JPH1045496A - Electrically conductive oxide thin film, article having the same and manufacture of article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the thin film which consists of an oxide represented by a specific formula and shows higher electric conductivity and also to provide an article having the thin film. SOLUTION: This thin film consists of an oxide represented by the formula Znx My Inz O(x+3y/2+3z/2)-d (wherein: M is at least one element of aluminum and gallium; x:y is a ratio in the range of 1.8:1 to 8:1;z:y is a ratio in the range of 0.4:1 to 1.4:1; and (d) is amount (d) of oxygen defect in the range of 0 to 1×10<-1> (x+3y/2+3z/2)), wherein the (00n) planes ((n) is a positive integer) of the oxide are substantially oriented. In this article, the above conductive oxide thin film is formed on an orientation control substrate or an orientation control film formed on a substrate, each of which is used for substratially orienting the (00n) planes of the oxide.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductive oxide thin film having excellent electric conductivity, an article such as an electrode using the conductive oxide, and a method for producing the same.
The conductive oxide thin film of the present invention not only has excellent conductivity, but also has excellent transparency in the entire visible region, so that it is particularly useful as an electrode for a display or a solar cell or the like that requires light transmittance. .

[0002]

2. Description of the Related Art So-called transparent conductive materials which are transparent and have electrical conductivity in the visible light region are known as liquid crystal displays,
It is used as a transparent electrode of various panel displays such as an EL display and a solar cell. As the transparent conductive material, a metal oxide semiconductor is generally used, including tin-doped indium oxide (ITO),
Various proposals have been made. Until now, ITO has often been used as a transparent electrode for panel-type displays. However, as displays become larger and higher definition, IT
O causes problems such as high resistance and coloring, and cannot be put to practical use. That is, in the case of ITO which has been practically used as a material for a transparent electrode, a large-sized transparent electrode satisfying both transparency and electric conductivity cannot be obtained. 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.

[0003] Therefore, the present inventors have YbFe ₂ O _d structure of the general formula _{Zn x M y In z O (} x + 3y / 2 + 3z / 2) -d ( wherein,
M is at least one element of 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, and (x + 3y / 2 + 3
z / 2) is 1 × 10 ^-1 times) and an oxide having a similar basic structure is compared with an 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 450 nm or less and having the same or higher electrical conductivity, and has been applied for a patent (Japanese Patent Application No. 7-65).
No. 840 and Japanese Patent Application No. 7-101321).

[0004]

[SUMMARY OF THE INVENTION The general formula Zn _x M _y In
_The oxide represented by _z O _{(x + 3y / 2 + 3z / 2) -d} is used as a transparent conductive thin film for an electrode or the like. Such a thin film is usually prepared to have a thickness of several hundreds to several thousand degrees, but even such a thin film is required to exhibit high electric conductivity. It is an object of the present invention, the general formula Zn _x M _y In _z O
_{(x + 3y / 2 + 3z / 2)} a thin film made of an oxide represented by _{(x + 3y / 2 + 3z / 2)} , wherein the conductive oxide thin film exhibits higher electric conductivity; a liquid crystal display having such a conductive oxide thin film;
It is an object of the present invention to provide an article that can be used as an electrode or the like useful for an L display, a solar cell, and the like. Another object of the present invention is to provide a method for easily manufacturing an article having a conductive oxide thin film having high electric conductivity as described above.

[0005]

The present invention relates to the following conductive oxide thin films, articles having the conductive oxide thin films, and a method of manufacturing the articles.

[0006] oxide thin formula _{Zn x M y In z O (} x + 3y / 2 + 3z / 2) -d ( wherein of the first aspect, M is at least one element of aluminum and gallium The ratio (x: y) is in the range of more than 1.8: 1 to 8: 1 or less, the ratio (z: y) is in the range of 0.4 to 1.4: 1, and the oxygen deficiency is d exceeds 0 and (x + 3y / 2 +
3z / 2) (1 × 10 ^-1 times), and the (00n) plane of the oxide (provided that
wherein n is a positive integer) is substantially oriented.

[0007] oxide thin formula _{Zn x M y In z O (} x + 3y / 2 + 3z / 2) -d ( wherein the second aspect, M is at least one element of aluminum and gallium The ratio (x: y) is in the range of more than 1.8: 1 to 8: 1 or less, the ratio (z: y) is in the range of 0.4 to 1.4: 1, and the oxygen deficiency is d exceeds 0 and (x + 3y / 2 +
3z / 2) is 1 × 10 ⁻¹ times), and at least one element of Zn, M and In is partially replaced with another element, and is replaced with Zn. The element which is substituted with M and In is an oxide thin film having a valence of 3 or more, and the element substituted with M and In is a (00n) plane (where n is a positive Are substantially oriented).

[0008] oxide thin formula _{Zn x M y In z O (} x + 3y / 2 + 3z / 2) -d ( wherein the third aspect, M is at least one element of aluminum and gallium The ratio (x: y) is in the range of more than 1.8: 1 to 8: 1 or less, the ratio (z: y) is in the range of 0.4 to 1.4: 1, and the oxygen deficiency is d exceeds 0 and (x + 3y / 2 +
3z / 2) is an oxide thin film obtained by injecting cations into an oxide represented by 1 × 10 ^-1 times, and the (00n) plane of the oxide (where n is a positive Are substantially oriented).

[0009] At least a part of at least one surface of the article substrate according to the first aspect is provided with the first substrate.
An article having the conductive oxide thin film according to any one of the third to third aspects, wherein the conductive oxide thin film is on an orientation control film for substantially aligning the (00n) plane of the oxide. An article characterized in that it is formed on a substrate.

[0010] An article having a conductive oxide thin film on at least a portion of at least one surface of the article substrate of the second aspect, the conductive oxide thin film, the general formula Zn _x M _y In _z O _{( x + 3y / 2 + 3z / 2) -d} (where M
Is an element of at least one of aluminum and gallium, wherein the ratio (x: y) is in the range of 0.2 to 1.8: 1 and the ratio (z: y) is in the range of 0.4 to 1.4: 1. Yes,
And the oxygen deficiency d exceeds 0, and (x + 3y / 2 + 3z /
2) in the range of 1 × 10 ⁻¹ times), and the conductive oxide thin film is formed on the orientation control substrate or on the orientation control film on the substrate by the oxidation. (0
0n) An article characterized by being formed such that its plane (where n is a positive integer) is substantially oriented.

[0011] An article having a conductive oxide thin film on at least a portion of at least one surface of the article substrate of the third aspect, the conductive oxide thin film, the general formula Zn _x M _y In _z O _{( x + 3y / 2 + 3z / 2) -d} (where M
Is an element of at least one of aluminum and gallium, wherein the ratio (x: y) is in the range of 0.2 to 1.8: 1 and the ratio (z: y) is in the range of 0.4 to 1.4: 1. Yes,
And the oxygen deficiency d exceeds 0, and (x + 3y / 2 + 3z /
2) 1 × 10 ^-1 times) and Zn,
At least one element of M and In is partially substituted with another element, and the element substituted with Zn has a valence of 2
Elements that are substituted with M and In have a valence of 3 or more.
An oxide thin film having a valency or higher and the conductive oxide thin film is formed on the (00n) plane of the oxide (where n is a positive number) on the orientation control substrate or on the orientation control film on the substrate. Is an integer, and is formed so as to be substantially oriented.

[0012] An article having a conductive oxide thin film on at least a portion of at least one surface of the article substrate of the fourth aspect, the conductive oxide thin film general 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, the ratio (x: y) is in the range of 0.2 to 1.8: 1, and the ratio (z : Y) is in the range of 0.4 to 1.4: 1, and the oxygen deficiency d exceeds 0, and (x + 3y / 2 + 3z /
2) is an oxide thin film obtained by injecting cations into an oxide represented by the following formula: 1 × 10 ^-1 times), and the conductive oxide thin film is formed on an orientation control substrate or a substrate. On the above orientation control film, a (00n) plane of the above oxide (however,
(n is a positive integer) formed so as to be substantially oriented.

[0013] manufacturing process formula of the first aspect _{Zn x M y In z O (} x + 3y / 2 + 3z / 2) -d ( wherein, M is at least one element of aluminum and gallium , The ratio (x: y) is in the range of 0.2 to 8: 1,
The ratio (z: y) is in the range of 0.4 to 1.4: 1, and the oxygen deficiency d exceeds 0 and is 1 × 10 ^-1 times (x + 3y / 2 + 3z / 2). A method of forming a thin film by sputtering using an oxide represented by the formula: on an orientation control substrate for substantially aligning the (00n) plane of the oxide, or An article having a conductive oxide thin film according to the first aspect (part of the article according to the first aspect) or a second article having a conductive oxide thin film formed on the orientation control film on a substrate having an orientation control film. A method for producing the article of the embodiment.

[0014] manufacturing process formula of the second aspect _{Zn x M y In z O (} x + 3y / 2 + 3z / 2) -d ( wherein, M is at least one element of aluminum and gallium , The ratio (x: y) is in the range of 0.2 to 8: 1,
The ratio (z: y) is in the range of 0.4 to 1.4: 1, and the oxygen deficiency d exceeds 0 and is 1 × 10 ^-1 times (x + 3y / 2 + 3z / 2). And Zn, M and
At least one element of In is partially substituted with another element, the element substituted with Zn has a valence of 2 or more, and the element substituted with M and In has a valence of 3 or more. A thin film formed by sputtering using an oxide having a valency or higher as a target, wherein the oxide thin film is formed on an orientation control substrate for substantially aligning the (00n) plane of the oxide or An article having a conductive oxide thin film according to the second aspect (part of the article according to the first aspect) or a third article having a conductive oxide thin film formed on the orientation control film on a substrate having an orientation control film. A method for producing the article of the embodiment.

The manufacturing method formulas of the third aspect _{Zn x M y In z O (} x + 3y / 2 + 3z / 2) -d ( wherein, M is at least one element of aluminum and gallium The ratio (x: y) is in the range of more than 1.8: 1 to 8: 1 or less, the ratio (z: y) is in the range of 0.4 to 1.4: 1, and the oxygen deficiency amount d Exceeds 0, and (x + 3y / 2 +
3z / 2) is a method of forming a thin film by sputtering using an oxide represented by the formula (1 × 10 ^-1 times) as a target, and then implanting cations. Forming an oxide film on an orientation control substrate for substantially orienting the (00n) plane of the oxide or on the orientation control film of a substrate having an orientation control film. A method for producing an article (a part of the article of the first embodiment) having the conductive oxide thin film or the article of the fourth embodiment.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below.
Kimizuka et al. Have reported on a composite oxide of In-Ga-Zn and a composite oxide of In-Al-Zn (N. Kimizuka, T. Mo.
hri, Y. Matsui and K. Shiratori, J. Solid State Che
m., 74, 98, 1988). Kimizuka et al., In
_An unknown crystal is synthesized from a powder of ₂ O ₃ , ZnO and Ga ₂ O ₃ or Al ₂ O _{3 by} a solid phase method, and InGaO ₃ (ZnO) _m and InAlO ₃ (Zn
O) _m ( _m = 2 to 7). These oxides are respectively also denoted as Zn _m GaInO _{3 + m} and Zn _m AlInO _{3 + m.} In the above report, InGaO ₃ (ZnO) _m and InAlO ₃ (ZnO) _m
Although only studies on the crystal structure of are described, the present inventors have reported the optical and electrical properties of these crystals, and furthermore, oxygen deficiency and element substitution,
Further, they have found that conductivity can be imparted by cation implantation, and have filed patent applications (Japanese Patent Application Nos. 7-65840 and 7-101321).

On the other hand, the conductive oxide thin film of the present invention and the conductive oxide thin film provided on the article of the present invention have a (00n) plane (where n is a positive integer) of the oxide. Are characterized by being substantially oriented, and having such a structure can exhibit higher conductivity. This will be described with reference to FIGS. Oxide represented by the general formula _{Zn x M y In z O (} x + 3y / 2 + 3z / 2) , the
Basically, it has an octahedral structure of InO ₆ , and forms a layer that spreads two-dimensionally by sharing its edges. FIG. 1 shows an electron model (white circles are In atoms and black circles are oxygen atoms) showing this structure. 1A is a diagram viewed from a direction perpendicular to the (00n) plane, and FIG. 1B is a diagram viewed from a direction parallel to the (00n) plane. FIG. 2 is a diagram schematically showing the relationship between the octahedron of InO ₆ and the (00n) plane of the octahedron, and furthermore, the substrate. Then, as schematically shown in FIG.
When the (n) plane is substantially oriented and a current (electrons) is applied thereto, the path of electrons becomes linear in a direction parallel to the (00n) plane. When a thin film is formed on the surface of the substrate, (00
When the n) plane is oriented substantially parallel to the surface of the substrate, a linear path of electrons is determined in the direction in which the surface of the substrate spreads. In the present invention, the general formula Zn _x M _y In _z
The conductive oxide thin film represented by O _{(x + 3y / 2 + 3z / 2)} exhibits high conductivity because its (00n) plane is substantially oriented. In a non-oriented film, the electron path becomes zigzag, whereas in an oriented film, the electron path becomes linear and higher conductivity is obtained.

[0018] During the first conductive oxide aspect thin formula _{Zn x M y In z O (} x + 3y / 2 + 3z / 2) -d, M is be a single one of aluminum and gallium Good
Aluminum and gallium may coexist. When aluminum and gallium coexist, the ratio between aluminum and gallium is not particularly limited. However, as the proportion of aluminum increases, the crystallization temperature tends to increase. As the gallium ratio increases, the crystallization temperature tends to decrease. The ratio (x: y) ranges from more than 1.8: 1 to 8: 1 or less. If x / y exceeds 8, the ZnO crystal structure becomes the main phase, and the characteristics of the conductive oxide thin film of the present invention are not exhibited. The preferred ratio (x: y) is 1.8 to
6.2: 1, more preferably 1.8-3.2: 1.
Range. The ratio (z: y) is in the range of 0.4 to 1.4: 1, and when z / y is less than 0.4, precipitation of ZnGa ₂ O ₄ phase or the like becomes remarkable, and the conductivity decreases. When z / y exceeds 1.4
In ₂ O ₃ phase precipitates and the transparency decreases. The preferred ratio (z: y) is in the range of 0.6 to 1.4: 1, more preferably in the range of 0.8 to 1.2: 1. The oxygen deficiency d is 0
And the range is 1 × 10 ⁻¹ times (x + 3y / 2 + 3z / 2). Considering the conductivity and the transmittance of visible light,
It is preferably in the range of 1 × 10 ⁻³ times to 1 × 10 ⁻¹ times (x + 3y / 2 + 3z / 2), and more preferably (x + 3
y / 2 + 3z / 2) in the range of 1 × 10 ⁻² to 1 × 10 ⁻¹ . Note that the oxygen deficiency is a value obtained by subtracting the number of oxygen ions contained in one mole of oxide crystal from the number of stoichiometric oxygen ions in a molar unit. The number of oxygen ions contained in the oxide crystal can be calculated, for example, by measuring the amount of carbon dioxide generated by heating the oxide crystal in carbon powder using an infrared absorption spectrum. Further, the number of stoichiometric oxygen ions can be calculated from the mass of the oxide crystal. The conductivity of the oxide thin film of the present invention, the amount of carrier electrons in the conduction band,
It is good when it is in the range of 1 × 10 ¹⁸ / cm ³ to 1 × 10 ²² / cm ³ . A more preferred amount is 1 × 10 ¹⁹ / cm ³ to
It is in the range of 5 × 10 ²¹ / cm ³ . Note that the amount of carrier electrons can be measured by, for example, a van der Pauw electric conductivity measuring device. The above-mentioned oxide thin film exhibits higher conductivity by having the orientation controlled as described above. That is, (00) of the oxide constituting the thin film
n) The plane (where n is a positive integer) is substantially oriented. As used herein, “substantially oriented” refers to a general formula Zn _x M _y In _z O _{(x + 3y / 2 + 3z / 2) -d} (where M is at least one of aluminum and gallium ₎ An element having a ratio (x: y) of more than 1.8: 1 to 8: 1 or less, a ratio (z: y) of 0.4 to 1.4: 1, and oxygen The loss amount d exceeds 0 and (x + 3y / 2 + 3
z / 2) is 1 × 10 ^-1 times), and the angles formed by the normals of the (00n) plane of any crystal grains forming the oxide thin film are within 60 °, preferably It means within 40 °, more preferably within 20 °. The conductive oxide thin film having such an orientation can be formed by being formed on a functional film or a functional substrate for controlling the orientation of the oxide thin film, as described later.

[0019] In the conductive oxide thin film of the second aspect of the conductive oxide thin film present invention of the second aspect, the general formula _{Zn x M y In z O (} x + 3y / 2 + 3z / 2) -d In the formula, M, the ratio (x: y) and the ratio (z: y) are the same as those of the conductive oxide thin film according to the first embodiment of the present invention. The oxygen deficiency d can be appropriately determined in consideration of the conductivity provided by the substitution of the element, and may be 0. The oxygen deficiency d is
If it is too large, it absorbs visible light and causes a decrease in transparency. Therefore, it is suitably 1 × 10 ⁻¹ or less of (x + 3y / 2 + 3z / 2). Further, in the conductive oxide thin film of the second aspect of the present invention, in addition to introducing oxygen vacancies, by substituting at least one element of Zn, M and In with another element, carrier Electrons are injected into the conduction band to develop conductivity. Zn is a divalent element, and the element that can be substituted with Zn is an element having a valence of two or more. Higher valence elements can provide greater carrier injection with less substitution. The valence of the replaceable element is usually divalent, trivalent,
Valence, pentavalent or hexavalent. Examples of the element having a valence of 2 or more include Be, Mg, Ca, Sr, Ba, Cd, Al, Si, Sc, and T.
i, V, Cr, Mn, Fe, Co, Ni, Zn, Ga, Ge, Y, Zr, N
b, Mo, Tc, Ru, Rh, Pd, In, Sn, Sb, La, Ce, Pr, N
d, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, H
f, Ta, W, Re, Os, Ir, Pt, Tl, Pb, Bi, and Po. Al, Ga, and In represented by M are trivalent elements.
Element with a valency or higher. 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, Fe, 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, Dy, Ho, Er, Tm, Y
b, Lu, Hf, Ta, W, Re, Os, Ir, Pt, Tl, Pb, Bi, Po
Can be mentioned. From the viewpoint of the balance between electric conductivity and transparency, the injection amount of carrier electrons is, for example, 1 ×
It is appropriate to set the range of 10 ¹⁸ / cm ³ to 1 × 10 ²² / cm ³ , and it is appropriate to adjust the substitution amount of each element so that the electron injection amount falls within the above range. The injection amount of carrier electrons is preferably 1 × 10 ¹⁰ / cm ^{3 to} 5 × 10 ^21.
/ Cm ³ . Some of the elements to be substituted have a property of absorbing light in the visible region.
Therefore, it is appropriate to select the substitution amount of the substitution element so that the average transmittance of light in the visible region is 70% or more, preferably 80% or more, and more preferably 90% or more. The above-mentioned oxide thin film exhibits higher conductivity by having the orientation controlled as described above. That is, the (00n) plane (where n is a positive integer) of the oxide constituting the thin film is substantially oriented. The conductive oxide thin film having such an orientation can be formed by being formed on a functional film or a functional substrate for controlling the orientation of the oxide thin film, as described later.

[0020] In the conductive oxide thin film of the third aspect of the conductive oxide thin film present invention of the third aspect, the general formula _{Zn x M y In z O (} x + 3y / 2 + 3z / 2) -d In the formula, Zn, M, the ratio (x: y) and the ratio (z: y) are the same as those of the conductive oxide thin film according to the first embodiment of the present invention. The oxygen deficiency d can be appropriately determined in consideration of the conductivity imparted by cation implantation, and may be zero. If the oxygen deficiency d is too large, it absorbs visible light and causes a decrease in transparency, so that (x + 3y / 2 + 3z / 2) 1 × 1
Is suitably at 0 ^-1 times or less. Furthermore, oxide cations are injected into the conductive oxide thin film of the third aspect of the present invention, represented by the general formula _{Zn x M y In z O (} x + 3y / 2 + 3z / 2) -d There is no particular limitation as long as it can form a solid solution without destroying the crystal structure of the product. However, ions having a small ion radius tend to form a solid solution in the crystal lattice, and the larger the ion radius, the more likely the crystal structure is broken. Examples of the above cations include H, Li, Be, B, C, Na, Mg, Al, Si, K, Ca, Sc, and T.
i, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Y, Z
r, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn, Sb, C
s, Ba, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, H
o, Er, Tm, Yb, Lu, Hf, Ta, W, Re, Os, Ir, Pt, A
u, Hg, Tl, Pb and Bi can be mentioned. From the viewpoint of the balance between electric conductivity and transparency, the amount of carrier electrons is preferably, for example, in the range of 1 × 10 ¹⁸ / cm ³ to 1 × 10 ²² / cm ^3. It is appropriate to adjust the amount of ion implantation so that the amount of carrier electron implantation falls within the above range. The injection amount of carrier electrons is preferably in the range of 1 × 10 ¹⁰ / cm ^{3 to} 5 × 10 ²¹ / cm ³ . The above-mentioned oxide thin film exhibits higher conductivity by having the orientation controlled as described above. That is, the (00n) plane (where n is a positive integer) of the oxide constituting the thin film is substantially oriented. The conductive oxide thin film having such an orientation can be formed by being formed on a functional film or a functional substrate for controlling the orientation of the oxide thin film, as described later.

Article of the First Aspect The article of the first aspect of the present invention has the conductive oxide thin film of any one of the first to third aspects on at least a part of at least one surface of the substrate. An article, wherein the conductive oxide thin film is formed on an alignment control substrate or an alignment control film on a substrate for substantially aligning the (00n) plane of the oxide. The thickness of the conductive oxide thin film can be appropriately determined according to the use of the article. Also,
The film thickness when this article is used as an electrode will be described later.

In general, control of the orientation characteristics of a polycrystalline thin film is important from the viewpoint of practical use of the thin film. The orientation characteristics of the polycrystalline thin film
Empirically, it can be controlled by selecting thin film forming conditions such as a thin film forming speed and a thin film forming temperature. However, it is not always easy to form a crystalline thin film having a desired orientation only by controlling the thin film forming speed and the thin film forming temperature. Therefore, in the present invention, a thin film is formed on the orientation control substrate or the orientation control film provided on the substrate. In this manner, a thin film in which the (00n) plane of the oxide is substantially oriented can be easily formed at a lower temperature. The ability to form at lower temperatures relaxes substrate material restrictions. That is, even a substrate having low heat resistance can be used. The crystallinity of a thin film generally depends on its substrate,
Alternatively, it is well known to reflect the crystallinity of the underlying layer. The phenomenon that another crystal grows on one crystal with some fixed orientation relation is called epitaxy (epitaxial
axy). Therefore, the orientation of the thin film can be controlled by appropriately selecting the underlayer. When the oxide thin film is used, for example, as an electrode for a display or the like, it is required to flow a current (electrons) in an in-plane direction of the oxide thin film. To this end, it is necessary to orient the (00n) plane of the oxide substantially in parallel to the in-plane direction of the oxide thin film. The crystal lattice constant of the control film is (00n) of the oxide formed thereon.
It is desirable that the value be equal to or substantially close to the lattice constant of the surface. For example, it is appropriate that the difference between the crystal lattice constant of the orientation control substrate or the orientation control film and the lattice constant of the (00n) plane of the oxide formed thereon is within ± 30%. However, from the viewpoint of easy orientation control, the above difference is preferably within ± 20%. In addition, in order to reflect the crystallinity of the orientation control film in the oxide formed thereon, it is appropriate that the orientation control film is at least not amorphous, but is crystalline such as single crystal or polycrystal. .

Further, the article of the present invention may be used for a transparent electrode. In the case of a transparent electrode, it is required that the orientation control substrate and the orientation control film provided on the substrate are transparent. ZnO can be mentioned as an example of a material that satisfies both the approximation of crystal lattice constant and the transparency. ZnO is a II-VI compound semiconductor having a band gap of about 3.2 eV. Its crystal structure belongs to the wurtzite hexagonal (point group 6 mm, space group P6 ₃ mc).
It is well known to exhibit piezoelectricity, and is used in solar cells and the like as a transparent conductive thin film having substantially the same conductivity as ITO. In a normal sputtering method, ZnO
The thin film is polycrystalline, and often has a thin film whose c-axis is perpendicular to the substrate surface. When the c-axis grows perpendicular to the substrate, a hexagonal (0001) plane appears on the surface.
The lattice constant of this plane is 3.24 °, and the (00
n) The lattice constant of the plane is almost equal to 3.30 °. The thickness of the ZnO thin film can be controlled so as to control the orientation of the thin film provided thereon, and is usually in the range of 100 to 1000 nm. The ZnO thin film having c-axis orientation can be prepared by, for example, a sputtering method. In the DC or RF diode sputtering method, zinc or zinc oxide is used as a target and glow discharge is performed on a substrate by performing a glow discharge with an Ar / O ₂ mixed gas of 1 × 10 ⁻² to 1 × 10 ⁻¹ Torr. Can be. The c-axis orientation of the ZnO thin film depends on film forming conditions such as a film forming speed and a substrate heating temperature. Under the above conditions, it is appropriate to perform sputtering at a substrate heating temperature in the range of 50 to 200 ° C. and a film formation rate of 1 μ / hr or less. Also, as described in Example 1, a c-axis oriented ZnO thin film can be produced by the RF magnetron sputtering method. In this case, the substrate heating temperature is set in the range of 300 to 500 ° C., and the film forming rate is increased. It is appropriate to perform sputtering at 1 μm / hr or more.

The substrate on which the orientation control film made of ZnO is formed may be, for example, a substrate such as glass or resin. 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 substrate. Many uses of a resin substrate are being studied, taking advantage of its light weight, thinness, flexibility, and high degree of freedom as compared with a glass substrate. The liquid crystal display is preferably used 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.

The orientation control substrate made of ZnO can be manufactured by a single crystal substrate of ZnO by a vapor growth method, a flux method, or a hydrothermal method. For example, when using the hydrothermal method, put the ZnO sintered body in a KOH + LiOH5.1N solution in a Pt tube, dissolve it, pressurize it to 700 to 1000 kg / cm, and further heat it to 340 to 385 ° C. Thus, a ZnO bulk single crystal can be formed on a ZnO 2 seed crystal.

ZnO is transparent in the wavelength range of 400 to 2500 nm, and substantially matches the transparent wavelength region of the oxide thin film, and is therefore excellent for use as a transparent electrode. Furthermore, ZnO powder and zinc metal raw materials are inexpensive and abundant, and have the advantage of being a stable and safe substance and having few social problems such as pollution.

Article of the Second Aspect An article of the second aspect of the present invention is an article having a conductive oxide thin film on at least a part of at least one surface of a substrate, wherein the conductive oxide thin film is the general 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 in the range of 0.2 to 1.8: 1 and the ratio (z: y) is
From 0.4 to 1.4: 1, and the oxygen deficiency d exceeds 0 and is 1 × 10 ⁻¹ times (x + 3y / 2 + 3z / 2). And the conductive oxide thin film has a (00n) plane (where n is a positive integer) of the oxide substantially on the orientation control substrate or on the orientation control film on the substrate. It is formed so as to be oriented. The conductive oxide thin film has a ratio (x: y) of
Except for the range of 0.2 to 1.8: 1, it is the same as the conductive oxide thin film of the first embodiment. The ratio (x: y) is 0.
When x / y is less than 0.2, the precipitation of the InGaO ₃ phase becomes remarkable, and the electric conductivity is reduced. From the viewpoint of high electric conductivity, a preferable ratio (x: y) is in a range of 0.3 to 1.6: 1, and more preferably in a range of 0.4 to 1.3: 1. Also,
The orientation control substrate and the orientation control film are the same as those of the first aspect of the present invention.
This is the same as that described in the article of the embodiment. The thickness of the conductive oxide thin film can be appropriately determined according to the use of the article. The film thickness when this article is used as an electrode will be described later.

Article of Third Embodiment An article of a third embodiment of the present invention is an article having a conductive oxide thin film on at least a part of at least one surface of a substrate, wherein the conductive oxide thin film is the general 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 in the range of 0.2 to 1.8: 1 and the ratio (z: y) is
0.4 to 1.4: 1, and the oxygen deficiency d exceeds 0, and is represented by 1 × 10 ⁻¹ times (x + 3y / 2 + 3z / 2)), and Zn, A part of at least one element of M and In is replaced by another element, and Zn
The element to be substituted has a valence of 2 or more, and M and In
Is an oxide thin film having a valence of 3 or more, and the conductive oxide thin film is formed on the orientation control substrate or on the orientation control film on the substrate. The (00n) plane (where n is a positive integer) is formed so as to be substantially oriented. The conductive oxide thin film is the same as the conductive oxide thin film of the second embodiment except that the ratio (x: y) is in the range of 0.2 to 1.8: 1. The ratio (x: y) is in the range of 0.2 to 1.8: 1. When x / y is less than 0.2, precipitation of the InGaO ₃ phase becomes remarkable, and the electric conductivity is reduced. From the viewpoint of high electric conductivity, a preferable ratio (x: y) is 0.3 to
It is in the range of 1.6: 1, more preferably 0.4-1.
The range is 3: 1. The orientation control substrate and the orientation control film are the same as those described in the article of the first embodiment of the present invention. The thickness of the conductive oxide thin film can be appropriately determined according to the use of the article. The film thickness when this article is used as an electrode will be described later.

Article of Fourth Aspect An article of a fourth aspect of the present invention is an article having a conductive oxide thin film on at least a part of at least one surface of a substrate, wherein the conductive oxide thin film is 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 in the range of 0.2 to 1.8: 1 and the ratio (z: y) is
0.4 to 1.4: 1, and the oxygen deficiency d exceeds 0 and is 1 × 10 ^-1 times (x + 3y / 2 + 3z / 2). An oxide thin film into which cations have been implanted, and the conductive oxide thin film is provided on the orientation control substrate or on the orientation control film on the substrate by the (00n) plane (where n Is a positive integer). The conductive oxide thin film is the same as the conductive oxide thin film of the second embodiment except that the ratio (x: y) is in the range of 0.2 to 1.8: 1. The ratio (x: y) is in the range of 0.2 to 1.8: 1. When x / y is less than 0.2, precipitation of the InGaO ₃ phase becomes remarkable, and the electric conductivity is reduced. From the viewpoint of high electric conductivity, a preferable ratio (x: y) is in a range of 0.3 to 1.6: 1, and more preferably, 0.1 to 1.6.
It is in the range of 4-1.3: 1. The orientation control substrate and the orientation control film are the same as those described in the article of the first embodiment of the present invention. The thickness of the conductive oxide thin film can be appropriately determined according to the use of the article. Also,
The film thickness when this article is used as an electrode will be described later.

Use as an electrode The articles of the first to fourth embodiments of the present invention can be used as an electrode. When used as an electrode, the orientation control substrate and the substrate and the orientation control film provided thereon are made of a transparent material as described above, and the conductive oxide thin film becomes the conductive layer.
The conductive layer constituting the electrode of the present invention may be a case where the conductive layer is composed only of the conductive oxide thin film or an oxide layer in which a crystal different from these oxides coexists. However, the coexistence amount of other crystals is selected within a range that does not cause a practical problem in terms of transparency and conductivity of the conductive layer. Examples of the oxide that can coexist with the conductive oxide thin film include ITO, In ₂ O ₃ , and SnO ₂ . However, it is not limited to these oxides. The thickness of the conductive layer in the electrode can be appropriately determined in consideration of the optical characteristics, conductivity, application, and the like required for the electrode. For example, in the case of a liquid crystal panel electrode, the lower limit is about 30 nm and the upper limit is about 1 nm.
μm. However, depending on the kind of element contained in the oxide, some have partial absorption in the visible region, and in that case, a relatively thin film thickness is preferable. For those having little or no absorption in the visible region, higher conductivity can be obtained by increasing the film thickness.
In the case of a transparent electrode of a display device such as a liquid crystal display or an EL display described later, it is preferable that the transparent electrode has a transmittance of 80% or more in a visible light region of 400 to 700 nm.
When a transparent electrode of a solar cell is used, it is preferable that the transmittance in a wavelength region of 500 to 900 nm, and further, a long-wavelength near-infrared wavelength region is 80% or more in order to transmit sunlight.

When the article of the present invention is used as an electrode, an underlayer may be provided between the substrate and the orientation control thin film for various purposes. Examples of such an underlayer include a color filter, a TFT layer, an EL light emitting layer, a metal layer, a semiconductor layer, and an insulating layer.
Further, two or more types of underlayers can be provided. The electrode made of the article of the present invention can be used for various applications. For example, it can be suitably used as an electrode of a liquid crystal display, an EL display, a solar cell, or the like. For liquid crystal displays, TFT type, STN type and MI
There are various types such as an M type, and in each case, an electric field is applied to the liquid crystal interposed between the transparent electrodes, and the principle of displaying by controlling the orientation direction of the liquid crystal is used. The electrode made of the article of the present invention can be used as the transparent electrode. Also,
The transparent electrode made of the article of the present invention can also be used as an EL display electrode. An EL display has a basic structure in which an EL light emitting layer is sandwiched between a transparent electrode and a back electrode, and an electrode made of the article of the present invention is most suitable as the above-mentioned transparent electrode.

The electrode made of the article of the present invention has high transparency and conductivity, and is therefore excellent as a solar cell electrode. A solar cell has a basic structure in which a semiconductor or an insulator is interposed between a transparent electrode and a back electrode. Since a solar cell is a device that converts light energy into electricity using the photovoltaic effect of a semiconductor interface, it is necessary to guide light to the semiconductor interface over as wide a spectral range as possible, and the transparency of the transparent electrode Must be high. Also,
A transparent electrode of a solar cell has a function of collecting photogenerated carriers generated at a semiconductor interface and guiding the generated carriers to a terminal. Therefore, in order to collect photogenerated carriers as effectively as possible, the conductivity of the transparent electrode must be high. The transparent electrode of the present invention,
Since the light can be guided to the semiconductor interface over a wide spectral range in the entire visible region including light having a wavelength shorter than 450 nm and has high conductivity, it is excellent as an electrode for a solar cell.

Method for Producing Conductive Oxide Thin Film and Article The conductive oxide thin film and article of the present invention can be produced by a thin film method such as a sputtering 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, and a sputtering method. Further, thermal CVD, plasma CVD, MOCVD, optical CVD and the like are known as CVD methods. However, the orientation of the generated oxide thin film differs depending on the film formation method and conditions. In the present invention, an oxide thin film can be easily formed at a relatively low temperature to form an oxide thin film on an orientation control substrate or an orientation control thin film. For example, to form an oriented oxide film by a sputtering method,
It is appropriate to heat the transparent substrate at a temperature of 100 ° C. to 500 ° C. under a pressure of × 10 ^{-4 to 1} Torr. As the sputtering target, a sintered body of metal or oxide, a mixed powder compact, or the like can be used.

In the CVD method, as a raw material of a metal element, In
_{(CH 3) 3, In (} C 2 H 5) 3, In (C 5 H 7 O 2) 3, In (C 11 H 9 O 2) 3, Ga
(CH ₃ ) ₃ , Ga (C ₂ H ₅ ) ₃ , Zn (CH ₃ ) ₂ , Zn (C ₂ H ₅ ) ₂ , Al (C
_{H 3) 3, Al (C} 2 H 5) 3 , such as an organic metal or InCl ₃ of, GaCl _3, ZnCl
_2. Chloride such as AlCl ₃ can be used. As the oxygen source, air, O ₂ , H ₂ O, CO ₂ , N ₂ O, etc. can be used. Film formation by the ion plating method
It can be carried out by evaporating a mixture or sintered body of a metal or oxide as a raw material by resistance heating, high frequency heating, electron impact or the like, and ionizing by DC discharge, RF discharge, electron impact or the like. When metal is used as raw material, air,
By forming a film while flowing O ₂ , H ₂ O, CO ₂ , N ₂ O or the like, a desired oxide thin film can be obtained. Film formation by vacuum evaporation is performed by evaporating a mixture or sintered body of metal or oxide as a raw material at a pressure of 10 ^-3 to 10 ^-6 Torr by resistance heating, high frequency heating, electron impact, laser impact, etc. Can be performed. When metal is used as a raw material,
A desired oxide thin film can be obtained by forming a film while flowing air, O ₂ , H ₂ O, CO ₂ , N ₂ O, or the like. CV
Even by a method D, an ion plating method, a vacuum deposition method, or the like, an oxide thin film can be easily formed at a relatively low temperature to form an oxide thin film on an orientation control substrate or an orientation control thin film.

In the case of the oxide thin film of the first embodiment, the general 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,
The ratio (x: y) is in the range of more than 1.8: 1 to 8: 1 or less, the ratio (z: y) is in the range of 0.4 to 1.4: 1, and the oxygen deficiency amount d is 0, and (x + 3y / 2 + 3z /
It is appropriate to use an oxide represented by the following formula (2) in the range of 1 × 10 ^-1 times). Further, on the orientation control substrate or the orientation control thin film on the substrate, using the oxide as a target, the heating temperature of the substrate is set in the range of 100 to 500 ° C., and the pressure at the time of film formation is 5 × 1.
When the thickness is in the range of 0 ^{-4 to 1} Torr, the oxide thin film of the first embodiment of the present invention is a layer comprising
0n) A conductive layer can be formed in which the plane (where n is a positive integer) is substantially oriented.

Production Method of First Aspect The conductive oxide thin film of the first aspect of the present invention, a thin film of an article having the conductive oxide thin film (article of the first aspect), and an article of the second aspect conductive thin film is obtained by introducing oxygen vacancies in the oxide thin film represented by the above sputtering Zn _x M _y in _z formed by _{O (x + 3y / 2 +} 3z / 2).
In general, oxygen vacancies in an oxide can be generated, for example, by extracting oxygen from the oxide. As a method of extracting oxygen atoms to form oxygen vacancies, a method of performing heat treatment on the oxide thin film in a reducing atmosphere or an inert gas atmosphere can be used. The heat treatment and / or reduction treatment is suitably performed at a temperature in the range of 100 to 1100 ° C., and a preferable temperature range is 300 to
900 ° C. Further, oxygen deficiency can be generated by controlling the oxygen partial pressure during film formation. The amount of oxygen vacancies can be adjusted by introducing an oxygen vacancy during the formation of the oxide thin film and further adding a step of extracting oxygen.

Manufacturing method of the second embodiment The conductive oxide thin film of the second embodiment of the present invention, the thin film of the article having the conductive oxide thin film (the article of the first embodiment), and the article of the third embodiment The thin film is formed by basically forming an oxide thin film having a desired composition by sputtering in the same manner as in the manufacturing method of the first embodiment, and further introducing oxygen vacancies into the obtained oxide as necessary. can get. However, as a sputtering target, the general formula Zn _x M _y In _z O
_{(x + 3y / 2 + 3z / 2)} (where x, y, z and M are the same as described above), and at least a part of at least one element of Zn, M and In is It is appropriate to use an oxide which is substituted by another element and which is substituted with Zn has a valence of 2 or more, and an element which is substituted with M and In has a valence of 3 or more. is there. Further, oxygen vacancies can be generated in the same manner as in the production method of the first aspect of the present invention.

Manufacturing Method of Third Embodiment The conductive oxide thin film of the third embodiment of the present invention, a thin film of an article having the conductive oxide thin film (article of the first embodiment), and an article of the fourth embodiment the thin film is basically similar to the method of manufacturing the first embodiment, the general formula Zn _x M _y in _z O
Forming an oxide thin film of a desired composition represented by _{(x + 3y / 2 + 3z / 2)} , further injecting cations into the obtained oxide thin film,
It can be obtained by introducing oxygen deficiency as necessary. 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 thin film. The injected cations form a solid solution in the crystal lattice and give carrier electrons to the conduction band to develop conductivity. When the oxide does not have oxygen deficiency, the cation implantation amount is 1 × 10 ¹⁸ / electron injection amount into the conduction band.
It is appropriate to select so as to be in the range of cm ³ to 1 × 10 ²² / cm ³ . When the oxide does not have oxygen vacancies, it is appropriate that the sum of the amount of carrier electrons generated by oxygen vacancies and the amount of electrons generated by cation injection be in the above range. The amount of carrier electrons is 1 × 1
If it is smaller than 0 ¹⁸ / cm ³ , sufficient electric conductivity cannot be obtained, and if it is larger than 1 × 10 ²² / cm ³ , absorption due to plasma vibration appears in the visible region and transparency is deteriorated. The amount of carrier electrons is preferably 1 × 10 ¹⁹ / cm ^{3 to} 5 × 10 ^21.
/ Cm ³ .

[0039]

The present invention will be described in more detail with reference to the following examples. Example 1 A ZnO powder (purity 99.99%, manufactured by Kojundo Chemical Laboratory Co., Ltd.) was weighed and placed in a 500 ml polyamide container having a diameter of 2 mm.
Of zirconia beads was added and wet-mixed for 1 hour using a planetary ball mill (Frits Japan). Ethanol was used as a dispersion medium. The powder was calcined in an alumina crucible in air at 1000 ° C. for 5 hours, and then subjected to pulverization again for 1 hour using a planetary ball mill. The calcined powder thus prepared is uniaxially pressed (100 kg / cm
² ) Formed into a disk shape with a diameter of 95 mm according to
It was fired at 00 ° C. for 6 hours to obtain a sintered body. This was polished to obtain a sputtering target. Using a sputtering device (Model BC1457, manufactured by Nihon Vacuum Co., Ltd.), Ar
A gas of / O ₂ = 40/10 was introduced into the apparatus, an RF power of 180 W was input for 40 minutes, and a thin film having a thickness of about 2000 ° was formed on a quartz glass substrate heated to 500 ° C.
Using an X-ray diffractometer (manufactured by Mac Science Corporation, MXP-18A), it was confirmed that ZnO crystals were formed in the obtained thin film. In order to know the degree of c-axis orientation, the X-ray rocking curve method was used to examine the average tilt angle of the c-axis from the substrate normal and the distribution around it.
Its tilt angle is within ± 0.1 ° and its standard deviation angle is 5.
0 ° or less, confirming that the c-axis orientation was high. Further, when this thin film was subjected to a heat treatment at 300 ° C. in the air, it did not show conductivity. The oxide thin film of the first embodiment was formed on the orientation control film (functional film) prepared as described above. The method is described below.

ZnO (manufactured by Kojundo Chemical Laboratory Co., Ltd., purity 9)
9.99%), Al ₂ O ₃ (manufactured by Kojundo Chemical Laboratory Co., Ltd., purity 99.99%), Ga ₂ O ₃ (manufactured by Kojundo Chemical Laboratory Co., Ltd., purity 99.99%) ) And In ₂ O ₃ (purity: 99.99%, manufactured by Kojundo Chemical Laboratory Co., Ltd.) were weighed so as to have the composition shown in Table 1. A 25% paraffin solution in heptane was added to the weighed sample at 10% of the weight of the powder and mixed and crushed in an automatic mortar for 1 hour. Uniaxial pressing using a mold (400kg
/ Cm ² ) to form a disk with a diameter of 95 mm.
Degreasing in air at 600 ° C for 2 hours, then 1400
C. for 5 hours to obtain a sintered body having a relative density of 70% or more. The surface of the sintered body was polished and fixed on a packing plate using an adhesive to obtain a sputtering target. This is supplied to a sputtering device (manufactured by Tokki Corporation, S
PM-303 type), RF power 230W, Ar
/ O ₂ = 18/2, pressure 1 × 10 ^-2 Torr, substrate heating 500
A thin film having a thickness of about 2,000 mm was formed on the substrate on which the orientation control film was formed under the condition of ° C. In the atmosphere,
After heat treatment at 800 ° C., 600 ° C.
Heat treated at 2 ° C. for 2 hours. The structure analysis of the obtained film was performed by using an X-ray diffractometer (MXP-18, MXP-18).
By using A), it was confirmed that crystals having a YbFe ₂ O ₄ type structure were generated. When the degree of c-axis orientation was examined by the X-ray rocking curve method with the axis perpendicular to the (00n) plane of the oxide as the c-axis, the average inclination angle of the c-axis from the substrate normal was 1.0 °. The standard deviation angle was 15 °. The composition of the film was analyzed using a fluorescent X-ray diffractometer (Rigaku Corporation, System 3080). To confirm the conductivity, a conductive resin material (D-550, manufactured by Fujikura Kasei Co., Ltd.) was applied to the four corners of the quadrangular thin film sample, and heated in an electric furnace heated to 100 ° C. for 30 minutes. Thus, an electrode was formed. Solder a lead wire to this electrode and use van der Pauw
The electrical conductivity, carrier concentration, and mobility were measured by a method of measuring electrical conductivity. In addition, in order to measure the light absorption characteristics, a self-recording spectrophotometer (manufactured by Hitachi Electric Co., Ltd., 330
) Was measured by a light transmission method while sweeping from a wavelength of 500 nm to a shorter wavelength side. 50% transmittance
The measurement results are shown in Table 2 together with the composition (atomic ratio) and the electrical characteristics of the film, with the wavelength at which the wavelength becomes the absorption edge wavelength.

[0041]

[Table 1]

[0042]

[Table 2]

Comparative Example 1 An oxide thin film according to the first embodiment was produced on a quartz glass substrate on which no orientation control film was produced by the method described in Example 1. Structural analysis of the formed film was performed using the X-ray diffraction apparatus, and it was confirmed that crystals having a YbFe ₂ O ₄ type structure were generated. Examination of the degree of c-axis orientation by the X-ray rocking curve method revealed that the average inclination angle of the c-axis from the substrate normal was about 5 °, the standard deviation angle was 30 to 40 °, and the The c-axis orientation was inferior to that in the case of manufacturing. Composition (atomic ratio) of the film analyzed by the X-ray fluorescence diffractometer, electric conductivity measured by a van der Pauw method electric conductivity measuring device, amount and mobility of carrier electrons, and further measured by using the spectrophotometer Table 3 shows the obtained absorption edge wavelengths.

[0044]

[Table 3]

Example 2 On a (0001) plane of a ZnO single crystal substrate as an orientation control substrate,
An oxide was produced in the same manner as in Examples 1-1 to 1-3. Structural analysis of the prepared film was performed using the X-ray diffractometer, and YbFe ₂ O
It was confirmed that crystals having a _4- type structure were formed. When the degree of c-axis orientation was examined by the X-ray rocking curve method, the average inclination angle of the c-axis from the substrate normal was 1.0 ° or less,
The standard deviation angle was 12 °, and c-axis orientation equal to or higher than that obtained when the film was formed on the orientation control film was obtained. Composition (atomic ratio) of the film analyzed by the X-ray fluorescence diffractometer, electric conductivity measured by a van der Pauw method electric conductivity measuring device, amount and mobility of carrier electrons, and further measured by using the spectrophotometer Table 4 shows the obtained absorption edge wavelengths.

[0046]

[Table 4]

Example 3 A ZnO thin film as an orientation control film was formed on a quartz glass substrate by the method described in Example 1. An oxide thin film according to the second embodiment was formed on the orientation control film. The method is described below. In ₂ O ₃ (High Purity Chemical Laboratory Co., Ltd.)
Manufactured by Kojundo Chemical Laboratory Co., Ltd., purity 99.99%), Ga ₂ O ₃ (manufactured by Kojundo Chemical Laboratory Co., Ltd., purity 99.99%), ZnO (manufactured by Kojundo Chemical Laboratory Co., Ltd., purity 99.99) %), Al ₂ O ₃ (manufactured by Kojundo Chemical Laboratory Co., Ltd., purity 99.99%), SnO ₂ (manufactured by Kojundo Chemical Laboratory Co., Ltd., purity 99.99%), SiO ₂ ( High purity chemical research institute, purity 99.99%), TiO ₂ (high purity chemical research institute, purity 99.99%), V ₂ O ₅ (high purity chemical research institute ( Co., Ltd., purity 99.99%), GeO ₂ (manufactured by Kojundo Chemical Laboratory Co., Ltd., purity 99.99%), ZrO ₂ (manufactured by Kojundo Chemical Laboratory Co., Ltd., purity 99.99%) 99%), MoO
₃ (High purity chemical laboratory Co., Ltd., purity 99.99%), N
b ₂ O ₅ (purity 99.99%, manufactured by Kojundo Chemical Laboratory Co., Ltd.)
And Ta ₂ O ₅ (manufactured by Kojundo Chemical Laboratory Co., Ltd., purity 99.99)
%) Of each powder was weighed so that the ratio of the metal elements contained in the mixed powder became the value shown in Table 5, a sintered body sputtering target was prepared in the same manner as in the method described in Example 1, and the thin film was formed. Produced. Structural analysis of the formed film was performed using the X-ray diffraction apparatus, and it was confirmed that crystals having a YbFe ₂ O ₄ type structure were generated. Table 5 shows the results obtained by measuring the electric conductivity, the amount of carrier electrons, and the mobility using a van der Pauw method electric conductivity measuring device, measuring the absorbance using the spectrophotometer, and determining the absorption edge wavelength.

[0048]

[Table 5]

Comparative Example 2 An oxide thin film of the second embodiment was formed on a quartz glass substrate on which no orientation control film was formed by the method described in Example 2. Structural analysis of the formed film was performed using the X-ray diffraction apparatus, and it was confirmed that crystals having a YbFe ₂ O ₄ type structure were generated. Examination of the degree of c-axis orientation by the X-ray rocking curve method revealed that the c-axis orientation was inferior to that produced on the orientation control film. The electric conductivity, the amount of carrier electrons,
The mobility was measured, the absorbance was measured using the spectrophotometer, and the absorption edge wavelength was determined. The results are shown in Table 6.

[0050]

[Table 6]

Example 4 A ZnO thin film as an orientation control film was formed on a quartz glass substrate by the method described in Example 1, and the oxide thin film of the second embodiment was formed on the orientation control film. It was produced by the method described in Example 3. However, the ratio of the metal elements contained in the target was weighed so as to be the value shown in Table 7. Structural analysis of the produced film was performed using the X-ray diffractometer, and it was confirmed that crystals having a YbFe ₂ O ₄ type structure were generated. Table 7 shows the electric conductivity measured by the van der Pauw electric conductivity measuring device, the amount and mobility of carrier electrons, and the absorption edge wavelength measured using the spectrophotometer.

[0052]

[Table 7]

Comparative Example 3 An oxide thin film of the second embodiment was formed on a quartz glass substrate on which no orientation control film was formed by the method described in Example 4. Structural analysis of the formed film was performed using the X-ray diffraction apparatus, and it was confirmed that crystals having a YbFe ₂ O ₄ type structure were generated. Examination of the degree of c-axis orientation by the X-ray rocking curve method revealed that the c-axis orientation was inferior to that produced on the orientation control film. The electric conductivity, the amount of carrier electrons,
The mobility was measured, the absorbance was measured using the spectrophotometer, and the absorption edge wavelength was determined. Table 8 shows the results.

[0054]

[Table 8]

Example 5 A ZnO thin film as an orientation control film was formed on a quartz glass substrate by the method described in Example 1, and the oxidation control described in Example 1-1 was formed on the orientation control film. An object thin film was prepared. However, no heat treatment was performed in an Ar atmosphere. H ⁺ ions were applied to this film at a dose rate of about 3 μA / cm ² , 3 × 1.
After implanting 0 ¹⁶ ions / cm ² , the electric conductivity, the amount of carrier electrons,
When the mobility was measured, the electric conductivity was 420 S / cm, the carrier concentration was 3 × 10 ²⁰ / cm ³ , and the mobility was 20 cm ² / Vsec.

Comparative Example 4 An oxide thin film described in Example 1-1 was formed on a quartz glass substrate on which no orientation control film was formed. However, as in Example 3, no heat treatment was performed in an Ar atmosphere. H ⁺ ions were implanted into this film under the same conditions as in Example 12, and the electric conductivity, the amount of carrier electrons, and the mobility were measured by a van der Pauw method electric conductivity measuring apparatus. / Cm, carrier concentration 3 × 10 ²⁰
/ Cm ³ , mobility 13 cm ² / Vsec, lower mobility and lower electrical conductivity than when the oxide was formed on the orientation control film.

[0057]

According to the present invention, the general formula Zn _x M _y In _z O
It is possible to control the orientation of the oxide thin film represented by _{(x + 3y / 2 + 3z / 2)} , the absorption edge is on the shorter wavelength side than 450 nm,
No coloring occurs even if the film thickness is larger than the ITO film.
It is possible to provide a conductive oxide thin film having a higher electric conductivity equal to or higher than that of the ITO film. Further, according to the present invention, an article including an electrode useful for a liquid crystal display, an EL display, a solar cell, or the like can be provided by using the above-described oriented oxide thin film. Further, according to the present invention, the above-mentioned conductive oxide thin film or article can be more easily manufactured using an orientation control film or an orientation control substrate.

[Brief description of the drawings]

Fig. 1 Electronic model showing the octahedral structure of InO ₆ (white circles indicate In
Atoms and the black circles are oxygen atoms). A is (00n)
FIG. 4B is a diagram viewed from a direction perpendicular to the plane, and B is a diagram viewed from a direction parallel to the (00n) plane.

FIG. 2 is a diagram schematically showing the relationship between the octahedron of InO ₆ and the (00n) plane of the octahedron, and furthermore, the relationship with the substrate.

FIG. 3 is an explanatory view showing that, when a (00n) plane is substantially oriented and a current (electrons) is applied thereto, an electron path becomes linear in a direction parallel to the (00n) plane.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical indication location G02F 1/1337 G02F 1/1343 1/1343 G09F 9/30 339 G09F 9/30 339 H01B 5/14 A H01B 5/14 H01L 21/203 S H01L 21/203 C04B 35/00 P

Claims (24)

[Claims] 1. A general formula _{Zn x M y In z O (} x + 3y / 2 + 3z / 2) -d
(Wherein, M is at least one element of aluminum and gallium, the ratio (x: y) is more than 1.8: 1 and 8: 1 or less, and the ratio (z: y) is 0 .4-1.
4: 1 and the oxygen deficiency d exceeds 0,
(X + 3y / 2 + 3z / 2) 1 × 10 ⁻¹ times), wherein the (00n) plane (where n is a positive integer) of the oxide is A conductive oxide thin film, which is substantially oriented. 2. A general formula _{Zn x M y In z O (} x + 3y / 2 + 3z / 2) -d
(Wherein, M is at least one element of aluminum and gallium, the ratio (x: y) is more than 1.8: 1 and 8: 1 or less, and the ratio (z: y) is 0 .4-1.
4: 1 and the oxygen deficiency d exceeds 0,
(X + 3y / 2 + 3z / 2) 1 × 10 ⁻¹ times), and at least one element of Zn, M and In is partially replaced by another element. And the element substituted with M and In are oxide thin films having a valence of 3 or more, and the (00n) plane of the oxide (provided that wherein n is a positive integer) is substantially oriented. 3. The amount of carrier electrons is 1 × 10 ¹⁸ / cm ³ or more.
^3. The conductive oxide thin film according to claim 2, wherein the oxygen deficiency d and the substitution amounts of Zn, M and In are selected so as to be in a range of 1 × 10 ²² / cm ³ . Wherein the general formula _{Zn x M y In z O (} x + 3y / 2 + 3z / 2) -d
(Wherein, M is at least one element of aluminum and gallium, the ratio (x: y) is more than 1.8: 1 and 8: 1 or less, and the ratio (z: y) is 0 .4-1.
4: 1 and the oxygen deficiency d exceeds 0,
(X + 3y / 2 + 3z / 2), which is an oxide thin film obtained by injecting cations into an oxide represented by (1 × 10 ⁻¹ times), wherein the (00n) plane of the oxide (however, wherein n is a positive integer) is substantially oriented. 5. The method according to claim 1, wherein the amount of carrier electrons is 1 × 10 ¹⁸ / cm ³ or more.
5. The conductive oxide thin film according to claim 4, wherein the oxygen deficiency amount d and the cation implantation amount are selected so as to be in a range of 1 × 10 ²² / cm ³ . 6. A general formula _{Zn x M y In z O (} x + 3y / 2 + 3z / 2) -d
Is a general formula Zn _x MInO _{(x + 3) -d} , wherein x is an integer of any of 2 to 7, y is 1, and z is 1. The conductive oxide thin film according to claim 1. 7. An article having the conductive oxide thin film according to any one of claims 1 to 6 on at least a part of at least one surface of a substrate, wherein the conductive oxide thin film is An article formed on an orientation control substrate or an orientation control film on the substrate for substantially orienting the (00n) plane of the oxide. 8. An article having a conductive oxide thin film on at least a portion of at least one surface of the substrate, the conductive oxide thin film, the general 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 in the range of 0.2 to 1.8: 1 and the ratio (z: y) is
From 0.4 to 1.4: 1, and the oxygen deficiency d exceeds 0 and is 1 × 10 ⁻¹ times (x + 3y / 2 + 3z / 2). And the conductive oxide thin film has a (00n) plane (where n is a positive integer) of the oxide substantially on the orientation control substrate or on the orientation control film on the substrate. An article characterized by being formed so as to be oriented. 9. An article having a conductive oxide thin film on at least a portion of at least one surface of the substrate, the conductive oxide thin film, the general 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 in the range of 0.2 to 1.8: 1 and the ratio (z: y) is
0.4 to 1.4: 1, and the oxygen deficiency d exceeds 0, and is represented by 1 × 10 ⁻¹ times (x + 3y / 2 + 3z / 2)), and Zn, A part of at least one element of M and In is replaced by another element, and Zn
The element to be substituted has a valence of 2 or more, and M and In
Is an oxide thin film having a valence of 3 or more, and the conductive oxide thin film is formed on the orientation control substrate or on the orientation control film on the substrate. An article characterized in that the (00n) plane (where n is a positive integer) is formed so as to be substantially oriented. 10. The amount of carrier electrons is 1 × 10 ¹⁸ / cm ^3.
The oxygen deficiency amount d is set so as to fall within the range of 1 × 10 ²² / cm ^3.
10. The article according to claim 9, wherein the substitution amount of Zn, M and In elements is selected. 11. An article having a conductive oxide thin film on at least a portion of at least one surface of the substrate, the conductive oxide thin film general 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 in the range of 0.2 to 1.8: 1 and the ratio (z: y) is
0.4 to 1.4: 1, and the oxygen deficiency d exceeds 0 and is 1 × 10 ^-1 times (x + 3y / 2 + 3z / 2). An oxide thin film into which cations have been implanted, and the conductive oxide thin film is provided on the orientation control substrate or on the orientation control film on the substrate by the (00n) plane (where n Is a positive integer) formed so as to be substantially oriented. 12. The amount of carrier electrons is 1 × 10 ¹⁸ / cm ^3.
The oxygen deficiency amount d is set so as to fall within the range of 1 × 10 ²² / cm ^3.
The article according to claim 11, wherein the amount of cation implantation is selected. 13. Formula of the conductive oxide film Zn _x M _y In
_z O _{(x + 3y / 2 + 3z / 2) -d} is a general formula Zn _x MInO in which _x is an integer of any of 2 to 7, y is 1, and z is 1.
The article according to any one of claims 8 to 12, represented by _{(x + 3) -d} . 14. The article according to claim 7, wherein the orientation control film is a ZnO thin film having a c-axis oriented perpendicular to the substrate. 15. The article according to claim 7, wherein the substrate is substantially transparent in a visible light region, and is used as an electrode. 16. The article according to claim 7, further comprising a base layer between the substrate and the orientation control film. 17. An underlayer comprising a filter layer, a TFT layer, and an E layer.
The article according to claim 16, wherein the article is one or more layers selected from the group consisting of an L layer, a semiconductor layer, and an insulating layer. 18. The method according to claim 7, wherein the orientation control substrate is a ZnO single crystal, and the c-axis of the single crystal is oriented perpendicular to the film forming surface of the substrate. Goods. 19. The article according to claim 7, which is used for a liquid crystal display, an EL display, or a solar cell. 20. general 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 in the range of 0.2 to 8: 1, and the ratio (z: y) is 0.2.
The target is an oxide represented by the range of 4 to 1.4: 1, and the amount of oxygen deficiency d exceeds 0 and is 1 × 10 ^-1 times (x + 3y / 2 + 3z / 2). A method of forming a thin film by a sputtering method, wherein the oxide thin film is formed on an alignment control substrate or a substrate having an alignment control film for substantially aligning the (00n) plane of the oxide. The method for manufacturing an article having the conductive oxide thin film according to claim 1 or the article according to claim 8, wherein the article is formed on an orientation control film. 21. A general 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 in the range of 0.2 to 8: 1, and the ratio (z: y) is 0.2.
4 to 1.4: 1, and the oxygen deficiency d exceeds 0 and is 1 × 10 ⁻¹ times (x + 3y / 2 + 3z / 2), and Zn, M and At least one element of In is partially substituted with another element, the element substituted with Zn has a valence of 2 or more, and the element substituted with M and In has a valence of 3 or more. A thin film formed by sputtering using an oxide having a valency or higher as a target, wherein the oxide thin film is formed on an orientation control substrate for substantially aligning the (00n) plane of the oxide or The method for producing an article having a conductive oxide thin film according to claim 2 or the article according to claim 9, wherein the article is formed on the orientation control film on a substrate having an orientation control film. 22. A general formula _{Zn x M y In z O (} x + 3y / 2 + 3z / 2) -d
(Wherein, M is at least one element of aluminum and gallium, the ratio (x: y) is in the range of more than 0.2: 1 to 8: 1 or less, and the ratio (z: y) is 0.4 ~ 1.
4: 1 and the oxygen deficiency d exceeds 0,
(X + 3y / 2 + 3z / 2) 1 × 10 ⁻¹ times), a thin film is formed by a sputtering method, and then cations are implanted. An object thin film is formed on an orientation control film for substantially orienting the (00n) plane of the oxide or on the orientation control film of a substrate having an orientation control film. An article having the conductive oxide thin film according to claim 4 or the article manufacturing method according to claim 11. 23. The method according to claim 20, wherein the orientation control film is a ZnO thin film having a c-axis oriented perpendicular to the substrate. 24. The method according to claim 20, wherein the orientation control substrate is a ZnO single crystal, and the c-axis of the single crystal is oriented perpendicular to the film forming surface of the substrate. Production method.