A mid-infrared pyroelectric detector based on metasurface integration

Abstract

This invention discloses a mid-infrared pyroelectric detector based on metasurface integration, comprising a metasurface pixel array. Each metasurface pixel in the array includes: an upper electrode plate made of metal, comprising a resonant double ring; the structure of the resonant double ring serves as the metasurface image plane structure; a dielectric layer made of pyroelectric material; and a lower electrode plate made of metal. The dielectric layer is disposed between the two metal layers of the upper and lower electrode plates. Electromagnetic waves are incident on the mid-infrared pyroelectric detector along the upper electrode plate. The metasurface image plane structure absorbs the incident electromagnetic waves. The upper electrode plate, dielectric layer, and lower electrode plate form a resonant cavity, which absorbs the electromagnetic waves entering the cavity. This invention achieves and enhances broadband electromagnetic absorption of the interlayer pyroelectric material by coupling the metasurface resonant mode with the cavity mode, thereby improving the broadband absorption efficiency and detection efficiency of the detector in the target wavelength band. This invention can be widely applied in the field of infrared detection technology.

Description

Technical Field

[0001] This invention relates to the field of infrared detection technology, and in particular to a mid-infrared pyroelectric detector based on metasurface integration. Background Technology

[0002] The mid-infrared band, specifically the electromagnetic wave band with wavelengths from 3 μm to 5 μm, is a band whose propagation is less absorbed by atmospheric components such as carbon dioxide and ozone, hence it is also known as the atmospheric window. Due to its high transmittance in the atmosphere, it becomes detectable. Furthermore, since all objects radiate infrared electromagnetic waves, the detection of this radiation is of great significance. Infrared detectors are an indispensable and crucial component in many fields, including temperature measurement, detection, and imaging.

[0003] Pyroelectric infrared detectors are another mainstream infrared detector besides photon detectors. Their main mechanism is that temperature changes cause the spontaneously polarized ordered electric dipoles inside to rotate, thereby generating an electric current. Typical pyroelectric detectors use a thin-film absorption layer independent of the upper electrode plate, or the upper electrode plate itself can be used as the absorption layer. However, this structure generally suffers from significant heat dissipation or low electromagnetic wave absorption efficiency.

[0004] Previous research has explored the design of detectors with metasurface structures to enhance absorption. However, to achieve a good balance between detection efficiency and absorption efficiency, numerous issues must be considered when designing metasurfaces, including structure, dielectric materials, and heat dissipation efficiency. Compared to typical thin-film absorbing layers, absorption efficiency needs further improvement. Meanwhile, most existing designs only enhance absorption at a single frequency, achieving narrowband detection efficiency improvements, which undoubtedly limits the broadband applications of such detectors. Therefore, there remains a practical need and room for exploration in improving the overall detection efficiency across a specific wideband. Summary of the Invention

[0005] In order to at least partially solve one of the technical problems existing in the prior art, the present invention aims to provide a mid-infrared pyroelectric detector based on metasurface integration.

[0006] The technical solution adopted in this invention is:

[0007] A mid-infrared pyroelectric detector based on metasurface integration, wherein the mid-infrared pyroelectric detector is composed of a metasurface pixel array, and each metasurface pixel in the array includes:

[0008] The upper electrode plate is made of metal and includes a resonant double ring; the structure of the resonant double ring serves as a metasurface image plane structure.

[0009] The dielectric layer is made of pyroelectric material;

[0010] The lower electrode plate is made of metal.

[0011] The dielectric layer is disposed between the two metal layers, the upper electrode plate and the lower electrode plate; electromagnetic waves are incident on the mid-infrared pyroelectric detector along the upper electrode plate; the metasurface image structure absorbs the incident electromagnetic waves; the upper electrode plate, the dielectric layer and the lower electrode plate form a resonant cavity, and the resonant cavity absorbs the electromagnetic waves entering the cavity.

[0012] Furthermore, the orthographic projection of the metasurface pixel is a square; this orthographic projection is a projection perpendicularly incident from the upper electrode plate to the lower electrode plate.

[0013] The resonant double ring comprises two concentric square rings: an inner ring and an outer ring; the outer rings of adjacent metasurface pixels are connected.

[0014] Furthermore, the resonant double ring is a nickel-chromium alloy resonant double ring.

[0015] Furthermore, the pyroelectric material is lithium tantalate.

[0016] Furthermore, the lower electrode plate is made of copper.

[0017] Furthermore, the thickness of the resonant double ring is 0.05 μm;

[0018] The outer wall length of the outer ring is 0.28 μm, and the inner wall length of the outer ring is 0.24 μm;

[0019] The outer wall length of the inner ring is 0.17 μm, and the inner wall length of the inner ring is 0.08 μm.

[0020] Furthermore, the thickness of the dielectric layer is 0.46 μm; the thickness of the lower electrode plate is 0.01 μm.

[0021] Furthermore, the nickel-chromium alloy resonant double ring satisfies the Drude model in a preset waveband.

[0022] Furthermore, the resonant double-ring structure generates a resonant response to the incident electromagnetic wave, corresponding to the first resonant frequency; the electromagnetic wave entering the resonant cavity is eventually absorbed by the interlayer medium after multiple reflections within the cavity, corresponding to the second resonant frequency.

[0023] Furthermore, the second resonant frequency is greater than the first resonant frequency.

[0024] The beneficial effects of this invention are: by coupling the metasurface resonant mode with the cavity mode, this invention realizes and enhances the broadband electromagnetic absorption of the interlayer pyroelectric material, thereby improving the broadband absorption efficiency and detection efficiency of the detector in the target band. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following description is provided with accompanying drawings of the relevant technical solutions in the embodiments of the present invention or the prior art. It should be understood that the accompanying drawings described below are only for the purpose of clearly illustrating some embodiments of the technical solutions of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the structure of the metasurface pixel in an embodiment of the present invention;

[0027] Figure 2 This is a schematic cross-sectional view of a metasurface pixel in an embodiment of the present invention;

[0028] Figure 3 This is a graph showing the absorption efficiency of electromagnetic waves at vertical incidence from 50THz to 120THz in an embodiment of the present invention.

[0029] Figure 4 This is a cross-sectional electric field distribution diagram under perpendicular incidence of a 66.17THz electromagnetic wave in an embodiment of the present invention;

[0030] Figure 5 In this embodiment of the invention, the frequency is 66.17 THz and the energy is 4 × 10⁻⁶. -10 Temperature distribution diagram of electromagnetic wave W incident perpendicularly after 0.2s;

[0031] Figure 6 This is a lumped parameter equivalent circuit model diagram of the absorber model in this embodiment of the invention;

[0032] Figure 7 This is a comparison diagram of the electromagnetic wave amplitude modulation effect of the absorber structure and equivalent circuit model in the embodiments of the present invention;

[0033] Figure 8 It was achieved with a chopping period of 0.2s, a frequency of 66.17THz, and an energy of 4×10⁻⁶. -10 A comparison of the temperature change of the center point of the lithium tantalate dielectric layer of the present invention and pyroelectric detectors with different structures within one second under the incident electromagnetic wave of W.

[0034] Figure 9 This is a comparison graph of the absorption efficiency and the current responsivity of the normalized pyroelectric detector in an embodiment of the present invention.

[0035] Figure 10 This is a schematic diagram of the structure of a mid-infrared pyroelectric detector based on metasurface integration in an embodiment of the present invention. Detailed Implementation

[0036] The embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. The step numbers in the following embodiments are set only for ease of explanation, and there is no limitation on the order between the steps. The execution order of each step in the embodiments can be adaptively adjusted according to the understanding of those skilled in the art.

[0037] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0038] In the description of this invention, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0039] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0040] To improve the detection efficiency of the detector across the entire mid-infrared band, this invention employs a design method that combines a broadband absorber with a pyroelectric detector. While maintaining compatibility with the detector's design structure, the integrated metasurface broadband absorbing structure enhances the energy utilization of the incident electromagnetic waves, thereby improving the detector's efficiency, sensitivity, and other performance characteristics. This invention proposes a hybrid structure combining a metasurface composite structure with a pyroelectric detector to improve detection efficiency. Its basic unit has a structure of a metasurface electrode—pyroelectric material—lower electrode; that is, the detector pixel adopts a basic metasurface unit structure of metal-dielectric layer-metal.

[0041] like Figure 10 As shown, this embodiment provides a mid-infrared pyroelectric detector based on metasurface integration. The detector is composed of a metasurface pixel array, where each metasurface pixel includes:

[0042] The upper electrode plate 1 is made of metal and includes a resonant double ring; the structure of the resonant double ring serves as a metasurface image plane structure.

[0043] Dielectric layer 2 is made of pyroelectric material;

[0044] The lower electrode plate 3 is made of metal;

[0045] The dielectric layer 2 is disposed between the two metal layers, the upper electrode plate 1 and the lower electrode plate 3; electromagnetic waves are incident on the mid-infrared pyroelectric detector along the upper electrode plate; the metasurface image structure absorbs the incident electromagnetic waves; the upper electrode plate, the dielectric layer and the lower electrode plate form a resonant cavity, which absorbs the electromagnetic waves entering the cavity.

[0046] In this embodiment, the incident electromagnetic wave, under the influence of the top-layer periodic structure and the Fabry-Perot resonant cavity formed by the electrode-pyroelectric material-bottom electrode plate on the metasurface, generates reflection low peaks at two resonant points. The coupling of the two resonant modes produces broadband reflection low peaks. Due to the total internal reflection characteristics of the bottom metal, the transmission is almost zero, thus achieving broadband, high-efficiency electromagnetic absorption of the incident mid-infrared radiation.

[0047] In addition, the incident electromagnetic wave creates a strong electric field locally on the metasurface structure, which excites electron migration and generates heat energy. The heat energy flow causes temperature changes, which cause the pyroelectric spontaneously polarized ordered electric dipoles to rotate, thereby generating an induced current.

[0048] As a further optional implementation, the resonant double ring is a nickel-chromium alloy resonant double ring. The dielectric constant of the nickel-chromium alloy satisfies the Drude model in the target wavelength band. Its plasma frequency ω p =2.9×10 15 rad / s, its collision frequency v c =1.65×10 14 Hz. The real part of the refractive index of the pyroelectric material lithium tantalate is approximately 2.1 in this wavelength range. The electrical conductivity of copper is 5.6 × 10⁻⁶. 6 S / m.

[0049] As a further optional implementation, the orthographic projection of the metasurface pixel is a square; the resonant double ring comprises two concentric square rings: an inner ring and an outer ring; the outer rings of adjacent metasurface pixels are connected. The centers of the double ring structure are the same and located at the axis of the dielectric layer.

[0050] The metal square ring of the metasurface pixel used has a perforated structure. The outer wall length of the metal outer ring that constitutes a single pixel is the same as the period of the detector unit, which is 0.28 μm, and the inner wall length of the outer ring is 0.24 μm.

[0051] The outer wall length of the metal square inner ring of the metasurface pixel used is 0.17 μm, and the inner wall length is 0.08 μm.

[0052] The thickness of the double-ring structure, that is, the thickness along the direction of electromagnetic wave propagation, is 0.05 μm.

[0053] As a further optional implementation, the intermediate dielectric layer is made of pyroelectric material lithium tantalate, and the dielectric layer thickness of the metasurface pixel is 0.46 μm.

[0054] As a further optional implementation, the lower electrode plate is made of copper; the thickness of the metal layer of the lower electrode plate is 0.01 μm.

[0055] In this embodiment, the detector pixel adopts an integrated design of a composite metasurface absorbing structure and a lithium tantalate pyroelectric dielectric. This includes a bottom metal substrate serving as the lower electrode and incident electromagnetic reflection layer, a top metal metasurface with a specific structural design, and an intermediate pyroelectric dielectric material layer providing current response. The basic infrared detection process or mechanism involves a resonant cavity-based electromagnetic absorption mode provided between the upper and lower metal layers and the interlayer dielectric. The additional resonant absorption peak provided by the top nickel-chromium alloy metasurface structure couples the resonant mode of the nickel-chromium alloy metasurface with the cavity mode, thereby achieving and enhancing the broadband electromagnetic absorption of the interlayer pyroelectric material. This significantly improves the broadband absorption and detection efficiency of the detector in the target wavelength band without affecting heat transfer efficiency.

[0056] The detector described above will be explained in detail below with reference to the accompanying drawings and specific embodiments.

[0057] like Figure 1 As shown, in this embodiment of the invention, the electromagnetic wave is incident along the Z direction, and is a plane wave with the electric field component parallel to the Y direction and the magnetic field direction parallel to the X direction and perpendicular to the metasurface.

[0058] The thickness described in the embodiments of the present invention refers to the length perpendicular to the pixel surface and along the direction of electromagnetic wave propagation.

[0059] Figure 1 This is a structural diagram of a unit or pixel in an embodiment of the present invention, combined with... Figure 2 Middle Figure 1 The cross-sectional view in the YOZ plane further illustrates the "hybrid" structure of the metasurface absorber and detector in this embodiment of the invention. Figure 2As shown, the top concentric nested composite square ring structure serves both as the metasurface image plane structure and as the upper electrode after the detector generates pyroelectric current. The close contact and connection between the outer ring and adjacent units allows the upper electrode to form a conductive mesh-like electrode. The middle layer uses a pyroelectric material as the dielectric layer, which, while generating pyroelectric current, also serves as the transmission medium for modulating the resonant mode of the incident wave. The bottom metal reflects all incident electromagnetic waves and simultaneously serves as the lower electrode of the detector.

[0060] When electromagnetic waves of 50-120 THz are incident perpendicularly, the following is obtained: Figure 3 The optimized absorption spectrum shown exhibits significant absorption peaks at 66.17 THz and 93.4 THz, respectively. Through the coupling of two absorption modes, an overall absorption efficiency exceeding 90% is achieved within the 60-100 THz band (3-5 μm). The absorption peak at 66.17 THz originates from the resonant response mode of the double-ring structure on the top surface to the incident electromagnetic wave. Figure 4 This shows that the electric field at this point is mainly concentrated within the inner ring of the surface structure; while the absorption peak at 93.4 THz originates from the Fabry-Perot resonant cavity formed by the supersurface electrode—pyroelectric material—lower electrode: part of the incident electromagnetic wave is reflected at the air-supersurface electrode interface, and the remainder enters the cavity composed of the dielectric layer and the bottom metal layer. After multiple reflections within the cavity, it is eventually absorbed by the interlayer dielectric, resulting in minimal reflection energy across the entire three-layer structure. Under the controlled optimization of this invention, at 93.4 THz, the reflected electromagnetic energies at the upper and lower interfaces of the cavity are approximately equal in magnitude but opposite in phase, thus canceling each other out to form the absorption peak.

[0061] The absorption principle of this embodiment can be further understood from the perspective of equivalent circuits. For example... Figure 1 The structure and electromagnetic field direction shown indicate that the dielectric in the electric field direction can be equivalent to a capacitor, while the conductor along the magnetic field direction can be equivalent to an inductor. Due to their relatively significant thickness, the dielectric and top layer structure have a certain influence on the phase of the incident electromagnetic wave; therefore, they can be understood as a transmission line and equivalent to a π-type circuit structure. The final circuit structure is... Figure 6The diagram shows that Z1 and Z2 represent the free-space wave impedances at the incident and exit ports, respectively, with Z1 = Z2 = 377 Ω. L1 and L2 are the equivalent inductances of the metal arms of the outer and inner metal rings of the top-layer structure perpendicular to the electric field direction, respectively, with optimized fitting values ​​of L1 = 0.8016 pH and L2 = 1.2443 pH. Resistors R1 and R2 represent the energy loss of the electromagnetic wave at the top layer, with R1 = 9.3 Ω and R2 = 221 Ω. Capacitor C1 is the equivalent capacitance of the gap between the inner and outer metal rings in the electric field direction, with C1 = 0.00389 fF. Inductors L3 and L4, and capacitors C2 and C3 are derived from the propagation medium as equivalent transmission lines, with L3 = 0.2415 pH, L4 = 0.6520 pH, C2 = 0.0013 fF, and C3 = 0.0087 fF. R3 represents the loss of the bottom metal, and R3 = 24.044Ω. Figure 7 A comparison diagram of the reflection coefficient spectrum of the lumped parameter equivalent circuit model and the metasurface absorber structure of the present invention is given, and the two have a good fitting effect.

[0062] The pyroelectric detection process in this embodiment involves the following energy conversion: the incident electromagnetic wave first undergoes metasurface modulation, and most of its electric field component is concentrated in the gaps between the top metal layers, such as... Figure 4 As shown, this localized strong electric field causes a change in the device temperature, i.e., an energy conversion from electromagnetic energy to thermal energy occurs, such as... Figure 5 As shown, changing temperature causes the dipoles inside the pyroelectric material to change from an ordered arrangement to a disordered arrangement. This transformation generates the directional movement of charges, thus forming an electric current. This current is transmitted to the external circuit through the upper and lower plates of the detector, realizing the conversion of optical signals into electrical signals.

[0063] In this embodiment, the temperature change at the center point of the pyroelectric material of the detector structure under periodic electromagnetic wave irradiation is as follows: Figure 8 As shown by the solid line, based on the pyroelectric induced current Where p is the pyroelectric coefficient of the pyroelectric material, and for lithium tantalate, p = 176 μC / m. 2 K, A = 0.0784 μm 2 Let dT / dt = 4683.45 K / s be the area of ​​the unit detector, and dT / dt = 4683.45 K / s be the temperature change rate. From this, its current responsivity can be calculated as R. i =i p / Φ=161.56μA / W, where Φ=4×10 -10 W represents the power of the incident electromagnetic wave.

[0064] A pyroelectric detector structure consisting of three homogeneous dielectric layers of the same thickness and material exhibits the following temperature change at the center point of its lithium tantalate volume under electromagnetic wave irradiation of the same frequency and power: Figure 8As shown by the dashed line, the pyroelectric infrared detector structure described in this embodiment is identical to that of the present invention, except that the top electrode uses a uniform nickel-chromium alloy instead of a double-ring metasurface structure. The temperature change rate of the metasurface integrated pyroelectric detector in this embodiment is significantly higher than that of the pyroelectric detector described above. This is due to the increased absorption rate after introducing the double-ring metasurface structure, and the stronger local electric field generates more heat, causing more drastic temperature changes.

[0065] The current responsivity of incident electromagnetic waves at different frequencies was calculated, and the normalized results were compared with the absorption curves as shown in the figure. Figure 9 As shown, the absorption efficiency and current responsivity exhibit a generally consistent trend. Improving the absorption rate can significantly increase the induced current of the detector.

[0066] As described above, this invention discloses a hybrid pyroelectric detector structure design based on metasurface-enhanced mid-infrared electromagnetic absorption and pyroelectric detection. Due to the coupling effect of the metasurface metal unit resonance and the three-layer resonant cavity, electromagnetic wave absorption peaks are reached at 66.17 THz and 93.4 THz, respectively. The coupling effect of these two elements results in an overall electromagnetic wave absorption efficiency of over 90% in the 3-5 μm range. Furthermore, this absorption spectrum can be well explained by fitting an equivalent circuit, further elucidating the contribution of each component of the structure to electromagnetic wave modulation and providing a reference direction for its design and improvement. In this invention, the detector's detection efficiency is characterized by its current responsivity, which is directly positively correlated with the rate of temperature change. This invention calculates the current responsivity by calculating the temperature change caused by the incident electromagnetic wave. Compared with traditional pyroelectric detector structures, the current responsivity of this invention is significantly improved, and its value is significantly positively correlated with the absorption rate. In addition, this structure features simple structure and low heat dissipation.

[0067] In summary, compared with the prior art, the present invention has the following advantages and beneficial effects: Compared with the ordinary pyroelectric detector structure, the introduced metasurface absorber structure significantly increases the detector's detection efficiency; compared with the general pyroelectric detector combined with a metasurface, the present invention has a broadband detectivity enhancement effect and a higher absorption enhancement effect; compared with directly adding a metasurface structure as an absorption layer, the present invention directly uses pyroelectric material as the metasurface structure dielectric layer and nickel-chromium alloy metasurface as the top electrode, reducing heat dissipation and process complexity; the present invention has a better matching effect between the modulation effect of the incident electromagnetic wave and the lumped equivalent circuit model at the absorber model level, which has certain reference value for general design processes.

[0068] In the foregoing description of this specification, references to terms such as "one embodiment," "another embodiment," or "some embodiments" indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0069] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

[0070] The above is a detailed description of the preferred embodiments of the present invention. However, the present invention is not limited to the above embodiments. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention. All such equivalent modifications or substitutions are included within the scope defined by the claims of this application.

Claims

1. A mid-infrared pyroelectric detector based on metasurface integration, characterized in that, The mid-infrared pyroelectric detector is composed of a metasurface pixel array, and each metasurface pixel in the array includes: The upper electrode plate is made of metal and includes a resonant double ring; the structure of the resonant double ring serves as a metasurface image plane structure; the resonant double ring is a nickel-chromium alloy resonant double ring; the nickel-chromium alloy resonant double ring satisfies the Drude model in a preset wavelength band. The dielectric layer is made of pyroelectric material; The lower electrode plate is made of metal. The dielectric layer is disposed between the two metal layers, the upper electrode plate and the lower electrode plate; electromagnetic waves are incident on the mid-infrared pyroelectric detector along the upper electrode plate; the metasurface image structure absorbs the incident electromagnetic waves; the upper electrode plate, the dielectric layer and the lower electrode plate form a resonant cavity, and the resonant cavity absorbs the electromagnetic waves entering the cavity; The resonant double-ring structure generates a resonant response to the incident electromagnetic wave, corresponding to 66.17 THz; the electromagnetic wave entering the resonant cavity is ultimately absorbed by the interlayer medium after multiple reflections within the cavity, corresponding to 93.4 THz; through the coupling of two absorption modes, a frequency within the range of 60-100 THz, i.e., 3-5 THz, is generated. The overall absorption efficiency within the band reaches over 90%.

2. The mid-infrared pyroelectric detector based on metasurface integration according to claim 1, characterized in that, The orthographic projection of the metasurface pixel is a square; The resonant double ring comprises two concentric square rings: an inner ring and an outer ring; the outer rings of adjacent metasurface pixels are connected.

3. The mid-infrared pyroelectric detector based on metasurface integration according to claim 1, characterized in that, The pyroelectric material is lithium tantalate.

4. The mid-infrared pyroelectric detector based on metasurface integration according to claim 1, characterized in that, The lower electrode plate is made of copper.

5. A mid-infrared pyroelectric detector based on metasurface integration according to claim 2, characterized in that, The thickness of the resonant double ring is 0.

05. ; The outer wall length of the outer ring is 0.

28. The inner wall length of the outer ring is 0.

24. ; The outer wall length of the inner ring is 0.

17. The inner wall length of the inner ring is 0.

08. .

6. A mid-infrared pyroelectric detector based on metasurface integration according to claim 1, characterized in that, The thickness of the dielectric layer is 0.

46. The thickness of the lower electrode plate is 0.01 mm. .

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