JPH0772928B2 - Magnetic head - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a magnetic head using a thin film magnetic material, and in particular, by using a magnetic thin film in which a crystal face having high corrosion resistance is oriented so as to coincide with the thin film surface, The present invention relates to a thin film magnetic head capable of improving yield in a magnetic head manufacturing process.

[Background of the Invention]

In recent years, the progress of magnetic recording technology has been remarkable, and in particular, the advent of the perpendicular magnetic recording system has significantly improved the magnetic recording density. FIG. 4 shows a typical conventional example of the magnetic head used in the perpendicular magnetic recording / reproducing disclosed in Japanese Patent Laid-Open No. 59-71115. In the figure, a part of the magnetic circuit of the magnetic head for perpendicular magnetic recording is composed of an extremely thin main pole 2, and this main pole 2 is made of a magnetic thin film having a high saturation magnetic flux density. Fe-Al is a magnetic material with a high saturation magnetic flux density.
-Si alloy, Fe-Ni alloy, Fe-Si alloy or Fe, Co,
At least one of Ni, B, C, N, Al, Si, P-containing metal-nonmetallic amorphous alloy, or Fe, Co, Ni at least one of Y, Ti, Zr, Hf, Metal containing Nb, Ta, etc.
Metal-based amorphous alloys have been conventionally used. Among these materials, metal-nonmetal and metal-metal amorphous alloys with a saturation magnetic flux density of 10 to 15 kilogauss (KG) are practically usable due to restrictions such as magnetostriction constant and crystallization temperature. It can be used. Further, the saturation magnetic flux density of the Fe-Al-Si alloy is about 10KG, and the Fe-Ni alloy is about 8KG. On the other hand, the Fe-Si alloy has a saturation magnetic flux density of about 18 KG, which is extremely high compared to other magnetic materials.
Magnetic materials having a high saturation magnetic flux density of about 15 kg or more are limited to those containing Fe as a main component, and it is necessary to increase the Fe content in order to increase the saturation magnetic flux density. However, in general, alloys containing Fe as a main component have problems in corrosion resistance, and when a magnetic head is manufactured using thin films of these alloys,
There has been a problem that the magnetic thin film is corroded in the magnetic thin film pattern forming process or the cleaning process in the magnetic head manufacturing process, and the product yield is reduced.

The above-mentioned problem is not limited to the thin-film magnetic head for perpendicular magnetic recording, but is also the same in the conventional thin-film magnetic head for inner surface magnetic recording, has a high saturation magnetic flux density, and has corrosion resistance to endure the magnetic head manufacturing process. A magnetic thin film has been desired.

[Object of the Invention]

The object of the present invention is to solve the above-mentioned problems of the prior art,
By improving the corrosion resistance of the magnetic thin film having a high saturation magnetic flux density, the corrosion of the magnetic thin film in the manufacturing process of the thin film magnetic head is reduced, and the product yield is improved.

[Outline of Invention]

In order to achieve the above object, in the present invention, a metal magnetic material having a body-centered cubic structure is used, and the {110} or {111} plane of this metal crystal having good corrosion resistance is substantially coincident with the film surface of the magnetic thin film. The main idea is to use the magnetic thin film oriented as described above in a magnetic head.

In order to obtain a high saturation magnetic flux density in the magnetic thin film of the present invention, it is necessary to use Fe or an alloy containing Fe as a main component, and these alloys generally have a body-centered cubic structure. As a result of investigating a difference in corrosion rate between crystal planes of a metal or an alloy having a body-centered cubic structure, the present inventors have found that the {110} plane or a plane near this plane, or {1} plane.
The inventors have completed the present invention by finding that the 11} plane or a plane in the vicinity thereof has a significantly slower corrosion rate than the {100} plane or a plane in the vicinity thereof.

The magnetic thin film used in the present invention is, for example, Fe, Fe-6 wt% Si alloy and Fe-6 wt% Al-9 wt% Si alloy, and Table 1 shows corrosion of these metals or alloys on the crystal plane. The change in speed is shown. In this case, an aqueous solution of hydrochloric acid and ferric chloride is used as the corrosive liquid, and {100} of each magnetic material is used.
The corrosion rate on the surface was 1.

As is clear from Table 1, the corrosion rate of the {110} plane is about 1/10 of the corrosion rate of the {100} plane of Fe or a body-centered cubic structure containing Fe as the main component. The {111} plane was about 1/5, and it was found that the {110} plane and the {111} plane had significantly better corrosion resistance than the {100} plane. Therefore, a magnetic thin film oriented so that the {110} and {111} planes of a metal crystal having a body-centered cubic structure are substantially aligned with the thin film plane is compared to the case where the {100} plane is the thin film surface. And has extremely excellent corrosion resistance. Also, {11
A thin film oriented so that the {0} plane matches the thin film surface is {1
It is more preferable because it has about twice as much corrosion resistance as a thin film oriented so that the 11} plane is aligned with the thin film surface. As described above, the magnetic head using the magnetic thin film oriented so that the {110} plane or the {111} plane is aligned with the thin film surface is not corroded in the magnetic thin film patterning process or the cleaning process in the magnetic head manufacturing process. It is less likely to occur and has an advantage that the yield of products can be improved.

The magnetic material used in the present invention is a magnetic metal or alloy having a body-centered cubic structure as described above, and more specifically, Fe or a metal or alloy containing Fe as a main component. For example, in weight%, Be <1.4%, Al <34%, Si <1
5%, Ti <2%, V <100%, Cr <100%, Mn <3%, Co <75%,
Ni <30%, Zn <8%, Ge <16%, As <10%, Mo <5%, Ru <1
0%, Rh <65%, Sn <5%, W <8%, Re <29%, Os <35%, Ir
Fe containing additional elements such as <40%, Pt <46%, Ce <6%
The alloy has a body-centered cubic structure, and these additive elements may be added not only in one kind but in two or more kinds at the same time. Of these additive elements, Al, V and Cr are F
If the addition amount to the e-alloy is increased, the saturation magnetic flux density becomes low and it becomes unsuitable for a thin-film magnetic head.

Further, in the present invention, a thin film produced by a sputtering method or a vacuum evaporation method is often in a thermally non-equilibrium state. In some cases, it may form a solid solution in the supersaturated state. Furthermore, even if a thin film is formed by a sputtering method or a vacuum deposition method by adding an element other than the above-mentioned additional element that produces a precipitate other than a body-centered cubic structure when solid-dissolved in Fe, the uniform body-center It may have a cubic structure.

In the present invention, as a method for producing a thin film in which the crystal orientation of the metal and alloy having a body-centered cubic structure is oriented, a single crystal is used for the substrate, and a method for selecting the type and crystal plane of the single crystal, There is a method of selecting the manufacturing conditions of the thin film. The types of single crystal substrates include {110} planes or {11} faces of crystals of Fe or magnetic alloys containing Fe as a main component.
It is desirable to use a single crystal substrate having an atomic arrangement symmetry and period similar to the atomic arrangement symmetry and period of the 1} plane.

The thin film forming method in the present invention includes vacuum deposition method, sputtering method, ion plating method, and CVD method.
Or various plating methods can be used.

Example of Invention

Hereinafter, one embodiment of the present invention will be described in more detail.

(Example 1) As a substrate, a Si single crystal whose surface was substantially aligned with the {100} plane was used, and an Fe thin film was deposited on this substrate using an ion beam sputtering apparatus. Ar was used as the sputtering gas, and the Ar gas pressure was 1 × 10 ⁻⁴ Torr. Also,
The ion acceleration voltage was 1.1 kV and the ion current was 60 mA. The substrate temperature was about 40 ° C. and the film thickness was 0.3 μm. The result of measuring this Fe thin film by the X-ray diffraction method is shown in FIG. The target was Cu. In the figure, the vertical axis represents the ratio between the maximum diffraction line intensity (I _max ) and each diffraction line intensity (I), and the horizontal axis represents the diffraction angle [2θ (deg)].

As a comparative example, using a glass substrate, an Fe thin film was prepared under the same conditions as in this example. The X-ray diffraction pattern of this Fe thin film is shown in FIG.

In the case of using a Si single crystal substrate in which the substrate surface of the present invention coincides with the {100} plane, as shown in FIG. 1 (a), the crystal is formed so that almost only the {110} plane is parallel to the thin film plane. An Fe thin film with orientated is obtained. On the other hand, when a glass substrate which is a comparative example is used, as shown in FIG.
The 0} plane, {100} plane, {211} plane, {310} plane, and {111} plane exist in parallel with the Fe thin film plane.

Next, using the Si single crystal substrate shown in FIG.
While forming the thin film, an operation of etching the surface of the thin film was performed using the second ion gun other than the one for forming the thin film. The film produced by this method was measured by the X-ray diffraction method. The acceleration voltage of the second ion gun was 200 V and the current density was 0.1 mA / cm ² . Fe produced by this method
The X-ray diffraction pattern of the thin film was almost the same as that shown in Fig. 1 (a), but in the case of Fig. 1 (a), {11
The half-value width of the 0} plane diffraction peak was about 1 degree (°), whereas when the etching operation was simultaneously performed using the second ion gun, the half-value width was about 0.2 °, and a thin film was formed. However, it was revealed that a magnetic thin film having a more excellent crystal orientation can be obtained by simultaneously performing the etching operation.

As described above, using the Si single crystal substrate, the {110} plane was oriented so as to match the thin film plane, and the thin film surface was composed of the {110} plane. As a result of cleaning the Fe thin film whose surface is not oriented with pure water for 5 minutes in the cleaning process in the magnetic head manufacturing process, the non-oriented Fe thin film on the glass substrate has a local corrosion of a density of about 40 pieces / cm ^2. On the other hand, in the Fe thin film on the Si single crystal substrate with the {110} plane oriented, the number of localized corrosion was reduced to about 5 / cm ² .

Further, in the Fe thin film formed by etching using the second ion gun while performing the etching operation, the number of localized corrosions was reduced to about 3 / cm ² .

As explained above, by using the Fe thin film oriented so that the {110} plane matches the thin film surface, the corrosion resistance of the thin film can be significantly improved, and the yield in the manufacturing process of the magnetic head using this can be significantly improved. It was confirmed that it can be improved.

(Example 2) As a substrate, a Si single crystal whose surface was substantially aligned with the {111} plane was used, and an Fe thin film was deposited on this substrate using an ion beam sputtering apparatus. The sputtering conditions are the same as in Example 1 above, Ar gas pressure 1 × 10 ⁻⁴ Torr, ion acceleration voltage 1.1 kV, current 60 mA, substrate temperature about 40 ° C., film thickness 0.3.
μm. As shown in FIG. 2, the X-ray diffraction pattern of this Fe thin film was found to have the strongest diffraction peak from {222} and was preferentially oriented so that the thin film surface became the {111} plane. This film also has {110} and {20
Diffraction lines from the 0}, {211}, and {220} planes were also observed, and {1
There are also crystal grains whose planes such as the 10}, {211}, and {100} planes coincide with the thin film surface. On the other hand, completely unoriented
The X-ray diffraction line intensity ratio of each surface obtained from Fe polycrystal is AS
TM Diffraction Data Card 6-0696 (American Society for T
According to esting Materials), it is as shown in Table 2.

As shown in Table 2, in the case of non-oriented polycrystalline {22
Diffraction line intensity on 2} plane Ratio to diffraction line intensity on {110} plane I
_{222} / I _{110} is 0.06, whereas the thin film shown in Fig. 2 has I _{222} / I _{110} of 2. This thin film has a thin film surface of {111} plane. It can be said that the crystal grains are strongly oriented so that

As described above, the Fe thin film oriented so that the {111} plane was aligned with the thin film surface was washed with pure water for 5 minutes in the same manner as in Example 1 above, and as a result, about 10 pieces / cm 2 were obtained. It was clarified that the local corrosion of the number of ² occurred, and on the contrary, the density of the local corrosion can be significantly reduced as compared with the Fe thin film shown in FIG. 1 (b) formed on the glass substrate.

As described above, it has been confirmed that the Fe thin film in which the crystal grain {111} plane is oriented so as to coincide with the thin film surface has a significantly improved corrosion resistance, and the thin film magnetic head using the Fe thin film can greatly improve the manufacturing yield. .

(Example 3) A glass substrate was used as a substrate, and a Fe-Si alloy thin film was deposited on the substrate using a high frequency bipolar sputtering device. A Fe-6.5 weight (wt)% Si alloy was used as the target. The X-ray diffraction pattern of the film prepared by changing the Ar gas pressure from 5 × ^-3 Torr to 5 × 10 ^-2 Torr is shown in FIG. 3 (a).
Shown in (b) and (c). The substrate temperature was 350 ° C.

In FIG. 3 (c) where the Ar gas pressure is 5 × 10 ⁻² Torr and in FIG. 3 (b) where the Ar gas pressure is 3 × 10 ⁻² Torr, the thin film surface is composed of various crystal planes. On the other hand, the thin film prepared under the conditions of Ar gas pressure of 2 × 10 ^-2 Torr or less, while being composed of crystals, has a thin film surface that coincides with the {110} plane, as shown in FIG. 3 (a). It was found that it consisted only of crystal grains. These Fe-Si alloy thin films were prepared using the above-mentioned Example 1
As a result of washing with pure water for 5 minutes in the same manner as in {11
The thin film of FIG. 3 (a) oriented so that the {0} plane was aligned with the thin film surface had a local corrosion density of about 6 pieces / cm ² , whereas the thin film of FIG. The thin films shown in FIGS. 3 (b) and (c), which were poor, were about 35 / cm ² and about 45 / cm ² . As described above, the Fe-Si alloy thin film in which the {110} planes of the crystal grains are aligned with the thin film surface has significantly improved corrosion resistance, and the yield of the magnetic head manufacturing process using this alloy thin film is improved. It was confirmed that it could be greatly improved.

In the present invention, the state of crystal grain orientation of the thin film can be measured by the X-ray diffraction pattern described above.
That is, in a completely non-oriented thin film, the X-ray diffraction intensity from each crystal face is as shown in Table 2 above, and the {110} faces of the crystal grains are preferentially oriented so that they coincide with the thin film face. In the thin film, the X-ray diffraction intensity of the planes other than the {110} plane becomes weak, and I _{hkl} / I _{110} becomes smaller than that of the non-oriented film. Then, in the thin film oriented so that only the {110} plane completely matches the thin film plane, diffraction lines from planes other than the {110} plane are not observed. Also, {11
In a thin film that is preferentially oriented so that the 1} plane coincides with the thin film plane, I _{222} / I _{100} becomes larger than that of a non-oriented thin film, and only the {111} plane is the thin film plane. In the thin film oriented so as to coincide with, the diffraction lines of planes other than the {111} plane are not observed. In the present invention, the use of a thin film in which a {110} plane or a {111} plane of a crystal grain is safely oriented so as to coincide with a thin film plane in a magnetic head improves corrosion resistance and yield in a magnetic head manufacturing process. Corrosion resistance even when using a thin film that is preferentially oriented as compared to a non-oriented thin film so that the {110} face or {111} face of the crystal grain matches the thin film face in the magnetic head. And is effective in improving the yield in the magnetic head manufacturing process.

The effects of the present invention are obtained not only in the above-described examples but also in metals and alloys having a body-centered cubic structure, and particularly when using a metal and an alloy having a body-centered cubic structure containing Fe or Fe as a main component. Since a magnetic thin film having a high saturation magnetic flux density and excellent corrosion resistance can be obtained, a magnetic head using the magnetic thin film has excellent recording characteristics and a high yield in the magnetic head manufacturing process.

〔The invention's effect〕

As described in detail above, as the magnetic thin film of the magnetic head of the present invention, a metal or alloy having a body-centered cubic structure, particularly Fe or an alloy containing Fe as a main component, is used, and the crystal plane {110} plane or By orienting the {111} plane so that it is substantially aligned with the thin film surface, a magnetic thin film having a high saturation magnetic flux density and excellent corrosion resistance can be obtained. In addition, the yield in the magnetic head manufacturing process can be greatly improved, and its industrial utility value is extremely large.

[Brief description of drawings]

FIG. 1A shows X of the magnetic thin film in Example 1 of the present invention.
The figure which shows a line diffraction pattern, FIG.1 (b) is a figure which shows the X-ray diffraction pattern in the comparative example, FIG.2 is the figure which shows the X-ray diffraction pattern of the magnetic thin film in Example 2 of this invention,
3 (a), (b), and (c) are diagrams showing an X-ray diffraction pattern in Example 3 of the present invention, and FIG. 4 is a longitudinal section showing an example of the structure of a conventional thin film magnetic head for perpendicular magnetic recording. It is a side view. 1 ... Non-magnetic substrate, 2 ... Main magnetic pole 3 ... Inorganic insulator layer, 4 ... Conductor coil 5 ... Organic insulator layer, 6 ... Upper magnetic layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Norio Ota 1-280, Higashi Koigakubo, Kokubunji City, Tokyo Inside Central Research Laboratory, Hitachi, Ltd. (56) Reference JP-A-59-207608 (JP, A) JP-A-59 -9905 (JP, A) JP-A-58-111119 (JP, A)

Claims (3)

[Claims] 1. A magnetic head using a magnetic thin film for at least part of a magnetic circuit, wherein at least part of the magnetic thin film is made of Fe or a metal or alloy containing Fe as a main component, and a crystal of the metal or alloy. The magnetic head is characterized by using a magnetic thin film oriented so that the {110} plane of is substantially aligned with the thin film surface of the magnetic thin film. 2. The magnetic head according to claim 1, wherein the metal or alloy forming the magnetic thin film has a body-centered cubic structure. 3. The alloy containing Fe as a main component is Be, Al or S.
i, Ti, V, Cr, Mn, Co, Ni, Zn, Ge, As, Mo, Ru, R
3. The magnetic head according to claim 2, further comprising at least one selected from h, Sn, W, Re, Os, Ir, Pt, and Ce.