JP7670682B2 - Electromagnetic wave permeable laminated member and manufacturing method thereof - Google Patents

Description

The present invention relates to an electromagnetic wave transparent laminated member and a method for manufacturing the same.

Traditionally, materials that are electromagnetically transparent and have a metallic luster have been suitable for use in devices that transmit and receive electromagnetic waves, as they combine the luxurious appearance that comes from their metallic luster with electromagnetic wave transparency.

When metal is used in components with a metallic luster, the transmission and reception of electromagnetic waves is practically impossible or is hindered. Therefore, there is a need for an electromagnetically transparent laminated component that combines both metallic luster and electromagnetic wave transparency in order to avoid impairing the transmission and reception of electromagnetic waves and to avoid compromising the design.

As a device for transmitting and receiving electromagnetic waves, such electromagnetically transparent laminated members are expected to be applied to various devices requiring communication, such as automobile door handles equipped with smart keys, in-vehicle communication devices, mobile phones, personal computers, and other electronic devices. Furthermore, with the development of IoT technology in recent years, applications are expected in a wide range of fields, such as home appliances such as refrigerators and lifestyle devices, where communication was not previously possible.

Regarding electromagnetic wave-transmitting laminated members, Patent Document 1 describes an electromagnetic wave-transmitting metallic gloss member comprising an indium oxide-containing layer provided on the surface of a base body, and a metal layer laminated on the indium oxide-containing layer, the metal layer including a plurality of portions that are at least partially discontinuous with each other.

Japanese Patent Application Publication No. 2018-69462

In conventional electromagnetically transparent laminated members, the metal layer could only be formed to a thickness of about 50 nm, depending on the formation method and type of substrate. If the thickness exceeds this, the metal islands formed in the shape of islands will overlap each other, causing a sudden drop in resistance and significantly impairing electromagnetic wave transparency. This requires that the thickness of the metal layer be controlled to the order of a few nanometers, which makes stable production difficult and causes problems such as reduced yields.

The present invention has been made to solve the above problems in the prior art, and aims to provide an electromagnetic wave-transmitting laminated member that has excellent electromagnetic wave transmittance and allows the thickness of the metal layer to be controlled over a wide range.

As a result of extensive research into solving the above problems, the inventors discovered that the above problems can be solved by setting the oxygen concentration in the indium oxide-containing layer within a specific range, and thus completed the present invention.

That is, the present invention is as follows.
[1]
A method for manufacturing a semiconductor device comprising: a substrate; an indium oxide-containing layer formed on the substrate; and a metal layer formed on the indium oxide-containing layer,
the metal layer includes a plurality of portions that are at least partially discontinuous with each other;
a ratio of oxygen atoms to the total of indium atoms and at least one metal atom M of Sn and Zn (O/(In+M) ratio) is 1.15 or less when the surface of the indium oxide-containing layer is measured by X-ray photoelectron spectroscopy;
Electromagnetic wave transparent laminated material.
[2]
The electromagnetic wave transparent laminate member according to [1], wherein the indium oxide-containing layer is provided in a continuous state.
[3]
The electromagnetic wave transparent laminate member according to the above [1] or [2], wherein the indium oxide-containing layer contains any one of indium oxide (In ₂ O ₃ ), indium tin oxide (ITO), or indium zinc oxide (IZO).
[4]
The electromagnetic wave transparent laminate member according to any one of [1] to [3], wherein the metal layer is a layer containing aluminum or an aluminum alloy.
[5]
The electromagnetic wave transparent laminate member according to any one of [1] to [4], wherein the indium oxide-containing layer has a thickness of 1 nm to 1000 nm.
[6]
The electromagnetic wave transparent laminate member according to any one of [1] to [5], wherein the metal layer has a thickness of 10 nm to 200 nm.
[7]
The electromagnetic wave transparent laminate member according to any one of the above [1] to [6], wherein the ratio of the thickness of the metal layer to the thickness of the indium oxide-containing layer (thickness of the metal layer/thickness of the indium oxide-containing layer) is 0.02 to 100.
[8]
The electromagnetic wave transparent laminate member according to any one of [1] to [7], having a sheet resistance of 100 Ω/□ or more.
[9]
The electromagnetic wave transparent laminate member according to any one of [1] to [8], wherein the plurality of portions are formed in an island shape.
[10]
The electromagnetic wave transparent laminate member according to any one of [1] to [9], wherein the substrate is a substrate film, a resin molded substrate, a glass substrate, or an article to be imparted with metallic luster.
[11]
an indium oxide-containing layer forming step of forming an indium oxide-containing layer on a substrate;
forming a metal layer on the indium oxide-containing layer;
The method for producing an electromagnetic wave transparent laminate member according to any one of [1] to [10], wherein the indium oxide-containing layer forming step uses a metal target containing indium as a main component, and forms an indium oxide-containing layer on the base by reactive sputtering while supplying an inert gas and an oxygen gas.

According to the present invention, it is possible to provide an electromagnetic wave-transmitting laminated member that has excellent electromagnetic wave transmittance and allows the thickness of the metal layer to be controlled over a wide range.

Fig. 1(a) is a schematic cross-sectional view of an electromagnetic wave transparent laminate member 1 according to one embodiment of the present invention, and Fig. 1(b) is an electron microscope photograph (SEM image) of the surface of the electromagnetic wave transparent laminate member 1 according to one embodiment of the present invention. 2(a) and 2(b) show examples of electron microscope photographs (TEM images) of a cross section of an electromagnetic wave transparent laminate member according to one embodiment of the present invention. FIG. 3 is a diagram for explaining a method for measuring the thickness of a metal layer of an electromagnetic wave transparent laminate member according to one embodiment of the present invention. 4(a) to 4(d) show electron microscope photographs (TEM images) of cross sections of the laminated members of Examples 4 to 7, respectively. 5(a) and 5(b) show electron microscope photographs (TEM images) of cross sections of the laminated members of Comparative Examples 1 and 3.

The present invention will be described in detail below with reference to the attached drawings. However, the present invention is not limited to the following embodiments, and can be modified as desired without departing from the gist of the present invention. In addition, the use of "to" to indicate a numerical range means that the numerical values before and after it are included as the lower and upper limits.

<1. Basic configuration>
An electromagnetic wave transparent laminate member according to an embodiment of the present invention comprises a base, an indium oxide-containing layer formed on the base, and a metal layer formed on the indium oxide-containing layer, the metal layer including a plurality of portions that are at least partially discontinuous with each other, and is characterized in that, when the surface of the indium oxide-containing layer is measured by X-ray photoelectron spectroscopy, the ratio of oxygen atoms to the sum of indium atoms and at least one metal atom M of Sn and Zn (O/(In+M) ratio) is 1.15 or less.

Figure 1(a) shows a schematic cross-sectional view of an electromagnetic wave-transmitting laminate member 1 in one embodiment of the present invention, and Figure 1(b) shows an example of an electron microscope photograph (SEM image) of the surface of an electromagnetic wave-transmitting laminate member 1 in one embodiment of the present invention. The image size in the electron microscope photograph is 1.2 μm × 0.9 μm.

As shown in FIG. 1(a), the electromagnetic wave transparent laminate member 1 includes a base 10, an indium oxide-containing layer 11 formed on the base 10, and a metal layer 12 formed on the indium oxide-containing layer 11.

The indium oxide-containing layer 11 is provided on the surface of the substrate 10. The indium oxide-containing layer 11 may be provided directly on the surface of the substrate 10, or may be provided indirectly via a protective film or the like provided on the surface of the substrate 10.

It is preferable that the indium oxide-containing layer 11 is provided in a continuous state, in other words, without gaps, on the surface of the substrate 10. By providing the indium oxide-containing layer 11 in a continuous state, the smoothness and corrosion resistance of the indium oxide-containing layer 11 and, in turn, the electromagnetic wave transparent laminate member 1 can be improved, and it also becomes easier to form the indium oxide-containing layer 11 without variation within the surface.

The metal layer 12 is laminated on the indium oxide-containing layer 11. The metal layer 12 includes a plurality of portions 12a. By being laminated on the indium oxide-containing layer 11, these portions 12a are at least partially discontinuous from each other, in other words, at least partially separated by gaps 12b. Because they are separated by gaps 12b, the sheet resistance of these portions 12a increases, and the interaction with radio waves decreases, allowing radio waves to pass through.

Each of these portions 12a is an aggregate of sputtered particles formed by vapor deposition, sputtering, etc. of metal. When the sputtered particles form a thin film on a substrate such as substrate 10, the surface diffusivity of the particles on the substrate affects the shape of the thin film.

In this specification, the term "discontinuous state" refers to a state in which the layers are separated from each other by gaps 12b, and as a result are electrically insulated from each other. By being electrically insulated, the sheet resistance increases, and the desired electromagnetic wave transparency is obtained. The form of discontinuity is not particularly limited, and examples include islands, cracks, etc.

Here, "island-like" refers to a structure in which the particles, which are aggregates of sputtered particles, are independent of each other and are laid out with a slight space between them or with some contact with each other, as shown in the electron microscope photograph (SEM image) of the surface of the metal layer of the electromagnetic wave-transmitting laminated member in Figure 1 (b).

A crack structure is a structure in which a metal thin film is divided by cracks. The metal layer 12 with a crack structure can be formed, for example, by providing a metal thin film layer on an indium oxide-containing layer formed on a substrate, and bending and stretching the metal thin film layer to generate cracks. In this case, by providing a brittle layer made of a material that has poor elasticity, i.e., that is prone to generating cracks by stretching, between the indium oxide-containing layer and the metal thin film layer, the metal layer 12 with a crack structure can be easily formed.

As mentioned above, there are no particular limitations on the manner in which the metal layer 12 is discontinuous, but from the standpoint of productivity, it is preferable for it to be "island-shaped."

The electromagnetic wave permeability of the electromagnetic wave permeable laminate member 1 can be evaluated, for example, by the amount of radio wave transmission attenuation. The amount of radio wave transmission attenuation can be measured, for example, by the method described later in the examples.

In addition, there is a correlation between the amount of radio wave transmission attenuation in the microwave band (28 GHz) and the amount of radio wave transmission attenuation in the millimeter wave radar frequency band (76 to 80 GHz), and the values are relatively close. Therefore, an electromagnetically transparent laminate member that has excellent electromagnetic wave transmission properties in the microwave band also has excellent electromagnetic wave transmission properties in the millimeter wave radar frequency band.

The radio wave transmission attenuation in the microwave band (28 GHz) is preferably less than 10 [-dB], more preferably less than 5 [-dB], and even more preferably less than 2 [-dB]. If the radio wave transmission attenuation in the microwave band (28 GHz) is 10 [-dB] or more, there is a problem that 90% or more of the radio waves are blocked.

The sheet resistance of the electromagnetic wave permeable laminate member 1 also correlates with the electromagnetic wave permeability.

The sheet resistance of the electromagnetic wave-transmitting laminated member 1 is preferably 100 Ω/□ or more. In this case, the radio wave transmission attenuation in the microwave band (28 GHz) can be less than 10 [-dB].

It is further preferable that the sheet resistance of the electromagnetic wave transparent laminate member 1 is 200 Ω/□ or more, even more preferable that it is 600 Ω/□ or more, and particularly preferable that it is 1000 Ω/□ or more.

The sheet resistance of the electromagnetic wave transparent laminated member 1 can be measured by eddy current measurement method in accordance with JIS-Z2316-1:2014.

The radio wave transmission attenuation and sheet resistance of the electromagnetic wave permeable laminated member 1 are affected by the material and thickness of the indium oxide-containing layer 11 and the metal layer 12.

<2. Base>
From the viewpoint of electromagnetic wave transparency, examples of the material for the base 10 include resin, glass, ceramics, and the like.

The substrate 10 may be a substrate film, a resin molded substrate, a glass substrate, or an article to which a metallic luster is to be imparted.

More specifically, examples of the substrate film that can be used include transparent films made of homopolymers or copolymers such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate, polyamide, polyvinyl chloride, polycarbonate (PC), cycloolefin polymer (COP), polystyrene, polypropylene (PP), polyethylene, polycycloolefin, polyurethane, acrylic (PMMA), and ABS.

These materials do not affect the brilliance or electromagnetic wave transmittance. However, from the viewpoint of later forming the indium oxide-containing layer 11 and the metal layer 12, it is preferable that the materials can withstand high temperatures such as vapor deposition and sputtering.

Therefore, among the above materials, for example, polyethylene terephthalate, polyethylene naphthalate, acrylic, polycarbonate, cycloolefin polymer, ABS, polypropylene, and polyurethane are preferred.

Among these, polyethylene terephthalate, cycloolefin polymer, polycarbonate, and acrylic are preferred because they offer a good balance between heat resistance and cost.

The substrate film may be a single-layer film or a laminated film. For ease of processing, the thickness is preferably, for example, 6 μm to 250 μm.

The substrate film may be subjected to plasma treatment or easy-adhesion treatment to strengthen the adhesion to the indium oxide-containing layer 11 and the metal layer 12. In addition, it is preferable that the substrate film does not contain particles.

It should be noted here that the substrate film is just one example of an object (substrate 10) on whose surface an indium oxide-containing layer 11 can be formed.

The substrate 10 includes not only the substrate film as described above, but also a resin molded substrate, a glass substrate, and the article itself to which metallic luster is to be imparted.

Examples of resin molded substrates and articles to which metallic luster should be imparted include vehicle structural parts, vehicle mounted items, housings for electronic devices, housings for home appliances, structural parts, machine parts, various automobile parts, electronic device parts, furniture, kitchen utensils and other household goods, medical equipment, building material parts, other structural parts, and exterior parts.

3. Indium oxide-containing layer
The indium oxide-containing layer 11 is formed on the substrate 10. The indium oxide-containing layer 11 may be provided directly on the surface of the substrate 10, or may be provided indirectly via a protective film or the like provided on the surface of the substrate 10.

It is preferable that the indium oxide-containing layer 11 is provided in a continuous state, in other words, without gaps, on the surface of the substrate 10 to which metallic luster is to be imparted. By providing the indium oxide-containing layer 11 in a continuous state, the smoothness and corrosion resistance of the indium oxide-containing layer 11, and therefore of the metal layer 12 and the electromagnetic wave transparent laminate member 1, can be improved. It also becomes easy to form the indium oxide-containing layer 11 without variation within the surface.

In this way, by providing an indium oxide-containing layer 11 on the substrate 10, i.e., by forming an indium oxide-containing layer 11 on the substrate 10 and then laminating a metal layer 12 described later on top of the indium oxide-containing layer 11, it becomes easier to form the metal layer 12 in a discontinuous state.

Although the details of the above mechanism are not entirely clear, it is believed that when sputtered particles formed by metal vapor deposition or sputtering form a thin film on a substrate, the surface diffusivity of the particles on the substrate affects the shape of the thin film, and that a discontinuous structure is more likely to form when the substrate temperature is high and the wettability of the metal layer to the substrate is low. It is also believed that providing an indium oxide-containing layer on the substrate promotes the surface diffusivity of the metal particles on the substrate, making it easier to grow the metal layer in a discontinuous state.

In addition, in the electromagnetic wave transparent laminated member according to an embodiment of the present invention, the indium oxide-containing layer 11 is characterized in that, when its surface is measured by X-ray photoelectron spectroscopy, the ratio of oxygen atoms to the sum of indium atoms and at least one metal atom M of Sn and Zn (O/(In+M) ratio) is 1.15 or less.

By having the above oxygen atomic ratio in the indium oxide-containing layer 11 be 1.15 or less, it becomes possible to control the thickness of the metal layer 12 formed on the indium oxide-containing layer 11 over a wide range.

In addition, in the above oxygen atomic ratio (O/(In+M) ratio), when the indium oxide-containing layer contains both Sn and Zn metal atoms, M means the total amount of both Sn and Zn metal atoms contained.

The indium oxide-containing layer 11 has an oxygen atomic ratio of 1.15 or less, preferably 1.13 or less. The lower limit of the oxygen atomic ratio is not particularly limited, but is, for example, 0.5 or more.

It is not clear why the thickness of the metal layer 12 can be controlled over a wide range because the oxygen atomic ratio in the indium oxide-containing layer 11 is 1.15 or less, but it is speculated as follows.

In other words, in the process of forming the metal layer 12, the ease of forming a discontinuous structure is related to surface diffusion on the member to which the metal layer 12 is applied (in this invention, the indium oxide-containing layer 11), and it is thought that the higher the temperature of the member to which the metal layer 12 is applied and the lower the wettability of the metal layer 12 to the member to which the metal layer 12 is applied, the easier it is to form a discontinuous structure.

In the present invention, by suppressing the oxygen concentration of the indium oxide-containing layer 11, which is the member to which the metal layer 12 is applied, to a certain value or less, the wettability can be further reduced, and the formation of a discontinuous structure is promoted. Therefore, it is presumed that the thickness of the discontinuous structure can be controlled over a wide range.

The indium oxide-containing layer 11 can include metal inclusions such as _indium oxide ( _In2O3 ), indium tin oxide (ITO), or indium zinc oxide (IZO).

By including the above-mentioned metal inclusions in the indium oxide-containing layer 11, a continuous film can be formed along the surface of the substrate. In this case, the metal layer 12 laminated on the indium oxide-containing layer 11 can be easily formed into, for example, an island-like discontinuous structure. Furthermore, in this case, the metal layer 12 can easily contain not only tin (Sn) or indium (In), but also various metals such as aluminum, which are usually difficult to form into a discontinuous structure and therefore difficult to apply to this application.

From the standpoints of sheet resistance, electromagnetic wave transparency, and productivity, the thickness of the indium oxide-containing layer 11 is typically preferably 1000 nm or less, more preferably 50 nm or less, and even more preferably 20 nm or less.

On the other hand, in order to make the laminated metal layer 12 discontinuous, the thickness of the indium oxide-containing layer 11 is preferably 1 nm or more, more preferably 2 nm or more, and even more preferably 5 nm or more.

<4. Metal Layer>
The metal layer 12 is formed on the indium oxide-containing layer 11. The metal layer 12 is a layer having a metallic appearance, and is preferably a layer having a metallic luster. There is no particular limitation on the material forming the metal layer 12, and it may contain a metal or a resin, or it may contain a metal and a resin.

In the electromagnetic wave-transmitting laminated member according to the embodiment of the present invention, the oxygen atomic ratio in the indium oxide-containing layer 11 is within a specific range, so that the thickness of the metal layer 12 can be controlled over a wide range. Therefore, the thickness of the metal layer 12 can be set within a wide range, for example, from 10 nm to 200 nm, improving yield and enabling stable production.

From the viewpoint of exhibiting sufficient metallic luster, the thickness of the metal layer 12 is usually preferably 10 nm or more, while from the viewpoint of sheet resistance and electromagnetic wave transmittance, it is usually preferable for the thickness to be 200 nm or less.

For example, the thickness of the metal layer 12 is preferably 10 nm to 100 nm, and more preferably 10 nm to 70 nm. This thickness is suitable for forming a uniform film with good productivity. In addition, the appearance of the final product, a resin molded product, is also good.

The metal layer 12 is formed on the indium oxide-containing layer 11 and includes a plurality of portions that are at least partially discontinuous from one another.

When the metal layer 12 is continuous on the indium oxide-containing layer 11, a sufficient metallic luster is obtained, but the amount of radio wave transmission attenuation becomes very large, so electromagnetic wave transparency cannot be ensured.

It is preferable that the metal layer 12 has a relatively low melting point as well as sufficient brilliance. This is because the metal layer 12 is preferably formed by thin film growth using sputtering.

For these reasons, a metal with a melting point of approximately 1100°C or less is suitable for the metal layer 12, and it is preferable that the metal layer 12 contains at least one metal selected from aluminum (Al), zinc (Zn), lead (Pb), copper (Cu), and silver (Ag), or an alloy containing the metal as the main component.

In particular, it is more preferable that the metal layer 12 contains aluminum or an aluminum alloy for reasons of the material's luster, stability, cost, etc.

Furthermore, when an aluminum alloy is used, it is preferable that the aluminum content in the metal layer 12 be 50 mass% or more.

The circular equivalent diameter of the portion 12a of the metal layer 12 is not particularly limited, but is usually 10 to 1000 nm. The average particle size of the multiple portions 12a means the average value of the circular equivalent diameters of the multiple portions 12a.

The circular equivalent diameter of portion 12a is the diameter of a perfect circle equivalent to the area of portion 12a.

In addition, the distance between each portion 12a is not particularly limited, but is typically 10 to 1000 nm.

The ratio of the thickness of the metal layer 12 to the thickness of the indium oxide-containing layer 11 (thickness of the metal layer 12/thickness of the indium oxide-containing layer 11) is preferably in the range of 0.02 to 100, more preferably in the range of 0.1 to 100, and even more preferably in the range of 0.3 to 35. By setting it in the above range, a uniform film can be formed with good productivity. In addition, the appearance of the resin molded product, which is the final product, is also good.
<5. Other Layers>

In addition, the electromagnetic wave transparent laminate member 1 according to an embodiment of the present invention may have other layers in addition to the above-mentioned indium oxide-containing layer 11 and metal layer 12 depending on the application.

Other layers include optical adjustment layers (color adjustment layers) made of highly refractive materials to adjust the appearance such as color, protective layers (scratch-resistant layers) to improve durability such as scratch resistance, barrier layers (corrosion-resistant layers), easy-adhesion layers, hard coat layers, anti-reflection layers, light extraction layers, and anti-glare layers.

<6. Manufacturing method of electromagnetic wave transparent laminate member>
The method for producing an electromagnetic wave transparent laminate member according to this embodiment includes an indium oxide-containing layer forming step of forming an indium oxide-containing layer on a substrate, and a metal layer forming step of forming a metal layer on the indium oxide-containing layer, and the indium oxide-containing layer forming step is characterized in that an indium oxide-containing layer is formed on the substrate by reactive sputtering using a metal target containing indium as a main component while supplying an inert gas and an oxygen gas. Each step will be described in detail below.

(1) Indium oxide-containing layer formation step In this step, an indium oxide-containing layer 11 is formed on a substrate 10. When the surface of the indium oxide-containing layer 11 is measured by X-ray photoelectron spectroscopy, the ratio of oxygen atoms to the total of indium atoms and at least one metal atom M of Sn and Zn (O/(In+M) ratio) is 1.15 or less.

In order to achieve the above oxygen ratio, in this process, a metal target containing indium as a main component is used, and an indium oxide-containing layer is formed on the substrate by reactive sputtering while supplying an inert gas and oxygen gas. With this method, an oxygen atomic ratio within the above-mentioned predetermined range can be achieved by appropriately setting the oxygen gas partial pressure ratio and performing reactive sputtering while adjusting the amount of oxygen supplied.

Conventionally, indium oxide-containing layers have often been formed using oxides of indium such as indium oxide (In ₂ O ₃ ), indium tin oxide (ITO), and indium zinc oxide (IZO) as targets. In such methods, the targets originally contain oxygen, making it difficult to adjust the oxygen concentration of the indium oxide-containing layer to be formed.

On the other hand, in the present invention, a metal target containing indium as the main component and not containing oxygen is used, and an indium oxide-containing layer is formed by reactive sputtering while supplying an inert gas and oxygen gas. This makes it possible to keep the oxygen concentration in the indium oxide-containing layer low, and as a result, the thickness of the metal layer 12 can be controlled over a wide range.

As reactive sputtering, for example, a direct current (DC) or radio frequency (RF) magnetron sputtering method can be applied at a pressure of 0.1 to 1.0 Pa.

The metal target mainly composed of indium is not particularly limited as long as it does not contain oxygen. For example, in addition to indium, tin (Sn) and zinc (Zn) may be contained. The composition formula can be expressed as In _x M _1-x (0.7≦x≦1, M=at least one metal element composed of Sn and Zn). Here, the "main component" means the component having the highest content (by mass) among all the components in the metal target.

It is preferable that the indium content in the metal target be 70% by mass or more, and more preferably 90% by mass or more.

When tin (Sn) is contained, it is preferable that the metal target contains, for example, 2.5 to 30 mass %, and it is more preferable that the metal target contains 3 to 10 mass %.

When zinc (Zn) is contained, it is preferable that the metal target contains, for example, 2 to 20 mass %, and more preferably 5 to 15 mass %.

As the inert gas, argon or nitrogen is usually used.
When argon is used as the inert gas, the oxygen gas partial pressure ratio ( _O2 /Ar+ _O2 ) can be appropriately set so as to obtain the oxygen atomic ratio in the present invention. The oxygen gas partial pressure ratio is usually preferably 28% or less, more preferably 27% or less, and even more preferably 26% or less. The oxygen gas partial pressure ratio is, for example, 10% or more and 26% or less.

The indium oxide-containing layer thus formed preferably contains an oxide of indium, such as indium oxide (In ₂ O ₃ ), indium tin oxide (ITO), or indium zinc oxide (IZO).

(2) Indium oxide-containing layer forming step Next, the metal layer 12 is laminated on the indium oxide-containing layer 11. In this case, for example, sputtering can be used. It is preferable that the indium oxide-containing layer 11 and the metal layer 12 are in direct contact with each other without any other layer being interposed between them. However, as long as the above-described mechanism of surface diffusion of the metal layer 12 on the indium oxide-containing layer 11 is ensured, other layers can be interposed between them.

<7. Uses of electromagnetic wave transparent laminated members>
The electromagnetic wave permeable laminate member of this embodiment has electromagnetic wave permeability, and is therefore preferably used in devices and articles that transmit and receive electromagnetic waves, and parts thereof, etc. Examples include structural parts for vehicles, vehicle-mounted items, housings for electronic devices, housings for home appliances, structural parts, machine parts, various automobile parts, parts for electronic devices, household goods such as furniture and kitchenware, medical equipment, parts for building materials, other structural parts and exterior parts, etc.

More specifically, vehicle-related products include instrument panels, console boxes, door knobs, door trim, shift levers, pedals, glove boxes, bumpers, bonnets, fenders, trunks, doors, roofs, pillars, seats, steering wheels, ECU boxes, electrical components, engine peripheral parts, drive system and gear peripheral parts, intake and exhaust system parts, and cooling system parts.

More specifically, examples of electronic devices and home appliances include home appliances such as refrigerators, washing machines, vacuum cleaners, microwave ovens, air conditioners, lighting equipment, electric water heaters, televisions, clocks, ventilation fans, projectors, and speakers, as well as electronic information devices such as personal computers, mobile phones, smartphones, digital cameras, tablet PCs, portable music players, portable game consoles, chargers, and batteries.

The present invention will be described more specifically below with reference to examples and comparative examples.
Various samples were prepared for the electromagnetic wave transparent laminate member 1, and the sheet resistance and radio wave attenuation were measured to evaluate the electromagnetic wave transparency, and the glossiness and L ^* were measured to evaluate the brilliance. In addition, the thicknesses of the indium oxide-containing layer and the metal layer, and the oxygen composition ratio of the indium oxide-containing layer were measured.
As the substrate 10, a base film was used.

[Electromagnetic wave transparency]
(1) Sheet Resistance Using a non-contact resistance measuring device NC-80MAP manufactured by Napson Corporation, the sheet resistance of a laminate of a metal layer and an indium oxide-containing layer was measured by an eddy current measurement method in accordance with JIS-Z2316.

(2) Radio Wave Transmission Attenuation Amount Radio wave transmission attenuation amount at 28 GHz was measured and evaluated using a free space method measuring device LAF-26.5A manufactured by Keycom Co., Ltd. and a spectrum analyzer MS4644BCXA signal analyzer NA9000A manufactured by Anritsu and Agilent.
(Evaluation of electromagnetic wave transparency)
Less than 2 [-dB]: ◎
2 [-dB] or more and less than 5 [-dB]: 〇 5 [-dB] or more and less than 10 [-dB]: △
10 [-dB] or more: ×

[Brilliance]
(3) 20° specular gloss and L ^*
The 20° specular gloss ([GU]) and L ^* of the metal layer were measured using a handheld glossmeter PG-II M manufactured by Nippon Denshoku Industries Co., Ltd. in accordance with JIS-Z8741.

(4) Film Thickness Measurement Method <Metal Layer Thickness>
Considering the variation in the metal layer, more specifically, the variation in the thickness of the portion 12a shown in Fig. 1(a), the average value of the thickness of the portion 12a was taken as the thickness of the metal layer. The thickness of each portion 12a was taken as the thickness at the thickest point in the vertical direction from the base 10. Hereinafter, this average value will be referred to as the "maximum thickness" for convenience. Figs. 2(a) and 2(b) show examples of electron microscope photographs (TEM images) of the cross section of the electromagnetic wave permeable laminate member.
In determining the maximum thickness, first, a square area 3 with sides of 5 cm as shown in FIG. 3 was appropriately extracted from the metal layer appearing on the surface of the electromagnetic wave transparent laminate member as shown in FIG. 2(a) and FIG. 2(b), and a total of five points "a" to "e" obtained by dividing the center lines A and B of the vertical and horizontal sides of the square area 3 into four were selected as measurement points.
Next, in the cross-sectional images of each of the selected measurement points, as shown in Fig. 2(a) and Fig. 2(b), a viewing angle region including approximately five portions 12a was extracted. The thicknesses of the individual portions 12a, i.e., 25 portions 12a (5 portions x 5 portions), were determined in each of the five measurement points, and the average value thereof was determined as the "maximum thickness."

<Thickness of indium oxide-containing layer>
The thickness of the indium oxide-containing layer was measured using the same method as for the metal layer. That is, the thicknesses of the indium oxide-containing layer were measured at the locations corresponding to the 25 portions 12a selected when measuring the thickness of the metal layer, and the average value of the thicknesses was calculated to be the thickness of the indium oxide-containing layer.

(5) Oxygen composition ratio of indium oxide-containing layer For the indium oxide-containing layer before the formation of the metal layer, a quantitative analysis was performed on the surface of the indium oxide-containing layer after cleaning the surface by 2 nm (etching depth of about 1 nm in terms of _SiO2 ) using an ESCA analyzer (Quantera SXM) manufactured by ULVAC-PHI, Inc., with a monochrome AlKα X-ray source at a photoelectron take-off angle of 45° with respect to the sample surface, and the element ratio (atomic %) was calculated. Then, the obtained In, Sn, O (atomic %) was used to calculate the oxygen composition ratio (M=Sn) of O/(In+M).

[Example 1]
A PET film (thickness 50 μm) on which a particle-free hard coat layer was formed was used as the substrate film. First, an In—Sn alloy target (Sn ratio 5 mass%) was used to form ITO on the hard coat layer by DC pulse sputtering (150 kHz) with an oxygen gas partial pressure ratio (O ₂ /(Ar+O ₂ )) of 26%. The temperature of the substrate film when forming the ITO layer was set to 130° C.
Next, an aluminum (Al) layer was formed on the ITO layer using AC sputtering (AC: 40 kHz) to obtain an electromagnetic wave transparent laminate member shown in Table 1. The obtained aluminum layer was a discontinuous layer. The temperature of the base film when forming the Al layer was set to 130°C.

[Examples 2 to 7]
Except for changing the time for forming the ITO layer and the time for forming the aluminum (Al) layer, the laminated members of Examples 2 to 7 shown in Table 1 were obtained in the same manner as in Example 1. Electron microscope photographs (TEM images) of the cross sections of the laminated members of Examples 4 to 7 are shown in Figures 4(a) to 4(d), respectively.

[Comparative Example 1]
A laminated member of Comparative Example 1 shown in Table 1 was obtained in the same manner as in Example 5, except that the oxygen gas partial pressure ratio ( _O2 /(Ar+ _O2 )) during ITO film formation in Example 5 was changed to 29%. An electron microscope photograph (TEM image) of a cross section of the laminated member of Comparative Example 1 is shown in Figure 5 (a).
[Comparative Examples 2 to 3]
Except for changing the time for forming the ITO layer and the time for forming the aluminum (Al) layer, the laminated members of Comparative Examples 2 to 3 shown in Table 1 were obtained in the same manner as in Comparative Example 1. An electron microscope photograph (TEM image) of a cross section of the laminated member of Comparative Example 3 is shown in FIG.
[Comparative Example 4]
A laminate member of Comparative Example 4 shown in Table 1 was obtained in the same manner as Comparative Example 1, except that the target material was changed to an ITO target (Sn ratio 10 mass%) and the oxygen gas partial pressure ratio ( _O2 /(Ar+ _O2 )) during ITO film formation was changed to 0%.
The evaluation results are shown in Table 1 below.

As is clear from Table 1, the laminated members of Examples 1 to 7 had high sheet resistance and low radio wave transmission attenuation, and showed excellent electromagnetic wave transmission. They also had sufficient brilliance. This is thought to be due to the promotion of the formation of a metal layer with an island-shaped discontinuous structure, as can be seen from the electron microscope photographs (TEM images) of the cross sections of the laminated members of Examples 4 to 7 shown in Figures 4(a) to 4(d).

On the other hand, the laminated members of Comparative Examples 1 to 4 had significantly lower sheet resistance and higher radio wave transmission attenuation, and were inferior in electromagnetic wave transmission to the Examples. This is thought to be because many of the island-shaped metal layer portions were formed by overlapping each other, as can be seen from the electron microscope photographs (TEM images) of the cross sections of the laminated members of Comparative Examples 1 and 3 shown in Figures 5(a) and 5(b).

It is believed that discontinuous structures can be formed using a similar technique for metals with relatively low melting points other than aluminum (Al), which was specifically used in the above examples, such as zinc (Zn), lead (Pb), copper (Cu), and silver (Ag).

The present invention is not limited to the above-described embodiments and can be modified as appropriate without departing from the spirit and scope of the invention.

Although various embodiments have been described above with reference to the drawings, it goes without saying that the present invention is not limited to such examples. It is clear that a person skilled in the art can come up with various modified or revised examples within the scope of the claims, and it is understood that these naturally fall within the technical scope of the present invention. Furthermore, the components in the above embodiments may be combined in any manner as long as it does not deviate from the spirit of the invention.

This application is based on a Japanese patent application (Patent Application No. 2020-040057) filed on March 9, 2020, the contents of which are incorporated by reference into this application.

The electromagnetic wave-transmitting laminated member according to the present invention can be used in devices and articles that transmit and receive electromagnetic waves, and their parts, etc. For example, it can be used in a variety of applications that require both design and electromagnetic wave transmittance, such as vehicle structural parts, vehicle-mounted items, housings for electronic devices, housings for home appliances, structural parts, machine parts, various automobile parts, electronic device parts, household goods such as furniture and kitchen utensils, medical equipment, building material parts, and other structural and exterior parts.

1 Electromagnetic wave transparent laminate member 10 Base body 11 Indium oxide-containing layer 12 Metal layer 12a Part 12b Gap

Claims (11)

A method for manufacturing a semiconductor device comprising: a substrate; an indium oxide-containing layer formed on the substrate; and a metal layer formed on the indium oxide-containing layer,
the metal layer includes a plurality of portions that are at least partially discontinuous with each other;
a ratio of oxygen atoms to the total of indium atoms and at least one metal atom M of Sn and Zn (O/(In+M) ratio) is 1.15 or less when the surface of the indium oxide-containing layer is measured by X-ray photoelectron spectroscopy;
Electromagnetic wave transparent laminated material. The electromagnetic wave transparent laminate member according to claim 1, wherein the indium oxide-containing layer is provided in a continuous state. 3. The electromagnetic wave transparent laminate member according to claim 1, wherein the indium oxide-containing layer contains any one of _indium oxide ( _In2O3 ), indium tin oxide (ITO), and indium zinc oxide (IZO). An electromagnetic wave transparent laminate member according to any one of claims 1 to 3, wherein the metal layer is a layer containing aluminum or an aluminum alloy. An electromagnetic wave transparent laminate member described in any one of claims 1 to 4, wherein the thickness of the indium oxide-containing layer is 1 nm to 1000 nm. An electromagnetic wave transparent laminate member described in any one of claims 1 to 5, wherein the thickness of the metal layer is 10 nm to 200 nm. An electromagnetic wave transparent laminate member according to any one of claims 1 to 6, wherein the ratio of the thickness of the metal layer to the thickness of the indium oxide-containing layer (thickness of the metal layer/thickness of the indium oxide-containing layer) is 0.02 to 100. An electromagnetic wave transparent laminate member according to any one of claims 1 to 7, having a sheet resistance of 100 Ω/□ or more. An electromagnetic wave-transmitting laminate member according to any one of claims 1 to 8, wherein the plurality of portions are formed in an island shape. An electromagnetic wave-transmitting laminate member according to any one of claims 1 to 9, wherein the substrate is a substrate film, a resin molded substrate, a glass substrate, or an article to which metallic luster is to be imparted. an indium oxide-containing layer forming step of forming an indium oxide-containing layer on a substrate;
forming a metal layer on the indium oxide-containing layer;
The method for producing an electromagnetic wave transparent laminate member according to any one of claims 1 to 10, wherein the indium oxide-containing layer forming step uses a metal target containing indium as a main component, and forms an indium oxide-containing layer on the base by reactive sputtering while supplying an inert gas and an oxygen gas.

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