JP4779798B2 - Oxide sintered body, target, and transparent conductive film obtained using the same - Google Patents

Description

  The present invention relates to an oxide sintered body, a target, and a transparent conductive film obtained by using the oxide sintered body, and more specifically, an oxide sintered body containing zinc oxide as a main component and further containing nickel and processed the same. The present invention relates to a target and a low resistance transparent conductive film excellent in chemical resistance obtained by a direct current sputtering method or an ion plating method.

The transparent conductive film has high conductivity and high transmittance in the visible light region. Transparent conductive films are used for solar cells, liquid crystal display elements, electrodes of various other light receiving elements, and various types of protective films for automobile windows, heat ray reflective films for buildings, antistatic films, refrigeration showcases, etc. It is also used as a transparent heating element for fogging.
As the transparent conductive film, tin oxide (SnO ₂ ) -based, zinc oxide (ZnO) -based, and indium oxide (In ₂ O ₃ ) -based thin films are known. As the tin oxide, those containing antimony as a dopant (ATO) and those containing fluorine as a dopant (FTO) are used. As the zinc oxide system, those containing aluminum as a dopant (AZO) and those containing gallium as a dopant (GZO) are used. The transparent conductive film most industrially used is an indium oxide type. Among them, indium oxide containing tin as a dopant is referred to as an ITO (Indium-Tin-Oxide) film, and since a low resistance film can be easily obtained, it has been widely used so far.

The low-resistance transparent conductive film is suitably used for surface elements such as solar cells, liquid crystals, organic electroluminescence, and inorganic electroluminescence, and touch panels. As a method for producing these transparent conductive films, a sputtering method or an ion plating method is often used. In particular, the sputtering method is an effective method when forming a material with a low vapor pressure or when precise film thickness control is required, and since the operation is very simple, it is widely used industrially. ing.
The sputtering method is a film forming method using a sputtering target as a thin film raw material. The target is a solid containing a metal element constituting a thin film to be formed, and a sintered body such as a metal, a metal oxide, a metal nitride, or a metal carbide, or a single crystal depending on the case. In this method, a vacuum apparatus is generally evacuated once and then a rare gas such as argon is introduced. Under a gas pressure of about 10 Pa or less, the substrate is the anode and the sputtering target is the cathode. An argon plasma is generated by causing a discharge, and the argon cations in the plasma collide with the sputtering target of the cathode, and particles of target components that are repelled by this are deposited on the substrate to form a film.

Sputtering methods are classified according to the method of generating argon plasma, those using high-frequency plasma are called high-frequency sputtering methods, and those using DC plasma are called DC sputtering methods.
In general, the direct current sputtering method is widely used industrially because the film forming speed is higher than that of the high frequency sputtering method, the power supply equipment is inexpensive, and the film forming operation is simple. However, in contrast to the high-frequency sputtering method, which can form a film even with an insulating target, in the direct current sputtering method, a conductive target must be used.
The deposition rate when depositing using the sputtering method is closely related to the chemical bonding of the target material. The sputtering method uses a phenomenon in which an argon cation having kinetic energy collides with a target surface, and a substance on the target surface receives energy and is ejected. The weaker the probability of popping out by sputtering increases.

In a method of forming a transparent conductive film of an oxide such as ITO by a sputtering method, an alloy target of an element constituting the film (In-Sn alloy in the case of an ITO film) is used in a mixed gas of argon and oxygen. A method of forming an oxide film by a reactive sputtering method, and a mixture of argon and oxygen using an oxide sintered body target of an element constituting the film (In-Sn-O sintered body in the case of an ITO film) There is a method of forming an oxide film by a reactive sputtering method in a gas.
Among them, the method using an alloy target supplies a large amount of oxygen gas during sputtering, but the film formation rate and film characteristics (specific resistance, transmittance) are greatly dependent on the amount of oxygen gas introduced during film formation. It is difficult to stably produce a transparent conductive film having a constant film thickness and desired characteristics. On the other hand, in the method using an oxide target, a part of oxygen supplied to the film is supplied by sputtering from the target, and the remaining deficient oxygen amount is supplied as oxygen gas. Therefore, the dependency of the film formation rate and film characteristics (specific resistance, transmittance) on the amount of oxygen gas introduced during film formation is smaller than when using an alloy target, and the film thickness and characteristics are more stable and constant. Since a transparent conductive film can be produced, a method using an oxide target is employed industrially.
In consideration of productivity and manufacturing cost, the direct current sputtering method is easier to form at high speed than the high frequency sputtering method. That is, when the same power is input to the same target and the film formation rates are compared, the direct current sputtering method is about two to three times faster. Also, the direct current sputtering method is advantageous in terms of productivity because the deposition rate increases as the high direct current power is input. For this reason, a sputtering target that can form a film stably even when high DC power is applied industrially is useful.
On the other hand, ion plating is a method in which a surface of a target material to be a film is locally heated by arc discharge to be sublimated and ionized and attached to a negatively charged workpiece to form a film. In any case, a film having good adhesion at a low temperature can be obtained, a very wide variety of substrate properties and film properties can be selected, an alloy or a compound can be formed, and the process is environmentally friendly. Ion plating is similar to sputtering, and a transparent conductive film having a certain film thickness and characteristics can be produced more stably by using an oxide tablet.

As described above, indium oxide-based materials such as ITO are widely used industrially, but non-indium-based materials have been demanded in recent years because rare metal indium is expensive.
As described above, zinc oxide materials such as GZO and AZO and tin oxide materials such as FTO and ATO are known as non-indium materials. In particular, zinc oxide-based materials are attracting attention as materials that are low in cost because they are abundantly embedded as resources and that exhibit low specific resistance and high transmittance comparable to ITO. However, the zinc oxide-based transparent conductive film obtained using this has the advantage of being easily dissolved in ordinary acids and alkalis, but on the other hand, it has poor resistance to acids and alkalis, and the etching rate can be controlled. Since it is difficult, high-definition patterning processing by wet etching, which is indispensable for liquid crystal display applications, is difficult. Therefore, its use is limited to solar cells that do not require patterning. For these reasons, it has been a problem to improve the chemical resistance of zinc oxide-based materials.

As an attempt to improve the chemical resistance of the zinc oxide-based transparent conductive film, there are the following examples. In Patent Document 1, zinc (ZnO) is co-added with chromium (Cr) and a donor impurity selected from group III element aluminum (Al) or the like or group IV element silicon (Si) or the like. A new impurity-codoped ZnO transparent conductive film and a target used to produce the thin film for the purpose of easily controlling the chemical properties of the ZnO-based transparent conductive film without significantly impairing the visible light transmittance and electrical resistivity. Materials and patterning techniques have been proposed.
However, since Cr is known to be highly toxic, it must be considered so as not to adversely affect the environment and the human body. Moreover, since it is necessary to control etching liquid to the temperature range lower than usual called 20-5 degreeC, it is difficult to apply industrially.

  Patent Document 2 proposes an impurity co-doped ZnO transparent conductive film in which cobalt (Co) or vanadium (V) is co-added instead of chromium (Cr), a target material used for manufacturing the thin film, and the like. Yes. However, cobalt (Co) is a rare metal like indium (In). Further, since vanadium (V) is toxic, it must be considered so as not to adversely affect the environment and the human body. Moreover, even if any is added, it is difficult to apply industrially because it is necessary to control the etching solution in a temperature range of 20 to 5 ° C., which is lower than usual, as in Patent Document 1.

Further, in Patent Document 3, a transparent conductive film in which an oxide film, a metal film, and an oxide film are stacked in this order on a base in (2n + 1) layers (n ≧ 1) contains Ni and Zn. An oxide film (NZ oxide film) or an oxide film containing Ni, Zn, and Ga (NZ oxide film containing Ga) is provided as at least part of the oxide film that forms the transparent conductive film. It is described that this transparent conductive film is excellent in moisture resistance and alkali resistance. However, the NZ oxide film constitutes a part of the laminated film and is preferably provided on both sides of the two interfaces formed by the metal film and the oxide film. The performance of the target for obtaining a material film, the film alone, has not been clarified. Nothing is stated about the acid resistance of the NZ oxide film containing Ga, and no detailed knowledge is given about the influence of the film composition and crystal phase on the acid resistance and alkali resistance.
JP 2002-075061 A JP 2002-075062 A JP-A-11-262968

  An object of the present invention is to provide an oxide sintered body containing zinc oxide as a main component and further containing nickel, a target obtained by processing the oxide sintered body, and a direct current sputtering method or an ion plating method using the same. An object of the present invention is to provide a low-resistance transparent conductive film excellent in chemical resistance obtained by the above.

  In order to solve the above-mentioned conventional problems, the present inventors have made extensive studies, and in an oxide sintered body containing zinc oxide as a main component and further containing nickel, the nickel content is reduced to Ni / (Zn + Ni). When the atomic ratio is set to 0.02 to 0.25, and this is processed into a target and used in a direct current sputtering method or the like, it is possible to obtain a zinc oxide-based transparent conductive film having high chemical resistance to acid / alkali and low resistance. In addition, it was found that the conductivity of the obtained zinc oxide-based transparent conductive film was further improved by using an oxide sintered body containing a specific amount of gallium and / or aluminum as a target, and the present invention was completed. It came to do.

That is, according to the first invention of the present invention, an oxide sintered body containing zinc oxide as a main component and further containing nickel, and mixing for 12 hours using a raw material powder having an average particle size of 3 μm or less. The molded body formed as described above is obtained by sintering in a sintering furnace at 1100 to 1600 ° C. for 10 to 30 hours in an atmosphere in which oxygen is introduced into the atmosphere, and the nickel content is Ni / (Zn + Ni). The atomic ratio is 0.02 to 0.25, no nickel oxide phase is contained , and the peak intensity ratio by X-ray diffraction measurement represented by the following formula (A) is 25% or less. There is provided an oxide sintered body characterized by having a specific resistance of 50 kΩcm or less.
I [Ni _x Zn _1-x O (200)] / I [ZnO (101)] × 100 (%) Formula (A)
(In the formula, I [Ni _x Zn _1-x O (200)] is a complex oxide Ni _x Zn _1-x O (x = 0.6, 0.7, 0.8) having a cubic rock salt structure. Or 0.9) (200) peak intensity of the phase, and I [ZnO (101)] represents the (101) peak intensity of the zinc oxide phase having a hexagonal wurtzite structure)

Further, according to the second invention of the present invention, an oxide sintered body containing zinc oxide as a main component and further containing nickel and gallium and / or aluminum, and having an average particle size of 3 μm or less A compact formed by mixing with powder for 12 hours or more is obtained by sintering in a sintering furnace at 1100 to 1600 ° C. for 10 to 30 hours in an atmosphere in which oxygen is introduced into the atmosphere. Alternatively, the aluminum content is more than 0 as the (Ga + Al) / (Zn + Ga + Al) atomic ratio and is 0.08 or less, and the nickel content is 0.02 to 0.25 as the Ni / (Zn + Ga + Al + Ni) atomic ratio. further nickel oxide phase containing Sarezu, moreover, the peak intensity ratio of X-ray diffraction measurement represented by the formula (a) below is not more than 25%, and the specific resistance is 5kΩ Oxide sintered body, characterized in that m or less is provided.
I [Ni _x Zn _1-x O (200)] / I [ZnO (101)] × 100 (%) Formula (A)
(In the formula, I [Ni _x Zn _1-x O (200)] is a complex oxide Ni _x Zn _1-x O (x = 0.6, 0.7, 0.8) having a cubic rock salt structure. Or 0.9) (200) peak intensity of the phase, and I [ZnO (101)] represents the (101) peak intensity of the zinc oxide phase having a hexagonal wurtzite structure)
According to the third invention of the present invention, in the first or second invention, the nickel content is 0.05 to 0.14 as a Ni / (Zn + Ni) or Ni / (Zn + Ga + Al + Ni) atomic ratio. An oxide sintered body characterized by the above is provided.
According to the fourth invention of the present invention, in the second invention, the content of gallium and / or aluminum is 0.01 to 0.05 as an atomic ratio of (Ga + Al) / (Zn + Ga + Al). An oxide sintered body characterized by the above is provided.

Furthermore, according to the fifth invention of the present invention, there is provided an oxide sintered body characterized in that, in any one of the first to fourth inventions, the density is 5.0 g / cm ² or more.

On the other hand, according to the sixth invention of the present invention, there is provided a target obtained by processing the oxide sintered body according to any one of the first to fifth inventions.

According to a seventh aspect of the present invention, there is provided the transparent conductive film according to the sixth aspect , wherein the transparent conductive film is formed on the substrate by sputtering or ion plating using a target.

According to an eighth aspect of the present invention, in the seventh aspect , the transparent conductive film containing zinc oxide as a main component and further containing nickel, wherein nickel is 0 in a Ni / (Zn + Ni) atomic ratio. 0.002 to 0.25 , which is mainly composed of a zinc oxide phase having a hexagonal wurtzite structure, and a peak intensity ratio by an X-ray diffraction measurement represented by the following formula (B) is 50% or more. The transparent conductive film according to claim 9, wherein the transparent conductive film does not contain a zinc oxide phase having a cubic rock salt structure .
I [ZnO (002)] / (I [ZnO (002)] + I [ZnO (100)]) × 100 (%) Formula (B)
(Wherein I [ZnO (002)] is the (002) peak intensity of the zinc oxide phase having a hexagonal wurtzite structure, and I [ZnO (100)] has a hexagonal wurtzite structure. (Shows the (100) peak intensity of the zinc oxide phase.)
According to the ninth aspect of the present invention, in the eighth aspect , gallium and / or aluminum is further contained in a (Ga + Al) / (Zn + Ga + Al) atomic ratio exceeding 0 and not exceeding 0.08. A transparent conductive film is provided.

According to the present invention, since the oxide sintered body contains zinc oxide as a main component and further contains a specific amount of nickel, if this is used as a sputtering target, arc discharge does not occur even in direct current sputtering, It becomes possible to form a transparent conductive film excellent in chemical resistance. Furthermore, the conductivity of the transparent conductive film obtained can be further improved by using an oxide sintered body containing a specific amount of gallium and / or aluminum.
The oxide sintered body of the present invention can be similarly used as a tablet for ion plating, and high-speed film formation is possible. The zinc oxide-based transparent conductive film of the present invention thus obtained is controlled to an optimal composition and crystal phase, and thus exhibits excellent chemical resistance without greatly impairing visible light transmittance and electrical resistivity. It is extremely useful industrially as a transparent conductive film that does not use relatively expensive indium.

  Hereinafter, the oxide sintered body of the present invention, the target, and the transparent conductive film obtained using the same will be described in detail.

1. Oxide sintered body The oxide sintered body of the present invention is an oxide sintered body containing zinc oxide as a main component and further containing nickel, and mixing is performed using raw material powder having an average particle size of 3 μm or less. The formed body formed for 12 hours or more was obtained by sintering in a sintering furnace at 1100 to 1600 ° C. for 10 to 30 hours in an atmosphere in which oxygen was introduced, and the nickel content was Ni / ( (Zn + Ni) atomic ratio is 0.02 to 0.25, no nickel oxide phase is contained , and the peak intensity ratio by X-ray diffraction measurement represented by the following formula (A) is 25%. The specific resistance is 50 kΩcm or less (hereinafter also referred to as a first oxide sintered body).
The oxide sintered body of the present invention is an oxide sintered body containing zinc oxide as a main component and further containing nickel and gallium and / or aluminum and having an average particle diameter of 3 μm or less. A molded body formed by mixing for 12 hours or more using a sinter is obtained by sintering in a sintering furnace at 1100 to 1600 ° C. for 10 to 30 hours in an atmosphere in which oxygen is introduced into the atmosphere, and gallium and / or The content of aluminum is more than 0 as a (Ga + Al) / (Zn + Ga + Al) atomic ratio and 0.08 or less, and the nickel content is 0.02 to 0.25 as an Ni / (Zn + Ga + Al + Ni) atomic ratio, further nickel oxide phase containing Sarezu, moreover, the peak intensity ratio of X-ray diffraction measurement represented by the formula (a) below is not more than 25%, and the resistivity is 5kΩcm Characterized in that it is a lower (hereinafter, referred to also as a second oxide sintered body).
I [Ni _x Zn _1-x O (200)] / I [ZnO (101)] × 100 (%) Formula (A)
(In the formula, I [Ni _x Zn _1-x O (200)] is a complex oxide Ni _x Zn _1-x O (x = 0.6, 0.7, 0.8) having a cubic rock salt structure. Or 0.9) (200) peak intensity of the phase, and I [ZnO (101)] represents the (101) peak intensity of the zinc oxide phase having a hexagonal wurtzite structure)

(1) First oxide sintered body The first oxide sintered body of the present invention is an oxide containing zinc oxide as a main component and further containing a specific amount of nickel. The nickel content is a ratio of 0.02 to 0.25 in terms of the Ni / (Zn + Ni) atomic ratio. Since nickel is contained in the above composition range, when this oxide sintered body is used as a target raw material, the chemical resistance of the transparent conductive film mainly composed of zinc oxide formed by sputtering or the like is improved. .

  Here, the chemical resistance of the transparent conductive film is divided into acid resistance and alkali resistance, and the relationship with the nickel content is described. When the nickel content is less than 0.02 in terms of the Ni / (Zn + Ni) atomic ratio, both the acid resistance and alkali resistance of the resulting transparent conductive film are insufficient. As will be described in detail below, the crystallinity of the film is lowered, so that sufficient acid resistance cannot be obtained. However, the alkali resistance is better as the nickel content is increased, and even when the content exceeds 0.25, the alkali resistance is sufficiently good. On the other hand, if the nickel content exceeds 0.25, the crystallinity of the film decreases, and the specific resistance also increases. In order to enable direct current (DC) sputtering, the specific resistance needs to be 50 kΩcm or less, and the tendency for the specific resistance to increase is not preferable. In order to reduce the specific resistance, it is desirable to add, for example, sintering in a reducing atmosphere or heat treatment during the production of the oxide sintered body. In order to obtain a low specific resistance and excellent acid resistance and alkali resistance, the nickel content is more preferably in the range of 0.05 to 0.14 in terms of the Ni / (Zn + Ni) atomic ratio. It is.

In the present invention, the oxide sintered body is mainly composed of a zinc oxide phase. This zinc oxide phase refers to a hexagonal wurtzite structure described in JCPDS card 36-1451, and oxygen deficiency. Also included are zinc-deficient non-stoichiometric compositions. Nickel, which is an additive element, is usually dissolved in the zinc site of the zinc oxide phase.
In the oxide sintered body of the present invention, in the oxide sintered body, squid not contain nickel oxide phase according to JCPDS card 47-1049, or, X-rays of the formula (A) The peak intensity ratio by diffraction measurement is 25% or less . If nickel is not dissolved in the zinc oxide phase and is contained in the oxide sintered body as a nickel oxide phase that is not a good conductor, it will be charged by the irradiation of argon ions during sputtering, causing dielectric breakdown. This is because arc discharge is generated and stable film formation by direct current (DC) sputtering becomes difficult.

Further, in the oxide sintered body of the present invention, a composite oxide Ni _x Zn _1-x O (x = 0.6, 0. ₀ ) containing nickel and zinc described in JCPDS cards 75-0270 to 75-0273. (7, 0.8 or 0.9) phase is defined by the following formula (A), the peak due to (101) of the zinc oxide phase having a hexagonal wurtzite structure obtained by X-ray diffraction measurement, and cubic The intensity ratio of the peak due to (200) of the complex oxide Ni _x Zn _1-x O (x = 0.6, 0.7, 0.8, or 0.9) phase having a crystal rock salt structure is 25% or less Included in range.
I [Ni _x Zn _1-x O (200)] / I [ZnO (101)] × 100 (%) Formula (A)

Here, I [Ni _x Zn _1-x O (200)] is a complex oxide Ni _x Zn _1-x O ( x = 0.6, 0) having a cubic rock salt structure obtained by X-ray diffraction measurement. .7, 0.8 or 0.9 ) phase (200) peak intensity, and I [ZnO (101)] is a hexagonal wurtzite structure zinc oxide phase ( 101) It shows the peak intensity.

The complex oxide Ni _x Zn _1-x O (x = 0.6, 0.7, 0.8 or 0.9) phase containing nickel and zinc in the oxide sintered body has the above strength ratio range. If it is present in excess, a zinc oxide phase having a cubic rock salt structure is formed in the film, so that the acid resistance is remarkably lowered.
Further, when the nickel content is high, the nickel oxide phase or the composite oxide Ni _x Zn _1-x O containing nickel and zinc (x = 0.6, 0.7, 0.8 or 0.9) Since a phase is easily generated, a compact formed using a raw material powder having an average particle size of 5 μm or less is baked at 1100 to 1600 ° C. for 10 to 30 hours in an atmosphere in which oxygen is introduced into a sintering furnace. It is necessary to produce an oxide sintered body by a process set to the condition of bonding.

The density of the oxide sintered body is preferably 5.0 g / cm ² or more. When the density is lower than 5.0 g / cm ² , DC sputtering becomes difficult and problems such as remarkable generation of nodules occur. Nodules are fine protrusions that occur in the erosion part of the target surface as a result of sputtering. Abnormal discharge and splash occur due to the nodules, which causes coarse particles ( Particles) float, and the particles adhere to the film in the middle of the film formation and cause the quality to deteriorate. However, when the film is formed by the ion plating method, cracking occurs if the sintered body density is too high, and therefore a relatively low density in the range of 3.5 to 4.5 g / cm ² is preferable.

  The oxide sintered body of the present invention is mainly composed of a zinc oxide phase in which nickel is dissolved, has a specific resistance of 50 kΩcm or less, and enables stable film formation by direct current (DC) sputtering. is there. In addition to nickel, other additive elements (for example, indium, titanium, tungsten, molybdenum, iridium, ruthenium, rhenium, and the like) may be included as long as the object of the present invention is not impaired.

(2) Second oxide sintered body The second oxide sintered body of the present invention is an oxide sintered body containing zinc oxide as a main component and further containing nickel and gallium and / or aluminum. Thus, the content of gallium and / or aluminum exceeds 0 as the (Ga + Al) / (Zn + Ga + Al) atomic ratio and is 0.08 or less, and the content of nickel is 0.02 as the Ni / (Zn + Ga + Al + Ni) atomic ratio. The specific resistance is 0.25 cm or less.

In the oxide sintered body, gallium and / or aluminum that contributes to improvement in conductivity must be included in the above composition range. When the total content of gallium and / or aluminum exceeds 0.08 in terms of the (Ga + Al) / (Zn + Ga + Al) atomic ratio, the transparent conductive film formed using the target made from the oxide sintered body of the present invention is used. Since the crystallinity of the film is lowered, the specific resistance is increased, and chemical resistance, particularly acid resistance is lowered.
Further, as described above, when the nickel content is less than 0.02 in terms of the Ni / (Zn + Ga + Al + Ni) atomic ratio, the transparent conductive film cannot obtain sufficient acid resistance and alkali resistance, and exceeds 0.25. In addition, sufficient acid resistance cannot be obtained, and the specific resistance increases, which is not preferable. In order to obtain low specific resistance and excellent acid resistance and alkali resistance, the total content of gallium and / or aluminum is 0.01 to 0.05 in terms of (Ga + Al) / (Zn + Ga + Al) atomic ratio, nickel It is more preferable that the content of Ni is in the range of 0.05 to 0.14 in terms of the Ni / (Zn + Ga + Al + Ni) atomic ratio.

  In the present invention, the oxide sintered body is mainly composed of a zinc oxide phase. This zinc oxide phase refers to a hexagonal wurtzite structure described in JCPDS card 36-1451, and oxygen deficiency. Also included are zinc-deficient non-stoichiometric compositions. The additive elements gallium, aluminum, and nickel are usually dissolved in the zinc site of the zinc oxide phase.

  When composed mainly of gallium and / or aluminum and a zinc oxide phase in which nickel is dissolved in the above composition range, it is possible to obtain conductivity of 5 kΩcm or less, more preferably 1 kΩcm or less. In film formation by direct current (DC) sputtering, higher power can be applied, and high-speed film formation is possible.

2. Production of Oxide Sintered Body In the present invention, the oxide sintered body is manufactured by , for example, (1) a step of forming a molded body from raw material powder, and (2) placing the molded body in a sintering furnace. And a method including a step of sintering. In the oxide sintered body of the present invention, the nickel oxide phase is not generated, but depends largely on, for example, the particle size of the raw material powder, the mixing conditions, and the firing conditions among the manufacturing conditions.

(1) Formation of molded body In the step of forming a molded body from the raw material powder, if it is the first oxide sintered body, nickel oxide powder is added to the zinc oxide powder as the raw material powder, and the second oxide is sintered. If it is a ligation, the gallium oxide powder and / or aluminum oxide powder containing the group III element of a periodic table are added and mixed with this. The group III element in the periodic table greatly contributes to a high-density and highly conductive sintered body.

As the raw material powder, it is necessary to use a powder having an average particle size of 3 μm or less. For example, if the first oxide sintered body, zinc oxide powder having an average particle size of 3 μm or less, nickel oxide powder having an average particle size of 3 μm or less, and if the second oxide sintered body, A gallium oxide powder having an average particle size of 3 μm or less and / or an aluminum oxide powder having an average particle size of 3 μm or less is used. And it is necessary to make ball mill mixing into 12 hours or more. Preferably, a mixed powder that has been mixed for 18 hours or more is effective in suppressing the formation of a nickel oxide phase in the oxide sintered body. When the average particle size exceeds 3 μm or the mixing time is less than 12 hours, the components are not uniformly mixed, and gallium and / or aluminum and nickel are not easily dissolved in the above composition range in the zinc oxide phase. Therefore, a nickel oxide phase or a large amount of complex oxide Ni _x Zn _1-x O (x = 0.6, 0.7, 0.8 or 0) in the zinc oxide phase of the obtained oxide sintered body .9) A phase is present, which is not preferable.

  In general, in the case of making a target oxide sintered body that can stably form a film in a zinc oxide-based oxide sintered body, it is preferable to use an oxide of an element added to zinc oxide as a raw material powder, It can also be produced from a raw material powder in which zinc oxide and other metals to be added are combined. However, if the metal powder (particles) added to the oxide sintered body is present, the metal particles on the surface of the target melt during the film formation, which increases the difference in composition between the target and the film. There is no.

The raw material powder is mixed and stirred using a known apparatus, added with a binder (for example, PVA) and granulated, then adjusted to a range of 10 to 100 μm, and the granules thus obtained are 1000 kg / cm ³ or more, for example. Press molding at a pressure of Subsequently, the raw material powder is press-molded with a metal mold to compress the powder, resulting in high-concentration condensed particles, an improved bulk density, and a higher-density molded body can be obtained. If the pressure is lower than 1000 kg / cm ² , the bulk density is not sufficiently improved, and a satisfactory density improvement effect cannot be expected.

(2) Sintering of molded body The sintering process following the molding process is a process in which the molded body is put into a sintering furnace and sintered, and the firing method may be a simple normal pressure firing method, The law may be used.

For example, in an atmosphere to introduce oxygen into the atmosphere of the sintering furnace, and 1100 ° C. to 1600 ° C., preferably at 1200 ° C. to 1500 ° C., over a period of 10 to 30 hours, preferably sintered 15-25 hours. When the temperature is lower than 1100 ° C., the sintering is insufficient, the density is lowered, and the resistance value of the sintered body is increased. In addition, a target manufactured from the obtained sintered body is not preferable because a film formation rate is slow and defects such as abnormal discharge occur during sputtering. At this time, the temperature can be raised at 1 to 3 ° C./min. After the sintering, when cooling, the introduction of oxygen can be stopped and the temperature can be lowered to 1000 ° C. at 10 ° C./min.

It is preferable that the density of the obtained oxide sintered body is 5.0 g / cm ² or more. When the density is lower than 5.0 g / cm ² , DC sputtering becomes difficult and problems such as remarkable generation of nodules occur.

3. Target The first or second oxide sintered body produced by the above method is processed by surface grinding or the like to obtain a predetermined dimension, and then adhered to a backing plate, whereby the target of the present invention (single Also referred to as one target). If necessary, several sintered bodies may be divided into divided shapes to form a large-area target (also referred to as a composite target).
The target includes a sputtering target and an ion plating target. In the ion plating method, such a material is sometimes referred to as a tablet, but in the present invention, it is collectively referred to as a target.
The target is based on a zinc oxide sintered body to which Ni is added (first target), or an oxide containing zinc oxide as a main component and gallium and / or aluminum and nickel as a solid solution. This is based on an oxide sintered body composed of a zinc phase (second target).

4). Production of transparent conductive film The transparent conductive film of the present invention is formed on a substrate by sputtering or ion plating in a film forming apparatus using the target of the present invention. In particular, the direct current (DC) sputtering method is industrially advantageous and preferable because it has less thermal influence during film formation and enables high-speed film formation.

  That is, the method of the present invention uses the first or second target prepared from the oxide sintered body and adopts sputtering conditions such as a specific substrate temperature, pressure, oxygen concentration, etc. It is a method of forming the transparent conductive film which consists of zinc oxide containing.

In order to form a transparent conductive film according to the present invention, it is preferable to use an inert gas such as argon as a sputtering gas and to use direct current sputtering. Further, the inside of the sputtering apparatus can be sputtered at a pressure of 0.1 to 1 Pa, particularly 0.3 to 0.8 Pa.
In the present invention, for example, after evacuating to 5 × 10 ⁻⁵ Pa or less, pure Ar gas is introduced, the gas pressure is set to 0.2 to 0.5 Pa, DC power 100 to 300 W is applied, and DC plasma is generated. And pre-sputtering can be performed. After performing this pre-sputtering for 5 to 30 minutes, it is preferable to perform sputtering after correcting the substrate position if necessary.

In the present invention, the film can be formed without heating the substrate, but the substrate can also be heated to 50 to 300 ° C., particularly 80 to 200 ° C. When the substrate has a low melting point such as a resin plate or a resin film, it is desirable to form the film without heating.
If the sputtering target produced from the oxide sinter of the present invention is used, a transparent conductive film excellent in chemical resistance and conductivity can be produced on a substrate by a direct current sputtering method. Therefore, the manufacturing cost can be greatly reduced. Moreover, the same transparent conductive film can be formed also when an ion plating tablet prepared from the above oxide sintered body is used.

5. Transparent conductive film The transparent conductive film of the present invention is formed on a substrate by a sputtering method or an ion plating method using a specific target by the above method.
That is, a transparent conductive film manufactured by a sputtering method or an ion plating method using a target processed from the oxide sintered body, (1) containing zinc oxide as a main component and further containing nickel A transparent conductive film containing nickel in an Ni / (Zn + Ni) atomic ratio of 0.02 to 0.25, and composed mainly of a zinc oxide phase having a hexagonal wurtzite structure. Or a film containing no zinc oxide phase having a cubic rock salt structure (hereinafter also referred to as a first film), or (2) A transparent conductive film containing zinc oxide as a main component and further containing nickel and gallium and / or aluminum, and having a (Ga + Al) / (Zn + Ga + Al) atomic ratio of 0 Beyond 0.08 in a proportion of less are contained in an amount of nickel in the Ni / (Zn + Ga + Al + Ni) atomic ratio 0.02-0.25, moreover, mainly zinc oxide phase a hexagonal wurtzite structure A film (hereinafter referred to as a second film ) that has a peak intensity ratio of 50% or more represented by the following formula (B) and does not contain a zinc oxide phase having a cubic rock salt structure. (It is also called).
I [ZnO (002)] / (I [ZnO (002)] + I [ZnO (100)]) × 100 (%) Formula (B)
(Wherein I [ZnO (002)] is the (002) peak intensity of the zinc oxide phase having a hexagonal wurtzite structure, and I [ZnO (100)] has a hexagonal wurtzite structure. (Shows the (100) peak intensity of the zinc oxide phase.)

  Conventional zinc oxide-based transparent conductive films dissolve easily in ordinary acids and alkalis, have poor resistance to acids and alkalis, and are difficult to control the etching rate. There is a problem that high-definition patterning processing is difficult. Since the present invention uses a sputtering target or an ion plating tablet which can be used for high-speed film formation by an industrially useful DC sputtering method or ion plating method and hardly generates arc discharge, the electrical and optical characteristics are used. A zinc oxide-based transparent conductive film having high chemical resistance to acids and alkalis can be obtained without impairing the properties. In particular, a zinc oxide-based transparent conductive film exhibiting high chemical resistance can be obtained by controlling the film composition and crystal phase.

  Since the transparent conductive film of the present invention is formed using the oxide sintered body as a raw material, the composition of the oxide sintered body is reflected. That is, the first film is a transparent conductive film containing zinc oxide as a main component and further containing nickel, and nickel is contained at a Ni / (Zn + Ni) atomic ratio of 0.02 to 0.25. The second film is a transparent conductive film containing zinc oxide as a main component and further containing nickel and gallium and / or aluminum, and has a (Ga + Al) / (Zn + Ga + Al) atomic ratio of 0. More than 0.08 and not more than 0.08, and nickel is contained at a Ni / (Zn + Ga + Al + Ni) atomic ratio of 0.02 to 0.25.

  This transparent conductive film exhibits excellent chemical resistance by containing zinc oxide as a main component and containing nickel in the above composition range. When the nickel content is less than 0.02 in terms of the Ni / (Zn + Ni) atomic ratio, the transparent conductive film does not exhibit sufficient acid resistance and alkali resistance, and when it exceeds 0.25, the crystal of the film Therefore, sufficient acid resistance cannot be obtained. However, the alkali resistance is better as the nickel content is increased, and even when the content exceeds 0.25, the alkali resistance is sufficiently good. When the nickel content exceeds 0.25 and the crystallinity of the film is lowered, the conductivity is also impaired.

The transparent conductive film can further exhibit higher conductivity by containing gallium and / or aluminum having the above composition range. When the content of gallium and / or aluminum exceeds 0.08 in terms of the (Ga + Al) / (Zn + Ga + Al) atomic ratio, the crystallinity of the film is lowered, so that sufficient acid resistance cannot be obtained.
Furthermore, in order for this transparent conductive film to exhibit excellent chemical resistance and low specific resistance, the total content of gallium and / or aluminum is 0.01 to 0 in terms of (Ga + Al) / (Zn + Ga + Al) atomic ratio. It is even more preferable that the nickel content is 0.05 to 0.14 in terms of Ni / (Zn + Ga + Al + Ni) atomic ratio.
In Patent Document 3, as described above, it is disclosed that an oxide film containing Ni, Zn, and Ga (a NZ oxide film containing Ga) has excellent moisture resistance and alkali resistance. It is shown that Ni is contained in an amount of 5 to 80 atomic% with respect to the total of Ni and Zn, and a very wide composition range is defined. However, the reason why such a wide composition range is specified is that only the evaluation of moisture resistance and alkali resistance of the film has been performed, and all of the above ranges are allowed in consideration of acid resistance. Do not mean. Furthermore, Patent Document 3 does not describe any influence on the acid resistance given by the film formation phase and crystallinity as described later.

The transparent conductive film of the present invention is composed mainly of a zinc oxide phase having a hexagonal wurtzite structure described in JCPDS card 36-1451. In order to obtain high conductivity and excellent acid resistance, as described above. The crystallinity of the film is important.
That is, it is important that the c-plane of the zinc oxide phase having a hexagonal wurtzite structure is oriented so as to be parallel to the substrate.
In particular, the peak intensity ratio between the c-plane (002) and a-plane (100) of the zinc oxide phase having a hexagonal wurtzite structure obtained by X-ray diffraction measurement defined by the following formula (B) is 50 % Or more is necessary .
I [ZnO (002)] / (I [ZnO (002)] + I [ZnO (100)]) × 100 (%) Formula (B)

  Here, I [ZnO (002)] is the (002) peak intensity of the zinc oxide phase having a hexagonal wurtzite structure obtained by X-ray diffraction measurement, and I [ZnO (100)] is The (100) peak intensity of a zinc oxide phase having a hexagonal wurtzite structure obtained by X-ray diffraction measurement is shown. When the ratio of peak intensities is less than 50%, conductivity is impaired and sufficient acid resistance cannot be obtained.

Further, when nickel is included in excess of 0.25 in the Ni / (Zn + Ni) atomic ratio or the Ni / (Zn + Ga + Al + Ni) atomic ratio, or the oxide sintered body as the raw material has a nickel oxide phase, nickel and zinc Nickel oxide or nickel having a cubic rock salt structure when a large amount of the complex oxide Ni _x Zn _1-x O (x = 0.6, 0.7, 0.8, or 0.9) phase is contained And the composite oxide Ni _x Zn _1-x O (x = 0.6, 0.7, 0.8, or 0.9) phase containing zinc and zinc are increased, and the transparent conductive film has a cubic rock salt. A zinc oxide phase having a structure is formed. The cubic structure zinc oxide phase not only increases the specific resistance of the transparent conductive film, but also reduces acid resistance, so it must not be contained in the film. Even if the X-ray diffraction intensity ratio of the formula (B) is 50% or more, sufficient acid resistance cannot be obtained when a zinc oxide phase having a cubic structure is included.

The transparent conductive film of the present invention is used as a wiring material for a liquid crystal display or the like. For that purpose, it is important that patterning can be performed by wet etching using a photoresist. That is, in order to enable patterning by wet etching, an appropriate etching rate in the range of 30 to 100 nm / min with respect to a weak acid organic acid (ITO-06N manufactured by Kanto Chemical Co., Ltd.) and a weak alkali On the other hand, it must be not etched.
Moreover, when using as a functional transparent conductive film, such as an antistatic use, minimum weather resistance is important. That is, it is necessary for the weak acid to be about the same as described above and exhibit an etching rate of 20 nm / min or less with respect to the weak alkali (5% KOH).
As described above, the transparent conductive film of the present invention uses a target obtained by processing an oxide sintered body in which nickel is added to zinc oxide, or an appropriate composition range of gallium and / or aluminum in addition to zinc oxide and nickel. Since it is manufactured by appropriately controlling the structure and crystallinity of the film using the target obtained by processing the oxide sintered body added in step 1, it has excellent acid resistance and alkali resistance. Therefore, it is possible to sufficiently satisfy the above etching characteristics.

In this invention, since the film thickness of a transparent conductive film changes with uses and cannot be prescribed | regulated in particular, it is 50-500 nm, Preferably it is 100-300 nm. If the thickness is less than 50 nm, a sufficient specific resistance cannot be ensured. On the other hand, if it exceeds 500 nm, a problem of coloring the film occurs, which is not preferable.
Moreover, the average transmittance | permeability in the visible region (400-800 nm) of a transparent conductive film is 80% or more, Preferably it is 85% or more, More preferably, it is 90% or more. When the average transmittance is less than 80%, application to an organic EL element or the like becomes difficult.

6). Transparent conductive base material In the present invention, the transparent conductive thin film is usually formed on a base material (substrate) selected from a glass plate, a quartz plate, a resin plate or a resin film, and is transparently conductive. It becomes a base material.

This transparent conductive substrate allows the transparent conductive film to function as an anode and / or a cathode of a display panel such as an LCD, PDP, or EL element. Since the substrate also serves as a light-transmitting support, it needs to have a certain strength and transparency.
Examples of the material constituting the resin plate or resin film include polyethylene terephthalate (PET), polyethersulfone (PES), polyarylate (PAR), polycarbonate (PC), etc., and these surfaces are coated with acrylic resin. It may be a resin plate or a resin film having a structured structure.
The thickness of the substrate is not particularly limited, but is 0.5 to 10 mm, preferably 1 to 5 mm for a glass plate or a quartz plate. 1 to 5 mm, preferably 1 to 3 mm. If it is thinner than this range, the strength is weak and handling is difficult. On the other hand, if it is thicker than this range, not only the transparency is poor, but also the weight is unfavorable.

  Any of an insulating layer, a semiconductor layer, a gas barrier layer, or a protective layer composed of a single layer or multiple layers can be formed on the substrate. The insulating layer includes a silicon oxide (Si—O) film or a silicon nitride oxide (Si—O—N) film, and the semiconductor layer includes a thin film transistor (TFT) and is mainly formed on a glass substrate. The gas barrier layer includes a silicon oxide (Si—O) film, a silicon nitride oxide (Si—O—N) film, a magnesium aluminate (Al—Mg—O) film, or a tin oxide-based (for example, a water vapor barrier film). (Sn—Si—O) film or the like is formed on the resin plate or resin film. The protective layer is for protecting the surface of the substrate from scratches and impacts, and various coatings such as Si-based, Ti-based, and acrylic resin-based are used. Note that the layer that can be formed over the substrate is not limited thereto, and a thin metal film having conductivity can be applied.

  The transparent conductive substrate obtained by the present invention has a transparent conductive film having excellent properties such as specific resistance, light transmittance, and surface flatness, so that it can be used as a component of various display panels. Very useful. Moreover, as an electronic circuit mounting component provided with the said transparent conductive base material, a laser component etc. other than an organic EL element can be mentioned.

  Hereinafter, the present invention will be described in more detail using examples, but the present invention is not limited to these examples.

(Raw material powder)
Raw material powder of zinc oxide powder having an average particle size of 3 μm or less, gallium oxide powder having an average particle size of 3 μm or less and / or aluminum oxide powder having an average particle size of 3 μm or less, and nickel oxide powder having an average particle size of 3 μm or less It was.

(Evaluation of sintered oxide)
The specific resistance of the obtained oxide sintered body was measured with respect to the polished surface by a four-point probe method. Moreover, the end material of the obtained oxide sintered body was pulverized, powder X-ray diffraction measurement was performed, and the generated phase was identified.

(Basic characteristic evaluation of transparent conductive film)
The film thickness of the obtained transparent conductive film was measured with a surface roughness meter (manufactured by Tencor). The specific resistance of the film was calculated from the product of the surface resistance and the film thickness measured by the four probe method. The optical properties of the film were measured with a spectrophotometer (manufactured by Hitachi, Ltd.). The formation phase of the film was identified by X-ray diffraction measurement (manufactured by PANalytical). The formation of a zinc oxide phase having a cubic rock salt structure was determined by reciprocal space mapping measurement using X-ray diffraction.

(Evaluation of chemical resistance of transparent conductive film)
A transparent conductive film having a thickness of about 200 nm was formed, and the chemical resistance was examined by the following procedure. About acid resistance, it immersed in the organic acid etching liquid ITO-06N (made by Kanto Chemical) for ITO set to 30 degreeC for 20 second, and determined by the etching rate per minute calculated | required from the film thickness difference before and behind immersion. Similarly, the alkali resistance was determined by immersing in a 5% KOH aqueous solution for 1 minute and determining the etching rate per minute.

Example 1
An oxide sintered body containing zinc oxide containing only nickel and not containing gallium and aluminum was produced as follows.
Zinc oxide powder and nickel oxide powder each having an average particle size of 3 μm or less were used as starting materials, and nickel oxide was blended so that the content as nickel was 0.11 in terms of Ni / (Zn + Ni) atomic ratio. The raw material powder was put into a resin pot together with water and mixed by a wet ball mill. At this time, hard ZrO ₂ balls were used and the mixing time was 18 hours. After mixing, the slurry was taken out, filtered, dried and granulated. The granulated product was molded by applying a pressure of 3 ton / cm ² with a cold isostatic press.
Next, the compact was sintered as follows. Sintering was performed at 1400 ° C. for 20 hours in an atmosphere in which oxygen was introduced into the atmosphere in the sintering furnace at a rate of 5 liters / minute per 0.1 m ^{3 of the} furnace volume. At this time, the temperature was raised at 1 ° C./min, and when cooling after sintering, oxygen introduction was stopped, and the temperature was lowered to 1000 ° C. at 10 ° C./min to produce an oxide sintered body made of zinc oxide and nickel. did. When the composition of the obtained oxide sintered body was analyzed, it was confirmed that it was almost the same as the blend composition. When the specific resistance value of the oxide sintered body was measured, it was confirmed that the specific resistance was 50 kΩcm or less. The density was 5.6 g / cm ² .
As a result of phase identification of the oxide sintered body by X-ray diffraction measurement, only a zinc oxide phase having a hexagonal wurtzite structure was confirmed, and it contained a nickel oxide phase having a cubic rock salt structure or containing nickel and zinc. A diffraction peak due to the complex oxide Ni _x Zn _1-x O (x = 0.6, 0.7, 0.8, or 0.9) phase was not confirmed. That is, the peak due to (101) of the zinc oxide phase having a hexagonal wurtzite structure defined by the formula (A) and the complex oxide Ni _x Zn _1-x O (x having a cubic rock salt structure are defined. = 0.6, 0.7, 0.8 or 0.9) The intensity ratio of the peak due to (200) of the phase was 0%.
Such an oxide sintered body was bonded to a backing plate made of oxygen-free copper using metallic indium to obtain a sputtering target. The diameter was 152 mm and the thickness was 5 mm, and the sputtering surface was polished with a cup grindstone so that the maximum height Rz was 3.0 μm or less.
Using this as a sputtering target, film formation by direct current sputtering was performed. A sputtering target was attached to a cathode for a non-magnetic material target of a DC magnetron sputtering apparatus (manufactured by Anelva) equipped with a DC power supply having no arcing suppression function. As the substrate, an alkali-free glass substrate (Corning # 7059) was used, and the target-substrate distance was fixed to 60 mm. After evacuating to 5 × 10 ⁻⁵ Pa or less, pure Ar gas was introduced, the gas pressure was set to 0.3 Pa, DC power was applied at 200 W to generate DC plasma, and pre-sputtering was performed. After sufficient pre-sputtering, a transparent conductive film was formed by placing a substrate directly above the sputtering target, that is, at a stationary facing position, and performing sputtering without heating.
Arc discharge did not occur and stable film formation was possible. It was confirmed that the composition of the obtained transparent conductive film was almost the same as that of the target. When the formation phase of the film was identified by X-ray diffraction measurement, it was composed only of a zinc oxide phase having a hexagonal wurtzite structure, and the presence of a zinc oxide phase having a cubic rock salt structure was not confirmed. The diffraction peak of the zinc oxide phase having the hexagonal wurtzite structure is only observed by c-plane (002) reflection, and is defined by the formula (B). The a-plane (100) of the zinc oxide phase The c-plane (002) peak intensity ratio with respect to was 100%. When the specific resistance of the film was measured, it was 2.5 × 10 ⁻³ Ωcm.
Next, when the etching rate at the time of immersing the obtained transparent conductive film in ITO-06N was measured, it was 30 nm / min and showed the etching rate with respect to a moderate acid. Etching was not performed at all with respect to 5% KOH, and sufficient alkali resistance was obtained. The results are shown in Table 1.

(Comparative Example 1)
A conventional zinc oxide oxide sintered body doped with gallium was prepared. Zinc oxide powder and gallium oxide powder were used as starting materials, and were mixed so that the content as gallium was 0.05 in terms of Ga / (Zn + Ga) atomic ratio.
When the specific resistance value of the obtained oxide sintered body was measured, it was confirmed that it was 1 kΩcm or less. The density was 5.5 g / cm ² . When the phase of the oxide sintered body was identified by X-ray diffraction measurement, only a zinc oxide phase having a hexagonal wurtzite structure was confirmed.
The oxide sintered body was bonded to form a sputtering target, and film formation was performed by direct current sputtering. Arc discharge did not occur and stable film formation was possible.
When the produced phase of the transparent conductive film obtained was identified by X-ray diffraction measurement, it was composed only of a zinc oxide phase having a hexagonal wurtzite structure, and the presence of a zinc oxide phase having a cubic rock salt structure was It was not confirmed. As for the diffraction peak of the zinc oxide phase having the hexagonal wurtzite structure, only reflection by the c-plane (002) is observed, and the zinc oxide phase is defined by the formula (B) and is defined with respect to the a-plane (100). The peak intensity ratio of the c-plane (002) was 100%. Moreover, when the specific resistance of the film was measured, it was 8.3 × 10 ⁻⁴ Ωcm.
Next, when the etching rate when the obtained transparent conductive film was immersed in ITO-06N was measured, it was 560 nm / min. It was revealed that the etching rate was considerably higher than the appropriate etching rate, and the acid resistance was low. When immersed in 5% KOH, the etching rate was 180 nm / min, and it was revealed that the alkali resistance was low. The results are shown in Table 1.

(Example 2)
An oxide sintered body mainly composed of zinc oxide containing gallium and nickel was produced. Zinc oxide powder, gallium oxide powder, and nickel oxide powder are used as starting materials. Nickel oxide is nickel so that the content of gallium oxide is 0.005 in terms of the Ga / (Zn + Ga) atomic ratio. Is added so that the Ni / (Zn + Ga + Ni) atomic ratio is 0.02.
Sintering was carried out in the same manner as in Example 1, and the composition of the obtained oxide sintered body was analyzed. When the specific resistance value of the oxide sintered body was measured, it was confirmed that the specific resistance was 5 kΩcm or less. The density was 5.5 g / cm ² . As a result of phase identification of the oxide sintered body by X-ray diffraction measurement, only a zinc oxide phase having a hexagonal wurtzite structure was confirmed, and it contained a nickel oxide phase having a cubic rock salt structure or containing nickel and zinc. A diffraction peak due to the complex oxide Ni _x Zn _1-x O (x = 0.6, 0.7, 0.8, or 0.9) phase was not confirmed. That is, the peak intensity ratio of the zinc oxide phase (101) to the composite oxide phase (200) containing nickel and zinc defined by the above formula (A) was 0%.
Such oxide sintered bodies were bonded to form a sputtering target, and a film was formed by direct current sputtering. Arc discharge did not occur and stable film formation was possible. It was confirmed that the composition of the obtained transparent conductive film was almost the same as that of the target. When the formation phase of the film was identified by X-ray diffraction measurement, it was composed only of a zinc oxide phase having a hexagonal wurtzite structure, and the presence of a zinc oxide phase having a cubic rock salt structure was not confirmed. As for the diffraction peak of the zinc oxide phase having the hexagonal wurtzite structure, only the c-plane (002) reflection is observed, and the a-plane of the zinc oxide phase defined by the above formula (B) ( 100), the c-plane (002) peak intensity ratio was 100%. When the specific resistance of the film was measured, it was 1.9 × 10 ⁻³ Ωcm.
Next, when the etching rate at the time of immersing the obtained transparent conductive film in ITO-06N was measured, it was 70 nm / min and showed the etching rate with respect to a moderate acid. When immersed in 5% KOH, it was 20 nm / min, and sufficient alkali resistance was obtained. The results are shown in Table 1.

(Example 3)
Except for changing the Ga / (Zn + Ga) atomic ratio to 0.08, the same composition and manufacturing method of Ni / (Zn + Ga + Ni) atomic ratio 0.02 as in Example 2 were used, and zinc oxide containing gallium and nickel was used. An oxide sintered body having a main component was produced.
When the composition of the obtained oxide sintered body was analyzed, it was confirmed that it was almost the same as the composition. When the specific resistance value of the oxide sintered body was measured, it was confirmed that the specific resistance was 5 kΩcm or less. The density was 5.5 g / cm ² . As a result of phase identification of the oxide sintered body by X-ray diffraction measurement, only a zinc oxide phase having a hexagonal wurtzite structure was confirmed, and it contained a nickel oxide phase having a cubic rock salt structure or containing nickel and zinc. A diffraction peak due to the complex oxide Ni _x Zn _1-x O (x = 0.6, 0.7, 0.8, or 0.9) phase was not confirmed. That is, the peak intensity ratio of the zinc oxide phase (101) to the composite oxide phase (200) containing nickel and zinc defined by the above formula (A) was 0%.
Such oxide sintered bodies were bonded to form a sputtering target, and a film was formed by direct current sputtering. Arc discharge did not occur and stable film formation was possible. It was confirmed that the composition of the obtained transparent conductive film was almost the same as that of the target. When the formation phase of the film was identified by X-ray diffraction measurement, it was composed only of a zinc oxide phase having a hexagonal wurtzite structure, and the presence of a zinc oxide phase having a cubic rock salt structure was not confirmed. As for the diffraction peak of the zinc oxide phase having the hexagonal wurtzite structure, only the c-plane (002) reflection is observed, and the a-plane of the zinc oxide phase defined by the above formula (B) ( 100), the c-plane (002) peak intensity ratio was 100%. When the specific resistance of the film was measured, it was 1.6 × 10 ⁻³ Ωcm.
Next, when the etching rate at the time of immersing the obtained transparent conductive film in ITO-06N was measured, it was 70 nm / min and showed the etching rate with respect to a moderate acid. When immersed in 5% KOH, it was 20 nm / min, and sufficient alkali resistance was obtained. The results are shown in Table 1.

(Comparative Example 2)
Except for changing the Ga / (Zn + Ga) atomic ratio to 0.10, zinc oxide containing gallium and nickel was prepared with the same composition and manufacturing method of Ni / (Zn + Ga + Ni) atomic ratio 0.02 as in Example 2. An oxide sintered body having a main component was produced. When the composition of the obtained oxide sintered body was analyzed, it was confirmed that it was almost the same as the composition. When the specific resistance value of the oxide sintered body was measured, it was confirmed to be 5 kΩcm or less. The density was 5.4 g / cm ² .
As a result of phase identification of the oxide sintered body by X-ray diffraction measurement, only a zinc oxide phase having a hexagonal wurtzite structure was confirmed, and it contained a nickel oxide phase having a cubic rock salt structure or containing nickel and zinc. A diffraction peak due to the complex oxide Ni _x Zn _1-x O (x = 0.6, 0.7, 0.8, or 0.9) phase was not confirmed. That is, the peak intensity ratio of the zinc oxide phase (101) to the composite oxide phase (200) containing nickel and zinc defined by the above formula (A) was 0%.
Such oxide sintered bodies were bonded to form a sputtering target, and a film was formed by direct current sputtering. Arc discharge did not occur and stable film formation was possible. It was confirmed that the composition of the obtained transparent conductive film was almost the same as that of the target.
When the formation phase of the film was identified by X-ray diffraction measurement, it was composed only of a zinc oxide phase having a hexagonal wurtzite structure, and the presence of a zinc oxide phase having a cubic rock salt structure was not confirmed. Although the diffraction peak of the zinc oxide phase having the hexagonal wurtzite structure was only observed due to c-plane (002) reflection, the peak intensity of the zinc oxide phase was lower than that of Example 2. It was suggested that the crystallinity was reduced due to gallium excess. Nevertheless, the peak intensity ratio of the c-plane (002) to the a-plane (100) of the zinc oxide phase defined by the above-mentioned formula (B) was 100%. When the specific resistance of the film was measured, it was 5.9 × 10 ⁻³ Ωcm.
Next, when the etching rate when the obtained transparent conductive film was immersed in ITO-06N was measured, it was 340 nm / min. It was revealed that the etching rate was considerably higher than a moderate etching rate and the acid resistance was low. When immersed in 5% KOH, it became clear that the etching rate was as low as 110 nm / min and the alkali resistance was not sufficient. It was speculated that the chemical resistance decreased due to the influence of the decrease in crystallinity of the zinc oxide phase having a hexagonal wurtzite structure due to the excessive content of gallium. The results are shown in Table 1.

(Comparative Example 3)
Zinc oxide containing gallium and nickel was prepared in the same manner as in Example 2 except that the Ga / (Zn + Ga) atomic ratio was changed to 0.08 and the Ni / (Zn + Ga + Ni) atomic ratio was changed to 0.01. An oxide sintered body having a main component was produced. When the composition of the obtained oxide sintered body was analyzed, it was confirmed that it was almost the same as the composition. When the specific resistance value of the oxide sintered body was measured, it was confirmed to be 5 kΩcm or less. The density was 5.5 g / cm ² .
As a result of phase identification of the oxide sintered body, only a zinc oxide phase having a hexagonal wurtzite structure was confirmed, and a nickel oxide phase having a cubic rock salt structure or a composite oxide Ni _x containing nickel and zinc A diffraction peak due to the Zn _1-x O (x = 0.6, 0.7, 0.8, or 0.9) phase was not confirmed. That is, the peak intensity ratio of the zinc oxide phase (101) to the composite oxide phase (200) containing nickel and zinc defined by the above formula (A) was 0%.
Such oxide sintered bodies were bonded to form a sputtering target, and a film was formed by direct current sputtering. Arc discharge did not occur and stable film formation was possible. It was confirmed that the composition of the obtained transparent conductive film was almost the same as that of the target. When the formation phase of the film was identified by X-ray diffraction measurement, it was composed only of a zinc oxide phase having a hexagonal wurtzite structure, and the presence of a zinc oxide phase having a cubic rock salt structure was not confirmed. As for the diffraction peak of the zinc oxide phase having the hexagonal wurtzite structure, only the c-plane (002) reflection is observed, and the a-plane of the zinc oxide phase defined by the above formula (B) ( 100), the c-plane (002) peak intensity ratio was 100%. When the specific resistance of the film was measured, it was 1.5 × 10 ⁻³ Ωcm.
Next, the etching rate when the obtained transparent conductive film was immersed in ITO-06N was measured and found to be 190 nm / min. It was revealed that the etching rate was higher than the appropriate etching rate, and the acid resistance was not sufficient. When immersed in 5% KOH, it was revealed that the etching rate was as low as 80 nm / min and the alkali resistance was not sufficient. It was speculated that the chemical resistance was lowered due to insufficient nickel content. The results are shown in Table 1.

Example 4
Except that the Ga / (Zn + Ga) atomic ratio was changed to 0.05 and the Ni / (Zn + Ga + Ni) atomic ratio was changed to 0.05, zinc oxide containing gallium and nickel was used as the main component in the same manner as in Example 2. An oxide sintered body was prepared. When the composition of the obtained oxide sintered body was analyzed, it was confirmed that it was almost the same as the composition. When the specific resistance value of the oxide sintered body was measured, it was confirmed that the specific resistance was 1 kΩcm or less. The density was 5.5 g / cm ² .
As a result of phase identification of the oxide sintered body by X-ray diffraction measurement, only a zinc oxide phase having a hexagonal wurtzite structure was confirmed, and it contained a nickel oxide phase having a cubic rock salt structure or containing nickel and zinc. A diffraction peak due to the complex oxide Ni _x Zn _1-x O (x = 0.6, 0.7, 0.8, or 0.9) phase was not confirmed. That is, the peak intensity ratio of the zinc oxide phase (101) to the composite oxide phase (200) containing nickel and zinc defined by the above formula (A) was 0%.
Such oxide sintered bodies were bonded to form a sputtering target, and a film was formed by direct current sputtering. Arc discharge did not occur and stable film formation was possible. It was confirmed that the composition of the obtained transparent conductive film was almost the same as that of the target. When the formation phase of the film was identified by X-ray diffraction measurement, it was composed only of a zinc oxide phase having a hexagonal wurtzite structure, and the presence of a zinc oxide phase having a cubic rock salt structure was not confirmed. As for the diffraction peak of the zinc oxide phase having the hexagonal wurtzite structure, only the c-plane (002) reflection is observed, and the a-plane of the zinc oxide phase defined by the above formula (B) ( 100), the c-plane (002) peak intensity ratio was 100%. When the specific resistance of the film was measured, it was 9.5 × 10 ⁻⁴ Ωcm.
Next, when the etching rate when the obtained transparent conductive film was immersed in ITO-06N was measured, it was 30 nm / min and was an appropriate etching rate. Etching was not performed at all with respect to 5% KOH, and sufficient alkali resistance was obtained. The results are shown in Table 1.

(Example 5)
Except for changing the Ga / (Zn + Ga) atomic ratio to 0.01 and the Ni / (Zn + Ga + Ni) atomic ratio to 0.11, the main component is zinc oxide containing gallium and nickel in the same manner as in Example 2. An oxide sintered body was prepared. When the composition of the obtained oxide sintered body was analyzed, it was confirmed that it was almost the same as the blend composition. When the specific resistance value of the oxide sintered body was measured, it was confirmed that the specific resistance was 1 kΩcm or less. The density was 5.4 g / cm ² .
As a result of phase identification of the oxide sintered body by X-ray diffraction measurement, only a zinc oxide phase having a hexagonal wurtzite structure was confirmed, and it contained a nickel oxide phase having a cubic rock salt structure or containing nickel and zinc. A diffraction peak due to the complex oxide Ni _x Zn _1-x O (x = 0.6, 0.7, 0.8, or 0.9) phase was not confirmed. That is, the peak intensity ratio of the zinc oxide phase (101) to the composite oxide phase (200) containing nickel and zinc defined by the above formula (A) was 0%.
The oxide sintered body was bonded to form a sputtering target, and film formation was performed by direct current sputtering. Arc discharge did not occur and stable film formation was possible. It was confirmed that the composition of the obtained transparent conductive film was almost the same as that of the target. When the formation phase of the film was identified by X-ray diffraction measurement, it was composed only of a zinc oxide phase having a hexagonal wurtzite structure, and the presence of a zinc oxide phase having a cubic rock salt structure was not confirmed. As for the diffraction peak of the zinc oxide phase having the hexagonal wurtzite structure, only the c-plane (002) reflection is observed, and the a-plane of the zinc oxide phase defined by the above formula (B) ( 100), the c-plane (002) peak intensity ratio was 100%. When the specific resistance of the film was measured, it was 9.7 × 10 ⁻⁴ Ωcm.
Next, when the etching rate when the obtained transparent conductive film was immersed in ITO-06N was measured, it was 30 nm / min and was an appropriate etching rate. Etching was not performed at all with respect to 5% KOH, and sufficient alkali resistance was obtained. The results are shown in Table 1.

(Example 6)
Zinc oxide containing gallium and nickel was prepared in the same manner as in Example 5, except that the Ga / (Zn + Ga) atomic ratio was changed to 0.03 and the Ni / (Zn + Ga + Ni) atomic ratio was changed to 0.11. An oxide sintered body having a main component was produced. When the composition of the obtained oxide sintered body was analyzed, it was confirmed that it was almost the same as the composition. When the specific resistance value of the oxide sintered body was measured, it was confirmed that the specific resistance was 1 kΩcm or less. The density was 5.5 g / cm ² .
As a result of phase identification of the oxide sintered body by X-ray diffraction measurement, only a zinc oxide phase having a hexagonal wurtzite structure was confirmed, and it contained a nickel oxide phase having a cubic rock salt structure or containing nickel and zinc. A diffraction peak due to the complex oxide Ni _x Zn _1-x O (x = 0.6, 0.7, 0.8, or 0.9) phase was not confirmed. That is, the peak intensity ratio of the zinc oxide phase (101) to the composite oxide phase (200) containing nickel and zinc defined by the above formula (A) was 0%.
Such oxide sintered bodies were bonded to form a sputtering target, and a film was formed by direct current sputtering. Arc discharge did not occur and stable film formation was possible. It was confirmed that the composition of the obtained transparent conductive film was almost the same as that of the target. When the formation phase of the film was identified by X-ray diffraction measurement, it was composed only of a zinc oxide phase having a hexagonal wurtzite structure, and the presence of a zinc oxide phase having a cubic rock salt structure was not confirmed. As for the diffraction peak of the zinc oxide phase having the hexagonal wurtzite structure, only the c-plane (002) reflection is observed, and the a-plane of the zinc oxide phase defined by the above formula (B) ( 100), the c-plane (002) peak intensity ratio was 100%. When the specific resistance of the film was measured, it was 9.4 × 10 ⁻⁴ Ωcm.
Next, when the etching rate when the obtained transparent conductive film was immersed in ITO-06N was measured, it was 30 nm / min and was an appropriate etching rate. Etching was not performed at all with respect to 5% KOH, and sufficient alkali resistance was obtained. The results are shown in Table 1.

(Example 7)
Mainly zinc oxide containing gallium and nickel was produced in the same manner as in Example 5 except that the Ga / (Zn + Ga) atomic ratio was changed to 0.05 and the Ni / (Zn + Ga + Ni) atomic ratio was 0.11. An oxide sintered body as a component was prepared. When the composition of the obtained oxide sintered body was analyzed, it was confirmed that it was almost the same as the composition. When the specific resistance value of the oxide sintered body was measured, it was confirmed that the specific resistance was 1 kΩcm or less. The density was 5.4 g / cm ² .
As a result of phase identification of the oxide sintered body by X-ray diffraction measurement, only a zinc oxide phase having a hexagonal wurtzite structure was confirmed, and it contained a nickel oxide phase having a cubic rock salt structure or containing nickel and zinc. A diffraction peak due to the complex oxide Ni _x Zn _1-x O (x = 0.6, 0.7, 0.8, or 0.9) phase was not confirmed. That is, the peak intensity ratio of the zinc oxide phase (101) to the composite oxide phase (200) containing nickel and zinc defined by the above formula (A) was 0%.
Such oxide sintered bodies were bonded to form a sputtering target, and a film was formed by direct current sputtering. Arc discharge did not occur and stable film formation was possible. It was confirmed that the composition of the obtained transparent conductive film was almost the same as that of the target. When the formation phase of the film was identified by X-ray diffraction measurement, it was composed only of a zinc oxide phase having a hexagonal wurtzite structure, and the presence of a zinc oxide phase having a cubic rock salt structure was not confirmed. As for the diffraction peak of the zinc oxide phase having the hexagonal wurtzite structure, only the c-plane (002) reflection is observed, and the a-plane of the zinc oxide phase defined by the above formula (B) ( 100), the c-plane (002) peak intensity ratio was 100%. When the specific resistance of the film was measured, it was 9.7 × 10 ⁻⁴ Ωcm.
Next, when the etching rate when the obtained transparent conductive film was immersed in ITO-06N was measured, it was 30 nm / min and was an appropriate etching rate. Etching was not performed at all with respect to 5% KOH, and sufficient alkali resistance was obtained. The results are shown in Table 1.

(Example 8)
Except for changing the Ga / (Zn + Ga) atomic ratio to 0.05 and the Ni / (Zn + Ga + Ni) atomic ratio to 0.14, the main component is zinc oxide containing gallium and nickel as in Example 2. An oxide sintered body was prepared. When the composition of the obtained oxide sintered body was analyzed, it was confirmed that it was almost the same as the composition. When the specific resistance value of the oxide sintered body was measured, it was confirmed that the specific resistance was 1 kΩcm or less. The density was 5.5 g / cm ² .
As a result of phase identification of the oxide sintered body by X-ray diffraction measurement, only a zinc oxide phase having a hexagonal wurtzite structure was confirmed, and it contained a nickel oxide phase having a cubic rock salt structure or containing nickel and zinc. A diffraction peak due to the complex oxide Ni _x Zn _1-x O (x = 0.6, 0.7, 0.8, or 0.9) phase was not confirmed. That is, the peak intensity ratio of the zinc oxide phase (101) to the composite oxide phase (200) containing nickel and zinc defined by the above formula (A) was 0%.
Such oxide sintered bodies were bonded to form a sputtering target, and a film was formed by direct current sputtering. Arc discharge did not occur and stable film formation was possible. It was confirmed that the composition of the obtained transparent conductive film was almost the same as that of the target. When the formation phase of the film was identified by X-ray diffraction measurement, it was composed only of a zinc oxide phase having a hexagonal wurtzite structure, and the presence of a zinc oxide phase having a cubic rock salt structure was not confirmed. As for the diffraction peak of the zinc oxide phase having the hexagonal wurtzite structure, only the c-plane (002) reflection is observed, and the a-plane of the zinc oxide phase defined by the above formula (B) ( 100), the c-plane (002) peak intensity ratio was 100%. When the specific resistance of the film was measured, it was 9.9 × 10 ⁻⁴ Ωcm.
Next, when the etching rate when the obtained transparent conductive film was immersed in ITO-06N was measured, it was 30 nm / min and was an appropriate etching rate. Etching was not performed at all with respect to 5% KOH, and sufficient alkali resistance was obtained. The results are shown in Table 1.

Example 9
Except that the Ga / (Zn + Ga) atomic ratio was changed to 0.005 and the Ni / (Zn + Ga + Ni) atomic ratio was changed to 0.25, zinc oxide containing gallium and nickel was used as the main component in the same manner as in Example 2. An oxide sintered body was prepared. When the composition of the obtained oxide sintered body was analyzed, it was confirmed that it was almost the same as the composition. When the specific resistance value of the oxide sintered body was measured, it was confirmed that the specific resistance was 5 kΩcm or less. The density was 5.6 g / cm ² .
As a result of phase identification of the oxide sintered body by X-ray diffraction measurement, only a zinc oxide phase having a hexagonal wurtzite structure was confirmed, and it contained a nickel oxide phase having a cubic rock salt structure or containing nickel and zinc. A diffraction peak due to the complex oxide Ni _x Zn _1-x O (x = 0.6, 0.7, 0.8, or 0.9) phase was not confirmed. That is, the peak intensity ratio of the zinc oxide phase (101) to the composite oxide phase (200) containing nickel and zinc defined by the above formula (A) was 0%.
Such oxide sintered bodies were bonded to form a sputtering target, and a film was formed by direct current sputtering. Arc discharge did not occur and stable film formation was possible. It was confirmed that the composition of the obtained transparent conductive film was almost the same as that of the target. When the formation phase of the film was identified by X-ray diffraction measurement, it was composed only of a zinc oxide phase having a hexagonal wurtzite structure, and the presence of a zinc oxide phase having a cubic rock salt structure was not confirmed. As a diffraction peak of the zinc oxide phase having the hexagonal wurtzite structure, not only the c-plane (002) but also the a-plane (100) peak was observed. However, the peak intensity was low, and the ratio of c-plane (002) to a-plane (100) was 70%. Next, when the specific resistance of the film was measured, it was 2.2 × 10 ⁻³ Ωcm.
Next, when the etching rate when the obtained transparent conductive film was immersed in ITO-06N was measured, it was 60 nm / min and showed an appropriate etching rate. In the case of 5% KOH, it was 10 nm / min, and although it was slightly etched, sufficient alkali resistance was obtained. The results are shown in Table 1.

(Example 10)
Except that the Ga / (Zn + Ga) atomic ratio was changed to 0.08 and the Ni / (Zn + Ga + Ni) atomic ratio was changed to 0.25, zinc oxide containing gallium and nickel was used as the main component in the same manner as in Example 2. An oxide sintered body was prepared. When the composition of the obtained oxide sintered body was analyzed, it was confirmed that it was almost the same as the composition. When the specific resistance value of the oxide sintered body was measured, it was confirmed that the specific resistance was 5 kΩcm or less. The density was 5.6 g / cm ² .
As a result of phase identification of the oxide sintered body by X-ray diffraction measurement, only a zinc oxide phase having a hexagonal wurtzite structure was confirmed, and it contained a nickel oxide phase having a cubic rock salt structure or containing nickel and zinc. A diffraction peak due to the complex oxide Ni _x Zn _1-x O (x = 0.6, 0.7, 0.8, or 0.9) phase was not confirmed. That is, the peak intensity ratio of the zinc oxide phase (101) to the composite oxide phase (200) containing nickel and zinc defined by the above formula (A) was 0%.
Such oxide sintered bodies were bonded to form a sputtering target, and a film was formed by direct current sputtering. Arc discharge did not occur and stable film formation was possible. It was confirmed that the composition of the obtained transparent conductive film was almost the same as that of the target. When the formation phase of the film was identified by X-ray diffraction measurement, it was composed only of a zinc oxide phase having a hexagonal wurtzite structure, and the presence of a zinc oxide phase having a cubic rock salt structure was not confirmed. As the diffraction peak of the zinc oxide phase having the hexagonal wurtzite structure, not only the c-plane (002) but also the a-plane (100) peak is observed, and the ratio of the c-plane (002) to the a-plane (100) is 50%. When the specific resistance of the film was measured, it was 2.4 × 10 ⁻³ Ωcm.
Next, when the etching rate when the obtained transparent conductive film was immersed in ITO-06N was measured, it was 100 nm / min and showed an appropriate etching rate. When immersed in 5% KOH, the etching rate was 20 nm / min, and although it was slightly etched, sufficient alkali resistance was obtained. The results are shown in Table 1.

(Comparative Example 4)
Zinc oxide containing gallium and nickel was prepared in the same manner as in Example 2 except that the Ga / (Zn + Ga) atomic ratio was changed to 0.08 and the Ni / (Zn + Ga + Ni) atomic ratio was changed to 0.27. An oxide sintered body having a main component was produced. When the composition of the obtained oxide sintered body was analyzed, it was confirmed that it was almost the same as the blend composition. When the specific resistance value of the oxide sintered body was measured, it was confirmed to be 5 kΩcm or less. The density was 5.6 g / cm ² .
As a result of phase identification of the oxide sintered body by X-ray diffraction measurement, only a zinc oxide phase having a hexagonal wurtzite structure was confirmed, and it contained a nickel oxide phase having a cubic rock salt structure or containing nickel and zinc. A diffraction peak due to the complex oxide Ni _x Zn _1-x O (x = 0.6, 0.7, 0.8, or 0.9) phase was not confirmed. That is, the peak intensity ratio of the zinc oxide phase (101) to the composite oxide phase (200) containing nickel and zinc defined by the above formula (A) was 0%.
Such oxide sintered bodies were bonded to form a sputtering target, and a film was formed by direct current sputtering. Arc discharge did not occur and stable film formation was possible. It was confirmed that the composition of the obtained transparent conductive film was almost the same as that of the target. In addition to X-ray diffraction measurement, the formation phase of the film was identified by reciprocal space mapping, and in addition to the zinc oxide phase having a hexagonal wurtzite structure, the presence of a zinc oxide phase having a cubic rock salt structure was found. confirmed. As for the diffraction peak of the zinc oxide phase having a hexagonal wurtzite structure, not only the c-plane (002) but also the a-plane (100) peak is observed, and the ratio of the c-plane (002) to the a-plane (100) is It was as low as 30%. When the specific resistance of the film was measured, it was as high as 6.2 × 10 ⁻³ Ωcm. Next, the etching rate when the obtained transparent conductive film was immersed in ITO-06N was measured and found to be 220 nm / min. It was revealed that the etching rate was higher than the appropriate etching rate, and the acid resistance was not sufficient. Similarly, when immersed in 5% KOH, it was revealed that the etching rate was as low as 70 nm / min and the alkali resistance was not sufficient. Due to the excessive nickel content, the formation of a zinc oxide phase with a cubic rock salt structure and the decrease in crystallinity of the zinc oxide phase with a hexagonal wurtzite structure affect the chemical resistance. Presumed to have declined. The results are shown in Table 1.

(Example 11)
Except for shortening the mixing time by a wet ball mill to 8 hours, the same composition and production method of Ga / (Zn + Ga) atomic ratio 0.03, Ni / (Zn + Ga + Ni) atomic ratio 0.11 as in Example 6, An oxide sintered body mainly composed of zinc oxide containing gallium and nickel was produced. When the composition of the obtained oxide sintered body was analyzed, it was confirmed that it was almost the same as the blend composition. When the specific resistance value of the oxide sintered body was measured, it was confirmed that the specific resistance was 1 kΩcm or less. The density was 5.0 g / cm ² . Phase identification of the oxide sintered body by X-ray diffraction measurement revealed that, besides the zinc oxide phase having a hexagonal wurtzite structure, a nickel oxide phase was not confirmed, but a cubic rock salt structure was taken. diffraction peaks due composite oxide _{Ni x Zn 1-x O (} x = 0.6,0.7,0.8 or 0.9) phase containing nickel and zinc was observed. The peak intensity ratio of the zinc oxide phase (101) to the composite oxide phase (200) containing nickel and zinc defined by the above formula (A) was 25%.
Such oxide sintered bodies were bonded to form a sputtering target, and a film was formed by direct current sputtering. Although arc discharge occurs very rarely, basically, stable film formation was possible. It was confirmed that the composition of the obtained transparent conductive film was almost the same as that of the target. When the formation phase of the film was identified by X-ray diffraction measurement, it was composed only of a zinc oxide phase having a hexagonal wurtzite structure, and the presence of a zinc oxide phase having a cubic rock salt structure was not confirmed. As a diffraction peak of the zinc oxide phase having the hexagonal wurtzite structure, not only the c-plane (002) but also a small a-plane (100) peak is observed, and the ratio of the c-plane (002) to the a-plane (100) Was 90%. When the specific resistance of the film was measured, it was 1.1 × 10 ⁻³ Ωcm.
Next, when the etching rate when the obtained transparent conductive film was immersed in ITO-06N was measured, it was 50 nm / min, which was an appropriate etching rate although faster than that of Example 6. Etching was not performed at all with respect to 5% KOH, and sufficient alkali resistance was obtained. The results are shown in Table 1. This Example 11 is a reference example.

(Comparative Example 5)
The same Ga / (Zn + Ga) atomic ratio 0.03 as in Example 6 except that nickel oxide powder having an average particle size of about 5 μm was used as a raw material powder and the mixing time by a wet ball mill was shortened to 2 hours. An oxide sintered body containing zinc oxide containing gallium and nickel as a main component was manufactured with a composition and manufacturing method of (Zn + Ga + Ni) atomic ratio of 0.11. When the composition of the obtained oxide sintered body was analyzed, it was confirmed that it was almost the same as the blend composition. When the specific resistance value of the oxide sintered body was measured, it was 1 kΩcm or less. The density was 4.8 g / cm ² .
Phase identification of oxide sinter by X-ray diffraction measurement showed that in addition to zinc oxide phase with hexagonal wurtzite structure, nickel oxide phase with cubic rock salt structure and composite containing nickel and zinc A diffraction peak due to the oxide Ni _x Zn _1-x O (x = 0.6, 0.7, 0.8, or 0.9) phase was confirmed. The peak intensity ratio of the zinc oxide phase (101) to the composite oxide phase (200) containing nickel and zinc defined by the above formula (A) was 70%.
The oxide sintered body was bonded to form a sputtering target, and direct current sputtering was performed. However, although the specific resistance of the oxide sintered body was low, arc discharge occurred frequently and stable film formation was not possible. The results are shown in Table 1.

(Example 12)
Al / (Zn + Al) atomic number ratio of 0.005, Ni / (Zn + Al + Ni) as in Example 2, except that aluminum oxide is added instead of gallium oxide powder instead of gallium oxide powder as a starting material. An oxide sintered body mainly composed of zinc oxide containing aluminum and nickel was manufactured by a composition and a manufacturing method with an atomic ratio of 0.02. When the composition of the obtained oxide sintered body was analyzed, it was confirmed that it was almost the same as the composition. When the specific resistance value of the oxide sintered body was measured, it was confirmed that the specific resistance was 5 kΩcm or less. The density was 5.4 g / cm ² .
As a result of phase identification of the oxide sintered body by X-ray diffraction measurement, only a zinc oxide phase having a hexagonal wurtzite structure was confirmed, and it contained a nickel oxide phase having a cubic rock salt structure or containing nickel and zinc. A diffraction peak due to the complex oxide Ni _x Zn _1-x O (x = 0.6, 0.7, 0.8, or 0.9) phase was not confirmed. That is, the peak intensity ratio of the zinc oxide phase (101) to the composite oxide phase (200) containing nickel and zinc defined by the above formula (A) was 0%.
Such oxide sintered bodies were bonded to form a sputtering target, and a film was formed by direct current sputtering. Arc discharge did not occur and stable film formation was possible. It was confirmed that the composition of the obtained transparent conductive film was almost the same as that of the target. When the formation phase of the film was identified by X-ray diffraction measurement, it was composed only of a zinc oxide phase having a hexagonal wurtzite structure, and the presence of a zinc oxide phase having a cubic rock salt structure was not confirmed. As for the diffraction peak of the zinc oxide phase having the hexagonal wurtzite structure, only the c-plane (002) reflection is observed, and the a-plane of the zinc oxide phase defined by the above formula (B) ( 100), the c-plane (002) peak intensity ratio was 100%. When the specific resistance of the film was measured, it was 1.9 × 10 ⁻³ Ωcm.
Next, when the etching rate when the obtained transparent conductive film was immersed in ITO-06N was measured, it was 70 nm / min and was an appropriate etching rate. Further, the etching rate when immersed in 5% KOH was 20 nm / min, and although it was slightly etched, sufficient alkali resistance was obtained. The results are shown in Table 1.

(Example 13)
Al / (Zn + Al) atomic number ratio 0.03, Ni / (Zn + Al + Ni) similar to Example 6, except that aluminum oxide powder was used instead of gallium oxide powder as a starting material in order to add aluminum instead of gallium. An oxide sintered body mainly composed of zinc oxide containing aluminum and nickel was manufactured with a composition and a manufacturing method having an atomic ratio of 0.11.
When the composition of the obtained oxide sintered body was analyzed, it was confirmed that it was almost the same as the blend composition. When the specific resistance value of the oxide sintered body was measured, it was confirmed that the specific resistance was 1 kΩcm or less. The density was 5.4 g / cm ² . As a result of phase identification of the oxide sintered body by X-ray diffraction measurement, only a zinc oxide phase having a hexagonal wurtzite structure was confirmed, and it contained a nickel oxide phase having a cubic rock salt structure or containing nickel and zinc. A diffraction peak due to the complex oxide Ni _x Zn _1-x O (x = 0.6, 0.7, 0.8, or 0.9) phase was not confirmed. That is, the peak intensity ratio of the zinc oxide phase (101) to the composite oxide phase (200) containing nickel and zinc defined by the above formula (A) was 0%.
Such oxide sintered bodies were bonded to form a sputtering target, and a film was formed by direct current sputtering. Arc discharge did not occur and stable film formation was possible. It was confirmed that the composition of the obtained transparent conductive film was almost the same as that of the target. When the formation phase of the film was identified by X-ray diffraction measurement, it was composed only of a zinc oxide phase having a hexagonal wurtzite structure, and the presence of a zinc oxide phase having a cubic rock salt structure was not confirmed. As for the diffraction peak of the zinc oxide phase having the hexagonal wurtzite structure, only the c-plane (002) reflection is observed, and the a-plane of the zinc oxide phase defined by the above formula (B) ( 100), the c-plane (002) peak intensity ratio was 100%. When the specific resistance of the film was measured, it was 9.5 × 10 ⁻⁴ Ωcm.
Next, when the etching rate when the obtained transparent conductive film was immersed in ITO-06N was measured, it was 30 nm / min and was an appropriate etching rate. Etching was not performed at all with respect to 5% KOH, and sufficient alkali resistance was obtained. The results are shown in Table 1.

(Example 14)
Al / (Zn + Al) atomic ratio 0.05, Ni / (Zn + Al + Ni) as in Example 8 except that aluminum oxide is used instead of gallium oxide powder instead of gallium oxide to add aluminum instead of gallium. An oxide sintered body mainly composed of zinc oxide containing aluminum and nickel was manufactured by a composition and a manufacturing method with an atomic ratio of 0.14.
When the composition of the obtained oxide sintered body was analyzed, it was confirmed that it was almost the same as the blend composition. When the specific resistance value of the oxide sintered body was measured, it was confirmed that the specific resistance was 1 kΩcm or less. The density was 5.4 g / cm ² . As a result of phase identification of the oxide sintered body by X-ray diffraction measurement, only a zinc oxide phase having a hexagonal wurtzite structure was confirmed, and it contained a nickel oxide phase having a cubic rock salt structure or containing nickel and zinc. A diffraction peak due to the complex oxide Ni _x Zn _1-x O (x = 0.6, 0.7, 0.8, or 0.9) phase was not confirmed. That is, the peak intensity ratio of the zinc oxide phase (101) to the composite oxide phase (200) containing nickel and zinc defined by the above formula (A) was 0%.
Such oxide sintered bodies were bonded to form a sputtering target, and a film was formed by direct current sputtering. Arc discharge did not occur and stable film formation was possible. It was confirmed that the composition of the obtained transparent conductive film was almost the same as that of the target. When the formation phase of the film was identified by X-ray diffraction measurement, it was composed only of a zinc oxide phase having a hexagonal wurtzite structure, and the presence of a zinc oxide phase having a cubic rock salt structure was not confirmed. As for the diffraction peak of the zinc oxide phase having the hexagonal wurtzite structure, only the c-plane (002) reflection is observed, and the a-plane of the zinc oxide phase defined by the above formula (B) ( 100), the c-plane (002) peak intensity ratio was 100%. When the specific resistance of the film was measured, it was 9.9 × 10 ⁻⁴ Ωcm.
Next, when the etching rate when the obtained transparent conductive film was immersed in ITO-06N was measured, it was 30 nm / min and was an appropriate etching rate. Etching was not performed at all with respect to 5% KOH, and sufficient alkali resistance was obtained. The results are shown in Table 1.

(Example 15)
Except that a part of the gallium added in Example 6 is replaced with aluminum to obtain a Ga / (Zn + Ga) atomic ratio of 0.025 and an Al / (Zn + Al) atomic ratio of 0.005, the same as in Example 6. , (Ga + Al) / (Zn + Ga + Al) atomic ratio of 0.03, Ni / (Zn + Al + Ni) atomic ratio of 0.11, and an oxide mainly composed of zinc oxide containing gallium, aluminum and nickel A sintered body was produced.
When the composition of the obtained oxide sintered body was analyzed, it was confirmed that it was almost the same as the blend composition. When the specific resistance value of the oxide sintered body was measured, it was confirmed that the specific resistance was 1 kΩcm or less. The density was 5.4 g / cm ² . As a result of phase identification of the oxide sintered body by X-ray diffraction measurement, only a zinc oxide phase having a hexagonal wurtzite structure was confirmed, and it contained a nickel oxide phase having a cubic rock salt structure or containing nickel and zinc. A diffraction peak due to the complex oxide Ni _x Zn _1-x O (x = 0.6, 0.7, 0.8, or 0.9) phase was not confirmed. That is, the peak intensity ratio of the zinc oxide phase (101) to the composite oxide phase (200) containing nickel and zinc defined by the above formula (A) was 0%.
Such oxide sintered bodies were bonded to form a sputtering target, and a film was formed by direct current sputtering. Arc discharge did not occur and stable film formation was possible. It was confirmed that the composition of the obtained transparent conductive film was almost the same as that of the target. When the formation phase of the film was identified by X-ray diffraction measurement, it was composed only of a zinc oxide phase having a hexagonal wurtzite structure, and the presence of a zinc oxide phase having a cubic rock salt structure was not confirmed. As for the diffraction peak of the zinc oxide phase having the hexagonal wurtzite structure, only the c-plane (002) reflection is observed, and the a-plane of the zinc oxide phase defined by the above formula (B) ( 100), the c-plane (002) peak intensity ratio was 100%. When the specific resistance of the film was measured, it was 1.0 × 10 ⁻³ Ωcm, which was slightly higher than Example 6.
Next, when the etching rate when the obtained transparent conductive film was immersed in ITO-06N was measured, it was 30 nm / min and was an appropriate etching rate. Etching was not performed at all with respect to 5% KOH, and sufficient alkali resistance was obtained. The results are shown in Table 1.

In Example 1, since the oxide sintered body contains zinc oxide as a main component and further contains a specific amount of nickel, when this is used as a sputtering target, arc discharge is generated even in direct current sputtering. The transparent conductive film excellent in chemical resistance could be formed. In Examples 2 to 10 and Examples 12 to 14, since the oxide sintered body further containing a specific amount of gallium and / or aluminum is used, the conductivity of the transparent conductive film obtained can be further improved. I understand.
Note that in Example 11 (Reference Example), the mixing time of the raw material powder of Example 6 in order to short-hidden, density of the obtained oxide sintered body is slightly smaller, the chemical resistance of the transparent conductive film obtained It can be seen that the conductivity is also affected by Example 6 .

  On the other hand, Comparative Example 1 is a conventional gallium-doped zinc oxide sintered body to which nickel is not added, and Comparative Examples 2 to 4 are those in which nickel and gallium are added. Since it deviates from the scope of the invention, the chemical resistance and conductivity of the transparent conductive film obtained using this were insufficient. In Comparative Example 5, since the mixing time of the raw material powder is extremely short and a nickel oxide phase is generated in the oxide sintered body, it can be seen that arc discharge is generated by sputtering and a transparent conductive film cannot be formed.

Claims (9)

An oxide sintered body containing zinc oxide as a main component and further containing nickel, which is formed by mixing a raw material powder having an average particle diameter of 3 μm or less and mixing for 12 hours or more , is placed in a sintering furnace. It is obtained by sintering at 1100 to 1600 ° C. for 10 to 30 hours in an atmosphere in which oxygen is introduced into the atmosphere, and the nickel content is 0.02 to 0.25 as the Ni / (Zn + Ni) atomic ratio. Further, the nickel oxide phase is not contained , and the peak intensity ratio by X-ray diffraction measurement represented by the following formula (A) is 25% or less and the specific resistance is 50 kΩcm or less. Oxide sintered body.
I [Ni _x Zn _1-x O (200)] / I [ZnO (101)] × 100 (%) Formula (A)
(In the formula, I [Ni _x Zn _1-x O (200)] is a complex oxide Ni _x Zn _1-x O (x = 0.6, 0.7, 0.8) having a cubic rock salt structure. Or 0.9) (200) peak intensity of the phase, and I [ZnO (101)] represents the (101) peak intensity of the zinc oxide phase having a hexagonal wurtzite structure) An oxide sintered body containing zinc oxide as a main component and further containing nickel and gallium and / or aluminum,
A formed body formed by mixing raw material powder having an average particle size of 3 μm or less for 12 hours or more is baked at 1100 to 1600 ° C. for 10 to 30 hours in an atmosphere in which oxygen is introduced into the sintering furnace. Obtained by
The content of gallium and / or aluminum is more than 0 as a (Ga + Al) / (Zn + Ga + Al) atomic ratio and 0.08 or less, and the content of nickel is 0.02 to 0.00 as an Ni / (Zn + Ga + Al + Ni) atomic ratio. 25, no nickel oxide phase is contained , and the peak intensity ratio by X-ray diffraction measurement represented by the following formula (A) is 25% or less and the specific resistance is 5 kΩcm or less. An oxide sintered body characterized by that.
I [Ni _x Zn _1-x O (200)] / I [ZnO (101)] × 100 (%) Formula (A)
(In the formula, I [Ni _x Zn _1-x O (200)] is a complex oxide Ni _x Zn _1-x O (x = 0.6, 0.7, 0.8) having a cubic rock salt structure. Or 0.9) (200) peak intensity of the phase, and I [ZnO (101)] represents the (101) peak intensity of the zinc oxide phase having a hexagonal wurtzite structure)   3. The oxide sintered body according to claim 1, wherein the nickel content is 0.05 to 0.14 as an atomic ratio of Ni / (Zn + Ni) or Ni / (Zn + Ga + Al + Ni).   The oxide sintered body according to claim 2, wherein the content of gallium and / or aluminum is 0.01 to 0.05 as a (Ga + Al) / (Zn + Ga + Al) atomic ratio. The oxide sintered body according to any one of claims 1 to 4, wherein the density is 5.0 g / cm ² or more.   A target obtained by processing the oxide sintered body according to claim 1.   A transparent conductive film formed on a substrate by sputtering or ion plating using the target according to claim 6. A transparent conductive film containing zinc oxide as a main component and further containing nickel,
Nickel is contained in an Ni / (Zn + Ni) atomic ratio of 0.02 to 0.25,
Moreover, it is mainly composed of a zinc oxide phase having a hexagonal wurtzite structure, a peak intensity ratio by an X-ray diffraction measurement represented by the following formula (B) is 50% or more, and a cubic rock salt structure. The transparent conductive film according to claim 7, wherein the zinc oxide phase is not contained.
I [ZnO (002)] / (I [ZnO (002)] + I [ZnO (100)]) × 100 (%) Formula (B)
(Wherein I [ZnO (002)] is the (002) peak intensity of the zinc oxide phase having a hexagonal wurtzite structure, and I [ZnO (100)] has a hexagonal wurtzite structure. (Shows the (100) peak intensity of the zinc oxide phase.)   Furthermore, gallium and / or aluminum are contained by more than 0 and 0.08 or less by (Ga + Al) / (Zn + Ga + Al) atomic ratio, The transparent conductive film of Claim 8 characterized by the above-mentioned.