JPH0885866A - Production of ito sintered compact - Google Patents

Abstract

PURPOSE: To obtain an ITO sintered compact capable of stably forming an ITO film having satisfactory specific resistance even at a low temp. of a substrate. CONSTITUTION: When powder consisting of indium oxide and tin oxide is compacted and sintered in a sintering furnace to produce an ITO sintered compact, sintering is carried out at 1,450-1,550 deg.C for 10-30hr in an atmosphere in which gaseous oxygen is allowed to flow so that the rate of substitution of oxygen is regulated to >=1.8×10<-2> per 1min per unit volume of the sintering furnace. The atmosphere is then changed over to a nonreducing atmosphere and sintering is carried out again.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a sputtering target used for producing a transparent conductive film, specifically, 200
By sputtering on a substrate heated below ℃, the transparency is good and the specific resistance is 2.0 × 10 ^-4 Ω.
The present invention relates to an ITO sintered body capable of obtaining a high quality film of about cm.

[0002]

2. Description of the Related Art In recent years, a color filter of a color liquid crystal display and a plastic substrate are coated with an ITO film. However, since these color filters and plastic substrates are poor in heat resistance, conventional sputtering cannot be performed at a high temperature (about 400 ° C.), and the substrate heating temperature is limited to 200 ° C. or less. An ITO sintered body that is sintered in an oxygen atmosphere or in the air at a temperature of 1600 ° C. or higher can obtain a film having a low specific resistance value by sputtering the substrate at a high temperature (for example, 400 ° C. or higher). In sputtering by heating the substrate at a low temperature of 200 ° C. or lower, the specific resistance value of the ITO film obtained is 2 × 10 ⁻⁴ Ω · cm or more, and it is difficult to obtain a film having a low specific resistance value.

In an oxygen atmosphere, 1450 to 1500
It is difficult to obtain a high density in an ITO sintered body that is sintered at a temperature of ℃ or more. Of course, although a high density can be obtained by increasing the oxygen flow rate, the temperature distribution in the furnace becomes uneven, and the sintered body is cracked and warped. Furthermore, by a method using a special apparatus such as a pressurized oxygen atmosphere sintering method or a hot pressing method, high density can be achieved and a film having a low specific resistance value can be obtained. For example, in Japanese Unexamined Patent Publication Nos. 4-51409 and 4-160047, the relative density is 80% or more by hot pressing, and the tin composition determined by line analysis by an electron beam microanalyzer is 0.8 to 1.2, which is the average composition. ITO sintered bodies in the double range are disclosed. These not only require enormous investment in the equipment, but also reduce the mass productivity and the price of the sintered body when manufacturing a large-sized sintered body required for film formation on a large area substrate. Is high, which is not preferable in production.

Therefore, even if the substrate temperature is as low as 200 ° C. or lower, the specific resistance value is good (2.0 × 10 ⁻⁴ Ω ·
(cm or less) A method has been proposed for providing a large-sized high-density ITO sintered body that can stably form an ITO film and can be manufactured with good productivity and at low cost. For example, Japanese Patent Application No. 6-2482
According to Japanese Patent Laid-Open No. 6, a powder consisting essentially of indium, tin, and oxygen is molded and then placed in a furnace, and oxygen gas around the compact is 1.8 × per minute with respect to the volume in the sintering furnace. 10
^-From 1300 ° C to 1450 while flowing at a rate of ^-2 or more
Disclosed is a method for producing a high-density ITO sintered body, which comprises raising the temperature to 50 ° C. within 50 minutes and sintering in the temperature range of 1450 to 1550 ° C.

[0005]

However, a high-density large-sized ITO sintered body can be obtained by an inexpensive manufacturing method, and an ITO film having a good specific resistance value can be stably formed even under the condition of a low substrate temperature. It is further desired to provide an ITO sintered body that can be produced.

[0006]

According to the present invention, in producing a high-density sintered body by sintering in an oxygen atmosphere, a powder consisting essentially of indium, tin, and oxygen is molded, and then 1450- In the sintering process in which the sintering is performed at a temperature of 1550 ° C., after performing the primary sintering by heating at high temperature in an oxygen atmosphere, the atmosphere gas is switched to a non-reducing atmosphere (for example, nitrogen gas) to perform the secondary sintering. To do. The ITO sintered body according to the production method of the present invention is substantially composed of indium, tin, and oxygen, and is of In ₂ O ₃ —SnO ₂ system. This composition itself is similar to that of a known ITO sintered body, and generally, the average composition of tin is 4 to 12% by weight, and the average composition of indium is in the range of 70 to 78% by weight.
However, by sputtering on a substrate heated to 200 ° C. or lower, a film having good transparency and a specific resistance value of about 2.0 × 10 ⁻⁴ Ω · cm can be obtained IT
It is an O sintered body.

[0007]

In general, it is said that when the density of the sintered body is improved, the surface resistance value of the sintered body is lowered, so that the plasma state during sputtering becomes stable. However, if the sintered body is manufactured at a sintering temperature of 1600 ° C. or higher as in the previously known method described above, a sintered body density of 6.0 g / cm ³ or more can be easily obtained. When sputtering is performed under the condition that the substrate temperature is low, an uncrystallized film or a disordered phase is generated, and a good quality film cannot be obtained. It is speculated that this is due to the coarsening of the Sn atoms aggregated in the sintered body. That is, the aggregated S
10% of the atoms released from the sintered body when sputtering is performed using a sintered body in which n atoms are coarsened.
The probability that a dozen or more atoms or a population of a dozen or so atoms that occupy the degree will be mainly composed of Sn atoms and the atomic population reaches the substrate as it is, so that a phase having a disordered crystal structure It is considered that it is directly formed on the substrate and deteriorates the specific resistance value of the film. The aggregated Sn atom can be evaluated by a line analysis of an electron beam microanalyzer (see JP-A-4-160047). On the other hand, when the substrate heating temperature at the time of sputtering is high, atoms in the film easily diffuse, so that even if the film has a disordered structure in the film formation state, while the sputtering is continued. Change to crystalline film. However, if the substrate heating temperature is low, the film thickness is thin, or the sputtering time is short, crystallization does not occur and a good film cannot be obtained. This is the reason why a film having a good specific resistance value cannot be obtained.

In the ITO sintered body of the present invention, 145
Despite the relatively low sintering temperature of 0 to 1550 ° C,
In addition to achieving a sintered body density of 6.0 g / cm ³ or more, the ITO sintered body has a tin composition in the range of 0.8 to 1.2 times the average composition in the line analysis of an electron beam microanalyzer. Therefore, no aggregation of Sn atoms is observed, and it becomes possible to obtain an ITO film having a good specific resistance value even when the film is formed at a low temperature.

Various elements related to the manufacturing method of the present invention will be described below. (Raw material powder) Indium oxide powder, mixed powder of indium oxide powder and tin oxide powder, indium oxide-tin oxide composite powder, mixed powder of indium oxide-tin oxide composite powder and indium oxide powder, etc. may be combined or alone. A raw material powder is prepared by blending it into a desired composition. When using indium oxide powder, it is necessary to make its average particle diameter 0.1 μm or less. The reason is that the average particle size is 0.1 μm.
If it exceeds, coarse particles mainly composed of indium oxide are present, which deteriorates the uniform dispersion of the composition in the raw material powder and deteriorates the formability and sinterability of the raw material powder, so that a high-density sintered body can be obtained. Because it will disappear.

(Mixing / Pulverizing) The tin oxide powder is blended in the indium oxide powder so that the tin composition of the sintered body is 20% by weight or less, for example, 7.8% by weight, and then the mixture is mixed and pulverized for granulation. Use as powder. As a method of mixing and pulverizing, there is, for example, ball mill mixing. Mixing time is preferably 1
It is 2 hours or more, more preferably 24 hours or more. It is desirable to add 1 to 4% by weight of a binder such as paraffin wax or polyvinyl alcohol at the time of mixing and pulverizing. The average particle size of the granulated powder is 10 μm or less.

(Molding) Next, the granulated powder is molded. To increase the sintered density to 6.0 g / cm ³ or more, 1 to
A molding pressure of n / cm ² or more is preferable.

(Placement of Tin Oxide Component) After molding, tin oxide powder for adjusting the atmosphere to give a constant vapor pressure, mixed powder of indium oxide powder and tin oxide powder, or indium oxide-tin oxide composite powder It is preferable to lay the molded product or the molded product on the back surface of the molded product, or place it on the entire surface of the molded product or around the molded product to sinter the molded product. ITO
In the production of a sintered body, tin oxide has a high vapor pressure, so
Since mass transfer occurs due to evaporation-re-deposition during sintering, it is difficult to increase the density. Therefore, by placing the tin oxide component on the entire surface of the molded body, the back surface or around the molded body,
The atmosphere in the sintering furnace is mainly filled with vapor of tin oxide component. If sintering is performed in this state, evaporation of tin atoms in the sintered body can be suppressed, and high density of the ITO sintered body can be achieved.
At this time, the amount of the tin oxide component placed is not limited, but the tin oxide component is preferably 5 to 40% by weight based on the weight of the molded body. Regarding the atmosphere in the sintering furnace, the vapor pressure of indium oxide does not cause the problem of tin. Further, these effects can also be achieved by introducing a gas mainly containing tin oxide, a gas of indium oxide-tin oxide, or a mixed gas of these gases and oxygen gas. The ratio of the mixed gas of the oxide gas and the oxygen gas is preferably 20 to 80% of the oxygen gas with respect to the oxide gas for the sake of high density without diminishing the gas effect of both.
Indium oxide here means InO, In ₂ O, I
n ₂ O ₃ and tin oxide are SnO, SnO ₂ and (SnO)
Mainly _2,3,4 .

(Sintering-Oxygen Substitution Ratio) When a powder containing tin oxide and / or a molded product thereof is placed, the oxygen gas does not have to flow, but the flow is better for higher density. . This is because oxygen gas also has the above-described effect of suppressing evaporation of tin atoms in the sintered body. When no oxide powder or its molded product is placed, the oxygen substitution rate in the furnace is represented by the flow rate of oxygen entering the furnace volume per minute, that is, oxygen substitution rate (per minute) = oxygen flow rate. (Liter / min) / volume in sintering furnace (cm ³ ) 1.8
It is set to x10 ^-2 or more, preferably 2.8 to 16.3 x 10 ^-2 . More preferably, it is 4.9 to 6.8 × 10 ^-2 . If it is less than 1.8 × 10 ^-2 , a tin composition shift will occur between the surface vicinity and the inside of the sintered body. 16.3 x 10
^{If it is} more than ^-2 , the temperature distribution in the furnace becomes uneven, resulting in non-uniform density of the ITO sintered body. The oxidizing gas is not limited to oxygen gas, and air can be used. In the case of air, the oxygen partial pressure in the furnace is measured to obtain a predetermined oxygen substitution rate.

(Sintering-temperature rising rate) In sintering, the temperature is from room temperature to 1
The temperature rising time up to 300 ° C. is about 23 hours, and the temperature rising time from 1300 ° C. to 1450 ° C. is within 50 minutes, preferably 7 to 30 minutes. From room temperature to 1
Since the binder removal process is performed up to 000 ° C., if the temperature rising time is short, the sintered body is cracked. Also, 1300
Up to ˜1450 ° C., since the sintering behavior is in the most active temperature range, the temperature rising time must be fast as long as the soaking in the furnace can be maintained. A large shrinkage ratio is obtained by heating in this temperature range, and a high-density sintered body can be manufactured. Further, the temperature rising time from 1450 ° C. to the sintering temperature of 1550 ° C. may be later than the temperature rising time from 1300 to 1450 ° C., but at least within 150 minutes,
Preferably, the temperature is raised within a range of 7 to 50 minutes to such an extent that uniform heating in the furnace can be maintained.

(Sintering-Sintering temperature) The sintering temperature is 1450 ° C.
Above and above 1550 ° C. If the temperature is lower than 1450 ° C., a high-density sintered body cannot be obtained, and since the SnO ₂ phase is stably present, it is difficult to obtain a high-quality ITO film having a low specific resistance value. Further, when the temperature is 1550 ° C. or higher, the tin composition in the line analysis of the electron beam microanalyzer is out of the range of 0.8 to 1.2 times the average composition.

(Sintering-holding time) The holding time when the sintering temperature is reached is 10 hours or longer, preferably 10 to 30 hours. If the holding time is less than 10 hours, the crystal grain size does not grow sufficiently and a high density sintered body cannot be obtained.

(Sintering-Nitrogen Substitution Rate) In the present invention,
After sintering at a temperature of 1450 to 1550 ° C. for 10 to 30 hours, the tin oxide vapor powder and its molded product in the furnace are taken out, and the introduction of oxygen gas is stopped to make the atmosphere non-reducing. . For this purpose, a vacuum is applied, and argon, carbon dioxide, etc. are introduced into the sintering furnace, but preferably inexpensive nitrogen gas is introduced. The nitrogen gas flow rate is flown into the furnace volume at a rate of 1.8 × 10 ^-2 or more per minute, and sintering is further performed for about 5 to 30 hours. That is,
By switching to nitrogen gas, oxygen vacancies are introduced due to oxygen deficiency inside, and vacancies are diffused. Therefore, as the nitrogen introduction time is extended, the density of the sintered body increases. The nitrogen substitution rate in the furnace is such that the nitrogen flow rate is 1.8 × 10 ⁻² or more per minute, preferably 4.9 to 6.8 × with respect to the volume in the furnace.
^Set to 10 ^-2 . If it is less than 1.8 × 10 ^-2 , the effect is thin, and even if 6.8 × 10 ^-2 or more is flown, the effect is not so great. The nitrogen gas substitution rate or the inert gas substitution rate is defined similarly to the oxygen substitution rate.

[0018]

EXAMPLES The present invention will be described below with reference to examples. Example 1 A tin oxide powder having an average particle diameter of 1 μm was mixed in an indium oxide powder having an average particle diameter of 0.07 μm so that the tin composition was 7.8% by weight, and a vinyl acetate binder of 3% by weight was added. After the addition, the mixture was mixed in a wet ball mill for 18 hours, dried and pulverized to have an average particle size of 10 μm or less, and this was used as a granulated powder. Further, the granulated powder was used for molding at 3 ton / cm ² . After the molded body was placed in a container in a furnace, sintering was performed in an oxygen atmosphere with an oxygen substitution rate of 2.8 × 10 ^-2 in the furnace. Sintering process is from room temperature to 1
The temperature was raised to 300 ° C in 23 hours and the temperature was raised from 1300 ° C to 3
The temperature was raised to 1450 ° C. over a heating time of 0 minutes. Then, the temperature was raised to 1500 ° C. with a temperature rising time of 10 minutes and kept at 1500 ° C. for 15 hours. Further, the atmosphere gas was switched to argon. The gas flow rate of argon is 1.8 × 10 per minute with respect to the internal volume of the furnace.
^{-Inflow at} a substitution rate of ^-2 or more and perform sintering for 10 hours,
A plate-shaped ITO sintered body having a size of 175 mm and a thickness of 6 mm was obtained. The density of the obtained sintered body was 6.4 g / cm ³ . Further, the surface of the polished sample was evaluated for uniformity of tin composition by electron beam microanalyzer (EPMA) beam analysis with a beam diameter of 1 μm. As a result, the tin content was 7.6.
Was in the range of up to 8.1% by weight. The above results are shown in Tables 1 and 2.

Further, using this ITO sintered body as a target material for sputtering, a sputtering test was conducted by a DC magnetron sputtering method. The sputtering conditions are as follows: input power 2 W / cm ² , pressure 0.4 Pa,
O ₂ partial pressure was 2% by volume, substrate heating temperature was 200 ° C., and continuous sputtering was performed for 1 hour.
A film was formed every 000 A (angstrom), and the specific resistance value was measured by the four-end probe method. Further, continuous sputtering was performed for 30 hours under the same sputtering conditions, and the specific resistance value was measured. The results are shown in Table 2.

Example 2 Nitrogen gas was used instead of argon in Example 1, and the sintering time was 5, 10, 30.
The time was set and the ITO sintered body was prepared and evaluated in the same manner as in Example 1 except for the above. The results are shown in Tables 1 and 2 (2-1, 2-2, 2-3).

(Example 3) Indium oxide powder having an average particle diameter of 0.07 μm was mixed with tin oxide powder having an average particle diameter of 1 μm so that the tin composition was 7.8% by weight, and 3% by weight of vinyl acetate was added. After adding the system binder, mix in a wet ball mill for 18 hours, and dry and pulverize to obtain an average particle size of 10
It was made to be not more than μm, and this was used as a granulated powder. Further, the granulated powder was used for molding at 3 ton / cm ² . After the molded body was placed in a container in a furnace, 20% by weight of the molded body of tin oxide powder having an average particle size of 1 μm was loaded on a plate around the molded body container. In the furnace, vapor gas was generated from the tin oxide as the temperature increased. Oxygen gas was forced into the furnace and mixed with the steam gas. Oxygen gas is 1.8 × 10 ^-2 per minute with respect to the internal volume of the sintering furnace.
Inflow was made at the above rate. In this mixed gas atmosphere,
Increase the temperature from room temperature to 1300 ° C in 23 hours,
The temperature was raised from 0 ° C. to 1450 ° C. over 30 minutes. Then, the temperature was raised to 1500 ° C. with a temperature rising time of 10 minutes, and after sintering was performed at 1500 ° C. for 15 hours, the atmosphere gas was switched to nitrogen gas, and the nitrogen gas flow rate was changed with respect to the furnace internal volume. 1.8 x per minute
A plate-shaped ITO having a size of □ 175 mm and a thickness of 6 mm was obtained by inflowing at a substitution rate of 10 ⁻² or more and sintering for 10 hours.
A sintered body was obtained. The physical properties and tin composition of the obtained sintered body were measured by the same method as in Example 1, and then used as a sputtering target material by the DC magnetron sputtering method by the same method as in Example 1. I went. The obtained results are shown in Tables 1 and 2.

Example 4 Indium oxide powder having an average particle size of 0.07 μm was mixed with tin oxide powder having an average particle size of 1 μm so that the tin composition was 7.8% by weight, and 3% by weight of vinyl acetate was added. After adding the system binder, mix in a wet ball mill for 18 hours, and dry and pulverize to obtain an average particle size of 10
It was made to be not more than μm, and this was used as a granulated powder. Further, the granulated powder was used for molding at 3 ton / cm ² . After the molded body is placed in a container in a furnace, 20% by weight of the molded body of tin oxide powder having an average particle size of 1 μm is loaded on a plate around the molded body container, and in a vapor gas atmosphere generated. At 23 ° C., the temperature was raised from room temperature to 1300 ° C. in 23 hours, and the temperature was raised from 1300 ° C. to 1450 ° C. over 30 minutes. Then, the temperature was raised to 1500 ° C. with a temperature rising time of 10 minutes, and after sintering was performed at 1500 ° C. for 15 hours, the atmosphere gas was switched to nitrogen gas, and the nitrogen gas flow rate was changed with respect to the furnace internal volume. , 1.8 × 10 ^-2 per minute
The plate-shaped ITO having a size of □ 175 mm and a thickness of 6 mm was made by inflowing at the above substitution rate and sintering for 10 to 30 hours.
A sintered body was obtained. The physical properties and tin composition of the obtained ITO sintered body were measured by the same method as in Example 1, and then used as a sputtering target material by the DC magnetron sputtering method by the same method as in Example 1. The test was conducted. The obtained results are shown in Tables 1 and 2 (4
-1, 4-2).

Comparative Example 1 Indium oxide powder having an average particle size of 0.07 μm was mixed with tin oxide powder having an average particle size of 1 μm so that the tin composition was 7.8% by weight, and 3% by weight of vinyl acetate was added. After adding the system binder, mix in a wet ball mill for 18 hours, and dry and pulverize to obtain an average particle size of 10
It was made to be not more than μm, and this was used as a granulated powder. Further, the granulated powder was molded at 3 ton / cm ² and then sintered in the atmosphere. In the sintering process, the temperature is raised from room temperature to 1300 ° C in 23 hours, and the temperature is raised from 1300 ° C to 30 minutes by 1
The temperature was raised to 450 ° C. Then, the temperature is raised to 1500 ° C. with a temperature rising time of 10 minutes, and 1500 ° C.
After performing the sintering for 15 hours, the atmosphere gas is switched to nitrogen gas, and the nitrogen gas flow rate is set to 1 with respect to the furnace internal volume.
Inflow at a replacement rate of 1.8 × 10 ^-2 or more per minute to 1
Sintering was performed for 5 hours to obtain a plate-shaped ITO sintered body having a size of □ 175 mm and a thickness of 6 mm. The physical properties and tin composition of the obtained ITO sintered body were measured by the same method as in Example 1, and then used as a sputtering target material by the DC magnetron sputtering method by the same method as in Example 1. The test was conducted. The obtained results are shown in Tables 1 and 2.

Comparative Example 2 Indium oxide powder having an average particle diameter of 0.07 μm was mixed with tin oxide powder having an average particle diameter of 1 μm so that the tin composition was 7.8% by weight, and 3% by weight of vinyl acetate was added. After adding the system binder, mix in a wet ball mill for 18 hours, and dry and pulverize to obtain an average particle size of 10
It was made to be not more than μm, and this was used as a granulated powder. Further, the granulated powder was used for molding at 3 ton / cm ² . After placing the molded body in the container in the furnace, the oxygen substitution rate in the furnace was set to 2.8 × 1.
Sintering was performed in an oxygen atmosphere of 0 ^-2 . In the sintering process, the temperature is raised from room temperature to 1300 ° C in 23 hours,
The temperature was raised from 300 ° C to 1450 ° C over 30 minutes. Then, the temperature was raised to 1600 ° C. with a temperature rising time of 30 minutes, and after sintering was performed at 1600 ° C. for 15 hours, the atmosphere gas was switched to nitrogen gas, and the nitrogen gas flow rate was changed with respect to the furnace internal volume. 1.8 x 10 per minute
^-Sintering for 15 hours by flowing in at a substitution rate of ^-2 or more,
A plate-shaped ITO sintered body having a size of 175 mm and a thickness of 6 mm was obtained. The physical properties and tin composition of the obtained ITO sintered body were measured by the same method as in Example 1, and then used as a sputtering target material by the DC magnetron sputtering method by the same method as in Example 1. The test was conducted. The obtained results are shown in Tables 1 and 2.

[0025]

[Table 1] (Table 1-1) Loading powder component Loading method Sintering temperature Introduced gas Substitution rate (℃) (Primary sintering) Example 1--1500 oxygen 2.8x10 ^-2 Example 2-1--1500 oxygen 2.8x10 ^-2 Example 2-2 --- 1500 oxygen 2.8x10 ^-2 Example 2-3 --- 1500 oxygen 2.8x10 ^-2 Example 3 SnO ₂ ambient 1500 oxygen 1.8x10 ^-2 Example 4-1 SnO ₂ ambient 1500 − − Example 4-2 SnO ₂ ambient 1500 − − Comparative example 1 − − 1500 Atmosphere − Comparative example 2 − − 1600 Oxygen 2.8 × 10 ⁻²

(Table 1-2) Sintering time Sintering atmosphere Substitution rate Sintering time (hr) (Secondary sintering) (hr) Example 1 15 Argon 1.8x10 ^-2 10 Example 2-1 15 Nitrogen 1.8 x10 ^-2 5 Example 2-2 15 Nitrogen 1.8x10 ^-2 10 Example 2-3 15 Nitrogen 1.8x10 ^-2 30 Example 4 15 Nitrogen 1.8x10 ^-2 10 Example 4-1 15 Nitrogen 1.8x10 ^-2 10 Example 4-2 15 Nitrogen 1.8x10 ^-2 30 Comparative Example 1 15 Nitrogen 1.8x10 ^-2 15 Comparative Example 2 15 Nitrogen 1.8x10 ^-2 15

[0027]

[Table 2] Specific resistance value by line analysis Sintered body density Tin composition after sintering (wt%) (x10 ^-4 Ω · cm) (g / cm ³ ) Warpage 1 hour 30 hours Example 17 8.8-8.1 1.7 1.7 6.4 None Example 2-1 7.8-8.2 1.7 1.9 6.3 None Example 2-2 7.7-8.0 1.7 1.7 6.4 None Example 2-3 7.3 to 8.1 1.8 1.8 6.6 None Example 3 7.6 to 8.3 1.7 1.7 6. 8 None Example 4-1 7.5-8.2 1.7 1.8 1.8 6.3 None Example 4-2 7.1-8.5 1.7 1.7 6.5 6.5 None Comparative Example 1 4 0.5-6.9 3.2 4.7 5.6 None Comparative Example 2 5.8-10.2 2.4 2.8 6.4 None

[0028]

EFFECTS OF THE INVENTION Since the present invention is constructed as described above, the specific resistance value is 2. even when the substrate heating temperature is 200 ° C. or lower in the film formation by sputtering.
It is possible to provide a high density ITO sintered body capable of stably obtaining an ITO film having a low resistance of 0 × 10 ⁻⁴ Ω · cm or less.

Claims (6)

[Claims] 1. A method for producing an ITO sintered body, which comprises sintering a molded body obtained by molding a powder of indium oxide and tin oxide, at 1450 to 1550 ° C. in an oxygen atmosphere.
After the sintering is performed at the temperature of 10 to 30 hours, the oxygen atmosphere is switched to a non-reducing atmosphere and the sintering is performed. 2. The method for producing an ITO sintered body according to claim 1, wherein the non-reducing atmosphere is formed by an inert gas or vacuum. 3. The flow rate of the inert gas with respect to the internal volume of the furnace,
The method for producing an ITO sintered body according to claim 2, wherein sintering is carried out by inflowing at an inert gas substitution rate of 1.8 × 10 ^-2 or more per minute. 4. The inert gas flow rate is set to 1 with respect to the internal volume of the furnace.
The ITO sintering according to claim 2, wherein the sintering is carried out at a temperature of 1450 to 1550 ° C. for 5 to 30 hours by inflowing at an inert gas substitution rate of 1.8 × 10 ⁻² or more per minute. Body manufacturing method. 5. An oxygen atmosphere, wherein the powder containing a tin oxide component for atmosphere adjustment and / or a molded product thereof is spread on the back surface of the molded product in an amount of 5 to 40% by weight of the tin oxide component based on the weight of the molded product. The manufacturing of the ITO sintered body according to any one of claims 1 to 4, wherein the ITO sintered body is placed on the entire surface of the molded body or around the molded body, and is formed by vapor gas obtained by evaporation of a tin oxide component. Method. 6. The oxygen atmosphere is formed by introducing oxygen gas at an oxygen substitution rate of 1.8 × 10 ⁻² or more per minute with respect to the furnace internal volume of the sintering furnace. Item 1
5. The method for manufacturing an ITO sintered body according to any one of to 4.