JP4130263B2 - Sputtering equipment and water-cooled cathode - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sputtering apparatus and a water-cooled cathode used therein, and more particularly to an improvement in a target cooling structure.
[0002]
[Prior art]
A general sputtering apparatus has a decompression chamber into which argon gas is introduced and argon gas is introduced, a cathode having a cooling water channel inside the decompression chamber, a target fixed on one surface of the cathode, An article holding mechanism that holds the article facing the target is disposed. The target is composed of a plate-like target material formed of a film forming material and a copper backing plate brazed to the back surface of the target material, and the backing plate serves as a cathode with the target material facing the article. It is fixed with bolts.
[0003]
The cathode usually has a box shape made of copper or the like, and a cooling water passage is formed in an airtight manner inside, and the cooling water is circulated from the outside through a pipe. As a result, heat generated by irradiation with argon ions is released from the target, and thermal deformation of the target is prevented. In addition, a plurality of permanent magnets are normally accommodated in the cooling water channel of the cathode, and a magnetic field is formed around the target so that the target is efficiently irradiated with argon ions.
[0004]
Further, although not general, other target cooling structures are disclosed in JP-A-61-231171, JP-A-63-100175, JP-A-1-298159, and JP-A-4-202662. JP-A-4-228565, JP-A-4-293771, JP-A-7-34235, JP-A-9-125245, and the like.
[0005]
[Problems to be solved by the invention]
By the way, the cathode of the conventional sputtering apparatus has a structure in which a cooling water channel is formed by cutting a copper block-shaped main body with an end mill, and the cooling water channel is closed with a copper lid, and in a reduced pressure atmosphere. Since it is disposed, a high-precision vacuum seal is required between the lid and the main body, and the manufacturing cost is high. In addition, since it is difficult to reduce the thickness with this structure, the necessary arrangement space is large, which has been a cause of restricting the degree of freedom of the apparatus structure.
[0006]
In addition, since the cathode is thick, the magnet is accommodated in the cathode and immersed in the cooling water in order to bring the magnet closer to the target, so that the magnet has a problem of being corroded by the cooling water, and unless the cathode is disassembled, the magnet Since the relative position between the target and the target cannot be changed, it is difficult to change the target consumption point due to the displacement of the magnet, and there is a problem that the target wear is localized and the service life is short. It was.
[0007]
The present invention has been made in view of the above circumstances, and a sputtering apparatus capable of reducing the manufacturing cost of the cathode, increasing the degree of freedom of the structure of the sputtering apparatus, preventing corrosion of the magnet, and extending the service life of the target. The issue is to provide.
[0008]
[Means for Solving the Problems]
In order to solve the above-described problems, a sputtering apparatus according to the present invention includes a decompression chamber, a water-cooled cathode disposed in the decompression chamber and having a target fixed on one surface thereof, and cooling for circulating cooling water through the water-cooled cathode. A water circulation path and a magnet disposed on the opposite side of the target fixing surface of the water-cooled cathode, the water-cooled cathode being bonded with two metal plates, the magnet holding the target fixing surface flat A cooling water channel is formed between the two metal plates by bulging the side metal plate.
[0009]
The second sputtering apparatus according to the present invention includes a decompression chamber, an unwinder and a winder for continuously running a long film in the decompression chamber, and portions of the film parallel to each other in a part of the travel path. A pair of water-cooled cathodes disposed between the parallel parts and having a target fixing surface facing each of the parallel parts, and a cooling water circulation path for circulating cooling water through the water-cooled cathodes, A magnet disposed between the pair of water-cooled cathodes, wherein the water-cooled cathode bonds two metal plates, and bulges the magnet-side metal plate while keeping the target fixing surface flat. Thus, a cooling water channel is formed between the two metal plates.
[0010]
The water-cooled cathode according to the present invention is a water-cooled cathode having a target fixing surface for fixing a target on one side, and two magnets are bonded together so that the target fixing surface is kept flat while the magnet is fixed. A cooling water channel is formed between the two metal plates by bulging the side metal plate.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a cross-sectional view showing a first embodiment of a sputtering apparatus according to the present invention. This sputtering apparatus is arranged in a vacuum chamber 1 capable of hermetically sealing the inside, and the vacuum chamber 1. A water-cooled cathode 2, a target 4 fixed to the lower surface (target fixing surface 2A) of the water-cooled cathode 2, a pair of cooling water pipes 12 (cooling water circulation path) for circulating cooling water through the water-cooled cathode 2, and a water-cooled cathode 2 is provided with a magnet 6 disposed on the side opposite to the target fixing surface 2A, and an article holding mechanism 20 for holding an article 26 to be deposited.
[0012]
The main feature of this embodiment is that a water-cooled cathode 2 as shown in FIGS. As shown in FIG. 4, the water-cooled cathode 2 has two metal plates 2B and 2C bonded together by diffusion bonding or brazing, and the metal plate 2C on the target fixing surface 2A side is kept flat, while the magnet 6 side is kept flat. A cooling water passage 46 is formed between the two metal plates by locally inflating the metal plate 2B to form the bulging portion 40.
[0013]
In the water-cooled cathode 2 of this embodiment, the planar shape of the bulging portion 40 is substantially U-shaped as shown in FIG. 3, and connects two straight hollow portions parallel to each other and the ends of these straight hollow portions. And a curved hollow portion. Further, the cross-sectional shape of the bulging portion 40 is a crushed semi-elliptical or semi-circular shape as shown in FIG. Cylindrical openings 44 are formed at both ends of the bulging part 40 as shown in FIG. 5, and the cooling water pipe 12 is inserted into these openings 44 and is hermetically fixed by brazing or the like. An inclined portion 42 that gently connects between the opening 44 and the bulging portion 40 is formed.
[0014]
Although the manufacturing method of the water-cooled cathode 2 is not limited, The following methods can be illustrated. First, two metal plates 2B and 2C are prepared, and a release agent is applied to one metal plate by printing or the like to form a release agent layer having a shape corresponding to the bulging portion 40. As the release agent, a hardly soluble inorganic powder such as barium sulfate or carbon powder is used, and it may be used by dispersing in a liquid such as polyvinyl alcohol or water at the time of coating. The solvent is removed by heating.
[0015]
Next, the other metal plate is placed on the side where the release agent layer is formed, and both are diffusion bonded by pressurization and heating. At this time, since the release agent particles slightly bite into the surface of the metal plate, the roughness of the inner surface of the cooling water passage 46 can be adjusted by adjusting the particle size and hardness of the release agent. When joining is completed, the end corresponding to the release agent layer is pry open to form the inclined portion 42 and the opening 44, the cooling water pipe 12 is connected in each opening 44, and corresponds to the bulging portion 40 to be formed The composite plate is placed in a mold in which the depressions are formed in advance, and both surfaces are restrained, and a high-pressure fluid such as water is injected to form the bulging portion 40. At this time, as shown in FIG. 4, by making the metal plate 2B on the side to be inflated thinner than the metal plate 2C on the side not to be inflated, the expansion tube can be easily processed. Conversely, if the metal plate 2B on the side to be inflated is made relatively thicker than the metal plate 2C on the side not to be inflated, the cooling water passage 46 and the target 4 can be brought close to each other, and the cooling efficiency Can be further enhanced.
[0016]
As the material of the metal plates 2B and 2C, any metal can be used if necessary, but generally copper, copper alloy, aluminum, aluminum alloy, etc. are preferable from the viewpoint of thermal conductivity. Although the thickness of the metal plates 2B and 2C is not limited, the metal plate 2B is preferably about 0.5 to 5 mm from the viewpoint of ease of expansion tube processing and strength, and the metal plate 2C is fastened to the target 4 by screws or the like. In order to fix by means, about 0.5-10 mm is preferable. The cross-sectional dimension of the cooling water passage 46 is determined according to the cooling water flow rate required for cooling the target.
[0017]
As shown in FIG. 3, the magnet 6 is a rectangular parallelepiped inner magnet 6A disposed corresponding to the center of the water-cooled cathode 2, and surrounds the inner magnet 6A away from the inner magnet 6A by a certain distance outward. The outer magnet 6B is installed in a square frame shape, and the magnetic field is formed so as to protrude from the surface of the target 4 as indicated by an arrow in FIG. The direction of the lines of magnetic force is not limited. As shown in FIG. 3, the bulging portion 40 of the water-cooled cathode 2 is formed along the gap between the inner magnet 6A and the outer magnet 6B, whereby the inner magnet 6A and the outer magnet 6B are formed on the surface of the target 4. Argon ions are concentrated and irradiated in a rectangular frame-shaped region corresponding to the area, and this portion generates heat particularly. On the other hand, since the cooling water passage 46 is formed immediately below the rectangular irradiation portion, the target 4 can be efficiently cooled.
[0018]
An insulating layer 3A is integrally formed with the water-cooled cathode 2 on the surface on the bulging portion 40 side and the outer peripheral end surface of the water-cooled cathode 2 with an insulator such as plastic, and the upper surface thereof is flattened. The thickness of the insulating layer 3A is desirably as thin as possible within a range in which sufficient insulating properties can be obtained. This is because the thinner the magnet 6 and the target 4 are, the closer it is.
[0019]
The target 4 is integrally composed of a plate-like backing plate 4B formed of a material having excellent thermal conductivity such as copper or a copper alloy, and a plate-like target material 4A fixed to one side of the backing plate 4B. The target material 4A is slightly smaller than the backing plate 4B, and the outer periphery of the backing plate 4B is exposed over a certain width, and this exposed portion is fixed to the target fixing surface 2A of the water-cooled cathode 2 by screws or the like. . Thereby, although the back surface of the backing plate 4B is in close contact with the target fixing surface 2A, a soft metal foil such as solder or indium may be interposed between the two in order to further improve the heat conductivity. The insulating layer 3B is formed over the entire circumference so as to cover the peripheral edge of the backing plate 4B of the target 4 and the outer peripheral surface of the insulating layer 3A, and consideration is given so that the backing plate 4B is not consumed.
[0020]
The magnet 6 may be fixed to the water-cooled cathode 2, but more preferably supported by a magnet holding mechanism (not shown) so that the position of the magnet 6 can be changed in a direction parallel to the water-cooled cathode 2. If such a holding mechanism is employed, after the target 4 is locally consumed, the positions of the magnet 6 and the bulging portion 40 are changed so that the portion with little consumption is irradiated with argon ions. It becomes easy.
[0021]
As shown in FIG. 1, a roughing decompression mechanism 28 such as a decompression pump and a vacuum decompression mechanism 30 including a liquid nitrogen trap and an oil diffusion pump are connected to the decompression chamber 1 via valves 29. In addition, the roughing decompression mechanism 28 and the vacuum decompression mechanism 30 are also connected via a valve 29. In addition, an argon supply mechanism 32 is connected to the decompression chamber 1 via a valve 31 from which argon gas having a predetermined pressure is supplied.
[0022]
As shown in FIG. 1, the cooling water pipe 12 connected to the water-cooled cathode 2 has an insulating layer 13 formed on the outer peripheral surface thereof, penetrates the decompression chamber 1 through an insulator 14, and is not shown. And is electrically connected to the sputtering power supply 16. The sputtering power source 16 applies an AC or DC voltage between the cooling water pipe 12 and the decompression chamber 1.
[0023]
A table-shaped article holding mechanism 20 is disposed below the target 4, and an article 26 is placed thereon. A cooling water passage is formed in the article holding mechanism 20 of this embodiment so that the placed article 26 can be cooled. In addition, a shutter 18 is disposed between the article 26 and the target 4, and particles of the sputtering material released from the target 4 are allowed to adhere to the article 26 for a desired time by the shutter 18. ing.
[0024]
According to the sputtering apparatus having the above configuration, since the water-cooled cathode 2 in which the interface between the two metal plates 2B and 2C bonded together is expanded to form the cooling water passage 46 is used, A vacuum seal is not required for production, the manufacturing cost is low, and the water-cooled cathode 2 is thin. Therefore, it is possible to increase the degree of freedom of the sputtering apparatus structure without taking a space for the arrangement.
[0025]
In addition, since the water-cooled cathode 2 is thin, the magnet 6 can be brought close to the target 4 simply by arranging the magnet 6 on the back side of the water-cooled cathode 2, and the magnet can be moved as in the case where the magnet is arranged in the cooling water channel. It is not corroded by cooling water. Furthermore, since the relative position between the magnet 6 and the target 4 can be changed without disassembling the water-cooled cathode 2, it is easy to change the consumable part of the target 4 due to the displacement of the magnet 6. The efficiency of use is also increased.
[0026]
[Second Embodiment]
FIG. 6 shows a second embodiment of the present invention. In the first embodiment, the cooling water pipe 12 extends from the end of the water-cooled cathode 2, but the water-cooled cathode 50 used in this embodiment is perpendicular to the surface opposite to the target fixing surface 2A. The cooling water pipe 12 extends.
[0027]
FIG. 7 shows an example of the water-cooled cathode 50. In this water-cooled cathode 50, the bulging portion 40 has a C-shape extending along the gap between the inner magnet 6A and the outer magnet 6B, and both end portions of the bulging portion 40 correspond to the gap between the inner magnet 6A and the outer magnet 6B. The cooling water pipe 12 is vertically connected to each of these ends. These cooling water pipes 12 are covered with an insulating layer 13, extend upward between the inner magnet 6 </ b> A and the outer magnet 6 </ b> B, and extend outward through the decompression chamber 1. Other configurations are the same as those of the first embodiment. According to such a second embodiment, the cooling water pipe 12 does not get in the way through the vicinity of the target 4. The cooling water pipe 12 may not be connected vertically to the water-cooled cathode 50, and may be connected in an inclined state.
[0028]
[Third Embodiment]
FIG. 8 shows a water-cooled cathode 60 used in the third embodiment of the present invention. In the water-cooled cathode 2 shown in FIG. 3, there is a portion where the cooling efficiency is relatively low between both ends of the bulging portion 40. A bulging portion 62 is formed, and a part of the cooling water flowing in from one cooling water pipe 12 flows to the other cooling water pipe 12 through the short-circuit bulging portion 62, and Cooling efficiency at the corresponding location is increased. The cross-sectional area of the flow path of the short-circuited bulge 62 is determined so that the cooling capacity at the location corresponding to the bulge 40 and the cooling capacity at the location corresponding to the short-circuit bulge 62 are equal.
[0029]
[Fourth Embodiment]
9 and 10 show a water-cooled cathode 70 employed in the fourth embodiment of the present invention. In the water-cooled cathode 70, the bulging portion 72 has a rectangular shape with a large area, and an inclined portion 76 and an opening 78 are formed on one end side thereof, and the cooling water pipe 12 is connected thereto.
[0030]
In this water-cooled cathode 70, the metal plate 2B on the side where the bulging portion 72 is formed is thick, the metal plate 2C on the target fixing surface 2A side is thin, and the portion corresponding to the cooling water passage 74 is an elastically deformable portion. 79. Thereby, when cooling water is supplied in a pressurized state from the cooling water pipe 12, the elastically deformable portion 79 is displaced toward the target 4, and the elastically deformable portion 79 is in close contact with the target 4. As described above, in this embodiment, when the cooling water is supplied, the close contact with the target 4 is improved, so that the cooling efficiency can be increased.
[0031]
Although not limited, in order to enable effective swelling, the thickness of the metal plate 2C is preferably about 0.5 to 5 mm, more preferably 1 to 3 mm. The pressure of the cooling water is preferably about 0.5 to 3 atmospheres added to the atmospheric pressure. In this example, the bulging portion 72 is wide so that the displacement is easy, but the bulging portion may have a shape as in the first embodiment or each of the embodiments described above.
[0032]
[Fifth Embodiment]
As shown in FIG. 11, the water-cooled cathode 2 of the fifth embodiment is curved so as to protrude toward the target fixing surface 2A without fixing the target, and is elastically curved by fixing the target. Is configured to be corrected. The water-cooled cathode 2 may be curved in the longitudinal direction, may be curved in the width direction, or may be curved in both the longitudinal direction and the width direction, that is, in a spherical shape. According to this configuration, the water-cooled cathode 2 is corrected to a flat surface by connecting the peripheral portion of the backing plate 4B and the water-cooled cathode 2 with a bolt or the like, and at the same time, the entire surface of the target fixing surface 2A is pressed against the target. The heat conduction between the water-cooled cathode 2 and the target can be improved.
[0033]
The appropriate curvature of the water-cooled cathode 2 is such that the value of the curvature W / h is 30 when the width W of the water-cooled cathode 2 in a certain direction and the protruding amount of the water-cooled cathode 2 are h / 2 as shown in FIG. It is good to be -2200. If the curvature is less than 30, the deformation of the water-cooled cathode 2 is too large, making it difficult to attach the target 4. If the curvature is greater than 2200, sufficient effects cannot be obtained.
[0034]
[Sixth Embodiment]
FIG. 12 shows a sixth embodiment of the present invention. In this embodiment, the unwinder 80 in which the long film F is wound in the decompression chamber 1, the pair of guide rolls 82 and 84, and the reversal that makes the portions of the film F face each other in parallel in a part of the traveling path. A roll 83 and a winder 86 for winding the film F are disposed.
[0035]
Between the parallel portions of the film F, a pair of water-cooled cathodes 2 having target fixing surfaces 2A facing each of the parallel portions are arranged in parallel to each other, and a target 4 is fixed to each target fixing surface 2A. The insulating layer 3B is formed on the opposite surface. In addition, a cooling water circulation path (not shown) for circulating the cooling water to the water-cooled cathode 2 is provided.
[0036]
Between each water-cooled cathode 2, magnets 6 (inner magnet 6 </ b> A and outer magnet 6 </ b> B) are arranged so as to be substantially the same distance from each water-cooled cathode, supported by a magnet position adjusting mechanism 88, and by these magnets 6. A magnetic field is formed near the surface of each target 4. When the magnet position adjusting mechanism 88 is adjusted, the position of each magnet 6 can be adjusted in a direction parallel to the water-cooled cathode 2. Other configurations not shown are the same as those in the first embodiment.
[0037]
According to the sputtering apparatus having such a configuration, the substance can be attached from the first target 4 while the film F is continuously running, and then the substance can be attached from the second target 4. Therefore, by making the materials of the first target 4 and the second target 4 different, a film composed of two layers can be formed by one sputtering operation. Even when the same substance is adhered, the film F can be cooled by the reversing roll 83 in the middle, so that a thicker film can be formed without affecting the film F.
[0038]
Further, since the magnet 6 can be used in common for each target 4, the structure of the apparatus can be simplified while enabling double sputtering, and both can be performed by scanning the magnet position adjusting mechanism 88. There is an advantage that the position of the magnet 6 with respect to the target 4 can be changed.
[0039]
【The invention's effect】
As described above, the sputtering apparatus according to the present invention uses the water-cooled cathode in which the interface between the two metal plates bonded together is expanded to form a cooling water channel, so that a vacuum is used to create the water-cooled cathode. Since a seal is not required, the manufacturing cost is low, and the water-cooled cathode is thin. Therefore, it is possible to increase the degree of freedom of the sputtering apparatus structure without taking up an arrangement space.
[0040]
Further, since the water-cooled cathode is thin, the magnet can be brought close to the target only by arranging the magnet on the back side of the water-cooled cathode, and the magnet is not corroded by the cooling water. Since the relative position of the magnet and the target can be changed without disassembling the water-cooled cathode, it is easy to change the target consumption point by the displacement of the magnet, and the use efficiency of the target is increased accordingly.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a first embodiment of a sputtering apparatus according to the present invention.
FIG. 2 is a side sectional view showing a water-cooled cathode of the same embodiment.
FIG. 3 is a plan view of the water-cooled cathode.
FIG. 4 is a front sectional view of the water-cooled cathode.
FIG. 5 is a partial sectional view of the water-cooled cathode.
FIG. 6 is a cross-sectional view showing a second embodiment of the present invention.
FIG. 7 is a plan view of a water-cooled cathode used in the second embodiment.
FIG. 8 is a plan view of a water-cooled cathode used in the third embodiment.
FIG. 9 is a plan view showing a water-cooled cathode according to a fourth embodiment.
10 is a cross-sectional view taken along line XX in FIG.
FIG. 11 is a side view of a water-cooled cathode according to a fifth embodiment.
FIG. 12 is a cross-sectional view of a sixth embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Decompression chamber 2,50,60,70 Water-cooled cathode 2A Target fixed surface 2B, 2C Metal plate 3A, 3B Insulator 4 Target 4A Target material 4B Backing plate 6 Magnet 6A Inner magnet 6B Outer magnet 12 Cooling water pipe 16 Sputtering power supply 20 Article holding mechanism 40, 72 Swelling portion 46 Cooling water passage 79 Elastic deformable portion 80 Unwinder 83 Reverse roll 86 Winder 88 Magnet position adjusting mechanism

Claims (6)

A vacuum chamber, a water-cooled cathode disposed in the vacuum chamber and having a target fixed to one surface thereof, a cooling water circulation path for circulating cooling water to the water-cooled cathode, and a side opposite to the target fixing surface of the water-cooled cathode The water-cooled cathode is bonded to two metal plates, and the two metal plates are bulged by expanding the metal plate on the magnet side while keeping the target fixing surface flat. A sputtering apparatus in which a cooling water channel is formed between plates. The magnet includes an inner peripheral magnet disposed corresponding to a central portion of the target, and an outer peripheral magnet disposed so as to surround the inner peripheral magnet so as to be separated from the inner peripheral magnet. The sputtering apparatus according to claim 1, wherein the cooling water channel is formed corresponding to a gap between the inner peripheral magnet and the outer peripheral magnet. The water-cooled cathode is curved so as to be convex toward the target fixing surface in a state where the target is not fixed, and is configured to be elastically corrected by fixing the target. The sputtering apparatus according to claim 1 or 2. An elastically deformable portion is formed at a portion corresponding to the cooling water channel on the target fixing surface of the water-cooled cathode, and when the pressurized cooling water is supplied to the cooling water channel, the elastic deformable portion is pressed against the target. The sputtering apparatus according to claim 1, wherein the sputtering apparatus is configured as described above. A decompression chamber, an unwinder and winder for continuously running a long film in the decompression chamber, a reversing roll that makes the portions of the film face each other in parallel in a part of the running path, and between the parallel portions A pair of water-cooled cathodes each having a target fixing surface disposed opposite to each of the parallel portions; a cooling water circulation path for circulating cooling water through the water-cooled cathodes; and a magnet disposed between the pair of water-cooled cathodes. The water-cooled cathode has two metal plates bonded together, and a cooling water channel is formed between the two metal plates by expanding the metal plate on the magnet side while keeping the target fixing surface flat. Sputtering apparatus characterized by being made. A water-cooled cathode having a target fixing surface for fixing a target on one side, by bonding two metal plates, and expanding the metal plate on the magnet side while keeping the target fixing surface flat A water-cooled cathode characterized in that a cooling water channel is formed between the two metal plates.

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