in an in-plane direction.

  (Additional remark 7) The said nonmagnetic intermediate | middle layer is formed from Cu, The magnetoresistive sensor of Additional remark 5 whose layer thickness exists in the range of 4 nm-6 nm.

  (Supplementary note 8) The magnetoresistive sensor according to supplementary note 3, wherein the free ferromagnetic layer and the pinned ferromagnetic layer are selected from the group consisting of Co, CoFe, CoFeB, and NiFe.

(Appendix 9) A magnetoresistive sensor,
A first conductor layer;
A first antiferromagnetic layer disposed on the first conductor layer;
A first pinned ferromagnetic layer disposed on the first antiferromagnetic layer;
A first nonmagnetic interlayer disposed on the first pinned ferromagnetic layer;
A free ferromagnetic layer disposed on the first nonmagnetic intermediate layer;
A second nonmagnetic intermediate layer disposed on the free ferromagnetic layer;
A second pinned ferromagnetic layer disposed on the second nonmagnetic intermediate layer;
A second antiferromagnetic layer disposed on the second pinned ferromagnetic layer;
A second conductor layer disposed on the second antiferromagnetic layer;
A magnetoresistive sensor comprising:

  (Supplementary note 10) The magnetoresistive sensor according to supplementary note 9, wherein a thickness of at least one of the first pinned ferromagnetic layer, the second pinned ferromagnetic layer, and the free ferromagnetic layer is in a range of 3 nm to 12 nm.

  (Supplementary note 11) The magnetoresistive sensor according to supplementary note 10, wherein the first and second pinned ferromagnetic layers and the free ferromagnetic layer are selected from the group consisting of Co, CoFe, CoFeB, and NiFe.

  (Supplementary note 12) The magnetoresistive sensor according to supplementary note 9, wherein at least one of the first and second pinned ferromagnetic layers and the free ferromagnetic layer has a laminated ferrimagnetic structure.

  (Supplementary note 13) The magnetoresistive sensor according to supplementary note 9, wherein the first and second nonmagnetic intermediate layers are made of Cu, and the layer thickness thereof is in the range of 4 nm to 6 nm.

(Supplementary note 14) A magnetoresistive sensor,
A first conductor layer;
A first free ferromagnetic layer disposed on the first conductor layer;
A first nonmagnetic intermediate layer disposed on the first free ferromagnetic layer;
A first pinned ferromagnetic layer disposed on the first nonmagnetic interlayer;
An antiferromagnetic layer disposed on the first pinned ferromagnetic layer;
A second pinned ferromagnetic layer disposed on the antiferromagnetic layer;
A second nonmagnetic interlayer disposed on the second pinned ferromagnetic layer;
A second free ferromagnetic layer disposed on the second nonmagnetic intermediate layer;
A magnetoresistive sensor comprising:

(Supplementary Note 15) A magnetoresistive sensor in which a magnetoresistive film is disposed between a first conductor layer and a second conductor layer,
The magnetoresistive sensor according to claim 1, wherein the magnetoresistive film has a layer pressure that is thicker than a layer pressure at which a maximum resistance change rate or resistance change amount is obtained when a current flows in an in-plane direction.

(Supplementary Note 16) The magnetoresistive film is a spin valve film having a free ferromagnetic layer and a pinned ferromagnetic layer,
The magnetoresistive sensor according to appendix 15, wherein at least one of the free ferromagnetic layer and the pinned ferromagnetic layer has a maximum resistance change rate or resistance change amount when a current flows in an in-plane direction.

(Supplementary note 17) A magnetoresistive head for reproducing information recorded on a recording medium,
A first electrode terminal;
A spin-valve magnetoresistive element provided on the first electrode terminal that is retracted from the medium facing surface of the head and converts a change in the signal magnetic field leaking from the recording medium into a resistance change;
A first flux guide that has one end exposed at the medium facing surface of the head and the other end overlapped with one end of the spin valve magnetoresistive element to guide the magnetic flux from the recording medium to the spin valve magnetoresistive element; ,
A second flux guide having one end overlapped with the other end of the spin valve magnetoresistive element;
A second electrode terminal provided on the spin valve magnetoresistive element;
A magnetoresistive head comprising:

  (Supplementary Note 18) The spin valve magnetoresistive element includes a free ferromagnetic layer provided on the first electrode terminal, a nonmagnetic intermediate layer provided on the free ferromagnetic layer, and a nonmagnetic intermediate layer. 18. The magnetoresistive head according to appendix 17, comprising a pinned ferromagnetic layer provided and an antiferromagnetic layer provided on the pinned ferromagnetic layer.

  (Supplementary note 19) The magnetoresistive head according to supplementary note 17, wherein at least one of the first and second flux guides is in contact with the spin valve magnetoresistive element.

(Supplementary note 20) a first magnetic shield disposed below the first electrode terminal;
A second magnetic shield disposed on the second electrode terminal;
The magnetoresistive head according to claim 17, wherein the second flux guide and the first magnetic shield are magnetically coupled via a flux path.

  (Supplementary Note 21) At least one of the first and second electrode terminals is in contact with a part of the film surface of the spin valve magnetoresistive element, and the one electrode terminal in the film surface is the spin electrode. 18. The magnetoresistive head according to appendix 17, which is smaller than the valve magnetoresistive element.

  (Supplementary Note 22) The other electrode terminal of the first and second electrode terminals is in contact with a part of the film surface of the spin valve magnetoresistive element, and the first and second electrode terminals have substantially the same size. The magnetoresistive head according to appendix 21.

(Supplementary note 23) Further comprising a magnetic domain control film disposed on both sides of the spin valve magnetoresistive element,
18. The magnetoresistive head according to appendix 17, wherein the magnetic domain control film is composed of either a high coercive force film or an antiferromagnetic film.

(Supplementary Note 24) A spin valve magnetoresistive head for reproducing information recorded on a recording medium,
A first magnetic shield;
An insulating layer provided on the first magnetic shield;
A spin-valve magnetoresistive element provided on the insulating layer and retreating from the medium facing surface of the head, which converts a change in signal magnetic field leaking from the recording medium into a resistance change;
A first flux guide that has one end exposed at the medium facing surface of the head and the other end overlapped with one end of the spin valve magnetoresistive element to guide the magnetic flux from the recording medium to the spin valve magnetoresistive element; ,
A second flux guide having one end disposed in contact with the other end of the spin valve magnetoresistive element;
An electrode terminal provided on the spin valve magnetoresistive element;
A second magnetic shield disposed on the electrode terminal;
A flux path connecting the second flux guide and the first magnetic shield;
A magnetoresistive head comprising:

  (Supplementary Note 25) The spin valve magnetoresistive element is provided on a free ferromagnetic layer provided on the insulating layer in contact with one end of the second flux guide, and on the free ferromagnetic layer. 25. The magnetoresistive head according to appendix 24, comprising: a nonmagnetic intermediate layer; a pinned ferromagnetic layer provided on the nonmagnetic intermediate layer; and an antiferromagnetic layer provided on the pinned ferromagnetic layer.

  (Supplementary note 26) The magnetism according to supplementary note 24, wherein the electrode terminal is in contact with a part of a film surface of the spin valve magnetoresistive element, and the electrode terminal is smaller than the spin valve magnetoresistive element in the film surface. Resistance head.

(Supplementary note 27) Further comprising a nonmagnetic layer disposed on the insulating layer and between the first and second flux guides,
25. The magnetoresistive head according to appendix 24, wherein the spin valve magnetoresistive element is provided on the nonmagnetic layer.

(Additional remark 28) It further comprises a magnetic domain control film disposed on both sides of the spin valve magnetoresistive element,
25. The magnetoresistive head according to appendix 24, wherein the magnetic domain control film is composed of either a high coercive force film or an antiferromagnetic film.

(Supplementary note 29) A magnetoresistive sensor,
A first antiferromagnetic layer;
A pinned ferromagnetic layer disposed on the first antiferromagnetic layer;
A nonmagnetic interlayer disposed on the pinned ferromagnetic layer;
A free ferromagnetic layer disposed on the nonmagnetic intermediate layer;
A second antiferromagnetic layer disposed on the free ferromagnetic layer and performing magnetic domain control of the free ferromagnetic layer by an exchange coupling force;
The portion of the second antiferromagnetic layer in contact with the magnetic field sensing part of the free ferromagnetic layer is composed of a compound of a constituent element of the second antiferromagnetic layer and a reactive element selected from the group consisting of fluorine and chlorine. A magnetoresistive sensor comprising:

  (Additional remark 30) The said 2nd antiferromagnetic layer is a magnetoresistive sensor of Additional remark 29 comprised from the alloy of manganese and another metal element.

  (Supplementary note 31) The magnetoresistive sensor according to supplementary note 30, wherein the second antiferromagnetic layer is made of an alloy selected from the group consisting of NiMn, PtMn, PdPtMn, and IrMn.

(Supplementary note 32) A method of manufacturing a magnetoresistive sensor,
Forming a first antiferromagnetic layer;
Forming a pinned ferromagnetic layer on the first antiferromagnetic layer;
Forming a nonmagnetic interlayer on the pinned ferromagnetic layer;
Forming a free ferromagnetic layer on the nonmagnetic intermediate layer;
Forming a second antiferromagnetic layer on the free ferromagnetic layer for controlling the magnetic domain of the free ferromagnetic layer by an exchange coupling force;
By irradiating the portion of the second antiferromagnetic layer in contact with the magnetic field sensing portion of the free ferromagnetic layer with a reactive element gas selected from the group consisting of fluorine and chlorine, the second antiferromagnetic layer is applied to the portion. Forming a compound of a constituent element of the magnetic layer and the reactive element;
A method of manufacturing a magnetoresistive sensor comprising each step.

It is sectional drawing of the CPP spin valve magnetoresistive sensor of 1st Embodiment of this invention. It is a figure which shows the structure of a sample (a). It is a figure which shows the structure of a sample (b). It is a figure which shows the structure of a sample (c). It is a figure which shows the structure of a sample (d). It is a figure which shows the structure of a sample (e). It is a figure which shows the structure of a sample (f). It is a figure which shows the structure of a sample (g). It is a figure which shows the structure of a sample (h). 10 (A) to 10 (C) and 10 (A ') to 10 (C') are diagrams showing a magnetoresistive sensor manufacturing process, and FIGS. 10 (A) to 10 (C) are cross-sectional views. FIGS. 10A to 10C are plan views, respectively. It is a figure which shows the manufacturing process of a magnetoresistive sensor. It is a figure which shows the manufacturing process of a magnetoresistive sensor. It is a figure which shows the manufacturing process of a magnetoresistive sensor. It is a figure which shows the manufacturing process of a magnetoresistive sensor. It is a figure which shows resistance variation amount (DELTA) R according to GMR size. It is a figure which shows resistance variation amount (DELTA) R of a sample (a)-a sample (f). It is a figure which shows resistance variation amount (DELTA) R by the layer thickness of a free layer. It is sectional drawing of the spin valve magnetoresistive head of 2nd Embodiment of this invention. 19 (A) to 19 (D) and 19 (A ') to 19 (D') are diagrams showing the manufacturing process of the magnetoresistive head, and FIGS. 19 (A) to 19 (D) are diagrams. Cross-sectional views in the height direction of the spin valve magnetoresistive element, and FIGS. 19A to 19D are cross-sectional views in the track width direction. It is a figure which shows the manufacturing process of a magnetoresistive head. It is a figure which shows the manufacturing process of a magnetoresistive head. It is sectional drawing of the spin valve magnetoresistive head of 3rd Embodiment of this invention. 23 (A) to 23 (C) and 23 (A ') to 23 (C') are diagrams showing the manufacturing process of the magnetoresistive head, and FIGS. 23 (A) to 23 (C) are diagrams. Cross-sectional views in the height direction of the spin valve magnetoresistive element, and FIGS. 23 (A ′) to 23 (C ′) are cross-sectional views in the track width direction. It is a figure which shows the manufacturing process of a magnetoresistive head. It is a figure which shows the manufacturing process of a magnetoresistive head. It is a figure which shows the structure of a reverse lamination type spin-valve GMR film | membrane. Is a diagram showing the relationship between the processing time and film properties when the spin valve GMR film was RIE treated with SF _6. It is a diagram showing the relationship between F, Ir, and Hua acting on the peak intensity of the free layer of Mn when the spin valve GMR film was RIE treated with SF _6. It is a figure which shows the X-ray-diffraction characteristic of the spin valve GMR film | membrane before and behind RIE process.

Explanation of symbols

2 Substrate 4 Lower terminal 6 Spin valve GMR film 8 Cap layer 10 Upper terminal 88 Spin valve magnetoresistive head 90 First magnetic shield 94, 98, 110 Electrode 100 Flux path 102 First flux guide 104 Second flux guide 106 Spin valve magnetism Resistive element (spin valve GMR film)
114 Second magnetic shield 116 Magnetic recording medium

Claims (4)

A magnetoresistive head for reproducing information recorded on a recording medium,
A first electrode terminal;
A spin-valve magnetoresistive element provided on the first electrode terminal that is retracted from the medium facing surface of the head and converts a change in the signal magnetic field leaking from the recording medium into a resistance change;
A first flux guide having one end exposed on the medium facing surface of the head and the other end overlapping with one end of the surface of the spin valve magnetoresistive element and magnetically coupled;
A second flux guide , one end of which overlaps the other end of the spin valve magnetoresistive element and is magnetically coupled;
A second electrode terminal provided on the spin valve magnetoresistive element,
The first electrode terminal is smaller in size than the spin valve magnetoresistive element in the film surface of the spin valve magnetoresistive element , and is electrically separated from the first flux guide or the spin valve magnetoresistive element Electrically connected only through, and
The first electrode terminal is electrically connected to the second flux guide electrically only through the spin valve magnetoresistive element or separated from the second flux guide; and
The second electrode terminal is smaller in size than the spin valve magnetoresistive element in the film surface of the spin valve magnetoresistive element , and is electrically separated from the first flux guide or the spin valve magnetoresistive element Electrically connected only through, and
The magnetoresistive head, wherein the second electrode terminal is electrically connected to the second flux guide only electrically or through the spin valve magnetoresistive element. A spin valve magnetoresistive head that reproduces information recorded on a recording medium by passing an electric current in a direction perpendicular to the film surface,
A first magnetic shield;
An insulating layer provided on the first magnetic shield;
A spin-valve magnetoresistive element provided on the insulating layer and retreating from the medium facing surface of the head, which converts a change in signal magnetic field leaking from the recording medium into a resistance change;
A first flux guide having one end exposed on the medium facing surface of the head and the other end overlapping with one end of the surface of the spin valve magnetoresistive element and magnetically coupled;
A second flux guide having one end disposed in electrical and magnetic contact with the other end in the plane of the spin valve magnetoresistive element;
An electrode terminal provided on the opposite side of the spin valve magnetoresistive element from the second flux guide and having a size smaller than the spin valve magnetoresistive element in the film surface of the spin valve magnetoresistive element ;
A second magnetic shield disposed on the electrode terminal;
A flux path for electrically and magnetically connecting the second flux guide and the first magnetic shield;
The electrode terminal is electrically connected to the first flux guide only electrically or through the spin valve magnetoresistive element; and
The magnetoresistive head according to claim 1, wherein the electrode terminal is electrically connected to the second flux guide only electrically through the spin valve magnetoresistive element. A first magnetic shield disposed below the first electrode terminal;
A second magnetic shield disposed on the second electrode terminal;
The magnetoresistive head according to claim 1, wherein the second flux guide and the first magnetic shield are magnetically coupled via a flux path. A magnetic domain control film disposed on both sides of the spin valve magnetoresistive element;
Magnetic domain control film magnetoresistive head according to any one of constituted claims 1-3 from either the high coercive force film and an antiferromagnetic film.

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