JP2005259346A - Method for manufacturing magnetic head, head suspension assembly, and magnetic disk device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance a stability to a high-temperature environment by reducing variation in resistance value of a magneto-resistive effect element before and after the element is placed in the high-temperature environment even in such a case. <P>SOLUTION: A TMR element 2 includes a tunnel barrier layer 26 made of an oxide layer. A protection film 4a is formed on an end surface of the TMR element 2 on the side of an air bearing. Between the protection film 4a and the end surface of the tunnel barrier layer 26 on the side of the air bearing, a layer 4c is formed of metal or oxide of a semiconductor in contact with the end surface of the tunnel barrier layer 26. The formation of the layer 4c includes a 1st stage of forming a film of the metal or semiconductor and a 2nd stage of oxidizing the metal or semiconductor of the film formed in the 1st stage. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method of manufacturing a magnetic head, a head suspension assembly, and a magnetic disk device.

  As the capacity of a hard disk drive (HDD) is reduced, a head with high sensitivity and high output is required. In response to this demand, the hard magneto-resistive head (GMR head), which is the current product, is undergoing hard improvement in characteristics, while the tunnel magnetoresistive head is expected to have a resistance change rate more than twice that of the GMR head. (TMR head) is also being developed vigorously.

  GMR heads and TMR heads generally have different head structures due to differences in the direction in which a sense current flows. In general, a CIP (Current In Plane) structure is a head structure that allows a sense current to flow parallel to the film surface, such as a GMR head, and a CPP (Current In Plane) head structure that allows a sense current to flow perpendicularly to the film surface, such as a TMR head. Perpendicular to Plane) structure. Since the CPP structure can use the magnetic shield itself as an electrode, the magnetic shield-element short circuit (insulation failure), which is a serious problem in narrowing the read gap of the CIP structure, does not occur essentially. Therefore, the CPP structure is very advantageous in increasing the recording density.

  As a head having a CPP structure, in addition to a TMR head, for example, a CPP-GMR head having a CPP structure while using a spin valve film (including a specular type and a dual spin valve type magnetic multilayer film) as a magnetoresistive effect element. Is also known (Patent Document 6).

Some magnetic heads include a magnetoresistive effect element having a magnetoresistive effect layer including an oxide layer. For example, in the TMR head, an oxide layer such as Al ₂ O ₃ is used as a tunnel barrier layer constituting a part of the magnetoresistive effect layer (Patent Documents 1 and 6). In the CPP-GMR head, a thin insulating layer is used as a current path control layer having a metal region partially in an insulating region formed between two layers in order to effectively reduce the area of a sense current path. In some cases, such an oxide layer is included (Patent Document 6).

  By the way, in the magnetic head, the end face of the magnetoresistive effect element appears on the side facing the magnetic recording medium (that is, the air bearing surface (hereinafter referred to as “ABS”) side). It is necessary to prevent corrosion of the end face of the metal layer that constitutes. Also, it is necessary to improve the slidability of the ABS in order to make it difficult to cause head crashes and damage to the magnetic recording medium. In particular, in a magnetic disk apparatus that employs a CSS (contact start / stop) system, the ABS of the magnetic head contacts the disk surface at the start and end of driving, so the ABS has high slidability (low friction). It is requested to have. Therefore, conventionally, in order to improve the above-described corrosion resistance and slidability, a protective film is formed on the ABS, and the end face on the ABS side of the magnetoresistive effect element is covered with this protective film. As this protective film, a DLC (Diamond-Like-Carbon) film is generally used (Patent Documents 1 to 6).

Patent Documents 1 and 2 disclose that a silicon film or a silicon oxide film is used as a base layer of a DLC film as a protective film so as to act as an adhesive layer. Patent Documents 3 and 4 disclose that a silicon film is used to act as an adhesive layer as a base layer of a DLC film as a protective film. Patent Document 5 discloses hard carbon or silicon, boron, titanium, aluminum, and their carbides as a base layer of a DLC film as a protective film (referred to as “intermediate layer” in Patent Document 5). It is disclosed that a layer composed of at least one selected from nitrides and oxides is used. Further, Patent Document 5 discloses that a sputtering method is used to form an underlayer of a DLC film. The sputtering target and sputtering gas are as follows: (i) a simple substance to be formed, a plate of the compound itself, and argon. And (ii) when the underlying layer to be formed is carbide, nitride, or oxide, there are a single plate and a method using hydrocarbon gas, ammonia gas, and oxygen gas, respectively. It is disclosed that this method may be used.
JP 2003-27258 A JP-A-8-297813 JP-A-9-231539 JP-A-9-128708 Japanese Patent Application Laid-Open No. 7-6340 JP 2003-60262 A

  As a result of the inventor's research, in a magnetic head having a magnetoresistive effect element having a magnetoresistive effect layer including an oxide layer, such as a TMR head, for example, silicon as an underlayer of a protective film formed on the ABS When a film was used, it was found that when the magnetic head was placed in a high temperature environment, the resistance value of the magnetoresistive element changed relatively greatly before and after that, and the stability of the characteristics against the high temperature environment was low.

  The present invention has been made in view of such circumstances, and is a magnetic head including a magnetoresistive effect element having a magnetoresistive effect layer including an oxide layer, and even before and after being placed in a high temperature environment. And a method of manufacturing a magnetic head having a small change in the resistance value of the magnetoresistive effect element and high stability in characteristics against a high temperature environment, and a head suspension assembly and a magnetic disk apparatus using such a magnetic head. Objective.

  As a result of further research by the present inventors, in a magnetic head including a magnetoresistive effect element having a magnetoresistive effect layer including an oxide layer, for example, when a silicon film is used as a base layer of a protective film formed on an ABS It has been found that the reason why the resistance value of the magnetoresistive element changes relatively greatly before and after the magnetic head is placed in a high temperature environment is as follows. That is, when the magnetic head is placed in a high temperature environment, oxygen present in the oxide layer constituting a part of the magnetoresistive effect layer moves to the underlayer, and thereby, in the oxide layer. As a result, the resistance value of the oxide layer is decreased, and as a result, the resistance value of the entire magnetoresistive element is decreased, so that the change in the resistance value of the magnetoresistive element is relatively large. It is considered a thing.

  Therefore, the present inventor, in the case where the underlayer of the protective film is a material that is not an oxide, is composed of a metal or semiconductor oxide between the underlayer of the protective film and the oxide layer that constitutes the magnetoresistive effect layer. If the formed layer is interposed so as to be in contact with the oxide layer constituting the magnetoresistive effect layer, it exists in the oxide layer constituting the magnetoresistive effect layer even when the magnetic head is placed in a high temperature environment. It was thought that oxygen would not easily get out of the oxide layer and stay in the oxide layer. This is because a metal or semiconductor oxide is already bonded to oxygen and has few oxygen bonds. Further, the present inventor, as described above, even when the magnetic head is placed in a high temperature environment, oxygen present in the oxide layer constituting the magnetoresistive effect layer remains in the oxide layer. It was considered that the change in the resistance value of the magnetoresistive effect element would decrease without the resistance value of the oxide layer decreasing so much. As will be described later, the present inventors have confirmed this experimentally.

Here, the following first to sixteenth aspects are presented as technical means for solving the above-described problems. The following eleventh aspect corresponds to the invention according to claim 1, and the following twelfth aspect corresponds to the invention according to claim 2.
A magnetic head according to a first aspect includes a base, a magnetoresistive effect element having a magnetoresistive effect layer formed on one surface of the base and including an oxide layer, and the base on the side facing the magnetic recording medium. A protective film formed on at least a part of the surface and the end surface of the magnetoresistive element on the side facing the magnetic recording medium, and an underlayer thereof, and the side on the side facing the magnetic recording medium The end face of the oxide layer forms a part of the end face of the magnetoresistive effect element on the side facing the magnetic recording medium, and is at least between the underlayer and the end face of the magnetoresistive effect element One or more layers are interposed so as to cover the end face of the oxide layer, the underlayer is made of a material that is not an oxide, and the end face of the magnetoresistive effect element is the most of the one or more layers. Side layer is a metal or semiconductor oxidation In those that are configured.

  According to the first aspect, in accordance with the above-described knowledge, even if the magnetoresistive effect element having the magnetoresistive effect layer including the oxide layer is provided, the magnetism is maintained before and after being placed in a high temperature environment. The change in resistance value of the resistance effect element is reduced, and the stability of characteristics against a high temperature environment is increased.

  The magnetic head according to a second aspect is the magnetic head according to the first aspect, wherein the magnetoresistive layer includes a tunnel barrier layer, a free layer formed on one surface side of the tunnel barrier layer, and the tunnel barrier layer. A pinned layer formed on the other surface side, and a pinned layer formed on a side of the pinned layer opposite to the tunnel barrier layer, wherein the oxide layer is the tunnel barrier layer. . The second aspect is an example in which the first aspect is applied to a TMR head.

  A magnetic head according to a third aspect is the magnetic head according to the first aspect, wherein an effective region that is effectively involved in magnetic detection in the magnetoresistive effect layer has a current in a direction substantially perpendicular to the film surface in the magnetoresistive effect layer. The magnetoresistive layer is a non-magnetic metal layer, a free layer formed on one surface side of the non-magnetic metal layer, and the other surface side of the non-magnetic metal layer. A pinned layer, a pinned layer formed on the opposite side of the pinned layer from the nonmagnetic metal layer, and an insulating region formed between any two layers over at least a region substantially overlapping the effective region A current path control layer partially having a metal region therein, and the oxide layer is the current path control layer. The third aspect is an example in which the first aspect is applied to a CPP-GMR head.

  A magnetic head according to a fourth aspect is the magnetic head according to any one of the first to third aspects, wherein the protective film is a DLC film. The fourth aspect is an example of a protective film, but in the first to third aspects, the protective film is not necessarily limited to the DLC film.

  The magnetic head according to a fifth aspect is the magnetic head according to any one of the first to fourth aspects, wherein the underlayer is made of Si or SiC. The fifth aspect is an example of the base layer.

  The magnetic head according to a sixth aspect is the magnetic head according to any one of the first to fifth aspects, wherein the oxide is Al, Si, Ti, V, Cr, Mn, Fe, Ni, Co, Cu, Zn, Zr. Nb, Mo, Hf, Ta and W are oxides of a material selected from the group consisting of Nb, Mo, Hf, Ta and W. In the sixth aspect, preferred examples of the oxide material constituting the layer in contact with the end face of the oxide layer constituting a part of the magnetoresistive effect layer are given. The embodiment is not limited to these examples.

  A magnetic head according to a seventh aspect is the magnetic head according to any one of the first to sixth aspects, wherein the magnetoresistive effect layer includes a metal layer laminated adjacent to the oxide layer, and the magnetic recording medium includes: The end face of the metal layer on the opposite side forms part of the end face of the magnetoresistive effect element on the side facing the magnetic recording medium, and the one or more layers form the end face of the metal layer. The layer on the end face side of the magnetoresistive effect element that is formed so as to cover most of the one or more layers is composed of the same element as the element that constitutes the oxide layer. A portion that covers the end surface and a portion that is made of the same metal oxide as the metal that forms the metal layer and covers the end surface of the metal layer are included.

  In the first to sixth aspects, the layer closest to the end face of the magnetoresistive effect element among the one or more layers is not manufactured as in the eighth and ninth aspects described later. In addition, in addition to the layer formed so as to constitute the magnetoresistive effect element, it may be constituted by adding a predetermined material from the outside to this layer. In the first to sixth aspects, the layer closest to the end face of the magnetoresistive effect element among the one or more layers is manufactured at the time of manufacture as in the tenth aspect described later. It may be configured by oxidizing the end of the layer itself formed to configure the magnetoresistive element. The magnetic head according to the seventh aspect is an example of the latter magnetic head.

  A magnetic head manufacturing method according to an eighth aspect is a manufacturing method for manufacturing a magnetic head according to any one of the first to sixth aspects, and is opposed to the magnetic recording medium before forming the protective film. Forming the layer closest to the end face of the magnetoresistive effect element among the one or more layers in a region including the end face of the magnetoresistive effect element on the side, the stage comprising: The method includes a first step of forming a metal or semiconductor film and a second step of oxidizing the metal or semiconductor film formed by the first step.

  The oxidation in the second stage may be natural oxidation placed in the atmosphere or in a controlled oxygen atmosphere, or may be forced oxidation such as plasma oxidation, radical oxidation, ion beam oxidation, exposure to ozone, or the like. This also applies to the eleventh aspect described later.

  According to the eighth aspect, after the metal or semiconductor is deposited on the end face of the magnetoresistive element, the metal or semiconductor is oxidized, so that oxygen is excessively attached to the end face of the magnetoresistive element. Such a situation can be prevented. When excessive oxygen adheres to the end face of the magnetoresistive effect element, when the magnetic head after manufacture is placed in a high temperature environment, the excess oxygen moves into the oxide layer constituting the magnetoresistive effect layer. When the resistance value of the magnetoresistive element increases, the resistance value changes relatively large. According to the eighth aspect, since oxygen can be prevented from excessively adhering to the end face of the magnetoresistive effect element, the resistance value of the magnetoresistive effect element can be reduced even when placed in a high temperature environment during use. Not only can the change in the resistance value due to the decrease be suppressed, but also the change in the resistance value due to the increase in the resistance value of the magnetoresistive effect element can be suppressed.

  A magnetic head manufacturing method according to a ninth aspect is a manufacturing method for manufacturing a magnetic head according to any one of the first to sixth aspects, wherein the magnetic head faces the magnetic recording medium before forming the protective film. Forming the layer closest to the end face of the magnetoresistive effect element among the one or more layers in a region including the end face of the magnetoresistive effect element on the side, the stage comprising: The method includes a step of performing ion beam deposition or sputtering without using oxygen as a process gas using a metal or semiconductor oxide as a target.

  According to the ninth aspect, by performing ion beam deposition or sputtering without using oxygen as a process gas using a metal or semiconductor oxide as a target, the oxide layer constituting the magnetoresistive effect layer is formed. Since the layer in contact with the end face is formed, it is possible to prevent a situation where oxygen is excessively attached to the end face of the magnetoresistive element. Therefore, according to the ninth aspect, similarly to the eighth aspect, even when the device is placed in a high temperature environment during use, it is possible to suppress a change in resistance value due to a decrease in the resistance value of the magnetoresistive element. Not only can this be done, but also a change in resistance value due to an increase in the resistance value of the magnetoresistive effect element can be suppressed. The eighth aspect requires an oxidation step after film formation, whereas the ninth aspect eliminates the need for a special step for oxidation, thereby facilitating manufacturing and reducing costs. Can do.

  When forming a layer in contact with the end face of the magnetoresistive effect element by performing ion beam deposition or sputtering using a metal or semiconductor oxide as a target, the electric current between the metal layers constituting the magnetoresistive effect element is determined. In order to improve the insulating properties of the layer so as to prevent a short circuit from occurring, not only a rare gas such as Ar gas but also oxygen gas is additionally introduced as a process gas to form the layer in an oxygen-rich state. Is common. However, when oxygen gas is also used as the process gas in this way, excessive oxygen adheres to the end face of the magnetoresistive effect element. When the manufactured magnetic head is placed in a high temperature environment, the excess oxygen is magnetized. The resistance value of the magnetoresistive effect element rises by moving into the oxide layer constituting the resistance effect layer, and the resistance value changes relatively greatly. On the other hand, according to the ninth aspect, as described above, such a situation is prevented.

  A magnetic head manufacturing method according to a tenth aspect is a method for manufacturing the magnetic head according to the seventh aspect, wherein the magnetoresistive element on the side facing the magnetic recording medium is formed before the protective film is formed. Forming the layer closest to the end face of the magnetoresistive effect element among the one or more layers in a region including the end face, wherein the stage constitutes the magnetoresistive effect element The step of oxidizing the edge of the layer formed to do so.

  The oxidation of the end of the layer formed to constitute the magnetoresistive effect element may be natural oxidation placed in the atmosphere or in a controlled oxygen atmosphere, or plasma oxidation, radical oxidation, ion beam oxidation, ozone Forced oxidation such as exposure to water may be used. This also applies to a thirteenth aspect described later.

  In the eighth and ninth aspects, apart from the layer formed to constitute the magnetoresistive effect element, a predetermined material is added to the layer from the outside, so that the magnetoresistive effect element is most The layer on the end face side is formed. On the other hand, in the tenth aspect, the layer closest to the end face of the magnetoresistive element is formed by oxidizing the end of the layer itself formed to constitute the magnetoresistive element. To do. Therefore, in the tenth aspect, since a step of adding a predetermined material from the outside is not necessary, manufacturing is further facilitated and costs can be further reduced.

  A magnetic head manufacturing method according to an eleventh aspect includes a base, a magnetoresistive effect element having a magnetoresistive effect layer formed on one surface of the base and including an oxide layer, and the side facing the magnetic recording medium. A protective film formed on at least a part of the surface of the substrate and an end face of the magnetoresistive element on the side facing the magnetic recording medium, and the oxide on the side facing the magnetic recording medium An end face of the layer forms a part of the end face of the magnetoresistive effect element on the side facing the magnetic recording medium, and at least the oxide is provided between the protective film and the end face of the magnetoresistive effect element. A magnetic head in which one or more layers are interposed so as to cover the end face of the layer, and the layer closest to the end face of the magnetoresistive effect element among the one or more layers is made of a metal or semiconductor oxide. A manufacturing method for manufacturing Before forming the protective film, a region of the magnetoresistive effect element that is closest to the magnetoresistive effect element in the region including the end face of the magnetoresistive effect element on the side facing the magnetic recording medium is formed. Forming a layer on the side, the step comprising: a first step of depositing a metal or semiconductor; and a second step of oxidizing the metal or semiconductor deposited by the first step. And.

  A magnetic head manufacturing method according to a twelfth aspect includes a base, a magnetoresistive effect element having a magnetoresistive effect layer formed on one surface of the base and including an oxide layer, and the side facing the magnetic recording medium. A protective film formed on at least a part of the surface of the substrate and an end face of the magnetoresistive element on the side facing the magnetic recording medium, and the oxide on the side facing the magnetic recording medium An end face of the layer forms a part of the end face of the magnetoresistive effect element on the side facing the magnetic recording medium, and at least the oxide is provided between the protective film and the end face of the magnetoresistive effect element. A magnetic head in which one or more layers are interposed so as to cover the end face of the layer, and the layer closest to the end face of the magnetoresistive effect element among the one or more layers is made of a metal or semiconductor oxide. A manufacturing method for manufacturing Before forming the protective film, a region of the magnetoresistive effect element that is closest to the magnetoresistive effect element in the region including the end face of the magnetoresistive effect element on the side facing the magnetic recording medium is formed. Forming the layer on the side, the step comprising performing ion beam deposition or sputtering without using oxygen as a process gas using a metal or semiconductor oxide as a target.

  A magnetic head manufacturing method according to a thirteenth aspect includes a base, and a magnetoresistive effect element having a magnetoresistive effect layer including an oxide layer and a metal layer formed on one side of the base and stacked adjacent to each other. A protective film formed on at least a part of the surface of the base on the side facing the magnetic recording medium and on the end surface of the magnetoresistive effect element on the side facing the magnetic recording medium. End surfaces of the oxide layer and the metal layer facing the recording medium form a part of the end surface of the magnetoresistive effect element facing the magnetic recording medium, and the protective film and the magnetoresistive element One or more layers are interposed between the end face of the effect element so as to cover at least the end face of the oxide layer and the metal layer, and the magnetoresistive effect element is the most of the one or more layers. The layer on the side of the end face is gold Alternatively, the oxide layer is made of a semiconductor oxide, and the layer on the end face side of the magnetoresistive effect element that is closest to the magnetoresistive element is composed of the same element as the element that forms the oxide layer. A manufacturing method for manufacturing a magnetic head, comprising: a portion that covers the end surface of a layer; and a portion that is made of an oxide of the same metal as the metal that forms the metal layer and covers the end surface of the metal layer, Before forming the protective film, in the region including the end face of the magnetoresistive effect element on the side facing the magnetic recording medium, the end face side of the magnetoresistive effect element closest to the one or more layers. Forming the layer, wherein the step includes oxidizing the end of the layer formed to form the magnetoresistive element.

  The manufacturing methods according to the eleventh to thirteenth aspects are basically the same as the manufacturing methods according to the eighth to tenth aspects, respectively. However, the magnetic head manufactured according to the eighth to tenth aspects includes: The magnetic head manufactured according to the eleventh to thirteenth aspects includes a layer in contact with the end face of the magnetoresistive effect element, whereas the underlayer of the protective film is included in addition to the layer in contact with the end face of the magnetoresistive effect element. In addition to this, a base layer of the protective film may be included, or the layer itself in contact with the end face of the magnetoresistive effect element may be the base layer of the protective film.

  Even if the layer itself in contact with the end face of the magnetoresistive effect element is the underlayer of the protective film, this layer is made of a metal or a semiconductor oxide. Similarly to the above, even if the magnetoresistive element is placed in a high temperature environment at the time of use, it is possible to suppress a change in the resistance value due to a decrease in the resistance value of the magnetoresistive element. Therefore, for example, in a magnetic head in which the underlayer of the protective film is formed so as to be in contact with the end face of the magnetoresistive effect element and the underlayer is formed of a silicon oxide film as disclosed in Patent Document 1, in the first place, Even when placed in a high-temperature environment during use, changes in the resistance value due to a decrease in the resistance value of the magnetoresistive effect element are suppressed.

  However, even in such a magnetic head, if a manufacturing method in which oxygen is excessively attached to the end face of the magnetoresistive element during the manufacturing process is employed, the manufactured magnetic head is placed in a high temperature environment. Then, the excessive oxygen moves into the oxide layer constituting the magnetoresistive effect layer, and as a result, the resistance value of the magnetoresistive effect element increases, so that the resistance value changes relatively greatly.

  On the other hand, according to the eleventh to thirteenth aspects, basically the same manufacturing methods as those of the eighth to tenth aspects are adopted, so that oxygen is excessively applied to the end face of the magnetoresistive element. Can be prevented, and even if the manufactured magnetic head is placed in a high temperature environment, not only can the change in resistance value due to a decrease in the resistance value of the magnetoresistive effect element be suppressed, A change in the resistance value due to an increase in the resistance value of the magnetoresistive element can also be suppressed.

  According to a fourteenth aspect of the present invention, there is provided a magnetic head manufacturing method according to any one of the eighth to thirteenth aspects, comprising the step of performing a heat treatment on the member on which the protective film is formed after the formation of the protective film. . This heat treatment is preferably performed at a temperature equal to or higher than the upper limit of the actual use environment of the magnetic head.

  In the fourteenth aspect, since the heat treatment is positively performed in advance, oxygen entry / exit to the oxide layer constituting the magnetoresistive element is further suppressed during actual use, for example, in the temperature range of actual use, and the magnetic field is reduced. The change in the resistance value of the resistive element is reduced.

  A head suspension assembly according to a fifteenth aspect includes a magnetic head, and a suspension that supports the magnetic head, the magnetic head being mounted in the vicinity of a tip portion, wherein the magnetic head is one of the first to seventh aspects. The magnetic head according to the aspect or the magnetic head manufactured by the manufacturing method according to any one of the eleventh to fourteenth aspects.

  The head suspension assembly according to the fifteenth aspect is the magnetic head according to any one of the first to seventh aspects, or the magnetic head manufactured by the manufacturing method according to any one of the eleventh to fourteenth aspects. Since it is used, it is possible to obtain a magnetic disk device or the like having high stability in characteristics against a high temperature environment.

  A magnetic disk apparatus according to a sixteenth aspect includes the head suspension assembly according to the fifteenth aspect, an arm portion that supports the assembly, and an actuator that moves the arm portion to position the magnetic head. It is.

  According to the sixteenth aspect, since the head suspension assembly according to the fifteenth aspect is used, stability of characteristics against a high temperature environment is improved.

  As described above, according to the present invention, a magnetoresistive effect including a magnetoresistive element having a magnetoresistive effect layer including an oxide layer can be obtained before and after being placed in a high temperature environment. It is possible to provide a method of manufacturing a magnetic head with little change in the resistance value of the element and high stability in characteristics against a high temperature environment, and a head suspension assembly and a magnetic disk apparatus using such a magnetic head.

  A magnetic head manufacturing method, a head suspension assembly, and a magnetic disk apparatus according to the present invention will be described below with reference to the drawings.

  [First magnetic head]

  FIG. 1 is a schematic perspective view schematically showing the first magnetic head. FIG. 2 is an enlarged cross-sectional view schematically showing portions of the TMR element 2 and the inductive magnetic transducer 3 of the magnetic head shown in FIG. FIG. 3 is a schematic view taken along the line A-A ′ in FIG. 2. FIG. 4 is an enlarged view in which the vicinity of the TMR element 2 in FIG. 2 is further enlarged. FIG. 5 is an enlarged view in which the vicinity of the TMR element 2 in FIG. 3 is further enlarged. In order to facilitate understanding, an X axis, a Y axis, and a Z axis that are orthogonal to each other are defined as shown in FIGS. 1 to 5 (the same applies to the drawings described later). The direction of the arrow in the Z-axis direction is called the + Z direction or + Z side, and the opposite direction is called the -Z direction or -Z side, and the same applies to the X-axis direction and the Y-axis direction. The X axis direction coincides with the moving direction of the magnetic recording medium. The Z-axis direction coincides with the track width direction of the TMR element 2.

  As shown in FIG. 1, the first magnetic head includes a slider 1 as a base, a TMR element 2 as a magnetoresistive effect element used as a reproducing magnetic head element, and an induction type magnetic as a recording magnetic head element. A conversion element 3 and a protective film 4a are provided and configured as a composite magnetic head. However, for example, only the TMR element 2 may be provided. In the first magnetic head, one element 2 and one element 3 are provided, but the number is not limited at all.

  The slider 1 has rail portions 11 and 12 on the surface facing the magnetic recording medium, and the surfaces of the rail portions 11 and 12 constitute an ABS (air bearing surface). In the example illustrated in FIG. 1, the number of rail portions 11 and 12 is two, but is not limited thereto. For example, it may have 1 to 3 rail portions, and the ABS may be a flat surface having no rail portions. In addition, various geometric shapes may be attached to the ABS to improve the flying characteristics. The magnetic head manufactured by the manufacturing method according to the present invention may have any type of slider.

  In the first magnetic head, the protective film 4a is provided only on the surfaces of the rail portions 11 and 12, and the surface of the protective film 4a constitutes ABS. However, the protective film 4a may be provided on the entire surface of the slider 1 facing the magnetic recording medium. The protective film 4a will be described later in detail.

  As shown in FIG. 1, the TMR element 2 and the inductive magnetic conversion element 3 are provided on the air outflow end portion TR side of the rail portions 11 and 12. The recording medium moving direction coincides with the X-axis direction in the figure, and coincides with the outflow direction of air that moves when the magnetic recording medium moves at high speed. Air enters from the inflow end LE and flows out from the outflow end TR. Bonding pads 5 a and 5 b connected to the TMR element 2 and bonding pads 5 c and 5 d connected to the inductive magnetic transducer 3 are provided on the end face of the air outflow end TR of the slider 1.

As shown in FIGS. 2 and 3, the TMR element 2 and the inductive magnetic conversion element 3 are stacked on a base layer 16 provided on a ceramic base 15 constituting the slider 1. The ceramic substrate 15 is usually made of AlTiC (Al ₂ O ₃ —TiC) or SiC. When Al ₂ O ₃ —TiC is used, it has conductivity, so that an insulating film made of, for example, Al ₂ O ₃ is used as the underlayer 16. The underlayer 16 may not be provided depending on circumstances.

  As shown in FIGS. 4 and 5, the TMR element 2 includes a lower electrode 21 formed on the base layer 16, an upper electrode 31 formed on the upper side of the lower electrode 21 (on the side opposite to the base 15), an electrode The lower metal layer 22, the pinned layer 24, the pinned layer 25, the tunnel barrier layer 26, the free layer 27, and the upper metal layer (cap layer) 28 serving as a protective film, which are laminated in order from the lower electrode 21 side, And an upper metal layer 29 as a base layer of the upper electrode 31. The pinned layer 24, the pinned layer 25, the tunnel barrier layer 26, and the free layer 27 constitute a magnetoresistive effect layer. The actual TMR element 2 generally has a multi-layered film structure instead of the film structure of the number of layers as shown in the figure. However, in the magnetic head shown in FIG. The minimum film structure necessary for the basic operation of the element 2 is shown.

  In the first magnetic head, the lower electrode 21 and the upper electrode 31 are also used as a lower magnetic shield and an upper magnetic shield, respectively. The electrodes 21 and 31 are made of a magnetic material such as NiFe, for example. Although not shown in the drawing, these electrodes 21 and 31 are electrically connected to the bonding pads 5a and 5b, respectively. Needless to say, a lower magnetic shield and an upper magnetic shield may be provided separately from the lower electrode 21 and the upper electrode 31.

  The lower metal layer 22 is a conductor, and is composed of, for example, a two-layer film including a lower Ta layer and an upper NiFe layer. In this example, the lower metal layer 22 extends widely on the electrode 21, but may be formed only on the magnetoresistive layer.

The pinned layer 24 is composed of an antiferromagnetic layer, and is preferably formed of a Mn-based alloy such as PtMn, IrMn, RuRhMn, FeMn, NiMn, PdPtMn, RhMn, or CrMnPt. The pinned layer 25 and the free layer 27 are each composed of a ferromagnetic layer, and are formed of a material such as Fe, Co, Ni, FeCo, NiFe, or FeCoNi, for example. The magnetization direction of the pinned layer 25 is fixed in a predetermined direction by an exchange coupling bias magnetic field with the pinned layer 24. On the other hand, in the free layer 27, the direction of magnetization freely changes in response to an external magnetic field that is basically magnetic information. The pinned layer 25 and the free layer 27 are not limited to a single layer. For example, a combination of a pair of magnetic layers having antiferromagnetic coupling and a nonmagnetic metal layer sandwiched therebetween. You may use the laminated body which consists of. An example of such a laminate is a ferromagnetic layer made of a three-layered CoFe / Ru / CoFe. In the first magnetic head, the pinned layer 24, the pinned layer 25, the tunnel barrier layer 26, and the free layer 27 are arranged in this order from the lower electrode 21 side, but the free layer 27 and the tunnel barrier layer are arranged from the lower electrode 21 side. 26, the pinned layer 25, and the pinned layer 24 may be disposed in this order, and the upper metal layer 28 may be formed in contact with the pinned layer 24. The tunnel barrier layer 26 is formed of an oxide such as Al ₂ O ₃ , NiO, GdO, MgO, Ta ₂ O ₅ , MoO ₂ , TiO _2, or WO _2, and constitutes an oxide layer.

  For example, the upper metal layer 28 may be a single layer film or a composite layer using a single substance of Ta, Rh, Ru, Os, W, Pd, Pt, or Au, or an alloy made of a combination of any two or more of these. It is formed of a layer film.

  The upper metal layer 29 serving as a base layer of the upper electrode 31 is a conductor and is formed of a nonmagnetic metal material such as Ta. In this example, the upper metal layer 29 is provided in order to maintain a magnetic shield gap (gap between the electrodes 21 and 31) at a desired interval. However, it is not always necessary to provide the upper metal layer 29.

As shown in FIGS. 3 and 5, longitudinal bias layers (magnetic domain control layers) 32 for applying a bias magnetic field for magnetic domain control to the free layer 27 are formed on both sides of the magnetoresistive effect layer in the Z-axis direction. ing. The longitudinal bias layer 32 is formed of a hard magnetic material such as Cr / CoPt (cobalt platinum alloy), Cr / CoCrPt (cobalt chromium platinum alloy), TiW / CoPt, TiW / CoCrPt, for example. Alternatively, the longitudinal bias layer 32 may be, for example, a layer in which a soft magnetic layer and an antiferromagnetic layer are stacked and exchange coupling is used. An insulating layer 34 is formed below the vertical bias layer 32. The insulating layer 34 is also interposed between the longitudinal bias layer 32 and the + Z side and −Z side end faces of the layers 24 to 28, so that the layers 24 to 28 are not electrically short-circuited by the longitudinal bias layer 32. Yes. An insulating layer 30 is formed between the lower metal layer 22 and the upper metal layer 29 in a region where the layers 32 and 34 are not formed. The insulating layer 30 covers the end surfaces on the −Y side of the layers 24 to 28. The insulating layers 34 and 30 are made of Al ₂ O ₃ or SiO ₂ . But you may comprise both or any one of the insulating layers 34 and 30 with nitrides, such as AlN.

  It should be noted that the layers 24 to 28 substantially overlap each other, and these overlapping regions are effective regions that are effectively involved in magnetic detection in the magnetoresistive effect layer (in the first magnetic head, in the magnetoresistive effect layer, A region where current flows in a direction substantially perpendicular to the surface).

As shown in FIGS. 2 and 3, the inductive magnetic transducer 3 has a light gap made of the upper electrode 31, the upper magnetic layer 36, the coil layer 37, alumina, etc. that also serves as a lower magnetic layer for the element 3. The layer 38 includes an insulating layer 39 made of a thermosetting photoresist (for example, an organic resin such as a novolak resin), a protective layer 40 made of alumina, or the like. As the material of the upper magnetic layer 36, for example, NiFe, FeN, FeCo, CoFeNi, or the like is used. The tip portions of the upper electrode 31 and the upper magnetic layer 36 that are also used as the lower magnetic layer are a lower pole portion 31a and an upper pole portion 36a that face each other with a light gap layer 38 such as a minute thickness of alumina, Information is written to the magnetic recording medium in the lower pole portion 31a and the upper pole portion 36a. The upper electrode 31 and the upper magnetic layer 36, which are also used as the lower magnetic layer, are connected to each other so as to complete the magnetic circuit at the coupling portion 41 whose yoke portion is opposite to the lower pole portion 31a and the upper pole portion 36a. Are combined. A coil layer 37 is formed inside the insulating layer 39 so as to spiral around the coupling portion 41 of the yoke portion. Both ends of the coil layer 37 are electrically connected to the bonding pads 5c and 5d described above. The number of turns and the number of layers of the coil layer 37 are arbitrary. Further, the structure of the inductive magnetic transducer 3 may be arbitrary. The upper electrode 31 may be divided into two layers with an insulating layer of Al ₂ O ₃ , SiO ₂ or the like sandwiched between the lower magnetic layer of the inductive magnetic transducer 3 and the upper electrode of the TMR element 2. .

  As shown in FIGS. 1 to 4, the protective film 4 a described above is formed on the ABS side end face of each of the layers 16, 21, 22, 24 to 29, 31, 32, 34, 36, and 40 and on the ABS side of the ceramic substrate 15. The surface is formed so as to cover the base layer 4b and the layer 4c. Here, for convenience of explanation, the layer 4c is referred to as a change reduction layer. The underlayer 4b is formed immediately below the protective film 4a, and the change reducing layer 4c is formed of the underlayer 4b and the ABS end face of each of the layers 16, 21, 22, 24 to 29, 31, 32, 34, 36, 40 and the ceramic. It is interposed between and in contact with the ABS side surface of the base body 15. In the first magnetic head, the change reducing layer 4c is formed so as to overlap with the protective film 4a and the underlying layer 4b. However, the present invention is not limited to this. For example, the ABS of the tunnel barrier layer 26 is used. You may form in the area | region which covers only the end surface of the side. One or more layers may be formed between the change reducing layer 4c and the base layer 4b.

  In the first magnetic head, the DLC film is formed as the protective film 4a. However, a film of another material can be used as the protective film 4a. The underlayer 4b is made of a material that is not an oxide, and the change reducing layer 4c is made of a metal or semiconductor oxide. In the first magnetic head, the change reducing layer 4c is made of the same material in any part thereof. Specifically, for example, the base layer 4b is made of Si or SiC, and the change reducing layer 4c is made of Al, Si, Ti, V, Cr, Mn, Fe, Ni, Co, Cu, Zn, Zr, Nb, It is composed of an oxide of a material selected from the group consisting of Mo, Hf, Ta and W.

  Here, the magnetic head of the comparative example compared with the first magnetic head will be described with reference to FIG. FIG. 7 is an enlarged sectional view schematically showing the main part of the magnetic head of this comparative example, and corresponds to FIG. 7, elements that are the same as or correspond to those in FIG. 4 are given the same reference numerals, and redundant descriptions thereof are omitted.

  The magnetic head according to the comparative example shown in FIG. 7 is different from the first magnetic head in that the change reducing layer 4c is not formed and the underlayer 4b is formed of the layers 16, 21, 22, 24 to 29, 31, It is only the point which is in contact with the ABS side end surface of 32, 34, 36, 40 and the ABS side surface of the ceramic substrate 15. In this comparative example, the base layer 4b is made of Si.

  In the magnetic head according to this comparative example, the resistance value of the TMR element 2 after placing the magnetic head in a high temperature environment is relatively large compared to the resistance value of the TMR element 2 before placing in the high temperature environment. On the other hand, in the first magnetic head, the resistance value of the TMR element 2 after the magnetic head is placed in a high temperature environment changes much compared to the resistance value of the TMR element 2 before the magnetic head is placed in a high temperature environment. do not do. These were confirmed by experiments described later.

  The reason is considered as follows. That is, in the magnetic head according to the comparative example, the base layer 4b made of Si having a relatively high ability to bond with oxygen is in contact with the end face on the ABS side of the tunnel barrier layer 26, which is an oxide layer. When placed in a high temperature environment, as shown in FIG. 8, the oxygen present in the tunnel barrier layer 26 moves to the base layer 4b, thereby reducing the oxygen in the tunnel barrier layer 26 and reducing the tunnel barrier. The resistance value of the layer 26 decreases, and as a result, the resistance value of the TMR element 2 as a whole decreases, so that the change in the resistance value of the TMR element 2 is considered to be relatively large. On the other hand, in the first magnetic head, the change reducing layer 4c made of a metal or a semiconductor (that is, an oxide of a metal or a semiconductor) that is already bonded with oxygen is formed on the ABS side end face of the tunnel barrier layer 26. 6, even if the magnetic head is placed in a high temperature environment, as shown in FIG. 6, oxygen existing in the tunnel barrier layer 26 hardly comes out of the tunnel barrier layer 26 and becomes tunnel barrier. It is considered that the resistance value of the tunnel barrier layer 26 does not decrease so much and the change in the resistance value of the TMR element 2 is reduced.

  FIG. 6 is a diagram schematically showing the state of oxygen in the tunnel barrier layer 26 in the high temperature environment of the first magnetic head. FIG. 8 is a diagram schematically showing the state of oxygen in the tunnel barrier layer 26 in the high temperature environment of the magnetic head according to the comparative example shown in FIG.

  [Second Magnetic Head Manufacturing Method]

  A second magnetic head manufacturing method according to an embodiment of the present invention will be described. This magnetic head manufacturing method is a method for manufacturing the first magnetic head.

First, a wafer process is performed. That is, a wafer 101 made of Al ₂ O ₃ —TiC or SiC to be the base 15 is prepared, and the matrix-shaped magnetic head formation regions on the wafer 101 are respectively described above by using a thin film formation technique or the like. Each layer is formed to have the structure described above.

  The outline of the wafer process will be described with reference to FIGS. 9 to 12 are diagrams schematically showing each process constituting the wafer process, and FIGS. 9A, 10A, 11A, and 12A are schematic plan views, respectively. It is. 9B is a schematic cross-sectional view taken along line CD in FIG. 9A, FIG. 10B is a schematic cross-sectional view taken along line CD in FIG. 10A, and FIG. FIG. 12B is a schematic cross-sectional view taken along line EF in FIG. 11A, and FIG. 12B is a schematic cross-sectional view taken along line EF in FIG. In FIG. 10A, TW indicates the track width defined by the TMR element 2.

  In the wafer process, first, the base layer 16, the lower electrode 21, the lower metal layer 22, the pinned layer 24, the pinned layer 25, the tunnel barrier layer 26, the free layer 27, and the cap layer 28 are sequentially stacked on the wafer 101 ( FIG. 9). At this time, the lower electrode 21 is formed by, for example, a plating method, and the other layers are formed by, for example, a sputtering method. Thereafter, the substrate in this state is once placed in the atmosphere. At this time, an oxide film (not shown) is formed on the upper surface of the cap layer 28.

  Next, the pinned layer 24, the pinned layer 25, the tunnel barrier layer 26, the free layer 27, the cap layer 28, and the oxide film on the cap layer 28 are partially removed and patterned by first ion milling. Next, the insulating layer 34 and the longitudinal bias layer 32 are formed in the removed portion by a lift-off method (FIG. 10).

  Next, by the second ion milling, the pinned layer 24, the pinned layer 24, the pinned layer 24, the pinned layer 24, which has a necessary width (width in the Y-axis direction) in the height direction of the TMR element 2 and extends in the Z-axis direction by a predetermined length. The layer 25, the tunnel barrier layer 26, the free layer 27, the cap layer 28, the oxide film (not shown) on the upper surface of the cap layer 28, the insulating layer 34 and the vertical bias layer 32 are partially removed and patterned. Next, an insulating film 30 is formed on the removed portion by a lift-off method (FIG. 11).

  Next, cleaning is performed to remove the oxide film formed on the upper surface of the cap layer 28 by performing dry etching such as sputter etching or ion beam etching in the same vacuum apparatus in which the upper metal layer 29 is formed. .

  Thereafter, the upper metal layer 29 is formed by sputtering or the like, and the upper electrode 31 is further formed by plating or the like (FIG. 12).

  Finally, a write gap layer 38, a coil layer 37, an insulating layer 39, an upper magnetic layer 36, and a protective film 40 are formed, and electrodes 5a to 5d and the like are further formed. Thereby, the wafer process is completed.

  FIG. 13A shows the wafer 101 in which this wafer process is completed. However, in FIG. 13A, elements formed on the wafer 101 are omitted, and only the region R of each magnetic head is shown.

  After the wafer process, the wafer 101 shown in FIG. 13A is cut, and each bar (bar-shaped magnetic head aggregate) 102 in which a plurality of magnetic head portions are arranged in a line is cut out by a diamond cutter or the like. FIG. 13B shows this bar 102. The upper surface of the bar 102 parallel to the XZ plane of FIG. 13B is the ABS side surface, and on this surface, the layers 16, 21, 22, 24-29, 31, 32, 34, 36, 40 are formed. End faces and the like, and electrodes 5a to 5d in FIG. 1 appear on the surface that is parallel to the YZ plane in FIG. 13B and are visible in the foreground. In FIG. Omitted. FIG. 13 is a schematic perspective view schematically showing a cutting process of the bar 102 after the wafer process.

  Next, lapping (mechanical polishing) is performed on the ABS side of the bar 102 shown in FIG. 13B in order to define the height (MR height) of the TMR element 2 and the like. In this process, for example, the bar 102 is set on a fixing jig, pressed against a surface plate, a suspension containing diamond abrasive grains is dropped, and the surface of the ABS is polished by rotating the surface plate.

  FIG. 14 shows the bar 102 after the lapping process. FIG. 14 is a schematic cross-sectional view along a plane parallel to the XY plane, schematically showing the bar 102 after the lapping process. Smear (such as a metal piece generated during polishing) usually occurs on the ABS side surface (left end surface in FIG. 14) of the bar 102 after lapping shown in FIG. However, in FIG. 14, illustration of the smear is omitted.

  Thereafter, in order to remove the smear, the ABS side surface of the bar 102 after lapping is etched. As this etching, for example, dry etching such as sputter etching or ion beam etching is performed. However, when the smear is at a level that does not affect the characteristics of the TMR element 2, the etching is not necessarily required.

  Next, after the bar 102 is once exposed to the atmosphere, the surface oxide layer (the bar 102 is temporarily removed) in the same vacuum apparatus in which the metal or semiconductor layer that should finally become the change reducing layer 4c is formed. Dry etching such as sputter etching or ion beam etching for removing the oxide layer formed on the ABS side surface by cleaning in the atmosphere and cleaning the surface is performed. In the second magnetic head manufacturing method, this etching is performed so as to completely remove the surface oxide layer. However, this etching may be performed so that the surface oxide layer remains without completely removing the surface oxide layer. In this case, like the fourth magnetic head described later, the surface oxide layer is a layer in contact with the end face on the ABS side of the magnetoresistive effect element.

  Next, the metal or semiconductor (for example, Al, Si, Ti, V, Cr, Mn, Fe, Ni, Co, Cu, Zn, Zr, Nb, Mo, Hf, Ta, or W) to be the change reducing layer 4c. A layer is formed on the ABS side surface of the bar 102 by sputtering or the like.

  Thereafter, the bar 102 is placed in the atmosphere, and the metal or semiconductor deposited on the ABS side surface of the bar 102 is oxidized by natural oxidation, thereby forming the change reducing layer 4c made of a metal or semiconductor oxide. (FIG. 15).

  Next, dry etching such as sputter etching for cleaning the surface or ion beam etching is performed in the same vacuum apparatus in which the base layer 4b and the protective film 4c are formed. Next, a base layer 4b made of, for example, Si is formed on the change reducing layer 4c by a sputtering method or the like, and a DLC film as a protective film 4a is formed on the base layer 4b by a plasma CVD method or the like.

  Thereafter, regions other than the rail portions 11 and 12 on the ABS side surface of the bar 102 are selectively etched to form the rail portions 11 and 12. Finally, the bar 102 is separated into individual magnetic heads by cutting by machining. Thereby, the first magnetic head shown in FIGS. 1 to 5 is completed.

  Even in the case of the first magnetic head, if a manufacturing method in which oxygen is excessively adhered to the end surface on the ABS side of the TMR element 2 during the manufacturing process, the manufactured magnetic head is put under a high temperature environment. If it is placed, the excess oxygen moves into the tunnel barrier layer 26, and as a result, the resistance value of the TMR element 2 rises, so that the resistance value changes relatively greatly.

  On the other hand, in the second magnetic head manufacturing method, as described above, after the metal or semiconductor layer to be the change reducing layer 4c is formed on the ABS side end face of the TMR element 2, the metal is formed. Alternatively, since the change reducing layer 4c is formed by oxidizing the semiconductor layer, it is possible to prevent a situation where oxygen is excessively attached to the end surface on the ABS side of the TMR element 2. Therefore, in the magnetic head manufactured by the second magnetic head manufacturing method, not only can the resistance value change due to the decrease in the resistance value of the TMR element 2 be suppressed even when the magnetic head is placed in a high temperature environment during use. Further, a change in resistance value due to an increase in the resistance value of the TMR element 2 can also be suppressed.

  In the present invention, the second magnetic head manufacturing method may be modified as described below. In addition, the modifications described below can be applied to the second magnetic head manufacturing method in any appropriate combination.

  First, the dry etching for removing the smear described above and the dry etching for cleaning the surface before forming the metal or semiconductor layer to be the change reducing layer 4c are performed separately. Alternatively, dry etching that serves as both may be performed.

  Secondly, the dry etching for removing the smear described above and the film formation of the metal or semiconductor layer to be the change reducing layer 4c are performed in the same vacuum apparatus, and they are not once released into the atmosphere between them. Also good.

  Third, dry etching for surface cleaning or the like before forming a metal or semiconductor layer to be the change reducing layer 4c may be omitted.

  Fourth, the oxidation of the metal or semiconductor layer to be the change reducing layer 4c is not limited to natural oxidation. For example, plasma oxidation, radical oxidation, ion beam oxidation, forced oxidation such as exposure to ozone is performed. You may go. Such forced oxidation may be performed in the same vacuum apparatus as the formation of the underlayer 4b, or may be once released to the atmosphere after the forced oxidation and before the formation of the underlayer 4b.

  Fifth, it is not necessary to perform dry etching for surface cleaning or the like before forming the base layer 4b.

  Sixth, after the protective film 4 is formed, heat treatment may be performed at a temperature equal to or higher than the actual use environment upper limit of the magnetic head. If the heat treatment is positively performed in advance in this way, during actual use, in and out of the temperature range of actual use, the entry and exit of oxygen to the tunnel barrier layer 26 is further suppressed, and the change in the resistance value of the TMR element 2 becomes smaller. preferable.

  [Third Magnetic Head Manufacturing Method]

  A third magnetic head manufacturing method according to an embodiment of the present invention will be described. This magnetic head manufacturing method is also a method for manufacturing the first magnetic head.

  The third magnetic head manufacturing method is different from the second magnetic head manufacturing method only in the points described below, and redundant description is omitted.

  The third magnetic head manufacturing method is the same as the second magnetic head manufacturing method until the ABS side surface of the bar 102 after lapping processing is etched in order to remove smear. However, if the smear is at a level that does not affect the characteristics of the TMR element 2, etching for removing the smear is not necessarily required.

  In the third magnetic head manufacturing method, after the bar 102 is once exposed to the atmosphere, sputter etching or ion beam for surface cleaning or the like is performed in the same vacuum apparatus in which the change reducing layer 4c is formed. Dry etching such as etching is performed.

  Then, using a metal or semiconductor (for example, Al, Si, Ti, V, Cr, Mn, Fe, Ni, Co, Cu, Zn, Zr, Nb, Mo, Hf, Ta or W) as a target, By performing ion beam deposition or sputtering without using oxygen as a process gas, the change reducing layer 4c is formed on the ABS side surface of the bar 102.

  Next, after performing dry etching such as sputter etching or ion beam etching for surface cleaning or the like in the same vacuum apparatus in which the change reducing layer 4c is formed, the base layer 4b made of, for example, Si is sputtered. A film is formed on the change reduction layer 4c by a method or the like, and a DLC film as a protective film 4a is formed on the base layer 4b by a plasma CVD method or the like.

  Thereafter, regions other than the rail portions 11 and 12 on the ABS side surface of the bar 102 are selectively etched to form the rail portions 11 and 12. Finally, the bar 102 is separated into individual magnetic heads by cutting by machining. Thereby, the first magnetic head shown in FIGS. 1 to 5 is completed.

  In the third magnetic head manufacturing method, as described above, the change reduction layer 4c is formed by performing ion beam deposition or sputtering without using oxygen as a process gas using a metal or semiconductor oxide as a target. Since the film is formed, it is possible to prevent a situation in which oxygen is excessively attached to the end surface on the ABS side of the TMR element 2. Therefore, in the magnetic head manufactured by the third magnetic head manufacturing method, not only can the resistance value change due to the decrease in the resistance value of the TMR element 2 be suppressed even when placed in a high temperature environment during use. Further, a change in resistance value due to an increase in the resistance value of the TMR element 2 can also be suppressed. Further, in the second magnetic head manufacturing method, in order to form the change reducing layer 4c, a step of oxidizing the layer after forming a metal or semiconductor layer is required, whereas the third magnetic head is formed. Since the manufacturing method does not require a special oxidation step, the manufacturing is facilitated and the cost can be reduced.

  In the present invention, the third magnetic head manufacturing method may be modified as described below. In addition, the modifications described below can be applied to the third magnetic head manufacturing method in any appropriate combination.

  First, the dry etching for removing the smear described above and the dry etching for cleaning the surface before forming the change reducing layer 4c are not performed separately but dry etching that serves as both. May be performed.

  Secondly, the above-described dry etching for removing smear and the formation of the change reducing layer 4c are performed in the same vacuum apparatus, and it is not necessary to leave the air once in the atmosphere.

  Third, dry etching for surface cleaning or the like before forming the change reducing layer 4c need not be performed.

  Fourth, the bar 102 may be once exposed to the atmosphere after the change reducing layer 4c is formed and before the base layer 4b is formed.

  Fifth, it is not necessary to perform dry etching for surface cleaning or the like before forming the base layer 4b.

  Sixth, after the protective film 4a is formed, heat treatment may be performed at a temperature equal to or higher than the upper limit of the actual use environment of the magnetic head. If the heat treatment is positively performed in advance in this way, during actual use, in and out of the temperature range of actual use, the entry and exit of oxygen to the tunnel barrier layer 26 is further suppressed, and the change in the resistance value of the TMR element 2 becomes smaller. preferable.

  [Fourth magnetic head]

  FIG. 16 is an enlarged cross-sectional view schematically showing the main part of the fourth magnetic head of the present invention, and corresponds to FIG. 16, elements that are the same as or correspond to the elements in FIG. 4 are given the same reference numerals, and redundant descriptions thereof are omitted.

  The fourth magnetic head is different from the first magnetic head only in the configuration of the change reducing layer 4c. In the first magnetic head, the change reducing layer 4c is made of the same material in any part thereof, whereas in the fourth magnetic head, the layers 21, 22, 24 to 24 in the change reducing layer 4c are used. Each of the portions 21a, 22a, 24a to 29a, 31a covering the 29, 31 is made of a material determined according to the material of the constituent layer of the TMR element 2 covered by the portion. That is, the portion 26a that covers the ABS side end face of the tunnel barrier layer 26 in the change reducing layer 4c is made of the same element as the element constituting the tunnel barrier layer 26, and is made of a metal or semiconductor oxide. A portion 25 a that covers the ABS-side end face of the pinned layer 25 in the change reducing layer 4 c is made of an oxide of the same metal as that of the pinned layer 25. Similarly, the respective portions 21a, 22a, 24a, 27a to 29a, 31a covering the layers 21, 22, 24, 27-29, 31 in the change reducing layer 4c are constituent layers of the TMR element 2 covered by the portions. It is comprised with the oxide of the same metal as the metal which comprises.

  The fourth magnetic head can provide the same advantages as the first magnetic head.

  [Fifth Magnetic Head Manufacturing Method]

  A fifth magnetic head manufacturing method of the present invention will be described. This magnetic head manufacturing method is a method of manufacturing the fourth magnetic head.

  The fifth magnetic head manufacturing method is different from the second magnetic head manufacturing method only in the points described below, and redundant description is omitted.

  The fifth magnetic head manufacturing method is the same as the second magnetic head manufacturing method until the ABS side surface of the bar 102 after lapping processing is etched to remove smear.

  In the fifth magnetic head manufacturing method, after that, the change reduction layer 4c described for the fourth magnetic head is formed by placing the bar 102 in the atmosphere and oxidizing the ABS side surface of the bar 102 by natural oxidation. , Formed as an ABS side surface oxide layer. By oxidizing the ABS side surface of the bar 102, the ABS side end portions of the respective layers formed to constitute the TMR element 2 are oxidized.

  Next, dry etching such as sputter etching for surface cleaning or ion beam etching is performed in the same vacuum apparatus as that for forming the base layer 4b. In the fifth magnetic head manufacturing method, this etching is performed so that the surface oxide layer (change reduction layer 4c in the fifth magnetic head manufacturing method) remains.

  Next, a base layer 4b made of Si, for example, is formed on the change reducing layer 4c by sputtering or the like, and a DLC film as a protective film 4a is formed on the base layer 4b by plasma CVD or the like.

  Thereafter, regions other than the rail portions 11 and 12 on the ABS side surface of the bar 102 are selectively etched to form the rail portions 11 and 12. Finally, the bar 102 is separated into individual magnetic heads by cutting by machining. Thereby, the fourth magnetic head shown in FIG. 16 is completed.

  In the fifth magnetic head manufacturing method, as described above, since the change reducing layer 4c is formed by oxidizing the ABS side surface of the bar 102, the end surface on the ABS side of the TMR element 2 undergoes surface oxidation. Therefore, oxygen in the oxide layer (tunnel barrier layer 26) of the TMR element 2 becomes difficult to move to the base layer 4b, and excessive oxygen adheres to the end face on the ABS side of the TMR element 2. Can be prevented. Therefore, in the magnetic head manufactured by the fifth magnetic head manufacturing method, not only can the resistance value change due to the decrease in the resistance value of the TMR element 2 be suppressed even when placed in a high temperature environment during use. Further, a change in resistance value due to an increase in the resistance value of the TMR element 2 can also be suppressed. Further, in the second and third magnetic head manufacturing methods, in order to form the change reducing layer 4c, a step of adding a predetermined material from the outside to the layer formed to constitute the TMR element 2 is required. On the other hand, since the fifth magnetic head manufacturing method does not require such a process, the manufacturing is facilitated and the cost can be reduced.

  In the present invention, the fifth magnetic head manufacturing method may be modified as described below. In addition, the modifications described below can be applied to the fifth magnetic head manufacturing method in any appropriate combination.

  First, the above-described dry etching for removing smear is not necessarily performed.

  Second, the oxidation of the ABS side surface of the bar 102 for forming the change reducing layer 4c is not limited to natural oxidation. For example, plasma oxidation, radical oxidation, ion beam oxidation, exposure to ozone, etc. You may perform the forced oxidation of. Such forced oxidation may be performed in the same vacuum apparatus as the formation of the underlayer 4b, or may be once released to the atmosphere after the forced oxidation and before the formation of the underlayer 4b.

  Third, dry etching for surface cleaning or the like before forming the base layer 4b need not be performed.

  Fourth, after the protective film 4a is formed, heat treatment may be performed at a temperature that is equal to or higher than the upper limit of the actual use environment of the magnetic head. If the heat treatment is positively performed in advance in this way, during actual use, in and out of the temperature range of actual use, the entry and exit of oxygen to the tunnel barrier layer 26 is further suppressed, and the change in the resistance value of the TMR element 2 becomes smaller. preferable.

  Fifth, the protective film 4a may be formed directly on the change reducing layer 4c without forming the base layer 4b.

  [Sixth Magnetic Head Manufacturing Method]

  A sixth magnetic head manufacturing method according to an embodiment of the present invention will be described. This magnetic head manufacturing method is a method of manufacturing a magnetic head obtained by modifying the magnetic head according to the comparative example shown in FIG.

The magnetic head manufactured by the sixth magnetic head manufacturing method is different from the magnetic head according to the comparative example shown in FIG. 7 in that the base layer 4b is a metal or semiconductor oxide (for example, SiO ₂ , Al ₂ O _3, etc.). ) Only. Therefore, in this magnetic head, the underlayer 4b is made of a metal or semiconductor oxide, like the change reducing layer 4c in the first magnetic head, and the underlayer 4b has the same function as the change reducing layer 4c. Fulfill. Therefore, in this magnetic head, as in the first magnetic head, even if the magnetic head is placed in a high temperature environment, as shown in FIG. It becomes difficult to go out of the layer 26 and stay in the tunnel barrier layer 26, and the resistance value of the tunnel barrier layer 26 does not decrease so much and the change in the resistance value of the TMR element 2 is reduced.

  However, even with such a magnetic head, if a manufacturing method in which oxygen adheres excessively to the end surface on the ABS side of the TMR element 2 during the manufacturing process, the manufactured magnetic head is placed under a high temperature environment. When this is placed, the excess oxygen moves into the tunnel barrier layer 26, and as a result, the resistance value of the TMR element 2 increases, so that the resistance value changes relatively greatly.

  In the sixth magnetic head manufacturing method, the second magnetic head manufacturing method is modified as follows.

  That is, the sixth magnetic head manufacturing method is the same as the second magnetic head manufacturing method until the ABS side surface of the bar 102 after the lapping process is etched in order to remove smear. However, if the smear is at a level that does not affect the characteristics of the TMR element 2, etching for removing the smear is not necessarily required.

  Next, after the bar 102 is once exposed to the atmosphere, sputter etching for surface cleaning or the like is performed in the same vacuum apparatus in which a metal or semiconductor layer to be finally formed as the base layer 4b is formed. Dry etching such as ion beam etching is performed.

  Next, a metal or semiconductor (eg, Al, Si, etc.) layer to be the base layer 4b is formed on the ABS side surface of the bar 102 by sputtering or the like.

  Thereafter, the bar 102 is placed in the atmosphere, and the metal or semiconductor deposited on the ABS side surface of the bar 102 is oxidized by natural oxidation, thereby forming the base layer 4b made of a metal or semiconductor oxide. Next, a DLC film as a protective film 4a is formed on the base layer 4b by a plasma CVD method or the like.

  Thereafter, regions other than the rail portions 11 and 12 on the ABS side surface of the bar 102 are selectively etched to form the rail portions 11 and 12. Finally, the bar 102 is separated into individual magnetic heads by cutting by machining. Thereby, the magnetic head described above is completed.

  In the sixth magnetic head manufacturing method, as described above, after the metal or semiconductor layer to be the underlayer 4b is formed on the end surface on the ABS side of the TMR element 2, the metal or semiconductor layer is formed. Since the base layer 4b is formed by oxidizing, it is possible to prevent a situation in which oxygen is excessively attached to the end surface of the TMR element 2 on the ABS side. Therefore, in the magnetic head manufactured by the sixth magnetic head manufacturing method, not only can the resistance value change due to the decrease in the resistance value of the TMR element 2 be suppressed even when the magnetic head is placed in a high temperature environment during use. Further, a change in resistance value due to an increase in the resistance value of the TMR element 2 can also be suppressed.

  In the present invention, the sixth magnetic head manufacturing method may be modified as described below. In addition, the modifications described below can be applied to the sixth magnetic head manufacturing method in any appropriate combination.

  First, the dry etching for removing the smear described above and the dry etching for cleaning the surface before forming the metal or semiconductor layer to be the base layer 4b are not performed separately. Alternatively, dry etching that serves as both may be performed.

  Secondly, the above-described dry etching for removing smear and film formation of a metal or semiconductor layer to be the underlayer 4b are performed in the same vacuum apparatus, and it is not necessary to release them into the atmosphere once between them. Good.

  Third, dry etching for surface cleaning or the like before forming a metal or semiconductor layer to be the base layer 4b may not be performed.

  Fourth, the oxidation of the metal or semiconductor layer to be the base layer 4b is not limited to natural oxidation, but for example, plasma oxidation, radical oxidation, ion beam oxidation, forced oxidation such as exposure to ozone is performed. May be. Such forced oxidation may be performed in the same vacuum apparatus as the formation of the protective film 4a, or may be once released to the atmosphere after the forced oxidation and before the formation of the protective film 4a.

  Fifth, after the protective film 4a is formed, heat treatment may be performed at a temperature that is equal to or higher than the upper limit of the actual use environment of the magnetic head. If the heat treatment is positively performed in advance in this way, during actual use, in and out of the temperature range of actual use, the entry and exit of oxygen to the tunnel barrier layer 26 is further suppressed, and the change in the resistance value of the TMR element 2 becomes smaller. preferable.

  [Seventh Magnetic Head Manufacturing Method]

  A seventh magnetic head manufacturing method according to an embodiment of the present invention will be described. This magnetic head manufacturing method is a manufacturing method for manufacturing the same magnetic head as the magnetic head manufactured by the sixth magnetic head manufacturing method.

  In the seventh magnetic head manufacturing method, the third magnetic head manufacturing method is modified as follows.

  That is, the seventh magnetic head manufacturing method is the same as the second magnetic head manufacturing method until the ABS side surface of the bar 102 after lapping processing is etched in order to remove smear. However, if the smear is at a level that does not affect the characteristics of the TMR element 2, etching for removing the smear is not necessarily required.

  In the seventh magnetic head manufacturing method, after the bar 102 is once exposed to the atmosphere, sputter etching or ion beam etching for surface cleaning or the like is performed in the same vacuum apparatus in which the underlayer 4b is formed. Perform dry etching.

  Next, by using an oxide of metal or semiconductor (for example, Al, Si, etc.) as a target and performing ion beam deposition or sputtering without using oxygen as a process gas, an underlayer is formed on the ABS side surface of the bar 102. 4b is formed. Next, a DLC film as a protective film 4a is formed on the base layer 4b by a plasma CVD method or the like.

  Thereafter, regions other than the rail portions 11 and 12 on the ABS side surface of the bar 102 are selectively etched to form the rail portions 11 and 12. Finally, the bar 102 is separated into individual magnetic heads by cutting by machining. Thereby, the magnetic head described above is completed.

  In the seventh magnetic head manufacturing method, as described above, the base layer 4b is formed by performing ion beam deposition or sputtering without using oxygen as a process gas using a metal or semiconductor oxide as a target. Since the film is formed, it is possible to prevent a situation in which oxygen is excessively attached to the end surface on the ABS side of the TMR element 2. Therefore, the magnetic head manufactured by the seventh magnetic head manufacturing method not only can suppress a change in resistance value due to a decrease in the resistance value of the TMR element 2 even if it is placed in a high temperature environment during use. Further, a change in resistance value due to an increase in the resistance value of the TMR element 2 can be suppressed. In the sixth magnetic head manufacturing method, in order to form the underlayer 4b, a step of oxidizing this layer after forming a metal or semiconductor layer is required, whereas the seventh magnetic head manufacturing method is used. Since the method does not require a special oxidation step, manufacturing is facilitated and costs can be reduced.

  In the present invention, the seventh magnetic head manufacturing method may be modified as described below. In addition, each modification described below can be applied to the seventh magnetic head manufacturing method in any appropriate combination.

  First, the dry etching for removing the smear and the dry etching for cleaning the surface before forming the base layer 4b are not performed separately, but dry etching that serves as both is performed. You may go.

  Secondly, the above-described dry etching for removing smear and film formation of the underlayer 4b are performed in the same vacuum apparatus, and it is not necessary to leave the air once in the atmosphere.

  Third, dry etching for surface cleaning or the like before forming the base layer 4b need not be performed.

  Fourth, the bar 102 may be once exposed to the atmosphere after the base layer 4b is formed and before the protective film 4a is formed.

  Fifth, after the protective film 4a is formed, heat treatment may be performed at a temperature that is equal to or higher than the upper limit of the actual use environment of the magnetic head. If the heat treatment is positively performed in advance in this way, during actual use, in and out of the temperature range of actual use, the entry and exit of oxygen to the tunnel barrier layer 26 is further suppressed, and the change in the resistance value of the TMR element 2 becomes smaller. preferable.

  [Eighth magnetic head]

  FIG. 17 is an enlarged cross-sectional view schematically showing portions of the GMR element 50 and the inductive magnetic transducer 3 of the eighth magnetic head. 18 is a schematic view taken along arrow B-B ′ in FIG. 17. FIG. 19 is an enlarged view in which the vicinity of the GMR element 50 in FIG. 18 is further enlarged. FIGS. 17 to 19 correspond to FIGS. 2, 3, and 5, respectively. 17 to 19, the same or corresponding elements as those in FIGS. 1 to 5 are denoted by the same reference numerals, and redundant description thereof is omitted.

  The eighth magnetic head is basically configured as a CPP-GMR head in which the magnetoresistive effect layer includes the current path control layer 53, as in the magnetic head disclosed in Patent Document 6, while the first magnetic head Similarly, the change reducing layer 4c is employed.

  The eighth magnetic head is different from the first magnetic head only in the points described below.

  In the eighth magnetic head, a GMR element 50 is formed in place of the TMR element 2 as shown in FIGS. The GMR element 50 is different from the TMR element 2 in that nonmagnetic metal layers 51 and 52 are formed in place of the tunnel barrier layer 26 and current path control is performed between the nonmagnetic metal layer 51 and the nonmagnetic metal layer 52. A layer 53 is formed. The pinned layer 24, the pinned layer 25, the nonmagnetic metal layer 51, the current path control layer 53, the nonmagnetic metal layer 52, and the free layer 27 formed in this order from the bottom are formed into a magnetoresistive effect layer (in the eighth magnetic head, So-called spin valve film). The nonmagnetic metal layers 51 and 52 are formed of a material such as Cu, Au, or Ag, for example.

  In the eighth magnetic head, the pinned layer 25, the nonmagnetic metal layers 51 and 52, the current path control layer 53, the free layer 27, and the cap layer 28 substantially overlap each other. This is an effective region that effectively participates in magnetic detection in the effect layer (in the eighth magnetic head, a region in which a current flows in a direction substantially perpendicular to the film surface in the magnetoresistive effect layer). In the eighth magnetic head, unlike the first magnetic head, the pinned layer 24 extends widely other than the region overlapping the effective region, as shown in FIGS. The lower surface of the pinned layer 24 is in electrical contact with the upper surface of the electrode 21 through the lower metal layers 22 and 23 throughout. Note that the pinned layer 24 may have the same width as the free layer 27.

  In the eighth magnetic head, the current path control layer 53 is a layer partially having a metal region in an insulating region made of an oxide such as Ta, Al, Co, Fe, Ni, etc. It has become. The thickness of the current path control layer 53 can be set to 2 nm or less, for example. Since the metal region is partially formed in the insulating region, the current path control layer 53 effectively reduces the area of the path of the sense current flowing between the upper metal layer 27 and the free layer 26, and The same effect as that obtained by reducing the area of the effective region can be obtained without actually reducing the area of the effective region. The current path control layer 53 may be formed at any one or more of the layers 24 and 25, the layers 25 and 51, the layers 52 and 27, and the layers 27 and 28, for example. Good. For example, when any of the layers 24, 25, and 27 is a laminate of a plurality of layers (a plurality of constituent layers), the current path control layer 53 includes two layers among the plurality of constituent layers. You may form in.

  In the first magnetic head, the upper metal layer 29 is formed as a base layer of the upper electrode 31, but in the eighth magnetic head, the upper metal layer 29 is not formed.

  The eighth magnetic head can be manufactured by the same manufacturing method as the second or third magnetic head manufacturing method.

  In the eighth magnetic head, similarly to the first magnetic head, the change reducing layer 4c made of a metal or semiconductor oxide is in contact with the end face on the ABS side of the current path control layer 53 made of an oxide layer. Therefore, even if the magnetic head is placed in a high temperature environment, oxygen existing in the current path control layer 53 is difficult to get out of the current path control layer 53 and stays in the current path control layer 53. Thus, the resistance value of the current path control layer 53 does not decrease so much, and the change in the resistance value of the GMR element 50 is reduced, and the stability of the characteristics against the high temperature environment is increased.

  A modification similar to that obtained by deforming the first magnetic head to obtain the fourth magnetic head may be applied to the eighth magnetic head. This magnetic head can be manufactured by the same manufacturing method as the fifth magnetic head manufacturing method.

  [Ninth magnetic disk unit]

  FIG. 20 is a schematic perspective view showing the configuration of the main part of the ninth magnetic disk device.

  The ninth magnetic disk device includes a magnetic disk 71 rotatably provided around a shaft 70, a magnetic head 72 that records and reproduces information on the magnetic disk 71, and a magnetic head 72 that is connected to the magnetic disk 71. An assembly carriage device 73 for positioning on the track.

  The assembly carriage device 73 is mainly composed of a carriage 75 that can be rotated about a shaft 74 and an actuator 76 that is, for example, a voice coil motor (VCM) that drives the carriage 75 to rotate.

  A base portion of a plurality of drive arms 77 stacked in the direction of the shaft 74 is attached to the carriage 75, and a head suspension assembly 78 on which a magnetic head 72 is mounted is fixed to the distal end portion of each drive arm 77. Yes. Each head suspension assembly 78 is provided at the tip of the drive arm 77 so that the magnetic head 72 at the tip of the head suspension assembly 78 faces the surface of each magnetic disk 71.

  In the ninth magnetic disk device, as the magnetic head 72, the first, fourth, or eighth magnetic head described above, or the second, third, fifth, sixth, or seventh magnetic head manufacturing method is used. The manufactured magnetic head is mounted. Therefore, according to the ninth magnetic disk device, the stability of the characteristics with respect to the environmental temperature is enhanced.

  A magnetic head of Sample 14 was manufactured in the same process as the second and third magnetic head manufacturing methods described above except that the change reducing layer 4c was not formed. The sample 14 does not have the change reducing layer 4c and corresponds to the magnetic head according to the comparative example shown in FIG.

  Magnetic heads of Samples 1 to 8 were manufactured in the same process as the second magnetic head manufacturing method. Samples 9 to 12 were manufactured in the same step as the third magnetic head manufacturing method. Further, Sample 13 was manufactured in the same process as the fifth magnetic head manufacturing method. The magnetic heads of Samples 1 to 12 correspond to the first magnetic head, and the magnetic head of Sample 13 corresponds to the fourth magnetic head.

  When the sample 14 is manufactured, the change reducing layer 4c is not formed, and when the samples 1 to 8 are manufactured, the metal or semiconductor layer having a changed material and film thickness is formed as shown in Table 2. Then, when the change reducing layer 4c is formed by natural oxidation and the samples 9 to 12 are manufactured, the material shown in Table 2 is used as a target, and ion beam deposition is performed without using oxygen as a process gas. When the change reducing layer 4c having the material and film thickness as shown in Table 2 is formed and the sample 13 is manufactured, the surface of the bar 102 (therefore, the TMR element 2 is configured as shown in Table 2). The change reducing layer 4c was formed by naturally oxidizing the end portions on the ABS side of the respective layers formed accordingly, but the other conditions were the same for all of the samples 1-14. The configuration of each main layer of Samples 1 to 14 was as shown in Table 1 below.

  When samples 1 to 8 were manufactured, natural oxidation when forming the change reducing layer 4c was performed by placing the bar 102 in the atmosphere for 30 minutes.

  Moreover, the conditions of the ion beam deposition for forming the change reducing layer 4c when manufacturing samples 9 to 12 were as follows. That is, using an ion beam deposition apparatus, the inside of the chamber is evacuated to a residual gas pressure of 1 × 10 −5 Pa, Ar gas is introduced from the gas introduction pipe to the target irradiation ion gun at a flow rate of 8 sccm, and the process gas is introduced into the chamber. For the target irradiation ion gun, the acceleration voltage was 1500 V, the acceleration current was 400 mA, and the neutralizer current was 600 mA.

  Further, when the sample 13 was manufactured, natural oxidation of each layer formed to form the TMR element 2 when forming the change reducing layer 4c was performed by placing the bar 102 in the atmosphere for 30 minutes.

  And about each sample 1-14, the high temperature test put for 240 hours in a 125 degreeC environment was done, and the resistance value of the TMR element 2 was measured before and after the high temperature test. Table 2 shows the resistance change rates calculated from the resistance values before and after the measured high temperature test for each sample 1-14. The resistance change rate was calculated according to the following formula.

      Resistance change rate = {(resistance value after high temperature test−resistance value before high temperature test) / resistance value before high temperature test} × 100 [%]

  As can be seen from Table 2, in the sample 14 of the comparative example, the resistance change rate is −3.8%, and the resistance value of the TMR element 2 is relatively greatly reduced after the high temperature test. On the other hand, in samples 1 to 12 corresponding to the first magnetic head and sample 13 corresponding to the fourth magnetic head, the resistance change rate is 1.1% or less in absolute value, and the TMR before and after the high temperature test. A change in the resistance value of the element 2 is suppressed.

  In addition, the change reduction layer 4c of Samples 1 to 13 had an insulating property to the extent that the operation of the TMR element 2 was not hindered.

  Needless to say, the thickness of the change reducing layer 4c is not limited to the example shown in Table 2.

  As mentioned above, although each embodiment of this invention was demonstrated, this invention is not limited to these.

It is a schematic perspective view which shows a 1st magnetic head typically. FIG. 2 is an enlarged cross-sectional view schematically showing portions of a TMR element and an inductive magnetic conversion element of the magnetic head shown in FIG. 1. FIG. 3 is a schematic view taken along the line A-A ′ in FIG. 2. FIG. 3 is an enlarged view in which the vicinity of the TMR element in FIG. 2 is further enlarged. FIG. 4 is an enlarged view in which the vicinity of the TMR element in FIG. 3 is further enlarged. FIG. 6 is a diagram schematically showing the state of oxygen in a tunnel barrier layer in a high temperature environment of the magnetic head shown in FIGS. 1 to 5. It is an expanded sectional view which shows typically the principal part of the magnetic head by a comparative example. It is a figure which shows typically the mode of the oxygen in the tunnel barrier layer in the high temperature environment of the magnetic head by the comparative example shown in FIG. It is a figure which shows typically 1 process in the 2nd magnetic head manufacturing method. It is a figure which shows typically the other process in the 2nd magnetic head manufacturing method. It is a figure which shows typically the other process in the 2nd magnetic head manufacturing method. It is a figure which shows typically the other process in the 2nd magnetic head manufacturing method. It is a schematic perspective view which shows the other process in the 2nd magnetic head manufacturing method. It is sectional drawing which shows typically the other process in the 2nd magnetic head manufacturing method. It is sectional drawing which shows typically the other process in the 2nd magnetic head manufacturing method. It is an expanded sectional view showing an important section of the 4th magnetic head typically. It is an expanded sectional view which shows typically the part of the GMR element and induction type | mold magnetic conversion element of an 8th magnetic head. It is the B-B 'arrow schematic diagram in FIG. It is the enlarged view which expanded further the GMR element vicinity in FIG. It is a schematic perspective view which shows the structure of the principal part of a 9th magnetic disc apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Slider 2 TMR element 3 Inductive magnetic conversion element 4a Protective film 4b Underlayer 4c Change reduction layer 21 Lower electrode (lower magnetic shield layer)
22 Lower metal layer 24 Pinned layer 25 Pinned layer 26 Tunnel barrier layer (oxide layer)
27 Free layer 28 Upper metal layer 29 Upper metal layer 30, 34 Insulating layer 31 Upper electrode (upper magnetic shield layer)
32 Longitudinal bias layer 50 GMR element 51, 52 Nonmagnetic metal layer 53 Current path control layer (oxide layer)

Claims (5)

A base, a magnetoresistive element having a magnetoresistive effect layer formed on one surface of the base and including an oxide layer, at least a part of the surface of the base facing the magnetic recording medium, and the magnetic recording A protective film formed on the end face of the magnetoresistive element on the side facing the medium, and the end face of the oxide layer on the side facing the magnetic recording medium faces the magnetic recording medium Forming one part of the end face of the magnetoresistive element on the side to be covered, and covering at least the end face of the oxide layer between the protective film and the end face of the magnetoresistive element A layer on the end face side of the magnetoresistive effect element among the one or more layers is a manufacturing method for manufacturing a magnetic head made of a metal or semiconductor oxide,
Before forming the protective film, a region of the magnetoresistive effect element that is closest to the magnetoresistive effect element in the region including the end face of the magnetoresistive effect element on the side facing the magnetic recording medium is formed. Forming the layer on the side,
The step includes: a first step of forming a metal or semiconductor film; and a second step of oxidizing the metal or semiconductor film formed by the first step. Production method. A base, a magnetoresistive element having a magnetoresistive effect layer formed on one surface of the base and including an oxide layer, at least a part of the surface of the base facing the magnetic recording medium, and the magnetic recording A protective film formed on the end face of the magnetoresistive element on the side facing the medium, and the end face of the oxide layer on the side facing the magnetic recording medium faces the magnetic recording medium Forming one part of the end face of the magnetoresistive element on the side to be covered, and covering at least the end face of the oxide layer between the protective film and the end face of the magnetoresistive element A layer on the end face side of the magnetoresistive effect element among the one or more layers is a manufacturing method for manufacturing a magnetic head made of a metal or semiconductor oxide,
Before forming the protective film, a region of the magnetoresistive effect element that is closest to the magnetoresistive effect element in the region including the end face of the magnetoresistive effect element on the side facing the magnetic recording medium is formed. Forming the layer on the side,
The method includes the step of performing ion beam deposition or sputtering without using oxygen as a process gas using a metal or semiconductor oxide as a target.   3. The method of manufacturing a magnetic head according to claim 1, further comprising a step of performing a heat treatment on the member on which the protective film is formed after the protective film is formed.   4. A magnetic head manufactured by the manufacturing method according to claim 1, comprising: a magnetic head; and a suspension that mounts the magnetic head near a tip portion and supports the magnetic head, wherein the magnetic head is manufactured by the manufacturing method according to claim 1. A head suspension assembly comprising:   5. A magnetic disk drive comprising: the head suspension assembly according to claim 4; an arm portion that supports the assembly; and an actuator that moves the arm portion to position the magnetic head.

Images