JP2005011519A - Thin film magnetic head and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin film magnetic head wherein the track width can be reduced, write fringing can be prevented and magnetic saturation can be effectively reduced and to provide a manufacturing method of the thin film magnetic head. <P>SOLUTION: A track width regulating section 14 having a track width Tw, which is smaller than the resolution obtained by the wavelength of the light used for exposure and development of a resist, is formed between a lower core layer 10 and an upper core layer 16. Since the width T1 of the upper core layer is larger than the track width Tw, magnetic saturation can be effectively reduced. Inclined faces 10a are formed on the upper surface of the lower core layer 10 so as to be inclined in directions away from the track width regulating section 14, thereby write fringing can be adequately prevented. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a thin film magnetic head for recording used in, for example, a floating magnetic head, and more particularly to a thin film magnetic head capable of preventing write fringing and reducing magnetic saturation as well as narrowing a track. The present invention relates to a head and a manufacturing method thereof.

  FIG. 12 is a partial front view showing the structure of a conventional thin film magnetic head (inductive head), and FIG. 13 is a partial cross-sectional view of the thin film magnetic head cut along line 13-13 shown in FIG. is there.

  Reference numeral 1 shown in FIGS. 12 and 13 denotes a lower core layer made of a magnetic material such as permalloy, and a gap layer 7 made of a nonmagnetic material is formed on the lower core layer 1.

  As shown in FIG. 13, a coil layer 5 is formed on the gap layer 7 via an organic insulating layer 4 made of polyimide, resist or the like.

  An organic insulating layer 6 such as polyimide or resist is formed on the coil layer 5, and an upper core layer 3 made of a magnetic material such as permalloy is further formed on the organic insulating layer 6. .

  As shown in FIG. 12, the front end portion 3a of the upper core layer 3 faces the lower core layer 1 through the gap layer 7, and the width dimension of the front end portion 3a is regulated by the track width Tw. The base end portion 3 b of the upper core layer 3 is in a state of being magnetically connected to the lower core layer 1.

In the inductive head shown in FIGS. 12 and 13, when a recording current is applied to the coil layer 5, a recording magnetic field is induced in the lower core layer 1 and the upper core layer 3, and the leading end 3 a and the lower core of the upper core layer 3 are induced. A magnetic signal is recorded on a recording medium such as a hard disk by a leakage magnetic field from between the layers 1.
Japanese Patent Laid-Open No. 10-143817

By the way, it is necessary to realize a narrow track as the recording density increases in the future.
As described above, the track width Tw is regulated by the width of the tip 3a of the upper core layer 3 (see FIG. 12), and the upper core layer 3 is formed by a so-called frame plating method.

  In the frame plating method, a resist layer is first applied to the entire surface on which the upper core layer 3 is to be formed, and a pattern of the upper core layer 3 is formed on the resist layer by exposure and development. Next, when a magnetic material is plated in the formed pattern and the resist layer is removed, the upper core layer 3 having the shape shown in FIGS. 12 and 13 is completed.

  By the way, the resolution of the resist layer is greatly related to the wavelength used in exposure and development, and the resolution can be increased by shortening the wavelength.

  However, of course, the resolution has a limit, and the track width Tw to be regulated by the width dimension of the front end portion 3a of the upper core layer 3 cannot be patterned with a dimension less than the limit value of the resolution. Therefore, with the inductive head having the structure shown in FIGS. 12 and 13, it is difficult to realize a narrow track as the recording density further increases.

  Further, by reducing the track width Tw, the volume of the tip portion 3a of the upper core layer 3 is reduced, and the problem of magnetic saturation becomes conspicuous as the recording frequency is increased, leading to deterioration of recording characteristics.

  Further, in the inductive head shown in FIG. 12 and FIG. 13, a so-called write magnetic field in which a leakage magnetic field generated between the tip 3a of the lower core layer 1 and the upper core layer 3 does not fall within the track width Tw but protrudes from the track width Tw. The problem of fringing is likely to occur.

  When the write fringing occurs, track position detection on the written recording medium cannot be performed with high accuracy, and a tracking servo error is caused and the recording characteristics are easily deteriorated.

  As shown in FIG. 12, the light fringing is generated by extending the width of the lower core layer 1 beyond the track width Tw, and the extended portions of the lower core layer 1 and the tip end portions of the upper core layer 3 are formed. This is easily caused by the short distance from 3a.

  By the way, Japanese Patent Laid-Open No. 10-143817 (Patent Document 1) discloses an inductive head structure that effectively prevents the occurrence of the above-described write fringing.

  However, in the invention disclosed in the above publication, a step of cutting the gap layer 7 extending beyond the track width Tw shown in FIG. 12 is required, and the surface of the lower core layer 1 exposed by cutting the gap layer 7 is further removed. While being able to cut away by ion milling and separating the distance between the lower core layer 1 and the tip 3a of the upper core layer 3, the magnetic powder adheres to both end faces of the tip 3a and the like. As a result, the manufacturing process becomes complicated, for example, a removal process becomes necessary.

  Further, in the invention disclosed in the above publication, it is still impossible to realize magnetic saturation prevention while reducing the track width.

  The present invention is intended to solve the above-described conventional problems, and provides a thin film magnetic head capable of preventing the occurrence of write fringing and effectively reducing magnetic saturation as well as narrowing the track, and a method of manufacturing the same. The purpose is that.

The present invention relates to a lower core layer and an upper core layer, and a track width restricting portion which is located between the lower core layer and the upper core layer and whose width dimension is restricted to be shorter than that of the lower core layer and the upper core layer. Have
The track width restricting portion includes a lower magnetic pole layer continuous with the lower core layer, an upper magnetic pole layer continuous with the upper core layer, and a gap layer located between the lower magnetic pole layer and the upper magnetic pole layer, or the track The width restricting portion includes an upper magnetic pole layer continuous with the upper core layer, and a gap layer positioned between the upper magnetic pole layer and the lower core layer,
On the upper surface of the lower core layer extending on both sides of the track width restricting portion, an inclined surface is formed in which the distance from the upper core layer gradually increases as the distance from the track width restricting portion increases in the track width direction. It is characterized by this.

  As described above, in the present invention, the track width regulating portion in which the width dimension in the track width direction is regulated by the track width is formed between the lower core layer and the upper core layer. In the track width restricting portion, an upper magnetic pole layer magnetically connected to the upper core layer is formed, and in the present invention, on the upper surface of the lower core layer extending from both sides of the track width restricting portion, Since an inclined surface that is inclined in a direction away from the upper core layer is formed, the distance between the upper magnetic pole layer and the lower core layer is appropriately separated, and the occurrence of write fringing can be effectively prevented. It has become.

  Further, the upper core layer formed on the upper magnetic pole layer has a width dimension larger than the track width, and can appropriately reduce magnetic saturation in the vicinity of the tip of the upper core layer. .

  Furthermore, in the present invention, as shown in the manufacturing method described later, the width dimension of the track width restricting portion (= track width) can be formed with a width equal to or smaller than the resolution of the wavelength used in the resist exposure and development. Thus, it is possible to realize narrowing of the track with the future increase in recording density.

  In the present invention, it is preferable that the track width regulated by the width dimension of the track width regulating portion is 0.4 μm or less. This dimension is a numerical value equal to or lower than the resolution when i-line is used in the resist exposure and development. More preferably, the track width is 0.2 μm or less.

  In the present invention, the inclination angle θ1 of the inclined surface formed on the upper surface of the lower core layer with respect to the track width direction is preferably 2 ° or more and 10 ° or less. Within this range, the occurrence of light fringing can be appropriately suppressed. In addition, the shielding function of the lower core layer can be sufficiently maintained.

Alternatively, the present invention provides a lower core layer and an upper core layer having a width dimension larger than the track width, and a track width restriction that is positioned between the lower core layer and the upper core layer and the width dimension is restricted to the track width. And
The track width restricting portion includes a lower magnetic pole layer continuous with the lower core layer, an upper magnetic pole layer continuous with the upper core layer, and a gap layer located between the lower magnetic pole layer and the upper magnetic pole layer, or the track The width restricting portion includes an upper magnetic pole layer continuous with the upper core layer, and a gap layer positioned between the upper magnetic pole layer and the lower core layer,
The track width regulated by the track width regulating unit is 0.4 μm or less.

  As described above, between the lower core layer and the upper core layer, the track width restricting portion in which the width dimension in the track width direction is restricted to the track width is formed. Since the upper core layer is formed with a width larger than the track width, the volume near the tip of the upper core layer is increased, and magnetic saturation can be reduced appropriately.

  Further, in the present invention, as shown in the manufacturing method described later, the width dimension (= track width) of the track width restricting portion may be formed with a width dimension equal to or smaller than the resolution of the wavelength used in the resist exposure and development. it can.

  In particular, in the present invention, the track width is formed to be 0.4 μm or less, and this dimension is a dimension that is less than the limit value of the resolution when i-line is used for the wavelength during exposure and development. More preferably, the track width is 0.2 μm or less.

  Further, in the present invention, the upper surface of the lower core layer extending on both sides of the track width restricting portion is an inclined surface in which the distance from the upper core layer gradually increases as the distance from the track width restricting portion increases in the track width direction. Is preferably formed.

  An upper magnetic pole layer that is magnetically connected to the upper core layer is formed in the track width restricting portion. With the above configuration, the distance between the upper magnetic pole layer and the lower core layer is appropriately increased, and write fringing is performed. Generation | occurrence | production can be suppressed effectively.

  In the present invention, the inclination angle θ1 of the inclined surface formed on the upper surface of the lower core layer with respect to the track width direction is preferably 2 ° or more and 10 ° or less.

  In the present invention, the height dimension of the track width restricting portion is preferably 2 μm or more and 3 μm or less. If it is within this range, the distance between the lower core layer and the upper magnetic pole layer is appropriately increased, the occurrence of write fringing can be suppressed, and the height of the upper magnetic pole layer can be increased. It becomes difficult to reach magnetic saturation. Moreover, within the height dimension, there is an advantage that the track width restricting portion can be easily formed.

  In the present invention, the gap layer is preferably formed of a nonmagnetic metal material that can be plated. The nonmagnetic metal material includes NiP, NiPd, NiW, NiMo, Au, Pt, Rh, Pd, It is preferable that it is selected from one or more of Ru and Cr.

The method of manufacturing the thin film magnetic head in the present invention is as follows.
(A) forming a resist layer on the lower core layer, and forming a groove having a predetermined width dimension and a predetermined length dimension in a height direction from a surface facing the recording medium in the resist layer;
(B) A track width restricting portion in which a lower magnetic pole layer, a nonmagnetic gap layer, and an upper magnetic pole layer are sequentially laminated in the groove, or a track width restricting portion in which a nonmagnetic gap layer and an upper magnetic pole layer are sequentially laminated. Forming, and
(C) removing the resist layer;
(D) cutting both side surfaces of the track width restricting portion in the track width direction to restrict the width dimension of the track width restricting portion to the track width;
(E) forming an inclined surface on the upper surface of the lower core layer extending on both sides of the track width restricting portion so that the distance from the upper core layer gradually increases as the distance from the track width restricting portion increases;
(F) forming an upper core layer having a width dimension larger than the track width on the track width regulating portion;
It is characterized by having.

  As described above, in the present invention, a resist layer is first applied on the lower core layer, and a pattern of the track width restricting portion is formed on the resist layer by exposure and development. The width dimension of the pattern to be the track width restricting portion largely depends on the wavelength of the light source at the time of exposure and development. For example, when i-line (wavelength = 365 nm) is used, the width dimension is about 0.4 μm. Can be made as small as possible.

  However, the numerical value of 0.4 μm is a resolution limit value when i-line is used, and a width smaller than 0.4 μm cannot be formed in the resist layer.

  Therefore, in the present invention, after the track width restricting portion is formed in the pattern of the resist layer, both end faces in the track width direction of the track width restricting portion are shaved, and the width dimension of the track width restricting portion (= track width) Is even smaller. Thereby, for example, when the width dimension of the pattern formed on the resist layer is about 0.4 μm which is the limit of the resolution of the i-line used in exposure and development, the width dimension of the track width restricting portion Can be formed at 0.4 μm or less. Thus, according to the present invention, the width dimension (= track width) of the track width restricting portion can be formed with a width dimension equal to or less than the resolution of the i line.

  In the present invention, the step of forming an inclined surface on the upper surface of the lower core layer extending from both sides of the track width restricting portion so that the film thickness of the lower core layer gradually decreases as the distance from the track width restricting portion increases. Thus, the occurrence of light fringing can be appropriately prevented.

  Further, in the present invention, an upper core layer having a width dimension larger than the track width is formed on the upper magnetic pole layer constituting the track width restricting portion by, for example, a frame plating method, so that the vicinity of the tip of the upper core layer is formed. The volume at can be increased, and magnetic saturation can be appropriately reduced.

  In the present invention, it is preferable that the step of regulating the width dimension of the track width regulating portion of (d) and the step of forming the inclined surface of (e) are simultaneously performed using an ion milling method. . Thereby, a manufacturing method can be simplified.

  In the present invention, the ion irradiation angle θ2 at the time of the ion milling preferably has an inclination of 45 ° or more and 75 ° or less with respect to a direction parallel to the height direction of the track width regulating portion. More preferably, the ion irradiation angle θ2 is not less than 55 ° and not more than 70 °.

  By having the ion irradiation angle θ2 described above, the track width can be reduced without drastically reducing the height dimension of the upper magnetic pole layer, as shown in the experimental results described later. At the same time, it is possible to easily form an inclined surface on the upper surface of the lower core layer by giving the above-described inclination to the ion irradiation angle.

  In the present invention, it is preferable that in the step (d), the track width regulated by the track width regulating portion is formed to 0.4 μm or less.

  As described above, by forming the track width to 0.4 μm or less, the track width can be made smaller than the limit value of the degree of development when i-line is used for resist exposure and development. . More preferably, the track width is 0.2 μm or less.

  In the present invention, in the step (e), the inclined surface formed on the upper surface of the lower core layer is formed with an inclination angle θ1 of 2 ° or more and 10 ° or less with respect to the track width direction. Is preferred.

  The track width is formed to be 0.4 μm or less, and the inclined surface formed on the upper surface of the lower core layer is formed with an inclination angle θ1 of 2 ° to 10 ° with respect to the track width direction. This can be achieved by setting the ion irradiation angle θ2 during ion milling to 45 ° or more and 75 ° or less.

  In the present invention, the gap layer constituting the track width restricting portion is preferably formed by plating together with the pole layer. Thereby, the pole layer and the gap layer can be formed by continuous plating.

  In addition, it is preferable to select one or more kinds of nonmagnetic metal materials capable of plating for forming the gap layer from NiP, NiPd, NiW, NiMo, Au, Pt, Rh, Pd, Ru, and Cr.

  According to the present invention, the track width restricting portion whose width dimension is restricted by the track width Tw is provided between the lower core layer and the upper core layer. The width dimension (= track width Tw) can be formed with a dimension smaller than the resolution of the wavelength used when the resist is exposed and developed. As a result, the track width can be reduced.

  Further, in the present invention, the upper core layer having a width dimension larger than the track width Tw can be formed on the track width restriction portion restricted by the track width Tw, and thereby the volume of the upper core layer can be increased. Generation of magnetic saturation can be effectively reduced.

  Furthermore, in the present invention, the lower core layer extending from both sides of the track width restricting portion is formed with an inclined surface that is inclined toward the direction away from the track width restricting portion. The distance from the upper magnetic pole layer constituting the restricting portion can be appropriately separated, and the occurrence of write fringing can be prevented appropriately.

  As described above, according to the present invention, it is possible to manufacture a thin film magnetic head that can be opposed to further higher recording density.

  In the manufacturing method according to the present invention, after forming the track width restricting portion using a resist, both side end surfaces of the track width restricting portion are shaved by ion milling, and the width dimension of the track width restricting portion is exposed and developed. In addition, the ion milling can be used to form an inclined surface on the upper surface of the lower core layer. As a result, the manufacturing process can be simplified.

  Further, the ion irradiation angle θ2 at the time of the ion milling is preferably 45 ° or more and 75 ° or less, and within this range, the problem of reattachment due to ion milling does not occur, and the rack width Tw is An inclined surface having an inclination angle θ1 of 2 ° or more and 10 ° or less can be formed on the upper surface of the lower core layer 10 and can be 0.4 μm or less, more preferably 0.2 μm or less.

  FIG. 1 is a partial front view showing the structure of a thin film magnetic head according to the present invention, and FIG. 2 is a partial sectional view of the thin film magnetic head cut from line 2-2 shown in FIG.

  The thin film magnetic head shown in FIG. 1 is an inductive head for recording. In the present invention, a reproducing head (MR head) using a magnetoresistive effect may be laminated below the inductive head.

  Reference numeral 10 shown in FIGS. 1 and 2 denotes a lower core layer formed of a magnetic material such as permalloy. When a reproducing head is stacked below the lower core layer 10, a shield layer that protects the magnetoresistive element from noise may be provided separately from the lower core layer 10, or The lower core layer 10 may function as an upper shield layer of the reproducing head without providing the shield layer.

  As shown in FIG. 1, a track width restricting portion 14 having a track width Tw is formed on the lower core layer 10. The track width Tw is preferably 0.4 μm or less. More preferably, it is 0.2 μm or less.

  In the present invention, the width dimension of the track width restricting portion 14, that is, the track width Tw can be formed with a width dimension equal to or smaller than the resolution of the wavelength used when the resist is exposed and developed by the manufacturing method described later. The numerical value of 0.4 μm is a limit value of resolution when i-line is used when a pattern is formed on a resist by exposure and development. According to the present invention, a track having a dimension smaller than the resolution of i-line is used. The width Tw can be regulated.

  In the embodiment shown in FIGS. 1 and 2, the track width restricting portion 14 has a laminated structure of a three-layer film of a lower magnetic pole layer 11, a gap layer 15, and an upper magnetic pole layer 12. Hereinafter, the magnetic pole layers 11 and 12 and the gap layer 15 will be described.

  As shown in FIGS. 1 and 2, a lower magnetic pole layer 11 that is the lowest layer of the track width restricting portion 14 is formed on the lower core layer 10 by plating. The lower magnetic pole layer 11 is magnetically connected to the lower core layer 10, and the lower magnetic pole layer 11 may be formed of the same material as or different from the lower core layer 10. Either a single layer film or a multilayer film may be used.

  As shown in FIGS. 1 and 2, a nonmagnetic gap layer 15 is laminated on the lower magnetic pole layer 11.

  In the present invention, the gap layer 15 is preferably made of a nonmagnetic metal material and plated on the lower magnetic pole layer 11. In the present invention, it is preferable to select one or more of NiP, NiPd, NiW, NiMo, NiRh, Au, Pt, Rh, Pd, Ru, and Cr as the nonmagnetic metal material. The layer 15 may be formed of a single layer film or a multilayer film.

  Next, an upper magnetic pole layer 12 that is magnetically connected to an upper core layer 16 (to be described later) is formed on the gap layer 15 by plating. The upper magnetic pole layer 12 may be formed of the same material as that of the upper core layer 16 or may be formed of a different material. Either a single layer film or a multilayer film may be used.

  As described above, if the gap layer 15 is formed of a nonmagnetic metal material, the lower magnetic pole layer 11, the gap layer 15, and the upper magnetic pole layer 12 can be continuously formed by plating.

  Further, as described above, the lower magnetic pole layer 11 and the upper magnetic pole layer 12 constituting the track width restricting portion 14 may be formed of the same material or different materials from the core layer to which each magnetic pole layer is magnetically connected. However, in order to improve the recording density, the lower magnetic pole layer 11 and the upper magnetic pole layer 12 facing the gap layer 15 are higher than the saturation magnetic flux density of the core layer to which each magnetic pole layer is magnetically connected. It preferably has a saturation magnetic flux density. Thus, since the lower magnetic pole layer 11 and the upper magnetic pole layer 12 have a high saturation magnetic flux density, it is possible to concentrate the recording magnetic field in the vicinity of the gap and improve the recording density.

  As shown in FIG. 1, the height dimension of the track width restricting portion 14 is H1. For example, the thickness of the lower magnetic pole layer 11 is about 0.4 μm, the thickness of the gap layer 15 is about 0.2 μm, and the thickness of the upper magnetic pole layer 12 is about 2 μm.

  The height H1 of the track width restricting portion 14 is preferably 2.0 μm or more and 3.0 μm or less. The height dimension H1 is more preferably 2.3 μm or more and 2.5 μm or less.

  Within the height dimension, the distance between the lower core layer 10 and the upper magnetic pole layer 12 can be appropriately separated, and the occurrence of light fringing can be suppressed. Further, since the height dimension of the upper magnetic pole layer 12 can be increased and the volume of the upper magnetic pole layer 12 can be increased, magnetic saturation can be suppressed under higher recording density.

  Further, as will be described later, the track width restricting portion 14 is formed by forming a groove in the resist layer and plating the metal material of each magnetic layer in the groove. With this height dimension, a groove having a predetermined shape and a predetermined dimension can be easily formed in the resist layer by exposure and development, and the track width restricting portion 14 that can cope with a narrow track can be easily formed.

  As shown in FIG. 2, the track width restricting portion 14 is formed with a predetermined length dimension in the height direction (Y direction in the drawing) from the surface facing the recording medium (ABS surface). On the layer 10, for example, a Gd determining insulating layer 17 made of an organic insulating material such as resist or polyimide is formed.

  The Gd determining insulating layer 17 is provided to regulate a gap depth (Gd) that greatly affects the electrical characteristics of the thin film magnetic head, and the gap depth is the front end of the Gd determining insulating layer 17. It is determined by the length dimension from the surface to the ABS surface. By providing the Gd determining insulating layer 17, the length of the upper magnetic pole layer 12 in the height direction (Y direction in the figure) can be increased as shown in FIG. 2, and the volume of the upper magnetic pole layer 12 can be increased. Therefore, there is an advantage that magnetic saturation can be prevented and recording characteristics can be improved.

  However, whether or not to provide the Gd determining insulating layer 17 is arbitrary, and when the Gd determining insulating layer 17 is not provided, the gap depth is determined by the length dimension of the track width regulating portion 14 in the height direction. The

Further, as shown in FIG. 2, an insulating layer 18 is formed from the rear end of the track width restricting portion 14 to the height direction. The insulating layer 18 is an inorganic insulating layer formed of, for example, an inorganic material, and it is preferable that one or more of Al ₂ O ₃ , SiN, and SiO ₂ is selected as the inorganic material.

  As shown in FIG. 2, the upper surface 18 a of the insulating layer 18 is on the same plane as the reference plane A when the joint surface between the upper magnetic pole layer 12 and the upper core layer 16 described later is a reference plane A. It is preferable to be formed flat.

  In the present invention, as shown in FIG. 2, a coil layer 19 is spirally formed on the insulating layer 18. Since the upper surface 18a of the insulating layer 18 is flattened, it can be formed with high pattern accuracy when forming the coil layer 19, so that the pitch between the conductor portions of the coil layer 19 is narrowed. be able to.

  Since the pitch between the conductor portions can be narrowed, the length dimension in the height direction of the upper core layer 16 described later can be shortened, and the magnetic path length formed through the lower core layer 10 can be shortened to reduce the recording characteristics. Improvements can be made.

  The coil layer 19 is preferably composed of a conductive material layer and a protective layer laminated thereon. In this case, the conductive material layer is a non-magnetic conductive layer having a single layer structure or a multilayer structure containing one or both of Cu and Au, and the protective layer is made of Ni, NiP, Pd, A nonmagnetic conductive layer having a single layer structure or a multilayer structure containing one or more elements selected from Pt, B, and Au is preferable.

  The protective layer may be exposed to the atmosphere before the organic insulating layer 20 is formed on the coil layer 19 after the coil layer 19 is patterned. It is provided to prevent the layer from oxidation.

  As shown in FIG. 2, an organic insulating layer 20 made of an organic material such as resist or polyimide is formed on the coil layer 19, and a magnetic material such as permalloy is further formed on the organic insulating layer 20. The upper core layer 16 is formed by frame plating or the like.

  As shown in FIG. 2, the distal end portion 16 a of the upper core layer 16 is magnetically connected to the upper magnetic pole layer 12, and the proximal end portion 16 b is a magnetic material formed on the lower core layer 10. It is magnetically connected and formed on a made lifting layer (back gap layer) 21. In the present invention, the lifting layer 21 may not be formed. In this case, the base end portion 16 b of the upper core layer 16 is formed in direct contact with the lower core layer 10.

  In the inductive head shown in FIGS. 1 and 2, when a recording current is applied to the coil layer 19, a recording magnetic field is induced in the lower core layer 10 and the upper core layer 16, and the track width restricting portion 14 passes through the gap layer 15. A leakage magnetic field is generated between the lower magnetic pole layer 11 and the upper magnetic pole layer 12 facing each other, and a magnetic signal is recorded on a recording medium such as a hard disk by the leakage magnetic field.

  By the way, in the present invention, in order to develop an inductive head having the structure shown in FIG. 1 in order to appropriately prevent the occurrence of write fringing and to reduce magnetic saturation as the recording density is further increased in the future. It came.

  In the inductive head shown in FIG. 1, a track width restricting portion 14 is formed between the lower core layer 10 and the upper core layer 16 so that the width dimension in the track width direction (X direction in the drawing) is restricted to the track width Tw. Yes.

  As described above, since the width dimension of the track width restricting portion 14 is formed with a width equal to or smaller than the resolution of the wavelength used in the resist exposure and development, it is possible to appropriately realize a narrow track. Specifically, the track width Tw can be regulated with a dimension of 0.4 μm or less. More preferably, the track width Tw is formed at 0.2 μm or less.

  In the present invention, as shown in FIG. 1, the width dimension of the upper core layer 16 in the track width direction (X direction in the drawing) is formed by T1, and the width dimension T1 is formed by a width dimension larger than the track width Tw. The Therefore, according to the present invention, the volume in the vicinity of the tip portion 16a of the upper core layer 16 can be increased, and magnetic saturation can be reduced more appropriately.

  Further, in the present invention, as shown in FIG. 1, an inclined surface 10 a is formed on the upper surface of the lower core layer 10 extending from both sides of the track width restricting portion 14, which is inclined in a direction away from the track width restricting portion 14.

  By forming the inclined surface 10a, the distance between the lower core layer 10 and the upper magnetic pole layer 12 constituting the track width restricting portion 14 is appropriately separated. Therefore, a leakage magnetic field generated from the upper magnetic pole layer 12 is generated in the lower core layer 10. It is less likely to protrude from the track width Tw by being dragged by the width dimension, and so-called write fringing can be suppressed.

  The inclination angle θ1 formed by the parallel line parallel to the track width direction (X direction in the figure) and the inclined surface 10a is preferably in the range of 2 ° to 10 °.

  If the angle θ1 of the inclined surface 10a is smaller than 2 °, a leakage magnetic field is likely to be generated between the lower core layer 10 and the upper magnetic pole layer 12, and the effect of suppressing the occurrence of write fringing cannot be expected so much.

  Further, when the angle θ1 of the inclined surface 10a is larger than 10 °, it is suitable as an effect of suppressing write fringing, but the lower core layer 10 also functions as a shield layer of a magnetoresistive effect element (not shown). If the angle θ1 of the inclined surface 10a is larger than 10 °, the thickness of the lower core layer 10 is reduced particularly in the vicinity of both sides, or the lower core layer 10 in the track width direction (X direction in the drawing). When the width dimension itself is shortened, there arises a problem that the function of the lower core layer 10 as a shield layer for the magnetoresistive effect element is deteriorated.

  Further, as shown in FIG. 1, a protruding portion 10 c extending in the Z direction in the figure may be formed from the upper surface of the lower core layer 10, and in this case, the upper surface of the protruding portion 10 c and the base end of the track width regulating portion 14 are formed. Are joined. Further, it is preferable that inclined surfaces 10b and 10b which are inclined in a direction away from the track width restricting portion 14 are formed on the upper surface of the lower core layer 10 extending from the base end of the raised portion 10c. The raised portion 10c shown in FIG. 1 is formed in a rectangular shape with a width dimension of the track width Tw, but may have other shapes. For example, a trapezoidal shape in which the upper surface is formed with a track width Tw and both end surfaces are inclined so that the width dimension gradually increases toward the lower core layer 10 direction (opposite to the Z direction in the drawing) may be used.

  In the present invention, the inclined surfaces 10a and 10b may not be formed on the lower core layer 10, and the upper surface of the lower core layer 10 may be formed parallel to the track width direction (X direction in the drawing). In such a case, there arises a problem that the above-described light fringing is likely to occur as compared with the case where the inclined surfaces 10a and 10b are formed.

  However, even if the upper surface of the lower core layer 10 is formed parallel to the track width direction, according to the present invention, it is possible to appropriately narrow the track and effectively suppress the occurrence of magnetic saturation. An effect that the conventional inductive head can do can be achieved. Further, when the raised portion 10c is formed in the lower core layer 10, the distance between the lower core layer 10 and the upper magnetic pole layer 12 can be increased, so that even if the inclined surface 10b is not formed, the write operation can be effectively performed. The occurrence of fringing can be suppressed.

FIG. 3 is a partial front view showing the structure of the thin film magnetic head according to the second embodiment of the present invention.
In this embodiment, the film configuration of the track width restricting portion 14 is different from that shown in FIG. 1, and the other configurations are the same.

  As shown in FIG. 3, the track width restricting portion 14 is composed of two layers of a gap layer 15 and an upper magnetic pole layer 12.

  As shown in FIG. 3, inclined surfaces 10 a and 10 a that are inclined in a direction away from the track width restricting portion 14 are formed on the upper surface of the lower core layer 10 extending from the base end of the gap layer 15. Thereby, generation | occurrence | production of light fringing can be suppressed appropriately.

  Further, as shown in FIG. 3, a raised portion 10c extending in the Z direction is formed on the upper surface of the lower core layer 10, and the upper surface of the raised portion 10c and the base end of the track width restricting portion 14 are joined. Also good. Further, it is preferable that inclined surfaces 10b and 10b which are inclined as the distance from the track width restricting portion 14 increases are formed on the upper surface of the lower core layer 10 extending from the base end of the raised portion 10c. Thereby, generation | occurrence | production of light fringing can be suppressed appropriately.

  4 to 10 are process diagrams showing a method of manufacturing the thin film magnetic head (inductive head) according to the present invention shown in FIGS. 4 to 7, the thin film magnetic head is represented by a partial front view, and in the processes of FIGS. 8 to 10, the thin film magnetic head is represented by a partial longitudinal sectional view.

  First, when the Gd determining insulating layer 17 is formed as shown in FIG. 8 and the subsequent drawings, it is necessary to form the Gd determining insulating layer 17 on the lower core layer 10 in advance.

  In FIG. 4, a resist layer 30 is applied on the lower core layer 10. The resist layer 30 is formed of H2.

  Next, as shown in FIG. 4, a groove 30a for forming the track width restricting portion 14 is formed in the resist layer 30 by exposure and development. As shown in FIG. 4, the width of the groove 30a in the track width direction (X direction in the drawing) is formed by T2, and the length in the height direction (Y direction in the drawing) is formed with a predetermined dimension.

  Here, for example, when i-line is used for the wavelength during exposure and development, the width T2 of the groove 30a formed in the resist layer 30 can be reduced to about 0.4 μm. However, the numerical value of 0.4 μm is a limit value of the degree of development when i-line is used, and the width T2 of the groove 30a cannot be formed with a smaller dimension.

  In order to increase the resolution, the wavelength used at the time of exposure and development may be made shorter, and an excimer laser or the like may be used to increase the resolution compared to the case where i-line is used. When an excimer laser is used, the width T2 of the groove 30a formed in the resist layer 30 can be reduced to about 0.3 μm.

  Next, as shown in FIG. 5, the track width restricting portion 14 is formed in the groove 30 a formed in the resist layer 30. In the embodiment of the present invention, as shown in FIG. 5, the track width restricting portion 14 has a laminated structure of a lower magnetic pole layer 11, a gap layer 15 and an upper magnetic pole layer 12 from the bottom. The lower magnetic pole layer 11 is magnetically connected to the lower core layer 10 and is formed by electroplating or the like. The upper magnetic pole layer 12 is magnetically connected to the upper core layer 16 and is formed by electroplating or the like.

  In the present invention, the gap layer 15 is preferably plated together with the pole layers 11 and 12. Thus, the magnetic pole layers 11 and 12 and the gap layer 15 can be continuously formed by plating.

  In addition, it is preferable to select one or more kinds of nonmagnetic metal materials that can be plated to form the gap layer 15 from NiP, NiPd, NiW, NiMo, Au, Pt, Rh, Pd, Ru, and Cr. .

  In the present invention, the track width restricting portion 14 does not have to be formed in a three-layer structure of the lower magnetic pole layer 11, the gap layer 15, and the upper magnetic pole layer 12, for example, two layers of the gap layer 15 and the upper magnetic pole layer 12. You may comprise by the laminated structure of these.

  Incidentally, as shown in FIG. 5, in the present invention, the track width restricting portion 14 is formed with a height dimension H3. The height dimension H3 is approximately the same as or slightly smaller than the film thickness H2 of the resist layer 30.

  Moreover, the height dimension H3 is formed larger than the height H1 of the track width restricting portion 14 shown in FIG. That is, in the process of FIG. 4, the height dimension H2 of the resist layer 30 that should regulate the height dimension H3 of the track width regulating portion 14 is formed in advance higher than the height dimension H1.

  The height dimension H3 is determined in consideration of the height H1 of the track width restricting portion 14 and further the amount of grinding in the grinding process by the CMP technique shown in FIG.

  In the grinding step, the height of the track width restricting portion 14 is reduced by about 1 μm. Also in the ion milling process shown in FIG. 6, the height of the track width restricting portion 14 is reduced.

  As already described, in the present invention, the height dimension H1 (see FIG. 1) of the track width restricting portion 14 after manufacture is preferably 2 μm or more and 3 μm or less, more preferably 2.3 μm or more. Although the height H1 is 2.5 μm or less, the height H3 of the track width restricting portion 14 shown in FIG. 5 is set in consideration of the grinding process and the ion milling process in order to secure the height H1. It is preferable to form it at 3.5 μm or more and 5.0 μm or less. More preferably, it is 4.0 μm or more and 4.2 μm or less.

  After the track width restricting portion 14 is formed in the groove 30a of the resist layer 30 as described above, the lifting layer 21 shown in FIG. 2 is formed.

  When the lifting layer 21 is formed on the lower core layer 10, after the step shown in FIG. 5, after removing the resist layer 30, a resist layer is formed again, and a pattern of the lifting layer 21 is formed on the resist layer. Then, the lifting layer 21 can be formed by plating a magnetic material in the pattern.

FIG. 6 shows a state where the resist layer for forming the lifting layer 21 is removed.
As shown in FIG. 6, in the vicinity of the ABS surface on the lower core layer 10, only the track width restricting portion 14 is formed in a standing state, and nothing is formed around it.

  In the present invention, in the state shown in FIG. 6, both side end surfaces 14 a, 14 a in the track width direction (X direction in the figure) of the track width restricting portion 14 are scraped to make the width dimension of the track width restricting portion 14 smaller.

  In the present invention, an ion milling method can be used as a method for scraping the side end surfaces 14a, 14a of the track width restricting portion 14.

  The ion milling method uses neutral ionized Ar (argon) gas. As shown in FIG. 6, ion milling is performed from an oblique direction (directions of arrows B and C).

  When ions are irradiated from the directions of arrows B and C, both end surfaces 14a and 14a of the track width restricting portion 14 are scraped by a physical action, and the width dimension of the track width restricting portion 14 gradually decreases. Go.

  As described above, in the present invention, it is preferable that the gap layer 15 constituting the track width restricting portion 14 is formed by plating with a nonmagnetic metal material selected. In this case, the gap layer 15 and the pole layers 11 and 12 are milled. Since the rates are almost the same for the three layers, both side end faces 14a, 14a of the track width restricting portion 14 are appropriately cut in the same plane.

  By the way, the width dimension of the track width restricting portion 14 is regulated as the track width Tw. According to the method of the present invention, the track width Tw is set to the limit of the degree of development of the wavelength used in the resist exposure development. It can be formed with a dimension smaller than the value.

  That is, as described above, in the process shown in FIG. 4, the groove 30a is formed in the portion of the resist layer 30 where the track width restricting portion 14 is to be formed. The width dimension T2 of the groove 30a is at least during exposure development. This is the limit value of the degree of development of the wavelength used, and the width dimension cannot be reduced any further.

  Therefore, the width dimension of the track width restricting portion 14 formed in the groove 30a of the resist layer 30 is T2 (see FIG. 6), but in the present invention, both end faces of the track width restricting portion 14 are shaved by ion milling or the like. As a result, the width dimension of the track width restricting portion 14 can be made smaller than T2, in other words, the track width Tw of the track width restricting portion 14 is developed with a wavelength used for resist exposure and development. It can be formed with a size smaller than the limit value of the degree (see FIG. 7).

  For example, when i-line is used in the exposure and development of the resist layer 30, the width dimension T2 of the groove 30a to be formed in the resist layer 30 is about 0.4 μm at the minimum. By cutting the both side end surfaces 14a, 14a of the track width restricting portion 14 by ion milling in the process shown in FIG. 5, the width dimension (= track width Tw) of the track width restricting portion 14 can be formed to 0.4 μm or less. is there. It is also possible to form the track width Tw at 0.2 μm or less by adjusting the ion milling time or ion irradiation angle.

  As shown in FIG. 7, when both side end surfaces 14a, 14a of the track width restricting portion 14 are finished by ion milling, the width dimension of the track width restricting portion 14 is set as the track width Tw. The upper surface of the lower core layer 10 extending from both sides of the track width restricting portion 14 is also cut off obliquely, and inclined surfaces 10 a and 10 a are formed on the upper surface of the lower core layer 10.

  As described above, according to the present invention, by ion milling, the both end surfaces 14a and 14a of the track width restricting portion 14 are shaved to restrict the width dimension of the track width restricting portion 14 to the track width Tw, and the lower core layer 10 It is possible to simultaneously perform the step of forming the inclined surfaces 10a, 10a on the upper surface of the magnetic layer. For example, the lower core layer 10 is prevented from being reattached by cutting the lower core layer 10, and further the lower core layer In order to set the inclination angle θ1 of the inclined surface 10a formed on the predetermined range (within the range of 2 ° to 10 ° as described above), the ion irradiation inclination angle θ2 (track) It is necessary to appropriately set the inclination angle of the ion irradiation with respect to the height direction (Z direction in the drawing) of the width restricting portion 14.

  In the present invention, the inclination angle θ2 of the ion irradiation is preferably in the range of 45 ° to 75 °.

  When the ion irradiation angle θ2 is set to 45 ° or more and 75 ° or less according to the experimental result described later, the etching rate of both end surfaces of the track width restricting portion 14 becomes a positive value, and both end surfaces of the track width restricting portion 14 are appropriately set. The track width Tw can be reduced to 0.4 μm or less.

  On the other hand, the upper surface of the upper magnetic pole layer 12 (that is, the upper surface of the track width restricting portion 14) is scraped by the ion irradiation, but the etching rate with respect to the upper surface of the upper magnetic pole layer 12 is about 40 ° to about 40 ° Therefore, when the ion irradiation angle θ2 is set to 45 ° or more, the etching rate can be reduced, and an extreme decrease in the height of the track width restricting portion 14 can be suppressed. .

  Further, when the ion irradiation angle θ2 is set, the etching rate at the joints D and D with the track width restricting portion 14 of the lower core layer 10 becomes a positive value. There is no worry that the upper surface of the lower core layer 10 is raised due to reattachment by ion milling.

  As already described, in the conventional thin film magnetic head (see FIG. 12), there is a step of cutting the surface of the gap layer 7 extending beyond the track width Tw and the lower core layer 10 formed thereunder by ion milling. In addition, the step of removing the re-adhering matter on the upper core layer 3 by the ion milling is necessary. However, the track width restricting portion 14 of the present invention has a raised shape of a three-layer plating structure including the gap layer 15. Therefore, the above-described ion milling process is not necessary, and therefore, the problem of reattachment due to the ion milling does not occur.

  Further, in the present invention, before the ion milling process (in the case of FIG. 5), even if the width dimension in the track width direction of the track width restricting portion 14 is formed to be slightly larger than the predetermined width, The track width Tw can be easily accommodated within a predetermined dimension range by correcting the amount of cutting of the both end faces 14a, 14a of the restricting portion 14.

  In the present invention, a plating underlayer for forming the track width restricting portion 14 is formed on the upper surface of the lower core layer 10 before forming the resist layer 30 in the step shown in FIG. The plating base layer provided in a portion other than the lower portion of the track width regulating portion 14 is appropriately removed by ion milling, and there is no need to consider the plating base layer removal step.

  As described above, in the present invention, when ion milling is performed at the above-described ion irradiation angle θ2, the track width Tw of the track width regulating portion 14 can be formed to 0.4 μm or less, preferably 0.2 μm or less, and the lower core layer The inclination angle θ1 of the inclined surface 10a formed on the upper surface of 10 can be adjusted within a range of 2 ° to 10 °.

  In particular, by setting the ion irradiation inclination angle θ2 in the range of 55 ° to 70 °, as shown in the experimental results to be described later, the etching rate on both end faces of the track width restricting portion 14 and the upper surface of the upper magnetic pole layer 12 are increased. The etching rate and the etching rate at the junction D of the lower core layer 10 with the track width restricting portion 14 can be adjusted within an appropriate range, and there is no adverse effect of reattachment due to ion milling, and the track of the track width restricting portion 14 It is possible to easily fit the dimension of the width Tw and the inclination angle θ1 of the inclined surface 10a on the upper surface of the lower core layer 10 within the predetermined range.

  In the present invention, ion milling is performed with the ion irradiation angle θ2 fixed at a constant angle within the range of 45 ° to 75 °, but the etching rate for keeping the track width Tw within a predetermined range. The appropriate range of the etching rate and the appropriate range of the etching rate for forming the inclined surface 10a on the upper surface of the lower core layer 10 are different. For example, the ion irradiation angle θ2 is initially set within the range of 60 ° to 75 °. After the side end surfaces 14a and 14a of the track width restricting portion 14 are cut and the track width Tw is reduced, the ion irradiation angle θ2 is changed from 45 ° to 60 °, and an appropriate inclination angle θ1 is formed on the upper surface of the lower core layer 10. You may form the inclined surface 10a which has.

  Further, in the present invention, if the ion irradiation angle θ2 described above, the joint D with the track width restricting portion 14 of the lower core layer 10 can be appropriately cut, so that the raised portion 10c as shown in FIGS. It can be formed on the lower core layer 10. Alternatively, the ion irradiation angle is set to a substantially vertical direction (about 0 ° to 15 °) with respect to the lower core layer 10 before the step of cutting both side end surfaces 14a, 14a of the track width regulating portion 14 shown in FIG. Using ion milling, first, only the upper surface of the lower core layer 10 may be shaved to form the raised portion 10c, and then the ion milling process shown in FIGS.

  As a result, as shown in FIGS. 1 and 3, the raised portion 10c can be formed in the lower core layer 10, and further on the upper surface of the lower core layer 10 extending from the base end of the raised portion 10c, as the distance from the track width restricting portion 14 increases. The inclined surfaces 10b and 10b can be formed to be inclined so that the film thickness of the lower core layer 10 is gradually reduced.

  Next, as shown in FIG. 8, the lower core layer 10 is covered with an insulating layer 18. In this case, the track width restricting portion 14 and the lifting layer 21 are also covered with the insulating layer 18.

In the present invention, the insulating layer 18 is formed by sputtering using an inorganic material. It is preferable to select one or more of Al ₂ O ₃ , SiN, and SiO _{2 as} the inorganic material.

Then, as shown in FIG. 8, the surface of the insulating layer 18 is cut to the line DD so that the surface of the track width restricting portion 14 is exposed by using a CMP technique or the like.
As a result, as shown in FIG. 9, the upper surface 18 a of the insulating layer 18 is formed to be planarized on the same plane as the surface 14 b of the track width restricting portion 14. The surface 21a of the lifting layer 21 is also exposed by the CMP grinding process.

  As already described, the height of the track width restricting portion 14 is cut by about 1 μm by this grinding process. And in the state after this process, the height dimension H1 (refer FIG. 1) of the said track width control part 14 is stored in the height dimension of 2 micrometers or more and 3 micrometers or less.

  Next, as shown in FIG. 9, a coil layer 19 is spirally formed on the insulating layer 18. As described above, since the surface 18a of the insulating layer 18 is flattened, the coil layer 19 can be formed with good pattern accuracy, and therefore, the pitch between the conductor portions can be reduced. it can.

  As shown in FIG. 10, the coil layer 19 is covered with an organic insulating layer 20 formed of an organic insulating material such as resist or polyimide, and the upper core layer 16 is further formed on the organic insulating layer 20 by a frame plating method or the like. The pattern is formed by the existing method. As shown in FIG. 10, the upper core layer 16 is formed in contact with the track width restricting portion 14 at the distal end portion 16a, and the lifting layer 21 is formed on the lower core layer 10 at the proximal end portion 16b. Formed in magnetic contact with the top.

  The width dimension in the track width direction (X direction in the drawing) of the tip portion 16a of the upper core layer 16 is formed with a width dimension T1 larger than the track width Tw as shown in FIGS. The reason why the track width Tw can be formed with the width dimension T1 larger than the track width Tw is that the track width Tw is already set by the width dimension of the upper magnetic pole layer 12 formed separately from the upper core layer 16. .

  In this way, the width dimension of the tip portion 16a of the upper core layer 16 can be formed with a width dimension larger than the track width Tw, so that the width dimension of the tip portion 16a is regulated to the track width Tw as compared with the prior art. The upper core layer 16 can be formed with improved pattern accuracy and the width T1 of the tip 16a of the upper core layer 16 can be increased, so that the volume of the upper core layer 16 can be increased. And the occurrence of magnetic saturation can be appropriately suppressed.

  In the present invention, the relationship between the ion irradiation angle and the etching rate at an arbitrary place was examined in the ion milling performed in the process of FIG.

  In the experiment, an inductive head having the shape shown in FIG. 6 was first formed. At this time, the width T2 in the track width direction (X direction in the drawing) of the track width restricting portion 14 was in the range of 0.55 to 0.6 μm. The height dimension H3 of the track width restricting portion 14 was in the range of 4 to 4.2 μm.

  In the measurement of the etching rate, the etching rate on the both end faces of the track width restricting portion 14, the etching rate on the upper surface of the upper magnetic pole layer 12, and the joint portion of the lower core layer 10 with the track width restricting portion 14 (see FIG. 6). The etching rate at the portion indicated by symbol D) was measured while changing the ion irradiation angle θ2 (see FIG. 6). The experimental results are shown in FIG.

  As shown in FIG. 11, when the ion irradiation angle θ2 is increased, the etching rate E on both end faces of the track width restricting portion 14 is linearly increased.

  By the way, as shown in FIG. 11, when the ion irradiation angle θ2 is about 0 ° or more and 40 ° or less, the etching rate E is a negative value. This means that re-adhesion by ion milling is performed. When the ion irradiation angle θ2 is within the above range, the magnetic particles scraped by the lower core layer 10 or the like are formed on both side end surfaces of the track width regulating portion 14. This causes a problem that the width dimension T2 of the track width restricting portion 14 in the track width direction becomes large.

  That is, at least the etching rate E needs to be a positive value in order to reduce the width dimension T2 of the track width restricting portion 14 to ensure a track width Tw of 0.4 μm or less.

  Next, the etching rate G on the upper surface of the upper magnetic pole layer 12 becomes the largest when the ion irradiation angle θ2 is about 40 ° to 45 °, and the etching rate G gradually decreases as the ion irradiation angle θ2 becomes larger than that. I understand that

  As shown in FIG. 11, the etching rate G is a positive value in any range of the ion irradiation angle θ2. That is, the upper surface of the upper magnetic pole layer 12 is scraped by ion milling, and the height of the upper magnetic pole layer 12 is reduced. However, it is preferable that the height dimension of the upper magnetic pole layer 12 is not reduced as much as possible. This is because when the height dimension of the upper magnetic pole layer 12 is reduced, the volume of the upper magnetic pole layer 12 is reduced, and magnetic saturation is easily achieved when the recording density is increased. Therefore, even if the etching rate G is a positive value, the value is preferably as small as possible.

  Next, the etching rate F at the junction D of the lower core layer 10 decreases linearly as the ion irradiation angle θ2 increases. In particular, when the ion irradiation angle θ2 becomes about 75 ° or more, the etching rate F Becomes negative. A negative value means reattachment by ion milling as described above.

  The etching rate F may be at least a negative value. When it is a negative value, the magnetic particles etched away by the track width restricting portion 14 or the like adhere to the joint portion D of the lower core layer 10, and the joint portion D rises. If so, the distance between the lower core layer 10 and the upper magnetic pole layer 12 becomes smaller, which leads to an increase in write fringing, which is not preferable.

  As described above, from the above viewpoint, in the present invention, the ion irradiation angle θ2 is set to 45 ° or more and 75 ° or less. If it is within this range, as shown in FIG. 11, the etching rate E on both end faces of the track width restricting portion 14 is a positive value and increases, so that the track width restricting portion 14 in the track width direction is increased. It has been confirmed that the width dimension T2 can be reduced and the track width Tw can be reduced to 0.2 μm or less in the present invention.

  On the other hand, when the ion irradiation angle is θ2, the etching rate G on the upper surface of the upper magnetic pole layer 12 has a positive value, but the value tends to be small, and the track width when the ion milling is finished. The height of the restricting portion 14 was about 3.3 μm to 3.5 μm.

  Next, if it is said ion irradiation angle (theta) 2, the etching rate F in the junction part D of the lower core layer 12 is a positive value, and the reattachment by ion milling does not occur. Therefore, it is possible to form the raised portion 10 c shown in FIG. 1 in the lower core layer 10.

  Further, by the ion irradiation angle θ2, the inclination angle θ1 of the inclined surface 10a formed on the upper surface of the lower core layer 10 can be within a range of 2 ° to 10 °.

  In the present invention, the ion irradiation angle θ2 is more preferably 55 ° or more and 70 ° or less. Within this range, the etching rate on the upper surface of the upper magnetic pole layer 12 can be appropriately reduced, and the etching rate on both end faces of the track width restricting portion 14 can be positive and increased. Further, the etching rate at the joint D of the lower core layer 10 can be positively ensured.

The partial front view which shows the structure of the thin film magnetic head in this invention, FIG. 1 is a partial cross-sectional view of a thin film magnetic head cut from line 2-2 shown in FIG. The partial front view which shows the structure of the other thin film magnetic head in this invention, 1 process drawing which shows the manufacturing method of the thin film magnetic head in this invention, FIG. 4 is a process diagram that is performed after the process illustrated in FIG. FIG. 5 is a process diagram following the process shown in FIG. FIG. 6 is a process diagram following the process shown in FIG. FIG. 7 is a process diagram following the process shown in FIG. FIG. 8 is a process diagram performed following the process shown in FIG. FIG. 9 is a process diagram following the process shown in FIG. FIG. 6 is a graph showing the relationship between the ion irradiation angle θ2 at the time of ion milling in the step of FIG. Partial front view showing the structure of a conventional thin film magnetic head, FIG. 13 is a partial cross-sectional view of the thin film magnetic head taken along line 13-13 shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Lower core layer 10a, 10b Inclined surface 10c Raised part 11 Lower pole layer 12 Upper pole layer 14 Track width control part 15 Gap layer 16 Upper core layer 17 Gd determination insulating layer 18 Insulating layer 19 Coil layer 20 Organic insulating layer 21 Lifting layer 30 resist layer

Claims (20)

A lower core layer and an upper core layer; and a track width restricting portion which is located between the lower core layer and the upper core layer and whose width dimension is restricted to be shorter than the lower core layer and the upper core layer,
The track width restricting portion includes a lower magnetic pole layer continuous with the lower core layer, an upper magnetic pole layer continuous with the upper core layer, and a gap layer located between the lower magnetic pole layer and the upper magnetic pole layer, or the track The width restricting portion includes an upper magnetic pole layer continuous with the upper core layer, and a gap layer positioned between the upper magnetic pole layer and the lower core layer,
On the upper surface of the lower core layer extending on both sides of the track width restricting portion, an inclined surface is formed in which the distance from the upper core layer gradually increases as the distance from the track width restricting portion increases in the track width direction. A thin film magnetic head characterized by that.   2. A thin film magnetic head according to claim 1, wherein a width dimension of the track width regulating portion is 0.4 [mu] m or less.   The thin film magnetic head according to claim 2, wherein the width dimension is 0.2 μm or less.   4. The thin film magnetic head according to claim 1, wherein an inclination angle θ <b> 1 with respect to a track width direction of an inclined surface formed on the upper surface of the lower core layer is 2 ° or more and 10 ° or less. A lower core layer and an upper core layer; and a track width restricting portion which is located between the lower core layer and the upper core layer and whose width dimension is restricted to be shorter than the lower core layer and the upper core layer,
The track width restricting portion includes a lower magnetic pole layer continuous with the lower core layer, an upper magnetic pole layer continuous with the upper core layer, and a gap layer located between the lower magnetic pole layer and the upper magnetic pole layer, or the track The width restricting portion includes an upper magnetic pole layer continuous with the upper core layer, and a gap layer positioned between the upper magnetic pole layer and the lower core layer,
A thin film magnetic head, wherein a width dimension of the track width regulating portion is 0.4 μm or less.   The thin film magnetic head according to claim 5, wherein the width dimension is 0.2 μm or less.   On the upper surface of the lower core layer extending on both sides of the track width restricting portion, an inclined surface is formed in which the distance from the upper core layer gradually increases as the distance from the track width restricting portion increases in the track width direction. The thin film magnetic head according to claim 5.   The thin film magnetic head according to claim 7, wherein an inclination angle θ <b> 1 with respect to the track width direction of an inclined surface formed on the upper surface of the lower core layer is 2 ° or more and 10 ° or less.   9. The thin film magnetic head according to claim 1, wherein a height dimension of the track width restricting portion is not less than 2 μm and not more than 3 μm.   10. The thin film magnetic head according to claim 1, wherein the gap layer is made of a nonmagnetic metal material that can be plated.   11. The thin film magnetic head according to claim 10, wherein the nonmagnetic metal material is selected from one or more of NiP, NiPd, NiW, NiMo, Au, Pt, Rh, Pd, Ru, and Cr. (A) forming a resist layer on the lower core layer, and forming a groove having a predetermined width dimension and a predetermined length dimension in a height direction from a surface facing the recording medium in the resist layer;
(B) A track width restricting portion in which a lower magnetic pole layer, a nonmagnetic gap layer, and an upper magnetic pole layer are sequentially laminated in the groove, or a track width restricting portion in which a nonmagnetic gap layer and an upper magnetic pole layer are sequentially laminated. Forming, and
(C) removing the resist layer;
(D) cutting both side surfaces of the track width restricting portion in the track width direction to restrict the width dimension of the track width restricting portion to the track width;
(E) forming an inclined surface on the upper surface of the lower core layer extending on both sides of the track width restricting portion so that the distance from the upper core layer gradually increases as the distance from the track width restricting portion increases;
(F) forming an upper core layer having a width dimension larger than the track width on the track width regulating portion;
A method of manufacturing a thin film magnetic head, comprising:   13. The thin film magnetic head according to claim 12, wherein the step of regulating the width dimension of the track width regulating portion of (d) and the step of forming the inclined surface of (e) are simultaneously performed using an ion milling method. Manufacturing method.   14. The thin film magnetic head according to claim 13, wherein the ion irradiation angle θ2 in the ion milling has an inclination of 45 ° or more and 75 ° or less with respect to a direction parallel to the height direction of the track width restricting portion. Manufacturing method.   15. The method of manufacturing a thin film magnetic head according to claim 14, wherein the ion irradiation angle [theta] 2 has an inclination of 55 [deg.] To 70 [deg.].   16. The method of manufacturing a thin film magnetic head according to claim 12, wherein in the step (d), the track width regulated by the track width regulating portion is formed to 0.4 μm or less.   The method of manufacturing a thin film magnetic head according to claim 16, wherein the track width is formed to 0.2 μm or less.   18. The step (e), wherein the inclined surface formed on the upper surface of the lower core layer is formed with an inclination angle θ1 of 2 ° or more and 10 ° or less with respect to the track width direction. A method of manufacturing a thin film magnetic head according to any one of the above.   19. A method of manufacturing a thin film magnetic head according to claim 12, wherein the gap layer constituting the track width restricting portion is formed by plating together with the pole layer.   The nonmagnetic metal material capable of being plated for forming the gap layer is selected from one or more of NiP, NiPd, NiW, NiMo, Au, Pt, Rh, Pd, Ru, and Cr. Manufacturing method of thin film magnetic head.

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