JP2004074180A - Joining method and device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a joining method efficiently suppressing warping caused in a target-backing plate assembly and joining the target-backing plate assembly and a cooling plate while correcting the warping in a brazing temperature region and hence enhancing yield and efficiency of production, and also to provide a device used for the same. <P>SOLUTION: In the joining method for joining the target-backing plate assembly and the cooling plate, the target-backing plate assembly is heated and vacuum-sucked and joined to the cooling plate when the target-backing plate assembly and the cooling plate are joined together. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention effectively suppresses warpage due to heating generated in the target-backing plate assembly and corrects the generated warpage when heating and joining the target-backing plate assembly and the cooling plate (cooling plate). The present invention relates to a method and an apparatus for joining with a cooling plate.
[0002]
[Prior art]
2. Description of the Related Art In recent years, sputtering has been used for forming thin films of semiconductor devices and various electronic devices. As is well known, this sputtering method irradiates a charged particle toward a target, strikes out the particle from the target by the particle impact force, and faces the target, for example, a substrate such as a wafer is composed of a target material. This is a film forming method for forming a thin film having a substance to be formed as a central component.
The target used in this sputtering film-forming method usually has a flat plate shape or a disk-like plate shape, and generally, this target is bonded to a backing plate.
[0003]
Since the target receives a large amount of impact of charged particles during sputtering, the temperature of the target gradually increases. For this reason, it is necessary to cool the target, and in many cases, a material with good thermal conductivity (backing plate) such as aluminum, copper, or an alloy thereof is used on the back surface of the target by using soldering, diffusion bonding, crimping, and the anchor effect. The target-backing plate assembly is formed by bonding such as bonding.
In order to cool the backing plate through an external cooling means, a cooling plate (cooling plate) having good thermal conductivity is further coupled to absorb the heat of the target.
[0004]
Generally, the target-backing plate assembly is joined using a Sn-Ag-based brazing material for joining the cooling plate. On the other hand, the bonding between the Ti target and the Al backing plate is firmly performed by, for example, a diffusion bonding method.
When the thus-joined target-backing plate assembly and cooling plate are joined, they are heated for brazing as described above, but the target-backing plate assembly has a difference in thermal expansion of the material. Therefore, there is a big problem that warpage occurs.
[0005]
[Problems to be solved by the invention]
The present inventors have found that even in the brazing temperature region, the warpage generated in the target-backing plate assembly is effectively suppressed, and while the generated warpage is corrected, the joining of the target-backing plate assembly and the cooling plate is performed. It is an object of the present invention to provide a bonding method and an apparatus therefor that can improve the production yield and the production efficiency.
[0006]
[Means for Solving the Problems]
The present invention uses a vacuum chuck to prevent or correct warpage generated in a target-backing plate assembly,
1. When joining the target-backing plate assembly and the cooling plate, the target-backing plate assembly is heated and evacuated, and joined to the cooling plate while suppressing warpage. 1. How to join the cooling plate with the cooling plate 2. The joining method according to the above 1, wherein a brazing material is inserted into the joining surface and the joining is performed by heating. 3. The joining method according to the above 1 or 2, wherein the cooling plate is made of copper, aluminum or an alloy thereof. 4. The bonding method according to any one of the above items 1 to 3, wherein the target-backing plate assembly is diffusion bonded. The bonding method according to any one of the above items 1 to 4, wherein a cooling groove is provided on a bonding surface of the cooling plate.
[0007]
Also, the present invention
6. Providing a heater for joining and a vacuum chuck coupled to the heater, installing a target-backing plate assembly on the vacuum chuck, and heating and joining the cooling plate while suppressing warpage of the target-backing plate assembly. 6. A device for joining a target-backing plate assembly and a cooling plate, 7. The joining apparatus according to the above item 6, wherein the brazing material is inserted into the joining surface and the joining is performed by heating. 8. The joining device according to the above item 6 or 7, wherein the cooling plate is made of copper, aluminum or an alloy thereof. 9. The bonding apparatus according to any one of the above items 6 to 8, wherein the bonding apparatus is a target-backing plate assembly that is diffusion bonded. 10. The joining device according to any one of the above items 6 to 9, wherein a cooling groove is provided on a joining surface of the cooling plate. The bonding apparatus according to any one of the above items 6 to 10, wherein the vacuum chuck is provided with a groove for vacuum suction.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
An example of a method and an apparatus for joining a target-backing plate assembly and a cooling plate according to the present invention will be described with reference to the drawings.
1 is a cross-sectional view showing the appearance of a method and apparatus for joining a target-backing plate assembly and a cooling plate, FIG. 2 is a plan view of a vacuum chuck, and FIG. 3 is a cross-sectional view of a vacuum suction unit of the vacuum chuck. It is.
As shown in FIG. 1, the apparatus of the present invention includes a heater 1, such as a hot plate, for heating and joining a target-backing plate assembly and a cooling plate. A vacuum chuck 2 is arranged so as to be connected to the heater 1.
The target-backing plate assembly 3 is placed on the vacuum chuck 2. In FIG. 1, as an example of the target-backing plate assembly 3, an assembly including a disk-shaped diffusion-bonded (DB) aluminum (Al) backing plate 4 and a target 5 is shown.
[0009]
As shown in FIG. 1, the target 5 is located on the vacuum chuck 2 side. The vacuum chuck 2 is sucked by a vacuum pump 6 in order to prevent deformation (warpage) of the target-backing plate assembly 3 due to heating during bonding, but the vacuum chuck 2 covers the entire surface of the target 5. It is preferable that the diameter of the target 5 be larger than that of the target 5.
The target 5 is held by suction on the vacuum chuck 2 and heated by a heater such as a hot plate, and then the cooling plate 7 is placed thereon and bonded via a brazing material or the like.
[0010]
Although a Sn-Ag brazing material is used as the brazing material, another brazing material may be used for bonding. There is no particular limitation on the material such as brazing material used in this way. Either brazing material or joining method can be used when the target-backing plate assembly 3 is deformed or warped under the influence of heat during joining.
As a material of the cooling plate 7, copper, aluminum, or an alloy thereof having good thermal conductivity is usually used. Although not shown, a plurality of grooves serving as cooling water passages are usually formed on the surface of the cooling plate on the backing plate side.
The aluminum (Al) backing plate 4 subjected to the diffusion bonding (DB) generates a warping force at the temperature of brazing due to the difference in thermal expansion. Warpage can be effectively suppressed.
[0011]
The surface of the vacuum chuck 2 in contact with the target 5 side has a number of concentric grooves 8 as shown in FIG. The groove 8 does not necessarily have to be concentric. For example, a spiral or rectangular groove may be used. There is no particular limitation on the shape of these grooves as long as they can be effectively vacuum-suctioned.
In the case of the concentric grooves 8, the suction portion of the vacuum chuck 2 may form the lateral grooves 9 communicating with the concentric grooves 8 as shown in FIG. 3.
[0012]
As described above, even in a heating region such as brazing of the target-backing plate assembly and the cooling plate, the warping generated in the target-backing plate assembly is effectively suppressed, and while the generated warpage is corrected, the target-backing is performed. A plate assembly and a cooling plate can be joined, a joining method and an apparatus can be provided that can improve the production yield and production efficiency, and furthermore, there is an excellent effect that defects and troubles in the sputtering process can be reduced. .
[0013]
[Examples and Comparative Examples]
Hereinafter, description will be made based on examples and comparative examples. This embodiment is merely an example, and the present invention is not limited to this example. That is, the present invention includes other aspects or modifications included in the technical concept of the present invention.
[0014]
(Example 1)
An Al vacuum chuck having a diameter of 670φ and a thickness of 50 mm was used. A plurality of concentric circular grooves as shown in FIG. 2 were formed on the suction side of the vacuum chuck. At the time of suction of the target-backing plate assembly, vacuum suction was performed at 6.7 × 10 ⁻² Pa.
Four targets-backing plate assemblies obtained by using a 600-φ diameter Ti plate as a target and a 640-φ Al plate as a backing plate and diffusion-bonding them were used. For bonding, a Sn-Ag brazing material (melting point: 190 ° C.) was used.
At the time of bonding, the heater was heated to 200 ° C. to perform bonding. As a result, the warpage of the four target-backing plate assemblies was 0.51 mm, 0.49 mm, 0.44 mm, and 0.56 mm at the maximum warpage, respectively, and the average warpage was 0.5 mm. .
In contrast, when bonding was performed without using the vacuum chuck, the warpage reached 1.5 mm. From the above, it was found that the effect of suppressing the warpage by vacuum suction of the target-backing plate assembly was extremely high.
[0015]
【The invention's effect】
According to the present invention, when the target-backing plate assembly is joined to the cooling plate, the target-backing plate assembly is heated and evacuated to be joined to the cooling plate. -The target-backing plate assembly and the cooling plate can be joined while effectively suppressing the warpage generated in the backing plate assembly and correcting the generated warpage, thereby improving the production yield and production efficiency. Has an effect. This has an excellent effect that defects and troubles in the sputtering process can be reduced.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing the appearance of a method and apparatus for joining a target-backing plate assembly and a cooling plate.
FIG. 2 is a plan view of a vacuum chuck.
FIG. 3 is a sectional view of a vacuum suction unit of the vacuum chuck.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Heater 2 Vacuum chuck 3 Target-backing plate assembly 4 Backing plate 5 Target 6 Vacuum pump 6
7 Cooling plate 8 Concentric groove 9 Transverse groove communicating with concentric groove 8

Claims (11)

When joining the target-backing plate assembly and the cooling plate, the target-backing plate assembly is heated and evacuated, and joined to the cooling plate while suppressing warpage. And the cooling plate. The joining method according to claim 1, wherein a brazing material is inserted into the joining surface and the joining is performed by heating. 3. The joining method according to claim 1, wherein the cooling plate is made of copper, aluminum, or an alloy thereof. The bonding method according to any one of claims 1 to 3, wherein the bonding method is a diffusion-bonded target-backing plate assembly. 5. The joining method according to claim 1, wherein a cooling groove is provided on a joining surface of the cooling plate. Providing a heater for joining and a vacuum chuck coupled to the heater, installing a target-backing plate assembly on the vacuum chuck, and heating and joining the cooling plate while suppressing warpage of the target-backing plate assembly. An apparatus for joining a target-backing plate assembly and a cooling plate. 7. The joining apparatus according to claim 6, wherein a brazing material is inserted into the joining surface and the joining is performed by heating. The joining device according to claim 6, wherein the cooling plate is made of copper, aluminum, or an alloy thereof. The bonding apparatus according to any one of claims 6 to 8, wherein the bonding apparatus is a diffusion-bonded target-backing plate assembly. The joining device according to any one of claims 6 to 9, wherein a cooling groove is provided on a joining surface of the cooling plate. The bonding apparatus according to claim 6, wherein the vacuum chuck includes a groove for vacuum suction.

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