JPH10102236A - Sputtering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sputtering device with a simple constitution capable of applying the magnetic field in the different directions to a substrate. SOLUTION: Oppositely to a sample stand 2 provided rotatably in a vacuum vessel 1, plural cathodes 3 are arranged on the concentric circumference, and plural magnets 41, 42 and 43 setting the magnetic fields in the different directions on the surface of a substrate 20 held to the sample stand 2 are integrally held by a magnet holding body and is provided with a rotating mechanism rotating the magnet holding body around the center axis. A moving mechanism placing the magnets 41, 42 and 43 near the substrate 20 at the time of coating formation and placing the magnets 41, 42 and 43 far from the substrate 20 at the time of cleaning the substrate 2 by a discharging means 6 is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sputtering apparatus for forming a magnetic thin film on a surface of a substrate, and more particularly to a sputtering apparatus for forming a thin film having magnetic anisotropy required for manufacturing a magnetic head and the like. is there.

[0002]

2. Description of the Related Art Sputtering apparatuses have conventionally been used to form a magnetic thin film on the surface of a substrate. this house,
In preparing a magnetic thin film for a magnetic head used for reading signals from a magnetic recording medium, it is necessary to prepare a thin film having magnetic anisotropy. FIG. 4 is a schematic front sectional view showing a configuration of a conventional sputtering apparatus capable of forming a thin film having such magnetic anisotropy, and FIG. 5 is a BB view of the apparatus of FIG. FIG. 2 is a schematic plan sectional view of the section of FIG.

[0003] The sputtering apparatus shown in FIG. 4 includes a vacuum vessel 1 provided with an exhaust system 11, a sample table 2 provided at a predetermined position in the vacuum vessel 1, and a vacuum chamber 1 in the vacuum vessel 1 opposed to the sample table 2. A plurality of cathodes 3 arranged at positions and a magnet 4 for setting a predetermined magnetic field on the surface of the substrate 20 held on the sample stage 2
1, and a shutter plate 5 disposed between the sample stage 2 and the cathode 3 to select a cathode 3 to be used.

The sample table 2 is a disk-shaped member, and holds a substrate 20 on its lower surface. The holding of the substrate 20 is performed by a mechanism that mechanically holds the periphery of the substrate 20. A rotating shaft 21 extending upward is fixed to the center of the upper surface of the sample table 2. The rotating shaft 21 is
A rotation mechanism (not shown) is connected, and the sample stage 2 rotates around a central axis A via a rotation shaft 21. The substrate 20 is disposed at a position eccentric from the center axis A of the sample table 2. Therefore, when the sample stage 2 rotates, the substrate 20 revolves around the central axis A of the sample stage 2.

As can be seen from FIGS. 4 and 5, a plurality of cathodes 3 are arranged at equal intervals on a concentric circle with the center axis A of the sample table 2. When the sample stage 2 rotates and stops at a predetermined position, the substrate 20 and the specific cathode 3 are coaxially opposed to each other. Each cathode 3 has a target 31 made of a predetermined material.
And a magnet mechanism 32 disposed below the target 31 so that a predetermined voltage is applied by a cathode power supply (not shown). The target 31 of each cathode 3 is often formed of a different magnetic material. This is because it is necessary to stack different kinds of thin films on the surface of the substrate 20.

The magnets 41 and 42 are two rod-shaped permanent magnets as can be seen from FIG. Two magnets 41, 4
Numerals 2 are arranged in parallel with a spacing slightly larger than the diameter of the substrate 20, and apply a magnetic field in a direction indicated by an arrow 400 in FIG. The two magnets 41, 4
Reference numeral 2 is fixed to the lower surface of the sample stage 2, and thus rotates with the rotation of the sample stage 2.

The shutter plate 5 arranged between the cathode 3 and the sample stage 2 is a disk-shaped member arranged coaxially with the sample stage 2. The shutter plate 5 has an opening 51 at the same distance as the radial distance of the cathode 3 from the center axis A. The size of the opening 51 is slightly larger than that of the cathode 3. A rotating shaft 52 is fixed to the center of the lower surface of the shutter plate 5 and extends downward. The shutter plate 5 rotates around the central axis A by a rotating mechanism (not shown) connected thereto. Then, in a state where the substrate 20 and the specific cathode 3 face each other, the rotation of the shutter plate 5 is stopped so that the opening 51 is located between the substrate 20 and the cathode 3, thereby selecting the specific cathode 3. It can be used for sputtering.

The apparatus shown in FIGS. 4 and 5 has a gas introduction system (not shown) for introducing a predetermined gas into the vacuum vessel 1. The gas introduction system is configured to introduce an inert gas such as argon and generate a sputter discharge by an electric field provided by the cathode 3.

In the sputtering apparatus shown in FIGS. 4 and 5, the substrate 20 is carried into the vacuum vessel 1 through a gate valve (not shown), and is held at a predetermined position on the sample table 2, and then the exhaust system 11 is operated. To evacuate the vacuum vessel 1 to a predetermined pressure. At the same time, the sample stage 2 and the shutter plate 5 are rotated so that a predetermined cathode 3 faces the substrate 20 and the opening of the shutter plate 5 is located between them.

In this state, the gas introduction system is operated to introduce a predetermined gas at a predetermined flow rate, and the cathode 3 facing the substrate 20 is operated. That is, the cathode power supply of the cathode 3 is operated to generate sputter discharge, and the target 31 is sputtered. The material of the sputtered target 31 reaches the surface of the substrate 20 through the opening 51 of the shutter plate 5, and a predetermined thin film is formed on the surface.

Next, the sample stage 2 and the shutter plate 5 are rotated so that the substrate 20 faces the other cathode 3 and the opening 51 of the shutter plate 5 is located therebetween. In this state, the other cathode 3 is operated while introducing a predetermined amount of a predetermined gas. Thereby, a thin film of the material of the target 31 constituting the another cathode 3 is laminated. In this way, a predetermined thin film is laminated while sequentially selecting the cathodes 3 to be used. Some or all of the plurality of cathodes 3 are provided with a target 31 made of a magnetic material, and a predetermined thin film including a magnetic thin film is laminated.

[0012]

One of the important fields of application of the technique of laminating magnetic thin films by sputtering as described above is the manufacture of magnetic heads used for reading signals from a magnetic recording medium. Recently, the anisotropic magnetoresistance effect (AM
Many magnetic heads using R (anisotropic magnetoresistance effect) are produced.

Among them, a giant magnetoresistive head (GMR)
In the manufacture of certain types of magnetic heads, a structure is used in which ferromagnetic thin films having uniaxial anisotropy are stacked in different directions.
In the manufacture of such a magnetic head, it is necessary to form a film by sputtering while applying a magnetic field in a different direction to the substrate. Can apply a magnetic field in only one direction, and has no function of applying a magnetic field in a different direction to the substrate 20. Therefore, for a magnetic device that needs to stack magnetic thin films having uniaxial anisotropy in such different directions, the film forming process could not be performed by a conventional sputtering apparatus.

To apply magnetic fields in different directions to the substrate, (1) rotate the magnet around the central axis of the substrate;
(2) An electromagnet is used for the magnet to electrically change the direction of the magnetic field. (3) The magnet is fixed, and the substrate is formed each time a film is formed by a method such as rotation by a rotation mechanism or rearrangement by an arm. , And the like.

However, in the arrangements (1) and (3), a rotation mechanism around the central axis of the substrate is required so as to be added to the rotation mechanism of the sample stage for revolving the substrate, and therefore, is mechanically very complicated. There is a disadvantage. Further, in the configuration of (2), it is necessary to provide complicated wiring in the vacuum vessel 1, and a troublesome problem such as protection of the wiring from electric discharge occurs. In addition, since the electromagnet is likely to be larger than the permanent magnet, there is a disadvantage that the configuration around the sample stage tends to be large.

The invention of the present application has been made to solve such a problem, and an object of the invention is to provide a sputtering apparatus having a simple configuration capable of applying a magnetic field to a substrate in different directions. And

[0017]

In order to achieve the above object, an invention according to claim 1 of the present application comprises a vacuum vessel provided with an exhaust system, a vacuum vessel provided at a predetermined position in the vacuum vessel and having a center around a central axis. A sample stage rotatably provided, and a plurality of cathodes arranged at a predetermined interval on a concentric circle with the center axis of the sample stage at a position in the vacuum vessel opposed to the sample stage; A plurality of magnets capable of setting magnetic fields in different directions are provided on the surface of the held substrate, and the substrate on which the film is to be formed is disposed at a predetermined position eccentric from the center axis of the sample stage and is opposed to the cathode to be used. A sputtering apparatus for performing film formation by stopping rotation of a sample stage so that a substrate is arranged at a position, wherein the plurality of magnets are disposed coaxially with the sample stage at a position between the sample stage and a cathode. Held together by the magnet holder The magnet holder has a shape that allows the passage of sputter particles from the cathode, and the magnet holder is arranged around the center axis. And a rotating mechanism for arranging a magnet to be used after being rotated at a position near the surface of the substrate. According to a second aspect of the present invention, in order to solve the above problem, in the configuration of the first aspect, the magnet held by the magnet holding body is:
A moving mechanism for moving the magnet holder so as to be able to take a first position close to the substrate and a second position separated from the substrate is provided, and for cleaning the substrate held on the sample stage. Discharge means for causing the discharge of the electric current is provided.

[0018]

Embodiments of the present invention will be described below. FIG. 1 is a schematic front sectional view showing a configuration of a sputtering apparatus according to an embodiment of the present invention.
FIG. 2 is a schematic plan sectional view of a section taken along line BB of the apparatus of FIG. FIGS. 1A and 1B show different operation states.

The sputtering apparatus shown in FIG. 1 includes a vacuum vessel 1 provided with an exhaust system 11, a sample table 2 provided at a predetermined position in the vacuum vessel 1 and provided rotatably around a central axis A. A plurality of cathodes 3 arranged at predetermined intervals on the circumference of the sample container 2 at a predetermined distance on the circumference of the center axis A of the sample table 2 at a position facing the sample table 2 and a substrate held by the sample table 2 A plurality of magnets 41, 42, 43, 44 capable of setting magnetic fields in different directions are provided on the surface of 20.

The vacuum container 1 is an airtight container provided with a gate valve (not shown). Exhaust system 11, for example provided with a diffusion pump or a cryopump or the like, the vacuum chamber 1 10 ^-5
It is configured to be able to exhaust to a pressure of about Pascal. The sample stage 2 has a disk-like shape similarly to the apparatus shown in FIG. 4, and has a rotating shaft 21 fixed to the upper surface, and is rotated around a central axis A by a rotating mechanism (not shown). Sample table 2
Has a chuck mechanism (not shown) for mechanically holding the periphery of the substrate 20, and is configured to hold the substrate 20 on the lower surface thereof. The substrate 20 is disposed at a position eccentric from the center axis A of the sample stage 2 as in the related art, and revolves around the center axis A of the sample stage 2 when the sample stage 2 rotates.

A plurality of cathodes 3 are arranged at equal intervals on a concentric circle with the center axis A of the sample stage 2 as in the prior art. When the sample table 2 rotates and stops at a predetermined position, the substrate 20 and the specific cathode 3 are coaxially opposed to each other. Each cathode 3
Is composed of a target 31 made of a predetermined material, and a magnet mechanism 32 disposed below the target 31.
A predetermined voltage is applied by a cathode power supply (not shown). The target 31 of each cathode 3
Are made of different magnetic materials, so that different kinds of thin films can be stacked on the surface of the substrate 20. The magnet mechanism 32 forms a magnetic field for magnetron sputtering on the surface of the target 31.

The configuration of the plurality of magnets 41, 42, 43, and 44 constitutes a major feature of the apparatus according to the present embodiment. The plurality of magnets 41, 42, 43, 44 are, as shown in FIGS. 1 and 2, formed of two sets of rod-shaped permanent magnets. Magnets 41, 42, 43, 4 constituting one set
Different magnetic poles appear on the upper surface of 4, and a unidirectional magnetic field is set along the surface of the substrate 20.

The two magnets 41, 42, 43, 4
No. 4 is capable of setting magnetic fields in different directions on the surface of the substrate 20. Specifically, the rod-shaped magnets 41, 42, 43, and 44 constituting each set are long in directions parallel to each other. And the magnets 4 constituting the first set
1, 42 and the magnets 43, 44 constituting the second set are 9
The shape is long in directions different by 0 degrees. As a result, unidirectional magnetic fields having directions different from each other by 90 degrees (indicated by arrows 400 and 401 in FIG. 2) are set by the magnets 41, 42, 43 and 44 of each set.

The plurality of magnetic fields 41, 42, 43, 4
As shown in FIGS. 1 and 2, the magnet holder 4 is fixed to the upper surface of a magnet holder 40 disposed coaxially with the sample stage 2 at a position between the sample stage 2 and the cathode 3. It is held together by the body 40. Each set of magnets 41, 42, 4
The reference numerals 3 and 44 are arranged at predetermined intervals so that their center points are on the concentric circumference of the central axis A.

The magnet holder 40 is a disk-shaped member.
A rotation shaft 45 is provided at the center of the lower surface. A rotating mechanism (not shown) is attached to the rotating shaft 45, and the magnet holder 40 is rotatable around a central axis A.
The rotation mechanism includes a motion transmission system such as a gear or a belt connected to the rotation shaft 45 and a rotation drive source such as a motor.

Further, when the substrate 20 and the specific cathode 3 face each other, the magnet holder 40
And an opening 46 located between the two. The opening 46 is
It is slightly larger than the cathode 3 and allows the sputtered particles flying from the cathode 3 to sufficiently pass through and reach the substrate 20.

Further, the magnet holder 40 is provided with a moving mechanism (not shown) for linearly moving the magnet holder 40 in the direction of the central axis A. This moving mechanism includes a magnet holder 40
The magnet holder 40 is moved via the rotation shaft 45 so that the magnet on the magnet holder 40 is separated from the first position close to the substrate 20 and from the substrate 20. It is configured to be able to take the second position.

The moving mechanism includes a rotating shaft 45 of the magnet holder 40.
And a linear drive source such as an air cylinder for moving the rotary shaft 45 or an arm fixed to the rotary shaft 45 up and down, and a linear guide for guiding the linear drive source. This moving mechanism may be configured such that a member capable of attaching and detaching the connection with the rotating shaft 45 is provided on the rotating mechanism described above, and the rotating shaft 45 is vertically moved in a state where the rotating shaft 45 is separated from the rotating mechanism. Good.

A shutter plate 5 is provided below the magnet holder 40. The shutter plate 5 has substantially the same configuration as the conventional one shown in FIGS.
That is, the shutter plate 5 is a disk-shaped member arranged coaxially with the sample table 2, and has the opening 51 at the same distance as the radial distance of the cathode 3 from the center axis A. The size of the opening 51 is slightly larger than that of the cathode 3. still,
In FIG. 2, the illustration of the shutter plate 5 is omitted.

At the center of the lower surface of the shutter plate 5, a rotating shaft 52 is fixed and extends downward. The shutter plate 5 is rotated around the central axis A by a connected rotating mechanism (not shown), and 51 can be located between the substrate 20 and the cathode 3. The shutter plate 5 prevents the sputtered material from unnecessarily flying from the unused cathode 3 to the substrate 20.

In the apparatus of this embodiment, the rotation shaft 52 of the shutter plate 5 has a cylindrical shape, and the rotation shaft 45 of the magnet holder 40 is inserted therein. Further, between the rotating shaft 52 of the shutter plate 5 and the wall of the vacuum vessel 1, and between the inner surface of the rotating shaft 52 of the shutter plate 5 and the magnet holder 4.
A vacuum seal (not shown) is provided between the 0 rotation shafts 45 to hermetically seal. The vacuum seal is a mechanical seal using a magnetic fluid or the like, and ensures hermetic sealing while allowing rotation of the rotating shafts 52 and 45. A similar vacuum seal (not shown) is provided between the rotation shaft of the sample stage 2 and the wall of the vacuum vessel 1.

The apparatus shown in FIGS. 1 and 2 is provided with a gas introduction system (not shown) for introducing a predetermined gas into the vacuum vessel 1 like the conventional apparatus. The gas introduction system introduces an inert gas such as argon and generates a sputter discharge by an electric field provided by the cathode.

Further, in the apparatus of this embodiment, the sample stage 2
Is provided with a discharging means 6 for generating a discharge for cleaning the substrate 20 held in the substrate. Discharge means 6
Is a power supply system including a sample stage power supply 61 for applying a predetermined voltage to the sample stage 2. The sample stage power supply 61 is configured to apply, for example, a high frequency having a predetermined frequency to the sample stage 2. When the discharge means 6 is guided in a state where a predetermined gas is introduced into the vacuum vessel 1 by a gas introduction system (not shown), the substrate 20 is subjected to high frequency sputtering. This high frequency sputtering removes dirt and the like on the surface of the substrate 20.

Next, the operation of the sputtering apparatus according to this embodiment having the above configuration will be described with reference to FIG.
FIG. 3 is a schematic perspective view illustrating the operation of the sputtering apparatus shown in FIGS.

First, the substrate 20 is carried into the vacuum vessel 1 through a gate valve (not shown), and is held at a predetermined position on the sample table 2. Then, the exhaust system 11 is operated to evacuate the vacuum vessel 1 to a predetermined pressure. Exhaust. At the same time, the rotation of the sample stage 2 and the shutter plate 5 is stopped, and the predetermined cathode 3 is
And the opening 51 of the shutter plate 5 is positioned therebetween. Further, as shown in FIG. 3A, a rotation mechanism and a movement mechanism (not shown) provided on the magnet holder 40 are operated so that the first set of magnets 41 and 42 is positioned near the substrate 20. To

In this state, a gas introduction system (not shown) is operated to introduce a predetermined gas at a predetermined flow rate, and the cathode 3 facing the substrate 20 is operated. That is, the cathode power supply of the cathode 3 is operated to generate sputter discharge, and the target 31 is sputtered. The sputtered magnetic material of the target 31 reaches the surface of the substrate 20 through the opening 51 of the shutter plate 5, and a first magnetic thin film is formed on the surface. At this time, since a predetermined unidirectional magnetic field is applied to the surface of the substrate 20 by the first set of magnets 41 and 42 located near the substrate 20, the created first magnetic thin film Has a uniaxial anisotropy along the direction (arrow 400).

Then, the sample stage 2 and the shutter plate 5 are rotated so that the substrate 20 faces the other cathode 3 and the opening of the shutter plate 5 is located between them. In addition, as shown in FIG. 3B, the rotation mechanism of the magnet holder 40 is operated so that the second set of magnets 43 and 44 is located near the substrate 20. In this state, the other cathode 3 is operated while introducing a predetermined gas in a predetermined amount. Thereby, the second magnetic thin film made of the material of the target 31 constituting the another cathode 3 is laminated. At this time, since the magnets 43 and 44 of the second set apply a magnetic field having a direction different from that of the first magnets 41 and 42 by 90 degrees, the second magnetic thin film to be formed is Direction different by 90 degrees compared to the first magnetic thin film (arrow 40)
1) It has uniaxial anisotropy.

Thus, a predetermined thin film is laminated while sequentially selecting the cathodes 3 to be used. Incidentally, a non-magnetic material may be used for the target 31 of the specific cathode 3 among the plurality of cathodes 3. For example, in manufacturing a certain type of magnetic head, a Ta (tantalum) sheet layer may be formed by laminating a magnetic thin film. In such a case, a Ta target 3 is used.

In the above-described film formation, the surface of the substrate 20 may be cleaned. In this surface cleaning, dirt such as oils and fats adhered to the surface of the substrate 20 and a surface protective film are removed by sputter etching. The cleaning is performed in the following procedure. That is, after holding the substrate 20 on the sample stage 2, the magnet holder 4
By operating the moving mechanism provided at 0, the magnets 41, 42, 43, and 44 are arranged at the second position separated from the substrate 20, as shown in FIG. In this state, the discharge unit 6 is operated while a predetermined amount of a predetermined gas is introduced by the gas introduction system. As a result, the surface of the substrate 20 is sputter-etched by high-frequency sputtering, thereby removing surface dirt and the like.

At this time, since the magnets 41, 42, 43, and 44 are located at the second positions separated from the substrate 20, the substrate 2
No magnetic field is applied to the zero surface. For this reason,
The state of the plasma generated by the high-frequency discharge is stable and uniform without being affected by the magnetic field, and stable and uniform cleaning is performed. The magnet 41 near the substrate 20,
If cleaning is performed with the 42, 43, and 44 positioned, the plasma becomes unstable or non-uniform due to the influence of the magnets 41, 42, 43, and 44, and the cleaning cannot be performed sufficiently. However, according to the device of the present embodiment, there is no such problem.

After the cleaning is completed in this manner, when the above-described magnetic thin film is formed, the moving mechanism of the magnet holding member 40 is operated, and as shown in FIG.
The magnet is arranged at a position near the substrate 20. Then, similarly, a film is formed on the substrate 20 after the cleaning. At this time, since the surface of the substrate 20 is clean, there is no problem in terms of adhesion of the thin film and the like.

In the sputtering apparatus according to this embodiment having the above-described configuration and operation, a plurality of magnets 41, 42, 43, and 44 for applying magnetic fields in different directions are integrally held by a magnet holder 40, and the magnets A specific set of magnets 41, 42,
Since 43 and 44 are selected, there is an advantage that application of magnetic fields in different directions to the substrate 20 can be performed with a simple configuration.

In the configuration of the sputtering apparatus of the present embodiment described above, the two sets of magnets 41, 42, 43 and 44 are 9
Although a magnetic field having a direction different from 0 degree is applied to the substrate 20, a magnetic field having another direction different from the other direction such as 180 degrees
It may be applied to 0. Further, the number of magnets may be three or more. Further, there is a case where one magnet is used for each magnet constituting each set, and therefore, the number of magnets is not always a multiple of two.

[0044]

As described above, according to the first aspect of the present invention, it is possible to provide a sputtering apparatus having a simple configuration capable of applying a magnetic field to a substrate in different directions. Also,
According to the second aspect of the present invention, in addition to the effect of the first aspect of the present invention, an effect of stably and uniformly cleaning the surface of the substrate can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic front sectional view showing a configuration of a sputtering apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic plan cross-sectional view of a cross section taken along line BB of the apparatus of FIG.

FIG. 3 is a schematic perspective view illustrating the operation of the sputtering apparatus shown in FIGS. 1 and 2.

FIG. 4 is a schematic front sectional view showing the configuration of a conventional sputtering apparatus capable of forming a thin film having magnetic anisotropy.

FIG. 5 is a schematic plan cross-sectional view of a cross section taken along line BB of the apparatus of FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vacuum container 11 Exhaust system 2 Sample stand 20 Substrate 3 Cathode 31 Target 40 Magnet holder 41 Magnet 42 Magnet 43 Magnet 44 Magnet 5 Shutter plate 6 Discharge means

Claims (2)

[Claims] 1. A vacuum vessel provided with an exhaust system, a sample table provided at a predetermined position in the vacuum vessel and rotatably provided around a central axis, and a position in the vacuum vessel facing the sample table. A plurality of cathodes arranged at predetermined intervals on a concentric circle with the center axis of the sample stage, and a plurality of magnets capable of setting magnetic fields in different directions on the surface of the substrate held on the sample stage A sputtering apparatus that arranges a substrate on which a film is to be formed at a predetermined position eccentric from the center axis of the sample stage, and stops the rotation of the sample stage so that the substrate is arranged at a position facing a cathode to be used to perform film formation. The plurality of magnets are integrally held by a magnet holding body disposed coaxially with the sample stage at a position between the sample stage and the cathode, and at a predetermined interval concentric with the central axis. It is arranged in, Has a shape that allows the passage of sputtered particles from the cathode, and furthermore, rotates the magnet holder about a central axis and arranges a magnet to be used at a position near the surface of the substrate. Is provided. 2. A moving mechanism for moving the magnet holder so that the magnet held by the magnet holder can take a first position close to the substrate and a second position separated from the substrate. 2. The sputtering apparatus according to claim 1, further comprising a discharge unit for generating a discharge for cleaning the substrate held on the sample stage.