JPS63468A - Opposed target type sputtering device - Google Patents

Abstract

PURPOSE:To form a thin film having a uniform thickness on a broad and long- sized substrate by dividing a rectangular target which is long in the transverse direction of the substrate to plural parts on a long side and providing a magnetic field generating means so as to generate magnetism at the divided points as well. CONSTITUTION:The rectangular target T which is long in the transverse direction of the substrate in an opposed target type sputtering device is bisected to T1, T2 and the magnetic field generating means 120 is disposed along a shielding ring 110 including the respective divided sides 110a. The magnetic field generating means 120 is constituted of a core 121 of a magnetic material which is a magnetic pole and a permanent magnet 122 coupled thereto. The permanent magnet 122 is set on the outside of a target holder 101 and the shielding ring 11 is set atop a magnet holder 105. The entire surface of the target T is approximately uniformly sputtered by sputtering the target T with the above-mentioned constitution, by which the film thickness is uniformly distributed in the transverse direction of the substrate.

Description

[Detailed Description of the Invention] [Field of Application] The present invention relates to a facing target type sputtering device in which targets are opposed to each other, and more specifically, the present invention relates to a facing target type sputtering device in which targets are opposed to each other, and more specifically, a sputtering device for transferring a wide and long substrate suitable for manufacturing magnetic recording media, etc. The present invention relates to a facing target type sputtering apparatus that continuously forms a desired thin film.

[Prior art] The above-mentioned facing target type sputtering apparatus is disclosed in Japanese Patent Application Laid-open No. 1983-
158380, Japanese Patent Application Laid-Open No. 59-53680, etc., a sputtering device generates a magnetic field in the direction of opposing targets in a tank to form a film on a substrate placed on the side of the target. Among various materials, it has the characteristic of being able to form films of magnetic materials at low temperatures and at high speeds, and is used in the production of magnetic thin films, B-molded magnetic recording media, etc.

However, when a conventional facing target type sputter layer is used to continuously form a film, such as a Co-Cr alloy film for a perpendicular magnetic recording medium, erosion concentrates in the center of the target, resulting in low target utilization efficiency. Got it (I
E E E T trans OnMaqneti
cs MAG17. p3175 (1981))
It was also found that film thickness distribution occurred in the width direction of the substrate, which caused problems in terms of productivity.

In contrast, the present inventors have
No. 59-116376,
We have proposed the configuration shown in FIG. 5, in which the core of the magnetic field generation mechanism is arranged around the target, and the magnetic field is generated around the target. That is, the figure shows only the target portion of the facing target type sputtering apparatus, and the facing target T.

The end portions 301a, 3 are placed around T', also serving as a shield.
Core 301.02a is bent so as to face the surface of target T+, T2. Legs 301b of 302, 30
2b are magnetically coupled with magnetic field generating sources 301' and 302' consisting of coils or permanent magnets that generate a magnetic field, and as shown in the figure, the magnetic field H is generated only around the targets T and T'. be. 31 in the figure
0 is the vacuum chamber wall, 311. 312 is a target holder, and 311a and 312a are cooling pipes for cooling the target. With this configuration, the magnetic field is formed directly between the cores without passing through the target, so the distribution of the magnetic field is stable without being affected by the permeability of the target material, saturation magnetization, or thickness of the target, and the magnetic field for plasma trapping is distributed directly around the target. As a result, the erosion area expanded from the center to the periphery, improving the target utilization rate. However, as the inside of the substrate becomes wider and the width of the target becomes wider, the thin film difference between the center and the edges becomes larger in the width direction of the substrate, and the center becomes more eroded and the overall target utilization rate decreases. It turns out that there is a problem.

[Object of the Invention] The present invention has been made in view of the above problems, and an object of the present invention is to provide an improved facing target type sputtering apparatus that has good productivity and is free from the above-mentioned problems even when using a wide target.

[Structure and operation of the invention] That is, the present invention
In an improvement of the facing target type sputtering apparatus disclosed in Japanese Patent Application Publication No. 59-116376, a magnetic field is generated in the direction facing the target by a magnetic field generating means around the target facing at a predetermined distance. In the facing target type sputtering apparatus, the target is a rectangle with a long substrate width direction, and is divided into a plurality of parts on the long side, and The means is a facing target type sputtering apparatus characterized in that the magnetic field is generated at the part where the target is divided.

In the present invention, the target is divided on the long side to have an appropriate thickness, and a magnetic field for plasma trapping is generated at the divided parts to divide the plasma space, so that each divided area is
It was discovered that the target acts in the same way as an independent target, and the entire area becomes an overlapping structure, which averages out the eroded area and improves the utilization rate of the target, while also greatly expanding the uniform area of the film thickness distribution in the width direction of the substrate. It has been done.

According to the present invention, the above-mentioned problems are solved from the above point, and since the target can be small, it has the advantage of being easy to manufacture and inexpensive.

The details of the present invention will be explained below based on examples.

FIG. 1 shows the overall configuration of the ip! Schematic diagram, Figure 2 is a plan view of one of the targets, Figure 3 is a side sectional view taken along line AB in Figure 2 perpendicular to the substrate; Figure 3 is a CD of Figure 2 parallel to the substrate surface. FIG.

As is clear from Fig. 1, this device is a
It has basically the same configuration as the facing target type sputtering apparatus known in Japanese Patent No. 158380 and the like.

That is, in the figure, 10 is a vacuum chamber, and 20 is a vacuum chamber 10.
An exhaust system 30 is composed of a vacuum pump, etc. for evacuating the air, and the exhaust system 30 introduces a predetermined gas into the vacuum chamber 10 to reduce the pressure inside the vacuum chamber 10 to 1.
This is a gas introduction system that is set to a predetermined gas pressure of about 0-1 to 10'' Torr.

In the vacuum chamber 10, there is a target section 1 as shown in the figure.
00. 100', rectangular targets T and T' with long sides facing a pair of substrates S are arranged so as to face each other in parallel across a space.

Target part 100. 100' have exactly the same configuration, and the following description will be based on one of the targets 100.

The target section 100 is different from the conventional one, and as is clear from the plan view of FIG. 2, the target T is T+.

The shield ring 110 is divided into two equal parts Tz, and the shield ring 110 is also divided into two by a dividing side 110a at the dividing point, similar to the target. A magnetic field generating means 120 for forming a plasma trapping magnetic field is disposed along and behind the shield link 110 including the divided side 110a, and forms a plasma trapping magnetic field partitioned for each divided target T+ and T2. It is supposed to be done.

The detailed structure of this target section 100 is configured as follows. In FIGS. 2 and 3, reference numeral 101 denotes a target holder made of a cylindrical body, which has a housing section for a permanent magnet (to be described later) of a magnetic field generating means 120 disposed at the dividing point of the target T in the center. is an insulating block 102 made of an insulating material such as Teflon (trade name of DuPont).
A cooling plate 103 having cooling grooves 103a formed in the upper surface for cooling the tarps T+ and Tz is fixed with bolts through the cooling plate 103 shown in the figure. The presser frame 1 is placed on the cooling plate 103.
04, targets T+ and Tz are fixed with bolts. A cooling pipe (not shown) is connected to the connection port 103b of the cooling plate 103, and the targets T+ and Tz are cooled by circulation of a cooling medium. Note that the upper surface of the target holder 101, the insulating block 102, the cooling plate 103. The 8-contact and stone surfaces of targets T+ and Tz are naturally sealed with a seal (not shown). With the above configuration, targets T+, Tz
It becomes easy to replace the targets T, +, and Tz, and the targets T, +, and Tz can be uniformly cooled to every corner, which is highly effective in terms of productivity and stable operation.

A magnet holder 105 made of a non-magnetic conductive material such as stainless steel is fixed to the outside of the target holder 101 with bolts. A shield link 110 can be attached to the upper surface of the magnet holder 105 in the figure, and a U-shaped holder part 105a is formed on the outside of its tip so that the core 121 and permanent magnet 122 of the magnetic field generating means 120 can be housed inside the magnet holder 105. and target T+, Tz and cooling [10
3 with a predetermined gap therebetween.

Core 121 of L company field generating means 120 and permanent magnet 122
As shown in the figure, a core 121 made of a plate-shaped material of soft magnetic material such as iron or permalloy is located at the upper tip side in the figure, and behind it a permanent magnet 122 is a target T+.

The fixing frame 106 is fixed with bolts or the like so that the magnetic poles are arranged to generate a magnetic field perpendicular to the Tz sputtering surface. The permanent magnets 122 are square bar-shaped magnets of a predetermined length arranged in parallel so that their combined magnetic field forms the plasma trapping magnetic field. Therefore, since the plasma trapping magnetic field is generated using the core 121 as a magnetic reference, the target T+
, Tz, a uniform magnetic field is generated around the target, and target usage efficiency is improved.

The shield link 110 connects the magnet holder 105 and the tarp T.
+, target T+ to cover the gap between Tz
, the holder part 1 of the magnet holder 105 protrudes toward Tz.
It is provided on the front of 05a. Therefore, the shield link 110 is connected to the magnet holder 105 and the target holder 101.
grounded through.

A wire mesh 107 made of stainless steel or the like is laid from the front surface (upper surface in the figure) of the shield link 110 to the outer surface of the holder portion 105a of the magnet holder. The wire mesh 107 prevents the sputter deposits deposited on these parts from peeling off during sputtering, that is, abnormal discharge, and also simplifies cleaning, resulting in great effects in terms of productivity and stable operation.

The shield link 110 is a jacket 1 through which the cooling medium passes.
11 is provided, and heating of the shield ring 110 is prevented by water cooling, so even if the sputtering speed is increased, there is little radiant heat to the substrate, so there is little thermal deformation of the substrate, and high-speed productivity is achieved.

The material of the shield ring 110 may be any conductive material, may be a soft magnetic material similar to the above-mentioned core 121, or may be made of other materials such as copper,
Stainless steel etc. may also be used. As is clear from the arrangement in the figure, when a soft magnetic material is used for the shield ring 110, the shield ring 110 is magnetically coupled to the core 121, so that the shield ring 110 can be used instead of or together with the core 121 in the magnetic field generating means 12.
0 magnetic field generation site, that is, acts as a magnetic pole. This configuration has the advantage that the magnetic pole position with respect to the targets T+ and T2 can be adjusted by adjusting the tip position of the shield ring 110.

Returning to FIG. 1, the target unit 100 with the above configuration,
Target T attached to and facing 100'.

A substrate holding means 40 for holding a long substrate S on which a magnetic thin film is formed is provided on the side of T'. The substrate holding means 40 includes a feed roll 41 and a support roll 42 that hold a roll-shaped substrate S, which are supported rotatably and parallel to each other by support brackets (not shown).
and a take-up roll 43, the substrate S is set as a target T'.

It is arranged so as to be held in a direction substantially perpendicular to the sputtering surface so as to face the space between the sputtering surfaces. Therefore, the substrate S can be moved by the take-up roll 43 in a direction perpendicular to the sputtering surface. Note that the surface temperature of the support roll 42 can be adjusted.

On the other hand, a power supply means 50 consisting of a DC power source for supplying sputtering power has its positive side connected to the ground and its negative side connected to the targets T and T', respectively. Therefore, the power supply means 5
Sputtering power from 0 is supplied between the anode and the cathode, with the ground as the anode and the targets T and T' as the cathode.

In order to protect the substrate S during press sputtering, a shutter (not shown) is provided between the substrate S and the targets T and T'.

As described above, the structure is basically the same as that of the Japanese Patent Application Laid-Open No. 57-158380 published by Kaiyo, and high-speed low-temperature sputtering is possible as is known. That is, targets T, T'
In the space between them, sputtering gas ions, γ electrons emitted by sputtering, etc. are bound by the action of the plasma trapping magnetic field, and a high-density plasma is formed. Therefore, sputtering of the targets T, T' is promoted, the precipitate increases from the space, the deposition rate on the substrate S increases, high-speed sputtering is possible, and the substrate S is on the side of the targets T, T'. Therefore, low-temperature sputtering is also possible.

By the way, according to the configuration in which the aforementioned targets T and T' are divided and the field generating means 120 is also divided according to the division of the targets, the magnetic field is transmitted to the cores 121 and 121 facing each other. 12
1' (hereinafter "-" indicates the same part of the target holder 100' (not shown) as the numerical part of the target holder 100) as Efi ffl and the periphery of the targets T+, T2, T+', T2'. The target T+ is formed to be circumferential.

The targets T+, T+' are weak enough to form a leakage magnetic field inside T2, T+', and T2'.
The distribution of the magnetic field formed at the periphery of the target T2゜T2
'The magnetic field can be formed almost independently of the distribution of the magnetic field formed at the periphery.

By the way, the targets T+, T+' and T2゜T
γ with high energy sputtered from the surface of 2'
The electrons are directed to the aforementioned targets T+, T+' and T2,
Although it is emitted in the space of T2', it is not affected by the magnetic field up to the center and outer periphery of the target, so the γ electron density is almost uniform, and the formation of Ar+ ions used for sputtering is almost uniform over the entire surface of the target. done to. The γ electrons that reach the strong magnetic field formed at the outer periphery of the target are restrained by the magnetic field in a spiral shape along the lines of magnetic force that are perpendicular to the outer periphery of the target, and the γ electrons reach the targets T1゜T+' and T2. , T2'. In this process, Ar+ ions are formed, so the ionized argon particles are attached to the target T+, T+' planes and T2
It is accelerated by a strong electric field near the T2' plane and sputters the target material, making it possible to form a film at high speed.

In particular, according to the present invention, the leakage magnetic flux generated from the magnetic poles of the magnetic field generation means provided around the target flows into the target surface through the air gap, that is, near the shield edge, the leakage magnetic flux is parallel to the target surface similar to the leakage magnetic field of magnetron sputtering. A magnetic field is also created. Therefore, the γ electrons drift along the magnetic flux formed almost horizontally between the shield edge and the target surface, so even near the shield edge Ar+
Ions multiply. As a result, target T+.

Since the entire surface of T+', T2, and T2' is sputtered and the erosion pattern becomes uniform, the efficiency of target use can be improved. In particular, since the distribution of the magnetic field is uniform even if the thickness of the target is changed, continuous sputtering can be performed for a long time, and productivity can be significantly improved.

Other effects of the present invention are that the uniformity of the film thickness in the width direction of the divided target is improved and the efficiency of adhering sputtered particles to the substrate is significantly improved.

Although the present invention has been described above based on Examples, the present invention is not limited to such Examples.

As an example suitable for continuous production of thin-film magnetic recording media, etc., a flexible substrate such as a polymer film such as a polyester film is rolled up as a substrate and formed while being continuously transferred. There is no t11 in that transfer method.
Needless to say, there is no limit to this, and the method can also be applied to a single-wafer method.

As for the structure of the target part, although a structure in which the target can be easily replaced is shown, it is of course possible to use other structures.

As described above, the present invention includes various aspects.

[Brief explanation of drawings]

Figure 1 is a schematic configuration diagram showing the outline of the entire configuration of the embodiment;
The figure is a plan view of one of the target parts. Figure 3 is the ABI of Figure 2! 4 is a side sectional view taken along line CD in FIG. 2, and FIG. 5 is a side sectional view showing the configuration of a conventional target section. 10: Vacuum chamber, 20: Exhaust system, 30: Gas introduction system 40:
Substrate holding means 50: Power supply means 120: vj1
Field generating means T, T', T+, T2: Target, S2 substrate Patent applicant: Teijin Ltd.

Claims (1)

[Claims] 1. Generating a magnetic field in a direction facing the target by a magnetic field generating means around a target facing each other at a predetermined distance;
In a facing target type sputtering apparatus in which a film is formed on a substrate that is transferred on the side of the target in an opposite direction, the target is a rectangle that is long in the width direction of the substrate;
A facing target type sputtering apparatus characterized in that the target is divided into a plurality of parts on a long side, and the magnetic field generating means is configured to generate the magnetic field also at the divided parts of the target. 2. Claim 1, wherein the magnetic field generating means comprises a core made of a magnetic material that serves as magnetic poles arranged around the target and at the dividing points, and a permanent magnet magnetically coupled to the core.
The facing target sputtering apparatus described in . 3. The facing target sputtering apparatus according to claim 2, wherein the permanent magnet is attached to the outside of the target holder. 4. The facing target sputtering apparatus according to claim 2 or 3, wherein the core is a shield ring. 5. The facing target sputtering apparatus according to any one of claims 1 to 4, wherein the shield ring is covered with a wire mesh. 6. The facing target sputtering apparatus according to any one of claims 1 to 5, wherein the shield ring has a cooling jacket. 7. The facing target sputtering apparatus according to any one of claims 1 to 6, wherein the target is removably fixed on a cooling plate having cooling grooves fixed on a target holder. .