KR101157123B1 - Ito sintered body and ito sputtering target - Google Patents

Abstract

An object of the present invention is to provide an ITO sputtering target material and an ITO sputtering target capable of forming a film of ITO having excellent physical properties at low cost, and an ITO sintered body suitable for these.

The present invention the width of the fine-particle-free zone from the grain boundary of the ITO sintered body, or the main grains of In ₂ O ₃ less than the average value of the parent phase of microparticles choedaegyeong 0.2㎛ present in the challenge to the main grain of In ₂ O ₃ matrix ITO sintered body is greater than the average value 0.3㎛ of, or, primary crystal grains of in ₂ O ₃ and the average value of choedaegyeong of microparticles over 0.2㎛ present in the parent phase, and, the fine particle-free zone from the boundary of the in ₂ O ₃ matrix The average value of the width | variety was solved by the ITO sintered compact which is 0.3 micrometer or more.

ITO Sintered Body, Sputtering Target

Description

ITO Sintered Body and ITO Sputtering Target {ITO SINTERED BODY AND ITO SPUTTERING TARGET}

BRIEF DESCRIPTION OF THE DRAWINGS The figure which shows the SEM image of the ITO sintered compact of Example 1. FIG.

2 is a diagram showing an SEM image of the ITO sintered compact of Example 1. FIG.

3 is a schematic view of an ITO sintered compact structure.

4 is a graph showing the oxygen partial pressure dependence of the resistivity of the ITO film formed on a glass substrate at 100 ° C.

5 is a graph showing the oxygen partial pressure dependence of the resistivity of the ITO film formed on a glass substrate at 250 ° C.

6 is a view showing an SEM image of the ITO sintered compact of Comparative Example 1. FIG.

7 is a view showing an SEM image of the ITO sintered compact of Comparative Example 1. FIG.

[Description of Symbols]

One… In ₂ O ₃ matrix, 2. Fine particles, 3... Grain boundary, 4.. Compound phase, 5... Fine particle free zone, 10... ITO Sintered Body

The present invention relates to an ITO sintered body and an ITO sputtering target. More specifically, the ITO sintered compact in which the microparticles of a certain size exist in the main grain In ₂ O ₃ mother phase, the ITO sintered compact in which the microparticles exist in the specific region in the In ₂ O ₃ mother phase, the specific region in the mother phase The present invention relates to an ITO sintered body in which fine particles of a size exist, a sputtering target material using them, and an ITO sputtering target.

In the ITO sintered compact used as an ITO sputtering target material, in order to improve the yield of film-forming, various examinations have been made in order to reduce or prevent generation | occurrence | production of arcing and a particle at the time of sputtering. For example, attempts have been made to prevent the occurrence of arcing by setting the surface roughness of the ITO sputtering target within a predetermined range (see Patent Documents 1 and 2).

In recent years, as well as the yield improvement of film formation, as well as the expansion of the use of the ITO film, the improvement of the physical properties of the ITO film itself obtained by the film formation by sputtering has been demanded. For example, an ITO film or the like showing a lower resistivity is desired.

Usually, in the film formation by sputtering, it is known that the resistivity of the obtained ITO film changes depending on the atmosphere at the time of sputtering, specifically, the partial pressure of oxygen mixed in an inert gas such as argon, so that the resistivity of the ITO film is minimized. The oxygen partial pressure is found and sputtering is performed by controlling the amount of oxygen introduced into the sputtering apparatus so as to obtain the oxygen partial pressure. If this optimum oxygen partial pressure is low, that is, it is cost-effective to form an ITO film of lower resistivity than a low oxygen partial pressure.

To date, the top data with reproducibility in ITO films is an ITO film having a resistivity of 7.7 × 10 ⁻⁵ (Ω · cm) formed by the Professor Hosono Hideo's team under the following conditions (Non-Patent Document 1). , Non-patent document 2). Deposition conditions; Substrate: Ultra-flat YSZ (yttria-stabilized zircornia) substrate, Substrate temperature: 900 ° C, Deposition method: Epitaxial growth by PLD method (Pulse Laser Deposition)

However, such unusual film forming conditions are not suitable for industrial production, and there is a problem that they cannot be put to practical use.

By the way, when the ITO sintered compact is cut horizontally in the thickness direction, and the obtained cut surface is etched and the microstructure is observed, the compound phase which exists in the state along the grain boundary other than the main grain In ₂ O ₃ and its grain boundary, In _{In some} cases, fine particles present in the ₂ O ₃ mother phase can be seen. However, as far as the present inventors know, it has not been studied at all about whether the fine structure of such an ITO sintered body and the yield of the film formation or the film properties of the film formation are related.

[Patent Document 1] Japanese Patent No. 2750483

[Patent Document 2] Japanese Patent No. 3152108

[Non-Patent Document 1] Hiromichi Ohta, Masahiro Orita, Masahiro Hirano, Hiroaki Tanji, Hiroshi Kawazoe and Hideo Hosono, “Highly conductive conductive indium-tin-oxide thin films epitaxially grown on yttria-stabilized zirconia (100) by pulsed-laser deposition ”, Appl. Phys. Lett. 76 (2000) p. 2740-2742.

[Non-Patent Document 2] H. OHTA, M. ORITA, M. HIRANO, and H. HOSONO, “Surface morphology and crystal quality of low resistive indium tin oxide grown on yttria-stabilized zirconia”, Journal of Applied Physics, 91 ( 2002) p.3547

The present invention relates to an ITO sputtering target material and an ITO sputtering target capable of forming a film of ITO having excellent physical properties at low cost, in particular, an ITO sputtering target material and an ITO sputtering target, in which a low-resistance film is obtained under conditions suitable for industrial production. It is a subject to provide an ITO sintered compact.

The present inventors have found that the fine particles present in noting the relationship between the fine particles and the deposition yield and a deposition film properties in the main crystal grains of In ₂ O ₃ matrix of the ITO sintered body, extensive studies by the bar, and In ₂ O ₃ matrix According to the ITO sintered body which controlled the size, the area | region where the microparticles exist, etc., the ITO sputtering target material and ITO sputtering target which can form the ITO film | membrane which is more excellent in physical properties, especially the low-resistance ITO film | membrane on conditions suitable for industrial production. It was found that the present invention can be achieved to complete the present invention.

That is, this invention relates to the following matters.

The ITO sintered compact according to the present invention is characterized in that the average value of the maximum diameters of the fine particles present in the In ₂ O ₃ mother phase as the main grain is 0.2 µm or more.

In addition, ITO sintered body according to the invention is characterized in that at least the average value of the width of the fine particle-free zone from the primary grains of In ₂ O ₃ matrix grain boundaries 0.3㎛.

In the ITO sintered body according to the present invention, the average value of the maximum diameters of the fine particles existing in the In ₂ O ₃ mother phase as the main grain is 0.2 µm or more, and the width of the fine particle free zone from the grain boundary of the In ₂ O ₃ mother phase. The average value of is 0.3 micrometer or more, It is characterized by the above-mentioned.

These ITO sintered compacts can be used suitably as a sputtering target material.

Moreover, the ITO sputtering target which concerns on this invention is characterized by including the said ITO sintered compact and a backing plate.

BEST MODE FOR CARRYING OUT THE INVENTION [

Hereinafter, the present invention will be described in detail.

In the ITO sintered compact according to the present invention, the average value of the maximum diameters of the fine particles existing in the In ₂ O ₃ mother phase as the main grains is 0.2 µm or more, or (2) from the grain boundaries of the In ₂ O ₃ mother phase as the main grains. The average value of the width of the fine particle free zone is 0.3 µm or more, or (3) The average value of the maximum diameter of the fine particles existing in the In ₂ O ₃ mother phase as the main grain is 0.2 µm or more, and the In ₂ O ₃ mother phase The average value of the width | variety of the fine particle free zone from the grain boundary of is 0.3 micrometer or more, It is characterized by the above-mentioned.

Here, the average value of the maximum diameters of the fine particles existing in the In ₂ O ₃ mother phase means that the cut surface obtained by cutting the ITO sintered body horizontally in the thickness direction using a diamond cutter is emery pager # 170, Polishing step by step using # 320, # 800, # 1500, # 2000, and finally buffing to finish the mirror surface and then etching solution at 40 ° C (nitric acid (60-61% aqueous solution, liver) Kagaku Co., Ltd., Nitric acid 1.38 green No. 1 class No. 28161-03), hydrochloric acid (35.0-37.0% aqueous solution, Kando Kagoku Co., Ltd., hydrochloric acid no.1 No. 18078-01) and water Is immersed in a volume ratio of HCl: H ₂ O: HNO ₃ = 1: 1: 0.08 for 9 minutes, and etched, and then exposed to an arbitrary area of 2 μm × 2 μm (except grain boundaries and grain boundaries). The maximum diameter of the fine particles observed in the compound present in the state, in a region not containing any of the free zones defined later. He said values bacteria. In addition, the largest diameter of a fine particle means the largest thing in the straight line (diameter) which connects arbitrary two points of the fine particle cross section observed. Observation of the fine particles is performed by SEM (scanning electron microscope) (magnification 30,000 times). Further, the fine particles present in the In ₂ O ₃ mother phase are regarded as heterogeneous compounds with In ₂ O ₃ on the SEM, and presumably In ₄ Sn ₃ O ₁₂ .

In the above observation method, the fine particle free zone means a region in the In ₂ O ₃ mother phase in which fine particles are not observed when SEM observation is performed at a magnification of 3,000 times (however, a compound phase region exists in a state along grain boundaries). Does not include). Fine average value of the width of the particle-free zone from the boundary of the In ₂ O ₃ matrix is exposed to the same conditions as in calculating the choedaegyeong average value of the fine particles present in the above-mentioned In ₂ O ₃ matrix, cutting, and etching the ITO sintered body observing the surface fold magnification 3,000 SEM, and capable of observing the whole using a SEM picture taken, in ₂ O ₃ in the picture Hairy lip sectional everything (there is at the end of the picture, in ₂ O ₃ matrix lip section The part which is not stamped out is excluded), and the half of the sum of the shortest and the longest in the distance from the In ₂ O ₃ matrix grain boundary to the fine particles in the normal direction is the In ₂ O ₃ matrix. The width of the fine particle free zone in the particle is divided by the number of In ₂ O ₃ parent grains as the measurement target.

Below, the ITO sintered compact of said (1)-(3) which is three aspects contained in this invention, and its manufacturing method are demonstrated in detail.

In the ITO sintered compact of one embodiment of the present invention, (1) the average value of the maximum diameters of the fine particles existing in the In ₂ O ₃ matrix as the main grains is 0.2 µm or more, preferably 0.3 µm or more, and more preferably 0.3 to 2 µm. It is an ITO sintered compact in the range.

Further, one aspect of the present invention of the ITO sintered body (2) of the main grain In ₂ O more than the average value of the width of the fine-particle-free zone from the grain boundary of the parent phase 0.3㎛ _3, preferably at least 0.4㎛, more preferably It is an ITO sintered compact in the range of 0.5-3 micrometers. If the average value of the width of the fine particle free zone is equal to or greater than the specific value, more preferably within the specific range, the area where no fine particles exist in the main grain In ₂ O ₃ matrix is widened, and thus the fine particles The boundary with the area where is present becomes clearer.

In the ITO sintered compact of one embodiment of the present invention, (3) the average value of the maximum diameters of the fine particles existing in the In ₂ O ₃ matrix as the main grains is 0.2 µm or more, preferably 0.3 µm or more, more preferably 0.3 to and the 2㎛ range, and, in the in ₂ O more than the average value of the width of the fine-particle-free zone from the grain boundary of the parent phase 0.3㎛ _3, preferably at least 0.4㎛, more preferably in the range of 0.5 ~ 3㎛ ITO sintered body. As described above, when the fine particles having a specific size are present in a specific region in the In ₂ O ₃ mother phase, it is expected to have all the advantages of the ITO sintered body of the above (1) and (2). Therefore, when such an ITO sintered compact is used as a sputtering target, the response to oxygen partial pressure at the time of film formation by sputtering becomes sensitive, and it is estimated that ITO film of lower resistivity can be formed into a film with comparatively low oxygen partial pressure.

The ITO sintered compact of these (1)-(3) can be manufactured by what is called a powder metallurgy method. In the powder metallurgy method, in general, a raw material powder is added to a raw material powder as necessary to compression molding, and the obtained molded product is degreased as necessary, and then the molded product is calcined to obtain a sintered compact. In order to obtain the ITO sintered compact of (3), it is necessary to carry out the baking process under specific conditions.

Specifically, raw material powders such as indium oxide (In ₂ O ₃ ) and tin oxide (SnO ₂ ) are mixed at a desired ratio, a binder is added as necessary, compression molding is performed to obtain a molded article, and the obtained molded article is subjected to necessity. The process up to degreasing can be performed by well-known means and conditions currently performed. Further, the specification, also referred to ITO, means a conventional, indium oxide (In ₂ O ₃₎ material obtained by adding 1 to 35% by weight of tin oxide (SnO ₂₎ on.

Specifically, the raw material powder may be calcined and classified as necessary, and the subsequent mixing of the raw material powder can be performed by, for example, a ball mill. Thereafter, the mixed raw material powder is filled into a molding die and compression molded to produce a molded body, and may be degreased under an air atmosphere or an oxygen atmosphere, or as in the filtration molding method described in JP-A-11-286002. The slurry made of the mixed raw material powder, the ion exchanged water, and the organic additive is injected into the filter forming mold made of a non-aqueous material for obtaining a molded body by depressurizing and draining water from the ceramic raw material slurry. You may prepare a molded object and dry-degrease this molded object.

The ITO sintered compact of this invention can be obtained by baking-processing the molded object obtained in this way on the specific conditions demonstrated below.

The baking treatment usually consists of a heating step, a heat retention step and a cooling step. The furnace which can be used for a baking process should just be a furnace of a well-known structure, and is not specifically limited.

In a heating process, the said molded object is put in a furnace, and a furnace is continuously or stepwise heated normally to 1400-1600 degreeC, Preferably it is 1550-1600 degreeC. At this time, you may mount a molded object on a baking board as needed. In view of the production efficiency of the obtained ITO sintered compact, it is preferable that the average of the temperature increase rate in a furnace through the whole heating process is 50-400 degreeC / hour.

Moreover, from the viewpoint of the density improvement of the obtained ITO sintered compact, it is preferable that the said heating process introduce | transduces oxygen in a furnace and is performed in oxygen atmosphere. The flow rate of oxygen introduced into the furnace is usually in the range of 0.1 to 500 m ³ / hour per 1 m ³ of furnace volume.

Next, in the heat retention step, the maximum temperature heated in the heating step is maintained for a predetermined time. The retention time is usually 3 to 20 hours in consideration of production efficiency. In the holding step, it is preferable to introduce oxygen into the furnace under the same conditions as the heating step.

Subsequently, in the cooling step, the furnace is continuously or stepwise cooled to room temperature to cool the molded body that has undergone the heating step and the warming step. From the viewpoint of controlling the average value of the maximum diameter of the fine particles present in the In ₂ O ₃ mother phase which is the main crystal grain of the obtained ITO sintered body and the average value of the width of the fine particle free zone from the grain boundary of the In ₂ O ₃ mother phase, It is preferable to adjust the temperature-fall rate of the temperature range from the highest temperature in heat retention process (same as the highest temperature in a heating process) to 400 degreeC. The average of the temperature-fall rate in this temperature range is 30 degreeC / hour or more and less than 100 degreeC / hour normally, Preferably it is 30-40 degreeC / hour. When the temperature-fall rate of the temperature range is within the above range, since the molded body after the heating step is gradually cooled, growth of fine particles in the In ₂ O ₃ matrix is accelerated and coarsened, and the average value of the maximum diameter of the fine particles is 0.2. can be controlled by ㎛ or larger, the fine particles may have, because aggregated to some extent, to control the average value of the fine particles of the free zone width from the boundary of the in ₂ O ₃ matrix to more than 0.3㎛.

On the other hand, in the said cooling process, the temperature fall rate of the temperature range from less than 400 degreeC to room temperature is not specifically limited. This is because the fine particles in the In ₂ O ₃ mother phase do not substantially grow in such a temperature range. Specifically, the temperature lowering rate may be appropriately set, and may be left to cool without adjusting the temperature lowering rate in particular, and may be naturally cooled to room temperature.

Further, from the viewpoint of controlling the fine particles, the average value of the free zone width from the boundary of the average value, In ₂ O ₃ matrix of choedaegyeong of fine particles present in the primary crystal grains of In ₂ O ₃ matrix of the ITO sintered body is obtained, the cooling step It is preferable to introduce | transduce oxygen on the conditions similar to a heating process, and to perform in oxygen atmosphere.

Although the reason is not clear, if the cooling step is carried out in an oxygen atmosphere, the growth of the fine particles in the In ₂ O ₃ mother phase is promoted, and the average value of the maximum diameter is increased, and the fine particles are placed in the center of the In ₂ O ₃ mother phase. It aggregates and precipitates and it becomes easy to obtain the ITO sintered compact of this invention.

Thus obtained ITO sintered compact is cut out to a desired shape as needed, grinding | polishing etc. can be used suitably as a sputtering target material.

Furthermore, an ITO sputtering target can be obtained by joining the said ITO sintered compact and the backing plate which is a cooling plate.

In this case, what is necessary is just to use a backing plate normally as a backing plate of a sputtering target, and the backing plate made from copper and copper alloy is mentioned. Moreover, the shape may also be a well-known thing, and is not specifically limited.

Bonding of an ITO sintered compact and a backing plate can be suitably performed by a well-known method, Although it does not specifically limit, The method of joining via bonding agents, such as In solder, from a cost and productivity point is mentioned preferably. Specifically, the ITO sintered body is cut out into a desired shape as necessary, ground, etc., if necessary, and then heated to a temperature equal to or higher than the melting point of the In solder, and the temperature is maintained, and the backing plate of the ITO sintered body A molten In solder may be applied to the surface to be joined, and may be pasted with a backing plate, allowed to cool while being pressurized, cooled to room temperature, or the like.

Hereinafter, although this invention is demonstrated further more concretely based on an Example, this invention is not limited to these Examples.

Example 1

The detoxified ITO molded body (In ₂ O ₃ : SnO ₂ (weight ratio) = 90: 10) was placed in a batch in a state where it was mounted on a firing plate, while flowing oxygen gas having an oxygen concentration of 100% in the furnace. (1 m ³ / h per 1 m ^{3 of} furnace volume) and the furnace was heated to 1600 ° C, held at that temperature for 8 hours, and then cooled to room temperature to obtain an ITO sintered compact.

The average temperature increase rate of the heating process at this time was 117 degreeC / hour and the average temperature-fall rate of the cooling process in the temperature range of 1600 degreeC to 400 degreeC was 30 degreeC / hour.

Firing conditions are shown below.

Firing conditions;

Room temperature → (50 ° C / hr) → 400 ° C → (100 ° C / hr) → 800 ° C × 4hr → (400 ° C / hr) → 1600 ° C × 8hr → (-175 ° C / hr) → 300 ° C → cooling → room temperature (Oxygen flow atmosphere through the whole process)

Next, the cut surface obtained by cutting the ITO sintered compact horizontally in the thickness direction at the position of 5 mm from the upper surface at the time of the sintering by a diamond cutter is used emery paper # 170, # 320, # 800, # 1500, # 2000. Polishing stepwise while rotating 90 degrees each, and finally buff polishing to finish the mirror surface, and then etching liquid at 40 ° C (nitric acid (60-61% aqueous solution, manufactured by Kando Kagaku Co., Ltd., 1.38 green nitrate) 28161-03), hydrochloric acid (35.0 to 37.0% aqueous solution, manufactured by Kando Kagaku Co., Ltd., hydrochloric acid rust grade No. 18078-01) and water in a volume ratio of HCl: H ₂ O: HNO ₃ = 1: 1: 0.08 Immersed for 9 minutes, and the exposed surface was observed by SEM at 3,000 times and 30,000 times magnification (JSM-6380A; manufactured by JEOL), and the average value of the maximum diameters of the fine particles existing in the In ₂ O ₃ mother phase and its It was determined for microparticles of mean value of the pre-zone width from the boundary of the in ₂ O ₃ matrix, respectively.

As a result, the average value of the maximum diameters of the fine particles existing in the In ₂ O ₃ mother phase was 0.3 µm, and the average value of the width of the fine particle free zone from the grain boundaries of the In ₂ O ₃ mother phase was 1 µm.

The SEM image (magnification; 3,000 times) of the ITO sintered compact at this time is shown in FIG. 1, and the SEM image (magnification; 30,000 times) which expanded the microparticle group part further is shown in FIG.

In addition, the structure of a part of the structure of an ITO sintered compact is shown in FIG. 3 (However, FIG. 3 shows the structure of the ITO sintered compact exaggerated typically for description, and the dimension, ratio, etc. of each component are real thing. Is not). In FIG. 3, 10 denotes the ITO sintered body as a whole, and the fine particles 2 are present in the In ₂ O ₃ mother phase 1 which is the main crystal of the ITO sintered body 10, and the grain boundary 3 is also present. The compound phase (4) exists in the state along. Further, the fine particles (2) there is the fine particle-free zone (5) in area which is not observed in the In ₂ O ₃ matrix (1).

Subsequently, the said ITO sintered compact was cut | disconnected to the moderate magnitude | size, and it grind | grinded by the planar grinding mill, and obtained the ITO sputtering target material of diameter 200mm x thickness 8mm. The obtained ITO sputtering target material was bonded to the copper backing plate through In solder, and the ITO sputtering target was produced.

Using this ITO sputtering target, the oxygen partial pressure in the sputtering apparatus is changed under the following conditions to perform sputtering, and an ITO film is formed on a glass substrate (manufactured by Corning; Corning # 1737; 50 mm x 50 mm x 0.8 mm) at 100 ° C or 250 ° C. Tabernacle. The resistivity of this ITO film was measured with ResiTest8308 (manufactured by Toyo Technica) based on the van der Pauw method.

As a result, the optimum oxygen partial pressure in the case of the glass substrate temperature of 100 degreeC was 9.3x10 <^-3> (Pa), and the resistivity of the ITO film at that time was 3.74x10 <^-4> ((ohm) * cm). In addition, the optimum oxygen partial pressure in the case of the glass substrate temperature of 250 degreeC was 8.1 * 10 <^-3> (Pa), and the resistivity of the ITO film at that time was 1.99 * 10 <^-4> (ohm * cm).

The results are collectively shown in Table 1, Table 2 and Figs. 4 and 5.

<Sputtering condition>

Deposition Conditions:

Device; DC magnetron sputter device, exhaust system; Cryopump, rotary pump

Reach vacuum degree; 3.0 × 10 ^-6 Pa

Sputter pressure; 0.4 Pa (nitrogen equivalent value, Ar pressure),

Oxygen partial pressure; 4.5 ～ 13 × 10 ^-3 Pa

Input power; 600 W (1.85 W / cm ² )

Substrate temperature; 100 ℃, 250 ℃

Film thickness; 1200Å

Glass substrates; Corning # 1737 (plate thickness 0.8 mm)

Comparative Example 1

According to the firing conditions shown below, the average temperature-fall rate of the cooling process in the temperature range of 1600 degreeC to 400 degreeC shall be 175 degreeC / hour, At the time of a cooling process, the oxygen gas in a furnace is replaced by atmospheric | air atmosphere, An ITO sintered body was obtained in the same manner as in Example 1, except that 1 m ³ / h was flowed per 1 m ^{3 of} volume.

Firing conditions;

Room temperature → (50 ° C / hr) → 400 ° C → (100 ° C / hr) → 800 ° C × 4hr → (400 ° C / hr) → 1600 ° C × 8hr → (-175 ° C / hr) → 300 ° C → cooling → room temperature

Treatment as the ITO sintered body obtained in Example 1, and by observing the exposed surface SEM, In ₂ O ₃ the average value of the fine particle choedaegyeong present in the mother phase and that In the width of the fine particle-free zone from the boundary of the ₂ O ₃ matrix The average value of

As a result, the average value of the maximum diameter of the fine particles existing in the In ₂ O ₃ mother phase was 0.13 µm, and the average value of the width of the fine particle free zone from the grain boundary of the In ₂ O ₃ mother phase was 0.2 µm. The SEM image (magnification; 3000 times) at this time is shown in FIG. 6, and the SEM image (magnification; 30,000 times) which further expanded the microparticle group part is shown in FIG.

Next, in the same manner as in Example 1, an ITO sputtering target having the same shape and the same size was produced. Except for using this ITO sputtering target, the ITO membrane was formed into a film by the conditions and methods similar to Example 1, and the resistivity of this ITO membrane was measured.

As a result, the optimum oxygen partial pressure in the case of the glass substrate temperature of 100 degreeC was 1.18x10 <^-2> (Pa), and the resistivity of the ITO film | membrane was 3.96x10 <^-4> (ohm * cm). The optimum oxygen partial pressure at the glass substrate temperature of 250 ° C. was 1.06 × 10 ⁻² (Pa), and the resistivity of the ITO film at that time was 2.03 × 10 ⁻⁴ (Ω · cm).

The results are collectively shown in Table 1, Table 2 and Figs. 4 and 5.

[Table 1]

[Table 2]

In Table 1, Table 2 and FIG. 4, FIG. 5, in the ITO sputtering target using the ITO sintered compact of Example 1, compared with the thing of the comparative example 1, the response to oxygen partial pressure at the time of film-forming is sensitive, and setting specific film-forming conditions is set. Even if it does not, it can be seen that an appropriate ITO film having a lower resistivity and excellent conductivity can be formed by appropriate oxygen partial pressure control during sputtering under conditions suitable for industrial production.

When the ITO sintered compact of the present invention is used as a sputtering target, an excellent ITO film having a lower resistivity can be obtained at a low oxygen partial pressure under conditions suitable for industrial production, without requiring special conditions, which is advantageous in terms of cost.

Claims (5)

ITO (Indium-Tin-Oxide) sintered compact, characterized in that the average value of the maximum diameters of the fine particles existing in the In ₂ O ₃ matrix as crystal grains is 0.2 µm or more and 2 µm or less. Crystal grains of In ₂ O microparticles free width average value 3㎛ ITO (Indium-Tin-Oxide ) , characterized in that the sintered or less than 0.3㎛ of the zone from the boundary of the _third matrix. The average value of the maximum diameters of the fine particles existing in the In ₂ O ₃ mother phase as the crystal grains is 0.2 µm or more and 2 µm or less, and the average value of the width of the fine particles free zone from the grain boundaries of the In ₂ O ₃ mother phase is 0.3 µm or more 3 ITO (Indium-Tin-Oxide) sintered body, characterized in that less than or equal to. 4. The method according to any one of claims 1 to 3, The ITO sintered compact is an ITO sintered compact, characterized in that the sputtering target material. An ITO sputtering target provided with the ITO sintered compact as described in any one of Claims 1-3, and a backing plate.

Images