JP2006209879A - Thin film magnetic head, its manufacturing method, head gimbal assembly, and hard disk drive - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly reliable and thin-film magnetic head preventing cracks around a viaplug when a substrate and a shield layer are bonded by the viaplug. <P>SOLUTION: The thin-film magnetic head 1 is provided with a reproducing part 3 stacked on a substrate 11 via a substrate layer 12. The reproducing part 3 is provided with a lower shield layer 13, a first upper shield layer 15, and an MR element 14 arranged therebetween. The lower shield layer 13 is electrically connected to the substrate 11 via a first viaplug 35a formed through the substrate layer 12 and a wiring line 37 formed on the substrate layer 12. The first viaplug 35a is formed by burying a viahole formed in the substrate layer 12 by wet etching. Plating electrode films are formed on the bottom and the side face of the viahole. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a thin film magnetic head, a hard disk device having the thin film magnetic head, and a method for manufacturing the thin film magnetic head, and more particularly to a structure of the thin film magnetic head and a method for forming the same.

  As a thin film magnetic head, a thin film magnetic head having a composite structure in which a reproducing unit having a magnetoresistive effect element (MR element) for reading and a recording unit having an inductive electromagnetic transducer for writing are joined in close proximity is widely used. It is used. As the MR element constituting the reproducing unit, a device using a spin valve film (hereinafter referred to as an SV film) is mainly used. On the other hand, a thin-film magnetic head using a ferromagnetic tunnel junction film (hereinafter referred to as a TMR film) as an MR element can expect a resistance change rate more than twice that of a thin-film magnetic head using an SV film. Has been done.

  MR elements are roughly classified into two structures based on the difference in the direction in which the sense current flows. One is called a CIP (Current In Plane) structure in which a sense current flows parallel to the film surface, and the other is a CPP (Current Perpendicular to Plane) structure in which a sense current flows perpendicular to the film surface. Called. Since the CPP structure can use the magnetic shield itself as an electrode, a short circuit (insulation failure) between the magnetic shield and the element, which is a problem in narrowing the read gap of the CIP structure, does not occur essentially. Therefore, the CPP structure is very advantageous for increasing the recording density.

  Since the TMR film basically has a CPP structure, the above-described advantages can be obtained. Also in the SV film, in order to secure the advantages of the above-described CPP structure, the CIP structure, which has been widely used in the past, is being converted to the CPP structure. For example, a multilayer structure such as a specular type or a dual type is an example.

In the CPP structure, the lower shield layer and the first upper shield layer stacked so as to sandwich the MR element from both sides are also used as electrodes for supplying a sense current. The lower shield film is provided on a substrate made of Al ₂ O ₃ .TiC (Altic) having excellent wear resistance. Altic has a higher electrical conductivity than Al ₂ O ₃ (alumina). A first insulating layer (underlayer) is provided on the upper surface of the substrate, and a lower shield layer is formed thereon. Then, the second insulating layer is interposed between the lower shield layer and the first upper shield layer, and the MR element is disposed inside the second insulating layer.

  A third insulating layer is provided on the first upper shield layer, and a recording unit is provided on the third insulating layer. The recording unit has a coil, a magnetic circuit, and a recording gap. The coil is supported by being insulated from the surroundings by an organic material or an insulating layer made of an organic material. The magnetic circuit guides the magnetic flux generated by the current flowing in the coil, and is supported by the lower magnetic pole / second upper shield layer facing the first upper shield layer via the third insulating layer, and the insulating layer. And an upper magnetic pole layer that faces the lower magnetic pole and the second upper shield layer and is magnetically coupled to the lower magnetic pole and the second upper shield layer at a position away from the surface facing the recording medium. . The lower magnetic pole / second upper shield layer and the upper magnetic pole layer each have a magnetic pole portion facing each other on the surface facing the recording medium, and the recording gap is disposed between these magnetic pole portions.

The thin film magnetic head has a very fine structure, and processes such as film formation, photolithography, and etching are used for manufacturing the thin film magnetic head. For example, in Patent Document 1, when patterning a member constituting a magnetic circuit, a base layer made of chromium is formed on a substrate, a magnetic circuit layer is formed in a predetermined pattern on the base layer, and the magnetic circuit layer is left. It is disclosed that the portion is covered with a photoresist and the magnetic circuit layer is removed by wet etching, and then the photoresist is removed and the exposed portion of the underlayer is removed by wet etching. Further, in Patent Document 2, when forming a via in an alumina layer, a plurality of metal layers are formed on the alumina layer, these metal layers are patterned, and wet etching is performed through the patterned metal layers. The selective removal of the alumina layer is disclosed.
JP-A-9-190918 Japanese Patent Laid-Open No. 9-135046

  In a conventional thin film magnetic head having a CPP structure, since the shield layer is magnetically and electrically insulated from the substrate, friction occurs between the thin film magnetic head and the recording medium during the recording / reproducing operation. The shield layer is charged. When charge is accumulated in the shield layer due to charging and a potential difference exceeding the withstand voltage between the recording medium and the recording medium is generated, a discharge occurs between the thin film magnetic head and the recording medium. In addition, discharge may occur between the lower shield layer and the first upper shield layer. These discharges destroy the MR element in the worst case.

  In order to prevent the above-described problems caused by charging, it is necessary to release charges accumulated in the shield layer to the substrate. Therefore, it is conceivable to provide a via plug that penetrates the base layer and connect the shield layer to the substrate via the via plug. A general method that can be considered as a connection method using via plugs will be described below.

  First, a base layer made of alumina is formed as a first insulating layer on a substrate made of Altic. On top of that, a Ti film is formed in a frame shape surrounding the periphery of the region where the via plug is formed, for alignment when forming the via plug. This Ti film also serves as a land for wiring. Next, a resist is applied so as to cover the base layer and the Ti film, and this resist is patterned so that a region surrounded by the Ti film is opened. Using the patterned resist as a mask, the underlayer is selectively removed by wet etching, and a via hole is formed in the underlayer. The reason why the underlayer is removed by wet etching is that wet etching has a higher etching rate than dry etching and can efficiently form a via hole.

  Next, an electrode film for plating and wiring for connecting the via plug and the shield layer are formed on the entire top surface of the substrate from which the underlayer has been selectively removed. Thereafter, a resist is applied, and this resist is patterned so that a region surrounded by the Ti film and a region for forming the shield layer are opened. Since the electrode film is exposed on the bottom surface of the opening due to the resist patterning, the via plug and the shield layer are formed by depositing permalloy in the opening by plating. Thereafter, the resist is removed, and then the whole is covered with an insulating film made of alumina, and the surface of the insulating film is planarized by chemical mechanical polishing (CMP). As described above, a configuration in which the substrate is connected to the shield layer via the via plug and the wiring is obtained.

  However, in the above-described method, as shown in FIG. 9, a cavity 536 is formed between the base layer 512 formed on the substrate 511 and the via plug 535. This is because when the base layer 512 is selectively removed by wet etching, the base layer 512 wraps under the Ti film 531 and isotropically etched, and when the electrode film 533 is further formed, the base layer 512 is etched. This is because the electrode film 533 is not formed behind the Ti film 531 on the side surface of the via hole 512a formed in the 512, and the side surface of the via hole 512a has poor adhesion with the plating material constituting the via plug 535. . Thus, when the cavity 536 is formed around the via plug 535, a crack may be generated in this portion. The generation of cracks is not preferable because it causes a decrease in the reliability of the thin film magnetic head.

  An object of the present invention is to prevent a crack from being generated around a via plug when the substrate and the shield layer are connected by a via plug, thereby obtaining a highly reliable thin film magnetic head or the like.

  In order to achieve the above object, a thin film magnetic head of the present invention includes a substrate, a first insulating layer formed on one surface of the substrate, and a pair of shield layers formed on the first insulating layer. And a reproducing unit including a magnetoresistive effect element disposed therebetween. In the thin film magnetic head of the present invention, at least the shield layer on the substrate side of the shield layer is electrically connected to the substrate through a via plug formed through the first insulating layer, The through-hole formed in the insulating layer has a shape in which the opening area is the smallest at the tip on the substrate side and increases with distance from the substrate, and a conductor film is formed on the bottom and side surfaces of the through-hole. Has been.

  Thus, in the thin film magnetic head of the present invention, since the shield layer is electrically connected to the substrate by the via plug, the problem due to charging is eliminated. Furthermore, by forming the via plug as described above, adhesion to the via hole is improved, and a cavity that causes a crack is not generated around the via plug.

  The through hole is preferably formed by wet etching. The via plug and the substrate-side shield layer may be connected via a wiring formed on the first insulating layer. A thin film magnetic head according to the present invention includes a recording unit including an inductive magnetic transducer disposed between a pair of opposing magnetic pole layers adjacent to a reproducing unit via a second insulating layer in a stacking direction on a substrate. Furthermore, it can also have.

  A method of manufacturing a thin film magnetic head according to the present invention includes a step of forming a first insulating layer on a substrate, and a magnetoresistive element disposed between the pair of opposing shield layers on the first insulating layer. A step of laminating and forming a reproducing portion including the step of forming a via plug penetrating the first insulating layer, and a step of electrically connecting at least the shield layer on the substrate side of the shield layer to the substrate through the via plug And having. In the thin film magnetic head of the present invention, the step of forming the via plug includes a step of forming a frame-like film made of Ti on the first insulating layer, and a step of forming the first insulating layer having the frame-like film formed thereon. A step of forming a resist layer with a pattern having an opening smaller than the opening of the frame-like film inside the opening of the frame-like film, and the first insulation using the resist layer as a mask Forming a through hole in the first insulating layer by wet etching the layer, forming a conductor film on the inner surface of the through hole, and depositing a material of a via plug in the via hole by a plating method; Have.

  In the method for manufacturing a thin film magnetic head of the present invention, a through hole is formed in the first insulating layer by wet etching using the resist layer formed on the first insulating layer as a mask. The through hole is formed in a taper shape around the opening just below the resist layer. However, since the size of the opening of the resist layer is made small in consideration of the size of the opening of the frame-like film made of Ti formed on the first insulating layer, the mask is then formed. When the via plug material is deposited and deposited in the through hole by plating, the through hole can be filled with the via plug material. Moreover, since the through hole is formed in a tapered shape, the conductor film can be formed not only on the bottom surface of the through hole but also on the side surface in the step of forming the conductor film on the inner surface of the through hole. Therefore, the adhesion of the via plug to the through hole is improved. As described above, the via plug is formed without forming a cavity around the through hole.

  In the method of manufacturing a thin film magnetic head of the present invention, the step of electrically connecting the substrate side shield layer to the substrate includes wiring for connecting the via plug and the substrate side shield layer on the first insulating layer. A step of forming may be included. Further, in the case where the material constituting the shield layer on the substrate side and the material constituting the via plug are the same, the manufacturing process can be simplified if the shield layer and the via plug on the substrate side are formed in a common process.

  The present invention further provides a wafer including the thin film magnetic head of the present invention described above, a head gimbal assembly, and a hard disk device.

  The wafer of the present invention is one in which at least one head element including the thin film magnetic head of the present invention is formed.

  The head gimbal assembly of the present invention includes a slider including the thin film magnetic head of the present invention and a suspension that elastically supports the slider.

  A hard disk device of the present invention supports the head gimbal assembly of the present invention, a disk-shaped recording medium that is driven to rotate, and the head gimbal assembly with the slider facing the recording medium and positions the slider relative to the recording medium. Positioning means.

  According to the present invention, as described above, no cavity is formed around the via plug that connects the substrate and the shield layer, and the adhesion of the via plug is improved, thereby preventing cracks from occurring around the via plug. As a result, a highly reliable thin film magnetic head or the like can be provided.

  FIG. 1 conceptually shows a cross-sectional view of the main part of a thin film magnetic head according to an embodiment of the present invention.

  The thin film magnetic head 1 according to this embodiment includes a substrate 11, a reproducing unit 2 for reading and a recording unit 3 for writing on a recording medium (not shown) formed on the substrate 11.

  The substrate 11 is made of Altic. Altic is superior in wear resistance and lubricity as compared with alumina, but has high conductivity. Therefore, the base layer 12 made of alumina is formed on the upper surface of the substrate 11, and the reproducing unit 2 and the recording unit 3 are laminated thereon.

  On the base layer 12, a lower shield layer 13 made of a magnetic material such as permalloy (NiFe) is formed. An MR element 14 is formed on the lower shield layer 13 at the end on the medium facing surface S side with one end thereof exposed to the medium facing surface S. As the MR element 14, various elements using a magnetosensitive film exhibiting a magnetoresistive effect, such as an AMR (anisotropic magnetic effect) element, a GMR (giant magnetoresistive effect) element, and a TMR (tunnel magnetoresistive effect) element are used. be able to. A first upper shield layer 15 made of a magnetic material such as permalloy is formed on the MR element 14. The lower shield layer 13, the MR element 14, and the first upper shield layer 15 constitute the reproducing unit 2. An insulating layer 16 a is formed in a portion where the MR element 14 does not exist between the lower shield layer 13 and the first upper shield layer 15.

  A second upper shield layer 17 made of a magnetic material such as permalloy or CoNiFe that can be formed by a plating method is formed on the first upper shield layer 15 via an insulating layer 16b. The second upper shield layer 17 has a function as the lower magnetic pole layer of the recording unit 3 in addition to the function as the upper shield layer of the MR element 14.

  An upper magnetic pole layer 19 is formed on the second upper shield layer 17 via a recording gap layer 18 for insulation. The recording gap layer 18 is formed at the end on the medium facing surface S side, with one end exposed on the medium facing surface S. As the material of the recording gap layer 18, for example, a nonmagnetic metal material that can be formed by sputtering, such as Ru or alumina, is used. As the material of the upper magnetic pole layer 19, for example, a magnetic material that can be formed by a plating method such as permalloy or CoNiFe is used. The second upper shield layer (lower magnetic pole layer) 17 and the upper magnetic pole layer 19 are magnetically connected by the connecting portion 21 at a position away from the medium facing surface S to form one magnetic circuit as a whole.

  Between the second upper shield layer 17 and the upper magnetic pole layer 19, two coils 20 a and 20 b made of a conductive material such as copper are formed between the medium facing surface S and the connection portion 21. Each of the coils 20a and 20b supplies magnetic flux to the second upper shield layer 17 and the upper magnetic pole layer 19, and is formed in a shape that circulates around the connection portion 21 so as to have a planar spiral shape. Opposed to each other. The coils 20a and 20b are insulated from the surroundings by an insulating layer. The number of turns of the coils 20a and 20b is arbitrary. In the present embodiment, the two-layer coils 20a and 20b are shown. However, the present invention is not limited to this, and may be one layer or three or more layers.

  The overcoat layer 22 is provided so as to cover the upper magnetic pole layer 19 and protects the above-described structure. As a material of the overcoat layer 22, an insulating material such as alumina is used.

  Further, a first via plug 35 a penetrating the base layer 12 is provided on the substrate 11. The first via plug 35 a is electrically connected to the lower shield layer 13 through the wiring 37. As the material of the first via plug 35a, the same material as that of the lower shield layer 13 can be used. Between the lower shield layer 13 and the lower magnetic pole / second upper shield layer 17, second via plugs 35 b penetrating the insulating layers 16 a and 16 b and the first upper shield layer 15 are provided. The lower shield layer 13, the first upper shield layer 15, and the lower magnetic pole / second upper shield layer 17 are electrically connected by a second via plug 35b.

  As described above, in the present embodiment, the lower shield layer 13 and the first upper shield layer 15 are electrically connected to the substrate 11 via the first via plug 35a. Accordingly, charging of each of these shield layers can be prevented, and in particular, destruction of the MR element 14 due to discharge between the lower shield layer 13 and the first upper shield layer 15 can be effectively prevented.

  Furthermore, in the present embodiment, the first upper shield layer 15 and the lower magnetic pole / second upper shield layer 17 are electrically connected by the second via plug 35b. A parasitic capacitance is generated between the lower magnetic pole / second upper shield layer 17 and the first upper shield layer 15 by using the insulating layer 16b as a capacitive layer, and between the lower shield layer 13 and the substrate 11, a lower capacitance is generated. Parasitic capacitance is generated with the formation 12 as a capacitive layer. If these parasitic capacitances are different from each other, external noise easily enters from the substrate 11 side, causing deterioration of the MR element 14 and an error. On the other hand, in this embodiment, since the lower magnetic pole and second upper shield layer 17 is also electrically connected to the substrate 11, the first upper shield layer 15 and the lower portion viewed from the first upper shield layer 15. The voltage between the magnetic pole-cum-second upper shield layer 17 and the voltage between the substrate 11 and the lower shield layer 13 viewed from the lower shield layer 13 are substantially equal, and the potential difference is substantially zero. Thereby, even if an external noise of any frequency enters from the substrate 11, it is possible to avoid the degradation and error of the MR element due to the influence of the external noise.

  Next, a method for forming the via plug 35a will be described with reference to FIGS.

  First, as shown in FIG. 2A, when the base layer 12 is formed on the substrate 11, the via plug 35a (see FIG. 1) and the lower shield layer 13 (see FIG. 1) are determined on the base layer 12. Ti films 31a and 31b to be alignment marks are formed in a predetermined shape by sputtering or the like. One Ti film 31a indicates a position where a via plug penetrating through the underlayer 12 is formed, and is formed in a frame shape having an opening 31c having a dimension equal to the lateral cross section of the via plug. The via plug is formed in the opening 31c. The other Ti film 31b is formed in a planar shape larger than the cross section of the lower shield layer 13 to be formed so that the lower shield layer 13 is formed thereon. This Ti film 31 b also has a function of improving the adhesion of the lower shield layer 13. The Ti films 31a and 31b also serve as lands when the via plug 35a and the lower shield layer 13 are connected by the wiring 37 (see FIG. 1).

  Next, as shown in FIG. 2B, a first resist 32 is applied so as to cover the base layer 12 and the Ti films 31a and 31b. Further, the applied first resist 32 is patterned so that an opening 32a is formed in a portion inside the Ti film 31a formed in a frame shape, and a part of the base layer 12 is exposed. The size of the opening 32a of the first resist 32 is made smaller than the size of the opening 31c of the Ti film 31a.

  Next, as shown in FIG. 2C, the underlying layer 12 is selectively removed by wet etching using the first resist 32 as a mask. As a result, a via hole 12a is formed in the base layer 12 so as to open to a region inside the Ti film 31a and reach the substrate 11. By wet etching, the underlayer 12 is isotropically etched by going around the opening 32 a of the first resist 32. As a result, the via hole 12a is formed in a tapered shape so that the opening area is the smallest on the upper surface of the substrate 11 and the opening area gradually increases as the distance from the upper surface of the substrate 11 increases. Here, the taper shape includes not only a linear taper but also a curved saddle shape, but in the present invention, for convenience of explanation, these shapes are referred to as a taper shape.

  As described above, the tapered via hole 12a is formed in the underlayer 12 by wet etching. As described above, the opening 32a of the first resist 32 is formed in the opening 31c of the Ti film 31a (FIG. 2A). Therefore, the side surface of the via hole 12a does not reach the Ti film 31a. In other words, the opening 32a of the first resist 32 has an opening 31c of the Ti film 31a so that the via hole 12a does not reach the Ti film 31a when the via hole 12a is formed by wet etching of the base layer 12. Form smaller than.

  The size of the opening 32a that satisfies this condition depends on the material of the base layer 12, the dimensions of each part of the base layer 12 and the Ti film 31a, the etching solution, and other etching conditions, and is determined by logical calculations and experiments. It can be obtained in advance. For example, when the Ti film 31a having a film thickness of 0.05 μm is formed on the base layer 12 made of alumina having a film thickness of 0.33 μm in a pattern having a rectangular opening having an opening of 24 μm × 24 μm. When the opening 32a of the first resist 32 has a rectangular shape of 18 μm × 18 μm (75% in length ratio with respect to the opening of the Ti film 31a) and wet etching is performed under the following conditions, the Ti film 31a The via hole 12a was able to be formed without wrapping under. The etching conditions at this time were as follows: the etching solution was a NaOH aqueous solution (ph 10.5), and the etching time was 3 minutes.

  Next, the first resist 32 is removed to expose the underlying layer 12 and the Ti films 31a and 31b as shown in FIG. 2D. Further, as shown in FIG. 2E, the first resist 32 and the inside of the via hole 12a are also included. A plating electrode film 33 made of, for example, permalloy or the like is formed on the entire surface exposed by removing the resist 32 by sputtering. Since the via hole 12a is formed in a tapered shape as described above and does not go under the Ti film 31a, the plating electrode film 33 is formed not only on the bottom surface but also on the side surface of the via hole 12a.

  Next, as shown in FIG. 2F, a second resist 34 is applied so as to cover the electrode film 33 for plating. Further, the applied second resist 34 is patterned so that the opening 34a on the via hole 12a and the opening 34b on the Ti film 31b are formed, and the plating electrode film 33 is formed in these openings 34a and 34b. Expose.

  Next, using the second resist 34 as a mask, a plating material made of, for example, permalloy is deposited on the exposed electrode film 33 for plating by a plating method, thereby forming the first via plug 35a as shown in FIG. 2G. And the lower shield layer 13 is formed simultaneously. Thus, the manufacturing process can be simplified by forming the first via plug 35a and the lower shield layer 13 in a common process.

  Next, the second resist 34 is removed, and the plating electrode film 33 is exposed as shown in FIG. 2H. The first via plug 35a and the lower shield layer 13 protrude from the plating electrode film 33. Further, as shown in FIG. 2I, a Ta film 36 is formed as a wiring material on the entire surface exposed by removing the second resist 34. The Ta film 36 and the plating electrode film 33 are patterned by milling to form a wiring 37 for connecting the first via plug 35a and the lower shield layer 13 through the Ti films 31a and 31b as shown in FIG. 2J. .

  Next, as shown in FIG. 2K, the insulating layer 38 made of alumina is formed by sputtering so as to cover the entire surface of the laminate thus far manufactured, and the surface of the insulating layer 38 is planarized by CMP. The via plug 35a and the lower shield layer 13 are exposed.

  Thereafter, the second via plug 35b is formed on the lower shield layer 13 in the same manner as the first via plug 35a, and the structure on the lower shield layer 13 is formed using a known method. The thin film magnetic head 1 can be manufactured.

  In the above-described series of steps, in the step of forming the via hole 12a for forming the via plug 35a penetrating the underlayer 12 in the underlayer 12, the tapered shape is formed so as to expand as the distance from the substrate 11 increases as described above by wet etching. Formed. However, since the size of the opening 32a of the first resist 32 is formed in consideration of the size of the opening 31c of the Ti film 31a, the Ti film 31a, like the Ti film 31a, is formed above the via hole 12a. There is no member that partially covers the opening of the via hole 12a. As a result, when the via plug 35a is formed by plating, the via hole 12a can be filled with a plating material, and the obtained via plug 35a has a shape in which the via hole 12a is filled without any gap. That is, the via plug 35a has the smallest cross-sectional area at the tip on the substrate 11 side in the underlayer 12 so that the cross-sectional area increases from the lower side to the upper side in the stacking direction on the substrate 11, and the substrate in the underlayer 12 11 is formed in a tapered shape having a cross-sectional area that gradually increases with distance from 11.

  In addition, in the step of forming the plating electrode film 33, there is no member above the via hole 12a as described above, and therefore the plating electrode film 33 is formed not only on the bottom surface but also on the side surface of the via hole 12a. Is formed. The plating electrode film 33 can also be formed on the side surface of the via hole 12a because the tapered via hole shape contributes greatly, and the tapered via hole 12a is achieved by wet etching.

  From the above, no cavity is formed between the base layer 12 and the via plug 35a, and the adhesion between them is improved. As a result, even in the configuration in which the substrate 11 and the lower shield layer 13 are connected by the via plug 35a, cracks are prevented from occurring around the via plug 35a, and the highly reliable thin film magnetic head 1 can be obtained.

  Further, in the present embodiment, the first via plug 35 a and the lower shield layer 13 are connected via the wiring 37. According to such a configuration, the conduction resistance between the substrate 11 and the lower shield layer 13 is arbitrarily adjusted by appropriately selecting the material of the wiring 37 and appropriately setting the length of the wiring 37. be able to. When a predetermined conduction resistance cannot be obtained only by the material and length of the wiring 37, a resistance element (not shown) is provided so that a predetermined resistance value is obtained between the first via plug 35a and the lower shield layer 13. The first via plug 35a and the lower shield layer 13 can be connected to each other through this resistance element.

  When the first via plug 35a and the lower shield layer 13 need only be connected, a via plug 45 penetrating the base layer 12 is provided between the substrate 11 and the lower shield layer 13 as shown in FIG. It is also possible to integrally form the lower shield layer 13 and connect the substrate 11 and the lower shield layer 13 by the via plug 45. In this case, since it is not necessary to connect the via plug 45 and the lower shield layer 13 by wiring, the step of forming the Ta film 36 shown in FIG. 2I and the wiring 37 by patterning the Ta film 36 shown in FIG. A forming step is not necessary.

  In the above-described embodiment, the example has the second via plug 35b that connects the lower shield layer 13, the first upper shield layer 15, and the lower magnetic pole and second upper shield layer 17, but the second via plug 35b The lower shield layer 13 and the first upper shield layer 15 may be connected. Even in this case, the destruction of the MR element 14 due to the discharge between the lower shield layer 13 and the first upper shield layer 15 can be sufficiently prevented. Further, the second via plug 35b may not be provided, and the substrate 11 and the lower shield layer 13 may be connected only by the first via plug 35a.

  A plurality of thin film magnetic heads of the present invention are formed side by side on a single wafer. FIG. 4 is a conceptual plan view of a wafer on which a number of structures including the thin film magnetic head shown in FIG. 1 are formed.

  The wafer 100 is partitioned into a plurality of head element assemblies 101. The head element assembly 101 includes a plurality of head elements 102 and serves as a unit of work for polishing the medium facing surface S of the thin film magnetic head 1 (see FIG. 1). A cutting allowance (not shown) for cutting is provided between the head element assemblies 101 and between the head elements 102. The head element 102 is a structure including the configuration of the thin film magnetic head 1, and necessary processing such as polishing for forming the medium facing surface S is performed to form the thin film magnetic head 1. This polishing process is generally performed with a plurality of head elements 102 cut out in a row.

  Next, a head gimbal assembly and a hard disk device including the thin film magnetic head of the present invention will be described. First, the slider 210 included in the head gimbal assembly will be described with reference to FIG. In the hard disk device, the slider 210 is arranged to face a hard disk that is a disk-shaped recording medium that is driven to rotate. The slider 210 includes the thin film magnetic head 1 obtained from the head element 102 (see FIG. 4), and the air bearing surface 200 is formed on the medium facing surface S facing the hard disk, so that the slider 210 has a substantially hexahedral shape as a whole. Yes. When the hard disk rotates in the z direction in FIG. 5, an air flow passing between the hard disk and the slider 210 generates a lift in the slider 210 in the downward direction in the y direction. The slider 210 floats from the surface of the hard disk by this lifting force. The x direction in FIG. 5 is the track crossing direction of the hard disk. On the air outflow side end surface 211 of the slider 210, electrode pads for signal input and output to the reproducing unit 2 and the recording unit 3 (see FIG. 1) are formed. This surface corresponds to the upper end surface in FIG.

  Next, the head gimbal assembly 220 will be described with reference to FIG. The head gimbal assembly 220 includes a slider 210 and a suspension 221 that elastically supports the slider 210. The suspension 221 includes, for example, a leaf spring-shaped load beam 222 formed of stainless steel, a flexure 223 that is provided at one end of the load beam 222 and is joined to the slider 210 to give the slider 210 an appropriate degree of freedom, And a base plate 224 provided at the other end of the beam 222. The base plate 224 is attached to an arm 230 of an actuator for moving the slider 210 in the track crossing direction x of the hard disk 262. The actuator includes an arm 230 and a voice coil motor that drives the arm 230. In the flexure 223, a part to which the slider 210 is attached is provided with a gimbal part for keeping the posture of the slider 210 constant.

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

  FIG. 6 shows an example of the head arm assembly. In this head arm assembly, a head gimbal assembly 220 is attached to one end of the arm 230. A coil 231 that is a part of the voice coil motor is attached to the other end of the arm 230. A bearing portion 233 attached to a shaft 234 for rotatably supporting the arm 230 is provided at an intermediate portion of the arm 230.

  Next, an example of the head stack assembly and the hard disk device according to the present embodiment will be described with reference to FIGS. FIG. 7 is an explanatory view showing a main part of the hard disk device, and FIG. 8 is a plan view of the hard disk device. The head stack assembly 250 has a carriage 251 having a plurality of arms 252. A plurality of head gimbal assemblies 220 are attached to the plurality of arms 252 so as to be arranged in the vertical direction at intervals. A coil 253 that is a part of the voice coil motor is attached to the carriage 251 on the opposite side of the arm 252. The head stack assembly 250 is incorporated in a hard disk device. The hard disk device has a plurality of hard disks 262 attached to a spindle motor 261. For each hard disk 262, two sliders 210 are arranged so as to face each other with the hard disk 262 interposed therebetween. Further, the voice coil motor has permanent magnets 263 arranged at positions facing each other with the coil 253 of the head stack assembly 250 interposed therebetween.

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

  In the hard disk device, the slider 210 is moved with respect to the hard disk 262 by moving the slider 210 in the track crossing direction of the hard disk 262 by the actuator. The thin film magnetic head included in the slider 210 records information on the hard disk 262 by the recording unit, and reproduces information recorded on the hard disk 262 by the reproducing unit.

  In addition, this invention is not limited to the said embodiment, A various change is possible. For example, in the present embodiment, a thin film magnetic head having a structure in which an MR element for reading is formed on the substrate side and an inductive electromagnetic transducer for writing is stacked thereon has been described. However, this stacking order is reversed. May be. In the above-described embodiment, the case where both the MR element and the inductive electromagnetic conversion element are included is described as an example. However, only the MR element may be included.

1 is a conceptual cross-sectional view of a thin film magnetic head according to an embodiment of the present invention. FIG. 6 is a conceptual cross-sectional view for explaining a manufacturing procedure of the first via plug shown in FIG. 1. FIG. 6 is a conceptual cross-sectional view for explaining a manufacturing procedure of the first via plug shown in FIG. 1. FIG. 6 is a conceptual cross-sectional view for explaining a manufacturing procedure of the first via plug shown in FIG. 1. FIG. 6 is a conceptual cross-sectional view for explaining a manufacturing procedure of the first via plug shown in FIG. 1. FIG. 6 is a conceptual cross-sectional view for explaining a manufacturing procedure of the first via plug shown in FIG. 1. FIG. 6 is a conceptual cross-sectional view for explaining a manufacturing procedure of the first via plug shown in FIG. 1. FIG. 6 is a conceptual cross-sectional view for explaining a manufacturing procedure of the first via plug shown in FIG. 1. FIG. 6 is a conceptual cross-sectional view for explaining a manufacturing procedure of the first via plug shown in FIG. 1. FIG. 6 is a conceptual cross-sectional view for explaining a manufacturing procedure of the first via plug shown in FIG. 1. FIG. 6 is a conceptual cross-sectional view for explaining a manufacturing procedure of the first via plug shown in FIG. 1. FIG. 6 is a conceptual cross-sectional view for explaining a manufacturing procedure of the first via plug shown in FIG. 1. FIG. 6 is a conceptual cross-sectional view for explaining a manufacturing procedure of the first via plug shown in FIG. 1. FIG. 6 is a conceptual cross-sectional view showing another form of the first via plug shown in FIG. 1. It is a top view of the wafer in which the thin film magnetic head of this invention was formed. It is a perspective view of the slider containing the thin film magnetic head of this invention. FIG. 6 is a perspective view of a head gimbal assembly including the slider shown in FIG. 5. It is a principal part side view of the hard disk drive containing the head gimbal assembly shown in FIG. FIG. 7 is a plan view of a hard disk device including the head gimbal assembly shown in FIG. 6. It is sectional drawing explaining the problem at the time of forming a via plug in the through-hole formed by wet etching.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Thin-film magnetic head 2 Reproduction | regeneration part 3 Recording part 11 Substrate 12 Underlayer 12a Via hole 13 Lower shield layer 14 MR element 15 1st upper shield layer 16a, 16b, 38 Insulating layer 17 Lower magnetic pole and 2nd upper shield layer 18 Recording gap layer 19 Upper magnetic pole layer 20a, 20b Coil 22 Overcoat layer 31a, 31b Ti film 32, 34 Resist 33 Plating electrode film 35a, 35b, 45 Via plug 36 Ta film 37 Wiring 100 Wafer 102 Head element 210 Slider 220 Head gimbal assembly 250 Head Stack assembly 262 hard disk

Claims (12)

A substrate,
A first insulating layer formed on one surface of the substrate;
A reproducing unit including a magnetoresistive effect element disposed between a pair of shield layers, formed by stacking on the first insulating layer,
At least the shield layer on the substrate side of the shield layer is electrically connected to the substrate through a via plug formed through the first insulating layer,
The via plug is formed by filling a through hole formed in the first insulating layer and having a shape in which the opening area is the smallest at the tip on the substrate side and increases as the distance from the substrate increases.
The through hole is a thin film magnetic head in which a conductor film is formed on a bottom surface and a side surface.   The thin film magnetic head according to claim 1, wherein the through hole is formed by wet etching.   3. The thin film magnetic head according to claim 1, wherein the via plug and the shield layer on the substrate side are connected via a wiring formed on the first insulating layer.   4. The thin film magnetic head according to claim 1, wherein a second via plug that electrically connects the pair of shield layers is formed on the shield layer on the substrate side.   The recording unit further comprising an inductive magnetic transducer disposed between a pair of opposing magnetic pole layers adjacent to the reproducing unit via a second insulating layer in a stacking direction on the substrate. 4. A thin film magnetic head according to any one of items 1 to 3.   The thin film magnetic head according to claim 5, wherein a second via plug that electrically connects the pair of shield layers and the magnetic pole layer is formed on the shield layer on the substrate side. Forming a first insulating layer on the substrate;
Forming a reproducing portion including a magnetoresistive effect element disposed between a pair of opposing shield layers on the first insulating layer by stacking;
Forming a via plug that penetrates the first insulating layer;
Electrically connecting at least the shield layer on the substrate side of the shield layer to the substrate through the via plug, and
The step of forming the via plug includes
Forming a frame-like film made of Ti on the first insulating layer;
Covering the first insulating layer on which the frame-shaped film is formed, a pattern having an opening smaller than the opening of the frame-shaped film inside the opening of the frame-shaped film, Forming a resist layer;
Forming a through hole in the first insulating layer by wet-etching the first insulating layer using the resist layer as a mask;
Forming a conductor film on the inner surface of the through hole;
Depositing a material of the via plug in the via hole by a plating method.   The step of electrically connecting the substrate-side shield layer to the substrate includes forming a wiring for connecting the via plug and the substrate-side shield layer on the first insulating layer. A method of manufacturing a thin film magnetic head according to claim 7. The step of forming the reproduction part includes a step of depositing a material of the shield layer on the first insulating layer by a plating method,
The thin film magnetic head according to claim 7, wherein the step of depositing the material of the via plug in the via hole is performed simultaneously with the step of depositing the material of the shield layer using the same material as the material of the shield layer. Manufacturing method.   A wafer on which at least one head element including the thin film magnetic head according to claim 1 is formed. A slider including the thin film magnetic head according to any one of claims 1 to 6;
A head gimbal assembly having a suspension for elastically supporting the slider. A head gimbal assembly according to claim 11;
A disk-shaped recording medium that is driven to rotate;
A hard disk device comprising: positioning means for positioning the head gimbal assembly relative to the recording medium while supporting the slider so as to face the recording medium.

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