JPH07210819A - Magnetic head and manufacturing method thereof - Google Patents

Abstract

(57) [Summary] [Purpose] To output the pseudo gap when reproducing the MIG head.
At the same time, it suppresses the peeling of the magnetic film from the substrate.
It [Structure] Oxide magnetic material substrate 1 and metal magnetic film 2 or
The diffusion prevention film 5 inserted at the interface of the metal nitride magnetic film is magnetically
The film thickness is 5 on the gap 4 forming surface and the parallel surface.
nm or more and 20 nm or less
On the row surface, the thickness is 0 nm or more and 4 nm or less. For diffusion prevention film
Aluminum oxide, silicon oxide, (Cr ₂N + CrN)
A mixed film is used. Furthermore, in the case of a metal nitride magnetic film, the expansion
Oxide magnetic material of metal nitride magnetic film without forming a dispersion prevention film
Near the interface with the base material over a range of 5 nm or more
Use a modulation structure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head used in a magnetic recording / reproducing apparatus.

[0002]

2. Description of the Related Art The demand for high-density magnetic recording is extremely strong, but in order to realize this, it is essential to improve the recording / reproducing characteristics of a magnetic head. Although there are various types of magnetic heads, the type that has been widely used in recent years is a magnetic head core half body in which a metal magnetic film having a high saturation magnetic flux density is formed on a high-permeability ferrite core, and the magnetic head core halves are connected via a magnetic gap So-called MIG (Metal I)
n Gap) head.

FIG. 1 shows an example of the structure. A pair of high-permeability core halves in which a metal magnetic film 2 and the like are formed by a thin film forming method such as a sputtering method on an oxide magnetic material substrate 1 in which track width regulating grooves, winding grooves and the like are formed are It is adhered so as to face each other through the magnetic gap by the glass 3 on the side surface of the magnetic permeability core half and the back part.

FIG. 2 shows an enlarged view of the structure near the magnetic gap. A diffusion prevention film 5 made of silicon oxide or the like is formed on almost the entire surface of the oxide magnetic material substrate 1.
Then, a metal magnetic film 2 having a high magnetic permeability and a high saturation magnetic flux density is formed thereon with a thickness of several μm. Further, a magnetic gap regulating film 6 made of a non-magnetic oxide is formed thereon to a thickness of 0.1 to 0.2 μm in order to obtain a necessary magnetic gap length, and finally wettability with the bonding glass 3 is formed. The Cr film 7 is formed with a thickness of 0.1 μm or less for improving

Here, the diffusion prevention film is for preventing diffusion between the ferrite substrate and the metal magnetic film, and is widely practiced (for example, Japanese Patent Publication No. 62-1455).
No. 10). That is, during glass bonding performed by heating to a temperature of 500 ° C. or higher, oxygen or iron in the ferrite substrate diffuses into the metal magnetic film, and the ferrite is altered to lower the magnetic permeability. It is a thin film for preventing the parallel portions from acting as a pseudo gap, and an oxide having a thickness of several nm to several tens nm is usually used.

However, the fact that the atoms constituting the ferrite diffuse into the metallic magnetic film also means that the two become integrated and the adhesive force increases, and conversely preventing the diffusion means the adhesive force between the metallic magnetic films. Is also to weaken.

In fact, in the magnetic head manufactured by us, when the diffusion prevention film is provided, the generation of the pseudo gap is suppressed and the reproduction characteristics are improved, but conversely, at the interface between the diffusion prevention film and the metal magnetic film, Peeling occurred frequently.

[0008]

SUMMARY OF THE INVENTION The present invention improves the diffusion prevention film to suppress the generation of pseudo gaps and prevent the reproduction characteristics from deteriorating, and at the same time prevent the peeling of the metal magnetic film to improve the productivity. It is an improvement.

[0009]

Therefore, according to the present invention, in order to solve the above problems, a diffusion prevention film is formed on a magnetic gap forming surface and a surface parallel to the magnetic gap forming surface to a required thickness. The other portions have a thickness less than that, or are not formed at all. As a means for realizing such a structure, a sputter etching method is used,
By sputtering gas particles mainly from the direction normal to the magnetic gap forming surface, the surface not parallel to the magnetic gap forming surface was preferentially etched.

When a metal nitride film is used as the magnetic film, no diffusion prevention film is formed at all including the magnetic gap forming surface, and instead, a composition modulation structure is formed near the interface with the oxide magnetic material. The above-mentioned problems can be solved by providing the metal magnetic film itself with a diffusion preventing effect.

[0011]

The reason why the diffusion layer becomes a problem as described above is that the magnetic permeability of that portion is lowered and it acts as a pseudo gap. Strictly speaking, however, it is only the diffusion layer parallel to the magnetic gap that acts as the pseudo gap, and it does not matter if the diffusion layer exists in the non-parallel portion.

Therefore, it is necessary to form the diffusion prevention film on the magnetic gap forming surface and on the surface parallel to the magnetic gap forming surface by a thickness necessary to suppress the generation of the pseudo gap. Even if it is formed with a thickness less than that, or if it is not formed at all, there is no problem in generating the pseudo gap.

Further, considering the adhesive force between the metal magnetic film and the oxide magnetic material substrate, if the diffusion preventing film is thin or the diffusion progresses due to no formation, the adhesive force between the two is improved. Therefore, it is possible to reduce the phenomenon in which the metal magnetic film is peeled off from the oxide magnetic material substrate by various machining processes when manufacturing the magnetic head.

In this case, if the thickness of the diffusion barrier film is 5 nm or less, generation of the diffusion layer cannot be suppressed. When the thickness is 20 nm or more, the diffusion barrier film itself acts as a pseudo gap. Therefore, the thickness of the diffusion prevention film formed on the magnetic gap formation surface and the surface parallel to the magnetic gap formation surface is 5 nm or more and 20 nm or more.
Must be: At the same time, since it is desirable that the thickness of the surface that is not parallel to the magnetic gap formation surface be less than that, the thickness becomes 0 nm or more and 4 nm or less.

Aluminum oxide or silicon oxide can be used as the material of the diffusion prevention film, but a chromium nitride material having a structure in which Cr ₂ N and CrN are mixed as a main component is preferable.

As a means for realizing such a structure, there is a method of utilizing the incident angle dependence of the sputtering rate. That is, once, the diffusion prevention film is similarly formed on the magnetic gap forming surface and the surface not parallel to the magnetic gap forming surface. However, after that, the core half is sputter-etched so that the sputter gas particles are incident from the direction normal to the magnetic gap formation surface.

In FIG. 3, the etching rate was measured when a sample in which various materials were formed on a MnZn single crystal ferrite substrate was tilted at 0 °, 30 °, 45 °, 60 ° and 90 ° with respect to the anode electrode. As shown, the material is 3 for the anode electrode
The sputtering rate becomes maximum when the sputtering gas enters from an angle inclined from 0 ° to 60 °. (FIG. 3) is a diagram summarizing the measurement results when Ar gas is used as the sputtering gas, the pressure is 4 mTorr (measured with a Baratron gauge installed near the Ar gas inlet), and the input power is 200 W. Almost the same result was obtained when the Ar gas pressure was in the range of 2 to 5 mTorr.

From the results shown in FIG. 3, when the sputter gas is made to enter from the direction normal to the magnetic gap forming surface, the etchback speed of the magnetic gap forming surface and the surface parallel to the magnetic gap forming surface is slow, and conversely The etch-back speed becomes faster on the surface that is not parallel to, and as a result, the structure of the present invention can be realized.

On the other hand, in the above-mentioned structure, it is necessary to make the diffusion preventing film formed on the surface not parallel to the magnetic gap forming surface thinner than the magnetic gap forming surface and the surface parallel to the magnetic gap forming surface. Therefore, in the case where the magnetic film is a metal nitride film, it is possible to form the metal magnetic film itself without a diffusion prevention film and provide a diffusion prevention function.

That is, a composition modulation structure in which a nitrided layer and a non-nitrided layer are finely laminated is formed in the vicinity of the interface between the metal nitride magnetic film which has been put into practical use in recent years and the oxide magnetic material substrate. With such a structure, Nb, Ta, Al, and Z which are always contained in the metal nitride magnetic film currently in practical use.
Elements such as r that have a high affinity for oxygen and nitrogen react and capture oxygen that has diffused from the oxide magnetic material substrate in the non-nitrided layer, thus suppressing the diffusion of oxygen in a wider range,
The thickness of the diffusion layer is suppressed to such an extent that the pseudo gap is not a problem. Further, the advantage of this method is that since the diffusion occurs between the metal magnetic film and the oxide magnetic material near the interface, the two are integrated and the adhesive strength is improved.

[0021]

EXAMPLES The effects of the present invention will be described below with reference to specific examples.

Example 1 Using MnZn single crystal ferrite having a composition of Fe ₂ O ₃ : 54.5 mol%, MnO: 27 mol% and ZnO: 18.5 mol%, the shape shown in FIG. 4 was used. And a magnetic head having a plane orientation, that is, a pair of core halves each having a protruding portion 8 protruding in a convex shape from a base portion, and the protruding portions facing each other through a magnetic gap 4. And a pair of adhesive glasses 3 which are welded to both side surfaces of the pair of core halves to connect the pair of core halves to each other, and each protruding portion 8 is formed on both side surfaces substantially orthogonal to the magnetic gap 4. A track width regulating groove that determines the track width is provided, and the length of each base portion in the track width direction gradually increases with distance from the projecting portion, and the projecting length of the projecting portion is 5 μm to 15 μm. The magnetic path surface is parallel to the {110} surface, the magnetic gap forming surface is the (100) surface, and the sliding surface with the magnetic recording medium is a surface within 30 degrees around the (110) surface. A magnetic head having a diffusion preventive film 5 containing aluminum oxide as a main component, a Fe ₈₆ Ta ₁₁ N ₁₃ magnetic film 2, a gap regulating film 6 made of crystallized glass, and a Cr film 7 was prepared.

In the magnetic head according to the present invention, the diffusion preventive film 5 is initially formed to a thickness of 10 nm, and then the Ar gas pressure 4 is applied.
As shown in (FIG. 5a), the film thickness is 7 nm on the magnetic gap formation surface by performing sputter etching with mTorr (measured with a Baratron gauge installed near the Ar gas inlet) and an applied power of 200 W. The thickness of the surface not parallel to the magnetic gap formation surface was 3 nm or less. Further, in the magnetic head according to the conventional technique, the diffusion prevention film is 7 n from the beginning.
m, and the film thickness on the magnetic gap forming surface is 7 nm and the film thickness on the non-parallel surface is 7 nm as shown in FIG. 5B.
Below. The reproduction output characteristics in each case are shown in (Fig. 6). In both cases, the undulation due to the pseudo gap is 1 dB.
It was below, and it was a level with no problem in practical use.

On the other hand, the peeling of the FeTaN magnetic film 2 from the ferrite substrate 1 showed a low occurrence rate in the case of the present invention in which the thickness of the diffusion preventing film in the non-parallel portion was thin, as shown in (Table 1).

[0025]

[Table 1]

(Example 2) Mn having the composition shown in Example 1
A magnetic head having the same shape and plane orientation as in Example 1 was produced using the Zn single crystal ferrite and the FeTaN magnetic film. However, the diffusion prevention film 5 was initially formed to a thickness of 14 nm, and then A
By carrying out sputter etching with r gas pressure of 3 mTorr and input power of 200 W, as shown in FIG. 7, all the diffusion prevention film 5 on the surface not parallel to the magnetic gap forming surface is removed, and only the magnetic gap forming surface is formed. 7 nm was formed. The reproduction output characteristics are shown in (FIG. 8), and the waviness due to the pseudo gap was 1 dB or less, which was at a practically no problem level.

On the other hand, the peeling of the magnetic film from the ferrite substrate was improved as compared with the prior art as shown in (Table 2).

[0028]

[Table 2]

(Example 3) Mn having the composition shown in Example 1
A magnetic head having the same shape and orientation as in Example 1 was produced using the Zn single crystal ferrite and the FeTaN magnetic film. However, silicon oxide is used for the diffusion prevention film, and the film thickness is 8 nm for the magnetic gap formation surface, and 8 nm or less (conventional technology) for the surface not parallel to the magnetic gap formation surface, and 4 nm or less (present invention). And The sputter etching conditions are also the same as in Example 1. The reproduction output characteristics are shown in (FIG. 9). The undulation due to the pseudo gap was 1 dB or less, which was a practically no problem level.

On the other hand, the peeling of the magnetic film from the ferrite substrate was improved as compared with the prior art, as shown in (Table 3).

[0031]

[Table 3]

(Example 4) Mn having the composition shown in Example 1
A magnetic head having the same shape and orientation as in Example 1 was produced using the Zn single crystal ferrite and the FeTaN magnetic film. However, (a) Cr film and (b) (Cr ₂ N + C) are used as the diffusion prevention film.
Three types of rN) mixed film and (c) CrN film were used, and the film thicknesses were all 7 nm on the magnetic gap forming surface and 4 nm or less on the surface not parallel to the magnetic gap forming surface. The sputter etching conditions were the same as in Example 1. Shows the reproduced output characteristics (Fig. 10), the (b) and (c) (Cr ₂
In the N + CrN) mixed film and the CrN film, the waviness due to the pseudo gap was 1 dB or less, which was a practically no problem level. However, in the Cr film (a), the waviness due to the pseudo gap is 2 dB or more, which is not suitable for practical use.

On the other hand, as shown in (Table 4), the Cr metal film has the lowest occurrence rate of the metal magnetic film from the ferrite substrate, followed by (Cr ₂ N + CrN), and then the CrN film rate.

[0034]

[Table 4]

From the above results, it was found that by using the (Cr ₂ N + CrN) film as the diffusion prevention film, the pseudo gap can be suppressed and at the same time, the peeling of the metal magnetic film from the ferrite substrate can be suppressed.

(Example 5) Mn having the composition shown in Example 1
A magnetic head having the same shape and orientation as in Example 1 was manufactured using the Zn single crystal ferrite and the FeTaN magnetic film. However, the diffusion preventing film was not formed, and the composition of the FeTaN film was modulated in three ranges (a) 4 nm, (b) 8 nm, and (c) 20 nm from the interface with the oxide magnetic material. That is, as shown in FIG. 11, the non-nitrided layer 9 has a thickness of 1 nm, the nitride layer 10 has a thickness of 1 nm, and the non-nitrided layer 9 has a thickness of 1 nm. ． ． In order of 2
Fe ₈₆ T of uniform composition after lamination of 4 cycles, 10 cycles
By depositing a ₁₁ N ₁₃ and heat-treating it, the N concentration is reduced to 0
It is periodically changed between 13 at%. As a matter of course, the compositions of Fe and Ta change in the opposite tendency to the N concentration.

The reproduction output characteristics in each case are shown in FIG. In the case where the composition modulation range of (a) is 4 nm, the undulation due to the pseudo gap of 3 dB or more occurred because the thickness was thin and the effect of preventing diffusion was insufficient. But (b)
In the case of (c), since the diffusion preventing effect is sufficient, the waviness due to the pseudo gap is 1 dB or less, which is a value having no practical problem.

The composition-modulating film of this embodiment is characterized in that it is a magnetic material having a very high magnetic permeability and excellent characteristics. Therefore, unlike other examples,
The composition modulation portion for preventing diffusion does not act as a pseudo gap. Therefore, according to the present embodiment, when the composition modulation range is 5 to 6 nm or more, the generation of the pseudo gap can be suppressed.

On the other hand, the peeling of the metal nitride film from the ferrite substrate showed a low value in each case as shown in (Table 5).

[0040]

[Table 5]

From the above results, if the metal nitride magnetic film is composition-modulated over the range of 5 nm or more from the interface of the oxide magnetic material substrate, the generation of the pseudo gap can be suppressed, and at the same time, the oxide magnetic property of the metal nitride magnetic film can be suppressed. It was found that peeling from the material substrate can also be suppressed.

[0042]

According to the present invention, in the MIG head for magnetic recording, the generation of the pseudo gap is suppressed, and at the same time,
Since the peeling of the metal magnetic film from the ferrite substrate can be suppressed, the reproducing characteristics of the magnetic head were improved and at the same time the productivity could be improved.

[Brief description of drawings]

FIG. 1 is an external view of a conventional MIG head.

FIG. 2 is a structural diagram near a magnetic gap of a MIG head according to a conventional technique.

FIG. 3 is a diagram showing a relationship between a substrate angle and a sputter etching rate when various materials arranged at an angle with respect to an anode electrode are sputter-etched.

FIG. 4 is an external view of a MIG head according to the present invention.

5A is a structural diagram in the vicinity of a magnetic gap of a MIG head using a conventional technique, and FIG. 5B is a structural diagram in the vicinity of a magnetic gap of an MIG head in Example 1 using the present invention.

6A is a reproduction output characteristic diagram of a MIG head using a conventional technique, and FIG. 6B is a reproduction output characteristic diagram of the MIG head according to the first embodiment using the present invention.

FIG. 7 is a structural diagram in the vicinity of a magnetic gap of an MIG head according to a second embodiment of the present invention.

FIG. 8 is a reproduction output characteristic diagram of the MIG head according to the second embodiment of the present invention.

FIG. 9A is a reproduction output characteristic diagram of a MIG head using a conventional technique, and FIG. 9B is a reproduction output characteristic diagram of a MIG head according to a third embodiment of the invention.

FIG. 10 (a) shows M in Example 4 using the present invention.
In the IG head, a reproduction output characteristic diagram when a Cr film is used as a diffusion prevention film is shown (b). In the MIG head of Example 4 using the present invention, a (Cr ₂ N + CrN) mixed film is used as a diffusion prevention film. (C) is a reproduction output characteristic diagram in the case of using a CrN film as the diffusion prevention film in the MIG head according to the fourth embodiment of the present invention.

FIG. 11 (a) shows M in Example 5 using the present invention.
In the structure diagram of the vicinity of the interface of the oxide magnetic material substrate of the metal nitride magnetic film of the IG head, when the composition modulation range is 2 cycles, (b) is the oxidation of the metal nitride magnetic film of the MIG head in Example 5 using the present invention. In the structure diagram near the interface of the physical magnetic material substrate, when the composition modulation range is 4 cycles, (c) is a structure diagram near the interface of the oxide magnetic material substrate of the metal nitride magnetic film of the MIG head according to the fifth embodiment of the present invention. And when the composition modulation range is 10 cycles

FIG. 12 (a) shows M in Example 5 according to the present invention.
In the IG head, a reproduction output characteristic diagram when the composition modulation range is 4 nm is shown (b). In the MIG head according to the fifth embodiment of the present invention, a reproduction output characteristic diagram when the composition modulation range is 8 nm is shown (c). In the MIG head according to the fifth embodiment of the present invention, a reproduction output characteristic diagram when the composition modulation range is 20 nm

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Oxide magnetic material substrate 2 Metal magnetic film 3 Adhesive glass 4 Magnetic gap 5 Diffusion prevention film 6 Gap control film 7 Cr film 8 Convex protruding part 9 Non-nitrided layer 10 Nitride layer

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Hiroshi Sakama 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (10)

[Claims] 1. Metal magnetic on at least one of a pair of high-permeability core halves facing each other via a magnetic gap, the substrate being made of an oxide magnetic material having a single crystal or a composite structure of single crystal and polycrystal. In a magnetic head in which a film is formed and a glass part for connecting a pair of core halves to each other is formed on both sides or the back of the core halves, at the interface between the oxide magnetic material substrate and the metal magnetic film. , A thin film for preventing the diffusion of the atoms constituting the both is formed, and the thickness of the diffusion prevention film formed on the surface not parallel to the magnetic gap forming surface is the same as the magnetic gap forming surface and the magnetic gap forming surface. A magnetic head characterized by being thinner than a film thickness of a diffusion prevention film formed on parallel surfaces. 2. A diffusion preventive film formed on a surface not parallel to the magnetic gap forming surface has a film thickness of 4 nm or less, and is formed on the magnetic gap forming surface and a surface parallel to the magnetic gap forming surface. The magnetic head according to claim 1, wherein the diffusion prevention film has a thickness of 5 nm or more and 20 nm or less. 3. Metal magnetic on at least one of a pair of high-permeability core halves facing each other via a magnetic gap, the substrate being made of an oxide magnetic material having a single crystal or a composite structure of single crystal and polycrystal. In a magnetic head in which a film is formed and a glass portion interconnecting a pair of core halves is formed on both sides or the back of the core halves, the magnetic gap forming surface and the magnetic gap forming surface are parallel to each other. Only on the face
A magnetic head comprising an oxide magnetic material substrate and a thin film for preventing diffusion of atoms constituting a metal magnetic film. 4. The diffusion barrier comprises at least Cr ₂ N and Cr.
The magnetic head according to claim 1, wherein the magnetic head is formed of a thin film containing N mixed therein. 5. The magnetic head according to claim 1, wherein the diffusion preventive film is formed of a thin film containing silicon oxide or aluminum oxide as a main component. 6. A diffusion preventive film is once formed, and then sputter etching is used to introduce sputter gas particles mainly from the direction normal to the magnetic gap forming surface, so that the surface is non-parallel to the magnetic gap forming surface. 6. The method of manufacturing a magnetic head according to claim 1, wherein the diffusion prevention film of 1) is preferentially thinned. 7. The magnetic head according to claim 1, wherein a thin film having a composition of Fe _X M _Y N _Z is used as the metal magnetic film. However, M is Ti, Zr, Hf,
One or more metals selected from the group of Nb, V, Ta, Cr, Mo, W, Mn, N represents nitrogen, 3 ≦ Y ≦ 30,
1 ≦ Z ≦ 20 and X + Y + Z = 100. 8. A metal nitride on a substrate, at least one of a pair of high-permeability core halves facing each other with a magnetic gap interposed therebetween is made of an oxide magnetic material having a single crystal or a composite structure of single crystal and polycrystal. In a magnetic head in which a magnetic film is formed and a glass portion interconnecting a pair of core halves is formed on both side surfaces or a back portion of the core halves, an oxide magnetic material substrate and a metal nitride magnetic film are formed. A magnetic head characterized in that the composition of the metal nitride magnetic film near the interface is modulated in the film thickness direction. 9. The thickness of the composition modulation portion of the metal nitride magnetic film is 5
9. The magnetic head according to claim 8, wherein the magnetic head has a thickness of at least nm. 10. The magnetic head according to claim 8, wherein the metal nitride magnetic film is a thin film having a composition represented by Fe _X M _Y N _Z. However, M is Ti, Zr, Hf, N
b, V, Ta, Cr, Mo, W, one or more metals selected from the group of Mn, N represents nitrogen, 3 ≦ Y ≦ 30, 1
≦ Z ≦ 20 and X + Y + Z = 100.