JP7120111B2 - Manufacturing method of cylindrical sputtering target - Google Patents

Description

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

A sputtering apparatus that performs sputtering while rotating a cylindrical sputtering target is known. A cylindrical sputtering target used in this type of sputtering apparatus has an inner peripheral surface of a cylindrical target material joined to an outer peripheral surface of a cylindrical backing tube, as disclosed in Patent Document 1.
In this bonding, a surface treatment bonding material that is the same as or similar to the bonding material is applied to the outer peripheral surface of the cylindrical backing tube and the inner peripheral surface of the cylindrical target material, which are the bonding surfaces, to form a surface treatment coating. A cylindrical backing tube is inserted into the target material to provide a gap for the joint between the two, the target material and the cylindrical backing tube are kept in a heated state, and a molten bonding material is poured into the gap. A joining method is known in which the supply is performed to fill the gap. Indium (In) is often used as the bonding material.

In this case, the surfaces of the target material and the surface treatment bonding material of the cylindrical backing tube are cooled after the surface treatment and reheated before bonding to fill the gap between the two with the bonding material. An oxide film is formed.
The formation of an oxide film on the surface of the bonding material for surface treatment hinders contact between the bonding material to be filled and the bonding material for surface treatment, which tends to cause defective bonding. A poorly bonded cylindrical sputtering target needs to be entirely heated to melt the bonding material, remove the target material from the backing tube, and perform bonding again. On the other hand, as the size of the substrate to be sputtered has increased, the target material has become longer, and from the viewpoint of improving production efficiency, there is a tendency to increase the power density during sputtering film formation, and there is also a desire to improve the bonding strength. there is

As a countermeasure, for example, in Patent Document 2, after filling the gap between the cylindrical target material and the cylindrical backing tube with a molten bonding material, a steel wire or steel plate is inserted and the bonding material is filled between them. is disclosed to agitate and integrate the filled bonding material and the surface treatment bonding material.
In Patent Document 3, a powder material having a specific gravity lighter than that of a solder material, which is a bonding material, is placed in a space between a cylindrical target material and a cylindrical backing tube, and then molten solder is injected into the space to obtain a powder material. is floating on the liquid surface of the solder material, and the solder material is physically agitated by injecting the powder material while vibrating it.
In Patent Document 4, a solid bonding material is filled in the gap between the cylindrical target material and the cylindrical backing tube, and the bonding material is heated and melted to reduce the contact area between the surface to be treated and the atmosphere. , suppresses the generation of an oxide film on the undercoating surfaces of the target material and the cylindrical backing tube.

JP 2014-37619 A Japanese Patent No. 6341146 JP 2012-177156 A JP 2018-111868 A

However, in the case of Patent Document 2, it takes time and effort to stir the bonding material. Moreover, in order to remove the oxide film of the applied bonding material over the entire surface, it is necessary to stir the entire gap between the target material and the backing tube. is high.
The same is true for Patent Document 3. A vibration source for vibrating the powder substance is required as a separate device, and if the solder material is not sufficiently agitated by the vibration of the powder substance, it may lead to poor bonding. There is
In the manufacturing method of Patent Document 4, if an oxide film adheres to the outer peripheral surface of the solid bonding material and the inner and outer peripheral surfaces of the target material and the backing tube before bonding, it becomes difficult to avoid defective bonding. Therefore, before placing the target material in the backing tube, it is necessary to remove the oxide film formed on the surface of the bonding material, the target material, and the inner and outer peripheral surfaces of the backing tube.

SUMMARY OF THE INVENTION In view of such circumstances, an object of the present invention is to suppress the influence of an oxide film, prevent the occurrence of poor bonding, and improve the yield.

In the method for manufacturing a cylindrical sputtering target of the present invention, the gap between the inner peripheral surface of a cylindrical target material and the outer peripheral surface of a cylindrical backing tube inserted inside the cylindrical target material is filled with a bonding material and bonded. In a method for manufacturing a cylindrical sputtering target, a surface treatment bonding material is applied to at least one member of the inner peripheral surface of the cylindrical target material and the outer peripheral surface of the cylindrical backing tube, and the thickness is 0.1 mm or more. A surface treatment step of forming a first surface treatment layer of 0.8 mm or less, and after the surface treatment step, the cylindrical backing tube is inserted into the cylindrical target material, and the cylindrical target material and the cylindrical backing a bonding step of filling a gap between the pipe and the tube with a molten filler bonding material; in the surface treatment step, at least the surface of the first surface treatment layer is scratched; and in the bonding step, the After heating until at least the surface of the first surface treatment layer is in a semi-molten state, the filling bonding material is filled.

The surface of the first surface treatment layer formed in the surface treatment process may be oxidized during cooling after application of the surface treatment bonding material and during reheating in the bonding process, forming an oxide film. On the other hand, since the first surface treatment layer is thickly formed, the surface of the first surface treatment layer becomes at least semi-molten during the bonding process, and the surface becomes saggy. At this time, even if an oxide film is formed on the surface by scratching the surface of the first undercoat layer in advance, the oxide film is destroyed at the scratched portion when the surface portion hangs down. divided by By filling the molten bonding material for filling while the surface hangs down, the bonding material for filling in the molten state enters the surface portion of the first ground treatment layer where the oxide film is divided, and these are mixed. . Also, part of the oxide film is swept 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 it is divided, the base treatment bonding material and the new filling bonding material can be integrated to form a strong bonding layer.
Since the first undercoat layer hangs down over the entire circumference, the oxide film can be divided over the entire circumference.

In this case, if the thickness of the first undercoat layer is less than 0.1 mm, the oxide film is less likely to sag even in a semi-melted state. If the thickness of the first surface treatment layer exceeds 0.8 mm, the surface treatment process will take a long time, and when it hangs down due to its own weight, the thickness will become too large, and a cylindrical backing tube will be inserted into the cylindrical target material. It may become impossible to do so.

As one embodiment of the method for manufacturing a cylindrical sputtering target, in the surface treatment step, the first surface treatment layer is applied to the other member opposite to the one member on which the first surface treatment layer is formed. and a scraping plate protruding radially into the gap and arranged in the one member on which the first surface treatment layer is formed. In the bonding step, the scraping plate scrapes off at least a portion of the oxide film formed on the surface of the second underlayer, and the cylindrical backing tube is inserted into the cylindrical target material. should be inserted.

In this manufacturing method, apart from the thick first ground layer, at least part of the oxide film is removed from the thin second ground layer by the scraping plate, so that the oxide film is newly filled. It is possible to more firmly bond the bonding material, the first surface treatment layer, and the second surface treatment bonding material. Moreover, since a portion of the oxide film can be removed by inserting the cylindrical backing tube into the cylindrical target material, the work is easy.

According to the present invention, it is possible to suppress the influence of the oxide film, prevent the occurrence of poor bonding, and improve the yield.

1 is a longitudinal sectional view showing a cylindrical sputtering target manufactured by the manufacturing method of the first embodiment; FIG. It is a flow chart explaining a manufacturing method of a cylindrical sputtering target. FIG. 4 is a vertical cross-sectional view of a cylindrical backing tube on which a base treatment layer is formed; FIG. 3 is a vertical cross-sectional view of a cylindrical target material on which an undercoat layer is formed; FIG. 4 is a vertical cross-sectional view showing a state before a cylindrical backing tube is inserted into a cylindrical target material and heated in the manufacturing method of the first embodiment; FIG. 6 is a longitudinal sectional view showing a reheated state from the state shown in FIG. 5; FIG. 7 is a longitudinal sectional view showing a state in which the cylindrical backing tube is lowered from the state shown in FIG. 6; FIG. 10 is a vertical cross-sectional view showing a state before inserting a cylindrical backing tube into a cylindrical target material in the manufacturing method of the second embodiment; It is a top view which shows a scraping plate. FIG. 6 is a longitudinal sectional view showing a cylindrical sputtering target manufactured by the manufacturing method of the second embodiment; FIG. 10 is a longitudinal sectional view showing a state before inserting a cylindrical backing tube into a cylindrical target material in a manufacturing method of a third embodiment;

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a method for manufacturing a cylindrical sputtering target according to the present invention will be described below with reference to the drawings.
First, the first embodiment will be described.
A cylindrical sputtering target 1, for example, as shown in FIG. The inner peripheral surface of 2 and the outer peripheral surface of cylindrical backing tube 3 are joined via joint portion 4 . In this case, the target material 2 and the backing tube 3 are arranged with their central axes aligned.

Since the target material 2 is elongated, it is generally constructed by connecting a plurality of divided target materials 2a divided in the length direction.

The material and dimensions of the target material 2 and the backing tube 3 are not particularly limited. A tubular member of 120 mm to 140 mm can be used, and the backing tube 3 is made of titanium, stainless steel, copper or copper alloy, and has an outer diameter of 119 mm to 139 mm and a length of 0.5 m to 4 m. can be done. In this case, the target material 2 is arranged on the outer circumference of the cylindrical backing tube 3 in a state in which a plurality of short divided target materials 2a having a length of about 30 cm are connected. With the backing tube 3 inserted into the target material 2, a radial gap of 0.5 mm to 1 mm is formed between the inner peripheral surface of the target material 2 and the outer peripheral surface of the backing tube 3. , a rod-shaped spacer (not shown) may be inserted to hold the gap. In this case, the target material 2 and the backing tube 3 are integrated together with the rod-shaped spacer at the joint 4 .

The joint portion 4 is made of, for example, an indium alloy (eg, In--Sn alloy, In--Bi alloy, In--Zn alloy) having an indium content of 60% by mass or more, pure indium, a tin alloy having a tin content of 60% by mass or more, or Pure tin or the like is used. The joint portion 4 is composed of a surface treatment joint material applied to the target material 2 and the backing tube 3, and a filling joint material filled in the gap between them, and is provided by integrating and solidifying these.

<Manufacturing method of cylindrical sputtering target>
When manufacturing this cylindrical sputtering target 1, the outer peripheral surface of the cylindrical backing tube 1 and the inner peripheral surface of the target material 2 are used as bonding surfaces, and the bonding material provided between these bonding surfaces is used for bonding.
As shown in FIG. 2, a heating process of the target material 2 and the backing tube 3, a surface treatment process of applying the surface treatment bonding material to the target material 2 and the backing tube 3, and a surface of cooling and solidifying the applied surface treatment bonding material. A treatment bonding material cooling step, a reheating step of reheating the solidified surface treatment bonding material, a bonding material filling step (bonding step) of filling the gap between the target material 2 and the backing tube 3 with the filling bonding material (bonding step), It has a bonding material cooling step of cooling and solidifying the bonding material. The order of steps will be described below.

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

(Surface treatment process)
In the heating step, the melted surface treatment bonding material is applied to the inner peripheral surface of each split target material 2a and the outer peripheral surface of the backing tube 3 in a heated state to form the surface treatment layers 41a and 41b, respectively. In this case, by applying ultrasonic vibrations with an ultrasonic soldering iron (not shown) equipped with a heater, the surface treatment bonding material is applied to the inner peripheral surface of the split target material 2a and the outer peripheral surface of the backing tube 3. The removal of the oxide film and the like is promoted, and the ground treatment bonding material can be applied to these surfaces.
The surface treatment process may be performed in the air, but if it is performed in an inert atmosphere such as argon or nitrogen, oxidation of the surfaces of the surface treatment layers 41a and 41b formed by the bonding material for surface treatment can be suppressed. Therefore, it is desirable to carry out in such an atmosphere.

(Surface treatment bonding material cooling process)
The surface treatment bonding material cooling step is performed by appropriate cooling means after the surface treatment step. As a result, the surface treatment bonding material is solidified, and as shown in FIGS. 3 and 4, surface treatment layers 41a and 41b are formed on the inner peripheral surface of each split target material 2a and the outer peripheral surface of the backing tube 3. Become. An oxide film 42 is formed on the surfaces of the underlying layers 41a and 41b.
In this case, the undercoating layers 41a and 41b are formed to have a thickness of 0.1 mm or more and 0.8 mm or less. When the thickness of the underlayers 41a and 41b is less than 0.1 mm, the oxide film 42 is less likely to be destroyed because it is less likely to sag even if it is in a semi-melted state in the reheating process described later. If the thickness of the undercoating layers 41a and 41b exceeds 0.8 mm, the undercoating process will take a long time, and when the target material 2 hangs down, the thickness of the lower end portion will be too large, and the backing tube 3 will be attached to the target material 2. may not be able to be inserted.
Moreover, the sum of the thicknesses of the surface treatment layers 41a and 41b on both the inner peripheral surface of the target material 2 and the outer peripheral surface of the backing tube 3 is preferably set to 0.2 mm or more and 0.9 mm or less. If the sum of these thicknesses is less than 0.2 mm, the thickness of any of the undercoat layers is less than 0.1 mm, and if it exceeds 0.9 mm, the backing tube 3 cannot be inserted into the target material 2. There is a risk. The gap between the inner peripheral surface of the target material 2 and the outer peripheral surface of the backing tube 3 is 0.5 mm or more and 1.0 mm or less. A ratio of 0.9 or less is preferable. For example, when the gap is 1.0 mm, the sum of the thicknesses of the base treatment layers is preferably 0.2 mm to 0.9 mm, and when the gap is 0.5 mm, the sum of the thicknesses of the base treatment layers is preferably 0.10 mm to 0.10 mm. 45 mm or less is preferable. That is, it is preferable that (the sum of the thicknesses of the undercoat layer)/(gap)=0.2 to 0.9.

Further, after the undercoating layers 41a and 41b are cooled and solidified, the oxide film 42 on the surface is scraped off with a cutter or the like and removed. By scraping off the oxide film 42, the surfaces of the underlying layers 41a and 41b are damaged. Alternatively, at least the surface may be scratched with a cutter or the like without removing the oxide film 42 . It is preferable that these scratches reach a depth equal to or greater than the thickness of the oxide film 42 formed on the underlying layers 41a and 41b and reach the bonding material under the oxide film 42. Next, as shown in FIG.

(Reheating process)
The divided target material 2a on which the surface treatment layer 41a is formed is mounted on the mounting table 11 shown in FIG. 5 in a state of being vertically connected. A concave portion 12 having an inner diameter substantially equal to that of the target material 2 is provided on the surface of the mounting table 11 , and the target material 2 is arranged so as to surround this concave portion 12 . On the other hand, the lower end of the backing tube 3 is closed with a plug 6 to prevent the bonding material from entering the backing tube 3. - 特許庁
The recess 12 is filled with the filling bonding material 40 in a molten state. As the filling bonding material 40, the same material as the surface treatment bonding material is used, and in this example, pure indium or an indium alloy is filled.

In this case, an annular spacer 5 is interposed between the divided target materials 2a that are connected vertically. The annular spacer 5 has the function of absorbing dimensional errors in the length direction of the split target materials 2a and the surface roughness of the end faces, and having the function of coaxially arranging these split target materials 2a, as well as the function of eliminating gaps between the split target materials 2a. It also has a function of a packing to close, and the divided target materials 2a can be accurately connected to each other in the length direction (height direction).
The annular spacer 5 is made of an elastic resin material or the like, and is made of PTFE (polytetrafluoroethylene) in this embodiment.
Since the annular spacer 5 is removed after the target material 2 and the backing tube 3 are joined, the outer diameter of the annular spacer 5 is set larger than the outer diameter of the target material 2 so that it can be easily removed.

A saucer 7 is provided at the upper end of the target material 2 for receiving the filling bonding material 40 overflowing from the gap between the target material 2 and the backing tube 3 .
Then, as shown in FIG. 5, the backing tube 3 is inserted into the target material 2 by about 80% of the total length and arranged coaxially. Although the oxide film 42 has been removed in the state shown in FIG. 5, it may remain on the surface of the underlying layers 41a and 41b.
After assembling in the state shown in FIG. 5, the target material 2 and the backing tube 3 are heated by a heater (not shown) arranged around the target material 2 . For example, by heating at 200° C. for 1 hour to 2 hours, the undercoating layers 41a and 41b are melted or at least semi-molten. The reheating at this time oxidizes the surfaces of the underlayers 41a and 41b to form an oxide film 42. Next, as shown in FIG. As described above, the surface treatment layers 41a and 41b are formed to have a large thickness and are scratched on the surface. Therefore, as shown in FIG. , the oxide film 42 is destroyed.

(Bonding Material Filling Step (Bonding Step))
When the lower end of the backing tube 3 is inserted into the recess 12 of the mounting table 11 as indicated by the arrow in FIG. The gap between the inner peripheral surface of the material 2 and the outer peripheral surface of the backing tube 3 is raised, and the filling bonding material 40 is filled between the inner peripheral surface of the target material 2 and the outer peripheral surface of the backing tube 3 .
At this time, since the oxide film 42 on the surfaces of the undercoating layers 41a and 41b is separated, they are pushed up by the filling bonding material 40 rising in the gap and discharged into the tray 7. FIG. Moreover, 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 integrated into the gap to be filled.

The volume of the concave portion 12 of the mounting table 11 is the gap formed between the outer peripheral surface of the backing tube 3 and the inner peripheral surface of the target material 2 when the lower end of the backing tube 3 is inserted to the vicinity of the bottom surface. It is sufficient that the filling bonding material 40 rises in the gap and slightly overflows to the upper end side of the target material 2 .
In this case, it can be confirmed that the filling bonding material 40 is filled between the target material 2 and the backing tube 3 without gaps in a state where the filling bonding material 40 overflows the upper end receiving pan 7 of the target material 2 .

By inserting the lower end of the backing tube 3 to the vicinity of the bottom surface of the recess 12 in this way, the gap between the target material 2 and the backing tube 3 is filled with the filling bonding material 40 without any gap.
Although not necessarily limited, the reheating step and the bonding material filling step (at least until the filling is completed) are preferably performed in an inert atmosphere to suppress oxidation of the bonding material and prevent further bonding. It is possible to improve the strength.

(Bonding material cooling process)
After filling the gap between the target material 2 and the backing tube 3 with the filling bonding material 40 , the target material 2 and the backing tube 3 are integrated by the bonding portion 4 by cooling and solidifying.
After that, the cylindrical sputtering target 1 is obtained by removing the annular spacer 5, the saucer 7, the protruding bonding material, etc., and cleaning them.

By the above-described method, the surface treatment layers 41a and 41b are formed thick and the surfaces thereof are scratched. After that, the gap between the backing tube 3 and the target material 2 is filled with the filling bonding material 40 . Therefore, the integration of the filling bonding material 40 and the surface treatment bonding materials 41a and 41b is not hindered by the oxide film 42, and the bonding strength of these materials can be improved for integration. A sputtering target 1 can be manufactured.
Moreover, the effect of the oxide film 42 can be suppressed by a simple operation of forming the thick underlayers 41a and 41b on the target material 2 and the backing tube 3 and scratching the surfaces thereof, thereby reducing the target. The material 2 and the backing tube 3 can be firmly joined.

8 to 10 show the manufacturing method of the second embodiment of the invention. In this embodiment and subsequent embodiments, the same parts as those in the above embodiment are denoted by the same reference numerals, and the description thereof is omitted. The same applies to the embodiment shown in FIG. 11 below.
In this second embodiment, the inner peripheral portion of the annular spacer 51 provided between the target materials 2 is protruded radially inward from the inner peripheral surface of the target material 2 to provide a backing during the bonding material filling process. When the tube 3 is inserted into the target material 2, the oxide film 42 on the underlayer 41b of the backing tube 3 is scraped off by the annular spacer 51. FIG.
That is, the inner peripheral portion of the annular spacer 51 provided on the target material 2 protrudes inward in the radial direction of the split target material 2a, and the inner diameter thereof is substantially the same as the outer diameter of the backing tube 3 (the same diameter or slightly smaller than the outer diameter of the backing tube 3). small diameter or slightly large diameter).
Further, as shown in FIG. 9, the scraping plate (annular spacer) 51 is provided with a hole 55 and a notch 56 . These holes 56 and notches 57 allow the melted filling bonding material to flow through the holes 55 and notches 56 in the bonding process. The holes 55 and the notches 56 may be formed in any shape other than the shape shown in FIG. 9, in any position, and in any number. Only one of 55 and notch 56 may be formed.

In the case of the second embodiment, the surface treatment layer 41a on the inner peripheral surface of the target material 2 is thickly formed as in the first embodiment, but the surface treatment layer 41b of the backing tube 3 is the surface of the target material 2. It is formed thinner than the processing layer 41a. The thick ground layer 41a is called a first ground layer, and the thin ground layer 41b is called a second ground layer. Therefore, in the case of the first embodiment, both the undercoat layers 41a and 41b are the first undercoat layers.
Further, after the surface treatment layers 41a and 41b are subjected to the surface treatment bonding material cooling step, the surface oxide film 42 is removed or at least the surface treatment layers 41a and 41b are scratched.

Then, in the bonding step, as shown in FIG. 8, the lower end of the backing tube 3 is inserted into the upper end of the target material 2, and these are reheated. By this reheating, an oxide film 42 is formed on both the underlayers 41a and 41b, and since the underlayer 41a (first underlayer) of the target material 2 is thick, it hangs down. Although the oxide film 42 is also formed on the surface treatment layer 41b (second surface treatment layer) of the backing tube 3, the surface treatment layer 41b is thin and does not sag.
Then, when the backing tube 3 is inserted into the target material 2 in this heated state, the scraping plate 51 provided on the target material 2 is formed so that its inner diameter is substantially the same as the outer diameter of the backing tube 3 . 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 scraping plate 51, and the oxide film 42 on the outer peripheral surface is scraped off. The scraped oxide film 42 is destroyed as a film, is pushed up by the filling bonding material 40 rising in the gap, and is discharged into the tray 7 . Moreover, 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 integrated into the gap to be filled.
On the other hand, on the outer peripheral surface of the backing tube 3 after the oxide film 42 has been removed by the scraping plate 51, the surface treatment layer 41b without the oxide film 42 remains thinly, and the filling bonding material 40 is deposited on the surface treatment layer 41b. Integrates evenly.
Since the surface treatment layer 41a (first surface treatment layer) on the inner peripheral surface of the target material 2 is thick, it hangs down as in the first embodiment, and the oxide film 42 is also destroyed.

In the example shown in FIG. 8 and the like, the target material 2 is composed of three divided target materials 2a, and the inner peripheral portion is so arranged that each annular spacer 51 between the divided target materials 2a functions as a scraping plate. is protruded from the split target material 2a, but as a scraping plate, any one of the annular spacers is provided with that function, and the other annular spacers 5 are the same as those in the first embodiment, The inner peripheral edge may be formed to have the same inner diameter as that of the split target material 2a, or the inner peripheral portions of all the annular spacers may protrude radially inward from the split target material 2a to function as scraping plates. good.
By removing the annular spacer 51 after joining, as shown in FIG. 10, the thickness of the joining portion 4 is reduced at the portion where the annular spacer 51 was provided.
Alternatively, the inner peripheral portion of the receiving pan 7 at the upper end of the target material 2 may be protruded radially inward in the same manner as the annular spacer 51, and the inner peripheral portion may be used as a scraping plate. In this case, it may be used together with the annular spacer 51 as a scraping plate.

FIG. 11 shows a state in the middle of manufacturing by the manufacturing method of the third embodiment of the present invention.
In the second embodiment described above, the oxide film of the undercoat layer 41b of the backing tube 3 is scraped off, but in the third embodiment, the oxide film 42 of the undercoat layer 41a of the target material 2 is removed. I have to. That is, the scraping plate 8 is provided at the lower end of the backing tube 3 , and when the backing tube 3 is inserted into the target material 2 , the surface treatment layer on the inner peripheral surface of the target material 2 is formed on the outer peripheral portion of the scraping plate 8 . The oxide film 42 of 41a is scraped off. The surface treatment layer 41a of the target material 2 is formed thin, and the surface treatment layer 41b of the backing tube 3 is formed thick. That is, in this embodiment, the surface treatment layer 41a of the target material 2 is the second surface treatment layer, and the surface treatment layer 41b of the backing tube 3 is the first surface treatment layer.
In this case, the scraping plate 8 may be fixed to the stopper 6 described above. The scraping plate 8 is formed to have an outer diameter approximately the same as the inner diameter of the target material 2 (matched, slightly smaller or slightly larger).

The oxide film 42 scraped from the inner peripheral surface of the target material 2 by the scraping plate 8 flows into the recess 12 and mixes with the filling bonding material 40 filling the recess 12, but is destroyed as a film. Therefore, it is not formed into a film again.
The oxide film 42 formed on the base treatment layer 41b of the backing tube 3 is sagging and destroyed by reheating because the base treatment layer 41b is formed thick.

In the above-described embodiment, the surface treatment bonding material is applied to both the target material 2 and the backing tube 3, but if either surface is in a state where the filling bonding material 40 is easily wetted, that surface Application of the bonding material for surface treatment may be omitted. In other words, during the bonding process, the bonding material for surface treatment may be applied to at least one of the target material 2 and the backing tube 3 to form the surface treatment layer 11 .

An experiment was conducted to confirm the effect of the present invention. The materials listed in Table 1 were used for the target material and the backing tube, and the base treatment bonding layer was formed with the thickness shown in Table 1, respectively. SIZ, which is the target species of Example 6, is an oxide sintered body of Si, In, and Zr. AZO of Example 7 is an oxide sintered body of Al and Zn. CuGa is an alloy of Cu and Ga, CuNi in Example 9 is an alloy of Cu and Ni, and CuCuO in Example 10 is a sintered body of Cu and CuO. A gap between the target material and the backing tube was set to 1.0 mm.
An In solder material was used as a bonding material for surface treatment. For surface treatment, heat with hot air until the surface temperature reaches 240°C to 260°C, apply the surface treatment bonding material while using an ultrasonic soldering iron in an air atmosphere, and when the surface is evenly wet, The melted bonding material was dropped, and the target material and the backing tube were coated thickly while being rotated, and cooled to room temperature.
The thickness of the surface treatment layer is obtained by measuring the thickness of the target material and the backing tube at arbitrary 8 points before and after forming the surface treatment layer, calculating the average value of the 8 points, (after the surface treatment layer is formed The thickness of the base treatment layer was determined by (average value of thickness of - average value of thickness before formation of base treatment layer).
After bonding, the bonding area ratio was measured by an ultrasonic inspection device. The bonding area ratio is the ratio of the bonded area excluding defective bonding points to the total area of the bonding surface between the target material and the backing tube. A bonding area ratio of 90% or more can be regarded as a pass.

Further, in Examples 1 to 10 and Comparative Examples 1 and 2, no scraping plate was installed and no scraping was performed. In Example 11, a scraping plate was installed as shown in FIG. 11 to scrape the inner peripheral surface of the target. In Example 12, a scraping plate was installed as shown in FIG. 8 to scrape the outer peripheral surface of the backing tube.
These results are shown in Table 1. In the table, BT indicates a backing tube and TG indicates a target material.

As can be seen from Table 1, when the thickness of the surface treatment layer of at least one of the target material and the backing tube was 0.1 mm or more and 0.8 mm or less, the bonding area ratio was 90% or more.
On the other hand, in Comparative Examples 1 and 2, both the target material and the backing tube had small thicknesses of the surface treatment layers, so that the bonding rate was less than 90%.

REFERENCE SIGNS LIST 1 Cylindrical sputtering target 2 Cylindrical target material 2a Divided target material 3 Cylindrical backing tube 4 Joint portion 40 Filling joint material 41a, 41b Surface treatment layer 42 Oxide film 5 Annular spacer 51 Annular spacer (scraping plate)
55 Hole 56 Notch 6 Plug 7 Receptacle 8 Scraping plate 11 Mounting table 12 Recess

Claims (2)

A method for manufacturing a cylindrical sputtering target in which the gap between the inner peripheral surface of a cylindrical target material and the outer peripheral surface of a cylindrical backing tube inserted inside the cylindrical target material is filled with a bonding material and bonded, A surface treatment bonding material is applied to at least one of the inner peripheral surface of the cylindrical target material and the outer peripheral surface of the cylindrical backing tube to form a first surface treatment layer of 0.1 mm or more and 0.8 mm or less. After the surface treatment step and the surface treatment step, the cylindrical backing tube is inserted into the cylindrical target material, and a molten bonding material for filling is inserted into the gap between the cylindrical target material and the cylindrical backing tube. In the surface treatment step, at least the surface of the first surface treatment layer is scratched, and in the bonding step, at least the surface of the first surface treatment layer is in a semi-molten state A method for producing a cylindrical sputtering target, characterized in that the filling bonding material is filled after heating until the target is heated to . In the surface treatment step, a second surface treatment layer thinner than the first surface treatment layer is formed on the other member opposite to the one member on which the first surface treatment layer is formed. a scraping plate protruding radially into the gap and arranged in the gap is provided along the circumferential direction on the one member on which the first surface treatment layer is formed; 2. The cylinder according to claim 1, wherein said cylindrical backing tube is inserted into said cylindrical target material while scraping at least part of the oxide film formed on the surface of said second undercoat layer with a plate. A method for manufacturing a type sputtering target.

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