JP6518809B1 - Sputtering target and packing method thereof - Google Patents

Abstract

The present invention provides a sputtering target that suppresses damage to the end of a cylindrical backing tube. The cylindrical sputtering target material 110 is joined to the inside of the cylindrical sputtering target material 110 with a bonding material, and the length in the central axis C direction from the length in the central axis C direction of the cylindrical sputtering target material 110 And a protective cap 130 covering the end 121 of at least one of the cylindrical backing tubes 120 in the direction of the central axis C. The protective cap 130 includes a synthetic resin. [Selected figure] Figure 1B

Description

  The present invention relates to a sputtering target and a method of packing the same.

  In recent years, with the rapid development of flat panel display (FPD: Flat Panel Display) manufacturing technology and solar cell manufacturing technology, the market for large-sized flat-screen TVs and solar cells is becoming large. In addition, with the development of these markets, in order to reduce the manufacturing cost of products, the enlargement of glass substrates is in progress. Currently, development of a device for the 2200 mm × 2400 mm size, which is said to be the eighth generation, is in progress.

  In particular, in a sputtering apparatus for forming a metal thin film or a metal oxide thin film on a large glass substrate, a flat sputtering target or a cylindrical (also referred to as rotary or rotary) sputtering target is used. The cylindrical sputtering target has advantages such as high target usage efficiency, less generation of erosion, and less generation of particles due to peeling of deposits, as compared with a flat type sputtering target. Thus, a cylindrical sputtering target is very useful as a thin film deposition application.

  Therefore, with the development of transportation and transportation means, in addition to shipping the cylindrical sputtering target in the country, cases are also shipping to overseas. Therefore, in consideration of transport distance, transportation means, environment and the like, a method that does not damage the cylindrical sputtering target product is desired.

  For example, Patent Document 1 covers a cylindrical sintered body, a cylindrical base member joined to the inner side of the sintered body via a bonding material, and openings at both ends of the base member, And a protective member (protective film) for sealing the hollow portion of the base material filled therein.

JP, 2017-179464, A

  Both ends of the base provided in the cylindrical sputtering target are provided with a seal surface on the inner peripheral surface side so that cooling water for cooling the heat generated during sputtering can be introduced. Therefore, in transportation of a cylindrical sputtering target, it is necessary not to damage this sealing surface. In addition, it is also necessary to suppress deformation of both ends of the substrate. Therefore, in particular, it is desirable to protect the end of the substrate.

  For example, the cylindrical sputtering target described in Patent Document 1 can suppress the occurrence of arcing during sputtering because dust and moisture from the outside do not adhere to the surface of the target. However, this patent does not mention protecting the end of the substrate from mechanical impact. Therefore, due to mechanical impact generated during transportation, both end portions of the base material may be in contact with the inner wall of the packaging box to cause damage to the sealing surface, or the end portion of the base material may be deformed. When the cylindrical sputtering target is used in a sputtering apparatus, there is a problem that cooling water leaks during sputtering or can not be installed in the sputtering apparatus. Thus, the means for protecting the end of the substrate (cylindrical backing tube) still has room for improvement.

  Then, this invention is created in view of the said situation, and makes it a subject to provide the sputtering target which can suppress the damage of the edge part of a cylindrical backing tube, and its packing method.

That is, according to one aspect of the present invention, a cylindrical sputtering target material is bonded to the inner side of the cylindrical sputtering target material via a bonding material, and the cylindrical sputtering target material has a longer axial direction than a length in the central axial direction. A cylindrical backing tube having a long length , and a protective cap for covering an end face, an outer peripheral surface, and an inner peripheral surface of an end of at least one of the cylindrical backing tubes in a central axial direction, the protective cap comprising: It is a sputtering target containing a synthetic resin.

  In one embodiment of the sputtering target according to the present invention, the protective cap covers both axial ends of the cylindrical backing tube.

  In one embodiment of the sputtering target according to the present invention, an axial one end of the protective cap forms a concave notch along the circumferential direction, and a central axis of at least one of the cylindrical backing tubes. The end of the direction is plugged into the cutout.

  In one embodiment of the sputtering target according to the present invention, the clearance between the outer inner peripheral surface of the cutout and the outer peripheral surface of the end portion in the central axis direction of the cylindrical backing tube is 0.1 mm or more and less than 1.0 mm. is there.

  In one embodiment of the sputtering target according to the present invention, the notch abuts on the end surface of the end portion of the cylindrical backing tube, the outer peripheral surface, and the inner peripheral surface.

  In one embodiment of the sputtering target according to the present invention, the protective cap further covers the end in the central axis direction of the cylindrical sputtering target material.

  In one embodiment of the sputtering target according to the present invention, the synthetic resin is silicone rubber, viton rubber, fluororubber, butyl rubber, acrylic rubber, ethylene propylene rubber, urethane rubber, polyester elastomer, polyolefin elastomer, fluoroelastomer, Silicone elastomer, butadiene elastomer, polyamide elastomer, polystyrene elastomer, urethane elastomer, polyurethane resin, flexible epoxy resin, fluoroplastic, polycarbonate, polypropylene, polyethylene, polyethylene terephthalate, and polyethylene naphthalate It is at least one of the

  In one embodiment of the sputtering target according to the present invention, the synthetic resin is polytetrafluoroethylene.

  In one embodiment of the sputtering target according to the present invention, the thickness of the protective cap is 2.0 mm or more.

  In one embodiment of the sputtering target according to the present invention, the thickness of the protective cap is 5.0 mm or less.

  In one embodiment of the sputtering target according to the present invention, the Young's modulus of the protective cap is 2000 MPa or less

  In one embodiment of the sputtering target according to the present invention, the cylindrical sputtering target material contains, as a main component, one selected from the group consisting of ITO, ZnO, IZO, and IGZO.

  In one embodiment of the sputtering target according to the present invention, a plurality of the cylindrical sputtering target materials are coaxially arranged.

  Further, according to another aspect of the present invention, there is provided a packing method of a sputtering target for packing the sputtering target described above, wherein the hollow portion of the cylindrical backing tube is adjusted to an inert gas or vacuum atmosphere; Forming a protective film so as to cover the openings at both ends of the mold backing tube and seal the inside of the hollow portion.

  In one embodiment of the packing method for a sputtering target according to the present invention, the pressure of the inert gas in the hollow portion is 30 to 60 kPa.

  In one embodiment of the packing method of a sputtering target according to the present invention, the inert gas is argon or nitrogen.

  In one embodiment of the packing method for a sputtering target according to the present invention, the dew point temperature of the inert gas in the hollow portion is -80 to -50 ° C.

  According to one embodiment of the present invention, damage to the end of the cylindrical backing tube can be suppressed.

It is a schematic sectional drawing for describing one Embodiment of the sputtering target which concerns on this invention. It is an enlarged view explaining a protective cap shown in Drawing 1A, and its circumference. It is an enlarged view explaining the protective cap shown in FIG. 1A. It is XX sectional drawing of FIG. 1A. It is a schematic sectional drawing which shows an example of the protective cap which is one Embodiment of the sputtering target which concerns on this invention. It is a schematic sectional drawing which shows another example of the protective cap which is one Embodiment of the sputtering target which concerns on this invention. It is a schematic sectional drawing which shows another example of the protective cap which is one Embodiment of the sputtering target which concerns on this invention. It is a schematic sectional drawing which shows another example of the protective cap which is one Embodiment of the sputtering target which concerns on this invention. It is a schematic sectional drawing which shows another example of the protective cap which is one Embodiment of the sputtering target which concerns on this invention. It is a schematic sectional drawing for describing other one Embodiment of the sputtering target which concerns on this invention. It is a flow figure showing an outline of one embodiment of a manufacturing method of a sputtering target concerning the present invention. It is a flow figure showing an outline of one embodiment of a packing method of a sputtering target concerning the present invention. It is a schematic sectional drawing which shows the sputtering target packaged by one Embodiment of the packing method of the sputtering target which concerns on this invention. It is an enlarged view explaining the protection cap of the sputtering target assembled in Examples 1-7 and comparative examples 1-3, and its circumference.

  Hereinafter, the present invention is not limited to the embodiments, and the components can be modified and embodied without departing from the scope of the invention. In addition, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in each embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, the components of the different embodiments may be combined as appropriate. The sputtering target in the present invention refers to a sputtering target with a protective cap.

As a result of intensive studies conducted by the inventor, the inventors of the present invention have a protective cap that covers at least one of the central axial ends of the cylindrical backing tube, and the protective film includes a synthetic resin. It has been found that the damage of can be suppressed.
Hereinafter, an embodiment of a sputtering target according to the present invention will be illustrated.

[1. Sputtering target]
One embodiment of a sputtering target according to the present invention will be described using the drawings. FIG. 1A is a schematic cross-sectional view for explaining an embodiment of a sputtering target according to the present invention. FIG. 1B is an enlarged view illustrating the protective cap shown in FIG. 1A and the periphery thereof. FIG. 1C is an enlarged view illustrating the protective cap shown in FIG. 1A. FIG. 2 is a cross-sectional view taken along line X-X of FIG. 1A. FIG. 3 is a schematic cross-sectional view showing an example of a protective cap which is an embodiment of a sputtering target according to the present invention. FIG. 4 is a schematic cross-sectional view showing another example of a protective cap which is an embodiment of a sputtering target according to the present invention. FIG. 5 is a schematic cross-sectional view showing another example of a protective cap which is an embodiment of a sputtering target according to the present invention. FIG. 6 is a schematic cross-sectional view for explaining another embodiment of the sputtering target according to the present invention. FIG. 7 is a schematic cross-sectional view showing another example of a protective cap which is an embodiment of a sputtering target according to the present invention.

  The sputtering target 100 is bonded to the cylindrical sputtering target material 110 and the inside of the cylindrical sputtering target material 110 via a bonding material, as shown in FIG. 1A, in the direction of the central axis C of the cylindrical sputtering target material 110. A cylindrical backing tube 120 whose length in the central axis C direction is longer than its length, and a protective cap 130 covering both ends 121 in the central axis C direction of the cylindrical backing tube 120 are provided. And the protective cap 130 contains a synthetic resin. Thus, the deformation of the end portion 121 can be suppressed without damaging the seal surface of the inner peripheral surface 121 a in the vicinity of the end portion 121 of the backing tube 120.

(Cylindrical sputtering target material)
The cylindrical sputtering target material 110 is provided to surround the outer circumferential surface 120 b of the cylindrical backing tube 120. The cylindrical sputtering target material 110 is preferably provided coaxially or substantially coaxially with the central axis C of the cylindrical backing tube 120. With such a configuration, when the sputtering target 100 is mounted on a sputtering apparatus and rotated about the cylindrical backing tube 120, the surface of the cylindrical sputtering target material 110 and the surface to be deposited (sample substrate) The intervals can be kept constant.

  The cylindrical sputtering target material 110 is formed into a hollow cylindrical shape. The relative density of the cylindrical sputtering target material 110 is preferably 99.0% or more, and more preferably 99.7% or more. In the present invention, the relative density is calculated by the Archimedes method. The average surface roughness (Ra) of the cylindrical sputtering target material 110 is preferably less than 0.5 μm from the viewpoint of suppressing abnormal discharge during sputtering.

  Furthermore, the material of the cylindrical sputtering target material 110 is not particularly limited as long as sputtering film formation is possible, and examples thereof include sintered bodies of metal oxides, metal nitrides, and metal oxynitrides. As the metal oxide, an oxide of a metal belonging to a typical element such as indium oxide, tin oxide, zinc oxide, or gallium oxide can be used.

  Specifically, a compound of tin oxide and indium oxide (Indium Tin Oxide: ITO), a zinc oxide (Zinc Oxide: ZnO), a compound of indium oxide and zinc oxide (Indium Zinc Oxide: IZO), indium oxide, zinc oxide and A compound selected from a compound of gallium oxide (Indium Gallium Zinc Oxide: IGZO) or the like can be used as the cylindrical sputtering target material 110.

(Cylindrical backing tube)
The cylindrical backing tube 120 forms a hollow portion V1 having a hollow structure on the inner peripheral surface 120a side, and has an outer surface shape along the inner peripheral surface 110a of the cylindrical sputtering target material 110, for example. The outer diameter of the cylindrical backing tube 120 is slightly smaller than the inner diameter of the cylindrical sputtering target material 110, and when the cylindrical backing tube 120 and the cylindrical sputtering target material 110 are coaxially stacked, The clearance between the cylindrical sputtering target material 110 and the cylindrical sputtering target material 110 is adjusted. A bonding material is provided in this clearance.

  The cylindrical backing tube 120 is preferably a metal that has good wettability with the bonding material and provides high bonding strength with the bonding material. For example, as a material which comprises the cylindrical backing tube 120, it is preferable to use copper (Cu) or titanium (Ti), or a copper alloy, a titanium alloy, or stainless steel (SUS). As the copper alloy, an alloy containing copper (Cu) as a main component such as chromium copper can be applied. When titanium (Ti) is used as the cylindrical backing tube 120, the lightweight and rigid cylindrical backing tube 120 can be obtained.

(Protective cap)
As shown in FIGS. 1B to 1C, the protective cap 130 has a cylindrical shape, and the inner inner circumferential surface 133b side forms a hollow portion V2 having a hollow structure, and a concave notch 131 is formed along the circumferential direction. Do. The protective cap 130 inserts the end 121 of the cylindrical backing tube 120 into the notch 131. This protects the deformation of the end 121 of the cylindrical backing tube 120 and the sealing surface of the inner peripheral surface 121 a of the end 121 of the cylindrical backing tube 120. The notch 131 preferably abuts on the end surface 121 b of the end portion 121 of the cylindrical backing tube 120, the outer peripheral surface 121 c, and the inner peripheral surface 121 a. As a result, the protective cap 130 does not come off the end 121 of the cylindrical backing tube 120 due to the vibration generated during transportation. Therefore, even if the sputtering target 100 is stored in the packaging box, the end 121 of the cylindrical backing tube 120 can be prevented from directly hitting the inner wall of the packaging box and preventing damage or rubbing. Also, the raised surface 131 b of the protective cap 130 abuts on the end surface 111 a of the end portion 111 of the cylindrical sputtering target material 110. Thereby, damage to the end portion 111 of the cylindrical sputtering target material 110 can be suppressed.

  From the viewpoint of securing the strength of the protective cap 130, the thickness D1 to D3 of the protective cap 130 is preferably 2.0 mm or more, more preferably 2.5 mm or more, and still more preferably 3.0 mm or more. Moreover, in consideration of packing the said sputtering target 100, 5.0 mm or less is preferable, 4.5 mm or less is more preferable, 4.0 mm or less is still more preferable. Here, D1 means, as shown in FIG. 2, the distance of the protective cap 130 from the outer peripheral surface 132a to the outer inner peripheral surface 132b on the line Lv extending radially outward from the central axis C of the protective cap 130. D2 means the distance of the protective cap 130 from the inner circumferential surface 133a of the protective cap 130 to the inner circumferential surface 133b. Moreover, D3 means the distance parallel to the central axis C from the concave surface 131a of the protective cap 130 to the end surface 134, as shown in FIG. 1B.

  In the protective cap 130, as shown in FIG. 3, a clearance W may be provided between the outer inner circumferential surface 132b of the notch 131 and the outer circumferential surface 121c of the end 121 of the cylindrical backing tube 120 in the central axis C direction. preferable. The clearance W is preferably 0.1 mm or more, more preferably 0.25 mm or more, and still more preferably 0.3 mm or more from the viewpoint of easily removing the protective cap 130 from the end 121 of the cylindrical backing tube 120. However, the clearance W is preferably less than 1.0 mm, more preferably 0.8 mm or less, and still more preferably 0.5 mm or less, in consideration of the fact that the protective cap 130 is not removed by vibration generated during transportation of the sputtering target 100. . Here, W is the distance from the outer inner circumferential surface 132 b of the protective cap 130 to the outer circumferential surface 121 c of the end portion 121 of the cylindrical backing tube 120 on the line extending radially outward from the central axis C of the protective cap 130. means. The inner peripheral surface 133a of the notch 131 is in contact with the inner peripheral surface 121a of the end 121 of the backing tube 120 in the direction of the central axis C from the viewpoint of protecting the sealing surface of the backing tube 120.

  Further, as shown in FIG. 4, the protective cap 130 preferably partially covers the end 121 of the cylindrical backing tube 120. That is, the end surface 111 a of the end portion 111 of the cylindrical sputtering target material 110 is separated from the raised surface 131 b of the protective cap 130 by a distance L. The distance L is preferably 5.0 mm or less from the viewpoint of protecting the end 121 of the cylindrical backing tube 120.

  The protective cap 130 preferably further covers the end 111 in the direction of the central axis C of the cylindrical sputtering target material 110 as shown in FIGS. 5 and 6. In FIG. 5, the step surface 131 b 1 is formed in the notch 131 of the protective cap 130, and the step surface 131 b 1 is in contact with the end surface 111 a of the cylindrical sputtering target material 110. The protective cap 130 extends parallel to the central axis C along the inner circumferential surface 111 b and the outer circumferential surface 111 c of the end portion 111 of the cylindrical sputtering target material 110. At that time, in the protective cap 130, it is preferable to cover the distance d1 parallel to the central axis C from the raised surface 131b of the protective cap 130 to the same position as the step surface 131b1 by 20 mm or less. Thus, damage and deformation of not only the end 121 of the cylindrical backing tube 120 but also the end 111 of the cylindrical sputtering target material 110 can be prevented more reliably. Further, in the protective cap 130, the outer peripheral surface 132a of the protective cap 130 is formed from the outer peripheral surface 111c of the end portion 111 of the cylindrical sputtering target material 110 on a line extending radially outward from the central axis C in order to soften mechanical impact. The distance d2 to reach is preferably 3 mm or more. Furthermore, as shown in FIG. 6, when the protective cap 130 is coated on the end 121 of the cylindrical backing tube 120, the outer circumferential surface 121 c of the end 121 of the cylindrical backing tube 120 is exposed to the outer inner circumferential surface 132 b of the protective cap 130. The hollow portion V3 is formed between them. Therefore, it is preferable that the protective cap 130 extends along a part of the inner circumferential surface 120 a of the cylindrical backing tube 120 from the viewpoint of not being detached by vibration generated during transportation of the sputtering target 100.

  In addition, as shown in FIG. 7, the protective cap 130 is cylindrical and forms a concave notch 131 for covering the end 121 of the backing tube 120. The hollow portion is not formed in the protective cap 130, so the hollow portion V1 of the cylindrical backing tube 120 is sealed. In such a case, it is preferable to form the through hole H (for example, φ5 mm or less) in the central axis C direction in the center of the protective cap 130 in consideration of vacuum evacuation when the sputtering target 100 is packaged. . The through holes H serve as gas flow paths for evacuating the gas present in the hollow portion V1 of the cylindrical backing tube 120 or for supplying the gas from the outside to the hollow portion V1 when the sputtering target 100 is packaged.

  The material of the protective cap 130 includes a synthetic resin that is resistant to external impact, and, for example, silicone rubber, viton rubber, fluororubber, butyl rubber, acrylic rubber, ethylene propylene rubber, urethane rubber, polyester elastomer, polyolefin elastomer , Fluorocarbon elastomer, silicone elastomer, butadiene elastomer, polyamide elastomer, polystyrene elastomer, urethane elastomer, polyurethane resin, flexible epoxy resin, fluorocarbon resin, polycarbonate, polypropylene, polyethylene, polyethylene terephthalate, and polyethylene naphthalate Can be mentioned. These may be used alone or in combination of two or more. Among them, polytetrafluoroethylene is preferable as the material of the protective cap 130 because it is chemically stable and excellent in heat resistance.

  The Young's modulus of the protective cap 130 is preferably 2500 MPa or less, more preferably 2000 MPa or less, and even more preferably 1600 MPa or less from the viewpoint of alleviating external impact. In the present invention, the Young's modulus of the protective cap 130 is measured in accordance with JIS K7127: 1999.

(Bonding material)
The bonding material is provided between the cylindrical backing tube 120 and the cylindrical sputtering target material 110. The bonding material is formed as a bonding layer 140 between them. The bonding material preferably bonds the cylindrical backing tube 120 and the cylindrical sputtering target material 110 and has good heat resistance and thermal conductivity. Moreover, since it is under a vacuum during sputtering, it is preferable to have the property that the outgassing in vacuum is small.

  Furthermore, from the viewpoint of production, the bonding material preferably has fluidity when bonding the cylindrical backing tube 120 and the cylindrical sputtering target material 110. In order to satisfy these characteristics, a low melting point metal material having a melting point of 300 ° C. or less can be used as the bonding material. For example, as the bonding material, a metal such as indium (In) or tin (Sn) or a metal alloy material containing any one of these elements may be used. Specifically, a single substance of indium or tin, an alloy of indium and tin, a solder alloy containing tin as a main component, or the like may be used.

  For example, as shown in FIG. 8, in the sputtering target 200, a plurality of cylindrical sputtering target materials 210 are coaxially arranged, and are bonded to the cylindrical backing tube 120 via a bonding material. The both ends 121 of the cylindrical backing tube 120 are covered with a protective cap 130. Note that by interposing sheet members such as a shock absorbing material between adjacent cylindrical sputtering target materials 210, damage to the end portion 211 of the cylindrical sputtering target material 210 or mechanical impact generated by transportation etc. Deformation can be suppressed.

[2. Method of manufacturing sputtering target]
Next, an embodiment of a method of manufacturing a sputtering target according to the present invention will be described using the drawings. FIG. 9 is a flow chart schematically showing an embodiment of a method of manufacturing a sputtering target according to the present invention.

  In one embodiment of the method of manufacturing a sputtering target according to the present invention, although an example in which an indium tin oxide (ITO) sintered body is a sintered body is shown, the material of the sintered body is not limited to ITO, and ZnO, IZO , IGZO and other metal oxide compounds can also be used.

  First, the raw material which comprises a sintered compact is prepared. In the present embodiment, indium oxide powder and tin oxide powder are prepared (S11, S12). The purity of these raw materials is generally 2N (99% by mass) or more, preferably 3N (99.9% by mass) or more, and more preferably 4N (99.99% by mass) or more. If the purity is lower than 2N, the sintered body contains a large amount of impurities, and thus the desired physical properties can not be obtained (for example, the transmittance of the formed thin film decreases, the resistance increases, and the particles are generated due to arcing) Problems can arise.

  Next, the powders of these raw materials are pulverized and mixed (S13). Grinding and mixing of the raw material powder may be carried out using a dry method using balls or beads (so-called media) such as zirconia, alumina, nylon resin, etc., a media stirring type mill using the balls or beads, or a medialess container It is possible to use a wet method such as a rotary mill, a mechanical agitation mill, or an air flow mill. Here, since the wet method is generally superior to the dry method in grinding and mixing ability, it is preferable to perform the mixing using the wet method.

  There is no particular limitation on the composition of the raw material, but it is desirable to adjust appropriately depending on the composition ratio of the target sintered body.

  Next, the raw material powder slurry is dried and granulated (S13). At this time, the slurry may be rapidly dried using rapid drying granulation. The rapid drying granulation may be performed by using a spray dryer and adjusting the temperature and volume of the hot air.

  Next, the mixture obtained by mixing and granulating as described above (the one which has been temporarily calcined when provided with temporary calcination) is pressure-formed to form a cylindrical shaped body (S14). By this process, it shape | molds in the shape suitable for the target sintered compact. Examples of molding processing include mold molding, cast molding, injection molding and the like, but in order to obtain a complicated shape such as a cylindrical shape, cold isostatic pressing (CIP) It is preferable to form by, for example. The pressure of molding by CIP is preferably 100 MPa or more and 200 MPa or less. By adjusting the molding pressure as described above, a molded body having a relative density of 54.5% or more can be formed. By setting the relative density of the compact to the above range, the relative density of the sintered body obtained by the subsequent sintering can be 99.7% or more.

Next, the cylindrical shaped body obtained in the forming step is sintered (S15). An electric furnace is used for sintering. The sintering conditions can be appropriately selected depending on the composition of the sintered body. For example, an ITO containing 10% by mass of SnO ₂ can be sintered by placing it in an oxygen gas atmosphere at a temperature of 1400 ° C. or more and 1600 ° C. or less for 10 hours or more and 30 hours or less. When the sintering temperature is lower than the lower limit, the relative density of the sintered body is reduced. On the other hand, when the temperature exceeds 1600 ° C., damage to the electric furnace and the furnace material is large, and maintenance is frequently required, so that the working efficiency is significantly reduced. In addition, if the sintering time is shorter than the lower limit, the relative density of the sintered body is reduced. In addition, the pressure at the time of sintering may be atmospheric pressure or may be a pressurized atmosphere.

  Next, the formed cylindrical sintered body is machined to a desired cylindrical shape using a machining machine such as a surface grinder, a cylindrical grinder, a lathe, a cutting machine, and a machining center (S16). . The machining performed here is a step of processing a cylindrical sintered body so as to have a desired shape and surface roughness, and finally, the cylindrical sputtering target material 110 is formed through this step.

  Next, the machined cylindrical sputtering target material 110 is subjected to ultrasonic cleaning treatment in pure water to remove machining grinding dust attached to the surface of the cylindrical sputtering target material 110. Subsequently, the cylindrical sputtering target material 110 is bonded (bonded) to the cylindrical backing tube 120 via the bonding material (S17). For example, when using indium as a bonding material, melted indium is injected into the gap between the cylindrical sputtering target material 110 and the cylindrical backing tube 120. Thus, the cylindrical sputtering target 100 can be obtained.

  Next, the protective cap 130 is coated on the end 121 in the central axis C direction of at least one of the cylindrical backing tubes 120 provided on the cylindrical sputtering target 100 (S18). The molding means of the protective cap 130 is not particularly limited, and injection molding (including insert molding, hollow molding, multicolor molding and the like), blow molding, compression molding, extrusion molding and the like can be mentioned.

  Thus, the cylindrical sputtering target 100 with a protective cap can be obtained.

[3. Packaging Method for Sputtering Target]
Next, an embodiment of a packing method of a sputtering target according to the present invention will be described using the drawings. FIG. 10 is a flowchart showing an outline of an embodiment of a packing method of a sputtering target according to the present invention. FIG. 11 is a schematic cross-sectional view showing the sputtering target packaged by the embodiment of the packaging method of the sputtering target according to the present invention.

  One embodiment of the packing method of the sputtering target according to the present invention is, as shown in FIG. 10, a step S21 of adjusting the inside of the hollow portion V1 of the cylindrical backing tube 120 to an inert gas or vacuum atmosphere; And forming a protective film 150 so as to cover the openings of the both end portions 121 of 120 and seal the inside of the hollow portion V1 of the backing tube 120.

(Inert atmosphere)
In order to replace the gas present in the hollow portion V1 of the cylindrical backing tube 120 with a desired gas, the gas in the hollow portion V1 is evacuated, and an inert gas is introduced into the evacuated hollow portion V1. Then, after the inert gas introduced into the hollow portion V1 is exhausted, the gas is filled into the hollow portion V1. Note that the exhaust of the gas in the hollow portion V1 and the introduction of the inert gas may be repeated a plurality of times. Thereby, the purity of the gas filled in the hollow portion V1 can be made close to the purity of the supplied gas. As a result, it is possible to fill the space with a high quality gas with little dust and moisture. And as shown in FIG. 11, the sputtering target 100 is packed by the protective film 150 in the state with which gas was filled.

As the gas to be filled in the hollow portion V1, it can be used, for example argon (Ar) or nitrogen (N _2). The pressure of the gas with which the hollow portion V1 is filled is preferably 30 kPa or more, more preferably 40 kPa or more, in consideration of the difference between the pressure of the hollow portion V1 and the atmospheric pressure outside. The pressure of the gas is preferably 60 kPa or less, more preferably 50 kPa or less, in consideration of volumetric expansion of the gas during transportation in air or the like.

  The hollow portion V1 preferably has a small amount of water. That is, it is preferable that the dew point temperature of the gas with which the hollow part V1 was filled is -80 to -50 degreeC from a viewpoint of suppressing dew condensation inside the protective film 150 depending on storage environment. By doing so, the inner side of the protective film 150 is not condensed, and it is possible to form a film without causing arcing or the like when using the sputtering target 100.

(Protective film)
For the protective film 150, a film-like resin is used. As a material of the protective film 150, it is possible to use a laminated film in which a plurality of films having different properties are laminated. For example, a laminated film in which a functional film is sandwiched between two polyethylene films can be used. The polyethylene film can use a material having a thermal melting temperature lower than that of the functional film. By the structure which a polyethylene film clamps a functional film, since polyethylene films melt | dissolve reliably at the time of heat sealing, sealing of a protective film can be performed reliably. The functional film preferably has at least one of oxygen permeability and moisture permeability lower than a polyethylene film. Further, in the functional film, it is preferable that at least one of the puncture strength and the tensile strength is higher than that of the polyethylene film.

Specifically, Unilon (registered trademark) manufactured by Idemitsu Unitech can be used as the functional film, preferably Saran Wrap (registered trademark) manufactured by Asahi Kasei Corp., and more preferably Evar (registered trademark) manufactured by Kuraray A film can be used. Here, the physical properties of the Unilon, Saran wrap, and Evar films are as follows. In addition, a functional film is not limited to the following film, A various film can be used according to the objective.
[Union]
Oxygen permeability (20 ° C 90% RH): 37 cc / d atm
Moisture permeability (40 ° C 90% RH): 90 g / m ² · day
・ Steel strength: 16.0 kgf (10.9 × 10 ^-3 MPa)
・ Tensile strength: 260MPa
[Saran Wrap]
Oxygen permeability (20 ° C 90% RH): 60 cc / d atm
Moisture permeability (40 ° C. 90% RH): 12 g / m ² · day
· Tensile strength: 470MPa
[Eval film]
-Oxygen permeability (20 ° C 90% RH): 30 cc / d atm
Moisture permeability (40 ° C. 90% RH): 5.3 g / m ² · day
・ Steel strength: 11.1 kgf (10.9 × 10 ^-3 MPa)
· Tensile strength: 40MPa

  The present invention will be specifically described based on examples and comparative examples. The descriptions of the following examples and comparative examples are merely specific examples for facilitating the understanding of the technical contents of the present invention, and the technical scope of the present invention is not limited by these specific examples. In addition, it demonstrates, using FIG. 12 which is an enlarged view explaining the protective cap of the sputtering target assembled in Examples 1-7 and Comparative Examples 1-3, and its periphery.

Example 1
First, three cylindrical sputtering target materials 210 described below and one cylindrical backing tube 120 described below were prepared. The cylindrical backing tube 120 is bonded to the inside of the cylindrical sputtering target material 210 via a bonding material so that the outer peripheral surface 121c of the end 121 of the cylindrical backing tube is exposed 9 mm in the central axis C direction, and the sputtering target I assembled 200.
<Cylindrical sputtering target material>
Cylindrical axial length: 243 mm
Cylindrical outer diameter: 153 mm
Cylinder inner diameter: 135 mm
Material: ITO
<Cylindrical backing tube>
Cylindrical axial length: 785 mm
Cylindrical outer diameter: 133 mm
Cylinder inner diameter: 126 mm
Material: Ti
<Bonding material>
Material: In

  Next, as shown in Table 1, it manufactured as follows so that average thickness D1-D3 of the protection cap 130 made from polypropylene might be 3 mm, respectively. The protective cap 130 was manufactured by injection molding.

  Protective caps 130 were coated on both ends 121 of the cylindrical backing tube 120 in the central axis C direction so that the clearance W was 0.3 mm. And the following evaluation of the said sputtering target 200 was performed.

Drop Test
First, an aluminum plate (length 300 mm × width 300 mm × thickness 10 mm) covered with a urethane material having a thickness of 20 mm was prepared. Next, the end face 121b of the backing tube 120 was dropped toward the central axis C in the direction of the central axis C from a position 300 mm away from the central plate. Next, the dropped sputtering target was recovered, the protective cap 130 was removed, and the end 121 of the cylindrical backing tube 120 and the end 211 of the cylindrical sputtering target material 210 were visually observed. The results are shown in Table 1.

(Example 2)
As shown in Table 1, evaluation and evaluation were carried out in the same manner as in Example 1 except that the clearance W was changed to 0.1 mm. The evaluation results are shown in Table 1.

(Example 3)
As shown in Table 1, evaluation and evaluation were carried out in the same manner as in Example 1 except that the thicknesses D1 to D3 of the protective cap 130 were changed to 5 mm. The evaluation results are shown in Table 1.

(Example 4)
As shown in Table 1, evaluation and evaluation were carried out in the same manner as in Example 1 except that the material of the protective cap 130 was changed to polytetrafluoroethylene (PTFE). The evaluation results are shown in Table 1.

(Example 5)
As shown in Table 1, evaluation and evaluation were carried out in the same manner as in Example 1 except that the material of the protective cap 130 was changed to silicone rubber. The evaluation results are shown in Table 1.

(Example 6)
As shown in Table 1, evaluation and evaluation were carried out in the same manner as in Example 1 except that the material of the protective cap 130 was changed to urethane rubber. The evaluation results are shown in Table 1.

(Example 7)
As shown in Table 1, evaluation and evaluation were carried out in the same manner as in Example 1 except that the cylindrical sputtering target material 210 was changed to IZO. The evaluation results are shown in Table 1.

(Comparative example 1)
Evaluation was carried out in the same manner as in Example 1 except that the clearance W was changed to 1.0 mm as shown in Table 1. The evaluation results are shown in Table 1.

(Comparative example 2)
As shown in Table 1, evaluation and evaluation were carried out in the same manner as in Example 1 except that the thicknesses D1 to D3 of the protective cap 130 were respectively changed to 1 mm. The evaluation results are shown in Table 1.

(Comparative example 3)
As shown in Table 1, evaluation and evaluation were carried out in the same manner as in Example 1 except that the material of the protective cap 130 was changed to stainless steel (SUS). The evaluation results are shown in Table 1.

  According to Table 1, in Examples 1 to 7, in the drop test, it is confirmed that the seal surface on the inner peripheral surface side of the end portion of the backing tube is not damaged and the end portion of the backing tube is not deformed did. Furthermore, it was confirmed that the end portion of the cylindrical sputtering target material was not damaged or deformed. Therefore, it may be useful to coat the end of the cylindrical backing tube with a protective cap, and the protective cap contains a synthetic resin.

100, 200 Sputtering target 110, 210 Cylindrical sputtering target material 110a Inner circumferential surface 111, 211 End 111a End face 111b Inner circumferential surface 111c Outer circumferential surface 120 Cylindrical backing tube 120a Inner circumferential surface 120b Outer circumferential surface 121 End 121a Inner circumferential surface 121b End face 121c Outer peripheral surface 130 Protective cap 131 Notch 131a Concave surface 131b1 Stepped surface 132a Outer peripheral surface 132b Outer inner peripheral surface 133a Inner inner peripheral surface 133b Inner inner peripheral surface 134 End surface 140 Bonding layer 150 Protective film C Central axis D1- D3 thickness d1, d2 distance H through hole L distance Lv line V1, V2 hollow portion W clearance

Claims (17)

Cylindrical sputtering target material,
A cylindrical backing tube joined to the inside of the cylindrical sputtering target material via a bonding material, and the length in the central axis direction is longer than the length in the central axis direction of the cylindrical sputtering target material;
A protective cap covering an end face, an outer peripheral surface, and an inner peripheral surface of at least one of axial end portions of the cylindrical backing tube;
The sputtering cap includes a synthetic resin.   The sputtering target according to claim 1, wherein the protective cap covers both axial ends of the cylindrical backing tube. One axial end of the protective cap forms a concave notch along the circumferential direction;
The sputtering target according to claim 1, wherein at least one central axial end of the cylindrical backing tube is inserted into the cutout.   4. The sputtering target according to claim 3, wherein a clearance between an outer inner peripheral surface of the notch and an outer peripheral surface of an end of the cylindrical backing tube in a central axis direction is 0.1 mm or more and less than 1.0 mm.   The sputtering target according to claim 3, wherein the notch abuts on an end surface of the end portion of the cylindrical backing tube, an outer peripheral surface, and an inner peripheral surface.   The sputtering target according to claim 3, wherein the protective cap further covers an end in a central axis direction of the cylindrical sputtering target material.   The synthetic resin includes silicone rubber, viton rubber, fluororubber, butyl rubber, acrylic rubber, ethylene propylene rubber, urethane rubber, polyester elastomer, polyolefin elastomer, fluorine elastomer, silicone elastomer, butadiene elastomer, polyamide elastomer, polystyrene 7. The elastomer according to claim 1, which is at least one selected from the group consisting of a polyurethane elastomer, a urethane elastomer, a polyurethane resin, a flexible epoxy resin, a fluorine resin, a polycarbonate, a polypropylene, a polyethylene, a polyethylene terephthalate and a polyethylene naphthalate. The sputtering target according to any one of the above.   The sputtering target according to any one of claims 1 to 6, wherein the synthetic resin is polytetrafluoroethylene.   The sputtering target according to any one of claims 1 to 8, wherein a thickness of the protective cap is 2.0 mm or more.   The sputtering target according to any one of claims 1 to 9, wherein a thickness of the protective cap is 5.0 mm or less.   The sputtering target according to any one of claims 1 to 10, wherein a Young's modulus of the protective cap is 2000 MPa or less.   The sputtering target according to any one of claims 1 to 11, wherein the cylindrical sputtering target material contains, as a main component, one selected from the group consisting of ITO, ZnO, IZO, and IGZO.   The sputtering target according to any one of claims 1 to 12, wherein a plurality of cylindrical sputtering target materials are coaxially arranged. It is a packing method of the sputtering target which packs the sputtering target of any one of Claims 1-13, Comprising:
Adjusting the inside of the hollow portion of the cylindrical backing tube to an inert gas or vacuum atmosphere;
Covering the openings at both ends of the cylindrical backing tube and forming a protective film so as to seal the inside of the hollow portion.   The method for packing a sputtering target according to claim 14, wherein the pressure of the inert gas in the hollow portion is 30 to 60 kPa.   The method for packing a sputtering target according to claim 14, wherein the inert gas is argon or nitrogen.   The packaging method of the sputtering target of any one of Claims 14-16 whose dew point temperature of the said inert gas in the said hollow part is -80 to -50 degreeC.