KR20130063518A - Polycrystalline alloy having glass forming ability, method of fabricating the same, alloy target for sputtering and method of fabricating the same - Google Patents

Abstract

PURPOSE: A crystalline alloy having glass forming ability, a method of fabricating the same, an alloy target for a sputtering, and a method of fabricating the same are provided to make a small composition deviation between a thin film composition and a target composition caused by a sputtering yield difference of a multi-component which comprises a target by having a very even micro-structure. CONSTITUTION: A crystalline alloy having glass forming ability comprises an alloy consisting of over 3 elements having glass forming ability. A mean size of a crystal grain of an alloy is in 0.1 to 5μm range. The alloy comprises Al of 5 to 20 atomic%, and one selected between Cu and Ni of 15 to 40 atomic%, and a residue comprises Zr. An alloy having glass forming ability obtains an amorphous ribbon with a casting thickness in 20 to 100μm range when casting a molten metal of the alloy at a cooling speed in 10^4-10^6 K/sec range.

Description

Polycrystalline alloy having glass forming ability, method of fabricating the same, alloy target for sputtering and method of fabricating the same

The present invention relates to a crystalline alloy composed of three or more metals having an amorphous forming ability and excellent thermal and mechanical stability, and an alloy target for sputtering made of such crystalline alloy.

The sputtering process refers to a technology of forming a thin film on the surface of a base material by supplying a target atom by colliding argon ions or the like at a high speed to a target to which a negative voltage is applied, thereby leaving the target atom. The sputtering process is used in the field of coating manufacturing for the improvement of wear resistance of various tools, molds, and automotive parts as well as the manufacture of micro devices such as semiconductor manufacturing process and MEMS.

When the nanocomposite thin film including an amorphous thin film or an amorphous phase is prepared using sputtering, an amorphous target may be used. The amorphous target may be formed of a multi-element metal alloy having high amorphous forming ability, and the heterogeneous metal elements separated from the amorphous target may form an alloy thin film having an amorphous phase on the surface of the base material.

However, such an amorphous target has an increased temperature due to the collision of ions in the sputtering process, and the increase in temperature may change the tissue near the surface of the target. That is, due to the thermally unstable amorphous phase, when the temperature of the target is increased, local crystallization may proceed on the target surface. Such localized crystallization may cause a change in the volume of the target and structure relaxation, which may increase the brittleness of the target, which may result in the target being easily destroyed during the sputtering process. If the target is destroyed during the process, it will cause a fatal problem in the production of the product. Therefore, it is very important to have a stable target without such destruction during the sputtering process.

The present invention is to solve various problems, including the above problems, and to provide a crystalline alloy and a method for producing the same, which has an amorphous forming ability and a thermal stability is significantly superior to amorphous. Another object of the present invention is to provide an alloy target for sputtering prepared using the crystalline alloy and a method of manufacturing the same. However, these problems are exemplary and do not limit the scope of the present invention.

According to one aspect of the invention, the alloy is composed of three or more elements having an amorphous forming ability, the average grain size of the alloy is in the range of 0.1 to 5㎛, the alloy is selected from 5 to 20 atomic% Al, Cu and Ni There is provided a crystalline alloy having an amorphous forming ability, in which at least one is from 15 to 40 atomic% and the balance is Zr.

According to another aspect of the invention, an alloy consisting of at least three elements having an amorphous forming ability, the average grain size of the alloy is in the range of 0.1 to 5㎛, the alloy is Al 5 or more and less than 20 atomic%, Cu and Ni Any one or more of 15 to 40 atomic%, Cr, Mo, Si, Nb, Co, Sn, In, Bi, Zn, V, Hf, Ag, Ti and Fe, the sum of any one or more of 8 atomic% or less (Greater than 0), a crystalline alloy having an amorphous forming ability is provided in which the balance is made of Zr.

The alloy having the amorphous forming ability may be an alloy that can obtain an amorphous ribbon with a casting thickness in the range of 20 to 100㎛ when casting the molten alloy of the alloy at a cooling rate of 10 ⁴ ~ 10 ⁶ K / sec.

In addition, the average grain size of the crystalline alloy may be in the range of 0.1 to 0.5㎛.

According to another aspect of the present invention, an alloy target for sputtering made of the above-described crystalline alloy may be provided.

According to another aspect of the invention, the average size of the crystal grains by heating the amorphous alloy or nanocrystalline alloy consisting of three or more metal elements having an amorphous forming ability in the temperature range below the melting temperature or more than the melting temperature of the amorphous alloy 0.1 to And controlling to be in a range of 5 μm, wherein the amorphous alloy or nanocrystalline alloy includes Al in a range of 5 to 20 atomic%, at least one selected from Cu and Ni, in a range of 15 to 35 atomic%, and the balance is Zr. A method for producing a crystalline alloy having an amorphous forming ability is provided.

According to another aspect of the invention, the average of the crystal grains by heating the amorphous alloy or nanocrystalline alloy consisting of three or more metal elements having an amorphous forming ability in the temperature range of more than the melting temperature above the crystallization start temperature of the amorphous alloy or nanocrystalline alloy And controlling the size to have a range of 0.1 to 5 μm, wherein the amorphous alloy or nanocrystalline alloy has a range of 5 to 15 atomic% Al, at least one of Cu and Ni to 15 to 30 atomic%, Cr At least one selected from among Mo, Si, Nb, Co, Sn, In, Bi, Zn, V, Hf, Ag, Ti, and Fe, 8 atomic% or less (greater than 0), and the balance consisting of Zr Provided is a method for producing a crystalline alloy having a forming ability.

At this time, the average size of the grains may be controlled to be in the range 0.1 to 0.5㎛.

According to another aspect of the invention, the step of preparing a plurality of amorphous alloys or nanocrystalline alloys consisting of three or more metal elements having an amorphous forming ability; And thermally pressurizing the plurality of amorphous alloys or nanocrystalline alloys in a temperature range below the melting temperature of the crystallization temperature of the amorphous alloys or nanocrystalline alloys to be less than a melting temperature to produce a crystalline alloy having an average size of crystal grains in the range of 0.1 to 5 μm. To include, wherein the amorphous alloy or nanocrystalline alloy is Al in the range of 5 to 20 atomic%, at least one selected from Cu and Ni ranges from 15 to 35 atomic%, the balance is made of Zr, the alloying target for sputtering The manufacturing method is manufactured.

According to another aspect of the invention, the step of preparing a plurality of amorphous alloys or nanocrystalline alloys consisting of three or more metal elements having an amorphous forming ability; And thermally pressurizing the plurality of amorphous alloys or nanocrystalline alloys in a temperature range below the melting temperature of the crystallization temperature of the amorphous alloys or nanocrystalline alloys to be less than a melting temperature to produce a crystalline alloy having an average size of crystal grains in the range of 0.1 to 5 μm. It includes; wherein the amorphous alloy or nanocrystalline alloy is Al in the range of 5 to 15 atomic%, at least one of Cu and Ni in the range of 15 to 30 atomic%, Cr, Mo, Si, Nb, Co, Sn, At least one selected from In, Bi, Zn, V, Hf, Ag, Ti, and Fe is in the range of 8 atomic% or less (over 0), and the balance is made of Zr.

At this time, the average size of the crystal grains may have a range of 0.1 to 0.5㎛.

The amorphous alloy or nanocrystalline alloy may be, for example, an amorphous alloy powder or a nanocrystalline alloy powder, wherein the amorphous alloy powder or nanocrystalline alloy powder, preparing a molten metal in which the three or more metal elements are dissolved; And spraying a gas into the molten metal. It may be prepared by an atomizing method comprising a.

As another example, the amorphous alloy or the nanocrystalline alloy may be an amorphous alloy ribbon or a nanocrystalline alloy ribbon, and the amorphous alloy ribbon or the nanocrystalline alloy ribbon may include preparing a molten metal in which the three or more metal elements are dissolved; And injecting the molten metal into a rotating roll. The melt spinning method may include a melt spinning method.

As another example, the amorphous alloy or the nanocrystalline alloy may be an amorphous alloy casting material or a nanocrystalline alloy casting material, and the amorphous alloy casting material or the nanocrystalline alloy casting material may include preparing a molten metal in which the three or more metal elements are dissolved. ;

Injecting the molten metal into the copper mold by using a pressure difference between the inside and the outside of the copper mold can be prepared by a copper mold casting method comprising a.

The amorphous alloy casting material or nanocrystalline alloy casting material may have a rod shape or plate shape.

According to another aspect of the present invention, by heating the amorphous alloy or nanocrystalline alloy in the temperature range below the melting temperature or more than the crystallization start temperature of the amorphous alloy or nanocrystalline alloy crystalline having a mean size of 0.1 to 5㎛ range The method includes preparing an alloy, wherein the amorphous alloy or nanocrystalline alloy is manufactured by casting a molten metal composed of three or more metal elements having an amorphous forming ability, wherein Al is any one selected from the range of 5 to 20 atomic%, Cu, and Ni. The above is provided the manufacturing method of the sputtering alloy target which consists of 15-35 atomic% range and remainder Zr.

According to another aspect of the present invention, by heating the amorphous alloy or nanocrystalline alloy in the temperature range below the melting temperature or more than the crystallization start temperature of the amorphous alloy or nanocrystalline alloy crystalline having a mean size of 0.1 to 5㎛ range It comprises the step of preparing an alloy, wherein the amorphous alloy or nanocrystalline alloy is produced by casting a molten metal consisting of three or more metal elements having an amorphous forming ability, Al is in the range of 5 to 15 atomic%, at least any one of Cu and Ni Any one or more selected from the range of 15 to 30 atomic%, Cr, Mo, Si, Nb, Co, Sn, In, Bi, Zn, V, Hf, Ag, Ti, and Fe is 8 atomic% or less (greater than 0) In the range, the balance is made of Zr, there is provided a crystalline alloy production method.

According to the embodiments of the present invention, the thermal / mechanical stability of the target is greatly improved, so that the target is not suddenly broken during the sputtering process, thereby stably performing the sputtering process. In addition, since it has a very uniform microstructure, there is an effect of minimizing the composition variation between the target composition and the thin film composition due to the difference in the sputtering yield of the multi-components constituting the target, and composition uniformity according to the thickness of the thin film There is an effect that can be secured. Of course, the scope of the present invention is not limited by these effects.

1 is a result of investigating the amorphous forming ability of Zr _{63 .9} Al ₁₀ Cu _{26 .1} copper mold suction casting (rod) according to an embodiment of the present invention using X-ray diffraction.
Figure 2 shows the DSC analysis showing the crystallization characteristics of Zr _{63 .9} Al ₁₀ Cu _{26 .1} copper mold suction casting (rod) according to an embodiment of the present invention.
3A to 3E show the results of observing the indentation traces with an electron microscope after cracking test of Zr _{63 .9} Al ₁₀ Cu _{26 .1} alloy cast material (rods) according to an annealing temperature according to an embodiment of the present invention.
Figures 4a to 4d is the result of observing the microstructure of Example 3, Comparative Examples 2 to 4.
5A to 5D show the results of observing the microstructure of alloy targets prepared by combining amorphous alloy rods, amorphous alloy powders, nanocrystalline alloy powders, and amorphous alloy ribbons, respectively.
6A and 6B show X-ray diffraction patterns of amorphous powders prepared by the atomizing method and nanocrystalline powders annealed at 600 ° C.
7 is a result of observing the target surface after sputtering of the crystalline alloy target (Zr _62.5 Al ₁₀ Mo ₅ Cu _22.5 ) prepared according to an embodiment of the present invention.
8A and 8B illustrate the results of observing the microstructure before sputtering of the crystalline alloy target (Zr _62.5 Al ₁₀ Mo ₅ Cu _22.5 ) of FIG. 7 and the surface of the target after sputtering.
9A and 9B show a result of observing a target fracture generated during sputtering of an amorphous alloy target having the same composition as that of the crystalline alloy target of FIG.
10A and 10B illustrate X-ray diffraction patterns before and after sputtering of the amorphous alloy target of FIG. 9.
11A and 11B illustrate the results of observing the indentation traces around the indentation traces before and after the sputtering test of the amorphous alloy target of FIG. 9.
12 is a result of observing the target surface after the sputtering of the cast alloy target having the same composition as the crystalline alloy target of FIG.
13A and 13B illustrate the results of observing the microstructure before sputtering of the cast material alloy target of FIG. 12 and the surface of the target after sputtering.
14 is an observation of the cast alloy targets broken during the solidification process.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be understood, however, that the invention is not limited to the disclosed embodiments, but may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, Is provided to fully inform the user. Also, for convenience of explanation, the components may be exaggerated or reduced in size.

The crystalline alloy according to the present invention can be obtained by heating an amorphous alloy or a nanocrystalline alloy composed of three or more metal elements having glass forming ability in a temperature range not lower than the crystallization start temperature of the amorphous alloy or the nano- Can be implemented. In the case of such an amorphous alloy, the crystallization occurs during the heating process, and the grain growth process is performed. In the case of the nanocrystalline alloy, the growth of the nanocrystal grains occurs. The heating conditions may be controlled such that the average grain size of the alloy target is in the range of 0.1 to 5 μm, strictly 0.1 to 1 μm, more strictly 0.1 to 0.5 μm, and even more strictly 0.3 to 0.5 μm. Can be.

In the present invention, the crystallization start temperature is a temperature at which an alloy in an amorphous state starts crystallization and has an inherent value depending on a specific alloy composition. Therefore, the crystallization start temperature of the nanocrystalline alloy may be defined as the temperature at which the amorphous alloy having the same composition as the nanocrystalline alloy starts to crystallize.

The amorphous alloy has substantially no specific crystal structure, and the metal alloy has a phase in which an X-ray diffraction pattern does not show a sharp peak at a specific Bragg angle and a broad peak is observed over a wide angle range. Can mean a sieve. In addition, the nanocrystalline alloy may mean a metal alloy body having an average size of less than 100nm.

The amorphous formability means a relative measure indicating how much the alloy of a specific composition can be easily amorphized up to a certain cooling rate. In general, to form an amorphous alloy through casting requires a high cooling rate of a certain level or more, and when used in a relatively slow casting method (for example, copper mold casting method), the amorphous forming composition range is reduced, Rapid solidification, such as melt spinning, in which a molten alloy is dropped onto a rotating copper roll and solidified with ribbon or wire rod, can achieve a maximum cooling rate of 10 ⁴ ~ 10 ⁶ K / sec or higher, thereby forming amorphous. The composition range is expanded. Therefore, the evaluation of how much amorphous formation ability a specific composition has in general is characterized by a relative value depending on the cooling rate of a given rapid cooling process.

This amorphous forming ability depends on the alloy composition and cooling rate, and in general, the cooling rate is inversely proportional to the casting thickness (cooling rate) ∝ (casting thickness) ^-2 ], thereby evaluating the critical thickness of the casting material that can obtain amorphous during casting. The ability to form amorphous can be relatively quantified. For example, according to the copper mold casting method, the critical casting thickness of the casting material (in case of a stick-shaped casting) capable of obtaining an amorphous structure can be expressed as a diameter. As another example, when the ribbon is formed by melt spinning, it can be expressed as a critical thickness of the ribbon in which amorphous is formed.

In the present invention, an alloy having an amorphous forming ability means that an alloy capable of obtaining an amorphous ribbon with a casting thickness in the range of 20 to 100 μm when the molten alloy of the alloy is cast at a cooling rate in the range of 10 ⁴ to 10 ⁶ K / sec. it means.

The alloy having an amorphous forming ability according to the present invention is composed of multi-components of three or more elements, the difference in atomic radius between the main elements is greater than 12%, the heat of mixing between the main elements (negative) Has

 At least three metal elements having an amorphous forming ability according to an embodiment of the present invention may be at least one selected from Zr, Al, Cu, and Ni. For example, it may be a ternary alloy made of Zr, Al, Cu, a ternary alloy made of Zr, Al, Ni, or a ternary alloy made of Zr, Al, Cu, and Ni.

At this time, the alloy is 5 to 20 atomic% Al, at least one selected from Cu and Ni is 15 to 40 atomic%, the balance may be made of Zr. Strictly, the Al may have a range of 6 to 13 atomic%, and at least one selected from Cu and Ni may have a range of 18 to 30 atomic%.

In another embodiment, at least three metal elements having such an amorphous forming ability are at least one selected from Zr, Al, Cu, and Ni, and M (M is Cr, Mo, Si, Nb, Co, Sn, In, Bi, Zn , V, Hf, Ag, Ti and Fe) may be an alloy of four or more system consisting of at least one selected from. For example, it may be a plural alloy composed of Zr, Al, Cu, M, a plural alloy composed of Zr, Al, Ni, M or a plural alloy composed of Zr, Al, Cu, Ni, M.

At this time, the alloy is less than 5 to 20 atomic%, at least one of Cu and Ni is 15 to 40 atomic%, M is 8 atomic% or less (greater than 0), the balance may be made of Zr. Strictly, the Al may have a range of 6 to 13 atomic%, at least one of Cu and Ni may have a range of 17 to 30 atomic%, and M may have a range of 5 atomic% or less (greater than 0).

The crystalline alloy according to the present invention has a very excellent thermal stability compared to the amorphous alloy of the same composition. That is, in the case of the amorphous alloy, due to thermal instability, the local crystallization is locally formed by locally transmitted thermal energy due to thermal instability, and nanocrystalline is locally formed. This local crystallization is weakened by the structural relaxation of the amorphous alloy and the fracture toughness is reduced.

However, alloys whose grain size is controlled through crystallization and / or grain growth from amorphous alloys or nanocrystalline alloys, such as the crystalline alloys according to the present invention, show no significant change in microstructure even when heat is applied from the outside. There is no destruction due to the thermal and mechanical instability of amorphous or nanocrystalline alloys.

The crystalline alloy according to the embodiments of the present invention can be successfully applied to the field requiring thermal stability, for example, it can be applied to the target for sputtering.

In order to form an amorphous thin film or a nanocomposite thin film through sputtering and reactive sputtering, an amorphous alloy target composed of a plurality of metal elements having an amorphous forming ability may be used. In the case of the sputtering target, the ions accelerated from the plasma during the process continuously collide with each other, so that the temperature of the sputtering target inevitably rises during the process. When the sputtering target is amorphous, local crystallization may occur at the target surface due to the temperature rise during the sputtering process, and such local crystallization may increase the brittleness of the target, which may result in the target being easily destroyed during the sputtering process.

On the other hand, the crystalline alloy according to the present invention has a microstructure in which crystal grains having a specific size range controlled by heat treatment are uniformly distributed, thereby greatly improving thermal / mechanical stability, thereby increasing the local structure even in the temperature rise of the target generated during sputtering. Does not change, and thus mechanical instability as described above does not appear. Therefore, in the case of the crystalline alloy target of the present invention it can be used to stably form an amorphous thin film or nanocomposite thin film using sputtering.

Hereinafter, a method of manufacturing an alloy target for sputtering using the crystalline alloy of the present invention will be described as an example.

Sputtering alloy using the crystalline alloy of the present invention, the above-described amorphous alloy or nanocrystalline alloy may be cast in a size and shape similar to the sputtering target used in practice, that is, the heat treatment, that is, the amorphous alloy or nanocrystalline alloy Crystalline alloy targets can be prepared by growing crystallization or grains through annealing.

As another method, a sputtering target may be manufactured by preparing a plurality of the above-described amorphous alloys or nanocrystalline alloys, and thermally pressing the plurality of amorphous alloys or nanocrystalline alloys together. Plastic deformation of an amorphous alloy or a nanocrystalline alloy may occur during the thermal pressing.

At this time, the annealing treatment or the thermal pressurization is performed in a temperature range below the melting temperature above the crystallization start temperature of the amorphous alloy or nanocrystalline alloy. The crystallization start temperature is defined as the temperature at which an alloy having a specific composition starts transitioning from an amorphous state to a crystalline state.

The amorphous alloy or nanocrystalline alloy prepared in plural may be, for example, an amorphous alloy powder or a nanocrystalline alloy powder. The agglomerates of these alloy powders are pressed and sintered in a sintered metal mold and bonded to each other, whereby a shape and size approximate to an actual target can be produced. In this case, the pressure sintering is carried out in the temperature range of more than the amorphous crystallization start temperature in the composition of the alloy powder below the melting temperature. During the heating process, the agglomerates of the amorphous alloy powder or the agglomerates of the nanocrystalline alloy powder are combined with each other by diffusion to cause crystallization and / or grain growth. At this time, the crystallization or grain growth is controlled such as time and / or temperature so that the size of the crystal grains has a specific range. Thus, an alloy which is finally crystallized or grain grown has a grain size of the alloy of 5 μm or less, for example 0.1 to 5 μm, strictly 0.1 to 1 μm, more strictly 0.1 to 0.5 μm, and even more. Strictly it may have a range of 0.3 to 0.5㎛.

In this case, the amorphous alloy powder or nanocrystalline alloy powder may be prepared by an atomizing method (automizing). Specifically, the molten metal is prepared by preparing an molten metal having three or more metal elements having an amorphous forming ability and spraying the molten metal with an inert gas such as argon gas while spraying the molten metal to form an alloy powder.

As another example, the plurality of amorphous alloys or nanocrystalline alloys may be amorphous alloy ribbons or nanocrystalline alloy ribbons. After stacking a plurality of such ribbons, the target can be formed by thermally pressurizing at a temperature range below the melting temperature or more than the crystallization start temperature in the composition of the alloy ribbon. In this case, the amorphous alloy ribbon laminate or the nanocrystalline alloy ribbon laminate may undergo crystallization and / or grain growth as the bonding progresses by mutual diffusion between ribbons. Meanwhile, the lamination interface between the stacked alloy ribbons in this process can be extinguished by mutual diffusion.

In this case, the amorphous alloy ribbon or nanocrystalline alloy ribbon may be prepared by a rapid solidification process such as melt spinning (melt spinning). Specifically, a ribbon-shaped amorphous alloy or a nanocrystalline alloy may be manufactured by preparing a molten metal in which at least three metal elements having an amorphous forming ability are dissolved, and rapidly melting the molten metal on a roll surface rotating at high speed.

As another example, the plurality of amorphous alloys or nanocrystalline alloys may be amorphous alloy casting materials or nanocrystalline alloy casting materials. In this case, the amorphous alloy casting material or the nanocrystalline alloy casting material may have a rod shape or a plate shape. In this case, a laminate in which a plurality of amorphous alloy casting materials are laminated or a laminate in which nanocrystalline alloy casting materials are laminated during the thermal pressing process may undergo crystallization and / or grain growth as a result of bonding by mutual diffusion between individual alloy casting materials. do. At this time, the interface between the alloy castings may be eliminated by mutual diffusion.

In this case, the amorphous alloy casting material or the nanocrystalline alloy casting material uses a suction method or a pressurizing method of injecting the molten metal into the inside of the mold by using a pressure difference between the inside and the outside of the mold such as copper having a high cooling ability. It may be prepared by. For example, in the case of a copper mold casting method, a molten metal containing three or more metal elements having an amorphous forming ability is prepared, and the molten metal is pressed or sucked and injected into the copper mold at a high speed through a nozzle to rapidly solidify it. Alloy casting material or nanocrystalline alloy casting material can be produced.

In the case of an alloy ribbon or an alloy casting material, as in the alloy powder, the finally crystallized alloy is adjusted so that the grain size of the alloy is in the above-described range.

Hereinafter, embodiments are provided to facilitate understanding of the present invention. It should be understood, however, that the following examples are for the purpose of promoting understanding of the present invention, but the present invention is not limited by the following examples.

Crystallization of Bar-shaped Amorphous Alloy Castings (Alloy Rods)

Figure 1 shows the results of the amorphous forming ability of the Zr-Al-Cu alloy rod according to an embodiment of the present invention by using X-ray diffraction, Figure 2 shows the crystallization characteristics according to the diameter of the Zr-Al-Cu alloy rod The DSC analysis results are shown. The compositions of Zr-Al-Cu were 63.9, 10, and 26.1 in atomic%, respectively. This is expressed as Zr _{63 .9} Al ₁₀ Cu _{26 .1} (the composition of the alloy is then expressed in this way).

The Zr _{63 .9} Al ₁₀ Cu _{26 .1} alloy rod was manufactured by copper mold suction casting after melting an alloy button having the composition by arc melting. The melting temperature (solid phase temperature) of the Zr _63.9 Al ₁₀ Cu _26.1 alloy rod was 913 ° C. (A), (b), (C) and (d) of FIG. 1 and FIG. 2 show alloy bars having alloy rod diameters of 2 mm, 5 mm, 6 mm, and 8 mm, respectively.

Referring to FIG. 1, a broad peak typically observed in an amorphous phase is observed in a diameter of 5 mm or less, but a crystalline peak is observed in 6 mm or more. Electron microscopy of alloy rods with diameters of 6 mm and 8 mm showed very fine nanocrystalline structures with average grain sizes of 100 nm or less.

In general, the cooling rate of the mold casting method, such as copper mold suction casting method has a lower cooling rate than the melt spinning method, it can be seen that the alloy has an amorphous forming ability as defined in the present invention. In addition, it can be seen that the alloy composition can produce an amorphous alloy having a thickness or diameter of 5 mm or less when the copper mold suction casting method is used.

Referring to FIG. 2, an exothermic peak was observed according to the crystallization behavior at the time of heating up to an alloy rod diameter of 6 mm, but no exothermic peak was observed for 8 mm. In the case of 6mm from this, it can be seen that an amorphous phase exists in part along with the nanocrystalline structure. When the diameter is 2mm, 5mm, and 6mm, it can be seen that the glass transition temperature (Tg) is 404.4 ° C, 400.9 ° C and 391.3 ° C, respectively, and the crystallization initiation temperatures are all around 450 ° C.

Table 1 shows the hardness and crack occurrence according to the annealing temperature of Zr _{63 .9} Al ₁₀ Cu _{26 .1} alloy rod with 2mm diameter and Zr _{63 .9} Al ₁₀ Cu _{26 .1} alloy rod with 8mm diameter. Hardness measurement was performed at 1 Kgf load and crack occurrence was determined by electron microscopy of indentation traces at 5 Kgf load. Annealing was carried out in a hot vacuum furnace and the annealing time was 30 minutes at all temperatures.

Raw materials Manufacturing method Metric After Hardness Test of Annealing Material According to Annealing Temperature
Hardness (Hv) and crack occurrence 500 ℃ 600 ℃ 700 ℃ 800 ℃ 900 ℃ Amorphous
Casting Bar
(ф2mm)
Copper mold
Suction casting method Hardness
(Hv) 705 725 710 599 473 Crack
The presence or absence ○ ○ × × ○ Nanocrystalline
Casting Bar
(ф8mm)
Copper mold
Suction casting method
Hardness
(Hv) 655 725 622 606 510 Crack
The presence or absence ○ ○ ○ × ○ Annealing: high temperature vacuum furnace, 30 minutes
● Hardness measurement: Hardness measurement 1Kgf Observation of load and cracks 5Kgf load

Referring to Table 1, both the alloy rods with a diameter of 2 mm and the alloy rods with a diameter of 8 mm showed a hardness increase as the annealing temperature increased below 600 ° C., but decreased again above 600 ° C. On the other hand, the 2mm diameter alloy rods did not crack at 700 ° C and 800 ° C, and the 8mm diameter alloy rods did not crack at 800 ° C.

3A to 3D show the results of observing the indentation when an alloy rod having a diameter of 2 mm is annealed at 600 ° C., 700 ° C., 800 ° C. and 900 ° C., respectively. FIG. 3E shows an alloy rod having a diameter of 8 mm at 800 ° C. The result of observing the case of annealing at is shown.

3A to 3C, when the crack occurs (FIG. 3A), the average grain size (hereinafter referred to as grain for convenience) shows a nanocrystalline structure having a size smaller than 0.1 μm, but no crack is observed (FIG. 3B). And 3c) shows uniformly distributed crystalline tissue having a size ranging from 0.1 μm to about 1 μm. In the case where the crystal grains exceeded 5 μm (FIG. 3D), cracks occurred. In the case of an alloy rod having a diameter of 8 mm as shown in FIG. 3e, when the microstructure similar to that of FIG. 3 (c) was shown, no crack was generated.

From this, it can be seen that when the amorphous alloy rod is annealed and partially crystallized or crystallized into a microstructure having nanocrystal grains, brittleness increases with increasing hardness. This increase in brittleness is believed to be due to the change of amorphous intrinsic free volume generated by the relaxation of the structure and the precipitation of nanocrystals in the amorphous matrix.

However, even when the amorphous alloy is completely crystallized, when the grain size is in the range of 0.1 μm to 5 μm, the phenomenon of brittleness due to such structure relaxation and precipitation of nanocrystals does not appear, and fracture toughness is remarkably improved. Can be. Table 2 shows the amorphous properties when an alloy casting material (2 mm diameter bar, 0.5 mm thick plate material) containing various amorphous phases or amorphous phases having various compositions in addition to the alloy composition (Example 1 of Table 2) described above was annealed at 800 ° C. The results for crack occurrence are summarized (annealed at 700 ° C. for Example 2 and Comparative Example 1). Tg, Tx, and Tm in Table 2 represent the glass transition temperature, the crystallization start temperature and the melting temperature (solid phase temperature), respectively. The grain size was measured by the grain diameter measurement method of the metal of KS D0205.

Referring to Table 2, the alloys of Examples 2 to 30 also showed very similar microstructures to the alloys of Example 1 after annealing, and no cracking was observed in the cracking test. Figure 4a shows the results of observing the microstructure after the crack generation test by the indenter of Example 3 by way of example.

On the other hand, cracks occurred in the case of the specimen (Comparative Example 1) which did not contain Al in the alloy and the specimen (Comparative Example 2) whose annealing temperature was higher than the melting point. In addition, in the case of the Example (comparative example 4) whose composition of Cu is less than 15 atomic% and the composition of M (that is, Co) is 8 weight% or more, the crack generation was also observed. On the other hand, in the case where other dissimilar metals were further added to Zr, Al, Cu, and Ni, cracking was observed when the composition of Al was 20 atomic% or more (Comparative Example 3). 4B to 4D show the results of observing the microstructure after the crack generation test of Comparative Examples 2 to 4.

Fabrication of Alloy Targets Using a plurality of Amorphous Alloy Rods

In Table 3, a plurality of 3 mm diameter amorphous alloy bars having the alloy composition (Zr _{63 .9} Al ₁₀ Cu _{26 .1} ) of Example 1 were prepared, laminated in a graphite mold, and thermally pressurized in an energizing press sintering apparatus. In the target, the results of observing the hardness and crack generation according to the bonding temperature is shown. At this time, the bonding temperature means the contact temperature of the graphite (graphite) mold. In addition, ΔTx in Table 3 means a temperature section between the glass transition temperature and the crystallization start temperature, that is, the temperature selected from the subcooled liquid temperature section.

According to starting materials
Sintered Material  Classification Manufacturing method Metric According to the bonding temperature Sintered Material After hardness test
Hardness( Hv ) And Crack occurrence
410 ℃
(△ Tx) 500 ℃ 700 ℃ 800 ℃ 900 ℃ Amorphous
Casting Bar
Sintered body Lee mold
Suction casting
(ф3mm)
+ Laminated Degree
(Hv) 652 670 691 565 498 Crack
The presence or absence ○ ○ × × ○ ● Sintering condition: Pressurized sintering device, holding time 30 minutes
● Bonding temperature: Graphite mold contact temperature

Referring to Table 3, cracks did not occur when the bonding temperatures were 700 ° C. and 800 ° C. in the same manner as the results shown in Table 1. As a result of observing this under an electron microscope, it showed a crystalline structure in which crystal grains of 1 μm or less were uniformly distributed. 5A shows the results of observing the microstructure of the alloy target bonded at 800 ° C. with an electron microscope.

Preparation of alloy target using amorphous alloy powder or nanocrystalline alloy powder

In Table 4, an alloy having the same composition as in Example 1 (Zr _{63 .9} Al ₁₀ Cu _{26 .1} ) was prepared in powder form, laminated on a graphite mold, and pressed into an alloy target manufactured by pressurizing and sintering with an energized pressure sintering apparatus. In this case, the results of observing the hardness and crack generation according to the sintering temperature is shown.

At this time, the alloy powder was prepared by the atomizing method. Specifically, the alloy button was prepared after melting the alloy by the arc melting method in accordance with the composition ratio of Zr, Al and Cu, and the alloy button was reused by high frequency using a powder manufacturing apparatus. Subsequently, the molten alloy was prepared by spraying with argon gas. The alloy powder thus prepared showed an amorphous phase, and the X-ray diffraction results of the alloy powder are shown in FIG. 6A.

The amorphous alloy powder thus prepared was immediately sintered from a graphite mold to produce an alloy target, or the amorphous alloy powder prepared as described above was annealed at 600 ° C. in a high vacuum furnace to prepare a nanocrystalline alloy powder, and then sintered to prepare it as a target. . 6b shows the X-ray diffraction results after annealing the amorphous alloy powder.

According to starting materials
Sintered Material  Classification
Manufacturing method Metric According to sintering temperature Sintered Material After hardness test
Hardness( Hv ) And Crack occurrence 420 ℃ 500 ℃ 700 ℃ 800 ℃ 900 ℃ Amorphous powder
Sintered Material
Gas atomizing +
Sintering
Hardness
(Hv) 582 678 656 591 523 Crack
The presence or absence ○ ○ × × ○ Nanocrystalline Powder Sintered Material
Gas atomizing +
600 ℃ annealing
Hardness
(Hv) - - 578 578 504 Crack
The presence or absence - - ○ × ○ ● Sintering condition: Pressurized sintering device, holding time 30 minutes
● Sintering temperature: Graphite mold contact temperature
Annealing: High vacuum furnace, 30 minutes

 Referring to the results of Table 4, cracks did not occur at 700 ° C. and 800 ° C. in the case of the alloy target prepared by sintering the amorphous alloy powder, and 800 ° C. in the case of the alloy target prepared by sintering the nanocrystalline alloy powder. There was no crack in. As a result of observing with an electron microscope, all the alloy targets without cracks showed crystalline structure in which crystal grains of 1 µm or less were uniformly distributed. 5B and 5C show the results of observing the microstructure of the alloy target obtained by sintering the amorphous alloy powder and the nanocrystalline alloy powder at 800 ° C., respectively, with an electron microscope.

Fabrication of alloy target using amorphous alloy ribbon

In Table 5, amorphous alloys having the same composition (Zr _{63 .9} Al ₁₀ Cu _{26 .1} ) as in Experimental Example 1 were prepared in the form of ribbons, and then a plurality of alloy ribbons were laminated in a graphite mold and pressed and sintered by a pressurized pressure sintering device ( In the alloy target produced by the combination), the results of observing the hardness and crack generation according to the pressing temperature is shown.

According to starting materials
Sintered Material Classification
Manufacturing method Metric According to sintering temperature Sintered Material After hardness test
Hardness( Hv ) And Crack occurrence 420 ℃ 500 ℃ 700 ℃ 800 ℃ 900 ℃ Melt Spinning
ribbon
Amorphous ribbon
+
Sintering Hardness
(Hv) 631 663 678 575 522 Crack
The presence or absence ○ ○ ○ × ○ ● Sintering condition: Pressurized sintering device, holding time 30 minutes
● Sintering temperature: Graphite mold contact temperature

At this time, the amorphous alloy ribbon was manufactured by the melt spinning method, specifically, after the alloy molten metal was prepared by the arc melting method in accordance with the composition ratio of Zr, Al and Cu, the alloy on the surface of 600mm diameter copper roll rotating at a high speed of 700rpm The molten metal was prepared by pouring through a nozzle and rapidly solidifying. At this time, the thickness of the amorphous alloy ribbon was 70㎛.

Referring to Table 5, no crack was generated when the sintering temperature was 800 ° C. As a result of observing this with an electron microscope, crystalline particles uniformly distributed below 1 μm were uniformly distributed as shown in FIG. 5D. Tissue is shown.

Sputtering Characteristics of Crystalline Alloy Target, Amorphous Alloy Target and Cast Alloy Target

FIG. 7 illustrates that the surface of the crystalline alloy target (Zr _62.5 Al ₁₀ Mo ₅ Cu _22.5 ) prepared by sintering an amorphous alloy powder at 800 ° C. is mounted on an actual sputtering apparatus, and 300 W DC plasma power is applied. Is shown. In addition, Fig. 8a shows the microstructure of the alloy before sputtering, and Fig. 8b shows the result of observing the surface of the target where sputtering occurred after sputtering.

7, 8a and 8b, it can be seen that the crystalline alloy target has a very smooth surface even after sputtering, and no significant change in the alloy structure was observed before and after sputtering. From this, it can be seen that the crystalline alloy target according to the embodiment of the present invention shows excellent thermal / mechanical stability without any change in the alloy structure even when the temperature increases during sputtering.

On the other hand, Figure 9a as a comparative example in the case of sputtering under the same conditions by using an amorphous alloy powder of the same composition (Zr _{62 .5} Al ₁₀ Mo ₅ Cu _{22 .5} ) using the amorphous alloy target sintered in the subcooled liquid temperature section The result of observing the generated target fracture is shown, and the result of observing the fracture surface with an electron microscope is shown in FIG. 9B.

9A and 9B, it can be seen that the amorphous alloy target may be destroyed during the sputtering process, and when the fracture surface is observed, the surface shows a flat brittle fracture. From this, it can be seen that the fracture path is broken by the fracture path penetrating the inside of the particle, not the interface of the powder particles.

10A and 10B show X-ray diffraction patterns of the amorphous alloy target before and after sputtering, and it can be seen from the X-ray diffraction results that the amorphous phase before sputtering was partially crystallized during the sputtering process.

11A and 11B show photographs of the periphery of the indentor observed with an electron microscope after the crack generation test (vertical load: 1 kgf) of the alloy target before and after the sputtering. In the case of the amorphous alloy target, the brittleness due to the precipitation of the nano-crystal grains in the sputtering process is increased, and thus cracks are generated during the crack generation test as shown in FIG. 11B.

In this case, in the case of amorphous alloy targets, the thermal stability is weak, so that local crystallization may occur in the temperature rise generated during sputtering. The local crystallization may increase the brittleness of the target, which may cause the target to break during the sputtering process. You can check it.

In FIG. 12, as another comparative example, the surface of the same alloy (Zr _{62 .5} Al ₁₀ Mo ₅ Cu _{22 .5} ), which is manufactured by a general casting method, is mounted on an actual sputtering apparatus and a 300W DC plasma power supply is applied. Observation results are shown. In addition, the microstructure of the alloy before sputtering is shown in Figure 13a, Figure 13b shows the result of observing the surface of the target after sputtering after sputtering.

12, 13a and 13b, it can be seen that in the case of the cast alloy target, the sputtering surface was uneven and very rough compared to the crystalline alloy target of the present invention (see FIG. 7), which is It is judged that the microstructure is coarse and uneven, so that sputtering occurs unevenly on the surface thereof.

In the case of a cast alloy target, as shown in FIG. 13A, a non-uniform microstructure in which coarse phases of various sizes and shapes having different compositions, such as columnar structure or dendritic type tablet, is mixed during the solidification process. Due to the nonuniformity of the microstructure, the sputtered surface is also formed nonuniformly as shown in FIG. 13B.

Due to the nonuniformity of the cast material alloy target, the uniformity of the thin film composition produced by sputtering may exhibit poor characteristics. In addition, a significant difference may appear between the composition of the target and the composition of the thin film formed through sputtering, and may adversely affect the thin film properties such as the composition of the thin film changes as the sputtering proceeds. Furthermore, particles may be generated from the target during sputtering to contaminate the sputtering chamber.

In addition, in the case of casting a multi-element alloy, various intermetallic compounds having high brittleness may be formed, so that the target may be brittle and fractured during processing of the target during or after casting. For example, FIG. 14 shows a result of cracking occurring during natural solidification after arc melting in a copper hearth in which a 3 inch cast alloy target having a composition of Zr _{63 .9} Al ₁₀ Cu _{26 .1} is water-cooled.

On the contrary, the crystalline alloy target according to the present invention has a microstructure in which fine grains are uniformly distributed, and as a result, very uniform sputtering occurs at the target surface. You can get it. In addition, unlike the cast alloy target, the generation of particles can be significantly improved.

Table 6 shows the composition of the thin film prepared by sputtering the crystalline alloy target and the cast alloy target of Zr _{62 .5} Al ₁₀ Mo ₅ Cu _{22 .5} composition. At this time, a voltage of DC 200 W was applied to the sputtering target, and the chamber pressure was 5 mTorr. The thickness of the deposited thin film was 10 μm, and the composition was analyzed by EPMA.

Referring to Table 6, it can be seen that the crystalline target is closer to the target composition of the thin film composition than the cast target.

Target type
Chemical composition at %) Zr Al Mo Cu Crystalline alloy 62.45 10.83 6.10 20.60 Cast alloy target 63.23 11.29 7.19 18.29

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

Claims (1)

As an alloy composed of three or more elements having an amorphous forming ability,
The average grain size of the alloy is in the range of 0.1 to 5㎛,
The alloy is 5 to 20 atomic% Al, at least one selected from Cu and Ni is 15 to 40 atomic%, the balance is made of Zr,
The alloy having an amorphous forming ability is an alloy capable of obtaining an amorphous ribbon at a casting thickness in the range of 20 to 100 μm when casting the molten metal of the alloy at a cooling rate in the range of 10 ⁴ to 10 ⁶ K / sec. alloy.

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