TWI431140B - Method for manufacturing sputtering standard materials for aluminum - based alloys - Google Patents

Description

Method for manufacturing aluminum-based alloy sputtering target material

The invention relates to a method for manufacturing an aluminum-based alloy sputtering target material with excellent qualification rate, and an aluminum-based alloy sputtering target material manufactured by the method.

The aluminum-based alloy sputtering target material is mainly produced by a dissolution method, a spray molding method, a powder method, or the like.

The dissolution method is a method in which a molten metal is molded by a mold to manufacture a wide variety of alloy sputtering target materials. However, when the amount of the alloy added is large, the dissolution method precipitates crystals of the coarse intermetallic compound, which is caused by cracking in the casting or molding process. Further, when a melting point such as ruthenium or a high-melting-point high-density element having a higher density than aluminum is used as the alloying element, solidification segregation is generated. Therefore, when a metal-based alloy sputtering target material such as ruthenium is produced by a dissolution method, the yield is lowered.

The spray molding method is a method in which a molten metal (melt) is atomized by a gas to accumulate particles which are quenched in a semi-solidified state to form a preform having a predetermined shape. However, an aluminum-based alloy containing a high melting point element having a high melting point such as yttrium causes occlusion in the melt nozzle at a low temperature. When the melt and the droplet temperature of the aluminum-bismuth alloy or the like are increased, the particles containing a large amount of liquid phase are scattered and scattered. The result will reduce the pass rate.

The method of mixing the monomer metal powder with the powder is mostly used for the production of an aluminum-based alloy having a composition which is difficult to manufacture. However, the metal powder of the rare earth element monomer is easily oxidized, so the powder method is difficult to be applied to the manufacture of an aluminum-based alloy sputtering target material containing a rare earth element.

Further, Patent Document 1 and Patent Document 2 disclose a method of producing a sputtering target material by a combination of a dissolution method and a powder method. Patent Document 1 discloses that first, (1) an inert gas atomization method is used to produce a bismuth-niobium alloy and a ruthenium-iridium alloy powder, and secondly, (2) the above two alloy powders are mixed and sintered to produce a ruthenium-iridium-ruthenium-based sputtering. The method of target material. Further, Patent Document 2 discloses a method of producing a sputtering target material by mixing a solid alloy powder produced by a rapid solidification method and a platinum monomer metal powder, and then treating the mixed powder by HIP (Hot Isostatic Pressing).

Prior technical literature Patent literature

Patent Document 1: Japanese Patent No. 3703648

Patent Document 2: Japanese Laid-Open Patent Publication No. 2006-144124

SUMMARY OF THE INVENTION An object of the present invention is to provide an aluminum-based alloy sputtering target material which can produce a rare earth element and a high melting point element having a melting point higher than that of aluminum at a good yield.

The gist of the present invention is as follows.

[1] A method for producing an aluminum-based alloy sputtering target material, which comprises a method for producing an aluminum-based alloy sputtering target material containing a rare earth element and a high melting point element X having a melting point higher than that of aluminum a step of preparing a first powder of an aluminum-based alloy containing a rare earth element (hereinafter abbreviated as "REM") produced by an atomization method, and mixing the first powder and a second powder containing one or more of the aforementioned high melting point elements X And a step of refining the mixed powder of the first powder and the second powder, wherein the first powder has a maximum particle diameter (a) of 10 to 200 μm and a maximum particle diameter of the second powder. (b) is 10 to 150 μm, and the ratio (a)/(b) of the maximum particle diameter (a) of the first powder to the maximum particle diameter (b) of the second powder is 0.5 to 5.

Further, it is preferable that the second powder is composed of one or more of the high melting point elements X.

[2] The production method according to [1], wherein the rare earth element is at least one of cerium and lanthanum.

[3] The production method according to [1] or [2] wherein the high melting point element X is at least one selected from the group consisting of titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, and nickel. .

[4] The production method according to any one of [1] to [3], which is to produce aluminum having 1.0 to 10 at% of the foregoing rare earth element, and 0.5 to 5 at% of the aforementioned high melting point element X. Base alloy sputtering target material.

[5] An aluminum-based alloy sputtering target material produced by the production method according to any one of [1] to [4].

The present invention can be produced at a good yield, mixing a first powder of an Al-REM-based aluminum-based alloy (hereinafter abbreviated as "Al-REM alloy") produced by an atomization method, and a high melting point element having a melting point higher than that of aluminum (below When the second powder composed of X is used, the Al-REM-X-based aluminum-based alloy (hereinafter referred to as "Al-REM-X alloy") sputtering target material having the largest particle diameter and ratio can be appropriately controlled.

Form of implementing the invention

The present inventors have made an Al-REM-X alloy sputtering target material containing an easily oxidizable rare earth element (REM) and a high melting point element (X) having a melting point higher than that of aluminum in order to provide a good yield which does not cause segregation. After reviewing, it is found that when mixing the first powder of the Al-REM alloy and the second powder of the high melting point element X, the maximum particle diameter (a) of the first powder and the maximum particle diameter of the second powder are appropriately controlled (b) And the ratio ((a)/(b)) can achieve the desired purpose to complete the present invention. In detail, the method of the present invention can prevent vibration segregation or rolling segregation during powder mixing, powder handling after mixing, and fine-graining treatment (especially when HIP-treated capsules are filled), and enhance the sputtering target material. Pass rate.

The manufacturing method of the present invention includes

(1) a step of preparing a first powder of an Al-REM alloy produced by an atomization method,

(2) a step of mixing the first powder and a second powder composed of a high melting point element X having a higher melting point than aluminum, and

(3) a step of making the mixed powder of the first powder and the second powder fine. Further, if necessary, the fines obtained in the above step (3) can be subjected to plastic working (forging, calendering, extrusion processing, etc.), rotary disk processing, milling processing, and the like. The above steps (1) to (3) will be described in detail below in order.

[step 1)]

The step (1) is to prepare a first powder of an Al-REM alloy produced by an atomization method. In the production method of the present invention, since the metal powder of the REM monomer is not used, the Al-REM alloy powder (first powder) is used, so that oxidation of the REM can be prevented.

The atomization method for producing the first powder is not particularly limited, and an atomization method (for example, a gas atomization method, a water atomization method, a centrifugal force atomization method, or the like) widely known in the field of aluminum alloy can be used. The atomization method has the advantages of easy control of the particle size distribution of the produced powder.

[Step (2)]

Next, the most characteristic step (2) of the method of the present invention will be explained.

The step (2) is a step of mixing the above Al-REM alloy powder (first powder) and a second powder having a melting point higher than that of the high melting point element (X) of aluminum. When the high melting point element (X) is added after the production of the Al-REM alloy powder as described above, the Al-REM alloy sputtering target material can be produced with good yield.

The above high melting point element X is an element having a melting point higher than that of aluminum, specifically a group 4 to 6 element of titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum or tungsten, and nickel. These high melting point elements may be contained in one type or two or more types. As described in detail later, when an aluminum-based alloy sputtering target material containing these elements and rare earth elements is particularly suitable for producing an aluminum-based alloy reflective film of an optical information recording medium, it is known that the above-mentioned high melting point element can be imparted with a lowering The thermal conductivity of aluminum-based alloys and the improvement of corrosion resistance. That is, the alloy composition and content of the aluminum-based alloy sputtering target material obtained by the method of the present invention can be appropriately determined by the use and characteristics of the aluminum alloy film obtained by using the sputtering target material. The details will be described later.

The second powder composed of the high melting point element X may be a single sweet potato powder of only one high melting point element or an alloy powder containing two or more high melting point elements. Further, two or more kinds of second powders having different compositions may be used.

In the production method of the present invention, the method for producing the second powder is not particularly limited, and it can be produced by any one of a mechanical pulverization method, a chemical reaction method, an electrolysis method, and an atomization method. For example, the second powder may be obtained by mechanically pulverizing the single metal of the high melting point element X after the melting by a mold.

The most characteristic feature of the mixing step of the above step (2) in the present invention is that the maximum particle diameter (a) of the first powder and the maximum particle diameter (b) of the second powder are appropriately controlled, and the ratio thereof ((a)/(b) )). Specifically, the maximum particle diameter (a) of the first powder is 10 to 200 μm, the maximum particle diameter (b) of the second powder is 10 to 150 μm, and the maximum particle diameter (a) of the first powder is the same as the foregoing The maximum particle diameter (b) of the two powders is mixed in such a manner that the ratio (a)/(b) is from 0.5 to 5. As shown in the examples below, when the maximum particle diameter and the ratio thereof are appropriately controlled, it is possible to prevent the vibration during the mixing of the powder, the conveyance of the mixed powder, and the refinement of the step (3) (especially when the capsule of the HIP treatment is filled). Segregation or rolling segregation improves the yield of the sputter target material.

The maximum particle diameter of the powder means that the particle size distribution of the powder is measured by the Fraunhofer method based on light diffraction and scattering, and when the relationship between the particle diameter and the frequency is known, the maximum particle diameter when the frequency of the large particle diameter side is 3.0% or less is removed. . The particle size distribution and the maximum particle diameter of the present Example were measured using a laser light diffraction ‧ scattering type particle size analyzer "Nikkei (microphone) MICROTRAC HRA (MODEL: 9320-X100)".

First, the maximum particle diameter (a) of the first powder (Al-REM alloy powder) is 10 μm or more (preferably 50 μm or more) and 200 μm or less (preferably 150 μm or less). When the maximum particle diameter (a) of the first powder exceeds 200 μm, the second powder easily moves between the first powders, so segregation tends to occur during mixing, transportation, and meticulating treatment. Further, the lower limit of the maximum particle diameter of the first powder is a value set within a practical range.

Further, the maximum particle diameter (b) of the second powder (metal or alloy powder of the other element X) is 10 μm or more (preferably 30 μm or more) and 150 μm or less (preferably 100 μm or less, more preferably 45 μm or less). When the maximum particle diameter (b) of the second powder exceeds 150 μm, the degree of mixing in the step (2) is lowered, and segregation is liable to occur. The lower limit of the maximum particle diameter of the second powder is a value set within a practical range.

Further, the maximum particle diameter ratio (a)/(b) of the first powder and the second powder is 0.5 or more (preferably 0.7 or more, more preferably 2 or more), 5 or less (preferably 4.5 or less, more preferably 4). the following). When the maximum particle diameter ratio (a)/(b) of the first powder and the second powder exceeds 5, the second powder easily moves between the first powders, so segregation tends to occur during mixing, transportation, and meticulating treatment. also. When the maximum particle diameter ratio (a)/(b) of the first powder and the second powder is less than 0.5, especially when the second powder composed of the element X having a relatively high density is used, the powder is not easily moved, and the step (2) is lowered. The degree of mixing is prone to segregation.

The maximum particle diameter (a) of the first powder, the maximum particle diameter (b) of the second powder, and the maximum particle diameter ratio (a)/(b) of the first powder and the second powder can be utilized, for example, in step (2). The first powder and the second powder produced by the atomization method or the like are controlled to the above range by classification (screening) or the like.

The mixing method in the step of mixing the first powder and the second powder is not particularly limited, and a known method such as a V-type mixer or the like can be used.

[Step (3)]

The aluminum-based alloy sputtering target material (fine matter) can be produced by refining the mixed powder obtained in the above step (2) in the step (3). Further, the fineness obtained in the step (3) can be further processed (for example, plastic working, rotary disc processing, milling processing, etc.), and the shape is added.

The method of refining the mixed powder is not particularly limited, but it is preferably a HIP treatment which can obtain a uniform fineness. The HIP treatment is preferably carried out at a temperature of from 400 to 600 ° C, more preferably from 500 to 570 ° C, at a pressure of 80 MPa or more, more preferably 85 MPa or more. The HIP treatment time is about 1 to 10 hours, more preferably 1.5 to 5 hours.

Further, a finening method other than the HIP treatment, for example, extrusion processing, and plastic working can be used to make the mixed powder fine.

The plastic working, the rotary disk processing, the milling processing, and the like which are performed as necessary are not particularly limited, and a known method can be employed.

The method of the present invention is suitable for the manufacture of aluminum-{rare earth element (REM)}-{melting point higher than aluminum element (X)} alloy sputtering target material. The REM is such as a lanthanide element (15 elements of 镧 to 镏) and 钪, 钇. It is preferably 钕 and/or 钇. The high melting point element X is as described above.

The sputtering target material obtained by the method of the present invention is particularly suitable for the production of an aluminum-based alloy reflective film for optical information recording. The above-mentioned reflective film is described in detail in, for example, Japanese Laid-Open Patent Publication No. 2005-158236. The above publication has described in detail that it contains 1.0 to 10.0 atomic % of REM (preferably ruthenium and/or osmium), and 0.5 to 5 atom% of titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten and The aluminum-based alloy reflective film selected from at least one of the nickel groups has excellent characteristics of low thermal conductivity, low melting temperature, high corrosion resistance, and high reflectance, and is therefore suitable for use in an optical information recording medium marked with a laser or the like. Further, such an aluminum-based alloy reflective film can be formed using a sputtering target material of the same composition.

The reflective film described in the above publication will be described in more detail below. When the aluminum-based alloy contains REM, the thermal conductivity can be greatly reduced. In REM, the effect of reducing the thermal conductivity by 钕 and 钇 is greater. The amount of REM is preferably in the range of 1.0 atom% or more and 10 atom% or less, more preferably 2.0 atom% or more and 7 atom% or less.

When the aluminum-REM alloy further contains at least one of titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten and nickel, the corrosion resistance can be improved. Further, the Group 4 to 6 element and nickel can lower the thermal conductivity of the aluminum-based alloy. Among these elements, the corrosion resistance of titanium, tantalum, niobium and chromium is improved. The content thereof is preferably 0.5 atom% or more and 5 atom% or less, more preferably 1.0 atom% or more and 3.0 atom% or less.

When the sputtering target material obtained by the method of the present invention is used as the reflective film, the composition of the sputtering target material may be 1.0 to 10 atom% (more preferably 2.0 atom% or more) of the composition of the reflective film. 7 atom% or less of REM (preferably 钕 and/or 钇), and 0.5 to 5 atom% (more preferably 1.0 atom% or more and 3.0 atom% or less) of titanium, zirconium, hafnium, vanadium, niobium, tantalum, An aluminum-based alloy of at least one high melting point element selected from the group consisting of chromium, molybdenum, tungsten, and nickel (preferably for the purpose of improving corrosion resistance) of titanium, niobium, tantalum, and chromium groups.

When the sputtering target material of the above composition is produced, the above step (1) may use a first powder of an aluminum-REM alloy containing 1.0 to 10 atomic % of REM, and the above step (2) may be used in an amount of 0.5 to 5 atom%. The second powder of the above high melting point element X.

The composition of the sputtering target material obtained by the above-described method of the present invention is preferred, but is not limited thereto. The present invention discloses a method for producing an Al-REM-X alloy sputtering target material containing a rare earth element (REM) and a high melting point element (X) having a melting point higher than that of aluminum, which can be produced by a good yield. The composition and content can be appropriately determined depending on the use and characteristics of a reflective film obtained by using the material. Therefore, when the manufacturing composition is different from the reflective film described in the above publication, a composition of a sputtering target material having a different composition of the reflecting film can be used, and such a material is also included in the scope of the present invention.

The present invention will be specifically described by the following examples, but the present invention is not limited to the following examples, and it is a matter of course that the present invention can be appropriately modified and implemented within the scope of the present invention.

Example 1

A variety of methods were used to fabricate aluminum-6 atomic % 钕 -1 atom% bismuth alloy sputter target materials, and the yield was evaluated.

First, an aluminum-6 atom% bismuth alloy powder (first powder) was produced by a nitrogen atomization method. A second powder having a volume of 1 atom% was added to the first powder and mixed using a V-type mixer. Further, in order to make the maximum particle diameter (a) of the first powder and the maximum particle diameter (b) of the second powder as shown in Table 1, the maximum particle diameter was adjusted using a sieve. The maximum particle size was measured using the above method.

Next, the mixed powder is filled into a capsule tube and then degassed and sealed. Thereafter, HIP treatment was carried out under the conditions of a maximum temperature of 550 ° C, a holding time of 2 hours, and a pressure of 85 MPa to produce an aluminum-6 atomic % 钕 -1 atom% bismuth alloy sputtering target material.

For the purpose of comparison, an aluminum-6 atom% 钕-1 atom% bismuth alloy sputtering target material was produced by the dissolution method and the spray molding method described below.

The dissolution method is as follows. A vacuum derivatization furnace was used, and a refractory crucible such as alumina or spinel was used, dissolved at an inert gas (argon) at a dissolution temperature of 1,350 ° C, and cast with a copper mold or an iron mold (210 mm × 210 mm × height 50 mm). After cutting the bottom of the obtained ingot (5 to 10 mm), it was cut into a thickness of 10 mm (product thickness: 5 mm + 5 mm), and then subjected to a rotary disk process to produce an aluminum-6 atom% 钕-1 atom% bismuth alloy sputtering target material.

The spray forming method is as follows. Using a spray molding apparatus (manufactured by Sumitomo Heavy Industries Co., Ltd.), droplets were formed by a nitrogen atomization method under the conditions of a liquid discharge temperature of 1300 ° C and a melt nozzle inner diameter of Φ 5.5 mm, and were deposited on a collector. The obtained preform was placed in a capsule tube, and after degassing and sealing, HIP treatment was carried out under the conditions of a temperature of 550 ° C, a pressure of 85 MPa, and a holding time of 2 hours. After the obtained fine material was forged and rolled, it was cut into a thickness of 10 mm (product thickness: 5 mm + 5 mm), and then subjected to a rotary disk process to produce an aluminum-6 atom% 钕-1 atom% bismuth alloy sputtering target material.

The yield of the resulting sputter target material was evaluated as the product weight/dissolution weight.

The results are shown in Table 1. In the present embodiment, based on the general criteria, an item having a yield of 40% or more is evaluated as qualified (A), and an item having less than 40% is evaluated as unacceptable (B). In addition to the segregation, the yield loss is also generated during plastic processing and machining.

It is known from Table 1 that the maximum particle diameter (a) of the first powder, the maximum particle diameter (b) of the second powder, and the maximum particle diameter ratio of the first powder to the second powder (a)/( b) No. 3, 4, 6, 9, and 10 manufactured in accordance with the method specified in the present invention can improve the yield of the product.

In contrast, Nos. 5, 7 and 8 which are incompatible with any of the above-mentioned requirements specified in the present invention which are incompatible with the scope of the present invention all reduce the yield of the product. When the previous method of the dissolution method (No. 1) and the spray molding method (No. 2) was used, the desired product yield was not obtained.

The present invention has been described with reference to the detailed and specific embodiments thereof, and various modifications and changes can be made without departing from the spirit and scope of the invention.

This application is based on the Japanese Patent Application (Japanese Patent Application No. 2008-150527) filed on Jun.

Industrial use possibility

The present invention mixes the first powder of the aluminum-REM-based aluminum-based alloy produced by the atomization method, and the second powder composed of the element having a higher melting point than the high-melting point of the aluminum, and appropriately controls the maximum particle size and ratio thereof, so that it can be good. The Al-REM-X series aluminum-based alloy sputtering target material was manufactured by the pass rate.

Claims (5)

The invention relates to a method for manufacturing an aluminum-based alloy sputtering target material, which is a method for manufacturing an aluminum-based alloy sputtering target material containing a rare earth element and a high melting point element X having a melting point higher than that of aluminum, and the characteristics thereof are prepared by a step of a first powder of a rare earth element-containing Al-REM alloy produced by an atomization method, and a step of mixing the first powder and one or more second powders composed of the high melting point element X, and a step of densifying a mixed powder of the powder and the second powder, wherein the first powder has a maximum particle diameter (a) of 10 to 200 μm, and the second powder has a maximum particle diameter (b) of 10 to 10 150 μm, and the ratio (a)/(b) of the maximum particle diameter (a) of the first powder to the maximum particle diameter (b) of the second powder is 0.5 to 5. The manufacturing method of claim 1, wherein the rare earth element is at least one of cerium and lanthanum. The manufacturing method of claim 1, wherein the high melting point element X is at least one element selected from the group consisting of titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, and nickel. The manufacturing method according to claim 1, wherein the aluminum-based alloy sputtering target material containing 1.0 to 10 at% of the foregoing rare earth element and 0.5 to 5 at% of the high melting point element X is produced. An aluminum-based alloy sputtering target material, which is produced by the manufacturing method according to any one of claims 1 to 4.