JP3081602B2 - Sputtering target material and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of a sputtering target material and a method for manufacturing the same, and more specifically, a sputtering target material made of aluminum or an aluminum alloy (hereinafter referred to as Al or Al alloy sputtering target material) and It belongs to the technical field related to its manufacturing method, and particularly relates to an Al or Al alloy sputtering target material for forming an electrode film for a semiconductor and its manufacturing method, and among them, it is suitable as an electrode (a thin film wiring and an electrode itself) of a liquid crystal display. Al or Al alloy sputtering target for forming an electrode film for a semiconductor and a method for manufacturing the same.

[0002]

2. Description of the Related Art Liquid crystal display: Liquid Cristal Dis
Play (hereinafter referred to as LCD) is becoming thinner, lighter, and consumes less power than conventional cathode-ray tubes, and can provide high-resolution images. Recently, in order to further improve the image quality of such LCDs, a thin film transistor, which is a semiconductor device, is used as a switching element inside the LCD.
LCDs with a built-in ster (hereinafter referred to as TFT) have been proposed and widely used. Here, TFT is
An active element formed by connecting a semiconductor electrode made of a thin film metal to a semiconductor thin film formed on an insulating substrate such as glass. The semiconductor electrode is an electrode used as a part of the TFT, and is defined to include a thin film wiring and the electrode itself (the same applies hereinafter). Note that, in the state of the TFT, the wiring and the electrode itself are electrically connected.

There are various characteristics required for the electrodes for semiconductors used in the above-mentioned LCDs. In particular, with the recent trend toward larger and higher definition LCDs, low resistivity has been required to prevent signal delay. It is becoming the most important required characteristic.

The above-mentioned semiconductor electrodes for LCD are formed by sputtering, and a sputtering target is used for this sputtering. The sputtering target serves as a sputtering source for forming a semiconductor electrode on a substrate by sputtering, and is usually a disk-shaped or plate-shaped plate material. At the time of sputtering, when the accelerated particles collide with the surface of the sputtering target, the atoms constituting the sputtering target are released into space by the exchange of momentum and deposited on the opposing substrate.

[0005] Conventionally, as a sputtering target material for forming such an electrode for a semiconductor for LCD, Ta, M
Refractory metals such as o, Cr, Ti, W, Zr, and Nb have been used. However, with the recent increase in the degree of integration of LSIs, the wiring width of circuits has been reduced to 1 μm or less, and Ta, Mo, C
High melting point metals such as r, Ti, W, Zr, and Nb have become difficult to apply because of their large specific resistance in the form of thin films. That is, an electrode material for a semiconductor formed by using a sputtering target material made of a high melting point metal as described above has a large specific resistance value, and therefore cannot respond to the miniaturization of the wiring width. Therefore, development of a low-resistivity electrode material for semiconductors that replaces the high melting point metal is desired.

[0006] Au, Cu and Al are examples of such low specific resistance electrode materials for semiconductors. However, Au has poor etching characteristics required to form a predetermined pattern after forming a sheet-like electrode, ie, an electrode film (such as a wiring film), and is expensive, and Cu has poor adhesion and corrosion resistance of the film. There are problems, none of which are practical. On the other hand, since Al has insufficient heat resistance, there is a problem that minute irregularities called hillocks are generated on the surface in a heating step (about 250 to 400 ° C.) after forming an electrode film, which is inevitable in a TFT manufacturing process. Normally, in a TFT-LCD, since the electrode film is the lowermost layer, if such a hillock occurs, the film cannot be laminated thereon, so that there is a problem that the condition is bad.

As a measure for avoiding the problem of hillock generation in the Al electrode film, for example, an electrode film made of an Al alloy containing an alloy component as described in JP-A-7-45555,
An Al alloy sputtering target for forming such an Al alloy electrode film has been proposed.

However, when a semiconductor electrode is formed on a substrate by sputtering using the above-mentioned sputtering target material made of Al or an Al alloy, there is a problem that particles are generated and splash is generated. That is, the particles scattered from the target are clustered and adhere directly to the thin film on the substrate, or are separated from the peripheral wall or component and then separated and adhere to the thin film on the substrate (ie, so-called particles). And the droplets of the target material are scattered and adhere to the thin film on the substrate (ie, so-called splash).

The problem of the generation of particles and splash has been addressed by minimizing the amount of inclusions present in the sputtering target material. For example, Japanese Patent Application Laid-Open No. 9-25564 discloses that in order to reduce particles, it is necessary to reduce the number of inclusions in the target as much as possible, specifically, to reduce the amount of inclusions having an average diameter of 10 μm or more by 40%. Individual/
It is disclosed to be less than cm ² . However, there is a problem that the generation of particles and splash is not sufficiently suppressed.

[0010] Among the above-mentioned problems of the generation of particles and splash, the generation of the splash has a serious problem because the performance of the thin film on the substrate and the performance of the semiconductor electrode formed thereon is seriously hindered. . In particular,
When an Al alloy sputtering target is used to prevent the occurrence of hillocks in the Al electrode film, splash tends to occur easily, and its elimination is desired.

The generation of such a splash is as described above.
The same applies not only to the formation of electrodes for semiconductors for LCDs but also to the formation of semiconductor integrated circuit wiring, magnetic recording, and reflective layers of magneto-optical recording media by sputtering using Al or Al alloy sputtering target materials. There is a problem that occurs.

[0012]

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and its object is to prevent the occurrence of splash during sputtering.
An object of the present invention is to provide an Al or Al alloy sputtering target material and a method for producing the same.

[0013]

In order to achieve the above object, a sputtering target material according to the present invention and a method for manufacturing the same are provided by a sputtering target material according to claims 1 and 2, and a sputtering target material according to claims 3 to 5. A method for manufacturing a target material is as follows.

That is, in the sputtering target material according to the first aspect, the maximum length of the internal inclusions is 20 μm.
A sputtering target material made of the following aluminum or aluminum alloy (first invention). According to this, generation of splash at the time of sputtering can be suppressed.

The sputtering target material according to claim 2 is the sputtering target material according to claim 1, wherein all of the inclusions have a maximum length of 10 μm or less (second invention). According to this, the generation of the splash becomes extremely difficult to occur, and the generation of the splash can be suppressed more reliably.

According to a third aspect of the present invention, there is provided a method for producing a sputtering target material comprising aluminum or an aluminum alloy by a spray forming method, wherein a gas outflow amount (Nm) in a gas atomizing step in the spray forming method is provided. ³ ) A method for producing a sputtering target material, characterized in that the value of molten metal outflow (kg) is at least ⁵ Nm ³ / kg (third invention). According to this manufacturing method, it is possible to obtain an Al or Al alloy sputtering target material in which the maximum lengths of the inclusions are all 20 μm or less.

According to a fourth aspect of the present invention, in the method of manufacturing a sputtering target material, the gas outflow (Nm ³ ) / the molten metal outflow is provided.
The method for producing a sputtering target material according to claim 3, wherein the value of (kg) is 10 Nm ³ / kg or more (fourth invention). According to this manufacturing method, it is possible to obtain an Al or Al alloy sputtering target material in which the maximum length of all the inclusions is 10 μm or less.

According to a fifth aspect of the present invention, in the method for producing a sputtering target material, nitrogen gas is used as an atomizing gas in the gas atomizing step, and the value of the gas outflow amount (Nm ³ ) / the molten metal outflow amount (kg) is set to 10 Nm ³ / The method for producing a sputtering target material according to claim 3, wherein the weight is at least kg (fifth invention). According to this manufacturing method,
It is possible to obtain an Al or Al alloy sputtering target material in which the maximum length of all the included inclusions is 10 μm or less and the nitrogen concentration is 0.1% by mass or less, and according to this target material, splash is generated during sputtering. Al or Al with low specific resistance
An alloy thin film can be formed.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is implemented, for example, as follows. An ingot is manufactured by a spray forming method using a molten metal of Al (aluminum) or an Al alloy. That is,
A molten metal of Al or Al alloy is gas-atomized and deposited to obtain an ingot. At this time, the value of gas outflow (Nm ³ ) / molten metal outflow (kg) in the gas atomizing step in the spray forming method is set to 5 Nm ³ / kg or more. Then, the maximum length of the Al or Al alloy sputtering target material according to the present invention, that is, the internal inclusions are all 20 μm or less.
A sputtering target material made of Al or an Al alloy can be obtained.

The present invention has been completed based on the knowledge obtained as a result of intensive studies for developing an Al or Al alloy sputtering target material in which splash is unlikely to occur. The details will be described below.

The present inventors have prepared Al sputtering target materials and Al alloy sputtering target materials having inclusions of various sizes, and performed sputtering using these as sputtering targets. The situation at that time was carefully investigated.

As a result, the splash is caused by the partial hindrance of the cooling of the target material around the inclusions, particularly immediately above the inclusions existing in the sputtering target material. The molten layer is melted by heating by the plasma to form a molten layer, and this molten layer is generated by being ejected as droplets by electromagnetic force.Also, the splash is reduced by the amount of inclusions described in JP-A-9-25564. Also that the size of inclusions has a greater correlation,
Inclusion size (maximum length, ie, length of maximum length)
When the particle size is 20 μm or less, it is found that splash hardly occurs and the generation of the splash can be suppressed. In particular, when the size of the inclusion is 10 μm or less, almost no splash occurs.

That is, in the Al sputtering target material and the Al alloy sputtering target material in which the size (maximum length) of all the included inclusions is not more than 20 μm, the cooling inhibition portion due to the inclusions during sputtering becomes small, and the molten layer is formed. Since it hardly occurs, the scattering of the molten layer as droplets, that is, the occurrence of splash drastically decreases, becomes difficult to occur, and the suppression of splash generation becomes sufficient, especially when the size of the above-mentioned inclusions is all 10 μm or less It was found that almost no splash was generated and it was extremely unlikely to occur.

The present invention has been completed on the basis of the above findings, and a sputtering target material according to the present invention is an Al or Al alloy sputtering target material in which the maximum length of all the inclusions is 20 μm or less. (A sputtering target material made of aluminum or an aluminum alloy), and therefore, it is difficult for splash to sufficiently occur during sputtering (first invention).

Here, the maximum length of the internal inclusions is
The maximum length is 20 μm or less.
This is because, if there is an inclusion exceeding m, splash is likely to occur due to the inclusion, and the suppression of the occurrence of splash becomes insufficient.

It is desirable that all of the maximum lengths of the inclusions are 10 μm or less. This is because, in such a case, the splash hardly occurs, and the splash hardly occurs, and the splash is more reliably suppressed (second invention).

Next, a method for producing a sputtering target material according to the present invention will be described.
As described above, it is possible to obtain an Al or Al alloy sputtering target material in which the maximum length of all the internal inclusions is 20 μm or less, that is, the Al or Al alloy sputtering target material according to the first invention (third invention). The details will be described below.

As described above, the method for producing a sputtering target material according to the present invention is a method for producing an Al or Al alloy sputtering target material (a sputtering target material made of aluminum or an aluminum alloy) by a spray forming method. This is a method for producing a sputtering target material, characterized in that the value of gas outflow (Nm ³ ) / molten metal outflow (kg) in the gas atomizing step in the forming method is 5 Nm ³ / kg or more.

Here, the spray forming method is a method in which a molten metal made of a molten metal is gas-atomized to form a spray of small spray droplets, and this spray is deposited to obtain an ingot. Therefore, the method for producing a sputtering target material according to the present invention, more specifically, Al or
By gas atomizing the molten Al alloy, forming a spray of spray droplets, depositing this spray to obtain an Al or Al alloy ingot, forging, rolling, machining, etc. the ingot.
A method for producing an Al or Al alloy sputtering target material, characterized in that the value of gas outflow (Nm ³ ) / molten metal outflow (kg) when gas atomizing the molten metal is 5 Nm ³ / kg or more. Is a method for producing an Al or Al alloy sputtering target material.

As described above, the method for producing a sputtering target material according to the present invention is a method for producing an Al or Al alloy sputtering target material by a spray forming method. Is gas-atomized into small particles in a molten or semi-molten state, and the inclusions are crushed and reduced in size, and the small-grained Al or Al alloy is sprayed onto the bottom plate or in a mold in a semi-molten state one after another. And deposited, thus forming an Al or Al alloy sputtering target material. At this time, if the value of gas outflow (Nm ³ ) / molten metal outflow (kg) in the gas atomizing step by spray forming is 5 Nm ³ / kg or more, the size of the inclusions after crushing (maximum length) ) Is all 20
μm or less, so that an Al or Al alloy sputtering target material in which the size of all the internal inclusions is 20 μm or less can be obtained.

Therefore, the method for producing a sputtering target material according to the present invention, as described above, sets the value of gas outflow (Nm ³ ) / molten metal outflow (kg) in the gas atomization step by spray forming to 5 Nm ³ / kg. That is all.

Therefore, according to the method for producing a sputtering target material according to the present invention, the Al or Al alloy sputtering target material in which the size (maximum length) of all the internal inclusions is 20 μm or less, ie, the first invention According to Al
Alternatively, an Al alloy sputtering target material can be obtained.

Here, the gas outflow amount (Nm ³ ) / the molten metal outflow amount (k) in the gas atomizing step in the spray forming method.
The reason why the value of g) is set to 5 Nm ³ / kg or more is that if the value is less than 5 Nm ³ / kg, the obtained Al or Al alloy sputtering target material has a considerable number of inclusions having a maximum length exceeding 20 μm. This is because, in such a sputtering target material, a splash easily occurs during sputtering, and the suppression of the splash is insufficient.

Gas outflow (Nm ³ ) / Molten outflow (kg)
Is 10 Nm ³ / kg or more, the size (maximum length) of the internal inclusions are all 10 μm or less, an Al or Al alloy sputtering target material, that is, the Al or Al alloy sputtering target according to the second invention. A material can be obtained (fourth invention).

The Al or Al alloy sputtering target material obtained by the spray forming method as described above has a higher oxygen concentration in the material than the Al or Al alloy sputtering target material obtained by the vacuum melting method or the like. This indicates that the former has more inclusions in the material than the latter. Nevertheless,
The former is less prone to splash during sputtering than the latter. This is because the former has a smaller size of inclusions in the material than the latter. That is, when the size of the inclusions is small as in the former case, even if the number of the inclusions is large, the influence is small and the occurrence of splash is unlikely to occur. In the latter method, a large number of inclusions with a size of more than 20 μm are formed, which is the starting point of the splash.

When a nitrogen gas is used as an atomizing gas in the gas atomizing step in the spray forming method in producing an Al or Al alloy sputtering target material by the spray forming method, the obtained Al or Al alloy sputtering target material is obtained. Increases the nitrogen concentration. An Al or Al alloy thin film such as an Al electrode film formed by sputtering using a sputtering target material having a high nitrogen concentration has a high nitrogen concentration, and the specific resistance value is increased by the influence of the nitrogen. For example, when an Al alloy thin film is formed using a sputtering target material made of an Al-Ti alloy (an Al alloy containing Ti), as shown in FIG. The electrical resistivity of the alloy thin film increases. Therefore, in view of the specific resistance value of such an Al or Al alloy thin film, it is used for forming this thin film.
It is preferable that the nitrogen concentration of the Al or Al alloy sputtering target material is low, and it is desired that the nitrogen concentration be 0.1 mass (mass)% or less. In other words, in order to suppress an increase in the electrical resistivity due to an increase in the nitrogen concentration, a material having an electrical resistivity equivalent to that at a nitrogen concentration of 0% has long been desired. It is desired that:

Therefore, when a nitrogen gas is used as the atomizing gas in the gas atomizing step in the spray forming method, a technique capable of reducing the nitrogen concentration of the obtained Al or Al alloy sputtering target material, especially 0.1.
We worked diligently to develop a technology that can reduce it to less than 1 mass%. As a result, the value of gas outflow (Nm ³ ) / molten metal outflow (kg) in the gas atomization step in the spray forming method, that is, the value of nitrogen gas outflow (Nm ³ ) / molten metal outflow (kg) is changed to 10 Nm ^3. / kg or more, nitrogen concentration: 0.1mass
% Of Al or Al alloy sputtering target material can be obtained.

The Al or Al alloy sputtering target material thus obtained is obtained by a manufacturing method having basically the same configuration as the manufacturing method according to the fourth aspect of the present invention. The sizes (maximum lengths) are all 10 μm or less, and therefore, splash is less likely to occur during sputtering.

Therefore, the spray forming method
In producing an Al or Al alloy sputtering target material, when nitrogen gas is used as an atomizing gas in the gas atomizing step in the spray forming method, the gas outflow rate (Nm
³ ) / If the value of the molten metal outflow (kg) is 10 Nm ³ / kg or more, the size (maximum length) of the included inclusions is 10 μm or less, and the nitrogen concentration is 0.1 mass% or less. Or Al
An alloy sputtering target material can be obtained (fifth invention). According to such an Al or Al alloy sputtering target material, the occurrence of splash during sputtering is unlikely to occur, and the specific resistance of Al or Al is small.
An Al alloy thin film can be formed.

As described above, when nitrogen gas is used as the atomizing gas in the gas atomizing step in the spray forming method, the value of gas outflow (Nm ³ ) / molten metal outflow (kg) in the gas atomizing step, ie, nitrogen gas outflow When the value of (Nm ³ ) / molten metal outflow (kg) is 10 Nm ³ / kg or more, an Al or Al alloy sputtering target material having a nitrogen concentration of 0.1 mass% or less can be obtained. This is because droplets (molten or semi-molten small particles) of Al or Al alloy formed by gas atomization are deposited on the bottom plate or in the mold, and then these droplets are cooled rapidly enough by nitrogen gas to solidify. However, this is because the reaction between Al and N hardly occurs, and the amount of nitride generated is reduced.

On the other hand, the nitrogen gas outflow (Nm ³ )
If the value of the molten metal outflow (kg) is less than 10 Nm ³ / kg, the cooling of the droplets deposited on the bottom plate or inside the mold becomes insufficient,
Insufficiency at the center of the deposit (deposited layer of droplets), which makes it relatively easy for Al to react with N, and this reaction produces more nitride, resulting in
The Al or Al alloy sputtering target material has a high nitrogen concentration, exceeding 0.1 mass%.

In the present invention, the maximum length of the inclusion is the length of the maximum length of the inclusion. For example,
When the shape of the inclusion is spherical, it is the diameter, and when it is a substantially rectangular parallelepiped, it is the length of the maximum side. The phrase “the maximum length of all the internal inclusions is 20 μm or less” means that any of the internal inclusions in the material has a maximum length of 20 μm or less.

The amount of molten metal flowing out in the gas atomizing step in the spray forming method is the amount of molten metal per unit time which flows out from the molten metal outlet of the container containing the molten metal. The gas outflow amount in the process is the amount per unit time of gas flowing out from the gas outlet of the atomizing gas source in order to gasify the outflowing molten metal.

The value of gas outflow (Nm ³ ) / molten metal outflow (kg) in the gas atomizing step in the spray forming method means that the unit of the molten metal outflow is kg / unit time and the unit of the gas outflow is Nm ³ / The ratio of gas outflow and molten metal outflow when indicated as unit time, ie, gas outflow (kg / unit time)
/ Molten metal outflow (Nm ³ / unit time). However, at this time, the unit of the unit time is the same for the case of the molten metal outflow and the case of the gas outflow. Above gas outflow (Nm ³ ) /
The value of the molten metal outflow (kg) is also called the gas / metal ratio.

For example, if the gas outflow is 40 Nm ³ / min and the molten metal outflow is 4 kg / min, the value of gas outflow (Nm ³ ) / molten metal outflow (kg) is 40 (Nm ³ / min). / 4 (kg / min), it is 40 (Nm ³ ) / 4 (kg), and therefore 10 Nm ³ / kg.

[0046]

EXAMPLES (Examples 1 to 3) An Al-2 at% Nd alloy was melted, and an ingot was manufactured by using the molten alloy by a spray forming method. That is, the molten metal of the Al-2at% Nd alloy was gas-atomized and deposited in a mold to obtain an Al-2at% Nd alloy ingot. At this time, nitrogen gas was used as an atomizing gas in the gas atomizing step in the spray forming method. Also, as shown in Table 2, the value of nitrogen gas outflow (Nm ³ ) / molten metal outflow (kg) in the gas atomizing step in this spray forming method was 6 Nm ³ / kg, 10 Nm ³ / kg,
Further, it was set to 15 Nm ³ / kg. The method for producing the Al-2 at% Nd alloy ingot (sputtering target material) corresponds to an example of the method for producing a sputtering target material according to the present invention.

The above ingot was forged, rolled, and machined to produce a φ4 inch Al-2 at% Nd alloy sputtering target material.

With respect to the Al-2 at% Nd alloy sputtering target material manufactured in this manner, the size (maximum length) and oxygen content of the internal inclusions were investigated, and the degree of splash generation during sputtering was determined. investigated.

At this time, regarding the investigation of the size of inclusions, a microscope sample is taken from the above sputtering target material, and after polishing this sample, the size of the inclusion is measured by observation using an optical microscope. Performed by the method.
Investigation of the amount of oxygen was carried out by collecting a sample for gas analysis from the above sputtering target material and performing gas analysis on the sample.

Regarding the investigation of the degree of splash generation, sputtering was performed for 1 hour under the sputtering conditions shown in Table 1 using the above sputtering target material, and after forming an Al-2 at% Nd alloy thin film on the substrate,
The surface of the thin film was observed using an optical microscope, and the number of splashes having a size (maximum length) of 10 μm or more was measured. At this time, the reason why the size having a size of 10 μm or more is measured in the splash is that the splash having a size of 10 μm or more causes a serious problem to the performance of the thin film and becomes a problem.

Table 2 shows the results of investigation on the size of the inclusions, the amount of oxygen, and the number of splashes having a size of 10 μm or more.

As can be seen from Table 2, the size (maximum length) of the inclusions was 20 μm or less in any of Examples 1 to 3. That is, the size of the inclusions of the Al-2 at% Nd alloy sputtering target material obtained by setting the value of nitrogen gas outflow (Nm ³ ) / molten metal outflow (kg) in the gas atomization step by the spray forming method to 6 Nm ³ / kg. The maximum length is 16 μm, and the maximum length of inclusions of the Al-2at% Nd alloy sputtering target material obtained with the value of nitrogen gas outflow (Nm ³ ) / molten metal outflow (kg) being 10 Nm ³ / kg Is 8
μm, nitrogen gas outflow (Nm ³ ) / molten metal outflow (kg)
The maximum length of the inclusions of the Al-2 at% Nd alloy sputtering target material obtained at 15 Nm ³ / kg was 4 μm. Hereinafter, these Al-2 at% Nd alloy sputtering target materials are referred to as a sputtering target material according to Example 1, a sputtering target material according to Example 2, and a sputtering target material according to Example 3, respectively, in this order.

Size (maximum length): The number of splashes of 10 μm or more is 10 in the case of the sputtering target material according to the first embodiment, 5 in the case of the sputtering target material according to the second embodiment, and 5 in the third embodiment. In the case of the sputtering target material according to the above, the number was three. That is, as shown in Table 2, the degree of occurrence of the splash of 10 μm or more on the performance of the thin film was extremely small in any of Examples 1 to 3. If the number of splashes of 10 μm or more can be reduced to 10 or less, the technical significance is large in that the problem of significantly miniaturizing the wiring width, which could not be achieved by the conventional technology, could be solved.

Comparative Example 1 An Al-2 at% Nd alloy was melted in the air, cast, rolled, machined, and machined to form a φ4 inch Al-2 at% Nd alloy sputtering target material (hereinafter referred to as Comparative Example 1). Such a sputtering target material) was manufactured.

With respect to the sputtering target material according to Comparative Example 1, the maximum length of inclusions, the number of splashes generated during sputtering, and the like were examined in the same manner as in Examples 1 to 3. Table 2 shows the results of these investigations. As can be seen from Table 2, the maximum length of the inclusions in the sputtering target material according to Comparative Example 1 was 60 μm, and the number of splashes having a size of 10 μm or more was as large as 54.

Comparative Example 2 An Al-2 at% Nd alloy was vacuum melted, cast, rolled, machined, and machined to form a φ4 inch Al-2 at% Nd alloy sputtering target material (hereinafter referred to as Comparative Example 2). Such a sputtering target material) was manufactured.

With respect to the sputtering target material according to Comparative Example 2, the maximum length of inclusions and the like were investigated in the same manner as in Examples 1 to 3. Table 2 shows the results of these investigations. As can be seen from Table 2, Comparative Example 2
The maximum length of the inclusions of the sputtering target material according to (1) was 30 μm, and the number of splashes having a size of 10 μm or more was as large as 25.

(Comparative Example 3) The value of nitrogen gas outflow (Nm ³ ) / molten metal outflow (kg) in the gas atomizing step of the spray forming method was 4 Nm ³ / kg as shown in Table 2. Except for this point, by the same method as in the case of Examples 1 to 3,
A 4 inch Al-2at% Nd alloy sputtering target material (hereinafter, referred to as a sputtering target material according to Comparative Example 3) was manufactured.

With respect to the sputtering target material according to Comparative Example 3, the maximum length of inclusions and the like were investigated in the same manner as in Examples 1 to 3. Table 2 shows the results of these investigations. As can be seen from Table 2, Comparative Example 3
The maximum length of the inclusions of the sputtering target material according to the above was 25 μm, and the number of splashes having a size of 10 μm or more was as large as 20 pieces.

Example 4 An Al-2 at% Nd alloy sputtering target material was manufactured in the same manner as in Examples 1-3. However, in order to change the maximum length of the inclusions in the sputtering target material, the value of nitrogen gas outflow (Nm ³ ) / molten metal outflow (kg) in the gas atomization step of the spray forming method was changed as a parameter. .

With respect to the above sputtering target materials, the maximum length of inclusions and the number of splashes generated during sputtering were investigated in the same manner as in Examples 1 to 3. Table 5 shows the results. Then, based on this result, a relationship between the maximum length of the inclusion and the number of splashes having a size of 10 μm or more was obtained. This result is shown in FIG.
Shown in

From FIG. 1, it can be seen that in the region where the maximum length of the inclusions exceeds 20 μm, the number of splashes having a size of 10 μm or more increases rapidly as the maximum length of the inclusions increases.
Inclusion maximum length: 10μ in the area of 20μm or less
It can be seen that the number of splashes of m or more is extremely small, and the occurrence of splash is unlikely to occur.

In the above Examples 1 to 4 and Comparative Example 3, nitrogen gas was used as the atomizing gas in the gas atomizing step in the spray forming method, and the results as described above were obtained. Alternatively, when using another atomizing gas such as argon gas,
Similar results are obtained.

(Examples 5 to 7) An Al-Ti alloy (an Al alloy containing Ti) was melted, and an ingot was manufactured by spray forming using the alloy. At this time, nitrogen gas was used as an atomizing gas in the gas atomizing step in the spray forming method. Also, outflow of nitrogen gas (Nm ³ ) / outflow of molten metal (kg) in this gas atomization process
Of a value, as shown in Table ³ 14.3Nm 3 /kg,12.9Nm 3 /kg,10.0
Nm ³ / kg was changed.

A sample for gas analysis was collected from the ingot, and the nitrogen content (nitrogen concentration) of the ingot was investigated by a method of analyzing the sample with nitrogen gas. After that, the above-mentioned ingot was forged, rolled, and machined to form a 4-inch diameter.
An Al-Ti alloy sputtering target material was manufactured. Further, sputtering was performed for 1 hour using the sputtering target material under the sputtering conditions shown in Table 4 to form an Al-Ti alloy thin film on the substrate. After the ordinary heat treatment, the electrical resistivity of the thin film was measured. This measurement measures the thin film by photolithography to a width of 100 μm.
This was processed into a pattern having a specific resistance of 10 μm in length, and the specific resistance was measured by a four probe method. Table 3 shows the results of this investigation. The nitrogen content is 0.015 each
, 0.018, 0.027 mass%
ss% or less. As a result, the increase in electrical resistivity due to each nitrogen content is also 0.11, 0.13, 0.20μΩcm
And 0.75 μΩcm or less (nitrogen content: 0.1 mass% or less).

(Examples 8 and 9) An Al-Nd alloy was melted and used to produce an ingot by spray forming. At this time, nitrogen gas was used as an atomizing gas in the gas atomizing step in the spray forming method. Table 3 shows the value of nitrogen gas outflow (Nm ³ ) / molten metal outflow (kg) in the gas atomization step.
14.3, 10.0 Nm ³ / kg.

The nitrogen content of the ingot was examined by the same method as in Examples 5 to 7. Table 3 shows the results of this survey.
Shown in Nitrogen content is 0.012 and 0.020 mass% respectively
And extremely low.

It is preferable that the nitrogen content is small because the electric resistivity is lowered. However, the nitrogen content will be described below based on Reference Examples 1 to 4.

(Reference Examples 1 and 2) The value of nitrogen gas outflow (Nm ³ ) / molten metal outflow (kg) in the gas atomizing step of the spray forming method was 8.88 and 8.93 Nm ³ / kg as shown in Table 3. . Except for this point, an Al-Ti alloy ingot was manufactured in the same manner as in Examples 5 to 7.

The nitrogen content of the above ingot was investigated by the same method as in Examples 5 to 7. Table 3 shows the results of this survey.
Shown in The nitrogen contents are 0.13 and 0.41 mass%, respectively, both exceeding 0.1 mass%.

(Reference Examples 3 and 4) The values of nitrogen gas outflow (Nm ³ ) / melt outflow (kg) in the gas atomizing step of the spray forming method were 9.0 and 8.9 Nm ³ / kg as shown in Table 3. . Except for this point, an Al-Nd alloy ingot was manufactured in the same manner as in Examples 8 and 9.

The nitrogen content of the ingot was examined by the same method as in Examples 5 to 7. Table 3 shows the results of this survey.
Shown in The nitrogen contents are as high as 0.11 and 0.33 mass%, respectively, and both exceed 0.1 mass%.

Example 10 An Al alloy sputtering target material was manufactured in the same manner as in Examples 1 to 3. However, instead of the Al-Nd alloy as the Al alloy,
Al-Ti alloy was used. Also, in order to change the nitrogen content in the sputtering target material, the nitrogen gas outflow (Nm
³ ) / The value of molten metal outflow (kg) was changed as a parameter.

Using the above sputtering target material, sputtering was performed for 1 hour under the sputtering conditions shown in Table 4 to form an Al—Ti alloy thin film on the substrate. After the ordinary heat treatment, the electrical resistivity of the thin film was measured. In this measurement, the thin film is
The pattern was processed into a pattern for measuring specific resistance of 100 μm and length of 10 μm, and the specific resistance was measured by a four probe method.

On the other hand, the nitrogen content of the above sputtering target material was measured in the same manner as in Examples 5 to 7.

Then, based on the result of the above measurement, the relationship between the nitrogen content in the sputtering target material and the electrical resistivity of the obtained thin film was obtained. The result is shown in FIG.
FIG. 2 shows that the lower the N content of the sputtering target material, the lower the electrical resistivity of the formed Al alloy thin film.

In the above Examples 1 to 10, Comparative Examples 1 to 3 and Reference Examples 1 to 4, the Al alloy is an Al—Nd alloy, an Al—Ti alloy.
Although the above results were obtained using alloys, Al-Ta, Al-Fe, Al-Co, Al-Ni, Al
The same tendency is obtained when other Al alloys such as -REM (rare earth element) are used.

[0078]

[Table 1]

[0079]

[Table 2]

[0080]

[Table 3]

[0081]

[Table 4]

[0082]

[Table 5]

[0083]

According to the sputtering target material (Al or Al alloy sputtering target material) of the present invention, splash is less likely to occur during sputtering. Therefore, the sputtering of Al electrode film etc.
Thin film or Al alloy thin film can be formed, Al thin film and
The performance of the Al alloy thin film can be improved.

According to the method for producing a sputtering target material according to the present invention, it is possible to obtain an Al or Al alloy sputtering target material in which splash is unlikely to occur during sputtering.

[Brief description of the drawings]

FIG. 1 is a diagram showing the relationship between the maximum length of inclusions and the number of splashes of 10 μm or more for a sputtering target material according to Example 4.

FIG. 2 is a view showing the relationship between the amount of N in a sputtering target material according to Example 10 and the electrical resistivity of a thin film obtained.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takashi Onishi 1-5-5 Takatsukadai, Nishi-ku, Kobe-shi, Hyogo Kobe Steel, Ltd. Kobe Research Institute (72) Inventor Masao Mizuno Nishi-ku, Kobe-shi, Hyogo 1-5-5 Takatsukadai Kobe Steel Engineering Co., Ltd.Kobe Research Institute (72) Inventor Teruyuki Takahara 1-5-5 Takatsukadai, Nishi-ku, Kobe City, Hyogo Prefecture Kobe Steel Co., Ltd.Kobe Research Institute (72) Inventor Toshihisa Suemitsu 1-5-5 Takatsukadai, Nishi-ku, Kobe-shi, Hyogo Pref.Kobe Steel Works, Ltd.Kobe Research Institute 58-219 (56) References JP-A-9-248665 (JP, A) JP-A-6-322529 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C23C 1 4/00-14/58 B22D 23/00 B22F 9/08 C22C 21/00

Claims (5)

(57) [Claims] 1. The maximum length of all internal inclusions is 20 μm.
A sputtering target material comprising the following aluminum or aluminum alloy. 2. The sputtering target material according to claim 1, wherein all of the inclusions have a maximum length of 10 μm or less. 3. A method for producing a sputtering target material made of aluminum or an aluminum alloy by a spray forming method, wherein a gas outflow amount (Nm) in a gas atomizing step in the spray forming method is provided.
³ ) / A method for producing a sputtering target material, wherein the value of molten metal outflow (kg) is 5 Nm ³ / kg or more. 4. The gas outflow (Nm ³ ) / molten metal outflow (k
The method for producing a sputtering target material according to claim 3, wherein the value of g) is 10 Nm ³ / kg or more. 5. The sputtering according to claim 3, wherein a nitrogen gas is used as an atomizing gas in the gas atomizing step, and a value of the gas outflow amount (Nm ³ ) / the molten metal outflow amount (kg) is 10 Nm ³ / kg or more. Target material manufacturing method.