Electromagnetic wave control element and manufacturing method thereof

Abstract

The invention provides an electromagnetic wave control element and a method for manufacturing the electromagnetic wave control element. The electromagnetic wave control element comprises a first pattern-shaped conductive layer, an insulating layer, and a layer containing a material of which the conductivity varies according to voltage.

Description

Technical Field

[0001] The invention relates to an electromagnetic wave control element and a manufacturing method thereof. Background Art

[0002] In recent years, research has been conducted on the application of electromagnetic wave control elements having a substrate and a pattern made of a conductive material and arranged on the surface of the substrate to optical elements for electromagnetic waves with a frequency of 0.1 THz to 10 THz (wavelength of 30 μm to 3000 μm) (hereinafter also referred to as electromagnetic waves in the terahertz band).

[0003] For example, Japanese Patent Application Laid-Open No. 2021-114647 discloses a radio wave reflection device including a metamaterial and a dielectric substrate, wherein the metamaterial includes a metasurface substrate and a pattern of a metal film provided on the surface of the metasurface substrate. Summary of the invention

[0004] Technical issues to be solved by the invention

[0005] Metamaterials are required to have various properties, and one of the requirements is the ability to change the transmittance of electromagnetic waves. In the radio wave reflection device disclosed in Japanese Patent Application Laid-Open No. 2021-114647, the transmittance of electromagnetic waves in the metamaterial is controlled by changing the distance between the metamaterial and the dielectric substrate.

[0006] In the above-mentioned method for controlling the transmittance of electromagnetic waves, the amount of change in the above-mentioned distance tends to become larger depending on the wavelength region of the electromagnetic waves, and there is room for improvement in the simplicity of controlling the transmittance of electromagnetic waves.

[0007] An object of the embodiments of the present invention is to provide an electromagnetic wave control element capable of easily controlling transmittance at least at a part of the wavelength of an electromagnetic wave by applying a voltage, and a method for manufacturing the same.

[0008] Means for solving technical problems

[0009] The specific means for solving the problem are as follows.

[0010] <1> An electromagnetic wave control element including a first patterned conductive layer, an insulating layer, and a layer containing a material whose conductivity changes with voltage.

[0011] <2> The electromagnetic wave control element according to <1>, further comprising a second patterned conductive layer on the side of the layer containing the material having a conductivity that varies with voltage opposite to the side on which the insulating layer is provided.

[0012] <3> The electromagnetic wave control element according to <1> or <2> above, wherein:

[0013] The minimum value of the transmission attenuation rate of the first patterned conductive layer with respect to electromagnetic waves of 0.2 THz to 0.4 THz is not less than -5.0 dB.

[0014] <4> The electromagnetic wave control element according to any one of <1> to <3> above, wherein:

[0015] The first patterned conductive layer includes two or more linear structures or linear openings.

[0016] <5> The electromagnetic wave control element according to <4> above, wherein:

[0017] The shortest distance between adjacent linear structures or linear openings is 1000 μm or less.

[0018] <6> The electromagnetic wave control element according to any one of <1> to <5> above, wherein:

[0019] The above-mentioned materials whose conductivity varies with voltage include two-dimensional materials.

[0020] <7> The electromagnetic wave control element according to <6> above, wherein:

[0021] The above two-dimensional material has carbon.

[0022] <8> The electromagnetic wave control element according to any one of <1> to <7> above, wherein:

[0023] The material whose conductivity varies with voltage includes graphene.

[0024] <9> The electromagnetic wave control element according to any one of <1> to <8> above, wherein:

[0025] The material whose conductivity changes with voltage includes a material with a band gap of 3.0 eV or more.

[0026] <10> The electromagnetic wave control element according to any one of <1> to <9> above, wherein:

[0027] The material whose conductivity varies with voltage includes an oxide semiconductor.

[0028] <11> The electromagnetic wave control element according to <10> above, wherein:

[0029] The oxide semiconductor contains at least one of In and Zn.

[0030] <12> The electromagnetic wave control element according to any one of <1> to <11> above, wherein

[0031] The first patterned conductive layer includes metal.

[0032] <13> The electromagnetic wave control element according to any one of <2> to <11> above, wherein:

[0033] The second patterned conductive layer includes metal.

[0034] <14> The electromagnetic wave control element according to any one of <1> to <11> above, wherein

[0035] The first patterned conductive layer includes metal wiring.

[0036] <15> The electromagnetic wave control element according to any one of <2> to <11> above, wherein

[0037] The second patterned conductive layer includes metal wiring.

[0038] <16> The electromagnetic wave control element according to any one of <1> to <11> above, wherein

[0039] The first patterned conductive layer includes an oxide conductor.

[0040] <17> The electromagnetic wave control element according to any one of <2> to <11> above,

[0041] The second patterned conductive layer includes an oxide conductor.

[0042] <18> The electromagnetic wave control element according to any one of <1> to <11> above, wherein

[0043] The first patterned conductive layer includes oxide conductor wiring.

[0044] <19> The electromagnetic wave control element according to any one of <2> to <11> above, wherein

[0045] The second patterned conductive layer includes oxide conductor wiring.

[0046] <20> The electromagnetic wave control element according to any one of <1> to <19>, further comprising a substrate on the side of the first patterned conductive layer opposite to the side on which the insulating layer is provided.

[0047] <21> The electromagnetic wave control element according to <20> above, wherein:

[0048] The loss tangent of the substrate at a frequency of 28 GHz is 0.05 or less.

[0049] <22> The electromagnetic wave control element according to <20> or <21>, wherein:

[0050] The substrate has a light transmittance of 5% or more with respect to light having a wavelength of 550 nm.

[0051] <23> The electromagnetic wave control element according to any one of <20> to <22>, wherein:

[0052] The above-mentioned substrate contains an inorganic compound.

[0053] <24> The electromagnetic wave control element according to <23> above, wherein:

[0054] The inorganic compound is one or more compounds selected from the group consisting of glass, ceramics, and silicon.

[0055] <25> The electromagnetic wave control element according to any one of <20> to <22>, wherein

[0056] The above-mentioned substrate contains a resin.

[0057] <26> The electromagnetic wave control element according to <25>, wherein the resin is one or more resins selected from the group consisting of cycloolefin polymers, polyimides, modified polyimides, liquid crystal polymers, and fluoropolymers.

[0058] <27> A method for manufacturing an electromagnetic wave control element, comprising:

[0059] forming a first patterned conductive layer on a substrate;

[0060] forming an insulating layer on the first patterned conductive layer; and

[0061] A step of forming a layer including a material whose conductivity varies with voltage on the insulating layer.

[0062] Effects of the Invention

[0063] According to one embodiment of the present invention, it is possible to provide an electromagnetic wave control element capable of easily controlling transmittance at at least a part of the wavelength of an electromagnetic wave by applying a voltage, and a method for manufacturing the same. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1 It is a plan view showing one embodiment of the first patterned conductive layer or the second patterned conductive layer.

[0065] Figure 2 It is a plan view showing another embodiment of the first patterned conductive layer or the second patterned conductive layer.

[0066] Figure 3 It is a plan view showing still another embodiment of the first patterned conductive layer or the second patterned conductive layer.

[0067] Figure 4 It is a schematic cross-sectional view showing one embodiment of the electromagnetic wave control element of the present invention. DETAILED DESCRIPTION

[0068] Hereinafter, the present invention will be described in detail.

[0069] In the present invention, a numerical range expressed by "to" means a range including the numerical values ​​described before and after "to" as the lower limit and the upper limit.

[0070] In the present invention, in the numerical range recorded in stages, the upper limit or lower limit recorded in a certain numerical range can also be replaced by the upper limit or lower limit of other numerical ranges recorded in stages. In addition, in the numerical range recorded in this specification, the upper limit or lower limit recorded in a certain numerical range can also be replaced by the value shown in the embodiment.

[0071] In the present invention, when observing a region where the layer or film exists, the term "layer" or "film" includes not only a case where the layer or film is formed on the entire region, but also a case where the layer or film is formed on only a part of the region.

[0072] In the present invention, the term "process" includes not only independent processes but also processes that cannot be clearly distinguished from other processes as long as the intended purpose of the process can be achieved.

[0073] In the present invention, "material whose electrical conductivity changes with voltage" refers to a material whose electrical conductivity changes depending on the presence or absence of applied voltage, the magnitude of the applied voltage, and the like.

[0074] In the present invention, "two-dimensional material" refers to a material that has a quantum confinement effect in one-dimensional direction and has conductivity in two-dimensional direction.

[0075] In the present invention, the "oxide conductor" refers to a material having oxygen among its constituent elements and having metallic conductivity.

[0076] In the present invention, when the embodiments are described with reference to the drawings, the structure of the embodiments is not limited to the structure shown in the drawings. In addition, the sizes of the components in the drawings are conceptual, and the relative relationship between the sizes of the components is not limited thereto.

[0077] [Electromagnetic wave control element]

[0078] The electromagnetic wave controlling element of the present invention includes a first patterned conductive layer, an insulating layer, and a layer containing a material whose conductivity changes with voltage.

[0079] The electromagnetic wave control element of the present invention can easily control the transmittance at least at a part of the wavelength of the electromagnetic wave by applying a voltage. The mechanism of producing the above effect is not clear, but it is presumed as follows.

[0080] The electromagnetic wave control element of the present invention includes a layer containing a material whose conductivity changes with voltage (hereinafter, also referred to as a "conductivity change layer".), and by applying a voltage to the conductivity change layer, the transmittance of the conductivity change layer at at least a portion of the wavelength of the electromagnetic wave can be changed. In addition, the first patterned conductive layer included in the electromagnetic wave control element of the present invention is formed in a pattern, so that the electromagnetic wave that has passed through the conductivity change layer can pass through the first patterned conductive layer.

[0081] Based on the same principle, the electromagnetic wave control element of the present invention can easily control the reflectivity, transmission phase, and reflection phase of the conductivity variable layer at least at a part of the wavelength of the electromagnetic wave by applying a voltage to the conductivity variable layer.

[0082] Furthermore, the electromagnetic wave control element of the present invention can easily control the transmission direction and reflection direction of the conductivity variable layer at least at a part of the wavelength of the electromagnetic wave by changing the voltage applied to the conductivity variable layer in the plane of the insulating layer. Although the mechanism of exerting the above effect is not clear, it is speculated that by changing the voltage applied to the conductivity variable layer in the plane of the insulating layer to change the transmittance, reflectivity, transmission phase and reflection phase of the conductivity variable layer, an amplitude type diffraction grating can be formed in the plane of the conductivity variable layer to control the transmission direction and reflection direction.

[0083] The electromagnetic wave control element of the present invention may further include a second patterned conductive layer on the side of the conductivity variable layer opposite to the side on which the insulating layer is provided.

[0084] The electromagnetic wave controlling element of the present invention may further include a substrate on the side of the first patterned conductive layer opposite to the side on which the insulating layer is provided.

[0085] The electromagnetic wave control element of the present invention may further include an application electrode in contact with at least the conductivity variable layer.

[0086] (First patterned conductive layer)

[0087] The first patterned conductive layer can include a metal or oxide conductor.

[0088] From the viewpoint of electromagnetic wave transmittance, it is preferred that a metal is contained. From the viewpoint of electromagnetic wave transmittance, the first patterned conductive layer preferably contains one or more selected from the group consisting of gold, silver, platinum, copper, and aluminum.

[0089] The shape of the metal is not particularly limited, and may be in a particle form or a non-particle form.

[0090] The first patterned conductive layer preferably includes metal wirings made of the above-mentioned metal. Examples of the first patterned conductive layer including metal wirings include a first patterned conductive layer including one or more linear structures made of metal. The linear structures will be described later.

[0091] The content of the metal relative to the total mass of the first patterned conductive layer is not particularly limited, and may be 80 mass % or more, 90 mass % or more, or 100 mass %.

[0092] Examples of oxide conductors include oxides containing In, Zn, Sn, Cd, etc. More specifically, examples include In2O3, ZnO, SnO2, CdO, solid solutions thereof, substances containing dopants, etc. More specifically, examples include InSnO, InZnO, Al-doped ZnO, Ga-doped ZnO, F-doped SnO, antimony-doped SnO, etc.

[0093] The first patterned conductive layer preferably includes an oxide conductor wiring including the above-mentioned oxide conductor. Examples of the first patterned conductive layer including the oxide conductor wiring include a first patterned conductive layer including one or more linear structures including an oxide conductor.

[0094] Furthermore, the first patterned conductive layer may include conductive carbon materials such as carbon nanotubes and multilayer graphene.

[0095] The first patterned conductive layer may be a single layer or a multi-layer layer.

[0096] The first patterned conductive layer may include one or more structures or openings. The first patterned conductive layer may include two or more structures or openings having different shapes, sizes, and the like.

[0097] The shape of the structure or opening is not particularly limited, and examples thereof include C-shape, U-shape, double ring shape, V-shape, L-shape, lattice shape, spiral shape, line shape, rectangular shape, circular shape, cross shape, etc. in the in-plane direction of the insulating layer.

[0098] The size of the structure or the opening is not particularly limited, but the maximum length of the structure or the opening is preferably equal to or smaller than the wavelength of the incident electromagnetic wave.

[0099] In the present invention, the maximum length of a structure or an opening refers to the longest length when a straight line is drawn from one end to the other end of the structure or the opening in the in-plane direction of the insulating layer.

[0100] From the viewpoint of smoothness, the width of the structure or the opening is preferably 3 μm to 400 μm. For example, when the structure is C-shaped, the width of the structure refers to the length in a direction perpendicular to the longitudinal direction of the C shape.

[0101] From the viewpoint of increasing the change in electromagnetic wave transmittance caused by the applied voltage, the first patterned conductive layer preferably includes one or more linear structures (hereinafter also referred to as "linear structures") or linear openings (hereinafter also referred to as "linear openings"), more preferably includes two or more, further preferably includes 3 to 10, and particularly preferably includes 4 to 8.

[0102] When the first patterned conductive layer includes two or more linear structures or linear openings, the shortest distance between adjacent linear structures or linear openings is preferably less than the wavelength of the incident electromagnetic wave, more preferably less than 1000 μm, and further preferably 400 μm to 800 μm.

[0103] In addition, the distance between adjacent linear structures or linear openings refers to the distance between adjacent linear structures or linear openings in the in-plane direction of the insulating layer. In addition, when the first patterned conductive layer includes three or more linear structures or linear openings, the distances between adjacent linear structures or linear openings are measured respectively, and the average value is used as the distance between adjacent linear structures or linear openings.

[0104] From the perspective of reducing polarization dependence, the structure or opening is preferably a shape that is symmetrical with respect to an arbitrary X-axis and a Y-axis orthogonal thereto in the in-plane direction of the insulating layer, for example, a cross shape, a Jerusalem cross shape, a circular shape, a square shape, etc.

[0105] From the perspective of electromagnetic wave transmittance, the minimum value of the transmission attenuation rate of the first patterned conductive layer for electromagnetic waves of 0.2THz to 0.4THz is preferably greater than -5.0dB, more preferably greater than -3.0dB, further preferably greater than -2.5dB, and particularly preferably greater than -1.0dB. The upper limit of the minimum value of the transmission attenuation rate is not particularly limited, but is preferably less than -0.1dB.

[0106] In the present invention, the transmittance of the first patterned conductive layer with respect to an electromagnetic wave of 0.3 THz is measured as follows using a terahertz time-domain spectroscopy system using a femtosecond pulse laser.

[0107] The first patterned conductive layer was fixed on a 10 mm Φ sample holder, and the transmission amplitude at vertical incidence was measured. The incident numerical aperture NA of the terahertz wave incident on the first patterned conductive layer was set to 1 / 6.

[0108] The transmission amplitude of the first patterned conductive layer was measured, and the transmission attenuation rate of the first patterned conductive layer for electromagnetic waves of 0.2 THz to 0.4 THz was calculated and the minimum value was obtained.

[0109] When the minimum value of the transmission attenuation rate of the first patterned conductive layer for electromagnetic waves of 0.2THz to 0.4THz cannot be determined by the above method, an image of the shape of the first patterned conductive layer is obtained using an optical microscope, and electromagnetic wave simulation is performed on the image to thereby determine the minimum value of the transmission attenuation rate of the first patterned conductive layer for electromagnetic waves of 0.2THz to 0.4THz.

[0110] From the viewpoint of electromagnetic wave transmittance, smoothness, and the like, the thickness of the first patterned conductive layer is preferably 10 nm to 1000 nm, more preferably 30 nm to 300 nm, and even more preferably 50 nm to 200 nm.

[0111] In the present invention, the thickness of the first patterned conductive layer, the second patterned conductive layer, etc. is determined based on the average value of five arbitrary points on a cross section of the electromagnetic wave control element in the thickness direction measured using a scanning electron microscope (SEM).

[0112] Furthermore, from the viewpoint of adhesion, it is preferable to provide a metal chromium layer, a metal titanium layer, a metal nickel layer, or the like between the substrate and the first patterned conductive layer.

[0113] (Insulation layer)

[0114] The specific resistance value of the insulating layer is preferably 10 7 Ωcm or more.

[0115] The specific resistance value of the insulating layer can be obtained by conversion from volume resistance measurement or surface resistance measurement using a ring electrode after removing the conductivity variable layer and the second patterned conductive layer on the insulating layer.

[0116] From the viewpoint of easily obtaining high insulation properties, the insulating layer preferably contains a material selected from aluminum oxide (Al2O3), SiO2, SiN x , SiON, MgO, Y2O3, TiO2, GeO2, Ta2O5, HfO2, Sc2O3, Ga2O3, ZrO2, Ln2O3 (lanthanide oxides), etc., or a mixture of two or more thereof. Furthermore, a laminated film of two or more thereof may be used.

[0117] The content of the above compound relative to the total mass of the insulating layer is preferably 50 mass % or more, more preferably 60 mass % or more, further preferably 70 mass % or more, particularly preferably 80 mass % or more, most preferably 90 mass % or more, and may be 100 mass %.

[0118] From the viewpoint of electromagnetic wave transmittance, the thickness of the insulating layer is preferably 500 nm to 8000 nm, more preferably 1000 nm to 7000 nm, and even more preferably 1500 nm to 6000 nm.

[0119] (Conductivity variation layer)

[0120] In the present invention, the conductivity changing layer refers to a layer containing a conductivity changing material.

[0121] The difference between the transmission attenuation rate of the conductivity variable layer when a voltage of 100 V is applied and the transmission attenuation rate when no voltage is applied is preferably 5 dB or more, more preferably 10 dB or more.

[0122] The transmission amplitude was measured using a terahertz time-domain spectroscopy system using a femtosecond pulse laser, and the transmission attenuation rate of the conductivity-changing layer was calculated based on the transmission amplitude.

[0123] The material whose conductivity changes with voltage (hereinafter, also referred to as “conductivity changing material”) preferably includes a two-dimensional material.

[0124] From the viewpoint of increasing the change in the electromagnetic wave transmittance caused by the applied voltage, the two-dimensional material preferably has carbon. As two-dimensional materials, graphene, layered crystals of P, As, Sb, and Bi, transition metal dichalcogenides represented by h-BN, AB2 (A; Ti, Zr, Hf, V, Nb, Ta, Mo, W, etc., B; O, S, Se, Te), 13-group chalcogenides such as GaS, GaSe, GaTe, and InSe, 14-group chalcogenides such as GeS, SnS2, SnSe2, and PbO, bismuth chalcogenides such as Bi2Se3 and Bi2Te3, divalent metal hydroxides such as M(OH)2 (M; Mg, Ca, Mn, Fe, Co, Ni, Cu, and Cd), halides such as MgBr2, CdCl2, CdI2, Ag2F, AsI3, and AlCl3, and perovskite nanosheets can be cited.

[0125] From the viewpoint of increasing the change in electromagnetic wave transmittance due to applied voltage, the conductivity-changing material preferably includes graphene. From the viewpoint of reducing radio wave loss, the mobility of graphene is preferably 1,000 cm 2 / Vs or more, more preferably 2,000cm 2 / Vs or more, particularly preferably 3,000cm 2 / Vs or more. The upper limit of the mobility of graphene is not particularly limited.

[0126] From the viewpoint of increasing the amount of change in electromagnetic wave transmittance caused by applied voltage, the conductivity changing material preferably includes an oxide semiconductor.

[0127] From the viewpoint of increasing the amount of change in electromagnetic wave transmittance due to applied voltage, the oxide semiconductor preferably contains at least one of In (indium) and Zn (zinc).

[0128] Examples of oxide semiconductors include indium oxide (In2O3), In-Ga-Zn-O (IGZO), In-Zn-O (IZO), In-Ga-O (IGO), In-Sn-O (ITO), In-Sn-Zn-O (ITZO), mixtures thereof, and substances to which dopants are added based on these compounds.

[0129] From the viewpoint of increasing the amount of change in electromagnetic wave transmittance caused by applied voltage, the conductivity-changing material preferably includes a material having a band gap of 3.0 eV or more.

[0130] Examples of the material having a band gap of 3.0 eV or more include the above-mentioned oxide semiconductors and the like.

[0131] In the present invention, the band gap is measured as follows.

[0132] The absorbance of the conductivity changing material in the wavelength range of 300 nm to 1100 nm was measured using an ultraviolet-visible-near-infrared spectrophotometer.

[0133] The absorbance measured by the above method is plotted on the vertical axis (ahv) R , on a graph with the horizontal axis being energy value (eV), converted to (ahv) R -eV curve. Here, the coefficient R is R = 1 / 2 for directly allowed transitions, R = 3 / 2 for directly forbidden transitions, R = 2 for indirectly allowed transitions, and R = 3 for indirectly forbidden transitions. (ahv) R -eV curve means that the vertical axis is (ahv) R , the horizontal axis is the energy value (eV) curve. a is absorbance, h is Planck's constant, and v is frequency.

[0134] As the ultraviolet-visible-near-infrared spectrophotometer, U-4150 manufactured by Hitachi High-Tech Corporation or an apparatus equivalent thereto can be used.

[0135] Wavelength 1 The energy value E 1 The wavelength can be converted into energy value according to the following relationship.

[0136] E 1 =1240 / λ 1

[0137] E 1 The unit is eV, λ 1 The unit is nm.

[0138] In the above (ahv) R -eV curve, calculate (ahv) R The tangent line of the rising part of the value is (ahv) R The energy value at the intersection of the tangent line of the portion before the value of rises is taken as the band gap energy.

[0139] From the viewpoint of increasing the change in electromagnetic wave transmittance caused by the applied voltage, the content of the conductivity changing material relative to the total mass of the conductivity changing layer is preferably 50 mass % or more, more preferably 60 mass % or more, further preferably 70 mass % or more, especially preferably 80 mass % or more, most preferably 90 mass % or more, and can also be 100 mass %.

[0140] When the conductivity changing material includes graphene, from the viewpoint of increasing the change in electromagnetic wave transmittance caused by the applied voltage, the content of graphene relative to the total mass of the conductivity changing material is preferably 50 mass% or more, more preferably 60 mass% or more, further preferably 70 mass% or more, particularly preferably 80 mass% or more, most preferably 90 mass% or more, and may also be 100 mass%.

[0141] When the conductivity changing material includes an oxide semiconductor, from the viewpoint of increasing the change in electromagnetic wave transmittance caused by the applied voltage, the content of the oxide semiconductor relative to the total mass of the conductivity changing material is preferably 50 mass % or more, more preferably 60 mass % or more, further preferably 70 mass % or more, particularly preferably 80 mass % or more, most preferably 90 mass % or more, and may also be 100 mass %.

[0142] From the viewpoint of electromagnetic wave transmittance, the thickness of the conductivity variable layer is preferably 0.1 nm to 1 μm, more preferably 0.1 nm to 300 nm, and even more preferably 0.1 nm to 150 nm.

[0143] (Second patterned conductive layer)

[0144] It is preferable that the second patterned conductive layer serves as a resonator for electromagnetic waves.

[0145] The second patterned conductive layer can include a metal or an oxide conductor. The metal and the oxide conductor have been described above, so their description is omitted here.

[0146] Furthermore, the second patterned conductive layer may include metal wiring or oxide conductor wiring.

[0147] Furthermore, the second patterned conductive layer may include conductive carbon materials such as carbon nanotubes and multilayer graphene.

[0148] The second patterned conductive layer may be a single layer or a multi-layer layer.

[0149] The second patterned conductive layer may include one or more structures or openings. The second patterned conductive layer may include two or more structures or openings having different shapes, sizes, and the like.

[0150] The shape of the structure or opening is not particularly limited, but is preferably the following shape: when electromagnetic waves in the terahertz frequency band are incident on the electromagnetic wave control element, the interaction between the incident electromagnetic waves and the electric field and magnetic field, etc., generates charge deviation and current in the structure, in the opening, between adjacent structures, between adjacent openings, etc., which can induce a response change of the electro-dielectric or magnetic properties.

[0151] The shape of the structure or opening is not particularly limited, and examples thereof include C-shape, U-shape, double ring shape, V-shape, L-shape, lattice shape, spiral shape, line shape, rectangular shape, circular shape, cross shape, etc. in the in-plane direction of the insulating layer.

[0152] From the viewpoint of increasing the amount of change in electromagnetic wave transmittance caused by the applied voltage, the second patterned conductive layer preferably includes openings of the above shape.

[0153] The size of the structure or the opening is not particularly limited, but the maximum length of the structure or the opening is preferably less than the wavelength of the incident electromagnetic wave, more preferably less than 1000 μm, and further preferably 10 μm to 800 μm.

[0154] From the viewpoint of smoothness, the width of the structure or the opening is preferably 3 μm to 400 μm.

[0155] When the structure or the opening is a split ring resonator, the gap is preferably 1 μm to 15 μm from the viewpoint of pattern smoothness.

[0156] A split ring resonator refers to a structure or an opening having a C-shape or a U-shape.

[0157] The arrangement position of the structure or the opening is not particularly limited, but is preferably an arrangement that resonates with electromagnetic waves in the terahertz frequency band.

[0158] Furthermore, the structure or the opening may be arranged on the surface of the substrate to form a periodic structure in which the phase shift of the electromagnetic wave in the terahertz frequency band increases or decreases continuously as the area from the center of the insulating layer surface toward the outside is formed. As an embodiment of the above-mentioned periodic structure, a structure in which structures with different diameters are arranged in concentric circles can be cited. The diameter variation range of the structures arranged in concentric circles can be set to 10 μm to 200 μm.

[0159] From the viewpoint of electromagnetic wave transmittance, smoothness, and the like, the thickness of the second patterned conductive layer is preferably 30 nm to 300 nm, and more preferably 50 nm to 200 nm.

[0160] (Base material)

[0161] The substrate used in the present invention is not particularly limited, and substrates made of known materials can be used.

[0162] The shape, structure, size, etc. of the substrate are not particularly limited and can be appropriately selected according to the purpose. The structure of the substrate may be a single-layer structure or a laminated structure.

[0163] The substrate may contain an inorganic compound or a resin.

[0164] As the resin, a substrate composed of a synthetic resin such as polybutylene terephthalate, polyethylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polystyrene, polycarbonate, polysulfone, polyethersulfone, polyarylate, allyl carbonate, polyamide, polyimide, modified polyimide, polyamideimide, polyetherimide, polybenzoxazole, polyphenylene sulfide, polycycloolefin, norbornene resin, polychlorotrifluoroethylene, etc., a liquid crystal polymer, an acrylic resin, an epoxy resin, a silicone resin, an ionomer resin, a cyanate resin, a cross-linked fumaric acid diester, a cyclic polyolefin, an aromatic ether, a maleimide olefin, cellulose, an episulfide compound, a substrate composed of a composite plastic material of the above-mentioned synthetic resin and silicon oxide particles, a substrate composed of the above-mentioned synthetic resin and metal nanoparticles, inorganic oxide nanoparticles or inorganic nitride nanoparticles. A substrate composed of a composite plastic material of the above-mentioned synthetic resin, etc. and carbon fibers or carbon nanotubes, a substrate composed of a composite plastic material of the above-mentioned synthetic resin, etc. and glass sheets, glass fibers or glass microspheres, a substrate composed of a composite plastic material of the above-mentioned synthetic resin, etc. and particles having a clay mineral or mica-derived crystalline structure, a laminated plastic substrate having at least one bonding interface between thin glass and any of the above-mentioned resins, a substrate composed of a composite material with barrier properties having at least one bonding interface by alternately laminating inorganic layers and organic layers (including layers of the above-mentioned synthetic resins), a stainless steel substrate or a metal multilayer substrate formed by laminating stainless steel and dissimilar metals, an aluminum substrate or an aluminum substrate with an oxide film having improved surface insulation by performing an oxidation treatment (for example, anodizing treatment) on the surface, etc.

[0165] Among them, from the viewpoints of loss tangent, adhesion to a pattern, heat resistance, etc., the resin is preferably one or more resins selected from the group consisting of cycloolefin polymers, polyimides, modified polyimides, liquid crystal polymers, and fluoropolymers.

[0166] From the viewpoints of strength, heat resistance, etc., the above-mentioned inorganic compound is preferably one or more compounds selected from the group including glass, ceramics and silicon. From the viewpoint of transmittance in the radio wave region, it is more preferably one or more compounds selected from the group including glass and silicon.

[0167] From the viewpoint of increasing the change in electromagnetic wave transmittance caused by the applied voltage, the loss tangent of the above-mentioned substrate at a frequency of 28 GHz is preferably 0.05 or less, more preferably 0.01 or less, further preferably 0.005 or less, and particularly preferably 0.001 or less.

[0168] The loss tangent of the base material can be adjusted by changing the material contained in the base material, etc.

[0169] In the present invention, the loss tangent of the substrate is measured by the following terahertz time domain spectroscopy (THz-TDS).

[0170] First, the substrate was cut into a test piece of 100 mm×100 mm.

[0171] Next, an optical system for transmission terahertz spectroscopy was prepared, and the loss tangent (frequency 0.3 THz) of the test piece was measured from the change in the time waveform of the optical field before and after the insertion of the test piece in an environment of temperature 25°C and humidity 10% RH.

[0172] When a pattern described later is formed on the surface of a substrate, the loss tangent is measured using a substrate etched with a solution such as ferric chloride.

[0173] From the viewpoint of increasing the change in electromagnetic wave transmittance according to the applied voltage, the transmittance of the above-mentioned substrate at a wavelength of 550nm is preferably 5% or more, more preferably 10% or more, further preferably 30% or more, and particularly preferably 50% to 100%.

[0174] In the present invention, the light transmittance of the substrate at a wavelength of 550 nm is measured as follows.

[0175] The light transmittance of the substrate at a wavelength of 550 nm is measured using a spectrophotometer (for example, UV-2450, manufactured by SHIMADZU CORPORATION).

[0176] The thickness of the substrate is not particularly limited, but is preferably 30 μm to 200 mm, more preferably 40 μm to 100 mm, and even more preferably 50 μm to 50 mm from the viewpoint of handleability.

[0177] The substrate may be produced by a conventionally known method or a commercially available substrate may be used.

[0178] Furthermore, as the substrate, a substrate obtained by impregnating a fabric such as glass cloth, a nonwoven fabric, etc. with the above resin can be used. Furthermore, the above resin or the like can be used as a substrate by forming a layer on at least one surface of the glass cloth or the like impregnated with the above resin to form a multilayer structure.

[0179] (Application electrode)

[0180] In order to apply voltage to the electromagnetic wave control element of the present invention, the electromagnetic wave control element can also include an application electrode that is in contact with at least the conductivity change layer. The application electrode is not particularly limited, and a conventionally known electrode can be used. Furthermore, the second patterned conductive layer in contact with the conductivity change layer can be directly used as the application electrode.

[0181] refer to Figure 1 to Figure 4, an embodiment of the electromagnetic wave control element of the present invention is described. In addition, the electromagnetic wave control element of the present invention is not limited to this.

[0182] Figure 1 One embodiment of the first patterned conductive layer or the second patterned conductive layer (hereinafter, also collectively referred to as “patterned conductive layer”) is shown.

[0183] Figure 1 The patterned conductive layer 10 shown includes linear structures 11 and linear structures 12 .

[0184] The width of the linear structure 11 is represented by L1 and the maximum length is represented by L2. The width of the linear structure 12 is represented by L4 and the maximum length is represented by L5. The shortest distance between adjacent linear structures 11 or 12 is represented by L3.

[0185] Figure 2 Another embodiment of the patterned conductive layer is shown.

[0186] Figure 2 The patterned conductive layer 20 shown has a pattern including linear openings 21 (portions surrounded by the lines are perforated).

[0187] The width of the opening 21 is indicated by symbol L6, and the maximum length is indicated by symbol L7.

[0188] Figure 3 Still another embodiment of the patterned conductive layer is shown.

[0189] Figure 3 The patterned conductive layer 30 shown has a pattern including linear openings 31 (portions surrounded by the lines are perforated) at both ends in one direction.

[0190] The width of the linear opening 31 is denoted by symbol L8 , the maximum length is denoted by symbol L9 , and the shortest distance between adjacent linear openings 31 is denoted by symbol L10 .

[0191] Figure 4 It is a schematic cross-sectional view showing an embodiment of an electromagnetic wave control element 40 of the present invention.

[0192] Figure 4 The electromagnetic wave control element 40 shown includes a substrate 41 , a first patterned conductive layer 42 , an insulating layer 43 , a conductivity variable layer 44 , and a second patterned conductive layer 45 .

[0193] exist Figure 4 In the embodiment, the insulating layer 43 covers the first patterned conductive layer 42 .

[0194] [Method for manufacturing electromagnetic wave control element]

[0195] The manufacturing method of the electromagnetic wave control element of the present invention includes: a process of forming a first patterned conductive layer on a substrate; a process of forming an insulating layer on the first patterned conductive layer; and a process of forming a layer containing a material whose conductivity changes with voltage (hereinafter also referred to as a "conductivity change layer") on the insulating layer.

[0196] The method for manufacturing an electromagnetic wave control element of the present invention may include a step of forming a second patterned conductive layer on the conductivity variable layer.

[0197] The method for manufacturing an electromagnetic wave control element of the present invention may include a step of providing an application electrode in contact with at least the conductivity change layer.

[0198] The preferred embodiments of the substrate, the first patterned conductive layer, the insulating layer, the conductivity change layer, the second patterned conductive layer and the application electrode in the manufacturing method of the electromagnetic wave control element involved in the present invention are the same as the preferred embodiments of the substrate, the first patterned conductive layer, the insulating layer, the conductivity change layer, the second patterned conductive layer and the application electrode in the electromagnetic wave control element involved in the present invention mentioned above.

[0199] (Step of forming a first patterned conductive layer)

[0200] There is no particular limitation on the method for forming the first patterned conductive layer, and examples include a method of performing a perforation process on a conductive film that is disposed on a substrate; a method of forming a sputtered film on the surface of the substrate by a sputtering method, then forming a resist pattern on the surface of the sputtered film, etching away the sputtered film not covered by the resist pattern, and then removing the resist pattern to form the first patterned conductive layer; or a method of forming a conductive film by a sputtering method after forming a resist pattern on the surface of the substrate, and removing unnecessary portions together with the resist pattern by a stripping method; a sputtering film-forming method performed via a metal mask, etc.

[0201] The method for forming the first patterned conductive layer is not limited to the above method, and may be formed by inkjet, dispenser, screen printing, or pattern plating instead of the above sputtering method. Also, a vapor deposition film may be formed by vapor deposition instead of the above sputtering method.

[0202] (Step of Forming Insulating Layer)

[0203] The method for forming the insulating layer is not particularly limited, and the insulating layer can be formed on the first patterned conductive layer by sputtering, CVD, ALD, thermal oxidation, sol-gel method, or the like.

[0204] (Step of Forming Conductivity Variable Layer)

[0205] The method for forming the variable conductivity layer is not particularly limited. For example, when the variable conductivity layer is a two-dimensional material, the variable conductivity layer can be formed by separately preparing a transfer sheet having the two-dimensional material and transferring the variable conductivity layer from the transfer sheet to the insulating layer. When the variable conductivity layer is a semiconductor material, the variable conductivity layer can be formed by sputtering, vapor deposition, MBE, CVD, ALD, PLD, sol-gel method, coating to form a nanoparticle film, and the like.

[0206] (Step of forming a second patterned conductive layer)

[0207] The method for forming the second patterned conductive layer is not particularly limited, and the second patterned conductive layer can be formed by the same method as that for the first patterned conductive layer.

[0208] (Step of providing application electrodes)

[0209] The method for manufacturing an electromagnetic wave control element of the present invention may include the step of providing an application electrode in contact with at least the conductivity variable layer. The application electrode can be provided by a conventionally known method.

[0210] Example

[0211] Hereinafter, the above-mentioned embodiment will be described in detail by way of examples, but the above-mentioned embodiment is not limited to these examples.

[0212] (Example 1)

[0213] A quartz substrate was prepared as the substrate. The loss tangent of the quartz substrate at a frequency of 28 GHz was 0.001, and the light transmittance at a wavelength of 550 nm was 92%.

[0214] Using a vacuum deposition apparatus (EBX-1000) manufactured by ULVAC, Inc., an Al vapor-deposited film (conductive film) with a thickness of 100 nm was formed on the entire surface of the quartz substrate.

[0215] A resist film was formed on the Al vapor-deposited film, and exposure and development were performed by photolithography to form a resist pattern.

[0216] Next, the Al deposited film region where the resist pattern was not formed was etched using a mixed acid (mixed acid Al etching solution manufactured by KANTO CHEMICAL CO., INC.), thereby forming a Figure 1 The first patterned conductive layer of the two types of linear structures 11 and 12 (hereinafter also referred to as “linear structures”) shown.

[0217] exist Figure 1 In FIG. 1 , the portion surrounded by a line indicates a portion where the Al vapor-deposited film remains.

[0218] The linear structures have the same shape. The linear structure 11 has a width L1 of 20 μm and a maximum length L2 of 270 μm. The linear structure 12 has a width L4 of 40 μm and a maximum length L5 of 270 μm. The shortest distance L3 between adjacent linear structures is 40 μm (average value).

[0219] The substrate on which the first patterned conductive layer was formed was measured using a terahertz time-domain spectroscopy system using a femtosecond pulse laser.

[0220] The substrate was fixed on a 10 mm Φ sample holder and the transmission amplitude at vertical incidence was measured. The incident numerical aperture NA of the terahertz wave incident on the first patterned conductive layer on the substrate surface was about 1 / 6.

[0221] The transmission amplitude of the first patterned conductive layer was measured, and the transmission attenuation rate of the first patterned conductive layer for electromagnetic waves of 0.2THz to 0.4THz was calculated and the minimum value was obtained. The results are shown in Table 1. The following examples and comparative examples were calculated in the same manner and are shown in Table 1.

[0222] An insulating layer (thickness: 5000 nm) of aluminum oxide (Al 2 O 3 ) was formed on the first patterned conductive layer using a magnetron sputtering device.

[0223] A transfer sheet (manufactured by Graphenea) was prepared by forming a single-layer graphene film on a copper foil by a CVD method.

[0224] Polymethyl methacrylate was spin-coated on the graphene layer of the transfer sheet composed of the copper foil and the single-layer graphene to form a coating film, and then a thermally conductive tape was attached to the coating film.

[0225] The transfer sheet to which the thermally conductive tape was attached was immersed in a ferric chloride solution to etch the copper foil, and then washed with pure water, thereby obtaining a laminate consisting of the graphene layer, the coating film, and the thermally conductive tape.

[0226] The graphene layer of the laminate was attached to the insulating layer, heated at 120° C., and the thermally conductive tape was peeled off.

[0227] Next, the coating film of the laminate was removed with acetone, and a one-molecular-layer (thickness of about 0.3 nm) conductivity variable layer (graphene layer) was formed on the surface of the insulating layer.

[0228] A resist film was formed on the conductivity variable layer, and exposure and development were performed by photolithography to form a resist pattern.

[0229] Using the above-mentioned vacuum deposition apparatus, a Ti vapor deposition film of 10 nm and an Al vapor deposition film of 100 nm were continuously formed on the conductivity variable layer having the resist pattern formed thereon.

[0230] The resist pattern was removed by a stripping method using acetone to form Figure 2 The second patterned conductive layer shown obtains an electromagnetic wave control element.

[0231] Figure 2 A pattern including linear openings 21 (hereinafter, also referred to as “linear openings”) (portions surrounded by the lines are perforated) is shown.

[0232] The width L6 of the linear opening 21 is 40 μm, and the maximum length L7 of the linear opening 21 is 270 μm.

[0233] In addition, the second patterned conductive layer serves as a resonator for electromagnetic waves.

[0234] (Example 2)

[0235] In the same manner as in Example 1, a quartz substrate was used as a substrate, an Al vapor-deposited film (conductive film) was formed, and a resist pattern was formed, thereby forming a first patterned conductive layer. In addition, in the same manner as in Example 1, an insulating layer (thickness 5000 nm) of aluminum oxide (Al2O3) was formed on the first patterned conductive layer.

[0236] A transfer sheet (manufactured by Institute for 2D materials LLC.) including a sapphire substrate, a copper layer, and a graphene layer was prepared.

[0237] Polymethyl methacrylate was spin-coated on the graphene layer of the transfer sheet to form a coating film, and then a thermally conductive tape was attached to the coating film.

[0238] The transfer sheet with the thermally conductive tape attached was immersed in a ferric chloride solution to etch the copper layer and peel off the sapphire substrate. Then, it was washed with pure water to obtain a laminate consisting of the graphene layer, the coating film and the thermally conductive tape.

[0239] The graphene layer of the laminate was attached to the insulating layer, heated at 120° C., and the thermally conductive tape was peeled off.

[0240] Next, the coating film of the laminate was removed with acetone, and a one-molecular-layer (thickness of about 0.3 nm) conductivity variable layer (graphene layer) was formed on the surface of the insulating layer.

[0241] Furthermore, in the same manner as in Example 1, a resist film was formed on the conductivity change layer, and a resist pattern was formed.

[0242] Then, in the same manner as in Example 1, an Al vapor deposition film is continuously formed on the conductivity variable layer having the resist pattern formed thereon, and the resist pattern is removed to form a Figure 2 The second patterned conductive layer shown is used to obtain an electromagnetic wave control element.

[0243] (Example 3)

[0244] The first patterned conductive layer is changed to Figure 3 An electromagnetic wave control element was manufactured in the same manner as in Example 2 except for the pattern shown.

[0245] Figure 3 A pattern including linear openings 31 (portions surrounded by the line are perforated) at both ends in the longitudinal direction is shown.

[0246] The width L8 of the linear opening 31 is 20 μm, the maximum length L9 of the linear opening 31 is 210 μm, and the shortest distance L10 between adjacent linear openings 31 is 250 μm.

[0247] (Example 4)

[0248] An electromagnetic wave control element was manufactured in the same manner as in Example 2 except that the second patterned conductive layer was not provided. However, in Example 4, a Ti / Au electrode was formed as an application electrode on the end portion of the graphene layer by the lift-off method.

[0249] (Comparative Example 1)

[0250] An electromagnetic wave control element was manufactured in the same manner as in Example 3 except that a resist pattern was formed on the Al vapor-deposited film formed on the quartz substrate and patterning of the Al vapor-deposited film was not performed.

[0251] <Measurement of radio wave shielding capability>

[0252] For dynamic metasurface elements (electromagnetic wave control elements), the transmission amplitude was measured and the transmission attenuation rate was calculated using a terahertz time-domain spectroscopy system using a femtosecond pulse laser.

[0253] The dynamic metasurface element was fixed on a Φ10 mm sample holder and the transmission amplitude at vertical incidence was measured. The incident numerical aperture NA of the terahertz wave incident on the dynamic metasurface element was about 1 / 6. In addition, electromagnetic waves were incident on the dynamic metasurface elements of Examples 2 and 4 from a direction perpendicular to the long axis direction of the line pattern.

[0254] The application electrode was grounded, and the transmission amplitude was measured when a voltage of 100 V was applied to the dynamic metasurface element of the first patterned conductive layer and when no voltage was applied, and the transmission attenuation rate of the dynamic metasurface element (electromagnetic wave control element) was calculated for electromagnetic waves of 0.28 THz in Example 1, 0.22 THz in Example 2, 0.31 THz in Example 3, 0.22 THz in Example 4, and 0.30 THz in Comparative Example 1. The results are shown in Table 1.

[0255] The larger the difference between the transmission attenuation rate when a voltage of 100 V is applied and the transmission attenuation rate when no voltage is applied, the larger the change in transmittance is.

[0256] In the electromagnetic wave control elements of Examples 2, 3 and Comparative Example 1, the second patterned conductive layer was directly used as an application electrode for ensuring grounding. In the electromagnetic wave control element of Example 4, a separately formed application electrode was set to ground.

[0257] <Method for measuring graphene mobility>

[0258] After laminating a graphene layer of a stack consisting of the thermally conductive tape, a coating of polymethyl methacrylate (PMMA) and a graphene layer on the surface of the SiO2 layer of a p-doped silicon substrate (volume resistivity 5Ω·cm, thickness 450μm) having a thermally oxidized SiO2 layer (thickness 300nm) on one side, the thermally conductive tape was peeled off by heating at 120°C.

[0259] Next, the PMMA coating of the stacked body was removed by using acetone, and the graphene layer was transferred onto the SiO2 layer of the p-doped silicon substrate.

[0260] On the surface of the graphene layer on the SiO2 layer, a resist pattern was formed by photolithography and oxygen plasma ashing was performed, thereby processing the graphene into a linear shape. Moreover, after the resist pattern was formed by photolithography, Ni (thickness 5nm) and Au (thickness 20nm) were evaporated and peeled off to form an electrode pattern, thereby producing a graphene field effect transistor element having a graphene channel with a width of 5μm and a length of 50μm.

[0261] The graphene field effect transistor element was placed in a vacuum probe and -3 Pa), and then heated at 200°C for 24 hours, and then cooled to 25°C.

[0262] Using a semiconductor parameter analyzer to measure I d -V g The mobility μ was calculated by the following equation 1. Here, L represents the graphene channel length, W represents the channel width, and C oxRepresents the electrostatic capacitance of the SiO2 layer, V d represents the drain voltage, I d represents the drain current, V g Indicates the gate voltage.

[0263] [Formula 1]

[0264]

[0265] The mobility of the graphene formed on the copper foil by CVD method used in Example 1 was 1,200 cm 2 The mobility of the graphene formed on the epitaxial copper thin film by CVD method used in Examples 2, 3, and 4 was 4,000 cm 2 / Vs.

[0266] [Table 1]

[0267]

[0268] It can also be seen from Table 1 above that the dynamic metasurface element of the embodiment having the first patterned conductive layer can control the transmittance at at least a part of the wavelength of the electromagnetic wave by the easy method of applying voltage, compared with the dynamic metasurface element not having the first patterned conductive layer (having an unpatterned conductive layer).

[0269] In addition, regarding the invention of Japanese Patent Application No. 2022-088993 filed on May 31, 2022, the entirety of the invention is incorporated into this specification by reference. Furthermore, all documents, patent applications, and technical standards described in this specification are incorporated into this specification by reference to the same extent as if each document, patent application, and technical standard was specifically and separately described as being incorporated by reference.

Claims

1. An electromagnetic wave control element comprising a first patterned conductive layer, an insulating layer, and a layer containing a material whose conductivity changes with voltage.

2. The electromagnetic wave control element according to claim 1, wherein: A second patterned conductive layer is further provided on the side of the layer including the material having a conductivity varying with voltage opposite to the side on which the insulating layer is provided.

3. The electromagnetic wave control element according to claim 1 or 2, wherein: The minimum value of the transmission attenuation rate of the first patterned conductive layer for electromagnetic waves of 0.2 THz to 0.4 THz is greater than or equal to -5.0 dB.

4. The electromagnetic wave control element according to claim 1 or 2, wherein: The first patterned conductive layer includes two or more linear structures or linear openings.

5. The electromagnetic wave control element according to claim 4, wherein: The shortest distance between adjacent linear structures or linear openings is 1000 μm or less.

6. The electromagnetic wave control element according to claim 1 or 2, wherein: The material whose conductivity varies with voltage comprises a two-dimensional material.

7. The electromagnetic wave control element according to claim 6, wherein: The two-dimensional material includes carbon.

8. The electromagnetic wave control element according to claim 1 or 2, wherein: The material whose conductivity varies with voltage includes graphene.

9. The electromagnetic wave control element according to claim 1 or 2, wherein: The material whose conductivity varies with voltage includes a material with a band gap of 3.0 eV or more.

10. The electromagnetic wave control element according to claim 1 or 2, wherein: The material whose conductivity varies with voltage includes an oxide semiconductor.

11. The electromagnetic wave control element according to claim 10, wherein: The oxide semiconductor includes at least one of In and Zn.

12. The electromagnetic wave control element according to claim 1, wherein: The first patterned conductive layer includes metal.

13. The electromagnetic wave control element according to claim 2, wherein: The second patterned conductive layer includes metal.

14. The electromagnetic wave control element according to claim 1, wherein: The first patterned conductive layer includes metal wiring.

15. The electromagnetic wave control element according to claim 2, wherein: The second patterned conductive layer includes metal wiring.

16. The electromagnetic wave control element according to claim 1, wherein: The first patterned conductive layer includes an oxide conductor.

17. The electromagnetic wave control element according to claim 2, wherein: The second patterned conductive layer includes an oxide conductor.

18. The electromagnetic wave control element according to claim 1, wherein: The first patterned conductive layer includes oxide conductor wiring.

19. The electromagnetic wave control element according to claim 2, wherein: The second patterned conductive layer includes oxide conductor wiring.

20. The electromagnetic wave control element according to claim 1 or 2, wherein: A substrate is further provided on the side of the first patterned conductive layer opposite to the side on which the insulating layer is provided.

21. The electromagnetic wave control element according to claim 20, wherein: The loss tangent of the substrate at a frequency of 28 GHz is less than 0.

05.

22. The electromagnetic wave control element according to claim 20, wherein: The substrate has a light transmittance of 5% or more for light with a wavelength of 550 nm.

23. The electromagnetic wave control element according to claim 20, wherein: The substrate includes an inorganic compound.

24. The electromagnetic wave control element according to claim 23, wherein: The inorganic compound is one or more compounds selected from the group consisting of glass, ceramics, and silicon.

25. The electromagnetic wave control element according to claim 20, wherein: The substrate comprises a resin.

26. The electromagnetic wave control element according to claim 25, wherein: The resin is one or more resins selected from the group consisting of cycloolefin polymers, polyimides, modified polyimides, liquid crystal polymers, and fluoropolymers.

27. A method for manufacturing an electromagnetic wave control element, comprising: forming a first patterned conductive layer on a substrate; forming an insulating layer on the first patterned conductive layer; and A step of forming a layer including a material whose conductivity varies with voltage on the insulating layer.

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