JPH09209140A - Sputtering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a film forming speed and the efficiency of using a target and to suppress the occurrence of arcing by disposing a magnet in the lower part of the target and generating parallel magnetic fields on the target surface at the time of forming the protective film of a magnetic recording medium by sputtering. SOLUTION: A cathode 8 of the device is composed of the target 10, a backing plate 14 and the magnet 11 for generating the magnetic field on the target surface 10a and is installed in a cathode case 15. At this time, a lifting means 21 is penetrated in the lower part of this cathode case 15 to make the target 10 freely liftable. A center pole 12 of a specified length constituting the magnet 11 and a magnet ring 13 of a rectangular annular shape to enclose this pole are formed to the polarities different from each other. As a result, the magnetic poles 12a, 13a of the magnet are so set as to be made higher than the target surface 10a in compliance with the consumption of the target 10 during sputtering by the height adjustment of the target 10, by which the ideal parallel magnetic films are generated and maintained on the target surface 10a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technical field of a manufacturing apparatus of a magnetic recording medium such as a magnetic tape, and particularly,
The present invention relates to a sputtering apparatus suitable for forming a protective film for a magnetic recording medium, which is formed by forming a magnetic thin film to be a magnetic layer on a support by vacuum evaporation.

[0002]

2. Description of the Related Art Conventionally, as a magnetic recording medium, a powder magnetic material such as an oxide magnetic powder or an alloy magnetic powder is used as a vinyl chloride-vinyl acetate copolymer, a polyester resin,
2. Description of the Related Art A coating type magnetic recording medium prepared by coating a magnetic coating material dispersed in an organic binder such as urethane resin or polyurethane resin on a non-magnetic support and drying it is widely used.

On the other hand, in the field of video tape recorders (VTRs) and the like, there is a strong demand for high-density magnetic recording in order to achieve high image quality, and as a magnetic recording medium corresponding thereto, Co-Ni alloy, C
Non-magnetic support of polyester film, polyamide, polyimide film, etc. for metal magnetic materials such as o-Cr alloys and Co-O based on plating or vacuum thin film forming technology (vacuum evaporation method, sputtering method, ion plating method, etc.) A so-called ferromagnetic metal thin film coating type magnetic recording medium, which is directly deposited on the body as a magnetic layer, has been proposed and has attracted attention.

In this ferromagnetic metal thin film type magnetic recording medium, a ferromagnetic metal thin film, which is a magnetic layer, is formed in order to improve electromagnetic conversion characteristics and obtain a larger output. In this case, oblique vapor deposition in which a magnetic material is obliquely vapor-deposited has been proposed and put to practical use.

It is considered that such a metal thin film medium will become the mainstream of high density magnetic recording media in the future because of its superior magnetic properties. However, magnetic recording media coated with ferromagnetic metal thin films are said to have problems with durability and rust resistance. Conventionally, organic materials such as lubricants and rust preventives by coating have been investigated, and fine particles have been used. A so-called undercoating technique has been studied in which a non-magnetic support is preliminarily coated before forming a magnetic layer.

[0006] However, these techniques cannot sufficiently cope with the use in a special environment and the harsh use such as the business use, and as a new method, vacuum deposition, sputtering, plasma CVD, etc. A surface protective film has been studied by a vacuum thin film forming means.

Under these circumstances, a manufacturing apparatus for a magnetic recording medium having excellent durability and rust resistance has been developed by the protective film forming technique by the sputtering method. However, since the film forming speed is slow, there is a problem that productivity is poor.

Therefore, in order to avoid such an inconvenience and to improve the film formation rate, a magnetron type sputtering apparatus is used in which a magnet is arranged below the target and the leakage magnetic field formed on the target surface is utilized thereby. Is used.

In this magnetron type sputtering apparatus, a circular magnet is used to eccentrically rotate the magnet to generate a magnetic field uniformly over a wider area, and a magnet using a square magnet. However, for a long object such as a magnetic tape, the one using the square magnet is adopted.

FIG. 7 and FIG. 8 show an example of the cathode 101 of the magnetron type continuous sputtering apparatus using the above rectangular magnet.

The cathode 101 is a backing plate 1 which is connected to a power source and has a function as a cathode electrode.
02, a rectangular target 103 adhered on the backing plate 102, and a pipe 104 through which a refrigerant such as water flows through the backing plate 102, the rectangular target 103 and the like.
The cooling mechanism portion 104 for cooling by a and 104b, a magnet 106 arranged below the backing plate 102 so as to face the rectangular target 103, and a cathode case 107 that houses the magnet 106.

The magnet 106 has a substantially E-shaped cross section and is composed of a center pole and a rectangular ring-shaped magnet ring surrounding the center pole. That is, the surfaces facing the rectangular target 103 have polarities different from each other (for example, the center pole is the S pole and the magnet ring is the N pole).

Therefore, when performing sputtering on the base film 108 conveyed to the cooling can 109 using this conventional sputtering apparatus,
By accelerating the ionized (plasma) argon ions, the kinetic energy of the argon target 10
The atoms of No. 3 can be ejected, and the ejected atoms can be deposited on the base film 108 to form a target thin film.

[0014]

By the way, in the above conventional apparatus, the base film 1 which is a non-magnetic support is used.
08 is driven in the clockwise direction in the figure by the cooling can 109. At this time, the surface of the target 103 is partially eroded corresponding to the shape of the magnet 106 arranged so as to face the rectangular target 103. The problem of so-called erosion arises. Erosion is a phenomenon in which the magnetic field generated by the magnet 106 is curved near the surface of the rectangular target 103 to confine the plasma, so that only the high plasma density portion is concentrated (sputtered).

As described above, when the sputtering is not uniform, the portion that is difficult to be sputtered is not used for forming the thin film, and the usage efficiency of the rectangular target 103 is reduced. Further, the progress of erosion causes a problem that the sputtering rate is reduced and the life of the target 103 is shortened.

In addition, when forming a thin film, the rectangular target 10 is used.
Since the magnetic field formed on the surface of No. 3 is curved, if a protective film is formed on the base film 108 conveyed as it is, a thick (dark) magnetic flux density portion on the target 103 is a thick film. Is deposited, and a thin film is deposited on the (thin) portion where the magnetic flux density is low.

Further, in the conventional apparatus in which a curved magnetic field is generated on the surface of such a rectangular target, a sputtered film is conversely adhered to a portion having a low plasma density, which causes dust, and further adheres. When the film was an insulating film, it was charged and caused arcing, damaging the base film.

For this reason, although various proposals have been made in the past regarding the shape and position of the magnet 106, those that generate an ideal parallel magnetic field on the surface of the rectangular target 103 have not yet been developed. Not not.

Therefore, the present invention has been proposed in view of the above circumstances, and in a so-called magnetron type continuous sputtering apparatus, by generating a parallel magnetic field optimum for sputtering on the surface of the target, It is intended to improve the use efficiency, the film formation rate, and the like, and to suppress the occurrence of arcing found in a sputtering apparatus.

[0020]

In order to achieve the above objects and solve the problems, a sputtering apparatus of the present invention comprises a target and a magnet for generating a magnetic field on the surface of the target, A sputtering apparatus for performing sputtering is characterized in that a magnetic pole of a magnet is provided near a surface of a target.

Further, the target is provided with an elevating means for changing the height.

Further, the magnet is composed of a center pole having different magnetic poles and an annular magnet ring surrounding the center pole, and a through hole is formed in the target corresponding to the magnetic pole of the magnet. .

In the sputtering apparatus of the present invention, since the magnetic poles of the magnet are provided in the vicinity of the surface of the target, a parallel magnetic field optimum for sputtering is generated on the surface of the target.

Further, the height of the magnet can be changed according to the consumption of the target during the sputtering by providing the raising / lowering means for changing the height of the target. Therefore, a parallel magnetic field optimum for the sputtering is formed on the surface of the target. Will be generated.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, the sputtering apparatus according to the present embodiment has a structure in which a vacuum chamber 1 is evacuated from exhaust ports 15 provided in the head and the lower part to make a vacuum inside. A feed roll 3 that rotates at a constant speed in the clockwise direction and a take-up roll 4 that rotates at a constant speed in the clockwise direction in the figure are provided. The base film 2, which is a support, is designed to run sequentially.

A cooling can 5 having a diameter larger than the diameter of each of the rolls 3 and 4 is provided in the middle of the traveling of the base film 2 from the feed roll 3 to the winding roll 4 side. . On the peripheral surface of this cooling can 5,
The base film 2 is wound, and therefore the cooling can 5 is also configured to rotate at a constant speed in the clockwise direction in the figure in synchronization with the rolls 3 and 4.

The feed roll 3, the take-up roll 4, and the cooling can 5 are respectively provided in the base film 2.
The cooling can 5 is provided with a cooling device (not shown) inside so as to suppress deformation and the like of the base film 2 due to temperature rise. Has been done.

Therefore, the base film 2 is sequentially fed from the feed roll 3, passes through the peripheral surface of the cooling can 5, and is wound up by the winding roll 4. Incidentally, the feed roll 3 and the cooling can 5 described above.
Guide rolls 6 and 7 are provided between the cooling can 5 and the take-up roll 4, respectively, and travels from the feed roll 3 to the cooling can 5 and from the cooling can 5 to the ticket taking roll 4. A predetermined tension is applied to the base film 2 to be smoothly moved.

A cathode 8 is provided below the cooling can 5 in the vacuum chamber 1, and a metallic magnetic material 9 is adhered to the upper surface of the cathode 8 as a target 10.

As the cathode 8, there are a so-called internal type in which the cathode 8 is entirely contained in the vacuum chamber 1 and a so-called external type in which only the surface 10a of the target 10 is contained in the vacuum chamber 1. However, in the present embodiment, any type can be applied.

The cathode 8 of the present embodiment is an internal type, and as shown in FIGS. 3 to 4, a backing plate 14 connected to a power source and having a function as a cathode electrode, and a backing plate 14 on the backing plate 14. Target 10 to be bonded and surface 10a of this target 10
The magnet 11 for generating a magnetic field has a main structure.

The cathode case 15 has a housing-shaped interior,
The backing plate 14, the target 10, the magnet 11 and the like are arranged. In addition, the cathode case 15
An elevating means 21 for elevating and lowering the target 10, which will be described later, penetrates the lower part of the. Furthermore, the cathode case 15
An insulator 16 is fixed to the side surface of the via a screw member 17.

The magnet 11 is a permanent magnet, as shown in FIG.
As shown in, the center pole 12 having a predetermined length
And a rectangular ring-shaped magnet ring 13 surrounding the center pole 12. The center pole 12 and the magnet ring 13 have polarities different from each other (for example, the center pole 12 is an S pole and the magnet ring 13 is N pole). Therefore,
The magnet 11 has an E-shaped vertical cross section. Of course, the magnet 12 may be an electromagnet connected to a power source.

Further, the magnet 11 which is the above-mentioned permanent magnet.
Has magnetic poles 12a and 13a on the tip side of the E-shaped cross section, and the screw member 1 is provided on these magnetic poles 12a and 13a.
The shield member 18 is fixed by 9.

Particularly, in the magnet 11 having an E-shaped cross section, as shown in FIG. 3, the magnetic pole 12a of the center pole 12 and the magnetic pole 13a of the magnet ring 13 are set at free positions with respect to the surface 10a of the target 10. It is made possible.

That is, in the present embodiment, FIG.
As shown in FIG.
0 and the backing plate 14 are arranged so as to support the elevating means 21, the cooling means 31, and the current supplying means 41, all of which are adapted to ascend and descend.

First, the elevating means 21 can be set at a position where the magnetic poles 12a and 13a of the magnet 11 are higher than the surface 10a of the target 10. As shown in FIG. 2, in this embodiment, four magnetic poles are provided. Has been.

This elevating means 21 is, as shown in FIG.
The support rod 23 is supported via the insulating joint 22, the bearing 24 receives the support rod 23, and the driving means 25. In this elevating means 21, a screw is formed on the outer circumference of the support rod 23, and a screw is formed on the inner circumference of the bearing 24. Therefore, the height of the target 10 and the backing plate 14 is changed by adjusting the support rod 23 and the bearing 24 by obtaining the driving force from the driving means 25.

Further, the support rod 23 is provided with a clamp member 26 for tightening the outer periphery thereof, and the clamp member 26 is fixed to the cathode case 15 via a screw member 27.

Next, the cooling means 31 is provided to protect the target 10, the backing plate 14 and the like from the plasma heat, and in the present embodiment, FIG.
As shown in FIG. 2, it is composed of two cooling members 32, 32 and a U-shaped conduit 32A. Then, the coolant such as water is made to flow in the direction of the arrow in FIG. 2 along the U-shaped conduit 32A arranged inside the backing plate 14.

As shown in FIG. 3, the cooling member 32 is a member whose inside is hollow so that a coolant such as water can flow, and the lower surface of the backing plate 14 is provided with an O-ring 33 and a fixing member 34. The magnet 11 and the cathode case 15 are provided to penetrate through the clamp member 36.

The cooling means 31 is provided on the upper side thereof.
Even if the elevating means 21 is moved up and down, a pipe joint 35 having a structure capable of coping with this lifting is provided.

Next, the current supply means 41 is for making the backing plate 14 connected to the power source and having a function as a cathode electrode. In the present embodiment, as shown in FIG. One is provided between the cooling members 32 and 32.

The current supply means 41 comprises an elevating means 21,
Like the cooling means 31, it has a rod shape, and the electrode tip is connected to the backing plate 14, and as shown in FIG.
An electrode cover 43 is formed around the electrode 42 and is connected to a power source. Although not specifically shown, this supply means 41, like the cooling means 31,
Even if the raising / lowering means 21 is raised / lowered, it can respond to this raising / lowering.

Then, the target 10 and the backing plate 14 are formed so as to conform to such a lifting structure. That is, the target 10 and the backing plate 14 have the magnetic poles 12 a, 1 of the magnet 11 at the center thereof.
A hole 39 is formed to pass through 3a.

As described above, the target 10 has a substantially donut shape in which the holes 10a for penetrating the magnetic poles 12a and 13a of the magnet 11 are formed (see FIG. 2). Therefore, by raising and lowering the target 10 by the raising and lowering means 21, the magnetic poles 12a and 13a of the magnet 11 are moved.
Are located on the surface 10a of the target 10.

The backing plate 14 is connected to a power source, and the target 10 is made of metal having a low melting point.
Is glued. The backing plate 14 is formed of copper having excellent thermal conductivity, but the material is not limited to this as long as the material has excellent thermal conductivity.

The backing plate 14 has a substantially donut shape, which has a shape corresponding to the shape of the target 10 located between the center pole 12 of the magnet 11 and the magnet ring 13. Therefore, the target 10 and the backing plate 14 are moved up and down by the elevating means 21, and the magnetic pole 1 of the magnet 11 is moved.
2a and 13a are located on the surface 10a of the target 10.

According to the sputtering apparatus having such a structure, the height of the target 10 can be changed by operating the four lifting means 21. Further, according to the elevating structure of the present embodiment, each magnetic pole 12a, 13a of the magnet 11 can be set higher than the surface 10a of the target 10 or can be set at any desired position.

Here, the elevation means 21 and the elevation means 21 do not change the height of the target 10 as in the present embodiment, but the magnet 11 is provided with the above-mentioned elevation means 21 and the like. By providing it, the magnetic poles 12a and 13a of the magnet 11 may be set at positions higher than the surface 10a of the target 10.

Further, in the present embodiment, as shown in FIG. 4, the flow path 36 is formed also in the magnetic pole 12a of the center pole 12 of the center of the magnet 11, and the pipes 37a, 37b through which the coolant such as water flows. Is provided. The pipes 37a and 37b here are detachably provided via pipe joints 38 and 38.

Therefore, with respect to the temperature rise of the target 10a, the backing plate 14, etc., the pipe 37
By flowing the refrigerant from a and 37b (from IN to OUT in FIG. 4), these targets 10a and the like can be cooled.

Since the sputtering apparatus of the present embodiment has the above-mentioned structure, when sputtering the base film 2 using this sputtering apparatus, ionized (plasma) argon ions are used. By accelerating, the atoms of the target 10 are ejected by the kinetic energy, and the ejected atoms are deposited on the base film 2 to form a target thin film. Here, the base film 2
Is weak to heat, it is cooled by the cooling can 5.

In the sputtering apparatus having the above structure, when the elevating means 21 is moved up and down by the driving means 25, the cooling means 31 and the current supplying means 41 are correspondingly moved.
Also, the height of the target 10 is changed during the patterning. Then, the magnetic pole 12 of the magnet 11 is adjusted according to the consumption of the target 10 during sputtering.
By setting a and 13a to be higher than the surface 10a of the target 10, the target 1
An ideal parallel magnetic field can be generated on the zero surface 10a.

The state of the parallel magnetic field will be described with reference to FIG. 5. In the conventional apparatus (FIG. 5A), the magnetic field generated by the magnet 106 is bent like a tunnel on the surface 10a of the target 103. Had occurred. For this reason, the plasma was confined in this curved state, and only the portion having a high plasma density was intensively sputtered. One of the causes is that the magnet 106 is arranged under the backing plate 102 in the conventional apparatus.

On the other hand, in the present embodiment (see FIG.
(B)) Since the magnetic poles 12a and 13a of the magnet 11 are provided at positions higher than the surface 10a of the target 10, an ideal parallel magnetic field is generated in a wide range of the surface 10a of the target 10. Like

Here, FIG. 6 shows measured magnetic field vectors of the target surface 10a of this embodiment and the conventional apparatus. That is, FIG. 6 shows the surface 1 of the target 10.
The magnetic field generated at 0a causes the surface 10 of the target 10 to
The distribution of so-called vector cosine (COSθ), which is the number of tilts from the parallel state corresponding to a, is investigated.

As is apparent from FIG. 6, the parallel magnetic field is generated far more on the surface 10a of the target 10 in the present embodiment than in the conventional device.

Therefore, in this embodiment, the magnetic poles 12a and 13a of the magnet 11 are operated by the elevating means 21 so as to be slightly higher than the surface 10a of the target 10 according to the consumption of the target 10 during sputtering. For example, unlike the conventional apparatus, the plasma is not confined, the sputtering rate is increased, and the target use efficiency is increased.

Further, when the film forming rate of the thin film was measured using the sputtering apparatus having the above structure, the film forming rate was higher than that of the conventional apparatus. Further, good results were obtained for the film thickness distribution of the target 10.

As described above, in the present embodiment, the present invention has been described by using the so-called rectangular magnet. However, the present invention uses a circular magnet to eccentrically rotate the magnet so that a magnetic field is applied to the target surface. Of course, it can also be applied to those that are generated.

[0063]

Since the sputtering apparatus of the present invention is provided so that the magnetic poles of the magnet are located near the surface of the target, a parallel magnetic field optimum for sputtering is generated on the surface of the target.

Therefore, the plasma density on the entire surface of the target is increased, the sputtering rate is increased, and the target use efficiency is increased.

By generating a parallel magnetic field optimum for sputtering on the surface of the target, a uniform film thickness distribution can be obtained on the support, and arcing can be achieved when the deposition film attached to the target is an insulating film. Will be reduced.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing a configuration of a sputtering device according to a first embodiment of the present invention.

FIG. 2 is a plan view of a target and a cathode case.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a sectional view taken along line BB of FIG. 2;

5A and 5B are schematic diagrams showing the magnetic fluxes of magnets in comparison with each other, where FIG. 5A shows the case of the conventional apparatus and FIG. 5B shows the case of the sputtering apparatus.

FIG. 6 is a diagram showing a difference in distribution of a magnetic field vector cosine (COSθ) on a target surface between the present embodiment and a conventional device.

FIG. 7 is a schematic diagram showing a schematic configuration of a conventional sputtering apparatus.

FIG. 8 is a cross-sectional view showing the structure of a cathode of a conventional sputtering device.

[Explanation of symbols]

 Reference Signs List 8 cathode 10 target 11 magnet 12 center pole 12a magnetic pole 13 magnet ring 13a magnetic pole 14 backing plate 21 elevating means 31 cooling means 39 through hole

Claims (3)

[Claims] 1. A sputtering apparatus comprising a target and a magnet for generating a magnetic field on the surface of the target, wherein a magnetic pole of the magnet is provided near the surface of the target in a sputtering apparatus for sputtering a support. A sputtering apparatus characterized by the above. 2. The sputtering apparatus according to claim 1, wherein the target is provided with an elevating means for changing the height. 3. The magnet comprises a center pole having different magnetic poles and an annular magnet ring surrounding the center pole, and a through hole is formed in the target in correspondence with the magnetic pole of the magnet. The sputtering device according to claim 1.