JPH04116154A - Sputtering device for forming magnetic film - Google Patents

Abstract

PURPOSE:To form a magnetic thin film having uniform and weak magnetic anisotropy at a high speed by sputtering a target consisting of a magnetic material, thereby forming the magnetic thin film in the uniform magnetic field perpendicular to a substrate. CONSTITUTION:A magnetic field generating means is provided on the rear surface of a target electrode 2 to generate a magnetron electric discharge. The magnetic field generating means is provided also on the side of a substrate electrode 8 to be imposed with a substrate 10 and the uniform magnetic field perpendicular to the substrate 10 is formed. The magnetic field generating means on the substrate electrode 8 side is formed of an electromagnet 11 and a cylindrical yoke 12 and the substrate imposing surface is disposed on the side inner than the end face on the target 3 side of the yoke 12. The target 3 consisting of a magnetic material is sputtered and the magnetic thin film having the polarities uniform in the direction of the magnetic field is formed on the substrate 10 in the uniform magnetic field perpendicular to the substrate 10.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a sputtering apparatus for forming a magnetic film, which forms the magnetic core of a magnetic head with a thin film.

[Conventional technology]

The magnetic thin film forming the magnetic core of a magnetic head is required to have magnetic properties such as high saturation magnetic flux density, low coercive force, high magnetic permeability, and uniform magnetic anisotropy. Among these, the saturation magnetic flux density mainly depends on the composition of the thin film material, whereas the coercive force, magnetic permeability, magnetic anisotropy, etc. strongly depend on the film formation conditions (magnetic field, substrate temperature, etc.). Therefore, in order to improve the magnetic properties that depend on these film formation conditions, conventionally, for example,
JP-A-58-100411 and JP-A-60-39
As shown in Publication No. 157, when forming a magnetic film on a flat substrate, the film does not have magnetic anisotropy immediately after it is formed, and the next magnetic annealing process produces a uniform magnetic anisotropy. For the purpose of generating orientation, a parallel and substantially uniform magnetic field is formed in the vicinity of the substrate during film formation, and means for rotating the substrate or the magnetic field is provided.

[Problem to be solved by the invention]

In order to improve the film formation rate by sputtering, (1) increase the power applied to the target electrode (2)
) There are methods such as providing a magnet on the back side of the target electrode and performing magnetron sputtering, which generates a strong discharge on the target due to the interaction of an electric field and a magnetic field.

When these methods are applied to conventional magnetic film sputtering equipment, in (1), the substrate is struck by high-energy charged particles in the plasma, which increases the substrate temperature, crystallizes the film, and deteriorates the magnetic properties. There is a risk that (
In 2), there were problems such as non-uniform magnetic anisotropy occurring in the film due to disturbance of the magnetic field distribution near the substrate, and it was not possible to increase the film formation rate as it was.

Furthermore, in the past, since the substrate or target was rotated during film formation, there were problems in that the mechanism was complicated and dust was generated from the rotating parts.

On the other hand, when forming a magnetic thin film on a substrate with a V-groove, the substrate Kl! Since it is difficult to form a film in a direct magnetic field, it is difficult to form a film in a conventional rotating magnetic field parallel to the substrate, which has no magnetic anisotropy. A magnetically anisotropic -like film with an axis of easy magnetization along the maximum inclination angle of the groove slope is obtained.

Therefore, an object of the present invention is to rapidly form a film having uniform and relatively weak magnetic anisotropy over the entire surface of the substrate when forming a magnetic thin film on a substrate with a V-groove processed using a magnetron sputtering device. Another object of the present invention is to provide a sputtering electrode that does not require a mechanism for rotating a substrate or a magnetic field.

[Means to solve the problem]

In order to achieve the above object, a first aspect of the present invention is to form a magnetic thin film in a uniform magnetic field perpendicular to a substrate in a sputtering apparatus using a magnetic material as a target material.

Further, in order to enable high-speed film formation, the second invention has a magnetic field generating means for generating magnetron discharge on the back side of the target electrode, and also has the magnetic field generating means on the side of the substrate electrode on which the substrate is placed. It has a magnetic field generating means for forming a uniform magnetic field on the substrate.

In addition, in order to form a magnetic thin film in a uniform magnetic field perpendicular to the layered substrate, the third invention is characterized in that the magnetic field generating means on the substrate electrode side includes an electromagnet disposed coaxially with the substrate electrode and a cylindrical shape. The cylindrical yoke is inscribed in the electromagnet, and the substrate mounting surface of the substrate electrode is arranged inside the end surface of the target pair of the cylindrical yoke. be.

Further, in order to form a stronger magnetic field, the fourth invention provides a method in which the magnetic field generating means on the substrate electrode side is formed of an electromagnet disposed coaxially with the substrate electrode, a cylindrical yoke, and a disk-shaped yoke, the cylindrical yoke is inscribed in the electromagnet;
The substrate mounting surface of the substrate electrode is disposed within 11[IVc] of the target-side end surface of the cylindrical yoke, and the disc-shaped yoke is located at or near the substrate mounting surface of the substrate electrode. It was placed in

Furthermore, in order to improve the control characteristics of the distribution of the ion current incident on the substrate, the fifth invention provides a first electromagnet 1 in which the magnetic field generating means on the substrate electrode side is arranged coaxially with the substrate electrode.
A film is formed from a cylindrical yoke and a second electromagnet, the cylindrical yoke is inscribed in the first electromagnet, and the substrate mounting surface of the substrate electrode is on the target side of the cylindrical yoke. The second electromagnet has an outer diameter smaller than the first electromagnet;
The electromagnet is disposed coaxially with the substrate electrode inside or behind the first electromagnet.

Furthermore, in order to form a magnetic i-thin film in a uniform magnetic field that passes directly through the layer substrate, the sixth invention provides a magnetic field generating means on the back side of the target electrode and a magnetic field generating means on the side of the substrate electrode. A cusp-shaped magnetic field is formed between the substrate electrodes.

[Effect]

The substrate electrode side magnetic field generating means generates a magnetic field having a polarity opposite to that of the target electrode side magnetic field generating means, thereby forming a cusp-shaped magnetic field between the target electrode and the substrate electrode. Because of this, the lines of magnetic force coming out from the target electrode surface are repelled and do not reach the substrate electrode surface, allowing the substrate to be placed in the magnetic field generated by the substrate electrode side magnetic field generating means.

Further, the yoke means is arranged to completely enclose the substrate placed on the substrate electrode, and the magnetic field generated by the substrate electrode side magnetic field generating means causes the substrate electrode to be placed inside the yoke means. A generally uniform, relatively weak magnetic field along the central axis is created, and the substrate is placed in a perpendicular, uniform magnetic field.

As described above, in a magnetic thin film forming apparatus using the magnetron sputtering method, it is possible to form a magnetic thin film having uniform and relatively weak magnetic anisotropy at high speed.

Furthermore, when forming a film in a conventional magnetic field parallel to the substrate, the direction of the axis of easy magnetization differs depending on the direction in which the substrate is installed. needed to be formed. However, as mentioned above, by making it possible to install the substrate in a uniform magnetic field, the maximum inclination angle force of the V-groove of the substrate is uniformly aligned over the entire surface of the substrate, regardless of the direction in which the substrate is installed. This makes it possible to form a magnetic film with a strong magnetic anisotropy, and eliminates the need for a mechanism for rotating the substrate or magnetic field.

〔Example〕

Hereinafter, the first invention showing the first invention and the second invention of the present invention will be described.
An example of this will be explained with reference to FIG.

1 is a vacuum chamber, 2 is a target electrode, 3 is a target, 4
is an insulating plate, 5 is an electromagnet, 6 is a casing of electromagnet 5, 7
is the yoke of the electromagnet 5, 8 is the substrate electrode, 9 is the insulator, 10
is the board, 11 is the electromagnet, 12 is the yoke, 13 is the electromagnet 1
1 casing, 14 a power source for the target electrode 2, 15
．． 16 are power sources for the electromagnets 5 and 11, respectively.

A case (FIG. 3) in which a substrate 10IIca thin film 20 having a surface 10' processed into a V-groove shape is formed in the above structure will be described. First, the inside of the vacuum chamber 1 is evacuated to a high vacuum using an exhaust means (not shown), and then argon gas (A
Then, a current is applied to the magnet 5.11 by the power source 15.16. At this time, the polarity of the power source 16 is adjusted so that the magnetic field generated by the electromagnet 5 and the magnetic field generated by the electromagnet 11 have opposite polarities. As a result, a more cusp magnetic field is formed between the target electrode 2 and the substrate electrode 8 as shown in FIG. is repelled by the magnetic lines of force 18 emitted from the electromagnet 11 and compressed toward the target electrode 2.

As a result, the electromagnet 11 is located near the inner center of the yoke 12.
Therefore, the magnetic field 1 is approximately uniform along the central axis direction of the magnet 11.
9 is formed and a substrate 10 is disposed inside the yoke 12.
As shown in FIG. 3, the F is placed in a substantially uniform magnetic field 19 that is substantially perpendicular to the substrate surface.

In this state, when power is applied to the target electrode 2 from the power source 14VC, glow discharge occurs in the space near the surface of the target 3, and the surface of the target 3 is sputtered.

A portion of the magnetic material sputtered from the target 3 adheres to the surface 10' of the groove formed in the figure 7 shape of the substrate 10.

At this time, since the substrate 10 is in a substantially uniform magnetic field 19 that is substantially perpendicular to the substrate 10, the magnetic thin film 20 attached to the surface 10' of one substrate 10 grows with polarity aligned in the direction of the magnetic field 19. do. Therefore, the magnetic thin film 20 has a surface 10'
The axis of easy magnetization is aligned in the direction of the maximum inclination angle, and it has --like magnetic anisotropy.

On the other hand, since the component of the magnetic field generated by the electromagnet 11 inside the electromagnet 11 is concentrated on the yoke 12, a substantially uniform magnetic field fe
Fi is a relatively weak magnetic field. As a result, the magnetization of the magnetic thin film 20 grown on the surface of the substrate 10 is relatively weak, and the magnetic anisotropy can be controlled relatively easily in the next step of magnetic annealing.

As described above, according to this embodiment, a magnetic thin film having relatively weak and uniform magnetic anisotropy can be formed at high speed using a magnetron sputtering apparatus that generates a relatively strong magnetic field on the target electrode.

Furthermore, by making it possible to install the substrate in a vertical and uniform magnetic field, we have achieved uniform magnetic anisotropy with the axis of easy magnetization aligned in the direction of the maximum inclination angle of the V-groove of the substrate over the entire surface of the substrate, regardless of how the substrate is installed. This makes it possible to form a magnetic film with magnetic properties, eliminating the need for a substrate or a mechanism for rotating the magnetic field.

Next, the second embodiment, which is the fourth invention of the present invention, will be described in the fourth embodiment.
This will be explained using figures.

The configuration of FIG. 4 is almost the same as that of FIG. 1 showing the first embodiment of the present invention, except that a yoke plate 21 is added to the surface of the substrate electrode 8 on which the substrate 10 is placed.

The yoke plate 21 has the effect of making the magnetic field distribution in the vicinity of the substrate 10 more uniform.As a result, the magnetic thin film 20 formed on the substrate 10 has its axis of easy magnetization aligned in the direction of the maximum inclination angle of the surface 10, and is magnetically The uniformity of anisotropy is further improved.

The ms diagram shows a third embodiment, which is the fifth invention of the present invention.

In FIG. 5, the basic configuration is the same as in FIG. 1 showing the first embodiment of the present invention, and an electromagnet 2 is housed in a casing 25 and connected to a power source 24 behind the substrate electrode 8.
It is characterized by the addition of 2.

The outer diameter of the electromagnet 22 is smaller than the inner diameter of the t-magnet 11, and a portion of the electromagnet 22 is disposed inside the electromagnet 11.

Here, the magnetic field shown in the first embodiment of the present invention is formed between the target electrode 2 and the substrate electrode 8.

Next, when the power supply 24 energizes the magnet 22, the electromagnet 24 is excited and generates a magnetic field. The magnetic field generated by the electromagnet 22 is combined with the magnetic field generated by the electromagnet 11.

Therefore, by controlling the magnetic field generated by the electromagnet 22 with the power supply 24, the magnetic field strength and distribution near the substrate 10 can be adjusted.

As a result, it becomes possible to further improve the uniformity of the weak magnetic anisotropy of the magnetic thin film 20 formed on the substrate 10.

In the three embodiments of the present invention shown above, the power supply 14 connected to the target electrode 2 was explained as a DC power supply.
Similar effects can be obtained even if the power source 14 is a high frequency power source.

[According to the detailed description of the invention, since the film can be formed in a relatively weak and uniform magnetic field perpendicular to the substrate, the magnetic anisotropy can be easily controlled in the next step of magnetic annealing. This method has the advantage that a magnetic thin film with a magnetic anisotropy can be formed at high speed using a magnetron sputtering device.

Furthermore, since there is no need to rotate the substrate or the magnetic field during film formation, the mechanism is simple and the amount of dust generated can be reduced.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of the electrode section of a magnetron sputtering apparatus according to the first embodiment of the present invention, and FIG. 2 is an enlarged sectional view of the electrode section of FIG. 1, showing the magnetic field distribution in the upper half. The figure shows the magnetic field distribution near the substrate. FIG. 4 is a vertical sectional view of the electrode portion of the second embodiment of the present invention, and FIG.
The figure is a longitudinal cross-sectional view of an electrode portion of a sixth embodiment of the present invention. Explanation of symbols 2...Target electrode, 3...Target, 5...
・Electromagnet, 8... Substrate electrode, 10... Substrate, 11.
...Electromagnet, 12...Yoke, 21...Yoke plate,
22...Electromagnet. Figure 2 is this! Electrode 15, ll) to FL class difference ''f! Lr Akato σ Summer Pr, Yofu wo no ＼ 23 K 〉/Fu Denkata,

Claims (6)

[Claims] 1. A sputtering apparatus for forming a magnetic film, which uses a magnetic material as a target material and forms a magnetic thin film in a uniform magnetic field perpendicular to a substrate. 2. A magnetic field generating means for generating a magnetron discharge is provided on the back side of the target electrode, and a magnetic field generating means is also provided on the side of the substrate electrode on which the substrate is placed for forming a uniform magnetic field perpendicular to the substrate. A sputtering device for forming a magnetic film, which is characterized by: 3. The magnetic field generating means on the substrate electrode side includes an electromagnet and a cylindrical yoke arranged coaxially with the substrate electrode,
The cylindrical yoke is inscribed in the electromagnet, and the substrate mounting surface of the substrate electrode is disposed inside an end surface of the cylindrical yoke on the target side. 2. The sputtering apparatus for forming a magnetic film according to 2. 4. The magnetic field generating means on the substrate electrode side includes an electromagnet disposed coaxially with the substrate electrode, a cylindrical yoke, and a disk-shaped yoke, and the cylindrical yoke is inscribed in the electromagnet, and The substrate mounting surface of the substrate electrode is arranged inside the target-side end surface of the cylindrical yoke, and the disc-shaped yoke is arranged at or near the substrate mounting surface of the substrate electrode. 3. A sputtering apparatus for forming a magnetic film according to claim 2. 5. The magnetic field generating means on the substrate electrode side includes a first electromagnet, a cylindrical yoke, and a second electromagnet arranged coaxially with the substrate electrode, and the cylindrical yoke is connected to the first electromagnet. and the substrate mounting surface of the substrate electrode is arranged inside the end surface of the cylindrical yoke on the target side, and the outer diameter of the second electromagnet is larger than the inner diameter of the first electromagnet. 3. The sputtering apparatus for forming a magnetic film according to claim 2, wherein the sputtering apparatus is small and arranged coaxially with the substrate electrode inside or behind the first electromagnet. 6. 3. The method for forming a magnetic film according to claim 2, wherein a cusp-shaped magnetic field is formed between the target electrode and the substrate electrode by the magnetic field generating means on the back side of the target electrode and the magnetic field generating means on the side of the substrate electrode. Sputtering equipment.