KR20220139301A - sputtering target - Google Patents

Abstract

In the sputtering target provided with the structure in which the thickness of the target member adjacent with the gap|interval differs from each other, it makes it possible to prevent mixing of the constituent material of a base material in a thin film. A target member comprising a plurality of target members, a substrate having a step, and a protection member provided between the target member and the substrate, wherein the target member disposed in the step portion of the substrate having a step has different thicknesses and different thicknesses. A sputtering target in which the edge part of the target member of the one of the smaller thickness has the part (this protruding part is called "protrusion part") which protruded rather than the step|step difference part of a base material among members is proposed.

Description

sputtering target

This invention relates to the sputtering target provided with the structure formed by providing and arrange|positioning the clearance gap between the adjacent target members.

Sputtering is one method of thin film formation technology. As an example of this, an inert gas such as Ar is introduced into a vacuum, a negative voltage is applied to the target member to generate a glow discharge, and the inert gas is ionized into a plasma by the glow discharge to form gas ions, and the gas ions is made to collide with the surface of the target member at high speed to make the particles of the film forming material constituting the target member bounce off, and these particles are adhered and deposited on the surface of the substrate forming the thin film, thereby forming a dense and strong thin film on the surface of the substrate. A method of forming is mentioned.

According to this sputtering method, in addition to being able to form a film even with a material that is difficult to form a film in a vacuum deposition method, such as a high-melting-point metal, alloy, ceramics, etc., a thin film having a large area can be formed with high precision, for example, information It is widely used in the manufacture of various electronic components, such as an apparatus, an AV apparatus, and a home appliance. Especially, thin films, such as ITO, IZO, and IGZO formed by the sputtering method, are widely used as an electrode of the display device centering on a liquid crystal display, a touch panel, EL display, etc.

In recent years, with the enlargement of a display panel, it came to be calculated|required to form the thin film which has a large area, and it was necessary to enlarge a target member also. By the way, it is difficult to form the target member used for sputtering from one target member which consists of a large area. Therefore, what is set as a sputtering target of a large area is employ|adopted by dividing a target member into a some target member, and joining a some target member on a base material (for example, refer patent document 1).

In this way, the target divided into a plurality of target members (also referred to as a “sputtering target”) is disposed on the substrate so that a gap is created between adjacent target members in order to avoid collision of the target member due to thermal expansion, It is common to join this base material and each target member with low-melting-point solder with favorable heat conduction, such as an In-type or Sn-type metal.

In addition, in such a divided sputtering target, since a gap is provided and disposed between the adjacent target members, the base material is exposed in the gap, and the base material is also sputtered in a very small amount during sputtering to form a film. There was concern that the constituent materials of the base material would mix in the thin film. Therefore, providing a protection member in the clearance gap between adjacent target members, and preventing a base material from being exposed in this clearance gap is proposed (for example, refer patent document 2, 3).

Japanese Patent Laid-Open No. 2005-232580 International Publication No. 2012/063523 pamphlet International Publication No. 2012/063524 pamphlet

In magnetron sputtering, the non-uniformity of the magnetic field strength affects, so that the distribution of ion current density on the magnetron cathode is non-uniform. Therefore, distribution of a sputtering rate became non-uniform|heterogenous, and there existed a case where consumption of a target member differed depending on the place. Specifically, for example, in the case of a flat target member, since it exists in the tendency for the sputtering rate in an edge part to become high, consumption of the edge part of a target member may become especially quick.

So, conventionally, as shown in FIG.6, FIG.7, compared with the thickness of the target member 3 of a center part, by increasing the thickness of the target member 3 of an edge part, the target life of an edge part is extended, and the target of a target Lowering the exchange frequency is being done. And in that case, in order to flatten a sputtering surface, it is common to make the thickness of the base material 2 arrange|positioned on the back side of the target member 3 also different across 2 C of steps|steps which consist of a vertical surface.

However, in this case, since the step portion 2C of the substrate 2 is exposed with the gap 4 interposed therebetween, when forming a thin film by sputtering, the step portion ( 2C) was sputtered, and there existed a subject that the constituent material (for example, Cu etc.) of the base material 2 will mix in the thin film formed into a film through the gap|interval 4 .

An object of the present invention is to provide a new sputtering target capable of preventing the constituent material of a base material from mixing in a thin film in a sputtering target having a structure in which the thicknesses of adjacent target members with a gap therebetween.

The present invention is a sputtering target provided with a plurality of target members and a step substrate, comprising a protection member provided between the target member and the substrate, and the target member disposed in a stepped portion of the step substrate, , having different thicknesses, and among the target members having different thicknesses, the end of the target member having the smaller thickness has a portion protruding from the step portion of the substrate (the protruding portion is referred to as a “projection”). suggest a target.

In the sputtering target proposed by the present invention, the end of the target member with a smaller thickness, that is, the target member on the step side of the substrate, is protruded from the step portion of the substrate, so that the step is covered with a protective member. Even if it does not exist, it is possible to prevent the constituent materials of the substrate (eg, Cu, etc.) from mixing into the thin film.

BRIEF DESCRIPTION OF THE DRAWINGS It is a top view which shows an example of the sputtering target of this invention.
It is a partial sectional perspective view which shows typically the structural example of an example of the sputtering target of this invention.
FIG. 3 is a partially enlarged cross-sectional view illustrating an enlarged part of FIG. 2 .
4 is a partially enlarged cross-sectional view schematically showing a sputtering target modification of the present invention.
5 is an example of the sputtering target of the present invention, showing the sputtering target produced in the embodiment, (A) is its plan view, (B) is its cross-sectional view, (C) is a part (B) of the dotted line It is a partially enlarged cross-sectional view of the part surrounded by ).
6 is a partial cross-sectional perspective view schematically showing a configuration example of an example of a conventional sputtering target.
FIG. 7 is a partially enlarged cross-sectional view illustrating an enlarged part of FIG. 6 .

Next, the present invention will be described based on examples. However, the present invention is not limited to the embodiments described below.

<Bone sputtering target>

In the sputtering target (referred to as "this sputtering target") 1 according to an example of the embodiment of the present invention, as shown in Figs. A plurality of target members 3, 3... are provided in), and a gap 4 is provided between the adjacent target members 3 and 3 . The base material 2 and the target member 3 are joined by a bonding material.

Moreover, the protection member 5 is provided between the said target member 3 and the said base material 2 along the clearance gap 4 between the target members 3 and 3 .

In addition, this sputtering target 1 has the same target member 3 (3A) and 3 (3A) as the target members 3 (3A) and the target member 3 with the same thickness of the adjacent target member sandwiching the gap|interval. Like (3A) and 3 (3B), the thickness of the target member adjacent across the clearance gap 4 is provided with different thicknesses.

The surface of some target member 3, 3... is arrange|positioned so that it may become flat, ie, at the same height.

This sputtering target 1 has shown the flat shape. However, the overall shape of the sputtering target of this invention is arbitrary, for example, a cylindrical shape may be sufficient.

When the sputtering target of this invention shows a cylindrical shape, the several target members 3 and 3 of cylindrical shape are penetrated, and the target member 3 adjacent to the surface side of the cylindrical base material 2, for example. , 3) may be provided in a multi-stage arrangement in the axial direction of the cylinder by providing a gap 4 between them. Moreover, the curved target member 3 which divided|segmented the cylinder longitudinally in the column axial direction may be arrange|positioned on the outer side surface of the cylindrical base material 2 in parallel in a circumferential direction. However, it is not limited to such a structure.

(Structure of a portion in which the adjacent target members 3 and 3 have the same thickness)

In the part where the thickness of the adjacent target members 3 and 3 is the same, the target members 3 (3A, 3 (3A)) adjacent to the sputtering surface side of the thickness part with the base material 2 are uniform are the clearance gaps 4 ), and along the gap 4, a protection member 5 is disposed between the target member 3 and the base material 2, and the target member 3 and the base material ( 2) is joined by a bonding material 6 .

The width of the gap 4 between the adjacent target members 3 (3A, 3A), in other words, the distance between the opposing tip ends of the adjacent target members 3A, 3A is 0.1 mm to 0.6 mm desirable.

Since the width|variety of the said clearance gap 4 is 0.1 mm or more, since it can prevent that target member 3 (3A), 3 (3A) collides and cracks due to thermal expansion, it is preferable. Since the target member does not sputter that much and abnormality arises in a film|membrane characteristic when distance becomes larger than 0.6 mm, it is preferable that it is 0.6 mm or less.

From such a viewpoint, the width of the gap 4 is preferably 0.1 mm or more, and more preferably 0.15 mm or more, and more preferably 0.2 mm or more. On the other hand, it is preferable that it is 0.6 mm or less, Especially, it is 0.5 mm or less, Especially, it is more preferable that it is 0.4 mm or less.

In addition, if this sputtering target 1 is equipped with the part from which the thickness of adjacent target members 3 (3A), 3 (3B) differs from each other, as shown, for example in FIG. 5, it will always be adjacent The thicknesses of the target members 3 (3A) and 3 (3A) to make do not need to be provided with the mutually equal part.

(Structure of parts with different thicknesses of adjacent target members 3 and 3)

On the other hand, in the part from which the thickness of the adjacent target members 3 and 3 differs, as shown in FIG. 3, the target member 3 (3A), 3 (3B) which adjoins across the clearance gap 4 The thickness is different, and the thickness of the base material 2 on the back side of these target members 3 (3A) and 3 (3B) also differs across the level|step difference part 2C. That is, the thickness of the base material 2 also differs across 2 C of steps|steps so that the height of the sputtering surface of adjacent target member 3A, 3B may become the same. In addition, the target member 3A with a smaller thickness is in a state in which the inside of the gap 4 protrudes toward the other target member 3B side rather than the step portion 2C of the base material 2 (this part is "Protrusion 3A a").

Among the base materials 2, a part with a large thickness is called "base material 2A", and a part with a small thickness is called "base material 2B" with step 2C interposed therebetween.

That is, this sputtering target 1 has the base material 2 from which thickness differs with the step part 2C interposed therebetween, and the some target member 3, 3... laminated|stacked on the surface side of the base material 2, have. Among them, 3 A of target members are laminated|stacked on 2 A of thick base materials, and the edge part of this target member 3A protrudes from 2 C of steps|steps, and is arrange|positioned. The target member 3B arrange|positioned across 3 A of target members and the clearance gap 4 is arrange|positioned so that the surface may become the same height as the surface of 3 A of target members.

In addition, on the surface of the base material 2A, the protective member 5 is disposed from the rising surface of the step 2C to a predetermined width from the edge on the back side of the target member 3A. It is constructed so that the surface is not exposed.

Although the standing surface of the step 2C is exposed, since the protrusion 3Aa of the target member 3A serves as a awning, the magnetron, gas ions, etc. entering from the gap 4 collide with the standing surface. It is difficult to do so, and the said rising surface of the level difference 2C is made difficult to sputter|spatter.

It is normal to provide the part from which the thickness of the adjacent target members 3 and 3 differs in the edge part area|region of this sputtering target 1, as shown in FIG. Since there exists a tendency for a sputtering rate to become high in the edge part area|region of a target member and consumption of a target member is quick, by enlarging the thickness of the target member of an edge part area|region, target life can be extended and replacement frequency of a sputtering target can be lowered|hung.

However, the place which provides the part from which the thickness of the adjacent target members 3 and 3 differs is arbitrary.

The protrusion width x of the protrusion 3Aa, in other words, the distance x between the step 2C of the base material 2A and the tip end of the protrusion 3Aa of the target member 3A, and in other words, the step 2C of the base material 2A ) and the distance x between the gap 4 is preferably 1 mm to 20 mm.

If the protruding width x is 1 mm or more, the position of the gap 4 is spaced apart from the stepped portion 2C of the substrate 2A by that much, and it is preferable because the stepped portion 2C is less likely to be sputtered. On the other hand, if the protruding width x is 20 mm or less, the cooling efficiency of the protrusion 3Aa is lowered, and the occurrence of abnormalities such as cracks or arcing due to the local heating of the protrusion 3Aa by sputtering can be prevented. It is preferable because

From this point of view, the projected width x is preferably 1 mm or more, more preferably 3 mm or more, especially 4 mm or more, and more preferably 5 mm or more. On the other hand, it is preferable that it is 20 mm or less, Especially, it is 15 mm or less, Especially, it is more preferable that it is 12 mm or less.

In addition, since it is preferable to adjust the protrusion width x of the protrusion 3Aa according to the height z of the step 2C in the base 2, it is 30 to 500% of the height z of the step 2C. Among them, 50% or more or 400% or less, and more preferably 100% or more or 300% or less among them.

The width y of the gap 4 of adjacent target members 3A, 3B, in other words, the distance y between the edge part of the protrusion part 3Aa in the target member 3A, and the edge part 3Ba of the target member 3B is It is preferably 0.1 mm to 0.6 mm.

Since the width y of the clearance gap 4 of target member 3A, 3B is 0.1 mm or more, since it can prevent that target member 3A, 3B collides and cracks due to thermal expansion, it is preferable. Since the target member does not sputter that much and abnormality arises in a film|membrane characteristic when distance becomes larger than 0.6 mm, it is preferable that it is 0.6 mm or less.

From such a viewpoint, it is preferable that the width y of the clearance gap 4 of target member 3A, 3B is 0.1 mm or more, Especially, it is 0.15 mm or more, Especially, it is more preferable that it is 0.2 mm or more. On the other hand, it is preferable that it is 0.6 mm or less, Especially, it is 0.5 mm or less, Especially, it is more preferable that it is 0.4 mm or less.

In addition, the structure of the part from which the thickness of the adjacent target members 3 and 3 differs is the same as the structure of the part with the same thickness of the adjacent target members 3 and 3 in points other than the above.

Although the thickness of the target member 3 (target member 3A, 3B is included) is not specifically limited, It is normal that they are 2 mm - 20 mm, It is preferable that they are 4 mm or more or 14 mm or less among them.

(heat transfer layer (7))

Moreover, it is preferable to provide the heat transfer layer 7 which consists of a material with higher thermal conductivity than the said target member 3A at least on the back surface of 3 Aa of protrusions of 3 A of said target members.

By providing the heat transfer layer 7 made of a material with high thermal conductivity on the back surface of the protrusion 3Aa, a cooling effect of suppressing the temperature rise of the protrusion 3Aa during sputtering can be imparted, and as a result, cracking It is possible to suppress the occurrence of arcing or arcing and also the discoloration of the protrusion 3Aa. Incidentally, it is thought that it is only the protrusion 3Aa that the temperature may rise.

At this time, when 3 A of target members are made from ceramics, indium, various metals, an alloy, etc. are mentioned as a material with higher thermal conductivity than 3 A of target members. Among them, the bonding material 6 for bonding the substrate 2 and the target member 3 is usually made of a material with high thermal conductivity, such as indium. , it is preferable to form the heat transfer layer 7 made of the bonding material 6 .

(Reference (2))

As for the base material 2, what shows a plate shape or a cylindrical shape is mentioned. However, it is not limited to these shapes.

If the base material 2 is provided with a portion having a large thickness (base material 2A) and a portion having a small thickness (base material 2B) with a step portion 2C interposed therebetween, it is integrally formed by one member in the thickness direction. may be used, or a plurality of members may be laminated in the thickness direction to form the stepped portion 2C.

For example, by excising a part of one member, a portion having a large thickness (base material 2A) and a portion having a small thickness (base material 2B) can be provided with the step portion 2C interposed therebetween.

Moreover, another member can be laminated|stacked on one member, and the large thickness part (base material 2A) and the small thickness part (base material 2B) can be provided with the stepped part 2C interposed therebetween.

The thickness of the base material 2 is not specifically limited.

On the other hand, it is preferable to determine the thickness of the part (base material 2B) with small thickness according to the thickness of these target members 3A, 3B so that the sputtering surface of target member 3A, 3B may become the same height. That is, it is preferable to make it the sum total of the thickness of 3 A of target members, and the thickness of the base material 2A, and the sum total of the thickness of the target member 3B, and the thickness of the base material 2 become the same.

The material of the base material 2 may just be a single metal, such as Ti, SUS, or Cu, or those alloys. However, it is not limited to these.

<Target member (3)>

As for the target member 3, what shows a plate shape or cylindrical shape is mentioned. However, it is not limited to these shapes.

In addition, it is preferable to determine the difference of the thickness of target member 3A and 3B according to the specification of a sputtering installation. Although it can select suitably according to the difference of the sputtering rate which generate|occur|produces by the magnetic force distribution etc. of the magnet provided on the back surface of a target, it is preferable that it is normally 30 % - 100% of 3 A of target members. When the difference is too small compared to the difference in the sputtering rate, the replacement frequency cannot be effectively lowered.

The target member 3 does not specifically limit the material. For example, a metal or oxide containing at least one of Cu, Al, In, Sn, Ti, Ba, Ca, Zn, Mg, Ge, Y, La, Al, Si, Ga, W ceramics").

Examples of the oxide include In-Sn-O, In-Ti-O, In-Ga-Zn-O, Ga-Zn-O, In-Zn-O, In-WO, In-Zn-WO, Zn-O, Sn-Ba-O, Sn-Zn-O, Sn-Ti-O, Sn-Ca-O, Sn-Mg-O, Zn-Mg-O, Zn-Ge-O, Zn-Ca- O, Zn-Sn-Ge-O, Cu ₂ O, CuAlO ₂ , CuGaO ₂ , CuInO ₂ and the like.

(protective member (5))

The protection member 5 is interposed between the target member 3 and the base material 2 along the gap 4 between the adjacent target members 3 and 3, and is exposed in the gap 4 It is arrange|positioned so that the surface of the base material 2 may be covered.

Since the protective member 5 covers the exposed surface of the substrate 2, during sputtering, the surface of the substrate 2 is sputtered in the gap 4, and the constituent material of the substrate 2 is formed into a film. Mixing in the thin film can be prevented.

Examples of the shape of the protective member 5 in plan view include a rectangular shape, a band shape, a cross band shape, and a lattice frame shape. However, it is not limited to the shape at the time of seeing these in planar view.

In addition, as shown in FIG. 4, the protective member 5 may show an L-shape so that it may cover|cover 2 C of steps|steps as a cross-sectional shape.

The thickness of the protective member 5 is not specifically limited. However, from a viewpoint of handling, it is preferable that it is 100 micrometers or more, Especially, it is 200 micrometers or more, Especially, it is more preferable that it is 300 micrometers or more. On the other hand, from a viewpoint of the thickness of a bonding layer, it is preferable that it is 1000 micrometers or less, Especially, it is 900 micrometers or less, Especially, it is more preferable that it is 800 micrometers or less.

The protective member 5 may have a single-layer structure or a multi-layer structure formed by laminating two or more layers in the thickness direction.

It is preferable that the material for the case where the protective member 5 has a single-layer structure and the material for the surface layer in the case of the multi-layer structure be composed of a material that does not adversely affect even if mixed into the thin film to be formed, or a material capable of suppressing sputtering phenomenon. do.

As a material which does not adversely affect even if it mixes in the thin film to form into a film, for example, all or a part of the element which comprises the composition of the target member 3, an alloy, an oxide containing these elements, etc. can be used.

On the other hand, as a material capable of suppressing the sputtering phenomenon, for example, a material having a larger volume resistance than the target member 3, ie, a high resistance material, can be used as the material for the gap arrangement member. When such a high-resistance material is used as the material of the gap arrangement member, it is preferable that the volume resistivity (Ω·cm) of the high-resistance material has a value of 10 times or more of the volume resistivity of the target member 3 .

As a specific example of a material for the case where the protective member 5 has a single-layer structure and a material for a surface layer in the case of a multi-layer structure, a metal material, a ceramic material, or a polymer material, or these two types constituting the target member 3 . The above composite materials are mentioned.

At this time, as a ceramic material, it is the ceramic material which consists of the same composition as the target member ₃ , or a part composition consists of the same material as the target member ₃ , or ceramics with high volume resistance, such as ZrO2 _and Al2O3. material is preferred. If it is a ceramic material with high volume resistance, entry of plasma to a divided part at the time of sputtering is suppressed, and sputtering of Zr or Al can be prevented effectively.

Here, as a metal material which comprises said target member 3, if the target member 3 is IGZO (In-Ga-Zn-O), for example, any 1 or more types of metal material of In, Zn, and Ga. What is necessary is just to be sufficient, and if the target member 3 is IZO (In-Zn-O), what is necessary is just In or a metal material of Zn.

Examples of the ceramic material described above include a material made of an oxide or nitride containing at least one of In, Zn, Al, Ga, Zr, Ti, Sn, and Mg. Specific examples thereof include In ₂ O ₃ , ZnO, Al ₂ O ₃ , ZrO ₂ , TiO ₂ , IZO, IGZO, and the like, and ZrN, TiN, AlN, GaN, ZnN, and InN.

On the other hand, the material of the back layer in the case where the protective member 5 has a multilayer structure is preferably a material that has a small difference in the coefficient of linear expansion with the base material 2 and is difficult to react with the bonding material 6 (eg, In solder).

From this viewpoint, a metal material, a ceramic material, or these composite materials are mentioned. Examples of the metal material include a single metal of any one of Cu, Al, Ti, Ni, Zn, Cr, and Fe, or an alloy containing any of these.

Further, when the protective member 5 has a multilayer structure of three or more layers, the intermediate layer preferably has good bonding properties to the surface layer and the back layer, and the coefficient of linear expansion of the material constituting the intermediate layer is the coefficient of linear expansion of the material constituting the surface layer and the back layer. It is desirable to design it to be an intermediate value of .

(bonding material (6))

The base material 2 and the target member 3 and the base material 2 and the protection member 5 are mutually joined by the bonding material 6 .

As the bonding material 6, if it can be used for bonding of the target member 3 of this kind and the base material 2, it will not specifically limit. For example, solder metals or solder alloys, such as In metal, In-Sn metal, or In alloy metal which added trace metal components to In are mentioned.

<Use>

This sputtering target can be used suitably as a sputtering target at the time of forming an oxide semiconductor thin film into a film, etc., for example. However, it is not limited to this use.

<Manufacture of this sputtering target>

A plurality of protection members 5 are disposed on the surface of the base material 2 at predetermined intervals, and both are joined by a bonding material 6 .

Next, the bonding material 6 is apply|coated to the back surface side of the target member 3, and the some target member 3 is provided between the target members 3 and 3 adjacent to the front side of the protection member 5. A gap 4 is provided and arranged. At this time, it arrange|positions so that the protection member 5 may be interposed between the target member 3 and the base material 2 along the clearance gap 4, and the protection member 5, the base material 2, and the target member 3 are joined together. What is necessary is just to join by (6).

At this time, it is preferable to apply|coat the bonding material 6 which consists of a material whose thermal conductivity is higher than the target member 3A also to the back surface of the protrusion part 3Aa of the said target member 3A as mentioned above.

As the bonding material 6, a material having a higher thermal conductivity than that of the target member 3A is selected, and the bonding material 6 is applied to the back surface of the protruding portion 3Aa to provide a heat transfer layer 7, whereby at the time of sputtering, the protruding portion ( The cooling effect which suppresses the temperature rise of 3Aa can be provided, and, as a result, generation|occurrence|production of arcing and discoloration of the protrusion part 3Aa can be suppressed.

However, such a method is an example of the manufacturing method of this sputtering target 1, and is not limited to this method.

<Explanation of Phrase>

In the present specification, when expressed as "X to Y" (X and Y are arbitrary numbers), "preferably greater than X" or "preferably greater than X" or "preferably greater than X" together with the meaning of "X or more and Y or less" unless otherwise specified. It also includes the meaning of "smaller than Y".

In addition, when expressed as "X or more" (X is an arbitrary number) or "Y or less" (Y is an arbitrary number), the intent is also "preferably greater than X" or "preferably less than Y" include

In addition, when expressed as "X≤" (X is an arbitrary number) or "Y≥" (Y is an arbitrary number), the intent of "It is preferable that it is X<" or "It is preferable that it is Y>" also includes

Example

Hereinafter, the present invention will be described based on Examples. However, this invention is not limited to the Example demonstrated here.

<Example 1>

As shown in FIG. 5, the target members 3A and 3B adjacent to each other with the gap 4 therebetween have different thicknesses, and using the substrate 2 having different thicknesses with the stepped portion 2C therebetween is used. , a disk-shaped sputtering target 1 having a diameter of 152.4 mm was produced.

The target members 3A and 3B were manufactured as follows.

Raw material In ₂ O ₃ , Ga ₂ O ₃ , and each raw material powder of ZnO was weighed at a mol ratio of 1:1:2, and mixed with a ball mill for 20 hours. Then, an aqueous polyvinyl alcohol solution diluted to 4% by mass as a binder was added and mixed in an amount of 8% by mass based on the total amount of powder, and then molded into a disk shape at a pressure of 500kgf/cm ² . The molded body was subjected to a firing treatment at 1400° C. in the air to obtain a disc-shaped sintered body. And this sintered compact was grind|polished on both surfaces with the plane grinder, and the disk processed object of diameter 152.4mm x thickness 10mm and diameter 152.4mm x thickness 5mm was manufactured. Then, according to the division|segmentation position, the disk processed body was cut in half, respectively, and the target member 3A made from IGZO of thickness 5mm, and the target member 3B made from IGZO of thickness 10mm were manufactured.

As the base material 2, it is made of oxygen-free copper (Cu), a step portion 2C having a height of 5 mm is provided in the central portion, and a thick portion having a thickness of 10 mm and a thin portion having a thickness of 5 mm are provided. A disk-shaped substrate having a diameter of 180 mm was prepared.

As the protection member 5, what formed the layer which consists of 100 _- micrometer _- thick Al2O3 by thermal spraying on the strip|belt-shaped Cu metal foil of thickness 0.5mm and width 20mm was used.

On the entire back surface of the target member 3A, In, which is made of the same material as that of the bonding material 6, and which is a low-melting-point solder, was applied beforehand. That is, the back surface of the protrusion part 3Aa of 3 A of target members formed the heat transfer layer 7 which consists of In.

And the target members 3A, 3B on the base material 2 so that mutual sputtering surfaces may become the same height, and provide the clearance gap 4 of width y 0.5mm between the target members 3A, 3B. While arranging, it has arrange|positioned so that the edge part of 3 A of target members with a smaller thickness may protrude from 2 C of steps|steps of the base material 2 . At this time, it arrange|positions so that the width x of the protrusion part 3Aa, in other words, the distance x between the stepped part 2C and the clearance gap 4 may become 5 mm. And the target members 3A, 3B and the base material 2 were joined by the bonding material 6 which consists of In which is a low melting-point solder, and the sputtering target 1 (sample) was produced.

<Example 2>

The sputtering target 1 (sample) was produced similarly to Example 1 except not having previously apply|coated In which is a low-melting-point solder to the back surface of the protrusion part 3Aa of 3 A of target members.

<Example 3>

The sputtering target 1 (sample) was produced similarly to Example 1 except width x of 3 A of protrusion parts of 3 A of target members being set to 10 mm.

<Example 4>

The sputtering target 1 (sample) was produced similarly to Example 3 except not having previously apply|coated In which is a low-melting-point solder to the back surface of the protrusion part 3Aa of 3 A of target members.

<Example 5>

The sputtering target 1 (sample) was produced similarly to Example 1 except having made it width x of 3 A of protrusions 3A of target member set to 20 mm.

<Example 6>

The sputtering target 1 (sample) was produced similarly to Example 5 except not having previously apply|coated In which is a low-melting-point solder to the back surface of the protrusion part 3Aa of 3 A of target members.

<Comparative Example 1>

Implementation except that the end of the target member 3A is arranged so that it does not protrude from the step portion 2C of the base material 2, and the distance x between the step portion 2C and the gap 4 is 0 mm. As in Example 1, a sputtering target (sample) was produced.

=Evaluation of the produced sputtering target=

The sputtering targets (samples) produced in Examples and Comparative Examples were evaluated as follows.

<Sputter evaluation test>

(Cu content)

Using the sputtering target (sample) produced in Examples and Comparative Examples, sputtering was performed under the following conditions, an IGZO thin film having a thickness of 14 µm was formed on an alkali-free glass substrate (manufactured by Nippon Denki Glass Corporation), and a substrate with an IGZO thin film was formed got it

And in this IGZO thin film-equipped board|substrate, the part immediately above the said clearance gap 4 corresponded to the clearance gap 4 of a sputtering target (sample) is cut out, and Cu which is a constituent material of a base material is an IGZO thin film by atomic absorption analysis. The amount contained in it (referred to as "Cu mixing amount") was measured.

(Sputtering conditions)

Device: DC magnetron sputter device, exhaust system cryopump, rotary pump

Reached vacuum: 3×10 ^-6 Pa

Sputter pressure: 0.4Pa

Oxygen partial pressure: 1×10 ^-3 Pa

Input wattage time: 2W/cm ²

Time: 10 hours

(arcing evaluation)

In addition, using an arcing counter (manufactured by LANDMARK TECHNOLOGY, format: μArc Monitor MAM Genesis MAM data collector Ver.2.02), the number of arcing generated in 10 hours is measured, and less than 120% of the number of arcing in the target without division. When it was "less", when it was 120 to 150%, it was evaluated as "medium", and when it was more than 150%, it was evaluated as "many".

(Evaluation of discoloration of protrusions)

In addition, by observing the appearance of the gap located in the erosion part after sputtering, it was evaluated whether or not discoloration was black.

It is estimated that this discoloration occurred because the target material was deformed as a result of local temperature rise without cooling of the protrusion.

From the above Examples and Comparative Examples and the test results performed by the present inventor so far, the thicknesses of the target members adjacent to each other with a gap therebetween are different and the sputtering surfaces of these adjacent target members have the same height. In a configuration in which the thickness of the base material on the back side of the target member differs across the step portion, by making the end of the target member having the smaller thickness protrude from the step portion of the base material, the step portion is covered by the protective member It has been found that even if there is not, it is possible to prevent the constituent materials of the substrate (eg, Cu, etc.) from being mixed into the thin film.

In addition, in the target member having a smaller thickness, since the bonding material does not contact the portion that protrudes from the step portion of the substrate, that is, the back surface of the projecting portion, the cooling effect of the bonding material cannot be obtained, and cracks or arcing may occur. There is this.

Therefore, as in Examples 1, 3, and 5, it can be seen that by coating the same material as the bonding material on the back surface of the protrusion to form a heat transfer layer, a cooling effect can be obtained and the occurrence of arcing can be suppressed. there was.

Furthermore, it was also found that a cooling effect can be obtained and discoloration can be prevented by forming a heat transfer layer by applying the same material as the bonding material on the back surface of the protrusion.

1: Sputtering target
2: description
2A: Substrate
2B: substrate
2C: step part
3: Target member
3A: target member
3B: target member
3Aa: protrusion
4: Gap
5: no protection
6: Bonding material
7: heat transfer layer

Claims (11)

A sputtering target provided with a plurality of target members and a step base material, the target member having a protective member provided between the target member and the base material, and the target member disposed in the step portion of the step base material, the thickness of each other The sputtering target is different, and among the target members having different thicknesses, the end of the target member having the smaller thickness has a portion (this projecting portion is called a “projection”) that protrudes from the step portion of the substrate. According to claim 1,
The sputtering target according to claim 1, wherein the protruding portion has a width of 1 mm to 20 mm protruding from the step portion of the substrate. 3. The method of claim 1 or 2,
The sputtering target of which the width|variety formed by protruding from the said protrusion part rather than the step|step difference part of a base material is 3 mm or more. 4. The method according to any one of claims 1 to 3,
The sputtering target of which the width|variety formed by protruding from the said protrusion part rather than the step|step difference part of a base material is 4 mm or more. 5. The method according to any one of claims 1 to 4,
The sputtering target of which the width|variety formed by protruding from the said protrusion part rather than the step part of a base material is 5 mm or more. 6. The method according to any one of claims 1 to 5,
The sputtering target of which the width|variety formed by protruding from the said protrusion part from the step|step difference part of a base material is 15 mm or less. 7. The method according to any one of claims 1 to 6,
The sputtering target of which the width|variety formed by the said protrusion protruding from the step|step difference part of a base material is 12 mm or less. 8. The method according to any one of claims 1 to 7,
The sputtering target provided with the layer which consists of a material whose thermal conductivity is higher than the said target member at least on the back surface of the said protrusion part. 9. The method according to any one of claims 1 to 8,
The sputtering target in which the said material with high thermal conductivity is the same material as the bonding material which joins the said target member and the said base material. 10. The method according to any one of claims 1 to 9,
The sputtering target whose said target member is a product made from ceramics. 11. The method according to any one of claims 1 to 10,
The sputtering target used for film-forming of an oxide semiconductor thin film.

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