JPH0653068A - Manufacture of magnetic thin film - Google Patents

Abstract

PURPOSE:To enable a magnetic thin film to maintain prescribed magnetic characteristics even in the case where a magnetic film is formed on a base part consisting of a material different from the magnetic material to be formed in a method of manufacturing the magnetic thin film. CONSTITUTION:In a method of manufacturing a sendust magnetic material 33, which makes the material 33 form on a ferrite substrate 24, a film growth is performed in an oxygen (or nitrogen) atmosphere in the early stages of the formation of the material 33, whereby an oxidized (or nitrided) oxide film 32 is formed and after that, the sendust magnetic film 33 consisting of a pure sendust is formed on the above oxide film 32 in an atmosphere not containing oxygen (or nitrogen).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a magnetic thin film, and more particularly to a method for manufacturing a magnetic thin film in which a magnetic film is formed on a base made of a material different from the magnetic material to be formed.

[0002]

2. Description of the Related Art Generally, a magnetic head for a magnetic recording medium having a high coercive force is required to have a high saturation magnetic flux density at the time of recording, and in order to obtain a sufficient reproducing sensitivity at the time of reproducing, the magnetic head is high in a high frequency region. It is required to have magnetic permeability.

Further, a metallic magnetic material such as Sendust (registered trademark) is known as a magnetic material capable of achieving a high saturation magnetic flux density, and ferrite is known as a magnetic material having a high magnetic permeability.

However, a magnetic head made of only a metallic magnetic material has good recording characteristics,
Since the electric resistance of the metal magnetic material is small during reproduction, the magnetic permeability decreases due to the eddy current. Especially, the higher the frequency used, the more remarkable the decrease in magnetic permeability and the poor reproduction characteristics. Further, in a magnetic head made of only ferrite, the characteristics at the time of reproduction are good, but the characteristics at the time of recording become poor.

Therefore, in order to improve both recording and reproducing characteristics, a composite head of a metal magnetic material and ferrite has been provided.

In this magnetic head, a pair of magnetic head cores made of ferrite is formed with a metallic magnetic material on the abutting surfaces (gap forming surfaces) by sputtering or the like, and the pair of magnetic head cores having the metallic magnetic film are formed. MIG (Meta
l In Gap) Head is common.

Therefore, the manufacturing process of the MIG head includes a step of forming a metal magnetic film on ferrite, which is a material different from the metal magnetic material.

FIG. 6 shows a schematic configuration of a conventional manufacturing apparatus (sputtering apparatus) 1 for forming a metal magnetic film (sendust) on ferrite. In the figure, 2 is a chamber, 3 is a target made of sendust, 4 is a substrate (ferrite substrate) on which a sendust film is formed,
Reference numeral 5 is a mounting table on which the substrate 4 is mounted, 6 is a vacuum pipe connected to a vacuum system for maintaining a predetermined vacuum pressure in the chamber 2, and 7 is a high frequency power supply (for example, 13.56 MHz).

When Sendust is formed on the ferrite substrate 4 by using the sputtering apparatus 1, conventionally, sputtering is performed in a constant atmosphere without changing the atmosphere in the chamber 2. 7 is a sectional view showing the ferrite substrate 4 on which the magnetic film 8 of sendust is formed.

[0010]

However, when the material of the substrate 4 (ferrite) and the material of the magnetic film to be grown on the substrate 4 (sendust) are different as described above, the molecular structure of ferrite and sendust is different. Due to the difference of (1), the magnetic film in which the molecular arrangement is disturbed over a predetermined range near the interface between the ferrite substrate 4 and the sendust magnetic film 8 (hereinafter,
This magnetic film is called the interface film 9).

As is well known, when a film is formed by a sputtering method or a vapor deposition method, the characteristics of the initially formed film are recorded, and the films are successively formed on the upper part of the film. A predetermined film thickness is required until the proper molecular arrangement is achieved.

Therefore, the ratio of the interface film 9 in the magnetic film 8 is increased, and the magnetic properties (characteristics such as permeability and retention) of the interface film 9 are higher than those of the sendust film having a normal molecular arrangement. Therefore, there is a problem in that the characteristics of the manufactured magnetic head are greatly deteriorated.

Further, as a means for solving this problem, as shown in FIG. 8, the underlayer 10 of the sendust magnetic film 8 is formed.
As a method of forming a sendust magnetic film 8 on the underlayer 10, a metal film of NiFe or Cr having a molecular structure similar to that of sendust or an oxide such as SiO ₂ is first formed on the ferrite substrate 4. There is.

In this method, however, the ferrite substrate 4
Although the magnetic characteristics are improved as compared with the case where the sendust magnetic film 8 is directly formed on the upper surface, since the sendust magnetic film 8 is formed on the underlayer 10 made of a different material, the molecular arrangement is not disturbed. However, there is a problem that sufficient magnetic characteristics cannot be obtained.

The present invention has been made in view of the above points, and a method of manufacturing a magnetic thin film capable of maintaining predetermined magnetic characteristics even when a magnetic film is formed on a base made of a different material. The purpose is to provide.

[0016]

In order to solve the above problems, the present invention provides a method for producing a magnetic thin film in which a magnetic thin film is formed by growing a magnetic material on a base made of a material different from this magnetic material. In the initial stage of forming the magnetic material, oxygen or nitrogen is supplied to the formation chamber in which the magnetic film is formed to make the formation chamber an oxygen or nitrogen atmosphere, and the oxidized or nitrided first magnetic film is grown. After that, by stopping the supply of oxygen or nitrogen to the formation chamber, the second magnetic thin film made of a pure magnetic material is grown on the first magnetic film.

[0017]

By forming the magnetic thin film by the above method, the first magnetic film formed by oxidizing or nitriding the magnetic material is first grown on the base, and then the pure magnetic material is formed on the first magnetic film. The second magnetic thin film is grown.

Since the first magnetic film is an oxide or nitride of the second magnetic thin film, its main structure is very similar. Therefore, as compared with the structure in which the magnetic thin film is formed on the underlayer made of a different material, the disorder of the molecular structure is reduced by growing the second magnetic thin film on the first magnetic film as the underlayer. The crystal orientation and smoothness of the second magnetic thin film are improved, and good soft magnetic characteristics (high magnetic permeability and low coercive force) can be obtained.

[0019]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 2 shows a sputtering apparatus 20 used in one embodiment of the method of the present invention. In the figure, reference numeral 21 denotes a chamber, which is placed on a base 22 to hermetically define the outside world and the inside. Further, 23 is a target made of sendust, and this target 2
3 is configured to also function as an electrode.

Further, 24 is a ferrite substrate on which a sendust film is formed, and this ferrite substrate 24 is mounted on a mounting table 25. The mounting table 25 is configured to also function as an electrode. Both the target 23 and the mounting table 25 function as electrodes, and the target 23 and the mounting table 25 function as a high frequency power source (for example, 13.56 MHz).
It is connected to 26.

Further, the base 22 is provided with two pipes 27 and 28 communicating with the chamber 21. 2 of them
Reference numeral 7 denotes a vacuum pipe, which is connected to a vacuum device (vacuum pump) 29. By operating the vacuum device 29, the inside of the chamber 21 is controlled to a predetermined vacuum pressure. Further, 28 is a sputter gas supply pipe, which is connected to the sputter gas supply device 30. By operating the sputtering gas supply device 30, an argon gas or a mixed gas of argon gas and oxygen is supplied into the chamber 21, and the inside of the chamber 21 is made an argon gas atmosphere or an argon gas atmosphere having a predetermined oxygen concentration. be able to.

Reference numeral 31 in the drawing is a control device, which is constituted by, for example, a microcomputer. The control device 31 controls the sputtering process of the sputtering device 20, and is connected to the high frequency power supply 26, the vacuum device 29, and the sputtering gas supply device 30 described above.

Next, a method of forming a sendust magnetic thin film on the ferrite substrate 24 by using the sputtering apparatus 20 will be described.

The sendust magnetic thin film is applied to the ferrite substrate 24.
In order to form it on the top, first, the target 23 and the ferrite substrate 24 are mounted at predetermined positions, and then the sputtering apparatus 20 is used.
To start. When the sputtering device 20 is activated, the control device 31 operates the vacuum device 29 and the sputtering gas supply device 30. As a result, the inside of the chamber 21 becomes an argon gas atmosphere having a predetermined degree of vacuum and a predetermined oxygen concentration.

Subsequently, the control device 31 activates the high frequency power source 26 to start the sputtering, and the sendust which is the target 23 is coated on the ferrite substrate 24. At this time, the inside of the chamber 21 is in an argon gas atmosphere having a predetermined oxygen concentration by the operation of the sputtering gas supply device 30 at the initial stage of film formation,
Sputtering is performed in this atmosphere. Therefore,
An oxide film 32 of sendust is first formed on the ferrite substrate 24.

FIG. 1A shows the ferrite substrate 24 before the start of sputtering, and FIG. 1B shows a state in which the oxide film 32 of sendust is formed on the ferrite substrate 24.

As is well known, ferrite is MO.Fe ₂
Since it is an oxide represented by O ₃ (M is a divalent metal ion), the compatibility with the oxide film 32, which is the same oxide, is relatively good. Therefore, the oxide film 32 is formed on the ferrite substrate 24.
The oxide film 32 is not peeled off from the ferrite substrate 24 even if it is formed. Further, since the oxide film 32 is an oxide of Sendust, its molecular structure is similar to that of Sendust.

When the oxide film 32 having a predetermined thickness is formed by performing the sputtering in the chamber 21 in the argon gas atmosphere having the predetermined oxygen concentration as described above, the control device 31 controls the sputtering gas supply device 30. Control and stop the supply of oxygen. However, since the vacuum device 29 is still operating, the inside of the chamber 21 eventually becomes a pure argon gas atmosphere containing no oxygen.

When the inside of the chamber 21 becomes a pure argon gas atmosphere containing no oxygen by stopping the sputtering gas supply device 30 as described above, the magnetic film formed thereafter is a pure sendust magnetic film which is not an oxide. Three
It becomes 3. Incidentally, FIG. 1C shows a state in which the sendust magnetic film 33 is formed on the oxide film 32.

Here, the oxide film 32 and the sendust magnetic film 3
The interface state with 3 will be considered. As described above, since the oxide film 32 is the oxide of the sendust magnetic film 33,
The molecular structure of the oxide film 32 is similar to that of the sendust magnetic film 33. When a film is formed by a sputtering method or a vapor deposition method, the formed film grows while history of the underlying molecular structure state.

Therefore, in the conventional method of directly forming a pure sendust magnetic film on a ferrite substrate made of a different material, the structure of the growing sendust magnetic film is disturbed and the magnetic characteristics are deteriorated.

However, in the method of the present invention in which the oxide film 32 is first formed on the ferrite substrate 24 and the sendust magnetic film 33 is formed on the oxide film 32, the sendust magnetic film 33 is formed on the oxide film 32 having a similar molecular structure. Because a film is formed,
The molecular structure of the sendust magnetic film 33 is not disturbed, and the crystal orientation and the smoothness on the surface of the sendust magnetic film 33 can be improved, thereby obtaining good soft magnetic properties (high magnetic permeability and low coercive force). You can

4 and 5 are photomicrographs for demonstrating the smoothness of the surface of the sendust magnetic film 33. FIG. 4 shows the surface of the sendust magnetic film formed by the conventional method, and FIG. 5 shows the surface of the sendust magnetic film 33 formed by the method of the present invention. By comparing the figures, it can be seen that the sendust magnetic film 33 formed by the method of the present invention has much better surface smoothness than the sendust magnetic film formed by the conventional method. .

FIG. 9 shows a sendust magnetic film 33 formed by the method of the present invention (shown as the present invention in the figure) and a sendust magnetic film formed by the conventional method (shown as the conventional article in the figure). The frequency characteristics of magnetic permeability are shown for comparison. As shown in the figure, the sendust magnetic film 33 formed by the method of the present invention has better characteristics in the previous frequency range than the sendust magnetic film formed by the conventional method, It can be seen that the characteristics are particularly excellent in the low frequency range.

10 and 11 show the orientation of the sendust magnetic film 33 formed by the method of the present invention (shown in FIG. 11) and the orientation of the sendust magnetic film formed by the conventional method (FIG. 10). , As shown in FIG. From each figure,
The peak intensity showing the orientation of the sendust magnetic film formed by the conventional method is about 1000 CPS, while the peak intensity showing the orientation of the sendust magnetic film 33 formed by the method of the present invention is about 1900 CPS. It can be seen that the Sendust magnetic film 33 formed by the method of the present invention has a stronger orientation.

In the above-described embodiment, the method of forming the oxide film 32 directly on the ferrite substrate 24 is shown. However, as shown in FIG. 3, the oxide film 32 is formed on the ferrite substrate 24.
Before being formed on the ferrite substrate 24, an underlayer (metal film of NiFe or Cr, or SiO ₂ etc.) 34 is first formed on the ferrite substrate 24, and an oxide film 32 and a sendust magnetic film 33 are sequentially formed on the underlayer 34. It may be a method.

Further, in the above-mentioned embodiment, before forming the pure sendust magnetic film 33, the inside of the chamber 21 is made an argon gas atmosphere having a predetermined oxygen concentration and the oxide film 3 is formed.
Although the method of forming No. 2 has been described, nitrogen gas is supplied into the chamber 21 in place of the above atmosphere to generate an argon gas atmosphere having a predetermined nitrogen concentration, and a nitride film of sendust is formed in place of the oxide film 32. The same effect can be obtained as a method.

Further, in the above-mentioned embodiment, the sputtering method is adopted as the film forming method, but other film forming methods such as the vapor deposition method can be applied to the present invention.

Further, in the above-mentioned embodiment, an example is shown in which sendust is used as the magnetic material and ferrite is used as the base material. However, when a material other than sendust and ferrite is used as the magnetic material and the base material, Of course, the method of the present invention can be applied.

[0041]

As described above, according to the present invention, the first magnetic film, which is obtained by oxidizing or nitriding the magnetic material, is first grown on the base portion, and subsequently, the pure magnetic material is formed on the first magnetic film. The second magnetic thin film is grown. Since the first magnetic film is an oxide or a nitride of the second magnetic thin film, its main structure is very similar, and therefore, compared with the structure in which the magnetic thin film is formed on the underlayer made of a different material, When the second magnetic thin film is grown on the first magnetic film as the underlayer, the crystal orientation and smoothness of the second magnetic thin film are improved, and good soft magnetic properties (high magnetic permeability, low retention) are obtained. Magnetic force) can be obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing how a magnetic film is formed by the method of the present invention.

FIG. 2 is a main part configuration diagram showing a sputtering apparatus used in the method of the present invention.

FIG. 3 is a cross-sectional view showing a magnetic film formed by a modification of the method of the present invention.

FIG. 4 is a diagram showing a surface of a sendust magnetic film formed by a conventional method.

FIG. 5 is a diagram showing the surface of a sendust magnetic film formed by the method of the present invention.

FIG. 6 is a main part configuration diagram showing a sputtering apparatus used in a conventional method.

FIG. 7 is a cross-sectional view showing a magnetic film formed by a conventional method.

FIG. 8 is a cross-sectional view showing a magnetic film formed by a conventional method.

FIG. 9 is a diagram showing a comparison of frequency characteristics of magnetic permeability of a sendust magnetic film formed by the method of the present invention and a sendust magnetic film formed by a conventional method.

FIG. 10 is a diagram showing the orientation of a sendust magnetic film formed by a conventional method.

FIG. 11 is a diagram showing the orientation of a sendust magnetic film formed by the method of the present invention.

[Explanation of symbols]

 20 Sputtering device 21 Chamber 22 Base 23 Target 24 Ferrite substrate 25 Mounting stage 26 High frequency power supply 27 Vacuum pipe 28 Oxygen supply pipe 29 Vacuum device 30 Sputter gas supply device 31 Control device 32 Oxide film 33 Sendust magnetic film 34 Underlayer

Claims (1)

[Claims] 1. A method of manufacturing a magnetic thin film, which comprises forming a magnetic thin film by growing a magnetic material on a base made of a material different from that of the magnetic material, wherein the magnetic film is formed in the initial stage of formation of the magnetic material. By supplying oxygen or nitrogen to the formation chamber to be formed, the formation chamber is made to have an oxygen or nitrogen atmosphere to grow an oxidized or nitrided first magnetic film, and then supply of oxygen or nitrogen to the formation chamber is performed. A method for producing a magnetic thin film, which comprises growing a second magnetic thin film made of the pure magnetic material on the first magnetic film by stopping.