JP4419040B2 - Backing plate - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a backing plate capable of easily brazing a target, particularly a target having low toughness, to a backing plate through a soft brazing material layer having a thickness of 0.1 to 1.0 mm.
[0002]
[Prior art]
In general, a Si thin film formed when fabricating a semiconductor device is obtained by sputtering using a Si target, and a DRAM storage capacitor thin film is composed of a composite oxide of Ba and Ti, and a composite oxide of Sr and Ti. Or a target made of a high dielectric composite oxide such as a composite oxide of Ba, Sr and Ti (hereinafter, these high dielectric composite oxides are collectively referred to as BaSrTi composite oxide). Furthermore, it is known that the optical recording protective film of the phase change optical disk can be obtained by sputtering using a ZnS—SiO ₂ target.
[0003]
All of these targets are obtained by applying a molten soft brazing material (for example, a molten In brazing material or an In-Sn brazing material) onto a normal backing plate, and then applying the target from above the backing plate coated with the molten soft brazing material. The target and backing plate are brazed by pressing. As shown in the cross-sectional view of FIG. 6, the target with the backing plate brazed via the soft brazing material layer 2 ′ formed in this way is used to fix the end of the backing plate 1 to the fixture of the sputtering apparatus 5. 6, the backing plate 1 is cooled by the water-cooled copper plate 7 that is cooled by supplying the cooling water to the cavity 8, and the target 3 is cooled. Various nonmetal or ceramic films are formed by sputtering in a vacuum atmosphere.
[0004]
In recent years, for mass production of electronic parts, recording medium parts, etc. and cost reduction, various films are formed by using high-speed sputtering in a high vacuum atmosphere using a large-sized target. Thus, various films are formed in a short time. Therefore, the water pressure of the cooling water supplied to the cavity of the water-cooled copper plate is further increased in order to increase the cooling efficiency of the target for high-speed film formation by high-power sputtering. When the water pressure of the cooling water is increased, the cooling efficiency is improved, but the center of the water-cooled copper plate 7 swells and pushes up the backing plate 1, and the backing plate 1 is deformed upward as shown by a one-dot chain line in FIG. The target 3 brazed to the plate 1 is also pushed up and bent upward as indicated by the dotted line in FIG. 6, and tensile residual stress in the A direction is generated on the target 3. When high-power sputtering in a high vacuum atmosphere is performed in a state in which tensile residual stress in the A direction is generated on the target 3, cracks are generated during sputtering when the target is a low-toughness target made of nonmetal or ceramics. In some cases, when the target is cracked, particles are generated in the obtained thin film, which may seriously affect the yield.
Further, the upward bending deformation of the target 3 keeps the inside of the sputtering apparatus in a high vacuum atmosphere, while the water-cooled copper plate side is in an air atmosphere, so that the backing plate 1 of FIG. It is also generated by being pushed upward, and the bending deformation of the target 3 becomes more conspicuous as the inside of the sputtering apparatus is put into a high vacuum atmosphere, which causes cracking of the target 3 during sputtering.
[0005]
In order to solve such a problem, the target is brazed to the backing plate through a soft brazing material layer in the range of 0.1 to 1.0 mm thicker than usual, and the bending deformation of the backing plate is increased. Absorption is performed with a thick soft brazing material layer.
In order to braze the target to the backing plate via a soft brazing material layer having a thickness in the range of 0.1 to 1.0 mm, as shown in the cross-sectional view of FIG. The melt soft soldering material 2 is thickly applied onto the thick solder soft soldering material 2 and the thick solder within the range of 0.1 to 1.0 mm as shown in the sectional view of FIG. A wire 10 having a thickness is placed as a spacer, and the target 3 is pressed and brazed, so that the thickness between the target 3 and the backing plate 1 is 0.1 as shown in the sectional view of FIG. It is manufactured by forming a soft brazing filler metal layer 2 'within a range of -1.0 mm.
[0006]
[Problems to be solved by the invention]
However, when a pure copper wire is placed as a spacer on the molten soft solder material thickly applied to the backing plate 1, the pure copper wire 10 has a specific gravity smaller than that of the molten soft solder material. As shown in the sectional view of (b), the target 3 having a large plane area is pressed from above the molten soft brazing material 2 in a state where it is floated on the molten soft brazing material. When the wire 10 moves along the plane of the backing plate 1 and the wire is displaced from a predetermined position, the wire may protrude from the soft brazing material in the worst case. This is because it is difficult to press a target with a large flat area while keeping it completely horizontal, and it is considered that the target is pressed slightly incline, and considerable skill is required to press the target horizontally. It was done.
[0007]
[Means for Solving the Problems]
Therefore, as a result of ingenuity in order to solve such problems, the present inventors integrated a protrusion within a range of height: 0.1 to 1.0 mm on the surface of the backing plate where the target is brazed. If a flat surface of the target is brazed by applying molten soft solder to the surface on which the protrusions of the backing plate are integrally formed and then brazing the flat surface of the target, the protrusions are fixed and integrated with the backing plate. Therefore, even if you are not an expert, you can easily and accurately thicken the flat surface of the target on the backing plate. Satisfaction: It was found that it can be attached via a brazing layer in the range of 0.1 to 1.0 mm.
[0008]
This invention has been made based on such knowledge,
The backing plate is characterized in that a protrusion is integrally formed on the target brazing surface of the backing plate.
This protrusion may be integrally attached to the target brazing surface of a normal disk-shaped backing plate by welding, may be integrally formed at the time of casting, or may be cut, and any attachment method may be used. good.
[0009]
The backing plate of the present invention will be specifically described with reference to FIGS.
FIG. 1 is a perspective view of a backing plate according to the present invention in which parallel line-shaped protrusions 11 are integrally provided on a surface of a backing plate to which a target is brazed. A protrusion 11 having a height of 0.1 to 1 mm is formed by welding to a copper backing plate 1.
FIG. 2 is a perspective view of a backing plate of the present invention in which a grid-like projection 12 is integrally provided on the surface of the backing plate to which the target is brazed, and this projection is made of pure copper wire shaped like a grid. A projection 12 having a height of 0.1 to 1 mm is formed by welding to a pure copper backing plate.
FIG. 3 is a perspective view of the backing plate of the present invention in which concentric protrusions 13 are integrally provided on the surface of the backing plate where the target is to be brazed. The protrusions are concentric rings made of ring-shaped pure copper wires having different diameters. The protrusion 13 having a height of 0.1 to 1 mm is formed by welding to a normal pure copper backing plate in a shape.
FIG. 4 is a perspective view of the backing plate of the present invention in which a spiral projection 14 is integrally provided on the surface of the backing plate to which the target is brazed, and a pure copper wire formed in a spiral shape is replaced with an ordinary pure copper backing plate. To form a protrusion 14 having a height of 0.1 to 1 mm.
FIG. 5 is a perspective view of the backing plate of the present invention in which at least three massive projections 15 are integrally provided on the surface of the backing plate to which the target is to be brazed, and FIG. 5 shows a pure copper hemisphere as a pure copper backing. A protrusion 15 having a height of 0.1 to 1 mm is formed by welding to a plate.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Example 1
A hot-press sintered body having a diameter of 305 mm and a thickness of 6 mm is produced by hot pressing (Ba _0.5 , Sr _0.5 ) TiO ₃ composite oxide powder, and the diameter is obtained by grinding the hot-press sintered body. A target having a size of 300 mm and a thickness of 5 mm was produced.
[0011]
On the other hand, a pure copper backing plate having a diameter of 300 mm and a thickness of 5 mm is prepared, and two linear pure copper wires having a thickness of 1 mm are prepared as spacers. A backing plate of the present invention as shown in FIG. 1 was produced by welding a wire to the backing plate.
[0012]
After applying the molten In brazing material on the backing plate of the present invention, the covering plate is immediately covered with the prepared target and solidified without paying special attention, and then the backing plate having a 1 mm thick In brazing material layer. An attached sputtering target could be produced.
[0013]
Conventional Example 1
After applying a molten In brazing material on a backing plate having a diameter of 300 mm and a thickness: 5 mm made of pure copper prepared in Example 1, a thickness of 1 mm is applied on the molten In brazing material. Two pieces of pure copper wire having a thickness of 1 are placed in parallel, and immediately after that, the target prepared in Example 1 is covered with no special attention and solidified, and then the backing is provided with an In brazing material layer having a thickness of 1 mm. A sputtering target with a plate was produced. When the obtained sputtering target with a backing plate was inspected, a part of the pure copper wire inserted as a spacer from the In brazing material layer between the backing plate and the target was exposed.
[0014]
【The invention's effect】
As described above, when the backing plate of the present invention is used, a sputtering target with a backing plate having a soft brazing material layer having a thickness of 0.1 to 1 mm can be produced without paying special attention. It can be easily produced by anyone without the need for it, and can greatly contribute to cost reduction.
[Brief description of the drawings]
FIG. 1 is a perspective view of a backing plate of the present invention.
FIG. 2 is a perspective view of a backing plate according to the present invention.
FIG. 3 is a perspective view of a backing plate according to the present invention.
FIG. 4 is a perspective view of a backing plate according to the present invention.
FIG. 5 is a perspective view of a backing plate according to the present invention.
FIG. 6 is a cross-sectional explanatory diagram for explaining a problem of a conventional sputtering target.
FIG. 7 is a cross-sectional explanatory diagram for manufacturing a conventional sputtering target with a backing plate.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Backing plate 2 Melting soft soldering material 2 'Soft soldering material layer 3 Target 4 Sputtering target 5 with backing plate 5 Sputtering device 6 Fixing tool 7 Cooling copper plate 8 Cavity 9 Container 10 Wire 11 Protrusion part 12 Protrusion part 13 Protrusion part 14 Protrusion part 15 protrusion

Claims (2)

In a backing plate for brazing a flat surface of a target through a soft brazing material layer, a protrusion as a spacer within a range of height: 0.1 to 1.0 mm is integrally formed on the target brazing surface of the backing plate. A backing plate characterized by being formed. The protrusion is formed by integrally forming at least two pure copper wires in a parallel line shape on the target brazing surface of the backing plate, and at least one pure copper wire formed in a ring shape is concentric with the backing plate. A single piece of pure copper wire formed in a square shape, a single piece of pure copper wire formed in a spiral shape, or at least three of the same 2. The backing plate according to claim 1, wherein the protrusions having a height are integrally formed.

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