JP2015121417A - Electromagnetic wave detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic wave detector capable of highly efficiently absorbing wavelengths of other wide wavelength bands excepting for a desired wavelength.SOLUTION: The electromagnetic wave detector which converts an electromagnetic wave into an electric signal and detects the electric signal includes: a structure including a lower metal layer, an insulation layer formed on the lower metal layer and an upper layer metal pattern with which a plurality of upper metal layers are disposed on the insulation layer; and a signal detection part which detects a temperature change of the structure by converting it into an electric signal. The upper layer metal pattern includes at least two kinds of upper metal layers of which the shape is determined so as to absorb electromagnetic waves of a specific wavelength through surface plasmon resonance with the electromagnetic waves of the specific wavelength, and between absorption wavelengths of two electromagnetic waves absorbed by the upper metal layer, the insulation layer and the upper layer metal pattern, a non-absorption wavelength band of non-absorbed electromagnetic waves is included.

Description

  The present invention relates to an electromagnetic wave detector, and more particularly to an electromagnetic wave detector that selectively excludes a specific wavelength from an incident electromagnetic wave and absorbs it to convert it into an electric signal.

In the conventional electromagnetic wave detector, a semiconductor material is used as a material of the light detection layer. However, since the semiconductor material has a band gap, only light having energy larger than the band gap can be detected. Not optimal.
Therefore, as a next-generation photodetector, research has been conducted to perform electromagnetic wave absorption using the plasmon effect in a metal structure. For example, Non-Patent Document 1 describes a detector provided with a structure having a lower metal layer, an insulating layer, and an upper metal layer having a periodic pattern and size. In such a detector, light absorption at a wavelength depending on the shape of the upper metal layer and the thickness of the insulating layer is possible by measuring the light absorption rate in the structure.

Jiaming Hao et al., APPLIED PHYSICS LETTERS vol. 96, pp. 251104 (2010)

However, in various fields, such as satellite observation of the earth, astronomical imaging, remote communication, biophotonic equipment, removal of unwanted fluorescence, and human observation during a fire, light detection without specific wavelengths is possible. Although demanded, the structure shown in Non-Patent Document 1 cannot detect light except for a specific wavelength.
On the other hand, the method of blocking a specific wavelength using an optical system such as a notch filter has a problem that the cost is high and the cutoff wavelength largely depends on the installation angle of the filter and the incident angle of light.

  Accordingly, an object of the present invention is to provide an electromagnetic wave detector capable of absorbing with high efficiency with respect to wavelengths in other wide wavelength bands except for a desired wavelength.

  The present invention is an electromagnetic wave detector that detects electromagnetic waves by converting them into electrical signals, and includes a lower metal layer, an insulating layer formed on the lower metal layer, and a plurality of upper metal layers on the insulating layer. An upper layer metal pattern, and a signal detection unit that detects a change in temperature of the structure by converting it into an electrical signal, and the upper layer metal pattern performs surface plasmon resonance with an electromagnetic wave having a specific wavelength. Including at least two types of upper metal layers whose shapes are determined so as to absorb electromagnetic waves of a specific wavelength, and absorbed between the absorption wavelengths of the two electromagnetic waves absorbed by the upper metal layer, the insulating layer, and the upper metal pattern. It is an electromagnetic wave detector characterized by having a non-absorption wavelength band of electromagnetic waves which are not.

  The electromagnetic wave detector according to the present invention can absorb electromagnetic waves with high efficiency in other wide wavelength bands except for a desired wavelength. That is, it is possible to detect an electromagnetic wave having a non-absorption wavelength band.

It is a perspective view of the electromagnetic wave detector concerning Embodiment 1 of this invention. It is sectional drawing of the electromagnetic wave detector concerning Embodiment 1 of this invention. It is a top view of the electromagnetic wave detector concerning Embodiment 1 of this invention. It is a conceptual diagram which shows the behavior of the electromagnetic field when electromagnetic waves enter into an electromagnetic wave detector. It is a light absorption spectrum when electromagnetic waves are incident on the electromagnetic wave detector. It is a top view of the electromagnetic wave detector concerning Embodiment 1 of this invention. It is a light absorption spectrum of the electromagnetic wave detector concerning Embodiment 1 of this invention. FIG. 6 is a layout diagram of another upper surface metal pattern of the electromagnetic wave detector according to the first exemplary embodiment of the present invention. It is the light absorption spectrum in the other upper surface metal pattern of the electromagnetic wave detector concerning Embodiment 1 of this invention. FIG. 6 is a layout diagram of another upper surface metal pattern of the electromagnetic wave detector according to the first exemplary embodiment of the present invention. FIG. 6 is a layout diagram of another upper surface metal pattern of the electromagnetic wave detector according to the first exemplary embodiment of the present invention. FIG. 6 is a layout diagram of another upper surface metal pattern of the electromagnetic wave detector according to the first exemplary embodiment of the present invention. FIG. 6 is a layout diagram of another upper surface metal pattern of the electromagnetic wave detector according to the first exemplary embodiment of the present invention. FIG. 6 is a layout diagram of another upper surface metal pattern of the electromagnetic wave detector according to the first exemplary embodiment of the present invention. It is an arrangement plan of other upper surface metal patterns (concentric pattern) of the electromagnetic wave detector concerning Embodiment 1 of the present invention. It is a light absorption spectrum in the other upper surface metal pattern (concentric pattern) of the electromagnetic wave detector concerning Embodiment 1 of this invention. It is sectional drawing which shows the signal detection structure of the electromagnetic wave detector concerning Embodiment 1 of this invention. It is sectional drawing which shows the other signal detection structure of the electromagnetic wave detector concerning Embodiment 1 of this invention. It is sectional drawing which shows the other signal detection structure of the electromagnetic wave detector concerning Embodiment 1 of this invention. It is sectional drawing of the manufacturing process of the electromagnetic wave detector concerning Embodiment 1 of this invention. It is sectional drawing of the manufacturing process of the electromagnetic wave detector concerning Embodiment 1 of this invention. It is sectional drawing of the manufacturing process of the electromagnetic wave detector concerning Embodiment 1 of this invention. It is sectional drawing of the manufacturing process of the electromagnetic wave detector concerning Embodiment 1 of this invention. It is sectional drawing of the manufacturing process of the electromagnetic wave detector concerning Embodiment 1 of this invention. It is an arrangement plan of the upper surface metal pattern of the electromagnetic wave detector concerning Embodiment 2 of the present invention. It is a light absorption spectrum of the electromagnetic wave detector concerning Embodiment 2 of this invention. It is an arrangement plan of other upper surface metal patterns of an electromagnetic wave detector concerning Embodiment 2 of the present invention. It is an arrangement plan of other upper surface metal patterns of an electromagnetic wave detector concerning Embodiment 2 of the present invention. It is sectional drawing of the electromagnetic wave detector concerning Embodiment 3 of this invention. It is sectional drawing of the other electromagnetic wave detector concerning Embodiment 3 of this invention. It is sectional drawing of the other electromagnetic wave detector concerning Embodiment 3 of this invention. It is sectional drawing of the electromagnetic wave detector concerning Embodiment 4 of this invention. It is sectional drawing of the other electromagnetic wave detector concerning Embodiment 4 of this invention. It is sectional drawing of the other electromagnetic wave detector concerning Embodiment 4 of this invention. It is sectional drawing of the electromagnetic wave detector concerning Embodiment 5 of this invention. It is a perspective view of the electromagnetic wave detector concerning Embodiment 6 of this invention. It is a light absorption spectrum of the electromagnetic wave detector concerning Embodiment 6 of this invention. It is sectional drawing of the electromagnetic wave detector concerning Embodiment 7 of this invention. It is the relationship between the film thickness of an insulating layer and the wavelength peak value of an absorption spectrum. It is a light absorption spectrum of the electromagnetic wave detector concerning Embodiment 7 of this invention. It is sectional drawing of the manufacturing process of the electromagnetic wave detector concerning Embodiment 7 of this invention. It is sectional drawing of the manufacturing process of the electromagnetic wave detector concerning Embodiment 7 of this invention. It is sectional drawing of the manufacturing process of the electromagnetic wave detector concerning Embodiment 7 of this invention. It is sectional drawing of the manufacturing process of the electromagnetic wave detector concerning Embodiment 7 of this invention. It is sectional drawing of the manufacturing process of the electromagnetic wave detector concerning Embodiment 7 of this invention. It is sectional drawing of the manufacturing process of the electromagnetic wave detector concerning Embodiment 7 of this invention. It is sectional drawing of the manufacturing process of the electromagnetic wave detector concerning Embodiment 7 of this invention. It is sectional drawing of the manufacturing process of the electromagnetic wave detector concerning Embodiment 7 of this invention. It is sectional drawing of the manufacturing process of the electromagnetic wave detector concerning Embodiment 7 of this invention. It is sectional drawing of the electromagnetic wave detector concerning Embodiment 8 of this invention. It is a light absorption spectrum of each metal pattern of the electromagnetic wave detector concerning Embodiment 8 of this invention. It is a light absorption spectrum of the electromagnetic wave detector concerning Embodiment 8 of this invention. It is sectional drawing of the other electromagnetic wave detector concerning Embodiment 8 of this invention. It is sectional drawing of the manufacturing process of the electromagnetic wave detector concerning Embodiment 8 of this invention. It is sectional drawing of the manufacturing process of the electromagnetic wave detector concerning Embodiment 8 of this invention. It is sectional drawing of the manufacturing process of the electromagnetic wave detector concerning Embodiment 8 of this invention. It is sectional drawing of the manufacturing process of the electromagnetic wave detector concerning Embodiment 8 of this invention. It is sectional drawing of the manufacturing process of the electromagnetic wave detector concerning Embodiment 8 of this invention. It is sectional drawing of the manufacturing process of the electromagnetic wave detector concerning Embodiment 8 of this invention. It is sectional drawing of the manufacturing process of the electromagnetic wave detector concerning Embodiment 8 of this invention. It is sectional drawing of the manufacturing process of the electromagnetic wave detector concerning Embodiment 8 of this invention. It is sectional drawing of the manufacturing process of the electromagnetic wave detector concerning Embodiment 8 of this invention. It is a perspective view of the electromagnetic wave detector array concerning Embodiment 9 of this invention. It is a perspective view of the electromagnetic wave detector array concerning Embodiment 10 of this invention. It is a light absorption spectrum of the electromagnetic wave detector array concerning Embodiment 10 of this invention.

  In the embodiment of the present invention, an electromagnetic wave detector will be described using an infrared wavelength region. However, the present invention is not limited to an infrared wavelength region, for example, visible, near infrared, terahertz (THz), microwave, radio wave region. It is also effective as a detector in the wavelength region. In the embodiment of the present invention, light is also referred to as electromagnetic waves. Moreover, in each embodiment, the same code | symbol is attached | subjected to the same element and description is abbreviate | omitted. The detector to which the absorber of the present invention is applied includes a bolometer, a thermopile, a SOI (Silicon-on-Insulator) diode type, a pyroelectric type, or a detector that detects distortion generated by absorbed heat, etc. All types of detectors are included. Other than the thermal type, if the insulating layer described below is changed to a semiconductor (including quantum wells and quantum dots), it can be applied to a quantum type detector.

Embodiment 1 FIG.
FIG. 1 is a perspective view of an electromagnetic wave detector 100 according to a first exemplary embodiment of the present invention, the whole being represented by 100. FIG. FIG. 2 is a cross-sectional view (a part) of the electromagnetic wave detector 100 of FIG. FIG. 3 is a top view when FIG. 1 is viewed from above.

  As shown in FIGS. 1 to 3, the electromagnetic wave detector 100 has a lower metal layer 1 having a flat surface, an insulating layer 2 formed on the lower metal layer 1, and a periodicity on the insulating layer 2. The upper metal pattern 3 is formed and periodically arranged, and has a signal detection structure 9 that converts light absorbed by the three structures into an electric signal.

  The upper metal pattern 3 and the lower metal layer 1 are preferably formed of a material that easily causes surface plasmon resonance, and is formed of a metal such as Au, Ag, Cu, Al, Ni, Cr, or Ti. In other words, a material having a negative dielectric constant is desirable. However, when a metal having a large conversion loss is used, wavelength selectivity, that is, monochromaticity may deteriorate, for example, the half-value width in the absorptivity characteristic is widened. Therefore, the type of metal is appropriately selected depending on the required half-value width of the detection wavelength. On the other hand, by using a metal with a large loss, it is possible to have broad absorption that detects a wide wavelength range.

The insulating layer 2 is preferably formed from an insulator such as silicon oxide (SiO ₂ ), silicon nitride (SiN), aluminum oxide, nickel oxide, or silicon. The same effect is also obtained in semiconductors such as Si and GaAs.

  The upper metal pattern 3 is formed in at least two or more different shapes or sizes having a function of absorbing light excluding a specific wavelength. The number of upper metal patterns 3 to be arranged can be selected as appropriate. Further, the upper layer metal pattern 3 can be arranged in a square lattice shape, a triangular lattice shape, a hexagonal lattice shape, or the like in a two-dimensional matrix-like arrangement. Alternatively, a one-dimensional arrangement may be used. Here, a square grid arrangement will be described as a representative example.

  In FIG. 2, the signal detection structure 9 is disposed below the lower metal layer 1, but it is sufficient that the light absorbed by the lower metal layer 1, the insulating layer 2, and the upper metal pattern 3 can be converted into an electrical signal. You may arrange | position in a side surface or each layer.

  Next, the principle of light absorption of the electromagnetic wave detector 100 according to the first exemplary embodiment of the present invention will be described. FIG. 4 is a conceptual diagram showing the behavior of the electromagnetic field when an electromagnetic wave is incident on the electromagnetic wave detector. When light (electromagnetic wave) is incident on the electromagnetic wave detector 100, light having a resonance wavelength that resonates with the upper metal pattern 3 periodically formed on the incident surface is selected from the incident light. Of the light of the selected wavelength, guided mode light guided to the insulating layer 2 is further selected.

Next, resonance occurs in the insulating layer 2 sandwiched between the upper metal pattern 3 and the lower metal layer 1, and light having a resonance wavelength is selected here. Here, since the insulating layer 2 is very thin compared to the wavelength of incident light, resonance in the thickness direction of the insulating layer 2 should not be dominant. Accordingly, the resonance in the in-plane direction of the upper metal pattern 3 (direction parallel to the surface of the insulating layer 2) is dominant. Here, since the upper metal pattern 3 is a square, resonance in a direction along one side of the square is dominant.
That is, the relationship between the length L of one side of the square and the absorption peak wavelength λ is
λ = n × L
It becomes. Here, n is a positive constant.

  On the incident surface side of the electromagnetic wave detector 100, the above resonance occurs. In particular, this means surface plasmon resonance, plasmon resonance, or resonance on a metal surface outside the visible range, and is called pseudo surface plasmon resonance. Similarly, it may be called a metamaterial, a plasmonic metamaterial, an antenna or the like in the sense that a specific wavelength is operated by a structure of a wavelength or less. However, essentially, as already described, the absorption is due to resonance at the surface of the upper metal pattern 3. Therefore, in the specification of the present invention, these names are not particularly distinguished and are assumed to be the same from the viewpoint of the phenomenon. In the specification, these resonances are referred to as surface plasmon resonance, plasmon resonance, or simply resonance.

  Thus, light is strongly localized around the upper metal pattern 3 by plasmon resonance at a specific wavelength. At this time, the localized light is accumulated mainly as heat in the electromagnetic wave detector 100.

  FIG. 5 is a light absorption spectrum when light (electromagnetic wave) is incident on the electromagnetic wave detector 100. As shown in FIG. 5, in the electromagnetic wave detector 100 shown in FIG. 4, only the wavelength component corresponding to the length of one side of the square of the upper metal pattern 3 is absorbed. At this time, it is known that the wavelength of light that is selectively absorbed does not vary greatly depending on the arrangement period S of the upper metal pattern 3. However, an incident electromagnetic wave having a wavelength shorter than the period may be diffracted and reflected, so that absorption does not occur or becomes weak. Therefore, by setting the arrangement period S of the upper metal pattern 3 to be smaller than the selective absorption wavelength λ, light absorption at a specific wavelength is possible without reducing the absorptance.

  Further, the sharpness of the electromagnetic wave absorption spectrum shown in FIG. 5 adjusts the manufacturing accuracy of the shape of the upper metal pattern 3, the uniformity of the end face shape, the uniformity of the film thickness, the type of metal, and the film thickness of the insulating layer 2. It changes by doing. By adjusting these, a broad absorption spectrum can be given, or a sharp absorption spectrum can be given.

  The wavelength of light that can be detected by the electromagnetic wave detector 100 is also affected by the film thickness d and material of the insulating layer 2 and the film thickness h of the upper metal pattern 3. According to the results shown in Non-Patent Document 1, when the thickness d of the insulating layer 2 is 10 nm, the thickness h of the upper metal pattern 3 is 40 nm, and the arrangement period S of the upper metal pattern 3 is 310 nm, the upper metal of 170 nm on one side In the pattern, an absorption peak with an absorption wavelength of 1.58 μm is obtained, and the measured absorption rate is reported to be 88% (theoretical value 97%). That is, even if the arrangement period of the upper metal pattern 3 is increased to 1.58 μm, it can be expected that the light absorptance of the target wavelength does not decrease.

  Here, an example in which the upper metal patterns 3 are arranged separately is given, but the upper metal pattern 3 is not limited to this as long as it can absorb light of a specific wavelength. For example, a shape in which a plurality of upper metal patterns 3 are partially connected may be used, and as shown in FIG. 6, the portions where the upper metal patterns 3 exist and the portions that do not exist are reversed ( An anti-dot pattern compared to a dot pattern, that is, a pattern in which the upper metal layer is removed only partially, such as a pattern in which through holes (white portions in FIG. 7) are periodically formed in a metal plate) . At that time, the absorption wavelength spectrum in the upper metal pattern 3 is affected by the period, size, shape, etc. of the removal pattern.

  Next, the film thickness h of the upper metal pattern 3 will be described. When the film thickness h of the upper metal pattern 3 is increased, resonance also occurs in the thickness direction, and therefore resonance also occurs in the height direction. Therefore, the incident angle dependency of the detection efficiency increases. As a result, light other than normal incidence is not absorbed at a specific wavelength, and the detection output tends to decrease. That is, it is preferable to satisfy at least h <L (the length of one side of the upper metal pattern 3) and to make the film thickness h as thin as possible.

The lower limit of the film thickness h will be described. The film thickness h is relative to the detection wavelength.
δ = (2 / μσω) ^1/2
μ and σ are the magnetic permeability and electric conductivity of the upper metal pattern 3, respectively.
ω is about twice as thick as the skin effect thickness δ (skin depth) expressed by the angular frequency of the electromagnetic wave having the detection wavelength (it varies depending on the wavelength, but in the infrared region, about several tens of nm to several hundreds of nm In general, it can be said that leakage of incident light is sufficiently small. Therefore, the minimum film thickness h must satisfy the above conditions. As shown in the following analysis, for the infrared wavelength range, if the film thickness h is about several tens to 100 nm or more, sufficient absorption occurs, and about 200 nm is sufficient. Thus, when the film thickness of the upper metal pattern 3 is thin, surface plasmon resonance occurs mainly in the in-plane direction of the upper metal pattern 3, and the wavelength of incident light to be absorbed is determined by the size of the upper metal pattern 3. .

On the other hand, when the film thickness h becomes thicker and becomes larger than 1/4 of L, resonance also occurs in the film thickness direction (direction perpendicular to the in-plane direction), and the incident angle dependence of the absorption characteristics is increased. growing. Further, since the resonance direction is not one place, there arises a problem that the absorption wavelength is increased.
As described above, when the film thickness of the upper metal pattern 3 is very thin, the absorption wavelength is mainly determined by resonance in the in-plane direction. As a result, the incident angle dependency of the absorption wavelength is reduced. As a result, even if the incident angle changes, the absorption characteristics such as the absorption wavelength and the absorption rate hardly change.

  On the other hand, the thickness of the lower metal layer 1 is preferably such that no transmission of incident light occurs, and is preferably about twice the wavelength for selective absorption or more.

  Next, the operation principle of the electromagnetic wave detector 100 according to the first exemplary embodiment of the present invention will be described. As shown in FIG. 1, the upper metal pattern 3 is periodically configured to include nine types of upper metal patterns A51 to I59. These upper metal pattern A51 to upper metal pattern I59 are formed in at least two different shapes or sizes, and as described above, only the wavelength component corresponding to the length of one square side of each pattern is absorbed. The

  At this time, the upper metal pattern A51 to the upper metal pattern D54 are used as the first absorption unit 14, and the square side length L and the absorption peak wavelength λ are set so that the absorption spectrum sum in each pattern is flat and absorption is performed in a wide band. Set. Similarly, the upper metal pattern E55 to the upper metal pattern I59 are used as the second absorption unit 15, and the square side length L and the absorption peak wavelength λ are set so that the absorption spectrum sum is flat and absorption is performed in a wide band.

  FIG. 7 shows a light absorption spectrum in the electromagnetic wave detector 3 at this time. As described above, light having a wavelength corresponding to the length of one side of each upper layer metal pattern is selectively absorbed, and the first absorption unit 14 has the first broad absorption band 12 and the second absorption unit 15 has the second wide band. An absorption band 13 is obtained, and the first broad absorption band 12 and the second broad absorption band 13 are set so as to cover a wavelength range that does not overlap each other. Thereby, the electromagnetic wave detector total absorption spectrum 4 having the non-absorption wavelength band 5 can be obtained.

  At this time, each of the upper metal pattern arrangement intervals is set to be equal to or less than the selective absorption wavelength, whereby the four absorptances of the absorption wavelengths 251 to 254 can be maintained without decreasing. For this reason, it is possible to design an electromagnetic wave detector having a high absorption rate in a wide band, and the non-absorption wavelength band 5 can be installed by designing the upper metal pattern 3.

  In FIG. 7, one non-absorption wavelength band 5 is obtained by obtaining the first broad absorption band 12 in the first absorption unit 14 and the second broad absorption band 13 in the second absorption unit 15. You may design so that two or more may be obtained. FIG. 8 shows a structure capable of obtaining two absorption wavelength bands. FIG. 9 shows an absorption wavelength spectrum obtained by the structure of FIG.

  By forming the first absorption unit 14, the second absorption unit 15, and the third absorption unit 16 by designing the upper metal pattern 3, the first broad absorption band 12, the second broad absorption band 13, and the third broad absorption band 17 is obtained. Between the first broad absorption band 12 and the second broad absorption band 13, there is a first non-absorption wavelength band 18, and between the second broad absorption band 13 and the third broad absorption band 17, there is a second non-absorption wavelength band 19. The total absorption spectrum 4 of the magnetic wave detector can be obtained.

  Although the number of patterns of the upper metal pattern 3 is described as nine in the present embodiment, any pattern configuration may be used as long as a high absorption rate can be obtained in a wide band and the non-absorption wavelength band 5 can be obtained, and the number is not limited to nine. For example, the number may be greater than nine, and may be smaller than nine as long as a wide-band wavelength can be detected with one pattern.

  The pattern arrangement method of the metal pattern 3 is not limited to the pattern arrangement as shown in FIG. 3 as long as it is periodic and the same pattern is arranged at an interval equal to or smaller than the selective absorption wavelength. For example, the arrangement pattern may be changed as shown in FIG. 10, or the first absorption unit 12 and the second absorption unit 13 are consolidated so that the intervals between the upper metal patterns are relatively uniform as shown in FIG. It is not necessary to arrange. Further, since the selective absorption wavelength λ becomes small in the upper metal pattern having a small area, the arrangement period S needs to be kept small. In that case, the number of arrangement may be changed for each upper metal pattern as shown in FIG.

  Moreover, although the example in which the lump in which the upper metal pattern 3 is periodically arranged is arranged in a 2 × 2 array shape is described in the above example, it is not limited thereto. For example, only one period may be arranged as shown in FIG. This is effective when the detection area is reduced to form a fine array sensor. Moreover, it can arrange | position arbitrarily with 3x3, 4x4. This is effective when acquiring a signal component averaged over a large area.

  As shown in FIG. 14, the shape of the upper metal pattern 3 may be a circle, rectangle, ellipse, triangle, concentric circle, bullseye, cross, H shape, split ring, or the like. In this embodiment, a square is described as a representative example. In an asymmetrical shape such as a triangle, rectangle, or ellipse, the absorption wavelength has a deflection dependency. Therefore, this action may be used as a deflection detection element.

  Also, a plurality of concentric patterns as shown in FIG. 15 may be formed by utilizing the feature that a specific wavelength can be obtained even in the upper metal pattern 3 having a concentric shape. In the concentric pattern as shown in FIG. 15, the absorption wavelength 270 obtained by the concentric circle outer peripheral pattern 70 and the absorption wavelength 271 obtained by the concentric inner pattern 71 are different as shown in FIG. Wavelength absorption may be performed. As described above, the upper metal pattern 3 may have a shape having resonance at a plurality of wavelengths.

  Next, the signal detection structure 9 will be described. FIG. 17 is a cross-sectional view showing the signal detection structure 9 according to the present embodiment. In the structure of FIG. 17, the heat sensitive layer 10 is disposed below the lower metal layer 1. The heat-sensitive layer 10 generates an electrical signal due to a temperature change generated when light of a specific wavelength is absorbed by the lower metal layer 1, the insulating layer 2, and the upper metal pattern 3. This electric signal is taken out from the electric signal take-out unit 8.

  At this time, examples of the heat-sensitive layer 10 include a resistance value of a resistor, a diode, and the like. However, the structure is not limited to this as long as it has a structure whose characteristics change due to a temperature change.

  Further, the arrangement of the signal detection structure 10 is not limited to the lower part of the lower metal layer 1, but may be provided on the side face or in the upper part in a range that does not significantly reduce the light absorption.

  18 and 19 show another signal detection structure 9. In the structure of FIG. 18, the graphene layer 7 is installed between the insulating layer 2 and the upper metal pattern 3, and the electric signal extraction unit 8 is installed outside thereof. At this time, an electromagnetic field is localized between the insulating layer 2 and the upper metal pattern 3 by incident light, and the electromagnetic field is absorbed by graphene. The light absorption rate of the graphene layer in normal light incidence is usually 2.3%, whereas in the graphene layer 7 installed in the resonator, electromagnetic waves are incident on the graphene layer 7 in the resonator. Since it repeats, all the light finally localized (100%) can be absorbed. That is, incident light can be converted into an electrical signal without converting it into a heat component. Even if the graphene layer 7 is arranged in the middle of the insulating layer 2, the same effect can be obtained.

  On the other hand, in the structure of FIG. 19, the heat component absorbed by the lower metal layer 1, the insulating layer 2, and the upper metal pattern 3 is converted into an electrical signal by the heat sensitive body 22 through the heat transfer body 21. The heat sensitive body 22 is maintained in a hollow state by a heat insulating support leg 23. The sensitivity of the heat sensitive body 22 can be improved by weakening the heat transfer in the heat insulating support legs 23, that is, by making the heat insulating support legs 23 have a fine structure. Here, as the heat sensitive body 22, an SOI diode structure, a bolometer, or the like can be used. The electrical signal extraction structure is not limited to the three examples shown in FIGS.

  Next, a method for manufacturing the electromagnetic wave detector 100 according to the embodiment of the present invention will be described with reference to FIGS. 20a to 20e.

  First, as shown in FIG. 20a, the signal detection structure 9 is formed. As described above, the signal detection structure 9 is preferably formed of a resistor whose resistance value changes with a temperature change or a diode whose characteristic changes with a temperature change. However, the characteristic changes with a temperature change. If it is a structure, it is not restricted to these. In addition, although a Si wafer, a metal film, or the like may be used as a support substrate below the signal detection structure 9, there is a concern about heat radiation from the support substrate, and a temperature change due to light absorption becomes small. In order to make the temperature change remarkable, it is preferable to use a hollow holding.

  Next, as shown in FIG. 20 b, the lower metal layer 1 is deposited on the signal detection structure 9. As described above, the material of the lower metal layer 1 is preferably a material having a negative dielectric constant such as Au, Ag, Cu, Al, Ni, Cr, Ti. The film thickness may be any film thickness that does not transmit incident light from the upper surface.

  Next, as shown in FIG. 20 c, an insulating layer 2 made of, for example, an oxide film, a nitride film, an organic solvent, or the like is formed on the lower metal layer 1. At that time, the surface of the insulating layer 2 is preferably formed in a parallel and flat shape with the surface of the lower metal layer 1, and planarization treatment such as CMP polishing or heat treatment may be performed.

  Next, as shown in FIG. 20d, an upper layer metal made of a material having a negative dielectric constant such as Au, Ag, Cu, Al, Ni, Cr, Ti, or the like is deposited on the insulating layer 2.

  Next, as shown in FIG. 20e, the upper metal is processed to form the upper metal pattern 3. In the processing, a semiconductor process such as photolithography, etching, or lift-off can be used.

  The electromagnetic wave detector 100 according to the first exemplary embodiment is manufactured through the above steps.

Embodiment 2. FIG.
FIG. 21 is an upper surface metal pattern of the electromagnetic wave detector according to the second exemplary embodiment. In the structure of FIG. 21, the pattern defect region 11 having a disturbed periodicity is provided in a partial region of the upper metal pattern arranged periodically. Thereby, it is possible to introduce a non-absorption wavelength into the broadband wavelength band. In particular, in a region where the period is disturbed in the periodic structure (especially often referred to as “defect region”) so as to be compatible with an optical device using a periodic structure such as a photonic crystal, coupling corresponding to the defect region is performed. Alternatively, a non-bonding mode is generated, and a defect mode can be introduced with high efficiency in a wide wavelength range.

  Also in the structure according to the second embodiment, as shown in FIG. 22, non-bonding (no absorption occurs) in a wide wavelength range, for example, a wavelength range covering the mid-infrared to long-wavelength infrared. It becomes possible to introduce a defect mode. By utilizing such a non-bonded defect mode, it is possible to realize a detector that does not absorb only a specific wavelength, that is, does not detect only a specific wavelength.

  Next, the configuration of the defective area will be described. For example, as shown in FIG. 21, in the case where structures are periodically arranged, it is possible to introduce a defect region by removing a specific structure. In the vicinity of the defect area, the arrangement period is different from other areas. For this reason, a region in which periodicity is disturbed is formed.

  More specifically, when the upper metal pattern is arranged with a period of 3 μm, for example, one of the upper metal patterns is removed. This removed area corresponds to a defective area. This is because the arrangement cycle of the upper metal pattern around the defect is 6 μm, and a region having a different arrangement cycle from the other upper metal pattern is formed in the defect region.

  Next, the non-bonded defect mode in the structure having a defect region according to the present embodiment will be briefly described. As already described, in the upper surface metal pattern, all wavelengths below the arrangement period of the pattern are diffracted and not absorbed. Therefore, by introducing a defect region, absorption does not occur or becomes weak at a wavelength of 6 μm. Thus, by introducing a defect region, it becomes possible to introduce a wavelength that is not absorbed.

  Regarding the introduction of the defect region, a removal type arrangement in which a part of the pattern as shown in FIG. 21 is removed is possible. Further, for example, as shown in FIG. 23, it is also possible to introduce a structure in which periodicity is disturbed, that is, a defect region, by a method such that the distance between the centers of only two specific upper metal patterns is made closer or away. is there. In the case of a superstructure in which unit units including a periodic structure as shown in FIG. 21 are further periodically arranged, defect regions are periodically formed. As shown in FIG. 24, the defects may have such a periodic arrangement (left diagram), or a single region (right diagram) within the superity. The defect configuration may be appropriately selected depending on the required detector specifications and the target wavelength.

Embodiment 3 FIG.
25a and 25b are cross-sectional views of the electromagnetic wave detector 100 according to the third exemplary embodiment. The difference from the first embodiment is that a part of the insulating layer 2 is removed by a processing step, and the other structure is the same. FIG. 25 a completely removes the insulating layer 2 existing at the lower part between the adjacent upper metal patterns 3, and FIG. 25 b partially removes the insulating layer 2 present at the lower part between the adjacent upper metal patterns 3. It has been removed.

  Here, a thermal time constant that is one of the performance values of the electromagnetic wave detector 100 and a heat capacity that determines the thermal time constant will be described. The heat capacity is a state quantity indicating how much the temperature of the system changes when heat enters and leaves the system. The heat capacity in the present invention is the sum of the signal detection structure 9 and the density ρ multiplied by the volume V of each of the lower metal layer 1, the insulating layer 2, and the upper metal pattern 3. That is, when the volume V of each layer is large, the heat capacity becomes large.

  On the other hand, the thermal time constant is one of the performance values of the electromagnetic wave detector 100 and is the temperature change tracking time of the electromagnetic wave detector 100 itself with respect to the input thermal component. This thermal time constant is a value proportional to the heat capacity described above. That is, in the structure with a large heat capacity, the time to follow the input heat component is delayed, and in the structure with a small heat capacity, it is faster.

  The thermal time constant is an important performance index when observing things that move at high speed, or those that rapidly increase or decrease in temperature. It can be said that the smaller the thermal time constant, the higher the temperature change followability of the detection target.

  Here, when comparing the electromagnetic wave detector 100 according to the first exemplary embodiment shown in FIG. 2 with the electromagnetic wave detector 100 shown in FIGS. 25a and 25b, the latter partly removes the insulating layer 2. As a result, the heat capacity is reduced, the thermal time constant is small, and a high-performance electromagnetic wave detector is obtained. On the other hand, as the surface plasmon effect, the portion of the insulating layer 2 removed by the electromagnetic wave detector 100 of the present embodiment does not affect the electromagnetic wave confinement effect, so that a highly efficient light confinement effect is maintained.

  As shown in FIG. 26, a part of the insulating layer 2 between the lower metal layer 1 and the upper metal pattern 3 may be removed. Thereby, the thermal time constant is further reduced, and a high-performance electromagnetic wave detector 100 can be obtained. Further, since the insulating layer 2 replaces the air layer, the air layer has a lower refractive index than the insulating layer, and the optical wavelength in the air layer is larger than that of the insulating layer 2. Therefore, the change in the resonance wavelength with respect to the change in the thickness of the air layer, that is, the height h of the insulating layer 2 is reduced. For this reason, the configuration as shown in FIG. 26 can achieve higher performance.

Embodiment 4 FIG.
27a and 27b are cross-sectional views of the electromagnetic wave detector 100 according to the fourth exemplary embodiment. The difference from the electromagnetic wave detector 100 of Embodiment 1 is that a part of the lower electrode layer 1 is removed, and the other structures are the same. FIG. 27 a completely removes the lower metal layer 1 existing at the lower part between the adjacent upper metal patterns 3, and FIG. 27 b partially removes the lower metal layer 1 present at the lower part between the adjacent upper metal patterns 3. Have been removed.

  Here, when the electromagnetic wave detector 100 according to the first exemplary embodiment shown in FIG. 2 is compared with the electromagnetic wave detector 100 shown in FIGS. 27a and 27b, the latter partly removes the lower electrode layer 1. As a result, the heat capacity can be kept small, a thermal time constant is small, and a high-performance electromagnetic wave detector can be obtained. On the other hand, as the surface plasmon effect, if the lower metal layer 1 below the upper metal pattern 3 exists, the portion of the lower electrode layer 1 removed in the present embodiment does not affect the electromagnetic wave confinement effect. An efficient light confinement effect is maintained.

  Note that the structures of the third and fourth embodiments can achieve higher effects when implemented at the same time. Further, for example, as shown in FIG. 28, a part of the insulating layer 2 may be removed. The upper metal pattern 3, the insulating layer 2, and the lower metal layer 1 may be shaped so as to leave only a part so that the shapes can be kept stable.

Embodiment 5 FIG.
FIG. 29 is a cross-sectional view of the electromagnetic wave detector 100 according to the fifth exemplary embodiment. The difference from the electromagnetic wave detector 100 of the first embodiment is that an upper layer non-metal pattern 20 is provided instead of the upper layer metal pattern 3, and the other structures are the same.

The upper metal pattern 3 may be any material that easily causes surface plasmon resonance, and is not limited to a metal. For this reason, in this embodiment, the upper non-metal pattern 20 that is not a metal is used. For example, although graphene is non-metallic and has extremely low electrical conductivity and can cause plasmon resonance, the use of the upper non-metallic pattern 20 made of graphene maintains a highly efficient optical confinement effect. . Further, the upper non-metallic pattern 20 may be a transition metal dichalcogenide (MX ₂ ) such as molybdenum disulfide (MoS ₂ ) having two-dimensionality substantially equivalent to graphene. Here, the transition metal dichalcogenide (MX ₂ ) is composed of a transition metal (M = Nb, Ta, Ti, Mo, etc.) and a chalcogen (X = S, Se, Te).

  In addition, since graphene is composed of one atomic layer, the heat capacity can be suppressed to be smaller than that of a structure using a metal thin film, the thermal time constant is small, and a high-performance electromagnetic wave detector 100 can be obtained.

Embodiment 6 FIG.
FIG. 30 is a perspective view of the electromagnetic wave detector 100 according to the sixth exemplary embodiment. The difference from the electromagnetic wave detector 100 of Embodiment 1 is that a part of the upper metal pattern 3 is replaced with another metal material, and the other structures are the same.

  When a metal having a large conversion loss such as Ni is used as the metal material of the upper metal pattern 3, the wavelength selectivity, that is, the monochromaticity is deteriorated, for example, the half-value width of the absorptivity characteristic is widened. Using this characteristic, it is possible to absorb light in a wider band. For example, among the upper layer metal pattern 3, the upper layer metal pattern A51 that performs surface plasmon absorption on the longest wavelength side is the upper layer metal pattern A72 that differs only in the material, and the upper layer metal pattern I59 that performs surface plasmon absorption on the shortest wavelength side is It changes to the upper metal pattern I73 from which only a material differs.

  FIG. 31 shows a light absorption spectrum at this time. By changing the material, the absorption spectrum 272 by the upper metal pattern A72 and the absorption spectrum 273 by the upper metal pattern I73 are more than the absorption spectrum 251 by the upper metal pattern A51 and the absorption spectrum 259 by the upper metal pattern I59 shown in FIG. It has an absorption spectrum in a wide wavelength range, and as a result, it is possible to absorb light of a further wideband wavelength.

Embodiment 7 FIG.
FIG. 32 is a cross-sectional view of the electromagnetic wave detector 100 according to the seventh exemplary embodiment. The difference from the electromagnetic wave detector 100 of the first embodiment is that the thickness of the insulating layer 2 under the upper metal pattern is different from each other, and the other structure is the same. As an example, although the size and shape of the upper metal pattern 3 are the same in FIG. 32, four types of insulating films A60 to D63 having different thicknesses of the insulating layer 2 are arranged. The film thickness is the thickest, and the film thickness of the insulating film D63 is the thinnest.

  FIG. 33 is a graph schematically showing the relationship between the film thickness of the insulating layer 2 and the wavelength peak value of the absorption spectrum. As the film thickness d of the insulating layer 2 is thinner, the wavelength peak value of the absorption spectrum is shifted to the longer wavelength side. By utilizing this relationship, a wide absorption band and a non-absorption wavelength band can be set.

  FIG. 34 shows an absorption spectrum obtained by the electromagnetic wave detector 100 according to the present embodiment. The absorption spectrum 260 by the insulating film A60 to the absorption spectrum 263 by the insulating film D63 show different wavelength peaks, and the first broad absorption band 12, the absorption spectrum 263, and the absorption spectrum are represented by the absorption spectrum 260 and the absorption spectrum 261, respectively. A second broad absorption band 13 is formed by H.264. The first wide absorption band 12 and the second wide absorption band 13 are set so as not to overlap each other. Thereby, the electromagnetic wave detector total absorption spectrum 4 having the non-absorption wavelength band 5 can be obtained. That is, the electromagnetic wave detector 100 having the same effect as when the size or shape of the upper metal pattern 3 is changed can be obtained.

  A wide absorption band and a non-absorption wavelength band can be obtained only by adjusting the film thickness of the insulating film 2, but a wider band can be obtained by combining with the means of the first embodiment for adjusting the size and shape of the upper metal pattern 3. Can be absorbed.

  Next, the manufacturing method of the electromagnetic wave detector 100 concerning this Embodiment is demonstrated using FIG. 35a-FIG. 35i.

  First, in the steps shown in FIGS. 35a to 35c, the signal detection structure 9, the lower metal layer 1, and the insulating layer 2 are formed using the same steps as in FIGS. 20a to 20c of the first embodiment.

  Next, as shown in FIGS. 35d to 35f, photolithography and other protective films (for example, photoresist) are formed so that the surface of the insulating layer 2 is partially exposed, and then the exposed portions are partially etched. Remove. By repeating this process, the insulating film 2 is etched stepwise, and the insulating layers 2 having different thicknesses are formed stepwise. Etching may be dry etching or wet etching. An etching stop layer may be formed in advance on the insulating layer 2.

  Next, as shown in FIG. 35g, after removing the protective film (for example, photoresist), an upper metal layer is deposited.

  Next, as shown in FIG. 35h, the upper metal layer 3 is formed by patterning the upper metal layer.

  Finally, as shown in FIG. 35 i, the insulating layer 2 is removed leaving the lower part of the upper metal pattern 3. Through the above steps, electromagnetic wave detectors having different thicknesses of the insulating layer 2 shown in FIG. 32 can be obtained.

It should be noted that the surface plasmon resonance is normally performed without omitting the step of removing a part of the insulating layer 2 shown in FIG. 35i and removing the insulating layer 2 other than the lower portion of the upper metal pattern 3. On the other hand, by performing the removal step shown in FIG. 35i, the thermal time constant can be reduced as shown in the third embodiment.
Further, as shown in the second embodiment, a wide absorption band and a non-absorption wavelength band may be formed by disposing a defect region. Specifically, the upper metal pattern 3 is shifted or removed in a region having a certain film thickness.
Further, as shown in the sixth embodiment, a wide absorption band and a non-absorption wavelength band may be formed by changing a part of the upper metal pattern 3 to another metal.

Embodiment 8 FIG.
FIG. 36 is a cross-sectional view of the electromagnetic wave detector 100 according to the eighth embodiment. The difference from the electromagnetic wave detector 100 of Embodiment 1 is that the film thickness of the upper metal pattern 3 is changed, and the other structures are the same.

  In the present embodiment, as the upper metal pattern 3, metal films A64 to D67 having different film thicknesses are arranged, and each metal film thickness h is one side length of the upper metal pattern 3 formed in a square shape. It is set to be larger than 1/4 of L.

  As described in the first embodiment, when the metal film thickness h is set to be larger than ¼ of the side length L of the upper metal pattern 3 formed in a square, the side length of the upper metal pattern 3 Not only the lateral resonance mode depending on L but also the longitudinal resonance mode depending on the metal film thickness h occurs, and a plurality of absorption peaks occur. In this embodiment, a wide absorption band and a non-absorption wavelength band are set using this effect.

  FIG. 37 is an absorption spectrum of the metal film A64 shown in FIG. When the square side length of the metal film A64 is a1 and the film thickness is a2, the absorption spectrum 264 by the lateral surface plasmon of the metal film A64 depending on the dimension a1 and the vertical surface plasmon of the metal film A64 depending on the dimension a2. Absorption spectrum 364 due to light absorption having two peak wavelengths occurs.

  FIG. 38 shows absorption spectra when four kinds of metal films A64 to D67 having different film thicknesses are arranged. From the four types of upper layer metal patterns 3, a total of eight types of absorption spectra are obtained: absorption spectra 264 to 267 by four types of lateral surface plasmons and absorption spectra 364 to 367 by four types of vertical surface plasmons.

  As shown in FIG. 38, the first broad absorption band 12 is formed by the absorption spectra 264 to 267 by the four types of lateral surface plasmons, and the second broad spectrum by the absorption spectra 364 to 367 of the other four types of vertical surface plasmons. An absorption band 13 is formed, and the first broad absorption band 12 and the second broad absorption band 13 are set so as not to overlap each other. Thereby, the electromagnetic wave detector total absorption spectrum 4 having the non-absorption wavelength band 5 can be obtained. That is, the same effect as when the size or shape of the upper metal pattern 3 is changed can be obtained.

  A wide absorption band and a non-absorption wavelength band can be obtained only by adjusting the film thickness of the upper metal pattern 3, but a wider band can be obtained by combining with the means of the first embodiment for adjusting the size and shape of the upper metal pattern 3. Can be absorbed.

  The upper metal pattern 3 may not be entirely metal. For example, as shown in FIG. 39, a part of the upper metal pattern may be formed of an insulator. This makes it possible to reduce the manufacturing cost and the thermal time constant by reducing the heat capacity.

  Next, a method for manufacturing the electromagnetic wave detector 100 according to the present embodiment will be described with reference to FIGS. 40a to 40i.

  First, in the steps shown in FIGS. 40a to 40c, the signal detection structure 9, the lower metal layer 1, and the insulating layer 2 are formed using the same steps as in FIGS. 20a to 20c of the first embodiment.

  Next, as shown in FIG. 40d, an upper metal layer is deposited.

  Next, as shown in FIG. 40e, a part of the upper metal layer 3 is covered with a mask layer such as a photoresist, and an upper metal layer is further deposited on the entire surface by sputtering or the like. Thereafter, the mask layer is removed, and the upper metal layer on the mask layer is also removed by lift-off.

  Next, as shown in FIG. 40f, after covering a wider portion with a mask layer, an upper metal layer is deposited on the entire surface by sputtering or the like. Thereafter, the mask layer is removed, and the upper metal layer on the mask layer is also removed by lift-off.

  Similarly, as shown in FIG. 40g, after covering a wider portion with a mask layer, an upper metal layer is deposited on the entire surface by sputtering or the like, then the mask layer is removed, and the upper metal layer on the mask layer is also lifted off. Remove with.

Next, after forming a mask layer as shown in FIG. 40h, the upper metal layer is patterned as shown in FIG. 40i to form an upper metal pattern. Finally, by removing the mask layer, upper metal patterns having different film thicknesses as shown in FIG. 36 can be formed. Thereby, the electromagnetic wave detector 100 according to the eighth exemplary embodiment is completed.
Further, as shown in the second embodiment, a wide absorption band and a non-absorption wavelength band may be formed by disposing a defect region. Specifically, the upper metal pattern 3 is shifted or removed in a region having a certain film thickness.
Further, as shown in the sixth embodiment, a wide absorption band and a non-absorption wavelength band may be formed by changing a part of the upper metal pattern 3 to another metal.

Embodiment 9 FIG.
FIG. 41 is a perspective view of the electromagnetic wave detector array according to the ninth exemplary embodiment, which is denoted as a whole by 101. An electromagnetic wave detector total absorption spectrum 4 having a uniform non-absorption wavelength band 5 by arranging one type of electromagnetic wave detector 100 described in any of the first to eighth embodiments in a two-dimensional shape (matrix shape). Can be obtained.

For example, the electromagnetic wave detector array 101 according to the present embodiment is effective when the non-absorption wavelength band 5 is one type and is clear. Taking the case of a human detection sensor at the time of a fire as an example, a flame when city gas or gasoline ignites has a characteristic emission spectrum called CO ₂ resonance radiation having a peak near a wavelength of 4.4 μm. For this reason, if the non-absorption wavelength band 5 is set in the vicinity of 4.4 μm, the presence of a person can be sensed regardless of the presence or absence of a flame.

Embodiment 10 FIG.
FIG. 42 is a perspective view of the electromagnetic wave detector array according to the tenth embodiment, the whole of which is represented by 101. A difference from the electromagnetic wave detector array 101 shown in Embodiment 9 is that four types of electromagnetic wave detectors 102 to 105 are arranged in a two-dimensional array.

  FIG. 43 is an absorption spectrum of the electromagnetic wave detector array 101 shown in FIG. Since the electromagnetic wave detector 102 to the electromagnetic wave detector 105 are designed to have the electromagnetic wave detector total absorption spectrums 402 to 405 each having a different non-absorption wavelength band 5, multiple types of image acquisition can be performed by one imaging. Is possible.

  When there are a plurality of non-absorption wavelength bands 5 to be detected, the electromagnetic wave detector array 101 according to the present embodiment works effectively. For example, in astronomical observation that requires various wavelength analysis, a large amount of wavelength information can be obtained by one imaging.

  As described in the first to tenth embodiments, in the electromagnetic wave detector according to the present invention, the surface plasmon mode is localized in the vicinity of the upper metal pattern due to the three-layer structure of the upper metal pattern-insulating layer-lower metal layer. A cavity is formed. Further, since the plasmon resonance wavelength is determined by the shape and size of the upper metal pattern, wavelength selective electromagnetic wave absorption is performed.

  That is, the size of the upper layer metal pattern on the plane corresponds to the wavelength of the electromagnetic wave detected by surface plasmon resonance, and the plurality of upper layer metal patterns have a plurality of different electromagnetic wave absorption spectra corresponding to them, A plurality of broad absorption bands are formed by summing up the absorption spectra. One or a plurality of non-absorption wavelength bands are formed by covering a wavelength region in which a plurality of wide-area light absorption bands do not compete with each other.

  Due to such an effect, an electromagnetic wave detector capable of absorbing with high efficiency can be provided for other wide wavelength bands except for a desired wavelength. By using the electromagnetic wave detector according to the present invention, it is possible to detect light having a non-absorption wavelength band in a plurality of types of upper layer metal patterns formed in different shapes or sizes without absorbing only the electromagnetic wave of the target wavelength. It becomes.

DESCRIPTION OF SYMBOLS 1 Lower metal layer, 2 Insulating layer, 3 Upper metal pattern, 4 Electromagnetic wave detector total absorption spectrum, 5 Non-absorption wavelength band, 6 Electromagnetic wave absorption spectrum peak, 7 Graphene layer, 8 Electric signal extraction part, 9 Signal detection structure, 10 Heat sensitive layer, 11 pattern defect, 12 1st wide absorption band, 13 2nd wide absorption band, 14 1st absorption unit, 15 2nd absorption unit, 16 3rd absorption unit, 17 3rd wide absorption band, 18 1st non- Absorption wavelength band 19 2nd non-absorption wavelength band, 20 Upper layer nonmetallic pattern, 21 Heat transfer body, 22 Heat sensitive body 23 Heat insulation support leg, 100 Electromagnetic wave detector.

Claims (11)

An electromagnetic wave detector for detecting electromagnetic waves by converting them into electric signals,
A structure including a lower metal layer, an insulating layer formed on the lower metal layer, and an upper metal pattern in which a plurality of upper metal layers are disposed on the insulating layer;
A signal detector that detects a change in temperature of the structure by converting it into an electrical signal,
The upper metal pattern includes at least two types of upper metal layers whose shapes are determined so as to absorb surface-plasmon resonance with electromagnetic waves of a specific wavelength and to absorb electromagnetic waves of the specific wavelength,
An electromagnetic wave detector characterized by having a non-absorption wavelength band of electromagnetic waves that are not absorbed between absorption wavelengths of two electromagnetic waves absorbed by the upper metal layer, the insulating layer, and the upper metal pattern. An electromagnetic wave detector for detecting electromagnetic waves by converting them into electric signals,
A structure including a lower metal layer, an insulating layer formed on the lower metal layer, and an upper metal pattern in which the upper metal layer is periodically arranged on the insulating layer;
A signal detector that detects a change in temperature of the structure by converting it into an electrical signal,
The insulating layer below the upper metal pattern includes at least two types of insulating layers whose thicknesses are determined so as to absorb electromagnetic waves of specific wavelengths by surface plasmon resonance with electromagnetic waves of specific wavelengths. ,
An electromagnetic wave detector having a non-absorption wavelength band of electromagnetic waves not absorbed between two absorption wavelengths of electromagnetic waves absorbed by the lower metal layer, the insulating layer, and the upper metal pattern. An electromagnetic wave detector for detecting electromagnetic waves by converting them into electric signals,
A structure including a lower metal layer, an insulating layer formed on the lower metal layer, and an upper metal pattern in which the upper metal layer is periodically arranged on the insulating layer;
A signal detector that detects a change in temperature of the structure by converting it into an electrical signal,
The upper metal pattern includes at least two types of upper metal layers whose film thicknesses are determined so that surface plasmon resonance with an electromagnetic wave of a specific wavelength absorbs the electromagnetic wave of the specific wavelength,
An electromagnetic wave detector characterized by having a non-absorption wavelength band of electromagnetic waves that are not absorbed between absorption wavelengths of two electromagnetic waves absorbed by the upper metal layer, the insulating layer, and the upper metal pattern.   The said upper metal pattern contains the said upper metal layer arrange | positioned with a fixed period, and this upper metal layer arrange | positioned with a different period between them. Electromagnetic wave detector.   The electromagnetic wave detector according to claim 1, wherein the upper metal pattern includes the upper metal layer made of different metal materials.   The electromagnetic wave detector according to claim 1, wherein the upper metal pattern is made of graphene or a transition metal chalcogenide.   The electromagnetic wave detector according to any one of claims 1 to 3, wherein a thickness of the insulating layer below the upper metal pattern is larger than a thickness of the other insulating layer.   The electromagnetic wave detector according to claim 7, wherein at least a part of the insulating layer disposed between the upper metal pattern and the lower metal layer is removed.   The electromagnetic wave detector according to any one of claims 1 to 3, wherein a film thickness of the lower metal layer below the upper metal pattern is larger than a film thickness of the other lower metal layer.   An electromagnetic wave detector array, wherein the electromagnetic wave detectors according to claim 1 are arranged in a matrix.   The electromagnetic wave detector array according to claim 10, comprising at least two electromagnetic wave detectors having different non-absorption wavelength bands.

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