WO2019049254A1

WO2019049254A1 - Cylindrical sputtering target

Info

Publication number: WO2019049254A1
Application number: PCT/JP2017/032230
Authority: WO
Inventors: 植田　稔晃; 晋岡野
Original assignee: 三菱マテリアル株式会社
Priority date: 2017-09-07
Filing date: 2017-09-07
Publication date: 2019-03-14
Also published as: KR102357819B1; CN111032904A; KR20200051581A

Abstract

The cylindrical sputtering target according to the present invention is provided with a cylindrical-shaped target member and a packing tube that is joined via a joining layer to the inner circumferential side of the target member. Thermal resistance in the radial direction of the packing tube is 6.5 x 10-5 K/W or less.

Description

Cylindrical sputtering target

The present invention relates to a cylindrical sputtering target provided with a cylindrical sputtering target material and a backing tube bonded to the inner peripheral side of the sputtering target material via a bonding layer.

A sputtering method using a sputtering target is widely used as a means for forming a thin film such as a metal film or an oxide film.
In general, a sputtering target has a structure in which a sputtering target material formed according to the composition of a thin film to be formed and a backing material holding the sputtering target material are joined via a bonding layer.
As a bonding material which constitutes a bonding layer interposed between the sputtering target material and the backing material, for example, In, Sn-Pb alloy, etc. may be mentioned. In order to reduce the workability and distortion at the time of bonding, a material having a relatively low melting point of, for example, 300 ° C. or less is used as the melting point of the bonding material constituting the bonding layer.

As the above-mentioned sputtering target, for example, a flat type sputtering target and a cylindrical sputtering target have been proposed.
The flat type sputtering target has a structure in which a flat target material and a flat backing material (backing plate) are stacked.
In the cylindrical sputtering target, for example, as described in Patent Document 1, a structure in which a cylindrical backing material (backing tube) is joined to the inner peripheral side of a cylindrical target material via a bonding layer. It is assumed. In order to cope with film formation on a large substrate, there has been proposed one in which the axial direction length of a target material of a cylindrical target is set to be relatively long, for example, 0.5 m or more.

In the flat type sputtering target, the efficiency of use of the target material is as low as about 20 to 30%, and continuous sputtering can not be performed, so that film formation could not be performed efficiently.
On the other hand, the cylindrical sputtering target has a sputtering surface on its outer peripheral surface, and since sputtering is performed while rotating the target, it is suitable for continuous film formation as compared with the case where a flat type sputtering target is used. In addition, since the erosion portion spreads in the circumferential direction, the use efficiency of the cylindrical sputtering target material is as high as 60 to 80%.
Furthermore, in the cylindrical sputtering target, cooling is performed from the inner peripheral side of the backing tube, and as described above, since the erosion portion spreads in the circumferential direction, the temperature rise of the cylindrical sputtering target material Can be suppressed, the power density at the time of sputtering can be increased, and the throughput of film formation can be further improved.

JP, 2014-037619, A

By the way, in recent years, in liquid crystal panels, solar cell panels and the like, since further cost reduction is required, it is required to further increase the power density at the time of sputtering to further improve the throughput of film formation.
Here, in the cylindrical sputtering target described above, the surface temperature of the cylindrical sputtering target material rises at the time of sputtering due to the further increase in power density, and the bonding layer made of a low melting point metal such as In melts out There was a problem that For this reason, in the conventional cylindrical sputtering target, a further increase in power density could not be realized.

Further, in the conventional cylindrical sputtering target, even if there is no problem at the beginning of use, as the use progresses, erosion progresses and the thickness of the sputtering target material locally decreases, and the cylindrical sputtering target There is a possibility that the bonding layer located on the inner peripheral side of the material may be melted out.
However, from the viewpoint of further cost reduction, in order to further improve the use efficiency of the cylindrical sputtering target material and reduce the frequency of replacement of the cylindrical sputtering target, cylindrical sputtering which can be used even when erosion proceeds A target is sought.

Furthermore, the axial direction length of the cylindrical sputtering target is long due to the enlargement of the substrate for film formation for further cost reduction in liquid crystal panels, solar cell panels etc., but the size in the radial direction is greatly changed It has not been. For this reason, the heat generated at the time of sputtering can not be efficiently dissipated to the inner peripheral side of the backing tube, and the temperature of the cylindrical sputtering target is likely to rise, again causing the possibility of melting of the bonding layer. there were.

Moreover, although the temperature rise of said cylindrical sputtering target is cooled by flowing a cooling water through the inside of a backing tube, the cooling water used for cooling of a cylindrical sputtering target is another cylindrical type depending on the sputtering device. Since there is one used for cooling the sputtering target, the temperature of the entire cylindrical sputtering target tends to rise easily, and the bonding layer inside the cylindrical sputtering target material tends to melt out.

The present invention has been made in view of the above-described circumstances, and suppresses the melting out of the bonding layer even when the power density during sputtering is set high or when the erosion progresses due to use. It is an object of the present invention to provide a cylindrical sputtering target that can perform stable film formation.

In order to solve the above problems, a cylindrical sputtering target according to an aspect of the present invention includes a cylindrical sputtering target material and a backing tube joined to the inner periphery of the sputtering target material via a bonding layer. And the thermal resistance in the radial direction of the backing tube is not more than 6.5 × 10 ⁻⁵ K / W.

According to the cylindrical sputtering target according to one aspect of the present invention configured as described above, the thermal resistance in the radial direction of the backing tube is 6.5 × 10 ⁻⁵ K / W or less. By efficiently dissipating the heat generated by the target material in the form to the backing tube side, the temperature rise of the cylindrical sputtering target can be suppressed, and the melting out of the bonding layer can be suppressed. Thus, sputtering can be performed with a high power density, and the throughput of film formation can be improved. In addition, even if the erosion progresses by use and the thickness of the cylindrical sputtering target material locally becomes thin, it becomes possible to perform sputtering film formation.

Here, in the cylindrical sputtering target according to one aspect of the present invention, the thermal resistance in the radial direction from the outer peripheral surface of the bonding layer to the inner peripheral surface of the backing tube is 1.2 × 10 ⁻⁴ K / W or less It is preferable that
In this case, the conduction of heat is promoted in the bonding layer and the backing tube, and the heat generated in the cylindrical sputtering target material can be more efficiently transferred to the backing tube side, thereby suppressing the melting out of the bonding layer. be able to.

In the cylindrical sputtering target according to one aspect of the present invention, the bonding strength between the bonding layer and the backing tube is preferably 4 MPa or more, and more preferably 8 MPa or more.
In this case, the sputtering target material and the backing tube are securely bonded via the bonding layer, and the heat generated from the cylindrical sputtering target material can be reliably transmitted to the backing tube side, and bonding is performed. It is possible to suppress the melting of the layer.

Furthermore, in the cylindrical sputtering target according to one aspect of the present invention, the backing tube preferably has a Vickers hardness of 100 Hv or more.
In this case, since the hardness of the backing tube is sufficiently ensured, deformation of the backing tube can be suppressed even when bending stress or the like acts on the cylindrical sputtering target, thereby reducing the load on the bonding layer be able to. Therefore, even when the bonding layer is softened by the temperature rise, the bonding layer is not pushed out.

In the cylindrical sputtering target according to one aspect of the present invention, the backing tube is preferably made of a copper alloy.
In this case, since the backing tube is made of a copper alloy, the thermal conductivity is excellent, and the thermal resistance in the radial direction of the backing tube can be lowered.

As described above, according to the present invention, it is possible to suppress the melting out of the bonding layer even when the power density at the time of sputtering is set high, or even when the erosion progresses by use, it is stable. It is possible to provide a cylindrical sputtering target capable of performing film formation.

It is a schematic explanatory drawing of the cylindrical sputtering target which concerns on one Embodiment of this invention. (A) is a cross-sectional view orthogonal to the axis O direction, and (b) is a cross-sectional view along the axis O. It is explanatory drawing which shows the calculation method of the thermal resistance of radial direction. It is explanatory drawing which shows the measuring method of joint strength of a joining layer and a backing tube.

Hereinafter, a cylindrical sputtering target according to an embodiment of the present invention will be described with reference to the attached drawings.

The cylindrical sputtering target 10 according to the present embodiment is, as shown in FIG. 1, a cylindrical sputtering target material 11 extending along the axis O, and the sputtering target material 11 inserted on the inner peripheral side of the sputtering target material 11 A cylindrical backing tube 12 is provided.
The cylindrical sputtering target material 11 and the backing tube 12 are bonded via the bonding layer 13.

The sputtering target material 11 has a composition corresponding to the composition of the thin film to be formed, and is made of various metals, oxides, and the like.
Further, for the size of the cylindrical sputtering target material 11, for example, the outer diameter D _T is in the range of 0.15 m ≦ D _T ≦ 0.17 m, and the inner diameter d _T is in the range of 0.12 m ≦ d _T ≦ 0.14 m. Inside, the axial line O direction length l _T is in the range of 0.5 m ≦ l _T ≦ 3 m.

The backing tube 12 is provided to hold the cylindrical sputtering target material 11 to ensure mechanical strength, and further supplies power to the cylindrical sputtering target material 11 and the cylindrical It has an effect of cooling the sputtering target material 11. Therefore, 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 SUS 304, copper or copper alloy, titanium or the like. . Specifically, for example, Co: 0.10 mass% to 0.30 mass%, P: 0.030 mass% to 0.10 mass%, Sn: 0.01 mass% to 0.50 mass%, Ni: 0.02 mass % Or more and 0.10 mass% or less, Zn: 0.01 mass% or more and 0.10 mass% or less, and the remaining portion can be made of a copper alloy having a composition of Cu or an unavoidable impurity.

In the present embodiment, the backing tube 12 has a Vickers hardness of 100 Hv or more. The Vickers hardness can be adjusted by the material of the backing tube 12 and the heat treatment conditions in the manufacturing process. The Vickers hardness of the backing tube 12 is preferably 120 Hv or more, but is not limited thereto. The Vickers hardness of the backing tube 12 may be 250 Hv or less.

Furthermore, in the present embodiment, the conductivity of the backing tube 12 is preferably 60% IACS or more. The conductivity of the backing tube 12 is more preferably 70% IACS or more, but is not limited thereto. The conductivity of the backing tube 12 may be 90% IACS or less.
The thermal conductivity of the backing tube 12 is preferably 200 W / (m · K) or more. The thermal conductivity of the backing tube 12 is preferably 300 W / (m · K) or more, but is not limited thereto. The thermal conductivity of the backing tube 12 may be 430 W / (m · K) or less.
For example, in the above-described copper alloy containing Co, P, Sn, Ni, and Zn, the conductivity can be 60 to 80% IACS, and the thermal conductivity can be 300 W / (m · K) or more.

Here, the size of the backing tube 12, for example in the range of the outer diameter _{D B} is 0.12 m ≦ _{D B} ≦ 0.14 m, in the range inside diameter _{d B} is 0.11m ≦ _{d B} ≦ 0.13m, axis The length l _{B in the} O direction is in the range of 0.5 m ≦ l _B ≦ 3 m.

The bonding layer 13 interposed between the cylindrical sputtering target material 11 and the backing tube 12 is formed when the cylindrical sputtering target material 11 and the backing tube 12 are bonded using a bonding material.
The bonding material forming the bonding layer 13 is made of, for example, a low melting point metal having a melting temperature of 157 ° C. or less such as In. The thickness t of the bonding layer 13 is in the range of 0.0005 m ≦ t ≦ 0.004 m.

Moreover, in the cylindrical sputtering target 10 according to the present embodiment, the bonding strength between the bonding layer 13 and the backing tube 12 is 4 MPa or more. The bonding strength is determined in the stacking direction (diameter of the sputtering target material 11 and the backing tube 12 in a state where the bonding portion between the cylindrical sputtering target material 11 and the bonding layer 13 stacked in the radial direction is fixed with an adhesive. Tensile strength when pulled in the direction). The bonding strength between the bonding layer 13 and the backing tube 12 may be 26 MPa or less. In the bonding step of the cylindrical sputtering target material 11 and the backing tube 12 with the bonding material, the heating temperature is in the range of 170 ° C. to 250 ° C., and the holding time at this heating temperature is 10 minutes to 120 minutes It is considered to be within the range. In the bonding step, the bonding material is preferably poured into the gap between the sputtering target material 11 and the backing tube 12 by the method described in JP-A-2014-37619.

Then, in this embodiment, the thermal resistance _{R B} in the radial direction of the backing tube 12 (the reference line r direction in FIG. 1 (a)) is less than 6.5 × ¹⁰ -5 K / W. Specifically, the thermal conductivity and the reference line r direction thickness of the backing tube 12 by considering the (difference between the outer diameter and the inner diameter), the thermal resistance in the radial direction in the backing tube 12 R _B is 6.5 × 10 ^-5 K / W or less.
In the present embodiment, the thermal conductivity of the backing tube 12 is 200 W / (m · K) or more, and the size of the backing tube 12 is designed accordingly. Thermal resistance _{R B} of the backing tube is preferably less 5.0 × ¹⁰ -5 K / W, but not limited thereto. Thermal resistance _{R B} of the backing tube may be 2.5 × ¹⁰ -5 K / W or more.

Furthermore, in the present embodiment, the thermal resistance in the direction of the reference line r from the outer peripheral surface of the bonding layer 13 to the inner peripheral surface of the backing tube 12 is set to 1.2 × 10 ⁻⁴ K / W or less. Specifically, the thermal conductivity of the backing tube 12 and its reference line r direction thickness (difference between the outer diameter and the inner diameter), the thermal conductivity of the bonding layer 13 and its reference line r direction thickness (the outer diameter and the inner diameter By considering the difference), the thermal resistance in the direction of the reference line r from the outer peripheral surface of the bonding layer 13 to the inner peripheral surface of the backing tube 12 is made not more than 1.2 × 10 ⁻⁴ K / W. The thermal resistance in the direction of the reference line r from the outer peripheral surface of the bonding layer 13 to the inner peripheral surface of the backing tube 12 is preferably 1.1 × 10 ⁻⁴ K / W or less, but is not limited thereto. The thermal resistance in the direction of the reference line r from the outer peripheral surface of the bonding layer 13 to the inner peripheral surface of the backing tube 12 may be 1.0 × 10 ⁻⁶ K / W or more.

Here, a method of calculating the thermal resistance in the radial direction of the cylindrical sputtering target 10 will be described with reference to FIG.
The temperature of the inner peripheral surface of the backing tube 12 is T ₁ , the temperature of the outer peripheral surface (the inner peripheral surface of the bonding layer 13) of the backing tube 12 is T ₂ , the inner peripheral surface of the sputtering target material 11 (the outer peripheral surface of the bonding layer 13) the temperature _{T 3,} the temperature of the outer peripheral surface of the sputtering target material 11 and _{T 4.}
The radius to the inner circumferential surface of the backing tube 12 is r ₁ , the radius to the outer circumferential surface of the backing tube 12 (the inner circumferential surface of the bonding layer 13) r ₂ , the inner circumferential surface of the sputtering target material 11 (bonding layer 13 The radius to the outer peripheral surface of the sputtering target material is r ₃ , and the radius to the outer peripheral surface of the sputtering target material 11 is r ₄ .

Then, the thermal resistance R _i of each layer of the backing tube 12, the bonding layer 13, and the cylindrical sputtering target material 11 is expressed by the following equation.

Here, λ ₁ is the thermal conductivity of the backing tube 12, λ ₂ is the thermal conductivity of the bonding layer 13, λ ₃ is the thermal conductivity of the cylindrical sputtering target material 11, and l is the cylindrical sputtering target material 11. It is the length (l _{T in} FIG. 1). When the cylindrical sputtering target is formed of a plurality of cylindrical sputtering target materials 11, the total length of the plurality of cylindrical sputtering targets 11 is obtained.

Then, the heat passing amount Q in the entire cylinder is expressed by the following equation, and the denominator of this equation becomes the thermal resistance R _{total of the} entire cylindrical sputtering target 10.

Using the above equation, the thermal resistance R _{B in the} direction of the reference line r in the backing tube 12, the thermal resistance R _J in the radial direction in the bonding layer 13, the thermal resistance R _T in the radial direction of the cylindrical sputtering target material 11, bonding The thermal resistance in the radial direction from the outer peripheral surface of the layer 13 to the inner peripheral surface of the backing tube 12 is calculated, and the materials and sizes of the backing tube 12 and the bonding layer 13 are designed to be within the above range.
Although the length l is taken into consideration in the above-mentioned mathematical expressions, in the cylindrical sputtering target 10, the heat source is uniformly disposed in the longitudinal direction of the cylindrical sputtering target material 11, so The thermal resistance R may be calculated in one dimension in the radial direction (the direction of the reference line r). Therefore, in the present specification, the thermal resistance R is calculated by setting the length l in each of the above-described mathematical expressions to one.

Or more in the cylindrical sputtering target 10 is this embodiment that is configured as shown in, the thermal resistance R _B of the reference line r direction in the backing tube 12 is less than 6.5 × 10 -5 ^{K / W} Therefore, the heat generated by the cylindrical sputtering target material 11 can be efficiently transmitted to the inner peripheral side of the backing tube 12, and the melting out of the bonding layer 13 made of a low melting point metal can be suppressed. Therefore, sputtering can be performed with high power density, and the throughput of film formation can be improved. In addition, even if the thickness of the cylindrical sputtering target material 11 is locally reduced due to the progress of erosion due to use, it can be used continuously.

Further, in the present embodiment, the thermal resistance in the radial direction from the outer peripheral surface of the bonding layer 13 to the inner peripheral surface of the backing tube 12 is 1.2 × 10 ⁻⁴ K / W or less. The heat generated by the sputtering target material 11 can be more efficiently transferred to the inner peripheral side of the backing tube 12, and the temperature rise of the cylindrical sputtering target material 11 can be suppressed. Therefore, melting out of the bonding layer 13 made of a low melting point metal can be suppressed.

Furthermore, in the present embodiment, since the bonding strength between the bonding layer 13 and the backing tube 12 is 4 MPa or more, the cylindrical sputtering target material 11 and the backing tube 12 are reliably bonded via the bonding layer 13. The heat generated by the sputtering target material 11 can be reliably transmitted to the backing tube 12 side, and the melting out of the bonding layer 13 can be suppressed.

Further, in the present embodiment, since the Vickers hardness of the backing tube 12 is 100 Hv or more, deformation of the backing tube 12 can be suppressed even when bending stress or the like acts on the cylindrical sputtering target 10, The load on the bonding layer 13 can be reduced. Therefore, even if the bonding layer 13 is softened by the temperature rise, the bonding layer 13 is not pushed out.

As mentioned above, although embodiment of this invention was described, this invention is not limited to this, It can change suitably in the range which does not deviate from the technical idea of the invention.
In the present embodiment, the cylindrical sputtering target shown in FIG. 1 has been described as an example, but the present invention is not limited to this, and a cylindrical sputtering target material and the inner periphery of this cylindrical sputtering target material It may be a cylindrical sputtering target provided with a backing tube bonded on the side via a bonding layer.

Below, the result of the confirmation test implemented in order to confirm the effect of the cylindrical sputtering target which concerns on this invention is demonstrated.

In the example, it is simulated that the bonding layer temperature T3 of the cylindrical sputtering target is likely to reach the maximum temperature, which is immediately before the replacement of the cylindrical sputtering target. Specifically, the outer diameter r4 of the cylindrical sputtering target material is set so that the thickness of the cylindrical sputtering target material decreases on average and the usage efficiency of the cylindrical sputtering target becomes about 80%. doing.

The cylindrical sputtering target material and backing tube shown in Table 1 are prepared, and these cylindrical sputtering target material and backing tube are bonded by the method described in JP-A 2014-37619 via the bonding layer of the materials shown in Table 1 Bonding was performed to obtain a cylindrical sputtering target.

CuGa of the cylindrical sputtering target material shown in Table 1 is a copper alloy having a composition of 32 mass% of Ga, the balance of Cu or unavoidable impurities, and AZO of 1.0 mass% of Al ₂ O ₃ , the balance of ZnO or inevitable impurities It is an oxide of composition.

The Cu alloy backing tube contains Co: 0.20 mass%, P: 0.06 mass%, Sn: 0.10 mass% or more, Ni: 0.05 mass%, Zn: 0.05 mass%, the balance being Cu or unavoidable It is a Cu alloy of the composition made into the impurity, and passes through the following manufacturing conditions. Hot extrusion including solution treatment of the ingot of the above composition under the conditions of a pre-extrusion processing temperature of 900 ° C., a post-extrusion cooling start temperature of 870 ° C. and a cross-sectional shrinkage of 96% after extrusion from the ingot of the above composition To obtain an extruded shell. Cold extrusion of the extruded raw pipe is carried out under the conditions of 23% cross-sectional shrinkage from extrusion to drawing completion, and then heat treatment is carried out at 500 ° C. for 3 hours to produce a Cu alloy backing tube raw pipe, A Cu alloy backing tube is manufactured by processing a backing tube base tube.

The backing tube made of Cu shown in Table 1 had a purity of 99.99 mass%.
The backing tube made of Mo shown in Table 1 had a purity of 99 mass%.
The Al alloy backing tube shown in Table 1 is made of JIS A 2017.
The backing tube made of Ti shown in Table 1 is made of JIS H 46002 type.

(Vickers hardness)
The hardness of the backing tube was measured in accordance with JIS Z 2244. Specifically, a sample for hardness measurement was taken from the backing tube, the measurement surface was polished, and the hardness was measured with a micro Vickers hardness tester. Table 1 shows the hardness of the backing tube.

(Thermal conductivity)
The thermal conductivity of the backing tube, the bonding layer, and the cylindrical sputtering target material was measured in accordance with JIS R 1611. A sample for thermal conductivity measurement was taken from the backing tube, the bonding layer, and the cylindrical sputtering target material, the measurement surface was polished, and the thermal conductivity was measured by a laser flash method.

(Thermal resistance)
The thermal resistance in the direction of the reference line r of the cylindrical sputtering target was calculated by the method described in the embodiment using the value of the thermal conductivity described above. The thermal resistance in the radial direction of the backing tube and the thermal resistance in the radial direction from the outer peripheral surface of the bonding layer to the inner peripheral surface of the backing tube are shown in Table 1.

(Bonding strength of bonding layer and backing tube)
As shown in FIG. 3 (a), a cylindrical sample was cut out from the side surface of the obtained cylindrical sputtering target using a wire cut or a band saw or the like. The end face (outer peripheral surface and inner peripheral surface) of this sample was cut off as shown in FIG. 3B to make a flat surface, and the outer peripheral surface of the sample was cut by lathing to obtain a measurement sample of φ 20 mm. The bonding portion between the sputtering target material of the measurement sample and the bonding layer was fixed by applying an adhesive from the outside. The tensile strength of this measurement sample was measured using a tensile tester INSTORON 5984 (manufactured by Instron Japan Co., Ltd.). The maximum load was 150 kN, and the displacement speed was 0.1 mm / min. This tensile strength was taken as the bonding strength between the bonding layer and the backing tube. The measured bonding strength is shown in Table 1.

Then, using these cylindrical sputtering targets, first, pre-sputtering was performed. The pre-sputtering conditions are: sputtering at a total pressure of 0.8 Pa and at an output of 1/10, 1/5, 1/3, 1/2 of the sputtering output shown in Table 2 for 5 minutes each. Thereafter, sputtering was performed for 8 hours under the conditions shown in Table 2, and after the sputtering, the presence or absence of melting of the bonding layer was confirmed.

If there is no melting out of the bonding layer in contact with the entire end face of the cylindrical sputtering target material "A", melting out of the bonding layer less than 1 mm in the direction of the axis O at all the end faces of the cylindrical sputtering target material In all the end faces of the sputtering target material of "B" and cylindrical shape that was 2 places or less, the melting out of the bonding layer less than 1 mm in the axis O direction melts out 3 or more places or the bonding layer of 1 mm or more What was confirmed was evaluated as "C", and what the shift | offset | difference of the sputtering target material was confirmed was evaluated as "D."

For the comparative example in which the thermal resistance in the radial direction in the backing tube is larger than that of the present invention, as a result of the sputtering test, melting of the bonding layer was confirmed.
On the other hand, in the example of the present invention in which the thermal resistance in the radial direction of the backing tube was within the scope of the present invention, the melting out of the bonding layer was suppressed.
Further, in the example of the present invention, the bonding strength between the bonding layer and the backing tube was 4 MPa or more, and it was confirmed that the sputtering target material and the backing tube were securely bonded via the bonding layer.
In the case where the backing tube had a hardness of 100 Hv or more, in particular, melting of the bonding layer was suppressed.

According to the cylindrical sputtering target of the present invention, it is possible to suppress the melting out of the bonding layer even when the power density at the time of sputtering is set high, or even when the erosion progresses by use, it is stable. Film formation can be performed.

10 cylindrical sputtering target 11 cylindrical sputtering target material 12 backing tube 13 bonding layer

Claims

A cylindrical sputtering target comprising: a cylindrical sputtering target material; and a backing tube bonded to the inner peripheral side of the sputtering target material via a bonding layer,
The cylindrical sputtering target, wherein a thermal resistance in a radial direction of the backing tube is 6.5 × 10 −5 K / W or less.
The cylindrical sputtering target according to claim 1, wherein the thermal resistance in the radial direction from the outer peripheral surface of the bonding layer to the inner peripheral surface of the backing tube is 1.2 x 10 -4 K / W or less. .
The cylindrical sputtering target according to claim 1 or 2, wherein the bonding strength between the bonding layer and the backing tube is 4 MPa or more.
The cylindrical sputtering target according to any one of claims 1 to 3, wherein the backing tube has a Vickers hardness of 100 Hv or more.
The cylindrical sputtering target according to any one of claims 1 to 4, wherein the backing tube is made of a copper alloy.