JPH0681143A - Sputtering target and its production - Google Patents

Abstract

PURPOSE:To prevent the peeling on the joined faces of a sputtering target member and its supporting member even in the case of large power sputtering, at the time of joining both members, by arranging an intermediate member by a specified metal between both members and executing explosive welding. CONSTITUTION:At the time of joining a target member 1 constituted of a metal such as A1, Al allay, Cu and Ti with a backing plate 2 as a supporting member made of a metal such as Al, Cu and stainless steel, an intermediate member 3 constituted of a thin sheet of Ti, Ni, Cu or the like is interposed between the target member 1 and the backing plate 2, the backing plate 2 and the intermediate member 3 are subjected to explosive welding, and in succession, the intermediate member 3 and the target 1 are subjected to explosive welding. Even if the temp. of the joined parts of the target 1 and the backing plate 2 is raised by large power sputtering treatment, no peeling of the target member 1 from the backing plate 2 occurs.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sputtering target and a method for manufacturing the same, and more particularly to a sputtering target including a target member made of a metal or an alloy, and a backing plate made of a metal or an alloy for supporting the target member. And a manufacturing method thereof.

[0002]

2. Description of the Related Art In an electronic device such as an LSI or a magnetic head, a wiring containing aluminum as a main component is formed as a thin film of, for example, about 1 μm on an insulating layer and then formed into a predetermined wiring pattern by lithography. . A sputtering method is often used for forming a thin film, and a sputtering target for this purpose is formed by joining a target member having a sputtering surface irradiated with accelerated ions and a backing plate forming a supporting member of the target member. There is a format.

Generally, the target member and the backing plate each have a circular or rectangular flat plate shape. The target member is appropriately selected according to the intended wiring composition, for example, aluminum, aluminum alloy,
Alternatively, the backing plate is made of a metal or alloy such as titanium, and the backing plate is also made of a metal or alloy such as aluminum, copper or stainless steel.

In the conventional sputtering target, the target member and the backing plate are joined by soldering, and the back surface of the target member opposite to the sputter surface is joined to one surface of the backing plate by soldering. As the material of the solder, for example, Sn-
Pb-based, Pb-Ag-based, or In-based solder is used, and the melting point of these solders is, for example, 150 to 2
It is about 30 ° C.

[0005]

In the sputtering method, in recent years, a high sputtering electric power tends to be adopted at the time of accelerating ions for the purpose of increasing the thin film forming rate. Therefore, the temperature of the sputter surface tends to rise, and the temperature of the joint between the target member and the backing plate tends to rise. When the temperature of the joint portion rises to, for example, the melting point of the solder or higher, the melting of the solder may cause the target to peel off from the backing plate and the sputtering may stop.

In view of the above, the present invention improves the joint between the target member generally made of metal or alloy and the backing plate forming the target supporting member, and employs a high sputtering power during sputtering. An object of the present invention is to provide a sputtering target having a structure that does not easily peel and a method for manufacturing the same.

Another object of the present invention is to solve the above problems and to provide a sputtering target having a special function.

[0008]

In order to achieve the above object, the method for producing a sputtering target of the present invention comprises:
The target member and a backing plate for supporting the target member are joined by explosion welding.

Further, the sputtering target of the present invention is a sputtering target including a target member (having a sputtering surface) and a target supporting member for supporting the target member, wherein the target member and the target supporting member are provided between the target member and the target supporting member. An intermediate member is provided, and the intermediate member and the target member and the target support member are joined by explosion welding.

Here, the sputtering target of the present invention and the target member of the sputtering target manufactured by the method of the present invention may be any metal or alloy capable of explosive welding. For example,
Aluminum, aluminum alloy, copper, titanium and the like are used for wiring of LSI and the like. The backing plate may be made of any metal or alloy. For example, when the target member is aluminum or aluminum alloy, stainless steel, aluminum, copper or the like is used.

In the present invention, the backing plate is not particularly limited to a plate-like shape, and various shapes may be adopted if explosive welding is possible. For example,
As the backing plate, it is also possible to adopt an annular shape having a circular or square outer periphery and an opening at the center.

In the sputtering target of the present invention, a thin plate of Ti, for example, is adopted as the intermediate member inserted between the target member and the backing plate. The material of the intermediate member may be different from that of the target member and the backing plate. The intermediate member and the backing plate, and the intermediate member and the target member are joined together by explosion welding.

The explosive welding employed in the present invention is also called, for example, explosive welding, and is a technique for joining materials such as metals or alloys by pressure welding with the impact generated by the explosion of explosives.

[0014]

In the sputtering target and the method for manufacturing the same of the present invention, since the target member and the backing plate are joined by explosion welding, the target member and the backing plate are joined by pressure welding. The temperature resistance of the joint is high, and even if the temperature of the joint rises significantly due to high sputtering power,
There is little risk of peeling at the joint.

Further, in the sputtering of the present invention, since the intermediate member inserted between the target member and the backing plate is adopted, this intermediate member can be used for various purposes. This intermediate member can be used for various purposes such as facilitating explosive welding, relaxing the difference in the coefficient of thermal expansion between the target member and the backing plate, and detecting the end of sputtering.

In the case of a sputtering target for forming a wiring film of LSI or the like, when aluminum or aluminum alloy is used for the target member and stainless steel or the like is used for the target support member, titanium and nickel are placed between them. Alternatively, it is preferable to insert a thin plate made of copper or the like. In this case, for example, the target supporting member and the thin plate are first joined by explosive bonding, and the target member is further joined by explosive bonding on the thin plate, whereby the joining is easily performed.

[0017]

The present invention will be described in more detail with reference to the drawings. FIG. 1 is a sectional view of a sputtering target according to an embodiment of the present invention. In the figure, the target member 1
Is made of, for example, an aluminum alloy, and has, for example, a circular sputter surface 11 on its upper surface. The lower surface of the target member 1 is joined to the upper surface of the backing plate 2 by explosive bonding via a thin disk 3 made of, for example, titanium. The backing plate 2 is made of, for example, stainless steel or copper, and has a disc shape that is considerably thicker than the target member 1 and the thin plate 3.

FIG. 3 is a cross-sectional view showing how the sputtering target of the above embodiment is manufactured. In the figure, the backing plate 2 and the thin plate 3 have already been joined by explosive welding by a method similar to the method described below. The target member 1 is supported above the thin plate 3 with a slight gap and a slight inclination. A thin buffer material 4 is placed on the target member 1 to protect the surface of the target member 1, and an explosive 5 is placed on the entire upper surface of the buffer material 4. At one place on the periphery of the explosive 5, there is a detonator 6 above it,
The detonator 6 is wired via a conductor 7 so as to be ignited by a switch (not shown).

When the detonator 6 ignites the explosive 5 in this state, the explosive 5 is sequentially ignited and explodes. Due to the impact of this explosion, the target member 1 is sequentially thinned from the detonator 6 side.
It drops up and is pressed against the thin plate 3. When the explosion welding is completed in this way, the buffer material 4 is peeled from the target member 1, the target member 1, the backing plate 2 and the thin plate 3 are integrally machined, and the whole is ground to a predetermined size. .

Thus, by interposing the thin plate 3 between the target member 1 and the backing plate 2,
In this case, even in the case of both members 1 and 2 whose hardnesses are greatly different due to the difference in their materials, it is possible to facilitate explosion welding by interposing a thin plate 3 of a material having an intermediate hardness between these members. . Further, as the thin plate 3, a material different in color, reflectance, conductivity or composition from the target member is used, and during sputtering, the color, reflectance, electrical conductivity, composition, etc. of the thin film on the wafer are A configuration for measuring a physical quantity can be adopted. by this,
During the sputtering process, it is possible to detect whether or not the sputtering for the thickness of the target member 1 has already been completed.

Further, by the thin plate 3 interposed in the middle,
It is also possible to reduce the difference in the coefficient of thermal expansion between the target member 1 and the backing plate 2. In this case, the stress generated at the boundary surface of the sputtering target is reduced due to the difference in thermal expansion coefficient between the target member 1 and the backing plate 2. For this purpose, the coefficient of thermal expansion of the thin plate 3 is
A material having a coefficient of thermal expansion intermediate between both members 1 and 2 is selected.

FIG. 2 is a sectional view of the sputtering target of the second embodiment of the present invention. In the figure, the backing plate 20 includes a flange portion 21 for supporting the sputtering target in the vacuum chamber, a top plate 22 for mounting the target member 1, and between the flange portion 21 and the top plate 22. It is composed of a tapered cylindrical side plate 23. A thin plate 3 forming an intermediate member is joined to the upper surface of the top plate 22 by explosion welding.
Further, a disk-shaped target member 1 is similarly joined to the upper surface of the thin plate 3 by explosion welding.

Cylindrical side plate 2 of backing plate 20
The inside 24 surrounded by 3 and the top plate 22 is a portion into which cooling water is introduced at the time of sputtering, and the target member 1 is cooled by the cooling water introduced into the backing plate 20. For this purpose, the backing plate 20 is manufactured as thin as possible as a whole, for example, a plate material having a thickness of about 6 mm. The target member 1 has a thickness of about 10 mm, and the thin plate has a thickness of about 1 mm.

Conventionally, the target member and the backing plate are joined by a solder material, and the melting point of the solder material is about 200.degree. Therefore, in order to increase the thin film formation rate, when a high sputtering power is adopted during ion acceleration, there is a risk of peeling at the joint due to melting of the solder, the sputtering target of the present invention, the explosion By adopting welding, the peeling temperature is, for example, about 300 ° C. or higher, so that the possibility of peeling the target member is small even when the sputtering power is high.

In particular, for the purpose of improving the quality of the thin film formed by sputtering, only the target atoms that are ejected from the sputtering surface by the ions in the vacuum chamber and that are incident on the thin film from the direction perpendicular to the thin film are used. In the high quality thin film forming method, the number of target atoms available per unit time is small. In such a case, by increasing the sputtering power and adopting ions having a large momentum, the number of target atoms knocked out by one ion can be increased. However, in the conventional sputtering target, it is difficult to adopt such high sputtering power because the target member may be peeled off due to the low melting point of the solder. However, the structure of the present invention makes it possible to employ a high-quality thin film forming method for increasing sputtering power without fear of peeling of the target member.

In the description of the above embodiments, L
Although the sputtering target used for SI or the like has been described as an example, the sputtering target of the present invention and the sputtering target manufactured by the method of the present invention are not necessarily required to form wiring for semiconductor devices such as LSI and electronic devices. The present invention is not limited to the sputtering target used, and is widely applicable to the sputtering of metals or alloys used for various purposes and applications.

Further, in the method of manufacturing the sputtering target of the present invention, it is not always necessary to employ the intermediate member, and the target member and the backing plate can also be directly explosion-welded. Preferably, such a configuration is adopted when the physical properties of the target member and the backing plate are close to each other.

[0028]

As described above, according to the present invention, according to the sputtering target of the present invention and the sputtering target manufactured by the method of the present invention, there is no fear of separation between the target member and the backing plate, and high sputtering power is used. A thin film can be formed by sputtering, and the production efficiency of semiconductor devices and the like can be improved.

Further, in the sputtering target of the present invention, since the intermediate member can be used for various purposes, the practical value thereof is further enhanced by the function of the added intermediate member.

[Brief description of drawings]

FIG. 1 is a sectional view of a sputtering target according to an embodiment of the present invention.

FIG. 2 is a sectional view of a sputtering target according to another embodiment of the present invention.

FIG. 3 is a cross-sectional view during manufacturing of the sputtering target for explaining the method of manufacturing the sputtering target of the example of the present invention.

[Explanation of symbols]

 1: Target member 11: Sputtering surface 2, 20: Backing plate 3: Intermediate member 4: Buffer material 5: Explosive powder 6: Detonator 7: Conductor wire

Claims (2)

[Claims] 1. A method of manufacturing a sputtering target, comprising joining a target member and a backing plate for supporting the target member by explosion welding. 2. A sputtering target comprising a target member and a target supporting member for supporting the target member, comprising a target member and an intermediate member arranged between the target supporting member, and the intermediate member. A sputtering target, wherein the target member and the target support member are joined together by explosion welding.