JP6233224B2 - Method for manufacturing bonding material sheet and cylindrical sputtering target - Google Patents

Description

  The present invention relates to a method of manufacturing a cylindrical sputtering target used for sputtering by a magnetron rotary cathode sputtering apparatus, and a bonding material sheet used in the manufacturing thereof.

  Conventionally, as a sputtering target, a flat plate sputtering target obtained by bonding a flat target material to a backing plate is generally used. The use efficiency of the target material is 20% to 30% when sputtering is performed by a magnetron sputtering method using a flat plate sputtering target. The reason for this is that, in the magnetron sputtering method, the plasma is concentrated and collides with a specific part of the target material due to the magnetic field, so that a phenomenon in which erosion progresses to a specific part of the surface of the target material occurs. This is because the life of the target material is reached when it reaches the backing plate.

  In response to this problem, it has been proposed to increase the usage efficiency of the target material by making the sputtering target cylindrical. This method uses a cylindrical sputtering target consisting of a cylindrical backing tube and a cylindrical target material formed on the outer periphery thereof, and a magnetic field generating facility and a cooling facility are installed inside the backing tube, Sputtering is performed while rotating the sputtering target. According to this method, the use efficiency of the target material can be increased to 60% to 70%.

  Further, as a joining method that does not cause cracking or peeling of the target at the time of sputtering, a method in which a gap layer is provided between a cylindrical base material (backing tube) and the cylindrical target material and joined with solder (for example, Patent Document 1). And a method of providing a gap having a predetermined width in a connecting portion between cylindrical sputtering target materials when joining a plurality of cylindrical sputtering targets (see, for example, Patent Document 2).

  However, in these methods, when the bonding layer is formed by injecting the bonding material into the space between the cylindrical target material and the cylindrical base material (backing tube), the space width is as narrow as about 1 mm. When a bonding material such as a low melting point solder is injected from the end portion of the target material, air is taken in and voids or sinks occur, and it is not easy to obtain a uniform bonding layer.

  In order to solve this problem, a method of injecting a molten joining material such as indium into a space between a cylindrical target material and a cylindrical base material (backing tube) using an inclination of an adapter (for example, Patent Document 3) is disclosed.

  However, in this method, since the molten bonding material such as indium is exposed to the air as it is, it is injected into the cavity while being oxidized. In addition, an oxide film floats on the beaker containing the bonding material in a molten state, and these are wound when being injected into the cavity. For this reason, the wettability between the molten bonding material and the cylindrical target or the backing tube is deteriorated, and the adhesion of the bonding material after cooling and solidification may be reduced.

JP 2008-184627 A JP 2008-184640 A JP 2011-084795 A

  Therefore, the present invention has been devised in view of the above-mentioned problems of the prior art, and in joining the target material made of a cylindrical ceramic sintered body and the backing tube, the oxide is not taken in and the air is not taken in. Sputtering is performed using a bonding material sheet that can be filled without being involved and a bonding layer having a sufficient bonding rate and bonding strength can be formed, and a sputtering target in which the target material and the backing tube are bonded by the bonding material sheet. It is an object of the present invention to provide a method for manufacturing a sputtering target that does not cause defects such as cracking, chipping, and peeling.

  In order to achieve the above object, the present inventors have conducted extensive research on the oxidation in the injection of molten bonding material such as indium in the atmosphere. As a result, in the rolled material of the bonding material (bonding material sheet), the state of the oxide film formed on the rolled surface does not easily change, and the non-oxidized internal bonding material can be melted and flow out in advance. all right. That is, it was found that the oxide film formed on the rolled surface of the bonding material sheet protected the inner non-oxidized bonding material. The present invention has been completed based on this finding.

In other words, the bonding material sheet according to the present invention for achieving the above object has a backing tube coaxially disposed in a hollow portion of a target material made of a cylindrical ceramic sintered body, and is bonded to a gap between the target material and the backing tube. Ri Na on the surface and the one end of the bonding material to form a heat-resistant coating to form a layer, without forming the heat-resistant coating on the other end portion of the bonding material, heat the film melting point, higher than the melting point of the bonding material Features.

In the bonding material sheet according to the present invention, the heat-resistant film is preferably an oxide film or a heat-resistant resin film, and the bonding material is preferably an indium-based low melting point bonding material .

The manufacturing method of a cylindrical sputtering target according to the present invention includes a backing tube coaxially disposed in a hollow portion of a target material made of a cylindrical ceramic sintered body, and a bonding layer is formed in a gap between the target material and the backing tube. A manufacturing method of a cylindrical sputtering target for manufacturing a cylindrical sputtering target, wherein a bonding material sheet formed by forming a heat-resistant coating on the surface of a bonding material is heated, and the bonding material is melted and injected into a gap to form a bonding layer And the melting point of the heat-resistant film is higher than the melting point of the bonding material .

  In the method for producing a cylindrical sputtering target according to the present invention, the heat-resistant film is preferably an oxide film or a heat-resistant resin film, and it is preferable to heat a bonding material sheet formed by processing the bonding material into a sheet shape by rolling.

  In the method for manufacturing a cylindrical sputtering target according to the present invention, it is preferable to install the bonding material sheet immediately above the gap.

  In the manufacturing method of the cylindrical sputtering target which concerns on this invention, it is preferable to wind a joining material sheet around the outer peripheral part of a backing tube, and to fix it with a heat resistant tape.

  In the manufacturing method of the cylindrical sputtering target according to the present invention, it is preferable that the bonding material sheet is wound around the outer peripheral portion of the backing tube and fixed with a ring, and the lower end portion has a taper. It is more preferable to fix so as to be interposed between the two.

  According to the present invention, in the method of manufacturing a cylindrical sputtering target in which a bonding layer is formed in the gap between the target material and the backing tube to manufacture the cylindrical sputtering target, the oxide is entrained by using the bonding material sheet. Alternatively, the bonding layer can be formed by injecting the molten bonding material into the gap.

  According to the present invention, by using a bonding material sheet, when a molten bonding material is injected into a gap to form a bonding layer, air is not taken in or smoothly without pulsation or the like. The injection operation can be performed in a short time, and a uniform bonding layer can be formed.

  ADVANTAGE OF THE INVENTION According to this invention, the sputtering target which does not generate | occur | produce defects, such as a crack, a chip | tip, and peeling at the time of sputtering, can be obtained by forming a joining layer using a joining material sheet at the time of manufacture of a cylindrical sputtering target.

It is the schematic which shows one form of the cylindrical sputtering target obtained by the manufacturing method of the cylindrical sputtering target of this invention, Comprising: It is sectional drawing cut | disconnected by the surface containing a central axis. It is a schematic diagram for demonstrating a mode that an internal indium flows out by heat melting of the joining material sheet | seat of this invention. It is a schematic diagram for demonstrating one form of the manufacturing method of the cylindrical sputtering target of this invention, Comprising: It is sectional drawing cut | disconnected by the surface containing a central axis. It is a schematic diagram for demonstrating the other form of the manufacturing method of the cylindrical sputtering target of this invention, Comprising: It is sectional drawing cut | disconnected by the surface containing a central axis. It is a schematic diagram for demonstrating the other form of the manufacturing method of the cylindrical sputtering target of this invention, Comprising: It is sectional drawing cut | disconnected by the surface containing a central axis.

  A specific embodiment to which the present invention is applied (hereinafter referred to as “the present embodiment”) will be described in detail with reference to the drawings in the following order. Note that the present invention is not limited to the following embodiments, and various modifications can be made without departing from the scope of the present invention.

1. 1. Cylindrical sputtering target 2. Bonding material sheet 3. Manufacturing method of bonding material sheet Manufacturing method of cylindrical sputtering target

[1. Cylindrical sputtering target]
(1-1. Outline of cylindrical sputtering target)
As shown in FIG. 1, a cylindrical sputtering target 1 has a target material 2 installed on the outer periphery of a backing tube 3, and the target material 2 and the backing tube 3 are joined via a joining layer 4. Yes. More specifically, the cylindrical sputtering target 1 is formed by coaxially arranging the backing tube 3 in the hollow portion of the target material 2 and joining them in a state in which their central axes coincide.

  The size of the cylindrical sputtering target 1 can be appropriately adjusted according to the material, customer demand, and the like, and is not particularly limited. For example, when a cylindrical ceramic sintered body having an outer diameter of 100 mm to 200 mm, an inner diameter of 80 mm to 180 mm, and a total length of 50 mm to 200 mm is used as the target material 2, the target material 2 is divided when used alone. The size of the cylindrical sputtering target 1 is appropriately determined depending on the situation.

(1-2. Target material)
The cylindrical ceramic sintered body that can be used as the cylindrical target material 2 can be appropriately selected depending on the application, and is not particularly limited. For example, an oxide mainly composed of at least one selected from indium (In), tin (Sn), zinc (Zn), aluminum (Al), niobium (Nb), tantalum (Ta), and titanium (Ti). Cylindrical ceramics sintered bodies composed of materials or the like can be used.

  In particular, a cylindrical ceramic sintered body mainly composed of indium oxide, which is easily compatible with a low melting point bonding material described later, specifically, indium oxide containing tin (ITO) and indium oxide containing cerium (Ce) ( A cylindrical ceramic sintered body composed of ICO), indium oxide (IGO) containing gallium (Ga), indium oxide (IGZO) containing gallium and zinc, or the like is suitably used as the target material 2.

  As shown in FIGS. 1 and 3, in order to improve the wettability of the target material 2 with the bonding material 6 forming the bonding layer 4, an underlayer of indium or an indium alloy is provided on the inner peripheral surface of the target material 2. It may be formed. When the wettability of the target material 2 is improved by the formation of the base layer, the air in the gap 5 is melted when the bonding layer 4 is formed in the gap 5 between the target material 2 and the backing tube 3. It becomes easy to extrude, and it becomes easy to discharge | release oxygen which causes an oxide film outside.

  The outer diameter and the total length of the target material 2 can be appropriately adjusted according to the size of the cylindrical sputtering target 1. The inner diameter can be appropriately adjusted according to the width of the gap 5 and the outer diameter of the backing tube 3, and these are not particularly limited. Further, as the target material 2, not only one composed of one cylindrical ceramic sintered body but also one obtained by connecting a plurality of cylindrical ceramic sintered bodies can be used. The method for connecting the cylindrical ceramic sintered bodies is not particularly limited, and a known method can be used.

(1-3. Backing tube)
The cylindrical backing tube 3 is made of a material having thermal conductivity capable of ensuring sufficient cooling efficiency that prevents the bonding layer 4 from being deteriorated and melted when the cylindrical sputtering target 1 is used. What is necessary is just to have the intensity | strength etc. which can support the cylindrical sputtering target 1. FIG. As the backing tube 3, for example, various materials such as copper or copper alloy, titanium or titanium alloy, molybdenum or molybdenum alloy, aluminum or aluminum alloy are used in addition to those made of general austenitic stainless steel, particularly SUS304. be able to.

  When the backing tube 3 is made of stainless steel, it is preferable to coat copper as an underlayer in order to improve wettability with the bonding material 6. Copper coating can be performed by electroplating or the like. Further, when the wettability of the backing tube 3 is improved by the formation of the underlayer, oxygen causing the oxide film is easily released to the outside in the same manner as when the wettability of the target material 2 is improved. Become.

  The total length of the backing tube 3 can be appropriately adjusted according to the size of the cylindrical sputtering target 1. The inner diameter can be appropriately adjusted according to the sputtering apparatus, and these are not particularly limited. The outer diameter of the backing tube 3 is preferably set in consideration of the difference in linear expansion coefficient between the backing tube 3 and the target material 2 together with the thickness of the underlayer.

For example, as the target material 2, ITO having a linear expansion coefficient at 20 ° C. of 7.2 × 10 ⁻⁶ / ° C. is used, and as the backing tube 3, the linear expansion coefficient at 20 ° C. is 17.3 × 10 ⁻⁶ / ° C. When the SUS304 is used, the width of the gap 5 between the target material 2 and the backing tube 3 is preferably 0.3 mm to 3.0 mm, more preferably 0.5 mm to 1.0 mm. The outer diameter of the tube 3 is set.

  If the width of the gap 5 is less than 0.3 mm, when the molten bonding material 7 is injected into the gap 5, the backing tube 3 may thermally expand and the target material 2 may be broken. On the other hand, if the width of the gap 5 exceeds 3.0 mm, it is difficult to place the backing tube 3 coaxially in the hollow portion of the target material 2 and to join them in a state in which their central axes coincide.

(1-4. Bonding layer)
The bonding layer 4 is made of indium, for example, and bonds the target material 2 and the backing tube 3 together. The role of the bonding layer 4 is to transfer heat between the target material 2 and the backing tube 3 in order to dissipate the heat generated on the cylindrical sputtering target 1 by the discharge with the coolant flowing inside the backing tube 3. It is in. That is, the bonding layer 4 only needs to have thermal conductivity, electrical conductivity, adhesive strength, and the like in the same manner as the backing tube 3 when the cylindrical sputtering target 1 is used.

[2. Bonding material sheet]
The bonding material sheet 9 according to the present embodiment is a sheet for forming the bonding layer 4 in the gap 5 between the target material 2 and the backing tube 3 as shown in FIG. The bonding material sheet 9 shown in FIG. 2 has a heat-resistant coating 8 having heat resistance formed on the surface and one end (the upper end in FIG. 2) of the bonding material 6 that is a material for forming the bonding layer 4. It is.

  In the bonding material sheet 9, from the viewpoint of injecting the molten bonding material 7 into the gap 5, it is preferable that the heat resistant coating 8 is not formed on the other end portion (the lower end portion in FIG. 2) of the bonding material 6. When the heat-resistant coating 8 is formed on the surface and both ends of the bonding material 6, the heat-resistant coating 8 on one end of the bonding material 6 may be removed before the bonding layer 4 is formed.

  In order to give the bonding layer 4 characteristics such as thermal conductivity, electrical conductivity, and adhesive strength in the same manner as the above-described backing tube 3, it is necessary to select the bonding material 6 used for forming the bonding layer 4. is there. For example, the bonding material 6 containing indium as a main component has a lower hardness during solidification than the bonding material 6 containing tin as a main component. Therefore, when the bonding layer 4 is formed using the bonding material 6 containing indium as a main component, in the process from the injection of the molten bonding material 7 to solidification, there is a problem such as cracking of the target material 2. It can be effectively prevented.

  Moreover, when forming the joining layer 4 using the joining material 6 which has an indium as a main component, indium is 50 mass% or more, Preferably it is 70 mass%-100 mass%, More preferably, it is 80 mass%-100 mass. It is necessary to use what contains%. In particular, it is preferable to use a low melting point bonding material containing 80% by mass or more, preferably 90% by mass to 100% by mass of indium as the bonding material 6. Such a low-melting-point bonding material is soft because the bonds between atoms or molecules are weak, and is excellent in workability because the hardness after cooling and solidification is in an appropriate range. In addition, the low melting point bonding material not only has excellent workability, but also has high fluidity at the time of melting. Therefore, it is possible to easily form the uniform bonding layer 4 with very few nests and sink marks.

  For example, indium metal having an indium content of 100% by mass is preferably used as the bonding material 6 because the thermal conductivity of indium metal is 81.6 W / m · K and excellent in thermal conductivity. Further, indium metal is preferable because it can be bonded with good adhesion when the target material 2 and the backing tube 3 are bonded by being liquefied and solidified.

  On the other hand, when the content of indium is less than 50% by mass, the wettability with the backing tube 3 is low, so that the bonding material 7 obtained by heating and melting such a bonding material 6 is used as the target material 2 and the backing tube 3. It is not possible to inject into the gap 5 without gaps with high filling properties.

  In addition to the indium-based low-melting-point bonding material described above, a resin paste containing indium powder, a conductive resin, or the like can be used as the bonding material 6. From the viewpoint of conductivity and spreadability, an indium-based material can be used. A low melting point bonding material is preferable, and an indium-based low melting point bonding material having a melting point of 130 ° C. to 160 ° C. is more preferable. In addition, it does not restrict | limit especially about components other than an indium, For example, tin, antimony (Sb), zinc, etc. can be contained as needed. The content of components other than indium is less than 50% by mass, preferably less than 30% by mass, and more preferably less than 20% by mass.

  The thickness of the heat-resistant coating 8 is not particularly limited as long as the bonding material 6 can be protected, and can be appropriately determined according to the thickness and width of the bonding layer 4 or the outer diameter of the backing tube 3. .

  Here, as a characteristic of the heat resistant coating 8 having heat resistance, it is required that the bonding layer 4 does not melt together with the bonding material 6, that is, has a melting point higher than the melting point of the bonding material 6. As shown in FIG. 2, by heating the bonding material sheet 9, only the inner bonding material 6 is melted and the bonding material 7 melted downward flows out, so that the thickness of the bonding material sheet 9 is gradually reduced. Become. When all the bonding materials 6 are melted, only the heat-resistant coating 8 remains. That is, the heat-resistant coating 8 is not melted at the melting temperature of the bonding material 6 and therefore remains in a solid state. Therefore, in the bonding material sheet 9, it is possible to fill the gap 5 with only the bonding material 6 necessary for forming the bonding layer 4 while preventing the entry of unnecessary substances such as air and oxides of the bonding material 6. A uniform bonding layer 4 can be formed.

  Examples of the heat-resistant coating 8 include an oxide coating and a heat-resistant resin film. Among these, an oxide coating is preferable. By forming such a heat-resistant coating 8 on at least the surface of the bonding material 6, even if the bonding material sheet 9 is heated to the melting point of the bonding material 6 or higher, the heat-resistant coating 8 does not melt and the molten bonding material 7 is melted. Alone can be injected into the gap 5 between the target material 2 and the backing tube 3 to form the bonding layer 4.

  The oxide film is preferably an oxide of the material of the bonding material 6 used for forming the bonding layer 4, such as indium oxide. Moreover, as a heat resistant resin film, a polyimide etc. are preferable.

  In addition, although mentioned later for details, from the viewpoint of fixing the bonding material sheet 9 to the backing tube 3 and forming the bonding layer 4, it is more preferable that the heat resistant coating 8 has an appropriate mechanical strength. Since the heat-resistant coating 8 has mechanical strength, deterioration of the bonding material 6 inside the bonding material sheet 9 due to external stimulation can be prevented, and the sheet shape can be maintained even when the bonding material 6 is fixed to the backing tube 3.

[3. Manufacturing method of bonding material sheet]
In the manufacturing method of the bonding material sheet 9, the ingot of the bonding material 6 is processed into a sheet shape by rough rolling, and then the heat-resistant coating 8 is formed on the surface of the bonding material sheet 9 by cold rolling. obtain. The heat-resistant coating 8 in the bonding material sheet 9 produced by such a manufacturing method firmly maintains its shape. In addition, the formation method of the heat-resistant film 8 is not limited to cold rolling, and can be appropriately selected according to the material and application.

  When the heat-resistant film 8 formed on the surface of the bonding material sheet 9 is an oxide film, the oxide film is removed when the bonding material sheet 9 obtained after the cold rolling is subjected to pickling or the like. It is not preferable.

  The rolling rate of the bonding material sheet 9 after the rough rolling is preferably 30% or more and 90% or less. Here, the rolling rate is calculated by the following formula.

    Rolling ratio (%) = (sheet thickness before cold rolling−sheet thickness after cold rolling) ÷ sheet thickness before cold rolling × 100

  When the heat-resistant film 8 formed on the surface of the bonding material sheet 9 is an oxide film, it is difficult to secure the strength of the oxide film because the bonding material sheet 9 is a thin film when the rolling rate of the bonding material sheet 9 is less than 30%. On the other hand, when the rolling rate of the bonding material sheet 9 exceeds 90%, a defect occurs in the oxide film, the internal bonding material 6 leaks from the defect, and the oxide film is damaged.

  When an oxide film is formed on the surface of the bonding material sheet 9, the oxide (heat resistant film 8) that becomes the outer film is easy even when the inside of the bonding material sheet 9 (bonding material 6) is heated to the melting point or higher. It does not melt into the gap 5 and does not enter the gap 5 between the target material 2 and the backing tube 3 until all of the bonding material 6 disappears. Therefore, before forming the bonding layer 4, the volume of the gap 5 is calculated in advance, and the weight of the necessary bonding material 6 is measured based on the calculated value, whereby the pure bonding material 6 containing no oxide or the like can be obtained. , Can be injected into the gap 5.

  When a heat resistant resin film is formed as the heat resistant coating 8 on the surface of the bonding material sheet 9, the ingot of the bonding material 6 is processed into a sheet shape by rough rolling, and then the heat resistant resin film is laminated on the surface. Then, the bonding material sheet 9 is produced. Lamination can be performed by appropriately selecting a known method.

[4. Manufacturing method of cylindrical sputtering target]
Hereinafter, the manufacturing method of the cylindrical sputtering target which concerns on this Embodiment is demonstrated.

(4-1. Outline of cylindrical sputtering target)
As shown in FIG. 3, in the cylindrical sputtering target 1, the backing tube 3 is coaxially disposed in the hollow portion of the target material 2, and the bonding layer 4 is formed by the bonding material 6 between the target material 2 and the backing tube 3. It is produced by. For example, the cylindrical sputtering target 1 uses a backing tube 3 made of SUS304 and a target material 2 made of a cylindrical ceramic sintered body made of ITO using an indium-based low melting point bonding material as the bonding material 6. Can be produced.

(4-2. Arrangement of backing tube and target material)
First, in the manufacturing method of the cylindrical sputtering target 1, as shown in FIG. 3, the backing tube 3 is coaxially disposed in the hollow portion of the target material 2.

  Here, it is important to arrange the backing tube 3 coaxially in the hollow portion of the target material 2, that is, in a state in which these central axes coincide with each other, and to join the two. If they are joined with their center axes shifted, the center of the outer diameter and the center of the inner diameter of the resulting cylindrical sputtering target 1 will be shifted. As a result, the cylindrical sputtering target 1 may expand non-uniformly due to the thermal load during sputtering, and the target material 2 may be cracked or peeled off.

  In addition, as a method of arrange | positioning the backing tube 3 coaxially in the hollow part of the target material 2, a well-known means can be used without being restrict | limited in particular. For example, the backing tube 3 can be coaxially disposed in the hollow portion of the target material 2 by positioning using an XY stage.

  Next, in the method for manufacturing the cylindrical sputtering target 1, one end in the axial direction of the gap 5 between the target material 2 and the backing tube 3 is sealed with a known sealing means such as an O-ring 16. And the target material 2 and the backing tube 3 are made to stand upright so that this sealing side may turn down.

(4-3. Arrangement of bonding material sheet)
Next, in the method of manufacturing the cylindrical sputtering target 1, as shown in FIG. 3, the one end side of the bonding material sheet 9 from which the heat-resistant coating 8 has been removed is directed downward, and the bonding material sheet 9 is directly above the gap 5. Arrange and wind around the outer periphery of the backing tube 3. Then, the heat resistant masking tape 10 is wound around and fixed to the outer peripheral portion of the bonding material sheet 9. At this time, the heat-resistant masking tape 10 covers at least the vicinity of the upper end portion of the bonding material sheet 9 and the vicinity of the upper end portion of the target material 2. By covering the bonding material sheet 9 with the heat resistant masking tape 10 in this way, it is possible to prevent the inflow of air from between the bonding material sheet 9 and the target material 2. As a result, the amount of oxygen that causes oxidation of the bonding material 6 can be reduced.

  Further, by holding the bonding material sheet 9 on the outer periphery of the backing tube 3 using a holder such as a heat-resistant masking tape 10, only the molten bonding material 7 is placed in the gap 5 between the target material 2 and the backing tube 3. Can be easily injected. Therefore, in the manufacturing method of the cylindrical sputtering target 1, the bonding material sheet 9 is installed on the backing tube 3 as described above, so that the bonding material 6 does not include oxides (oxide film), air, and other unnecessary materials. A simple bonding layer 4 can be formed.

(4-4. Formation of bonding layer)
Next, in the manufacturing method of the cylindrical sputtering target 1, band heaters 11 and 12 are attached to the outer peripheral surfaces of the target material 2 and the bonding material sheet 9 as shown in FIG. The formation condition of the bonding layer 4 is appropriately selected according to the composition of the cylindrical ceramic sintered body used as the target material 2, the material of the backing tube 3, and the like, and is not particularly limited. .

  When the bonding material sheet 9 is heated, as shown in FIGS. 2 and 3, the bonding material sheet 9 is wound around the outer periphery of the backing tube 3, so that the molten bonding material 7 flows downward from the inside of the bonding material sheet 9. , And injected all over the gap 5 at once. As described above, by providing the base layer on the target material 2 and the backing tube 3, the wettability is further increased, and the air in the gap 5 is easily pushed out by the molten bonding material 7. It becomes easy to release oxygen to the outside.

  On the other hand, the heat-resistant film 8 on the surface of the bonding material 6 remains attached to the heat-resistant masking tape 10 and therefore does not flow into the gap 5. After all of the molten bonding material 7 is injected into the gap 5, the molten bonding material 7 is solidified by cooling the gap 5 to form the bonding layer 4. Then, by forming the bonding layer 4, the target material 2 and the backing tube 3 are bonded to obtain the cylindrical sputtering target 1.

  In the same manner as the above-described backing tube 3, the cylindrical sputtering target 1 has a bonding layer 4 having characteristics such as thermal conductivity, electrical conductivity, and adhesive strength in a gap 5 between the target material 2 and the backing tube 3. By forming, the joining rate and joining strength of the target material 2 and the backing tube 3 can be improved significantly.

  Here, the bonding rate refers to the volume of the bonding layer 4 when the bonding material 7 is formed by injecting the bonding material 7 that is obtained by heating and melting the bonding material 6 into the gap 5 with respect to the volume of the gap 5 (melted). The filling amount of the bonding material 7). The filling amount of the molten bonding material 7 can be measured by an ultrasonic flaw detector. The bonding strength refers to a yield point determined by a tensile tester based on a metal material tensile test method (JIS Z2241).

  In the manufacturing method of the cylindrical sputtering target 1, as described above, the inflow of air from the outside is suppressed as much as possible by holding the bonding material sheet 9 on the outer periphery of the backing tube 3 using the heat-resistant masking tape 10. Therefore, it is possible to prevent air bubbles from being mixed into the bonding layer 4 and oxidation of the bonding material 6.

  Therefore, in the manufacturing method of the cylindrical sputtering target 1, it is possible to prevent the introduction of bubbles and unnecessary substances such as oxides (oxide films) of the bonding material 6 in the bonding layer 4. The necessary amount of the bonding material 6 can be filled in the gap 5. As a result, unlike the bonding layer in which unnecessary substances are included in the conventional method, the filling amount of the molten bonding material 7 can be increased by using the bonding layer 4 composed of only the bonding material 6. The bonding rate of the bonding layer 4 can be 90.0% or more, preferably 95% or more.

  Moreover, in the manufacturing method of the cylindrical sputtering target 1, the bonding strength of the bonding layer 4 is 1.0 MPa or more, preferably 5 by using the bonding layer 4 including only the bonding material 6 from which the above-described unnecessary substances are removed. 0.0 MPa or more.

  Therefore, in the obtained cylindrical sputtering target 1, the bonding rate and bonding strength between the target material 2 and the backing tube 3 can be greatly improved. Therefore, the target material 2 during sputtering using the cylindrical sputtering target 1. Can be effectively prevented.

(4-5. Other holding method of bonding material sheet in backing tube)
As another holding method of the bonding material sheet 9 in the backing tube 3, for example, a method of holding using a holder such as the aluminum ring 13 shown in FIG. 4 or the tapered aluminum ring 15 shown in FIG. Can be mentioned.

  When the aluminum ring 13 is used as a holder, the tightening can be stronger than the heat-resistant masking tape 10, so that the inflow of air from the outside can be further blocked. When the tapered aluminum ring 15 is used as a holder, the taped 14 makes it easy for the molten bonding material 7 to flow into the narrow gap 5, and the molten bonding material 7 is quickly and easily injected into the gap 5. be able to.

  In the manufacturing method of the cylindrical sputtering target 1, even if these holders are used, only the molten bonding material 7 is easily inserted into the gap 5 between the target material 2 and the backing tube 3 in the same manner as the heat resistant masking tape 10. The uniform bonding layer 4 can be formed.

(4-6. Method for forming other bonding layer)
When the molten bonding material 7 is injected into the gap 5 between the target material 2 and the backing tube 3 to form the bonding layer 4, a pressure difference between the gap 5 and the molten bonding material 7 may be used. The pressure difference can be generated by pressurizing the molten bonding material 7 and / or depressurizing the gap 5.

  Examples of the method for generating the pressure difference include a method in which the molten bonding material 7 is pressurized with compressed air in the direction of the gap 5, and a method in which the gap 5 is decompressed with a vacuum pump. The injection of the molten bonding material 7 due to the pressure difference can densely fill the molten bonding material 7 in the gap 5 without applying external force such as vibration when the cylindrical sputtering target 1 is manufactured. The filling rate of the molten bonding material 7 can be increased. Furthermore, bubbles and the like can be removed by the pressure difference between the gap 5 and the molten bonding material 7, and the occurrence of defects such as cracks and chips can be significantly reduced.

  In the case where the pressure difference between the gap 5 and the molten bonding material 7 is used, the bonding material sheet 9 may be placed on either the upper end portion or the lower end portion of the target material 2.

  As described above, in the method of manufacturing the cylindrical sputtering target 1, the backing tube 3 is coaxially arranged in the hollow portion of the target material 2 made of a cylindrical ceramic sintered body, and the gap between the target material 2 and the backing tube 3 is set. 5, using the bonding material sheet 9, the molten bonding material 7 is heated and melted and poured to form the bonding layer 4, and the cylindrical sputtering target 1 is manufactured.

  When the bonding material sheet 9 is heated during the formation of the bonding layer 4 in the production of the cylindrical sputtering target 1, bonding is caused by the difference in melting point between the inside (bonding material 6) and the outside (heat resistant coating 8) of the bonding material sheet 9. Only the material 6 is melted to form a molten bonding material 7, which flows into the gap 5 between the target material 2 and the backing tube 3, thereby forming a uniform bonding layer 4 with reduced contamination of unwanted materials such as oxide film and bubbles. Can do.

  As a result, by using the bonding material sheet 9 at the time of producing the cylindrical sputtering target 1, the cylindrical sputtering target 1 that does not cause defects such as cracking, chipping, and peeling during sputtering can be obtained.

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail using an Example and a comparative example, this invention is not limited to these Examples and a comparative example.

Example 1
In Example 1, five cylindrical ceramic sintered bodies made of ITO having an outer diameter of 100 mm, an inner diameter of 82 mm, and a total length of 200 mm were prepared. The inner peripheral surface of these cylindrical ceramic sintered bodies was ground using a machining center (manufactured by DMG Mori Seiki Co., Ltd., DMC635V) to obtain the target material 2, and indium was wetted using an ultrasonic iron.

  On the other hand, as the backing tube 3, a cylindrical backing tube 3 made of SUS304 having an outer diameter of 80 mm, an inner diameter of 70 mm, and a total length of 1100 mm was prepared. The backing tube 3 was masked with a heat-resistant masking tape 10 so that excessive bonding material 6 did not adhere to portions other than the bonding surface. Next, a base layer made of a copper plating layer having a thickness of 1 μm was formed on the surface of the backing tube 3 by electrolytic plating.

  Thereafter, in Example 1, as shown in FIG. 3, using the XY stage, the backing tube 3 is arranged coaxially in the hollow portion of the divided target material 2, and the divided target material 2 and the backing tube 3 are One end of the openings at both ends of the gap 5 formed between them is sealed with a heat-resistant O-ring 16, and the combined body composed of the divided target material 2 and the backing tube 3 is erected so that the sealed side is downward. It was. Thereafter, a removable dummy pipe (not shown) having an outer diameter of 80 mm, an inner diameter of 70 mm, and an overall length of 200 mm was fixed to the upper end of the backing tube 3 with the heat-resistant masking tape 10, and the backing tube 3 was extended upward.

  In Example 1, an indium-based material containing 80% by mass of indium, 10% by mass of tin, 5% by mass of antimony, and 5% by mass of zinc is put into a heated mold and melted (melting point: 160 ° C.). Then, indium oxide floating on the surface was removed and cooled to obtain an ingot. From a roughly rolled plate having a thickness of 20 mm obtained by roughly rolling an ingot, a plate having a thickness of 5 mm (rolling rate: 75%) was obtained by cold rolling to obtain a bonding material sheet 9. This bonding material sheet 9 is cut into a width of 251 mm and a height of 193 mm with a shear so as to have a weight of 1.7 kg, and as shown in FIG. 3, wound around the uppermost target material 2 and heat resistant masking tape. 10 was wound around and fixed.

  In this state, a band heater 11 with an output of 150 W (manufactured by Sakaguchi Electric Heat Co., Ltd.) is attached to the outer peripheral surfaces of all the divided target materials 2 constituting the target material 2 and the wound bonding material sheet 9, and the set temperature is set to 180. Heated as ° C. Further, the part of the bonding material sheet 9 was melted by heating to 190 ° C. with the band heater 12.

  As shown in FIG. 2, during melting, the molten bonding material 7 flows out from the inside of the bonding material sheet 9, and the surface oxide film (heat-resistant film 8) remains attached to the heat-resistant masking tape 10, and the pouring is completed. . After the molten bonding material 7 in the attached bonding material sheet 9 was poured into the gap 5, the switch was sequentially turned off from the band heater 11 located below and cooled to room temperature (20 ° C.). After confirming that the molten bonding material 7 was completely solidified, the heat-resistant masking tape 10, the heat-resistant O-ring 16, the silicon packing and the dummy pipe (not shown) were removed, and the cylindrical sputtering target 1 was obtained.

  In Example 1, with respect to the obtained cylindrical sputtering target 1, the filling amount of the bonding material 6 is measured using an ultrasonic flaw detector (manufactured by KJTD, SDS-WIN). From this measured value, The joining rate between the target material 2 and the backing tube 3 was evaluated. Specifically, those with a joining rate of 95.0% or more are “excellent (◯)”, those with a joining ratio of 90.0% or more and less than 95.0% are “good (Δ)”, and those having a joining rate of less than 90.0% Alternatively, the target material 2 dropped out of the backing tube 3 and the bonding rate could not be evaluated was evaluated as “defective (×)”.

  In addition, the bonding strength between the target material 2 and the bonding layer 4 is to measure the bonding strength using a tensile tester (manufactured by Shimadzu Corporation, Autograph) based on a metal material tensile test method (JIS Z2241). It was evaluated by. Specifically, those having a bonding strength of 5.0 MPa or more are “excellent (◯)”, those having a bonding strength of 1.0 MPa to less than 5.0 MPa are “good (Δ)”, those having a bonding strength of less than 1.0 MPa, or targets The material 2 dropped out from the backing tube 3 and the bonding strength could not be evaluated was evaluated as “defective (×)”.

  As a result of evaluating the joining rate and joining strength of the obtained cylindrical sputtering target 1 by the above method, it was confirmed that both were excellent. In addition, when the cylindrical sputtering target 1 is attached to a magnetron rotary cathode sputtering apparatus and a discharge test is performed at an output of 300 W in an argon atmosphere of 3.0 Pa, cracks and chips are generated in the split target material 2 during sputtering. It never happened.

  In Example 1, these results are summarized in Table 1. In “Defects” in Table 1, “Yes” or “No” indicates the result of whether or not a defect such as cracking, chipping or peeling of the cylindrical sputtering target 1 occurred.

(Example 2)
In Example 2, a cylindrical sputtering target 1 was obtained in the same manner as in Example 1 except that pure indium was used as the material of the bonding material sheet 9. As a result of evaluating the joining rate and joining strength of the cylindrical sputtering target 1 in the same manner as in Example 1, it was confirmed that both were excellent. Further, when a discharge test was performed in the same manner as in Example 1, the split target material 2 was not cracked or chipped during sputtering.

  In Example 2, these results are summarized in Table 1 in the same manner as in Example 1.

(Example 3)
In Example 3, cold rolling was performed from a rough rolled plate having a thickness of 20 mm obtained by rough rolling to obtain a plate having a thickness of 10 mm (a rolling rate of 50%) to obtain a bonding material sheet 9, and the bonding material. A cylindrical sputtering target 1 was obtained in the same manner as in Example 1, except that the sheet 9 was cut into a width of 251 mm and a height of 96.5 mm so as to have a weight of 1.7 kg with a shear. As a result of evaluating the joining rate and joining strength of the cylindrical sputtering target 1 in the same manner as in Example 1, it was confirmed that both were excellent. Further, when a discharge test was performed in the same manner as in Example 1, the split target material 2 was not cracked or chipped during sputtering.

  In Example 3, these results are summarized in Table 1 in the same manner as in Example 1.

Example 4
In Example 4, fixing of the bonding material sheet 9 wound immediately above the uppermost target material 2 of Example 1 from the heat-resistant masking tape 10, as shown in FIG. 4, an outer diameter of 100 mm, an inner diameter of 92 mm, A cylindrical sputtering target 1 was obtained in the same manner as in Example 1 except that the aluminum ring 13 had a total length of 200 mm. As a result of evaluating the joining rate and joining strength of the cylindrical sputtering target 1 in the same manner as in Example 1, it was confirmed that both were excellent. Further, when a discharge test was performed in the same manner as in Example 1, the split target material 2 was not cracked or chipped during sputtering.

  In Example 4, these results are summarized in Table 1 in the same manner as in Example 1.

(Example 5)
In Example 5, the shape of the lower end portion of the aluminum ring 13 of Example 4 was added with a taper 14 of 45 degrees with an inner diameter of 82 mm, resulting in a tapered aluminum ring 15 with a total length of 205 mm. Except for this, a cylindrical sputtering target 1 was obtained in the same manner as in Example 1. As a result of evaluating the joining rate and joining strength of the cylindrical sputtering target 1 in the same manner as in Example 1, it was confirmed that both were excellent. Further, when a discharge test was performed in the same manner as in Example 1, the split target material 2 was not cracked or chipped during sputtering.

  In Example 5, these results are summarized in Table 1 in the same manner as in Example 1.

(Comparative Example 1)
In Comparative Example 1, a ring-shaped casting adapter having an outer diameter of 122 mm, an inner diameter of 82 mm, and a height of 20 mm and having a taper of 45 degrees on the inner diameter side is installed in the cylindrical ceramic sintered body at the upper end, and the embodiment of 1.7 kg A cylindrical sputtering target was obtained in the same manner as in Example 1 except that 1 bonding material 6 was melted and injected in a beaker. In Comparative Example 1, since a long time was required for pouring, about 50% of the bonding material 6 was solidified in the beaker. When the joining rate and joining strength of the cylindrical sputtering target were tried to be evaluated in the same manner as in Example 1, the split target material 2 was peeled off from the joining layer and dropped from the backing tube 3.

  For this reason, in Comparative Example 1, the evaluation of the joining rate and the joining strength and the discharge test could not be performed.

(Comparative Example 2)
In Comparative Example 2, a ring-shaped casting adapter having an outer diameter of 122 mm, an inner diameter of 82 mm, and a height of 20 mm and having a taper of 45 degrees on the inner diameter side is installed in the cylindrical ceramic sintered body at the upper end, and the embodiment of 1.7 kg A cylindrical sputtering target was obtained in the same manner as in Example 1 except that 1 bonding material 6 was dissolved in a unit of 170 g in a beaker and injected in 10 batches. In Comparative Example 2, pouring was performed, but pouring was intermittent, and a large number of voids were generated in the bonding material 6.

  In Comparative Example 2, the joining rate and joining strength of this cylindrical sputtering target were evaluated in the same manner as in Example 1, and the results are summarized in Table 1.

  In Examples 1 to 5, a bonding material sheet containing 80% by mass or more of indium and having a thickness of 5 mm to 10 mm, that is, a rolling rate of 50% to 75% was used. In addition, a cylindrical sputtering target was prepared using any one of a heat-resistant masking tape, an aluminum ring, and a tapered aluminum ring as a holding tube for holding the bonding material sheet on the backing tube. As a result, as shown in Table 1, the obtained cylindrical sputtering target has excellent characteristics such as a bonding rate of 95% or more and a bonding strength of 5 MPa or more, and defects such as cracking, chipping and peeling occur during sputtering. There wasn't.

  Therefore, from Example 1 to Example 5, in the method for manufacturing a cylindrical sputtering target, a bonding material sheet having an oxide film formed on its surface is used, and the bonding material is bonded to the backing tube using any of the jigs described above. It was found that an excellent cylindrical sputtering target free from the above-described problems can be produced by holding the sheet and forming a bonding layer in the gap between each divided target material and the backing tube.

  On the other hand, in Comparative Example 1 and Comparative Example 2, by using a molten bonding material, a bonding layer is formed in the gap between each divided target material and the backing tube by using a ring-shaped casting adapter divided into one or ten times. A cylindrical sputtering target was prepared. As a result, as shown in Table 1, the obtained cylindrical sputtering target could not obtain a desired bonding rate and bonding strength, and problems such as cracking, chipping, and peeling occurred during sputtering.

  Therefore, from Comparative Example 1 and Comparative Example 2, in the method of manufacturing a cylindrical sputtering target, when forming a bonding layer in the gap between each divided target material and the backing tube, a desired bonding material is used by using a molten bonding material. It has been found that a cylindrical sputtering target that does not have characteristics and causes the above-described problems during sputtering can be obtained.

  DESCRIPTION OF SYMBOLS 1 Cylindrical sputtering target, 2 target material (divided target material), 3 backing tube, 4 joining layer, 5 gap | interval, 6 joining material, 7 molten joining material, 8 heat resistant coating, 9 joining material sheet, 10 heat resistant masking tape 11, 12 Band heater, 13 Aluminum ring, 14 taper, 15 Tapered aluminum ring, 16 O ring (heat resistant O ring)

Claims (12)

A backing tube is coaxially arranged in the hollow part of a target material made of a cylindrical ceramic sintered body, and a heat-resistant coating is formed on the surface and one end of the bonding material that forms a bonding layer in the gap between the target material and the backing tube. Ri greens and, without forming a heat resistant coating on the other end portion of the bonding material,
The bonding material sheet , wherein the heat-resistant film has a melting point higher than that of the bonding material.   The bonding material sheet according to claim 1, wherein the heat resistant coating is an oxide coating.   The bonding material sheet according to claim 1, wherein the heat resistant coating is a heat resistant resin film. The bonding material sheet according to any one of claims 1 to 3, wherein the bonding material is an indium-based low melting point bonding material . A cylindrical sputtering target in which a backing tube is coaxially disposed in a hollow portion of a target material made of a cylindrical ceramic sintered body, and a bonding layer is formed in a gap between the target material and the backing tube to produce a cylindrical sputtering target. A manufacturing method of
Heating a bonding material sheet formed with a heat-resistant coating on the surface of the bonding material, melting the bonding material and injecting it into the gap to form a bonding layer ;
The method of manufacturing a cylindrical sputtering target, wherein the melting point of the heat resistant coating is higher than the melting point of the bonding material .   The method for manufacturing a cylindrical sputtering target according to claim 5, wherein the heat resistant coating is an oxide coating.   The method for manufacturing a cylindrical sputtering target according to claim 5, wherein the heat resistant coating is a heat resistant resin film.   The method for manufacturing a cylindrical sputtering target according to any one of claims 5 to 7, wherein a bonding material sheet obtained by processing the bonding material into a sheet shape by rolling is heated.   The method for manufacturing a cylindrical sputtering target according to any one of claims 5 to 8, wherein the bonding material sheet is installed immediately above the gap.   The method for manufacturing a cylindrical sputtering target according to claim 9, wherein the bonding material sheet is wound around an outer peripheral portion of the backing tube and fixed with a heat-resistant tape.   The method for manufacturing a cylindrical sputtering target according to claim 9, wherein the bonding material sheet is wound around an outer peripheral portion of the backing tube and fixed with a ring.   The method for producing a cylindrical sputtering target according to claim 11, wherein a ring having a taper at a lower end is fixed so that the taper is interposed between the bonding material sheet and the gap.

Images