JP2013147368A - Ceramic cylindrical sputtering target material, and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow reduction of the generation of arcing and particle during sputtering when a ceramic cylindrical sputtering target material is used in a magnetron rotating cathode sputtering apparatus or the like, because the ceramic cylindrical sputtering target material has no divided parts or few numbers thereof over the entire target material since the ceramic cylindrical sputtering target material is a one-piece article having a high density and a length of ≥500 mm, and does not need to be used by stacking a large number of sputtering target materials long-sized.SOLUTION: A ceramic cylindrical sputtering target material has a length of ≥500 mm and a relative density of ≥95%, and is a one-piece article, and is made of an ITO having a Sn content of 1 to 10 mass% in terms of SnO.

Description

  The present invention relates to a ceramic cylindrical sputtering target material and a manufacturing method thereof, and more particularly to a high-density and long ceramic cylindrical sputtering target material and a manufacturing method thereof.

  A magnetron type rotary cathode sputtering device has a magnetic field generator inside a cylindrical target, and performs sputtering while rotating the target while cooling from the inside of the target. The entire surface of the target material becomes erosion and becomes uniform. It is shaved. For this reason, the use efficiency of the flat plate type magnetron sputtering apparatus is 20 to 30%, while the magnetron type rotary cathode sputtering apparatus can obtain a remarkably high use efficiency of 60% or more. Further, by rotating the target, it is possible to input a larger power per unit area as compared with the conventional flat plate type magnetron sputtering apparatus, so that a high deposition rate can be obtained.

  In recent years, glass substrates used in flat panel displays and solar cells have been enlarged, and in order to form a thin film on the enlarged substrate, a long cylindrical target exceeding 3 m in length is required. ing.

  Such a rotary cathode sputtering method is widely used for metal targets that can be easily processed into a cylindrical shape and have high mechanical strength. However, since the ceramic target material has low strength and is brittle, cracks and deformation are likely to occur during production. For this reason, in a ceramic target, although a short cylindrical target material could be manufactured, a long cylindrical target material with high performance could not be manufactured.

  In Patent Document 1, in a long cylindrical target produced by stacking short cylindrical target materials, each target material is bonded on the basis of the outer peripheral surface of the cylindrical target, and the steps generated in the divided portions of the target are detected. A technique for suppressing arcing and particle generation due to a step by making the thickness 0.5 mm or less is disclosed. However, in this technique, when the cylindrical target material is short, a long cylindrical target cannot be obtained unless a large number of target materials are stacked. The number increases. If there is a divided portion, the occurrence of arcing due to the divided portion is inevitable even if there is no step. For this reason, in the technique in which the number of division parts is large, the number of occurrences of arcing increases. In addition, since discharge concentrates on the divided portions during sputtering, if the number of divided portions is large, cracks starting from the divided portions are likely to occur during sputtering. Bonding a large number of target materials takes time and is inefficient in manufacturing.

  In Patent Document 2, in firing a hollow cylindrical ceramic sintered body, the ceramic molded body is mounted on a plate-shaped ceramic molded body having a sintering shrinkage rate equivalent to that of the ceramic molded body. Disclosed is a technique for preventing cracking during firing and obtaining a fired body having a relative density of 95% or more by placing and firing. However, even in this technique, when a ceramic powder is molded, degreased and fired to produce a long cylindrical ceramic sintered body having a length of 500 mm or more, cracking occurs in any of the steps of molding, degreasing or firing. There was a problem.

  Patent Document 3 discloses a technique for manufacturing an ITO cylindrical target material having a length of 500 mm or more by a thermal spraying method. However, the cylindrical target material obtained by the thermal spraying method cannot increase the relative density, and the relative density is at most about 70%. When sputtering is performed using a target material having a low relative density, the number of occurrences of arcing increases. For this reason, when sputtering is performed using a long cylindrical target material obtained by a thermal spraying method, the number of occurrences of arcing increases.

JP 2010-1000093 A JP 2005-281862 A JP-A-10-68072

  An object of the present invention is to provide a high-density and long ceramic cylindrical sputtering target material.

  The present inventor has found a method of manufacturing a ceramic cylindrical sputtering target material that does not generate cracks or deformation during manufacturing even if the formed body is long, and manufactures a high-density and long ceramic cylindrical sputtering target material. Succeeded in doing.

That is, the present invention is a ceramic cylindrical sputtering target material having a length of 500 mm or more and a relative density of 95% or more and being an integral product.
The ceramic cylindrical sputtering target material preferably has an outer diameter of 140 mm or more and an inner diameter of 130 mm or more.

The ceramic cylindrical sputtering target material is, for example,
The content of Sn is 1 to 10% by mass in terms of SnO _2, made of ITO,
Made of AZO having an Al content of 0.1 to 5% by mass in terms of Al ₂ O ₃ , or an In content of 40 to 60% by mass in terms of In ₂ O ₃ , and a Ga content of Ga ₂ It can be made from IGZO having a content of 20 to 40% by mass in terms of O ₃ and a Zn content of 10 to 30% by mass in terms of ZnO.

The present invention also provides:
A ceramic cylindrical sputtering target comprising the ceramic cylindrical sputtering target material bonded to a backing tube with a bonding material.

The present invention also provides:
Step 1 for preparing granules from a slurry containing ceramic raw material powder and an organic additive,
Step 2 for producing a cylindrical shaped body by CIP molding the granules,
Step 3 for degreasing the molded body, and Step 4 for firing the degreased molded body.
A method for producing a ceramic cylindrical sputtering target material comprising:
In the step 1, the amount of the organic additive is 0.1 to 1.2% by mass with respect to the amount of the ceramic raw material powder.

  In the method for producing the ceramic cylindrical sputtering target material, the organic additive preferably contains a binder, and the binder is polyvinyl alcohol having a polymerization degree of 200 to 400 and a saponification degree of 60 to 80 mol%.

  Since the ceramic cylindrical sputtering target material of the present invention is an integral product having a length of 500 mm or more, it is not necessary to stack a large number of sputtering target materials to make them long. For this reason, when the ceramic cylindrical sputtering target material of the present invention is used in a magnetron rotary cathode sputtering apparatus or the like, there are no divided parts in the entire target or the number thereof is small, so that arcing or particles are generated during sputtering. Few. Moreover, since the ceramic cylindrical sputtering target material of the present invention has a high density, there is little arcing during sputtering.

  The method for producing a ceramic cylindrical sputtering target material of the present invention can efficiently produce the ceramic cylindrical sputtering target material without causing cracks or deformation.

<Ceramics cylindrical sputtering target material>
The ceramic cylindrical sputtering target material of the present invention has a length of 500 mm or more and a relative density of 95% or more, and is an integral product. An integral product does not consist of a plurality of parts, but means that the entire target material is a single article that is not divided as an object. Therefore, the ceramic cylindrical sputtering target material of the present invention is distinguished from a cylindrical target material having a length of 500 mm or more formed by stacking or joining a plurality of cylindrical target materials.

The ceramic cylindrical sputtering target material of the present invention can be manufactured, for example, by a manufacturing method described later.
As mentioned above, ceramic target materials are low in strength and brittle, so the conventional sintering method produces cracks, deformations, etc. during manufacturing, and manufactures an integrated ceramic cylindrical sputtering target material with a length of 500 mm or more. I couldn't. For this reason, conventionally, a long cylindrical sputtering target material having a length of less than 500 mm has to be connected to form a long cylindrical sputtering target material. With such a configuration, since the number of divided portions generated between the target material and the target material increases, when sputtering is performed using the target material having this configuration, the number of occurrences of arcing due to this divided portion Will increase.

  Since the ceramic cylindrical sputtering target material of the present invention is a long body integrally having a length of 500 mm or more, it is not necessary to connect a large number of target materials to form a long body. In the ceramic cylindrical sputtering target material of the present invention, depending on the required length, sputtering can be performed using only one, or sputtering can be performed by connecting a plurality. When sputtering is performed using only one, since there is no divided portion, arcing due to the divided portion does not occur. Even when sputtering is performed by connecting a plurality of pieces, since the ceramic cylindrical sputtering target material constituting the same has a length of 500 mm or more, the target length can be obtained with a small number. For this reason, since the number of division | segmentation parts is few compared with the case where many short target materials are connected and a long cylindrical sputtering target material is formed, the frequency | count of the occurrence of arcing resulting from a division | segmentation part is few.

  In the conventional thermal spraying method, it is possible to produce a long ceramic cylindrical sputtering target material having a length of 500 mm or more integrally, but the cylindrical target material obtained by the thermal spraying method has a high relative density. 70%. For this reason, when sputtering is performed using a cylindrical target material obtained by a thermal spraying method, the number of occurrences of arcing increases. Since the ceramic cylindrical sputtering target material of the present invention has a relative density of 95% or more, the number of arcing generated during sputtering is smaller than that of the cylindrical target material obtained by the thermal spraying method.

  The ceramic cylindrical sputtering target material of the present invention has a length of 500 mm or more, preferably 750 mm or more, more preferably 1000 mm or more, and further preferably 1500 mm or more. When sputtering is performed using one target material of the present invention, the longer the target material, the larger the area of film formation becomes possible, and arcing due to the divided portions does not occur. When performing sputtering by connecting a plurality of target materials of the present invention, the longer the target material, the smaller the number of the target materials, the desired length can be reduced, and the number of divided portions can be reduced, resulting in the divided portions. The number of occurrences of arcing can be reduced.

  The upper limit of the length of the ceramic cylindrical sputtering target material of the present invention is not particularly limited, but is about 3400 mm due to limitations of the magnetron rotary cathode sputtering apparatus.

  The ceramic cylindrical sputtering target material of the present invention preferably has an inner diameter of 100 mm or more. When the inner diameter is as described above, efficient film formation is possible by the rotary cathode sputtering method.

  The roundness, cylindricity and runout tolerance of the ceramic cylindrical sputtering target material of the present invention are preferably within 1 mm, more preferably within 0.5 mm, and even more preferably within 0.1 mm. The smaller the roundness, the cylindricity, and the runout tolerance, the more preferable arcing is unlikely to occur.

  The ceramic cylindrical sputtering target material of the present invention has a relative density of 95% or more, preferably 99% or more, more preferably 99.5% or more. As the relative density of the target material is higher, the target material can be prevented from cracking due to thermal shock or temperature difference during sputtering, and the target material thickness can be effectively utilized without waste. In addition, generation of particles and arcing is reduced, and good film quality can be obtained. The upper limit of the relative density is not particularly limited, but is usually 100%.

  There are no particular limitations on the type of ceramic that is the material of the ceramic cylindrical sputtering target material of the present invention. For example, indium oxide-tin oxide-based material (ITO), aluminum oxide-zinc oxide-based material (AZO), and indium oxide- Examples thereof include gallium oxide-zinc oxide based materials (IGZO).

When the ceramic is ITO, the Sn content in the target material is preferably 1 to 10% by mass, more preferably 2 to 10% by mass, and further preferably 3 to 10% by mass in terms of SnO _2. . When the Sn content is within the above range, there is an advantage that the target material has low resistance.

When the ceramic is AZO, the content of Al in the target material is preferably 0.1 to 5% by mass, more preferably 1 to 5% by mass, and further preferably 2 to 5% in terms of Al ₂ O ₃ content. % By mass. When the Al content is within the above range, there is an advantage that the target material has low resistance.

When the ceramic is IGZO, the content of In in the target material is 40 to 60% by mass in terms of In ₂ O ₃ , the content of Ga is 20 to 50% by mass in terms of Ga ₂ O ₃ , Zn The content of is preferably 5 to 30% by mass in terms of ZnO, the content of In is 40 to 55% by mass in terms of In ₂ O ₃ , and the content of Ga is 25 to 25% in terms of Ga ₂ O _3. More preferably, the content of 35% by mass and the content of Zn is 15 to 30% by mass in terms of ZnO, the content of In is 40 to 50% by mass in terms of In ₂ O ₃ and the content of Ga is Ga ₂ O. More preferably, it is 25 to 35% by mass in terms of ₃ amounts, and the content of Zn is 20 to 30% by mass in terms of ZnO. When the contents of In, Ga and Zn are within the above ranges, there is an advantage that good TFT (Thin Film Transistor) characteristics can be obtained by sputtering.
<Ceramics cylindrical sputtering target>
The ceramic cylindrical sputtering target of the present invention is formed by bonding the ceramic cylindrical sputtering target material to a backing tube with a bonding material.

  The backing tube usually has a cylindrical shape to which a ceramic cylindrical sputtering target material can be bonded. There is no restriction | limiting in particular in the kind of backing tube, According to target material, it can select and use from the conventionally used backing tube suitably. For example, examples of the material for the backing tube include stainless steel and titanium.

  There is no restriction | limiting in particular also in the kind of said bonding material, According to the target material, it can select from the conventionally used bonding material suitably, and can use it. For example, the bonding material may be indium solder or the like.

  One ceramic cylindrical sputtering target material may be joined to the outside of one backing tube, or two or more may be joined on the same axis. When two or more pieces are joined side by side, the gap between the ceramic cylindrical sputtering target materials, that is, the length of the divided portion is usually 0.05 to 0.5 mm, preferably 0.05 to 0.3 mm, more preferably 0. .05 mm. As the length of the divided portion is shorter, arcing is less likely to occur during sputtering. However, if it is less than 0.05 mm, the target materials may collide and break due to thermal expansion during bonding or sputtering.

There is no restriction | limiting in particular also in the bonding method, The method similar to the conventional ceramic cylindrical sputtering target can be employ | adopted.
<Method for manufacturing ceramic cylindrical sputtering target material>
The method for producing the ceramic cylindrical sputtering target material of the present invention,
Step 1 for preparing granules from a slurry containing ceramic raw material powder and an organic additive,
Step 2 for producing a cylindrical shaped body by CIP molding the granules,
Step 3 for degreasing the molded body, and Step 4 for firing the degreased molded body.
A method for producing a ceramic cylindrical sputtering target material comprising:
In the step 1, the amount of the organic additive is 0.1 to 1% by mass with respect to the amount of the ceramic raw material powder.

By this manufacturing method, the ceramic cylindrical sputtering target material of the present invention can be efficiently manufactured without generating cracks or deformations.
In this production method, the organic additive preferably contains a binder, and the binder is preferably polyvinyl alcohol having a degree of polymerization of 200 to 400 and a degree of saponification of 60 to 80 mol%.
(Process 1)
In step 1, granules are prepared from a slurry containing ceramic raw material powder and an organic additive.

  By preparing granules from the ceramic raw material powder and the organic additive and subjecting the granules to the CIP molding in Step 2, the filling property of the raw materials is improved, and a high-density molded body can be obtained. Further, uneven filling is less likely to occur, and uniform filling is possible. Uneven press is less likely to occur.

The ceramic raw material powder is a powder capable of producing ceramics which are constituent materials of the target material by this manufacturing method.
For example, when the ceramic is ITO, a mixed powder of In ₂ O ₃ powder and SnO ₂ powder can be used as the ceramic raw material powder. The ITO powder can be used alone or mixed with In ₂ O ₃ powder and SnO ₂ powder. May be used. In ₂ O ₃ powder, SnO ₂ powder and ITO powder each have a specific surface area of usually 1 to 40 m ² / g measured by BET (Brunauer-Emmett-Teller) method. The mixing ratio of the In ₂ O ₃ powder, the SnO ₂ powder, and the ITO powder is appropriately determined so that the content of the constituent elements in the target material is within the above-described range. In this production method, when a mixed powder of In ₂ O ₃ powder and SnO ₂ powder is used as a ceramic raw material powder, the content (mass%) of the SnO ₂ powder in the ceramic raw material powder is finally obtained. It is confirmed that it can be equated with the Sn content (mass%) in terms of SnO ₂ content.

When the ceramic is AZO, a mixed powder of Al ₂ O ₃ powder and ZnO powder can be used as the ceramic raw material powder, and the AZO powder can be used alone or mixed with Al ₂ O ₃ powder and ZnO powder. Also good. The Al ₂ O ₃ powder, ZnO powder, and AZO powder each have a specific surface area of usually 1 to 40 m ² / g measured by the BET method. The mixing ratio of the Al ₂ O ₃ powder, the ZnO powder, and the AZO powder is appropriately determined so that the content of the constituent elements in the target material is within the above range. In this production method, when a mixed powder of Al ₂ O ₃ powder and ZnO powder is used as the ceramic raw material powder, the content (mass%) of the Al ₂ O ₃ powder in the ceramic raw material powder is finally obtained. It has been confirmed that it can be equated with the Al content (mass%) in terms of Al ₂ O ₃ content in the material.

When the ceramic is IGZO, a mixed powder of In ₂ O ₃ powder, Ga ₂ O ₃ powder and ZnO powder can be used as the ceramic raw material powder, and the IGZO powder alone or In ₂ O ₃ powder, Ga ₂ it may be mixed with O ₃ powder and ZnO powder. In ₂ O ₃ powder, Ga ₂ O ₃ powder, ZnO powder and IGZO powder each have a specific surface area measured by the BET method of usually 1 to 40 m ² / g. The mixing ratio of the In ₂ O ₃ powder, the Ga ₂ O ₃ powder, the ZnO powder, and the IGZO powder is appropriately determined so that the content of the constituent elements in the target material is within the above range. In this production method, when a mixed powder of In ₂ O ₃ powder, Ga ₂ O ₃ powder and ZnO powder is used as the ceramic raw material powder, In ₂ O ₃ powder, Ga ₂ O ₃ powder and ZnO powder in the ceramic raw material powder are used. The content (mass%) of In is the In content (mass%) in terms of In ₂ O ₃ in the target material finally obtained, and the Ga content (mass% in terms of Ga ₂ O ₃ ). ) And Zn content (% by mass) in terms of ZnO, it has been confirmed that it can be equated.

  When ceramic raw material powder obtained by mixing two or more kinds of powders having different particle diameters is used, powder particles with small particle diameters enter between powder particles with large particle diameters, which increases the density of the compact. There is an advantage that the strength of the sintered body is also improved.

There are no particular limitations on the method of mixing the powder, and for example, each powder and zirconia balls can be placed in a pot and ball mill mixed.
The organic additive is a substance added in order to suitably adjust the properties of the slurry and the molded body. Examples of the organic additive include a binder, a dispersant, and a plasticizer.

  In step 1, the amount of the organic additive is 0.1 to 1.2% by mass, preferably 0.2 to 1.0% by mass, more preferably 0.4 to 0%, based on the amount of the ceramic raw material powder. 0.8% by mass. When the blending amount of the organic additive is more than 1.2% by mass, the strength of the molded body during the removal of the solvent is greatly reduced, and it becomes easy to degrease and cracks. It may be difficult to increase the density. When the said compounding quantity of an organic additive is less than 0.1 mass%, sufficient effect of each component may not be acquired. When the blending amount of the organic additive is within the above range, a ceramic cylindrical sputtering target material having a length of 500 mm or more and a relative density of 95% or more can be manufactured.

  The binder is added to bind the ceramic raw material powder in the molded body and increase the strength of the molded body. As a binder, the binder normally used when obtaining a molded object in the well-known powder sintering method can be used.

  Among them, polyvinyl alcohol (PVA) is preferable, and polyvinyl alcohol having a polymerization degree of 200 to 400 and a saponification degree of 60 to 80 mol% is preferable. When such a binder is used, even if the amount of the binder added is small, granules that are easily crushed at the time of CIP molding are prepared. As a result, it is possible to produce a long ceramic cylindrical target material with high density without causing cracks or deformation. For example, when the blending amount of the organic additive is within the above range and the binder is further used, an integrated ceramic cylindrical target material can be stably produced with a length of 750 mm or more and a relative density of 95% or more.

  Generally, when an attempt is made to produce a long ceramic cylindrical target material by the steps of forming, degreasing and firing ceramic powder, cracks occur in any of the steps of forming, degreasing and firing. For this reason, in the conventional manufacturing method, it was not possible to manufacture an integrated ceramic cylindrical target material having a length of 500 mm or more and a relative density of 95% or more. In the case of a CIP molded body, cracking at the time of molding is considered to occur because the springback force increases when it is long or large. In the case of a cast-molded body, it is considered that cracks are caused by moisture unevenness and particle segregation. Increasing the binder amount can eliminate molding cracks, but increasing the binder amount causes the cylindrical molded body to become brittle and crack during degreasing or firing. Excessive binder addition is not preferable because the binder is segregated and becomes a starting point of degreasing cracks.

  In the production method of the present invention, by using the above-mentioned binder, a molded body that is difficult to break can be obtained by adding a small amount of binder, even if it is a long molded body. Hard to break. That is, when the binder is used, cracks are unlikely to occur in any of the steps of molding, degreasing and firing, and a long ceramic cylindrical target material can be stably obtained.

The reason why such an effect can be obtained by using the binder is considered as follows.
For example, when preparing a granule by spray drying a slurry containing raw material powder, a binder and water, in the droplets formed by spraying the slurry, water moves to the outside of the droplets by drying, and together with the raw material powder And the binder also moves outside the droplet. Water volatilizes out of the droplet, and as a result, the raw material powder and the binder are densely aggregated on the surface of the droplet to form granules having a hard coating. This granule becomes hollow because the raw material powder, the binder and water move to the outer peripheral portion, and the hollow portion has a negative pressure. The granules sink, trying to eliminate the pressure difference. Such depressed granules are stiff and are not easily crushed during molding. For this reason, a molded object is not densified but produces the coarse defect used as the starting point of a crack. It is considered that this is the main cause of the occurrence of cracks when producing a long shaped body.

  When a binder having a polymerization degree of 200 to 400 is used, a slurry having a low viscosity is obtained with little entanglement of the polymer that is a component of the binder. When a binder with a low binder degree is used with a constant binder ratio, a slurry having a low viscosity and a high concentration of raw material powder is produced. For this reason, since there is little movement of water in the droplets during spraying of the slurry, the inside of the granule is not easily hollowed out and is not easily depressed. Since the entanglement of the binder in the granule is small, the binding force of the binder is weak, and the granule is easily crushed. Further, when the high-concentration slurry is sprayed, the raw material powder and the binder cannot be aggregated on the surface portion of the droplet, so that the surface portion is difficult to be dense and the strength of the granules is lowered. For these reasons, it is considered that a ceramic body powder that is densely filled with CIP molding can be obtained that is difficult to break.

  When a binder having a low saponification degree of 60 to 80 mol% is used, in the slurry composed of the raw material powder, the binder and water, the hydrophobic group of the binder is adsorbed to the powder, and a highly dispersible slurry is obtained. When the slurry is sprayed at a temperature equal to or higher than the cloud point, the binder precipitates in a short time and does not move to the outside of the liquid droplets, so the granules are dried with the binder uniformly dispersed throughout the granules, and granules with low surface strength are obtained. It is done. For these reasons, it is considered that a ceramic body powder that is densely filled with CIP molding can be obtained that is difficult to break.

  As described above, granules having a lower degree of polymerization and saponification of polyvinyl alcohol, which is a binder, can be easily crushed. For this reason, it is preferable that the polymerization degree of polyvinyl alcohol as a binder is 400 or less and the saponification degree is 80 mol% or less. On the other hand, when the degree of polymerization and the degree of saponification are too small, the resulting molded product becomes too soft and the handling properties are lowered. For this reason, it is preferable that the polymerization degree of polyvinyl alcohol as a binder is 200 or more and the saponification degree is 60 mol% or more. The polyvinyl alcohol as the binder has a polymerization degree of 250 to 350 and a saponification degree of 65 to 75 mol%, more preferably a polymerization degree of 280 to 320 and a saponification degree of 68 to 72 mol%.

  The addition amount of polyvinyl alcohol as a binder is preferably 0.1 to 1.0% by mass, more preferably 0.1 to 0.65% by mass, and still more preferably 0.1 to 0. 3% by mass. As the amount of polyvinyl alcohol added increases, plasticity increases and molding cracks are less likely to be cracked. On the other hand, the strength reduction of the molded body during removal of the solvent increases, and it becomes easier to degrease cracks. , It may be difficult to increase the density. For this reason, the said range is suitable.

  The dispersant is added to increase the dispersibility of the raw material powder and the binder in the slurry. Examples of the dispersant include ammonium polycarboxylate and ammonium polyacrylate.

  The plasticizer is added to increase the plasticity of the molded body. Examples of the plasticizer include polyethylene glycol (PRG) and ethylene glycol (EG).

  There is no restriction | limiting in particular in the dispersion medium used when preparing the slurry containing ceramic raw material powder and an organic additive, According to the objective, it can select from water, alcohol, etc. suitably and can be used.

  The method for preparing the slurry containing the ceramic raw material powder and the organic additive is not particularly limited. For example, a method in which the ceramic raw material powder, the organic additive, and the dispersion medium are placed in a pot and ball mill mixed can be used.

There is no restriction | limiting in particular in the method of preparing a granule from a slurry, For example, a spray drying method, a rolling granulation method, an extrusion granulation method etc. can be used. Of these, the spray-drying method is preferable because the granules have high fluidity and are easy to produce granules that are easily crushed during molding. The conditions of the spray drying method are not particularly limited, and can be carried out by appropriately selecting the conditions usually used for granulating the ceramic raw material powder.
(Process 2)
In step 2, the granules prepared in step 1 are CIP-molded (Cold Isostatic Pressing) to produce a cylindrical shaped body. When a molded body is produced by CIP molding, it is possible to obtain a long cylindrical molded body having a uniform density and less directivity, which is difficult to break even when degreasing and firing.

  As a mold used for CIP molding, there is a mold that can be used to produce a long cylindrical molded body that is usually used for CIP molding, such as a cylinder having a cylindrical core (mandrel) that can be sealed up and down. A urethane rubber mold having a shape can be used.

Pressure during CIP molding is usually 800 kgf / cm ² or more, preferably 1000 kgf / cm ² or more, more preferably 3000 kgf / cm ² or more. The higher the pressure, the denser the granules, and the higher the density and strength of the molded body. There is no particular limitation on the upper limit of the pressure during CIP molding, and it is usually 5000 kgf / cm ² .

After pressurizing the CIP molding, when depressurizing the range pressure of 200 kgf / cm ² or less, it is preferred that the pressure reduction rate below 200kgf / cm ² · h, that below 100kgf / cm ² · h Is more preferably 50 kgf / cm ² · h or less. When the pressure is reduced within a pressure range of 200 kgf / cm ² or less, since the springback force generated in the molded body is strong, the molded body is easily cracked. When the pressure reduction speed is 200 kgf / cm ² · h or less, the springback force becomes weak and the molded body is difficult to break. When depressurization is performed at such a depressurization rate, a high-density and long ceramic cylindrical target material can be stably produced. For example, when the binder is used, the blending amount of the organic additive is within the above range, and the decompression speed is adopted, the integrated ceramic cylindrical target material is stable with a length of 1000 mm or more and a relative density of 95% or more. Can be manufactured. There is no restriction | limiting in particular in the lower limit of the pressure reduction speed, Usually, it is 30 kgf / cm < ² >.

There is no particular limitation on the pressure reduction rate in the range of a pressure higher than 200 kgf / cm ^2, is usually 200~1000kgf / cm ² · h.
(Process 3)
In step 3, the molded body produced in step 2 is degreased. Degreasing is performed by heating the compact.

The degreasing temperature is usually 600 to 800 ° C, preferably 700 to 800 ° C, more preferably 750 to 800 ° C. The higher the degreasing temperature, the higher the strength of the molded body. However, when the temperature exceeds 800 ° C, shrinkage of the molded body occurs.

  The degreasing time is usually 3 to 10 hours, preferably 5 to 10 hours, more preferably 10 hours. The longer the degreasing time is, the higher the strength of the molded body is. However, the degreasing is almost completed by heating for 10 hours. Therefore, even if the degreasing time is longer, the strength of the molded body does not increase.

The temperature rising rate is preferably 50 ° C./h or less, more preferably 30 ° C./h or less, and further preferably 20 ° C./h or less in the temperature range up to 400 ° C. When the solvent is removed up to 400 ° C. and the temperature is increased at a high speed during the removal, the molded body is likely to be cracked. When the temperature rising rate is in the above range, a long and dense ceramic cylindrical target material can be stably produced. For example, when the binder is used, the blending amount of the organic additive is within the above range, the decompression speed during CIP molding is within the above range, and the heating rate during degreasing is within the above range, a length of 1500 mm or more, relative An integrated ceramic cylindrical target material having a density of 95% or more can be stably produced. At a temperature higher than 400 ° C., the removal of the solvent is completed, so that the lead time can be shortened, and the temperature can be increased at a higher rate, for example, about 80 ° C./h.
(Process 4)
In step 4, the molded body degreased in step 3 is fired.

There is no restriction | limiting in particular in a baking furnace, The baking furnace conventionally used for manufacture of a ceramic target material can be used.
When the ceramic is ITO, the firing temperature is usually 1450 to 1700 ° C, preferably 1500 to 1650 ° C, and more preferably 1550 to 1600 ° C. When ceramics are AZO or IGZO, it is 1250-1500 degreeC normally, Preferably it is 1300-1450 degreeC, More preferably, it is 1350-1400 degreeC. The higher the firing temperature is, the higher the density of the target material is obtained. However, when the firing temperature is too high, the sintered structure of the target material is enlarged and easily cracked.

  The firing time is usually 3 to 30 hours, preferably 5 to 10 hours, more preferably 5 to 8 hours. The longer the firing time, the more easily the target material is densified. However, if the firing time is too long, the sintered structure of the target material is enlarged and easily broken.

  The temperature rising rate is usually 100 to 500 ° C./h. The temperature lowering rate is usually 10 to 100 ° C./h, preferably 10 to 50 ° C./h, more preferably 10 to 30 ° C./h. Cracks due to thermal stress differences are less likely to occur as the rate of temperature drop is smaller, but the thermal stress difference does not normally change even when the temperature is lower than 10 ° C / h.

The firing atmosphere is not particularly limited, and is usually an air atmosphere or an oxygen atmosphere.
The obtained sintered body is subjected to necessary processing such as cutting and used as a sputtering target material.

The evaluation method of the sputtering target material obtained in the Example and the comparative example is as follows.
1. Relative density The relative density of the sputtering target material was measured based on the Archimedes method. Specifically, the aerial weight of the sputtering target material is divided by the volume (= weight of the sputtering target sintered body in water / water specific gravity at the measurement temperature), and the theoretical density ρ (g / cm ³ ) based on the following formula (X) The percentage value relative to the relative density (unit:%).

（式（Ｘ）中、Ｃ₁〜Ｃ_iはそれぞれターゲット材の構成物質の含有量（重量％）を示し、ρ₁〜ρ_iはＣ₁〜Ｃ_iに対応する各構成物質の密度（ｇ/ｃｍ³）を示す。）。
２．スパッタリングターゲット材または成形体の割れの評価
スパッタリングターゲット材および成形体を目視で観察し、スパッタリングターゲット材または成形体に割れが認められた場合には「×」、認められなかった場合には「○」と評価した。
＜ＩＴＯターゲット＞
［実施例１］
ＢＥＴ法により測定された比表面積が１０ｍ²／ｇであるＳｎＯ₂粉末とＢＥＴ法により測定された比表面積が１０ｍ²／ｇであるＩｎ₂Ｏ₃粉末とを、ＳｎＯ₂粉末の含有量が１質量％になるように配合し、ポット中でジルコニアボールによりボールミル混合して、セラミックス原料粉末を調製した。

(In Formula (X), C _{1 to} C _i indicate the content (% by weight) of the constituent material of the target material, respectively, and ρ _{1 to} ρ _i are the densities (g of each constituent material corresponding to C _{1 to} C _i ). / cm ³ ).
2. Evaluation of cracking of sputtering target material or molded body The sputtering target material and molded body were visually observed. If the sputtering target material or molded body was found to be cracked, "X", otherwise, "○"".
<ITO target>
[Example 1]
And In ₂ O ₃ powder, which is the ratio specific surface area measured by the BET method was measured by SnO ₂ powder and the BET method is 10 m ² / g surface area of 10 m ² / g, the content of SnO ₂ powder 1 A ceramic raw material powder was prepared by blending to a mass% and ball mill mixing with zirconia balls in a pot.

  In this pot, 0.1% by mass of polyvinyl alcohol (polymerization degree: 280, saponification degree: 68 mol%) as a binder as a binder, and 0.3% by mass of a polymer as a dispersing agent as a binder. As an ammonium carboxylate and a dispersion medium, 15% by mass of water was added to the ceramic raw material powder, and a slurry was prepared by ball mill mixing. The ratio of the total amount of organic additives (the total amount of polyvinyl alcohol and the amount of ammonium polycarboxylate) to the amount of the ceramic raw material powder was 0.4% by mass.

This slurry was supplied to a spray drying apparatus, and spray drying was performed under the conditions of an atomizing rotation speed of 10,000 rpm and an inlet temperature of 250 ° C. to prepare granules.
There is a lid that can be sealed up and down, and a cylindrical urethane rubber mold with an inner diameter of 210 mm (thickness 10 mm) and a length of 1219 mm with a cylindrical core (mandrel) with an outer diameter of 165 mm is filled while tapping the granules. After sealing the rubber mold, CIP molding was performed at a pressure of 800 kgf / cm ² to prepare a cylindrical molded body. Decompression rate after CIP molding at high pressure range than ^{200kgf / cm 2 300kgf / cm 2} · h, at 200 kgf / cm ² or less in the pressure range was 200kgf / cm ² · h. The length of the obtained molded body was 1212 mm.

  This molded body was heat degreased. The degreasing temperature was 700 ° C., the degreasing time was 10 hours, and the heating rate was 20 ° C./h in the temperature range up to 400 ° C., and 50 ° C./h in the temperature range higher than 400 ° C.

The degreased molded body was fired to produce a sintered body. Firing was performed in an air atmosphere at a firing temperature of 1600 ° C., a firing time of 10 hours, a heating rate of 300 ° C./h, and a cooling rate of 50 ° C./h.
The obtained sintered body was cut to produce an ITO cylindrical sputtering target material having an outer diameter of 155 mm, an inner diameter of 135 mm, and a length of 1000 mm.

  The three target materials were joined with In solder to an SUS304 backing tube having an outer diameter of 133 mm, an inner diameter of 123 mm, and a length of 3200 mm to produce an ITO target. The interval between the target materials (the length of the divided portion) was 0.2 mm.

Table 1 shows the relative density of the target material and the evaluation of cracks in the target material and the molded body.
[Examples 2 to 20, Comparative Examples 1 to 9]
Examples 2 to 20 and Comparative Examples 1 to 9 were performed under the following conditions.

The content of SnO ₂ powder in the ceramic raw material powder, the polymerization degree and saponification degree of polyvinyl alcohol, and the addition amount of polyvinyl alcohol and the addition amount of ammonium polycarboxylate were set to the conditions shown in Table 1, except that In the same manner, granules were prepared.

This granule was CIP-molded to produce a cylindrical molded body having the length shown in Table 1. For CIP molding, the same urethane rubber mold as in Example 1 was used for Examples 2, 3, 9 to 18 and Comparative Example 6, and the urethane rubber mold used in Example 1 for other Examples and Comparative Examples. A urethane rubber mold having the same core and the same inner diameter as that of the length of the molded body having the length shown in Table 1 was used. The pressure reduction rate in the pressure range of 200 kgf / cm ² or less after CIP molding was set to the conditions shown in Table 1. The other CIP molding conditions were the same as in Example 1. In Comparative Example 5, cracks occurred in the molded body during the molding process.

  The molded body in which cracking did not occur in the molding process was heated and degreased. The heating rate in the temperature range up to 400 ° C. was set to the conditions shown in Table 1, and the other degreasing conditions were the same as in Example 1. In Comparative Examples 1-4 and 8-9, cracks occurred in the molded bodies in the degreasing process.

  The degreased molded body in which cracking did not occur in the degreasing step was fired under the same conditions as in Example 1 to produce a sintered body. The obtained sintered body was cut to produce an ITO cylindrical sputtering target material having the outer diameter, inner diameter, and length shown in Table 1.

  In order to obtain the number of divided parts shown in Table 1, a plurality of target materials (one more than the number of divided parts) are provided on a SUS304 backing tube having an outer diameter of 133 mm, an inner diameter of 123 mm, and a length of 3200 mm. Were bonded with In solder to produce an ITO target. The interval between the target materials (the length of the divided portion) was 0.2 mm.

Table 1 shows the relative density of each target material obtained and the evaluation of cracks in the target material and the molded body.
<AZO target>
[Example 21]
The ratio specific surface area measured by the BET method was measured by Al ₂ O ₃ powder and the BET method is 5 m ² / g surface area and ZnO powder is 10 m ² / g, the content of Al ₂ O ₃ powder It mix | blended so that it might become 0.5 mass%, and the ball mill mixing was carried out with the zirconia ball | bowl in the pot, and the ceramic raw material powder was prepared.

Granules were prepared in the same manner as in Example 1 except that this ceramic raw material powder was used.
This granule has a lid capable of sealing up and down, and uses a cylindrical urethane rubber mold having an inner diameter of 213 mm (thickness of 10 mm) and a length of 1233 mm having a cylindrical core (mandrel) having an outer diameter of 167 mm. CIP molding was performed under the same conditions as in No. 1, and cylindrical molded bodies having the lengths shown in Table 2 were produced.

This molded body was degreased under the same conditions as in Example 1.
The degreased compact was fired under the same conditions as in Example 1 to produce a sintered body. The obtained sintered body was cut to produce an AZO cylindrical sputtering target material having the outer diameter, inner diameter and length shown in Table 2.

  The three target materials were joined with In solder to an SUS304 backing tube having an outer diameter of 133 mm, an inner diameter of 123 mm, and a length of 3200 mm to produce an AZO target. The interval between the target materials (the length of the divided portion) was 0.2 mm.

Table 2 shows the relative density of the target material and the evaluation of cracks in the target material and the molded body.
[Examples 22 to 33, Comparative Examples 10 to 18]
Examples 22 to 33 and Comparative Examples 10 to 18 were performed under the following conditions.

The content of Al ₂ O ₃ powder in the ceramic raw material powder, the polymerization degree and saponification degree of polyvinyl alcohol, the addition amount of polyvinyl alcohol and the addition amount of ammonium polycarboxylate were set to the conditions shown in Table 2, and the other examples. Granules were prepared in the same manner as in No. 21.

This granule was CIP molded to produce a cylindrical molded body having the length shown in Table 2. For CIP molding, the same urethane rubber mold as in Example 21 was used for Examples 22, 28 to 30, 33, and Comparative Example 14, and the urethane rubber mold used in Example 21 was used for other Examples and Comparative Examples. A urethane rubber mold having the same core and the same inner diameter as that of the length of the molded body having the length shown in Table 2 was used. The pressure reduction rate in the pressure range of 200 kgf / cm ² or less after CIP molding was set to the conditions shown in Table 2. The other CIP molding conditions were the same as in Example 21. In Comparative Example 13, cracks occurred in the molded body during the molding process.

  The molded body in which cracking did not occur in the molding process was heated and degreased. The temperature increase rate in the temperature range up to 400 ° C. was set to the conditions shown in Table 2, and other degreasing conditions were the same as in Example 21. In Comparative Examples 10-12 and 16-18, cracks occurred in the molded bodies in the degreasing process.

  The degreased molded body that was not cracked in the degreasing step was fired under the same conditions as in Example 21 to produce a sintered body. The obtained sintered body was cut to produce an AZO cylindrical sputtering target material having the outer diameter, inner diameter and length shown in Table 2.

  In order to obtain the number of divided parts shown in Table 2, a plurality of target materials (one more than the number of divided parts) are provided on a SUS304 backing tube having an outer diameter of 133 mm, an inner diameter of 123 mm, and a length of 3200 mm. Were joined by In solder to produce an AZO target. The interval between the target materials (the length of the divided portion) was 0.2 mm.

Table 2 shows the relative density of each target material obtained and the evaluation of cracks in the target material and the molded body.
<IGZO target>
[Example 34]
The specific surface area specific surface area measured by the BET method was measured by Ga ₂ O ₃ powder and the BET method measured specific surface area of 10 m ² / g by In ₂ O ₃ powder and the BET method is 10 m ² / g There the ZnO powder is _{^{10m 2 / g, in 2 O}} 3 content of the powder is 44.2 weight%, content of Ga ₂ O ₃ powder is 29.9 mass%, the content of ZnO powder 25. A ceramic raw material powder was prepared by blending to 9% by mass and ball mill mixing with zirconia balls in a pot.

  Example 1 was performed except that this ceramic raw material powder was used, and polyvinyl alcohol (polymerization degree: 500, saponification degree: 90 mol%) was used instead of polyvinyl alcohol (polymerization degree: 280, saponification degree: 68 mol%). Granules were prepared.

CIP molding using a cylindrical urethane rubber mold with a lid that can seal the granules up and down, an inner diameter of 218 mm (thickness 10 mm) and a length of 653 mm with a cylindrical core (mandrel) of 171 mm in outer diameter CIP molding was performed under the same conditions as in Example 1 except that the decompression speed in the pressure range of 200 kgf / cm ² or less was changed to 300 kgf / cm ² · h, and a cylindrical shape having the length shown in Table 3 A molded body was prepared.

This molded body was degreased under the same conditions as in Example 1.
The degreased compact was fired under the same conditions as in Example 1 to produce a sintered body. The obtained sintered body was cut to produce an IGZO cylindrical sputtering target material having the outer diameter, inner diameter and length shown in Table 3.

  The six target materials were joined with In solder to an SUS304 backing tube having an outer diameter of 133 mm, an inner diameter of 123 mm, and a length of 3200 mm to produce an IGZO target. The interval between the target materials (the length of the divided portion) was 0.2 mm.

Table 3 shows the relative density of the target material and the evaluation of cracks in the target material and the molded body.
[Examples 35-44, Comparative Examples 19-25]
Examples 35 to 44 and Comparative Examples 19 to 25 were performed under the following conditions.

In ₂ O ₃ powder content, Ga ₂ O ₃ powder content and ZnO powder content, degree of polymerization and saponification of polyvinyl alcohol, addition amount of polyvinyl alcohol and addition of ammonium polycarboxylate in ceramic raw material powder Granules were prepared in the same manner as in Example 34, except that the amount was changed as shown in Table 3.

This granule was CIP-molded to produce a cylindrical molded body having the length shown in Table 3. For CIP molding, the same urethane rubber mold as in Example 34 was used for Examples 35-36 and Comparative Examples 19-20, 22-25, and the urethane used in Example 34 for other Examples and Comparative Examples. A urethane rubber mold having the same core and inner diameter as the rubber mold and having such a length as to obtain a molded body having the length shown in Table 2 was used. The pressure reduction rate in the pressure range of 200 kgf / cm ² or less after CIP molding was set to the conditions shown in Table 3. The other CIP molding conditions were the same as in Example 34. In Comparative Example 20, cracks occurred in the molded body during the molding process.

  The molded body in which cracking did not occur in the molding process was heated and degreased. The temperature increase rate in the temperature range up to 400 ° C. was set to the conditions shown in Table 3, and other degreasing conditions were the same as in Example 34. In Comparative Examples 19 and 23 to 25, cracks occurred in the molded body in the degreasing process.

  The degreased compact that did not crack in the degreasing step was fired under the same conditions as in Example 34 to produce a sintered body. The obtained sintered body was cut to produce an IGZO cylindrical sputtering target material having the outer diameter, inner diameter and length shown in Table 3.

  In order to obtain the number of divided parts shown in Table 3, a plurality of target materials (one more than the number of divided parts) are provided on a SUS304 backing tube having an outer diameter of 133 mm, an inner diameter of 123 mm, and a length of 3000 mm. Were joined by In solder to produce an IGZO target. The interval between the target materials (the length of the divided portion) was 0.2 mm.

  Table 3 shows the relative density of each target material obtained and the evaluation of cracks in the target material and the molded body.

表１〜３に示されたとおり、本発明の製造方法を実施した実施例１〜４４では、ターゲットの作製過程においてターゲット材および成形体の割れが発生せず、５００ｍｍ以上の長さを有し、９５％以上の相対密度を有するＩＴＯ円筒形スパッタリングターゲット材、ＡＺＯ円筒形スパッタリングターゲット材またはＩＧＺＯ円筒形スパッタリングターゲット材、およびこれらから形成されるターゲットが得られた。

As shown in Tables 1 to 3, in Examples 1 to 44 in which the production method of the present invention was performed, the target material and the molded body were not cracked in the target production process, and had a length of 500 mm or more. In addition, an ITO cylindrical sputtering target material, an AZO cylindrical sputtering target material or an IGZO cylindrical sputtering target material having a relative density of 95% or more, and a target formed from these were obtained.

  In the comparative example which implemented the manufacturing method which is not the manufacturing method of this invention, when the quantity of an organic additive is more than 1.2 mass% with respect to the quantity of ceramic raw material powder, a crack will generate | occur | produce in a degreasing process. Or when the relative density of the target material is lower than 95% and the amount of the organic additive is less than 0.1% by mass with respect to the amount of the ceramic raw material powder, cracks occurred in the molded body in the molding process. . In the comparative example, a ceramic cylindrical sputtering target material having a length of 500 mm or more and a relative density of 95% or more could not be produced.

Claims (7)

  A ceramic cylindrical sputtering target material having a length of 500 mm or more and a relative density of 95% or more and being an integral product. And the content of Sn is made ITO 1 to 10% by mass SnO ₂ weight terms, ceramics cylindrical sputtering target material according to claim 1. _2. The ceramic cylindrical sputtering target material according to claim 1, wherein the ceramic cylindrical sputtering target material is made of AZO having an Al content of 0.1 to 5 mass% in terms of Al ₂ O ₃ content. The content of In is 40 to 60% by mass in terms of In ₂ O ₃ , the content of Ga is 20 to 40% by mass in terms of Ga ₂ O ₃ , and the content of Zn is 10 to 30% by mass in terms of ZnO. The ceramic cylindrical sputtering target material according to claim 1, wherein the ceramic cylindrical sputtering target material is made of a certain IGZO.   A ceramic cylindrical sputtering target obtained by bonding the ceramic cylindrical sputtering target material according to claim 1 to a backing tube with a bonding material. Step 1 for preparing granules from a slurry containing ceramic raw material powder and an organic additive,
Step 2 for producing a cylindrical shaped body by CIP molding the granules,
Step 3 for degreasing the molded body, and Step 4 for firing the degreased molded body.
A method for producing a ceramic cylindrical sputtering target material comprising:
In the said process 1, the quantity of the said organic additive is 0.1-1.2 mass% with respect to the quantity of the said ceramic raw material powder, The manufacturing method of the ceramic cylindrical sputtering target material characterized by the above-mentioned.   The ceramic cylindrical sputtering target according to claim 6, wherein the organic additive includes a binder, and the binder is polyvinyl alcohol having a polymerization degree of 200 to 400 and a saponification degree of 60 to 80 mol%. A method of manufacturing the material.