JPH05143938A - Magneto-resistance effect type magnetic head - Google Patents

Abstract

PURPOSE:To avert the damage to be given to an MR magnetosensitive part at the time of working, such as ion etching by forming the MR magnetosensitive part after forming a front end electrode. CONSTITUTION:The MR magnetosensitive part 3 is formed after the front end electrode 4a is formed. The damage to be given to the MR magnetosensitive part 3 is averted at the time of working, such as ion etching, in the stage of forming particularly the front end electrode 4a of the MR magnetosensitive part 3. Since the characteristic of the front end significantly affects the reproduced outputs and Barkhausen noises, the amelioration of the damage at the front end of the MR magnetosensitive part 3 leads to an effective improvement in the characteristics. Further, a grounding passage for grounding the front end of the MR magnetosensitive part 3 via the electrode 4a-a 1st magnetic material body 1 is formed, by which a discharge current is passed through the grounding passage and the flow thereof through the MR magnetosensitive part 3 is averted in the event of generation of an electric discharge. The accident, such as burn of the magnetosensitive part 3 is thus averted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetoresistive effect type magnetic head, a so-called MR type magnetic head.

[0002]

2. Description of the Related Art As a reproducing magnetic head of various magnetic heads, for example, a magnetic recording / reproducing head of a hard disk drive, an MR type magnetic head excellent in short wavelength sensitivity is being used.

An example of this type of magnetic head is shown in FIG.
As shown in a perspective view of a part of which is shown in cross section, a thin film magnetic head structure having a composite structure of an MR reproducing magnetic head and an inductive recording head can be adopted.

In this case, on the base 15, between the front ends,
A magnetic gap g is formed so as to face a surface (hereinafter abbreviated as a contact surface) 14 facing or facing the magnetic recording medium, and the MR type head has a function as a magnetic shield body. Film-shaped first and second magnetic bodies 1 serving as magnetic cores forming a magnetic path
And 2 are laminated, and the contact surface 1 is placed in the magnetic gap g.
4, a front end of a magnetoresistive effect sensing portion (hereinafter referred to as MR sensitive portion) 3 or at least a front end electrode 4a thereof formed of at least a magnetoresistive effect thin film (hereinafter referred to as MR thin film) faces the contact surface 14. Will be placed. Reference numeral 4b is a rear end electrode of the MR magnetic sensing part 3, and electrodes 4a and 4b are each formed of a conductive thin film. Reference numeral 16 denotes a bias conductor which is arranged across the MR magnetic sensing section 3 with an insulating layer 17 interposed therebetween. By energizing the bias conductor, the MR magnetic sensing section 3 is magnetized in a desired direction, and its magnetoresistive characteristic is shown. To operate in the characteristic region showing excellent linearity and high sensitivity. Reference numeral 18 denotes a head winding formed in a spiral pattern so as to go around the magnetic coupling portions of the respective rear portions of the first and second magnetic bodies 1 and 2, and these bias conductors 16 and The head winding 18 is formed by simultaneously patterning the same conductive thin film, for example.

In this way, the first and second magnetic bodies 1
An MR type magnetic head having a so-called shield type configuration in which the MR magnetic sensing section 3 is disposed between the first and second magnetic bodies 1 and 2 is used as a magnetic core, and thus, on the magnetic path. The inductive magnetic head is formed by winding the head winding 18 to form a composite structure.

In this MR type magnetic head, as shown in the schematic circuit diagram of FIG. 8, one end of the MR magnetic sensing section 3 is set to the ground potential V _SS, and a constant current is applied between both ends, that is, between the electrodes 4a and 4b. A resistance change due to a signal magnetic field based on recording on the magnetic recording medium is detected as a voltage change from the source 19 through the sense current is.

When manufacturing such a magnetic head, M
After the R magnetic sensing part 3 is manufactured, a conductive layer is deposited on the entire surface by sputtering, vapor deposition or the like, and then pattern etching by photolithography is performed to form the electrodes 4a and 4b. Alternatively, the MR magnetic sensing part 3 is covered with an insulating layer at one end, and a window is opened in the insulating layer by a photolithographic etching on the front end and the rear end of the MR magnetic sensitive part 3, and then the same method as described above is used. A method is employed in which the electrodes 4a and 4b are formed in contact with the front end and the rear end of the MR magnetic sensing part 3.

The patterning of these electrodes and the formation of the contact windows of the electrodes with respect to the insulating layer are generally carried out by physically removing the respective materials by ion etching which can carry out anisotropic etching.

Therefore, in this ion etching step, there is a problem in reliability such that the MR magnetic sensitive portion 3 is also partially damaged such as being damaged to deteriorate the characteristic of the magnetic sensitive portion 3 or the characteristic is varied. ..

In particular, since the signal magnetic flux from the magnetic recording medium is introduced into the MR magnetic sensing section 3 from the front end facing the contact surface 14, the tip is damaged and its magnetic permeability μ
Is lowered, the signal magnetic flux is introduced into the first and second magnetic bodies 1 and 2 which are arranged so as to sandwich the signal magnetic flux, and remarkably lowers the reproduction sensitivity.

Further, as shown in FIG. 2, in the MR magnetic sensing section 3, in order to reduce Barkhausen noise,
The two layers of MR thin films 1a and 1b are thinned to a thickness of several tens of liters.
laminated by interposing a non-magnetic film 23 made of l ₂ O ₃ or the like,
Both MR thin films 1a and 1b are magnetostatically coupled with almost no exchange interaction, and are stacked so as to be electrically conductive, and the interaction of spins of both MR thin films 1a and 1b suppresses the generation of a domain wall. It is desirable to adopt such a structure.

In this case, for example, if the upper MR thin film 1b is damaged by the above-mentioned ion etching and its magnetic characteristics are deteriorated, the interaction of the above-mentioned spins is impaired and Barkhausen noise is increased. ..

Further, in the case where such an MR type magnetic head is a flying type magnetic head provided on a slider which is levitated by an air flow caused by a relative transition caused by the rotation of a magnetic recording medium such as a hard disk, it is particularly preferable. There is a problem of destruction of the MR magnetic sensing part due to discharge.

That is, in this flying type magnetic head,
Generally, when the operation is started and stopped, it is in contact with the magnetic recording medium. However, static electricity is generated and accumulated on the surface of the magnetic recording medium due to the above-mentioned air flow and the like. The contact surface 1 of the MR magnetic sensing part 3 in the grounded state when the MR type magnetic head approaches or contacts.
4, a discharge is generated between the MR magnetic sensing part facing the magnetic recording layer 4, that is, the front end of the MR thin film or its front electrode 4a, and a large current due to this discharge flows in the MR thin film. However, since the MR thin film is an extremely thin metal film having a thickness of several hundred liters due to its sensitivity, it causes an accident of being destroyed by this discharge current.

[0015]

SUMMARY OF THE INVENTION In the MR type magnetic head of the present invention, there is a problem of characteristic deterioration due to damage at the time of forming an electrode, especially at the front end of the MR magnetic sensing part, a problem of Barkhausen noise, and a discharge. We will try to solve the problem of destruction due to electric current.

[0016]

As shown in a perspective view of a cross section of a part of an example of the present invention, as shown in FIG. The first and second magnetic bodies 1 and 2 forming a magnetic gap g facing the contact surface 14) are stacked, and a direction substantially perpendicular to the contact surface 14 is formed in the magnetic gap g. The magnetoresistive effect magnetic sensitive portion (MR magnetic sensitive portion) 3 is provided so as to extend.

Then, the front end electrode 4a and the rear end electrode 4b, which respectively contact the front end and the rear end of the MR magnetic sensing part 3, are arranged on the other surfaces with the MR magnetic sensing part 3 interposed therebetween.

Further, in the method of manufacturing a magnetic head according to the present invention, the MR magnetic sensing section 3 is formed on the substrate 15 having the first magnetic body 1.
Of forming the front end electrode 4a on the front electrode 4a, and then forming the MR magnetic sensing part 3 on the front electrode 4a by bringing the front end thereof into contact with the front end electrode 4a. A step of contacting, that is, electrically contacting and forming the rear end electrode 4b, and forming the second magnetic body 2 at the front end and the first magnetic body 2.
The MR type magnetic head described above is manufactured by adopting the step of forming a magnetic gap g facing the MR magnetic sensing part 3 with the front end of the magnetic body 1 and forming and depositing it.

According to another aspect of the present invention, the first magnetic body 1 is made electrically conductive, and the front end electrode 4a of the MR magnetic sensing section 3 is arranged in contact with the first magnetic body 1 so that the MR magnetic sensing section 3 is provided. Are electrically grounded via the front end electrode 4 a and the first magnetic body 1.

Further, according to another aspect of the present invention, in each of the above-mentioned constitutions, as shown in FIG.
It is constituted by two layers of magnetoresistive effect thin films (MR thin films) 1a and 1b.

Still another aspect of the present invention is a composite head structure in which the first and second magnetic bodies 1 and 2 are magnetic cores, and a thin film head winding 18 magnetically coupled to the magnetic cores is provided. ..

[0022]

According to the structure and the manufacturing method of the present invention, since the MR magnetic sensing portion 3 is formed after the front end electrode 4a is formed, M
It is possible to avoid damage to the MR magnetic sensing portion, especially when the front end electrode 4a is formed, such as ion etching.

In the MR magnetic sensing portion 3, the signal magnetic field entering the MR magnetic sensing portion 3 is actually attenuated at a depth of several μm, for example, 3 μm from the contact surface 14 thereof. Since the effective region that works as an MR effect is a part of the front end side, the characteristic of this front end is
It has a great influence on the reproduction output and Barkhausen noise. Therefore, the improvement of the damage on the front end of the MR magnetic sensing part 3 according to the present invention can effectively improve these characteristics.

Further, according to the present invention, since the ground path for grounding the front end of the MR magnetic sensing section 3 through the electrode 4a and the first magnetic body 1 is formed, when the above-mentioned discharge occurs,
This discharge current flows through the ground passage and the MR sensing unit 3
Therefore, it is possible to effectively avoid an accident in which the MR magnetic sensing section 3 is damaged by burning or the like.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of a magnetic head having a composite structure of a reproducing magnetic head of the MR magnetic head of the present invention and an inductive recording magnetic head will be described with reference to FIG.

In this case, as shown in the process diagram of FIG. 3, for example, in a flying head, first, as shown in FIG. 3A, the slider itself or a substrate 15 made of a substrate or the like attached to the slider is first provided. , To the required pattern, FeNi
The thin film-shaped first magnetic body 1 made of, for example, is formed by well-known so-called frame plating or the like, and is embedded.
A nonmagnetic insulating layer 17 such as SiO ₂ or Al ₂ O ₃ is formed by sputtering or the like, and its surface is flattened. Then, the front end electrode 4a is formed in contact with the first magnetic body 1 as shown in the schematic plan view of FIG. The electrode 4a can be formed by forming a conductive layer, for example, a metal layer on the entire surface, ion etching by photolithography, or the like, as described above.

Then, as shown in FIG. 3B, a similar process of embedding the front end electrode 4a of the insulating layer 17 and planarizing the upper surface of the front electrode 4a is performed.

Then, the MR is crossed over the front end electrode 4a.
The magnetic sensitive section 3 is formed. The MR magnetic sensing part 3 may have a single-layer MR thin film structure, or the M magnetic sensing part 3 shown in FIG.
It is also possible to have a two-layer structure in which the R thin films 1a and 1b are laminated with an extremely thin nonmagnetic thin film 23 interposed therebetween. These MR thin films 1a and 1b are formed of sputtered films of NiFe, NiCo, NiFeCo, etc., and Al ₂
A predetermined pattern is formed by ion etching or the like using photolithography with a sputtered film of a nonmagnetic thin film 23 made of O ₃ , SiO ₂ or the like being interposed.

Thereafter, a similar insulating layer 17 is covered to cover the MR magnetic sensing portion 3, and a rear electrode contact window 17W is formed on the rear end of the MR magnetic sensing portion 3 by ion etching using photolithography. To do.

At this time, even if the MR sensitive portion 3 is damaged by performing ion etching to open the window of the insulating layer 17, it is on the rear end side of the MR sensitive portion 3, and therefore the characteristics thereof are almost the same. Has no effect.

Then, a conductive layer is formed and patterned on the entire surface including the inside of the window 17W as in the case of the front end electrode 4a.

After that, the insulating layer 17 is formed so as to cover the MR magnetic sensing portion 3, the bias conductor 16 is formed across the MR magnetic sensing portion 3, and the head winding 18 is simultaneously formed on the entire surface of the conductive layer. It is formed by dynamic sputtering, vapor deposition, and subsequent patterning.

Then, an insulating layer 17 is further coated thereon, a window is formed in, for example, the central portion of the head winding 18, and a second magnetic material is connected to the first magnetic material 1 through this window. 2, a magnetic layer of FeNi or the like is entirely sputtered, vapor-deposited, formed on this by plating or the like, and patterned as necessary. Then, the front surface is entirely polished to form the contact surface 14.

In this way, the first and second magnetic bodies 1 and 2 forming the magnetic gap g facing the contact surface 14 with the magnetic recording medium are stacked between the front ends, and the magnetic gap g The MR magnetic sensing portion 3 is provided so as to extend in a direction substantially perpendicular to the contact surface, and a front end electrode 4a and a rear end electrode 4b which contact the front end and the rear end of the MR magnetic sensing portion 3 are provided. A magnetoresistive MR type magnetic head according to the present invention, which is arranged on the other surfaces with the MR magnetic sensing portion 3 interposed therebetween, is constituted.

In this case, by making the first magnetic body 1 electrically conductive and electrically grounding the first magnetic body 1, the front end electrode of the MR sensing section 3 is brought into contact with the first magnetic body 1. Since 4a is arranged, the magnetoresistive effect magnetic sensing portion MR is electrically grounded via the front end electrode 4a and the first magnetic body 1.

Further, in this case, the MR magnetic sensing section 3 has a three-layer structure in which the two MR thin films 1a and 1b are magnetostatically coupled via the non-magnetic thin film 23 (MR two-layer structure). It is said that the structure is designed to improve Barkhausen noise.

In this case, the first and second magnetic bodies 1
And 2 have a composite type head structure in which the magnetic core is used as the magnetic core, and the inductive recording head provided with the thin film head winding 18 magnetically coupled to the magnetic core is integrally provided.

In the examples of FIGS. 1 and 4, the bias conductor 16 and the rear end electrode 4b have a positional relationship in which they do not overlap with each other, so that there is no fear of dielectric breakdown between them.

However, in the structure of the present invention, since the front end electrode 4a and the rear end electrode 4b are arranged on the surfaces opposite to each other with respect to the MR magnetic sensing section 3, the rear end electrode 4b is formed.
As shown in the schematic cross-sectional view of FIG. 5 and the schematic plan view of FIG. 6, it is possible to have a wide structure extending to a position reaching the contact surface 14 or a position close to the contact surface 14, The electric resistance of this can be made sufficiently small. 5 and 6, parts corresponding to those in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted.

[0040]

According to the above-described structure and manufacturing method of the present invention, since the front end electrode 4a is formed and the MR magnetic sensing portion 3 is formed later, the MR magnetic sensing portion 3, particularly the front end electrode 4a is formed. It is possible to avoid damage given to the MR magnetic sensing part 3 during processing such as ion etching in FIG.

In the MR magnetic sensing section 3, since the effective region which substantially acts as the MR effect is a part of the front end side as described above, the characteristic of the front end is the reproduction output,
It has a great influence on Barkhausen noise. Therefore, according to the present invention, the damage on the front end of the MR magnetic sensing part 3 can be effectively improved.

Further, according to the present invention, since the ground path for grounding the front end of the MR magnetic sensing section 3 via the electrode 4a and the first magnetic body 1 is formed, when the above-mentioned discharge occurs,
This discharge current flows through the ground passage and the MR sensing unit 3
Therefore, it is possible to effectively avoid an accident in which the MR magnetic sensing section 3 is damaged by burning or the like.

[Brief description of drawings]

FIG. 1 is a perspective view showing a cross section of a part of an example of a magnetic head according to the present invention.

FIG. 2 is a cross-sectional view of an example of a magnetoresistive effect magnetic sensing unit.

FIG. 3 is a process drawing of an example of the manufacturing method of the present invention.

FIG. 4 is a plan view of another example of the magnetic head according to the present invention.

FIG. 5 is a cross-sectional view of another example of the magnetic head according to the present invention.

FIG. 6 is a plan view of another example of the magnetic head according to the present invention.

FIG. 7 is a perspective view showing a cross section of a part of a conventional MR type magnetic head.

FIG. 8 is a circuit diagram of a conventional MR type magnetic head.

[Explanation of symbols]

 1 1st magnetic body 2 2nd magnetic body 3 magnetoresistive effect magnetic sensitive part (MR magnetic sensitive part) 4a front end electrode 4b rear end electrode

Claims (5)

[Claims] 1. A first magnetic body and a second magnetic body, which form a magnetic gap facing the surface facing the magnetic recording medium or facing the magnetic recording medium, are stacked between the front ends of the magnetic recording medium. A magnetoresistive effect magnetic sensing portion is provided so as to extend in a direction substantially perpendicular to the facing or facing surface, and a front end electrode and a rear end contacting the front end and the rear end of the magnetoresistive effect magnetic sensitive portion, respectively. A magnetoresistive effect type magnetic head, wherein the electrodes are arranged on the other surfaces with the magnetoresistive effect magnetism sensing portion interposed therebetween. 2. A step of depositing and forming a front end electrode of a magnetoresistive effect magnetic sensing portion on a substrate having a first magnetic body, and thereafter, forming the magnetoresistive effect magnetic sensitive portion on the front electrode, the front portion thereof. A step of contacting the ends to form a deposit, a step of subsequently contacting the rear end of the magnetoresistive effect magnetic sensitive part to form a rear end electrode, and a second magnetic body to the front end thereof A step of forming a magnetic gap facing the magnetoresistive effect magnetic sensitive portion between the first magnetic body and the front end of the first magnetic material, and depositing the magnetic gap. .. 3. The first magnetic body has conductivity, the front end electrode of the magnetoresistive effect sensitive section is arranged in contact with the first magnetic body, and the magnetoresistive effect sensitive section is located at the front side. The magnetoresistive effect magnetic head according to claim 1, wherein the magnetoresistive head is electrically grounded via an end electrode and the first magnetic body. 4. The magnetic according to claim 1, wherein the magnetoresistive effect magnetic sensitive portion has a three-layer structure in which two layers of magnetoresistive effect thin films are magnetostatically coupled to each other through a nonmagnetic thin film. Resistance effect magnetic head. 5. The magnetic head according to claim 1, wherein the first and second magnetic bodies are magnetic cores, and an inductive magnetic head is provided with a thin film head winding magnetically coupled to the magnetic cores. A magnetoresistive effect magnetic head having a composite type head structure.