TW201317380A - Target assembly and manufacturing method thereof - Google Patents

Abstract

The present invention provides a target assembly and a manufacturing method thereof, in which an alloy target or a compound target can be stably manufactured by cold spray method. A method for manufacturing a target assembly relating to one embodiment of the present invention comprises manufacturing a mixture powder comprising a first powder consisting of a metal element, and a second powder consisting of an alloy or a compound containing the aforesaid metal element as an essential component; and then forming a target layer comprising the alloy or the compound of the metal element by using the mixture powder as a raw material, onto a substrate surface by cold spray method. Thereby, it is possible to stably manufacture the alloy target or the compound target by cold spray method.

Description

Target assembly and method of manufacturing same

The present invention relates to a target assembly having a target layer formed by a cold spray method and a method of manufacturing the same.

Conventionally, a Cu-Ga-based target such as Cu-Ga or Cu-Ga-In is used for sputtering deposition of a light absorbing layer of, for example, a thin film solar cell. As a method of producing such an alloy target, Patent Document 1 below proposes that a melt of a CuGa alloy is formed into a Cu-Ga alloy preform by a spray molding method, and the preform is further subjected to hot isostatic pressing (HIP). The method is sintered to a Cu-Ga alloy sputtering target.

Further, a method of producing a target using a spray method is also known. For example, Patent Document 2 below discloses that Ti powder and TiO ₂ powder are sprayed on a raw material tube at a high temperature and a high speed to form Ti and TiO ₂ . A method of forming a target of a mixture. Further, Patent Document 3 listed below discloses a method of forming a target layer composed of a metal deposited film on a substrate by a cold spray method using a metal powder as a raw material.

[Previous Technical Literature]

[Patent Literature]

Patent Document 1 Japanese Patent Laid-Open Publication No. 2010-265544

Patent Document 2 Japanese Patent Laid-Open Publication No. 2003-239067

Patent Document 3 WO2008/081585

In the method described in Patent Document 1, since the target is produced by a combination of an injection molding method and a hot isostatic pressing method, the number of steps is large, and productivity and production cost increase become a problem. However, the spray method described in Patent Document 2 cannot be avoided. The oxygen concentration is increased along with the melting of the raw material, making it difficult to produce a high-density target. Further, in the method described in Patent Document 3, since it is impossible to stably deposit an alloy powder or a compound powder which is harder than the metal powder, it is difficult to produce an alloy target or a compound target.

In view of the above, it is an object of the present invention to provide a target assembly capable of stably producing an alloy target or a compound target by a cold spray method and a method of manufacturing the same.

In order to achieve the above object, a method for producing a target assembly according to one aspect of the present invention includes: producing a first powder composed of a metal element and a second powder composed of an alloy or a compound containing the metal element as a main component; A mixed powder of powder.

A target layer composed of an alloy or a compound of the foregoing metal element is formed on the surface of the substrate by a cold spray method using the above mixed powder as a raw material.

A target assembly according to one aspect of the present invention includes a substrate and a target layer.

The target layer is formed on the surface of the substrate, and Cu particles are interposed between the CuGa particles and the CuGa particles.

[Formation of the Invention]

A method of producing a target assembly according to an embodiment of the present invention includes: producing a mixed powder of a first powder composed of a metal element and a second powder composed of an alloy or a compound containing the metal element as a main component; .

A target layer composed of an alloy or a compound of the foregoing metal element is formed on the surface of the substrate by a cold spray method using the above mixed powder as a raw material.

The first powder is a powder of a soft metal which can be applied by a cold spray method. The end is composed. On the other hand, the second powder is generally harder than these pure metals, and there are many difficulties in forming the film by the cold spray method only for the second powder. Therefore, in the above production method, the mixed powder of the first powder and the second powder is used as a raw material, and the first powder is interposed between the surface of the substrate and the second powder, and between the second powder. It is possible to form a deposited film of an alloy material or a compound material. Therefore, the alloy target or the compound target can be produced by the cold spray method.

The metal element constituting the first powder can be, for example, Cu (copper), Al (aluminum), In (indium), Sn (tin), Ti (titanium), Ni (nickel), Co (cobalt), or Cr (chromium). Ta (钽), Mo (molybdenum), etc. can be applied to various soft metals of the cold spray method. The alloy or the compound constituting the second powder is not particularly limited, and examples of the compound include oxides, nitrides, borides, tellurides, and carbides.

In one embodiment, Cu powder is used for the first powder, and CuGa (copper-gallium alloy) powder is used for the second powder. In this case, for example, a CuGa-based target layer formed on the light absorbing layer of the thin film solar cell can be obtained.

When the CuGa-based target layer is formed, the mixing ratio of the first powder to the mixed powder may be 20 atom% or more and 50 atom% or less. Therefore, a CuGa alloy target layer having a relative density of 95% or more and containing 30 atom% or more and 60 atom% or less of Ga can be stably formed.

The substrate for forming the target layer may have a flat shape or a cylindrical shape. When the base body has a cylindrical shape, the target layer is formed on the outer peripheral side surface of the base body. The forming method is not particularly limited. For example, the target layer can be formed on the surface of the substrate by rotating the substrate about the axis of the substrate while moving the nozzle in the axial direction of the substrate.

Embodiments of the present invention will be described below with reference to the drawings.

[Target component]

Fig. 1 is a schematic cross-sectional view showing the structure of a target assembly according to an embodiment of the present invention. The target assembly 10 of the present embodiment has a base 11 and a target layer 12 as a back tube.

The base 11 is made of a metal material such as Cu, Al, Ti, or SUS (stainless steel). In Fig. 1, the base 11 has a cylindrical shape having an axis in the X-axis direction. The inside of the base 11 is formed with a flow path for circulating cooling water. Further, in order to form a fixed magnetic field on the outer peripheral side surface of the base 11, a magnetic element (not shown) is disposed inside the base 11.

The target layer 12 is formed on the outer peripheral side surface of the base 11 so as to cover the surface of the base 11. The thickness of the target layer 12 is not particularly limited and is, for example, 3 mm to 20 mm.

2 is a schematic view showing the internal structure of a target layer. The target layer 12 of the present embodiment is composed of a mixed layer of Cu particles (G1) and CuGa particles (G2). The Cu particles (G1) are sandwiched between the CuGa particles (G2) and the surface of the substrate 11, and sandwiched between the CuGa particles (G2), and these spaces are bonded to each other. Therefore, the target layer 12 having a specific thickness of more than 90% of the relative density can be constructed.

The Ga content of the target layer 12 is not particularly limited and may be appropriately set depending on, for example, the use or specifications. In the present embodiment, the Ga content of the target layer 12 is 30 atom% or more and 60 atom% or less, and a CuGa-based alloy target which can be used for forming a light absorbing layer of a thin film solar cell can be formed.

The target layer 12 is formed on the outer peripheral side surface of the base 11 by a cold spray method using a mixed powder of Cu powder and CuGa powder as a raw material. A method of manufacturing the target assembly 10 will be described below.

[Method of Manufacturing Target Assembly]

Figure 3 is a view showing the steps of the method of manufacturing the target assembly of the embodiment. flow chart. This embodiment has an adjustment step (ST1) of pure Cu powder, an adjustment step (ST2) of CuGa alloy powder, a mixing step (ST3), and a cold spraying step (ST4).

First, pure Cu powder and CuGa alloy powder (ST1, ST2) were adjusted.

The purity of the pure Cu powder is not particularly limited and is, for example, 99.99% or more. As the CuGa alloy powder, a Ga content of, for example, 36 atom% or more and 73 atom% or less can be used. The Ga content can be appropriately set depending on the Ga content of the target layer 12 to be produced and the like.

The shape of the pure Cu powder and the CuGa alloy powder is not particularly limited. However, in order to deposit the target layer 12 by the cold spray method, it is preferably a spherical or nearly spherical powder from the viewpoint of film formation efficiency. . Therefore, the method for producing the powder is preferably an atomization method, a rotary electrode method, a vacuum spray quenching method, or the like.

The particle diameter of the pure Cu powder and the CuGa alloy powder is not particularly limited, but the formation of the high-density target layer 12 is preferably as small as possible. In the present embodiment, the particle diameter of the pure Cu powder is, for example, 10 μm or less, and the particle diameter of the CuGa alloy powder is, for example, 200 to 300 μm or less.

Next, a mixed powder of pure Cu powder and CuGa alloy powder (ST3) was produced.

When mixing pure Cu powder and CuGa alloy powder, various mixers can be used. The mixing ratio of the pure Cu powder in the mixed powder is not particularly limited, but the mixing ratio of the pure Cu powder in the mixed powder is 15 atom% or more and 50 atom% or less, and the target having a relative density of 97% or more can be stably formed. Layer 12. The Ga composition ratio of the CuGa alloy powder is set in accordance with the mixing ratio of the pure Cu powder and the Ga composition ratio in the target layer 12 to be formed.

Next, the above mixed powder is used as a raw material by cold spray method. The outer peripheral side surface of the base 11 forms the target layer 12 (ST4).

The cold spray method is a film formation method in which a raw material powder that maintains a solid phase state is impacted with a substrate by a supersonic flow to form a film. Since the raw material powder is not melted or gasified to impact the substrate, deterioration of material properties and oxidation of the film by heat can be minimized. Therefore, the sputtering method which forms a film after melting or gasifying the raw material is different in principle from the film forming technique.

Fig. 4 is a schematic view showing a method of forming the target layer 12 of the embodiment. The nozzle 20 is used for film formation. The nozzle 20 is connected to a gas source 21 that pressurizes an inert gas, a powder supply source 22 that supplies raw material powder to the nozzle 20, and the like. The nozzle 20 is disposed so as to face the surface of the base 11 that rotates around the axis 11a at a specific speed, and discharges the raw material powder together with the inert gas at a high speed to deposit the raw material powder on the surface of the base 11.

In general, if a soft metal such as Cu strikes the surface of the substrate at a supersonic speed, the powder itself can be formed into a film by plastic deformation. On the other hand, the CuGa alloy is harder than pure Cu, and even if it hits the surface of the substrate at supersonic speed, it is mostly bounced back on the surface of the substrate without plastic deformation. Therefore, when only a CuGa alloy powder is used as a raw material powder, it is difficult to form a film, and even if a film is formed, since peeling is likely to occur due to low adhesion, it is difficult to obtain an alloy film having a desired film thickness.

Therefore, in the present embodiment, a mixed powder of pure Cu powder and CuGa alloy powder is used as a raw material powder, and pure Cu powder is interposed between the surface of the substrate 11 and the CuGa alloy powder, and between the CuGa alloy powders to form CuGa. A deposited film of an alloy material. Thereby, the CuGa-based alloy target can be produced by the cold spray method.

The ejection speed of the raw material powder coming out from the nozzle 20 can be pure The sufficient speed (critical velocity) at which the Cu powder adheres to the surface of the substrate 11 is not particularly limited, and may be, for example, 500 m/s or more.

The inert gas used in the gas source 21 is also not particularly limited, and for example, N ₂ (nitrogen), He (helium), Ar (argon), or the like can be used. The gas pressure and the gas flow rate can be appropriately set depending on the type of gas, the injection speed, and the like. For example, the gas pressure can be set to about 0.65 MPa, and the gas flow rate can be set to 15 L/min.

The raw material powder may also be heated to a suitable temperature inside the nozzle 20. Thereby, the adhesion strength to the surface of the substrate 11 can be improved, and the target layer 12 having a relatively high density can be formed. The heating temperature may be set to be lower than the melting point of the raw material powder (pure Cu powder and CuGa alloy powder), and may be set, for example, at 500 °C.

In order to obtain the target layer 12 of the target thickness, the nozzle 20 can also be moved back and forth (scanned) in the axial direction of the substrate 11. The distance between the surface of the base 11 and the nozzle 20 is also not particularly limited, and can be set, for example, to 7 mm or more and 12 mm or less.

As described above, the target assembly 10 shown in Fig. 1 can be manufactured. On the other hand, in the above embodiment, a cylindrical back pipe is used as the base 11, but a flat metal base may be used instead. By forming the target layer as described above, the metal substrate can be used to manufacture a target assembly having a backing plate.

[Examples]

The embodiments of the present invention are described below, but the present invention is not limited thereto.

(Comparative Example 1)

Cu-30at%Ga alloy powder having an average particle diameter of 100 μm produced by atomization was used as a raw material powder, and Cu was formed on the surface of a disk-shaped substrate made of a 4 inch diameter aluminum alloy (A5052) by a cold spray method. -30 at% Ga alloy target layer.

N ₂ (pressure 0.65 MPa, flow rate 15 L/min) of the raw material powder was used, the heating temperature of the raw material powder was 500 ° C, the scanning speed was 20 mm/sec, the number of scans was 20, and the substrate and the nozzle were used. The distance is set to 7mm.

As a result of the film formation, although a CuGa alloy-based film having a thickness of 0.05 to 0.15 mm was obtained, it was easy to peel off and it was difficult to measure the relative density.

(Comparative Example 2)

A Cu-30at%Ga alloy powder having an average particle diameter of 100 μm produced by an atomization method was used as a raw material powder, and a Cu-30at%Ga alloy was formed on the surface of a disk-shaped substrate made of copper having a diameter of 4 inches by cold spraying. Target layer.

N ₂ (pressure 0.65 MPa, flow rate 15 L/min) of the raw material powder was used, the heating temperature of the raw material powder was 500 ° C, the scanning speed was 20 mm/sec, the number of scans was 20, and the substrate and the nozzle were used. The distance is set to 7mm.

As a result of the film formation, although a CuGa alloy-based film having a thickness of 0.05 to 0.15 mm was obtained, it was easy to peel off and it was difficult to measure the relative density.

(Example 1)

A mixed powder of a Cu-40at%Ga alloy powder having an average particle diameter of 100 μm produced by an atomization method and a pure Cu powder having an average particle diameter of 8 μm produced by an atomization method was prepared. The blending molar ratio of the CuGa alloy powder to the pure Cu powder was set to 68:32. Using this mixed powder as a raw material powder, a Cu-30at%Ga alloy target layer was formed on the surface of a disk-shaped substrate made of a 4 inch diameter aluminum alloy (A5052) by a cold spray method.

N ₂ (pressure 0.65 MPa, flow rate 15 L/min) of the raw material powder was used, the heating temperature of the raw material powder was 500 ° C, the scanning speed was 20 mm/sec, the number of scans was 20, and the substrate and the nozzle were used. The distance is set to 7mm.

As a result of the film formation, the thickness of the target layer on the substrate is 5.0 to 5.5 mm. The determination of the relative density is obtained by calculating the ratio of the apparent density of the deposited layer to the theoretical density. In this example, the relative density of the target layer was 98.1%.

(Example 2)

In addition to changing the composition ratio of the CuGa alloy powder to a molar ratio of Cu-37.5 at% Ga, CuGa alloy powder and pure Cu powder to 80:20, and changing the material of the substrate to a copper product, Under the same conditions as in Example 1, a Cu-30at%Ga alloy target layer was formed on the substrate by cold spraying. As a result of the film formation, the thickness of the target layer on the substrate was 4.5 to 5.0 mm, and the relative density was 97.0%.

(Example 3)

In addition to changing the composition ratio of the CuGa alloy powder to a ratio of the molar ratio of Cu-36 at% Ga, CuGa alloy powder to pure Cu powder to 85:15, and changing the material of the substrate to a copper product, Under the same conditions, a Cu-30at%Ga alloy target layer was formed on the substrate by cold spraying. As a result of the film formation, the thickness of the target layer on the substrate was 0.5 to 1.0 mm, and the relative density was 92.0%.

(Example 4)

In addition to changing the composition ratio of the CuGa alloy powder to a ratio of the molar ratio of Cu-73 at% Ga, CuGa alloy powder to pure Cu powder to 70:30, and changing the material of the substrate to a copper product, Under the same conditions, a Cu-50at%Ga alloy target layer was formed on the substrate by cold spraying. As a result of the film formation, the thickness of the target layer on the substrate was 5.0 to 5.5 mm, and the relative density was 99.0%.

(Example 5)

In addition to changing the shape of the base to a cylindrical shape of 4 inches in diameter, Under the same conditions as in Example 1, a Cu-30at%Ga alloy target layer was formed on the substrate by cold spraying. As a result of the film formation, the thickness of the target layer on the substrate was 5.0 to 5.5 mm, and the relative density was 98.1%.

(Example 6)

In addition to changing the composition ratio of the CuGa alloy powder to a ratio of the molar ratio of Cu-60 at% Ga, CuGa alloy powder to pure Cu powder to 50:50, and changing the material of the substrate to stainless steel (SUS304), Under the same conditions as in Example 1, a Cu-30at%Ga alloy target layer was formed on the substrate by a cold spray method. As a result of the film formation, the thickness of the target layer on the substrate was 3.5 to 4.0 mm, and the relative density was 97.3%.

(Example 7)

In addition to changing the composition ratio of the CuGa alloy powder to a ratio of Cu-60 at% Ga, CuGa alloy powder and pure Cu powder to a molar ratio of 50:50, and changing the material of the substrate to a copper product, and the substrate and the nozzle A Cu-30at%Ga alloy target layer was formed on the substrate by a cold spray method under the same conditions as in Example 1 except that the distance between the two was set to 12 mm. As a result of the film formation, the thickness of the target layer on the substrate was 3.0 to 3.5 mm, and the relative density was 95.1%.

The conditions and results of Comparative Examples 1, 2 and Examples 1 to 7 are shown in Table 1.

As shown in Table 1, in the comparative examples 1 and 2 which used only the CuGa alloy powder as a raw material, the target layer could not be formed. On the other hand, in Examples 1 to 7 in which a mixed powder of a CuGa alloy powder and a pure Cu powder was used as a raw material, it was confirmed that an appropriate target layer can be formed.

Further, in Examples 1, 2, and 4 to 7 in which the mixing ratio of the pure Cu powder in the mixed powder of the pure Cu powder and the CuGa alloy powder is 20 to 50 at%, Cu- having a relative density of 95% or more can be obtained. 30~60at%Ga alloy target. Thereby, it is possible to form a film by sputtering which is less stable and unstable.

The embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications may be added without departing from the spirit and scope of the invention.

For example, in the above embodiment, an example in which a pure Cu powder and a CuGa alloy powder are used to form a CuGa alloy-based sputtering layer will be described, but the invention is not limited thereto. The present invention is also applicable to the formation of, for example, a TiMo alloy-based sputter layer. In this case, a mixed powder of pure Ti powder and TiMo alloy powder can be used as a spray material. In addition to this, a pure metal powder such as Al, In, Sn, Ni, Co, Cr, Ta, or Mo, or an alloy powder or a compound powder can be used to form a sputtering layer of the alloy.

10‧‧‧ Target components

11‧‧‧ base

11a‧‧‧Axis

12‧‧‧ Target layer

20‧‧‧ nozzle

21‧‧‧ gas source

22‧‧‧ powder supply source

G1‧‧‧Cu particles

G2‧‧‧CuGa particles

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic cross-sectional view showing the structure of a target assembly according to an embodiment of the present invention.

2 is a schematic view showing the internal structure of a target layer.

Fig. 3 is a flow chart showing the steps of a method of manufacturing the target assembly of the embodiment.

Fig. 4 is a schematic view showing a method of forming a target layer of the embodiment.

Claims (7)

A method for producing a target assembly, comprising: preparing a mixed powder of a first powder composed of a metal element and a second powder composed of an alloy or a compound containing the metal element as a main component; As a raw material, a target layer composed of an alloy or a compound of the foregoing metal element is formed on the surface of the substrate by a cold spray method. The method of producing a target module according to the first aspect of the invention, wherein the first powder is a Cu powder, and the second powder is a CuGa powder. The method of producing a target assembly according to the second aspect of the invention, wherein the mixing ratio of the first powder to the mixed powder is 20 atom% or more and 50 atom% or less. The method of manufacturing a target assembly according to the first aspect of the invention, wherein the base system is cylindrical, and the target layer is formed on an outer peripheral side surface of the base. A target assembly comprising: a substrate; a target layer formed on the surface of the substrate and having Cu particles interposed between the CuGa particles and the CuGa particles. The target assembly of claim 5, wherein the target layer is formed of a CuGa alloy containing 30 atom% or more and 60 atom% or less of Ga, and has a relative density of 97% or more. The target assembly of claim 5, wherein the base system is a metal cylinder.