JPH1012438A - Alloy magnetic film with substrate for magnetic head, its manufacture and magnetic head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a ferromagnetic body layer of Fe3 O4 from being generated on a substrate at a thermal treatment by forming an area of an alloy magnetic film, which is on the side adjoining a buffer layer, into an oxygen enriched layer. SOLUTION: In an alloy magnetic film with a substrate for a magnetic head wherein an alloy magnetic film comprising an Fe-M-C system nanocrystal alloy (M: group IV B, VB, IIIA, IVA elements) or Fe-M system alloy (M: group IVB, VB, IIIA, IVA elements) is formed on a substrate of α-Fe3 O4 with a buffer layer in between, an area of the alloy magnetic film on the side adjoining the buffer layer is formed into an oxygen enriched layer. An oxygen content of the oxygen enriched layer of the alloy magnetic film is 3 to 15 atomic %. By this, at a thermal treatment after film formation, a reducing power of the alloy magnetic film is relaxed by the oxygen enriched layer, so that the substrate is prevented from generating a magnetite on an interface between the buffer layer and that.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an alloy magnetic film used for a magnetic head of a magnetic disk device such as a computer, a method of manufacturing the same, and a magnetic head.

[0002]

2. Description of the Related Art In the field of magnetic recording, a magnetic recording medium having a high coercive force and a high residual magnetic flux density has been used in accordance with an increase in recording signal density. There is a demand for a magnetic film having high saturation magnetization and high magnetic permeability as a core material of a magnetic head for performing the following.

As such a magnetic film having a high saturation magnetization and a high magnetic permeability, a Fe-MC-based nanocrystalline alloy (M: IVB group, VB
Group, IIIA and IVA elements) and Fe-M alloys (M: I
Magnetic films of VB group, VB group, IIIA group, and IVA group) are known. These alloy magnetic films are formed by sputtering on a substrate.

On the other hand, α-Fe ₂ O ₃ (hematite) having good CSS characteristics is used for the substrate.

[0005]

However, when the above alloy magnetic film is formed on an α-Fe ₂ O ₃ substrate, there is a problem that the magnetic film is easily peeled off.

In order to avoid this, an Al ₂ O ₃ layer is formed as a buffer layer on an α-Fe ₂ O ₃ substrate. However, heat treatment in an inert gas atmosphere or under vacuum for the purpose of obtaining soft magnetism after the formation of the alloy magnetic film causes F
Ferromagnetic Fe ₃ O ₄ (magnetite) in which e ₂ O ₃ is reduced is generated. Since the Fe ₃ O ₄ ferromagnetic layer causes a magnetic interaction with the magnetic film, a high magnetic permeability cannot be obtained in the alloy magnetic film.

An object of the present invention is to provide an Fe-MC-based nanocrystalline alloy or an alloy magnetic film made of an Fe-based alloy formed on a substrate of α-Fe ₂ O ₃ via a buffer layer during heat treatment of the substrate. Alloy magnetic film with a substrate for a magnetic head having high saturation magnetization and high magnetic permeability having high magnetic permeability maintained in the alloy magnetic film while preventing formation of a ferromagnetic layer of ₃ O ₄ , method for manufacturing the same, and magnetic head It is to provide.

[0008]

The above object is achieved by an alloy magnetic film for a magnetic head, a method of manufacturing the same, and a magnetic head according to the present invention. In short, an Fe-MC-based nanocrystalline alloy (where M is an element of the IVB, VB, IIIA, or IVA group) or Fe on a substrate of α-Fe ₂ O ₃ via a buffer layer. -M-based alloy (M: IVB group, VB
In the alloyed magnetic film with a magnetic head substrate formed with an alloyed magnetic film made of a group III, IIIA, or IVA element, a region adjacent to the buffer layer of the alloyed magnetic film is formed in an oxygen-rich layer. Alloy magnetic film with a substrate for a magnetic head.

[0009] Preferably, the oxygen content of the oxygen-rich layer of the alloy magnetic film is 3 atomic% or more and 15 atomic%. Fe-MC
Based nanocrystalline alloy is Fe-Si-Al-Hf-Ta-
C, Fe-Si-Hf-C, Fe-Si-Al-Hf-
C, Fe-Hf-C and Fe-Si-Hf-Ta-C
One selected from the group consisting of: The Fe-M-based alloy is an alloy mainly composed of one selected from the group consisting of Fe-Si-Al, Fe-Si and Fe-Al.
The buffer layer is made of Al ₂ O ₃ or cobalt oxide Cox
Oy (however, y / x = 1 to 4/3).

In another embodiment of the present invention, a buffer layer is formed by sputtering on a substrate of α-Fe ₂ O ₃ , heat treatment is performed if desired, and then Fe is formed on the buffer layer by sputtering.
-MC-based nanocrystalline alloy (where M: IVB group, VB group,
Forming an alloy magnetic film made of a group IIIA or IVA element) or an Fe-M alloy (where M is a group IVB, VB, IIIA or IVA element);
In a method of manufacturing an alloy magnetic film with a substrate for a magnetic head,
The alloy magnetic film was first sputtered under an oxygen-containing inert gas, and then under an oxygen-free inert gas to form an alloy magnetic film in which the region adjacent to the buffer layer was an oxygen-rich layer. A method for producing an alloy magnetic film with a substrate for a magnetic head, characterized in that:

[0011] The Fe-MC nanocrystalline alloy is made of Fe-S
i-Al-Hf-Ta-C, Fe-Si-Hf-C, F
e-Si-Al-Hf-C, Fe-Hf-C and Fe
-Si-Hf-Ta-C. Fe-M based alloy is Fe-Si-Al, Fe-S
It is an alloy mainly containing one selected from the group consisting of i and Fe-Al.

According to still another aspect of the present invention, in a magnetic head configured by joining two core halves with a predetermined gap length and joining them, each of the core halves includes:
_On a substrate of α-Fe ₂ O ₃ , Fe-
MC-based nanocrystalline alloy (however, M: group IVB, group VB, II
An alloy magnetic film made of a group IA or IVA element) or an Fe-M alloy (M: an element of group IVB, VB, IIIA or IVA) is enriched in the region adjacent to the buffer layer. A magnetic head formed as an oxygen layer.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings.

As shown in FIG. 1, the alloy magnetic film 1 of the present invention
Is formed on a substrate 3 of α-Fe ₂ O _{3 with} a buffer layer 2 interposed therebetween to form an alloy magnetic film with a substrate. In the present invention, the ferromagnetic Fe ₃ O ₄ (magnetite) is prevented from being generated at the interface with the buffer layer 2 of the substrate 3 by the heat treatment for obtaining soft magnetism after the formation of the alloy magnetic film 1. For this purpose, a region of the alloy magnetic film 1 adjacent to the buffer layer 2 was formed in the oxygen-rich layer 1a.

The present inventors have investigated and studied the cause of the formation of magnetic material Fe ₃ O ₄ (magnetite) at the interface with the buffer layer 2 of the substrate 3 due to the heat treatment after the formation of the alloy magnetic film 1. . As a result, during the heat treatment after the formation of the alloy magnetic film 1,
It was found that the alloy magnetic film 1 functions as a reducing agent, and the reducing power reaches the substrate 3 via the buffer layer 2 to reduce Fe ₃ O ₄ .

Therefore, the region on the buffer layer 2 side of the alloy magnetic film 1 is formed in the oxygen-rich layer 1a, and oxygen is supplied from the oxygen-rich layer 1a to the alloy magnetic film 1 during heat treatment after film formation. It is considered that even if the alloy magnetic film 1 acts as a reducing agent during the heat treatment, the reducing power can be reduced, and the reduction of α-Fe ₂ O _{3 in} the substrate 3 can be prevented. Then, Fe ₃ O ₄ is not generated on the interface between the substrate 3 and the alloy magnetic film 1.

Therefore, in the present invention, as described above, the region on the buffer layer 2 side of the alloy magnetic film 1 is formed in the oxygen-rich layer 1a. Hereinafter, the present invention will be described in detail.

The alloy magnetic film 1 is made of a Fe—MC nanocrystalline alloy (M: IVB, VB, IIIA, IVA group) or a Fe—M alloy (M: IVB group). , VB
Group, IIIA, and IVA elements). Preferred examples of the Fe-MC-based nanocrystalline alloy include Fe-Si-A
1-Hf-Ta-C, Fe-Si-Hf-C, Fe-S
i-Al-Hf-C, Fe-Hf-C and Fe-Si
-Hf-Ta-C or Fe-Al-Hf-Ta-C
And so on. Preferred examples of the Fe-M alloy include Fe
-Si-Al, an alloy mainly composed of one selected from the group consisting of Fe-Si and Fe-Al, for example, Fe-Si, Fe-Al, Fe-Si-Al, Fe-Al
-Si-Al-Hf or Fe-Si-Al-Hf-
Ta and the like.

The alloy magnetic film 1 is formed on the buffer layer 2 of the substrate 3 by sputtering with an alloy as a target under an inert gas.
Form on top. The sputtering gas is Ar, the sputtering gas pressure is 1 to 2 mTorr, the cathode power is 0.5 to 3 kW, and the substrate temperature is 0 to 200 ° C.

In the present invention, when the alloy magnetic film 1 is sputtered, oxygen is first introduced into the layer of the alloy magnetic film 1 formed on the buffer layer 2 by sputtering under an inert gas containing oxygen. Then, a region of the alloy magnetic film 1 on the buffer layer 2 side is formed in the oxygen-rich layer 1a. The oxygen content of the oxygen-containing inert gas is suitably less than 20%, preferably 2% or more and 12% or less in terms of sccm with respect to the total amount of gas introduced into the sputtering chamber. The content is 3 atomic% or more and 15 atomic% or less. The total thickness of the alloy magnetic film 1 is suitably 1 μm or more and 20 μm or less in consideration of the track width, magnetic recording, and readability of a magnetic head.

According to the present invention, before forming the alloy magnetic film 1 on the buffer layer 2, the buffer layer 2 can be subjected to a heat treatment as required for the purpose of removing distortion of the buffer layer 2 and the like. It is sufficient that the heat treatment after the formation of the buffer layer 2 be performed in the air or in a vacuum at 300 to 1000 ° C. for 30 minutes to 2 hours.

After the alloy magnetic film 1 is formed, it is subjected to a necessary heat treatment for the purpose of obtaining soft magnetism before being used for manufacturing a magnetic head. The heat treatment conditions are 5 × 10 ⁻⁷ to
The substrate temperature is set to 600 to 800 ° C. and the time is set to about 10 to 60 minutes under a vacuum of 5 × 10 ⁻⁶ Torr or an inert gas.

The buffer layer 2 is made of Al ₂ O ₃ , CoO, C
o ₃ O ₄ (generally CoxOy, where y / x = 1 to 4)
/ 3) or the like. Among them, CoxOy releases oxygen when heat-treating the alloy magnetic film 1 and can assist in preventing reduction of α-Fe ₂ O ₃ of the substrate 3. Therefore, CoxOy is preferred as the material of the buffer layer 2 over Al ₂ O ₃ .

The buffer layer 2 is formed by reactive sputtering using a metal such as Al or Co as a target under an oxygen-containing inert gas (sputtering gas) or under a sputtering gas of an inert gas or an inert gas containing oxygen. These oxides can be formed on the substrate 3 by sputtering using an oxide target of Al, Co, or the like.

As the substrate 3, α-Fe ₂ O ₃ (hematite) capable of improving CSS characteristics is used. The thickness of the substrate 3 is about 200 to 500 μm.

According to the present invention, the side adjacent to the buffer layer 2 of the alloy magnetic film 1 is the oxygen-rich layer 1a. Therefore, during the heat treatment after the formation of the alloy magnetic film 1, the alloy magnetic film 1 is used as a reducing agent. Even if it works, its reducing power can be reduced by the supply of oxygen from the oxygen-rich layer 1a, and the formation of ferromagnetic Fe ₃ O ₄ (magnetite) at the interface with the buffer layer 2 of the substrate 3 can be prevented. . Therefore, there is no problem that the Fe ₃ O ₄ ferromagnetic layer is formed on the substrate 3 and magnetically interacts with the alloy magnetic film 1. The Fe—M—C nanocrystal alloy or the Fe—M alloy is used. The magnetic film having high saturation magnetization and high magnetic permeability can be obtained while maintaining the high magnetic permeability of the alloy magnetic film 1 made of

To produce a magnetic head from the above alloy magnetic film 1, the following procedure may be used. First, as shown in FIG. 2, a substrate 3 ′ of α-Fe ₂ O ₃ similar to the substrate 3 is adhered on the alloy magnetic film 1 by using a glass 4, and a magnetic film structure 5 is formed.
Is prepared. As shown in FIG. 3, the magnetic film structure 5 is cut in the thickness direction on which the alloy magnetic film 1 is formed to form a pair of core half blocks 18 and 19, and the core half block 18 has a winding groove. After forming 20, both core half blocks 18, 1
If necessary, the core half block 1 facing the winding groove 20 may be used to strengthen the joining of the butting surfaces 9.
9 are formed with chamfered portions 22 on both side surfaces, and concave portions 23 are formed on the opposite sides of the gap 21 of both core half blocks. Then, the butting surfaces 18a and 19a of the two core half blocks 18 and 19 are polished to form the gap 2
Form one.

The two core half-blocks 18 and 19 in which the gap portion 21 is formed are formed by melting and filling the chamfered portion 22 and the concave portion 23 with mold glass.
Is melted and pressed by heating at 500 ° C. to 650 ° C. for 30 minutes to 1 hour. Finally, in order to form a tape sliding surface, R polishing and other molding and winding are performed to obtain the magnetic head 10.

Hereinafter, embodiments of the present invention will be described.

Embodiment 1 According to the present invention, a buffer layer of Al ₂ O ₃ is formed on a substrate of α-Fe ₂ O ₃ , and an alloy magnetic film is formed on the buffer layer so that the buffer layer side becomes an oxygen-rich layer. Thus, an alloy magnetic film with a substrate was produced.

The substrate is α-Fe ₂ manufactured by Tokin Co., Ltd.
An O ₃ substrate (trade name: HN02) was used. Buffer layer,
DC facing target type sputtering was used for forming the alloy magnetic film. The alloy magnetic film was formed after forming a buffer layer on the substrate and then subjecting the substrate to a heat treatment in the air for one hour.
The alloy magnetic film was an Fe-Si-Al-Hf-C alloy.
While flowing 100 sccm of argon as an inert gas, oxygen was added for 4 minutes from the start of sputtering of the alloy magnetic film.
It was introduced into the sputtering chamber at a flow rate of 7, 10, 15, or 20 sccm. For comparison, a case where the oxygen introduction amount was 0 sccm was also tested.

The conditions for forming the buffer layer and the alloy magnetic film are as follows.

Film formation conditions of buffer layer (Al ₂ O ₃ ) Sputtering method: DC facing target type Target: Al Target size: 100 mmφ Sputtering gas: 30 sccm Ar-20 sccm O
₂ Gas pressure: 1.0 mTorr Cathode power: 0.5 kW Substrate temperature: 300 ° C. Film thickness: 100 nm

Alloy magnetic film (Fe-Si-Al-Hf-
C) Film formation conditions Sputtering method: DC facing target method Target: Fe-Si-Al-Hf-C Target size: 100 mmφ Sputtering gas: Ar Gas pressure: 1-2 mTorr Cathode power: 1.5 kW Substrate temperature: room temperature Film thickness : 2.7 μm Deposition rate: 675 nm / min

After the formation of the alloy magnetic film, in order to obtain soft magnetism, 700 ° C. and 20 ° C. in a high vacuum of 2 × 10 ⁻⁶ Torr.
Heat treatment. Thereafter, the magnetic properties of the magnetic film were measured. Magnetic properties are measured by the ferrite yoke method (measurement frequency:
2 MHz). The results are shown in Table 1 and FIG. Note that the above-described film forming conditions of the magnetic film are conditions under which uniaxial anisotropy is easily imparted in view of device characteristics.

[0036]

[Table 1]

As shown in Table 1, in the alloy magnetic film according to the present invention, when the amount of oxygen introduced was 4 sccm, as compared with the case of the conventional alloy magnetic film (the amount of oxygen introduced was 0 sccm), 1.
A magnetic permeability of 5 times or more was obtained. Oxygen introduction amount is 20 scc
When m, the magnetic properties are almost the same as those of the conventional alloy magnetic film. Therefore, the oxygen introduction amount is larger than 0 sccm and 20
When the flow rate of oxygen-containing inert gas relative to the total flow rate of the gas introduced into the sputtering chamber is less than 20% in sccm ratio, the conventional alloy magnetic film (oxygen introduction amount 0 scc)
m), the oxygen permeability is 2 scc in particular.
When the flow rate of the oxygen-containing inert gas with respect to the total flow rate of the gas introduced into the sputtering chamber is 2% or more and 12% or less, the magnetic permeability in the hard axis direction exceeds 1600, and When the amount is around 4 sccm, the magnetic permeability becomes maximum.

From the result of the composition analysis of the alloy magnetic film (Fe-Si-Al-Hf-C) formed under the same conditions except that oxygen gas was introduced from the start to the end of sputtering, the amount of oxygen Was estimated to be 2 sccm or more and 12 sccm or less (the oxygen flow rate of the oxygen-containing inert gas with respect to the total gas flow introduced into the sputtering chamber was 2% or more and 12% or less in sccm ratio). As a result, it was found that when the oxygen content of the oxygen-rich layer was 3 atomic% or more and 15 atomic% or less, the magnetic permeability in the hard axis direction exceeded 1600.

As shown in Table 1, when the oxygen introduction amount was 15 sccm, the oxygen introduction time was 2 minutes and 4 minutes, and the thickness of the oxygen-rich layer was about 1350 nm and about 2700 nm.
(Calculated from the deposition rate). The results show that the amount of oxygen introduced, that is, the thickness of the oxygen-rich layer has little effect on the magnetic permeability.

From the alloy magnetic film with a substrate of this embodiment, FIG.
And a magnetic head is manufactured as described in FIG.
When used for magnetic recording and reading of information on a magnetic recording medium, it was confirmed that the device operated without any problem.

[0041]

As described above, according to the present invention,
On the buffer layer formed on the α-Fe ₂ O ₃ substrate, F
Since the alloy magnetic film made of the e-MC-based nanocrystalline alloy or the Fe-M-based alloy was formed such that the buffer layer side became an oxygen-rich layer, during the heat treatment after the formation of the alloy magnetic film,
The oxygen-rich layer can reduce the reducing power of the alloy magnetic film and prevent the formation of ferromagnetic Fe ₃ O ₄ (magnetite) on the substrate at the interface with the buffer layer. Therefore, Fe ₃ O ₄
By eliminating the interaction with the alloy magnetic film due to the formation of the ferromagnetic layer, the high magnetic permeability of the Fe-MC-based nanocrystalline alloy or the Fe-M-based alloy magnetic film can be maintained without lowering. Thus, a magnetic film having high saturation magnetization and high magnetic permeability can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a layer configuration of an alloy magnetic film with a substrate according to the present invention.

FIG. 2 is a cross-sectional view showing a magnetic film structure when a magnetic head is manufactured using the alloy magnetic film of FIG. 1;

FIG. 3 is a perspective view showing a magnetic head manufactured from the magnetic film structure of FIG. 2;

FIG. 4 is a diagram showing the relationship between the amount of oxygen introduced and the magnetic properties during the formation of an oxygen-rich layer in an example.

[Explanation of symbols]

 Reference Signs List 1 alloy magnetic film 1a oxygen-rich layer 2 buffer layer 3 substrate 3 'substrate 4 glass 5 magnetic film structure 10 magnetic head 18, 19 core half 21 gap portion

Claims (10)

[Claims] 1. An Fe-MC-based nanocrystalline alloy (M: I) on a substrate of α-Fe ₂ O ₃ via a buffer layer.
VB group, VB group, IIIA group, IVA group element) or Fe-M
In the alloy magnetic film with a substrate for a magnetic head formed with an alloy magnetic film made of a base alloy (M: IVB group, VB group, IIIA group, IVA group element), the side of the alloy magnetic film adjacent to the buffer layer An alloy magnetic film with a substrate for a magnetic head, wherein the region is formed in an oxygen-rich layer. 2. The oxygen-rich layer of the alloy magnetic film having an oxygen content of 3
2. The alloy magnetic film according to claim 1, which is at least 15 atomic%. 3. The method according to claim 1, wherein the Fe-MC nanocrystalline alloy is Fe-
Si-Al-Hf-Ta-C, Fe-Si-Hf-C,
Fe-Si-Al-Hf-C, Fe-Hf-C and F
3. The alloy magnetic film according to claim 1, wherein the alloy magnetic film is one kind selected from the group consisting of e-Si-Hf-Ta-C. 4. An Fe-M based alloy comprising: Fe—Si—Al;
1 selected from the group consisting of Fe-Si and Fe-Al
3. The alloy magnetic film according to claim 1, which is an alloy containing a seed as a main component. 5. The alloy magnetic film according to claim 1, wherein the buffer layer is made of Al ₂ O ₃ . 6. The buffer layer is made of cobalt oxide CoxOy.
5. The alloy magnetic film according to claim 1, wherein y / x = 1 to 4/3. 7. A buffer layer is formed by sputtering on a substrate of α-Fe ₂ O ₃ and, if desired, subjected to a heat treatment.
Fe-MC-based nanocrystalline alloys (M: IVB, VB, IIIA, IVA elements) or Fe-M-based alloys (M: IVB, VB
In the method of manufacturing an alloy magnetic film with a substrate for a magnetic head, the alloy magnetic film is composed of an element of group III, group IIIA or group IVA), and further subjected to a heat treatment. An alloy with a substrate for a magnetic head, wherein the alloy is formed under an active gas and then under an inert gas containing no oxygen to form an alloy magnetic film in which a region adjacent to the buffer layer is an oxygen-rich layer. Manufacturing method of magnetic film. 8. An Fe—MC—based nanocrystalline alloy comprising:
Si-Al-Hf-Ta-C, Fe-Si-Hf-C,
Fe-Si-Al-Hf-C, Fe-Hf-C and F
8. The method according to claim 7, wherein the method is one selected from the group consisting of e-Si-Hf-Ta-C. 9. An Fe-M based alloy comprising: Fe—Si—Al;
1 selected from the group consisting of Fe-Si and Fe-Al
The method according to claim 7, wherein the alloy is a seed-based alloy. 10. A magnetic head formed by joining two core halves with a predetermined gap length and joining them, wherein each of said core halves is provided on an α-Fe ₂ O ₃ substrate with a buffer layer interposed therebetween. And Fe-MC nanocrystalline alloys (where M is an element of group IVB, VB, IIIA or IVA)
Alternatively, an Fe-M alloy (where M: IVB group, VB group, I
A magnetic head characterized in that an alloy magnetic film made of an element of group IIA or IVA) is formed in a region adjacent to the buffer layer in an oxygen-rich layer.