阅读说明：本技术 分割溅射靶 (Segmented sputter target ) 是由 矢野智泰 打田龙彦 寺村享祐 于 2020-07-30 设计创作，主要内容包括：本发明提供在溅射处理时可抑制背板的构成材料混入到成膜的薄膜中的分割溅射靶。[解决手段]所述分割溅射靶具备：基体；相邻的靶构件彼此空开间隙地被配置于上述基体的表面上的多个靶构件；设置于上述基体的表面与上述多个靶构件之间的接合材；和保护构件,其按照下述方式被设置于上述基体的表面上：至少覆盖彼此相邻的靶构件的间隙,以使上述基体表面不会从上述间隙被溅射,其中,上述保护构件具有：沿第1方向延伸的第1部分；沿与上述第1方向交叉的方向延伸的第2部分；和连接上述第1部分及上述第2部分的第3部分。(The invention provides a divided sputtering target which can prevent the constituent material of a backing plate from mixing into a formed thin film during sputtering treatment. [ solution ] the divided sputtering target comprises: a substrate; a plurality of target members disposed on the surface of the base body such that adjacent target members are spaced apart from each other; a bonding material provided between the surface of the base and the plurality of target members; and a protective member provided on the surface of the base body in the following manner: at least covering a gap between adjacent target members so that the substrate surface is not sputtered from the gap, wherein the protective member includes: a 1 st portion extending in a 1 st direction; a 2 nd portion extending in a direction intersecting the 1 st direction; and a 3 rd part connecting the 1 st part and the 2 nd part.)

1. A divided sputtering target comprising:

a substrate;

a plurality of target members disposed on the surface of the base body such that adjacent target members are spaced apart from each other;

a bonding material provided between the surface of the base and the plurality of target members; and

a protective member provided on a surface of the base body in the following manner: covering at least a gap of target members adjacent to each other so that the base surface is not sputtered from the gap,

wherein the protection member has: a 1 st portion extending in a 1 st direction; a 2 nd portion extending in a direction intersecting the 1 st direction; and a 3 rd part connecting the 1 st part and the 2 nd part.

2. The segmented sputter target of claim 1, wherein the 1 st segment, the 2 nd segment and the 3 rd segment are integrally formed.

3. The split sputtering target according to claim 1, wherein the 1 st part and the 2 nd part are made of the same material, and the 3 rd part is made of a material different from the 1 st part and the 2 nd part.

4. The divided sputtering target according to claim 1 or 2, wherein the extending direction of the 1 st segment intersects the extending direction of the 2 nd segment orthogonally.

5. The segmented sputtering target according to any one of claims 1 to 3, wherein a 3 rd portion connecting the 1 st portion and the 2 nd portion has a rounded corner portion.

6. The segmented sputtering target according to any one of claims 1 to 5, wherein the protective member has a laminated structure of 2 or more layers.

7. The sputtering target according to claim 6, wherein the outermost layer of the protective member is composed of a ceramic material or a polymer material.

8. The divided sputtering target according to claim 7, wherein the ceramic material is an oxide, nitride, fluoride, or oxyfluoride containing at least one or more selected from In, Zn, Al, Ga, Zr, Ti, Sn, Y, and Mg.

9. The segmented sputtering target according to any one of claims 1 to 8, wherein the target member is a flat plate having a substantially rectangular shape.

Technical Field

The present invention relates to a divided sputtering target, and more particularly, to a divided sputtering target in which a protective member is provided in a gap between adjacent target members so that a backing plate is not exposed.

Background

In recent years, sputtering is often used for manufacturing electronic components such as information equipment, AV equipment, and home electric appliances, and for example, in display equipment such as a liquid crystal display device, a semiconductor element such as a thin film transistor is formed by sputtering. This is due to: the sputtering method is extremely effective as a method for forming a thin film constituting a transparent electrode layer or the like over a large area with high accuracy.

In recent semiconductor devices, however, an oxide semiconductor typified by IGZO (In — Ga — Zn — O) has attracted attention instead of amorphous silicon. Further, in the oxide semiconductor, it is also desired to form an oxide semiconductor thin film by a sputtering method in the same manner as amorphous silicon. However, since the oxide semiconductor sputtering target used for sputtering is made of ceramic as a raw material, it is difficult to form a large-area target from one target member. Therefore, an oxide semiconductor sputtering target having a large area is manufactured by preparing a plurality of oxide semiconductor target members having a certain size, disposing each oxide semiconductor target member on a base called a backing plate having a desired size, and bonding the base and each target member (see, for example, patent document 1).

The backing plate of this sputtering target is usually made of copper or a copper alloy, and a low melting point solder having good heat conductivity such as an In-based or Sn-based metal is used for bonding the backing plate and the target member. For example, in manufacturing an oxide semiconductor sputtering target having a large area, a backing plate having a desired area is prepared, the surface of the backing plate is divided into a plurality of partitions, and a plurality of oxide semiconductor target members having areas corresponding to the partitions are prepared. Then, a plurality of target members are arranged on the backing plate, and the target members are bonded to the backing plate via a low-melting-point solder. In the joining, the adjacent target members are arranged so as to form a gap of 0.1mm to 1.0mm at room temperature, taking into account the difference in thermal expansion between the backing plate and the target members.

In the divided sputtering target obtained by bonding the plurality of oxide semiconductor target members, since the target members are arranged with the gap provided therebetween as described above, there is a concern that the following problems arise: in the sputtering process, the backing plate is also sputtered from the gap between the target members, and the backing plate material is mixed into the thin film of the oxide semiconductor to be formed. Thus, the following operations are performed: processing is performed so that the cross section of the end portion of each target member is inclined, and plasma does not reach the surface of the backing plate during sputtering (for example, patent document 2); further, a protective member is provided in a gap between adjacent target members so that the backing plate is not exposed (for example, patent document 3).

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2005-232580

Patent document 2: japanese laid-open patent publication No. 2-254164

Patent document 3: international publication No. 2012/063524 pamphlet

Disclosure of Invention

Problems to be solved by the invention

In the divided sputtering target as described above, the method proposed in patent document 2 and the like does not require a protective member to be provided in the gap between the divided target members, but cannot be said to be a simple method because the end portions of the divided target members need to be processed. Therefore, the method proposed in patent document 3 and the like is generally applied.

In the method proposed in patent document 3 or the like, that is, the method of providing the protective member in the gap between the adjacent target members, when the single target member is arranged on the surface of the rectangular large-area backing plate, the long protective member is prepared and cut into a desired length, and as shown in fig. 3, for example, the protective member of the 1 st portion extending in the 1 st direction and the protective member of the 2 nd portion extending in the direction intersecting the 1 st direction are produced. Next, the sputtering target can be manufactured by bonding the respective protective members to the backing plate so that the gaps between the target members correspond to the portions where the protective members are provided, and bonding the respective target members via the bonding material.

The divided sputtering target manufactured by the operation as described above is such that the 1 st part and the 2 nd part of the protective member are not bonded as shown in fig. 3, and a gap (interface) is strictly speaking present. Therefore, even when the target member is bonded, the gap of the protective member is exposed, and the constituent material of the backing plate may be mixed into the thin film to be formed during the sputtering process.

Accordingly, an object of the present invention is to provide a divided sputtering target capable of suppressing the mixing of the constituent material of the backing plate into the thin film during sputtering.

Means for solving the problems

The present inventors have studied such a problem and, as a result, have obtained the following findings: by providing the 1 st part and the 3 rd part connecting the 1 st part and the 2 nd part of the protective member, it is possible to suppress the mixing of the constituent material of the backing plate into the thin film at the time of the sputtering process. The present invention has been completed based on the knowledge. According to the present invention, the following divided sputtering target can be provided.

The divided sputtering target of the present invention comprises:

a substrate;

a plurality of target members disposed on the surface of the base body such that adjacent target members are spaced apart from each other;

a bonding material provided between the surface of the base and the plurality of target members; and

a protective member provided on the surface of the base body in the following manner: covering at least the gaps of the target members adjacent to each other so that the surface of the substrate is not sputtered from the gaps,

wherein, above-mentioned protection component 2 part and 3 rd part spare have: a 1 st portion extending in a 1 st direction; a 2 nd portion extending in a direction intersecting the 1 st direction; and a 3 rd part connecting the 1 st part and the 2 nd part.

Effects of the invention

According to the present invention, by using the protective member having the 1 st portion extending in the 1 st direction, the 2 nd portion extending in the direction intersecting with the 1 st direction, and the 3 rd portion connecting the 1 st portion and the 2 nd portion, it is possible to suppress the mixing of the constituent material of the backing plate into the thin film at the time of sputtering.

Drawings

Fig. 1 is a perspective view showing one embodiment of a divided sputtering target of the present invention.

Fig. 2 is a plan view showing a state before the target member is bonded in the production of the divided sputtering target of fig. 1.

Fig. 3 is an enlarged plan view of a portion where the 1 st portion and the 2 nd portion of the protective member intersect in the conventional divided sputtering target.

Fig. 4 is an enlarged plan view of a portion where the 1 st part and the 2 nd part of the protective member intersect in the divided sputtering target of the present invention.

Fig. 5 is an enlarged plan view showing another embodiment of a portion where the 1 st portion and the 2 nd portion of the protective member intersect.

Fig. 6 is an enlarged plan view showing another embodiment of a portion where the 1 st portion and the 2 nd portion of the protective member intersect.

Fig. 7 is an enlarged sectional view showing another embodiment of a portion where the 1 st portion and the 2 nd portion of the protective member intersect.

Fig. 8 is a perspective view showing another embodiment of a portion where the 1 st portion and the 2 nd portion of the protective member intersect.

FIG. 9 is a sectional view A-A' of the segmented sputtering target shown in FIG. 1.

Fig. 10 is an external view showing the shape of the protective member produced in example 1.

Fig. 11 is a perspective view illustrating a state in which the protective member manufactured in example 1 is bonded to a surface of a back plate.

Fig. 12 is a perspective view of the divided sputtering target produced in example 1.

Fig. 13 is an external view showing the shape of the protective member produced in example 2.

Detailed Description

A divided sputtering target according to an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a perspective view showing one embodiment of the divided sputtering target of the present invention, and fig. 2 is a plan view of a state before a target member is bonded when the divided sputtering target of fig. 1 is manufactured, as viewed from the top surface. The divided sputtering target 1 of the present invention includes: a base body 10; and a plurality of target members 20a, 20b, 20c, 20d arranged on the surface of the substrate 10 with the adjacent target members 20 spaced apart from each other by a gap 30. The divided sputtering target shown in fig. 1 is composed of 4 target members, but may be composed of 6 or more target members depending on the size of the substrate 10.

The width of the gap between the 4 target members 20a, 20b, 20c, 20d is adjusted in consideration of the difference in thermal expansion coefficient between the substrate 10 and the target members, but each target member is disposed with a gap of about 0.1 to 1.0 mm.

The 4 target members 20a, 20b, 20c, and 20d are arranged on the surface of the substrate 10 with a constant gap 30, but as shown in fig. 2, a protective member 40(401, 402, and 403) is provided on the surface of the substrate 10 so as to cover at least the gap 30. By providing the protective member 40(401, 402, 403) on the surface of the base material 10, the base material 10 can be prevented from being sputtered from the gap 30 of the target members 20 adjacent to each other. The protective member 40 may be attached to the surface of the base 10 using low-melting-point solder, conductive double-sided tape, or the like at a position corresponding to the gap 30 formed between the target members 20.

Each target member 20 is bonded to the base 10 using a bonding material (not shown). The bonding material is not particularly limited, and a known bonding material, for example, low melting point solder of In or Sn can be used as appropriate. The joining of the substrate 10 and each target member 20 is performed by: the base 10 and each target member 20 are heated to a temperature at which the bonding material melts, the bonding material is applied to the surface of the base 10, and each target member 20 is placed on the melted bonding material and cooled to room temperature.

Fig. 4 is an enlarged plan view of a portion where the 1 st part and the 2 nd part of the protective member intersect in the divided sputtering target of the present invention. The protection member 40, as shown in fig. 4, has: a 1 st portion 401 extending in a 1 st direction (left-right direction in fig. 4); a 2 nd portion 402 extending in a direction (up-down direction in fig. 4) intersecting the 1 st direction; and a 3 rd portion 403 connecting the 1 st portion 401 and the 2 nd portion 402. In the conventional divided sputtering target, for example, when manufacturing the divided sputtering target shown in fig. 1, a protective member (1 st member) corresponding to the protective member 401 and a protective member (2 nd member) corresponding to the protective member 402 are prepared, and are bonded to the surface of the base as shown in fig. 3. Therefore, the 1 st member and the 2 nd member of the protective member are not connected, and even if they are disposed so as not to generate a gap, there is a possibility that a gap (interface) exists between the 1 st member and the 2 nd member of the protective member, and the constituent material of the backing plate is mixed into the thin film at the time of sputtering. In the present invention, as shown in fig. 4, by providing the 3 rd portion 403 connecting the 1 st portion 401 and the 2 nd portion 402, the gap (interface) between the 1 st portion 401 and the 2 nd portion 402 disappears, and the constituent material of the back plate can be suppressed from being mixed into the thin film at the time of sputtering.

A protective member such as that shown in fig. 4 can be formed, for example, by connecting part 1 and part 2 402 with part 3 403. The protective member may be formed using a ceramic material or a polymer material as described below, and may be connected by the 3 rd portion 403 by welding the 1 st portion 401 and the 2 nd portion 402 formed of a ceramic material with the same ceramic material, or may be connected by the 3 rd portion 403 by melting the 1 st portion 401 and the 2 nd portion 402 formed of a polymer material with the same polymer material.

Further, in one embodiment, the protective member may also have the 1 st, 2 nd, and 3 rd portions 401, 402, and 403 integrally formed as shown in fig. 5. The integrally formed protective member shown in fig. 5 can be obtained by, for example, cutting a flat plate-like ceramic material or polymer material into a cross-letter shape as shown in fig. 5. In the case where the protective member is cut out from a flat plate-like material and integrally formed, it is preferable to perform processing such that a 3 rd portion 403 connecting a 1 st portion 401 and a 2 nd portion 402 has a rounded portion R, as shown in fig. 6. By rounding the intersection of the 1 st part 401 and the 2 nd part 402, the material constituting the back sheet can be further suppressed from being mixed into the film.

In fig. 4 to 6, an embodiment in which the extending direction of the 1 st portion and the extending direction of the 2 nd portion intersect so as to be orthogonal to each other (i.e., a cross-shaped protective member) is shown as the protective member, but the protective member is not limited thereto, and may be formed in a shape corresponding to the shape of the gap 30 formed between the target members 40.

Further, as another embodiment of the protective member, a 3 rd part 403 connecting the 1 st part 401 and the 2 nd part 402 may also be integrally formed with the 2 nd part 402 as shown in fig. 7. That is, the 3 rd portion 403 may be formed integrally with the 2 nd portion 402 so as to cover the 1 st portion 401 at the intersection of the 1 st portion 401 and the 2 nd portion 402. The protective member of the embodiment shown in fig. 7 can be manufactured by, for example, preparing 2 long protective members (401 and 402) and overlapping the 2 protective members (401 and 402) in a cross-letter shape. In this case, a portion where 2 protection members overlap may be regarded as the 3 rd portion 403. Fig. 7 is an enlarged cross-sectional view showing another embodiment of the portion where the 1 st part and the 2 nd part of the protective member intersect, but does not show an adhesive material such as a low-melting-point solder or a conductive double-sided tape when the base 10 and the protective member 40 are adhered.

With the protective member shown in fig. 7, since the 3 rd portion 403 is integrally formed with the 2 nd portion 402 in such a manner as to cover the 1 st portion 401, a level difference is generated between the upper surface of the 2 nd portion 402 and the upper surface of the 3 rd portion 403. Since the target member is disposed as shown in fig. 2 for a part of the protective member 40, when there is a level difference, it is necessary to apply a bonding material to such an extent that the level difference is buried.

As described above, when 2 elongated protection members (401 and 402) are prepared and 2 protection members (401 and 402) are overlapped in a cross-letter shape, as shown in fig. 8, a notch 401A may be formed in a part of the 1 st member 401, a notch 402A may be formed in a part of the 2 nd member 402, and the notches 401A and 402A may be fitted to each other to form the integrated protection member 40, in order to eliminate a difference in level at the intersection of the 1 st part 401 and the 2 nd part 402.

Fig. 9 shows a sectional view a-a' of the divided sputtering target 1 shown in fig. 1. As described above, the protective member 40 (the 1 st member 401) (the adhesive member is not shown) is adhered to the surface of the base 10, the bonding material 50 is provided to have a thickness approximately equal to the thickness of the protective member 40 (the 1 st member 401), and the target members 20a and 20b are disposed thereon with a predetermined gap.

The substrate 10 is also referred to as a backing plate, and the same material as that of a backing plate used in a known sputtering target can be used without particular limitation, and for example, a material having excellent electrical conductivity and excellent thermal conductivity such as a copper-based material, a titanium-based material, or an aluminum-based material can be used. Although not illustrated in fig. 9, the cooling mechanism may be provided on the back surface side of the base 10 (i.e., on the side opposite to the side on which the target members 20a and 20b are provided) so that the target members 20a and 20b can be indirectly cooled through the base 10.

The divided sputtering target in the present invention is not limited to the flat plate-shaped divided sputtering target shown in fig. 1 and the like, and may have a cylindrical shape. A flat plate-shaped divided sputtering target is a divided sputtering target in which a plurality of flat plate-shaped target members having a substantially rectangular shape are arranged on and bonded to a flat plate-shaped base. On the other hand, the cylindrical sputtering target is the following sputtering target: a sputtering target in which a plurality of cylindrical target members (hollow cylinders) are arranged and joined in a multistage manner in the direction of the cylinder axis of a cylindrical base body while penetrating the cylindrical base body; or a sputtering target in which a plurality of curved target members obtained by longitudinally cutting a hollow cylinder in the direction of the cylinder axis are arranged and bonded in the circumferential direction on the outer surface of the cylindrical base. These plate-like or cylindrical divided sputtering targets can be suitably used for a sputtering apparatus having a large area.

When a plurality of divided sputtering targets are arranged, the gap between adjacent divided sputtering targets varies depending on the difference in thermal expansion between the base material (backing plate) used and the sputtering target and the size of the divided sputtering target, but is usually arranged so as to form a gap of 0.1mm to 1.0mm at room temperature.

The shape of the target member is also not limited, but when a flat divided sputtering target is produced, a plurality of flat target members having a substantially rectangular shape are preferably used. The composition of the target member is also not particularly limited, and for example, oxides such as IGZO, ZTO, and ITO, or metals such as Al may be applied, and the composition is also not limited.

Examples of the material constituting the protective member include metal materials such AS Zn, Ti, and Sn, ceramic materials made of oxides, nitrides, fluorides, or oxyfluorides containing any one or more of In, Zn, Al, Ga, Zr, Ti, Sn, Y, and Mg, and polymer materials such AS phenol resin, melamine resin, epoxy resin, urea resin, vinyl chloride resin, polyethylene, polypropylene, polyvinyl chloride, polypropylene, polystyrene, polyvinyl acetate, ABS resin, AS resin, acrylic resin, polyacetal, polycarbonate, polyester, polyphenylene ether, polyarylate, polysulfone, polyphenylene sulfide, polyether ether ketone, polyimide resin, and fluororesin.

The protective member of the divided sputtering target shown in fig. 9 is a single layer, but the protective member may have a laminated structure of 2 or more layers. In this case, the outermost layer of the protective member is preferably made of the ceramic material or the polymer material. For example, a protective member having a 2-layer structure including a lower layer made of a metal material such as Zn, Ti, Sn, Cu, SUS, or the like and an upper layer made of a ceramic material or a polymer material may be formed. In the case where a ceramic material is used for the upper layer, the upper layer made of a ceramic material may be formed on the lower layer made of a metal material by an evaporation method, a sputtering method, a plasma spraying method, a coating method, or the like.

In the case where the protective member has a 2-layer or more laminated structure formed of different materials as described above, it is preferable that the protective member is cooled while monitoring a temperature rise or the like so that the influence of heat does not affect the protective member as much as possible when the 3 rd portion 403 connecting the 1 st portion 401 and the 2 nd portion 402 is formed by welding as shown in fig. 4. By performing the joining in this manner, even when different materials are laminated, the interlayer peeling caused by the difference in thermal expansion between the two materials can be suppressed. If the protective member is partially peeled off, the base material is exposed or the lower layer of the protective member is exposed, and in some cases, the constituent material of the base material or the lower layer of the protective member may be mixed into the thin film to be formed during sputtering.

The thickness of the protective member is preferably 0.0001mm to 1.0 mm. The width of the protective member is not particularly limited as long as it can cover the gap formed between the adjacent target members, but is preferably 5mm to 20mm, and more preferably 10 to 20mm, in consideration of workability and the like.

The divided sputtering target of the present invention can be applied to either of the dc sputtering method and the high-frequency sputtering method, but is particularly suitable for the dc sputtering method because generation of particles can be suppressed.

Examples

Next, embodiments of the present invention will be specifically described with reference to the following examples, but the present invention is not limited to these examples.

< preparation of Back sheet >

As a back plate, a copper plate having a diameter of 110mm and a thickness of 6mm was prepared.

< preparation of target Member >

In is mixed with₂O₃、Ga₂O₃And ZnO in a molar ratio of 1: 1: 2, and the mixture was weighed and mixed, and the mixture was mixed with a ball mill for 20 hours. Next, a polyvinyl alcohol aqueous solution diluted to 4 mass% as a binder was added to the mixed raw material powder so that the total amount of the mixed raw material powder became 8 mass%, and the mixture was mixed, and then the mixture was mixed at 500kgf/cm²Is molded under the pressure of (3). Then, the mixture was fired at 1450 ℃ for 8 hours in the air to obtainTo a plate-like sintered body. Both surfaces of the obtained sintered body were polished by a flat grinder to produce an IGZO target member having a diameter of 101mm and a thickness of 5 mm. The obtained circular target member was cut into 4 circular arc members so as to form an arc having a center angle of 90 degrees.

< preparation of protective Member >

A copper plate having a thickness of 0.3mm was prepared, and ZrO was thermally sprayed on one surface of the copper plate₂The upper layer is made of ZrO₂A2-layer structure of a protective member 1 having a lower layer made of Cu is formed.

< example 1>

With respect to the protective member 1 obtained as described above, 1 protective member having a width of 20mm and a length of 110mm and 2 protective members having a width of 20mm and a length of 45mm were prepared. Next, these 3 protective members were arranged so as to form a cross character as shown in fig. 10, and the long protective member and the short protective member were joined by welding. Further, welding is performed carefully while monitoring the temperature rise of the protective member by using a welding rod capable of narrowing the welding width.

Next, the protective member 1 having a cross-letter shape obtained by the above-described operation is bonded to the surface of the back plate with an adhesive interposed therebetween as shown in fig. 11.

Next, as shown In fig. 12, 4 pieces of target members were bonded to the backing plate via a low melting point solder (not shown) containing In, and a divided sputtering target was produced. At this time, the target members were arranged so that the gap between the target members became 0.5 mm.

< example 2>

A divided sputtering target was produced in the same manner as in example 1, except that the protective member 1 was cut out so as to have a cross-letter shape as shown in fig. 13.

< example 3>

In the production of the protective member 1, Al is thermally sprayed on one surface of a copper plate₂O₃Instead of spraying ZrO₂Otherwise, the protection member 2 was produced in the same manner. Next, a divided sputtering target was produced in the same manner as in example 1, except that the protective member 2 was used instead of the protective member 1.

< comparative example 1>

A divided sputtering target was produced in the same manner as in example 1, except that the long protective member and the short protective member were not joined by welding. Further, the gap between the longer protective member and the shorter protective member at this time was 0.8 mm.

< sputtering evaluation test >

The sputtering evaluation test described below was performed on each of the divided sputtering targets obtained as described above.

First, an IGZO thin film having a thickness of 14 μ M was formed on a glass substrate (EAGLE XG (registered trademark), manufactured by Corning Incorporated) by using a sputtering apparatus (EX-3013M, manufactured by vacuum machine industries, Ltd.). Next, a portion directly above the intersection of the ten characters corresponding to the divided sputtering target was cut out from the glass substrate after the film formation.

The thin film on the surface of the cut glass substrate was subjected to atomic absorption spectroscopy, and the amount of Cu mixed in the IGZO thin film was measured. The amount of Cu in the IGZO thin film produced using each divided sputtering target is as shown in table 1.

[ Table 1]

As shown in table 1, when a protective member having a 1 st portion extending in a 1 st direction, a 2 nd portion extending in a direction intersecting the 1 st direction, and a 3 rd portion connecting the 1 st portion and the 2 nd portion was produced (examples 1 to 3), the amount of Cu mixed into the IGZO film was less than 2 mass ppm (not more than the detection limit of atomic absorption spectroscopy). On the other hand, in the case of producing a conventional protective member not having the 3 rd section connecting the 1 st section and the 2 nd section (comparative example 1), the amount of Cu mixed into the IGZO film was 15 mass ppm at the intersection.

From the above evaluation results, it is clear that: according to the divided sputtering target of the present invention, impurities can be effectively prevented from being mixed into the thin film to be formed. Therefore, it can be said that the divided sputtering target of the present invention is useful for forming a thin film having a large area.

Description of the symbols

1 divided sputtering target

10 base (backboard)

20. 20a, 20b, 20c, 20d target members

30 gap

40 protective member

50 joining material

401 protecting part 1 of a component

402 protection of part 2 of the Member

403 part 3 of the protection Member

401A part 1 gap

402A portion 2 indentation.