KR20210039329A - Cylindrical sputtering target, In-based solder material, and manufacturing method of cylindrical sputtering target - Google Patents

Abstract

The cylindrical sputtering target of the present invention is a cylindrical sputtering target having a sputtering target material forming a cylindrical shape and a backing tube bonded to the inner circumferential side of the sputtering target material via a solder layer, wherein the solder layer is an In-based solder material It consists of, and characterized in that the oxygen content is 100 massppm or less.

Description

Cylindrical sputtering target, In-based solder material, and manufacturing method of cylindrical sputtering target

The present invention relates to a cylindrical sputtering target having a cylindrical sputtering target material and a backing tube bonded to the inner circumferential side of the sputtering target material via a solder layer, an In-based solder material, and a method for producing a cylindrical sputtering target. About.

This application claims priority based on Japanese Patent Application No. 2018-151553 for which it applied to Japan on August 10, 2018, and uses the content here.

As a means for forming a thin film such as a metal film or an oxide film, a sputtering method using a sputtering target is widely used.

As the above-described sputtering target, for example, a flat sputtering target in which a sputtering surface forms a circular or square shape, and a cylindrical sputtering target in which a sputtering surface is a cylindrical surface have been proposed.

In the above-described flat plate sputtering target, the use efficiency of the target material was as low as about 20 to 30%, and film formation could not be performed efficiently.

On the other hand, in the cylindrical sputtering target, its outer peripheral surface (cylindrical surface) is a sputtering surface, and sputtering is performed while rotating the target, so that the piece putter region along the axial direction formed on a part of the target surface is in the circumferential direction. Go to. As a result, the erosion portion widens in the circumferential direction. Therefore, it has an advantage that the use efficiency of the cylindrical sputtering target material is increased to 60 to 80% compared to the case where a flat sputtering target is used.

In the cylindrical sputtering target, it is configured to be cooled from the inner circumference side of the backing tube, and the cylindrical sputtering target material is sputtered while rotating, so that the temperature increase in the piece sputtering region is suppressed, and the power density at the time of sputtering Since can be increased, it becomes possible to further improve the throughput of film formation.

For this reason, in recent years, the need for a cylindrical sputtering target tends to increase.

In the above-described cylindrical sputtering target, for example, as described in Patent Documents 1 and 2, a cylindrical sputtering target material formed according to the composition of the thin film to be formed, and the sputtering target material are disposed on the inner peripheral side of the sputtering target material, The backing tube holding the sputtering target material has a structure in which a solder layer is interposed therebetween.

As a solder material constituting the solder layer interposed between the sputtering target material and the backing tube, for example, a solder material made of an In and an In alloy or the like can be mentioned. In order to reduce workability and deformation at the time of bonding, the melting point of the solder material constituting the solder layer is, for example, 300°C or less, and a material having a relatively low melting point is used.

For example, in Patent Document 1, a solder material containing In and Ga is used. In addition, in Patent Document 2, a solder material containing In or InSn is used.

Japanese Patent Application Publication No. 2006-257510 Japanese Patent Publication No. 5909006

However, in recent years, since additional cost reduction is required for liquid crystal panels, solar panels, and the like, it is required to further increase the power density during sputtering to further improve the throughput of film formation.

In the cylindrical sputtering target described above, when the bonding strength between the sputtering target material and the backing tube is insufficient, the heat of the sputtering target material cannot be efficiently transferred to the backing tube side.

For this reason, when the power density at the time of sputtering is further increased and the surface temperature of the cylindrical sputtering target material is increased by sputtering, cooling is insufficient, the solder layer composed of a low melting point metal such as In is eluted, or the sputtering target material cracks. There was a fear that it would become. For this reason, in the conventional cylindrical sputtering target, an additional increase in power density could not be realized.

In the cylindrical sputtering target, the load applied to the bonding interface is large due to heat expansion and shaft pipe, microscopic peeling occurs at the bonding interface, and there is a concern that the cooling performance of the sputtering target may not be sufficiently exhibited. Moreover, there exists a possibility that the sputtering target material will fall off.

This invention has been made in view of the above-described circumstances, and it is possible to secure the strength in the solder layer formed between the sputtering target material and the backing tube, and even when used with increased power density, a cylindrical shape capable of stably sputtering film formation. An object of the present invention is to provide a sputtering target, an In-based solder material, and a method for producing a cylindrical sputtering target.

In order to solve the above problems, as a result of intensive examination by the present inventors, when the sputtering target material and the backing tube are joined via the solder material, the solder material is oxidized, and the oxide of the solder is formed between the bonding surface of the sputtering target material and the backing tube. It adhered to the bonding surface, whereby the bonding strength between the sputtering target material and the backing tube was lowered, the heat transfer from the sputtering target material to the backing tube was inhibited, and the knowledge was obtained that the heat dissipation property was also decreased.

The present invention was made based on the above-described knowledge, and a cylindrical sputtering target according to an aspect of the present invention includes a sputtering target material forming a cylindrical shape, and a backing tube bonded to the inner circumferential side of the sputtering target material through a solder layer. A cylindrical sputtering target provided with, wherein the solder layer is made of an In-based solder material and has an oxygen content of 100 massppm or less.

According to the cylindrical sputtering target according to an aspect of the present invention having such a configuration, since the oxygen content in the solder layer is 100 massppm or less, a large amount of oxide of solder adheres to the bonding surface of the sputtering target material and the bonding surface of the backing tube. As a result, the bonding strength between the sputtering target material and the backing tube can be ensured. Further, the heat generated by the sputtering target material can be efficiently transferred to the backing tube side during sputtering film formation, and the heat dissipation property is excellent.

Therefore, even in the case of sputtering film formation with a high power density, it is possible to stably perform sputtering film formation.

In the cylindrical sputtering target according to an aspect of the present invention, the solder layer preferably has an In content of 95 mass% or more.

In this case, since the solder layer has an In content of 95 mass% or more, melting of the solder layer can be further suppressed even when the melting point of the solder layer is relatively high and the power density is increased.

In the cylindrical sputtering target according to an aspect of the present invention, the solder layer may contain Ga in a range of 0.01 mass% or more and 2 mass% or less.

In this case, since the solder layer contains 0.01 mass% or more of Ga, it becomes possible to further improve the strength of the solder layer. On the other hand, since the Ga content in the solder layer is limited to 2 mass% or less, it is possible to suppress a decrease in the melting point of the solder layer, and even when the power density is increased, the melting of the solder layer can be suppressed. I can.

An In-based solder material according to an aspect of the present invention is characterized in that the oxygen content is 100 massppm or less.

According to the In-based solder material of this configuration, since the oxygen content is 100 mass ppm or less, when the material to be joined is joined using this In-based solder material, it is possible to suppress the adhesion of the oxide of the solder to the bonding surface of the bonded body. Can improve the bonding strength of the material to be joined.

In the In-based solder material as an aspect of the present invention, it is preferable that the In content is 94 mass% or more.

In this case, in the In-based solder material, since the In content is 94 mass% or more, a solder layer having a relatively high melting point can be formed.

In the In-based solder material according to an aspect of the present invention, Ga may be contained in a range of 0.01 mass% or more and 3 mass% or less.

In this case, since it contains Ga that is more susceptible to oxidation than In, Ga is preferentially oxidized during solder bonding. And, since the specific gravity of Ga oxide is small, it floats in molten solder. By removing this floating Ga oxide, it becomes possible to suppress the oxygen content in the solder layer to a low level. Further, when the In-based solder material contains Ga, it becomes possible to improve the strength of the solder layer.

A method of manufacturing a cylindrical sputtering target according to an aspect of the present invention is a method of manufacturing a cylindrical sputtering target having a sputtering target material forming a cylindrical shape, and a backing tube bonded to an inner circumferential side of the sputtering target material through a solder layer, It is characterized in that the sputtering target material and the backing tube are solder-joined using the In-based solder material described above in a non-oxidizing atmosphere. Here, the In-based solder material described above has an oxygen content of 100 massppm or less.

According to the method of manufacturing a cylindrical sputtering target according to an aspect of the present invention having such a configuration, in a non-oxidizing atmosphere, the sputtering target material and the backing tube are formed using an In-based solder material having an oxygen content of 100 mass ppm or less. Since solder bonding is performed, a solder layer having an oxygen content of 100 massppm or less can be formed, the bonding strength between the sputtering target material and the backing tube is ensured, and a cylindrical sputtering target having excellent heat dissipation properties can be manufactured.

A method of manufacturing a cylindrical sputtering target according to an aspect of the present invention is a method of manufacturing a cylindrical sputtering target having a sputtering target material forming a cylindrical shape, and a backing tube bonded to an inner circumferential side of the sputtering target material through a solder layer, With respect to the gap between the sputtering target material and the backing tube, the In-based solder material described above is flowed in an amount equal to or more than twice the volume of the gap, and the excess In-based solder material is recovered. And a solder material solidification step of solidifying the In-based solder material supplied to the gap, and soldering the sputtering target material and the backing tube.

The In-based solder material described above has an oxygen content of 100 ppm by mass or less and contains Ga in a range of 0.01 mass% or more and 3 mass% or less.

According to the method of manufacturing a cylindrical sputtering target according to an aspect of the present invention having such a configuration, an In-based solder material containing Ga is added to the gap between the sputtering target material and the backing tube, which is twice the volume of the gap. Since there is provided a solder material supply step of pouring in the above amount and recovering the excess In-based solder material, regardless of the atmosphere at the time of bonding, the Ga oxide generated when the In-based solder material starts to flow into the gap Can be removed, the oxygen content in the solder layer can be reliably reduced, the bonding strength between the sputtering target material and the backing tube is ensured, and a cylindrical sputtering target excellent in heat dissipation properties can be manufactured. Further, since Ga in the In-based solder material is oxidized and removed, the Ga content in the solder layer is lower than the Ga content in the In-based solder material.

In the method of manufacturing a cylindrical sputtering target according to an aspect of the present invention, in the solder material supplying step, the sputtering target material and the backing tube are respectively erected, and the In-based solder material is formed at the lower end and upper ends of the gap. It is preferable to supply from one or both sides of the side, and to recover excess In-based solder material from the upper end side of the gap.

In this case, since the In-based solder material is supplied from one or both of the lower and upper ends of the gap and is recovered from the upper end of the gap, the Ga oxide having a small specific gravity is efficiently removed from the gap. It can be removed from, and it becomes possible to more reliably reduce the oxygen content in the solder layer.

As described above, according to the present invention, the strength in the solder layer formed between the sputtering target material and the backing tube can be ensured. Therefore, even when the power density is increased and used, it becomes possible to provide a cylindrical sputtering target capable of stably forming a sputtering film, an In-based solder material, and a method of manufacturing a cylindrical sputtering target.

1A is a schematic explanatory diagram of a cylindrical sputtering target according to an embodiment of the present invention, and is a cross-sectional view orthogonal to the axis O direction.
1B is a schematic explanatory view of a cylindrical sputtering target according to an embodiment of the present invention, and is a cross-sectional view taken along the axis O.
2 is a flowchart showing a method of manufacturing a cylindrical sputtering target according to the first embodiment of the present invention.
3 is a flowchart showing a method of manufacturing a cylindrical sputtering target according to a second embodiment of the present invention.
4A is an explanatory view showing a method of collecting a tensile test piece for measuring the bonding strength between a sputtering target material and a backing tube.
4B is an explanatory view showing a method of collecting a tensile test piece for measuring the bonding strength between a sputtering target material and a backing tube.

Hereinafter, a method for producing a cylindrical sputtering target according to an embodiment of the present invention, and a cylindrical sputtering target will be described with reference to the accompanying drawings.

(First embodiment)

Cylindrical sputtering target 10 according to the present embodiment, as shown in Figs. 1A and 1B, a sputtering target material 11 forming a cylindrical shape extending along the axis O, and the inner periphery of the sputtering target material 11 It has a cylindrical backing tube 12 inserted in the side.

The cylindrical sputtering target material 11 and the backing tube 12 are joined via the solder layer 13.

The sputtering target material 11 has a composition according to the composition of the thin film to be formed, and is composed of various metals and oxides, for example, silicon (Si), copper (Cu), alumina-containing zinc oxide (AZO), etc. It consists of.

The size of this cylindrical sputtering target material 11 is, for example, the outer diameter D _T within the range of 150 mm ≤ D _T ≤ 170 mm, the inner diameter d _T within the range of 120 mm ≤ d _T ≤ 140 mm, axis line The length L _T in the O direction is within the range of 500 mm ≤ L _T ≤ 3000 mm.

The backing tube 12 is formed to hold the cylindrical sputtering target material 11 to secure mechanical strength, and further supplies power to the cylindrical sputtering target material 11, and the cylindrical sputtering target It has the same function as the cooling of the ash (11).

The backing tube 12 is required to be excellent in mechanical strength, electrical conductivity, and thermal conductivity, and is made of, for example, stainless steel such as SUS304, titanium, and copper alloy.

The size of the backing tube 12 is, for example, the outer diameter D _B in the range of 119 mm ≤ D _B ≤ 139 mm, the inner diameter d _B in the range of 110 mm ≤ d _B ≤ 130 mm, and the length L in the axis O direction. _B is within the range of 510 mm ≤ L _B ≤ 3100 mm.

When the solder layer 13 interposed between the cylindrical sputtering target material 11 and the backing tube 12 is bonded to the cylindrical sputtering target material 11 and the backing tube 12 using a solder material Is formed.

The thickness t of the solder layer 13 is in the range of 0.5 mm ≤ t ≤ 4 mm.

In the cylindrical sputtering target 10 according to the present embodiment, the solder layer 13 is made of an In-based solder material, and the oxygen content is 100 massppm or less. The oxygen content of the solder layer 13 is more preferably 50 massppm or less. The lower the oxygen content of the solder layer 13 is, the more preferable it is, but extremely lowering the oxygen content results in an increase in cost. For this reason, the oxygen content of the solder layer 13 may be 1 mass ppm or more.

The content of In in the solder layer 13 of the cylindrical sputtering target 10 is preferably 95 mass% or more, more preferably 98 mass% or more, and 99.99 mass% or less.

As the In-based solder material of the present embodiment used when forming the solder layer 13, an oxygen content limited to 100 massppm or less is used.

The content of In in the In-based solder material is preferably 94 mass% or more, more preferably 96 mass% or more, and 99.99 mass% or less.

In the method for producing an In-based solder material according to the present embodiment, it is preferable to perform deoxidation treatment in which the In raw material is melted and kept at a temperature of 250°C or more and 350°C or less for 3 minutes or more in vacuum. This makes it possible to limit the oxygen content of the In-based solder material to 100 massppm or less. In the deoxidation treatment, it is more preferable that the temperature is 270°C or more and 330°C or less, and it is more preferable that the holding time is 6 minutes or more and 60 minutes or less.

Hereinafter, the manufacturing method of the cylindrical sputtering target 10 which is this embodiment is demonstrated using FIG.

(Solder underlayer formation step S01)

A molten In-based solder material is applied to the inner circumferential surface of the sputtering target material 11 and the outer circumferential surface of the backing tube 12 to form a solder base layer, respectively.

In this solder base layer formation step S01, the sputtering target material 11 and the backing tube 12 are heated, and the molten In-based solder material is applied while applying ultrasonic vibration with an ultrasonic iron or the like equipped with a heater, To form an underlying solder layer. In addition, the heating temperature in this solder base layer forming step S01 is in the range of 170°C or more and 250°C or less. Here, in this solder base layer forming process S01, it is preferable to form a solder base layer by the method described in Unexamined-Japanese-Patent No. 2014-037619. It is more preferable that the heating temperature in the solder underlayer formation step S01 is 190°C or more and 230°C or less.

(Cooling process S02)

In the state in which the underlying solder layer is formed, in order to assemble the sputtering target material 11 and the backing tube 12, it is once cooled to room temperature.

(Assembly process S03)

The sputtering target material 11 and the backing tube 12 with the underlying solder layer are aligned and assembled. At this time, a space having a predetermined size is formed between the inner peripheral surface of the sputtering target material 11 and the outer peripheral surface of the backing tube 12 using a spacer or the like. In addition, in this assembling step S03, it is preferable to assemble the sputtering target material 11 and the backing tube 12 by the method described in JP 2014-037619 A.

(Solder bonding process S04)

A molten In-based solder material is poured into the gap between the inner circumferential surface of the assembled sputtering target material 11 and the outer circumferential surface of the backing tube 12, and the sputtering target material 11 and the backing tube 12 are solder-joined.

In this solder bonding step S04, it is performed in a non-oxidizing atmosphere such as a _{reducing atmosphere or an inert gas atmosphere such as N 2 gas or Ar gas.} Thereby, it becomes possible to suppress mixing of oxygen at the time of solder bonding, and to limit the oxygen content in the solder layer 13 formed after bonding to 100 massppm or less.

The heating conditions in this solder bonding step S04 are in the range of 170°C or more and 250°C or less, and the holding time at this heating temperature is in the range of 10 minutes or more and 120 minutes or less. As for the heating conditions in the solder bonding process S04, it is more preferable that the heating temperature is 190 degreeC or more and 230 degreeC or less, and it is more preferable that the holding time is 30 minutes or more and 90 minutes or less.

If the heating temperature in the solder bonding step S04 is less than 170°C, there is a concern that the In-based solder material may not be dissolved. In addition, when the heating temperature exceeds 250°C, there is a fear that oxidation of the underlying solder layer may be promoted.

If the holding time at the heating temperature is less than 10 minutes, heating may be insufficient and the In-based solder material flowing therein may be solidified, or the solder may partially harden and voids may occur. In addition, when the holding time at the heating temperature exceeds 120 minutes, there is a fear that oxidation of the underlying solder layer may be accelerated.

From the above point of view, in the present embodiment, the heating conditions in the solder bonding step S04 are defined as described above.

In this solder bonding step S04, it is preferable to pour a solder material into the gap between the sputtering target material 11 and the backing tube 12 by the method described in JP 2014-037619 A.

By the process as described above, the cylindrical sputtering target 10 which is this embodiment is manufactured.

According to the cylindrical sputtering target 10 of the present embodiment having the configuration as described above, the oxygen content in the solder layer 13 interposed between the sputtering target material 11 and the backing tube 12 is 100 massppm or less. Therefore, the bonding surface of the sputtering target material 11 and the bonding surface of the backing tube 12 do not adhere much of the oxide of the solder, so that the bonding strength between the sputtering target material 11 and the backing tube 12 can be secured. I can.

In addition, since the sputtering target material 11 and the backing tube 12 are firmly bonded to each other, the heat generated from the sputtering target material 11 can be efficiently transferred to the backing tube 12 side at the time of sputtering film formation, resulting in heat dissipation. The characteristics are excellent.

In addition, since the solder layer 13 is made of an In-based solder material and the In content is 95 mass% or more, the melting point of the solder layer 13 is relatively high, and even when the power density is increased, the solder layer ( 13) Melting can be suppressed.

Therefore, even if the power density is increased, it becomes possible to stably perform sputtering film formation.

Since the In-based solder material of the present embodiment has an oxygen content of 100 mass ppm or less, it is possible to suppress adhesion of the oxide of the solder to the bonding surface of the sputtering target material 11 and the bonding surface of the backing tube 12, It becomes possible to improve the bonding strength of the sputtering target material 11 and the backing tube 12.

According to the manufacturing method of the cylindrical sputtering target according to the present embodiment, the In-based solder material of the present embodiment in which the oxygen content is 100 massppm or less in a non-oxidizing atmosphere such as a _{reducing atmosphere or an inert gas atmosphere such as N 2 gas or Ar gas.} By using, since the sputtering target material 11 and the backing tube 12 are solder-joined, the solder layer 13 with an oxygen content of 100 massppm or less can be formed, and the sputtering target material 11 and the backing tube The bonding strength of (12) is ensured, and the cylindrical sputtering target 10 excellent in heat dissipation properties can be manufactured.

(2nd embodiment)

Next, a second embodiment of the present invention will be described. In this second embodiment, in Figs. 1A and 1B, the sputtering target material 11 and the backing tube 12 have the same configuration as in the first embodiment, and the material of the solder layer 13 is first. It is different from 1 embodiment.

The solder layer 13 in the second embodiment is made of an In-based solder material, has an oxygen content of 100 massppm or less, and contains Ga in a range of 0.01 mass% or more and 2 mass% or less. . The content of Ga in the solder layer 13 is more preferably 1.0 mass% or less.

The content of In in the solder layer 13 is preferably 95% by mass or more, more preferably 98% by mass or more, and preferably 99.99% by mass or less.

The In-based solder material according to the present embodiment used when forming the solder layer 13 has an oxygen content of 100 ppm by mass or less, and contains Ga in a range of 0.01 mass% or more and 3 mass% or less. The content of Ga in the In-based solder material is more preferably 2.0 mass% or less.

The content of In in the In-based solder material is preferably 94 mass% or more, more preferably 96 mass% or more, and 99.99 mass% or less.

The In-based solder material according to this embodiment is manufactured as follows. First, the In raw material and the Ga raw material are melted and held for a certain period of time, and then cooled and solidified, and the upper portion of the solder ingot obtained by solidifying is removed. Since Ga is more easily oxidized than In, Ga oxide is produced. Further, since Ga oxide has a small specific gravity, Ga oxide is present on the upper portion of the solder ingot obtained by solidification. Thus, it becomes possible to remove the Ga oxide by removing the upper portion of the solder ingot.

By the above process, it is possible to obtain an In-based solder material containing Ga in the range of 0.01 mass% or more and 3 mass% or less and the oxygen content is limited to 100 mass ppm or less.

Below, the manufacturing method of the cylindrical sputtering target 10 which is this embodiment is demonstrated using FIG.

(Solder underlayer formation step S101)

First, on the inner circumferential surface of the sputtering target material 11 and the outer circumferential surface of the backing tube 12, a molten In-based solder material according to this embodiment is applied to form a solder base layer, respectively.

In this solder base layer forming step S101, it is preferable to form the solder base layer by the same procedure as in the first embodiment.

(Cooling process S102)

Next, in order to assemble the sputtering target material 11 and the backing tube 12 in a state in which the underlying solder layer is formed, it is once cooled to room temperature.

(Assembly process S103)

Next, the sputtering target material 11 and the backing tube 12 having the underlying solder layer are aligned and assembled. At this time, a space having a predetermined size is formed between the inner peripheral surface of the sputtering target material 11 and the outer peripheral surface of the backing tube 12 using a spacer or the like. In addition, in this assembling process S103, it is preferable to assemble the sputtering target material 11 and the backing tube 12 by the same procedure as in the first embodiment.

In this embodiment, the sputtering target material 11 and the backing tube 12 are respectively erected and disposed, and the gap between the sputtering target material 11 and the backing tube 12 is formed so as to extend in the vertical direction. Has been.

(Solder material supply process S104)

Next, with respect to the gap between the inner circumferential surface of the assembled sputtering target material 11 and the outer circumferential surface of the backing tube 12, the In-based solder material of this embodiment was poured in an amount equal to or more than twice the volume of the gap. , Recover excess In-based solder material.

In this embodiment, as described above, the sputtering target material 11 and the backing tube 12 are respectively erected and disposed, and the gap between the sputtering target material 11 and the backing tube 12 is vertical Since it is formed so as to extend in the direction, the In-based solder material is supplied from one or both of the lower and upper ends of the gap, and the excess In-based solder material is recovered from the upper end of the gap. have.

In this solder material supply step S104, Ga contained in the In-based solder material is preferentially oxidized to generate Ga oxide. And, by pouring in an amount equal to or more than twice the volume of the gap, it becomes possible to reliably remove the Ga oxide generated when the In-based solder material is supplied to the gap from the gap. Thereby, it becomes possible to reduce the oxygen content in the solder layer 13 to 100 massppm or less. Further, since Ga is oxidized and consumed, the Ga content in the solder layer 13 is less than the Ga content in the In-based solder material.

(Solder material solidification step S105)

Next, the In-based solder material supplied to the gap is solidified, and the sputtering target material 11 and the backing tube 12 are solder-joined.

By the process as described above, the cylindrical sputtering target 10 which is this embodiment is manufactured.

According to the cylindrical sputtering target 10 of the present embodiment having the configuration as described above, the solder layer 13 interposed between the sputtering target material 11 and the backing tube 12 is made of an In-based solder material, Since the oxygen content is 100 massppm or less, it becomes possible to exhibit the same effects as in the first embodiment.

In this embodiment, since the solder layer 13 contains 0.01 mass% or more of Ga, it becomes possible to improve the strength of the solder layer 13. On the other hand, since the Ga content in the solder layer 13 is limited to 2 mass% or less, it is possible to suppress a decrease in the melting point of the solder layer 13, and even when the power density is increased, the solder layer ( 13) Melting can be suppressed.

Since the In-based solder material of the present embodiment has an oxygen content of 100 mass ppm or less, it becomes possible to exhibit the same effects as in the first embodiment.

In this embodiment, since the In-based solder material contains Ga in a range of 0.01 mass% or more and 3 mass% or less, during solder bonding, Ga, which is more oxidized than In, preferentially oxidizes. Since Ga oxide has a small specific gravity, it floats in the molten solder material.

By removing this floating Ga oxide, it becomes possible to suppress the oxygen content in the solder layer 13 to 100 massppm or less. Moreover, when the In-based solder material contains Ga, it becomes possible to improve the strength of the solder layer 13.

According to the manufacturing method of the cylindrical sputtering target 10 of this embodiment, with respect to the gap between the sputtering target material 11 and the backing tube 12, an In-based solder material containing Ga is twice the volume of the gap. Since the solder material supply step S104 for pouring in the above amount and recovering the excess In-based solder material is provided, the Ga oxide generated when the In-based solder material is started to be poured can be removed from the gap, and the solder layer The oxygen content in (13) can be reliably reduced, the bonding strength between the sputtering target material 11 and the backing tube 12 is ensured, and the cylindrical sputtering target 10 excellent in heat dissipation properties can be manufactured. .

In the present embodiment, in the solder material supply step S104, the sputtering target material 11 and the backing tube 12 are respectively erected and formed, and the In-based solder material is formed either on the lower end side and the upper end side of the gap, or Since the In-based solder material is supplied from both sides and the excess In-based solder material is recovered from the upper end of the gap, the Ga oxide having a small specific gravity can be efficiently removed from the gap, and in the solder layer 13 It becomes possible to more reliably reduce the oxygen content of.

As mentioned above, although the embodiment of this invention was demonstrated, this invention is not limited to this, It can change suitably within the range which does not deviate from the technical idea of the invention.

In the present embodiment, the cylindrical sputtering target shown in Figs. 1A and 1B has been described as an example, but the present invention is not limited thereto, and a sputtering target material having a cylindrical shape, and a solder layer on the inner peripheral side of the cylindrical sputtering target material. It may be a cylindrical sputtering target provided with a backing tube interposed therebetween, and may be, for example, a split type or a dog bone type.

In addition, in the first embodiment, as the In-based solder material, an oxygen content of 100 massppm or less may be used, and a Ga content in the range of 0.01 mass% or more and 3 mass% or less may be used.

Example

Hereinafter, the result of the confirmation test conducted to confirm the effect of the cylindrical sputtering target according to the present invention and the method for producing the cylindrical sputtering target will be described.

A sputtering target material, a backing tube, and a solder material shown in Table 1 were prepared. As raw materials for the solder material, In with a purity of 99.99 mass% or more and Ga with a purity of 99.99 mass% or more were used.

As for the size of the sputtering target material, the outer diameter D _T was 162 mm, the inner diameter d _T was 135 mm, and the axial length L _T was 600 mm.

As for the size of the backing tube, the outer diameter D _B was 133 mm, the inner diameter d _B was 125 mm, and the axial length L _B was 620 mm.

When the In-based solder material did not contain Ga, it was heated in a vacuum at 300° C. and held for the time shown in Table 1 to perform deoxidation treatment. However, in Comparative Example 1, no deoxidation treatment was performed.

The Ga content and the oxygen content in the In-based solder material before bonding were measured as follows. Table 1 shows the evaluation results.

Then, the sputtering target material and the backing tube were aligned and erected. The solder material shown in Table 1 was supplied from the lower end side of the gap between the sputtering target material and the backing tube, and when the amount of solder material supplied exceeded the volume of the gap, it was recovered at the upper end side of the gap. Thereby, the sputtering target material and the backing tube were solder-joined under the conditions shown in Table 1 by the method described in Japanese Patent Application Laid-Open No. 2014-037619 to manufacture a cylindrical sputtering target.

The "solder material supply amount" in Table 1 represents the supply amount when the volume of the gap is 1.

With respect to the obtained cylindrical sputtering target, the Ga content, oxygen content, bonding rate, bonding strength, and temperature during sputtering in the solder layer were evaluated as follows.

(Composition of In-based solder material before bonding)

1 g of the molten In-based solder material was sampled with a stainless steel jig. In accordance with the infrared absorption method described in JIS Z 2613 "General Rules for Quantifying Oxygen in Metallic Materials", the oxygen content was measured using TC600 manufactured by LECO.

Using the sample sampled in the same manner, the Ga content was measured with an ICP emission spectrometer.

(Composition of the solder layer after bonding)

The obtained cylindrical sputtering target was cut, the solder layer was cut with a cutter knife, and 1 g was sampled. In accordance with the infrared absorption method described in JIS Z 2613 "General Rules for Quantifying Oxygen in Metallic Materials", the oxygen content was measured using TC600 manufactured by LECO.

Using the sample sampled in the same manner, the Ga content was measured with an ICP emission spectrometer.

(Joining rate)

The bonding area ratio was measured using an ultrasonic flaw detection apparatus. The bonding area ratio was calculated as the ratio of the area of the bonding area excluding the area of the bonding defective area to the total area of the bonding surface. The total area of the bonding surface was taken as the total area of the inner circumferential surface of the sputtering target material.

(Joint strength)

As shown in FIG. 4A, 20 cylindrical samples were cut from the side surface of the obtained cylindrical sputtering target using a wire cut. The cross-section (outer circumferential surface and inner circumferential surface) of this sample was cut out as shown in Fig. 4B to be a flat surface, and the outer circumferential surface of the sample was machined to obtain a φ20 mm tensile test piece. This tensile test piece was attached to a tensile tester INSTRON5984 (manufactured by Instron Japan), and tensile strength was measured. Further, the maximum load was 150 kN and the displacement speed was set to 0.1 mm/min. Table 2 shows the average value of the tensile strength of the measured 20 samples as the bonding strength.

In the sample processing step, a lot of peeling between the sputtering target and the backing tube occurred, and the fact that a sufficient number of samples was not obtained was described as "peel".

(Temperature during sputtering)

A temperature sensing seal was affixed to the end face of the cylindrical sputtering target, and the maximum reached temperature when sputtering was performed under the following conditions was measured.

Power: DC

Power: 8 kW/m or 16 kW/m

Gas pressure: 0.4 Pa

Gas: Ar

Rotation speed: 10 rpm

Discharge time: 60 min

Target size: (φ162 ㎜-φ135 ㎜) × 600 ㎜

In Comparative Example 1 in which an In-based solder material containing no Ga and having an oxygen content of 170 massppm was used, the oxygen content in the solder layer was 170 massppm, and the sputtering target material and the backing tube were peeled off during the tensile test. It became, and the bonding strength could not be measured. Further, the temperature when sputtering at an electric power of 8 kW/m became 80°C, and when sputtering at an electric power of 16 kW/m, the solder layer was melted.

In Comparative Example 2 using an In-based solder material having a Ga content of 0.005 mass% and an oxygen content of 110 mass ppm, the oxygen content in the solder layer was 110 mass ppm, and the bonding strength was lowered to 4 MPa. Moreover, the temperature when sputtering at an electric power of 8 kW/m became 65 degreeC, and the temperature at the time of sputtering at an electric power of 16 kW/m became 145 degreeC.

An In-based solder material having a Ga content of 0.02 mass% and an oxygen content of 30 mass ppm was used, but in Comparative Example 3 in which the amount of solder material supplied was equivalent to the volume of the gap, the oxygen content in the solder layer was 110 It became massppm, and the bonding strength was lowered to 2 MPa. Further, the temperature when sputtering at an electric power of 8 kW/m became 70° C., and when sputtering at an electric power of 16 kW/m, the solder layer was melted.

In Comparative Example 4 in which an In-based solder material containing no Ga and having an oxygen content of 150 massppm was used and soldered in an Ar gas atmosphere, the oxygen content in the solder layer was 160 massppm, and at the time of the tensile test. The sputtering target material and the backing tube were peeled off, and the bonding strength could not be measured. Further, the temperature when sputtering at an electric power of 8 kW/m became 80°C, and when sputtering at an electric power of 16 kW/m, the solder layer was melted.

In Comparative Example 5, in which an In-based solder material containing no Ga and having an oxygen content of 30 massppm was used and soldered in an air atmosphere, the oxygen content in the solder layer was 180 massppm, and at the time of the tensile test. The sputtering target material and the backing tube were peeled off, and the bonding strength could not be measured. Further, the temperature when sputtering at an electric power of 8 kW/m became 85°C, and when sputtering at an electric power of 16 kW/m, the solder layer was melted.

On the other hand, Invention Example 1 in which an In-based solder material having a Ga content of 0.01 mass% or more and 3 mass% or less and an oxygen content of 30 mass ppm was used, and the amount of solder material supplied was twice the volume of the gap. In 6 to 6, the Ga content in the solder layer is in the range of 0.01 mass% or more and 2 mass% or less, and the oxygen content is 100 massppm or less. Moreover, the bonding strength became 10 MPa or more, and the sputtering target material and the backing tube were able to be firmly bonded. Further, the temperature when sputtering at an electric power of 8 kW/m became 50°C or less, and the temperature when sputtering at an electric power of 16 kW/m was 95°C or less.

In Examples 8 to 10 of the present invention in which solder bonding was performed in an Ar atmosphere using an In-based solder material containing no Ga and having an oxygen content of 90 mass ppm or less, the oxygen content in the solder layer was 100 mass ppm or less. Became. Moreover, the bonding strength became 8 MPa or more, and the sputtering target material and the backing tube could be joined firmly. Moreover, the temperature when sputtering with an electric power of 8 kW/m became 50 degrees C or less, and the temperature when sputtering with an electric power of 95 kW/m became 95 degrees C or less.

In Example 7 of the present invention, in which an In-based solder material having a Ga content of 5 mass% and an oxygen content of 30 mass ppm was used, and the amount of the solder material supplied was twice the volume of the gap, the Ga content in the solder layer This was 4.5 mass%, and the oxygen content became less than 10 massppm. Moreover, the bonding strength became 16 MPa, and the sputtering target material and the backing tube were able to be firmly bonded. Moreover, the temperature when sputtering at 8 kW/m electric power was 45 degreeC. However, when sputtering at an electric power of 16 kW/m, the solder layer melted. Although the heat dissipation property was good, since the melting point of the solder layer itself was low, it is presumed that it melted. For this reason, when sputtering film formation with a high power density, it is preferable to limit the Ga content of the In-based solder material to 3 mass% or less.

From the above point of view, according to the example of the present invention, the strength in the solder layer formed between the sputtering target material and the backing tube can be secured, and even when used with increased power density, a cylindrical sputtering target capable of stably forming a sputtering film. , It was confirmed that the In-based solder material, and a method for producing a cylindrical sputtering target can be provided.

Industrial applicability

According to the cylindrical sputtering target of the present invention, the strength in the solder layer formed between the sputtering target material and the backing tube can be ensured, and even when the power density is increased and used, sputtering film can be stably formed.

10: cylindrical sputtering target
11: sputtering target material
12: backing tube
13: solder layer

Claims (9)

A cylindrical sputtering target comprising a sputtering target material forming a cylindrical shape and a backing tube bonded to an inner circumferential side of the sputtering target material through a solder layer,
The solder layer is made of an In-based solder material and has an oxygen content of 100 massppm or less. The method of claim 1,
The solder layer is a cylindrical sputtering target, wherein the In content is 95 mass% or more. The method according to claim 1 or 2,
The said solder layer contains Ga in the range of 0.01 mass% or more and 2 mass% or less, The cylindrical sputtering target characterized by the above-mentioned. In-based solder material, characterized in that the oxygen content is 100 massppm or less. The method of claim 4,
An In-based solder material having an In content of 94 mass% or more. The method according to claim 4 or 5,
An In-based solder material containing Ga in a range of 0.01 mass% or more and 3 mass% or less. A method for manufacturing a cylindrical sputtering target comprising a sputtering target material forming a cylindrical shape and a backing tube bonded to an inner circumferential side of the sputtering target material through a solder layer,
A method for producing a cylindrical sputtering target, wherein the sputtering target material and the backing tube are solder-joined using the In-based solder material according to any one of claims 4 to 6 in a non-oxidizing atmosphere. A method for manufacturing a cylindrical sputtering target comprising a sputtering target material forming a cylindrical shape and a backing tube bonded to an inner circumferential side of the sputtering target material through a solder layer,
A solder material supply for pouring the In-based solder material according to claim 6 in an amount equal to or more than twice the volume of the gap with respect to the gap between the sputtering target material and the backing tube, and recovering the excess In-based solder material. Process,
And a solder material solidification step of solidifying the In-based solder material supplied to the gap and soldering the sputtering target material and the backing tube. The method of claim 8,
In the solder material supply process, the sputtering target material and the backing tube are respectively erected, and the In-based solder material is supplied from one or both of the lower and upper ends of the gap, and the excess In-based A method of manufacturing a cylindrical sputtering target, characterized in that the solder material is recovered from the upper end side of the gap.

Images