JPH08337419A - Infrared-ray reflecting film - Google Patents

Abstract

PURPOSE: To provide an IR reflecting film almost perfectly transmitting visible light over a region to short wavelength and having high IR reflectance. CONSTITUTION: This IR reflecting film is represented by the general formula, M (1)XM (2)y Inz O(x+3y/2+3z/2)-d [where M (1) is at least one of Mg and Zn, M (2) is at least one of Al and Ga, the ratio of x:y is (0.2-1.8):1, the ratio of z:y is (0.4-1.4):1 and oxygen deficiency (d) is 3×10<-5> -1×10<-1> time as much as (x+3y/2+3z/2)]. Other element may be substd. for part of at least one among M (1), M (2) and In in the above-mentioned formula [where the lower limit of (d) is o]. The valence of an element substd. for M (1) is >=2 and that of each of elements substd. for M (2) and In is >=3. This IR reflecting film may be a film obtd. by implanting cations into a film of an oxide represented by the above-mentioned formula [where the lower limit of (d) is 0].

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an infrared reflective film suitable for windows and curtain walls used in buildings and automobiles for reducing air conditioning costs.

[0002]

2. Description of the Related Art For the purpose of improving the habitability of cars and houses and reducing the air conditioning load, there is a demand for glass that has the ability to block solar radiation energy (infrared rays) while transmitting visible light. As the glass having the ability to block infrared rays, there are infrared absorbing glass and infrared reflecting glass.

Infrared absorbing glass contains Fe as a component of ordinary float plate glass, and a small amount of Ni, Co,
It is a glass whose color tone is adjusted by the addition of Se or the like, and absorbs the near infrared light region of sunlight well. Three color tones such as blue, bronze, and gray have been developed. Since the infrared absorbing glass absorbs solar radiation energy and does not reflect it, it has an advantage that no annoyance occurs due to reflected light in the neighborhood.

On the other hand, the infrared reflective glass is a thin film formed by depositing a metal target on the surface of a plate glass by a sputtering method. As the metal target, Au, Ag, Cu, Ti, stainless steel or the like is generally used, and a multi-layer film coating can also be formed. For the purpose of transmitting more visible light, SnO ₂ , instead of metal,
Infrared reflective glass has been developed in which metal oxides such as In ₂ O ₃ and ITO are formed into a thin film by a sputtering method or the like.

[0005]

Infrared absorbing glass is
It is excellent in that it does not cause annoyance to the neighborhood due to reflected light, but it has the drawback that the once-absorbed infrared rays are re-emitted and the heat insulation is not sufficient. Further, since glass is a poor conductor of heat, there is a problem in that a temperature difference between a place where solar radiation is received and a place where solar radiation is not received is likely to occur, causing a thermal cracking phenomenon.

[0006] Unlike the infrared absorbing glass, the infrared reflecting glass on which a metal thin film is formed reflects infrared rays and is therefore excellent in heat insulation. However, since a considerable amount of visible light is also reflected, there is a drawback that the visible light is less transmitted to the room and the room becomes dark. further,
Depending on the type of coating, a lot of electromagnetic waves are reflected, so that damage such as TV ghost may occur.

Infrared reflective glass having a thin film of a metal oxide such as SnO ₂ , In ₂ O ₃ and ITO instead of metal has a better visible light than infrared reflective glass having a metallic film. Excellent in passing through. However, the transmission on the short wavelength side is not sufficient, and it cannot be said that the visible light is completely transmitted. Therefore, there is a problem in terms of aesthetics because it changes color to some extent. In particular, when the film thickness is increased to increase the infrared reflectance, there is a problem that the coloring becomes remarkable.

[0008] Therefore, an object of the present invention is to provide an infrared reflection film which almost completely transmits visible light to the short wavelength side and has a high infrared reflectance. Further, the object of the present invention is to transmit visible light to the short wavelength side almost completely, and to suppress reflection of visible light, thereby reducing annoyance to the neighborhood due to reflected light, and infrared rays. It is to provide an infrared reflective film having a high reflectance.

[0009]

The present invention has the general formula M
(1) _x M (2) _y In _z O _{(x + 3y / 2 + 3z / 2) -d} (wherein
M (1) is at least one of magnesium and zinc
Two elements, M (2) is at least one element of aluminum and gallium, and has a ratio (x: y)
Is in the range of 0.2 to 1.8: 1, the ratio (z: y) is in the range of 0.4 to 1.4: 1, and the oxygen deficiency amount d is
(x + 3y / 2 + 3z / 2) 3 × 10 ⁻⁵ to 1 × 10 ⁻¹ times the range of the oxide). (Referred to as an infrared reflective film).

Further, the present invention provides the general formula M (1) _x M
(2) _y In _z O _{(x + 3y / 2 + 3z / 2) -d} (wherein M (1) is at least one element of magnesium and zinc, and M (2) is aluminum and gallium. Of at least one element, and the ratio (x: y) is 0.2 to
It is in the range of 1.8: 1 and the ratio (z: y) is 0.4 to
1.4: 1, and the oxygen deficiency amount d is 0 to (x
+ 3y / 2 + 3z / 2) is a range of 1 × 10 ^-1 times)),
And at least one of M (1), M (2) and In
Some of the elements of the species are replaced by other elements, M
The element substituted with (1) has a valence of 2 or more, and M
(2) The element substituting for In is composed of an oxide having a valence of 3 or more, and relates to an infrared reflective film (hereinafter, referred to as an infrared reflective film of the second aspect).

In addition, the present invention provides the general formula M (1) _x M
(2) _y In _z O _{(x + 3y / 2 + 3z / 2) -d} (wherein M (1) is at least one element of magnesium and zinc, and M (2) is aluminum and gallium. Of at least one element, and the ratio (x: y) is 0.2 to
It is in the range of 1.8: 1 and the ratio (z: y) is 0.4 to
1.4: 1, and the oxygen deficiency amount d is 0 to (x
(+ 3y / 2 + 3z / 2) in the range of 1 × 10 ⁻¹ times)), and an infrared reflective film comprising an oxide obtained by injecting cations into the oxide ( Hereinafter, it is referred to as an infrared reflective film of the third aspect). The present invention will be described below.

Infrared reflective film of the first embodiment of the present invention M (1) _x M (2) _y In _z O _{(x + 3y / 2 + 3z / 2) -d}
In the above, M (1) is at least one element of magnesium and zinc. Therefore, M (1) may be either magnesium or zinc alone, or M (1) may coexist with magnesium or zinc. When magnesium and zinc coexist, the ratio of magnesium and zinc is not particularly limited. However, as the proportion of magnesium increases, the absorption edge tends to shift to the shorter wavelength side, and the transparency tends to increase.

M (2) may be either aluminum or gallium alone, or M (2) may coexist with aluminum and gallium. When aluminum and gallium coexist, the ratio of aluminum and gallium is not particularly limited. However, the crystallization temperature tends to increase as the proportion of aluminum increases. Increasing the proportion of gallium tends to lower the crystallization temperature.

The ratio (x: y) is in the range of 0.2 to 1.8: 1, and when x / y is less than 0.2, precipitation of the InGaO ₃ phase becomes remarkable. If x / y exceeds 1.8, the crystal structure becomes unstable. The preferred ratio (x: y) is 0.3-
The range is 1.6: 1, and more preferably 0.4-1.
The range is 3: 1. The ratio (z: y) is 0.4 to 1.
In the range of 4: 1 and z / y is less than 0.4, ZnGa
Precipitation of ₂ O ₄ phase, etc. becomes remarkable. When z / y exceeds 1.4, the 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,
The range is more preferably 0.8 to 1.2: 1.

The oxygen deficiency amount d is 3 × 1 of (x + 3y / 2 + 3z / 2)
It is in the range of 0 ⁻⁵ to 1 × 10 ⁻¹ . If the oxygen deficiency amount d is small, there is no problem, but if it is too large, it will absorb visible light and reduce transparency, and the oxygen deficiency amount d will be (x + 3y / 2 +
When it exceeds 3 × 10 ⁻¹ times 3z / 2), visible light is absorbed, which is not preferable. The range of the oxygen deficiency amount d is preferably (x + 3y / 2 + 3z / 2) 1 × 10 ⁻³ to 1 × 10 ^3.
-1 times the range, more preferably 1 of (x + 3y / 2 + 3z / 2)
It is in the range of × 10 ^-2 to 1 × 10 ^-1 times.

The oxygen deficiency amount is a value obtained by subtracting the number of oxygen ions contained in 1 mol of oxide crystal from the stoichiometric amount of oxygen ions in units of mol. The number of oxygen ions contained in the oxide crystal can be calculated, for example, by heating the oxide crystal in carbon powder and measuring the amount of carbon dioxide produced by the infrared absorption spectrum. In addition, the number of stoichiometric oxygen ions can be calculated from the mass of oxide crystals.

The visible light and infrared light transmittance of the infrared reflective film of the present invention is good when the amount of carrier electrons in the conduction band is within a predetermined range. The amount of such carrier electrons is in the range of 1 × 10 ¹⁸ / cm ³ to 1 × 10 ²² / cm ³ . The preferable amount of carrier electrons is 1 ×
It is in the range of 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 method electric conductivity measuring device.

The oxide represented by the general formula M (1) M (2) InO _4-d used in the present invention has the general formula Mg _a Zn _1-a
It can also be represented by A1 _b Ga _1-b InO _4-d, where a is in the range 0 to 1 and b is in the range 0 to 1. Mg _a
Specific examples of the oxide represented by Zn _1-a A1 _b Ga _1-b InO _4-d used in the present invention include, for example, MgA1In.
O _4-d , ZnA1InO _4-d , MgGaInO _4-d , Z
nGaInO _4-d , Mg _a Zn _1-a A1InO _4-d , M
g _a Zn _1-a GaInO _4-d , MgA1 _b Ga _1-b In
O _4-d and ZnA1 _b Ga _1-b InO _4-d can be mentioned. In the formula, a and b can be appropriately determined depending on the composition in consideration of the optical characteristics required for the oxide.

Infrared reflective film of the second aspect of the present invention In the infrared reflective film of the second aspect of the present invention, the general formula M
(1) _x M (2) _y In _z O _{(x + 3y / 2 + 3z / 2) -d}
M (1), M (2), ratio (x: y) and ratio (z:
About y), it is the same as that of the infrared reflective film of the said 1st aspect of this invention. Furthermore, in the infrared reflective film of the second aspect of the present invention, a part of at least one element of M (1), M (2) and In is substituted with another element, and M The element substituted with (1) has a valence of 2 or more, and the element substituted with M (2) and In has a valence of 3 or more. By substituting a part of at least one element of M (1), M (2), and In with another element, electrons can be injected into the oxide. In the infrared reflective film of the second aspect of the present invention, carrier electrons are injected into the conduction band by substituting a part of the metal ions with another metal ion, in addition to introducing oxygen vacancies, and visible light and The infrared transmittance can be changed.

Mg and Zn represented by M (1) are divalent elements, and the element capable of substituting these elements has a valence of 2
It is an element with a valency or higher. It is possible to give a larger carrier injection amount with a smaller amount of substitution for an element having a higher valence. The valences of substitutable elements are usually divalent, trivalent, tetravalent,
It is pentavalent or hexavalent. Examples of the element having a valence of 2 or more include Be, Mg, Ca, Sr, Ba, Cd, and A.
l, Si, Sc, Ti, V, Cr, Mn, Fe, Co,
Ni, Zn, Ga, Ge, Y, Zr, Nb, Mo, T
c, 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.

A1, Ga and In represented by M (2) are trivalent elements, and the element capable of substituting for these is an element having a valence of 3 or more. It is possible to give a larger carrier injection amount with a smaller amount of substitution for an element having a higher valence. The valence of the substitutable 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.

By substituting a part of M (1), M (2) and / or In as described above,
Carrier electrons are injected into the conduction band. From the viewpoint of transparency in the visible light and infrared regions, the injection amount of carrier electrons is, for example, 1 × 10 ¹⁸ / cm ³ to 1 × 10 ^22.
It is suitable to be in the range of / cm ³ , and it is suitable to adjust the substitution amount of each element so that the injection amount of electrons is in the above range. Injection amount of carrier electrons is 1 × 10 ¹⁸ /
If it is less than cm ³ , sufficient absorption in the infrared region cannot be obtained, and if it exceeds 1 × 10 ²² / cm ³ , absorption due to plasma vibration appears in the visible region and the transparency of visible light decreases. The injection amount of carrier electrons is preferably 1 × 10 ¹⁹ /
The range is from cm ^{3 to} 5 × 10 ²¹ / cm ³ . Further, depending on the kind of the element to be replaced, there is one having 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, more preferably 90% or more.

As a specific example of the oxide constituting the infrared reflecting film of the second aspect, the general formula M (1) _x M (2) _y In _z
In O _{(x + 3y / 2 + 3z / 2) -d} , M (1) M (2) InO _{4-d in} which x, y and z are 1 is represented by M (1), M (1), M
Examples thereof include (2) and / or In in which a part of In is substituted with another element. Specific examples of the substitutable element are as described above. General formula M (1) M (2) InO _4-d
The oxide represented by the general formula Mg _a Zn _1-a A1 _b G
It can also be represented by a _1-b InO _4, where a is in the range 0 to 1 and b is in the range 0 to 1. Therefore, oxides of the second aspect, the general formula _{Mg a Zn 1-a A1 b} Ga 1-b I
In nO ₄ , Mg, Zn, A1, Ga and In are partially replaced with other elements.

The above Mg _a Zn _1-a A1 _b Ga _1-b I
Examples of the oxide represented by nO ₄ include MgA1InO
₄ , ZnA1InO ₄ , MgGaInO ₄ , ZnGaI
nO ₄ , Mg _a Zn _{1-a A 1} InO ₄ , Mg _a Zn _1-a
GaInO ₄ , MgA1 _b Ga _1-b InO ₄ , ZnA1
It can be mentioned _b Ga _1-b InO _4. In the formula, a and b can be appropriately determined depending on the composition in consideration of the optical characteristics required for the infrared reflective film.

By substituting a part of at least one of M (1), M (2) and In with another element, carrier electrons are injected into the conduction band. The injection of carrier electrons into the conduction band is also caused by the introduction of oxygen vacancies as described above. Therefore, in the oxide of the second aspect of the present invention, carrier electrons are injected into the conduction band by element substitution or element substitution and oxygen deficiency. The amount of carrier electrons is 1 × 10 ¹⁸ / cm ³ to
The range of 1 × 10 ²² / cm ³ is suitable, and the substitution amount of each element or the substitution amount of elements and the oxygen deficiency amount is appropriately adjusted so that the amount of carrier electrons is in the above range. Is. The amount of carrier electrons is preferably 1 × 10 ¹⁹
/ Cm ^{3 to} 5 × 10 ²¹ / cm ³ .

Infrared Reflective Film of the Third Aspect of the Invention In the infrared reflective film of the third aspect of the invention, the general formula M
(1) _x M (2) _y In _z O _{(x + 3y / 2 + 3z / 2) -d}
M (1), M (2), ratio (x: y) and ratio (z:
About y), it is the same as that of the infrared reflective film of the said 1st aspect of this invention. Furthermore, the infrared reflective film of the third aspect of the present invention is obtained by implanting cations into the oxide represented by the above general formula. In the infrared reflective film of the third aspect of the present invention, carrier electrons are injected into the conduction band by injecting cations in addition to introducing oxygen vacancies,
It is possible to change the absorption in the visible and infrared regions.

The cations injected into the infrared reflective film of the third aspect of the present invention are represented by the general formula M (1) _x M (2) _y In _z.
There is no particular limitation as long as it can form a solid solution without destroying the crystal structure of the oxide represented by O _{(x + 3y / 2 + 3z / 2) -d} . However, ions having a smaller ionic radius tend to be more likely to form a solid solution in the crystal lattice, and the larger the ionic radius, the easier it is to break the crystal structure. Examples of the above cations include 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.

As a specific example of the oxide constituting the infrared reflecting film of the third aspect, the general formula M (1) _x M (2) _y In _z
O _{(x + 3y / 2 + 3z / 2) -d} , in which x, y and z are 1 and M (1) M (2) InO _4-d is an cation-implanted oxide. Can be mentioned. General formula M
(1) M (2) InO oxide represented by the _4-d has the general formula _{Mg a Zn 1-a A1 b} Ga can also be represented by _1-b InO _4, a range in a is 0-1 wherein And b is in the range of 0 to 1. Therefore, oxide used in the third embodiment, the general formula _{Mg a Zn 1-a A1 b} Ga oxide represented by _1-b InO ₄ can be obtained by injecting a cation.

The above Mg _a Zn _1-a A1 _b Ga _1-b I
As described above, the oxide represented by nO ₄ includes, for example, MgA1InO ₄ , ZnA1InO ₄ , and MgGaInO.
_{4, ZnGaInO 4, Mg a Zn} 1-a A1InO 4,
Mg _a Zn _1-a GaInO ₄ , MgA1 _b Ga _1-b In
_{O 4, ZnA1 b Ga 1-} b InO 4 can be cited. In the formula, a and b can be appropriately determined depending on the composition in consideration of the optical characteristics required for the infrared reflective film.

The infrared reflective film of the present invention may be not only the above oxides but also an oxide layer in which crystals different from these oxides coexist. However, the coexistence amount of other crystals is selected within a range that does not cause practical problems in terms of film transparency. Examples of the oxide that can coexist with the oxide of the present invention include ITO and In.
₂ O ₃ , SnO ₂ , ZnO and the like can be mentioned. However, it is not limited to these oxides.

The infrared reflecting film of the present invention is provided on at least a part of at least one surface of the substrate, and has a (00n) plane (where n is a positive integer) of the oxide constituting the infrared reflecting film. It may also be oriented substantially parallel to the surface of the substrate. Such an infrared reflective film has good transparency in the short wavelength region.

The film thickness of the infrared reflective film of the present invention can be appropriately determined in consideration of the optical characteristics required for the film and the intended use.
For example, the lower limit is about 10 nm and the upper limit is about 2 μm. However, depending on the type of element contained in the oxide, there are some that partially absorb in the visible region, and in that case,
A relatively thin membrane is preferred. Further, for those having little or no absorption in the visible region, higher conductivity can be obtained by increasing the film thickness.

The substrate on which the infrared reflecting film of the present invention is provided may be a transparent substrate such as glass or resin. For example, plate glass, window glass for automobiles, window material for houses, window material for cooking utensils and the like can be mentioned.

The infrared reflective film of the present invention can be manufactured by a thin film method. As a typical thin film method, C
There are a VD method, a spray method, a vacuum deposition method, an ion plating method, an MBE method, a sputtering method, a sol-gel method, a spray pyrolysis method and the like. Further, as a CVD method, thermal CV is used.
D, plasma CVD, MOCVD, photo CVD, etc. can be mentioned.

A chemical method such as a CVD method or a spray method is simpler in equipment than a physical method such as a vacuum vapor deposition method or a sputtering method, and is suitable for a large substrate. Furthermore, heat treatment at 350 to 500 [deg.] C. is required when performing the drying and firing steps for promoting the reaction and stabilizing the characteristics, which is suitable for the case where the glass substrate is directly manufactured. The physical method can form a film at a low substrate temperature of 150 to 300 ° C., and is therefore suitable not only for directly manufacturing on a glass substrate but also for manufacturing on various base layers. Among them, the sputtering method is particularly excellent in that it has high productivity and can uniformly form a film on a large area substrate.

For example, in the case of the sputtering method, a target having a desired composition is used and 10 ^-4 to 10 ^-1 Tor is used.
The film can be formed by heating the substrate in the range of room temperature to 500 ° C. under the pressure of r. As the sputtering target, a metal or oxide sintered body, a mixed powder compact, or the like can be used. Further, the orientation of the oxide film formed can be controlled by the film forming method and conditions. For example, in order to form an oriented oxide film by a sputtering method, under a pressure of 5 × 10 ^{−4 to 1} Torr,
By heating the substrate in the range of 100 ° C. to 900 ° C., a film is formed in which the (00n) plane of the oxide (where n is a positive integer) is oriented substantially parallel to the surface of the substrate. can do.

In the CVD method, as a raw material of the metal element, I
n (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 (C
_{H 3) 3, Ga (C} 2 H 5) 3, Zn (CH 3) 2, Z
n (C ₂ H ₅ ) ₂ , Al (CH ₃ ) ₃ , Al (C
₂ H ₅ ) ₃ , Mg (CH ₃ ) ₂ , Mg (C ₂ H ₅ ) ₂ or other organic metals, InCl ₃ , GaCl ₃ , ZnCl ₂ ,
Chlorides such as AlCl ₃ and MgCl ₂ can be used.
Further, as a raw material of oxygen, air, O ₂ , H ₂ O, C
O ₂ , N ₂ O, etc. can be used.

Film formation by the ion plating method is carried out by evaporating a mixture of metal or oxide as a raw material or a sintered body by resistance heating, high frequency heating, electron impact, etc., and by DC discharge, RF discharge, electron impact, etc. It can be performed by ionizing. When metal is used as the raw material,
A predetermined oxide film can be obtained by forming a film while flowing air, O ₂ , H ₂ O, CO ₂ , N ₂ O or the like.

The film formation by the vacuum evaporation method has a pressure of 10 ^-3 to 1
It can be carried out by forming a film on a substrate by evaporating a mixture of metal or oxide as a raw material or a sintered body in 0 ^-6 Torr by resistance heating, high frequency heating, electron impact, laser impact or the like. .. When a metal is used as a raw material, a predetermined oxide film can be obtained by forming a film while flowing air, O ₂ , H ₂ O, CO ₂ , N ₂ O or the like.

The CVD method, the ion plating method,
Also in the vacuum deposition method, an oriented oxide film can be formed by appropriately selecting the film forming conditions.

The transmittance of the infrared reflective film of the first aspect of the present invention is determined by M (1) _x M (2) _y In formed by the thin film method.
It can be changed by introducing oxygen vacancies into the oxide represented by _{z 2} O 3 _{(x + 3y / 2 + 3z / 2)} . Generally, the oxygen deficiency of an oxide can be generated by, for example, extracting oxygen from the oxide. As a method for extracting oxygen atoms to create oxygen vacancies, a method such as heat treatment of the above oxide 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. A preferable temperature range is 300 to 900 ° C. In addition, an oxide having oxygen vacancies can be formed by controlling the oxygen partial pressure at the time of forming the oxide film. The amount of oxygen vacancies can be adjusted by introducing oxygen vacancies at the time of forming the oxide and then adding a step of extracting oxygen.

The infrared reflecting film of the second aspect of the present invention is basically the same as the infrared reflecting film of the first aspect.
It can be obtained by a thin film method and introducing oxygen deficiency if necessary.

For example, in the case of performing the sputtering method, the target is represented by the general formula M (1) _x M (2) _y In _z O
_{(x + 3y / 2 + 3z / 2)} (wherein M (1) is at least one element of magnesium and zinc, and M (2) is at least one element of aluminum and gallium. , The ratio (x: y) is in the range of 0.1 to 2.2: 1 and the ratio (z: y) is in the range of 0.4 to 1.8: 1), and M ( 1), a part of at least one element of M (2) and In is substituted with another element, and the element substituted with M (1) has a valence of 2 or more, As the element substituting for M (2) and In, it is suitable to use an oxide having a valence of 3 or more. For example, when forming a film having a composition of In ₂ Ga ₂ Zn _0.99 Ge _0.01 O ₇ , a sintered body or a mixed powder compact having the same composition can be used as a target.

To prepare an oriented infrared reflective film by the sputtering method, the above-mentioned oxide is used as a target and the heating temperature of the substrate is 100 to 900 ° C.
It is suitable to form the oxide film with the pressure of 5 × 10 ^{−4 to 1} Torr in the film formation range. As a result, a film made of an oxide,
An infrared reflective film having a crystal structure in which the (n) plane (where n is a positive integer) is oriented substantially parallel to the surface of the substrate can be obtained.

Further, the oxygen deficiency can be generated by, for example, extracting oxygen from the oxide, as in the first aspect of the present invention. As a method for extracting oxygen atoms to create oxygen vacancies, a method such as heat treatment of an oxide in a reducing atmosphere or an inert gas atmosphere can be used.

The infrared reflecting film of the third aspect of the present invention is basically the same as the infrared reflecting film of the first aspect.
An oxide having a desired composition represented by the general formula M (1) _x M (2) _y In _z O _{(x + 3y / 2 + 3z / 2)} is formed, and cations are injected into the obtained oxide. However, it can be obtained by introducing oxygen deficiency if necessary. The oxide can be formed by a thin film method or the like. When forming the above oxide, oxygen vacancies may be introduced during the formation of the oxide depending on the conditions. Further, as an example of the thin film method, the method described for the infrared reflective film of the first aspect can be similarly used.

An ion implantation method is used for the implantation of positive ions. As the ion implantation method, the one used in the super-large scale integrated circuit manufacturing process or the like as a means for introducing impurities into a solid can be used as it is. This can be performed by ionizing the element of the cation to be injected, accelerating it to several tens keV or more, and implanting it in the oxide.

The injected cations give carrier electrons to the conduction band and change the transmittance of visible light and infrared light. When the oxide has no oxygen deficiency, the injection amount of cations is 1 × 10 ¹⁸ / cm ³ to 1 in the injection amount of electrons into the conduction band.
It is appropriate to select it within the range of × 10 ²² / cm ³ . When the oxide has oxygen vacancies, it is appropriate that the total of the amount of carrier electrons generated by oxygen vacancies and the amount of electrons generated by cation injection falls within the above range. The amount of carrier electrons is 1 × 10 ¹⁸ / c
If it is smaller than m ³ , sufficient infrared absorption cannot be obtained and 1
If it is larger than × 10 ²² / cm ³ , absorption due to plasma vibration appears in the visible region and the transparency is lowered. The amount of carrier electrons is preferably 1 × 10 ¹⁹ / cm ^{3 to} 5 × 10 ²¹ /
It is in the range of cm ³ .

[0049]

EXAMPLES Examples of the present invention will be described in detail below. Example 1 ZnO: Ga ₂ O ₃ : In ₂ O ₃ was formed on a normal soda lime glass substrate by RF magnetron sputtering.
= 16: 43: 41 as a target, Ar: O ₂ = 18: 2, pressure 6 × 10 ⁻³ Torr,
An infrared reflection film having a thickness of 3000 angstrom was formed under the condition that the substrate temperature was 400 ° C. Next, in the atmosphere,
Annealed at 00 ° C. for 1 hour. The composition of the obtained film was Zn ₁₁ Ga ₄₇ In ₄₁ O _{145 as} a result of analysis by fluorescent X-ray. Furthermore, when the crystallinity of this film was examined by XRD, a diffraction peak on the (009) plane was observed and it was an oriented film.

The spectral transmittances of this film and the ITO film were measured and are shown in FIG. From FIG. 1, the film of the present invention has an absorption edge of 390 nm, has a better transmittance on the shorter wavelength side than the conventional ITO film, and has an infrared region (0.9
It can be seen that even at (μm or more), the light is sufficiently reflected.

Example 2 A target of a sintered body having a composition of ZnGaInO ₄ by RF magnetron sputtering on a normal soda lime glass substrate, Ar: O ₂ = 18: 2, pressure 1 ×.
An infrared reflection film having a thickness of 3000 angstrom was formed at 10 ^-2 Torr and a substrate temperature of 450 ° C. The composition of the obtained film was found to be Zn ₂₅ Ga ₃₆ I as a result of analysis by fluorescent X-ray.
n ₃₉ O ₁₃₈ . Moreover, as a result of the crystallinity analysis by XRD, only the diffraction peak of the (009) plane was observed, and it was found that the film was an alignment film. When the spectral transmittance of this film was measured, it showed almost the same spectral transmittance as the film of Example 1. The absorption edge was 385 nm, and the transmittance was better on the shorter wavelength side than the conventional ITO film. further,
It was confirmed that light was sufficiently reflected in the infrared region (0.9 μm or more).

Example 3 ZnO: Ga ₂ O ₃ : In ₂ O was formed on a normal soda-lime glass substrate by RF magnetron sputtering.
Targeting a sintered body having a composition of ₃ = 45: 25: 35, Ar: O ₂ = 19.5: 0.5, a pressure of 8 × 10 ⁻³ T
An infrared reflective film having a thickness of 3000 angstrom was formed at a substrate temperature of 400 ° C. orr. Next, after annealing this for 10 hours at 500 ° C. in the atmosphere, N ₂ : H ₂ = 9
A reduction heat treatment was performed at 400 ° C. for 10 hours while flowing a gas of 8: 2. The composition of the obtained film was Zn ₃₉ Ga ₂₈ In ₃₃ O _{131 as} a result of analysis by fluorescent X-ray. Furthermore, X
As a result of the crystallinity analysis by RD, only the diffraction peak of the (009) plane was observed, and it was found that the film was an alignment film. When the spectral transmittance of this film was measured, it showed almost the same spectral transmittance as the film of Example 1. Its absorption edge is 380 nm
The transmittance was better on the shorter wavelength side than the conventional ITO film. In addition, infrared region (0.9μm or more)
It was confirmed that the light was reflected sufficiently.

Example 4 By RF magnetron sputtering on a quartz substrate,
ZnO: Ga ₂ O ₃ : In ₂ O ₃ = 40: 29: 31 was added to the sintered body having the composition of SnO ₂ as a target.
Ar: O ₂ = 19.5: 0.5, pressure 8 × 10 ⁻³ Tor
An infrared reflective film having a thickness of 3000 angstroms was formed at a substrate temperature of 450 ° C. As a result of analysis by fluorescent X-ray, the composition of the obtained film was Zn ₃₃ Ga ₃₄ In ₃₃ O ₁₃₄ and contained 1% of Sn. When the crystallinity was examined by XRD, only the diffraction peak of the (009) plane was observed, and it was found to be an alignment film. When the spectral transmittance of this film was measured, it showed almost the same spectral transmittance as the film of Example 1. The absorption edge was 385 nm, and the transmittance was better on the shorter wavelength side than the conventional ITO film. Furthermore, it was confirmed that light was sufficiently reflected in the infrared region (0.9 μm or more).

Example 5 By RF magnetron sputtering on a quartz substrate,
_{ZnO: Ga 2 O 3: In} 2 O 3: Al 2 O 3 = 37:
Targeting the sintered body of the composition of 25: 33: 5, A
Under the conditions of r: O ₂ = 18: 2, pressure of 6 × 10 ⁻³ Torr and substrate temperature of 450 ° C., an infrared reflective film having a thickness of 600 Å was formed. The composition of the obtained film was Zn ₃₃ Ga ₂₈ In ₃₃ Al ₆ O _{134 as} a result of analysis by fluorescent X-ray. Furthermore, when the crystallinity was examined by XRD, a diffraction peak on the (009) plane was observed, and it was found to be an alignment film. When the spectral transmittance of this film was measured, it showed almost the same spectral transmittance as the film of Example 1. The absorption edge was 385 nm, and the transmittance was better on the shorter wavelength side than the conventional ITO film. Furthermore, it was confirmed that light was sufficiently reflected in the infrared region (0.9 μm or more).

Example 6 ZnO: Ga ₂ O ₃ : In ₂ O was formed on a normal soda-lime glass substrate by RF magnetron sputtering.
₃ : MgO = 30: 30: 34: 6 As a target, a sintered body having a composition of Ar: O ₂ = 18: 2 and a pressure of 6 × 10
^-3 Torr, thickness 3000 at substrate temperature 400 ℃
An angstrom infrared reflection film was formed. The composition of the obtained film was found to be Zn ₂₄ Ga _{34 as} a result of analysis by fluorescent X-ray.
It was In ₃₄ Mg ₈ O ₁₃₈ . Furthermore, when the crystallinity was examined by XRD, a diffraction peak on the (009) plane was observed, and it was found to be an alignment film. When the spectral transmittance of this film was measured, it showed almost the same spectral transmittance as the film of Example 1. The absorption edge was 390 nm, and the transmittance was better on the shorter wavelength side than the conventional ITO film. Furthermore, it was confirmed that light was sufficiently reflected in the infrared region (0.9 μm or more).

[0056]

According to the present invention, it is possible to provide an infrared reflecting film which almost completely transmits visible light to the short wavelength side and has a high infrared reflectance. In particular, according to the present invention, as a result of using a film of a Zn-Ga-In-based oxide having a new composition as an infrared reflection film, infrared rays can be sufficiently reflected, so that it is possible to prevent temperature rise due to sunlight in a room or in a company. ,
The cost of air conditioning can be reduced, and since the transmittance on the short wavelength side is good, an infrared reflection film that can almost completely absorb visible light into a room or a vehicle can be obtained. In addition, since the transmittance on the short wavelength side in the visible light region is good, there is no coloring, and an infrared reflective film that is aesthetically good can be obtained. Furthermore, the infrared reflective film of the present invention has the infrared reflectance equivalent to that of the ITO film, and has a wide visible light transmittance and a wide transmission range as compared with the ITO film, and as a result, suppresses the reflection of visible light. Therefore, it is possible to reduce annoyance to the neighborhood due to reflected light. That is, since the infrared reflective film of the present invention has almost no visible light reflection, it is an infrared reflective film having little adverse effect on the neighborhood.

[Brief description of drawings]

FIG. 1 shows the spectral transmittances of an infrared reflective film and an ITO film of Example 1 of the present invention.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location // G02B 5/30 G02B 5/30

Claims (3)

[Claims] 1. The general formula M (1) _x M (2) _y In _z O
_{(x + 3y / 2 + 3z / 2) -d} (wherein M (1) is at least one element of magnesium and zinc, and M (2) 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, the ratio (z: y) is in the range of 0.4 to 1.4: 1, and the oxygen deficiency amount d is Is (x + 3y / 2 + 3z / 2) 3 × 10 ^-5
In the range of 1 × 10 ⁻¹ times). 2. The general formula M (1) _x M (2) _y In _z O
_{(x + 3y / 2 + 3z / 2) -d} (wherein M (1) is at least one element of magnesium and zinc, and M (2) 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, the ratio (z: y) is in the range of 0.4 to 1.4: 1, and the oxygen deficiency amount d is Is 1 from 0 to (x + 3y / 2 + 3z / 2)
10 ^-1 times), and M (1), M
Part of at least one element of (2) and In is substituted with another element, and the element substituted with M (1) has a valence of 2 or more, and M (2) And an element substituting for In is made of an oxide having a valence of 3 or more. 3. The general formula M (1) _x M (2) _y In _z O
_{(x + 3y / 2 + 3z / 2) -d} (wherein M (1) is at least one element of magnesium and zinc, and M (2) 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, the ratio (z: y) is in the range of 0.4 to 1.4: 1, and the oxygen deficiency amount d is Is 1 from 0 to (x + 3y / 2 + 3z / 2)
An infrared reflection film comprising an oxide represented by the formula (10 ^-1 times the range) in which cations are injected.