JP2019163493A - Transparent oxide-laminated film, method of manufacturing transparent oxide-laminated film, and transparent resin substrate - Google Patents

Abstract

To provide a transparent oxide-laminated film having excellent transparency, favorable water vapor barrier performance, and chemical resistance, and a method of manufacturing the transparent oxide-laminated film, and a transparent resin substrate using the transparent oxide-laminated film.SOLUTION: The transparent oxide-laminated film is provided that is formed by laminating a plurality of transparent oxide films containing Zn and Sn, each layer being an amorphous transparent oxide film different in a number-of-metal-atoms ratio of Zn to Sn. The method of manufacturing the transparent oxide-laminated film is provided that uses a target made of Sn-Zn-O-based oxide sintered body to perform sputtering, by which method, at least a first target having an oxide sintered object with the number-of-metal-atoms ratio of Sn/(Zn+Sn) being 0.18 or more and 0.29 or less and a second target having an oxide sintered object with the number-of-metal-atoms ratio of Sn/(Zn+Sn) being 0.44 or more and 0.90 or less are used to form the transparent oxide laminated-film.SELECTED DRAWING: None

Description

  The present invention relates to a transparent oxide laminated film, a method for producing a transparent oxide laminated film, and a transparent resin substrate. Specifically, the present invention relates to an amorphous transparent oxide laminated film having excellent water vapor barrier properties and chemical resistance, a method for producing the same, and a transparent resin substrate on which the transparent oxide laminated film is formed.

  The water vapor barrier resin substrate whose surface of a transparent resin substrate such as a plastic substrate or a film substrate is covered with a metal oxide film such as silicon oxide or aluminum oxide is used to prevent the invasion of water vapor and the deterioration of food and chemicals. It is used for packaging applications. In recent years, they are also used for liquid crystal display elements, solar cells, electroluminescence display elements (EL elements), quantum dot (QD) display elements, quantum dot sheets (QD sheets), and the like.

  In recent years, water vapor barrier transparent resin substrates used in electronic devices, especially display elements, have become more flexible, such as flexibility in shape and curved surface display, in addition to demands for lighter and larger sizes in accordance with the development of display elements. There is also a demand for such as. For this reason, the glass substrate that has been used so far has a strict response, and the adoption of a transparent resin substrate has begun.

  However, since the transparent resin base material has a water vapor barrier property inferior to that of the glass substrate, there is a problem that the water vapor passes through the base material and deteriorates the EL display element, the QD display element, and the like. Also, when forming the base material, the water vapor barrier layer is damaged by the erosion by the adhesive used for the adhesive layer and the chemical solution used for patterning the transparent conductive layer, and the barrier function is impaired. There is also a problem in that the EL display element, the QD display element, and the like are deteriorated through the material. In order to improve such problems, a transparent resin substrate in which a metal oxide film is formed on a resin base material has been developed.

For example, Patent Document 1 describes a water vapor barrier transparent resin substrate in which a transparent conductive film of tin oxide or the like is formed on a transparent film by a sputtering method. According to the description in Patent Document 1, it is described that the water vapor transmission rate by the Mocon method is less than 0.01 g / m ² / day.

In Patent Document 2, a barrier film using a laminate of an inorganic film and an organic film is proposed. Patent Document 2 describes that the water vapor transmission rate at this time is 0.01 g / m ² / day or less, the thickness of the inorganic film is 30 nm to 1 μm, and the thickness of the organic layer is 10 nm to 2 μm. .

JP 2005-103768 A Japanese Patent No. 5161470

In recent years, with the practical application of EL display elements and QD display elements, in the case of a display, for example, an organic EL display, when water vapor is mixed into the organic EL display element, damage caused by moisture greatly affects the interface between the cathode layer and the organic layer. However, it is known that peeling between the organic layer and the cathode portion and dark spots, which are portions that do not emit light, are generated, resulting in a significant decrease in performance. Water vapor permeability required of the water vapor barrier transparent resin substrate that can be used in these displays (WVTR) is, 0.01g ^/ m 2 ^/ day or less, preferably 0.005g ^/ m 2 ^/ day and word It has been broken.

  In addition, these displays have demands for flexibility and the like, and there are many requests for thinning the water vapor barrier transparent resin substrate. The barrier film has a demand of 100 nm or less. Furthermore, there is a strong demand for chemical resistance. Regarding chemical resistance, in order to protect the metal oxide layer from chemicals such as acids, alkalis, and organic solvents, studies have been made to provide a chemical resistant layer made of an organic compound on the metal oxide layer.

  For example, it is chemical resistance with respect to alkaline aqueous solution and acidic aqueous solution used at the etching process at the time of patterning the transparent electrode of the barrier film with a transparent electrode. Generally, the transparent electrode etching process is a procedure of resist coating, resist exposure, resist development, transparent electrode etching, and resist stripping. An alkaline aqueous solution is used in the resist development process and the resist stripping process, and an acidic aqueous solution is used in the transparent electrode etching process. Use. Moreover, when forming a base material, the adhesive agent and sealing material of an adhesive layer may contain an acidic and basic solvent. As a result, when the water vapor barrier transparent layer is partially eroded, the water vapor barrier property is impaired. Therefore, chemical resistance is regarded as important. Since formed elements such as liquid crystal elements, organic EL elements, TFT elements, semiconductor elements and solar cells are vulnerable to water and oxygen, when the water vapor barrier transparent layer is eroded by these chemicals, etc. Dark spots and missing dots occur, causing a problem that the semiconductor element and the solar cell do not function. In order to improve this, there is a need to develop a transparent resin substrate in which a metal oxide film is formed on a resin base material.

On the other hand, in Patent Document 1, the water vapor transmission rate is measured by the Mocon method. However, it is difficult to accurately measure 0.01 g / m ² / day or less by the Mocon method, and the actual water vapor of the membrane is not measured. The question remains about barrier properties. In addition, the film used is 200 μm, and the thickness of the barrier film is as thick as 100 to 200 nm, which is inferior in flexibility.

In Patent Document 2, a barrier film using a laminate of an inorganic film and an organic film has been proposed. However, since the film formation process differs between the inorganic film and the organic film, film formation in each other process is necessary. Therefore, it is conceivable that the productivity deteriorates and the characteristics deteriorate due to foreign matters. In addition, in order to achieve a water vapor transmission rate of 0.01 g / m ² / day or less, there is a description that the structure is three or more layers and the organic layer is about 500 nm, and the flexibility is poor. .

  Therefore, in order to use a film formed by a sputtering method as a barrier film used for an EL display element, a QD display element, etc., it has a good water vapor transmission barrier performance with a thin film thickness and high chemical resistance. It has been demanded.

  The present invention has been made paying attention to such a demand, and has a transparent oxide laminated film having excellent transparency, good water vapor barrier performance, and chemical resistance, a method for producing the same, and a method using the same. An object is to provide a transparent resin substrate.

  The present inventors are suitable for water vapor barrier performance and chemical resistance in a laminated film composed of a plurality of amorphous transparent oxide films having different metal atom number ratios of Zn and Sn with respect to the above-described problems. As a result, the present invention has been completed.

  That is, one embodiment of the present invention is a transparent oxide stacked film in which a plurality of transparent oxide films containing Zn and Sn are stacked, and each layer has an amorphous ratio in which the number of metal atoms of Zn and Sn is different. It consists of a transparent oxide film.

  According to one embodiment of the present invention, by changing the metal atom number ratio of Zn and Sn in each layer, a layer having a water vapor barrier performance and a layer having chemical resistance are formed, respectively, thereby providing a good water vapor barrier performance. And a transparent oxide laminated film having chemical resistance.

  At this time, according to one embodiment of the present invention, the first transparent oxide film having a metal atom number ratio of Sn / (Zn + Sn) of 0.18 or more and 0.29 or less and the metal atom number ratio of Sn / ( At least a second transparent oxide film having Zn + Sn) of 0.44 or more and 0.90 or less may be included.

  When Sn / (Zn + Sn) is 0.18 or more and 0.29 or less, the water vapor barrier performance is excellent, and when Sn / (Zn + Sn) is 0.44 or more and 0.90 or less, a transparent oxide film having excellent chemical resistance Become.

  In one embodiment of the present invention, the transparent oxide film of at least one of the layers contains Ta and Ge, and Ta / (Zn + Sn + Ge + Ta) is 0.1 in the atomic ratio of Zn, Sn, Ta, and Ge. 01 or less, Ge / (Zn + Sn + Ge + Ta) may be 0.04 or less.

  Ta and Ge are components derived from the target, which improves the conductivity of the target itself, thereby increasing the deposition rate, and increasing the target density enables stable deposition. It becomes like this.

  In one embodiment of the present invention, the thickness of the transparent oxide stacked film may be 100 nm or less.

  By setting the film thickness to 100 nm or less, a transparent oxide laminated film excellent in flexibility can be obtained.

In one embodiment of the present invention, the transparent oxide multilayer film may have a water vapor transmission rate of 0.001 g / m ² / day or less by a differential pressure method specified in accordance with the K7129 method of JIS standard.

  By satisfying the above requirements, it can be said that the transparent oxide laminated film has excellent water vapor barrier performance.

  In one embodiment of the present invention, the transparent oxide multilayer film has chemical resistance to acid or alkali, and has a color difference ΔEab before and after being immersed in a solution of 5% hydrochloric acid or 5% sodium hydroxide for 5 minutes. The change value may be 1.0 or less.

  By satisfying the above requirements, it can be said that the transparent oxide laminated film has excellent chemical resistance.

  In one embodiment of the present invention, the transparent oxide laminated film has chemical resistance to acid or alkali, and the film changes before and after being immersed in a 5% concentration hydrochloric acid or 5% concentration sodium hydroxide solution for 5 minutes. The amount may be 2.0 nm or less.

  By satisfying the above requirements, it can be said that the transparent oxide laminated film has excellent chemical resistance.

  Another aspect of the present invention is a method for producing a transparent oxide multilayer film that is sputtered using a target composed of a Sn—Zn—O-based oxide sintered body, and at least in a metal atom number ratio, Sn / Zn A first target having an oxide sintered body in which (Zn + Sn) is 0.18 or more and 0.29 or less, and an oxidation in which Sn / (Zn + Sn) is 0.44 or more and 0.90 or less in terms of the number of metal atoms A transparent oxide laminated film is formed using a second target having a sintered product.

  According to another aspect of the present invention, a transparent oxide film excellent in water vapor barrier performance can be formed by sputtering using the first target, and chemical resistance can be obtained by sputtering using the second target. A transparent oxide film having excellent properties can be formed.

  Another aspect of the present invention is a transparent resin substrate in which the transparent oxide laminated film described above is formed on at least one surface of a transparent resin base material.

  According to the other aspect of this invention, it can be set as the transparent resin substrate which has both the water vapor | steam barrier property which was excellent in forming the transparent oxide laminated film mentioned above, and chemical resistance.

  At this time, in another aspect of the present invention, the transparent oxide film having Sn / (Zn + Sn) of 0.44 or more and 0.90 or less in the metal atom ratio can be the outermost layer.

  Since such a transparent oxide film has chemical resistance, it is preferably formed on the outermost layer of the transparent resin substrate.

  According to the present invention, a transparent oxide multilayer film having excellent transparency, good water vapor barrier performance, and chemical resistance can be provided by high-mass productivity direct current sputtering.

Hereinafter, the transparent oxide laminated film according to the present invention, the method for producing the transparent oxide laminated film, and the transparent resin substrate will be described in the following order. In addition, this invention is not limited to the following examples, In the range which does not deviate from the summary of this invention, it can change arbitrarily.
1. 1. Transparent oxide laminated film 2. Manufacturing method of transparent oxide laminated film Transparent resin substrate

<1. Transparent oxide laminated film>
One embodiment of the present invention is a transparent oxide multilayer film in which a plurality of transparent oxide films containing Zn and Sn are stacked, and the amorphous transparent oxide having different metal atom number ratios of Zn and Sn in each layer It consists of a material film. Thus, by changing the metal atom number ratio of Zn and Sn in each layer, a layer having a water vapor barrier performance and a layer having a chemical resistance are formed respectively, thereby providing a good water vapor barrier performance and chemical resistance. It can be set as the transparent oxide laminated film which has.

  The amorphous transparent oxide laminated film of the present invention (hereinafter sometimes simply referred to as an oxide laminated film) is mainly used as a water vapor barrier film. For the purpose of preventing deterioration by covering the surface of a flexible display element such as a liquid crystal display element, a solar cell, an electroluminescence (EL) display element, etc., as a metal oxide film by sputtering and blocking water vapor, etc. It's being used.

  This is because when the oxide laminated film is a crystalline film, a crystal grain boundary exists in the film, and water vapor permeates through the crystal grain boundary, so that the water vapor barrier performance is deteriorated. Moreover, in the said patent document 1, although the tin oxide type film | membrane is proposed as this amorphous film, when forming a tin oxide type film | membrane by sputtering method, the target material which comprises the sputtering target used for sputtering is the following. A tin oxide system that is the same component as the film is used. Although this tin oxide target material generally has high acid resistance, the relative density of the target material is low, and there are many problems such that the target material cannot be stably formed due to cracking of the target material during sputtering. In the transparent oxide multilayer film according to the present invention, the above-mentioned concern has been solved by using a Sn—Zn—O-based sputtering target described later.

  That is, the oxide sputtered laminated film according to an embodiment of the present invention is an amorphous transparent oxide film containing Zn and Sn, and has different metal atom number ratios of Zn and Sn. It is characterized by being laminated. The number of transparent oxide films to be stacked is not particularly limited, but may be at least two layers. The two transparent oxide films having different metal atom number ratios of Zn and Sn are the first transparent oxide film having a metal atom number ratio of Sn / (Zn + Sn) of 0.18 to 0.29. The second transparent oxide film having a metal atom number ratio of Sn / (Zn + Sn) of 0.44 or more and 0.90 or less is preferable.

  When the first transparent oxide film has a metal atom number ratio of Sn / (Zn + Sn) of 0.18 or more and 0.29 or less, good water vapor barrier performance (low water vapor transmission rate) can be obtained. .

When the above-mentioned metal atom number ratio Sn / (Zn + Sn) is less than 0.18, the SnO ₂ ratio decreases, so that the precipitation of ZnO having strong crystallinity increases and a part of the film crystallizes partially (finely The crystal state) increases and the inflow of water vapor from the crystal grain boundary increases, so that an oxide sputtered film having a desired water vapor barrier property cannot be obtained.

On the other hand, when the above-mentioned metal atom number ratio Sn / (Zn + Sn) is larger than 0.29, the SnO ₂ ratio is not increased so that the stress of the film is increased and further the generation of heat during the film formation is increased. Further, peeling of the film and damage to the substrate occur, and it is impossible to obtain an oxide sputtered film having a water vapor barrier property that can be used for OLED, QD and the like.

  The second transparent oxide film can have good chemical resistance by setting the metal atom ratio to 0.44 or more and 0.90 or less in Sn / (Zn + Sn).

Zinc oxide (ZnO) is easily dissolved in chemicals such as acids and alkalis, and has a drawback of poor resistance to chemicals such as acids and alkalis. For example, high-definition patterning processing by wet etching is difficult. However, the tin oxide (SnO ₂ ) system has extremely high chemical resistance. Therefore, the second transparent oxide film of amorphous containing Zn and Sn, to obtain a chemical resistance of acid, alkali or the like in that the main component from SnO _2.

  When the metal atom number ratio Sn / (Zn + Sn) is smaller than 0.44, the chemical resistance is inferior because the ZnO ratio is not increased.

  On the other hand, when the above metal atom number ratio Sn / (Zn + Sn) is larger than 0.90, the density of the sintered compact of the target used when sputtering is low, and there is a possibility that cracking defects of the sintered compact occur during sputtering. high.

  The first transparent oxide film and the second transparent oxide film are composed of the same kind of oxide. For this reason, it is possible to use the sputtering method widely used industrially for film formation. The sputtering method is effective because it has high productivity and can form a uniform film thickness. In addition, although depending on the sputtering apparatus, in the case of a sputtering apparatus in which a plurality of targets are installed, targets used for the first oxide film and the second oxide film (first target and second target described later) are used. It can be installed and sputtered at the same time. In addition, since the first oxide film and the second oxide film are both amorphous oxide films containing Zn and Sn, the adhesion of the films when stacked is high, and the films Since the film is amorphous, the film stress generated during film formation can be relaxed.

  At least one of the first transparent oxide film and the second transparent oxide film further contains Ta and Ge, and Ta / (Zn + Sn + Ge + Ta) of the metal atom number ratio of Ta and Zn, Sn, and Ge. Is preferably 0.01 or less, and Ge / (Zn + Sn + Ge + Ta) of the above-mentioned Ge / Zn, Sn, Ta metal atom number ratio is preferably 0.04 or less.

  Even if Ta or Ge is contained, the crystallization temperature is 600 ° C. or higher, so that an amorphous film structure is easily obtained. In addition, since the crystallization temperature is high, the amorphous state can be easily maintained even when there is a thermal influence in the mass production process. Further, by adding Ta and Ge at the above ratio, there is an effect of further improving the characteristics of the sputtering target containing Zn and Sn.

  Hereinafter, the additive elements (Ta, Ge) will be briefly described. The sputtering target material is formed by bonding (bonding) an oxide sintered body composed only of Sn—Zn to a backing plate made of a copper material, a stainless steel material, or the like using a bonding material such as indium (In). can get.

An oxide sintered body composed only of Sn—Zn has insufficient conductivity and may have a large specific resistance value. This is because it is necessary to perform sputtering with a larger energy as the specific resistance value is larger at the time of sputtering, and the deposition rate cannot be increased. Therefore, it is necessary to increase the conductivity of the sintered body used for the target. Since Zn ₂ SnO ₄ , ZnO, and SnO ₂ are poorly conductive materials in the oxide sintered body, even if the compounding ratio is adjusted to adjust the amount of the compound phase and ZnO, SnO ₂ Cannot be improved significantly.

Therefore, it is preferable to add Ta (tantalum). Since Ta is substituted for Zn in the ZnO phase, Zn in the Zn ₂ SnO ₄ phase or Sn, and Sn in the SnO ₂ phase, it dissolves, so that the ZnO phase of the wurtzite crystal structure, Zn of the spinel crystal structure A compound phase other than the ₂ SnO ₄ phase and the SnO ₂ phase having a rutile crystal structure is not formed. By adding Ta, the conductivity is improved while maintaining the density of the oxide sintered body.

  In addition, the sintered density of the oxide sintered body composed only of Sn—Zn is around 90% and may not be sufficient. If the density of the oxide sintered body is low, there is a problem that the oxide sintered body is broken during sputtering, and thus the film cannot be stably formed.

Therefore, it is preferable to add a predetermined amount of Ge (germanium). In the oxide sintered body, Ge is substituted for Zn in the ZnO phase, Zn in the Zn ₂ SnO ₄ phase, or Sn in the Zn ₂ SnO ₂ phase and is dissolved in solid solution, so that ZnO having a wurtzite crystal structure No compound phase other than the phase, the Zn ₂ SnO ₄ phase having the spinel crystal structure, and the SnO ₂ phase having the rutile crystal structure is formed. The addition of Ge has the effect of densifying the oxide sintered body. Thereby, the sintered density of the oxide sintered body can be further increased.

  Accordingly, the oxide sintered body further contains Ta and Ge, and Ta / (Zn + Sn + Ge + Ta) of the metal atom number ratio of Ta and Zn, Sn, Ge is 0.01 or less, and the Ge, Zn, Sn, It is preferable that Ge / (Zn + Sn + Ge + Ta) of the Ta metal atom number ratio is 0.04 or less. Note that the approximate lower limit value for obtaining the above effect by addition of Ta and Ge is 0.0005 in terms of the number of metal atoms for both Ta and Ge.

When Ta / (Zn + Sn + Ge + Ta) of the metal atom number ratio of Ta and Zn, Sn, Ge is larger than 0.01, another compound phase, for example, a compound phase such as Ta ₂ O ₅ or ZnTa ₂ O ₆ is generated. The conductivity cannot be improved significantly. Further, when Ge / (Zn + Sn + Ge + Ta) of the metal atom number ratio of Ge and Zn, Sn, Ta is larger than 0.04, another compound phase, for example, a compound phase such as Zn ₂ Ge ₃ O ₈ is generated. The density of the oxide sintered body is reduced, and the target is easily broken during sputtering.

  Sputtering using a target to which Ta and Ge are added does not affect the formed oxide sputtered film. For example, the influence such as water vapor transmission rate is not confirmed. The same applies to chemical resistance. Therefore, even if Ta is included at a ratio of Ta / (Zn + Sn + Ge + Ta) of 0.01 or less and Ge / (Zn + Sn + Ge + Ta) of 0.04 or less, the water vapor barrier performance is not deteriorated and it has good characteristics. It is possible to obtain an amorphous oxide sputtered film. The same applies to chemical resistance.

  The film thickness of the oxide stacked film is preferably 100 nm or less, and more preferably 90 nm or less. By setting it as such a film thickness, the oxide laminated film excellent in flexibility can be provided.

  The thickness of the transparent oxide laminated film including the first oxide film and the second oxide film may be 100 nm or less, preferably 90 nm or less. Therefore, there is no limitation on the individual thicknesses of the first oxide film and the second oxide film.

In one embodiment of the present invention, it is preferable that the water vapor permeability of the oxide multilayer film by a differential pressure method specified in accordance with the JIS standard K7129 method is 0.001 g / m ² / day or less. As described above, the water vapor transmission rate (WVTR) required for the water vapor barrier transparent resin substrate that can be used for the display is 0.01 g / m ² / day or less, preferably 0.005 g / m ² / day. It is said that The water vapor permeability of the oxide multilayer film of the present invention is 0.001 g / m ² / day or less, and can be sufficiently applied to these.

  Note that the water vapor transmission rate is mainly influenced by the first oxide film, and particularly by the film thickness. As the water vapor transmission rate increases, the water vapor transmission rate decreases as the film thickness increases. Therefore, each film thickness is appropriately set in consideration of the required water vapor transmission rate.

In one embodiment of the present invention, the second oxide film has chemical resistance. The chemical resistance is evaluated by a color difference ΔEab. The color difference is evaluated using the L * a * b * color system (CIE 1976). In the L * a * b * color system, L * represents lightness, a * and b * represent hue and saturation, and are represented by chromaticity. L * is a numerical value from 0 to 100 and is large. It turns white. a * is the axis from red to green, + a is the red direction, -a is the green direction, b * is the axis from yellow to blue, + b is the yellow direction, -b is the blue direction, When both a * b * are 0, the color is achromatic. The color difference ΔEab is calculated by the CIE 1976 color difference calculation formula. L *, a *, and b * before and after the evaluation are measured, and the difference between before and after the evaluation is ΔL *, Δa *, and Δb *, and the color difference ΔEab is ((ΔL *) ² + (Δa *) ² + (Δb *) ² ) ^Obtained by ^1/2 .

  In one embodiment of the present invention, chemical resistance confirms chemical resistance against acids and alkalis. The acid resistance is 5% hydrochloric acid, and the alkali resistance can be evaluated as a color difference ΔEab change value before and after immersion in a 5% sodium hydroxide solution for 5 minutes. When this color difference ΔEab is large, the color changes before and after the treatment, and it is presumed that the oxide laminated film is eluted and discolored by the chemical. When the color difference ΔEab change value is 1.0 or less, more preferably 0.5 or less, it can be determined that the oxide laminated film is less eluted by chemicals and has chemical resistance.

  In one embodiment of the present invention, chemical resistance can also be confirmed by a change in the thickness of the film after immersion in acid or alkali. The thickness change before and after immersion in the chemical was confirmed by the ICP-AES method for the amount of dissolution of Zn and Sn in the chemical in which the sample was immersed. Amount). The acid resistance is 5% hydrochloric acid, and the alkali resistance is as long as the decrease in film thickness (film change amount) after being immersed in a 5% sodium hydroxide solution for 5 minutes is 2.0 nm or less. It can be judged that there is chemical nature.

As described above, the tin oxide (SnO ₂ ) system has extremely high chemical resistance. The amorphous second transparent oxide film containing Zn and Sn is made to be 0.44 or more and 0.90 or less in Sn / (Zn + Sn) by Sn / (Zn + Sn) as a main component with SnO ₂ as a main component. Thus, the color difference ΔEab change value can be 0.5 or less, and the film change amount can also be 2.0 nm or less.

  As mentioned above, according to the transparent oxide laminated film which concerns on one Embodiment of this invention, it can have outstanding transparency, favorable water vapor | steam barrier property, and chemical resistance.

<2. Manufacturing method of transparent oxide laminated film>
Next, the manufacturing method of the transparent oxide laminated film which concerns on one Embodiment of this invention is demonstrated. One embodiment of the present invention is a method for manufacturing a transparent oxide multilayer film, in which sputtering is performed using a target formed of a Sn—Zn—O-based oxide sintered body, and at least a metal atom number ratio is Sn / ( A first target having an oxide sintered body in which Zn + Sn is 0.18 or more and 0.29 or less, and an oxide in which Sn / (Zn + Sn) is 0.44 or more and 0.90 or less in terms of the number of metal atoms A transparent oxide multilayer film is formed using a second target having a sintered body.

  As described above, the method for producing a transparent oxide multilayer film according to one embodiment of the present invention performs sputtering using a Sn—Zn—O-based oxide sintered body, and the metal atomic ratio of Zn and Sn is different. Two amorphous laminated films are obtained. That is, a transparent oxide film excellent in water vapor barrier performance can be formed by sputtering using the first target, and a transparent oxide film excellent in chemical resistance can be formed by sputtering using the second target. Can be formed.

  A sintered body in which Sn / (Zn + Sn) of the metal atom number ratio of Zn and Sn contained in the oxide sintered body used for sputtering of the first oxide film is 0.18 or more and 0.29 or less. Sn / (Zn + Sn) of the metal atom number ratio of Zn and Sn contained in the oxide sintered body used when sputtering the first target and the second oxide film is 0.44 or more and 0.90 or less. A target composed of a second target having a sintered body is prepared. The technical significance of the composition range of each sintered body is as described above.

  In addition, the total film thickness of the sputtered oxide stacked film is preferably 100 nm or less, and more preferably 90 nm or less. As described above, in this way, it is possible to provide an oxide laminated film having good water vapor barrier performance and more excellent flexibility. Note that the thicknesses of the first oxide film and the second oxide film are not particularly limited.

  Sputtering may be performed using a sputtering target composed of the above-described oxide sintered body. The sputtering apparatus is not particularly limited, and a direct current magnetron sputtering apparatus or the like can be used.

As sputtering conditions, the degree of vacuum in the chamber is adjusted to 1 × 10 ⁻⁴ Pa or less. An inert gas is introduced into the atmosphere in the chamber. The inert gas is argon gas or the like, and preferably has a purity of 99.999% by mass or more. The inert gas contains 4 to 10% by volume of oxygen with respect to the total gas flow rate. Since the oxygen concentration affects the surface resistance value of the film, the oxygen concentration is set to a predetermined resistance value. Thereafter, a predetermined direct current power source is used to put between the sputtering target and the base material, plasma is generated by direct current pulsing, and sputtering is performed to form a film. Note that the film thickness is controlled by the film formation time.

  Sputtering forms a second oxide film after forming a first oxide film. At this time, when a plurality of targets can be installed in the sputtering apparatus, the first target used for the first oxide film and the second target used for the second oxide film are installed, and sputtering is continuously performed. It is possible to improve productivity by forming continuously with the same apparatus. Moreover, it is the same type of target and has good film adhesion and affinity.

  As mentioned above, according to the manufacturing method of the transparent oxide laminated film which concerns on one Embodiment of this invention, it is the oxide which has the outstanding transparency, favorable water vapor | steam barrier performance, and chemical resistance in DC sputtering with high mass-productivity. A laminated film can be obtained.

<3. Transparent resin substrate>
A transparent resin substrate according to an embodiment of the present invention is obtained by forming at least two amorphous transparent oxide laminated films having different metal atom number ratios of Zn and Sn on a transparent base material. . The transparent oxide multilayer film is formed on at least one surface of the substrate, and the first oxide film has a Sn / (Zn + Sn) ratio of Zn / Sn metal atom number of 0.18 or more and 0. It is preferable that Sn / (Zn + Sn) of the metal atom number ratio of Zn and Sn is 0.44 or more and 0.90 or less in the second oxide film. The film thickness of the transparent oxide multilayer film is preferably 100 nm or less, and more preferably 90 nm or less.

  As the transparent substrate, polyethylene terephthalate, polyethylene, naphthalate, polycarbonate, polysulfone, polyethersulfone, polyarylate, cycloolefin polymer, fluororesin, polypropylene, polyimide resin, epoxy resin, and the like can be used. The thickness of the transparent resin substrate is not particularly limited, but is preferably 50 to 150 μm in view of flexibility, cost, and device needs.

  The sputtering method for the transparent substrate may be performed as described in the method for producing the transparent oxide laminated film. The technical significance such as the preferred metal atom number ratio and film thickness of Zn and Sn is as described above.

  Moreover, the transparent resin substrate according to an embodiment of the present invention has an amorphous sputtered oxide film containing Zn and Sn formed on at least one surface of a base material and having a water vapor barrier property. However, it may be laminated through another film. For example, a silicon oxide film, a silicon nitride oxide film, a resin film, a wet coat film, a metal film, an oxide film, or the like is formed on the substrate, and then the oxide sputter film is used as a water vapor barrier layer. You may form in at least one.

  In one embodiment of the present invention, the second oxide film is preferably the outermost layer. In other words, the second oxide film having chemical resistance is preferably formed on the outer side (surface side) of the first oxide film. Specifically, in the subsequent step, a second oxide film is formed on the outermost surface on the surface side where acid or alkaline chemicals are used in a step of producing a transparent electrode, a step of applying an adhesive, or the like. The first oxide film mainly has a water vapor barrier property, and when this surface is formed on the surface side, it is weak in chemical resistance, and there is a high possibility that the water vapor barrier property is impaired by the chemical. By forming the second oxide film of the present invention on the outer side (surface side) of the first oxide film, it is possible to maintain both chemical resistance and water vapor barrier characteristics.

  For example, a flexible OLED display element, a flexible QD display element, or a QD sheet, which is one of flexible display elements, can be formed using the transparent resin substrate according to an embodiment of the present invention.

  As mentioned above, according to the transparent resin substrate which concerns on one Embodiment of this invention, it has the outstanding transparency, favorable water vapor | steam barrier performance, and chemical resistance by direct current | flow sputtering with high mass productivity.

  Hereinafter, examples of the present invention will be specifically described with reference to comparative examples. However, the technical scope of the present invention is not limited to the description of the following examples, and changes are made within the scope suitable for the present invention. Of course, it is also possible to carry out by adding.

In the following examples, SnO ₂ powder and ZnO powder were used. In addition, when adding an additive element, Ta ₂ O ₅ powder was used as the additive element Ta and GeO ₂ powder was used as the additive element Ge.

(Example 1)
In Example 1, a sintered body manufactured so as to have zinc oxide as a main component and tin oxide as a metal atom number ratio Sn / (Zn + Sn) of 0.26, and tin oxide as a metal atom number ratio Sn / ( A sputtering target (manufactured by Sumitomo Metal Mining Co., Ltd.) was produced using a sintered body produced to have a Zn + Sn ratio of 0.49, and this sputtering target was used to perform sputtering to form a film. As this sputtering apparatus, a direct current magnetron sputtering apparatus (manufactured by ULVAC, SH-550 type) was used.

The amorphous oxide sputtered film was formed under the following conditions. A target was attached to the cathode, and a resin film substrate was disposed immediately above the cathode. The distance between the target and the resin film substrate was 80 mm. The resin film base material on which the film was formed was stationary on the opposite surface of the cathode, and the film formation was performed on the stationary surface. As the resin film substrate, a PEN film (manufactured by Teijin, thickness 50 μm) was used. When the degree of vacuum in the chamber reaches 2 × 10 ⁻⁴ Pa or less, argon gas having a purity of 99.9999% by mass is introduced into the chamber to a gas pressure of 0.6 Pa and argon containing 5% oxygen. In a gas, a DC power source (MDX, MDX) is used as a DC power source, DC power 1500 W adopting 20 kHz DC pulsing is introduced between the sputtering target and Teijin PEN film substrate, and DC pulsing Plasma was generated, and a first oxide film having a metal atom number ratio Sn / (Zn + Sn) of 0.26 was formed on the Teijin PEN film substrate to a thickness of 50 nm by sputtering. Next, a second oxide film having a metal atom number ratio Sn / (Zn + Sn) of 0.49 was formed to a thickness of 50 nm by sputtering.

  The crystallinity, water vapor transmission rate (WVTR), and chemical resistance of the formed oxide sputtered film were confirmed. Crystallinity was measured by X-ray diffraction, and diffraction peaks were observed. Water vapor permeability was measured by a differential pressure method (DELTATAPRM-UH manufactured by Technolox). Moreover, the transmittance | permeability was made into the visible light average transmittance | permeability in wavelength 550nm, and it measured with the spectrophotometer. The chemical resistance was evaluated by immersing the sample in 5% hydrochloric acid or 5% sodium hydroxide aqueous solution for 5 minutes. In addition, the chemical | medical agent temperature in that case is normal temperature. The sample before and after chemical immersion was measured using a spectrocolorimeter (Konica Minolta Co., Ltd. model: CM-5), and the color difference ΔEab was calculated. In addition, the amount of decrease in the thickness before and after chemical immersion (film change amount) was determined by confirming the amount of Zn and Sn dissolved by the ICP-AES method (ICPS-8100 manufactured by Shimadzu Corporation) using the chemical solution in which the sample was immersed. The amount of film change was estimated from the film formation area and film density. In the chemical resistance evaluation, a transparent oxide laminated film formed on a glass substrate was used so that the base material was not dissolved. The results are shown in Table 1.

(Example 2)
In Example 2, the first oxide film has a metal atom number ratio Sn / (Zn + Sn) of 0.18, and the second oxide film has a metal atom number ratio Sn / (Zn + Sn) of 0.59. A transparent oxide laminated film was obtained and measured in the same manner as in Example 1 except that sputtering was performed. The results are shown in Table 1.

(Example 3)
In Example 3, a first oxide film is formed by sputtering to a thickness of 70 nm, and then a second oxide film having a metal atomic ratio Sn / (Zn + Sn) of 0.68 is formed by sputtering. A transparent oxide laminated film was obtained and measured in the same manner as in Example 1 except that the film was formed at 20 nm. The results are shown in Table 1.

Example 4
In Example 4, the same procedure as in Example 1 was performed, except that the first oxide film was formed to a thickness of 15 nm by sputtering, and then the second oxide film was formed to a thickness of 15 nm by sputtering. A transparent oxide laminated film was obtained and measured. The results are shown in Table 1.

(Example 5)
In Example 5, the first oxide film having a metal atom number ratio Sn / (Zn + Sn) of 0.22 was formed by sputtering to a film thickness of 15 nm, and the metal atom number ratio Sn / (Zn + Sn) was 0.59. A transparent oxide multilayer film was obtained and measured in the same manner as in Example 1 except that the second oxide film was formed by sputtering to a film thickness of 15 nm. The results are shown in Table 1.

(Example 6)
In Example 6, a first oxide film is formed by sputtering to a thickness of 20 nm, and then a second oxide film having a metal atom number ratio Sn / (Zn + Sn) of 0.68 is formed by sputtering. A transparent oxide laminated film was obtained and measured in the same manner as in Example 1 except that the film was formed at 10 nm. The results are shown in Table 1.

(Example 7)
In Example 7, a first oxide film having a metal atomic ratio Sn / (Zn + Sn) of 0.22, Ta / (Zn + Sn + Ge + Ta) of 0.01, and Ge / (Zn + Sn + Ge + Ta) of 0.04 is formed by sputtering. A transparent oxide laminated film was obtained and measured in the same manner as in Example 1 except that the film was formed with a thickness of 30 nm and the second oxide film was formed with a thickness of 20 nm by sputtering. The results are shown in Table 1.

(Example 8)
In Example 8, a first oxide film having a metal atom number ratio Sn / (Zn + Sn) of 0.18 was formed to a thickness of 85 nm by sputtering, and the metal atom number ratio Sn / (Zn + Sn) was 0.79. Transparent oxidation is performed in the same manner as in Example 1 except that a second oxide film having a thickness of Ta / (Zn + Sn + Ge + Ta) of 0.01 and Ge / (Zn + Sn + Ge + Ta) of 0.04 is formed to a thickness of 15 nm by sputtering. The product laminated film was obtained and measured. The results are shown in Table 1.

Example 9
In Example 9, a first oxide film having a metal atom number ratio Sn / (Zn + Sn) of 0.28, Ta / (Zn + Sn + Ge + Ta) of 0.01, and Ge / (Zn + Sn + Ge + Ta) of 0.04 was formed by sputtering. A second oxide film having a metal atomic ratio Sn / (Zn + Sn) of 0.68, Ta / (Zn + Sn + Ge + Ta) of 0.01, and Ge / (Zn + Sn + Ge + Ta) of 0.04 was formed by sputtering. Except for this, a transparent oxide laminated film was obtained in the same manner as in Example 1, and the measurement was performed. The results are shown in Table 1.

(Comparative Example 1)
In Comparative Example 1, a first oxide film having a metal atom number ratio Sn / (Zn + Sn) of 0.18 is formed by sputtering, and a metal atom number ratio Sn / (Zn + Sn) of 0.29 is obtained. A transparent oxide laminate film was obtained and measured in the same manner as in Example 1 except that the oxide film was formed by sputtering. The results are shown in Table 1.

(Comparative Example 2)
In Comparative Example 2, a first oxide film having a metal atom number ratio Sn / (Zn + Sn) of 0.16 is formed by sputtering, and a metal atom number ratio Sn / (Zn + Sn) of 0.49 is obtained. A transparent oxide laminate film was obtained and measured in the same manner as in Example 1 except that the oxide film was formed by sputtering. The results are shown in Table 1.

(Comparative Example 3)
In Comparative Example 3, the first oxide film having a metal atom number ratio Sn / (Zn + Sn) of 0.35 was formed by sputtering to a film thickness of 15 nm, and the metal atom number ratio Sn / (Zn + Sn) was 0.79. Transparent oxidation is performed in the same manner as in Example 1 except that a second oxide film having a thickness of Ta / (Zn + Sn + Ge + Ta) of 0.01 and Ge / (Zn + Sn + Ge + Ta) of 0.04 is formed to a thickness of 15 nm by sputtering. The product laminated film was obtained and measured. The results are shown in Table 1.

From Table 1, in Examples 1 to 9 included in the present invention, the water vapor transmission rate by the differential pressure method specified according to the K7129 method of JIS standard is 0.001 g / m ² / day or less (1.0 × 10 ⁻³ or less). g / m ² / day or less), and it was found that the film had good water vapor barrier performance. Furthermore, it was found that the color difference ΔEab in the chemical resistance evaluation was 1.0 or less, and the film change amount was 2.0 nm or less, thus having good chemical resistance.

  On the other hand, in Comparative Example 1 where Sn / (Zn + Sn) of the second oxide film was 0.29, the transparent oxide laminated film was dissolved in acid or alkali in the chemical resistance evaluation.

In Comparative Example 2 in which Sn / (Zn + Sn) of the first oxide film is 0.16 and Comparative Example 3 in which Sn / (Zn + Sn) of the first oxide film is 0.35, the JIS standard is used. water vapor transmission rate according to the specified differential pressure method in accordance with K7129 method ^{of, 0.001g / m 2 /day(1.0×10 -3 g} / m 2 / day) are over, poor in water vapor barrier property I understood. Further, the transmittance measured at a wavelength of 550 nm was 90% or more, and it was found to have transparency. The crystallinity was amorphous in all of Examples 1 to 9 as a result of X-ray diffraction measurement.

  As described above, according to the present invention, a transparent oxide multilayer film having excellent transparency, good water vapor barrier performance, and chemical resistance can be obtained by DC sputtering with high mass productivity.

  Although one embodiment and each example of the present invention have been described in detail as described above, it will be understood by those skilled in the art that many modifications that do not substantially depart from the novel matters and effects of the present invention are possible. It will be easy to understand. Therefore, all such modifications are included in the scope of the present invention.

  For example, a term described with a different term having a broader meaning or the same meaning at least once in the specification or the drawings can be replaced with the different term in any part of the specification or the drawings. Further, the transparent oxide laminated film, the method for producing the transparent oxide laminated film, and the configuration of the transparent resin substrate are not limited to those described in the embodiment and the examples of the present invention, and various modifications can be made. is there.

  By using the transparent oxide laminated film according to the present invention, it becomes possible to form a water vapor barrier transparent resin substrate, and by using the water vapor barrier transparent resin substrate, the degree of freedom of shape, phase display, etc. It is possible to produce a liquid crystal display element, an electroluminescence display element (EL display element), a quantum dot display element (QD display element), electronic paper, a film type solar cell, and the like. Therefore, the present invention is extremely valuable industrially.

Claims (10)

A transparent oxide laminated film in which a plurality of transparent oxide films containing Zn and Sn are laminated,
A transparent oxide multilayer film composed of amorphous transparent oxide films having different metal atom number ratios of Zn and Sn in each layer.   A first transparent oxide film having a metal atom number ratio of Sn / (Zn + Sn) of 0.18 or more and 0.29 or less and a metal atom number ratio of Sn / (Zn + Sn) of 0.44 or more and 0.90. The transparent oxide laminated film according to claim 1, which has at least a second transparent oxide film which is the following. The transparent oxide film of at least one layer contains Ta and Ge,
In the atomic ratio of Zn, Sn, Ta, and Ge,
The transparent oxide laminated film according to claim 1 or 2, wherein Ta / (Zn + Sn + Ge + Ta) is 0.01 or less and Ge / (Zn + Sn + Ge + Ta) is 0.04 or less.   The transparent oxide multilayer film according to any one of claims 1 to 3, wherein the transparent oxide multilayer film has a thickness of 100 nm or less. 5. The water vapor transmission rate according to any one of claims 1 to 4, wherein the transparent oxide laminated film has a water vapor transmission rate of 0.001 g / m ² / day or less by a differential pressure method specified in accordance with a JIS standard K7129 method. Transparent oxide laminated film.   The transparent oxide laminated film has chemical resistance to acid or alkali, and the color difference ΔEab change value before and after being immersed in a 5% concentration hydrochloric acid or 5% concentration sodium hydroxide solution for 5 minutes is 1.0 or less. The transparent oxide laminated film according to any one of claims 1 to 5.   The transparent oxide laminated film has chemical resistance to acid or alkali and has a film change amount of 2.0 nm or less before and after being immersed in a solution of 5% hydrochloric acid or 5% sodium hydroxide for 5 minutes. The transparent oxide laminated film of any one of Claim 1 thru | or 6. A method for producing a transparent oxide multilayer film, wherein sputtering is performed using a target composed of a Sn-Zn-O-based oxide sintered body,
at least,
A first target having an oxide sintered body in which Sn / (Zn + Sn) is 0.18 or more and 0.29 or less in a metal atom number ratio;
Transparent oxide multilayer film forming a transparent oxide multilayer film using a second target having an oxide sintered body with Sn / (Zn + Sn) being 0.44 or more and 0.90 or less in terms of the number of metal atoms Manufacturing method.   A transparent resin substrate in which the transparent oxide multilayer film according to claim 1 is formed on at least one surface of a transparent resin base material.   The transparent resin substrate according to claim 9, wherein a transparent oxide film having Sn / (Zn + Sn) of 0.44 or more and 0.90 or less in terms of the number of metal atoms is the outermost layer.