CA2918933A1 - Sputtering target and method for producing same - Google Patents
Sputtering target and method for producing same Download PDFInfo
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- CA2918933A1 CA2918933A1 CA2918933A CA2918933A CA2918933A1 CA 2918933 A1 CA2918933 A1 CA 2918933A1 CA 2918933 A CA2918933 A CA 2918933A CA 2918933 A CA2918933 A CA 2918933A CA 2918933 A1 CA2918933 A1 CA 2918933A1
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- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/01—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
- 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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- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/01—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
- 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
- C04B35/457—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 based on tin oxides or stannates
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- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/64—Burning or sintering processes
- C04B35/645—Pressure sintering
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C18/00—Alloys based on zinc
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- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
- C23C14/06—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the coating material
- C23C14/08—Oxides
- C23C14/086—Oxides of zinc, germanium, cadmium, indium, tin, thallium or bismuth
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- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
- 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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- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B2235/3284—Zinc oxides, zincates, cadmium oxides, cadmiates, mercury oxides, mercurates or oxide forming salts thereof
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- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B2235/3293—Tin oxides, stannates or oxide forming salts thereof, e.g. indium tin oxide [ITO]
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- C04B2235/65—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes
- C04B2235/652—Reduction treatment
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Abstract
This sputtering target is a sintered compact formed from a ZnSn oxide that has a composition represented by the chemical formula ZnxSnyOz (where x + y = 2 and z = x + 2y - a (x+2y)) and satisfies the conditions of a loss coefficient a = 0.002 to 0.03 and an oxygen component ratio z = 2.1 to 3.8, wherein variations in the average specific resistance in the direction of thickness of the sintered compact are 50% or less.
Description
DESCRIPTION
SPUTTERING TARGET AND METHOD FOR PRODUCING THE SAME
TECHNICAL FIELD
[0001]
The present invention relates to a sputtering target which enables a uniform semiconductor film, a protective film for a metal thin film, or the like to be stably formed of a ZnSn oxide by direct-current (DC) sputtering, and a method for producing the same.
Priority is claimed on Japanese Patent Application No. 2013-163051, filed August 6, 2013, and Japanese Patent Application No. 2014-157914, filed August 1, 2014, the contents of which are incorporated herein by reference.
BACKGROUND ART
SPUTTERING TARGET AND METHOD FOR PRODUCING THE SAME
TECHNICAL FIELD
[0001]
The present invention relates to a sputtering target which enables a uniform semiconductor film, a protective film for a metal thin film, or the like to be stably formed of a ZnSn oxide by direct-current (DC) sputtering, and a method for producing the same.
Priority is claimed on Japanese Patent Application No. 2013-163051, filed August 6, 2013, and Japanese Patent Application No. 2014-157914, filed August 1, 2014, the contents of which are incorporated herein by reference.
BACKGROUND ART
[0002]
In a liquid crystal display, a solar cell, or the like, it is suggested to use, as the material of an electrode which is electrically-conductive and transparent to allow light to pass through, a mixture (ZnSn oxide (ZTO)) of zinc oxide (ZnO) and tin oxide (Sn02).
Furthermore, since both of ZnO and SnO2 are semiconductors, ZTO can be used as not only a transparent electrode but also as an oxide semiconductor (for example, refer to PTL 1). Particularly, a Zn2SnO4 thin film, which is a semiconductor having a practical mobility, can be formed at room temperature using a ZTO sputtering target.
This may be formed on, for example, an organic film to be used as the material of a thin-film transistor (TFT). In this case, unlike the case of the transparent electrode mentioned above, the conductivity of the sputtering target is not allowed to be high.
Therefore, film formation is generally carried out according to a radio-frequency (RF) sputtering method instead of a direct-current (DC) sputtering method.
In a liquid crystal display, a solar cell, or the like, it is suggested to use, as the material of an electrode which is electrically-conductive and transparent to allow light to pass through, a mixture (ZnSn oxide (ZTO)) of zinc oxide (ZnO) and tin oxide (Sn02).
Furthermore, since both of ZnO and SnO2 are semiconductors, ZTO can be used as not only a transparent electrode but also as an oxide semiconductor (for example, refer to PTL 1). Particularly, a Zn2SnO4 thin film, which is a semiconductor having a practical mobility, can be formed at room temperature using a ZTO sputtering target.
This may be formed on, for example, an organic film to be used as the material of a thin-film transistor (TFT). In this case, unlike the case of the transparent electrode mentioned above, the conductivity of the sputtering target is not allowed to be high.
Therefore, film formation is generally carried out according to a radio-frequency (RF) sputtering method instead of a direct-current (DC) sputtering method.
[0003]
In addition, since the Zn2SnO4 thin film is transparent and has a highly refractive property, the Zn2SnO4 thin film is used as the protective film of a transparent far-infrared reflective film formed of a metal film such as an Au thin film, an Ag thin film, or a Cu thin film. In order to obtain good far-infrared reflection performance while ensuring a high transmittance, for example, the Zn2SnO4 thin film as a transparent and highly refractive film is laminated on the Ag thin film. For the lamination, a sputtering method is also employed.
In addition, since the Zn2SnO4 thin film is transparent and has a highly refractive property, the Zn2SnO4 thin film is used as the protective film of a transparent far-infrared reflective film formed of a metal film such as an Au thin film, an Ag thin film, or a Cu thin film. In order to obtain good far-infrared reflection performance while ensuring a high transmittance, for example, the Zn2SnO4 thin film as a transparent and highly refractive film is laminated on the Ag thin film. For the lamination, a sputtering method is also employed.
[0004]
As described above, since Zn2SnO4 itself has a high resistance, a sputtering target formed of Zn2SnO4 does not reach such a conductivity that enables DC
sputtering.
In order to form the Zn2SnO4 thin film using the sputtering target, the RF
sputtering method has to be employed, and this results in a low film-forming rate. Here, in order to decrease the resistance of the sputtering target for forming the Zn2SnO4 thin film, allowing ZnSnO3 to be a primary phase, or adding a dopant to decrease the resistance of the sputtering target and enable DC sputtering, is suggested (for example, refer to PTLs 2 to 4).
CITATION LIST
PATENT LITERATURE
As described above, since Zn2SnO4 itself has a high resistance, a sputtering target formed of Zn2SnO4 does not reach such a conductivity that enables DC
sputtering.
In order to form the Zn2SnO4 thin film using the sputtering target, the RF
sputtering method has to be employed, and this results in a low film-forming rate. Here, in order to decrease the resistance of the sputtering target for forming the Zn2SnO4 thin film, allowing ZnSnO3 to be a primary phase, or adding a dopant to decrease the resistance of the sputtering target and enable DC sputtering, is suggested (for example, refer to PTLs 2 to 4).
CITATION LIST
PATENT LITERATURE
[0005]
[PTL 1] Japanese Unexamined Patent Application, First Publication No.
[PTL 2] Japanese Unexamined Patent Application, First Publication No.
[PTL 3] Japanese Unexamined Patent Application, First Publication No.
[PTL 4] Japanese Unexamined Patent Application, First Publication No.
SUMMARY OF INVENTION
TECHNICAL PROBLEM
[PTL 1] Japanese Unexamined Patent Application, First Publication No.
[PTL 2] Japanese Unexamined Patent Application, First Publication No.
[PTL 3] Japanese Unexamined Patent Application, First Publication No.
[PTL 4] Japanese Unexamined Patent Application, First Publication No.
SUMMARY OF INVENTION
TECHNICAL PROBLEM
[0006]
As described above, in a ZTO sputtering target containing ZnSnO3 as a primary phase suggested in PTLs 2 and 3, the specific resistance of the target can be decreased.
Nevertheless, a sputter-deposited film formed by using the ZTO sputtering target has a high carrier concentration and a low resistance and is not appropriate as a semiconductor film.
As described above, in a ZTO sputtering target containing ZnSnO3 as a primary phase suggested in PTLs 2 and 3, the specific resistance of the target can be decreased.
Nevertheless, a sputter-deposited film formed by using the ZTO sputtering target has a high carrier concentration and a low resistance and is not appropriate as a semiconductor film.
[0007]
On the other hand, it is suggested to treat a sputtering target containing Zn2Sna4 under a reducing atmosphere and accelerate an increase in oxygen deficiency in a ZnSn oxide in order to realize a decrease in resistance. However, this method increases the number of processes, resulting in poor productivity. Furthermore, even when the sputtering target having a high density is subjected to a reducing treatment, the reduction does not progress through the inside of the target although the increase in oxygen deficiency in the surface of the target is accelerated, which results in variation in the reduced state in the thickness direction of the target. Therefore, the increase in the oxygen deficiency in the center portion of the target cannot be expected.
On the other hand, it is suggested to treat a sputtering target containing Zn2Sna4 under a reducing atmosphere and accelerate an increase in oxygen deficiency in a ZnSn oxide in order to realize a decrease in resistance. However, this method increases the number of processes, resulting in poor productivity. Furthermore, even when the sputtering target having a high density is subjected to a reducing treatment, the reduction does not progress through the inside of the target although the increase in oxygen deficiency in the surface of the target is accelerated, which results in variation in the reduced state in the thickness direction of the target. Therefore, the increase in the oxygen deficiency in the center portion of the target cannot be expected.
[0008]
For example, when a ZTO sputtering target having a greater size than a diameter of 100 mm and a thickness of 10 mm is manufactured, a phase in which the effect of reduction is insufficient remains toward the inside of the target although the surface of the target is sufficiently reduced. Therefore, variation in the specific resistance occurs in the thickness direction of the sputtering target. When sputtering is carried out using the sputtering target, the surface of the target has a low specific resistance and thus DC
sputtering is enabled. However, when the inside of the target is sputtered as the sputtering proceeds, a portion having a high specific resistance is exposed to the surface, and thus abnormal discharge frequently occurs. Therefore, the sputtering cannot be stably carried out, and the film-forming rate is also changed. As described above, there are problems in that DC sputtering cannot be stably carried out, and a uniform film cannot be formed.
For example, when a ZTO sputtering target having a greater size than a diameter of 100 mm and a thickness of 10 mm is manufactured, a phase in which the effect of reduction is insufficient remains toward the inside of the target although the surface of the target is sufficiently reduced. Therefore, variation in the specific resistance occurs in the thickness direction of the sputtering target. When sputtering is carried out using the sputtering target, the surface of the target has a low specific resistance and thus DC
sputtering is enabled. However, when the inside of the target is sputtered as the sputtering proceeds, a portion having a high specific resistance is exposed to the surface, and thus abnormal discharge frequently occurs. Therefore, the sputtering cannot be stably carried out, and the film-forming rate is also changed. As described above, there are problems in that DC sputtering cannot be stably carried out, and a uniform film cannot be formed.
[0009]
In addition, the ZTO sputtering target disclosed in PTL 3 contains ZnSnO3 as its primary phase and also contains a Sn02 phase. When the Sn02 phase is present in the sputtering target, the Sn02 phase becomes the cause of abnormal discharge or the occurrence of particles in the sputter-deposited film formed by using the DC
sputtering, and there is a further problem in that the target itself easily cracks.
In addition, the ZTO sputtering target disclosed in PTL 3 contains ZnSnO3 as its primary phase and also contains a Sn02 phase. When the Sn02 phase is present in the sputtering target, the Sn02 phase becomes the cause of abnormal discharge or the occurrence of particles in the sputter-deposited film formed by using the DC
sputtering, and there is a further problem in that the target itself easily cracks.
[0010]
Here, an object of the present invention is to provide a sputtering target formed of a ZnSn oxide, which has a further lower target-specific resistance over the entire region in a thickness direction, always enables stable DC sputtering until the end of the service life of the target, is less likely to crack even during sputtering, and is suitable for forming a semiconductor film, a protective film for a metal thin film, or the like, by -- uniformly and sufficiently accelerating an increase in the oxygen deficiency and accelerating a reduction reaction during sintering in the thickness direction (erosion depth direction) of the ZnSn oxide (ZTO) sputtering target, and a method of manufacturing the same.
SOLUTION TO PROBLEM
Here, an object of the present invention is to provide a sputtering target formed of a ZnSn oxide, which has a further lower target-specific resistance over the entire region in a thickness direction, always enables stable DC sputtering until the end of the service life of the target, is less likely to crack even during sputtering, and is suitable for forming a semiconductor film, a protective film for a metal thin film, or the like, by -- uniformly and sufficiently accelerating an increase in the oxygen deficiency and accelerating a reduction reaction during sintering in the thickness direction (erosion depth direction) of the ZnSn oxide (ZTO) sputtering target, and a method of manufacturing the same.
SOLUTION TO PROBLEM
[0011]
Paying attention to the fact that, in the above-mentioned ZnSn oxide (ZTO) sputtering target, the specific resistance of the target is low at the surface of the target and is increased toward the inside of the target, it was found that it is effective to also decrease the specific resistance of the inside of the target, and as a method of uniformizing a change in the specific resistance, it is effective to dry and granulate a mixture of predetermined amounts of a zinc oxide (ZnO) powder and a tin oxide (Sn02) powder, carry out a heat treatment on the resultant under a reducing atmosphere, and then carry out pressing sintering on the resultant in a non-oxidizing atmosphere.
In the heat treatment, reduction is accelerated to affect the inside of the mixture, the reduction proceeds over the entirety of the mixture, and an oxygen-deficient state is generated.
Accordingly, the specific resistance of the target is decreased over the entire region in the thickness direction of the target, and movement of oxygen atoms during sintering is accelerated. As a result, the density of a sintered body is enhanced. It was determined that a ZTO sputtering target which always enables stable DC sputtering is obtained consequently.
Paying attention to the fact that, in the above-mentioned ZnSn oxide (ZTO) sputtering target, the specific resistance of the target is low at the surface of the target and is increased toward the inside of the target, it was found that it is effective to also decrease the specific resistance of the inside of the target, and as a method of uniformizing a change in the specific resistance, it is effective to dry and granulate a mixture of predetermined amounts of a zinc oxide (ZnO) powder and a tin oxide (Sn02) powder, carry out a heat treatment on the resultant under a reducing atmosphere, and then carry out pressing sintering on the resultant in a non-oxidizing atmosphere.
In the heat treatment, reduction is accelerated to affect the inside of the mixture, the reduction proceeds over the entirety of the mixture, and an oxygen-deficient state is generated.
Accordingly, the specific resistance of the target is decreased over the entire region in the thickness direction of the target, and movement of oxygen atoms during sintering is accelerated. As a result, the density of a sintered body is enhanced. It was determined that a ZTO sputtering target which always enables stable DC sputtering is obtained consequently.
[0012]
Here, a mixture obtained by mixing a zinc oxide (ZnO) powder and a tin oxide (Sn02) powder, which are commercially available, at a mixing ratio of Zn and Sn of 1:1 in terms of atomic ratio using a wet type ball mill or a beads mill, was dried, granulated, inserted into a carbon crucible, and then subjected to a heat treatment at 800 C for 3 hours in a vacuum. Thereafter, the obtained powder was crushed, subjected to pressing sintering under conditions of 900 C, 3 hours, and 29.4 MPa (300 kgf/cm2), thereby obtaining a ZnSn oxide (ZTO) sintered body. The ZTO sintered body was machined to a predetermined shape and thus a ZTO sputtering target was produced. It was confirmed that the specific resistance of the target was further decreased over the entire region in the thickness direction of the target. It was confirmed that during formation of a ZTO film using the ZTO sputtering target, stable DC sputtering is always enabled.
Here, a mixture obtained by mixing a zinc oxide (ZnO) powder and a tin oxide (Sn02) powder, which are commercially available, at a mixing ratio of Zn and Sn of 1:1 in terms of atomic ratio using a wet type ball mill or a beads mill, was dried, granulated, inserted into a carbon crucible, and then subjected to a heat treatment at 800 C for 3 hours in a vacuum. Thereafter, the obtained powder was crushed, subjected to pressing sintering under conditions of 900 C, 3 hours, and 29.4 MPa (300 kgf/cm2), thereby obtaining a ZnSn oxide (ZTO) sintered body. The ZTO sintered body was machined to a predetermined shape and thus a ZTO sputtering target was produced. It was confirmed that the specific resistance of the target was further decreased over the entire region in the thickness direction of the target. It was confirmed that during formation of a ZTO film using the ZTO sputtering target, stable DC sputtering is always enabled.
[0013]
This was achieved by the heat treatment in the reducing atmosphere in a stage of the mixture before carrying out the pressing sintering. Therefore, reduction was sufficiently carried out over the entire region of the mixture and an oxygen-deficient state was achieved over the entire region in the thickness direction to the inside of the ZTO
sintered body that was subjected to the pressing sintering. It was found that this contributes to a further decrease in the specific resistance of the target.
This was achieved by the heat treatment in the reducing atmosphere in a stage of the mixture before carrying out the pressing sintering. Therefore, reduction was sufficiently carried out over the entire region of the mixture and an oxygen-deficient state was achieved over the entire region in the thickness direction to the inside of the ZTO
sintered body that was subjected to the pressing sintering. It was found that this contributes to a further decrease in the specific resistance of the target.
[0014]
Therefore, the present invention has been obtained on the basis of the above-described finding and employs the following constitutions in order to solve the above-described problems.
(1) A sputtering target of the present invention is a sintered body formed of a ZnSn oxide which has a composition expressed by a chemical formula: ZnxSny0, (x+y=2, and z-=x+2y-a(x+2y)) and which has a deficiency coefficient of a=0.002 to 0.03 and a fraction of oxygen of z=2.1 to 3.8, in which a variation of specific resistances with respect to an average of specific resistances in a thickness direction of the sintered body is 50% or lower.
(2) In the sputtering target of (1), a density ratio is 90% or higher.
(3) In the sputtering target of (1) and (2), a bending strength is 100 N/mm2 or higher.
(4) In the sputtering target of (1) to (3), the specific resistance is 1 acm or lower.
(5) The present invention is a method for producing the sputtering target of (1) to (4), and the manufacturing method includes a heat treatment process of drying and granulating a mixture of predetermined amounts of a zinc oxide powder and a tin oxide powder and thereafter heating the mixture in a reducing atmosphere; and a sintering process of carrying out pressing sintering on the mixture subjected to the heat treatment in a non-oxidizing atmosphere to obtain a sintered body, in which an oxygen-deficiencies are increased in the heat treatment process.
(6) In the producing method of (5), the heat treatment process and the sintering process are continuously carried out in a heating furnace.
ADVANTAGEOUS EFFECTS OF INVENTION
Therefore, the present invention has been obtained on the basis of the above-described finding and employs the following constitutions in order to solve the above-described problems.
(1) A sputtering target of the present invention is a sintered body formed of a ZnSn oxide which has a composition expressed by a chemical formula: ZnxSny0, (x+y=2, and z-=x+2y-a(x+2y)) and which has a deficiency coefficient of a=0.002 to 0.03 and a fraction of oxygen of z=2.1 to 3.8, in which a variation of specific resistances with respect to an average of specific resistances in a thickness direction of the sintered body is 50% or lower.
(2) In the sputtering target of (1), a density ratio is 90% or higher.
(3) In the sputtering target of (1) and (2), a bending strength is 100 N/mm2 or higher.
(4) In the sputtering target of (1) to (3), the specific resistance is 1 acm or lower.
(5) The present invention is a method for producing the sputtering target of (1) to (4), and the manufacturing method includes a heat treatment process of drying and granulating a mixture of predetermined amounts of a zinc oxide powder and a tin oxide powder and thereafter heating the mixture in a reducing atmosphere; and a sintering process of carrying out pressing sintering on the mixture subjected to the heat treatment in a non-oxidizing atmosphere to obtain a sintered body, in which an oxygen-deficiencies are increased in the heat treatment process.
(6) In the producing method of (5), the heat treatment process and the sintering process are continuously carried out in a heating furnace.
ADVANTAGEOUS EFFECTS OF INVENTION
[0015]
As described above, in the sintered body of the ZnSn oxide (ZTO) sputtering target of the present invention, the oxygen-deficient state remains, and the oxygen-deficiencies are increased over the entire region of the inside of the sintered body.
Therefore, the specific resistance is decreased over the entire region in the thickness direction (erosion depth direction) of the target to a level such that DC
sputtering is enabled. Furthermore, a variation in the specific resistance in the thickness direction of the target is decreased. As a result, DC sputtering can be stably carried out until the end of the service life of the target, and cracking of the target during the sputtering can also be suppressed. Furthermore, a uniform film can be formed.
As described above, in the sintered body of the ZnSn oxide (ZTO) sputtering target of the present invention, the oxygen-deficient state remains, and the oxygen-deficiencies are increased over the entire region of the inside of the sintered body.
Therefore, the specific resistance is decreased over the entire region in the thickness direction (erosion depth direction) of the target to a level such that DC
sputtering is enabled. Furthermore, a variation in the specific resistance in the thickness direction of the target is decreased. As a result, DC sputtering can be stably carried out until the end of the service life of the target, and cracking of the target during the sputtering can also be suppressed. Furthermore, a uniform film can be formed.
[0016]
In addition, the producing method of the present invention includes the heat treatment process of drying and granulating the mixture of the predetermined amounts of the zinc oxide powder and the tin oxide powder and thereafter heating the mixture in the reducing atmosphere; and the sintering process of carrying out pressing sintering on the mixture subjected to the heat treatment in the non-oxidizing atmosphere to obtain the sintered body. Therefore, an increase in the oxygen-deficiencies is accelerated in the heat treatment process, and the sintering is carried out while the oxygen-deficient state remains in the sintering process. As a result, a state in which reduction proceeds to the inside of the sintered body is achieved, and the oxygen-deficiencies are uniformly increased over the entire region of the inside of the sintered body. According to the producing method of the present invention, a ZTO sputtering target in which the specific resistance is low over the entire region in the thickness direction of the target and a variation in the specific resistance is small can be produced.
In addition, the producing method of the present invention includes the heat treatment process of drying and granulating the mixture of the predetermined amounts of the zinc oxide powder and the tin oxide powder and thereafter heating the mixture in the reducing atmosphere; and the sintering process of carrying out pressing sintering on the mixture subjected to the heat treatment in the non-oxidizing atmosphere to obtain the sintered body. Therefore, an increase in the oxygen-deficiencies is accelerated in the heat treatment process, and the sintering is carried out while the oxygen-deficient state remains in the sintering process. As a result, a state in which reduction proceeds to the inside of the sintered body is achieved, and the oxygen-deficiencies are uniformly increased over the entire region of the inside of the sintered body. According to the producing method of the present invention, a ZTO sputtering target in which the specific resistance is low over the entire region in the thickness direction of the target and a variation in the specific resistance is small can be produced.
[0017]
Therefore, according to the sputtering target of the present invention, since the specific resistance of the target is low over the entire region in the thickness direction of the target and is uniform in the target plane, stable DC sputtering is always enabled, which contributes to the enhancement of productivity.
BRIEF DESCRIPTION OF DRAWINGS
Therefore, according to the sputtering target of the present invention, since the specific resistance of the target is low over the entire region in the thickness direction of the target and is uniform in the target plane, stable DC sputtering is always enabled, which contributes to the enhancement of productivity.
BRIEF DESCRIPTION OF DRAWINGS
[0018]
FIG. 1 is a view illustrating measurement of a specific resistance in a sputtering in-plane direction of a sputtering target.
DESCRIPTION OF EMBODIMENTS
FIG. 1 is a view illustrating measurement of a specific resistance in a sputtering in-plane direction of a sputtering target.
DESCRIPTION OF EMBODIMENTS
[0019]
Next, an oxide sputtering target according to an embodiment of the present invention, and an embodiment of a method for producing the same will be described.
The sputtering target of the embodiment is formed of a sintered body formed of a ZnSn oxide having a composition expressed by the chemical formula: ZnxSnyOz.
The composition of zinc (Zn) and tin (Sn) is set such that x+y=2 is satisfied and that the fractions thereof are in the range of those in a ZnSn oxide film to be formed.
Furthermore, since Zn2SnO4 itself has a high specific resistance, the specific resistance of the target is decreased by making the ZnSn oxide (Zn2Sn04) to be in an oxygen-deficient state. It is preferable that the fraction z of oxygen (0) in the ZnSn oxide which is in the oxygen-deficient state be z=2.1 to 3.8.
Next, an oxide sputtering target according to an embodiment of the present invention, and an embodiment of a method for producing the same will be described.
The sputtering target of the embodiment is formed of a sintered body formed of a ZnSn oxide having a composition expressed by the chemical formula: ZnxSnyOz.
The composition of zinc (Zn) and tin (Sn) is set such that x+y=2 is satisfied and that the fractions thereof are in the range of those in a ZnSn oxide film to be formed.
Furthermore, since Zn2SnO4 itself has a high specific resistance, the specific resistance of the target is decreased by making the ZnSn oxide (Zn2Sn04) to be in an oxygen-deficient state. It is preferable that the fraction z of oxygen (0) in the ZnSn oxide which is in the oxygen-deficient state be z=2.1 to 3.8.
[0020]
Here, when a deficiency coefficient representing the acceleration of an increase in the oxygen-deficiencies is referred to as a, the fraction z of oxygen in the chemical formula: ZnxSnyOz of the ZnSn oxide of which the oxygen-deficiencies are increased can be expressed as z=x+2y-a(x+2y). A ZnO powder and an SnO2 powder are mixed so as to satisfy the conditions of x+y=2, and the mixture is subjected to a heat treatment, thereby adjusting the deficiency coefficient a of the mixture and the fraction of oxygen is changed. When the mixture of which the deficiency coefficient a is adjusted is subjected to hot pressing under a non-oxidizing atmosphere, a sintered body formed of the ZnSn oxide of which the oxygen-deficiencies are increased can be obtained.
In addition, the fraction of oxygen of z=2.1 to 3.8 is achieved as a range of the deficiency coefficient of a=0.002 to 0.03.
Here, when a deficiency coefficient representing the acceleration of an increase in the oxygen-deficiencies is referred to as a, the fraction z of oxygen in the chemical formula: ZnxSnyOz of the ZnSn oxide of which the oxygen-deficiencies are increased can be expressed as z=x+2y-a(x+2y). A ZnO powder and an SnO2 powder are mixed so as to satisfy the conditions of x+y=2, and the mixture is subjected to a heat treatment, thereby adjusting the deficiency coefficient a of the mixture and the fraction of oxygen is changed. When the mixture of which the deficiency coefficient a is adjusted is subjected to hot pressing under a non-oxidizing atmosphere, a sintered body formed of the ZnSn oxide of which the oxygen-deficiencies are increased can be obtained.
In addition, the fraction of oxygen of z=2.1 to 3.8 is achieved as a range of the deficiency coefficient of a=0.002 to 0.03.
[0021]
In the sputtering target of this embodiment, the deficiency coefficient is in a 5 range of a=0.002 to 0.03. When the deficiency coefficient a is higher than 0.03, a portion of tin oxide (Sn02) in the structure is reduced, and there is a possibility that metal tin (Sn) may be eluted. When Sn is eluted, Sn adheres to a furnace during producing, which results in not only damage to the furnace but also a reduction in productivity due to the need for cleaning of the furnace. In addition, there is a problem of a variation in 10 the composition of the sputtering target due to the eluted portion of Sn. On the other hand, when the deficiency coefficient a is lower than 0.002, since the specific resistance of the target is not reduced, and it becomes difficult to carry out DC
sputtering. Here, in this embodiment, the deficiency coefficient a is in a range of 0.002 to 0.03.
In addition, the deficiency coefficient a is more preferably 0.008 to 0.02, and is not limited thereto.
When the fraction z of oxygen is lower than 2.1, the ratio of the ZnO powder becomes too high, and thus there is concern that the film-forming rate may be lowered.
On the other hand, when the fraction z of oxygen is higher than 3.8, the ratio of the Sn02 powder becomes too high, and there is concern that an increase in the specific resistance, an increase in abnormal discharges, cracking during sputtering, or the like may easily occur. Here, in this embodiment, the fraction z of oxygen is in a range of 2.1 to 3.8.
In addition, the fraction z of oxygen is more preferably 2.7 to 3.6, and is not limited thereto.
In the sputtering target of this embodiment, the deficiency coefficient is in a 5 range of a=0.002 to 0.03. When the deficiency coefficient a is higher than 0.03, a portion of tin oxide (Sn02) in the structure is reduced, and there is a possibility that metal tin (Sn) may be eluted. When Sn is eluted, Sn adheres to a furnace during producing, which results in not only damage to the furnace but also a reduction in productivity due to the need for cleaning of the furnace. In addition, there is a problem of a variation in 10 the composition of the sputtering target due to the eluted portion of Sn. On the other hand, when the deficiency coefficient a is lower than 0.002, since the specific resistance of the target is not reduced, and it becomes difficult to carry out DC
sputtering. Here, in this embodiment, the deficiency coefficient a is in a range of 0.002 to 0.03.
In addition, the deficiency coefficient a is more preferably 0.008 to 0.02, and is not limited thereto.
When the fraction z of oxygen is lower than 2.1, the ratio of the ZnO powder becomes too high, and thus there is concern that the film-forming rate may be lowered.
On the other hand, when the fraction z of oxygen is higher than 3.8, the ratio of the Sn02 powder becomes too high, and there is concern that an increase in the specific resistance, an increase in abnormal discharges, cracking during sputtering, or the like may easily occur. Here, in this embodiment, the fraction z of oxygen is in a range of 2.1 to 3.8.
In addition, the fraction z of oxygen is more preferably 2.7 to 3.6, and is not limited thereto.
[0022]
Furthermore, in the sputtering target of this embodiment, a variation with respect to the average of the specific resistance in the thickness direction of the sintered body is 50% or lower. The reason for this limitation is that when the variation exceeds 50%, stable DC sputtering cannot be carried out, and a uniform film cannot be formed. By decreasing the variation in the specific resistance in the thickness direction of the target, DC sputtering can be stably carried out until the end of the service life of the target, and a uniform film can be formed. Moreover, cracking of the target can be suppressed during sputtering. It is more preferable that a variation with respect to the average of the specific resistance in the thickness direction of the sintered body be 30% or lower.
Furthermore, in the sputtering target of this embodiment, a variation with respect to the average of the specific resistance in the thickness direction of the sintered body is 50% or lower. The reason for this limitation is that when the variation exceeds 50%, stable DC sputtering cannot be carried out, and a uniform film cannot be formed. By decreasing the variation in the specific resistance in the thickness direction of the target, DC sputtering can be stably carried out until the end of the service life of the target, and a uniform film can be formed. Moreover, cracking of the target can be suppressed during sputtering. It is more preferable that a variation with respect to the average of the specific resistance in the thickness direction of the sintered body be 30% or lower.
[0023]
Here, in the sputtering target of this embodiment, in a case where the density ratio is 90% or higher, cracking is less likely to occur during sputtering, and it becomes possible to improve the film-forming rate. In order to reliably exhibit the operational effect, the density ratio is preferably 95% or higher.
Here, in the sputtering target of this embodiment, in a case where the density ratio is 90% or higher, cracking is less likely to occur during sputtering, and it becomes possible to improve the film-forming rate. In order to reliably exhibit the operational effect, the density ratio is preferably 95% or higher.
[0024]
In addition, in the sputtering target of this embodiment, in a case where the bending strength is 100 Nimm2 or higher, cracking is less likely to occur during sputtering, and it becomes possible to enhance the film-forming rate. In order to reliably exhibit the operational effect, the bending strength is preferably 130 I\l/nun2 or higher.
In addition, in the sputtering target of this embodiment, in a case where the bending strength is 100 Nimm2 or higher, cracking is less likely to occur during sputtering, and it becomes possible to enhance the film-forming rate. In order to reliably exhibit the operational effect, the bending strength is preferably 130 I\l/nun2 or higher.
[0025]
Moreover, in the sputtering target of this embodiment, in a case where the specific resistance is 1Q=cm or lower, DC sputtering can be stably carried out, and it becomes possible to improve the film-forming rate. In order to reliably exhibit the operational effect, the specific resistance is preferably 0.1 SI=cm or lower.
Moreover, in the sputtering target of this embodiment, in a case where the specific resistance is 1Q=cm or lower, DC sputtering can be stably carried out, and it becomes possible to improve the film-forming rate. In order to reliably exhibit the operational effect, the specific resistance is preferably 0.1 SI=cm or lower.
[0026]
In addition, an object of the producing method of this embodiment is to obtain a ZTO sputtering target which enables DC sputtering, obtains an appropriate target-specific resistance for formation of a semiconductor film or a metal thin film protective film, and has a decreased variation in the specific resistance in the thickness direction of the target.
In addition, the producing method of this embodiment includes a heat treatment process of drying and granulating a mixture of predetermined amounts of a zinc oxide (ZnO) powder and a tin oxide (Sn02) powder and thereafter heating the mixture in a reducing atmosphere, and a sintering process of carrying out pressing sintering on the mixture subjected to the heat treatment in a non-oxidizing atmosphere to obtain a sintered body.
The oxygen-deficient state of ZnO is promoted in the heat treatment process.
The deficiency coefficient a that represents the oxygen-deficient state is changed according to the temperature and the treatment time of a reducing treatment in the heat treatment process and is increased as the temperature is increased or the time is lengthened.
In addition, an object of the producing method of this embodiment is to obtain a ZTO sputtering target which enables DC sputtering, obtains an appropriate target-specific resistance for formation of a semiconductor film or a metal thin film protective film, and has a decreased variation in the specific resistance in the thickness direction of the target.
In addition, the producing method of this embodiment includes a heat treatment process of drying and granulating a mixture of predetermined amounts of a zinc oxide (ZnO) powder and a tin oxide (Sn02) powder and thereafter heating the mixture in a reducing atmosphere, and a sintering process of carrying out pressing sintering on the mixture subjected to the heat treatment in a non-oxidizing atmosphere to obtain a sintered body.
The oxygen-deficient state of ZnO is promoted in the heat treatment process.
The deficiency coefficient a that represents the oxygen-deficient state is changed according to the temperature and the treatment time of a reducing treatment in the heat treatment process and is increased as the temperature is increased or the time is lengthened.
[0027]
In the heat treatment process, a mixture, which is obtained by mixing a ZnO
powder and a Sn02 powder to satisfy x+y=2 in a composition expressed by the chemical formula: ZnõSnyOz using a wet type ball mill or a beads mill, is dried, granulated, inserted into a carbon crucible, and subjected to a heat treatment in a vacuum. By the heat treatment, oxygen deficiency is accelerated, and a range of the deficiency coefficient of oxygen (0) of a=0.002 to 0.03 can be realized. In the subsequent sintering process, the obtained mixture is subjected to pressing sintering under conditions of 800 C to 980 C, 2 hours to 9 hours, and 9.8 MPa to 49 MPa (100 kgf/cm2 to 500 kgf/cm2), specifically, conditions of 900 C, 3 hours, and 29.4 MPa (300 kgf/cm2), thereby obtaining a ZnSn oxide (ZTO) sintered body. In the sintered body obtained in this sintering process, the oxygen-deficient state remains over the entire region in the thickness direction even after the sintering. The sintered body is naturally cooled and taken out of the furnace. Then, the sintered body is machined and adhered to a backing plate, thereby producing a ZTO sputtering target. As a result, a variation in the specific resistance in the thickness direction of the target can be decreased, and DC
sputtering can be stably carried out until the end of the service life of the target.
In the heat treatment process, a mixture, which is obtained by mixing a ZnO
powder and a Sn02 powder to satisfy x+y=2 in a composition expressed by the chemical formula: ZnõSnyOz using a wet type ball mill or a beads mill, is dried, granulated, inserted into a carbon crucible, and subjected to a heat treatment in a vacuum. By the heat treatment, oxygen deficiency is accelerated, and a range of the deficiency coefficient of oxygen (0) of a=0.002 to 0.03 can be realized. In the subsequent sintering process, the obtained mixture is subjected to pressing sintering under conditions of 800 C to 980 C, 2 hours to 9 hours, and 9.8 MPa to 49 MPa (100 kgf/cm2 to 500 kgf/cm2), specifically, conditions of 900 C, 3 hours, and 29.4 MPa (300 kgf/cm2), thereby obtaining a ZnSn oxide (ZTO) sintered body. In the sintered body obtained in this sintering process, the oxygen-deficient state remains over the entire region in the thickness direction even after the sintering. The sintered body is naturally cooled and taken out of the furnace. Then, the sintered body is machined and adhered to a backing plate, thereby producing a ZTO sputtering target. As a result, a variation in the specific resistance in the thickness direction of the target can be decreased, and DC
sputtering can be stably carried out until the end of the service life of the target.
[0028]
In addition, in the above description, a case of producing the sintered body by using different heating furnaces for the heat treatment process and the sintering process is described. However, the heat treatment process and the sintering process may also be continuously carried out by using the same heating furnace. For example, sintering may also be carried out by filling a carbon mold with granulated powder, heating the powder to 900 C in a vacuum, and in this state, carrying out hot pressing of the heated powder at a pressing pressure of 29.4 MPa (300 kgf/cm2) for 3 hours. Here, an increase in the oxygen-deficiencies is accelerated by the heating in the stage prior to applying the pressing pressure to the powder. After the oxygen-deficiencies are increased, the sintering proceeds. Therefore, even after the sintering, the oxygen-deficient state remains over the entire region in the thickness direction, and the sintered body similar to that in a case of using different heating furnaces is obtained.
In addition, in the above description, a case of producing the sintered body by using different heating furnaces for the heat treatment process and the sintering process is described. However, the heat treatment process and the sintering process may also be continuously carried out by using the same heating furnace. For example, sintering may also be carried out by filling a carbon mold with granulated powder, heating the powder to 900 C in a vacuum, and in this state, carrying out hot pressing of the heated powder at a pressing pressure of 29.4 MPa (300 kgf/cm2) for 3 hours. Here, an increase in the oxygen-deficiencies is accelerated by the heating in the stage prior to applying the pressing pressure to the powder. After the oxygen-deficiencies are increased, the sintering proceeds. Therefore, even after the sintering, the oxygen-deficient state remains over the entire region in the thickness direction, and the sintered body similar to that in a case of using different heating furnaces is obtained.
[0029]
Next, the sputtering target according to the embodiment of the invention and the method of producing the same will be described in detail with reference to Examples.
Next, the sputtering target according to the embodiment of the invention and the method of producing the same will be described in detail with reference to Examples.
[0030]
EXAMPLES
First, a zinc oxide (ZnO) powder having a 4N purity and an average particle size of D50=1.0 pm, and a tin oxide (Sn02) powder having a 4N purity and an average particle size of D50=1511M were prepared. The powders were weighed to achieve the compositions shown in Table 1. The weighed powders as the raw material and zirconia balls (with a diameter of 5 mm and a diameter of 10 mm having the same weight) that weighed three times the weight of the powders (ratio by weight) were put into a plastic container and subjected to wet mixing in a ball mill device for 24 hours, thereby obtaining a mixed powder. As the solvent used at this time, for example, alcohol is used. In addition, instead of the above-mentioned zirconia balls, by using zirconia beads (with a diameter of 0.5 mm) and carrying out mixing in a bead mill device, a mixed powder may also be obtained.
EXAMPLES
First, a zinc oxide (ZnO) powder having a 4N purity and an average particle size of D50=1.0 pm, and a tin oxide (Sn02) powder having a 4N purity and an average particle size of D50=1511M were prepared. The powders were weighed to achieve the compositions shown in Table 1. The weighed powders as the raw material and zirconia balls (with a diameter of 5 mm and a diameter of 10 mm having the same weight) that weighed three times the weight of the powders (ratio by weight) were put into a plastic container and subjected to wet mixing in a ball mill device for 24 hours, thereby obtaining a mixed powder. As the solvent used at this time, for example, alcohol is used. In addition, instead of the above-mentioned zirconia balls, by using zirconia beads (with a diameter of 0.5 mm) and carrying out mixing in a bead mill device, a mixed powder may also be obtained.
[0031]
A slurry obtained through ball mill mixing (or bead mill mixing) was dried, granulated, and loaded into a heating furnace. Here, heating was started and transitioned to the heat treatment process. In the heat treatment process, the temperature was increased to 800 C in a vacuum and an increase in the oxygen-deficient state was accelerated. Thereafter, the temperature of the heating furnace was further increased to be transitioned to the sintering process. In Examples 1 to 7, sintering was carried out through hot pressing at a temperature of 900 C and a pressing pressure of 29.4 MPa (300 kgf/cm2) for 3 hours. In Example 8, sintering was carried out through hot pressing at a temperature of 930 C and a pressing pressure of 34.3 MPa (350 kgf/cm2) for 3 hours.
In Example 9, sintering was carried out through hot pressing at a temperature of 900 C
and a pressing pressure of 34.3 MPa (350 kgf/cm2) for 3 hours. In Example 10, sintering was carried out through hot pressing at a temperature of 850 C and a pressing pressure of 29.4 MPa (300 kgf/cm2) for 3 hours. In addition, the sintering process was carried out in a vacuum.
The sintering process finished, and the obtained sintered bodies were taken out of the heating furnace and then were machined, thereby producing ZTO
sputtering targets 5 of Examples 1 to 10 having a diameter of 125 mm.
A slurry obtained through ball mill mixing (or bead mill mixing) was dried, granulated, and loaded into a heating furnace. Here, heating was started and transitioned to the heat treatment process. In the heat treatment process, the temperature was increased to 800 C in a vacuum and an increase in the oxygen-deficient state was accelerated. Thereafter, the temperature of the heating furnace was further increased to be transitioned to the sintering process. In Examples 1 to 7, sintering was carried out through hot pressing at a temperature of 900 C and a pressing pressure of 29.4 MPa (300 kgf/cm2) for 3 hours. In Example 8, sintering was carried out through hot pressing at a temperature of 930 C and a pressing pressure of 34.3 MPa (350 kgf/cm2) for 3 hours.
In Example 9, sintering was carried out through hot pressing at a temperature of 900 C
and a pressing pressure of 34.3 MPa (350 kgf/cm2) for 3 hours. In Example 10, sintering was carried out through hot pressing at a temperature of 850 C and a pressing pressure of 29.4 MPa (300 kgf/cm2) for 3 hours. In addition, the sintering process was carried out in a vacuum.
The sintering process finished, and the obtained sintered bodies were taken out of the heating furnace and then were machined, thereby producing ZTO
sputtering targets 5 of Examples 1 to 10 having a diameter of 125 mm.
[0032]
COMPARATIVE EXAMPLE
For comparison of the ZTO sputtering targets of Examples described above, 10 ZTO sputtering targets of Comparative Examples 1 to 4 shown in Table 1 were prepared.
Hot pressing conditions were the same as those of Example 1. In all of Comparative Examples 1 to 4, similar to the case of each of Examples, a mixed powder was obtained by mixing the ZnO powder and the Sn02 powder. However, in Comparative Example 1, the Sn02 powder was mixed in a large proportion, and thus the fraction z of oxygen was 15 higher than 3.8. In Comparative Example 2, the ZnO powder was mixed in a large proportion, and thus the fraction z of oxygen was lower than 2.1. In addition, in Comparative Examples 3 and 4, mixing of the ZnO powder and the Sn02 powder was carried out in the same manner as in Examples 3 and 6 to 10. However, in both of Comparative Examples 3 and 4, the deficiency coefficient a that represents the oxygen-deficient state was outside the range of this embodiment.
COMPARATIVE EXAMPLE
For comparison of the ZTO sputtering targets of Examples described above, 10 ZTO sputtering targets of Comparative Examples 1 to 4 shown in Table 1 were prepared.
Hot pressing conditions were the same as those of Example 1. In all of Comparative Examples 1 to 4, similar to the case of each of Examples, a mixed powder was obtained by mixing the ZnO powder and the Sn02 powder. However, in Comparative Example 1, the Sn02 powder was mixed in a large proportion, and thus the fraction z of oxygen was 15 higher than 3.8. In Comparative Example 2, the ZnO powder was mixed in a large proportion, and thus the fraction z of oxygen was lower than 2.1. In addition, in Comparative Examples 3 and 4, mixing of the ZnO powder and the Sn02 powder was carried out in the same manner as in Examples 3 and 6 to 10. However, in both of Comparative Examples 3 and 4, the deficiency coefficient a that represents the oxygen-deficient state was outside the range of this embodiment.
[0033]
<Deficiency Coefficient a>
Here, the deficiency coefficient a of the ZnSn oxide that forms the obtained ZTO sputtering targets of Examples and Comparative Examples was calculated in the following procedure.
(Procedure 1) A ZnSn oxide powder obtained by crushing the target was heated at 100 C for 1 hour and dried.
(Procedure 2) 1 g of the ZnSn oxide powder after being dried was weighed and was put into a crucible that was subjected to a heat treatment in advance to have a constant weight. Here, the weight of the ZnSn oxide powder after being dried is referred to as a, and the weight of the crucible is referred to as b.
(Procedure 3) In an electric furnace, the powder was heated at 800 C for 2 hours, and the heated powder was naturally cooled for 30 minutes to 60 minutes in a desiccator and then was precisely weighed. This was repeated until a constant weight was achieved. The weight of the ZnSn oxide powder and the crucible after the heat treatment is referred to as c.
(Procedure 4) The deficiency coefficient a of oxygen was calculated according to the following calculation expression. In addition, the atomic weight of oxygen is referred to as [0], the atomic weight of Zn is referred to as [Zn], and the atomic weight of Sn is referred to as [Sn].
<Deficiency Coefficient a>
Here, the deficiency coefficient a of the ZnSn oxide that forms the obtained ZTO sputtering targets of Examples and Comparative Examples was calculated in the following procedure.
(Procedure 1) A ZnSn oxide powder obtained by crushing the target was heated at 100 C for 1 hour and dried.
(Procedure 2) 1 g of the ZnSn oxide powder after being dried was weighed and was put into a crucible that was subjected to a heat treatment in advance to have a constant weight. Here, the weight of the ZnSn oxide powder after being dried is referred to as a, and the weight of the crucible is referred to as b.
(Procedure 3) In an electric furnace, the powder was heated at 800 C for 2 hours, and the heated powder was naturally cooled for 30 minutes to 60 minutes in a desiccator and then was precisely weighed. This was repeated until a constant weight was achieved. The weight of the ZnSn oxide powder and the crucible after the heat treatment is referred to as c.
(Procedure 4) The deficiency coefficient a of oxygen was calculated according to the following calculation expression. In addition, the atomic weight of oxygen is referred to as [0], the atomic weight of Zn is referred to as [Zn], and the atomic weight of Sn is referred to as [Sn].
[0034]
[Expression 1]
(c ¨ b ¨ a) 1(c ¨ b) = [0] x a(x + 2 y) [Zn]x x +[Sn]x y + [0]x (x + 2 y)
[Expression 1]
(c ¨ b ¨ a) 1(c ¨ b) = [0] x a(x + 2 y) [Zn]x x +[Sn]x y + [0]x (x + 2 y)
[0035]
Procedures 1 to 4 were repeated three times, and the average value of the obtained deficiency coefficients a is shown in Table 1.
= [0036]
[Table 1]
ZnõSny0, composition Deficiency X Y z coefficient a ' _ -Example 1 0.2 1.8 3.793 0.01 Example 2 0.4 1.6 3.594 0.01 Example 3 1 1 2.994 0.01 Example 4 1.6 0.4 2.395 0.01 Example 5 1.8 0.2 2.195 0.01 Example 6 1 1 2.999 = 0.002 Example 7 1 1 2.982 0.03 Example 8 1 1 2.994 0.01 Example 9 1 1 2.994 0.01 Example 10 1 1 2.994 0.01 Comparative 0.1 1.9 3.893 0.01 Example 1 Comparative 1.9 0.1 2.095 0.01 Example 2 Comparative 1 1 Higher than Lower than Example 3 2.999 0.001 Comparative 1 1 2.976 0.04 Example 4 [0037]
<Measurement of Specific Resistance>
For the obtained ZTO sputtering targets of Examples and Comparative Examples, the specific resistance was measured by a resistance-measuring apparatus.
Here, a ZTO sputtering target having a diameter of 125 mm and a thickness of mm was produced by the above-described producing method and was cut to 2 nun and 10 5 mm from the surface (0 mm) in an erosion depth direction (thickness direction of the target), and the specific resistances at the positions were measured. A
variation in the specific resistance in the thickness direction was expressed as a percentage of a variation =
= coefficient. In addition, the variation coefficient was obtained by dividing the standard deviation of the specific resistances in the thickness direction of the target by the average value of the specific resistances in the thickness direction of the target.
[0038]
In addition, at the positions of the surface (0 mm) of the ZTO sputtering target of Examples and Comparative Examples, and 2 mm and 5 mm from the surface (0 mm), for five (A to E) measurement points in a sputtered target plane shown in FIG 1, the specific resistances were measured. The average value of the measured specific resistances in the plane is shown in Table 2. As the measurement points A to E, on the XY
coordinates having the center of the sputtered surface as the origin, there were A (X=0 mm, Y=55 mm), B (X=-55 mm, Y=0 mm), C (X=0 mm, Y=0 mm), D (X=55 nun, Y=0 mm) and E (X=0 mm, Y=-55 mm).
During this measurement, the specific resistance (Q=cm) was measured by a four-probe method using a low-resistivity meter (Loresta-GP) manufactured by Mitsubishi Chemical Corporation as the resistance-measuring apparatus. During the measurement, the temperature was 23 5 C, and the humidity was 50 20%.
[0039]
<Density Ratio>
For each of the obtained ZTO sputtering targets of Examples and Comparative Examples, the density ratio was obtained.
After the sintered body was machined to predetermined dimensions, the bulk density thereof was obtained by measuring the weight thereof and was divided by a theoretical density pfn, thereby calculating the density ratio. In addition, the theoretical density pfr, was calculated by the following expression on the basis of the weight of the s _ raw material. In addition, the density of Sn02 is referred to as pl, the mass%
of Sn02 is referred to as C1, the density of ZnO is p2, and the mass% of ZnO is referred to as C2.
[0040]
[Expression 2]
P fn = (Ci 1100 C2 /100 +
[0041]
<Bending Strength>
According to the same method as that of the ZTO sputtering targets of Examples and Comparative Examples shown in Table 1, each of test pieces (3 mmx4 mmx35 mm) corresponding to each composition was produced, a stress curve thereof was measured at a pushing speed of 0.5 mm/min using Autograph AG-X manufactured by Shimadzu Corporation, the maximum point stress in an elastic region was obtained, and this was determined as the bending strength.
_ . [0042]
[Table 2]
Specific resistance in thickness direction of Variation target (.cm) in specific resistance Density Bending Cutting Cutting Cutting in ratio strength amount amount amount thickness (%) (N/mm2) 0 mm 2 mm 5 mm direction (%) Example 1 0.19 0.35 0.18 32 90 Example 2 0.15 0.25 0.19 21 93 , Example 3 0.11 0.15 , 0.08 25 92 Example 4 0.18 0.22 0.25 13 92 Example 5 0.08 0.02 0.09 49 94 Example 6 0.75 0.63 0.52 15 93 Example 7 0.04 0.08 0.05 30 93 Example 8 0.04 0.03 0.05 20 97 Example 9 0.05 0.06 0.08 20 95 Example 10 0.06 0.07 0.11 27 87 Comparative 1.5 3.2 2.1 31 92 Example 1 Comparative 0.05 0.04 0.09 36 88 105 Example 2 Outside of Outside of Outside of Comparative measurement measurement measurement - 93 Example 3 range range range Comparative 0.03 0.05 0.05 22 94 87 Example 4 [0043]
5 Next, for the obtained ZTO sputtering target of Examples and Comparative Examples, the number of times of occurrences of abnormal discharge during sputtering, the film-forming rate, and the presence or absence of cracking of the target during sputtering were measured.
[0044]
10 <Number of Times of Abnormal Discharge>
Next, for the obtained ZTO sputtering target of Examples and Comparative Examples, the number of times of occurrences of abnormal discharge during sputtering was measured in the following procedure.
By using the ZTO sputtering targets of Examples and Comparative Examples, a film-forming test was carried out under the following film-forming conditions.
= Power supply: two conditions of DC800W/DC1200W
= Total pressure: 0.4 Pa = Sputtering gas: Ar=28.5 sccm, 02=1.5 sccm = Target-substrate (TS) distance: 70 mm Sputtering was carried out for 1 hour under the above film-forming conditions, and the number of times of occurrences of abnormal micro-arc discharge was automatically measured by an arcing counter attached to a sputtering power supply device. The measurement results are shown in Table 3.
[0045]
<Measurement of Film-Forming Rate>
For the measurement of the film-forming rate, sputtering was carried out for seconds under the above-described film-forming conditions to allow a target material to be deposited on a glass substrate subjected to masking, and the height of a stepped portion formed after removing the masking was measured by using a step profiler, thereby calculating the film-forming rate. The measurement results are shown in Table 3.
[0046]
<Observation of Target Cracking>
After measuring the number of times of occurrences of abnormal discharge it .
described above, the target surface was visually observed, and the presence or absence of cracking was checked. The observation results are shown in Table 3. In Table 3, a case where cracking of the target was confirmed is represented by "present", and a case where cracking of the target was not confirmed is represented by "absent".
[0047]
[Table 3]
Number of Number of times of Cracking of Film-forming times of Cracking of Film-forming occurrences target during rate occurrences target during rate of abnormal sputtering (nm/sec) of abnormal sputtering (nm/sec) discharge discharge Example 1 35 Absent 4.8 42 Present 6.6 Example 2 20 Absent 4.3 25 Present 6.4 Example 3 0 Absent 4.1 2 Present 6.2 Example 4 2 Absent 3.5 5 Present 4.9 Example 5 1 Absent 2.6 3 Present 3.6 Example 6 2 Absent 3.8 2 Present 5.4 Example 7 1 Absent 4.4 5 Present 6.2 Example 8 1 Absent 4.2 1 Absent 6.3 Example 9 1 Absent 4.2 2 Absent 6.3 Example 10 154 Absent 4.0 389 Present 5.8 Unable to Unable to Comparative measure due measure due 5489 Present 9345 Present Example 1 to abnormal to abnormal discharge discharge Comparative 2 Absent 2.0 45 Present 2.8 Example 2 Comparative Example 3 Unable to carry out DC sputtering Unable to carry out DC sputtering Comparative Unable to evaluate due to elution of Sn Unable to evaluate due to elution of Sn Example 4 [0048]
According to the results shown in each of the tables above, it was found that in all of the ZTO sputtering targets of Examples, the deficiency coefficient a was in a range of 0.002 to 0.03, a decrease in resistance could be achieved over the entire region in the =
= target thickness direction, and a variation in the thickness direction of the target was small. Moreover, during sputtering carried out using the ZTO sputtering targets of Examples described above, the occurrence of abnormal discharge can be significantly reduced, and furthermore, cracking of the target was not confirmed under the conditions of DC800W. Therefore, since the specific resistance of the target could be low over the entire region in the thickness direction of the target, stable DC sputtering was always enabled, and thus a uniform film could be formed while improving the film-forming rate.
[0049]
In addition, in Example 10 in which the density ratio was 87% and the bending strength was 891=1/mm2, cracking of the target was not confirmed under the conditions of DC800W, but cracking of the target was confirmed under the conditions of DC1200W.
In addition, the number of times of abnormal discharge was slightly high.
In contrast, in Example 8 in which the density ratio was 97% and the bending strength was 141 Nimm2, and in Example 9 in which the density ratio was 95%
and the bending strength was 130 Nimm2, it was confirmed that cracking of the target was not confirmed even under the conditions of DC1200W, and the number of times of occurrences of abnormal discharge was suppressed.
[0050]
On the other hand, in all of the ZTO sputtering targets of Comparative Examples, similar to Examples, a mixed powder was obtained by mixing the ZnO powder and the SnO2 powder. In Comparative Example 1, since the Sn02 powder was mixed in a large proportion and thus the fraction z of oxygen was higher than 3.8, the specific resistance was high, and the number of times of abnormal discharge was also high.
Moreover, since cracking was confirmed during sputtering, film formation could not be carried out.
In Comparative Example 2, since the ZnO powder was mixed in a large proportion and thus the fraction z of oxygen was lower than 2.1, the film-forming rate was not enhanced.
In Comparative Examples 3 and 4, the deficiency coefficient a that represents the oxygen-deficient state was outside a range of 0.002 to 0.03. In Comparative Example 3, the deficiency coefficient a was too low, the conductivity was low, and thus the specific resistance in the thickness direction of the target was so high as to be outside the measurement range, and thus DC sputtering could not be carried out. In Comparative Example 4, since the deficiency coefficient a was too high, metal (Sn) was eluted in the sputtering target, and thus sputtering could not be carried out.
[0051]
As described above, according to the present invention, the specific resistance was lowered over the entire region in the thickness direction of the ZTO
sputtering target, and the variation in the target could be decreased. This effect is similarly applied even when the target shape is flat (flat plate shape) or cylinder. In addition, although the reducing atmosphere is achieved by carrying out the heat treatment process of the present invention in a vacuum by using the carbon crucible, a reducing gas such as CO, SO2, or H2 may also be used. In addition, although the sintering process in Examples and Comparative Examples is carried out in a vacuum, the same effect is obtained as long as the non-oxidizing atmosphere is achieved.
INDUSTRIAL APPLICABILITY
[0052]
According to the sputtering target of the present invention, a semiconductor film, a protective film for a metal thin film, or the like can be stably formed by direct-current (DC) sputtering until the end of the service life of the target. In addition, according to the method of manufacturing the sputtering target of the present invention, a sputtering target, which enables a semiconductor film, a protective film for a metal thin film, or the like to be stably formed by direct-current (DC) sputtering until the end of the service life of the target, can be produced.
Procedures 1 to 4 were repeated three times, and the average value of the obtained deficiency coefficients a is shown in Table 1.
= [0036]
[Table 1]
ZnõSny0, composition Deficiency X Y z coefficient a ' _ -Example 1 0.2 1.8 3.793 0.01 Example 2 0.4 1.6 3.594 0.01 Example 3 1 1 2.994 0.01 Example 4 1.6 0.4 2.395 0.01 Example 5 1.8 0.2 2.195 0.01 Example 6 1 1 2.999 = 0.002 Example 7 1 1 2.982 0.03 Example 8 1 1 2.994 0.01 Example 9 1 1 2.994 0.01 Example 10 1 1 2.994 0.01 Comparative 0.1 1.9 3.893 0.01 Example 1 Comparative 1.9 0.1 2.095 0.01 Example 2 Comparative 1 1 Higher than Lower than Example 3 2.999 0.001 Comparative 1 1 2.976 0.04 Example 4 [0037]
<Measurement of Specific Resistance>
For the obtained ZTO sputtering targets of Examples and Comparative Examples, the specific resistance was measured by a resistance-measuring apparatus.
Here, a ZTO sputtering target having a diameter of 125 mm and a thickness of mm was produced by the above-described producing method and was cut to 2 nun and 10 5 mm from the surface (0 mm) in an erosion depth direction (thickness direction of the target), and the specific resistances at the positions were measured. A
variation in the specific resistance in the thickness direction was expressed as a percentage of a variation =
= coefficient. In addition, the variation coefficient was obtained by dividing the standard deviation of the specific resistances in the thickness direction of the target by the average value of the specific resistances in the thickness direction of the target.
[0038]
In addition, at the positions of the surface (0 mm) of the ZTO sputtering target of Examples and Comparative Examples, and 2 mm and 5 mm from the surface (0 mm), for five (A to E) measurement points in a sputtered target plane shown in FIG 1, the specific resistances were measured. The average value of the measured specific resistances in the plane is shown in Table 2. As the measurement points A to E, on the XY
coordinates having the center of the sputtered surface as the origin, there were A (X=0 mm, Y=55 mm), B (X=-55 mm, Y=0 mm), C (X=0 mm, Y=0 mm), D (X=55 nun, Y=0 mm) and E (X=0 mm, Y=-55 mm).
During this measurement, the specific resistance (Q=cm) was measured by a four-probe method using a low-resistivity meter (Loresta-GP) manufactured by Mitsubishi Chemical Corporation as the resistance-measuring apparatus. During the measurement, the temperature was 23 5 C, and the humidity was 50 20%.
[0039]
<Density Ratio>
For each of the obtained ZTO sputtering targets of Examples and Comparative Examples, the density ratio was obtained.
After the sintered body was machined to predetermined dimensions, the bulk density thereof was obtained by measuring the weight thereof and was divided by a theoretical density pfn, thereby calculating the density ratio. In addition, the theoretical density pfr, was calculated by the following expression on the basis of the weight of the s _ raw material. In addition, the density of Sn02 is referred to as pl, the mass%
of Sn02 is referred to as C1, the density of ZnO is p2, and the mass% of ZnO is referred to as C2.
[0040]
[Expression 2]
P fn = (Ci 1100 C2 /100 +
[0041]
<Bending Strength>
According to the same method as that of the ZTO sputtering targets of Examples and Comparative Examples shown in Table 1, each of test pieces (3 mmx4 mmx35 mm) corresponding to each composition was produced, a stress curve thereof was measured at a pushing speed of 0.5 mm/min using Autograph AG-X manufactured by Shimadzu Corporation, the maximum point stress in an elastic region was obtained, and this was determined as the bending strength.
_ . [0042]
[Table 2]
Specific resistance in thickness direction of Variation target (.cm) in specific resistance Density Bending Cutting Cutting Cutting in ratio strength amount amount amount thickness (%) (N/mm2) 0 mm 2 mm 5 mm direction (%) Example 1 0.19 0.35 0.18 32 90 Example 2 0.15 0.25 0.19 21 93 , Example 3 0.11 0.15 , 0.08 25 92 Example 4 0.18 0.22 0.25 13 92 Example 5 0.08 0.02 0.09 49 94 Example 6 0.75 0.63 0.52 15 93 Example 7 0.04 0.08 0.05 30 93 Example 8 0.04 0.03 0.05 20 97 Example 9 0.05 0.06 0.08 20 95 Example 10 0.06 0.07 0.11 27 87 Comparative 1.5 3.2 2.1 31 92 Example 1 Comparative 0.05 0.04 0.09 36 88 105 Example 2 Outside of Outside of Outside of Comparative measurement measurement measurement - 93 Example 3 range range range Comparative 0.03 0.05 0.05 22 94 87 Example 4 [0043]
5 Next, for the obtained ZTO sputtering target of Examples and Comparative Examples, the number of times of occurrences of abnormal discharge during sputtering, the film-forming rate, and the presence or absence of cracking of the target during sputtering were measured.
[0044]
10 <Number of Times of Abnormal Discharge>
Next, for the obtained ZTO sputtering target of Examples and Comparative Examples, the number of times of occurrences of abnormal discharge during sputtering was measured in the following procedure.
By using the ZTO sputtering targets of Examples and Comparative Examples, a film-forming test was carried out under the following film-forming conditions.
= Power supply: two conditions of DC800W/DC1200W
= Total pressure: 0.4 Pa = Sputtering gas: Ar=28.5 sccm, 02=1.5 sccm = Target-substrate (TS) distance: 70 mm Sputtering was carried out for 1 hour under the above film-forming conditions, and the number of times of occurrences of abnormal micro-arc discharge was automatically measured by an arcing counter attached to a sputtering power supply device. The measurement results are shown in Table 3.
[0045]
<Measurement of Film-Forming Rate>
For the measurement of the film-forming rate, sputtering was carried out for seconds under the above-described film-forming conditions to allow a target material to be deposited on a glass substrate subjected to masking, and the height of a stepped portion formed after removing the masking was measured by using a step profiler, thereby calculating the film-forming rate. The measurement results are shown in Table 3.
[0046]
<Observation of Target Cracking>
After measuring the number of times of occurrences of abnormal discharge it .
described above, the target surface was visually observed, and the presence or absence of cracking was checked. The observation results are shown in Table 3. In Table 3, a case where cracking of the target was confirmed is represented by "present", and a case where cracking of the target was not confirmed is represented by "absent".
[0047]
[Table 3]
Number of Number of times of Cracking of Film-forming times of Cracking of Film-forming occurrences target during rate occurrences target during rate of abnormal sputtering (nm/sec) of abnormal sputtering (nm/sec) discharge discharge Example 1 35 Absent 4.8 42 Present 6.6 Example 2 20 Absent 4.3 25 Present 6.4 Example 3 0 Absent 4.1 2 Present 6.2 Example 4 2 Absent 3.5 5 Present 4.9 Example 5 1 Absent 2.6 3 Present 3.6 Example 6 2 Absent 3.8 2 Present 5.4 Example 7 1 Absent 4.4 5 Present 6.2 Example 8 1 Absent 4.2 1 Absent 6.3 Example 9 1 Absent 4.2 2 Absent 6.3 Example 10 154 Absent 4.0 389 Present 5.8 Unable to Unable to Comparative measure due measure due 5489 Present 9345 Present Example 1 to abnormal to abnormal discharge discharge Comparative 2 Absent 2.0 45 Present 2.8 Example 2 Comparative Example 3 Unable to carry out DC sputtering Unable to carry out DC sputtering Comparative Unable to evaluate due to elution of Sn Unable to evaluate due to elution of Sn Example 4 [0048]
According to the results shown in each of the tables above, it was found that in all of the ZTO sputtering targets of Examples, the deficiency coefficient a was in a range of 0.002 to 0.03, a decrease in resistance could be achieved over the entire region in the =
= target thickness direction, and a variation in the thickness direction of the target was small. Moreover, during sputtering carried out using the ZTO sputtering targets of Examples described above, the occurrence of abnormal discharge can be significantly reduced, and furthermore, cracking of the target was not confirmed under the conditions of DC800W. Therefore, since the specific resistance of the target could be low over the entire region in the thickness direction of the target, stable DC sputtering was always enabled, and thus a uniform film could be formed while improving the film-forming rate.
[0049]
In addition, in Example 10 in which the density ratio was 87% and the bending strength was 891=1/mm2, cracking of the target was not confirmed under the conditions of DC800W, but cracking of the target was confirmed under the conditions of DC1200W.
In addition, the number of times of abnormal discharge was slightly high.
In contrast, in Example 8 in which the density ratio was 97% and the bending strength was 141 Nimm2, and in Example 9 in which the density ratio was 95%
and the bending strength was 130 Nimm2, it was confirmed that cracking of the target was not confirmed even under the conditions of DC1200W, and the number of times of occurrences of abnormal discharge was suppressed.
[0050]
On the other hand, in all of the ZTO sputtering targets of Comparative Examples, similar to Examples, a mixed powder was obtained by mixing the ZnO powder and the SnO2 powder. In Comparative Example 1, since the Sn02 powder was mixed in a large proportion and thus the fraction z of oxygen was higher than 3.8, the specific resistance was high, and the number of times of abnormal discharge was also high.
Moreover, since cracking was confirmed during sputtering, film formation could not be carried out.
In Comparative Example 2, since the ZnO powder was mixed in a large proportion and thus the fraction z of oxygen was lower than 2.1, the film-forming rate was not enhanced.
In Comparative Examples 3 and 4, the deficiency coefficient a that represents the oxygen-deficient state was outside a range of 0.002 to 0.03. In Comparative Example 3, the deficiency coefficient a was too low, the conductivity was low, and thus the specific resistance in the thickness direction of the target was so high as to be outside the measurement range, and thus DC sputtering could not be carried out. In Comparative Example 4, since the deficiency coefficient a was too high, metal (Sn) was eluted in the sputtering target, and thus sputtering could not be carried out.
[0051]
As described above, according to the present invention, the specific resistance was lowered over the entire region in the thickness direction of the ZTO
sputtering target, and the variation in the target could be decreased. This effect is similarly applied even when the target shape is flat (flat plate shape) or cylinder. In addition, although the reducing atmosphere is achieved by carrying out the heat treatment process of the present invention in a vacuum by using the carbon crucible, a reducing gas such as CO, SO2, or H2 may also be used. In addition, although the sintering process in Examples and Comparative Examples is carried out in a vacuum, the same effect is obtained as long as the non-oxidizing atmosphere is achieved.
INDUSTRIAL APPLICABILITY
[0052]
According to the sputtering target of the present invention, a semiconductor film, a protective film for a metal thin film, or the like can be stably formed by direct-current (DC) sputtering until the end of the service life of the target. In addition, according to the method of manufacturing the sputtering target of the present invention, a sputtering target, which enables a semiconductor film, a protective film for a metal thin film, or the like to be stably formed by direct-current (DC) sputtering until the end of the service life of the target, can be produced.
Claims (6)
1. A sputtering target, which is a sintered body formed of a ZnSn oxide which has a composition expressed by a chemical formula: Zn x Sn y O z, (x+y=2, and z=x+2y-.alpha.(x+2y)) and which has a deficiency coefficient of a=0.002 to 0.03 and a fraction of oxygen of z=2.1 to 3.8, wherein a variation of specific resistance with respect to an average of specific resistances in a thickness direction of the sintered body is 50% or lower.
2. The sputtering target according to Claim 1, wherein a density ratio is 90%
or higher.
or higher.
3. The sputtering target according to Claim 1 or 2, wherein a bending strength is 100 N/mm2 or higher.
4. The sputtering target according to any one of Claims 1 to 3, wherein the specific resistance is 1 .OMEGA..cndot.cm or lower.
5. A method for producing the sputtering target according to any one of Claims 1 to 4, the method comprising:
a heat treatment process of drying and granulating a mixture of predetermined amounts of a zinc oxide powder and a tin oxide powder and thereafter heating the mixture in a reducing atmosphere; and a sintering process of carrying out pressing sintering on the mixture subjected to the heat treatment in a non-oxidizing atmosphere to obtain a sintered body, wherein an oxygen-deficiencies are increased in the heat treatment process.
a heat treatment process of drying and granulating a mixture of predetermined amounts of a zinc oxide powder and a tin oxide powder and thereafter heating the mixture in a reducing atmosphere; and a sintering process of carrying out pressing sintering on the mixture subjected to the heat treatment in a non-oxidizing atmosphere to obtain a sintered body, wherein an oxygen-deficiencies are increased in the heat treatment process.
6. The method for producing the sputtering target according to Claim 5, wherein the heat treatment process and the sintering process are continuously carried out in a heating furnace.
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|---|---|---|---|
| JP2013163051 | 2013-08-06 | ||
| JP2013-163051 | 2013-08-06 | ||
| JP2014-157914 | 2014-08-01 | ||
| JP2014157914A JP6233233B2 (en) | 2013-08-06 | 2014-08-01 | Sputtering target and manufacturing method thereof |
| PCT/JP2014/070572 WO2015020029A1 (en) | 2013-08-06 | 2014-08-05 | Sputtering target and method for producing same |
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| JP (1) | JP6233233B2 (en) |
| KR (1) | KR102237339B1 (en) |
| CA (1) | CA2918933A1 (en) |
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| JP2022105853A (en) * | 2021-01-05 | 2022-07-15 | 三菱マテリアル株式会社 | Oxide sputtering target, and method of producing oxide sputtering target |
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| JP3533333B2 (en) * | 1998-08-21 | 2004-05-31 | Ｔｄｋ株式会社 | Sputtering target for interference film of optical recording medium and method of manufacturing the same |
| JP4797712B2 (en) * | 2006-03-08 | 2011-10-19 | 東ソー株式会社 | ZnO-Al2O3-based sintered body, sputtering target, and method for producing transparent conductive film |
| JP4552950B2 (en) | 2006-03-15 | 2010-09-29 | 住友金属鉱山株式会社 | Oxide sintered body for target, manufacturing method thereof, manufacturing method of transparent conductive film using the same, and transparent conductive film obtained |
| JP4730204B2 (en) | 2006-05-24 | 2011-07-20 | 住友金属鉱山株式会社 | Oxide sintered compact target and method for producing oxide transparent conductive film using the same |
| JP4994068B2 (en) * | 2006-08-09 | 2012-08-08 | 出光興産株式会社 | Oxide conductive material and manufacturing method thereof |
| JP2009009816A (en) * | 2007-06-28 | 2009-01-15 | Idemitsu Kosan Co Ltd | Oxide conductive material and its manufacturing method |
| JP2009123957A (en) * | 2007-11-15 | 2009-06-04 | Sumitomo Chemical Co Ltd | Oxide semiconductor material and manufacturing method therefor, electronic device, and field-effect transistor |
| JP5024226B2 (en) | 2008-08-06 | 2012-09-12 | 日立金属株式会社 | Oxide sintered body and manufacturing method thereof, sputtering target, semiconductor thin film |
| JP2010070410A (en) * | 2008-09-17 | 2010-04-02 | Idemitsu Kosan Co Ltd | Method for producing oxide sintered compact |
| JP2012066968A (en) * | 2010-09-24 | 2012-04-05 | Kobelco Kaken:Kk | Oxide sintered compact and sputtering target |
| JP5651095B2 (en) | 2010-11-16 | 2015-01-07 | 株式会社コベルコ科研 | Oxide sintered body and sputtering target |
| JP5460619B2 (en) * | 2011-01-13 | 2014-04-02 | 住友重機械工業株式会社 | Target and film forming apparatus provided with the same |
| JP2012148937A (en) * | 2011-01-20 | 2012-08-09 | Sumitomo Chemical Co Ltd | Electrically conductive composite oxide, zinc oxide type sintered body, method for manufacturing it and target |
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| JP6233233B2 (en) | 2017-11-22 |
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