KR20100067120A - Indium oxide transparent conductive film and method for producing the same - Google Patents

Abstract

Disclosed is a transparent conductive film which is formed as an amorphous film by using a sputtering target which comprises an oxide sintered body containing barium in addition to indium oxide and tin. This transparent conductive film is characterized by containing barium in addition to indium oxide and tin, and is also characterized in that the molar ratio y of tin relative to 1 mole of indium is less than the value (-2.9 x 10Ln(x)-6.7 x 10) which is expressed by using the molar ratio x of barium relative to 1 mole of indium, and the crystallization temperature by annealing is not less than 100°C.

Description

Indium oxide transparent conductive film and its manufacturing method {INDIUM OXIDE TRANSPARENT CONDUCTIVE FILM AND METHOD FOR PRODUCING THE SAME}

The present invention can be formed as an amorphous film, the amorphous film can be easily patterned by weak acid etching, can be easily crystallized, and the crystallized film is a low resistance and high transparent conductive film. And to a method for producing the same.

Indium oxide-tin oxide (composite oxide of In ₂ O ₃ -SnO ₂ , hereinafter referred to as "ITO") film has high visible light transmittance and high conductivity, and thus a heat conductive film for preventing condensation of a liquid crystal display device or glass as a transparent conductive film. Although widely used for infrared reflecting films and the like, there is a problem that it is difficult to form an amorphous film.

On the other hand, as an amorphous film, an indium zinc oxide (IZO) transparent conductive film is known, but such a film has a problem of being inferior in transparency to an ITO film and becoming yellowish.

Therefore, the present applicant has previously proposed an amorphous amorphous conductive film formed by adding silicon to an ITO film as a transparent conductive film and formed under predetermined conditions (see Patent Document 1). However, when silicon is added, there is a tendency of high resistance. There was a problem.

Patent Document 1: Japanese Patent Application Laid-Open No. 2005-135649 (claims)

In view of such circumstances, the present invention can be formed as an amorphous film, and the amorphous film can be easily patterned by weak acid etching, can be easily crystallized, and the crystallized film has low resistance and An object of the present invention is to provide a transparent conductive film having a high transmittance and a method of manufacturing the same.

In order to solve the above-mentioned problems, the present invention has been repeatedly studied. As a result, an indium oxide-based transparent conductive film containing barium is an amorphous film having low resistance and excellent transparency, and can be easily patterned by weak acid etching. Furthermore, it discovered that it could crystallize easily, and applied for it previously (Japanese Patent Application No. 2007-095783).

Also in this case, regarding the composition range whose crystallization temperature is 100 degrees C or less, although there existed the subject that conditions were severe in order to form into a film of an amorphous force, this invention also solves the said subject.

The first aspect of the present invention is a transparent conductive film formed of a film of amorphous by using a sputtering target containing indium oxide and tin and containing barium and comprising an oxide sintered body, and contains indium oxide and tin. in addition, and also contains barium, and the mole ratio (y) of indium tin on one mole is represented by the molar ratio (x) of barium per mol of the indium ^{(-2.9 × 10 -2 Ln (x} ) -6.7 × 10 - ^It is less than the value of ² ), and the crystallization temperature by annealing is 100 degreeC or more, It exists in the transparent conductive film characterized by the above-mentioned.

In this first aspect, by forming tin and barium into an indium oxide-based transparent conductive film having a predetermined composition range, the film is formed as an amorphous film relatively easily and can be etched into a weakly acidic etchant.

A second aspect of the present invention is the transparent conductive film according to the first aspect, wherein a partial pressure of water is formed under a condition of 1.0 × 10 ⁻⁴ Pa or more and 1.0 × 10 ⁻¹ Pa or less. .

In this second aspect, the film is formed under a predetermined partial pressure of water, and the film is formed as an amorphous film relatively easily to enable etching with a weakly acidic etchant.

A third aspect of the present invention is the transparent conductive film according to the first or second aspect, wherein the film of amorphous force contains hydrogen.

In this third aspect, the film is formed under a predetermined water pressure, and hydrogen is accepted in the state in which the hydrogen is bound in the film, and the film is formed as an amorphous film relatively easily, and etching to a weakly acidic etchant is possible.

A 4th aspect of this invention is a transparent conductive film in which the crystal | crystallization was carried out by annealing after film-forming in the transparent conductive film in any one of 1st-3rd aspect.

In this 4th aspect, after forming into a film of an amorphous force, it can crystallize easily by annealing and can provide weak acid resistance.

A fifth aspect of the present invention is the transparent conductive film according to the fourth aspect, wherein the annealing is performed at 100 to 300 ° C.

In this fourth aspect, the film is crystallized at a relatively low temperature.

A sixth aspect of the present invention is the transparent conductive film according to the fourth or fifth aspect, wherein the resistivity of the transparent conductive film after annealing is 5.0 × 10 ⁻⁴ Ω · cm or less.

In such a sixth aspect, the resistivity after annealing is very low, and the resistivity can be set to a low resistance film having a resistivity of 5.0 × 10 ⁻⁴ Ω · cm or less.

According to a seventh aspect of the present invention, a sputtering target containing an indium oxide and tin and an oxide sintered body containing barium is used to contain indium oxide and tin, and also to contain barium and one mole of indium. When a film of amorphous is formed in which the molar ratio y of tin to y is less than the value of (-2.9 × 10 ⁻² Ln (x) −6.7 × 10 ⁻² ) expressed as the molar ratio x of barium to 1 mole of indium. The partial pressure of water at the time of film-forming is 1.0 * 10 <^-4> Pa or more 1.0 * 10 <^-1> Pa or less, The manufacturing method of the transparent conductive film characterized by the above-mentioned.

In this seventh aspect, by forming an indium oxide-based transparent conductive film having a predetermined composition containing barium under a predetermined water pressure, a film can be formed relatively easily as an amorphous film and can be etched with a weakly acidic etchant.

An eighth aspect of the present invention is the method for producing a transparent conductive film according to the seventh aspect, wherein the crystallization temperature by annealing the amorphous film is 100 ° C or more.

In this eighth aspect, since the crystallization temperature is an amorphous film of 100 ° C. or more, a film can be formed as an amorphous film relatively easily, and a film capable of etching with a weakly acidic etchant can be obtained.

A ninth aspect of the present invention is a method for producing a transparent conductive film according to the seventh or eighth aspect, wherein the film is crystallized by annealing after forming an amorphous film.

In this ninth aspect, after the film is formed as an amorphous film, it can be easily crystallized by annealing, thereby imparting weak acid resistance.

A tenth aspect of the present invention is the method for producing a transparent conductive film according to the ninth aspect, wherein the crystallization by annealing is performed at 100 to 300 ° C.

In this tenth aspect, the film is crystallized at a relatively low temperature at 100 to 300 ° C.

An eleventh aspect of the present invention is the method for producing a transparent conductive film according to the tenth aspect, wherein the resistivity of the transparent conductive film after annealing is 5.0 × 10 ⁻⁴ Ω · cm or less.

In this eleventh aspect, the resistivity after annealing is very low, and a resistivity film of 5.0 × 10 ^-4 Ω · cm or less can be obtained.

According to the present invention, a film in which tin and barium are added to indium oxide is formed into an amorphous film having a composition in a predetermined range and having a predetermined crystallization temperature, so that the amorphous film can be relatively easily formed. Can be easily patterned and easily crystallized, and the crystallized film can be obtained as a transparent conductive film having low resistance and high transmittance.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the crystallization temperature of test Examples A1-A18 and A68-A73 of this invention.
2 is a view showing the crystallization temperatures of Test Examples B1 to B18 and B68 to B73 of the present invention.
3 is a view showing a change in the optimum oxygen partial pressure of Reference Test Examples C1 to C73 of the present invention.

(The best mode for carrying out the invention)

The sputtering target for the transparent conductive film used for forming the indium oxide transparent conductive film of the present invention is an oxide sintered body mainly containing indium oxide, containing tin, and containing barium, while barium remains the oxide, Or it may exist as a complex oxide or as a solid solution, and is not specifically limited.

It is preferable to form content of barium using the sputtering target contained in 0.00001 mol or more and less than 0.10 mol with respect to 1 mol of indium. If it is less than this, the effect of the addition is not remarkable. If it is more than this, the resistance of the formed transparent conductive film becomes high and the yellow light tends to deteriorate. In addition, the barium content in the transparent conductive film formed of said sputtering target becomes content similar to content in the used sputtering target.

Moreover, it is preferable to form into a film using the sputtering target contained in content of tin with respect to 1 mol of indium, 0.001-0.3 mol, Preferably it is 0.005-0.3 mol. If it is in this range, the density and mobility of the carrier electrons of a sputtering target can be controlled suitably, and electroconductivity can be maintained in a favorable range. Moreover, when it adds beyond this range, since it reduces the mobility of the carrier electron of a sputtering target, and acts in the direction which degrades electroconductivity, it is unpreferable. In addition, content of tin in the transparent conductive film formed of said sputtering target becomes content similar to content in the used sputtering target. The compositional analysis of such an indium oxide transparent conductive film may be performed by dissolving the entire amount of the single film and analyzing it by ICP. In the case where the film itself has an element configuration, the cross section of the corresponding portion may be cut out by FIB or the like if necessary, and an elemental analysis device (EDS, WDS, ozer analysis, etc.) attached to the SEM or TEM may be used. It is possible to specify.

Since the sputtering target has a resistance value that can be sputtered by DC magnetron sputtering, sputtering is possible with relatively inexpensive DC magnetron sputtering, but of course, a high frequency magnetron sputtering device may be used.

By using such a sputtering target for transparent conductive films and forming a film under the conditions of a partial pressure of water of 1.0 × 10 ^-4 Pa or more and 1.0 × 10 ^-1 Pa or less, an amorphous indium oxide transparent conductive film can be formed in the same composition. have.

Here, in order to make the partial pressure of water into the above-mentioned predetermined range, it is an atmospheric gas (generally Ar and a gas containing oxygen as needed, for example) which is introduce | transduced into film-forming chamber at the time of film-forming, for example, the pressure of ^10-4 Pa bands. Water vapor may be introduced through a mass flow controller or the like, and in the case of a high vacuum with an attained vacuum of less than 10 ⁻⁴ Pa, the pressure is preferably about 1/100 to 1/10 of the atmospheric gas. In addition, under conditions where the degree of vacuum is poor at about 10 ⁻⁴ to 10 ⁻³ Pa, the main component of the residual gas is water. That is, since the attained vacuum degree is almost corresponded to the partial pressure of water, the state of the desired partial pressure of water can be obtained without introduce | transducing steam specially.

Since the indium oxide transparent conductive film of the present invention contains a predetermined amount of barium, the film is formed in an amorphous form by performing the film formation at a temperature higher than room temperature and lower than a crystallization temperature, that is, a crystallization temperature of 100 ° C or higher. . In addition, such an amorphous film has an advantage of being able to be etched with a weakly acidic etchant. Here, in this specification, an etching is included in a patterning process and is for obtaining a predetermined pattern.

Moreover, although the resistivity of the obtained transparent conductive film changes with content of barium, resistivity is 1.0 * 10 <^-4> -1.0 * 10 <^{-3> (} ohm) * cm.

Moreover, the crystallization temperature of the film formed into a film changes with content of barium contained, and it rises as content increases, but can crystallize by annealing on the temperature conditions of 100 degreeC-300 degreeC. Since such a temperature range is used in a conventional semiconductor manufacturing process, it may be crystallized in such a process. Moreover, it is preferable to crystallize at 100 degreeC-300 degreeC among this temperature range, It is more preferable to crystallize at 150 degreeC-250 degreeC, It is most preferable to crystallize at 200 degreeC-250 degreeC.

Here, annealing means heating to a desired temperature for a predetermined time in the atmosphere, in an atmosphere, in a vacuum, or the like. Although the fixed time is generally about several hours to several hours, industrially, if the effect is the same, a short time is preferable.

Here, in the transparent conductive film of the present invention, the molar ratio y of tin to 1 mol of indium is represented by the molar ratio x of barium to 1 mol of indium (-2.9 x 10 ^-2 Ln (x) -6.7 x Using a sputtering target with a composition range of less than 10 ⁻² ) and forming a partial pressure of water under the conditions of 1.0 × 10 ⁻⁴ Pa or more and 1.0 × 10 ⁻¹ Pa or less, the film formation temperature is set to be somewhat high and set to about 100 ° C. It is also said that an amorphous film can be obtained.

Here, whether or not it can form a film as an amorphous film needs to be formed at a film formation temperature lower than the crystallization temperature in the composition of the film to be formed as described above, and the smaller the content of tin or barium, the more the crystallization temperature. The lower the content of tin and barium, the higher the crystallization temperature. However, by forming a partial pressure of water under the conditions of 1.0 × 10 ^-4 Pa or more and 1.0 × 10 ^-1 Pa or less, the crystallization temperature of each composition is increased. It can be made about 50-100 degreeC high compared with the case where the partial pressure of water is formed into less than 1.0x10 <^-4> Pa. Thus, the molar ratio y of tin to 1 mole of indium is less than the value of (-2.9 × 10 ⁻² Ln (x) −6.7 × 10 ⁻² ) expressed as the molar ratio x of barium to 1 mole of indium. In the range, when the partial pressure of water is formed at less than 1.0 × 10 ⁻⁴ Pa, the crystallization temperature is less than 100 ° C., especially near room temperature, and even if the film forming conditions for obtaining an amorphous film are quite strict, the partial pressure of water is 1.0 ×. By carrying out the conditions of 10 ^-4 Pa or more and 1.0x10 ^-1 Pa or less, crystallization temperature can be raised, for example to 100 degreeC or more, For example, even if it is about 100 degreeC film-forming conditions, an amorphous film is obtained. Can be.

When the partial pressure of water is lower than 1.0 × 10 ⁻⁴ Pa, the effect of raising the crystallization temperature as described above is not remarkable, while on the other hand, when the partial pressure of water is larger than the upper limit (1.0 × 10 ⁻¹ Pa), it is obtained. Although the film is amorphous, the specific resistance of the film does not decrease when annealed and crystallized, which makes it difficult to obtain a crystallized film of 5.0 × 10 ⁻⁴ Ω · cm or less, which is not preferable.

Moreover, the range of the value more than (-2.9 * 10 <^-2> Ln (x) -6.7 * 10 <^-2> ) represented by the molar ratio (y) of tin with respect to 1 mol of indium is the molar ratio (x) of barium with respect to 1 mol of indium. is, in the film formation at a lower than normal conditions, the water partial pressure of 1.0 × 10 ^-4 Pa, so that the crystallization temperature can be formed a film of more than 100 ℃ amorphous (refer to Japanese Patent Application No. 2007-095783), a water partial pressure of 1.0 × 10 ^- Although it is not necessary to form into a film under the conditions of ⁴ Pa or more and 1.0x10 <^-1> Pa or less, it is needless to say that even if it forms on these conditions, an amorphous film will be formed.

Next, although the manufacturing method of the sputtering target used by this invention is demonstrated, this is only illustrated and the manufacturing method is not specifically limited.

First, starting materials constituting the sputtering target of the present invention are generally powders of In ₂ O ₃ , SnO ₂ , and BaCO ₃ , but In ₂ O ₃ and BaCO ₃ are preliminarily plasticized to BaIn ₂ O ₄ , where In is to use a mixture of ₂ O ₃ and SnO ₂ are preferred. This is to prevent the generation of pores due to gas generation by decomposition of BaCO ₃ . Moreover, you may use these single substance, a compound, complex oxide, etc. as a raw material. In the case of using a single element or a compound, a process such as making an oxide in advance is performed.

The method of mixing and molding these raw material powders at a desired blending ratio is not particularly limited, and conventionally known various wet methods or dry methods can be used.

As a dry method, the cold press method, the hot press method, etc. are mentioned. In the cold press method, a mixed powder is filled into a molding die, a molded article is produced, and fired. In the hot press method, the mixed powder is fired and sintered in a molding die.

As the wet method, for example, it is preferable to use a filtration molding method (see Japanese Patent Application Laid-Open No. H11-286002). The filtration molding method is a filtration molding mold made of a water-insoluble material for depressurizing and draining water from a ceramic raw material slurry to obtain a molded body. The filtration molding method includes a molding lower mold having at least one drain hole and a lower mold for mounting on the molding lower mold. It consists of a filter having water permeability, and a molding mold sandwiched from the upper surface side through a sealing member for sealing the filter, and assembled to disassemble the lower mold, the molding mold, the sealing member, and the filter, respectively. A slurry comprising a mixed powder, ion-exchanged water and an organic additive is prepared by using a filtration type mold in which water in the slurry is drained under reduced pressure only from the filter face side, and the slurry is injected into the filtration type mold, and the filter The molded product was produced by depressurizing and draining water in the slurry only from the surface side, and after drying and degreasing the obtained ceramic molded product, Sung.

The baking temperature of the thing molded by the cold press method or the wet method is 1300-1650 degreeC, More preferably, it is 1500-1650 degreeC, The atmosphere is an atmospheric atmosphere, an oxygen atmosphere, a non-oxidizing atmosphere, or a vacuum atmosphere. On the other hand, in the hot press method, it is preferable to sinter at 1200 degreeC, The atmosphere is a non-oxidizing atmosphere, a vacuum atmosphere, etc. In addition, after baking by each method, the machining for shaping | molding and processing to a predetermined dimension is made into a target.

(Example)

EMBODIMENT OF THE INVENTION Hereinafter, although this invention is demonstrated based on an Example, it is not limited to this.

(Sputtering Target Manufacturing Examples 1 to 67)

In ₂ O ₃ powder, SnO ₂ powder, and BaCO ₃ powder of purity> 99.9% were prepared.

First, a total amount of 200 g was prepared at a ratio of 58.6 wt% of BET = 27 m ² / g In ₂ O ₃ powder and 41.4 wt% of BET = 1.3 m ² / g BaCO ₃ powder, and mixed with a ball mill in a dry state. , calcined for 3 hours in the atmosphere at 1100 ℃, BaIn ₂ O ₄ to obtain a powder.

Subsequently, Ba and Sn occupy the BaIn ₂ O ₄ powder, BET = 5m ² / g In ₂ O ₃ powder, and BET = 1.5m ² / g SnO ₂ powder with respect to 1 mol of In. About 1.0 kg was prepared by the total amount by the ratio equivalent to mole, and this was mixed with the ball mill. Then, PVA aqueous solution was added as a binder, it mixed, dried, and cold-pressed, and the molded object was obtained. The molded product was degreased at an elevated temperature of 60 ° C./h at 600 ° C. for 10 hours, and then calcined at 1600 ° C. for 8 hours in an oxygen atmosphere to obtain a sintered body. Specifically, the firing conditions are elevated to 100 ° C./h from room temperature to 800 ° C., heated to 400 ° C./h from 800 ° C. to 1600 ° C., and maintained for 8 hours, and then 100 ° C./h from 1600 ° C. to room temperature. It is a condition called cooling on condition. Then, this sintered compact was processed and the target was obtained. At this time, the density and the bulk resistivity are 6.88 g / cm ³ and 2.81 × 10 ⁻⁴ Ω · cm, respectively, in the composition of 32, and 6.96 g / cm ³ and 2.87 × 10 ⁻ , respectively, in the composition of 22, respectively. ^{It was 4} ohm * cm.

(Test Examples A1 to A18)

The sputtering targets of each of Production Examples 1 to 18 were respectively attached to a 4-inch DC magnetron sputtering device, the substrate temperature was set at room temperature (about 20 ° C.), the partial pressure of water was 1.0 × 10 ⁻⁴ Pa, and the oxygen partial pressure was 0 to 3.0. The transparent conductive films of Test Examples A1 to A18 were obtained while changing between sccm (corresponding to 0 to 1.1 × 10 ⁻² Pa).

The sputter | spatter conditions were as follows, and the film | membrane of thickness 1200Å was obtained.

Target dimension: φ = 4in. t = 6mm

Sputter Method: DC Magnetron Sputter

Exhaust System: Rotary Pump + Cryopump

Reach Vacuum Degree: 5.3 × 10 ^-6 [Pa]

Ar pressure: 4.0 × 10 ^-1 [Pa]

Oxygen pressure: 0 to 1.1 x 10 ^-2 [Pa]

Hydraulic pressure: 1.0 × 10 ^-4 [Pa]

Substrate Temperature: Room Temperature

Sputter Power: 130W (Power Density 1.6W / cm ² )

Substrate used: Corning # 1737 (glass for liquid crystal display) t = 0.8mm

In Test Examples A1 to A18, the relationship between the oxygen partial pressure and the resistivity in film formation at room temperature and the oxygen partial pressure and the resistivity after 250 ° C. annealing were determined.

Table 1 shows the molar ratios of Ba and Sn, the crystalline state (amorphous film is designated as a and the crystallized film is denoted as c) for room temperature film formation, and the crystallization temperature of the amorphous film with respect to 1 mol of In of each sample. Indicated.

In Table 1, the resistivity at the time of film formation means the resistivity of the film at the optimum oxygen partial pressure at room temperature film formation. In addition, the resistivity after annealing was made into the resistivity in the optimum oxygen partial pressure at the time of annealing at 250 degreeC.

In addition, the crystallization temperature shown in Table 1 was calculated | required as follows. After annealing at 250 ° C., the film formed at room temperature at the lowest oxygen partial pressure was annealed at 100 ° C. to 300 ° C. (500 ° C. if necessary) at 50 ° C. for 1 hour in air, and the film was analyzed by thin film XRD. The diffraction line is detected by increasing the annealing temperature with respect to the hollow peak showing the amorphous film formed at room temperature. The initial temperature was determined as the crystallization temperature. In addition, as another calculation method of the crystallization temperature, a high temperature thin film XRD method can also be used.

In addition, Test Examples A1 to A18 were plotted in FIG. 1, where the crystallization temperature was represented by 100 to 300 ° C., and the crystallization temperature was represented by 350 ° C. or more.

As a result, it turned out that all the samples have a crystallization temperature of 100 degreeC-300 degreeC.

(Test Examples B1 to B18)

The sputtering targets of each of Production Examples 1 to 18 were respectively attached to a 4-inch DC magnetron sputtering device, the substrate temperature was room temperature (about 20 ° C), the partial pressure of water was 1.0 × 10 ^-3 Pa, and the oxygen partial pressure was 0 to 3.0. The transparent conductive films of Test Examples B1 to B18 were obtained while changing between sccm (corresponding to 0 to 1.1 × 10 ⁻² Pa).

The sputter | spatter conditions were as follows, and the film | membrane of thickness 1200Å was obtained.

Target dimension: φ = 4in. t = 6mm

Sputter Method: DC Magnetron Sputter

Exhaust System: Rotary Pump + Cryopump

Reach Vacuum Degree: 5.3 × 10 ^-6 [Pa]

Ar pressure: 4.0 × 10 ^-1 [Pa]

Oxygen pressure: 0 to 1.1 x 10 ^-2 [Pa]

Water pressure: 1.0 × 10 ^-3 [Pa]

Substrate Temperature: Room Temperature

Sputter Power: 130W (Power Density 1.6W / cm ² )

Substrate used: Corning # 1737 (glass for liquid crystal display) t = 0.8mm

About test Examples B1-B18, the relationship between the oxygen partial pressure and resistivity in film-forming at room temperature, and the relationship between the oxygen partial pressure and resistivity after 250 degreeC annealing were calculated | required.

Table 2 shows the molar ratios of Ba and Sn, the crystalline state (amorphous film is designated as a and the crystallized film is denoted as c) in room temperature film formation, and the crystallization temperature of the amorphous film with respect to 1 mol of In of each sample. Indicated. In addition, crystallization temperature, resistivity at the time of film-forming, and resistivity after annealing are as above-mentioned.

Moreover, Test Examples B1-B18 were plotted in FIG. 2, and crystallization temperature showed 100-300 degreeC, and crystallization temperature showed 350 degreeC or more as (circle).

As a result, it turned out that crystallization temperature is 100 degreeC-300 degreeC with respect to all the samples.

(Reference Test Examples C1 to C67)

The sputtering targets of each of Production Examples 1 to 67 were each attached to a 4-inch DC magnetron sputtering device, the substrate temperature was set at room temperature (about 20 ° C.), the partial pressure of water was 1.0 × 10 ⁻⁵ Pa, and the oxygen partial pressure was 0 to 3.0. The transparent conductive films of Reference Test Examples C1 to C67 were obtained while changing between sccm (corresponding to 0 to 1.1 × 10 ⁻² Pa).

The sputter | spatter conditions were as follows, and the film | membrane of thickness 1200Å was obtained.

Target dimension: φ = 4in. t = 6mm

Sputter Method: DC Magnetron Sputter

Exhaust System: Rotary Pump + Cryopump

Reach Vacuum Degree: 5.3 × 10 ^-6 [Pa]

Ar pressure: 4.0 × 10 ^-1 [Pa]

Oxygen pressure: 0 to 1.1 x 10 ^-2 [Pa]

Hydraulic pressure: 1.0 × 10 ^-5 [Pa]

Substrate Temperature: Room Temperature

Sputter Power: 130W (Power Density 1.6W / cm ² )

Substrate used: Corning # 1737 (glass for liquid crystal display) t = 0.8mm

For Reference Test Examples C1 to C67, the relationship between the oxygen partial pressure and the resistivity in film formation at room temperature and the oxygen partial pressure and the resistivity after 250 ° C annealing were determined.

Table 3 and Table 4 show the molar ratios of Ba and Sn, the crystalline state (amorphous film is designated as a and the crystallized film is denoted as c) in room temperature film formation with respect to 1 mol of In of each sample, and the The crystallization temperature is shown. In addition, crystallization temperature, resistivity at the time of film-forming, and resistivity after annealing are as above-mentioned.

Using the sputtering targets of Production Examples 1 to 67, the relationship between the oxygen partial pressure at room temperature (about 20 ° C.) and the resistivity of the film formed at the partial pressure was obtained to find the optimum oxygen partial pressure, and the film formed at each oxygen partial pressure. From the relationship between the resistivity after annealing the film at 250 ° C. and the deposition oxygen partial pressure, the oxygen partial pressure at which the resistivity after annealing is the lowest is set as the optimum oxygen partial pressure at the time of film formation at 250 ° C., and the optimum oxygen partial pressure is different. It judged whether or not it was, and made different things (circle) and nearly same things into (circle), and was shown in FIG.

As a result, the molar ratio (y) of tin to 1 mol of indium is equal to or more than the value of (-2.9 × 10 ^-2 Ln (x) -6.7 × 10 ^-2 ) represented by the molar ratio (x) of barium to 1 mol of indium. When the film is below the value of (-2.0 × 10 ⁻¹ Ln (x) −4.6 × 10 ⁻¹ ) and is in the range excluding y = 0, the deposition oxygen partial pressure after the film formation becomes low resistance, and annealing It was found that the deposition oxygen partial pressure at which the subsequent film becomes low resistance is different, or the optimum oxygen partial pressure at 250 ° C. is different from the optimum oxygen partial pressure at room temperature. That is, in these composition ranges, it is not the optimum oxygen partial pressure determined from the resistivity immediately after the film formation, but the film formed at the oxygen partial pressure after which the crystallized film after annealing becomes the lowest resistance becomes more preferable because the resistivity of the film after annealing becomes lower.

The molar ratio y of tin to 1 mole of indium is less than the value of (-2.9 × 10 ⁻² Ln (x) −6.7 × 10 ⁻² ) expressed by the molar ratio x of barium to 1 mole of indium. In the range, it turned out that crystallization temperature is a range smaller than 100 degreeC.

On the other hand, as shown in FIG. 1 and FIG. 2, when the film is formed with a partial pressure of water in a predetermined range, the molar ratio y of tin to 1 mol of indium is represented by the molar ratio x of barium to 1 mol of indium. Even in the range below the value of (-2.9 × 10 ⁻² Ln (x) −6.7 × 10 ⁻² ), the crystallization temperature was increased to 150 ° C. or higher, and it was found that the film was easily formed into an amorphous film.

(Test Examples A68 to A73)

The target of manufacture examples 68-73 which consist of a sintered compact of the composition shown in following Table 5 was obtained similarly to sputtering target manufacture examples 1-67.

The sputtering targets of each of Production Examples 68 to 73 were respectively attached to a 4-inch DC magnetron sputtering device, the substrate temperature was room temperature (about 20 ° C), the partial pressure of water was 1.0 × 10 ^-4 Pa, and the oxygen partial pressure was 0 to 3.0. The transparent conductive films of Test Examples A68 to A73 were obtained while changing between sccm (corresponding to 0 to 1.1 × 10 ⁻² Pa).

The sputter | spatter conditions were as follows, and the film | membrane of thickness 1200Å was obtained.

Target dimension: φ = 4in. t = 6mm

Sputter Method: DC Magnetron Sputter

Exhaust System: Rotary Pump + Cryopump

Reach Vacuum Degree: 5.3 × 10 ^-6 [Pa]

Ar pressure: 4.0 × 10 ^-1 [Pa]

Oxygen pressure: 0 to 1.1 x 10 ^-2 [Pa]

Hydraulic pressure: 1.0 × 10 ^-4 [Pa]

Substrate Temperature: Room Temperature

Sputter Power: 130W (Power Density 1.6W / cm ² )

Substrate used: Corning # 1737 (glass for liquid crystal display) t = 0.8mm

About test Examples A68-A73, the relationship between oxygen partial pressure and resistivity in film-forming at room temperature, and the relationship between oxygen partial pressure and resistivity after 250 degreeC annealing were calculated | required.

Table 5 shows the molar ratios of Ba and Sn, the crystalline state (amorphous film is designated as a and the crystallized film is denoted as c) for room temperature film formation, and the crystallization temperature of the amorphous film with respect to 1 mol of In of each sample. Indicated. In addition, crystallization temperature, resistivity at the time of film-forming, and resistivity after annealing are as above-mentioned.

Test Examples A68 to A73 were also plotted in Fig. 1 together with Test Examples A1 to A18, where the crystallization temperature was 100 to 300 ° C and the crystallization temperature was 350 ° C or higher.

As a result, it turned out that crystallization temperature is 100 degreeC-300 degreeC with respect to all the samples.

(Test Examples B68 to B73)

The sputtering targets of each of Production Examples 68-73 were each attached to a 4-inch DC magnetron sputtering device, the substrate temperature was room temperature (about 20 ° C), the partial pressure of water was 1.0 × 10 ^-3 Pa, and the oxygen partial pressure was 0 to 3.0. The transparent conductive films of Test Examples B68 to B73 were obtained while changing between sccm (corresponding to 0 to 1.1 × 10 ⁻² Pa).

The conditions of sputter | spatter were the same as Test Examples A68-A73, and the film | membrane of thickness 1200Å was obtained.

About test Examples B68-B73, the relationship between oxygen partial pressure and resistivity in film-forming at room temperature, and the relationship between oxygen partial pressure and resistivity after 250 degreeC annealing were calculated | required.

Table 6 shows the molar ratios of Ba and Sn, the crystalline state (amorphous film is denoted as a and the crystallized film is denoted as c) in room temperature film formation, and the crystallization temperature of the amorphous film with respect to 1 mol of In of each sample. Indicated. In addition, crystallization temperature, resistivity at the time of film-forming, and resistivity after annealing are as above-mentioned.

Moreover, Test Examples B68-B73 were plotted in FIG. 2 with Test Examples B1-B18, and crystallization temperature showed 100-300 degreeC, and crystallization temperature showed 350 degreeC or more as (circle).

As a result, it turned out that crystallization temperature is 100-300 degreeC with respect to all the samples.

(Reference Test Examples C68 to C73)

The sputtering targets of each of Production Examples 68-73 were each attached to a 4-inch DC magnetron sputtering device, the substrate temperature was room temperature (about 20 ° C), the partial pressure of water was 1.0 × 10 ^-5 Pa, and the oxygen partial pressure was 0 to 3.0. The transparent conductive films of Reference Test Examples C68 to C73 were obtained while changing between sccm (corresponding to 0 to 1.1 × 10 ⁻² Pa).

The conditions of sputter | spatter were the same as Test Examples A68-A73, and the film | membrane of thickness 1200Å was obtained.

For Reference Test Examples C68 to C73, the relationship between the oxygen partial pressure and the resistivity in film formation at room temperature and the oxygen partial pressure and the resistivity after 250 ° C. annealing were determined.

Table 7 shows the molar ratios of Ba and Sn, the crystalline state (amorphous film is denoted as a and the crystallized film is denoted as c) in room temperature film formation, and the crystallization temperature of the amorphous film with respect to 1 mol of In of each sample. Indicated. In addition, crystallization temperature, resistivity at the time of film-forming, and resistivity after annealing are as above-mentioned.

Moreover, the result of test Examples C68-C73 was plotted in FIG. 3 with reference test examples C1-C67. That is, for the targets of Production Examples 68 to 73, the relationship between the oxygen partial pressure at room temperature (about 20 ° C.) and the resistivity of the film formed at the partial pressure was obtained to find the optimum oxygen partial pressure, and the films formed at each oxygen partial pressure were obtained. From the relationship between the resistivity after annealing at 250 ° C. and the deposition oxygen partial pressure, the oxygen partial pressure at which the resistivity after annealing is the lowest is set as the optimum oxygen partial pressure at the time of film formation at 250 ° C., and the optimum oxygen partial pressure is different. It judged whether it was or not, and made different things (circle) and nearly same things into (circle), and was shown in FIG.

(Existence confirmation test of hydrogen)

The sputtering target of Preparation Example 13 was attached to a 4-inch DC magnetron sputtering device, respectively, and the substrate temperature was room temperature (about 20 ° C.), the partial pressure of water was 1.0 × 10 ⁻² Pa (as Example 1), 5.0 × 10 ^{−. 3} Pa (referred to as example 2) and 5.0 × 10 ^-5 Pa conducted in three conditions (comparative examples referred to as 1) example 1, example 2 and Comparative example 1 of the transparent conductive film was obtained.

The sputter | spatter conditions were as follows, and the film | membrane of thickness 1200Å was obtained.

Target dimension: φ = 4in. t = 6mm

Sputter Method: DC Magnetron Sputter

Exhaust System: Rotary Pump + Cryopump

Reach Vacuum Degree: 5.3 × 10 ^-5 [Pa]

Ar pressure: 4.0 × 10 ^-1 [Pa]

Oxygen pressure: 0 [Pa]

Water pressure: 1.0 × 10 ^-2 , 5.0 × 10 ^-3 , 5.0 × 10 ^-5 [Pa]

Substrate Temperature: Room Temperature

Sputter Power: 130W (Power Density 1.6W / cm ² )

Substrate used: Corning # 1737 (glass for liquid crystal display) t = 0.8mm

Here, when the crystal state of the sample formed under each condition was analyzed by thin film XRD, it was confirmed that it is amorphous in Example 1 and Example 2, and crystallized in Comparative Example 1.

In addition, about presence of hydrogen in each film | membrane, the measurement shown below about the sample of Example 1 and the comparative example 1 using time-of-flight type secondary ion mass spectrometry (TOF-SIMS, TRIFT IV by ULVAC PHI) The conditions were confirmed by comparing (H ⁺ ionized water) / (total ionized water) detected.

[Measuring conditions]

Primary ion: Au ⁺

Acceleration voltage: 30 kV

Scanning Conditions: Raster Scan (200 × 200 μm)

Table 8 shows (count of H ⁺ ions) / (count of all ions) which is a result of TOF-SIMS analysis of the sample formed into a film.

Here, the H ⁺ ions are also detected in the sample of Comparative Example 1 formed in an atmosphere in which the water pressure at the time of film formation is 5.0 × 10 ⁻⁵ and substantially no water is present, but this can be judged as the background. That is, in a recent study, it was reported that H ⁺ ions were detected from an indium oxide film formed at a partial pressure lower than that of Comparative Example 1 (Jpn. J. Appl. Phys., Vol. 46, No. 28). , 2007, pp. L685-L687), it can be inferred that the detected hydrogen ions contained in the film a slight moisture adhering to the substrate during film formation. Therefore, in the present invention, the reference value is set to 7.75 × 10 ^−4, which is (H ⁺ ionized water) / (total ionized water) of a sample formed in an atmosphere having a water pressure of 5.0 × 10 ⁻⁵ or less in an atmosphere substantially free of water. Then, the increased (H ⁺ ionized water) / (total ionized water) than this is taken as hydrogen ions contained in the membrane.

Therefore, when Examples 1 and 2 and Comparative Example 1 (count of H ⁺ ions) / (count of all ions) are compared, it can be seen that the moisture pressure at the time of film formation increases as the water pressure increases. Therefore, as in Examples 1 and 2, it was confirmed that by controlling the water pressure at the time of film formation, the amount of hydrogen due to water intake in the film can be changed. In addition, it is estimated that hydrogen received in the film has an effect of inhibiting crystallization of the film by hydrogen termination of dangling bonds (unbonded hands) of atoms in the film.

Claims (11)

A transparent conductive film formed as a film of amorphous by using a sputtering target containing indium oxide and tin and containing barium and an oxide sintered body, which contains indium oxide and tin, and also contains barium and indium The molar ratio y of tin to 1 mole is less than the value of (-2.9 × 10 ⁻² Ln (x) −6.7 × 10 ⁻² ), expressed as the molar ratio x of barium to 1 mole of indium, The crystallization temperature by which is 100 degreeC or more, The transparent conductive film characterized by the above-mentioned. The transparent conductive film according to claim 1, wherein the partial pressure of water is formed under a condition of 1.0 × 10 ⁻⁴ Pa or more and 1.0 × 10 ⁻¹ Pa or less. The transparent conductive film according to claim 1 or 2, wherein the amorphous film contains hydrogen. The transparent conductive film according to any one of claims 1 to 3, wherein the transparent conductive film is a film which is crystallized by annealing after film formation. The transparent conductive film according to claim 4, wherein the annealing is performed at 100 to 300 ° C. The resistivity of the transparent conductive film after annealing is 5.0x10 <^{-4> (} ohm) * cm or less, The transparent conductive film of Claim 4 or 5 characterized by the above-mentioned. Using a sputtering target comprising an oxide sintered body containing indium oxide and tin and also containing barium, the molar ratio (y) of tin to mol of indium containing tin and When depositing an amorphous film, which is less than the value of (-2.9 × 10 ⁻² Ln (x) −6.7 × 10 ⁻² ) expressed by the molar ratio (x) of 1 mol of indium, the partial pressure of water at the time of film formation is 1.0. A method for producing a transparent conductive film, characterized in that the content of × 10 ^-4 Pa or more and 1.0 × 10 ^-1 Pa or less. The method for producing a transparent conductive film according to claim 7, wherein the crystallization temperature by annealing the film of the amorphous force is 100 ° C or more. The method for manufacturing a transparent conductive film according to claim 7 or 8, wherein the amorphous film is formed by crystallization by annealing after film formation. The method for producing a transparent conductive film according to claim 9, wherein the crystallization by annealing is performed at 100 to 300 deg. The method for producing a transparent conductive film according to claim 10, wherein the resistivity of the transparent conductive film after annealing is 5.0 × 10 ⁻⁴ Ω · cm or less.

Images