JPH07262829A - Transparent conductive film and method for forming the same - Google Patents

Abstract

(57) [Summary] [Objective] The object of the present invention is to achieve a resistivity of 1 x 1 without compromising transparency under low temperature conditions suitable for thin film transistor manufacturing processes.
It is to obtain a transparent conductive film of 0 ⁻⁴ Ωcm or less. [Structure] A transparent conductive film in which a specific crystal plane is preferentially oriented with respect to the substrate surface is formed by a sputtering method using a gas containing krypton or a gas containing xenon. In addition, a transparent conductive film in which two or more layers having different carrier densities or mobilities were alternately laminated was formed by the sputtering method. [Effect] The transparent conductive film has a specific resistance that is transparent in the visible light region 1 due to the effect of reducing carrier scattering in crystal grains and crystal grain boundaries.
A conductive film of × 10 ⁻⁴ Ωcm could be formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transparent conductive film which can be used as a transparent electrode of a display device such as a liquid crystal display and a method for forming the same.

[0002]

2. Description of the Related Art A transparent conductive film is indispensable as a transparent electrode for a liquid crystal display or the like. When the transparent conductive film is used as an electrode of a liquid crystal display, depending on the driving method of each pixel electrode forming a matrix, the structure and material of the driving element,
The characteristics required of the transparent conductive film are slightly different, but the specific resistance of the transparent conductive film is low in response to the reduction in pixel pitch as the liquid crystal panel becomes finer regardless of the driving method. Is required. For example, STN (super twisted
The nematic) method requires a sheet resistance of 10 to 12 Ω / □ or less and a conductive film thickness of 100 nm or less. The advantage of low resistance is not limited to high resolution. When the specific resistance of the transparent conductive film is on the order of 10 ^-5 Ωcm, an active matrix type thin film transistor (TFT)
The transparent conductive film can be applied to the source and drain electrodes, and the cost can be reduced by reducing the number of steps for forming the element. It is known that the specific resistance of the transparent conductive film decreases as the substrate temperature during film formation increases, and the transparent conductive film preparation temperature is preferably 300 ° C. or higher. However, the formation temperature of the transparent conductive film is limited by the structure of the device. For example, in the active matrix method, the transparent conductive film forming temperature must be 250 ° C. or lower so as not to damage the TFT element formed previously. Also in the color STN (super twisted nematic) method, the transparent conductive film needs to be formed on the organic color filter, so that the thin film forming temperature is limited to a low temperature of 250 ° C. or lower. Moreover, the low specific resistance peculiar to the STN method is also required. Thus, in the future, in order to meet the demands for higher definition, colorization and lower price of displays, a technique for producing a low resistance film at an increasingly low temperature is required.

As a transparent conductive film which has been widely studied or put into practical use to date, Sn-doped In ₂ O _{3 is used.}
SnO ₂ , I doped with (ITO), F or Sb
There is ZnO doped with n, Al, Si and the like. It is known that each of these films is an n-type semiconductor having an energy gap of 3.5 eV or more, and it is known that the donor ion and oxygen deficiency due to the stoichiometric composition act as a donor. A vapor deposition method and a sputtering method are generally used as a method for producing the transparent conductive film. Examples of the low-resistance transparent conductive film include, for example, Journal of Applied Physics, Vol. 54 (1983), pages 3497 to 3501 (J. Appl. Phy.
s. 54 (1983) p. 3497-3501).
An ITO film (thickness: 90 nm) showing a specific resistance of 1.3 × 10 ⁻⁴ Ωcm at a substrate temperature of 250 ° C. was prepared, but no visible light transmittance was described.

[0004]

As described above, the transparent conductive film to be sought after has a specific resistance of 1 × 10 ⁻⁴ Ωcm or less and must be formed under a temperature condition of 250 ° C. or less. However, the known ones are not sufficient. To reduce the value of resistivity, increase the number of conduction carriers, or
Alternatively, it is necessary to increase the mobility of carriers. It is necessary to increase the amount of doping and the amount of oxygen vacancies in order to increase the number of conduction carriers, but it is necessary to increase the amount of oxygen vacancies because all of the added elements do not work effectively as dopants and the crystal structure is stabilized. There is a limit to increasing the carrier density due to the limitation. On the other hand, in order to increase the mobility, it is necessary to reduce the carrier scattering at the crystal grain boundaries of the film or the carrier scattering due to the dopants and defects in the crystal grains.

An object of the present invention is to provide a method for forming a transparent conductive film having a specific resistance of 1 × 10 ^-4 Ωcm or less without impairing the transparency under a temperature condition of 250 ° C. or less.

[0006]

In order to achieve the above object, the present invention provides three methods for increasing the mobility of a transparent conductive film. The first is to use krypton or xenon having a larger atomic weight than argon, which is usually used as an inert gas, when forming a transparent conductive film by sputtering. By this method, it is possible to obtain a transparent conductive film which is a polycrystalline body having a larger crystal grain size than before, and it is possible to enhance the mobility by improving the crystallinity and reducing the grain boundary portion. Further, oxygen vacancies are more likely to occur than in the case of using argon, which brings about an effect of increasing the carrier density.
Similar effects can be obtained by mixing not only krypton or xenon but also oxygen, hydrogen, steam or the like during sputtering. Especially 2-5 × 10
It is effective to mix oxygen of about ^-5 Torr to reduce the resistance. Further, the sputtering method may be not only the DC sputtering method but also the high frequency sputtering method or the ion beam sputtering method. If it is a magnetron system, the effect is further enhanced.

The second method, as shown in FIG. 1, is to preferentially orient a specific crystal plane with respect to the substrate surface in each crystal grain of the transparent conductive film which is a polycrystalline body. By having such characteristics, it is possible to reduce the scattering of carriers at the crystal grain boundaries as described above, and it is possible to obtain a transparent conductive film having a low resistance. In the present invention, the effect is extremely remarkable particularly when the film is in a single crystal state where no crystal grain boundary exists. As for the specific crystal plane that is preferentially oriented with respect to the substrate surface, the crystal plane having a low crystallographic index is more effective in lowering the resistance. This is the (100) plane when the crystal has a cubic crystal or a symmetry close to it, such as ITO or doped SnO ₂ .

As a method of preferentially orienting a specific crystal plane with respect to the substrate surface, as shown in FIG. 4, for example, a method of using a single crystal or a polycrystal of magnesium oxide, strontium titanate or the like as the substrate. There is.
In that case, the crystal plane of the transparent conductive film that is preferentially oriented can be selected by appropriately selecting the crystal orientation of the surface of the crystal substrate used and the thin film forming conditions. In addition to magnesium oxide and strontium titanate, the crystal substrate used has a corundum structure such as rock salt and other perovskites, garnets and alumina, a spinel structure, and a fluorite structure such as BaF _2. Those with In particular, the cubic YSZ (yttrium-stabilized zirconia) substrate has a lattice constant of 0.1.
Since 5139 nm is close to 1/2 of the lattice constant of ITO, I
It is effective for the TO film.

In addition to such a method, there is a method of forming a thin metal layer on a substrate and forming a transparent conductive film layer on the thin metal layer. A metal film is easily crystallized even if formed at a low temperature, and it is easy to preferentially orient a specific crystal plane with respect to the substrate surface. By forming the transparent conductive film on the crystallized metal layer, the transparent conductive film is crystallized and a specific crystal plane can be preferentially oriented with respect to the substrate surface. In that case, the thickness of the metal layer needs to be 15 nm or less in order to maintain the transmittance of light in the visible region. The layer made of this metal does not necessarily need to be present between the substrate and the transparent conductive film as shown in FIG. 5, and even when it is present only in a part thereof as shown in FIG. Effectively contributes to the crystal growth of the layer. Further, even if the layer made of this metal is not directly formed on the substrate but is formed on an insulating layer such as silicon oxide or silicon nitride as shown in FIG. 7, it is effective. Is. As the metal, gold, silver, platinum, copper, rhodium, palladium, aluminum, chromium and the like are preferable.

Even when the transparent conductive film is directly formed on the glass substrate without using the crystalline substrate or the crystalline underlayer, the oriented film can be formed by selecting the film forming conditions. The use of krypton or xenon described above as the sputtering gas has the effect of coarsening the crystal grains, and can enhance the effect of the orientation of the crystal grains of the transparent conductive film. Further, irradiating the surface of the substrate with appropriate ions as an ion beam or irradiating plasma during film formation is also an effective method for enhancing the orientation of the transparent conductive film.

A third method for obtaining a transparent conductive film having a low resistance is to form the transparent conductive film with two or more layers having different carrier densities or mobilities. As described above, the conductive carriers of the transparent conductive film are supplied by the doped impurity elements and oxygen vacancies, but these carrier sources simultaneously serve as scattering sources for the carriers and thus reduce the mobility. The present invention has improved such a point, and the transparent conductive film is mainly composed of a layer for supplying a carrier and a layer for transporting the supplied carrier, which have different functions. In this case, since the carrier supply layer may have a low mobility, it is possible to increase the carrier density by introducing impurity elements, oxygen defects and the like as much as possible. On the other hand, the carrier transport layer can maintain a sufficiently high mobility by reducing impurity elements and oxygen defects. Such a laminated film functions if there is one carrier supply layer and one carrier transport layer as shown in FIG. 2 or FIG. In order to further enhance the effect, a multi-layer film in which carrier supply layers and carrier transport layers are alternately laminated as shown in FIG. 8 may be used. At that time, the thickness of each layer is preferably 50 nm or less. Further, it is effective not only to provide one type of each of the carrier supply layer and the carrier transport layer, but also to alternately stack a plurality of carrier supply layers and a plurality of carrier transport layers.

Even in the transparent conductive film having such a laminated structure, grain growth of electrons in each layer is achieved by crystal growth so that a specific crystal plane in each layer is preferentially oriented with respect to the substrate surface. Since the scattering due to γ is reduced, the effect of increasing the mobility by stacking is increased. When growing crystals so that a specific crystal plane of each laminated layer is preferentially oriented with respect to the substrate surface, use a single crystal such as magnesium oxide or strontium titanate as the substrate as described above. Is effective. Furthermore, the crystal grain size of each layer can be increased by forming the carrier supply layer and the carrier transport layer by sputtering using a gas containing xenon or a gas containing krypton.

[0013]

According to the present invention, due to the effect of reducing carrier scattering due to grain boundaries, impurity elements, oxygen vacancies, etc., even at a temperature condition of 250 ° C. or lower at which sufficient mobility cannot be obtained by the known method. A transparent conductive film having low resistance can be manufactured. By using the low-resistance transparent conductive film of the present invention as a pixel electrode or wiring material of a liquid crystal display device, the thickness or width of the electrode or wiring can be reduced, so that the pixel size can be reduced, and thus a high-definition display can be obtained. The device can be easily manufactured. Further, since such a low-resistance transparent conductive film can be used as a source electrode or a drain electrode forming a thin film transistor used for driving an active matrix type liquid crystal display device, the process of manufacturing the thin film transistor is simplified. The cost can be greatly reduced.

[0014]

EXAMPLES The present invention will be described below with reference to examples.
The present invention is not limited to this.

(Example 1) 1) A glass substrate having an optically polished surface was mounted in an ion beam sputtering apparatus, and the glass substrate was evacuated to a pressure of 1 × 10 ^-6 Torr. In this device, In ₂ O ₃ -10 wt% SnO ₂
A sintered body is attached as a target. While maintaining the glass substrate at 250 ° C, 2x Ar / O ₂ mixed gas
An ITO film having a thickness of 100 nm was formed by sputtering under the conditions of a beam voltage of 1 KV and a beam current of 80 mA while introducing a pressure of 10 ⁻⁴ Torr.

2) Similar to 1), an ITO film was formed on the glass substrate by the ion beam sputtering method. At this time, the sputtering gas was a Xe / O ₂ mixed gas, and the other conditions were the same as in 1).

3) Similar to 1), an ITO film was formed on the glass substrate by the ion beam sputtering method. At this time, the sputtering gas was a Kr / O ₂ mixed gas, and the other conditions were the same as in 1).

4) I formed under the conditions shown in 1) to 3)
The specific resistance, carrier density, and mobility of the TO film were investigated. Further, the crystalline state of these ITO films was examined by X-ray diffraction method. The results are summarized in Table 1. It can be seen that the mobility increases as the sputtering gas is changed from Ar to Kr to Xe. At the same time, as the sputtering gas is changed from Ar to Kr to Xe, the transfer carrier density is also increased. As a result, the specific resistance decreases as the sputtering gas is changed from Ar to Kr to Xe. Further, as the order of Ar → Kr → Xe is changed, the crystal grain size of the formed ITO film becomes larger and the lattice constant becomes smaller. It is considered that the oxygen deficiency is increased because the lattice constant is decreased. From the above, by changing the sputtering gas from Ar → Kr → Xe, I
It has been found that the crystal grains of the TO film become coarse, and at the same time, the oxygen deficiency in the ITO film increases, resulting in a reduction in the specific resistance.

[0019]

[Table 1]

(Example 2) 1) A glass substrate whose surface was optically polished was mounted in a DC magnetron sputtering apparatus, and the glass substrate was evacuated to a pressure of 1 × 10 ^-6 Torr. In this device, In ₂ O ₃ -10 wt% Sn
An O ₂ sintered body was attached as a target. While maintaining the glass substrate at 250 ° C., add 5 × 1 Ar / O ₂ mixed gas.
An ITO film having a thickness of 100 nm was formed by introducing a pressure of 0 ^-3 Torr and using a sputtering power of DC 320 W.

2) In the same manner as 1), an ITO film was formed on the glass substrate by the DC magnetron sputtering method. At this time, the sputtering gas was a Xe / O ₂ mixed gas, and the other conditions were the same as in 1).

3) I formed under the conditions shown in 1) and 2)
The specific resistance, carrier density and mobility of the TO film were investigated. Moreover, the surface morphology of these was examined by a scanning electron microscope. The results are shown in Table 2. Sputtering gas is Ar
The crystal grain of the film was increased by changing from Xe to Xe. In addition, the mobility has increased correspondingly, and as a result, the specific resistance has decreased. The same effects as in Example 1 were also observed with the DC sputtering method.

[0023]

[Table 2]

(Embodiment 3) A substrate having a (100) surface of YSZ single crystal optically polished and a glass substrate having a surface optically polished are mounted in an ion beam sputtering apparatus, respectively, and exhausted to a pressure of 1 × 10 ⁻⁶ Torr. did. Wearing the _{In 2} O _{3 -10wt%} SnO 2 sintered body as the target in this device. While maintaining these substrates at 250 ° C., an Ar / O ₂ mixed gas was introduced up to a pressure of 2 × 10 ⁻⁴ Torr to form an ITO film having a thickness of 100 nm under the conditions of a beam voltage of 1 KV and a beam current of 80 mA. .

The specific resistance, carrier density and mobility of the formed ITO film were measured. In addition, their crystalline state was examined by an X-ray diffraction method. The results are summarized in Table 3.
The ITO film on the glass substrate was non-oriented. The crystallinity of the ITO film when the YSZ single crystal was used as the substrate was better than that of the glass substrate, and the (100) plane of the IT0 film was oriented. The carrier density did not differ significantly depending on the substrate and orientation. However, there was a large dependence of the mobility on the substrate. In the YSZ single crystal substrate, the mobility increased due to the (100) orientation of the ITO film, and as a result, the specific resistance decreased.

[0026]

[Table 3]

Example 4 1) A magnesium oxide single crystal (100) surface optically polished substrate and a surface optically polished glass substrate were mounted in an ion beam sputtering apparatus, and 1 × 10 5
Evacuated to a pressure of ^-6 Torr. In this device, In ₂ O ₃ -1
A 0 wt% SnO ₂ sintered body was mounted as a target.
While maintaining these substrates at 250 ° C., a mixed gas of Xe / O ₂ was introduced up to a pressure of 2 × 10 ⁻⁴ Torr, and while rotating the substrates, ITO having a thickness of 100 nm was formed under the conditions of a beam voltage of 1 KV and a beam current of 80 mA. A film was formed. This film forming condition is referred to as condition 1.

2) Magnesium oxide single crystal (100)
An ITO film was formed on the substrate and the glass substrate whose surfaces were optically polished by the ion beam sputtering method. On this occasion,
The substrate temperature, Xe / O ₂ mixed gas pressure, beam voltage, and beam current conditions were the same as in 1), and the substrate was kept stationary during film formation. This film forming condition is set to Condition 2.

3) The specific resistance, carrier density and mobility of the ITO film formed in 1) and 2) were measured. In addition, their crystalline state was examined by an X-ray diffraction method. The results are summarized in Table 4. The ITO film on the glass substrate is non-oriented under the condition 1, but has a strong (100) orientation under the condition 2. On the other hand, when the magnesium oxide single crystal is used as the substrate, the crystallinity of the film is much better than that of the glass substrate. Under condition 1, the (111) orientation is strong (40
Almost no diffraction peak of (0) appears, but (100) orientation was strong under the condition 2. The carrier density does not differ much depending on the substrate and orientation. But,
A large substrate dependence appeared in the mobility. In the glass substrate, the mobility is increased due to the appearance of (100) orientation. When a magnesium oxide single crystal was used as the substrate, the mobility was higher in the (100) orientation than in the (111) orientation. From the above results, it was found that the (100) orientation is effective for increasing the mobility.

[0030]

[Table 4]

(Embodiment 5) 1) A glass substrate having an optically polished surface is mounted in the same DC magnetron sputtering apparatus as in Embodiment 2 and 1 × 1.
Evacuated to a pressure of 0 ^-6 Torr. Platinum and I
An n ₂ O ₃ -10 wt% SnO ₂ sintered body was mounted as a target so that a platinum film and an ITO film could be formed without breaking the vacuum state. Glass substrate at 200 ℃
Set the target to platinum while holding at
₂ Mixed gas was introduced up to the pressure of 5 × 10 ^-3 Torr, and direct current 1
First, a platinum film having a thickness of 5 nm was formed with a sputtering power of 00W.

2) Following 1), the target is In
Instead of the ₂ O ₃ -5 wt% SnO ₂ sintered body, an ITO film having a thickness of 100 nm was formed on the platinum film with a DC 320 W sputtering power.

3) The transparent conductive film shown in FIG. 5 was formed by the above steps 1) to 2). From the X-ray diffraction of this film, it was found that the ITO film on the platinum film was (100) oriented. The specific resistance measured on the surface of this laminated film was 0.90 × 10 ⁻⁴ Ωcm. The spectral characteristics of the transmittance of this laminated film are shown in FIG. Wavelength 350nm to 800nm
Showed a transmittance of 85% or more in the visible light region. Since the platinum layer is thin, it does not adversely affect the transmittance.

(Example 6) 1) A glass substrate having an optically polished surface was mounted in an ion beam sputtering apparatus, and the glass substrate was evacuated to a pressure of 1 × 10 ^-6 Torr. In this device, In ₂ O ₃ -10 wt% SnO ₂
A sintered body and an In ₂ O ₃ -5 wt% SnO ₂ sintered body were attached as targets, and two types of I were used without breaking the vacuum state.
The TO film can be formed. While maintaining this glass substrate at 250 ° C., a mixed gas of Xe / O ₂ was introduced up to a pressure of 2 × 10 ⁻⁴ Torr, a beam voltage of 1 KV,
Under the conditions of beam current _{80mA, In 2 O 3 -5wt%} Sn
An ITO film having a thickness of 100 nm was formed using the O ₂ sintered body.

2) An ITO film was formed on a glass substrate by an ion beam sputtering method using an In ₂ O ₃ -10 wt% SnO ₂ sintered body as a target. At this time, the same conditions as in 1) were used except for the target used.

3) The specific resistance, carrier density, mobility and Sn concentration of the ITO film formed by 1) and 2) were measured. The results are summarized in Table 5. 5wt% SnO ₂
The ITO film formed with the sintered body as the target is 10 wt.
The carrier density is lower but the mobility is higher than when the target is a% SnO ₂ sintered body.

[0037]

[Table 5]

4) In the same manner as 1), a target was an In ₂ O ₃ -10 wt% SnO ₂ sintered body and a 50 nm ITO film was formed by an ion beam sputtering method. At this time, the conditions other than the target were the same as those in 1). Next, the target was In ₂ O ₃ -5w without breaking the vacuum.
Replaced with t% SnO ₂ sintered body, 50 nm IT on this film
An O film was formed. As described above, the laminated ITO shown in FIG.
A film was formed. The specific resistance of this film is 0.85 × 10 ^-4 Ωcm
Therefore, the effect of lowering the specific resistance was obtained as compared with the case of each single layer.

Example 7 A substrate obtained by optically polishing the (100) plane of a magnesium oxide single crystal was mounted in an ion beam sputtering apparatus, and the substrate was evacuated to a pressure of 1 × 10 ^-6 Torr. In this apparatus, an In ₂ O ₃ -10 wt% SnO ₂ sintered body and an In ₂ O ₃ -5 wt% SnO ₂ sintered body were mounted as targets, and two types of ITO were used without breaking the vacuum state.
It was made possible to form a film. Substrate at 250 ° C
Xe / O ₂ mixed gas at 2 × 10 ^-4 Torr
Beam pressure 1KV, beam current 80
The In ₂ O ₃ -10 wt% SnO ₂ sintered body and the In ₂ O ₃ -5 wt% SnO ₂ sintered body were alternately used under the condition of mA,
An ITO multilayer film as shown in FIG. 8 was formed. that time,
The thickness of one layer was 10 nm, and the total number of layers was 10. The specific resistance of this multilayer film was 0.75 × 10 ⁻⁴ Ωcm.

(Embodiment 8) An active matrix type display device having the pixel structure shown in FIG. 10 was produced by using the laminated transparent conductive film shown in Embodiment 1 as a pixel electrode. In the pixel structure of FIG. 10, since the specific resistance of the pixel electrode 11 is reduced by about 40% as compared with the conventional material,
The width of the pixel electrode could be reduced accordingly. As a result, the size of one pixel can be reduced by about 10% as compared with the conventional type. As a result, it is possible to increase the pixel density in the display device having the same display area as compared with the conventional type.

[0041]

EFFECTS OF THE INVENTION According to the present invention, the scattering of carriers in the crystal grains or in the crystal grain boundaries is reduced, and the mobility is improved.
A transparent conductive film showing a specific resistance of 10 ⁻⁴ Ωcm or less could be obtained.

[Brief description of drawings]

FIG. 1 shows a cross-sectional view of a transparent conductive film according to an example of the present invention.

FIG. 2 shows a cross-sectional view of a laminated transparent conductive film according to an example of the present invention.

FIG. 3 shows a sectional view of a laminated transparent conductive film according to another embodiment of the present invention.

FIG. 4 shows a cross-sectional view of a transparent conductive film formed on a single crystal substrate according to an example of the present invention and having a specific crystal orientation with respect to the substrate.

FIG. 5 is a thickness 15 of a laminated layer on a substrate according to an embodiment of the present invention.
The cross-sectional view of the transparent conductive film which has a specific crystal orientation formed on the metal layer of nm or less is shown.

FIG. 6 is a cross-sectional view of a transparent conductive film having a specific crystal orientation, in which a layer made of a metal and having a thickness of 15 nm or less is provided in a part between the substrate and the transparent conductive film according to the example of the present invention.

FIG. 7 is a cross-sectional view of a laminated film according to an example of the present invention, in which a metal layer having a thickness of 15 nm or less is provided between an insulating film layer formed on a substrate and a transparent conductive film.

FIG. 8 is a cross-sectional view of a transparent conductive film in which a transparent conductive film having a high mobility and a low carrier density and a transparent conductive film having a low mobility and a high carrier density are alternately stacked on a substrate according to an example of the present invention.

9 is a transmission spectrum of the transparent conductive film of Example 5. FIG.

FIG. 10 is a schematic view of a liquid crystal display device using the low resistance transparent conductive film manufactured in Example 8 as a pixel electrode.

[Explanation of symbols]

1 ... Transparent conductive film having specific crystal orientation, 2 ... Substrate,
3 ... Layer of transparent conductive film having high mobility and low carrier density, 4 ... Layer of transparent conductive film having low mobility and high carrier density, 5 ... Single crystal substrate, 6 ... Thickness 15n made of metal
m or less layer, 7 ... Insulating film layer, 11 ... Pixel electrode (ITO
Film), 12 ... Source electrode, 13 ... Drain electrode, 14 ...
Amorphous silicon film, 15 ... Molybdenum layer, 16 ...
Silicon nitride film, 17 ... Gate electrode (chrome), 18 ... Gate terminal, 19 ... Protective layer.

Claims (15)

[Claims] 1. Containing one or more cations and oxygen,
In a thin film having a transmittance of 70% or more for light having a wavelength of 500 nm to 800 nm and a specific resistance of 1 × 10 ^-2 Ωcm or less, the thin film is formed by sputtering using a gas containing xenon. And a transparent conductive film. 2. Containing one or more cations and oxygen,
In a thin film having a transmittance of 70% or more for light having a wavelength of 500 nm to 800 nm and a specific resistance of 1 × 10 ^-2 Ωcm or less, the thin film is formed by sputtering using a gas containing krypton. And a transparent conductive film. 3. A transparent conductive film according to claim 1, wherein the thin film is formed by ion beam sputtering. 4. The transparent conductive film according to claim 1, wherein the thin film is formed by direct current or high frequency sputtering. 5. Containing one or more cations and oxygen,
In a thin film having a transmittance of 70% or more for light having a wavelength of 500 nm to 800 nm and a specific resistance of 1 × 10 ^-2 Ωcm or less, a specific crystal plane of the thin film is preferentially oriented with respect to the substrate surface. A transparent conductive film characterized in that 6. The transparent conductive film according to claim 1, wherein a specific crystal plane of the thin film is preferentially oriented with respect to the substrate surface. 7. The transparent film according to claim 5, wherein the thin film exhibits cubic crystal symmetry, and the (100) plane of the thin film is preferentially oriented with respect to the substrate surface. Conductive film. 8. Containing one or more cations and oxygen,
In a thin film having a transmittance of 70% or more for light with a wavelength of 500 nm to 800 nm and a specific resistance of 1 × 10 ^-2 Ωcm or less, the thin film is composed of two or more layers having different carrier densities or mobilities. A transparent conductive film. 9. The transparent film according to claim 8, wherein the thin film is composed of two layers, and one layer forming the thin film has a lower carrier density and a higher mobility than the other layers forming the thin film. Conductive film. 10. The thin film according to claim 8, wherein the thin film is composed of two types of layers having different carrier densities or mobilities,
A transparent conductive film, wherein one layer has a lower carrier density and a higher mobility than the other layer, and the two types of layers are alternately laminated. 11. A transparent conductive film according to claim 8, wherein a specific crystal plane of each layer constituting the thin film is preferentially oriented with respect to a substrate surface. 12. The layer according to claim 8, wherein each layer constituting the thin film exhibits cubic crystal symmetry, and the (100) plane of each layer is preferentially oriented with respect to the substrate surface. A transparent conductive film characterized by the above. 13. The transparent conductive film according to claim 12, wherein the thin film is formed by sputtering using a gas containing xenon or a gas containing krypton. 14. A display device comprising the transparent conductive film according to claim 1 as a pixel electrode or a wiring material. 15. An active matrix type liquid crystal display device equipped with a thin film transistor using the transparent conductive film according to claim 1 for either a source electrode or a drain electrode.