Ultra-wide spectrum infrared signal detector based on metasurface optical antenna and preparation method thereof

Abstract

The present invention discloses an ultra-wide spectrum infrared signal detector based on a super surface optical antenna and a preparation method, which belongs to the field of signal detection technology, and includes a substrate, a doping layer, a silicon dioxide layer, a super surface optical antenna layer, an ohmic electrode, a Schottky electrode and a common electrode; wherein the super surface optical antenna layer is composed of a metal nano tip array with a width of 0.5 to 5 mm, and the metal nano tip array is a metal layer with a periodic nano tip structure, which has a strong localized surface plasmon sensing ability to the incident electromagnetic wave, and can generate localized surface plasmon oscillation with the corresponding infrared signal, and its response speed is relatively high, which belongs to ultra-high speed response, and can generate a very strong response signal in a very short time, so as to quickly detect infrared signals with a band of 1 to 70 um. In addition, the detector provided by the present invention has a size of millimeter or sub-millimeter, has high sensitivity, high speed and miniaturization characteristics, and can realize the detection of ultra-wide spectrum infrared signals with a fast response speed in a small volume.

Description

Technical Field

[0001] The present invention belongs to the technical field of signal detection, and more specifically, relates to an ultra-wide spectrum infrared signal detector based on a metasurface optical antenna and a preparation method thereof. Background Art

[0002] Infrared detection is widely used in many fields such as security monitoring systems, material testing, space signal detection, aerospace, industrial and agricultural production, etc.

[0003] Common infrared detectors mainly include temperature detectors, high-temperature superconducting detectors, and semiconductor detectors made of silicon or gallium arsenide. The principles of these detectors are mature and have been put into practical use. However, in situations where high-speed, high-sensitivity, and miniaturized signal detection are required, the performance of existing infrared detectors is insufficient. First, existing infrared detectors are often equipped with refrigeration devices, and their spectrum imaging devices still need to be equipped with complex and precise driving mechanisms, which are large in size and mass. Secondly, the array scale of existing infrared detectors is small, with fewer pixels, and the detectable band range is narrow (such as 1 to 3 microns, 3 to 8 microns, etc.). In addition, due to the lack of effective electromagnetic wave sensing units, the adaptability in different bands is quite different, and the ultra-wide spectrum cannot be evenly covered, and the response speed is slow. Summary of the invention

[0004] In response to the above defects or improvement needs of the prior art, the present invention provides an ultra-wide-spectrum infrared signal detector based on a metasurface optical antenna and a preparation method thereof, which aims to solve the technical problems of large size, slow response and narrow detection band in the prior art.

[0005] To achieve the above-mentioned purpose, in a first aspect, the present invention provides an ultra-wide spectrum infrared signal detector based on a metasurface optical antenna, comprising a substrate, a doping layer, a silicon dioxide layer, a metasurface optical antenna layer, an ohmic electrode, a Schottky electrode and a common electrode;

[0006] The doped layer is located on the upper surface of the substrate; the silicon dioxide layer is located on the upper surface of the doped layer; the metasurface optical antenna layer and the ohmic electrode are both made on the doped layer, the metasurface optical antenna layer forms a Schottky contact with the doped layer, the internal gap is filled by the silicon dioxide layer, and the ohmic electrode forms an ohmic contact with the doped layer; the Schottky electrode and the ordinary electrode are both located on the upper surface of the silicon dioxide layer, and are both connected to the metasurface optical antenna layer;

[0007] The metasurface optical antenna layer is composed of a metal nanotip array with a width of 0.5 to 5 mm, which has localized surface plasmon characteristics for incident infrared electromagnetic waves and is used to detect infrared signals with a wavelength of 1 to 70 μm. The metal nanotip array is a metal layer with a periodic nanotip structure. The nanotip structure is a nanoscale pointed structure composed of metal nanotips.

[0008] When the metal nanotip is parallel to the doping layer, the metal nanotip array is a planar structure, the metal nanotip is a planar metal nanotip, the width of the planar metal nanotip is 20 to 80 nm, the height is 80 to 300 nm, and the tip angle is 10 to 60 degrees;

[0009] When the metal nanotips are perpendicular to the doping layer, the metal nanotips array is a three-dimensional structure, the metal nanotips are upright metal nanotips, the upright metal nanotips are upright prism structures, and the number of their edges N is ≥ 6; the angle of the sharp angle formed by the intersection of the reverse extension lines of each edge is 10 to 40 degrees; the length of the lower bottom surface is 30 to 200nm, the length of the upper bottom surface is 10 to 100nm, and the slant height is 80 to 300nm.

[0010] Further preferably, the metal nanotip array comprises a plurality of identical metal nanotip units, and the metal nanotip units are composed of the metal nanotips.

[0011] Further preferably, when the metal nanotip array is a planar structure, the above-mentioned metal nanotip array also includes a plurality of identical micron elements; the micron element is a micron structure and has a polygonal shape; the metal nanotip units are distributed on the outside or inside of each edge of the micron element, together forming a micro-nano structure.

[0012] Further preferably, the period, number and geometric parameters of the metal nanotip units in the metal nanotip array are different, the sharpness of the nanotips and the nanotip electron concentration in the metasurface optical antenna layer are different, and the nanotip signal strength is also different.

[0013] Further preferably, by applying a voltage with a load resistor to the Schottky electrode and the common electrode, or by applying a voltage with a load resistor to the Schottky electrode and the common electrode, the nanotip electron concentration and signal strength are enhanced, thereby realizing the detection of infrared signals.

[0014] Further preferably, the material of the metal nanotip is titanium and gold.

[0015] In a second aspect, the present invention provides a method for preparing the ultra-wide spectrum infrared signal detector proposed in the first aspect of the present invention, comprising the following steps:

[0016] S1, implanting doping ions on the substrate by metal organic compound chemical vapor deposition to form a doping layer;

[0017] S2, preparing a silicon dioxide layer on the doped layer by plasma enhanced chemical vapor deposition;

[0018] S3, photolithography an ohmic electrode contact hole pattern on the silicon dioxide layer by a positive resist process, and etching the silicon dioxide layer at the position of the ohmic electrode contact hole pattern to obtain an ohmic electrode contact hole; photolithography an ohmic electrode pattern by a negative resist process, and sequentially evaporate the stacked Ni / Ge / Au layers by electron beam evaporation, remove excess metal and photoresist by stripping, and anneal the alloy to form an ohmic electrode in ohmic contact with the doped layer at the ohmic electrode contact hole;

[0019] S4, photolithography a Schottky contact hole pattern on the silicon dioxide layer by a positive photoresist process, and etching the silicon dioxide layer at the position of the Schottky contact hole pattern to form a Schottky contact hole;

[0020] S5, photolithography of Schottky electrode patterns and common electrode patterns on the silicon dioxide layer by negative resist process, sequentially evaporating the stacked Ti / Au layers by electron beam evaporation, and stripping off excess metal and photoresist to form Schottky electrodes and common electrodes respectively;

[0021] S6. Preparing a metal nanotip array with a width of 0.5 to 5 mm on the silicon dioxide layer and forming a Schottky contact with the doping layer through a Schottky contact hole to form a metasurface optical antenna layer; specifically comprising:

[0022] For a metal nanotip array with a planar structure, an electron beam exposure method is used to photolithography a planar pattern composed of metal nanotips on the metal nanotip array on a silicon dioxide layer, wherein the width of the metal nanotips is 20 to 80 nm, the height is 80 to 300 nm, and the angle of the sharp angle is 10 to 60 degrees; and the silicon dioxide layer is etched by inductively coupled plasma etching or reactive ion etching using the pattern as a mask; for a metal nanotip array with a three-dimensional structure, a polygonal mask is generated on the silicon dioxide layer by electron beam exposure, and then a three-dimensional structure composed of metal nanotips on the metal nanotip array is generated by inductively coupled ion beam etching; wherein the three-dimensional structure is a vertical prism structure, and the number of its edges N is ≥ 6; the angle of the sharp angle formed by the intersection of the reverse extension lines of each edge is 10 to 40 degrees; the side length of the lower bottom surface is 30 to 200 nm, the side length of the upper bottom surface is 10 to 100 nm, and the oblique height is 80 to 300 nm;

[0023] Then, the stacked Ti / Au layers are evaporated in sequence by electron beam evaporation or magnetron sputtering coating to obtain a metal nanotip array with a width of 0.5 to 5 mm, which forms Schottky contact with the doped layer through Schottky contact holes, thereby forming a supersurface optical antenna layer.

[0024] Further preferably, when the metal nanotip array is a planar micro-nano structure, the method for preparing the ultra-wide spectrum infrared signal detector further comprises step S7, which is located between the above steps S4 and S5;

[0025] Step S7 includes: using ultraviolet photolithography to photoetch a pattern composed of each micron element on the metal nanotip array on the silicon dioxide layer, and using electron beam evaporation to form each micron element in contact with the doped layer Schottky at the Schottky contact hole.

[0026] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0027] 1. The present invention provides an ultra-wide spectrum infrared signal detector based on a metasurface optical antenna, comprising a metasurface optical antenna layer, wherein a metal nanotip array is a metal layer with a periodic nanotip structure, and its width is 0.5 to 5 mm. Combined with the corresponding geometric parameters of the metal nanotip, it has a very strong localized surface plasmon sensing capability for the incident infrared band electromagnetic signal, and can generate localized surface plasmon oscillation with the corresponding infrared signal. Its response speed is relatively high, belonging to ultra-high-speed response, and can generate a very strong response signal in a very short time, thereby quickly detecting infrared signals with a band of 1 to 70 um; and the detector provided by the present invention has a size of millimeter or submillimeter level, has the characteristics of high sensitivity, high speed and miniaturization, and can realize the detection of ultra-wide spectrum infrared signals with a fast response speed in a relatively small volume.

[0028] 2. The ultra-wide spectrum infrared signal detector provided by the present invention has a super-surface optical antenna that is made using nanotechnology and can be used in 1mm 2 Millions to tens of millions of nano-tip sensing units can be integrated within this size, so it is very small and light.

[0029] 3. The ultra-wide spectrum infrared signal detector provided by the present invention, when the metal nanotip array is a planar structure, can include metal nanotip units and micron elements at the same time, and each metal nanotip unit is distributed on the outside or inside of each edge of the micron element to form a micro-nano structure together. Under the premise of achieving the detection of ultra-wide spectrum infrared signals with a faster response speed in a smaller volume, the cost of the infrared signal detector is greatly reduced.

[0030] 4. The ultra-wide spectrum infrared signal detector provided by the present invention only needs a small amount of electronic resources such as low-voltage DC or AC signals to assist its operation to realize the detection of ultra-wide spectrum infrared signals, which greatly saves peripheral circuit resources.

[0031] 5. The ultra-wide spectrum infrared signal detector provided by the present invention changes the sharpness and nanotip electron concentration of the nanotips in the metasurface optical antenna layer by setting the period, number and geometric parameters of the metal nanotips in the metal nanotip array, thereby controlling the nanotip signal intensity and realizing accurate detection of infrared signals in the band of 1 to 70 um. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a longitudinal cross-sectional schematic diagram of an ultra-wide-spectrum infrared signal detector based on a metasurface optical antenna provided in Example 1 of the present invention;

[0033] Figure 2 is a top view schematic diagram of an ultra-wide spectrum infrared signal detector based on a metasurface optical antenna provided in Example 1 of the present invention;

[0034] Figure 3 is a schematic diagram of a planar metal nanotip array and its detailed structure provided in Example 1 of the present invention;

[0035] Figure 4 is a schematic diagram of an upright metal nanotip array and its detailed structure provided in Example 1 of the present invention;

[0036] Figure 5 It is a schematic diagram of the metal nanotip array of micro-nano structure and its detailed structure provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0038] Embodiment 1,

[0039] An ultra-wide spectrum infrared signal detector based on a metasurface optical antenna, such as Figure 1 As shown, it includes a substrate 1, a doping layer 2, a silicon dioxide layer 3, a metasurface optical antenna layer 4, an ohmic electrode 5, a Schottky electrode 6 and a common electrode 7;

[0040] Among them, the doped layer 2 is located on the upper surface of the substrate 1; the silicon dioxide layer 3 is located on the upper surface of the doped layer 2, and the thickness is 100 to 300 nm; the supersurface optical antenna layer 4 and the ohmic electrode 5 are both made on the doped layer, the supersurface optical antenna layer 4 forms a Schottky contact with the doped layer 2, and its internal gap is filled by the silicon dioxide layer, and the ohmic electrode 5 forms an ohmic contact with the doped layer 2, but is not connected to the supersurface optical antenna layer 4; the Schottky electrode 6 and the ordinary electrode 7 are both located on the upper surface of the silicon dioxide layer, and are connected to the supersurface optical antenna layer 4 through a metal sheet or a metal wire (such as Figure 2As shown in the figure, but none of them is in contact with the doped layer 2; the silicon dioxide layer 3, the metasurface optical antenna layer 4 and the ohmic electrode 5 jointly cover the upper surface of the doped layer 2. In this embodiment, the distance between the Schottky electrode 6 and the metasurface optical antenna layer 4 is 1mm to 5mm, and the distance between the ordinary electrode 7 and the metasurface optical antenna layer 4 is 1mm to 5mm.

[0041] The metasurface optical antenna layer 4 is composed of a metal nanotip array with a width of 0.5 to 5 mm, which has localized surface plasmon characteristics for the incident infrared electromagnetic wave and is used to detect infrared signals with a wavelength of 1 to 70 um; the metasurface is an artificial composite structure or composite material with extraordinary physical properties that natural materials do not have, and uses a sub-wavelength metal structure with a periodic size much smaller than the incident wavelength to sense the incident electromagnetic wave. Among them, the metal nanotip array is a metal layer with a periodic nanotip structure; the nanotip structure is a nanoscale pointed structure composed of metal nanotips. Further, the metal nanotip array includes a plurality of identical metal nanotip units, the metal nanotip unit is composed of one or more of the above-mentioned metal nanotips (in this embodiment, the metal nanotip unit is composed of one metal nanotip), the metal nanotip is a nanostructure, and its material is titanium and gold; wherein, the silicon dioxide of the silicon dioxide layer insulates the gaps between and inside the metal nanotip units. The metal nanotip array is a planar structure or a three-dimensional structure.

[0042] Specifically, when the metal nanotip is parallel to the doping layer, the metal nanotip array is a planar structure, the metal nanotip is a planar metal nanotip, the width d of the planar metal nanotip is 20 to 80 nm, the height h is 80 to 300 nm, and the tip angle θ is 10 to 60 degrees; Specifically, in an optional embodiment, the metal nanotip unit is composed of a planar metal nanotip, which is a nanostructure, such as Figure 3 As shown, in this embodiment, the planar metal nanotip is an isosceles triangle. At this time, the metal nanotip array is composed of only planar metal nanotips. The sharp corners of each planar metal nanotip are in the same direction. Two adjacent planar metal nanotips are connected by metal sheets or metal wires. The spacing between the metal nanotips is p = 10-100nm; wherein, the planar metal nanotip is stacked by titanium with a thickness of 20nm and gold with a thickness of 200nm, and the thickness of the metal nanotip array is 50-220nm. It should be noted that the shape of the above-mentioned planar metal nanotip is not limited to an isosceles triangle, but can also be other pointed shapes or shapes with a certain curvature at the sharp corners.

[0043] When the metal nanotips are perpendicular to the doping layer, the metal nanotips array is a three-dimensional structure, the metal nanotips are upright metal nanotips, and the upright metal nanotips are upright prism structures, and the number of edges N is ≥ 6; Figure 4As shown, the number of edges in this embodiment is 6, and the sharp angle α formed by the intersection of the reverse extension lines of each edge is 10 to 40 degrees; the side length a1 of the lower bottom surface is 30 to 200 nm, the side length a2 of the upper bottom surface is 10 to 100 nm, the oblique height h is 80 to 300 nm, and the spacing p of the metal nanotips is 10 to 100 nm.

[0044] In order to further save the cost of the ultra-wide spectrum infrared signal detector, when the metal nanotip array is a planar structure, the metal nanotip array also includes a plurality of identical micron primitives, two adjacent micron primitives are connected by metal sheets or metal wires, and the material of the micron primitives can be titanium and gold; the micron primitive is a micron structure, and the shape is polygonal; the metal nanotip units are distributed on the outside or inside of each side of the micron primitive, and together constitute a micro-nano structure. Specifically, in an optional embodiment, the shape of the micron primitive is an isosceles triangle, and two adjacent micron primitives are connected by metal sheets or metal wires, such as Figure 5 As shown, the metal nanotip units composed of a planar metal nanotip are evenly distributed on the outside of each edge of the micron element (at this time, two adjacent planar metal nanotips do not need to be connected), that is, the metal nanotip units form protrusions or depressions on each edge of the micron element.

[0045] Furthermore, in order to distinguish ultra-wide spectrum infrared signals, the size of the metal nanotip array in the present invention is millimeter-level or sub-millimeter-level (specific width T = 0.5-5mm), and the corresponding geometric parameters are set for the metal nanotip, so that the metal nanotip array has a strong localized surface plasmon sensing ability to the incident infrared electromagnetic wave 8, thereby quickly obtaining the detection ability of infrared signals. Specifically, the metal nanotip adopts a pointed structure, so that a large number of electrons are gathered at the tip of the nanotip. At this time, the incident electromagnetic wave can induce high-intensity electron oscillations. The pointed shape parameters are mainly determined by the angle. Considering the wavelength size of the infrared band, and for the micro-nano structure, the nanotip can be made on the existing micron structure, it is necessary to ensure that there are enough nanotips on the detector to form an array to achieve effective infrared detection.

[0046] Furthermore, due to the different periods, numbers and geometric parameters of the metal nano-tips in the metal nano-tip array, the sharpness and electron concentration of the nano-tips in the metasurface optical antenna layer are different, and the nano-tip signal strength is also different; by setting the period, number and geometric parameters of the metal nano-tips in the metal nano-tip array, the sharpness and electron concentration of the nano-tips in the metasurface optical antenna layer are changed, and the nano-tip signal strength is controlled to achieve accurate detection of infrared signals; in addition, during the detection process, under the condition of small interference from conventional background and environmental signals, the nano-tip electron concentration and signal strength can be enhanced by applying a 2V voltage with a load resistor to the Schottky electrode 6 and the ordinary electrode 7, so that the metal nano-tip detects the infrared electromagnetic wave signal. In the case of a weak incident electromagnetic wave signal, by applying a 0.1-5V reverse DC bias to the ohmic electrode 5 and the Schottky electrode 6, the depletion layer width of the metal of the metasurface optical antenna layer 4 in the contact area with the doping layer 2 is increased, and the nano-tip signal strength of the metasurface optical antenna layer 4 is enhanced to achieve accurate detection of infrared signals.

[0047] It should be noted that the substrate can be a GaAs substrate or a Si substrate with a thickness of 200 to 500 μm; and when the substrate is a GaAs substrate, the doped layer is an N-type GaAs layer or a P-type GaAs layer; when the substrate is a Si substrate, the doped layer is an N-type Si layer or a P-type Si layer. When the doped layer is N-type, a pentavalent impurity element phosphorus (P) can be selected as a dopant; when the doped layer is P-type, a trivalent impurity element boron (B) can be selected as a dopant; specifically, in this embodiment, the thickness of the doped layer is 1 μm to 2 μm, and the doping concentration of the dopant is 1×10 16 cm -3 ~9×10 18 cm -3 Furthermore, the materials of the ohmic electrode are nickel, germanium and gold, with thicknesses of 25nm, 250nm and 25nm respectively; the materials of the Schottky electrode are titanium and gold, with thicknesses of 20nm and 200nm respectively; the materials of the ordinary electrode are titanium and gold, with thicknesses of 20nm and 200nm respectively.

[0048] Embodiment 2,

[0049] A method for preparing an ultra-wide spectrum infrared signal detector according to Embodiment 1 of the present invention comprises the following steps:

[0050] S1, doping ions are implanted into substrate 1 by metal organic chemical vapor deposition, with a doping concentration of 1×10 16 cm -3 ~9×10 18 cm -3, thereby forming a doping layer 2, the thickness of which is 1um to 2um; in this embodiment, the substrate 1 is a GaAs substrate, and the doping layer 2 is an N-type GaAs layer;

[0051] S2, preparing a silicon dioxide layer 3 on the doping layer 2 by plasma enhanced chemical vapor deposition, wherein the silicon dioxide layer 3 has a thickness of 100 to 300 nm;

[0052] S3, photolithography of an ohmic electrode contact hole pattern on the silicon dioxide layer 3 by a positive resist process, and etching the silicon dioxide layer at the position of the ohmic electrode contact hole pattern by a wet etching process (the etching depth in this embodiment is the thickness of the silicon dioxide layer) to obtain an ohmic electrode contact hole; photolithography of an ohmic electrode pattern by a negative resist process, and sequentially evaporation of stacked Ni / Ge / Au layers (whose thicknesses are 20-80nm / 100-300nm / 20-80nm, respectively) by electron beam evaporation, stripping off excess metal and photoresist, and annealing the alloy to form an ohmic electrode 5 in ohmic contact with the doped layer 2 at the ohmic electrode contact hole;

[0053] S4, photolithography of a Schottky contact hole pattern on the silicon dioxide layer by a positive photoresist process, and etching the silicon dioxide layer at the position of the Schottky contact hole pattern by a wet etching process (the etching depth in this embodiment is greater than the thickness of the silicon dioxide layer), to form a Schottky contact hole;

[0054] S5, photolithography of Schottky electrode patterns and common electrode patterns on the silicon dioxide layer 3 by negative resist process, sequentially evaporating stacked Ti / Au layers (thicknesses of which are 100-250 nm / 20-80 nm, respectively) by electron beam evaporation, and removing excess metal and photoresist to form Schottky electrodes 6 and common electrodes 7, respectively;

[0055] S6. Prepare a metal nanotip array with a width of 0.5 to 5 mm on the silicon dioxide layer 3 and form a Schottky contact with the doping layer through the Schottky contact hole to form a supersurface optical antenna layer. Specifically, first, for the metal nanotip array with a planar structure, an electron beam exposure method is used to photolithography a planar pattern composed of each metal nanotip on the metal nanotip array on the silicon dioxide layer 3, wherein the width of the metal nanotip is 20 to 80 nm, the height is 80 to 300 nm, and the sharp angle is 10 to 60 degrees; and the silicon dioxide layer is etched by inductively coupled plasma etching or reactive ion etching using the pattern as a mask; for the metal nanotip array with a three-dimensional structure, after a polygonal mask is generated on the silicon dioxide layer by electron beam exposure, a three-dimensional structure composed of each metal nanotip on the metal nanotip array is generated by inductively coupled ion beam etching; wherein the three-dimensional structure is a right prism structure, and the number of its edges N is ≥ 6; the sharp angle formed by the intersection of the reverse extension lines of each edge is 10 to 40 degrees; the side length of the lower bottom surface is 30 to 200 nm, the side length of the upper bottom surface is 10 to 100 nm, and the oblique height is 80 to 300 nm. Then, the stacked Ti / Au layers are evaporated in sequence by electron beam evaporation or magnetron sputtering coating to obtain a metal nanotip array with a width of 0.5 to 5 mm, which forms Schottky contact with the doped layer through Schottky contact holes, thereby forming a supersurface optical antenna layer.

[0056] Furthermore, when the metal nanotip array is a planar micro-nano structure, the method for preparing the ultra-wide spectrum infrared signal detector further includes: step S7, located between the above steps S4 and S5;

[0057] Step S7 includes: using ultraviolet photolithography to photoetch a pattern composed of each micron element on the metal nanotip array on the silicon dioxide layer, and using electron beam evaporation to form each micron element in contact with the doped layer Schottky at the Schottky contact hole.

[0058] It should be noted that the above-mentioned ohmic electrode contact hole pattern, Schottky electrode pattern, ordinary electrode pattern, plane pattern composed of each metal nanotip on the metal nanotip array, pattern composed of each micron element on the metal nanotip array and their relative position relationship are all pre-set, and specific reference can be made to the detailed description of the ultra-wide spectrum infrared signal detector in Example 1.

[0059] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An ultra-wide spectrum infrared signal detector based on a metasurface optical antenna, characterized in that: include: Substrate, doping layer, silicon dioxide layer, metasurface optical antenna layer, ohmic electrode, Schottky electrode and ordinary electrode; The doping layer is located on the upper surface of the substrate; The silicon dioxide layer is located on the upper surface of the doped layer; the metasurface optical antenna layer and the ohmic electrode are both made on the doped layer, the metasurface optical antenna layer forms a Schottky contact with the doped layer, the internal gap is filled by the silicon dioxide layer, and the ohmic electrode forms an ohmic contact with the doped layer; the Schottky electrode and the ordinary electrode are both located on the upper surface of the silicon dioxide layer, and are both connected to the metasurface optical antenna layer; The metasurface optical antenna layer is composed of a metal nanotip array with a width of 0.5 to 5 mm, which has localized surface plasmon characteristics for incident infrared electromagnetic waves and is used to detect infrared signals with a wavelength of 1 to 70 μm; the metal nanotip array is a metal layer with a periodic nanotip structure; wherein the nanotip structure is a nanoscale pointed structure composed of metal nanotips; When the metal nanotip is parallel to the doping layer, the metal nanotip array is a planar structure, the metal nanotip is a planar metal nanotip, the planar metal nanotip has a width of 20 to 80 nm, a height of 80 to 300 nm, and a tip angle of 10 to 60 degrees; When the metal nanotips are perpendicular to the doping layer, the metal nanotips array is a three-dimensional structure, the metal nanotips are upright metal nanotips, and the upright metal nanotips are upright prism structures, the number of edges N of which is ≥6; the angle of the sharp angle formed by the intersection of the reverse extension lines of each edge is 10 to 40 degrees; the side length of the lower bottom surface is 30 to 200 nm, the side length of the upper bottom surface is 10 to 100 nm, and the oblique height is 80 to 300 nm.

2. The ultra-wide spectrum infrared signal detector according to claim 1, characterized in that: The metal nanotip array comprises a plurality of identical metal nanotip units; the metal nanotip units are composed of the metal nanotips.

3. The ultra-wide spectrum infrared signal detector according to claim 2, characterized in that: When the metal nanotip array is a planar structure, the metal nanotip array also includes a plurality of identical micron elements; the micron element is a micron structure with a polygonal shape; the metal nanotip units are distributed on the outside or inside of each edge of the micron element, together forming a micro-nano structure.

4. The ultra-wide spectrum infrared signal detector according to any one of claims 1 to 3, characterized in that: The periods and numbers of the metal nanotip units in the metal nanotip array and the geometric parameters of the metal nanotips are different, the sharpness and nanotip electron concentration of the nanotips in the metasurface optical antenna layer are different, and the nanotip signal strength is also different.

5. The ultra-wide spectrum infrared signal detector according to any one of claims 1 to 3, characterized in that: By applying a voltage with a load resistor to the Schottky electrode and the common electrode, or applying a voltage with a load resistor to the Schottky electrode and the common electrode, the nanotip electron concentration and signal strength are enhanced, thereby realizing the detection of infrared signals.

6. The ultra-wide spectrum infrared signal detector according to any one of claims 1 to 3, characterized in that: The materials of the metal nanotip are titanium and gold.

7. The method for preparing the ultra-wide spectrum infrared signal detector according to claim 1, characterized in that: The following steps are involved: S1, implanting doping ions on the substrate by metal organic compound chemical vapor deposition to form a doping layer; S2, preparing a silicon dioxide layer on the doped layer by plasma enhanced chemical vapor deposition; S3, photolithography an ohmic electrode contact hole pattern on the silicon dioxide layer by a positive photoresist process, and etching the silicon dioxide layer at the position of the ohmic electrode contact hole pattern to obtain an ohmic electrode contact hole; The ohmic electrode pattern is photolithographically formed by a negative resist process, and the stacked Ni / Ge / Au layers are sequentially evaporated by an electron beam evaporation method, and the excess metal and photoresist are removed by stripping, and the ohmic electrode in ohmic contact with the doped layer is formed at the ohmic electrode contact hole after annealing the alloy; S4, photolithography a Schottky contact hole pattern on the silicon dioxide layer by a positive photoresist process, and etching the silicon dioxide layer at the position of the Schottky contact hole pattern to obtain a Schottky contact hole; S5, photolithography of Schottky electrode patterns and common electrode patterns on the silicon dioxide layer by negative resist process, sequentially evaporating the stacked Ti / Au layers by electron beam evaporation, and stripping off excess metal and photoresist to form Schottky electrodes and common electrodes respectively; S6. Preparing a metal nanotip array with a width of 0.5 to 5 mm on the silicon dioxide layer and forming a Schottky contact with the doping layer through a Schottky contact hole to form a metasurface optical antenna layer; specifically comprising: For a metal nanotip array with a planar structure, an electron beam exposure method is used to photolithography a planar pattern composed of metal nanotips on the metal nanotip array on a silicon dioxide layer, wherein the width of the metal nanotips is 20 to 80 nm, the height is 80 to 300 nm, and the sharp angle is 10 to 60 degrees; and the silicon dioxide layer is etched by inductively coupled plasma etching or reactive ion etching using the pattern as a mask; for a metal nanotip array with a three-dimensional structure, a polygonal mask is generated on the silicon dioxide layer by electron beam exposure, and then a three-dimensional structure composed of metal nanotips on the metal nanotip array is generated by inductively coupled ion beam etching; the three-dimensional structure is a vertical prism structure, and the number of its edges N is ≥ 6; the sharp angle formed by the intersection of the reverse extension lines of each edge is 10 to 40 degrees; the side length of the lower bottom surface is 30 to 200 nm, the side length of the upper bottom surface is 10 to 100 nm, and the oblique height is 80 to 300 nm; Then, the stacked Ti / Au layers are evaporated in sequence by electron beam evaporation or magnetron sputtering coating to obtain a metal nanotip array with a width of 0.5 to 5 mm, which forms Schottky contact with the doped layer through Schottky contact holes, thereby forming a supersurface optical antenna layer.

8. The method for preparing the ultra-wide spectrum infrared signal detector according to claim 7, characterized in that: When the metal nanotip array is a planar micro-nano structure, it also includes step S7, which is located between steps S4 and S5; The step S7 includes: using ultraviolet photolithography to etch a pattern composed of each micron element on the metal nanotip array on the silicon dioxide layer, and using electron beam evaporation to form each micron element in contact with the doped layer Schottky at the Schottky contact hole.

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