JPH0411624B2 - - Google Patents

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 to 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] As is known from Japanese Patent Application Laid-open Nos. 57-158380 and 59-53680, the above-mentioned facing target sputtering device generates a magnetic field in the opposite direction of targets facing each other in a vacuum chamber. This is a sputtering device that forms a film on a substrate placed on the side of a target, and is capable of forming films of magnetic materials at low temperatures and at high speeds among various materials, and is used for manufacturing magnetic thin films, thin-film magnetic recording media, etc. has been done.

However, conventional facing-target sputtering layers are used to form films, such as Co-coal for perpendicular magnetic recording media.
It was found that when a Cr alloy film was continuously formed, the erosion of the target concentrated in the center, resulting in low target utilization efficiency (IEEE Trans on
Magnetics MAG17.p3175 (1981)). Furthermore, it was found that film thickness distribution occurred also in the width direction of the substrate, which caused problems in terms of productivity.

In contrast, the present inventors have
No. 59-116376 proposed the structure shown in FIG. 5, that is, a structure in which the core of the magnetic field generating mechanism is disposed around the target and a magnetic field is generated around the target. That is, the figure shows only the target portion of the facing target type sputtering device, and the end portion 301 is provided around the facing targets T and T' to also serve as a shield.
Legs 30 of the cores 301, 302 with a and 302a bent so as to face the surfaces of the targets T ₁ and T ₂
Magnetic field generation sources 301' and 302' made of coils or permanent magnets for generating magnetic fields are magnetically coupled to 1b and 302b, so that the magnetic field H is generated only around the targets T and T' as shown in the figure. It is something. In the figure, 310 is the vacuum chamber wall, 31
1,312 is a target holder, 311a,3
12a is a cooling pipe 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 around the target. The erosion area expanded from the center to the periphery, improving the target utilization rate. However, as the substrate width becomes wider and the target width becomes wider, the difference in the thin film between the center and the edge becomes larger in the width direction of the substrate, and the center becomes more eroded and the overall utilization rate of the target decreases. It turns out that there is a problem.

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

[Structure and operation of the invention] That is, the present invention
In this improvement of the facing target type sputtering device disclosed in Japanese Patent Application Laid-Open No. 59-116376, a magnetic field is generated in the direction facing the target by a magnetic field generating means around the targets facing each other at a predetermined distance. In the opposed target type sputtering apparatus, the target is a rectangle with a long width direction of the substrate, 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 length, and a plasma trapping magnetic field is generated at the divided points to divide the plasma space. By doing so, each divided region can be divided into two regions in the same way as independent targets. It was discovered that the eroded area is averaged, the utilization rate of the target is improved, and the uniform area of the film thickness distribution in the width direction of the substrate is greatly expanded.

According to the present invention, the above-mentioned problems are solved from the above points, and the target can be small, so
It also 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 is a schematic diagram showing the overall configuration of the embodiment;
The figure is a plan view of one of the targets, the third figure is a side sectional view taken along line AB in figure 2, which is perpendicular to the substrate, and the third figure
The figure is a side sectional view taken along line CD in FIG. 2, which is parallel to the substrate surface.

As is clear from FIG. 1, this apparatus has basically the same construction as the opposed target type sputtering apparatus known from the above-mentioned Japanese Patent Laid-Open Publication No. 57-158380.

That is, in the figure, 10 is a vacuum chamber, 20 is an exhaust system consisting of a vacuum pump etc. for evacuating the vacuum chamber 10, and 30 is a system for introducing a predetermined gas into the vacuum chamber 10 to increase the pressure inside the vacuum chamber 10 to 10 ^-1 ~ This is a gas introduction system that is set to a predetermined gas pressure of approximately 10 ^-4 Torr.

In the vacuum chamber 10, as shown in the figure, rectangular targets T and T' with long sides facing the pair of substrates S are arranged so as to face each other in parallel with a space between them. It has been set up.

The target units 100 and 100' have exactly the same configuration, and the following explanation will be based on one target 100.

The target section 100 is different from the conventional one, and as is clear from the plan view of _FIG .
It is divided into two parts T ₂ , and the shield ring 1
10 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 magnetic field for plasma trapping is arranged along and behind the shield ring 110 including the dividing side 110a, and is arranged behind the shield ring 110 including the dividing side 110a.
A magnetic field for plasma trapping is formed divided by T ₁ and T ₂ .

The detailed structure of this target section 100 is constructed as follows. 1 in Figures 2 and 3
01 is a target holder made of a cylindrical body, which has a storage part 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, and a Teflon (trade name of DuPont) is placed on top of the holder. )
A cooling plate 103 having cooling grooves 103a for cooling the targets T ₁ and T ₂ on its upper surface as shown in the figure is fixed with bolts through an insulating block 102 made of an insulating material such as. And on the cooling plate 103,
The targets T ₁ and T ₂ are fixed by bolts using the holding frame 104 . Connection port 103 of cooling plate 103
A cooling pipe (not shown) is connected to b, and the targets T ₁ and T ₂ are cooled by circulation of a cooling medium. Note that the target holder 101
The contact surfaces of the upper surface of the insulating block 102, the cooling plate 103, and the targets T ₁ and T ₂ are naturally sealed with packing (not shown). With the above configuration, the targets T ₁ and T ₂ can be easily replaced, and the targets T ₁ and T ₂ can be uniformly cooled to every corner, which is highly effective in terms of productivity and stable operation.

On the outside of the target holder 101, there is a magnet holder 105 made of a non-magnetic conductive material such as stainless steel.
is fixed with bolts. Magnet holder 1
05 is a diagram in which a shield ring 110 can be attached to the upper surface, and a core 121 of a magnetic field generating means 120 is installed inside the shield ring 110.
A U-shaped holder portion 105a is formed outside the tip of the permanent magnet 122 so as to accommodate the permanent magnet 122, and is arranged to have a predetermined gap from the targets _T1 , _T2 and the cooling plate 103.

Core 121 of magnetic field generating means 120 and permanent magnet 1
22, 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 placed to attract spatter of targets T ₁ and T _{2 .} 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 surface. In addition, permanent magnet 1
Reference numeral 22 indicates square bar-shaped magnets having a predetermined length arranged in parallel so that their combined magnetic field forms the plasma trapping magnetic field. Therefore, the magnetic field for plasma trapping is core 1
21 as the magnetic pole, the target T ₁ ,
A uniform magnetic field is created around T ₂ and target usage efficiency is improved.

The shield ring 110 protrudes toward the targets T ₁ and T ₂ so as to cover the gap between the magnet holder 105 and the targets T ₁ and T ₂ .
It is provided on the front surface of the holder part 105a of 05. Therefore, the shield ring 110 is grounded via the magnet holder 105 and target holder 101.

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 ring 110 to the outer surface of the holder portion 105a of the magnet holder. The wire mesh 107 prevents the spatter deposits deposited on these parts from peeling off in the spatter, that is, abnormal discharge, and also simplifies cleaning, resulting in great effects in terms of productivity and stable operation. The shield ring 110 is a jacket 11 through which the cooling medium passes.
1 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 realized.

The material of the shield ring 110 may be any conductive material, may be a soft magnetic material similar to the above-described core 121, or may be made of copper, stainless steel, or the like. 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, and therefore acts as a magnetic field generating portion of the magnetic field generating means 120 instead of or in addition to the core 121. In other words, it acts as a magnetic pole. This configuration has the advantage that the magnetic pole position relative to the targets T ₁ and T ₂ can be adjusted by adjusting the tip position of the shield ring 110.

Returning to FIG. 1, the target section 1 with the above configuration
00,100' and facing target T,
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 three rolls, a feed roll 41 holding a roll-shaped substrate S, a support roll 42, and a take-up roll 43, which are supported rotatably and parallel to each other by support brackets (not shown). The roll is arranged to hold the substrate S in a direction substantially perpendicular to the sputtering surface so as to face the space between the targets T' and T. Therefore, the substrate S can be moved by the take-up roll 43 in a direction perpendicular to the sputtering surface. In addition,
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 sputter power has its positive side connected to the ground and its negative side connected to the targets T and T', respectively. Therefore, the sputtering power from the power supply means 50 is supplied between the anode and the cathode, with the ground as the anode and the targets T and T' as the cathode.

In addition, 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 mentioned above, the structure is basically the same as that of the above-mentioned Japanese Patent Application Laid-open No. 57-158380, and as is known, high-speed low-temperature sputtering is possible. That is, in the space between targets T and T', sputter 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 and T' is promoted and the amount of precipitation increases from the space,
The deposition rate on the substrate S is increased and high-speed sputtering is possible, and since the substrate S is on the side of the targets T and T', 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 magnetic field generating means 120 is also divided according to the division of the targets, the magnetic field is generated by the cores 121 and 121' (hereinafter "'" is not shown) facing each other. The omitted target holder 100' is formed so as to surround the periphery of the targets T ₁ , T ₂ , T ₁ ', and T ₂ ' by using the same numbers as the target holder 100 as magnetic poles, and _T1 ,
Since the leakage magnetic field is weak enough to be formed inside T ₂ , T ₁ ′, and T ₂ ′, the distribution of the magnetic field formed at the periphery of targets T ₁ , T ₁ ′ and the periphery of targets T ₂ , T ₂ ′ The magnetic field can be formed almost independently of the distribution of the magnetic field formed by the magnetic field.

By the way, high energy γ sputtered from the surfaces of targets T ₁ , T ₁ ' and T ₂ , T ₂ '
Electrons are emitted into the space between the targets T ₁ , T ₁ ′ and T ₂ , T ₂ ′, but since they are not affected by the magnetic field near the center and outer periphery of the targets, the γ electron density is almost uniform. The formation of Ar ⁺ ions used in sputtering occurs almost uniformly over the entire surface of the target. The γ electrons that reach the strong magnetic field formed at the outer periphery of the target are restrained in a spiral shape by the magnetic field along the lines of magnetic force formed perpendicular to the outer periphery of the target, and are directed to the targets T ₁ , T ₁ ′. and T ₂ ,
It moves back and forth between T ₂ ′. In this process, Ar ⁺ ions are formed, so the ionized argon particles are accelerated by a strong electric field near the target T ₁ , T ₁ ′ planes and T ₂ , T ₂ ′ planes, sputtering the target material, and forming a film at high speed. I can do it. 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, it flows parallel to the target surface similar to the leakage magnetic field of a magnetron sputter. A magnetic field is also formed. Therefore, the γ electrons drift along the magnetic flux that is formed approximately horizontally between the shield end and the target surface, so that Ar ⁺ ions proliferate even near the shield end. As a result, the entire surfaces of the targets T ₁ , T ₁ ' and T ₂ , T ₂ ' are sputtered and the erosion pattern becomes uniform, thereby improving the efficiency of target use. 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.

Another effect of the present invention is that the uniformity of the film thickness in the width direction of the divided target is improved and the efficiency of adhering sputter 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. Needless to say, there are no restrictions on the transfer method, and a single-wafer method can also be applied.

As for the structure of the target part, although the 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]

FIG. 1 is a schematic configuration diagram showing the outline of the entire configuration of the embodiment, FIG. 2 is a plan view of one of the target parts,
Fig. 3 is a side sectional view taken along line AB in Fig. 2, Fig. 4 is a side sectional view taken along line CD in Fig. 2, and Fig. 5 is a side sectional view showing the structure of a conventional target section. be. 10... Vacuum chamber, 20... Exhaust system, 30... Gas introduction system, 40... Substrate holding means, 50... Power supply means, 120... Magnetic field generating means, T, T',
_T1 , _T2 ...Target, S...Substrate.

Claims (1)

[Claims] 1. A magnetic field generating means generates a magnetic field in a direction facing the target around targets facing each other at a predetermined distance, and a film is formed on the sides of the target on a substrate that is transferred in the opposite direction. 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 magnetic field generating means is configured to generate the magnetic field also at the divided parts of the target. A facing target sputtering device characterized by: 2. The facing target type according to claim 1, wherein the magnetic field generating means comprises a core made of a magnetic material serving as magnetic poles arranged around the target and at the dividing points, and a permanent magnet magnetically coupled to the core. Spatuta device. 3. The opposed target sputtering apparatus according to claim 2, wherein the permanent magnet is attached to the outside of the target holder. 4. The opposed target sputtering apparatus according to claim 2 or 3, wherein the core is a shield ring. 5. The opposed target sputtering apparatus according to any one of claims 1 to 4, wherein the shield ring is covered with a wire mesh. 6. The opposed target sputtering apparatus according to any one of claims 1 to 5, wherein the shield ring has a cooling jacket. 7. The opposed 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.