CN113423861A

CN113423861A - Method for manufacturing cylindrical sputtering target

Info

Publication number: CN113423861A
Application number: CN202080014649.2A
Authority: CN
Inventors: 冈野晋; 大友健志
Original assignee: Mitsubishi Materials Corp
Current assignee: Mitsubishi Materials Corp
Priority date: 2019-03-25
Filing date: 2020-03-10
Publication date: 2021-09-21
Also published as: WO2020195787A1; JP7120111B2; KR20210143161A; JP2020158806A

Abstract

The invention comprises the following steps: a priming step of applying a priming bonding material to at least one of an inner peripheral surface of the cylindrical target and an outer peripheral surface of the cylindrical liner tube to form a first priming layer of 0.1mm to 0.8 mm; and a bonding step of inserting the cylindrical liner tube into the cylindrical target after the foundation treatment step, and filling a gap between the cylindrical target and the cylindrical liner tube with a filling bonding material in a molten state, wherein at least the surface of the first foundation treatment layer is scratched in the foundation treatment step, and wherein the bonding step is performed after heating at least the surface of the first foundation treatment layer to a semi-molten state and filling the filling bonding material.

Description

Method for manufacturing cylindrical sputtering target

Technical Field

The present invention relates to a method for manufacturing a cylindrical sputtering target used in a sputtering apparatus.

The present application claims priority based on patent application No. 2019-057175 filed in japanese application at 25.3.2019, and the contents thereof are incorporated herein by reference.

Background

A sputtering apparatus is known which performs sputtering while rotating a cylindrical sputtering target. As shown in patent document 1, in a cylindrical sputtering target used in such a sputtering apparatus, the inner peripheral surface of a cylindrical target material is joined to the outer peripheral surface of a cylindrical liner tube. In this joining, the following joining method is known: after a base treatment bonding material that is the same as or similar to the bonding material is applied to the outer peripheral surface of the cylindrical liner tube that is to be bonded surface and the inner peripheral surface of the cylindrical target to form a base treatment coating, the cylindrical liner tube is inserted into the target with a gap provided therebetween for the bonded portion, the target and the cylindrical liner tube are heated, and the bonding material in a molten state is supplied to the gap to fill the gap. Generally, indium (In) is used as a bonding material.

In this case, the surfaces of the base treatment bonding material of the target and the cylindrical liner tube are oxidized by cooling after the base treatment, reheating before bonding for filling the bonding material into the gap between the both, or the like, and an oxide film is formed.

The contact between the filled bonding material and the base treatment bonding material is inhibited by the formation of an oxide film on the surface of the base treatment bonding material, and poor bonding is likely to occur. The cylindrical sputtering target in which the bonding failure occurs needs to perform the following operations: after the entire assembly is heated to melt the joining material, the target material is detached from the backing tube and joining is performed again. On the other hand, the target material is elongated as the size of the substrate to be sputtered increases, and from the viewpoint of improving the production efficiency, the power density at the time of sputtering film formation tends to be increased, and improvement of the bonding strength is also expected.

As a countermeasure, for example, patent document 2 discloses the following technique: after filling the gap between the cylindrical target and the cylindrical liner with the bonding material in a molten state, the bonding material filled in the gap is stirred with a steel wire or a steel plate interposed therebetween, and the filled bonding material and the base treatment bonding material are integrated.

In patent document 3, a powder material having a lower specific gravity than solder as a bonding material is put into a space between a cylindrical target and a cylindrical liner tube, and then molten solder is poured into the space so that the powder material floats on the surface of the solder, and the powder material is vibrated and poured, thereby physically stirring the solder.

In patent document 4, a solid bonding material is filled in a gap between a cylindrical target and a cylindrical liner tube, and the bonding material is heated and melted, thereby reducing a contact area between a base treatment surface and the atmosphere and suppressing generation of an oxide film on the base treatment surface of the target and the cylindrical liner tube.

Patent document 1: japanese patent laid-open publication No. 2014-37619

Patent document 2: japanese patent No. 6341146

Patent document 3: japanese patent laid-open No. 2012 and 177156

Patent document 4: japanese patent laid-open publication No. 2018-111868

However, in the case of patent document 2, the work for stirring the joining materials takes time and effort. In addition, in order to remove the oxide film of the bonding material applied over the entire surface, it is necessary to stir the entire gap between the target and the backing tube, and there is a high possibility that a bonding failure occurs in a portion where stirring is insufficient.

Similarly, patent document 3 also requires a separate vibration source for vibrating the powder material as another device, and may cause a bonding failure if the stirring of the solder by the vibration of the powder material is insufficient.

In the manufacturing method of patent document 4, if an oxide film is deposited on the outer peripheral surface of the solid bonding material or the inner and outer peripheral surfaces of the target and the backing tube before bonding, it is difficult to avoid poor bonding. Therefore, it is necessary to remove the oxide film formed on the surface of the bonding material or on the inner and outer peripheral surfaces of the target and the backing tube before disposing the target in the backing tube.

Disclosure of Invention

In view of such circumstances, an object of the present invention is to suppress the influence of an oxide film to prevent occurrence of a bonding failure and to improve the yield.

A method for manufacturing a cylindrical sputtering target according to an aspect of the present invention is a method for manufacturing a cylindrical sputtering target in which a gap between an inner peripheral surface of a cylindrical target material and an outer peripheral surface of a cylindrical liner tube inserted inside the cylindrical target material is filled with a bonding material and bonded, the method including: a priming step of applying a priming bonding material to at least one of an inner peripheral surface of the cylindrical target and an outer peripheral surface of the cylindrical liner tube to form a first priming layer of 0.1mm to 0.8 mm; and a bonding step of inserting the cylindrical liner tube into the cylindrical target after the base treatment step, and filling a gap between the cylindrical target and the cylindrical liner tube with a filling bonding material in a molten state, wherein in the base treatment step, at least a surface of the first base treatment layer is scratched, and in the bonding step, the filling bonding material is filled after heating until at least the surface of the first base treatment layer is in a semi-molten state.

The surface of the first base treatment layer formed in the base treatment step may be oxidized to form an oxide film during a cooling period after the base treatment bonding material is applied and during a reheating period when the bonding step is performed. In contrast, since the first base treatment layer is formed thick, the surface of the first base treatment layer is in at least a semi-molten state during the bonding step, and the surface is in a hanging state. At this time, by leaving a scratch on the surface of the first base treatment layer in advance, even if an oxide film is formed on the surface, the oxide film at the scratched portion is broken when the surface portion hangs down, and at the same time, hangs down to be separated. By filling the filler bonding material in a molten state in a state where the surface is suspended, the filler bonding material in a molten state enters the surface portion of the first base treatment layer where the oxide film has been separated, and is mixed with them. In addition, a part of the oxide film is washed away from the gap by the filling of the filling bonding material. Even if a part of the oxide film remains in the gap, since the oxide film is already separated, a strong bonding layer can be formed by integrating the base treatment bonding material with a new filling bonding material.

In addition, since the first base treatment layer is suspended over the entire circumference, the oxide film can be divided over the entire circumference.

In this case, if the thickness of the first base treatment layer is less than 0.1mm, the first base treatment layer is less likely to sag even in a semi-molten state, and thus the oxide film is less likely to be broken. If the thickness of the first undercoat layer exceeds 0.8mm, the undercoat treatment process takes time, and if the first undercoat layer hangs down due to its own weight, the thickness may become too large, and the cylindrical liner may not be inserted into the cylindrical target.

As another aspect of the method of manufacturing a cylindrical sputtering target, in the backing treatment step, a second backing treatment layer may be formed on the other member on the opposite side of the one member on which the first backing treatment layer is formed, the second backing treatment layer being thinner than the first backing treatment layer, and a scraper may be provided along the circumferential direction on the one member on which the first backing treatment layer is formed, the scraper being arranged so as to protrude radially into the gap, and in the joining step, the cylindrical liner may be inserted into the cylindrical target while scraping at least a part of an oxide film formed on the surface of the second backing treatment layer with the scraper.

In this manufacturing method, at least a part of the oxide film is removed from the thin second base treatment layer by the squeegee separately from the thick first base treatment layer, and therefore, the newly filled bonding material can be more firmly bonded to the first base treatment layer and the second base treatment layer. Further, since a part of the oxide film is removed by the operation of inserting the cylindrical liner tube into the cylindrical target material, the operation is easy.

According to the present invention, the influence of the oxide film is suppressed to prevent the occurrence of poor bonding, thereby improving the yield.

Drawings

Fig. 1 is a longitudinal sectional view showing a cylindrical sputtering target manufactured by the manufacturing method of the first embodiment.

Fig. 2 is a flowchart illustrating a method for manufacturing a cylindrical sputtering target.

Fig. 3 is a longitudinal sectional view of a cylindrical liner tube on which a base treatment layer is formed.

Fig. 4 is a longitudinal sectional view of a cylindrical target material on which a base treatment layer is formed.

Fig. 5 is a vertical cross-sectional view showing a state before the cylindrical liner tube is inserted into the cylindrical target and heated in the manufacturing method of the first embodiment.

Fig. 6 is a vertical cross-sectional view showing a state where reheating is performed from the state shown in fig. 5.

Fig. 7 is a longitudinal sectional view showing a state where the cylindrical liner is lowered from the state shown in fig. 6.

Fig. 8 is a longitudinal sectional view showing a state before the cylindrical liner tube is inserted into the cylindrical target material in the manufacturing method of the second embodiment.

Fig. 9 is a plan view showing the squeegee.

Fig. 10 is a longitudinal sectional view showing a cylindrical sputtering target manufactured by the manufacturing method of the second embodiment.

Fig. 11 is a longitudinal sectional view showing a state before the cylindrical liner tube is inserted into the cylindrical target in the manufacturing method of embodiment 3.

Detailed Description

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

First, a first embodiment will be explained.

For example, as shown in fig. 1, in a cylindrical sputtering target 1, a cylindrical liner tube (hereinafter, also referred to as a liner tube) 3 is inserted into a cylindrical target material (hereinafter, also referred to as a target material) 2, and the inner peripheral surface of the target material 2 and the outer peripheral surface of the cylindrical liner tube 3 are joined to each other via a joint portion 4. At this time, the target 2 and the backing tube 3 are arranged with their central axes aligned.

The target material 2 is long, and is generally configured by connecting a plurality of divided target materials 2a divided in the longitudinal direction.

The material and size of the target 2 and the backing tube 3 are not particularly limited, and for example, a cylindrical member having an inner diameter of 120mm to 140mm, which is made of a metal such as copper or silver, or a ceramic such as AZO which is an oxide sintered body of Al or Zn, may be used as the target 2, and a cylindrical member having an outer diameter of 119mm to 139mm and a length of 0.5m to 4m, which is made of titanium, stainless steel, or copper or a copper alloy, may be used as the backing tube 3. At this time, the target 2 is disposed on the outer periphery of the cylindrical liner tube 3 in a state where a plurality of short divided targets 2a having a length of about 30cm are connected. In a state where the liner tube 3 is inserted into the target 2, a gap of 0.5mm to 1mm is formed in the radial direction between the inner peripheral surface of the target 2 and the outer peripheral surface of the liner tube 3, and a rod-shaped spacer (not shown) for maintaining the gap may be inserted into the gap, and in this case, the target 2 and the liner tube 3 are integrated by the joint 4 together with the rod-shaped spacer.

For example, an indium alloy (e.g., In-Sn alloy, In-Bi alloy, In-Zn alloy) having an indium content of 60 mass% or more, pure indium, a tin alloy having a tin content of 60 mass% or more, pure tin, or the like is used for the bonding portion 4. The joint 4 is formed by integrating and curing a base treatment bonding material applied to the target 2 and the backing tube 3 and a filling bonding material filled in the gap therebetween.

< method for producing cylindrical sputtering target >

In the case of manufacturing this cylindrical sputtering target 1, the outer peripheral surface of the cylindrical liner tube 3 and the inner peripheral surface of the target material 2 are used as joint surfaces, and these joint surfaces are joined by a joining material provided therebetween.

As shown in fig. 2, the method includes a heating step of the target 2 and the backing tube 3, a base treatment step of applying the base treatment bonding material to the target 2 and the backing tube 3, a base treatment bonding material cooling step of cooling and solidifying the applied base treatment bonding material, a reheating step of reheating the solidified base treatment bonding material, a bonding material filling step (bonding step) of filling the gap between the target 2 and the backing tube 3 with the bonding material for filling, and a bonding material cooling step of cooling and solidifying the filled bonding material. The following description will be made in order of steps.

(heating step)

The target 2 and the backing tube 3 are heated, and the inner peripheral surface of the target 2 and the outer peripheral surface of the backing tube 3, which are the joint surfaces of the target 2 and the backing tube, are heated to a temperature equal to or higher than the melting point (or liquidus temperature) of the base treatment joint material.

(substrate treating Process)

In the heating step, the base treatment bonding material in a molten state is applied to the inner peripheral surface of each of the divided targets 2a and the outer peripheral surface of the backing tube 3 in a heated state, thereby forming the

base treatment layers

41a and 41b, respectively. At this time, the undercoating bonding material is applied while applying ultrasonic vibration by an ultrasonic iron (not shown) equipped with a heater, whereby the contamination on the inner peripheral surface of the divided target 2a and the outer peripheral surface of the backing tube 3, the removal of the oxide film, and the like are promoted, and the undercoating bonding material can be fused with these surfaces.

The base treatment step may be performed in the atmosphere, but if it is performed in an inert gas atmosphere such as argon or nitrogen, oxidation of the surface of the

base treatment layers

41a and 41b formed of the base treatment bonding material can be suppressed, and therefore, it is desirable to perform it in such a gas atmosphere.

(substrate treatment bonding Material Cooling step (substrate treatment step))

The base treatment bonding material cooling step is performed by an appropriate cooling mechanism after the base treatment step. As a result, the foundation treatment bonding material is solidified, and as shown in fig. 3 and 4, the foundation treatment layers 41a and 41b are formed on the inner peripheral surface of each of the divided targets 2a and the outer peripheral surface of the backing tube 3. An oxide film 42 is formed on the surface of the base processed

layers

41a and 41 b. At this time, the

base treatment layers

41a and 41b are formed to have a thickness of 0.1mm or more and 0.8mm or less. If the thickness of the primer treatment layers 41a and 41b is less than 0.1mm, the oxide film 42 is less likely to be broken because the layers are less likely to sag even when they are in a semi-molten state in a reheating step described later. If the thickness of the foundation treatment layers 41a and 41b exceeds 0.8mm, the foundation treatment process takes time, and if the layers hang down due to their own weight, the thickness of the lower end portion becomes too large, and there is a possibility that the backing tube 3 cannot be inserted into the target 2.

The sum of the thicknesses of the foundation treatment layers 41a and 41b on both the inner peripheral surface of the target 2 and the outer peripheral surface of the backing tube 3 may be set to 0.2mm to 0.9 mm. If the sum of their thicknesses is less than 0.2mm, the thickness of one of the substrate processing layers will be less than 0.1mm, and if it exceeds 0.9mm, the liner 3 may not be inserted into the target 2. The gap between the inner peripheral surface of the target 2 and the outer peripheral surface of the backing tube 3 is 0.5mm to 1.0mm, and the ratio of the sum of the thicknesses of the

base treatment layers

41a and 41b to the gap may be 0.2 to 0.9. For example, in the case of a gap of 1.0mm, the sum of the thicknesses of the base treatment layers is preferably 0.2mm or more and 0.9mm, and in the case of a gap of 0.5mm, the sum of the thicknesses of the base treatment layers is preferably 0.10mm or more and 0.45mm or less. That is, the sum of the thicknesses of the base treatment layers)/(the gap is preferably 0.2 to 0.9.

After the

base treatment layers

41a and 41b are cooled and solidified, the oxide film 42 on the surface is scraped off by a cutter or the like. By the operation of scraping the oxide film 42, the surfaces of the foundation treatment layers 41a and 41b are left scratched. Alternatively, the oxide film 42 may not be removed and at least the surface may be scratched by a cutter or the like. The scratches are preferably formed to a depth equal to or greater than the thickness of the oxide film 42 formed on the base processed

layers

41a and 41b so as to reach the bonding material below the oxide film 42.

(reheating step (joining step))

The divided targets 2a on which the base treatment layer 41a is formed are mounted on the mounting table 11 shown in fig. 5 in a vertically connected state. A recess 12 having an inner diameter substantially equal to the inner diameter of the target 2 is provided on the surface of the mounting table 11, and the target 2 is disposed so as to surround the recess 12. On the other hand, the lower end of the liner 3 is blocked off with a plug 6 to prevent the infiltration of the jointing material into the liner 3.

The filling bonding material 40 is filled in the recess 12 in a molten state. As the bonding material for filling 40, the same material as the base process bonding material is used, and in this example, pure indium or an indium alloy is filled.

At this time, the annular spacer 5 is interposed between the divided targets 2a connected vertically. The annular spacer 5 absorbs dimensional errors in the longitudinal direction of the divided targets 2a and surface roughness of the end faces, and has a function of coaxially arranging the divided targets 2a and a function of a sealing material that seals gaps generated between the divided targets 2a, and can accurately connect the divided targets 2a to each other in the longitudinal direction (height direction).

The annular spacer 5 is made of an elastic resin material or the like, and in the present embodiment, is made of PTFE (polytetrafluoroethylene), PFA (perfluoroalkoxy fluororesin), FEP (tetrafluoroethylene/hexafluoropropylene copolymer), PCTFE (polychlorotrifluoroethylene), ETFE (ethylene/tetrafluoroethylene copolymer), or the like.

In addition, the annular spacer 5 is detached after joining the target 2 and the backing tube 3, and therefore the outer diameter of the annular spacer 5 is set larger than the outer diameter of the target 2 for easy removal.

Further, a receiving plate 7 for receiving the filling bonding material 40 that overflows from the gap between the target 2 and the backing tube 3 is provided at the upper end of the target 2.

Then, as shown in fig. 5, the backing tube 3 is coaxially disposed so as to be inserted into the target 2 by about 80% of the total length of the inside thereof. In the state shown in fig. 5, the oxide film 42 is removed, but may remain on the surface of the foundation treatment layers 41a and 41 b.

After the assembly in the state shown in fig. 5, the target 2 and the backing tube 3 are heated by a heater (not shown) disposed around the target 2. For example, the

base treatment layers

41a and 41b are heated at 200 ℃ for 1 to 2 hours to be in a molten state or at least a semi-molten state. By the reheating, the surfaces of the foundation treatment layers 41a and 41b are oxidized to form the oxide film 42. As described above, the

base treatment layers

41a, 41b are formed to have a large thickness and have scratches left on the surfaces, and therefore, as shown in fig. 6, hang down by their own weight when melted to flow to the lower end portion, whereby the oxide film 42 is broken.

(bonding material filling step (bonding step))

As shown by the arrows in fig. 6, when the lower end side of liner tube 3 is inserted into recess 12 of mounting table 11, filler bonding material 40 in a molten state rises to a gap between the inner circumferential surface of target 2 and the outer circumferential surface of liner tube 3 so as to be extruded from recess 12, and filler bonding material 40 is filled between the inner circumferential surface of target 2 and the outer circumferential surface of liner tube 3, as shown in fig. 7.

At this time, the oxide film 42 on the surface of the foundation treatment layers 41a and 41b is separated and pushed up by the filling bonding material 40 rising in the gap, and discharged into the pad 7. Even if a part of the oxide film 42 remains in the filling bonding material 40, it is dispersed in the filling bonding material 40 and is integrated therewith to be filled in the gap.

The volume of the recess 12 of the mounting table 11 may be equal to or greater than the volume of the gap formed between the outer circumferential surface of the backing tube 3 and the inner circumferential surface of the target 2 when the lower end of the backing tube 3 is inserted near the bottom surface, and preferably the filling bonding material 40 that rises in the gap slightly protrudes from the upper end side of the target 2.

At this time, it was confirmed that: in a state where the filler bonding material 40 has overflowed the receiving plate 7 at the upper end of the target 2, the filler bonding material 40 is filled between the target 2 and the backing tube 3 without a gap.

By inserting the lower end of the backing tube 3 near the bottom surface of the recess 12 in this manner, the filler bonding material 40 is filled in the gap between the target 2 and the backing tube 3 without a gap.

Further, although not necessarily limited thereto, it is preferable that the reheating step and the bonding material filling step (at least until the filling is completed) be performed in an inert gas atmosphere to suppress oxidation of the bonding material and further improve the bonding strength.

(bonding material cooling step)

The gap between the target 2 and the backing tube 3 is filled with the filler bonding material 40, and then the target 2 and the backing tube 3 are integrated by the joint 4 by cooling and solidifying the filler bonding material.

Then, the annular spacer 5, the adapter 7, the protruding bonding material, and the like are removed and cleaned, thereby obtaining the cylindrical sputtering target 1.

By the method described above, the

base treatment layers

41a and 41b are formed thick, the surfaces are scratched, and when they are reheated, they are brought into a semi-molten state, whereby the oxide film 42 is broken and separated on the surfaces of the

base treatment layers

41a and 41b hanging down by their own weight, and then the filler bonding material 40 is filled in the gap between the backing tube 3 and the target 2. Therefore, the integration of the filling bonding material 40 and the undercoating bonding material can be integrated without being hindered by the oxide film 42, while improving the bonding strength thereof, and a high-quality cylindrical sputtering target 1 can be manufactured.

Further, the influence of the oxide film 42 can be suppressed by a simple operation of forming the thick

base treatment layers

41a and 41b on the target 2 and the backing tube 3 and leaving scratches on the surfaces thereof, so that the target 2 and the backing tube 3 can be firmly joined.

Fig. 8 to 10 show a manufacturing method according to a second embodiment of the present invention. In addition, the same portions as those of the above-described embodiment are denoted by the same reference numerals after the embodiment, and the description thereof is omitted. The same applies to the embodiment of fig. 11.

In the second embodiment, the inner circumferential portion of the annular spacer 51 provided between the targets 2 is made to protrude radially inward from the inner circumferential surface of the target 2, and when the liner tube 3 is inserted into the target 2 in the bonding material filling step, the oxide film 42 of the base treatment layer 41b of the liner tube 3 is scraped off by the annular spacer 51.

That is, the inner peripheral portion of the annular spacer 51 provided on the target 2 protrudes radially inward of the divided target 2a, and the inner diameter is formed to be substantially the same as the outer diameter of the liner tube 3 (the same diameter, or a slightly smaller or larger diameter).

As shown in fig. 9, the scraper (annular spacer) 51 is provided with a hole 55 and a cutout 56. In the bonding step, the hole 55 and the cut portion 56 allow the molten bonding material for filling to flow through the hole 55 and the cut portion 56. The hole 55 and the cutout portion 56 may be formed in any shape, position and number other than the shape shown in fig. 9, and only one of the hole 55 and the cutout portion 56 may be formed as long as the molten filler bonding material can pass through the hole.

In the case of the second embodiment, the base processed layer 41a on the inner peripheral surface of the target 2 is formed to be thick as in the first embodiment, but the base processed layer 41b of the backing tube 3 is formed to be thinner than the base processed layer 41a of the target 2. The thick base processed layer 41a is used as a first base processed layer, and the thin base processed layer 41b is used as a second base processed layer. Therefore, in the case of the first embodiment, both the two

base treatment layers

41a, 41b are the first base treatment layer.

After the base treatment bonding material cooling step, the oxide film 42 on the surface of each of the

base treatment layers

41a and 41b is removed, or at least a scratch reaching the

base treatment layers

41a and 41b is left.

Then, in the joining step, as shown in fig. 8, the lower end portion of the backing tube 3 is reheated while being inserted into the upper end portion of the target 2. By this reheating, the oxide film 42 is formed on the two base processed

layers

41a and 41b, and the base processed layer 41a (first base processed layer) of the target 2 is thick, and thus is in a suspended state. The oxide film 42 is also formed on the base treated layer 41b (second base treated layer) of the liner 3, but the base treated layer 41b is thin and does not sag.

Then, when the backing tube 3 is inserted into the target 2 in this heated state, the inner diameter of the scraper 51 provided in the target 2 is formed to be substantially the same as the outer diameter of the backing tube 3, and therefore, when the backing tube 3 is inserted, the outer peripheral surface of the backing tube 3 is scraped by the inner peripheral portion of the scraper 51, and the oxide film 42 on the outer peripheral surface is scraped off. The scraped oxide film 42 is a broken film, pushed up by the filling bonding material 40 rising in the gap, and discharged into the receiving tray 7. Even if a part of the oxide film 42 remains in the filling bonding material 40, it is dispersed in the filling bonding material 40 and is integrated therewith to be filled in the gap.

On the other hand, the foundation treatment layer 41b having no oxide film 42 remains thin on the outer peripheral surface of the liner tube 3 after the oxide film 42 is removed by the squeegee 51, and the filler bonding material 40 is uniformly fused and integrated with the foundation treatment layer 41 b.

Since the undercoat layer 41a (first undercoat layer) on the inner peripheral surface of the target 2 is thick, the oxide film 42 is also broken while hanging down as in the first embodiment.

In the example shown in fig. 8 and the like, the target 2 is configured by three divided targets 2a, and the inner peripheral portions of the respective annular spacers 51 between the divided targets 2a are made to protrude from the divided targets 2a so as to function as scrapers, but any one of the annular spacers may be made to have this function as a scraper, and the other annular spacers 5 may be made to have the same inner diameter as the divided targets 2a as in the first embodiment, or the inner peripheral portions of all the annular spacers may be made to protrude radially inward from the divided targets 2a so as to function as scrapers.

In addition, by removing the annular spacer 51 after the joining, as shown in fig. 10, the thickness of the joined portion 4 becomes thinner at the portion where the annular spacer 51 is originally provided.

The inner peripheral portion of the upper end flange 7 of the target 2 may be protruded radially inward like the annular spacer 51, and the inner peripheral portion may be used as a scraper. In this case, the annular spacer 51 serving as a scraper can be used together.

Fig. 11 shows a state in the manufacturing process of the manufacturing method of embodiment 3 of the present invention.

In the second embodiment, the oxide film of the base treated layer 41b of the backing tube 3 is scraped off, but in the 3 rd embodiment, the oxide film 42 of the base treated layer 41a of the target 2 is removed. That is, the scraper 8 is provided at the lower end of the backing tube 3, and when the backing tube 3 is inserted into the target 2, the oxide film 42 of the undercoat layer 41a on the inner circumferential surface of the target 2 is scraped off by the outer circumferential portion of the scraper 8. The base processed layer 41a of the target 2 is formed thinly, and the base processed layer 41b of the backing tube 3 is formed thickly. That is, in this embodiment, the base treatment layer 41a of the target 2 is the second base treatment layer, and the base treatment layer 41b of the backing tube 3 is the first base treatment layer.

In this case, the scraper 8 may be fixed to the plug 6. The scraper 8 is formed so that its outer diameter is substantially the same as (the same as, or slightly smaller than, or slightly larger than) the inner diameter of the target 2.

The oxide film 42 scraped off from the inner peripheral surface of the target 2 by the scraper 8 flows into the concave portion 12 and is mixed into the filling bonding material 40 filled in the concave portion 12, but the oxide film is broken and is not reformed into a film shape.

Since the oxide film 42 formed on the base treated layer 41b of the liner 3 is formed thick on the base treated layer 41b, it is suspended by reheating and is broken.

In the above embodiment, the primer bonding material is applied to both the target 2 and the backing tube 3, but if the surface of either is in a state of being easily wetted by the filler bonding material 40, the application of the primer bonding material to the surface may be omitted. In other words, the foundation treatment bonding material may be applied to at least one of the target 2 and the backing tube 3 to form the foundation treatment layers 41a and 41b in the bonding step.

Examples

Experiments were conducted to confirm the effects of the present invention. The target and the backing tube used the materials in table 1, and the base treatment bonding layer was formed in the thickness of table 1. The target type SIZ of example 6 is an oxide sintered body of Si, In, and Zr, the AZO of example 7 is an oxide sintered body of Al and Zn, the CuGa of example 8 is an alloy of Cu and Ga, the CuNi of example 9 is an alloy of Cu and Ni, and the CuO of example 10 is a sintered body of Cu and CuO. The gap between the target and the backing tube was set to 1.0 mm.

As the base process bonding material, In solder was used. In the substrate treatment, the substrate is heated by hot air to a surface temperature of 240 to 260 ℃, the substrate treatment bonding material is coated by an ultrasonic iron in an atmospheric atmosphere, after the surface is uniformly wetted, the molten bonding material is dropped, thick coating is performed while rotating the target and the liner tube, and cooling is performed to normal temperature.

The thickness of the base treatment layer was determined by measuring the thickness of the target and the thickness of the backing tube at any 8 points before and after the formation of the base treatment layer, calculating the average value of the 8 points, and determining the thickness of the base treatment layer from (the average value of the thicknesses after the formation of the base treatment layer-the average value of the thicknesses before the formation of the base treatment layer). Specifically, any 8 points for measuring the thickness of the target and the liner were 4 points measured equally in the circumferential direction at the upper end and the lower end, respectively.

After the joining, the joining area ratio was measured by an ultrasonic flaw detection device. The joint area ratio is a ratio of a joint area other than the poor joint position to the total area of the joint surfaces of the target and the backing tube. A joint area ratio of 90% or more can be regarded as acceptable.

In examples 1 to 10 and comparative examples 1 and 2, no scraper was provided and no scraping was performed. In example 11, a scraper was provided as shown in FIG. 11, and the inner peripheral surface of the target was scraped off. In example 12, a scraper was provided as shown in fig. 8, and the outer peripheral surface of the liner was scraped off.

These results are shown in table 1. In the table, BT represents a backing tube, TG represents a target material.

[ Table 1]

As is clear from table 1, when the thickness of the base treatment layer of at least one of the target and the backing tube is 0.1mm or more and 0.8mm or less, the bonding area ratio is 90% or more.

In contrast, in comparative examples 1 and 2, since the thicknesses of the base treatment layers of the target and the backing tube were small, the bonding rate was less than 90%.

Industrial applicability

Description of the symbols

1-cylindrical sputtering target, 2-cylindrical target, 2 a-divided target, 3-cylindrical liner, 4-joint, 40-joining material for filling, 41a, 41 b-base treatment layer, 42-oxide film, 5-annular spacer, 51-annular spacer (scraper), 55-hole, 56-cut, 6-plug, 7-land, 8-scraper, 11-stage, 12-recess.

Claims

1. A method for manufacturing a cylindrical sputtering target, wherein a gap between an inner peripheral surface of a cylindrical target material and an outer peripheral surface of a cylindrical liner tube inserted inside the cylindrical target material is filled with a bonding material and bonded, the method comprising the steps of:

a priming step of applying a priming bonding material to at least one of an inner peripheral surface of the cylindrical target and an outer peripheral surface of the cylindrical liner tube to form a first priming layer of 0.1mm to 0.8 mm; and

a bonding step of inserting the cylindrical liner tube into the cylindrical target material after the base treatment step, and filling a gap between the cylindrical target material and the cylindrical liner tube with a filling bonding material in a molten state,

in the substrate treating process, a scratch is left on at least the surface of the first substrate treatment layer,

in the bonding step, the filler bonding material is filled after heating until at least the surface of the first base treatment layer is in a semi-molten state.

2. The method for producing a cylindrical sputtering target according to claim 1,

in the base treatment step, a second base treatment layer is formed on the other member on the opposite side of the one member on which the first base treatment layer is formed, the second base treatment layer being thinner than the first base treatment layer, and a squeegee is provided in the circumferential direction on the one member on which the first base treatment layer is formed, the squeegee being arranged so as to protrude radially into the gap,

in the bonding step, the cylindrical liner tube is inserted into the cylindrical target while at least a part of the oxide film formed on the surface of the second base treatment layer is scraped off by the scraper.