KR101024197B1 - Al-Ni-La-Cu-BASED Al-GROUP ALLOY SPUTTERING TARGET AND MANUFACTURING METHOD THEREOF - Google Patents

Abstract

An object of the present invention is to provide a technique capable of reducing the splash generated when a film is formed using an Al-Ni-La-Cu-based Al-based alloy sputtering target containing Ni, La, and Cu. An Al-Ni-La-Cu-based Al-based alloy sputtering target containing Ni, La, and Cu, and a portion of 1 / 4t (t is thickness) to 3 / 4t in a cross section perpendicular to the plane of the sputtering target When observed with a scanning electron microscope (2000 times), (1) Average particle diameter of the Al-Ni-based intermetallic compound with respect to the total area of the Al-Ni-based intermetallic compound with respect to Al and Ni as the main area 0.3 to 3 Al-La-Cu-based intermetallic compound with respect to Al-La-Cu-based intermetallic compound mainly composed of Al, La and Cu, with a total area of 70 µm of Al-Ni-based intermetallic compound The total area of the Al-La-Cu based intermetallic compound having an average particle diameter of 0.2 to 2 µm relative to the total area of ≧ 70%.

Sputtering Targets, Splashes, Collectors, Nozzles, Gas Atomizers

Description

Al-Ni-La-Cu-based Al-based alloy sputtering target and manufacturing method thereof {Al-Ni-La-Cu-BASED Al-GROUP ALLOY SPUTTERING TARGET AND MANUFACTURING METHOD THEREOF}

The present invention relates to an Al-Ni-La-Cu-based Al-based alloy sputtering target containing Ni, La, and Cu, and a method for manufacturing the same. Specifically, an initial step of sputtering when forming a thin film using a sputtering target The present invention relates to an Al-Ni-La-Cu-based Al-based alloy sputtering target capable of reducing an initial splash occurring at

Al-based alloys have low electrical resistivity and are easy to process, such as liquid crystal displays (LCDs), plasma display panels (PDPs), and electro luminescence displays (ELDs). Display, field emission display (FED), MEMS (Micro Electro Mechanical Systems), such as flat panel display (FPD: Flat Panel Display), touch panel, electronic paper, etc. , Wiring films, electrode films, reflective electrode films and the like.

For example, an active matrix liquid crystal display includes a TFT substrate having a thin film transistor (TFT) as a switching element, a pixel electrode composed of a conductive oxide film, and a wiring including scan lines and signal lines. In general, a thin film of pure Al or Al-Nd alloy is used for the wiring material constituting the scan line or the signal line. When various electrode portions formed by these thin films are in direct contact with the pixel electrode, insulating aluminum oxide or the like is applied to the interface. Since the contact electric resistance increases, a barrier metal layer made of a high melting point metal such as Mo, Cr, Ti, and W is provided between the wiring material of Al and the pixel electrode until now to reduce the contact electric resistance. come.

However, the method of interposing a barrier metal layer as mentioned above has a problem that a manufacturing process is complicated and a production cost rises.

Thus, in order to provide a technique (direct contact technique) that allows the conductive oxide film constituting the pixel electrode to be in direct contact with the wiring material without interposing the barrier metal layer, the Al-Ni alloy, Nd, or Y is used as the wiring material. A method of using an Al-Ni alloy thin film further containing rare earth elements such as is proposed (Japanese Patent Application Laid-Open No. 2004-214606). When an Al-Ni alloy is used, conductive Ni-containing precipitates and the like are formed at the interface, and generation of insulating aluminum oxide and the like is suppressed, so that the contact electrical resistance can be suppressed low. In addition, when Al-Ni-rare earth element alloys are used, heat resistance becomes higher.

By the way, the sputtering method using the sputtering target is employ | adopted generally for formation of an Al base alloy film. The sputtering method forms a plasma discharge between a substrate and a sputtering target made of the same material as the thin film material, and strikes the atoms of the sputtering target by colliding a gas ionized by the plasma discharge with the sputtering target. It is a method of manufacturing a thin film by depositing on a board | substrate. Unlike the vacuum deposition method, the sputtering method has the advantage that a thin film having the same composition as the sputtering target can be formed. In particular, an Al-based alloy film formed by sputtering is capable of dissolving an alloying element such as Nd that is not dissolved in equilibrium and exhibits excellent performance as a thin film. Development of the sputtering target is in progress.

In recent years, in order to cope with productivity expansion of FPD, the film-forming speed | rate at the time of a sputtering process tends to become faster than before. In order to increase the deposition rate, it is easiest to increase the sputtering power, but if the sputtering power is increased, sputtering defects such as splashes (fine molten particles) occur, and defects occur in the wiring film. This results in a deterioration such as deterioration.

Therefore, for the purpose of preventing the occurrence of splashes, for example, Japanese Patent Application Laid-Open No. Hei 10-147860, Japanese Patent Application Laid-Open No. Hei 10-199830, Japanese Patent Application Laid-Open No. Hei 11-293454, and Japanese Patent Application The method described in publication 2001-279433 is proposed. Among these, Japanese Patent Application Laid-Open No. 10-147860, Japanese Patent Application Laid-open No. Hei 10-199830, and Japanese Patent Application Laid-Open No. 11-293454 all disclose fine pores in which the sputtering target is caused by the occurrence of the splash. It is made based on the viewpoint that it is derived from and controls the dispersion state of the compound particle of Al and a rare earth element in the Al mother phase (Unexamined-Japanese-Patent No. 10-147860), or the compound of Al and a transition element in an Al mother phase By controlling the dispersion state of Japanese Patent Application Laid-Open No. 10-199830, or by controlling the dispersion state of an intermetallic compound of Al with an additional element in the sputtering target (Japanese Patent Application Laid-open No. Hei 11-293454). To prevent the occurrence of. In addition, Japanese Patent Application Laid-Open No. 2001-279433 discloses surface defects caused by machining by adjusting the hardness of the spatter surface and then finishing machining in order to reduce arcing (abnormal discharge) which is the cause of the splash. A method of suppressing the occurrence of is disclosed.

On the other hand, the technique which mainly prevents the curvature of the sputtering target produced by the heating at the time of manufacture of a large sputtering target is disclosed (Japanese Patent Application Laid-Open No. 2006-225687). Japanese Patent Application Laid-Open No. 2006-225687 discloses an Al-Ni-rare earth element alloy sputtering target, and a compound having an aspect ratio of 2.5 or more and a circular equivalent diameter of 0.2 µm or more in a cross section perpendicular to the sputtering target plane. By presenting more than a predetermined number, the method which can suppress the deformation of a sputtering target is proposed.

As described above, various techniques for reducing sputtering and improving sputtering defects have been proposed until now, but further improvement is required. In particular, the initial splash occurring at the initial stage of sputtering causes a serious problem because it lowers the yield of FPD, but the above-described Japanese Patent Application Laid-open No. Hei 10-147860 and Japanese Patent Application Laid-open No. Hei 10-199830 , Japanese Patent Application Laid-Open No. 11-293454 and Japanese Patent Application Laid-Open No. 2001-279433 do not allow the splash generation prevention technique to be effectively prevented from occurring early. Al-Ni-La-Cu-based alloys which are useful as wiring materials that can be in direct contact with the conductive oxide film constituting the pixel electrode among Al-based alloys, and can also be applied as wiring materials that can be in direct contact with the semiconductor layer of the thin film transistor. In the Al base alloy sputtering target used for formation of an Al base alloy film, the technique which can solve the said subject is not yet proposed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to reduce splashes, particularly initial splashes, generated when forming a film using an Al-Ni-La-Cu-based Al-based alloy sputtering target containing Ni, La, and Cu. It's about providing the technology that can be done.

The summary of this invention is shown below.

[1] An Al-Ni-La-Cu-based Al-based alloy sputtering target containing Ni, La, and Cu,

When t is set to the thickness in the direction perpendicular to the plane of the sputtering target, the area of 1 / 4t to 3 / 4t in the cross section perpendicular to the plane of the sputtering target is magnified using a scanning electron microscope. When observed at 2000 times,

(1) The total area of Al-Ni-based intermetallic compounds having an average particle diameter in the range of 0.3 µm or more and 3 µm or less with respect to the total area of Al-Ni-based intermetallic compounds mainly composed of Al and Ni is the area ratio. Is 70% or more, and

(2) The total area of Al-La-Cu-based intermetallic compounds having an average particle diameter of 0.2 µm or more and 2 µm or less with respect to the total area of Al-La-Cu-based intermetallic compounds mainly composed of Al, La, and Cu, Al-Ni-La-Cu-based Al-based alloy sputtering target having an area ratio of 70% or more.

[2] Ni: 0.05 atomic% or more and 5 atomic% or less,

La: 0.10 atomic% or more and 1 atomic% or less,

Cu: 0.10 atomic% or more and 2 atomic% or less

The Al-Ni-La-Cu system Al-based alloy sputtering target as described in [1] containing them.

[3] A method for producing an Al-Ni-La-Cu-based Al-based alloy sputtering target according to [1] or [2],

850-1000 degreeC molten metal of Al-Ni-La-Cu type | system | group Al group alloy whose Ni amount is 0.05 atomic% or more and 5 atomic% or less, La amount is 0.10 atomic% or more and 1 atomic% or less, and Cu amount is 0.10 atomic% or more and 2 atomic% or less The first step of obtaining

A second step of gas atomizing the molten metal of the Al-based alloy at a gas / metal ratio of 6 Nm 3 / kg or more to refine the Al-based alloy;

A third step of depositing the micronized Al-based alloy on the collector under a spray distance of 900 to 1200 mm to obtain a preform of the Al-based alloy;

A fourth step of densifying the preform of the Al-based alloy by means of densification means to obtain a dense body of the Al-based alloy;

A fifth step of performing plastic working on the dense body of the Al-based alloy to obtain a plastic-worked body of the Al-based alloy;

The manufacturing method of the Al-Ni-La-Cu type | system | group Al base alloy sputtering target containing the 6th process of carrying out annealing to the said plastics processed body of an Al base alloy.

The Al-Ni-La-Cu-based Al-based alloy sputtering target of the present invention is an intermetallic compound (Al-Ni-based intermetallic compound mainly composed of Al and Ni and Al, La and Al) present in the sputtering target as described above. Since the particle size distribution of the Al-La-Cu-based intermetallic compound mainly composed of Cu is properly controlled, generation of splashes, in particular, generation of initial splashes, is suppressed, so that sputtering defects are effectively suppressed.

According to the present invention, it is possible to provide a technique capable of reducing the splash, particularly the initial splash, generated when forming a film by using an Al-Ni-La-Cu-based Al-based alloy sputtering target containing Ni, La, and Cu. .

MEANS TO SOLVE THE PROBLEM This inventor earnestly examined in order to provide the Al base alloy sputtering target which can reduce the splash which arises at the time of sputtering film-forming, especially the initial splash which arises at the initial stage at the time of sputtering film-forming.

As a result, the intermetallic compound (the Al-Ni-based intermetallic compound mainly composed of Al and Ni and the Al-La-based metal mainly composed of Al and La) contained in the Al-Ni-La-based Al-based alloy sputtering target The particle size distribution of the compound) has a significant correlation with the occurrence of the initial splash, and therefore, it was found that the desired purpose is achieved by appropriately controlling the particle size distribution of the intermetallic compound (Japanese Patent Application No. 2006- 313506). Hereinafter, the above-described invention may be referred to as "Al-Ni-La-based Al-based alloy sputtering target of related art".

The inventors of the present application have repeatedly studied Al-Ni-La-based Al-based alloy sputtering targets. Specifically, the Al-Ni-La-Cu-based Al-based alloy sputtering target in which Cu is further added to the Al-Ni-La-based Al-based alloy sputtering target is included in the sputtering target in the same manner as described above. The compounds were examined in detail, and the intermetallic compounds (Al-Ni-based binary intermetallic compounds mainly composed of Al and Ni) contained in the sputtering targets described above, and Al-La mainly composed of Al, La, and Cu. The particle size distributions of the -Cu-based ternary intermetallic compounds are all significantly correlated with the occurrence of the initial splash. Therefore, it is found that the desired purpose is achieved by appropriately controlling the particle size distribution of the intermetallic compounds. The present invention has been completed.

In the present specification, "Al-Ni-based intermetallic compound mainly composed of Al and Ni" is a method described in detail later, and the sputtering target is an EDX (Energy Dispersive X-ray Fluoressence Spectrometer, energy dispersing type X). When analyzed by SEM (Scanning Electron Microscope) equipped with a line analyzer, the peaks of Al and Ni are strongly detected and the peaks of elements other than these are substantially detected as shown in FIG. Means not detected. As typical Al-Ni system intermetallic compounds, a binary inter metallic compounds such as Al ₃ Ni.

In addition, "Al-La-Cu type intermetallic compound which mainly uses Al, La, and Cu" means that when analyzing a sputtering target by the same method as the above, Al, La, as shown in FIG. 2D mentioned later, It means that peaks of La and Cu are strongly detected and peaks of elements other than these are substantially not detected. As typical Al-La-Cu intermetallic compound, there may be mentioned ternary intermetallic compounds such as Al ₇ Cu ₂ La.

In addition, in this specification, "it can prevent (reduce) the generation | occurrence | production of an initial splash" means that the average value of the splash which generate | occur | produces when sputtering is performed on the conditions shown in the Example mentioned later (sputtering time 81 second). It means less than 8 pieces / cm 2. As described above, in the present invention, the sputtering time is set to 81 seconds, and since the splash in the initial stage of sputtering film formation is evaluated, the above-described Japanese Patent Application Laid-Open does not evaluate the occurrence of the splash in the initial stage. The evaluation criteria differ from the technique of 10-147860, Unexamined-Japanese-Patent No. 10-199830, Unexamined-Japanese-Patent No. 11-293454, and Unexamined-Japanese-Patent No. 2001-279433.

First, the Al-Ni-La-Cu system Al base alloy made into object in this invention is demonstrated.

The Al-based alloy sputtering target of the present invention contains Ni, La, and Cu in the mother phase Al. The reason for selecting these alloying elements is as follows. In the Al-based alloy film formed by using the Al-Ni-La-Cu-based Al-based alloy sputtering target, the effect of reducing the contact electrical resistance with the pixel electrode in direct contact with the Al-based alloy film by containing Ni is effective. Obtained. Also. By containing La, the effect of improving the heat resistance of the Al-based alloy film is obtained. Moreover, the effect of improving the corrosion resistance of an Al group alloy film is acquired by containing Cu.

In addition, when referring to the Al-Ni-rare earth element alloy sputtering target, Japanese Unexamined Patent Application Publication No. 2006-225687 also discloses a technique targeting the sputtering target having the above composition, but the rare earth element as in the present invention As an example, the Al-Ni-La-Cu-based Al-based alloy sputtering target containing La is not intended. Of course, Japanese Patent Application Laid-Open No. 2006-225687 discloses an Al-Ni-La-Cu-based Al-based alloy sputtering target of the present invention, in order to prevent the occurrence of an initial splash, There is no technical idea of the present invention to control the particle size distribution. In addition, the compound (intermetallic compound) prescribed | regulated by Unexamined-Japanese-Patent No. 2006-225687 is a disk-shaped compound whose aspect ratio is 2.5 or more and circle equivalent diameter is 0.2 micrometer or more, and this invention has a spherical compound, The shape of the intermetallic compound is different. In addition, both also differ in the manufacturing method. As will be described in detail later, the present invention is similarly to Japanese Patent Application Laid-Open No. 2006-225687, but preferably an Al-based alloy preform is produced by a spray forming method, but Japanese Patent Application Laid-Open No. 2006-225687 In the publication, in particular, in the present invention, the gas / metal ratio is 6Nm3 / kg, in particular, while the nozzle diameter ø is controlled to 2.5 to 10 mm and the gas pressure is controlled to 0.3 to 1.5 MPa to secure a predetermined disk-like compound. The above control ensures the desired particle size distribution. Since Japanese Patent Application Laid-Open No. 2006-225687 does not consider gas / metal ratio at all, even if it is based on the manufacturing method disclosed in Japanese Patent Application Laid-Open No. 2006-225687, Al-Ni-La of the present invention. It is not possible to manufacture a Cu-based Al-based alloy sputtering target.

Moreover, as a splash generation suppression technique of an Al-based alloy sputtering target, for example, in addition to the above-mentioned Japanese Patent Application Laid-Open No. 2006-225687, the above-mentioned Japanese Patent Application Laid-Open No. 2004-214606, Japanese Patent Application Laid-Open No. 10- As in 147860, Japanese Patent Application Laid-open No. Hei 10-199830, and Japanese Patent Application Laid-open No. Hei 11-293454, a technique for controlling the dispersion state of Al, rare earth elements, and intermetallic compounds in the Al matrix is disclosed. Is disclosed. However, all of them are not specifically disclosed for the Al-Ni-La-Cu-based Al-based alloy sputtering target targeted in the present invention. As in the present invention, an Al-based alloy containing La as a rare earth element and further containing Cu includes the above-mentioned patent document and is not disclosed in any of the patent documents disclosed in the prior art column.

The present invention, as described in detail below, Al-Ni-La-Cu-based Al-based alloy sputtering target containing La and Cu in the Al-Ni-based alloy, and rare earth elements other than La in the Al-Ni-based alloy The shape of the intermetallic compound differs greatly from the Al-Ni-rare earth element alloy sputtering target (eg, Al-Ni-Nd alloy sputtering target disclosed in Japanese Patent Application Laid-Open No. 2006-225687) containing It is based on the new knowledge. In the Al-Ni-La-Cu-based Al-based alloy sputtering target of the present invention, as shown in Figs. 2A to 2D described above, Al is a binary intermetallic compound made of Ni and 3 made of Al, La, and Cu. A primary intermetallic compound exists, and a ternary intermetallic compound composed of Al, Ni, and La is substantially absent. On the other hand, in the Al-Ni-Nd alloy sputtering target of Unexamined-Japanese-Patent No. 2006-225687, the ternary-type intermetallic compound which consists mainly of Al, Ni, and Nd exists, and the binary metal between which the Al and Ni consists of There is almost no compound. Among the Al-Ni-rare earth element-based Al-based alloy sputtering targets, the technique of the present invention is positioned particularly as a technique specialized for Al-Ni-La-Cu-based Al-based alloy sputtering targets.

It is preferable that the quantity of Ni contained in the Al-based alloy of this invention exists in the range of 0.05 atomic% or more and 5 atomic% or less. These ranges are determined in consideration of the experimental results using the aforementioned "Al-Ni-La-based Al-based alloy sputtering target of the related art". When the lower limit of the amount of Ni is less than 0.05 atomic%, the area ratio occupied by the intermetallic compound of less than 0.3 μm increases, and the intermetallic compound drops off when machining the sputtering target surface, thereby increasing the surface area of the unevenness. The number of increases. On the other hand, when the upper limit of the amount of Ni exceeds 5 atomic%, the area ratio of the intermetallic compound of more than 3 µm increases, and the surface unevenness increases when machining the sputtering target surface, thereby mixing non-conductive inclusions such as oxides. As this increases, the number of initial splashes increases. As for content of Ni, it is more preferable that they are 0.1 atomic% or more and 4 atomic% or less, and it is still more preferable that they are 0.2 atomic% or more and 3 atomic% or less.

Moreover, it is preferable that the quantity of La contained in the Al-based alloy of this invention exists in the range of 0.10 atomic% or more and 1 atomic% or less. These ranges are determined in consideration of the experimental results using the aforementioned "Al-Ni-La-based Al-based alloy sputtering target of the related art". If the lower limit of La amount is less than 0.10 atomic%, the area ratio of the intermetallic compound of less than 0.2 占 퐉 increases, and the intermetallic compound drops off when machining the sputtering target surface, thereby increasing the surface area of the unevenness. The number of increases. On the other hand, when the upper limit of La amount exceeds 1 atomic%, the area ratio occupied by the intermetallic compound of more than 2 µm increases, and the surface unevenness becomes large when machining the sputtering target surface, thereby mixing non-conductive inclusions such as oxides. As this increases, the number of initial splashes increases. As for content of La, it is more preferable that they are 0.15 atomic% or more and 0.8 atomic% or less, and it is still more preferable that they are 0.2 atomic% or more and 0.6 atomic% or less.

It is preferable that content of Cu exists in the range of 0.10 atomic% or more and 2 atomic% or less. These ranges are computed based on the experimental result of the Example mentioned later. When the lower limit of the amount of Cu is less than 0.10 atomic%, the area ratio of the intermetallic compound of less than 0.2 µm increases, and the intermetallic compound drops off when machining the sputtering target surface, thereby increasing the surface area of the unevenness. The number of increases. On the other hand, when the upper limit of the amount of Cu exceeds 2 atomic%, the area ratio of the intermetallic compound of more than 2 µm increases, and the surface unevenness increases when machining the sputtering target surface, thereby mixing non-conductive inclusions such as oxides. As this increases, the number of initial splashes increases. As for content of Cu, it is more preferable that they are 0.10 atomic% or more and 1 atomic% or less.

The Al-based alloy used in the present invention contains Ni, La, and Cu as described above, and the remainder is Al and inevitable impurities. Examples of unavoidable impurities include elements inevitably incorporated in the manufacturing process and the like, such as Fe, Si, C, O, and N, and the amounts thereof are respectively 0.05% by weight or less, Si: 0.05% by weight or less. It is preferable to set it as 0.05 weight% or less, O: 0.05 weight% or less, and N: 0.05 weight% or less.

Next, the intermetallic compound which characterizes this invention is demonstrated.

In the sputtering target of the present invention, the following intermetallic compounds present in the sputtering target satisfy the following requirements (1) and (2).

(1) Al-Ni having an average particle diameter in the range of 0.3 µm or more and 3 µm or less with respect to the total area of the Al-Ni-based intermetallic compound mainly composed of Al and Ni. The total area of the intermetallic compound is 70% or more in area ratio.

(2) Al having an average particle diameter of 0.2 µm or more and 2 µm or less with respect to the total area of the Al-La-Cu-based intermetallic compound mainly composed of Al, La, and Cu. The total area of the -La-Cu based intermetallic compound is 70% or more in area ratio.

As described above, in the Al-Ni-La-Cu-based Al-based alloy sputtering target targeted in the present invention, when the intermetallic compound in the SEM reflecting electron image is analyzed by the measuring method described in detail later, it is observed. The main intermetallic compounds that can be used are Al-Ni-based binary intermetallic compounds and Al-La-Cu-based ternary intermetallic compounds as described above, and Al-Ni-Nd-based Al-based alloys that have been typically used up to now. Al-Ni-La tertiary intermetallic compounds of the same kind as the Al-Ni-Nd ternary intermetallic compounds seen when the sputtering target is observed by the same measuring method are substantially absent (described above with reference to FIGS. 2A to 2D). See).

In the present invention, for each of the above-described intermetallic compounds, an increase in the area ratio (drop ratio) of the intermetallic compound having an average particle diameter within a predetermined range is based on the results of experiments in which an initial splash can be effectively prevented. In this case, the droplet ratio of these intermetallic compounds is set as much as possible (in the present invention, 70% or more).

The mechanism of prevention of splash generation by the intermetallic compound is estimated as follows.

That is, it is considered that the cause of the initial splash is that the intermetallic compound is eliminated when the surface of the sputtering target is generally machined to increase the surface area of the unevenness. And (1) When speaking about the Al-Ni type intermetallic compound which mainly uses Al and Ni, when the area ratio which the intermetallic compound whose average particle diameter is less than 0.3 micrometer occupies becomes large, the number of initial splashes will increase and mean particle size will be increased. If the area ratio of the intermetallic compound exceeding 3 µm increases, the incorporation of non-conductive inclusions such as oxides increases due to the increase in surface irregularities due to machining, resulting in an increase in the number of initial splashes. This tendency is similarly observed for the Al-La-Cu-based intermetallic compound mainly composed of Al, La, and Cu. When the area ratio occupied by the intermetallic compound having an average particle diameter of less than 0.2 µm increases, If the number of occurrences increases and the area ratio of the intermetallic compound with an average particle diameter of more than 2 µm increases, the incorporation of non-conductive inclusions such as oxides increases due to the increase in surface irregularities by machining. The number of initial splashes is increased.

In addition, the range of the average particle diameter of the intermetallic compound which contributes to the prevention of the initial splash is slightly different between the Al-Ni-based intermetallic compound and the Al-La-Cu-based intermetallic compound, these intermetallic compounds and the Al mother phase It is estimated that the interface strength of is attributable to being different. That is, the interface strength of the Al-La-Cu-based intermetallic compound and the Al mother phase is larger than that of the Al-Ni-based intermetallic compound and the Al mother phase.

In this invention, the droplet ratio of the intermetallic compound whose average particle diameter satisfy | fills the said range shall be 70% or more in area ratio. The more the said dripping rate, the better, and also in any intermetallic compound, it is preferable that it is 75% or more, for example, and it is more preferable that it is 80% or more.

The measuring method of the particle size distribution of the said intermetallic compound made into object by this invention is as follows.

First, an Al-Ni-La-Cu-based Al-based alloy sputtering target containing Ni, La, and Cu is prepared.

Next, about the measurement surface of the said sputtering target (from 1 / 4t (t is thickness) to 3 / 4t arbitrary parts in the cross section of the perpendicular | vertical direction (rolling surface normal direction, ND) with respect to a plane) And SEM with EDX (in later examples, Quanta 200FEG manufactured by Philips or Supra-35 manufactured by Carl Zeiss) were observed at a magnification of 2000 times to take a reflection electron image. In addition, the said measurement surface is mirror-polished previously. One-view size shall be about 60 micrometers x 50 micrometers. The photographed reflected electron image was analyzed using an analyzer ("NanoHunter NS2K-Pro" manufactured by Nano System Co., Ltd.), and the average particle diameter of the Al-Ni-based intermetallic compound and the Al-La-Cu-based intermetallic compound (Circle equivalent diameter) and the area ratio which the intermetallic compound of the said average particle diameter occupies in all the intermetallic compounds. In this way, the area ratio of the total 3 fields is calculated | required, and let the average value be the area ratio of each intermetallic compound.

According to the above measurement method, the Al-Ni-based intermetallic compound and the Al-La-Cu-based intermetallic compound are easily distinguished by the color tone difference (light tea). The reflection electron image of the Al-Ni-based intermetallic compound is gray, and the Al-La-Cu-based intermetallic compound is white.

For reference, in Fig. 1A to Fig. 1C, the SEM reflecting electron image (Fig. 1A) obtained by the method described above with respect to No. 5 (Example 1) of Table 1 described in Examples described later, Al-Ni-based intermetallics The image of a compound (FIG. 1B) and the image of an Al-La-Cu system intermetallic compound (FIG. 1C) are shown. As shown in Fig. 1A, the reflected electron image of the Al-La-Cu-based intermetallic compound is whitened as compared with the Al-Ni-based intermetallic compound.

2B to 2D, the parent image (in Fig. 2A, 1), gray compound (in Fig. 2A, 2), and white compound (Fig. The result of EDX analysis of the composition of 3) in 2a is respectively shown. As shown in FIG. 2B, the mother phase 1 is substantially composed of Al alone, and the gray compound (2) is substantially composed of Al and Ni as shown in FIG. 2C, and the white compound (3). As shown in FIG. 2D, it was confirmed that silver was substantially composed of Al, La, and Cu.

Next, a method of manufacturing the sputtering target of the present invention will be described.

First, a molten Al-Ni-La-Cu-based Al-based alloy having a Ni amount of 0.05 atom% or more and 5 atom% or less, La amount of 0.10 atom% or more and 1 atom% or less and Cu amount of 0.10 atom% or more and 2 atom% or less is prepared. .

Next, using the Al-based alloy described above, an Al-based alloy preform (intermediate before obtaining the final dense body) is preferably produced by spray forming, and then the preform is densified by densification means.

Here, the spray-forming method is a method of atomizing various molten metals with gas, depositing quenched particles in a semi-melt state, a reaction solid state, and a solid state to obtain a casting (preform) having a predetermined shape. According to this method, it is possible to obtain a large-scale preform, which is difficult to obtain by melt casting, powder sintering, etc. in a single process, to refine the crystal grains, and to uniformly disperse alloy elements. have.

The manufacturing process of a preform melt | dissolves within the range of (liquid temperature +150 degreeC)-(liquid temperature +300 degreeC), and the process of obtaining the molten metal of an Al-type alloy, and the molten metal of an Al-based alloy, gas outflow amount / molten metal The process of atomizing the gas / metal ratio represented by the ratio of the outflow amount by gas atomization under the condition of 6Nm3 / kg or more, and the process of obtaining the preform by depositing the refined Al-based alloy on the collector under the spraying distance of about 900 to 1200 mm. It includes.

Hereinafter, each process for obtaining a preform is explained in full detail, referring FIG. 3 and FIG.

3 is a cross-sectional view partially showing an example of an apparatus used to manufacture the preform of the present invention. 4 is an enlarged view of a main part of X in FIG. 3.

The apparatus shown in FIG. 3 includes an induction melting furnace 1 for dissolving Al-based alloys, gas atomizers 3a and 3b provided below the induction melting furnace 1, and a collector 5 for depositing a preform. Equipped. The induction melting furnace 1 has a nozzle 6 for dropping the molten metal 2 of an Al-based alloy. In addition, the gas atomizers 3a and 3b have gas holes 4a and 4b of the bobbin for atomizing the gas, respectively. The collector 5 has drive means (not shown), such as a stepping motor, for lowering the collector 5 so that the height of a preform deposition surface may become constant even if manufacture of a preform advances.

First, an Al-based alloy of the above-described composition is prepared. After injecting this Al-based alloy into the induction melting furnace 1, it is preferably dissolved in an inert gas (for example, Ar gas) atmosphere within the range of approximately + 150 ° C to + 300 ° C relative to the liquidus temperature of the Al-based alloy. do.

Melting temperature is generally performed in the range of liquid temperature +50 degreeC to +200 degreeC (for example, Unexamined-Japanese-Patent No. 9-248665), but in this invention, particle size distribution of the two types of intermetallic compounds mentioned above is made. In order to control suitably, it set in the said range. In the case of the Al-Ni-La-Cu-based Al-based alloy targeted in the present invention, it is carried out at approximately 850 to 1000 ° C. If the melting temperature is less than 850 ° C., clogging of the nozzles occurs in spray forming. On the other hand, if the temperature exceeds 100 ° C., the droplet temperature becomes high. Therefore, the area ratio of the Al-Ni-based intermetallic compound having an average particle diameter of 3 μm or more occupies As it increases, the desired splash reduction effect is not obtained (see later examples). It is preferable that the melting temperature of an alloy exists in the range of (liquid temperature +150 degreeC)-(liquid temperature +300 degreeC). In the case of the Al-Ni-La-Cu-based Al-based alloy targeted in the present invention, the temperature is preferably 850 to 1000 ° C, more preferably 900 to 1000 ° C.

Next, the molten metal 2 of the alloy obtained as described above is dropped through the nozzle 6 in the chamber (not shown) in an inert gas atmosphere. In the chamber, high-pressure inert gas jets are sprayed onto the molten alloy 2 from the gas holes 4a and 4b of the bobbins formed in the gas atomizers 3a and 3b, thereby minimizing the molten alloy.

It is preferable to perform gas atomization using inert gas or nitrogen gas, and oxidation of a molten metal is suppressed by this. As an inert gas, argon gas etc. are mentioned, for example.

Here, gas / metal ratio shall be 6 Nm <3> / kg or more. The gas / metal ratio is represented by the ratio of gas outflow amount (Nm 3) / melt outflow amount (kg). In the present specification, the gas outflow amount means the total amount (finally used amount) of the gas flowing out from the gas holes 4a and 4b of the bobbin in order to gas atomize the molten Al alloy. In addition, in this specification, a molten metal outflow quantity means the total amount of the molten metal which flows out from the molten metal outlet (nozzle 6) of the container (induction melting furnace 1) in which molten metal of Al-group alloy was contained.

If the gas / metal ratio is less than 6 Nm 3 / kg, the droplet size tends to be large, so that the cooling rate decreases and the droplet ratio of the Al-Ni intermetallic compound having an average particle diameter of more than 3 µm increases, so that a desired effect is not obtained. (See later examples).

The larger the gas / metal ratio is, the better it is, for example, preferably 6.5 Nm 3 / kg or more, and more preferably 7 Nm 3 / kg or more. In addition, although the upper limit is not specifically limited, Taking into consideration the stability, cost, etc. of the droplet flow at the time of gas atomization, it is preferable to set it as 15Nm <3> / kg, and it is more preferable that it is 10Nm <3> / kg.

In addition, when the angle formed by the opposed gas atomizing nozzle central axes 6a and 6b is 2α, it is preferable to control α in the range of 1 to 10 degrees. The angle 2α formed by the opposed gas atomizing nozzle central axes 6a and 6b is a line (spray axis A) when the molten metal 2 falls directly below as shown in FIG. Equivalent] means the total angle of the respective inclinations α of the gas atomizers 4a and 4b. Hereinafter, this alpha is called "gas atomization exit angle (alpha)". As for gas atomization exit angle (alpha), it is more preferable that they are 1 degree or more and 7 degrees or less.

Subsequently, the Al base alloy (droplets) refined as described above is deposited on the collector 5 to obtain a preform.

Here, it is preferable to control spray distance within the range of 900-1200 mm. The spray distance defines the accumulation position of the droplets, and as shown in FIG. 3, from the tip end portion (Al in FIG. 3) of the nozzle 6 to the center (A2 in FIG. 3) of the collector 5. Means the distance (L). As will be described later, since the collector 5 is inclined at the collector angle β, the spray distance L is strictly sprayed by the front end of the nozzle 6 and the horizontal line of the center A2 of the collector 5. The distance of the point (A3 in FIG. 3) which intersects the axis A is meant. Here, the spray shaft A defines the direction in which the droplet of the Al base alloy falls directly below for the convenience of explanation.

In general, the spray distance in the spray forming is often controlled at about 500 mm. However, in the present invention, in order to obtain a desired particle size distribution for the two types of intermetallic compounds, the spray distance is set in the above-described range. See example. If it is less than 900 mm, since droplets of a high temperature state accumulate on a collector, cooling rate will fall and the droplet ratio of the Al-Ni type intermetallic compound of average particle diameter 3 micrometers or more increases, and a desired effect is not acquired. On the other hand, when spray distance exceeds 1200 mm, yield will fall. As for the spray distance L, it is more preferable to exist in the range of about 950-1100 mm.

Moreover, it is preferable to control the collector angle (beta) in 20-45 degrees. Collector angle (beta) means the inclination of the collector 5 with respect to the spray axis A as shown in FIG.

In the above, the preferable method for obtaining a preform was demonstrated.

The Al-based alloy preform obtained in this manner may be densified by a densification means to obtain a dense body, and then a sputtering target may be produced by a conventional method of performing plastic working on the dense body.

First, an Al-based alloy dense body is obtained by subjecting the preform to densification means. As the densification means, it is preferable to perform a method of pressurizing the preform in substantially the same direction, in particular hot hydrostatic pressing (HIP: Hot Isostatic Pressing) for pressing in hot. Specifically, HIP treatment is preferably performed at a temperature of 400 to 600 ° C, more preferably 500 to 570 ° C under a pressure of 80 MPa or more, more preferably 90 MPa or more. The time of the HIP treatment is preferably about 1 to 10 hours, more preferably within the range of 1.5 to 5 hours.

Next, plastic working is performed on the dense body of the Al-based alloy to obtain a fired body of the Al-based alloy.

Specifically, it is preferable to obtain a slab by forging an Al-based alloy dense body.

The forging condition is not particularly limited as long as it is a method usually used for producing a sputtering target. For example, the Al-based alloy dense body before forging is about 500 ° C, more preferably about 480 to 500 ° C for about 1 to 3 hours. Preferably, forging is performed after heating 1.5 to 2.5 hours.

The slab obtained as described above is subjected to rolling under conditions of a rolling temperature of 300 to 550 ° C, more preferably 350 to 500 ° C and a total reduction ratio of 40 to 90%, more preferably 50 to 80%. As shown in Examples later, in the present invention, it is necessary to precisely control the rolling conditions as described above, and if any of the rolling is performed under conditions outside the above ranges, the desired crystal structure cannot be obtained.

Here, the total reduction ratio is represented by the following formula.

Total rolling reduction (%)

= {(Thickness before rolling start)-(thickness after rolling end)} / (thickness before rolling start) × 100

In addition, since the Al-based alloy produced by the spray forming method is difficult to change the structure during processing, it can be produced by either cold rolling or hot rolling, but in order to increase the processing rate per one pass as described above, Since it is effective to heat an Al base alloy material and process it in the temperature range with low deformation resistance, it is preferable to employ hot rolling.

Next, heating (annealing) is performed at a temperature of 250 to 500 ° C, more preferably 250 to 400 ° C for 0.5 to 4 hours, more preferably 1.5 to 3.5 hours. The atmosphere at the time of heat processing is not specifically limited, Although it can carry out in any atmosphere in air | atmosphere, inert gas, and vacuum, in consideration of productivity, cost, etc., it is preferable to heat in air | atmosphere.

After performing the above heat treatment, if the machining is performed in a predetermined shape, a desired sputtering target is obtained.

The Al-Ni-La-Cu alloy sputtering target of the present invention can be in direct contact with the wiring material of the Al-Ni-La-Cu alloy film which can be in direct contact with the conductive oxide film constituting the pixel electrode, and the semiconductor layer of the thin film transistor. It is especially suitably used for producing the wiring material of the Al-Ni-La-Cu alloy film.

(Example)

Hereinafter, although an Example is given and this invention is demonstrated more concretely, this invention is not limited to the following Example, It is also possible to add and implement a change suitably in the range which can be adapted to the meaning of this invention, They are all included in the technical scope of this invention.

(First embodiment)

Using an Al-based alloy having various compositions shown in Tables 1 and 2, an Al-based alloy preform (density: about 50 to 60%) was obtained by the following spray forming method.

(Spray forming condition)

Melting temperature: 800 to 1100 ℃

Gas / Metal Ratio: 5 to 8 Nm3 / kg

Spray distance: 800 to 1300 mm

Gas atomization exit angle α (see FIG. 4): 7 °

Collector angle (β): 35 °

The preform thus obtained was enclosed in a capsule and degassed, and a hot hydrostatic press (HIP) was performed on the entire capsule to obtain an Al-Ni-La-Cu-based Al-based alloy compact. HIP process was performed by HIP temperature: 550 degreeC, HIP pressure: 85 Mpa, and HIP time: 2 hours.

Next, the obtained dense body is forged to form a plate-shaped metal material and further subjected to rolling so that the plate thickness is approximately the same as that of the final product (sputtering target), followed by annealing and machining (circular punching and lathe processing). Al- (0.02 to 6.0 atomic%) Ni- (0.05 to 1.5 atomic%) La- (0.05 to 2.5 atomic%) Cu-based Al-based alloy sputtering target (size: diameter 101.6 mm x thickness 5.0 mm) Was prepared. Detailed conditions are as follows.

Heating condition before forging: 2 hours at 500 ℃

Heating condition before rolling: 2 hours at 400 ℃

Total rolling reduction: 50%

Annealing condition: 2 hours at 250 ℃

Next, using each sputtering target obtained by the above method, the number of splashes (initial splashes) generated when sputtering was performed under the following conditions was measured.

First, DC magnetron sputtering was performed on the Si wafer substrate (size: diameter 100.0 mm x thickness 0.50 mm) using the sputtering apparatus of the "sputtering system HSR-542S" by Shimadzu Corporation. Sputtering conditions are as follows.

Back pressure: 3.0 × 10 ^-6 Torr or less

Ar gas pressure: 2.25 × 10 ^-3 Torr

Ar gas flow rate: 30sccm

Sputtering Power: 811 W

Interval distance: 51.6 mm, substrate temperature: room temperature

Sputtering Time: 81 Seconds

Thus, 16 thin films (total thickness 0.2mm) were formed with respect to one sputtering target. Therefore, sputtering was performed for 81 (seconds) x 16 (sheets) = 1296 seconds.

Next, using the particle counter (TOPM wafer surface inspection apparatus WM-3), the position coordinates, the size (average particle diameter), and the number of particles recognized on the surface of the thin film were measured. Here, it is assumed that the size is 3 µm or more as particles. Subsequently, the surface of this thin film was observed under an optical microscope (magnification: 1000 times), and the shape of a hemispherical shape was regarded as a splash, and the number of splashes per unit area was measured.

Specifically, the above-mentioned sputtering process is performed on one thin film in the same manner for 16 thin films continuously while replacing the Si wafer substrate, and the average value of the number of splashes is referred to as "number of initial splashes." It was set as. In this embodiment, the number of initial splashes obtained in this manner is less than 8 / cm 2 as "initial splash reduction effect: pass (A)", and the number of 8 or more cm 2 or more is "no initial splash reduction effect: rejection". (B) ”.

These results are written together in Table 1. For reference, the particle size distribution of the Al-Ni-based intermetallic compound is shown in FIG. 5 and the particle size distribution of the Al-La-Cu-based intermetallic compound is shown in FIG. .

From Table 1 and Table 2, it can consider as follows.

Nos. 2 to 6, 9 to 11, 14 to 16, 19 to 21, 24 to 26, 28 to 30, Al-Ni-La-Cu alloy sputtering target Al-Ni-based intermetallic compound and Al-La-Cu Since the particle size distribution of the intermetallic compound is properly controlled, the number of initial splashes is less than 8 / cm 2, and the effect of reducing initial splash is excellent.

On the other hand, the number 1 is an example using an Al-based alloy with a small amount of Ni, the number 7 is an example using an Al-based alloy with a large amount of Ni, the number 8 is an example using an Al-based alloy with a small amount of La, and the number 12 is an Al group with a large amount of La Example using an alloy, No. 13 is an example of using an Al-based alloy with a small amount of Cu, No. 17 is an example of using an Al-based alloy having a large amount of Cu, all Al-Ni-based intermetallic compound and Al- to contribute to the prevention of the initial splash Since the area ratio of the La-Cu system intermetallic compound is small, the generation of the initial splash could not be prevented effectively.

No. 18 is a low melting temperature of the Al-Ni-La-Cu alloy, and since nozzle clogging occurred in spray forming, spray forming was stopped and subsequent electron microscope observation and image analysis could not be performed.

No. 22 is a high melting temperature of the Al-Ni-La-Cu-based alloy, and since the area ratio of the Al-Ni-metal intermetallic compound that contributes to preventing the occurrence of the initial splash is small, the initial splash can be effectively prevented. Could not.

Numeral 23 is a low gas / metal ratio in the gas atomization process of the molten Al-Ni-La-Cu alloy. Therefore, the occurrence of the initial splash could not be prevented effectively.

No. 27 is an example of a short spray distance in the process of depositing an Al-Ni-La-Cu alloy on a collector. Since the area ratio of the Al-Ni-based intermetallic compound which contributes to the prevention of the initial splash is small, The occurrence of splash could not be prevented effectively.

No. 31 is a long spray distance in the process of depositing an Al-Ni-La-Cu-based alloy on the collector, and a decrease in yield occurred in spray forming. Therefore, it did not advance to a subsequent process and the electron microscope observation and image analysis could not be performed.

FIG. 1A is an SEM reflecting electron image in No. 5 (Example 1) of Table 1, FIG. 1B is an image of an Al—Ni-based intermetallic compound in the SEM reflecting electron image, and FIG. 1C is Al in the SEM reflecting electron image. A diagram showing an image of a La-Cu based intermetallic compound.

FIG. 2A is a diagram showing an SEM reflecting electron image in No. 5 (Example 1) of Table 1. FIG.

FIG. 2B is a diagram showing a result of EDX analysis of the composition of 1 (parent phase) in FIG. 2A. FIG.

It is a figure which shows the result of EDX analysis of the composition of 2 (gray compound) in FIG. 2A.

It is a figure which shows the result of EDX analysis of the composition of 3 (white compound) in FIG. 2A.

3 is a cross-sectional view partially showing an example of an apparatus used to manufacture a preform.

4 is an enlarged view of a main part of X in FIG. 3;

FIG. 5 is a graph showing the particle size distribution of Al-Ni-based intermetallic compounds for No. 5 (Examples) in Table 1. FIG.

FIG. 6 is a graph showing the particle size distribution of Al-La-Cu based intermetallic compounds for No. 5 (Examples) in Table 1. FIG.

<Explanation of symbols for the main parts of the drawings>

1: induction melting furnace

2: molten Al alloy

3a, 3b: gas atomizer

4a, 4b: gas hole of bobbin

5: collector

6: nozzle

6a, 6b: gas atomizing nozzle central axis

A: spray shaft

Al: distal end of the nozzle 6

A2: center of collector 5

A3: the point where the horizontal line of the center A2 of the collector 5 intersects the spray axis A

L: Spray Distance

α: gas atomizing exit angle

β: collector angle

Claims (4)

Al-Ni-La-Cu-based Al-based alloy sputtering target containing Ni, La and Cu, When t is set to the thickness in the direction perpendicular to the plane of the sputtering target, the area of 1 / 4t to 3 / 4t in the cross section perpendicular to the plane of the sputtering target is magnified using a scanning electron microscope. When observed at 2000 times, (1) The total area of Al-Ni-based intermetallic compounds having an average particle diameter in the range of 0.3 µm or more and 3 µm or less with respect to the total area of Al-Ni-based intermetallic compounds mainly composed of Al and Ni is the area ratio. Is 70% or more, and (2) The total area of Al-La-Cu-based intermetallic compounds having an average particle diameter of 0.2 µm or more and 2 µm or less with respect to the total area of Al-La-Cu-based intermetallic compounds mainly composed of Al, La, and Cu, Al-Ni-La-Cu system Al base alloy sputtering target which is 70% or more by area ratio. Ni: 0.05 atomic% or more and 5 atomic% or less, La: 0.10 atomic% or more and 1 atomic% or less, Cu: Al-Ni-La-Cu system Al-base alloy sputtering target containing 0.10 atomic% or more and 2 atomic% or less. It is a manufacturing method of the Al-Ni-La-Cu type | system | group Al base alloy sputtering target of Claim 1, 850-1000 degreeC of Al-Ni-La-Cu type | system | group Al-type alloy whose Ni amount is 0.05 atomic% or more and 5 atomic% or less, La amount is 0.10 atomic% or more and 1 atomic% or less, and Cu amount is 0.10 atomic% or more and 2 atomic% or less The first step of obtaining a molten metal, A second step of gas atomizing the molten metal of the Al-based alloy at a gas / metal ratio of 6 Nm 3 / kg or more to refine the Al-based alloy; A third step of depositing the micronized Al-based alloy on the collector under a spray distance of 900 to 1200 mm to obtain a preform of the Al-based alloy; A fourth step of densifying the preform of the Al-based alloy by means of densification means to obtain a dense body of the Al-based alloy; A fifth step of performing plastic working on the dense body of the Al-based alloy to obtain a plastic-worked body of the Al-based alloy; The manufacturing method of the Al-Ni-La-Cu type | system | group Al base alloy sputtering target containing the 6th process of carrying out annealing to the plastic workpiece of the said Al base alloy. It is a manufacturing method of the Al-Ni-La-Cu type | system | group Al base alloy sputtering target of Claim 2, 850-1000 degreeC molten metal of Al-Ni-La-Cu type | system | group Al group alloy whose Ni amount is 0.05 atomic% or more and 5 atomic% or less, La amount is 0.10 atomic% or more and 1 atomic% or less, and Cu amount is 0.10 atomic% or more and 2 atomic% or less The first step of obtaining A second step of gas atomizing the molten metal of the Al-based alloy at a gas / metal ratio of 6 Nm 3 / kg or more to refine the Al-based alloy; A third step of depositing the micronized Al-based alloy on the collector under a condition of a spray distance of 900 to 1200 mm to obtain a preform of the Al-based alloy; A fourth step of densifying the preform of the Al-based alloy by means of densification means to obtain a dense body of the Al-based alloy; A fifth step of performing plastic working on the dense body of the Al-based alloy to obtain a plastic-worked body of the Al-based alloy; The manufacturing method of the Al-Ni-La-Cu type | system | group Al base alloy sputtering target containing the 6th process of carrying out annealing to the plastic workpiece of the said Al base alloy.

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