CN112577613B - Bowknot antenna coupled terahertz detector and preparation method thereof - Google Patents
Bowknot antenna coupled terahertz detector and preparation method thereof Download PDFInfo
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J5/00—Radiation pyrometry, e.g. infrared or optical thermometry
- G01J5/10—Radiation pyrometry, e.g. infrared or optical thermometry using electric radiation detectors
- G01J5/20—Radiation pyrometry, e.g. infrared or optical thermometry using electric radiation detectors using resistors, thermistors or semiconductors sensitive to radiation, e.g. photoconductive devices
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y40/00—Manufacture or treatment of nanostructures
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q1/00—Details of, or arrangements associated with, antennas
- H01Q1/12—Supports; Mounting means
- H01Q1/22—Supports; Mounting means by structural association with other equipment or articles
- H01Q1/2283—Supports; Mounting means by structural association with other equipment or articles mounted in or on the surface of a semiconductor substrate as a chip-type antenna or integrated with other components into an IC package
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q1/00—Details of, or arrangements associated with, antennas
- H01Q1/36—Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewith
- H01Q1/38—Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewith formed by a conductive layer on an insulating support
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q1/00—Details of, or arrangements associated with, antennas
- H01Q1/44—Details of, or arrangements associated with, antennas using equipment having another main function to serve additionally as an antenna, e.g. means for giving an antenna an aesthetic aspect
Abstract
The invention provides a bowtie antenna coupled terahertz detector, which comprises: the silicon substrate, the silicon dioxide supporting layer, the six-nitrogen five-niobium thin film heat-sensitive layer and the electrode layer are grown on the silicon substrate, the six-nitrogen five-niobium thin film heat-sensitive layer is grown on the silicon dioxide supporting layer to form a six-nitrogen five-niobium nano bridge structure, the electrode layer is also used as a coupling antenna and comprises two groups of electrodes and a bow-tie antenna, the electrodes and the bow-tie antenna are located on the six-nitrogen five-niobium thin film heat-sensitive layer, the tail end of the bow-tie antenna is connected with one group of electrodes respectively, and the tip end of the bow-tie antenna is directly connected with two ends of the six-nitrogen five-niobium nano bridge. The size of the thermosensitive film detection unit is below one hundred nanometers, the size of the contact part of the thermosensitive film detection unit and the tip of the antenna is also below one hundred nanometers, the heat conduction of the device is reduced to a limit level through the contact connection shape design of the antenna and the quinqueniobium hexanitride film, and the sensitivity and the response speed of the device are obviously improved.
Description
Technical Field
The invention relates to the technical field of terahertz detection, in particular to a bowtie antenna coupled terahertz detector and a preparation method thereof.
Background
The terahertz wave is electromagnetic wave with frequency range of 0.1THz to 10THz, and is between microwave and infrared, and its wave band can cover the characteristic spectrum of semiconductor, plasma, organism and biomacromolecule, so that it can obtain rich biological and material information by using THz wave. In addition, the terahertz wave has the characteristics of low quantum energy and small absorption of THz waves by a plurality of non-metal nonpolar materials, so that the THz technology can be widely applied to the fields of radar, remote sensing, homeland security and anti-terrorism, atmosphere and environment monitoring, medical diagnosis and the like. However, due to the lack of efficient terahertz radiation sources, detectors and functional devices, terahertz spectrum resources are not fully developed and utilized, and therefore, the research on efficient terahertz radiation sources and detection technologies is of great importance.
At present, the radiation power of a terahertz light source is generally low, so that the development of a terahertz detector with high sensitivity and high signal-to-noise ratio is extremely important. Because terahertz energy is low and the reception of terahertz signals is easily affected by environmental noise, the traditional high-sensitivity terahertz detector usually needs to work at a low temperature, and has a complex structure, a large volume and high manufacturing cost, so that the development of a terahertz detector capable of working at room temperature becomes a research hotspot of a terahertz detection technology.
Common terahertz detectors capable of working at room temperature mainly include microbolometers, pyroelectric detectors, kohlai detectors and the like, wherein the microbolometers have attracted wide attention due to the advantages of simple structure, low cost, easy compatibility with silicon-based integrated circuits, capability of preparing multi-pixel array devices and the like. However, the response speed is slow, about tens of milliseconds, which is not favorable for high-speed imaging and communication, and the sensitivity of the terahertz detector is lower than that of a terahertz detector working at low temperature and still needs to be greatly improved.
Microbolometers belong to thermosensitive devices and work by converting limited power absorbed from the outside into effective heat energy, so that the conversion efficiency is an important factor for determining the performance of the device. Through searching the existing documents, the existing research is mostly considered from the aspect of electromagnetic field, namely starting from the antenna coupling efficiency, the energy of the antenna coupled to the thermosensitive unit is improved, and the sensitivity of the device is further improvedAnd response speed. The dipole antenna and the bow-tie antenna both have stronger electromagnetic coupling capacity, but because the input impedance of the bow-tie antenna is smaller than that of a plane dipole antenna, the integral impedance matching of devices is difficult to meet (the input impedance of the terahertz detector is usually larger than 1k ohm), and therefore the dipole antenna is mostly adopted in the terahertz detector. For example, Tu Xue-Cou et al published on Chinese Physics B under the name Nb5N6A microbolometer array for terahertz detection, wherein a room temperature hexa-N-penta-Nb terahertz detector comprises a silicon substrate, a silicon dioxide layer, a gold electrode layer and a hexa-N-penta-Nb film heat-sensitive layer, an antenna used in the article is a gold film planar dipole antenna, a prepared microbridge has three dimensions of 3 Mum x 3 Mum, 3 Mum x 6 Mum and 3 Mum x 12 Mum, the maximum optical voltage response rate of 580V/W is achieved at 0.28THz, and the corresponding NEP is
Compared with some normal-temperature terahertz detectors reported previously, the terahertz detector is improved. However, simulation shows that the size of the end of a planar dipole antenna working in a terahertz waveband is generally about 10 micrometers, when a thermosensitive unit is connected with the antenna, the contact area is large, heat energy converted by electromagnetic coupling can be quickly dissipated through the dipole antenna, that is, heat energy coupled from the outside cannot be fully utilized. Therefore, there is still room for improvement in the sensitivity of the detector.
Disclosure of Invention
The invention aims to provide a bowtie antenna coupled terahertz detector and a preparation method thereof.
The technical solution for realizing the purpose of the invention is as follows: a terahertz detector coupled with a bowtie antenna comprises a silicon substrate, a silicon dioxide supporting layer, a six-nitrogen five-niobium film heat-sensitive layer and an electrode layer, wherein the silicon dioxide supporting layer grows on the silicon substrate, the six-nitrogen five-niobium film heat-sensitive layer grows on the silicon dioxide supporting layer to form a six-nitrogen five-niobium nano bridge structure, the electrode layer is also used as a coupling antenna and comprises two groups of electrodes and bowtie antennas, the two groups of electrodes and the bowtie antennas are located on the six-nitrogen five-niobium film heat-sensitive layer, the tail ends of the bowtie antennas are connected with one group of electrodes respectively, and the tips of the bowtie antennas are directly connected with two ends of the six-nitrogen five-niobium nano bridge.
Furthermore, the size of the hexa-nitrogen penta-niobium nano bridge is in a nano level, the length is controlled to be 30-80 nm, and the width is controlled to be 30-80 nm.
Furthermore, the six-nitrogen five-niobium nano bridge adopts a suspended structure and is realized by forming an air cavity through photoetching and etching the silicon dioxide supporting layer and the silicon substrate.
Furthermore, the bowtie antenna is connected with the hexaazapentaniobium nanobridge in a triangular tip contact connection mode, the width of the triangular tip contact connection mode is determined by the width of the hexaazapentaniobium nanobridge, and the length of the triangular tip contact connection mode is determined by the resonance length of the antenna.
Further, each set of electrodes includes one or two square electrodes.
The preparation method of the bowtie antenna coupled terahertz detector comprises the following steps:
step 4, drawing a pattern of the antenna tip through electron beam exposure and alignment, then growing a layer of gold film, and connecting the antenna tip and the antenna tail end together after stripping;
and 6, drawing windows at two ends of the niobium hexa-nitride nanobridge by photoetching, and etching away the silicon dioxide supporting layer and the silicon substrate in the area where the windows are located by means of reactive ion etching to form the niobium hexa-nitride nanobridge suspended structure.
Further, the method for growing the gold film in the step 2 is magnetron sputtering or electron beam evaporation, and the method for growing the gold film in the step 4 is electron beam evaporation.
Furthermore, positive electron beam glue is adopted for drawing the nano-bridge pattern in the step 5, and the exposure pattern is the nano-bridge complementary pattern.
Compared with the prior art, the invention has the following remarkable advantages: 1) compared with a dipole antenna, the bow-tie antenna has a tip with a smaller size, can realize a smaller contact area with a heat-sensitive unit of the detector, and reduces heat loss; 2) the size of the thermosensitive film detection unit is below one hundred nanometers, so that the heat capacity of the device is greatly reduced, the response time of the device is greatly shortened, and high-speed imaging and communication are possible; 3) compared with the structure reported before, the size of the contact part of the thermosensitive film detection unit and the antenna tip is less than one hundred nanometers, so that the thermal conductivity of the device is reduced to a limit level, the sensitivity of the device is obviously improved, and the device can efficiently detect low-energy terahertz signals at room temperature.
Drawings
FIG. 1 is a schematic diagram of a cross-section and overall plan structure of a detector.
FIG. 2 is a schematic structural diagram of a bowtie antenna tip and a hexaazapentaniobium thin film nanobridge.
Fig. 3 is a diagram of the input impedance and port transmission characteristics of a bowtie antenna.
Fig. 4 is a schematic diagram of a bow-tie antenna coupled terahertz detector.
Fig. 5 is a simulation diagram of temperature distribution of different sizes of hexa-n-penta-niobium bridges and antennas connected with different contacts. (a) The temperature distribution simulation graph is that a micron-sized six-nitrogen five-niobium thin-film heat-sensitive bridge and an antenna are connected through square contacts, (b) the temperature distribution simulation graph is that a nanometer-sized six-nitrogen five-niobium thin-film heat-sensitive bridge and an antenna are connected through square contacts, and (c) the temperature distribution simulation graph is that a nanometer-sized six-nitrogen five-niobium thin-film heat-sensitive bridge and a bowtie antenna are connected through triangular tip contacts.
FIG. 6 is a graph showing the temperature of the center point of the thermal sensitive unit as a function of time during the thermal simulation of the device. (a) The graph is a graph of the temperature of the center points of the thermosensitive units of the micron-scale thermosensitive unit and the dipole antenna structure device changing with time, and the graph (b) is a graph of the temperature of the center points of the thermosensitive units of the nanoscale thermosensitive unit and the bowtie antenna structure device changing with time.
FIG. 7 is a flow chart of the process for fabricating the detector.
Fig. 8 is a design layout required for preparing a hexaazapentaniobium nanobridge by an electron beam exposure process.
FIG. 9 is an SEM image of a 30nm gap obtained after stripping by electron beam evaporation of long gold.
Fig. 10 is an SEM image of the etched hexaazapentaniobium nanobridge.
The reference numbers in the drawings: 1 is a square gold electrode, 2 is a bow tie antenna, 3 is a hexaazapentaniobium thin film nanobridge, 4 is an air cavity, 5 is a square contact connection, and 6 is a triangular tip contact connection.
Detailed Description
In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.
The invention provides a bowtie antenna coupling terahertz detector with a nanometer tip, which reduces the heat capacity and heat conduction of a device and improves the sensitivity and response speed of the device by a nanometer-sized hexaazapentaniobium thin-film heat-sensitive unit and a mode of directly connecting with the bowtie antenna tip.
As shown in fig. 1-2, the bow-tie antenna coupled terahertz detector mainly consists of four parts: the silicon substrate, a silicon dioxide supporting layer, a hexa-nitrogen penta-niobium film heat-sensitive layer and a gold electrode layer. Wherein: a silicon dioxide support layer is grown on a silicon substrate. The six-nitrogen five-niobium film heat-sensitive layer grows on the silicon dioxide supporting layer, and a six-nitrogen five-niobium nano bridge 3 is formed through an electron beam exposure system. The gold electrode layer is also used as a coupling antenna and comprises four square electrodes 1 and a bowtie antenna 2 which are positioned on the six-nitrogen-five-niobium film heat-sensitive layer. The square electrodes 1 are connected with the tail ends of the bowtie antennas 2 in pairs respectively, and the tips of the bowtie antennas 2 are directly connected with the hexaazapentaniobium nanometer bridge 3.
As an alternative embodiment, two square electrodes 1 may be used, each connected to one end of the bow-tie antenna 2. Other shapes of electrodes may also be used.
As a preferred embodiment, the hexaazapentaniobium nanobridge 3 adopts a suspended structure, and is realized by forming an air cavity 4 through photoetching, etching and the like of a silicon dioxide support layer and a silicon substrate.
As a preferred embodiment, the size of the niobium pentaniobate hexanitrogen nanobridge 3 is in the nanometer level, the length is controlled to be 30-80 nm, and the width is controlled to be 30-80 nm.
In a preferred embodiment, the bow-tie antenna 2 is connected with the hexaazapentaniobium nanobridge 3 by a triangular tip contact connection 6, the width of the triangular tip contact connection 6 is determined by the width of the hexaazapentaniobium nanobridge 3, and the length is determined by the resonance length of the antenna. The impedance of the impedance matching circuit can reach more than 1k ohm through the auxiliary design of simulation software, and the impedance matching is realized. As shown in FIG. 3, the left graph is the input impedance characteristic of the bowtie antenna, the right graph is the port transmission characteristic, the input impedance of the antenna reaches the maximum resonance value of 1.3k ohm at 0.65THz, and the reflection coefficient S is11Up to-22 dB.
The working principle of the bowtie antenna coupling terahertz detector is shown in fig. 4, when a terahertz signal is incident, the planar bowtie antenna 2 couples the signal to the hexaazapentaniobium film nano-bridge 3 to cause temperature change, the resistance value of the hexaazapentaniobium film nano-bridge 3 is changed due to the thermosensitive characteristic of the hexaazapentaniobium film, and the change of the electrical property can be detected through the electrode and transmitted to the reading circuit by applying constant bias current, so that the detection of the terahertz signal is realized.
In order to further explain the influence of the size of the six-nitrogen five-niobium film heat-sensitive bridge 3 and the contact connection shape mode of the antenna on the heat conduction and the sensitivity of the device, the invention carries out temperature distribution simulation on six-nitrogen five-niobium film heat-sensitive bridges with different sizes and terahertz detectors adopting different contact connection modes, and except that the size of the six-nitrogen five-niobium film heat-sensitive bridge and the contact connection shape of the six-nitrogen five-niobium film heat-sensitive bridge and the antenna are different, other external conditions are the same. The simulation results are shown in fig. 5, wherein (a) is a graph showing a simulation of temperature distribution of a micron-sized hexaazapentaniobium thin film thermal bridge through an electrode and antenna square contact connection 5, (b) is a graph showing a simulation of temperature distribution of a nanometer-sized hexaazapentaniobium thin film thermal bridge and antenna through a square contact connection 5, and (c) is a graph showing a simulation of temperature distribution of a nanometer-sized hexaazapentaniobium thin film thermal bridge and bow-tie antenna through a triangular tip contact connection 6.
In the figure, the temperature at the center of the bridge is 305K (a), 309.5K (b), 313K (c), respectively. As can be seen by comparing the two figures (a) and (b), the same connection shape (via the electrode and antenna square contact connection 5) but the size of the hexaazapentaniobium thin film thermal bridge is different, (b) the small size of the hexaazapentaniobium thin film thermal bridge in the figure is less thermally conductive; comparing the two figures (b) and (c), it can be seen that the same size of the hexa-nitrogen-penta-niobium nano-bridge is obtained, but the contact connection shapes are different, and the thermal conductivity of the figure (c) adopting the triangular tip contact connection 6 mode is smaller, so that the thermal conductivity of the device can be greatly reduced by adopting the structure of the nano-sized hexa-nitrogen-penta-niobium film thermal-sensitive bridge and the triangular tip contact connection 6 of the bowknot antenna, thereby improving the sensitivity and the voltage response rate of the device.
We calculate the device thermal conductance by simplifying the model using the following formula:
wherein A is the cross-sectional area of the material, l is the length of the material, k is the thermal conductivity of the material, and since the gold antennas are arranged at both ends of the niobium-nitride-oxide nano bridge, the thermal conductivity between the device and the metal antenna can be obtained by the following formula:
Gantenna with a shield＝2kAntenna with a shieldwAntenna with a shieldtAntenna with a shield/lAntenna with a shield
Suppose kAntenna with a shield＝317w/(mk)，wAntenna with a shield50nm (the width of the antenna and the nanobridge contact),tantenna with a shield100nm (thickness of antenna), lAntenna with a shieldBased on the above calculation formula, G can be obtained at 12 μm (length of antenna)Antenna with a shield≈2.64×10-7W/K is reduced by one order of magnitude compared with the thermal conductivity of the borometer reported previously (Optics Express 26,15585 and 15593(2018)), so that the voltage responsivity and the sensitivity of the device can be improved by one order of magnitude.
In addition, the invention greatly shortens the response time of the device. The size of the thermosensitive unit of the detector is reduced to be less than one hundred nanometers, thermal simulation is carried out on the device, the simulation result of the temperature of the central point of the thermosensitive unit changing along with time is shown in figure 6, wherein the time required for reaching thermal balance corresponds to the response time of the device. (a) The diagram shows a micron-sized thermal cell and dipole antenna structure, referred to in Nb5N6 microbolometer arrays for terahertz detection, by Tu Xue-Cou et al, which takes about 15.3 μ s to reach thermal equilibrium; (b) the diagram shows a nanoscale thermal element and bow-tie antenna structure of the present invention that takes only 75ns to reach thermal equilibrium. The comparison shows that the invention reduces the thermal conductance of the device, improves the sensitivity and greatly shortens the response time of the device.
The preparation method of the bowtie antenna coupling terahertz detector is shown in fig. 7 and mainly comprises the following micro-nano processing steps:
And 2, putting the prepared substrate into a magnetron sputtering system, and firstly carrying out ion milling in a secondary chamber to remove surface molecular level impurities and enable the film and the substrate to be combined more easily, wherein the specific ion milling conditions are shown in table 1.
Table 1: ion milling conditions
| Gas species | Flow of gas | Working air pressure | Ion beam current | Time of cleaning |
| Ar | 10sccm | 300V | 30mA | 1min |
And 3, conveying the substrate subjected to ion milling into a main chamber of a magnetron sputtering system, and growing a hexaazapentaniobium film by radio frequency sputtering, wherein the specific conditions are shown in Table 2.
Table 2: conditions for growing hexa-nitrogen-penta-niobium film by radio frequency sputtering
And 4, spin-coating LOR10B and AZ1500 double-layer glue on the sample with the grown hexaazapentaniobium film to facilitate later-stage stripping, wherein the specific spin-coating conditions are shown in Table 3. And drying, exposing the dried sample by using an ultraviolet exposure machine, drawing the terminal graphs of the electrode and the antenna, developing by using an orthofilm developing solution for 17s, fixing by using deionized water for 30s, and drying the residual moisture on the surface by using a nitrogen gun.
Table 3: photoresist spin coating conditions
And 5, synchronously performing step 2, putting the sample into a magnetron sputtering system for ion milling, and then growing the gold film by adopting direct current sputtering, wherein the specific conditions are shown in Table 4.
Table 4: conditions for growing gold film by DC sputtering
| Target material | Gas species | Flow of gas | Sputtering gas pressure | Sputtering power | Time of sputtering |
| Gold (Au) | Ar | 100sccm | 4mTorr | 80w | 100s |
And 6, taking out the sample, soaking the sample in an acetone solution for 2-3 minutes, performing low-power ultrasonic treatment for 1-2 minutes, soaking the sample in an orthofilm developing solution for 1 minute, and performing low-power ultrasonic treatment with alcohol and water for 1 minute to complete stripping of the gold electrode.
And 7, synchronously performing step 4, spin-coating AZ1500 and drying, exposing the dried sample in an ultraviolet exposure machine, preliminarily drawing a six-nitrogen five-niobium micro-bridge pattern, developing and fixing, then etching in an RIE etching machine to preliminarily form a six-nitrogen five-niobium micro-bridge structure, wherein the used process gas is SF6, and the specific etching parameters are shown in Table 5.
Table 5: reactive ion etching conditions
| Etching material | Reaction gas | Flow of gas | Etching pressure intensity | Etching power | Etching time |
| Nb5N6 | SF6 | 40sccm | 4Pa | 100w | 90s |
| SiO2 | CF4/ |
30/10sccm | 4Pa | 150w | 4min |
| Si | SF6 | 40sccm | 8Pa | 70w | 9min |
And 8, spin-coating a layer of PMMA A4 electron beam glue on the etched sample, wherein the specific conditions are shown in Table 3. And (3) placing the dried sample in a RAITH EBPG5200 electron beam exposure system for exposure, drawing a pattern of the antenna tip by alignment, developing for 90s in a MIBK IPA 1:3 solution, fixing for 60s in an IPA solution, washing with deionized water, and drying by using a nitrogen gun.
And 9, placing the sample in an electron beam evaporation system to grow the gold film, wherein the tip of the antenna has smaller size, and the gap between the antennas is smaller, so that the method can be used for facilitating subsequent stripping.
And step 10, taking out the sample, heating the sample in a N-methyl pyrrolidone solution in a water bath at the temperature of 80 ℃ for more than 1 hour, performing low-power ultrasound for 1 to 2 minutes, performing low-power ultrasound for 2 to 3 minutes respectively by using acetone, alcohol and water, blow-drying the sample by using a nitrogen gun, and observing the stripping effect under an SEM (scanning electron microscope). FIG. 9 shows the SEM effect after stripping with this method, the edge is smooth and the gap is only 30 nm.
And step 12, placing the sample in an RIE etching machine for etching, wherein the process parameters are the same as those in step 7. And soaking the etched sample in N-methyl pyrrolidone solution for 1-2 minutes to remove the photoresist. The photoresist removed sample can be observed for etching effect by SEM, and FIG. 10 is SEM picture of etched hexaazapentaniobium nanobridge.
Step 13, spin-coating a layer of AZ4620 photoresist on the sample, wherein the specific conditions are shown in Table 3, then drying, placing the sample in an ultraviolet exposure machine for exposure after drying, developing in a positive photoresist developer for 2min, fixing in deionized water for 30s, drying by using a nitrogen gun, then placing the sample in RIE for etching, firstly etching off the silicon oxide layer at the window, then etching the silicon substrate below the window until the silicon substrate below the hexanitropentaniobium nanobridge is etched through to form an air cavity, and the specific etching parameters are shown in Table 5.
And step 14, soaking the etched sample in acetone, alcohol and water respectively to remove the photoresist, wherein the whole process cannot be carried out by ultrasonic waves, and the etched sample is taken out of the water and then is naturally dried, so that a nitrogen gun cannot be used.
In summary, the invention considers that the energy coupled to the heat-sensitive unit by the antenna affects the heat conversion efficiency, and also considers the heat conduction generated by the heat-sensitive unit after being heated and the gold electrode connected with the heat-sensitive unit, thereby improving the performance of the device in terms of heat transfer.
The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.
Claims (4)
1. Bowtie antenna coupled terahertz detector, its characterized in that includes: the silicon dioxide supporting layer grows on the silicon substrate, the six-nitrogen five-niobium thin film heat-sensitive layer grows on the silicon dioxide supporting layer to form a six-nitrogen five-niobium nano-bridge structure, the electrode layer is also used as a coupling antenna and comprises two groups of electrodes and a bow-tie antenna, the electrodes are positioned on the six-nitrogen five-niobium thin film heat-sensitive layer, the tail ends of the bow-tie antenna are respectively connected with one group of electrodes, and the tip ends of the bow-tie antenna are directly connected with two ends of the six-nitrogen five-niobium nano-bridge;
the size of the niobium pentaniobate hexanitrogen nano bridge is in a nano level, the length is controlled to be 30-80 nm, and the width is controlled to be 30-80 nm; the bowtie antenna is connected with the hexaazapentaniobium nano-bridge in a triangular tip contact connection mode, the width of the triangular tip contact connection is determined by the width of the hexaazapentaniobium nano-bridge, and the length of the triangular tip contact connection is determined by the resonance length of the antenna;
the preparation method of the bowtie antenna coupled terahertz detector comprises the following steps:
step 1, growing a hexa-nitrogen penta-niobium film thermosensitive layer on a silicon dioxide supporting layer through magnetron sputtering;
step 2, drawing the patterns of the electrode and the tail end of the antenna on the six-nitrogen-five-niobium thin film heat-sensitive layer by photoetching, and then growing a layer of gold thin film;
step 3, preliminarily drawing a hexaazapentaniobium microbridge graph by photoetching, and forming a hexaazapentaniobium microbridge in a reactive ion etching mode;
step 4, drawing a pattern of the antenna tip through electron beam exposure and alignment, then growing a layer of gold film, and connecting the antenna tip and the antenna tail end together after stripping;
step 5, drawing a nano bridge graph through electron beam exposure and alignment, and forming the hexaazapentaniobium nano bridge in a reactive ion etching mode;
drawing windows at two ends of the niobium hexa-nitride nanobridge by photoetching, and etching away the silicon dioxide supporting layer and the silicon substrate in the area where the windows are located by means of reactive ion etching to form a niobium hexa-nitride nanobridge suspended structure;
the nano bridge graph is drawn in the step 5 by adopting positive electron beam glue, and the exposure graph is the nano bridge complementary graph.
2. The bow-tie antenna coupled terahertz detector of claim 1, wherein the hexaazapentaniobium nanobridge is in a suspended structure, and is realized by forming an air cavity through photoetching and etching a silicon dioxide supporting layer and a silicon substrate.
3. The bow-tie antenna coupled terahertz detector of claim 1, wherein each set of electrodes comprises one or two square electrodes.
4. The bow-tie antenna coupled terahertz detector as claimed in claim 1, wherein the method for growing the gold film in step 2 is magnetron sputtering or electron beam evaporation, and the method for growing the gold film in step 4 is electron beam evaporation.
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| CN103855228A (en) * | 2014-02-21 | 2014-06-11 | 上海大学 | Terahertz detector based on optical antenna |
| CN110006534A (en) * | 2019-04-11 | 2019-07-12 | 南京大学 | A kind of preparation method of the micro-nano bolometer for Terahertz detection |
| CN111682096A (en) * | 2020-05-12 | 2020-09-18 | 中国科学院上海微系统与信息技术研究所 | Preparation method of planar superconducting nano bridge junction |
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| DE102006027983A1 (en) * | 2005-09-02 | 2007-03-22 | Terstappen, André Hans | Butterfly antenna with amplifier for digital video broadcast reception by mobile devices, includes conductive bridging strips making electrical connection between wings |
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