Electromagnetic wave permeable laminated member and manufacturing method thereof

Abstract

An electromagnetic-wave-transmissive laminated member provided with 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 includes a plurality of portions that are, at least partially, in a mutually non-continuous state. The oxygen atom ratio (O / (In + M) ratio) relative to the total of indium atoms and at least one type of metal atom from among Sn and Zn when the surface of the indium oxide-containing layer is measured by X-ray photoelectron spectroscopy is 1.15 or below.

Description

[Technical field]

[0001] The present invention relates to an electromagnetic wave transparent laminate member and a method for producing the same. [Background technology]

[0002] 2. Description of the Related Art Conventionally, members having electromagnetic wave transparency and metallic luster have been suitably used in devices that transmit and receive electromagnetic waves because they combine the luxurious appearance resulting from their metallic luster with electromagnetic wave transparency.

[0003] When metal is used in a metallic luster-like component, transmission and reception of electromagnetic waves is substantially impossible or is hindered. Therefore, in order to avoid impeding transmission and reception of electromagnetic waves and impairing the design, an electromagnetic wave-transmitting laminated component that combines both metallic luster and electromagnetic wave transmittance is required.

[0004] Such electromagnetically transparent laminated members are expected to be applied as devices for transmitting and receiving electromagnetic waves to various devices requiring communication, such as door handles of automobiles equipped with smart keys, in-vehicle communication devices, mobile phones, personal computers, and other electronic devices. Furthermore, with the recent development of IoT technology, applications are expected in a wide range of fields, such as home appliances such as refrigerators and lifestyle devices, which did not previously involve communication.

[0005] Regarding electromagnetic wave-transmitting laminated members, Patent Document 1 describes an electromagnetic wave-transmitting metallic glossy member comprising an indium oxide-containing layer provided on the surface of a base, 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 from one another. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2018-69462 Summary of the Invention [Problem to be solved by the invention]

[0007] The metal layer in the electromagnetic wave-transmitting laminated member of the conventional technology could only be formed to a thickness of about 50 nm, depending on the formation method and the type of substrate. If the thickness exceeds this, the metal formed in islands will overlap each other, causing a sudden drop in resistance, and the electromagnetic wave transmittance will be significantly impaired. Therefore, the thickness of the metal layer needs to be controlled to the order of a few nanometers, which makes stable production difficult and causes a problem of reduced yield.

[0008] The present invention has been made to solve the above problems in the prior art, and aims to provide an electromagnetic wave-transmittable laminate member that has excellent electromagnetic wave transmittance and allows the thickness of the metal layer to be controlled over a wide range. [Means for solving the problem]

[0009] As a result of extensive research into solving the above problems, the present inventors have found that the above problems can be solved by setting the oxygen concentration in an indium oxide-containing layer within a specific range, and have thus completed the present invention.

[0010] 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; When the surface of the indium oxide-containing layer 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. Electromagnetic wave transparent laminated material. [2] The electromagnetic wave transparent laminate member according to [1] above, wherein the indium oxide-containing layer is provided in a continuous state. [3] The electromagnetic wave transparent laminate member according to [1] or [2], wherein the indium oxide-containing layer contains any one of indium oxide (In2O3), indium tin oxide (ITO), or indium zinc oxide (IZO). [4] The electromagnetic wave transparent laminate member according to any one of the above [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 the above [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 the above [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 a ratio of a thickness of the metal layer to a 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 the above [1] to [7], which has a sheet resistance of 100 Ω / □ or more. [9] The electromagnetic wave transparent laminate member according to any one of the above [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 the above [1] to [9], wherein the substrate is any one of a substrate film, a resin molded substrate, a glass substrate, and 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] above, 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. Effect of the Invention

[0011] According to the present invention, it is possible to provide an electromagnetic wave transparent laminate member which has excellent electromagnetic wave transparency and in which the thickness of the metal layer can be controlled within a wide range. [Brief description of the drawings]

[0012] [Figure 1] 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. [Diagram 2] FIG. 2(a) and FIG. 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. [Diagram 3] 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. [Figure 4] 4(a) to 4(d) show electron microscope photographs (TEM images) of the cross sections of the laminated members of Examples 4 to 7, respectively. [Diagram 5] 5(a) and 5(b) show electron microscope photographs (TEM images) of the cross sections of the laminated members of Comparative Examples 1 and 3. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The present invention will be described in detail below with reference to the accompanying drawings, but 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 symbol "to" indicating a numerical range is used to mean that the numerical values ​​before and after it are included as the lower and upper limits.

[0014] <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.

[0015] Fig. 1(a) shows 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) shows an example of 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. The image size in the electron microscope photograph is 1.2 µm × 0.9 µm.

[0016] 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.

[0017] 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.

[0018] The indium oxide-containing layer 11 is preferably provided in a continuous state, in other words, without any gaps, on the surface of the base 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 therefore of the electromagnetic wave permeable laminate member 1, can be improved, and the indium oxide-containing layer 11 can be easily formed without variation within the surface.

[0019] 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. Since 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.

[0020] 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.

[0021] In this specification, the term "discontinuous state" means that the gaps 12b separate the layers from each other, and as a result, the layers are electrically insulated from each other. The electrical insulation increases the sheet resistance, and the desired electromagnetic wave transmittance is obtained. The form of the discontinuity is not particularly limited, and examples thereof include islands, cracks, and the like.

[0022] 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 laminate in Figure 1(b).

[0023] The crack structure is a structure in which a metal thin film is divided by cracks. The metal layer 12 having the 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, the metal layer 12 having the crack structure can be easily formed by providing a brittle layer made of a material that has poor elasticity, i.e., is easily prone to cracks due to stretching, between the indium oxide-containing layer and the metal thin film layer.

[0024] As described above, the form in which the metal layer 12 is discontinuous is not particularly limited, but from the viewpoint of productivity, it is preferable that the metal layer 12 be discontinuous in an "island-like" form.

[0025] The electromagnetic wave transmission of the electromagnetic wave transparent 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.

[0026] Furthermore, 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.

[0027] 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.

[0028] The sheet resistance of the electromagnetic wave transparent laminate member 1 also correlates with the electromagnetic wave transparency.

[0029] The sheet resistance of the electromagnetic wave transparent laminate member 1 is preferably 100 Ω / □ or more. In this case, the radio wave transmission attenuation in the microwave band (28 GHz) can be made less than about 10 [-dB].

[0030] The sheet resistance of the electromagnetic wave transparent laminate member 1 is more preferably 200 Ω / □ or more, even more preferably 600 Ω / □ or more, and particularly preferably 1000 Ω / □ or more.

[0031] The sheet resistance of the electromagnetic wave transparent laminate member 1 can be measured by an eddy current measurement method in accordance with JIS-Z2316-1:2014.

[0032] The radio wave transmission attenuation and sheet resistance of the electromagnetic wave transparent laminate member 1 are affected by the materials and thicknesses of the indium oxide-containing layer 11 and the metal layer 12, etc.

[0033] <2.Base> From the viewpoint of electromagnetic wave transparency, the base 10 may be made of, for example, resin, glass, ceramics, etc.

[0034] The substrate 10 may be a substrate film, a resin molding substrate, a glass substrate, or an article to which a metallic luster is to be imparted.

[0035] 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.

[0036] These materials do not affect the brilliance or electromagnetic wave transmittance. However, from the viewpoint of forming the indium oxide-containing layer 11 and the metal layer 12 later, it is preferable that the material can withstand high temperatures such as vapor deposition and sputtering.

[0037] Therefore, among the above materials, for example, polyethylene terephthalate, polyethylene naphthalate, acrylic, polycarbonate, cycloolefin polymer, ABS, polypropylene, and polyurethane are preferable.

[0038] Among these, polyethylene terephthalate, cycloolefin polymer, polycarbonate, and acrylic are preferred because they have a good balance between heat resistance and cost.

[0039] The substrate film may be a single-layer film or a laminated film. From the viewpoint of ease of processing, the thickness is preferably, for example, 6 μm to 250 μm.

[0040] The substrate film may be subjected to a plasma treatment or an easy-adhesion treatment in order to strengthen the adhesion to the indium oxide-containing layer 11 and the metal layer 12. In addition, the substrate film preferably does not contain particles.

[0041] It should be noted here that the base film is merely one example of an object (substrate 10) on whose surface the indium oxide-containing layer 11 can be formed.

[0042] The substrate 10 includes, in addition to the substrate film as described above, a resin molded substrate, a glass substrate, and the article itself to which a metallic luster is to be imparted.

[0043] Examples of resin molded product 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, household goods such as furniture and kitchen utensils, medical equipment, building material parts, other structural parts, and exterior parts.

[0044] <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.

[0045] The indium oxide-containing layer 11 is preferably provided in a continuous state, in other words, without gaps, on the surface of the substrate 10 to which metallic luster should be imparted. By providing the indium oxide-containing layer 11 in a continuous state, it is possible to improve the smoothness and corrosion resistance of the indium oxide-containing layer 11, and further the metal layer 12 and the electromagnetic wave transparent laminate member 1. It also becomes easy to form the indium oxide-containing layer 11 without variation within the surface.

[0046] In this way, by providing the indium oxide-containing layer 11 on the base 10, that is, by forming the indium oxide-containing layer 11 on the base 10 and then laminating the metal layer 12 described later thereon, it becomes easier to form the metal layer 12 in a discontinuous state.

[0047] Although the details of the above mechanism are not entirely clear, when sputtered particles formed by vapor deposition or sputtering of metal form a thin film on a substrate, the surface diffusivity of the particles on the substrate affects the shape of the thin film, and it is believed that a discontinuous structure is more likely to be formed when the substrate temperature is high and the wettability of the metal layer to the substrate is low. It is also believed that the provision of 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.

[0048] In addition, in the electromagnetic wave transparent laminate member according to the 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.

[0049] When the oxygen atomic ratio in the indium oxide-containing layer 11 is 1.15 or less, the thickness of the metal layer 12 formed on the indium oxide-containing layer 11 can be controlled in a wide range.

[0050] 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 therein.

[0051] The indium oxide-containing layer 11 has an oxygen atomic ratio of 1.15 or less, and 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.

[0052] The reason why the thickness of the metal layer 12 can be controlled in a wide range by setting the oxygen atomic ratio in the indium oxide-containing layer 11 to 1.15 or less is not clear, but is presumed to be as follows.

[0053] In other words, in the process of forming the metal layer 12, the ease of forming a discontinuous structure is thought to be 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 easier to form a discontinuous structure when the temperature of the member to which the metal layer 12 is applied is high and the wettability of the metal layer 12 to the member to which the metal layer 12 is applied is low.

[0054] In the present invention, the wettability can be further reduced 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, and the formation of the discontinuous structure is promoted. Therefore, it is presumed that the thickness of the discontinuous structure can be controlled in a wide range.

[0055] The indium oxide-containing layer 11 may include metal inclusions such as indium oxide (In2O3), indium tin oxide (ITO), or indium zinc oxide (IZO).

[0056] By including the metal inclusion 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 include 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.

[0057] From the viewpoints of sheet resistance, electromagnetic wave transparency, and productivity, the thickness of the indium oxide-containing layer 11 is usually preferably 1000 nm or less, more preferably 50 nm or less, and further preferably 20 nm or less.

[0058] 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.

[0059] <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.

[0060] In the electromagnetic wave transparent laminate 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 the yield and enabling stable production.

[0061] From the viewpoint of exerting a 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, the thickness is usually preferably 200 nm or less.

[0062] For example, the thickness of the metal layer 12 is more preferably 10 nm to 100 nm, and further 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.

[0063] 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.

[0064] When the metal layer 12 is continuous on the indium oxide-containing layer 11, a sufficient metallic luster can be obtained, but the amount of radio wave transmission attenuation becomes very large, making it impossible to ensure electromagnetic wave transparency.

[0065] The metal layer 12 is preferably one that can exhibit sufficient brilliance and has a relatively low melting point, because the metal layer 12 is preferably formed by thin film growth using sputtering.

[0066] For these reasons, a metal having a melting point of about 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.

[0067] In particular, for reasons of the luster, stability, cost, and the like of the material, it is more preferable that the metal layer 12 contains aluminum or an aluminum alloy.

[0068] When an aluminum alloy is used, the aluminum content in the metal layer 12 is preferably 50 mass % or more.

[0069] The equivalent circle diameter of the portions 12a of the metal layer 12 is not particularly limited, but is usually 10 to 1000 nm. The average particle diameter of the portions 12a means the average value of the equivalent circle diameters of the portions 12a.

[0070] The circle equivalent diameter of the portion 12a refers to the diameter of a perfect circle equivalent to the area of ​​the portion 12a.

[0071] The distance between the portions 12a is not particularly limited, but is usually 10 to 1000 nm.

[0072] 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 further 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>

[0073] Furthermore, the electromagnetic wave transparent laminate member 1 according to the embodiment of the present invention may include, in addition to the indium oxide-containing layer 11 and the metal layer 12 described above, other layers depending on the application.

[0074] Other layers include an optical adjustment layer (color adjustment layer) made of a highly refractive material or the like for adjusting the appearance such as color, a protective layer (scratch-resistant layer) for improving durability such as scratch resistance, a barrier layer (corrosion-resistant layer), an easy-adhesion layer, a hard coat layer, an anti-reflection layer, a light extraction layer, and an anti-glare layer.

[0075] <6. Manufacturing method of electromagnetic wave permeable laminated 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.

[0076] (1) Indium oxide-containing layer forming process 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.

[0077] 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 a substrate by reactive sputtering while supplying an inert gas and an oxygen gas. With this method, the oxygen gas partial pressure ratio is appropriately set, and the amount of oxygen supplied is adjusted while performing reactive sputtering, thereby achieving the above-mentioned predetermined range of oxygen atomic ratio.

[0078] Conventionally, indium oxide-containing layers have often been formed using oxides of indium such as indium oxide (In2O3), 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 that is formed.

[0079] On the other hand, in the present invention, an indium oxide-containing layer is formed by reactive sputtering using a metal target containing indium as the main component and not containing oxygen, while supplying an inert gas and an oxygen gas. This makes it possible to keep the oxygen concentration in the indium oxide-containing layer low, and as a result, it is possible to control the thickness of the metal layer 12 in a wide range.

[0080] As the reactive sputtering, for example, a direct current (DC) or radio frequency (RF) magnetron sputtering method at a pressure of 0.1 to 1.0 Pa can be applied.

[0081] There are no particular limitations on the metal target containing indium as a main component, so long as it does not contain oxygen. For example, in addition to indium, it may contain tin (Sn) and zinc (Zn), etc. The composition formula is In X M 1-X (0.7≦x≦1, M=at least one metal element selected from Sn and Zn). Here, the term "main component" refers to the component that has the highest content (by mass) of all the components in the metal target.

[0082] The indium content in the metal target is preferably 70 mass % or more, and more preferably 90 mass % or more.

[0083] When tin (Sn) is contained, the metal target preferably contains 2.5 to 30 mass %, and more preferably contains 3 to 10 mass %, for example.

[0084] When zinc (Zn) is contained, it is preferable that the metal target contains it in an amount of, for example, 2 to 20 mass %, and more preferably 5 to 15 mass %.

[0085] 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.

[0086] The indium oxide-containing layer thus formed preferably contains an oxide of indium, such as indium oxide (In2O3), indium tin oxide (ITO), or indium zinc oxide (IZO).

[0087] (2) Indium oxide-containing layer forming process 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.

[0088] <7. Uses of electromagnetic wave transparent laminated materials> 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.

[0089] More specifically, vehicle-related parts include instrument panels, console boxes, door handles, 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.

[0090] 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. EXAMPLES

[0091] The present invention will be described more specifically below with reference to examples and comparative examples. Various samples of the electromagnetic wave permeable laminated member 1 were prepared, and the sheet resistance and radio wave attenuation were used to evaluate the electromagnetic wave permeability, and the glossiness and L * 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.

[0092] [Electromagnetic wave transparency] (1) Sheet resistance The sheet resistance of the laminate of the metal layer and the indium oxide-containing layer was measured by an eddy current measurement method using a non-contact resistance measuring device NC-80MAP manufactured by Napson Corporation in accordance with JIS-Z2316.

[0093] (2) Radio wave transmission attenuation The radio wave transmission attenuation at 28 GHz was measured and evaluated using a Keycom free space method measuring device LAF-26.5A and an Anritsu / Agilent spectrum analyzer MS4644BCXA signal analyzer NA9000A. (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: ×

[0094] [Glitter] (3) 20° specular gloss and L * The 20° specular gloss ([GU]) and L of the metal layer were measured according to JIS-Z8741 using a handheld gloss meter PG-II M manufactured by Nippon Denshoku Industries Co., Ltd. * was measured.

[0095] (4) Film thickness measurement method <Thickness of metal layer> 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. Fig. 2(a) and Fig. 2(b) show examples of electron microscope photographs (TEM images) of the cross section of an electromagnetic wave permeable laminate member. In determining the maximum thickness, first, a square area 3 with sides of 5 cm as shown in Figure 3 was appropriately extracted from the metal layer appearing on the surface of an electromagnetic wave transparent laminated member as shown in Figures 2(a) and 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 Figures 2(a) and 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 for each of the five measurement points, and the average value of these was taken as the "maximum thickness."

[0096] <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.

[0097] (5) Oxygen composition ratio of indium oxide-containing layer For the indium oxide-containing layer before the metal layer was formed, quantitative analysis was performed on the surface of the indium oxide-containing layer after cleaning it by 2 nm (etching depth of about 1 nm in terms of SiO2) using a monochrome AlKα X-ray source at a photoelectron take-off angle of 45° to calculate the element ratio (atomic%). Then, the obtained In, Sn, and O (atomic%) were used to calculate the oxygen composition ratio (M=Sn) of O / (In+M).

[0098] [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 (O2 / (Ar+O2)) 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 substrate film when forming the Al layer was set to 130°C.

[0099] [Examples 2 to 7] Except for changing the time for forming the ITO layer and the time for forming the aluminum (Al) layer, the laminate 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 laminate members of Examples 4 to 7 are shown in Figures 4(a) to 4(d), respectively.

[0100] [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 and 3 shown in Table 1 were obtained in the same manner as in Comparative Example 1. An electron microscope photograph (TEM image) of the cross section of the laminated member of Comparative Example 3 is shown in Figure 5(b). [Comparative Example 4] The laminate member of Comparative Example 4 shown in Table 1 was obtained in the same manner as in Comparative Example 1, except that the target material was changed to an ITO target (Sn ratio 10% by 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.

[0101] [Table 1]

[0102] 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 thus exhibited excellent electromagnetic wave transmittance. They also had sufficient luster. This is believed to be due to the promotion of the formation of a metal layer with an island-like 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).

[0103] On the other hand, the laminated members of Comparative Examples 1 to 4 had significantly low sheet resistance and high radio wave transmission attenuation, and were inferior in electromagnetic wave transmission to the Examples. This is thought to be because many of the island-like 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).

[0104] It is believed that discontinuous structures can be formed by a similar method 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).

[0105] The present invention is not limited to the above-described embodiment, and can be embodied by making appropriate modifications without departing from the spirit of the invention.

[0106] 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 also naturally belong to the technical scope of the present invention. Furthermore, the components in the above-mentioned embodiments may be arbitrarily combined within the scope of the invention.

[0107] 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. [Industrial Applicability]

[0108] The electromagnetic wave permeable laminate member according to the present invention can be used for devices and articles that transmit and receive electromagnetic waves, and parts thereof, etc. For example, it can be used for various applications that require both design and electromagnetic wave permeability, 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 parts and exterior parts. [Explanation of symbols]

[0109] 1. Electromagnetic wave transparent laminated member 10 Base 11 Indium oxide-containing layer 12 metal layer 12a part 12b Gap

Claims

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. 2. The electromagnetic wave transparent laminate member according to claim 1, wherein the indium oxide-containing layer is provided in a continuous state.

3. The indium oxide-containing layer is ２ O ３ 3. The electromagnetic wave transparent laminate member according to claim 1 or 2, comprising any one of indium tin oxide (ITO), indium zinc oxide (IZO), or indium tin oxide (ITO).

4. The 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.

5. The electromagnetic wave transparent laminate member according to any one of claims 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 claims 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 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.

8. The electromagnetic wave transparent laminate member according to any one of claims 1 to 7, having a sheet resistance of 100 Ω / □ or more.

9. The electromagnetic wave transparent laminate member according to any one of claims 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 claims 1 to 9, wherein the substrate is any one of a substrate film, a resin molded substrate, a glass substrate, and 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 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.

Images