CN108699675B - Sputtering target material, method for producing same, and sputtering target - Google Patents
Sputtering target material, method for producing same, and sputtering target Download PDFInfo
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- C23C14/22—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the process of coating
- C23C14/34—Sputtering
- C23C14/3407—Cathode assembly for sputtering apparatus, e.g. Target
- C23C14/3414—Metallurgical or chemical aspects of target preparation, e.g. casting, powder metallurgy
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- C04B35/453—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on zinc, tin, or bismuth oxides or solid solutions thereof with other oxides, e.g. zincates, stannates or bismuthates
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- C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/626—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B
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- C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
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- C23C14/34—Sputtering
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Abstract
The sputtering target material of the present invention contains an oxide of at least one selected from In, Ga, Zn, Sn, and Al. The sputtering target had an area of 1000 μm without iron on the surface2The above discolored part or the area having iron-derived surface of 1000 μm2In the case of the above discolored part, the ratio of the discolored part is 0.02 pieces/1200 cm2The following. The sputtering target is suitably produced by a method including at least one magnetic separation step in the production step thereof.
Description
Technical Field
The invention relates to a sputtering target and a manufacturing method thereof. The present invention also relates to a sputtering target provided with the sputtering target material.
Background
The sputtering method is extremely effective as a method for forming a thin film over a large area with high accuracy, and is being utilized in recent years for display devices such as liquid crystal display devices.
However, In the field of semiconductor device technology such as a recent thin film transistor (hereinafter also referred to as "TFT"), an oxide semiconductor typified by an In-Ga-Zn composite oxide (hereinafter also referred to as "IGZO") has attracted attention instead of amorphous silicon, and a sputtering method is also being used to form an IGZO thin film. It is known that when a specific transition metal such as Fe or Cu is mixed into an oxide semiconductor thin film typified by IGZO, the TFT characteristics are deteriorated. The effect of Fe and Cu mixed in the thin film is extremely large for the oxide semiconductor even if the amount is in the order of several ppm. For example, in a thin film semiconductor device in which Fe and Cu are mixed, field effect mobility among various characteristics of a TFT tends to be lower and an ON/OFF ratio also tends to be lower than in a thin film semiconductor device in which they are not mixed. Such defects are pointed out as a great hindrance to the increase in area of the display panel of today, and improvement of the technology as early as possible is being demanded.
Therefore, patent document 1 proposes the following technique: in the divided sputtering target obtained by joining a plurality of target members, the gap between the joined members is filled with a ceramic material or the like, thereby preventing the mixing of Cu from the base material.
Patent document 2 discloses a technique of lengthening the target member itself to reduce the number of gaps between the joining members as much as possible. As in this document, the target member is made longer, so that the effect of preventing Cu and Fe from being mixed into the base material can be obtained.
Documents of the prior art
Patent document
Patent document 1: international publication No. 2012/063523
Patent document 2: japanese patent laid-open publication No. 2013-147368
Disclosure of Invention
However, the techniques described in patent documents 1 and 2 both adopt only a method of using a high-purity product as a raw material from the viewpoint of preventing impurities from being mixed into the target material itself, and do not perform a treatment of removing several ppm of impurities originally contained in the raw material or impurities mixed in a manufacturing process. Among the impurities, iron is used as a material for equipment and instruments such as stainless steel, and may be mixed in at various stages in the actual production process of the target material, and such mixing may become a serious problem in the technical field of oxide semiconductors.
In addition to the conventional flat-plate magnetron sputtering apparatus, a rotary magnetron cathode sputtering apparatus has also become popular in recent years. A rotary magnetron cathode sputtering apparatus has a magnetic field generating device inside a cylindrical target, and performs sputtering while cooling the target from the inside and rotating the target. In the rotary magnetron cathode sputtering apparatus, the entire surface of the target material is eroded and uniformly cut. Therefore, the use efficiency of the target is usually 20 to 30% in the case of the flat magnetron sputtering apparatus, and the use efficiency of the target can be made 70% or more in the case of the rotary magnetron cathode sputtering apparatus, and particularly high use efficiency can be obtained. In such a cylindrical target, since most of the target material is used for sputtering, the influence of impurities mixed therein is larger than that of a flat plate type.
Therefore, the problem of the present invention is: provided are a sputtering target material, a method for producing the same, and a sputtering target, which can solve the various disadvantages of the conventional techniques described above.
The present invention provides a sputtering target material containing an oxide of at least one selected from In, Ga, Zn, Sn and Al. The sputtering target had an area of 1000 μm without iron on the surface2The above discolored part or the surface of the alloy has an area of 1000 μm derived from iron2In the case of the above discolored part, the ratio of the discolored part is 0.02 pieces/1200 cm2The following.
The present invention also provides a sputtering target comprising the sputtering target material and a base material.
The present invention also provides a preferable method for producing the sputtering target. The manufacturing method includes at least one magnetic separation step in the manufacturing step of the sputtering target.
Detailed Description
The present invention will be described below based on preferred embodiments thereof. The sputtering target material of the present invention contains an oxide of at least one selected from In, Ga, Zn, Sn, and Al. The oxide may be any of indium oxide, gallium oxide, zinc oxide, tin oxide, or aluminum oxide. Alternatively, the oxide may be a composite oxide of any two or more elements selected from In, Ga, Zn, Sn, and Al. Specific examples of the composite oxide include, but are not limited to, In-Ga oxide, In-Zn oxide, Zn-Sn oxide, In-Ga-Zn oxide, In-Zn-Sn oxide, In-Al-Zn oxide, In-Ga-Zn-Sn oxide, and In-Al-Zn-Sn oxide. The sputtering target of the present invention preferably contains an oxide of at least one selected from In, Ga, Zn, Sn, and Al, and does not contain a transition metal element other than these elements.
The sputtering target of the present invention is composed of a sintered body containing the above oxide. The shape of the sintered body and the sputtering target is not particularly limited, and conventionally known shapes such as a flat plate shape and a cylindrical shape can be used, but the following description exemplifies an oxide cylindrical sintered body and an oxide cylindrical sputtering target as shapes which are particularly effective in the present invention. The following description is also applicable to the case of shapes other than the cylindrical shape.
< oxide cylindrical sintered body >
The oxide cylindrical sintered body is a sintered body containing an oxide of at least one selected from In, Ga, Zn, Sn, and Al. The relative density of the oxide cylindrical sintered body is not particularly limited, but the higher the relative density, the less the influence on the vacuum system of the sputtering apparatus, and it is advantageous in forming a good thin film. From this viewpoint, the relative density is preferably 90% or more, more preferably 95% or more, and still more preferably 98.0% or more. The relative density was measured by the method described in the examples described later.
< oxide cylindrical sputtering target >
The oxide cylindrical sputtering target is made of the above oxide cylindrical sintered body. The cylindrical oxide sputtering target is produced by applying appropriate processing to a cylindrical sintered oxide. For example, the cutting process is performed. The size of the cylindrical oxide sputtering target is not particularly limited, but the outer diameter is preferably 140mm to 170mm, the inner diameter is preferably 110mm to 140mm, and the length is preferably 50mm or more. The length is appropriately determined according to the purpose.
One of the characteristics of the cylindrical oxide sputtering target of the present invention is to suppress the amount of iron mixed as an impurity contained therein. Specifically, the sputtering target of the present invention preferably has an area of 1000 μm without iron on the surface2The above color change section. Alternatively, the sputtering target of the present invention has an area of 1000 μm derived from iron on the surface2In the case of the above discolored part, the proportion of the discolored part is preferably 0.02 pieces/1200 cm2The following. When iron is mixed into the sputtering target material of the present invention, the mixed portion exhibits a color different from that of a portion not mixed with iron. Therefore, in the present invention, the site of iron incorporation is referred to as a discolored part. When the iron-mixed portion is present on the surface of the sputtering target, the discolored portion can be observed by visual observation. In this sense, the discolored portion observed on the surface of the sputtering target may be referred to as a "surface discolored portion". The discolored part being formed of an oxide of iron, e.g. Fe2O3、Fe3O4And the like, which in any chemical structure negatively affect the performance of the TFT produced from the sputtering target of the present invention. Therefore, what kind of chemical structure the iron constituting the color-changing portion has is not an essential problem in the present invention, and the presence of the color-changing portion containing iron becomes a problem. Further, when "iron" is referred to in the present invention, an alloy, an oxide, or the like also contains iron contained as a component.
The inventor of the application discovers for the first time: when iron is not mixed into the sputtering target of the present invention or even if the amount of iron is a specific value or less even when iron is mixed, the performance of a TFT manufactured using the sputtering target of the present invention can be effectively prevented from being degraded. From this viewpoint, the area of the sputtering target having no iron-derived surface is 1000 μm2The above discolored part or the surface of the alloy has an area of 1000 μm derived from iron2In the case of the above discolored part, the proportion of the discolored part is preferably 0.02 pieces/1200 cm2Hereinafter, more preferably 0.01 pieces/1200 cm2The following. The minimum area of the color-changing part was set to 1000 μm2The reason for (2) is that when the area of the discolored part is 1000. mu.m2Hereinafter, even when iron is mixed into the film by sputtering, the amount of iron does not affect the performance degradation of the TFT characteristics. Namely, having an area of 1000 μm on the surface2In the case of the above discolored part, the ratio is 0.02 pieces/1200 cm2In the following case, there is a possibility that the amount of iron mixed in the sputtering target is sufficiently small, and even if iron is mixed in the film by sputtering, the performance of the TFT is not deteriorated by this amount.
The identification and number measurement of the discolored part in the sputtering target are performed by visually observing the outer surface, and the area measurement is performed by using a microscope such as a microscope (microscope) capable of measuring a scale. A mode for making the sputtering target have no discolored part or a mode for suppressing the amount of discolored part to a specific value or less even if the sputtering target has the discolored part will be described later.
< oxide cylindrical sputtering target >
The above cylindrical oxide sputtering target material is bonded to a base material with a bonding material, thereby obtaining a cylindrical oxide sputtering target. The substrate generally has a cylindrical shape capable of bonding a cylindrical sputtering target. The type of the base material is not particularly limited, and a conventionally used base material can be appropriately selected and used. Examples of the material of the substrate include stainless steel, titanium, and copper. The type of the bonding material is not particularly limited, and a conventionally used bonding material can be appropriately selected and used. Examples of the bonding material include indium solder.
The oxide cylindrical sputtering target may be bonded to one substrate on the outer side, or may be bonded to two or more substrates arranged on the same axis. When two or more oxide cylindrical sputtering targets are bonded in line, the length of the gap between the oxide cylindrical sputtering targets, that is, the length of the dividing portion is usually 0.05mm to 0.5 mm. The shorter the length of the segment, the less likely arcing occurs during sputtering, but when the length is less than 0.05mm, the targets may collide with each other and break due to thermal expansion during the bonding step and sputtering. The method for bonding the substrate and the cylindrical oxide sputtering target is also not particularly limited, and the same method as the conventionally known method can be employed.
< method for producing cylindrical oxide sintered body >
The cylindrical sintered oxide compact is suitably produced by a method including the steps of pulverizing, classifying and mixing raw material powders. In any stage of this step, iron may be mixed as an impurity. Specifically, iron is mixed in at least one step of the above-mentioned pulverization, classification and mixing, or is originally contained in the raw material powder. For any reason, it is advantageous to perform magnetic separation for removing iron by magnetic attraction. In the present invention, "magnetic separation" refers to a step of removing impurities such as iron adhering to a magnet. By performing magnetic separation, not only iron but also other impurities such as Ni and Ni alloys, oxides, Co and Co alloys, oxides, and the like, which are attached to the magnet, can be removed.
The manufacturing method may include a step of preparing a slurry containing the raw material powder and the organic additive. Alternatively, the production method may include a step of preparing a slurry containing the raw material powder subjected to magnetic separation and the organic additive. In any case, it is advantageous to perform magnetic separation in which iron contained in the slurry is removed by magnetic attraction. In addition, the present manufacturing method may include a step of manufacturing granulated powder from the slurry before magnetic separation or the slurry after magnetic separation, and in this case, it is advantageous to perform magnetic separation on the granulated powder thus manufactured to remove iron by magnetic attraction.
In the present production method, magnetic separation by magnetic force is preferably performed at least once between the steps of preparing the raw material powder and molding the cylindrical oxide compact. Specifically, examples thereof include: (A) magnetic separation of raw material powder, (B) magnetic separation of powder after treatment in the case where the step of pulverizing, classifying, mixing or the like is included in the raw material powder, (C) magnetic separation of slurry in the case where the step of preparing slurry containing the raw material powder and an organic additive is included, and (D) magnetic separation of granulated powder in the case where the step of preparing granulated powder from the slurry is included. Among the above, it is particularly preferable to perform magnetic separation of the slurry (C). When magnetic separation is performed in a state of being dispersed in a solvent like slurry, the contained iron is likely to come close to the magnet, and the magnetic separation efficiency is advantageously increased. When the slurry is magnetically separated, the viscosity of the slurry is preferably 200mPa · s or less at the temperature during magnetic separation. When the viscosity of the slurry exceeds 200mPa · s, the slurry may hardly pass through the magnetic separator, and iron contained in the slurry may hardly come close to the magnet. For the above reasons, the viscosity of the slurry is more preferably 100mPa · s or less, and particularly preferably 80mPa · s or less. The lower limit of the viscosity of the slurry is not particularly limited, but is usually 1 mPas or more.
The number of times of magnetic separation in each step is not limited to one. For example, it is advantageous to perform magnetic separation a plurality of times by further performing magnetic separation, such as magnetic separation, on the slurry subjected to magnetic separation, thereby improving the magnetic separation efficiency.
The cylindrical sintered oxide body can be efficiently produced by the method described below. In particular, the method for producing the cylindrical oxide sintered body is not particularly limited except for the production conditions related to the magnetic separation described above, and is not limited to the production method described below. A preferred embodiment of the method for producing a cylindrical oxide sintered body includes the steps of: a step 1 of producing granulated powder from a slurry containing a raw material powder and an organic additive; a step 2 of subjecting the granulated powder to CIP molding to produce a cylindrical molded body; a step 3 of degreasing the molded body; and a step 4 of firing the degreased molded body. Hereinafter, each step will be described.
< working procedure 1 >
Step 1 is to produce granulated powder from a slurry containing a raw material powder and an organic additive. As the raw material powder, In can be used, for example2O3Powder of Ga2O3Powder, ZnO powder, SnO2Powder and Al2O3Any one of the powders or a mixed powder of any two or more of the powders. In the case of using the mixed powder, the mixing ratio of each powder is appropriately determined by the content of the constituent element in the present oxide cylindrical sintered body. For example, when the finally obtained sintered body has an atomic ratio of In: Ga: Zn: O of 1:1:1:4, the ratio of each raw material powder contained In the raw material powder is determined so that the contents of In, Ga, Zn, and O In the sintered body have an atomic ratio of 1:1:1: 4. In addition, powders that have been reacted and dissolved in advance may be used alone; in this case, for example, when the finally obtained sintered body has an atomic ratio In: Ga: Zn: O of 1:1:1:4, IGZO powder having a content In atomic ratio In: Ga: Zn: O of 1:1:1:4 may be used alone. In the present manufacturing method, the ratio of each element in the raw material powder can be regarded as being equivalent to the ratio of each element in the finally obtained sintered body and target material.
In the present invention, the mixed powder of the above-described oxide powders for producing the granulated powder is also referred to as "raw material powder". Alternatively, when the oxide powder is used alone, the powder alone is referred to as "raw material powder". From In2O3Powder of Ga2O3Powder, ZnO powder, SnO2Powder and Al2O3Mixed powder and sheet made of any two or more of the powders in combinationThe powder has a specific surface area of usually 1m measured by the BET (Brunauer-Emmett-Teller; Brunauer-Emmett-Teller) method2/g～40m2/g。
When the mixed powder is used as the raw material powder, the method for mixing the respective oxide powders is not particularly limited, and for example, the respective oxide powders and zirconia balls may be charged into a bowl and ball-milled. After mixing in a ball mill, the zirconia balls and the mixed powder were separated by sieving.
The raw material powder may be subjected to magnetic separation treatment using a dry magnetic separator (for example, CG-150HHH, manufactured by Nippon Magnetics Co., Ltd.). The stronger the magnetic force of the magnetic separator, the more effective the removal of iron. Since stainless steel used for devices and appliances, which is one of the causes of iron contamination, is generally weak in magnetic force, it is desirable to set the magnetic force of the magnetic separator to be strong, specifically, 3000G or more, more preferably 7000G or more, and still more preferably 10000G or more, and in this case, iron can be removed more efficiently.
The organic additive added to the raw material powder before or after magnetic separation is a substance for appropriately adjusting the properties of the slurry and the molded article. Examples of the organic additive include a binder, a dispersant, and a plasticizer. The binder is added to the molded article to bind the raw material powder and to improve the strength of the molded article. As the binder, a binder generally used in obtaining a molded body by a known powder sintering method can be used. Examples of the binder include polyvinyl alcohol. The dispersant is added to improve the dispersibility of the raw material powder in the slurry. Examples of the dispersant include ammonium polycarboxylate and ammonium polyacrylate. The plasticizer is added to improve the moldability of the molded article. Examples of the plasticizer include polyethylene glycol (PEG) and Ethylene Glycol (EG).
The dispersion medium used in the preparation of the slurry containing the raw material powder and the organic additive is not particularly limited, and may be appropriately selected from water and water-soluble organic solvents such as alcohols according to the purpose. The method for producing the slurry containing the raw material powder and the organic additive is not particularly limited, and for example, a method of placing the raw material powder, the organic additive, the dispersion medium, and the zirconia balls in a bowl and performing ball milling and mixing can be used.
The slurry thus obtained can be subjected to magnetic separation treatment using a wet magnetic separator (for example, a permanent magnetic filter manufactured by Nippon Magnetics Co., Ltd.). The magnetic force can be the same as that used in the magnetic separation of the raw material powder by the dry magnetic separator described above.
The method of producing the granulated powder using the slurry before or after the magnetic separation is not particularly limited. For example, spray drying, rotary granulation, extrusion granulation, and the like can be used. Among these, the spray drying method is preferably used from the viewpoint of easy production of a granulated powder which has high flowability and is easily crushed at the time of molding. The conditions for the spray drying method are not particularly limited, and granulation of the raw material powder can be carried out by appropriately selecting the conditions generally used.
The granulated powder obtained by granulation can be subjected to magnetic separation treatment using a dry magnetic separator (for example, CG-150HHH, manufactured by Nippon Magnetics Co., Ltd.). The magnetic force can be the same as in the case of magnetic separation of the raw material powder by the dry magnetic separator and magnetic separation of the slurry by the wet magnetic separator described above.
< step 2 >
In step 2, CIP molding (cold isostatic pressing) is performed on the pellets obtained in step 1 to produce a cylindrical molded article. The pressure at the time of CIP molding is usually 800kgf/cm2The above. A higher pressure can give a denser molded body, and thus the density and strength of the molded body can be increased.
< step 3 >
Step 3 is to degrease the molded article obtained in step 2. Degreasing is generally performed by heating the molded body. The degreasing temperature is usually preferably 600 to 800 ℃, more preferably 700 to 800 ℃, and still more preferably 750 to 800 ℃. The strength of the molded article is increased as the degreasing temperature is higher, but shrinkage of the molded article may occur when the temperature exceeds 800 ℃, and therefore, it is preferable to perform degreasing at 800 ℃ or lower.
< step 4 >
The firing step of step 4 is firing the molded article degreased in step 3. The firing furnace used for firing is not particularly limited, and a conventionally used firing furnace can be used for producing the oxide sintered body. The firing temperature is preferably 1300 to 1700 ℃. The firing time is usually 3 to 30 hours, provided that the firing temperature is within this range. The atmosphere for firing is usually atmospheric air or an oxygen atmosphere.
The sputtering target can be obtained by subjecting the cylindrical oxide sintered body obtained in the above steps to cutting or the like. A sputtering target can be obtained by bonding the sputtering target material to a base material. The sputtering target thus obtained is suitable for use in the production of an oxide semiconductor. Since the sputtering target suppresses the incorporation of iron, the oxide semiconductor obtained using the sputtering target becomes less likely to deteriorate its characteristics. Therefore, the use of the sputtering target can improve the production yield of the oxide semiconductor device.
Examples
The present invention will be described in more detail below with reference to examples. However, the scope of the present invention is not limited to these examples.
The evaluation methods of the oxide sintered bodies obtained in the examples and comparative examples described below are as follows.
1. Relative density
The relative density of the oxide sintered body was measured based on the archimedes method. Specifically, the mass in air of the oxide sintered body is divided by the volume (mass in water of the oxide sintered body/specific gravity of water at the measurement temperature) so as to correspond to the theoretical density ρ (g/cm) based on the following formula (1)3) The percentage values of (d) are relative density (unit: %).
In the formula (1), C1～CiEach represents the content (% by mass) in terms of oxide of the constituent material of the sintered body, (% by mass)1～ρiIs represented by the formula1～CiDensity in terms of oxide (g/cm) of corresponding constituent substance3)。
2. Viscosity of the slurry
The slurry was collected before passing through the magnetic separator and the viscosity of the slurry was measured. The viscosity of the slurry was measured by using a rotary viscometer (PC-10C, product of MALCOM Co., Ltd.).
3. Iron-based surface color change
When iron is mixed into the oxide sintered body and exposed to the target surface, the portion containing iron is oxidized to become red. Not all iron precipitates on the oxide surface, but the present invention scales with the proportion of discolored parts appearing on the surface and sets as a relative evaluation of the amount of iron incorporated. The discolored part was visually observed at 1m on the target surface2In which several places with the area of 1000 μm are generated2The above color change section.
< example 1 >
The specific surface areas measured by the BET method were all 5m2In of/g2O3Powder of Ga2O3The powder and the ZnO powder were mixed so that the atomic ratio of In to Ga to Zn to O was 1:1:1:4, thereby obtaining a mixed powder. This mixed powder was ball-milled and mixed in a bowl with zirconia balls to prepare an IGZO raw material powder.
After mixing by a ball mill, the zirconia balls and the raw material powder were separated by a sieve, and the raw material powder was subjected to magnetic separation treatment using a dry magnetic separator (12000G). To the raw material powder subjected to the magnetic separation treatment, 0.3 mass% of polyvinyl alcohol (binder), 0.5 mass% of ammonium polycarboxylate (dispersant), 0.3 mass% of polyethylene glycol (plasticizer), and 50 mass% of water (dispersion medium) were added, and ball-milled and mixed to prepare a slurry. The viscosity of the slurry is 200 mPas or less.
The slurry was subjected to magnetic separation treatment (10000G) using a wet magnetic separator. Then, the slurry was supplied to a spray drying apparatus, and spray-dried at an atomizing rotation speed of 14000rpm, an inlet temperature of 200 ℃, and an outlet temperature of 80 ℃ to produce granulated powder. The resultant granulated powder was subjected to magnetic separation treatment (12000G) using a dry magnetic separator.
The granulated powder after the magnetic separation treatment was filled while tapping (tapping) a cylindrical urethane rubber mold. The urethane rubber die was a cylindrical mandrel (mandrel) having an inner diameter of 225mm (wall thickness of 10mm) and a length of 400mm, and an outer diameter of 150mm was disposed inside. After sealing the urethane rubber mold, at 800kgf/cm2CIP molding was performed under the pressure of (3) to produce a cylindrical molded article.
Subsequently, the molded body was heated to degrease. The degreasing temperature was set to 600 ℃, the degreasing time was set to 10 hours, and the temperature rising rate was set to 20 ℃/hour. The degreased molded article was fired under conditions of a firing temperature of 1500 ℃, a firing time of 12 hours, and a temperature rise rate of 300 ℃/hour. The atmosphere is set to the atmosphere. After completion of the firing, the obtained fired product was cooled at a cooling rate of 50 ℃/hr.
The sintered body thus obtained had a relative density of 99.7%. The obtained sintered body was cut to obtain an IGZO cylindrical sputtering target having an outer diameter of 153mm, an inner diameter of 135mm and a length of 250 mm. The outer diameter is machined by using a grinding wheel, the outer diameter is held by a jig and the inner diameter is machined, and then the inner diameter is held by a jig and the outer diameter is finished, thereby performing cutting. Thus, 100 cylindrical IGZO sputtering targets were produced, and the area was 1000 μm when the outer surface was visually observed2The generation of the above surface discolored part was 0 pieces/1200 cm2. The production conditions and the results of the generation rate of the surface discolored part are shown in table 1 below.
The obtained IGZO cylindrical sputtering target was bonded to a titanium base material using indium as a bonding material, and a sputtering target having a thickness of 1000 μm2The IGZO cylindrical sputtering target having the above surface discolored part.
< example 2 >
An IGZO cylindrical sputtering target was produced in the same manner as in example 1, except that the raw material powder was not subjected to magnetic separation treatment. The sputtering target was evaluated in the same manner as in example 1. The results are shown in Table 1.
< example 3 >
An IGZO cylindrical sputtering target was produced in the same manner as in example 1, except that the raw material powder and the slurry were not subjected to magnetic separation treatment. The sputtering target was evaluated in the same manner as in example 1. The results are shown in Table 1.
The IGZO cylindrical sputtering target material prepared by using indium as a bonding material does not have a thickness of 1000 μm2The target material having the above discolored surface portion was bonded to the titanium substrate, and the absence of 1000 μm was obtained2The IGZO cylindrical sputtering target having the above surface discolored part.
< example 4 >
An IGZO cylindrical sputtering target was produced in the same manner as in example 1, except that the raw material powder and the granulated powder were not subjected to the magnetic separation treatment. The same evaluation as in example 1 was performed for this sputtering target. The results are shown in Table 1.
< example 5 >
An IGZO cylindrical sputtering target was produced in the same manner as in example 1, except that the slurry and the granulated powder were not subjected to the magnetic separation treatment. The same evaluation as in example 1 was performed for this sputtering target. The results are shown in Table 1.
< comparative example 1 >
An IGZO cylindrical sputtering target was produced in the same manner as in example 1, except that no magnetic separation treatment was performed. The same evaluation as in example 1 was performed for this sputtering target. The results are shown in Table 1.
TABLE 1
From the results shown in table 1, it can be seen that: the sputtering target of each example subjected to the magnetic separation treatment had a very small amount of iron-derived surface discolored parts, whereas the sputtering target of comparative example 1 obtained without the magnetic separation had more iron-derived surface discolored parts than those observed in each example.
Industrial applicability
According to the present invention, the incorporation of iron into the thin film can be prevented, and the manufacturing yield of the oxide semiconductor device can be improved.
Claims (8)
1. A method for producing a sputtering target comprising an oxide of at least one selected from the group consisting of In, Ga, Zn, Sn and Al,
which comprises a step of preparing a slurry containing the oxide and a step of magnetically separating the slurry,
wherein the slurry having a viscosity of 80 mPas or less is magnetically separated by a magnetic force of 3000G or more.
2. The method for manufacturing a sputtering target according to claim 1, comprising a step of magnetically separating the raw material powder of the sputtering target.
3. The method of manufacturing a sputtering target according to claim 2, wherein the raw material powder of the sputtering target is magnetically separated by a magnetic force of 3000G or more.
4. The method for producing a sputtering target according to any one of claims 1 to 3, comprising a step of producing a granulated powder from the slurry and a step of magnetically separating the granulated powder.
5. The method for manufacturing a sputtering target according to claim 4, wherein the granulated powder is magnetically separated by a magnetic force of 3000G or more.
6. A method for producing a sputtering target comprising an oxide of at least one selected from the group consisting of In, Ga, Zn, Sn and Al,
which comprises a step of preparing a slurry containing the oxide and having a viscosity of 80 mPas or less, a step of producing a granulated powder from the slurry, and a step of magnetically separating the granulated powder,
wherein the granulated powder is magnetically separated by a magnetic force of 3000G or more.
7. The method for manufacturing a sputtering target according to claim 6, comprising a step of magnetically separating the raw material powder of the sputtering target.
8. The method of manufacturing a sputtering target according to claim 7, wherein the raw material powder of the sputtering target is magnetically separated by a magnetic force of 3000G or more.
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| JP2016064641 | 2016-03-28 | ||
| PCT/JP2016/089114 WO2017168906A1 (en) | 2016-03-28 | 2016-12-28 | Sputtering target material, manufacturing method therefor, and sputtering target |
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| JP2020001940A (en) * | 2018-06-25 | 2020-01-09 | 株式会社トクヤマ | Method of manufacturing granulated particle for producing ceramic |
| JP2020196660A (en) * | 2019-05-30 | 2020-12-10 | 株式会社コベルコ科研 | Sintered oxide and sputtering target |
| WO2020241227A1 (en) * | 2019-05-30 | 2020-12-03 | 株式会社コベルコ科研 | Oxide sintered body and sputtering target |
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| JP2007138198A (en) * | 2005-11-15 | 2007-06-07 | Tateho Chem Ind Co Ltd | Magnesium oxide sintered compact for vapor deposition |
| US8118906B2 (en) * | 2007-10-29 | 2012-02-21 | Heraeus Inc. | Methodology for recycling Ru and Ru-alloy deposition targets and targets made of recycled Ru and Ru-based alloy powders |
| JP2009197310A (en) * | 2008-02-25 | 2009-09-03 | Kobe Steel Ltd | Sputtering target |
| JP2009256719A (en) * | 2008-04-16 | 2009-11-05 | Hirasho:Kk | Sputtering target |
| CN101445270A (en) * | 2008-10-20 | 2009-06-03 | 雷亚林 | Preparation of high pure gold redrock nano-titanium dioxide |
| JP5546143B2 (en) * | 2009-03-03 | 2014-07-09 | 住友電気工業株式会社 | Composite oxide sintered body for forming transparent thin film and transparent thin film forming material |
| JP5750060B2 (en) * | 2012-01-18 | 2015-07-15 | 三井金属鉱業株式会社 | Ceramic cylindrical sputtering target material and manufacturing method thereof |
| JP5925535B2 (en) * | 2012-03-12 | 2016-05-25 | 三井金属鉱業株式会社 | Gallium-indium composite oxide powder |
| KR20230152795A (en) * | 2012-11-08 | 2023-11-03 | 가부시키가이샤 한도오따이 에네루기 켄큐쇼 | Display device |
| JP2015214437A (en) * | 2014-05-08 | 2015-12-03 | 出光興産株式会社 | Oxide sintered body and sputtering target |
| JP6281437B2 (en) * | 2014-07-30 | 2018-02-21 | 住友金属鉱山株式会社 | Oxide sintered body, manufacturing method thereof, and sputtering target using this oxide sintered body |
| JP5976855B2 (en) * | 2015-01-23 | 2016-08-24 | Ｊｘ金属株式会社 | Method for producing sputtering target for forming transparent electrode film |
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| JPWO2017168906A1 (en) | 2019-02-07 |
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