KR100628542B1 - The sinter of metal oxide compound and use thereof - Google Patents

Abstract

Even when the ITO thin film used for the transparent electrode of a flat panel display etc. is formed at the substrate temperature more than crystallization temperature, the thin film which does not have a domain structure and is excellent in etching characteristic is provided flatly. Moreover, also when using in the area | region where the film thickness like a touch panel is thin, it is providing the transparent conductive film excellent in heat resistance and moisture resistance, and small change rate of resistivity.

Evaporation material / sputtering target using a metal oxide sintered body consisting of In, Sn, Mg and 0 and Mg content (atomic ratio) of Mg / (In + Sn + Mg): 2.0 to 20.0%, In, Sn, Mg And a transparent conductive film made of 0 and having an Mg content (atomic ratio) of Mg / (In + Sn + Mg): 2.0 to 20.0%, and a flat panel display, a touch panel, and the like including the transparent conductive film.

Description

The sinter of metal oxide compound and use thereof

1 is a view showing a domain structure of a conventional ITO thin film.

2 is a view showing the surface of a conventional IT0 thin film.

3 is a view showing the surface of the thin film obtained in Example 1. FIG.

4 is a view showing the surface of the thin film obtained in Example 2. FIG.

5 is a view showing the surface of the thin film obtained in Example 3. FIG.

6 is a view showing the surface of a thin film obtained in Comparative Example 1. FIG.

7 is a view showing the results of heat resistance tests of the films obtained in Examples 4 and 5 and Comparative Examples 2 and 3. FIG.

8 is a view showing the results of moisture resistance tests of the membranes obtained in Examples 4 and 5 and Comparative Examples 2 and 3. FIG.

9 is a diagram showing the surface of a film obtained in Comparative Example 3. FIG.

10 is a view showing the results of moisture resistance tests of the membranes obtained in Examples 6, 7 and Comparative Example 4. FIG.

11 shows the results of heat resistance tests of the films obtained in Examples 8, 9 and Comparative Example 5. FIG.

12 is a view showing the results of moisture resistance tests of the membranes obtained in Examples 8, 9 and Comparative Example 5. FIG.

The present invention relates to a conductive metal oxide sintered body, a target, a thin film and a use thereof.

Indium Tin Oxide (ITO) thin film is characterized by high electrical conductivity and high transmittance, and can also be easily processed finely, so that display electrodes for flat panel displays, resistive touch panels, windows for solar cells, antistatic films, and electromagnetic waves It is used in a wide range of fields such as anti-films, anti-fog films, and sensors. Such ITO thin film production methods can be roughly classified into physical film formation methods such as spray pyrolysis, chemical vapor deposition, electron beam deposition, ion plating, and sputtering. Among these, in the physical film-forming method, it is used in various fields as a film-forming method by which film formation with a large area is easy and a high performance film | membrane is obtained.

When the IT0 thin film is manufactured by the physical film forming method, the raw materials to be used (sputtering target in the case of the sputtering method, vapor deposition method in the case of the vacuum deposition method and ion plating) are alloys made of indium metal and metal tin or indium oxide. Composite oxides consisting of tin oxide are used. The method using the double ITO composite oxide has become the mainstream of the ITO thin film production method because the change in the resistance value and the transmittance of the obtained film is little and the control of the film forming conditions is easy compared with the method using the IT alloy.

With the development of the information society in recent years, the level of technology required for the above-mentioned flat panel display and touch panel is increasing. Therefore, the characteristic which has not been a problem until now also about an ITO thin film has been pointed out as a problem. Specifically, there are problems in the film structure and durability of the ITO thin film.

First, the structural problem of the membrane will be described.

When the ITO thin film is formed at room temperature, an amorphous film is obtained except under special conditions. However, in consideration of heat resistance stability and weather resistance, it is preferable to crystallize the thin film. The crystallization temperature of ITO is 150 degreeC, and it is necessary to form into a film forming temperature more than this temperature in order to obtain a crystallized film. However, when the crystalline ITO thin film is formed through a film forming step using a plasma such as sputtering or ion plating, a characteristic domain structure is formed in the ITO thin film. As for the domain structure, 10-30 nm crystal grains well equipped with the crystal orientation as shown in FIG. 1 gather, and the grain area of 200-300 nm is formed. This domain structure is a collection of small particles each having a different crystal orientation, and is mainly oriented in (111), (110) or (100). Moreover, this orientation has the characteristic that resistance to plasma damage is different. For this reason, the sputtering speed at the time when the film formed during the film formation is re-spattered by the plasma is different. As a result, as shown in FIG. 2, the (100) plane is thick, and the thin film with an uneven surface thin in the (100) plane is formed. Such a film is seen as a film produced by using a plasma such as a sputtering method or ion plating.

On the other hand, in the field of thin film displays in which ITO thin films are used well, especially liquid crystal displays, the enlargement and miniaturization of screens are proceeding at a rapid force. For this reason, there is a demand for a large-area, low-resistance and easy microprocessing film as a request for a transparent conductive film.

However, when the film is formed at a high substrate temperature by using a sputtering method capable of a uniform film over a large area, a film with a high unevenness on the surface as described above is formed, and etching residues are likely to occur. That is, a problem arises that a thin film is not suitable for microfabrication.

Next, the problem of durability is demonstrated. The ITO thin film has a problem that the resistivity of the thin film increases in an environment of high temperature or high humidity. For example, regarding heat resistance, it is known that resistivity increases by 5 to 30% by leaving it to stand for 30 minutes at the temperature of 200 degreeC or more in air | atmosphere. Regarding the moisture resistance, it is known that the resistivity increases by 10 to 200% by standing at 60 캜 for 90 hours at 90% RH.

The phenomenon of the increase in resistivity is remarkable as the thickness of the ITO thin film becomes thinner. For this reason, it is especially a problem in the field of the resistive touch panel which uses an ITO thin film with a thin film thickness, and it was an important subject to be solved.

In addition, the sintered density of the ITO sintered body is increased to reduce the discharge stability and the amount of nodules (black foreign matter formed on the target surface when the ITO target is continuously sputtered in a mixed gas atmosphere of argon gas and oxygen gas). Research has been in full swing. For example, as in Japanese Patent Publication No. 5-30905, sintering is carried out in a pressurized oxygen atmosphere with a pressure of 1 atm or higher, and indium oxide powder and tin oxide powder having an average particle diameter of 0.1 µm or less, as in Japanese Patent Application Laid-Open No. 4-160047. Is heat treated at a temperature of 1350 ° C. or above in an oxygen atmosphere, and the obtained heat-treated powder is pulverized again and sintered in an oxygen-free atmosphere at a temperature of 500 to 1000 ° C. or higher and a pressure of 100 kg / cm 2 or higher, as a sintering aid as in USP-5433901. A method of sintering by adding 0.05 to 0.25% by weight of Al ₂ O ₃ , Y ₂ O _3, or MgO is proposed. However, in terms of these aspects, there has been a problem in that the problems related to the flatness and durability of the film cannot be solved.

An object of the present invention is to provide a film film excellent in etching characteristics without having a domain structure even when an ITO thin film used for a transparent electrode or the like of a flat panel display is formed at a substrate temperature higher than the crystallization temperature. Moreover, also when using in the area | region where a film thickness is thin like a touch panel, it is providing the transparent conductive film excellent in heat resistance and moisture resistance, and small change rate of resistivity.

Moreover, it is providing the vapor deposition material and sputtering target used when forming such a thin film.

The present inventors have conducted extensive studies on conductive metal oxides doped with different elements in ITO, and have found that the above problems can be solved in an ITO thin film containing magnesium as a dopant. .

In other words, the present invention comprises (1) substantially composed of indium, tin, magnesium, and oxygen, and magnesium oxide is contained in a ratio of 2.0 to 20.0% by an atomic ratio of Mg / (In + Sn + Mg). (2) evaporation material using this sintered body, (3) sputtering target using this sintered body, (4) substantially consisting of indium, tin, magnesium and oxygen, and magnesium is 2.0 to 20.0 in an atomic ratio of Mg / (In + Sn + Mg). The transparent conductive film and (5) which are contained in the ratio of% are related with the apparatus which consists of a transparent conductive film.

Hereinafter, the present invention will be described in detail.

The sintered compact concerning this invention, the sputtering target which consists of this sintered compact, a vapor deposition material, a thin film, and the apparatus which consists of this thin film are manufactured with the following method.

The method for producing the magnesium-containing ITO sintered body is not particularly limited, but the sintered body for use in the sputtering target is preferably a density of 98% or more, and such a sintered body is, for example, by the following method It can manufacture.

Further, the relative density is (D) according to the present invention, and shows a relative value of the theoretical density (d) obtained in the additive average of the true density of the In ₂ O _3, SnO ₂ and MgO. The theoretical density (d) obtained from the average of the averages means that when the mixing amount (g) of In ₂ O ₃ , SnO _2, and MgO powder in the target composition is a, b, and c, respectively, the true density is 7.179, 6.95, Using 3.65 (g / cm 3), it is obtained by d = (a + b + c) / ((a / 7.179) + (b / 6.95) + (c / 3.65)). And when the measurement density of a sintered compact is d1, the relative density D% is calculated | required by Formula: D = (d1 / d) * 100.

First, the powder is mixed. The indium oxide powder, the tin oxide powder and the magnesium oxide powder may be mixed, or the indium oxide powder for magnesium oxide and the magnesium oxide powder may be mixed. If the average particle diameter of the powder used is large, the density after sintering does not sufficiently increase and the relative Since the sintered compact of density 99% or more becomes difficult to obtain, it is preferable that the average particle diameter of the powder to be used is 1.5 micrometers or less, More preferably, it is 0.1-1.5 micrometers. Here, it is preferable that the mixing amount of tin oxide is 1.9 to 14% by the atomic ratio of Sn / (Sn + In). More preferably, it is 4-11%. This is because, when the ITO thin film is produced using the target of the present invention, the resistivity of the film is the lowest.

Moreover, as for the mixed amount of magnesium oxide, 2.0-20.0% is preferable at the atomic ratio of Mg / (In + Sn + Mg). More preferably, it is 2.0-10.0%, More preferably, it is 2.0 to 5.0%, Especially preferably, it is 2.0%-3.0%. If the amount of magnesium oxide added is less than the above range, the effect of the present invention is less than the above range, and the resulting thin film exhibits a domain structure and the weather resistance of the film is lowered. The powder may be mixed by dry mixing or wet mixing using a ball mill or the like.

Next, the magnesium oxide containing ITO sintered compact is produced using the obtained mixed powder. Although it does not specifically limit about the manufacturing method of a sintered compact, For example, it can manufacture by the following method.

A binder or the like is added to a mixed powder of indium oxide, tin oxide and magnesium oxide obtained as described above, and molded by a molding method such as a press method or an injection method to produce a molded article. When manufacturing a molded object by the press method, after filling a solid solution powder with a predetermined metal mold | die, it presses by the pressure of 100-300 kg / cm <2> using a powder press. If the moldability of the powder is poor, a binder such as paraffin or polyvinyl alcohol may be added as necessary.

In the case of producing a molded article by injection method, a binder, a dispersant, ion-exchanged water is added to the ITO mixed powder, and mixed by a ball mill or the like to prepare an injection molded slurry. Subsequently, injection is performed using the obtained slurry. It is preferable to perform defoaming of a slurry before inject | pouring a slurry into a mold. Defoaming may be carried out by adding a polyalkylene glycol-based defoaming agent to the slurry, for example, to perform defoaming in vacuum. Subsequently, the injection molding is dried.

Next, the obtained molded object is subjected to compaction treatment such as cold hydrostatic pressure press (CIP) as necessary. At this time, the CIP pressure is preferably 2ton / cm 2 or more, preferably 2-5ton / cm 2, in order to obtain a sufficient consolidation effect. Here, when the first molding is performed by the injection method, the debinding treatment may be performed for the purpose of removing water remaining in the molded body after CIP and organic matter such as a binder. Moreover, even when the first molding is performed by the press method, when the binder is used at the time of molding, it is preferable to perform the same binder removal treatment.

The molded product thus obtained is introduced into the sintering furnace and sintered. As the sintering method, any method can be used, but atmospheric sintering is preferable in consideration of the cost of the production equipment. However, it goes without saying that other conventionally known sintering methods such as hot press (HP), hot hydrostatic press (HIP) and oxygen pressure sintering can be used. Although the sintering conditions can be appropriately selected, the sintering temperature is preferably 1450 to 1650 ° C in order to obtain a sufficient density increase effect and to suppress evaporation of tin oxide. Moreover, as an atmosphere at the time of sintering, it is preferable that it is air | atmosphere or a pure oxygen atmosphere. Moreover, in order to acquire sufficient density increase effect also about a sintering time, it is good that it is 5 hours or more, Preferably it is 5 to 30 hours. Thus, magnesium-containing ITO sintered body which is invention of Claim 1 of this application can be produced.

Next, by processing the obtained sintered compact in a desired form, a magnesium-containing ITO vapor deposition material, which is the invention of claim 1 of the present application, is produced. In addition, a magnesium-containing ITO sputtering target of the invention of claim 3 is produced by joining a magnesium-containing ITO sintered body processed in a desired form to a backing plate made of oxygen-free copper, using indium solder or the like as necessary.

Using the obtained vapor deposition material or sputtering target, the magnesium containing ITO thin film which is a transparent conductive film of this invention of Claim 4 on a board | substrate, such as a glass substrate and a film substrate, can be obtained. The film forming means is not particularly limited, and examples thereof include a dc sputtering method, an rf sputtering method, a sputtering method in which rf is superimposed on dc, a vacuum deposition method (ion plating), and the like.

A thin film having a flat structure and excellent etching characteristics without a domain structure which is the first effect of the present invention is particularly effective for a film formation method via plasma such as a sputtering method or an ion plating method. Moreover, stabilization of the resistivity which is a 2nd effect is effective also when it forms into a film by any method.

Co-deposition or spontaneous sputtering is carried out by using a deposition material or a sputtering target prepared as three kinds of indium oxide, tin oxide and magnesium oxide, or two kinds of mixed oxides of the three kinds and the remaining oxides. You may form into a film by. In addition, a part or all of an individual vapor deposition source or a sputtering target may be substituted and used for a metal or an alloy.

After the thin film formed on the substrate is etched in a desired pattern as necessary, the apparatus of the present invention of claim 5, for example, a flat panel display, a touch panel, a window for a solar cell, an antistatic film, an electromagnetic wave prevention film, an anti-fog film, a sensor, and the like. Can be configured.

In addition, considering that the thin film according to the present invention is used in an apparatus requiring fine processing such as a flat panel display or a touch panel, the film thickness is preferably 5000 kPa or less. This is because when the film thickness exceeds 5000 GPa, not only the transparency of the film is lost but also the value of the line end space and the film thickness required for the micromachining becomes close to the micromachining. The range of the more preferable film thickness differs depending on the display used. For resistive touch panel applications, 80 to 500 mW is preferable, and in the case of a display having a matrix type electrode structure such as an STN type liquid crystal display, 2000 is preferable. It is preferable to set it as -3500 Pa.

Hereinafter, the present invention will be described in more detail with examples, but the present invention is not limited thereto.

Example 1

450 g of indium oxide powder, 50 g of tin oxide powder, and 7.2 g of magnesium oxide powder were placed in a pot made of polyethylene, and mixed with a dry ball mill for 72 hours to prepare a mixed powder.

This powder was put into a mold and pressed at a pressure of 300 kg / cm 2 to obtain a molded body. The compact was subjected to densification by CIP at a pressure of 3 ton / cm 2. Next, the molded body was placed in a pure oxygen atmosphere sintering furnace and sintered under the following conditions.

(Sintering condition)

Sintering temperature: 1500 ℃, Heating rate: 25 ℃ / Hr, Sintering time: 6 hours, Oxygen pressure: 50mmH ₂ O (gauge pressure), Oxygen flux: 2.7cm / min

The density of the obtained sintered compact was measured by Alchimedes method and found to be 7.00 g / cm 3 (relative density: 99.3%). The composition analysis of the sintered compact was performed using EPMA (Electron Prove Micro Analysis). The results are shown in Table 1.

The sintered compact was processed into a sintered compact having a diameter of 4 inches by 6 mm by a wet processing method, and bonded to a backing plate made of oxygen-free copper using indium solder to be a target.

This target was sputtered on the following sputtering conditions, and the thin film was evaluated.

(Sputtering Condition)

Substrate: Glass substrate, DC power: 200 W, Gas pressure: 5.0 mTorr, Ar gas flow rate: 50 SCCM, O ₂ gas flow rate: 0.1 SCCM, substrate temperature: 200 ° C, film thickness: 3000 kPa

The resistivity of the obtained film was 790 µΩ · cm, and the transmittance at 550 nm was 86.2%. In addition, the transmittance | permeability was measured as the transmittance which contained the glass substrate as an air reference. Corning company # 7059 was used for the glass substrate.

Next, the surface of the obtained thin film was observed using AFM. The results are shown in the photograph of FIG. No domain structure was observed.

Next, the composition of the membrane was investigated using EPMA. The results are shown in Table 2.

Example 2

450 g of indium oxide powder, 50 g of tin oxide powder, and 15 g of magnesium oxide powder were placed in a polyethylene pot, and mixed by a dry ball mill for 72 hours to prepare a mixed powder.

This powder was placed in a mold and pressed at a pressure of 300 kg / cm 2 to form a molded body. The molded body was subjected to densification by CIP at a pressure of 3 ton / cm 2. Next, this molded product was placed in a pure oxygen atmosphere sintering furnace and sintered under the same conditions as in Example 1.

The density of the obtained sintered compact was measured by Alchimedes method and found to be 6.86 g / cm 3 (relative density: 98.6%). The composition analysis of the sintered compact was performed using EPMA (Electron Prove Micro Analysis). The results are shown in Table 1.

The sintered compact was processed into a sintered compact having a diameter of 4 inches by 6 mm by a wet processing method, and bonded to a backing plate made of oxygen-free copper using indium solder to be a target.

This target was sputtered on the following sputtering conditions, and the thin film was evaluated.

(Sputtering Condition)

Substrate: Glass substrate, DC power: 200 W, Gas pressure: 5.0 mTorr, Ar gas flow rate: 50 SCCM, O ₂ gas flow rate: 0.1 SCCM, substrate temperature: 200 ° C, film thickness: 3000 kPa

The resistivity of the obtained film was 1800 µΩ · cm, and the transmittance at 550 nm was 85.9%. The measurement conditions of the transmittance were made into the same conditions as in Example 1.

Next, the surface of the obtained thin film was observed using AFM. The results are shown in the photograph of FIG. No domain structure was observed.

Next, the composition of the membrane was investigated using EPMA. The results are shown in Table 2.

Example 3

450 g of indium oxide powder, 50 g of tin oxide powder, and 34 g of magnesium oxide powder were placed in a polyethylene pot, and mixed with a dry ball mill for 72 hours to prepare a mixed powder.

This powder was put into a mold and pressed at a pressure of 300 kg / cm 2 to obtain a molded body. The compact was subjected to densification by CIP at a pressure of 3 ton / cm 2. Next, this molded product was placed in a pure oxygen atmosphere sintering furnace and sintered under the same conditions as in Example 1.

The density of the obtained sintered compact was measured by Alkimedes method and found to be 6.65 g / cm 3 (relative density: 98.7%). The composition analysis of the sintered compact was performed using EPMA. The results are shown in Table 1.

The sintered compact was processed into a sintered compact having a diameter of 4 inches by 6 mm by a wet processing method, and bonded to a backing plate made of oxygen-free copper using indium solder to be a target.

This target was sputtered on the following sputtering conditions, and the thin film was evaluated.

(Sputtering Condition)

Substrate: Glass substrate, DC power: 200 W, Gas pressure: 5.0 mTorr, Ar gas flow rate: 50 SCCM, O ₂ gas flow rate: 0.1 SCCM, substrate temperature: 200 ° C, film thickness: 3000 kPa

The resistivity of the obtained film was 3500 µΩ · cm, and the transmittance at 550 nm was 85.9%. The measurement conditions of the transmittance were made into the same conditions as in Example 1.

Next, the surface of the obtained thin film was observed using AFM. The results are shown in the photograph of FIG. No domain structure was observed.

Next, the composition of the membrane was investigated using EPMA. The results are shown in Table 2.

Comparative Example 1

450 g of indium oxide powder and 50 g of tin oxide powder were placed in a polyethylene pot and mixed for 72 hours by a dry ball mill to prepare a mixed powder.

This powder was put into a mold and pressed at a pressure of 300 kg / cm 2 to obtain a molded body. The compact was subjected to densification by CIP at a pressure of 3 ton / cm 2. Next, this molded product was placed in a pure oxygen atmosphere sintering furnace and sintered under the same conditions as in Example 1.

The density of the obtained sintered compact was measured by Alkimedes' method and was 7.12 g / cm 3 (relative density: 99.4%). The composition analysis of the sintered compact was performed using EPMA. The results are shown in Table 1.

The sintered compact was processed into a sintered compact having a diameter of 4 inches by 6 mm by a wet processing method, and bonded to a backing plate made of oxygen-free copper using indium solder to be a target.

This target was sputtered on the following sputtering conditions, and the thin film was evaluated.

(Sputtering Condition)

Substrate: Glass substrate, DC power: 200 W, Gas pressure: 5.0 mTorr, Ar gas flow rate: 50 SCCM, O ₂ gas flow rate: 0.1 SCCM, substrate temperature: 200 ° C, film thickness: 3000 kPa

The resistivity of the obtained film was 200 µΩ · cm, and the transmittance at 550 nm was 86.7%. The measurement conditions of the transmittance were made into the same conditions as in Example 1.

Next, the surface of the obtained thin film was observed using AFM. The results are shown in the photograph of FIG. Domain structure was observed.

Next, the composition of the membrane was investigated using EPMA. The results are shown in Table 2.

Example 4

450 g of indium oxide powder, 50 g of tin oxide powder, and 3.6 g of magnesium oxide powder were placed in a pot made of polyethylene, and mixed by a dry ball mill for 72 hours to prepare a mixed powder.

This powder was put into a mold and pressed at a pressure of 300 kg / cm 2 to obtain a molded body. The compact was subjected to densification by CIP at a pressure of 3 ton / cm 2. Next, this molded product was placed in a pure oxygen atmosphere sintering furnace and sintered under the same conditions as in Example 1. The density of the obtained sintered compact was measured by Alkimedes method and found to be 7.09 g / cm 3 (relative density: 9 9.7%). The composition analysis of the sintered compact was performed using EPMA. The results are shown in Table 1.

The sintered compact was processed into a sintered compact having a diameter of 4 inches by 6 mm by a wet processing method, and bonded to a backing plate made of oxygen-free copper using indium solder to be a target.

This target was sputtered on the following sputtering conditions, and the thin film was evaluated.

(Sputtering Condition)

Substrate: Glass substrate, DC power: 200 W, Gas pressure: 5.0 mTorr, Ar gas flow rate: 50 SCCM, O ₂ gas flow rate: 0.1 SCCM, substrate temperature: 300 ° C, film thickness: 120 kPa

Next, the composition of the membrane was investigated using EPMA. The results are shown in Table 2.

The obtained thin film was subjected to a heat resistance test under the following conditions, and the change rate (%) of the resistivity was determined by (resistance after test-resistivity before test) x 100 / resistance before test.

(Heat test condition)

Atmosphere: In air, Temperature: 100 to 250 ° C, Holding time: 30 minutes

The results are shown in FIG. Regardless of the temperature of 100 to 250 ° C, the resistivity hardly changed.

Next, the moisture-proof test was done about the thin film obtained similarly on the following conditions, and the change rate of resistivity was investigated. In addition, change rate (%) was calculated | required by (resistivity after test-resistivity before test) x 100 / resistance before test.

(Humidity test condition)

Temperature: 60 degrees Celsius humidity: 90% RH, holding time: 500 hours

The results are shown in FIG. Even after 500 hours passed, the resistivity remained stable and hardly changed.

Example 5

Using the target produced by the same conditions as in Example 1, the film was formed under the same sputtering conditions as in Example 4, and then subjected to the heat test and the moisture resistance test under the same conditions as in Example 4. The results of the heat resistance test are shown in FIG. 7. Regardless of the temperature of 100 to 250 ° C, the resistivity hardly changed.

The results of the moisture resistance test are shown in FIG. 8. After 500 hours had elapsed, the resistivity remained stable and hardly changed.

Comparative Example 2

Using the target produced by the same conditions as the comparative example 1, the film was formed under the same sputtering conditions as in Example 4, and then subjected to the heat test and the moisture resistance test under the same conditions as in Example 4. The results of the heat resistance test are shown in FIG. 7. An increase in resistivity of about 5% at 200 ° C and about 24% at 250 ° C was observed by the heat treatment at 200 to 250 ° C. The resistivity was greatly increased by the heat treatment at high temperature.

The results of the moisture resistance test are shown in FIG. 8. It increased after 300 hours, and the increase of the resistivity of 80% was observed after 500 hours.

Comparative Example 3

450 g of indium oxide powder, 50 g of tin oxide powder, and 1.8 g of magnesium oxide powder were placed in a pot made of polyethylene, and mixed by a dry ball mill for 72 hours to prepare a mixed powder.

This powder was put into a mold and pressed at a pressure of 300 kg / cm 2 to obtain a molded body. The compact was subjected to densification by CIP at a pressure of 3 ton / cm 2. Next, the molded body was placed in a pure oxygen atmosphere sintering furnace and sintered under the following conditions.

(Sintering condition)

Sintering temperature: 1500 ℃, Heating rate: 25 ℃ / Hr, Sintering time: 6 hours, Oxygen pressure: 50mmH ₂ O (gauge pressure), Oxygen rate: 2.7cm / min

The density of the obtained sintered compact was measured by Alchimedes' method and was 7.12 g / cm 3 (relative density: 99.9%). The composition analysis of the sintered compact was performed using EPMA. The results are shown in Table 1.

The sintered compact was processed into a sintered compact having a diameter of 4 inches by 6 mm by a wet processing method, and bonded to a backing plate made of oxygen-free copper using indium solder to be a target.

This target was sputtered on the following sputtering conditions, and the thin film was evaluated.

(Sputtering Condition)

Substrate: Glass substrate, DC power: 200 W, Gas pressure: 5.0 mTorr, Ar gas flow rate: 50 SCCM, O ₂ gas flow rate: 0.1 SCCM, substrate temperature: 200 ° C, film thickness: 3000 kPa

The resistivity of the obtained film was 210 µm and the transmittance at 550 nm was 86.6%. Next, the surface of the obtained thin film was observed using AFM. The results are shown in the photograph of FIG. No domain structure was observed.

Next, the composition of the membrane was investigated using EPMA. The results are shown in Table 2.

Next, a heat resistance test and a moisture resistance test were carried out under the same conditions as in Example 4. The results of the heat resistance test are shown in FIG. 7. An increase in resistivity of about 2% at 200 ° C and about 10% at 250 ° C was observed by the heat treatment at 200 to 250 ° C. The resistivity was greatly increased by the heat treatment at high temperature.

The results of the moisture resistance test are shown in FIG. 8. It increased after 300 hours, and the increase of the resistivity of 45% was observed after 500 hours.

Example 6

Using the target obtained in Example 4, an ITO thin film was produced on the polycarbonate substrate.

(Sputtering Condition)

Substrate: Polycarbonate, DC Power: 200 W, Gas Pressure: 5.0 mTorr, Ar Gas Flow Rate: 50 SCCM, O ₂ Gas Flow Rate: 0.25 SCCM, Substrate Temperature: 70 ° C, Film Thickness: 120 Pa

The composition analysis of the obtained thin film was performed using EPMA. The results are shown in Table 2.

Next, the heat resistant test was done about the obtained thin film on condition of the following, and the change rate of resistivity was investigated.

(Heat test condition)

Atmosphere: In air, Temperature: 80 ° C, Holding time: 90 minutes

The change rate of the resistivity was + 15%.

Next, the moisture resistance test was done on the conditions similar to Example 4 about the thin film obtained similarly, and the change rate of resistivity was investigated. The results are shown in FIG.

Even after 500 hours, the resistivity remained stable and hardly changed.

Example 7

Using the target obtained in Example 1, an ITO thin film was produced on the polycarbonate substrate. It produced under the same conditions as in Example 6.

The composition analysis of the obtained thin film was performed using EPMA. The results are shown in Table 2.

Next, the heat resistant test was done about the obtained thin film on Example 6 and the following conditions, and the change rate of resistivity was investigated. The change in resistivity was + 11%.

Next, the moisture resistance test was done on the conditions similar to Example 6 about the thin film obtained similarly, and the change rate of resistivity was investigated. The results are shown in FIG. Even after 500 hours, the resistivity remained stable and hardly changed.

Comparative Example 4

Using the target obtained in Comparative Example 1, an ITO thin film was produced on a polycarbonate substrate. It produced under the same conditions as in Example 6.

The composition analysis of the obtained thin film was performed using EPMA. The results are shown in Table 2.

Next, the heat resistance test was done on the conditions similar to Example 6 about the obtained thin film, and the change rate of resistivity was investigated. The change in resistivity was + 45%.

Next, the moisture resistance test was done on the conditions similar to Example 6 about the thin film obtained similarly, and the change rate of resistivity was investigated. The results are shown in FIG. It increased after 300 hours, and the increase of the resistivity of 100% was observed after 500 hours.

Example 8

450 g of indium oxide powder, 50 g of tin oxide powder, and 3.6 g of magnesium oxide powder were placed in a pot made of polyethylene, and mixed by a dry ball mill for 72 hours to prepare a mixed powder. A proper amount was put into the mold from this powder, and it pressed at the pressure of 300 kg / cm <2>, and was made into the molded object. The compact was subjected to densification by CIP at a pressure of 3 ton / cm 2. The size of the obtained molded object was 23 mm x 16 mmt. It was 4.0 g / cm <3> (relative density: 56.3%) when the density of the obtained molded object was measured in the form.

Next, the composition analysis of this molded object was performed using EPMA. The results are shown in Table 1.

As a vapor deposition material, this molded object was formed into a film by the vacuum deposition method on the following conditions, and the thin film was evaluated.

(Vacuum deposition conditions)

Substrate: Glass Substrate, Film Thickness: 120Å, Oxygen Partial Pressure: 2 × 10 ^-4 torr

Next, the composition of the membrane was examined using EPMA. The results are shown in Table 2.

The obtained thin film was subjected to a heat resistance test under the same conditions as in Example 4 to investigate the rate of change of the resistivity. The results are shown in FIG. Regardless of the temperature of 100 to 250 ° C, the resistivity hardly changed.

Next, the moisture-proof test was done on the conditions similar to Example 4 about the thin film obtained similarly, and the change rate of resistivity was investigated. The results are shown in FIG. Even after 500 hours, the resistivity remained stable and hardly changed.

Example 9

450 g of indium oxide powder, 50 g of tin oxide powder, and 7.2 g of magnesium oxide powder were placed in a pot made of polyethylene, and mixed by a dry ball mill for 72 hours to prepare a mixed powder. A proper amount was put into the mold from this powder, and it pressed at the pressure of 300 kg / cm <2>, and was made into the molded object. The compact was subjected to densification by CIP at a pressure of 3 ton / cm 2. The size of the obtained molded object was 23 mm x 16 mmt. It was 3.9 g / cm <3> (relative density: 55.2%) when the density of the obtained molded object was measured in the form.

Next, the composition analysis of this molded object was performed using EPMA. The results are shown in Table 1.

This molded product was formed into a film by vacuum deposition under the same conditions as in Example 8 to evaluate the thin film.

Next, the composition of the membrane was examined using EPMA. The results are shown in Table 2.

The obtained thin film was subjected to a heat resistance test under the same conditions as in Example 4 to investigate the rate of change of the resistivity. The results are shown in FIG. Regardless of the temperature of 100 to 250 ° C, the resistivity hardly changed.

Next, the moisture-proof test was done on the conditions similar to Example 4 about the thin film obtained similarly, and the change rate of resistivity was investigated. The results are shown in FIG. After 500 hours had elapsed, the resistivity remained stable and hardly changed.

Comparative Example 5

450 g of indium oxide powder and 50 g of tin oxide powder were placed in a polyethylene pot, and mixed by a dry ball mill for 72 hours to prepare a mixed powder. A proper amount was put into the mold from this powder, and it pressed at the pressure of 300 kg / cm <2>, and was made into the molded object. The compact was subjected to densification by CIP at a pressure of 3 ton / cm 2. The size of the obtained molded object was 23 mm x 16 mmt. It was 4.1 g / cm <3> (relative density: 57.3%) when the density of the obtained molded object was measured in the form.

Next, the composition analysis of this molded object was performed using EPMA. The results are shown in Table 1.

This molded product was formed into a film by vacuum deposition under the same conditions as in Example 8 to evaluate the thin film.

Next, the composition of the membrane was examined using EPMA. The results are shown in Table 2.

The results of the heat resistance test are shown in FIG. By carrying out the heat treatment at 200 to 250 ° C, an increase in resistivity of about 7% at 200 ° C and about 30% at 250 ° C was observed. By the heat treatment at high temperature, the resistivity significantly increased.

The results of the moisture resistance test are shown in FIG. 12. It increased after 300 hours, and the increase of the resistivity of 90% was observed after 500 hours.

Example 10

Using the target obtained in Example 1, a thin film having a thickness of 5000 kPa was produced on the glass substrate under the same conditions as in Example 1.

The transmittance of the obtained thin film was measured. Measurement wavelengths were 400, 500, 550, 600, 700, and 800 nm, and the same glass substrate was measured as the transmittance of only the film as a reference.

The results are shown in FIG. A transmittance of 80% or more was obtained over the electric field.

TABLE 1

TABLE 2

TABLE 3

The magnesium oxide containing ITO sintered compact of this invention of Claim 1, the vapor deposition material of invention of Claim 2, or the sputtering target of invention of Claim 3 can manufacture the magnesium oxide containing ITO thin film which has the outstanding characteristic as this material. That is, since the flat film is obtained without having a domain structure peculiar to the ITO thin film, the thin film of the invention of claim 4 excellent in fine processing in which etching residues are unlikely to be obtained can be obtained. Moreover, also when using in the area | region where the film thickness like a touch panel is thin, the transparent conductive film with a small rate of change of resistivity is obtained.

Moreover, according to invention of Claim 5, the various apparatus which has the outstanding characteristic using the said ITO thin film can be comprised.

Moreover, according to invention of Claim 6, the thin film excellent in transparency and microprocessability of a film can be provided.

In addition, according to the invention of claim 7, it is possible to provide a sputtering target having excellent discharge stability and low amount of nodules.

Claims (7)

A transparent conductive film made of indium, tin, magnesium, and oxygen, and containing magnesium at a ratio of 2.0 to 20.0% by an atomic ratio of Mg / (In + Sn + Mg). In the metal oxide sintered body for forming the transparent conductive film of claim 1, A metal oxide sintered body consisting of indium, tin, magnesium and oxygen, containing magnesium at a ratio of 2.0 to 20.0% by an atomic ratio of Mg / (In + Sn + Mg), and having a sintered density of 98% or more. In the sputtering target for forming the transparent conductive film of Claim 1, Indium, tin, magnesium and oxygen, magnesium is contained in the ratio of 2.0 to 20.0% by the atomic ratio of Mg / (In + Sn + Mg), characterized in that using a metal oxide sintered body having a sintered density of 98% or more Spattering target. The method of claim 1, A transparent conductive film, wherein the film has a thickness of 5000 kPa or less. An apparatus comprising the transparent conductive film according to claim 1. delete delete

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