WO2015159804A1

WO2015159804A1 - Laminate, conductive laminate and electronic device

Info

Publication number: WO2015159804A1
Application number: PCT/JP2015/061144
Authority: WO
Inventors: 尚洋眞下; 和久吉岡; 富田　倫央
Original assignee: 旭硝子株式会社
Priority date: 2014-04-15
Filing date: 2015-04-09
Publication date: 2015-10-22
Also published as: TW201545897A; JPWO2015159804A1

Abstract

Provided is a laminate which is capable of obtaining a crystalline indium tin oxide layer by a heat treatment, and which is capable of decreasing the visibility of an etching pattern that is formed on the indium tin oxide layer. This laminate comprises a transparent base, a foundation layer and an indium tin oxide layer. The foundation layer is laminated on the transparent base, and contains silicon, oxygen and nitrogen. The indium tin oxide layer is laminated on the foundation layer, and is mainly composed of an amorphous indium tin oxide. This laminate has a reflectance difference (∆R) of 1% or less after a heat treatment at a heat treatment temperature of 150°C with a heat treatment duration of 30 minutes. The reflectance difference (∆R) is the absolute value of the difference between the average reflectance (R₁) [%] of positions where the indium tin oxide layer is present and the average reflectance (R₂) [%] of positions where the indium tin oxide layer is absent.

Description

LAMINATE, CONDUCTIVE LAMINATE, AND ELECTRONIC DEVICE

The present invention relates to a laminate, a conductive laminate, and an electronic device.

Since the transparent conductive film has conductivity and optical transparency, it is used as a transparent electrode, a dustproof film, and an electromagnetic wave shielding film. In recent years, a transparent conductive film has attracted attention as a capacitive touch panel electrode. An indium tin oxide film is preferably used as the transparent conductive film.

In the case of an electrostatic capacitance type touch panel electrode, an indium tin oxide film pattern is formed by etching. For this reason, the indium tin oxide film is required to have good etching properties. In addition, the indium tin oxide film is required to have low etching pattern visibility so that the appearance of a touch panel or the like is improved. Furthermore, the indium tin oxide film is required to have optical transparency, electrical conductivity, durability against mechanical contact, and the like.

As a method for producing an indium tin oxide film, a method of performing sputtering while heating a substrate is known. According to the above method, an indium tin oxide film that is crystalline and has good conductivity and durability can be produced. However, since it is crystalline, the etching property is not good.

On the other hand, as a method for producing an indium tin oxide film, a method of performing sputtering at room temperature and a method of performing sputtering by introducing moisture are known. According to the above method, an indium tin oxide film that is amorphous and has good etching properties can be produced. However, since it is amorphous, conductivity and durability are not good.

In order to solve such a problem, a method is known in which an amorphous indium tin oxide film is formed, then etched and further heat-treated to form a crystalline indium tin oxide film. . According to the said method, etching property, electroconductivity, and durability become favorable. Hereinafter, such a method is referred to as a crystallization method.

In general, as the thickness of the indium tin oxide film decreases, the transmittance increases, so the visibility of the etching pattern decreases. However, in the case of the crystallization method, when the thickness is reduced, crystallization by heat treatment becomes difficult, so that conductivity and durability are not improved. About electroconductivity, it can improve by making the content rate of the tin oxide in indium tin oxide high. However, when the content ratio of tin oxide is increased to a certain extent, crystallization by heat treatment becomes difficult, and thus conductivity is not necessarily improved.

Conventionally, various manufacturing methods have been proposed as a method for manufacturing a transparent conductive film (for example, see Patent Document 1). Moreover, in order to suppress peeling between the base material and the transparent conductive film, it is known to provide a base layer between the base material and the transparent conductive film (see, for example, Patent Documents 2 and 3).

JP 2009-224152 A JP 2002-197925 A JP 2005-093318 A

The present invention has been made to solve the above-mentioned problems, and a crystalline indium tin oxide layer can be obtained by heat treatment, and the visibility of an etching pattern formed on the indium tin oxide layer is also improved. It aims at providing the laminated body which can be reduced. Another object of the present invention is to provide a conductive laminate having a crystalline indium tin oxide layer and having low visibility of an etching pattern formed in the indium tin oxide layer. Furthermore, this invention aims at provision of the electronic device which has such an electroconductive laminated body.

The laminate of the present invention has a transparent substrate, an underlayer, and an indium tin oxide layer. The underlayer is laminated on the transparent substrate and contains silicon, oxygen, and nitrogen. The indium tin oxide layer is laminated on the base layer and is mainly made of amorphous indium tin oxide. The laminated body of the present invention has the following reflectance difference ΔR of 1% or less by heat treatment at a heat treatment temperature of 150 ° C. and a heat treatment time of 30 minutes. The reflectance difference ΔR is the average reflectance R ₁ [%] at a wavelength of 480 nm or more and 650 nm or less at a position where the indium tin oxide layer exists, with the transparent substrate side being the light incident surface, and the indium tin oxide layer is It is the absolute value of the difference from the average reflectance R ₂ [%] at a wavelength of 480 nm or more and 650 nm or less at a position where it does not exist.

The conductive laminate of the present invention has a transparent substrate, an underlayer, and an indium tin oxide layer. The underlayer is laminated on the transparent substrate and contains silicon, oxygen, and nitrogen. The indium tin oxide layer is laminated on the underlayer and is mainly made of crystalline indium tin oxide. In the conductive laminate of the present invention, the following reflectance difference ΔR is 1% or less. The reflectance difference ΔR is the average reflectance R ₁ [%] at a wavelength of 480 nm or more and 650 nm or less at a position where the indium tin oxide layer exists, with the transparent substrate side being the light incident surface, and the indium tin oxide layer is It is the absolute value of the difference from the average reflectance R ₂ [%] at a wavelength of 480 nm or more and 650 nm or less at a position where it does not exist.

The electronic device of the present invention has the conductive laminate of the present invention.

In the present invention, an underlayer containing silicon, oxygen, and nitrogen is disposed between the transparent substrate and the amorphous indium tin oxide layer. This underlayer improves the crystallization of the indium tin oxide layer by heat treatment. Moreover, the visibility of the etching pattern formed in the indium tin oxide layer is also reduced by this base layer.

Sectional drawing which shows an example of the laminated body of this invention. Sectional drawing which shows an example of the electroconductive laminated body of this invention.

FIG. 1 is a cross-sectional view showing an example of the laminate of the present invention.
The stacked body 10 includes, for example, a transparent base material 11, an underlayer 12, and an amorphous indium tin oxide layer 13 in this order. Here, the indium tin oxide layer 13 becomes a crystalline indium tin oxide layer by heat treatment.

(Transparent substrate)
The transparent substrate 11 is, for example, polyolefin such as polyethylene or polypropylene, polyester such as polyethylene terephthalate, polybutylene terephthalate or polyethylene naphthalate, polyamide such as nylon 6 or nylon 66, polyimide, polyarylate, polycarbonate, polyacrylate or polyether. Sulphone, polysulfone, and unstretched or stretched plastic films of these copolymers are preferred. In addition, the transparent base material 11 can also use another highly transparent plastic film and glass base material. The transparent base material 11 may have a single layer structure or a laminated structure having two or more layers having different compositions. As the transparent substrate 11, a polyethylene terephthalate film is particularly preferable.

A hard coat layer, a primer layer, an undercoat layer, or the like may be provided on one or both surfaces of the transparent substrate 11. Here, the hard coat layer makes the transparent substrate 11 difficult to be damaged. The primer layer improves the adhesion between the organic material and the inorganic material. The undercoat layer is a refractive index adjusting layer or the like that reduces the visibility of the etching pattern formed on the indium tin oxide layer 13. The transparent substrate 11 may be subjected to surface treatment such as easy adhesion treatment, plasma treatment, corona treatment and the like. The thickness of the transparent substrate 11 is preferably 10 μm or more and 200 μm or less, and more preferably 25 μm or more and 180 μm or less from the viewpoints of flexibility, durability, and the like.

(Underlayer)
The underlayer 12 is provided to promote crystallization of the indium tin oxide layer 13. According to the underlayer 12, compared to a silicon oxide layer (SiO ₂ layer), a silicon nitride layer (Si ₃ N ₄ layer), a magnesium fluoride layer (MgF ₂ layer), an aluminum oxide layer (Al ₂ O ₃ layer), etc. Thus, crystallization can be greatly promoted. In particular, even when the thickness of the indium tin oxide layer 13 is small or when the ratio of tin in the indium tin oxide layer 13 is high in terms of oxide, it can be crystallized well.

The underlayer 12 contains silicon, oxygen, and nitrogen as essential components. The ratio of each element can be appropriately selected according to the effect of promoting crystallization, the required refractive index, and the like. Furthermore, another element may be included, for example, aluminum (Al) or carbon (C) may be included.

When the underlayer 12 contains nitrogen, for example, resistance to alkalinity (hereinafter, also referred to as alkali resistance) is significantly increased as compared with an underlayer made of silicon oxide. Thereby, when passing through the process exposed to alkaline chemicals, such as an etching process, damage, such as film | membrane peeling and a fault, can be suppressed. Further, since the underlayer 12 contains nitrogen, it becomes harder than an underlayer made of, for example, silicon oxide. Thereby, the abrasion resistance of the laminated body 10 is also improved.

From the viewpoint of the crystallinity and resistance value of the indium oxide layer 13 after heat treatment, the ratio of the number of molecules of N ₂ / O ₂ contained in the underlayer 12 is preferably 0.03 or more and 15 or less, and 0.05 or more and 10 The following is more preferable, and 0.07 to 5 is particularly preferable. The ratio of the number of molecules can be measured by electron beam spectroscopic analysis or secondary ion mass spectrometry.

The refractive index of the underlayer 12 at a wavelength of 500 nm is preferably 1.48 or more, more preferably 1.49 or more. The refractive index of the underlayer 12 at a wavelength of 500 nm is preferably 2.00 or less, more preferably 1.95 or less, and even more preferably 1.9 or less. An arbitrary refractive index in the above range can be obtained by adjusting the ratio of silicon, oxygen, and nitrogen in the underlayer 12. By adjusting the refractive index of the underlayer 12, the refractive index of the entire constituent layer can be adjusted regardless of the refractive index of each layer (hereinafter also simply referred to as a constituent layer) constituting the laminate 10 excluding the base layer 12. Adjustment is easy. When the refractive index of the underlayer 12 is within the above range, the effect of reducing the visibility of the etching pattern formed on the indium tin oxide layer 13 is great.

The thickness of the underlayer 12 is preferably 1 nm or more. When the thickness is 1 nm or more, the effect of promoting crystallization of the indium tin oxide layer 13 is large. Moreover, when thickness is 1 nm or more, the effect of reducing the visibility of the etching pattern formed in the indium tin oxide layer 13 is large. From the viewpoint of promoting crystallization and reducing the visibility of the etching pattern, the thickness of the underlayer 12 is more preferably 3 nm or more, further preferably 5 nm or more, and particularly preferably 7 nm or more. The thickness of the underlayer 12 is preferably 100 nm or less, more preferably 80 nm or less, and even more preferably 70 nm or less from the viewpoint of productivity. The underlayer 12 may have a single layer structure or a laminated structure having two or more layers having different compositions. In the case of a laminated structure, the refractive index of the foundation layer 12 may be read as the refractive index of the foundation film layer 12 in contact with the indium oxide layer 13, and the thickness may be read as the entire film thickness of the foundation layer 12 of the lamination structure.

(Indium tin oxide layer)
The indium tin oxide layer 13 is amorphous and becomes crystalline by heat treatment. Since it is amorphous, the etching property is improved. Moreover, durability becomes favorable by becoming crystalline by heat processing. The indium tin oxide layer 13 may be patterned by etching to provide a portion 13a where the indium tin oxide layer 13 is present and a portion 13b where the indium tin oxide layer 13 is not present. The indium tin oxide layer 13 may have a single layer structure, or may have a laminated structure having two or more layers having different compositions. The indium tin oxide layer 13 is preferably in contact with the underlayer 12 because crystallization by heat treatment is good.

Note that amorphous and crystalline materials can be distinguished by the resistance change rate. First, the evaluation object is immersed in an HCl solution (concentration: 1.5 mol / L) for 5 minutes. From the sheet resistance before and after immersion, the rate of change in resistance (sheet resistance after immersion / sheet resistance before immersion) is determined. Those having a resistance change rate of 200% or less are crystalline, and those having a resistance change rate exceeding 200% are amorphous. When the resistance change rate is 200% or less, the crystalline portion and the amorphous portion are mixed, and when the resistance change rate is about 100%, the whole is almost crystallized.

The indium tin oxide layer 13 is mainly composed of indium tin oxide, which is an oxide of indium and tin. Examples of the oxide constituting the indium tin oxide include indium oxide, tin oxide, and a composite oxide of indium oxide and tin oxide.

The indium tin oxide preferably contains 5% by mass to 17% by mass of tin in terms of oxide (SnO ₂ , the same applies hereinafter). When tin is contained in an amount of 5% by mass or more in terms of oxide, the sheet resistance when crystallized is lowered. On the other hand, when tin is contained in an amount of 17% by mass or less in terms of oxide, crystallization becomes easy. The indium tin oxide preferably contains 6% by mass or more of tin in terms of oxide, more preferably 7% by mass or more, and particularly preferably 8% by mass or more. Further, the indium tin oxide preferably contains 15% by mass or less of tin in terms of oxide.

The indium tin oxide layer 13 is preferably made of only indium tin oxide, but can contain components other than indium tin oxide as necessary and within the limits not departing from the spirit of the present invention. Examples of components other than indium tin oxide include oxides such as aluminum, zirconium, gallium, silicon, tungsten, zinc, titanium, magnesium, cerium, and germanium. Content of components other than indium tin oxide layer 13 in indium tin oxide layer 13 is 10 mass% or less in the whole indium tin oxide layer 13, 5 mass% or less is preferable, and 3 mass% or less is more preferable. 1% by mass or less is particularly preferable.

The thickness of the indium tin oxide layer 13 is preferably 10 nm or more. When the thickness is 10 nm or more, crystallization is good and sheet resistance after crystallization is also low. From the viewpoint of crystallization and sheet resistance, the thickness is more preferably 15 nm or more. On the other hand, the thickness is preferably 40 nm or less because the film formation time is shortened and the transmittance is increased. From the viewpoint of film formation time, transmittance, and reflectance difference ΔR, the thickness is more preferably 35 nm or less, and further preferably 30 nm or less.

The indium tin oxide layer 13 is crystallized by heat treatment. The heat treatment can usually be performed in the atmosphere. In view of good crystallization of the indium tin oxide layer 13, the heat treatment temperature is preferably 100 ° C. or higher, and the heat treatment time is preferably 3 minutes or longer. On the other hand, since damage to the transparent substrate 11 is suppressed and productivity is improved, the heat treatment temperature is preferably 170 ° C. or less, and the heat treatment time is preferably 180 minutes or less.

The laminate 10 preferably has a reflectance difference ΔR of 1% or less when the indium oxide layer 13 is crystallized by heat treatment. As heat treatment conditions, for example, the heat treatment temperature is 150 ° C. and the heat treatment time is 30 minutes. When the reflectance difference ΔR after the heat treatment is 1% or less, the visibility of the etching pattern formed on the indium tin oxide layer 13 is sufficiently lowered. The reflectance difference ΔR after the heat treatment is more preferably 0.7% or less.

The reflectance difference ΔR is the average reflectance R ₁ at a wavelength of 480 nm or more and 650 nm or less at the position where the indium tin oxide layer 13 exists with respect to the laminated body 10 after the heat treatment, with the transparent substrate 11 side being the light incident surface. %] And an absolute value (ΔR = | R ₁ −R ₂ |) between the average reflectance R ₂ [%] at a wavelength of 480 nm to 650 nm at a position where the indium tin oxide layer 13 is not present. Even when the indium tin oxide layer 13 is not present, the underlayer 12 is preferably present from the viewpoint of the visibility of the etching pattern, alkali resistance, and scratch resistance.

The adjustment of the reflectance difference ΔR can be performed by adjusting the thickness and refractive index of each layer after the heat treatment, and in particular by adjusting the thickness and refractive index of the underlayer 12. As already described, the refractive index of the underlayer 12 varies greatly depending on the proportion of the constituent elements. Thereby, the refractive index of the entire constituent layer can be easily adjusted regardless of the refractive index of the constituent layer excluding the base layer 12.

Next, the conductive laminate 20 will be described.
FIG. 2 is a cross-sectional view showing an example of the conductive laminate 20. The conductive laminate 20 is obtained by heat-treating the laminate 10. The conductive laminate 20 includes, for example, a transparent substrate 11, an underlayer 12, and a crystalline indium tin oxide layer 21 in this order. The transparent substrate 11 and the foundation layer 12 are the same as the transparent substrate 11 and the foundation layer 12 in the laminate 10.

Since the indium tin oxide layer 21 is crystalline, durability is improved. The indium tin oxide layer 21 may be provided with a portion 21a where the indium tin oxide layer 21 exists and a portion 21b where the indium tin oxide layer 21 does not exist by pattern formation by etching. Examples of the etching pattern include a large number of transparent electrodes. The indium tin oxide layer 21 is preferably in contact with the underlayer 12 because crystallization is good.

The indium tin oxide layer 21 is mainly composed of indium tin oxide, which is an oxide of indium and tin. Examples of the oxide constituting the indium tin oxide include indium oxide, tin oxide, and a composite oxide of indium oxide and tin oxide. The indium tin oxide layer 21 may have a single layer structure or a laminated structure having two or more layers having different compositions.

The specific resistance of the indium tin oxide layer 21 is preferably 2.8 × 10 ⁻⁴ Ω · cm or less. In the case of the said specific resistance, it becomes a thing suitable for an electronic device. The specific resistance is preferably 2.4 × 10 ⁻⁴ Ω · cm or less, and more preferably 2.3 × 10 ⁻⁴ Ω · cm or less.

The indium tin oxide preferably contains 5% by mass to 17% by mass of tin in terms of oxide. When tin is contained in an amount of 5% by mass or more in terms of oxide, the specific resistance is lowered. On the other hand, when tin is contained in an amount of 17% by mass or less in terms of oxide, crystallization is good. The indium tin oxide preferably contains 6% by mass or more of tin in terms of oxide, more preferably 7% by mass or more, and particularly preferably 8% by mass or more. Further, the indium tin oxide preferably contains 15% by mass or less of tin in terms of oxide.

The indium tin oxide layer 21 is preferably composed only of indium tin oxide, but can contain components other than indium tin oxide as necessary and within the limits not departing from the spirit of the present invention. Examples of components other than indium tin oxide include oxides such as aluminum, zirconium, gallium, silicon, tungsten, zinc, titanium, magnesium, cerium, and germanium. Content of components other than indium tin oxide 21 in indium tin oxide layer 21 is 10 mass% or less in the whole indium tin oxide layer 21, 5 mass% or less is preferable, and 3 mass% or less is more preferable. 1% by mass or less is particularly preferable.

The thickness of the indium tin oxide layer 21 is preferably 10 nm or more. When the thickness is 10 nm or more, crystallization is improved and sheet resistance is reduced. From the viewpoint of crystallization and sheet resistance, the thickness is more preferably 15 nm or more. On the other hand, the thickness is preferably 40 nm or less because the film formation time is shortened and the transmittance is increased. From the viewpoint of film formation time, transmittance, and reflectance difference ΔR, the thickness is more preferably 35 nm or less, and further preferably 30 nm or less.

The conductive laminate 20 preferably has the following reflectance difference ΔR of 1% or less. When the reflectance difference ΔR is 1% or less, the visibility of the etching pattern formed on the indium tin oxide layer 21 is sufficiently low. The reflectance difference ΔR is preferably 0.7% or less.

The reflectance difference ΔR is the average reflectance R ₁ [%] at a wavelength of 480 nm or more and 650 nm or less at the position where the indium tin oxide layer 21 exists with the transparent substrate 11 side as the light incident surface, and indium tin oxide. This is the absolute value (ΔR = | R ₁ −R ₂ |) of the difference from the average reflectance R ₂ [%] at a wavelength of 480 nm or more and 650 nm or less at a position where the layer 21 does not exist. Even when the indium tin oxide layer 21 is not present, the underlayer 12 is preferably present from the viewpoint of the visibility of the etching pattern, alkali resistance, and scratch resistance.

The adjustment of the reflectance difference ΔR can be performed by adjusting the thickness, refractive index and the like of each layer, and particularly by adjusting the thickness and refractive index of the underlayer 12. As already described, the refractive index of the underlayer 12 varies greatly depending on the proportion of the constituent elements. Thereby, the refractive index of the entire constituent layer can be easily adjusted regardless of the refractive index of the constituent layer excluding the base layer 12.

The conductive laminate 20 is preferably used for an electronic device, for example, an electronic device having a display unit and a touch panel arranged on the front surface of the display unit. In particular, the conductive laminate 20 is used as a substrate having a transparent electrode in a touch panel. Examples of the touch panel include a resistive film type that specifies a touch position by contacting upper and lower electrodes, and a capacitive coupling method that senses a change in capacitance.

Next, the manufacturing method of the laminated body 10 and the electroconductive laminated body 20 is demonstrated.
The laminated body 10 can be manufactured by forming an indium tin oxide layer 13 after forming the base layer 12 on the transparent substrate 11. The film forming method is not necessarily limited, and a sputtering method, an ion plating method, and a vacuum evaporation method can be applied, and the sputtering method is particularly preferable.

The underlayer 12 is formed by sputtering using, for example, a sputtering target mainly made of silicon. At this time, it is preferable to adjust the ratio of the introduced gas as follows.

First, it is preferable to perform pre-sputtering by introducing argon gas and oxygen gas. At this time, it is preferable to adjust the ratio of the argon gas and the oxygen gas so that the sputtering state becomes the metal mode or the transition mode. Here, the metal mode and the transition mode are states in which a film having absorption in visible light due to lack of oxygen is to be formed. The proportion of oxygen gas is preferably 0.1% by volume or more, more preferably 0.3% by volume or more, and further preferably 0.5% by volume or more with respect to the total amount of argon gas and oxygen gas. The proportion of oxygen gas is preferably 30% by volume or less, more preferably 20% by volume or less, and still more preferably 10% by volume or less with respect to the total amount of argon gas and oxygen gas.

Next, it is preferable to perform sputtering by introducing nitrogen gas while maintaining the ratio of argon gas and oxygen gas at the above ratio, that is, introducing argon gas, oxygen gas, and nitrogen gas. At this time, it is preferable to adjust the ratio of the argon gas and the nitrogen gas so that the sputtering state becomes the reaction mode. The reaction mode is a state in which silicon, oxygen, and nitrogen react to form a film having transparency to visible light. The proportion of nitrogen gas is preferably 30% by volume or more, more preferably 40% by volume or more, and still more preferably 45% by volume or more with respect to the total amount of argon gas and nitrogen gas. Further, the ratio of nitrogen gas is preferably less than 50% by volume, more preferably 49.7% by volume or less, and further preferably 49.5% by volume or less with respect to the total amount of argon gas and nitrogen gas.

Thus, when argon gas and oxygen gas are introduced, the ratio of argon gas and oxygen gas is adjusted so as to be in the metal mode or transition mode, and further, argon gas, oxygen gas, and nitrogen gas are introduced. It is preferable to adjust the ratio of argon gas and nitrogen gas so that the reaction mode is achieved. According to such a method, it is possible to form the underlayer 12 having a large effect of promoting crystallization of the indium tin oxide layer 13.

The indium tin oxide layer 13 is formed by sputtering using a sputtering target made of indium tin oxide, for example. It is preferable that a sputtering target contains 5 mass% or more and 17 mass% or less of tin in oxide conversion in indium tin oxide. The indium tin oxide in the sputtering target is preferably composed of a sintered body obtained by mixing and sintering tin oxide (SnO ₂ ) and indium oxide (In ₂ O ₃ ).

The indium tin oxide layer 13 is formed, for example, by introducing a mixed gas in which oxygen gas is mixed in an amount of 0.5% by volume to 10% by volume, preferably 0.8% by volume to 6% by volume in argon gas. Sputtering is preferably performed. By performing sputtering while introducing such a mixed gas, it is possible to form a film that is amorphous, can be easily crystallized by heat treatment, and has low specific resistance after crystallization.

The conductive laminate 20 is obtained by heat-treating the laminate 10. The heat treatment can usually be performed in the atmosphere. In view of good crystallization of the indium tin oxide layer 13, the heat treatment temperature is preferably 100 ° C. or higher, and the heat treatment time is preferably 3 minutes or longer. On the other hand, since damage to the transparent substrate 11 is suppressed and productivity is improved, the heat treatment temperature is preferably 170 ° C. or less, and the heat treatment time is preferably 180 minutes or less.

Hereinafter, the present invention will be specifically described with reference to examples. Examples 1 to 5 are examples of the present invention, and examples 6 to 9 are comparative examples of the present invention. Note that the present invention is not limited to these examples. Moreover, the thickness of each layer is calculated | required from an optical characteristic or the film-forming speed | rate, and the conveyance speed of a base material, and is not actually measured.

(Example 1)
As a transparent substrate, a polyethylene terephthalate film having a thickness of 100 μm was prepared by subjecting the surface to an easy adhesion treatment. On this transparent substrate, a silicon oxynitride film (SiO _x N _y film) was formed as a base layer. The thickness of the underlayer is 10 nm. The refractive index of the underlayer is 1.49. The refractive index is a value at a wavelength of 500 nm and was measured by ellipsometry.

The underlayer was formed as follows. First, using a boron-doped silicon target, argon gas and oxygen gas were introduced, and pre-sputtering was performed with a DC pulse power source. The ratio of oxygen gas to the total amount of argon gas and oxygen gas is 5% by volume. The sputtering state at this time is a metal mode or a transition mode.

Thereafter, nitrogen gas was introduced in addition to the above argon gas and oxygen gas. At this time, the ratio of nitrogen gas to the total amount of argon gas and nitrogen gas was 45% by volume. Note that the ratio of oxygen gas to the total amount of argon gas and oxygen gas was the same as in pre-sputtering (5 vol%). The state of sputtering at this time is a reaction mode.

Sputtering was continued while introducing argon gas, oxygen gas, and nitrogen gas under the above conditions to form an underlayer on the transparent substrate. The thickness of the underlayer was adjusted by the sputtering rate and the conveyance speed of the transparent substrate.

After the formation of the underlayer, an amorphous indium tin oxide layer (ITO layer) having a thickness of 25 nm was formed on the underlayer to obtain a test piece. The ITO layer is formed by using a target (10% by mass of tin oxide (SnO ₂ )) and 90% by mass of indium oxide (In ₂ O ₃ ) made of indium tin oxide containing 10% by mass of tin in terms of oxide. Using a mixed and sintered target), argon gas and oxygen gas were introduced, and sputtering was performed by a DC power source. The ratio of oxygen gas to the total amount of argon gas and oxygen gas is 1% by volume. The thickness of the ITO layer was adjusted by the sputtering rate and the conveyance speed of the transparent substrate and the like.

(Example 2)
A base layer and an ITO layer were formed in the same manner as in Example 1 except that the base layer formation conditions were changed and the refractive index of the base layer was changed to 1.59. The formation conditions of the underlayer are as follows. In the introduction of argon gas and oxygen gas during pre-sputtering, the ratio of oxygen gas to the total amount of argon gas and oxygen gas was set to 2% by volume. The sputtering state at this time is a metal mode or a transition mode. In the subsequent introduction of argon gas, oxygen gas, and nitrogen gas during sputtering, the ratio of nitrogen gas to the total amount of argon gas and nitrogen gas was 48% by volume. Note that the ratio of oxygen gas to the total amount of argon gas and oxygen gas was the same as in pre-sputtering. The state of sputtering at this time is a reaction mode.

(Example 3)
A base layer and an ITO layer were formed in the same manner as in Example 1 except that the base layer formation conditions were changed and the refractive index of the base layer was changed to 1.80. The formation conditions of the underlayer are as follows. In the introduction of argon gas and oxygen gas during pre-sputtering, the ratio of oxygen gas to the total amount of argon gas and oxygen gas was set to 1% by volume. The sputtering state at this time is a metal mode or a transition mode. In the subsequent introduction of argon gas, oxygen gas, and nitrogen gas during sputtering, the ratio of nitrogen gas to the total amount of argon gas and nitrogen gas was 49 vol%. Note that the ratio of oxygen gas to the total amount of argon gas and oxygen gas was the same as in pre-sputtering. The state of sputtering at this time is a reaction mode.

(Example 4)
A base layer and an ITO layer were formed in the same manner as in Example 1 except that the base layer formation conditions were changed and the refractive index of the base layer was changed to 1.95. The formation conditions of the underlayer are as follows. In the introduction of argon gas and oxygen gas at the time of pre-sputtering, the ratio of oxygen gas to the total amount of argon gas and oxygen gas was set to 0.5% by volume. The sputtering state at this time is a metal mode or a transition mode. In the subsequent introduction of argon gas, oxygen gas, and nitrogen gas at the time of sputtering, the ratio of nitrogen gas to the total amount of argon gas and nitrogen gas was 49.5% by volume. Note that the ratio of oxygen gas to the total amount of argon gas and oxygen gas was the same as in pre-sputtering. The state of sputtering at this time is a reaction mode.

(Example 5)
A base layer and an ITO layer were formed in the same manner as in Example 1 except that the thickness of the ITO layer was changed to 20 nm to obtain a test piece.

(Example 6)
A base layer and an ITO layer were formed in the same manner as in Example 1 except that the base layer was changed to a silicon oxide film (SiO ₂ film) to obtain a test piece. The SiO ₂ film was formed by sputtering with a DC pulse power source using a boron-doped silicon target, introducing argon gas and oxygen gas. The ratio of oxygen gas to the total amount of argon gas and oxygen gas was 50% by volume. The state of sputtering at this time is a reaction mode. The refractive index of the underlayer is 1.47.

(Example 7)
A base layer and an ITO layer were formed in the same manner as in Example 1 except that the base layer was changed to a silicon oxide film (Si ₃ N ₄ film) to obtain a test piece. Note that the Si ₃ N ₄ film was formed by sputtering with a DC pulse power supply using a boron-doped silicon target and introducing argon gas and nitrogen gas. The ratio of nitrogen gas to the total amount of argon gas and nitrogen gas was 50% by volume. The state of sputtering at this time is a reaction mode. The refractive index of the underlayer is 2.04.

(Example 8)
A base layer and an ITO layer were formed in the same manner as in Example 1 except that the base layer was changed to an aluminum oxide film (Al ₂ O ₃ film) to obtain a test piece. The Al ₂ O ₃ film was formed by sputtering with a DC pulse power source using a pure aluminum target, introducing argon gas and nitrogen gas. The ratio of nitrogen gas to the total amount of argon gas and nitrogen gas was 50% by volume. The state of sputtering at this time is a reaction mode. The refractive index of the underlayer is 2.04.

(Example 9)
A test piece was produced by forming an underlayer and an ITO layer in the same manner as in Example 6 except that the thickness of the ITO layer was changed to 20 nm.

Next, the test piece of each example was heat-treated in air at 150 ° C. for 30 minutes. The following evaluation was performed about the test piece after heat processing. The results are shown in Table 1. In the table, the flow ratio (oxygen) of Examples 1 to 5 is the ratio of oxygen gas to the total amount of argon gas and oxygen gas when introducing argon gas and oxygen gas during pre-sputtering. In the table, the flow ratio (nitrogen) of Examples 1 to 5 is the ratio of nitrogen gas to the total amount of argon gas and nitrogen gas when argon gas, oxygen gas, and nitrogen gas are introduced during subsequent sputtering. is there.

[Sheet resistance, specific resistance]
The specimens before and after the heat treatment were cut into a size of 10 mm × 10 mm, and the sheet resistance of the ITO layer was measured using a Hall effect measurement system (Nanometrics, model: HL5500PC). Using this sheet resistance, the specific resistance of the ITO layer was determined by the following formula (1).
Specific resistance [Ω · cm] = sheet resistance value [Ω / □] × ITO layer thickness [cm] (1)

[Rate of change in resistance]
The test piece after the heat treatment was immersed in an HCl solution (concentration 1.5 mol / L) for 5 minutes. From the sheet resistance of the ITO layer before and after immersion, the resistance change rate (sheet resistance after immersion / sheet resistance before immersion × 100 [%]) was determined. The rate of change in resistance approaches 100% when the ITO layer is crystalline and the etching rate is slow. On the other hand, the rate of change in resistance increases beyond 200% when the ITO layer is amorphous and the etching rate increases. In addition, also about the test piece before heat processing, the resistance value change rate of the ITO layer was measured similarly. As a result, it was confirmed that the resistance change rate exceeded 200% and was amorphous. Sheet resistance was measured by the above method.

As in Examples 1 to 5, when the base layer containing silicon, oxygen, and nitrogen is provided, the rate of change in resistance of the ITO layer after the heat treatment is reduced, and the ITO layer is sufficiently crystallized. Moreover, when it has the said base layer, the sheet resistance of the ITO layer after heat processing also becomes small. In particular, even when the ITO layer is thin as in Example 5, the ITO layer is sufficiently crystallized and sheet resistance is reduced. Moreover, in the case of the said base layer, the refractive index of the wide range of 1.49 or more and 1.95 or less is obtained. Therefore, when the etching pattern is formed in the ITO layer, it becomes easy to reduce the visibility of the etching pattern formed in the ITO layer together with other layers.

Further, composition analysis was performed by photoelectron spectroscopy for the underlayer 12 of Examples 1 to 5 in which the effect of reducing the sheet resistance was recognized. As a result, the ratio of the number of molecules of N ₂ / O ₂ in the underlayer 12 of Examples 1 to 5 was 0.05 or more and 3.6 or less. For example, the molecular number ratio of N ₂ / O ₂ in Example 1 is 0.06, the molecular number ratio of N ₂ / O _{2 in} Example 2 is 0.07, and the molecular number ratio of N ₂ / O _{2 in} Example 3 is 1 The ratio of N ₂ / O ₂ molecules in Example 4 and Example 4 was 3.6.

Next, assuming the following test pieces, the visibility of the etching pattern formed on the ITO layer was evaluated by calculation. Note that Example 10 is an example of the present invention, and Example 11 is a comparative example of the present invention.

(Example 10)
The transparent substrate was a polyethylene terephthalate film having a refractive index of 1.53 with respect to light having a wavelength of 500 nm and a thickness of 100 μm. On this transparent substrate, urethane acrylate containing a titanium oxide filler was laminated to a thickness of 1 μm as an undercoat layer. The undercoat layer has a refractive index of 1.55 with respect to light having a wavelength of 500 nm.

On this undercoat layer, a first silicon oxynitride layer having a refractive index of 1.70 with respect to light having a wavelength of 500 nm was laminated so as to have a thickness of 47 nm. Further, a second silicon oxynitride layer having a refractive index of 1.50 with respect to light having a wavelength of 500 nm was laminated on the first silicon oxynitride layer so as to have a thickness of 20 nm. Here, the base layer includes a first silicon oxynitride layer and a second silicon oxynitride layer. An ITO layer having a refractive index of 1.83 with respect to light having a wavelength of 500 nm was laminated on the underlayer so as to have a thickness of 25 nm.

The reflectance difference ΔR was calculated for such a test piece. In the calculation, the vacuum between the light source and the test piece and between the test piece and the measuring instrument is assumed to be a vacuum (refractive index is 1), and the angle between the normal of the surface of the test piece and the light traveling direction is zero. It was assumed that light was incident on the test piece from the transparent substrate side. The portion of ITO layer for obtaining an average reflectivity R ₂ is not present, it consisted of the transparent substrate and the underlayer. As a result, the reflectance difference ΔR was 0.02%.

(Example 11)
The test piece was the same as that of Example 10 except that the configuration of the underlayer was changed. The underlayer was a silicon oxide layer having a refractive index of 1.47 with respect to light having a wavelength of 500 nm and a thickness of 30 nm. When the reflectance difference ΔR was calculated in the same manner as in Example 11, the reflectance difference ΔR was 1.35%.

DESCRIPTION OF SYMBOLS 10 ... Laminated body, 11 ... Transparent base material, 12 ... Underlayer, 13 ... Amorphous indium tin oxide layer, 20 ... Conductive laminated body, 21 ... Crystalline indium tin oxide layer.

Claims

A transparent substrate;
Laminated on the transparent substrate, and an underlayer containing silicon, oxygen, and nitrogen;
An indium tin oxide layer that is laminated on the underlayer and mainly comprises amorphous indium tin oxide;
After heat treatment at a heat treatment temperature of 150 ° C. and a heat treatment time of 30 minutes, when the transparent substrate side is the light incident surface, the average reflectance R 1 at a wavelength of 480 nm to 650 nm at the position where the indium tin oxide layer is present. And a reflectance difference ΔR that is an absolute value of a difference between [%] and an average reflectance R 2 [%] at a wavelength of 480 nm to 650 nm at a position where the indium tin oxide layer is not present is 1% or less. body.
The laminate according to claim 1, wherein the underlayer and the indium tin oxide layer are in contact with each other.
The laminate according to claim 1 or 2, wherein the indium tin oxide layer has a thickness of 40 nm or less.
The laminate according to any one of claims 1 to 3, wherein the indium tin oxide layer contains 5 mass% or more and 17 mass% or less of tin in terms of oxide.
A transparent substrate;
Laminated on the transparent substrate, and an underlayer containing silicon, oxygen, and nitrogen;
An indium tin oxide layer that is laminated on the underlayer and mainly comprises crystalline indium tin oxide;
When the transparent substrate side is a light incident surface, an average reflectance R 1 [%] at a wavelength of 480 nm or more and 650 nm or less at a position where the indium tin oxide layer is present, and the indium tin oxide layer is present. A conductive laminate in which a reflectance difference ΔR, which is an absolute value of a difference from an average reflectance R 2 [%] at a wavelength of 480 nm or more and 650 nm or less at a position where it is not, is 1% or less.
The laminate according to claim 5, wherein the underlayer and the indium tin oxide layer are in contact with each other.
The conductive laminate according to claim 5 or 6, wherein the indium tin oxide layer has a thickness of 40 nm or less.
The conductive laminate according to any one of claims 5 to 7, wherein the indium tin oxide layer contains 5 mass% or more and 17 mass% or less of tin in terms of oxide.
An electronic device having the conductive laminate according to any one of claims 5 to 8.