JPH09195039A - Laminated target and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the peeling between a substrate and an evaporating material, in a substrate as a laminated target made of metal and an evaporating material composed of metal different from the above, and joined by a hot isotropic pressing method by providing an intermediate layer suppressing diffusion between the substrate and the evaporating material. SOLUTION: An intermediate layer 4 composed of Ni is formed on the outer circumferential face of a columnar substrate made of a soft steel, e.g. composed of a rod body solid in the cross section by a plating method. The circumference of this stock is joined with a target material (evaporating material 3 composed of Cr by a hot insotropic pressing method. Next, a through hole 7 for a cooling water path is formed on the center part of a columnar substrate by boring working to form the columnar substrate into a cylindrical substrate 2, and both edges and the outer circumference are subjected to finish working into a prescribed shape to obtain a chromium target 1. In this target, since the progress of the diffusion between the substrate 2 and evaporating material 3 can be suppressed by the intermediate layer 4, the formation of intermetallic compounds caused by the above diffusion is reduced, and deterioration in its joining strength caused by the formation of brittle intermetallic compounds of Fe-Cr series can be suppressed.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to sputtering,
The present invention relates to a laminated target which is an evaporation source used in a vapor deposition apparatus and a manufacturing method thereof, and more specifically to a laminated target used in an arc ion plating apparatus and a manufacturing method thereof.

[0002]

2. Description of the Related Art Generally, an evaporation source (target) used in a vapor deposition method such as a sputtering method or an arc ion plating method (AIP method) is, for example, Japanese Patent Publication No.
As disclosed in Japanese Patent No. 2230, there is known a chromium target for hot isostatic pressing (HIP) of an evaporation material made of chromium. This chrome target is manufactured by vacuum-sealing an evaporator made of high-purity metal chrome powder in a metal capsule made of steel or stainless steel, molding the capsule by the HIP method, and then removing the metal capsule,
Appropriate hot working is performed to obtain a desired shape.

However, in such a manufacturing method, since it is necessary to reduce the particle size of the chromium powder which is the evaporation material, the evaporation material is expensive and difficult to obtain.
In addition, since heat treatment is basically required in the step after pressure molding and no consideration is given to cracking, the chromium target after molding becomes brittle. Therefore, in order to improve the above-mentioned evaporation material and cracks, for example, as shown in FIG. 4, a sputtering target 11 in which an evaporation material 13 made of Cr powder is bonded to the outer peripheral surface of a columnar or cylindrical substrate 12 by HIP is used. Is proposed in Japanese Patent Laid-Open No. 5-39566. In this target 11, since the evaporation material 13 is sintered to increase its density, it can be used regardless of the particle size of the evaporation material 13, resulting in a significant cost reduction. Furthermore, the internal defects of the evaporation material 13 are reduced, and the bonding strength between the substrate 12 and the evaporation material 13 is improved, and as a result, cracks are less likely to occur.

Further, the same publication describes a brazing method as a method for joining an evaporation material and a substrate. By this method, for example, when producing a tubular target, in the hollow portion of the tubular evaporation material previously produced by powder molding method,
Insert the stainless backing tube (base),
In-Sn, In-Pb, Sn- are formed between the evaporation material and the substrate.
A brazing material such as Ag is filled and bonding processing is performed.

[0005]

However, the conventional target bonded by the above HIP method is mainly used for the sputtering method, and this kind of target is
When used in the IP method, the following can be considered. In the AIP method, when the arc spot is concentrated on a limited area on the target, peeling occurs at the interface between the substrate and the evaporation material.

It is presumed that the cause of this peeling is the tensile stress generated at the interface due to the difference in linear thermal expansion coefficient between the substrate and the evaporation material, and the intermetallic compound generated at the interface. That is, in the area where the arc spots are concentrated,
It is considered that the target is partially heated and a large stress is generated at the interface between the substrate and the evaporation material. And, at the interface between the target made of steel base and chromium vaporizer,
It is considered that brittle intermetallic compounds are formed from the base material composed of the combination of Fe-Cr.

For the above reasons, when the target in which the evaporation material is in contact with the substrate is used in the AIP method, there is a problem that the substrate and the evaporation material are easily separated from each other. or,
The conventional target to be joined by the brazing method is AI
Even when used in the P method, a large tensile stress is generated at the interface for the same reason as above. Further, in the conventional cylindrical target produced by the HIP method, once peeling occurs at the interface,
The cooling ability of the target is significantly reduced, and the desired film quality cannot be obtained. Then, the arc spots are likely to be unevenly distributed on the target, and the film thickness distribution is deteriorated. Also, in the case of joining by the conventional brazing method, since the evaporation material which is a sintered body is processed into a cylindrical shape by machining, it is extremely difficult to process the inner surface of the evaporation material, and the material loss is very large. Further, there is a problem that it is difficult to align the evaporation material and the substrate with each other, and high precision is required for the dimensions of these diameters. Further, since the evaporation material and the substrate are bonded via the brazing material, there is a drawback that the bonding strength is weak and cracking and peeling are more likely to occur.

On the other hand, chromium is a very brittle material, and a chromium target made of an evaporation material containing this as a main component is also fragile. Therefore, when the cylindrical chromium target manufactured by the conventional manufacturing method is installed in the AIP apparatus, the inside of the vacuum container is contaminated by the jetting of the refrigerant due to the cracking of the target, and it is necessary to take measures to prevent this.

The present invention has been made in view of the above problems. An intermediate layer for suppressing the diffusion of the base material and the evaporation material is formed even in the AIP method in which the ionization energy of the metal is large and the local heating of the target cannot be avoided. By forming
An object of the present invention is to provide a laminated target capable of preventing the base material and the evaporation material from peeling off, and a method for manufacturing the laminated target.

[0010]

In order to achieve the above object, the laminated target of the present invention comprises a metal base body and an evaporation material made of a metal different from the base body, which are joined by a hot isostatic pressing method. In the laminated target formed as described above, a metal intermediate layer that suppresses diffusion of the substrate and the evaporation material is provided between the substrate and the evaporation material (claim 1). ).

As described above, when the intermediate layer is provided between the substrate and the evaporation material, hot isostatic pressing causes diffusion between the substrate and the intermediate layer and between the intermediate layer and the evaporation material. That is, since the intermediate layer is made of a material that suppresses the diffusion of the base material and the evaporation material, the progress of the diffusion of the base material and the evaporation material is suppressed. Therefore, the amount of the intermetallic compound produced by the diffusion of the base material and the evaporation material is reduced, and the reduction of the bonding strength due to the production of brittle intermetallic compound such as Fe—Cr intermetallic compound is suppressed.

And, as described in claim 2,
By forming the base into a cylindrical shape and joining the evaporation material through the intermediate layer provided on the outer peripheral surface of the base, it becomes possible to pass the refrigerant through the laminated target. As a result, the cooling efficiency of the laminated target is improved, and the cooling performance of the target does not decrease due to the separation of the base material and the evaporation material, so that the deterioration of the evaporation material is prevented and the desired film hardness is obtained.

Further, as described in claim 3,
An interface between the base and the intermediate layer, wherein the base is made of a metal containing Fe as a main component, the evaporation material is made of a metal containing Cr as a main component, and the intermediate layer is made of a metal containing Ni as a main component. Fe-Ni-based intermetallic compound is formed in the vicinity, and when a Cr-Ni-based intermetallic compound is formed in the vicinity of the interface between the evaporation material and the intermediate layer, Fe-Ni-based and Cr-Ni-based compounds are formed.
Since the intermetallic compound has high strength, the bonding strength near each interface is improved. Further, the laminated target as described above can be used in an arc ion plating apparatus.

As a method of manufacturing such a laminated target, for example, in a method of manufacturing a laminated target in which an evaporation material made of a metal different from this substrate is bonded to a metal base by a hot isostatic pressing method, By the plating method,
An intermediate layer that suppresses diffusion of the substrate and the evaporation material may be formed on the substrate (Claim 5). According to this, an intermediate layer having a uniform thickness is formed and the film quality distribution is constant. At the same time, the adhesive strength is high, which contributes to the effect of preventing peeling.

Then, the evaporation material is made of a metal containing Cr as a main component, the intermediate layer is made of a metal containing Ni as a main component, and the thickness of the intermediate layer is set to 50 μm or more to prevent the diffusion of the evaporation material. At the same time, a high-strength Cr-Ni-based intermetallic compound is formed. Further, when the base body is made of a metal containing Fe as a main component, the intermediate layer is made of a metal containing Ni as a main component, and the thickness of the intermediate layer is 100 μm or more, diffusion of the base body is prevented and A strong Fe-Ni intermetallic compound is formed. Further, the substrate is made of a metal containing Fe as a main component, the evaporation material is made of a metal containing Cr as a main component, and the intermediate layer is
Made of a metal whose main component is Ni, and the thickness of the intermediate layer is 200
When the thickness is at least μm, diffusion between the evaporation material and the substrate becomes difficult to occur, formation of brittle Fe—Cr based intermetallic compounds is prevented, and Cr—Ni based and Fe—Ni based intermetallic compounds are formed.
Therefore, the bonding strength of the intermediate layer is improved and peeling can be prevented.

In the method for manufacturing a laminated target, a metal foil for suppressing diffusion of the base and the evaporation material is interposed between the base and the evaporation material, and the thickness of the metal foil is 10 to 10.
When the thickness is 50 μm, the step of forming the intermediate layer becomes simple.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. First, a method for manufacturing the chromium target 1 according to this embodiment will be described with reference to FIG. The figure shows an outline of the manufacturing process of the chromium target 1. First, an intermediate layer 4 made of Ni is formed by plating on the outer peripheral surface of a mild steel columnar base body 2a made of a rod having a solid cross section.
a. As the plating method, the electroplating method is adopted as a method capable of forming the most dense metal film in order to prevent the diffusion of Fe element and Cr element by the HIP treatment described later. As in the conventional procedure of the electroplating method, the columnar substrate 2a, which is the object to be plated, is immersed in the electrolytic solution 5 containing Ni (FIG. 2 (I) (I
I))), using this columnar substrate 2a as a cathode for electrolysis,
Ni ions existing in the electrolytic solution 5 are deposited on the immersion surface of the columnar substrate 2a to form the intermediate layer 4 on the outer peripheral surface of the columnar substrate 2a (FIG. 2 (III)).

After the intermediate layer 4 is formed in this way, a target material (evaporating material) 3 made of Cr is bonded to the periphery of the chromium target material 1a by the hot isostatic pressing method (HIP method). As the procedure of this HIP treatment, the chromium target material 1a is placed near the center of the stainless steel cylindrical capsule 6 (FIG. 2 (IV)), and the cylindrical space in the gap between the chromium target material 1a and the capsule 6 is used. After the target raw material 3a is filled (FIG. 2 (V)), the capsule 6 is vacuum-sealed and hot isostatic pressing is performed. Here, as the target raw material 3a, powdery
Cr metal powder is used, and this Cr powder is sintered by the HIP process to form the target material 3. As a result, in the chromium target material 1a, the target material 3 is bonded so as to surround the intermediate layer 4 formed on the outer peripheral surface of the columnar substrate 2a (FIG. 2 (VI)).

For the chromium target material 1a,
After the HIP process, the capsule 6 is removed, a through hole 7 for a cooling water channel is formed in the center of the columnar substrate 2a by boring, and both ends and the outer periphery are finished into a predetermined shape,
As a result, the chromium target 1 according to this embodiment is obtained (FIG. 2 (VII)). Next, the chromium target 1 obtained by the above manufacturing method will be described.

FIG. 1 is a sectional view of a chromium target 1 according to this embodiment. As shown in the figure, the chromium target 1 includes a cylindrical base 2 and the base 2.
And a concentric cylindrical target material 3, and an intermediate layer 4 is provided between the outer peripheral surface of the base body 2 and the inner peripheral surface of the target material 3. The target material 3 is bonded to the outer peripheral surface of the intermediate layer 4 as a layer having a predetermined thickness, and the HIP method is used as the bonding method. Therefore, when the target material 3 is formed with high density and few defects. Moreover, it is not necessary to align the substrate 2 and the target material 3 with each other.

That is, in the chromium target 1, the base material 2 made of mild steel and the target material 3 made of Cr are
Since it is joined by HIP treatment through the intermediate layer 4 made of Ni which prevents diffusion of Fe element and Cr element, the base 2
And the intermediate layer 4, the diffusion between the target material 3 and the intermediate layer 4,
That is, diffusion occurs between Fe element and Ni element, and Cr element and Ni element. As a result, an Fe-Ni-based intermetallic compound is formed near the interface between the substrate 2 and the intermediate layer 4, and the target material 3
A Cr—Ni based intermetallic compound is formed near the interface between the intermediate layer 4 and the intermediate layer 4. These intermetallic compounds have higher strength than the Fe-Cr-based intermetallic compound and have sufficient strength against the stress generated under the normal use conditions of the chromium target 1. In this way, diffusion of Fe element or Cr element in the opposite direction is suppressed, and formation of a brittle Fe-Cr intermetallic compound caused by diffusion bonding of the Fe-based material and the Cr-based material can be prevented.

Therefore, the bonding strength at the contact surface between the substrate 2 and the intermediate layer 4, the target material 3 and the substrate 2 is improved, and the substrate 2 and the target material 3 can be prevented from peeling off. Since the intermediate layer 4 is formed by plating on the outer peripheral surface of the substrate 2 with a uniform thickness, the Fe-Ni-based and Cr-Ni-based intermetallic compounds are uniformly distributed in the circumferential direction and the longitudinal direction of the intermediate layer 4. It is dispersed, and peeling is less likely to occur over the entire chromium target 1.

As described above, since diffusion occurs on the outer peripheral surface and the inner peripheral surface of the intermediate layer 4, when the intermediate layer 4 is thin, one of Fe element and Cr element diffuses to the other. It is considered that a brittle Fe-Cr intermetallic compound is formed near the center of the intermediate layer 4. Therefore, by increasing the thickness of the intermediate layer 4, the diffusion of Fe element or Ni element is further suppressed. Further, these show the tendency when the HIP condition is constant, and the progress of diffusion of Fe element or Ni element changes depending on the HIP processing conditions such as heating temperature and holding time. Intermediate layer 4 that can prevent diffusion of Fe element and Cr element when it is short
Is thin.

On the other hand, since the diffusion rates of Fe element and Ni element are different, the thickness of the intermediate layer 4 capable of suppressing the respective diffusion is also different. Therefore, under normal HIP treatment conditions, if the thickness of the intermediate layer 4 is 50 μm or more, the diffusion of Cr element is suppressed by the intermediate layer 4 by almost 100%, and thus the Cr—Ni-based intermetallic compound is used. Are formed, and the contact strength between the target material 3 and the intermediate layer 4 is improved. When the thickness of the intermediate layer 4 is 100 μm or more, the diffusion of Fe element is suppressed by about 80% by the intermediate layer 4, so
A -Ni-based intermetallic compound is formed, and the bonding strength between the base 2 and the intermediate layer 4 is improved. Furthermore, the thickness of the intermediate layer 4 is set to 200 μm.
When it is formed in a thickness of m or more, the diffusion of Cr element and Fe element is suppressed by the intermediate layer 4 by almost 100%.
Fe-Ni intermetallic compound is formed and brittle Fe-Cr
The formation of the intermetallic compound is prevented, the bonding strength at the contact surfaces of the target material 3 and the intermediate layer 4, the substrate 2 and the intermediate layer 4 is improved, and peeling can be prevented. The upper limit thickness of the intermediate layer 4 is preferably about 250 μm in consideration of manufacturing cost.

As shown in FIG. 1, the base 2 of the chromium target 1 is a hollow body having a through hole 7 for a cooling water passage. Through this through hole 7, inside the substrate 2,
A coolant for cooling the target material 3 can be circulated. Further, in the chromium target 1 of the present embodiment, as described above, the formation of the brittle Fe—Cr-based intermetallic compound due to the reaction between the substrate 2 and the target material 3 is prevented, so that the refrigerant flows through the inside of the substrate 2. Even if it is, peeling between the substrate 2 and the target material 3 is suppressed, and a decrease in cooling ability of the target material 3 is prevented. Since the cooling ability of the target material 3 is ensured in this manner, the deterioration of the film quality is prevented and the desired film hardness is obtained. At this time, since the base body 2 is made of a high-strength material, ejection of the refrigerant is prevented, and even if the chromium target 1 is equipped as a target of the arc ion plating device, the vacuum container is prevented from being contaminated.

Then, a columnar chromium target 1 for an arc ion plating apparatus was produced by the above production method. At this time, the intermediate layer 4 has a thickness of
Considering the diffusion rate of Fe element and Cr element at the processing temperature,
It was set to 200 μm. Also, HIP processing conditions are 1280 ℃, 10
It was kept under 00 kgf / cm ² for 2 hours. FIG. 3 shows the result of line analysis of the bonding surface of the chromium target 1 after the HIP treatment. (A), (b) and (c) of FIG.
The diffusion status of elements and Cr elements is shown.
The leftmost layer is the substrate 2, the central layer is the intermediate layer 4, and the rightmost layer is the target material 3. From the figure (a), the diffusion of Fe element is about 80%, 20% near 100 μm.
It can be seen that almost 100% is suppressed in the vicinity of 0 μm. On the other hand, from the figure (c), the diffusion of Cr element is 50 μm.
It can be seen that almost 100% is suppressed in the vicinity.

The bonding strength between the substrate 2 and the target material 3 of the obtained chromium target 1 is about 20 kgf / mm ²
Met. This value was a value exceeding the maximum tensile stress of the joint surface obtained by thermal stress analysis under the usage environment of the chromium target 1. In fact, even when the chromium target 1 was used to perform an operation of concentrating the arc spot characteristic of the AIP method in a limited area, no peeling between the substrate 2 and the target material 3 was observed.

Further, between the substrate 2 and the target material 3, Ni
The intermediate layer 4 can also be formed by interposing a metal foil containing as a main component. That is, in the manufacturing method of the chromium target 1, instead of the electric Ni plating treatment, a metal foil made of Ni, for example, is attached to the surface of the columnar substrate 2 to form the intermediate layer 4. This simplifies the process of forming the intermediate layer 4. It is preferable to use a metal foil having a thickness of 10 to 50 μm. The metal foil may be formed in a tape shape and wound around the outer peripheral surface of the substrate 2, which facilitates the work itself.

The present invention is not limited to the above-described embodiment. For example, the base 2 and the target material 3 can be joined by a diffusion joining method such as hot pressing instead of HIP treatment. . Further, in the present embodiment, the columnar substrate 2a is formed into a cylindrical shape by boring, but by using the cylindrical substrate 2 in advance, the step of processing the substrate 2 into a cylindrical shape can be omitted. The intermediate layer 4 is not limited to Ni, but Pt, Co, Ti, Zr, etc. can be used.

[0030]

As described above, according to the laminated target of the present invention, the metal intermediate layer for suppressing the diffusion of the base and the evaporation material is provided between the base and the evaporation material. ,
It is possible to suppress a decrease in bonding strength due to the formation of a brittle intermetallic compound. Since the base has a cylindrical shape and the evaporation material is bonded via the intermediate layer provided on the outer peripheral surface of the base, the cooling ability of the target is secured and a desired film quality can be obtained.

The base is made of a metal containing Fe as a main component, the evaporation material is made of a metal containing Cr as a main component, the intermediate layer is made of a metal containing Ni as a main component, and an interface between the base and the intermediate layer is formed. A Fe-Ni intermetallic compound is formed in the vicinity, and a Cr-Ni intermetallic compound is formed in the vicinity of the interface between the evaporation material and the intermediate layer, so a high-strength intermetallic compound is formed and the bonding strength is improved. Can be improved. Furthermore, the laminated target of the present invention can be used in an arc ion plating apparatus.

Further, according to the method of manufacturing a laminated target of the present invention, since the intermediate layer for suppressing the diffusion of the substrate and the evaporation material is formed on the substrate by the plating method, the intermediate layer having a uniform thickness is formed. It can be formed and contributes to the prevention of peeling. And the evaporation material is made of a metal whose main component is Cr,
Since the intermediate layer is made of a metal containing Ni as a main component and the thickness of the intermediate layer is 50 μm or more, diffusion of the evaporation material can be prevented. The base is made of a metal containing Fe as a main component, the intermediate layer is made of a metal containing Ni as a main component, and the thickness of the intermediate layer 4 is 1
Since it is at least 00 μm, diffusion of the substrate can be prevented. Furthermore, the base is made of a metal whose main component is Fe, and the evaporation material is Cr.
Is used as a main component, the intermediate layer is made of a metal containing Ni as a main component, and the thickness of the intermediate layer is 200 μm or more. It is possible to prevent the formation of intercalation compounds.

In the method of manufacturing the laminated target,
A metal foil that suppresses the diffusion of the base material and the evaporation material is interposed between the base material and the evaporation material, and the thickness of the metal foil is 10 to 10.
Since it is 50 μm, the step of forming the intermediate layer can be simplified.

[Brief description of the drawings]

FIG. 1A is a sectional view of a chromium target according to an embodiment of the present invention, and FIG. 1B is a sectional view taken along line AA of FIG.

FIG. 2 is an explanatory diagram showing an outline of a method for manufacturing the chromium target.

FIG. 3 is a result of a line analysis of the above chromium target,
(A) is a graph showing the diffusion state of Fe element, (b) is a graph showing the diffusion state of Ni element, (c) is a graph showing the diffusion state of Fe element.

4A is an explanatory view showing a conventional cylindrical chromium target, FIG. 4B is a sectional view taken along the line BB in FIG. 4A, and FIG. 4C is an explanatory view showing a conventional cylindrical chromium target.

[Explanation of symbols]

 1 Chromium Target (Layered Target) 2 Substrate 3 Target Material (Evaporation Material) 4 Intermediate Layer

Claims (9)

[Claims] 1. A laminated target formed by joining a metal base and an evaporation material made of a metal different from the base by a hot isostatic pressing method, wherein the base and the evaporation material are connected to each other. A laminated target, comprising a metal intermediate layer that suppresses diffusion of the substrate and the evaporation material. 2. The laminated target according to claim 1, wherein the substrate has a cylindrical shape, and the evaporation material is provided through the intermediate layer provided on the outer peripheral surface of the substrate. 3. The base is made of a metal containing Fe as a main component, the evaporation material is made of a metal containing Cr as a main component, and the intermediate layer is made of a metal containing Ni as a main component. An Fe-Ni intermetallic compound is formed near the interface with the intermediate layer, and a Cr-Ni intermetallic compound is formed near the interface between the evaporation material and the intermediate layer. Item 1. The laminated target according to item 1 or 2. 4. The laminated target according to claim 1, which is used in an arc ion plating device. 5. A method of manufacturing a laminated target, comprising a metal base and an evaporation material made of a metal different from the base bonded to the base by a hot isostatic pressing method. A method for manufacturing a laminated target, comprising forming an intermediate layer on the substrate, which suppresses the diffusion of Al. 6. The evaporation material is made of a metal containing Cr as a main component, the intermediate layer is made of a metal containing Ni as a main component, and the thickness of the intermediate layer is 50 μm or more. Item 6. A method for manufacturing a laminated target according to Item 5. 7. The substrate is made of a metal containing Fe as a main component, the intermediate layer is made of a metal containing Ni as a main component, and the thickness of the intermediate layer is 100 μm or more. 5. The method for manufacturing the laminated target according to item 5. 8. The base is made of a metal containing Fe as a main component, the evaporation material is made of a metal containing Cr as a main component, and the intermediate layer is made of a metal containing Ni as a main component. The method for manufacturing a laminated target according to claim 5, wherein the thickness is 200 μm or more. 9. A method for manufacturing a laminated target, comprising a metal base and an evaporation material made of a metal different from the base bonded to the base by a hot isostatic pressing method. A method of manufacturing a laminated target, wherein a metal foil that suppresses diffusion of the substrate and the evaporation material is interposed, and the thickness of the metal foil is 10 to 50 μm.