JPH06158303A - Target for sputtering and its produciton - Google Patents

Abstract

PURPOSE:To form a high density Si-Al alloy layer capable of prolonging the service life of a target at considerably increased density with enhanced efficiency of utilization of materials. CONSTITUTION:An Si-Al alloy layer 3 is formed on the peripheral surface 2a of a columnar substrate 2 by thermally spraying a mixture of Si powder with Si-Al alloy powder consisting of 5-70wt.% Al and the balance Si to produce the objective target 1 for sputtering.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sputtering target in which a target material is bonded to an outer peripheral surface of a substrate by a thermal spraying method, and a manufacturing method thereof.

[0002]

2. Description of the Related Art Conventionally, as a sputtering target (hereinafter, simply referred to as a target), a disk-shaped or rectangular plate-shaped planar type target has been widely used. However, in the case of performing sputtering on a large area substrate such as glass or a mirror, the planar type target has a very low material usage efficiency of about 30 to 40%, and it is not possible to perform continuous sputtering or sputtering of long objects. Therefore, a cylindrical target is being used recently. In particular, a silicon oxide film formed by reactive sputtering using a cylindrical target of silicon is often used as a protective film on the surface of a substrate.

This silicon cylindrical target is obtained by mixing pure silicon powder or p-type silicon powder added with a slight amount of boron as an impurity with aluminum powder having a small specific resistance to several percent by weight in order to enable direct current sputtering. As a mixture, this mixture is melted by using plasma generated in an inert gas atmosphere or in the atmosphere, and sprayed on the outer peripheral surface of a stainless backing tube (base),
A cylindrical target having a silicon-aluminum alloy layer. Here, the aluminum powder not only lowers the specific resistance of the silicon-aluminum alloy but also functions as a binder for joining the silicon powders.

[0004]

By the way, in the above-mentioned target, since an aluminum oxide film is usually formed on the surface of the aluminum powder, even if the aluminum powder is melted during thermal spraying, the aluminum oxide film is not formed. There is a drawback in that it is not melted and remains as it is as a passivation film, and the adhesion between the aluminum powder and the silicon powder is reduced by this passivation film. Due to this defect, the density of the silicon-aluminum alloy layer sprayed on the outer peripheral surface of the backing tube is as low as about 50 to 60%, so that there is a drawback that the use efficiency of the material and the life of the target are reduced. .

The present invention has been made in view of the above circumstances, and aluminum oxide serving as a passivation film does not exist in the silicon-aluminum alloy layer, and the density of the alloy layer is improved, and therefore, It is an object of the present invention to provide a sputtering target and a method for manufacturing the same, which can improve the use efficiency of materials and the life of the target.

[0006]

In order to solve the above problems, the present invention employs the following sputtering target and its manufacturing method. That is, in the sputtering target according to claim 1, the outer peripheral surface of the columnar substrate is
It is characterized in that a silicon-aluminum alloy layer formed by spraying a mixture of silicon powder and silicon-aluminum alloy powder is provided.

According to a second aspect of the present invention, there is provided a sputtering target according to the first aspect, wherein the silicon-aluminum alloy powder contains aluminum in an amount of 5 to 70% by weight with the balance being silicon. It has a feature.

The method for manufacturing a sputtering target according to a third aspect is characterized in that a mixture of silicon powder and silicon-aluminum alloy powder is sprayed on the outer peripheral surface of a columnar substrate.

Here, the reason for using the mixture of silicon powder and silicon-aluminum alloy powder is that when chemically active aluminum is made into a chemically stable silicon-aluminum alloy, the aluminum is oxidized. This is because it becomes difficult to generate aluminum oxide which is a passivation film. The silicon / aluminum alloy powder is preferably a silicon / aluminum alloy containing aluminum in an amount of 5 to 70% by weight. This is because if the content of aluminum is less than 5% by weight, it becomes difficult to dissolve and a uniform alloy phase cannot be obtained, and if the content of aluminum exceeds 70% by weight, the aluminum oxide on the surface of the silicon-aluminum alloy powder is aluminum oxide. This is because a passivation film containing as a main component is generated, the adhesion between the silicon powder and the silicon / aluminum alloy powder is reduced, and the density of the sprayed silicon / aluminum alloy is reduced.

The reason why the thermal spraying method is used is that the silicon powder and the silicon-aluminum alloy powder can be melted in a very short time to form a uniform silicon-aluminum alloy and be attached to the outer peripheral surface of the substrate. is there.

[0011]

In the sputtering target according to the first aspect of the present invention, since the aluminum oxide as a passivation film does not remain in the silicon-aluminum alloy layer sprayed on the outer peripheral surface of the substrate, the density of the alloy layer is improved. Therefore, the use efficiency of the material and the life of the target are improved.

Further, in the sputtering target according to the second aspect, a uniform alloy phase is obtained by using the silicon-aluminum alloy powder as an alloy containing 5 to 70% by weight of aluminum and the balance being silicon. The passivation film containing aluminum oxide as a main component does not occur on the surface of this alloy powder.

In the method of manufacturing a sputtering target according to the third aspect of the present invention, the mixture of silicon powder and silicon-aluminum alloy powder is sprayed onto the outer peripheral surface of the columnar substrate, so that the surface of the powder is sprayed from aluminum oxide during spraying. The high-density silicon-aluminum alloy layer is formed on the outer peripheral surface of the substrate in a very short time without the possibility of the formation of a passive film.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a cylindrical target. In this target 1, a silicon-aluminum alloy layer 3 formed by spraying a mixture of silicon powder and a silicon-aluminum alloy powder is concentrically formed on an outer peripheral surface 2a of a cylindrical stainless backing tube (base) 2. It is the configured configuration.

Next, a method of manufacturing the target 1 will be described. First, a mixture of silicon powder and silicon-aluminum alloy powder is prepared. Here, as the silicon powder, pure silicon powder which is an intrinsic semiconductor, p-type silicon powder to which a trace amount of boron or the like is added as an impurity, n-type silicon powder to which a trace amount of phosphorus or the like is added as an impurity are preferably used. Further, the silicon-aluminum alloy powder has a composition containing aluminum in an amount of 5 to 70% by weight with the balance being silicon, and the silicon powder and the aluminum powder are mixed at a predetermined ratio, heated and melted, and then pulverized to obtain a fine powder. It is a powdery alloy powder.

Next, this mixture is melted by using plasma generated in an inert gas atmosphere or in the air, and the outer peripheral surface 2a of the backing tube 2 made of stainless steel is melted.
Then, the silicon-aluminum alloy layer 3 having a concentric circle shape is formed on the outer peripheral surface 2a. In this way, the cylindrical target 1 having the high-density silicon-aluminum alloy layer 3 can be manufactured.

Table 1 shows the respective compositions of the targets of the above-mentioned examples, targets (comparative examples) and conventional targets (conventional examples) in which the composition of the silicon-aluminum alloy powder deviates from the above-mentioned examples, and the ratio of these targets. The density (percentage of the actual density with respect to the theoretical density) is shown. Here, the silicon powder is two kinds, that is, pure silicon powder and p-type silicon powder added with a slight amount of boron as an impurity.

[0018]

[Table 1]

From Table 1, it can be seen that the specific densities of the targets of the examples exceed 80%, which is a great improvement over the comparative examples and the conventional examples. Further, it can be seen that the target of the comparative example also has an improved specific density as compared with the conventional example. Furthermore, when sputtering was performed using the target of the above example, it was confirmed that both the material usage efficiency and the target life were improved.

As described above, according to the target 1 of this embodiment, the outer surface 2a of the cylindrical backing tube 2 is formed by spraying a mixture of silicon powder and silicon-aluminum alloy powder on silicon-aluminum. Since the alloy layer 3 is formed concentrically, the silicon-aluminum alloy layer 3
The density of the material itself can be significantly improved, and therefore, the use efficiency of the material can be improved and the life of the target can be improved. Further, since the cylindrical backing tube 2 is used, it is possible to effectively supply cooling water, arrange magnets, etc., and it is possible to omit the step of processing the base body into a cylindrical shape, thereby achieving cost reduction. You can

Further, according to the target manufacturing method of this embodiment, the outer peripheral surface 2a of the cylindrical backing tube 2 is formed.
Since a mixture of silicon powder and silicon-aluminum alloy powder is sprayed onto the surface of the silicon-aluminum alloy powder, there is no risk of a passivation film being formed on the surface of the silicon-aluminum alloy powder during spraying, and a high density is achieved on the outer peripheral surface 2a of the backing tube 2. The silicon-aluminum alloy layer 3 can be formed.

[0022]

As described above, according to the first aspect of the present invention.
According to the sputtering target described, since the silicon-aluminum alloy layer formed by spraying the mixture of silicon powder and silicon-aluminum alloy powder is provided on the outer peripheral surface of the columnar substrate, the silicon-aluminum alloy layer itself The density can be significantly improved, and thus, the use efficiency of the material can be improved and the life of the target can be improved.

According to the sputtering target of the second aspect, the silicon-aluminum alloy powder contains aluminum in an amount of 5 to 70% by weight and the balance is silicon, so that a uniform alloy phase is obtained. It is possible to prevent the formation of a passivation film containing aluminum oxide as a main component on the surface of the alloy powder.

According to the method of manufacturing a sputtering target according to claim 3, the outer peripheral surface of the columnar substrate is
Since a mixture of silicon powder and silicon / aluminum alloy powder is sprayed, there is no risk of a passivation film being formed on the surface of the silicon / aluminum alloy powder during spraying, and high density is achieved on the outer peripheral surface of the substrate in an extremely short time. The silicon-aluminum alloy layer can be formed.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a sputtering target of the present invention.

[Explanation of symbols]

 1 target for sputtering 2 backing tube 2a outer peripheral surface 3 silicon-aluminum alloy layer

Claims (3)

[Claims] 1. A sputtering target, characterized in that a silicon / aluminum alloy layer formed by spraying a mixture of silicon powder and a silicon / aluminum alloy powder is provided on the outer peripheral surface of a columnar substrate. 2. The sputtering target according to claim 1, wherein the silicon-aluminum alloy powder is aluminum.
A target for sputtering, characterized in that the target is contained in an amount of up to 70% by weight, and the balance is made of silicon. 3. A method for producing a sputtering target, which comprises spraying a mixture of silicon powder and silicon-aluminum alloy powder onto the outer peripheral surface of a columnar substrate.