JP2000026119A - Article having transparent electrically conductive oxide thin film and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture the article having excellent electric conductivity and superior transparency throughout the entire visible ray region by providing the article with a transparent conductive oxide thin film which is formed on a substrate with a laser ablation method using a zinc-indium based oxide as a material of a target. SOLUTION: In the manufacture of this article, a transparent conductive oxide thin film is formed on at least one surface of a substrate in at least a part of the surface by a laser ablation method using a zinc-indium based oxide target which consists of a material represented by the formula ZnxMyInzO(x+3y/2+3z/2) (M is at least any one element of Al and Ga; the ratio x:y is 0.2:1 to 8:1; and the ratio z:y is 0.4:1 to 1.4:1), wherein: the formation of the thin film is performed in an oxygen atmosphere having an about 1×10-6 to 100 Pa oxygen partial pressure; also as the laser, a laser beam of any wavelength in the range of the ultraviolet region to the infrared region can be used and the laser beam intensity used at the time of performing laser beam irradiation is about 0.0001 to 1,000 J/cm2.pulse; and as a material of the substrate, any organic or inorganic material can be used and the substrate temp. used is about 0 to 1,000 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an article having a zinc-indium-based conductive oxide thin film and a method for producing the conductive oxide thin film of the article by a laser ablation method.

[0002] The thin film of the article of the present invention not only has excellent electric conductivity, but also has excellent transparency in the entire visible range, so that it can be used as a substrate for an organic EL or a color filter for a display requiring light transmission. It is particularly useful as a substrate for a battery or an electrode for a solar cell. Further, the production method of the present invention is a method capable of producing a crystalline zinc-indium-based conductive oxide thin film having little composition deviation from the oxide used as the target and having c-axis orientation.

[0003]

2. Description of the Related Art So-called transparent conductive materials which are transparent in the visible light region and have electrical conductivity are known as liquid crystal displays, ELs.
It is used as a transparent electrode of various panel-type displays such as displays and solar cells.

As a transparent conductive material, a metal oxide semiconductor is generally used, and various proposals have been made, including tin-doped indium oxide (ITO). In particular, ITO has been frequently used as a transparent electrode for panel-type displays. However, in recent years, panel displays have become larger and have higher definition, and the resistivity of ITO is often insufficient. That is, in a large-sized display, the distance between the ends of the transparent electrode becomes long, so that the resistance value between the end points is increased. In addition, higher definition increases the resistance value between the end points in order to reduce the width of the electrode. Generally, in order to reduce the resistance value between the end points, the thickness of the electrode may be increased. However, in the case of the ITO electrode, if the thickness is increased, the electrode is colored yellow and the transparency is impaired. This is because ITO has a phenomenon in which light having a wavelength of 450 nm or less is absorbed by indirect transition. When the thickness of the electrode is small, this is hardly noticeable. However, as the thickness of the electrodes increases, they become clearly recognized by the human eye. For this reason, it has not been possible to obtain a large-sized or high-definition transparent electrode satisfying both transparency and electric conductivity in ITO conventionally used as a material for a transparent electrode. For these reasons, development of a material that is transparent and has high conductivity even in the short wavelength region of 450 nm or less in the visible region has been an issue.

[0005] The present inventors have YbFe2Od structure, general formula _{Zn x M y In z O (} x + 3y / 2 + 3z / 2) - d ( wherein, M is one of aluminum and gallium At least one element, the ratio (x: y) is in the range of 0.2: 1 to 8: 1, the ratio (z: y) is in the range of 0.4 to 1.4: 1, and the oxygen deficiency amount d
Is greater than 0 and in the range of 1x10 ^-1 times (x + 3y / 2 + 3z / 2)
And an oxide having a similar basic structure were compared with the ITO thin film (containing 5 mol% of Sn with respect to In),
It has been found that this is a novel transparent conductive material having high transparency in the short wavelength region of 0 nm or less and having the same or higher electric conductivity (for example, see Japanese Patent Application Laid-Open No. 8-295514).

[0006] the general formula _{Zn x M y In z O (} x + 3y / 2 + 3z / 2) oxide represented by _-d is used, for example, the electrode as a transparent conductive thin film. Such a thin film is usually prepared to have a thickness of several tens to several hundreds of nm, but even such a thin film is required to exhibit high electric conductivity. Therefore, the present inventors have found that a thin film made of an oxide represented by the general formula Zn _x M _y In _z O _{(x + 3y / 2 + 3z / 2) -d} , An article that can be used for a conductive oxide thin film, a display having such a conductive oxide thin film, an EL display, a solar cell, and the like, was filed separately (Japanese Patent Application Laid-Open No. 10-45496).

Furthermore the general formula _{Zn x M y In z O (} x + 3y / 2 + 3z / 2) on the orientation control board conductive oxide thin film comprising an oxide represented by _-d or orientation of the substrate By using an orientation control substrate or an orientation control film that is easy to obtain or produce in place of ZnO and that has an article on the control film, an article that can have a larger area is provided. Japanese Patent Application 10
-18479).

Generally, such a transparent conductive thin film can be manufactured by a thin film method. Representative examples of the thin film method include a CVD method, a spray method, a vacuum evaporation method, an ion plating method, an MBE method, a sputtering method, a sol-gel method, and a spray pyrolysis method. Further, examples of the CVD method include a thermal CVD method, a plasma CVD method, an MOCVD method, and a photo CVD method. Chemical methods such as the CVD method and the spray method have simpler facilities than physical methods such as the vacuum evaporation method and the sputtering method and are suitable for manufacturing large substrates. Furthermore, when a drying or firing step is performed for accelerating the reaction or stabilizing the characteristics, a heat treatment at 350 to 500 ° C. is required, so that it is suitable for directly manufacturing on a glass substrate.

The physical method is to increase the substrate temperature during film formation by 150
Since the temperature can be as low as 300 ° C., it is suitable not only when a thin film is manufactured directly on a glass substrate, but also when it is manufactured on various underlayers. Among them, the sputtering method is particularly excellent in terms of high productivity and uniform deposition on a large-area substrate.

[0010]

However, the above-mentioned prior art has the following problems. In the sputtering method, since the target is sputtered by plasma, the composition is liable to change due to a difference in sputtering rate depending on the element. For example, when manufacturing an InGaZnO ₄ thin film using a sputtering method, the composition of the sputtering target is changed to InGaZn
O ₄ and was of a can not be obtained a thin film of interest. A thin film of the InGaZnO ₄ composition can be obtained only by forming a film by using an In _1.79 Ga _1.00 Zn _3.98 O _y sintered body as a sputtering target and further controlling the oxygen partial pressure in the reaction system. This is because the sputtering rates of Zn and In components are smaller than that of Ga. Further, the thin film produced by the sputtering method has a non-uniform composition of the particles sputtered as described above, and tends to cause non-uniform grain growth, and therefore, the particle size distribution width is large. In that case, the thin film produced by the sputtering method has problems that the single crystallinity is low, the number of lattice defects is large, and the visible light transmittance at 450 to 800 nm is relatively low.

Therefore, an object of the present invention is to provide a compound having high single crystallinity.
With few lattice defects, low surface resistivity, and 450 ~ 8
An object of the present invention is to provide an article having a zinc-indium oxide-based conductive thin film having excellent visible light transmittance at 00 nm. Further, an object of the present invention is to provide a zinc-indium-based alloy which is easy to manufacture because the thin film composition is in good agreement with the target composition, has a low surface resistivity, and has an excellent visible light transmittance at 450 to 800 nm including the substrate. An object of the present invention is to provide a method for manufacturing an article having an oxide-based conductive thin film.

[0012]

SUMMARY OF THE INVENTION The present invention comprises forming a conductive oxide thin film on at least a part of at least one surface of a substrate by a laser ablation method using a zinc-indium oxide as a target. The present invention relates to a method for manufacturing an article having a conductive oxide thin film. Further, the present invention relates to an article having a conductive oxide thin film formed by the above-mentioned manufacturing method.

[0013]Production method  The method for producing an article having the conductive oxide thin film of the present invention includes:
Laser targeting zinc-indium oxide
-At least one side of the substrate by ablation method
Forming a conductive oxide thin film on at least a part of
Including. In particular, the production method of the present invention
Laser ablation method for forming oxide thin film
It is characterized by the following.

The laser ablation method is a method of synthesizing a thin film through an ablation process using a laser beam, and has recently been receiving attention as an alternative to the sputtering method. Ablation is a phenomenon in which both rapid heat generation and photochemical reaction occur on the surface of an object irradiated with strong light energy, and components explosively vaporize. As a feature of film formation by laser ablation,
(1) Easy to synthesize a high melting point thin film, (2) Film formation is possible in a clean atmosphere that does not require a raw material heating source, (3) Wide variation of gas partial pressure in the film formation chamber, (4) Target and (5) The film composition can be digitally controlled, and the like.

In the laser ablation method, a high-temperature superconductor oxide thin film represented by yttrium / barium / copper oxide (abbreviated as YBCO) and a dielectric oxide thin film such as strontium / titanium oxide (SrTiO ₃ ) are manufactured. This is one of the thin film manufacturing methods used for about 10 years.

In the laser ablation method, the degree of pressure reduction is lower than that of the sputtering method, and the oxygen partial pressure in the reaction system can be increased. It is advantageous. High-temperature superconductors, especially YBCO, have a weak ability to retain oxygen and tend to be short of carriers. Usually, a post-treatment called annealing, in which the sample is gently heated in oxygen, is added, but a process in which the reaction system completes thinning and control of the amount of oxygen is superior.

Considering that all oxide crystals can be decomposed into a layer lattice (molecular layer) of one atomic layer to several atomic layers,
The development of techniques for reconstructing molecular layers is a means of systematic search for new materials and new functions.

In recent years, there have been reports on the production of indium oxide (IO) thin films and ITO thin films which are transparent oxide conductors by laser ablation. (For example, IO:
EJTarsa, JHEnglish, JSSpeck, Appl.Phys.Let
t. 62 (1993) 2332. ITO: JPZheng, HSKwok, Thin S
olid Films 232 (1993) 99.) However, there is no production example of a transparent conductive thin film other than IO and ITO.
_{n x M y In z O (} x + 3y / 2 + 3z / 2) Film Formation Example has not been reported with regard _-d.

The present inventors prototyped an InGaZnO ₄ thin film by a laser ablation method. As a result, the composition deviation of the thin film was within 5% of the target composition, and it was found that the laser ablation method could provide a thin film having higher crystallinity than a conventional method such as a sputtering method.
Furthermore, the thin film produced by the laser ablation method has a low surface resistivity,
The visible light transmittance in nm was also found to be high, and the invention was completed based on such knowledge. In the laser ablation method, a limited surface is instantaneously vaporized.
It is considered that even when a metal oxide having a high vapor pressure such as GaZnO ₄ , for example, a composite oxide thin film of zinc oxide is manufactured, a thin film having no composition deviation such as a sputtering method can be manufactured.

In the production method of the present invention, a zinc-indium oxide is used as a target. The zinc-indium oxide used as the target may be an oxide further containing aluminum and / or gallium. The zinc-indium oxide target,
For example, it can be an oxide having the following composition. General formula Zn _x M _y In _z O _{(x + 3y / 2 + 3z / 2)} (where M is at least one element of aluminum and gallium, and the ratio (x: y) is 0.2: 1 to 8) : 1 and the ratio (z: y) is in the range of 0.4 to 1.4: 1). General formula Zn _x M _y In _z O _{(x + 3y / 2 + 3z / 2)} (where M is at least one element of aluminum and gallium, and the ratio (x: y) is 0.2: 1 to 8) : 1 and the ratio (z: y) is in the range of 0.4 to 1.4: 1), and at least a part of at least one element of Zn, M and In is replaced with another element. Elements substituted with Zn have a valence of 2 or more, and elements substituted with M and In have a valence of
An oxide (2) having three or more valences.

In the oxide (2), a carrier electron is injected into a conduction band by substituting a part of a metal ion with another metal ion in addition to introducing an oxygen vacancy, thereby exhibiting conductivity. Can be.

Zn is a divalent element, and an element which can be substituted with Zn is an element having a valence of 2 or more. Higher valence elements can provide greater carrier injection with less substitution. The valence of the replaceable element is usually divalent, trivalent, tetravalent, pentavalent or hexavalent. Examples of the element having a valence of 2 or more include Be, Mg, Ca, and S.
r, Ba, Cd, Al, Si, Sc, Ti, V, Cr,
Mn, Fe, Co, Ni, Zn, Ga, Ge, Y, Z
r, Nb, Mo, Tc, Ru, Rh, Pd, In, S
n, Sb, La, Ce, Pr, Nd, Pm, Sm, E
u, Gd, Tb, Dy, Ho, Er, Tm, Yb, L
u, Hf, Ta, W, Re, Os, Ir, Pt, Tl,
Pb, Bi, and Po can be mentioned.

A1, Ga, and In represented by M are trivalent elements, and the elements that can be substituted with these are elements having a valence of three or more. Higher valence elements can provide greater carrier injection with less substitution. The valence of the replaceable element is usually trivalent, tetravalent, pentavalent or hexavalent. Examples of the element having a valence of 3 or more include Al, Si, Sc, Ti, V, Cr, Mn, and F.
e, Co, Ni, Ga, Ge, Y, Zr, Nb, Mo,
Tc, Ru, Rh, Pd, In, Sn, Sb, La, C
e, Pr, Nd, Pm, Sm, Eu, Gd, Tb, D
y, Ho, Er, Tm, Yb, Lu, Hf, Ta, W,
Re, Os, Ir, Pt, Tl, Pb, Bi and Po can be mentioned. Some of the elements to be substituted have a property of absorbing light in the visible region. Therefore, the substitution amount of the substitution element is such that the average transmittance of light in the visible region is 70% or more, preferably 80% or more, and more preferably 9% or more.
It is appropriate to select so as to be 0% or more.

The oxide may or may not have oxygen deficiency. In the manufacturing method of the present invention, the amount of oxygen deficiency d in the formed thin film can be controlled by controlling the substrate temperature, the oxygen partial pressure in the atmosphere, and the like, as described later. In the production method of the present invention,
The composition of the formed thin film hardly changes depending on the density of the target. However, in consideration of damage to the target due to laser pulse irradiation, the oxide used as the target has a relative density of preferably 40% or more, more preferably 70% or more. In addition, the composition of the formed thin film has little deviation from the target,
Since it is 5%, the target composition can be the same as the desired thin film composition. However, the target composition can be changed if necessary.

In the manufacturing method of the present invention, the laser abrasion
Of conductive oxide thin film by oxygen method in oxygen atmosphere
To form a thin film with excellent crystallinity and transparency
It is appropriate from the viewpoint that it can be performed. Acid in the atmosphere
The elementary partial pressure is, for example, 1 × 10 ^-6~ 100Pa range,
Preferably 1 × 10^-3In the range of ~ 1Pa
Wear. Control of the oxygen partial pressure in the thin film forming apparatus is usually performed by mass
Flow pure oxygen gas through the flow controller
Can be controlled by laser ablation.
What can be done with the radical gun installed in the device is apparent
This is appropriate from the viewpoint of increasing the oxygen pressure of the oil. In addition,
A cal gun generates activated gas molecules and irradiates the substrate
It is a device for performing.

The laser used in the laser ablation method of the production method of the present invention may be any wavelength from the ultraviolet region to the infrared region, that is, 0.19 to 11 μm, preferably 0.19 to 11 μm.
0.3 μm is possible, and either continuous oscillation or pulse oscillation can be employed. Laser intensity at the time of laser irradiation, 0.0001~1000J / cm ² · pulse, and desirably 0.1~100J / cm ² · pulse. Substrate temperature is 0 to 1000
° C, desirably 25 to 600 ° C.

In the manufacturing method of the present invention, any of an organic material and an inorganic material may be used as the thin film deposition substrate. In accordance with the substrate temperature determined in consideration of the physical properties of the thin film, the substrate material can be appropriately selected from materials having a substrate temperature equal to or lower than the melting point of the substrate. According to the manufacturing method of the present invention, a uniform thin film can be manufactured regardless of the type of the substrate material. For example, an inorganic material such as glass or an organic material substrate such as a resin can be used. In particular, when used for electrodes, these substrates are suitably transparent substrates.

Glass substrates are often used for liquid crystal displays and the like. It is preferable to use glass having high transparency in the visible region and excellent flatness. Examples of the resin substrate include a polyester substrate and a PMMA (polymethyl methacrylate) substrate. Many uses of resin substrates are being studied, taking advantage of being lighter, thinner, and more flexible in shape than glass substrates. It is preferable to use a color liquid crystal display in consideration of workability, impact resistance, durability, suitability for an assembly process, and the like, in addition to high transparency in a visible region and excellent flatness.

According to the manufacturing method of the present invention, a thin film having few defects of metal oxides can be manufactured, so that the crystallinity is high. Is also excellent. Also,
Oxygen deficiency, that is, the carrier concentration can be controlled by adjusting the oxygen pressure during film formation, and the amount of carrier electrons is 1 × 1
It is appropriate to control so as to be in the range of 0 ¹⁸ / cm ³ to 1 × 10 ²² / cm ³ . Note that carriers can be further introduced by performing an annealing treatment and a heat reduction treatment after film formation as in the case of the sputtering method.

In the manufacturing method of the present invention, a desired thin film can be formed by heteroepitaxially growing a thin film by alternately forming two or more targets by laser ablation.

As mentioned above, all oxide crystals are 1
Considering that the atomic layer can be decomposed into a layered lattice (molecular layer) of several atomic layers, the development of a technology for reconstructing the molecular layer is a means of systematic search for new substances and new functions. For example, InGaZnO ₄
Is a kind of superlattice composed of three kinds of atomic layers. Therefore, if we develop a technology to accurately stack molecular layers while taking into account the electrostatic interaction and lattice size consistency between In ₂ O ₃ and (ZnGa) O _2.5 layers, it is possible to replace some of the atoms Carrier generation is promoted (valence control), and the carrier generation layer and the carrier transfer layer can be separated. The conductive carriers generated by the valence control flow into the carrier moving layer without being scattered by the impurity ions, and electric conduction occurs in the carrier moving layer. Furthermore, by changing the combination of layers, the possibility of a new substance can be systematically examined. Further, the development of a thin film deposition technique for each atomic layer or molecular layer of an oxide enables synthesis of an artificially designed crystal lattice and search for new physical properties and phenomena thereby.

In the manufacturing method of the present invention, a thin film can be heteroepitaxially grown by alternately forming two or more targets by laser ablation by laser ablation. Thereby, deposition can be performed for each atomic layer or molecular layer, and so-called atomic layer growth or molecular layer growth can be performed. For example, InGa
When a ZnO ₄ thin film is formed, heteroepitaxially grown InGaZn is formed by alternately performing laser ablation film formation using two targets of In ₂ O ₃ and (ZnGa) O _2.5.
O ₄ thin films can be produced. In particular, in the case of InGaZnO ₄ , the crystal structure can be divided into a moving layer for carrier electrons and a generating layer for carrier electrons (for example, Jpn.
J. Appl. Phys. Vol. 34 (1995) pp. L1550−L1552 Par
t 2, No. 11B, 15 November 1995), the manufacturing method using the laser ablation method of the present invention is more advantageous than other thin film manufacturing methods. The control of the atomic layer or molecular layer for heteroepitaxial growth can be easily controlled by the laser irradiation time, oxygen pressure, and laser output. In addition, by appropriately selecting the composition and combination of the targets, various types of oxide thin films can be formed.

In the manufacturing method of the present invention, cations can be implanted into the conductive oxide thin film formed by the laser ablation method. By injecting cations, carrier electrons are injected into the conduction band, so that conductivity can be exhibited.

The cations to be implanted are not particularly limited as long as they can form a solid solution without destroying the crystal structure of the oxide. However, ions having a small ionic radius tend to form a solid solution in the crystal lattice, and the larger the ionic radius, the more likely the crystal structure is broken. As the above cations, for example, H, Li, Be, B,
C, Na, Mg, Al, Si, K, Ca, Sc, Ti,
V, Cr, Mn, Fe, Co, Ni, Cu, Zn, G
a, Ge, Y, Zr, Nb, Mo, Tc, Ru, Rh,
Pd, Ag, Cd, In, Sn, Sb, Cs, Ba, L
a, Ce, Pr, Nd, Pm, Sm, Eu, Gd, T
b, Dy, Ho, Er, Tm, Yb, Lu, Hf, T
a, W, Re, Os, Ir, Pt, Au, Hg, Tl,
Pb and Bi can be mentioned.

For ion implantation, ion implantation is used. In the ion implantation method, a method used for manufacturing a super-large-scale integrated circuit or the like can be used as it is as a means for introducing impurities into a solid. This can be performed by ionizing the cation element to be implanted, accelerating it to tens of keV or more, and implanting it into an oxide. The amount of cation implantation is such that the amount of carrier electrons is 1 × 10 ¹⁸ / cm ³ to 1 × 10
The range of ²² / cm ³ can be appropriately selected in consideration of the oxygen deficiency d.

According to the manufacturing method of the present invention, the deviation between the target composition and the film composition is within 5%, the surface resistivity is low, and the visible light transmittance at 450 to 800 nm including the substrate is high. it can be produced _{x M y in z O (x} + 3y / 2 + 3z / 2) article having a transparent conductive oxide thin film comprising an oxide represented by _-d.

[0037]Article having conductive oxide thin film  The article of the present invention is obtained by the production method of the present invention.
Conductive on at least a part of at least one surface of the substrate
An article having a conductive oxide thin film, wherein the conductive oxide
The thin film is a zinc-indium oxide, and the laser
It is formed by an ablation method. Above
The lead-indium oxide is made of aluminum and / or gas.
It may further include lium. Aluminum and steel
Aluminum and gallium ratio if coexisting
Is not particularly limited. However, the ratio of aluminum increases
Then, the crystallization temperature tends to increase. Gallium ratio
Increases, the crystallization temperature tends to decrease.

Further, the conductive oxide thin film may have the following composition. Formula Zn _x M _y In _z O
_{(x + 3y / 2 + 3z / 2) -d} (where M is at least one element of aluminum and gallium, and the ratio (x: y) is 0.
It is in the range of 2: 1 to 8: 1, and the ratio (z: y) is 0.4 to 1.4: 1.
And the oxygen deficiency d exceeds 0, (x + 3y / 2 + 3
(3/2) which is in the range of ¹ × 10 ⁻¹ times of z / 2). In the general formula _{Zn x M y In z O (} x + 3y / 2 + 3z / 2) -d ( wherein, M is at least one element selected from aluminum and gallium, the ratio (x: y) of 0.2: 1 88: 1, the ratio (z: y) is in the range of 0.4 to 1.4: 1, and the oxygen deficiency d exceeds 0, and 1 × 10 ^{− of} (x + 3y / 2 + 3z / 2). ^And a part of at least one of Zn, M and In is replaced by another element, and the element to be replaced with Zn has a valence of 2 or more. There is an oxide (4) in which the element substituted with M and In has a valence of 3 or more. General formula Z
_{n x M y In z O (} x + 3y / 2 + 3z / 2) -d ( wherein, M is at least one element selected from aluminum and gallium, the ratio (x:
y) is in the range of 0.2: 1 to 8: 1, and the ratio (z: y) is 0.4 to
1.4: 1 and the oxygen deficiency d exceeds 0, (x +
3y / 2 + 3z / 2) ¹ × 10 ⁻¹ times)), and cations are implanted into the oxide (5).

It is appropriate that the amount of carrier electrons in the conductive oxide thin film is in the range of 1 × 10 ¹⁸ / cm ³ to 1 × 10 ²² / cm ³ . If the amount of carrier electrons is smaller than 1 × 10 ¹⁸ / cm ³ , sufficient electric conductivity cannot be obtained and 1 × 10 ²²
If it is larger than / cm ^{3, the} absorption due to the plasma vibration appears in the visible region, and the transparency is deteriorated. The amount of carrier electrons is
Preferably, it is in the range of 1 × 10 ¹⁹ / cm ^{3 to} 5 × 10 ²¹ / cm ³ . The amount of carrier electrons can be measured by, for example, a van der Pauw electrical conductivity measuring device.

In the oxide (3), the oxygen deficiency d
Is within the above range, the amount of carrier electrons can be within the above range. In the oxide (4), Zn,
Elements to be substituted for M and In are as described in the above description of the production method. In addition, the amount of carrier electrons is, for example, an oxygen deficiency amount d and a substitution amount of Zn, M, and In elements are selected so as to be in a range of 1 × 10 ¹⁸ / cm ³ to 1 × 10 ²² / cm ^3. . In the oxide (5), the ions to be implanted are as described in the above description of the manufacturing method. The amount of carrier electrons is, for example, 1 × 10
^The oxygen deficiency amount d should be in the range of ¹⁸ / cm ³ to 1 × 10 ²² / cm ³
In addition, the amount of cation implantation is selected.

Further, in the article of the present invention, the conductive oxide thin film (thin film before ion implantation) has a (00n) plane (where n is a natural number) of the above oxide on a substrate made of an inorganic or organic material. It may be formed so as to be oriented vertically. The substrate material is as described in the above description of the manufacturing method.

The thin film or its precursor may be formed by heteroepitaxial growth by alternately performing laser ablation film formation using two targets, as described in the above manufacturing method.

The article of the present invention has a substrate which is substantially transparent in the visible light region and can be used for electrodes, liquid crystal displays, EL displays or solar cells. When this transparent conductive film is used as an electrode for a display or a solar cell or the like that requires light transmissivity, there is a great effect on extending the life of the element.

[0044]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples, and can be implemented with appropriate modifications.

Example 1 In ₂ O ₃ (manufactured by Kojundo Chemical Laboratory Co., Ltd., purity 99.9%), Ga
₂ O ₃ (high purity chemical laboratory Co., Ltd., purity 99.99%) and ZnO (high purity chemical laboratory Co., Ltd., purity 99.99%) powder were mixed with the metal element contained in the mixed powder. The weight was weighed so that the ratio became the value shown in Table 1. The weighed powder was mixed with 200 g of zirconia beads having a diameter of 2 mm in a polyamide container having a capacity of 500 ml and wet-mixed for 1 hour using a planetary ball mill manufactured by Blitz Japan. Ethanol was used as a dispersion medium. Each of the mixed powders was calcined in an alumina crucible in the atmosphere at 1000 ° C. for 5 hours, and then subjected to a crushing treatment again using a planetary ball mill for 1 hour. The calcined powder thus prepared was formed into a disk shape having a diameter of 20 mm by uniaxial pressure molding, and was heated at 1550 ° C. in the atmosphere.
It was fired for 2 hours to obtain a sintered body. # 80 on the obtained sintered body surface
Polishing was performed using a diamond polishing plate of No. 0, and a target for laser ablation was formed as a smooth surface.

A target for laser ablation was mounted on a target holder (manufactured by Inconel), and a quartz glass substrate was mounted on the substrate holder. After being introduced into the apparatus, the inside of the apparatus was evacuated using a vacuum pump until a predetermined degree of vacuum was reached. . Next, the target holder and the substrate holder were rotated in order to improve the uniformity of the formed film. The substrate temperature during film formation is 400 ° C. Oxygen gas (20 CCM) was introduced to improve the crystallinity of the formed film, and the oxygen partial pressure was increased. The total pressure at this time was 0.77 Pa. Irradiate an excimer laser pulse (5 Hz, 4 J / cm ² ) under these conditions.
The IGZO thin film was formed for a minute. Fluorescent X
As a result of analysis by a line, the composition was In ₉₉ Ga ₁₀₁ Zn ₉₇ O
It was ₃₉₆ . Further, when the crystallinity was examined by XRD, a diffraction peak on the (009) plane was observed, and it was confirmed that the film was an oriented film. The conductivity of the film was measured by a four-probe method and found to be 280 S / cm. Further, as a result of measuring the spectral transmittance of the obtained film, the absorption edge was 386 nm.

Example 2 A target for laser ablation was prepared by the method described in Example 1.
Was prepared. Laser ablation target
As a target holder and a quartz glass substrate as a substrate holder
After installing them in the
The inside of the apparatus was evacuated to a predetermined degree of vacuum using a pump.
Next, in order to improve the uniformity of the deposited film,
The holder and the substrate holder were rotated. Substrate temperature during film formation
Is 400 ° C. Purpose of improving the crystallinity of the film after film formation
To introduce oxygen gas (20CCM)
The apparent oxygen partial pressure was increased using F output (50 W). At this time
Was 0.77 Pa. Excimer laser under these conditions
Pulse (5Hz, 4J / cm ^Two) To form a film for 30 minutes.
A thin film was prepared. The resulting membrane was analyzed by X-ray fluorescence
As a result, its composition is In₉₈Ga₁₀₀Zn₉₈O₃₉₅Met. Further
Then, when the crystallinity was examined by XRD, diffraction of the (009) plane
A peak was observed and it was confirmed that the film was oriented.
Was. The conductivity of the above film was measured by the four probe method.
285 S / cm. Further, the spectral transmittance of the obtained film
As a result of the measurement, the absorption edge was 386 nm.

Example 3 In ₂ O ₃ (manufactured by Kojundo Chemical Laboratory Co., Ltd., purity 99.9%) and Ga ₂ O ₃ (manufactured by Kojundo Chemical Laboratory Co., Ltd., purity 99.99%)
And ZnO (High Purity Chemical Laboratory Co., Ltd., purity 99.99%) mixed powders with a molar ratio of 1: 1 were formed into discs with a diameter of 20 mm by uniaxial pressing, respectively, at 1300 ° C in air. By firing for 2 hours, an In ₂ O ₃ sintered body and a (ZnGa) O _2.5 sintered body were obtained. The surface of the obtained sintered body was polished using a # 800 diamond polishing plate, and each of the surfaces was used as a target for laser ablation as a smooth surface. The target for laser ablation was mounted on the target holder, and the quartz glass substrate was mounted on the substrate holder, respectively, and introduced into the apparatus. Then, the inside of the apparatus was evacuated using a vacuum pump until a predetermined degree of vacuum was reached. Next, the target holder and the substrate holder were rotated in order to improve the uniformity of the formed film. The substrate temperature during film formation is 400 ° C. Oxygen gas (20 CCM) was introduced to improve the crystallinity of the film after the film formation, and the apparent oxygen partial pressure was increased. The total pressure at this time was 0.77 Pa. Under these conditions, an excimer laser pulse (5 Hz, 4 J / cm ² )
A film was formed for 30 minutes while replacing the n ₂ O ₃ and (ZnGa) O _2.5 targets every 10 pulses, to produce an IGZO thin film. As a result of analyzing the obtained film by fluorescent X-ray, the composition was In ₉₆ Ga ₁₀₀
Zn ₉₉ O ₃₉₃ . The conductivity of the film was measured by a four-probe method, and was 305 S / cm. Further, as a result of measuring the spectral transmittance of the obtained film, the absorption edge was 388 nm.

[0049]

[Table 1]

Comparative Example 1 An RF output of 200 W and a target of InGaZnO ₄ sintered body were formed on a quartz glass substrate by RF magnetron sputtering.
A thin film having a thickness of 200 nm was formed under the conditions of Ar: O ₂ = 18: 2, a pressure of 6 × 10 ⁻³ Torr, and a substrate temperature of 500 ° C. As a result of analyzing the obtained film by X-ray fluorescence, the composition was Zn ₂₆ Ga ₁₀₀ In ₅₆ O ₂₆₀
Met. Furthermore, when the crystallinity was examined by XRD, a diffraction peak on the (009) plane was observed, and it was confirmed that the film was an oriented film. The conductivity of the film was measured by a four-probe method and found to be 240 S / cm. Further, as a result of measuring the spectral transmittance of the obtained film, the absorption edge was 384 nm.

Comparative Example 2 RF magnetron sputtering was performed on a quartz glass substrate.
In₁₇₉Ga₁₀₀Zn₃₉₈O ₈₂₆With the sintered body as the target, R
F output 200W, Ar: O_Two= 18: 2, pressure 6 × 10^-3Torr, substrate temperature
A thin film having a thickness of 200 nm was formed at 500 ° C. Got
As a result of analyzing the film by fluorescent X-ray, the composition was In₉₉Ga
₁₀₀Zn₉₈O₃₉₆Met. Furthermore, the crystallinity is adjusted by XRD.
As a result, the diffraction peak of the (009) plane was observed,
It was confirmed that it was. The conductivity of the above film is 4
It was 280 S / cm when measured by the probe method. Sa
As a result of measuring the spectral transmittance of the obtained film, the absorption edge was
It was 385 nm.

[0052]

[Table 2]

[0053]

[Table 3]

[0054]

[Table 4]

[0055]

According to the present invention, the thin film composition is well matched with the target composition, so that the production is easy, the surface resistivity is low, and the visible light transmittance at 450 to 800 nm including the substrate is excellent. A method for manufacturing an article having a zinc-indium oxide-based conductive thin film can be provided. Furthermore, according to the present invention, the single crystallinity is high, the number of lattice defects is small, the surface resistivity is low, and 450 to 800
An article having a zinc-indium oxide-based conductive thin film having excellent visible light transmittance in nm can be provided. When the transparent conductive film, which is an article of the present invention, is used as, for example, an electrode for a display or a solar cell that requires light transmission, there is a great effect on extending the life of the element.

Continuing from the front page (72) Inventor Masahiro Orita 2-7-5 Nakaochiai, Shinjuku-ku, Tokyo Inside Hoya Co., Ltd. (72) Inventor Hideo Hosono 4259 Nagatsuda-cho, Yokohama City, Kanagawa Prefecture In-house Ceramics Research Laboratory, Tokyo Institute of Technology (72) Inventor Hiroshi Kawasoe 4259 Nagatsuda-cho, Yokohama-shi, Kanagawa Prefecture F-term in the Institute of Applied Ceramics, Tokyo Institute of Technology 4K029 AA08 BA44 BA45 BA49 BA50 BC09 BD01 CA02 DB05 DB20 DC05

Claims (14)

[Claims] 1. An article having a conductive oxide thin film including forming a conductive oxide thin film on at least a portion of at least one surface of a substrate by a laser ablation method using a zinc-indium oxide as a target. Manufacturing method. 2. The method according to claim 1, wherein the zinc-indium oxide is an oxide further containing aluminum and / or gallium. 3. A zinc - indium-based oxide target is the general formula _{Zn x M y In z O (} x + 3y / 2 + 3z / 2) ( wherein, M represents at least one element of aluminum and gallium Wherein the ratio (x: y) is in the range of 0.2: 1 to 8: 1 and the ratio (z: y) is in the range of 0.4 to 1.4: 1). 2. The production method according to 2. 4. A zinc - indium-based oxide target is the general formula _{Zn x M y In z O (} x + 3y / 2 + 3z / 2) ( wherein, M represents at least one element of aluminum and gallium And the ratio (x: y) is in the range of 0.2: 1 to 8: 1 and the ratio (z: y) is in the range of 0.4 to 1.4: 1), and Z
At least one element of n, M, and In is partially replaced with another element, and the element to be replaced with Zn has a valence of 2
3. The method according to claim 1, wherein the element having a valence of 3 or more and being substituted with M and In is an oxide having a valence of 3 or more. 4. 5. The manufacturing method according to claim 1, wherein the conductive oxide thin film is formed by a laser ablation method in an oxygen atmosphere. 6. The production method according to claim 5, wherein the oxygen partial pressure inside the laser ablation apparatus is controlled by a radical gun installed in the apparatus. 7. The method according to claim 1, wherein cations are implanted into the conductive oxide thin film formed by the laser ablation method.
7. The production method according to any one of 6. 8. The laser ablation method uses continuous oscillation or pulse oscillation as laser oscillation, a laser wavelength of 0.19 to 11 μm, and a laser intensity of 0.000 during laser irradiation.
The method according to any one of claims 1 to 7, wherein the method is performed under the conditions of 1 to 1000 J / cm ² · pulse and a substrate temperature of 0 to 1000 ° C. 9. The manufacturing method according to claim 1, wherein the thin film is heteroepitaxially grown by alternately forming two or more targets by laser ablation. 10. An article having a conductive oxide thin film formed by the production method according to claim 1. Description: 11. The method of claim 11, wherein carrier electrons in the conductive oxide thin film
1 × 10¹⁸/cm^Three~ 1 × 10 ^{twenty two}/cm^ThreeClaim 10
Articles described in. 12. The substrate is made of an inorganic or organic material,
And (00n) of the conductive oxide thin film formed on the substrate.
The article according to claim 10 or 11, wherein the faces (where n is a natural number) are substantially oriented. 13. The article according to claim 10, wherein the substrate is substantially transparent in a visible light region, and is used as an electrode. 14. The article according to claim 10, which is used for a liquid crystal display, an EL display, or a solar cell.