Ion irradiation based superconducting thin film and device thermal performance regulation method
By introducing vacancy defects into superconducting thin films and devices through ion irradiation technology, the limitations of thermal performance control in existing technologies have been overcome, enabling precise performance optimization of superconducting devices and improving their sensitivity and stability.
Patent Information
- Application Number
- CN202510159807.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-13
- Publication Date
- 2025-11-21
- Estimated Expiration
- 2045-02-13
AI Technical Summary
Existing technologies make it difficult to adjust the thermal properties after the superconducting thin films and their devices have been processed, and the control precision is limited, which cannot meet the needs of complex applications.
Ion irradiation technology was used, and the ion type, incident energy, incident angle and ion implantation dose were determined by simulation using SRIM software. Ion implantation equipment was used to process superconducting thin films and devices to introduce vacancy defects to change their thermal conductivity and microstructure.
This technology enables precise control of the thermal properties of superconducting thin films and devices without altering the chemical composition of the materials, thereby improving the sensitivity, response speed, and operational stability of the devices and providing a new path for performance optimization.
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Figure CN120187269B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of superconducting devices, and particularly relates to a superconducting thin film based on ion irradiation and a method for regulating the thermal performance of a superconducting device. BACKGROUND
[0002] Superconducting thin films and their devices play a crucial role in cutting-edge scientific fields such as high-sensitivity detection and sensing, quantum computing, and astronomical observation. In particular, superconducting single-photon detectors (SNSPDs) prepared based on ultra-thin film technology utilize the extremely high response sensitivity of superconducting materials to photons in a low-temperature environment, enabling precise detection of individual photons. This characteristic enables SNSPDs to exhibit outstanding performance in applications such as quantum communication, quantum technology, laser ranging, and biological fluorescence spectrum detection, making them indispensable key devices in related fields.
[0003] However, despite the significant advantages of superconducting thin films and their devices in terms of performance, effectively regulating their thermal performance remains a major technical challenge in current research. The regulation of thermal performance has a decisive impact on the sensitivity, response speed, and operational stability of superconducting devices. Taking SNSPDs as an example, their core working mechanism relies on the formation and stable expansion of hot spots in superconducting nanowires after absorbing photons, and the formation of hot spots is closely related to the thermal diffusion capacity of nanowire materials and substrates. Specifically, the thermal conduction efficiency between the nanowire and the substrate directly affects the relaxation time of the hot spot, and thus the sensitivity and detection wavelength range of the detector. Therefore, by regulating the thermal performance of the material, such as reducing the thermal conduction capacity between the nanowire and the substrate interface, the hot spot relaxation time can be prolonged, thereby improving the performance of the detector.
[0004] Currently, the main methods for regulating the thermal performance of superconducting thin films and their devices include selecting high-thermal-conductivity substrate materials (such as sapphire), optimizing the preparation process of the thin film (such as adjusting the thickness and geometric structure), and regulating the microstructure of the material (such as the grain state) during preparation. However, these traditional methods have certain limitations. First, they often rely on material selection and preparation process optimization, but once the device is manufactured, it is difficult to further adjust or optimize the thermal performance of the device, i.e., it is difficult to perform post-processing adjustment after the device is processed; second, the precision of thermal performance regulation by these methods is limited, which cannot meet the increasingly complex application requirements. In particular, under the premise of not changing the chemical composition of the material, how to achieve precise regulation of the thermal performance remains a technical bottleneck that needs to be solved.
[0005] Therefore, it is necessary to develop a method for accurately regulating the thermal performance of superconducting thin films and their devices, especially to achieve post-processing optimization without changing the chemical composition of the material, which has important scientific significance and application value. SUMMARY
[0006] In view of the above-mentioned disadvantages of the prior art, the purpose of the present application is to provide a method for regulating the thermal performance of superconducting thin films and devices based on ion irradiation, so as to solve the problem that the regulation method in the prior art is difficult to adjust after the device processing is completed, and the regulation precision of the thermal performance of superconducting thin films and devices is limited.
[0007] To achieve the above-mentioned purpose and other related purposes, the present application provides a method for regulating the thermal performance of superconducting thin films and devices based on ion irradiation, which comprises the following steps:
[0008] S1. Providing a substrate and growing a superconducting thin film on the substrate;
[0009] S2. Preparing a superconducting device with a micron or nanometer level line width structure;
[0010] S3. Using SRIM software to respectively simulate ion implantation of the superconducting thin film and the superconducting device, and determining the ion type, incident energy, incident angle and ion implantation dose;
[0011] S4. According to the determined ion type, incident energy, incident angle and ion implantation dose, using ion implantation equipment to respectively perform ion irradiation treatment on the superconducting thin film and the superconducting device;
[0012] S5. Testing the thermal performance of the superconducting thin film and the superconducting device after ion irradiation treatment, so as to determine the regulation effect of the ion irradiation treatment on the superconducting thin film and the superconducting device.
[0013] Preferably, in step S1, a magnetron sputtering method is used to grow a superconducting thin film on the substrate.
[0014] Preferably, in step S1, the substrate comprises one of a DBR substrate, a sapphire substrate, a silicon wafer substrate and a magnesium oxide substrate.
[0015] Preferably, in step S1, the material of the superconducting thin film comprises one of NbN, NbTiN, WSi or MoGe.
[0016] Preferably, in step S2, the preparation method of the superconducting device with a micron or nanometer level line width structure comprises the following steps:
[0017] Coating photoresist on the superconducting thin film;
[0018] Using electron beam exposure to transfer a pattern to the photoresist, after development and fixing treatment, etching and removing the excess photoresist to form a micron or nanometer level line width structure.
[0019] Preferably, the step of preparing the superconducting device further comprises forming an electrode structure, and the manufacturing process of the electrode structure comprises the following steps:
[0020] Preparation of a mask for the electrode pattern;
[0021] Coating a photoresist on the thin film of the micro- or nano-scale line width structure, transferring the electrode pattern on the mask to the photoresist by ultraviolet exposure, and forming the electrode pattern after developing, fixing and etching.
[0022] Preferably, the superconducting device prepared in step S2 is a superconducting nanowire single-photon detector.
[0023] Preferably, the ion type in step S4 comprises one of helium ions, nitrogen ions and argon ions.
[0024] Preferably, the incident energy in step S4 is 15 keV to 45 keV.
[0025] Preferably, the incident angle in step S4 is 0° to 40°.
[0026] Preferably, the ion implantation dose in step S4 is 1×10 14 to 1×10 17 ions / cm 2 .
[0027] Preferably, before the ion irradiation treatment in step S4, a protective layer is deposited on the superconducting thin film and the superconducting device to improve the irradiation resistance of the superconducting thin film and the superconducting device; wherein the material of the protective layer is AlN, and the thickness of the protective layer is 1 to 3 nm.
[0028] Preferably, the thermal properties of the superconducting thin film in step S5 include electron inelastic scattering rate, and the thermal properties of the superconducting device include boundary thermal conductivity and two-photon thermal relaxation time.
[0029] As described above, the ion irradiation-based method for adjusting the thermal properties of a superconducting thin film and a device thereof has the following beneficial effects:
[0030] The application determines the ion type, incident energy, incident angle and ion implantation dose during ion irradiation through SRIM simulation, and performs ion irradiation treatment on the superconducting thin film and superconducting device through the ion implantation equipment. In the ion irradiation process, by controlling the ion type, incident energy, incident angle, ion implantation dose and implantation time, vacancies are introduced into the superconducting thin film and superconducting device, so as to change the thermal conductivity and microstructure, change the inelastic scattering rate of the superconducting thin film, and change the boundary thermal conductivity and two-photon thermal relaxation time of the superconducting device. The thermal performance regulation method in the application can accurately regulate the thermal performance of the superconducting thin film or superconducting device without changing the chemical composition of the material, and even after the device is processed, the regulation method in the application can still be used for post-processing optimization, so that the sensitivity, response speed and working stability of the superconducting device can be accurately regulated, which has important scientific significance and application value. The thermal performance regulation method in the application not only provides a new technical path for improving the performance of the superconducting device, but also promotes its wider application in the fields of quantum technology and high-sensitivity detection. BRIEF DESCRIPTION OF DRAWINGS
[0031] Figure 1 A process flow diagram of the thermal performance regulation process of the superconducting thin film and device based on ion irradiation of the application is shown.
[0032] Figure 2 A conceptual diagram showing that the ion irradiation in the specific embodiment of the application acts on the superconducting thin film.
[0033] Figure 3a A distribution diagram of He ions obtained in the SRIM simulation in the specific embodiment 1 of the application is shown. + , N + , Ar + ) at different energies bombarding the NbN superconducting thin film.
[0034] Figure 3b A distribution diagram of He ions obtained in the SRIM simulation in the specific embodiment 1 of the application is shown. +
[0035] Figure 3c A change of He ion distribution concentration under different ion implantation doses in the SRIM simulation in the specific embodiment 2 of the application is shown. +
[0036] Figure 3d A change of DPA under the action of He ions under different ion implantation doses in the SRIM simulation in the specific embodiment 2 of the application is shown. +
[0037] Figure 4a A change of DPA under the action of He ions under different ion implantation doses in the SRIM simulation in the specific embodiment 2 of the application is shown.+ Effect of ions on the number of defects in NbN superconducting thin films at different incident energies.
[0038] Figure 4b shows the change of the electron inelastic scattering rate of the superconducting thin film before and after ion irradiation in Example 1 of the present invention. + Effect of ions on the number of defects in NbN superconducting thin films at different incident angles.
[0039] Figure 5 shows the change of the electron inelastic scattering rate of the superconducting thin film before and after ion irradiation in Example 1 of the present invention.
[0040] Figure 6a shows the change of the boundary thermal conductivity of the superconducting device before and after ion irradiation treatment in Example 2 of the present invention.
[0041] Figure 6b shows the change of the two-photon thermal relaxation time of the superconducting device before and after ion irradiation treatment in Example 2 of the present invention.
[0042] Element number explanation
[0043] 1 Si substrate
[0044] 2 Ta2O5 / SiO2layer
[0045] 31 Ta2O5layer
[0046] 32 SiO2layer
[0047] 4 NbN thin film
[0048] 5 vacancy defect DETAILED DESCRIPTION
[0049] The present application now will be described by way of specific examples which are intended to be illustrative only and not limiting of the application. Other advantages and benefits of the present application will become apparent to those skilled in the art upon reading and understanding the following detailed description and accompanying drawings. The present application may be practiced in other specific ways which will be apparent to those skilled in the art upon reading and understanding the following detailed description and accompanying drawings.
[0050] Before further description of the application, it should be understood that the application will be described in relation to a specific embodiment thereof and that changes can be made in carry out the application in other embodiments which will be apparent to those skilled in the art from the description hereinafter without departing from the spirit of the application. The terms used in the specific examples which follow are to be construed to cover specific embodiments and are not to be construed as limiting the scope of the application. Unless otherwise indicated, the procedures in the following examples were carried out in accordance with conventional procedures or as recommended by the manufacturer.
[0051] When the embodiments give numerical ranges, it is understood that every numerical range is a continuum of values and that only discrete values are selected from the continuum by the endpoints of the range. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. Except in the Examples, or where otherwise explicitly indicated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present application, exemplary methods and materials are described below. Other features, objects, and advantages of the application will be apparent from the description of the preferred embodiments and from the claims.
[0052] Referring to Figure 1 The present application provides a method for controlling the thermal properties of superconducting thin films and devices based on ion irradiation, which comprises the following steps:
[0053] S1, providing a substrate and growing a superconducting thin film on the substrate;
[0054] S2, preparing a superconducting device with a micron or nanometer level line width structure;
[0055] S3, using SRIM software to simulate ion implantation of the superconducting thin film and the superconducting device respectively, and determining the ion type, incident energy, incident angle and ion implantation dose;
[0056] S4, using ion implantation equipment to perform ion irradiation treatment on the superconducting thin film and the superconducting device respectively according to the ion type, incident energy, incident angle and ion implantation dose determined in step S3;
[0057] S5, testing the thermal properties of the superconducting thin film and the superconducting device after ion irradiation treatment to determine the control effect of the ion irradiation treatment on the superconducting thin film and the superconducting device.
[0058] Specifically, the equipment used in the method for controlling the thermal properties includes a data processing module, ion implantation equipment and a testing device. The data processing module is used to analyze the simulation results of the SRIM software and set the irradiation parameters. The ion implantation equipment includes ion implanters with different energies or different beam currents, which are used to perform ion irradiation treatment on the superconducting thin film and the superconducting device. The testing device is used to measure the thermal properties of the superconducting thin film and the superconducting device. The PPMS (comprehensive physical property testing) system is used to measure the magnetic resistance of the superconducting thin film to obtain the inelastic scattering time of the thin film. The self-made current-voltage testing device is used to measure the I-V curve of the superconducting device at different temperatures to obtain the boundary thermal conductivity of the superconducting device. The double-photon detection platform device is used to measure the double-photon thermal relaxation time of the superconducting device.
[0059] First, step S1 is performed to provide a substrate and grow a superconducting thin film on the substrate.
[0060] As an example, the superconducting thin film is grown on the substrate by using a magnetron sputtering method in step S1.
[0061] Specifically, when the superconducting thin film is prepared by using the magnetron sputtering method, the thickness, crystal structure of the superconducting thin film, and the substrate temperature, sputtering power, and gas pressure and other parameters have a significant influence on the superconducting performance of the grown superconducting thin film. By optimizing the process parameters, a high-quality superconducting thin film can be prepared, which has a high critical current density and low resistance; preferably, the thickness of the superconducting thin film is 7 nm to 12 nm, and the crystal structure thereof is mainly polycrystalline.
[0062] As an example, the substrate in step S1 includes one of a DBR substrate, a sapphire substrate, a silicon wafer substrate, and a magnesium oxide substrate.
[0063] As an example, the material of the superconducting thin film in step S1 includes one of NbN, NbTiN, WSi, or MoGe.
[0064] Specifically, the superconducting critical temperature (Tc) of NbN (niobium nitride) is usually around 15.6 K, which makes it exhibit excellent superconducting performance in a low-temperature environment; the zero-resistance critical temperature (Tc) of WSi (tungsten-silicon compound) is usually between 3.8 K and 5 K, and the specific temperature depends on the thickness of the thin film, the silicon content, and the preparation process, but is not excessively limited in the specific embodiments of the present application; MoGe (molybdenum-germanium alloy) has a relatively high superconducting transition temperature (Tc) that can reach 7 K.
[0065] In specific embodiments, before growing the superconducting thin film, a DBR layer is also formed on the substrate, and the DBR layer includes a plurality of stacked Ta2O5 / SiO2 layers 2, wherein each Ta2O5 / SiO2 layer 2 includes a Ta2O5 layer 31 and a SiO2 layer 32, and preferably, the DBR layer includes 13 stacked Ta2O5 / SiO2 layers 2, and the Ta2O5 / SiO2 layers 2 are used to improve the absorption of the superconducting thin film to 1550 nm light; during ion irradiation, by controlling the ion type, incident energy, incident angle, ion implantation dose, and implantation time, vacancy defects 5 are introduced into the superconducting thin film, so as to change its thermal conductivity and microstructure.
[0066] Then step S2 is performed to prepare a superconducting device with a micron or nanometer level line width structure.
[0067] Specifically, the superconducting device is manufactured on the basis of step S1, and as an example, the preparation method of the superconducting device with a micron or nanometer level line width structure in step S2 includes the following steps:
[0068] S21, coating a photoresist on the superconducting thin film;
[0069] S22, the pattern is transferred to the photoresist by electron beam exposure, and after development and fixing treatment, the excess photoresist is etched and removed, forming a micron or nanometer level line width structure.
[0070] Specifically, the thickness of the photoresist needs to be determined according to the device design requirements, and after coating the photoresist, pre-baking is performed, and then the pattern is transferred to the photoresist using electron beam exposure; after exposure, post-baking is performed, and after development, fixing and cleaning, etching is performed, wherein the etching includes reactive ion etching or ion beam etching, the superconducting thin film not protected by the photoresist is etched away, forming the required micron or nanometer level line width structure. In the method for preparing a superconducting device in the specific embodiment of the application, the exposure dose, development time and etching parameters need to be optimized, which will not be limited here.
[0071] As an example, the step of preparing a superconducting device further includes step S23, forming an electrode structure, and the manufacturing process of the electrode structure includes the following steps:
[0072] S231, preparing a mask for the electrode pattern
[0073] S232, coating photoresist on the thin film forming the micron or nanometer level line width structure, transferring the electrode pattern on the mask to the photoresist by ultraviolet exposure, and forming the electrode pattern after development, fixing and etching treatment.
[0074] As an example, the superconducting device prepared in step S2 is a superconducting nanowire single photon detector (SNSPD).
[0075] Specifically, the SNSPD is based on the characteristics of superconducting materials. When a photon is absorbed by a superconducting nanowire, its energy will destroy the local superconducting state, forming a "hot spot" and causing the resistance of the nanowire to increase instantaneously. This change in resistance will trigger a measurable electrical signal, thereby enabling single photon detection.
[0076] Then, step S3 is performed, and SRIM software is used to simulate ion implantation of the superconducting thin film and the superconducting device respectively, to determine the ion type, incident energy, incident angle and ion implantation dose.
[0077] Specifically, the ion type depends on the characteristics of the target material; the incident energy determines the penetration depth of the ion in the material, when using the SRIM software to simulate ion irradiation, input the ion type and target material, the software will calculate the ion range under different incident energies, and then select the appropriate energy according to the needs; the incident angle can be selected according to the experimental design, preferably 0°, i.e. perpendicular incidence; the ion implantation dose refers to the number of ions implanted per unit area, in SRIM, after setting the ion type, incident energy and target material, running the simulation can obtain the ion implantation dose distribution and ion distribution peak concentration; according to the simulation results, the ion type, incident energy, incident angle and ion implantation dose can be adjusted, and the simulation is run again, and after multiple simulations, the ion type, incident energy, incident angle and ion implantation dose are determined.
[0078] Then, step S4 is performed, and the superconducting thin film and the superconducting device are respectively subjected to ion irradiation treatment by using an ion implantation device according to the ion type, the incident energy, the incident angle and the ion implantation dose determined in step S3.
[0079] Specifically, referring to Figure 2 For the conceptual diagram of the ion irradiation acting on the superconducting device, the superconducting device includes a DBR high-reflection substrate, the DBR high-reflection substrate includes a Si substrate 1 (silicon wafer substrate) and a NbN thin film 4 with a nanoscale line width structure, and a DBR layer is further formed between the two, the DBR layer includes a plurality of stacked Ta2O5 / SiO2 layers 2, wherein each Ta2O5 / SiO2 layer 2 includes a Ta2O5 layer 31 and a SiO2 layer 32, preferably, the DBR layer includes 13 layers of stacked Ta2O5 / SiO2 layers 2, and the Ta2O5 / SiO2 layer 2 is used to improve the absorption of the NbN thin film 4 to 1550 nm light; in the ion implantation process, by controlling the ion type, the incident energy, the incident angle, the ion implantation dose and the implantation time, vacancy defects 5 are introduced into the superconducting device, so as to change its thermal conductivity and microstructure.
[0080] As an example, the ion type in step S4 includes one of helium ions, nitrogen ions and argon ions.
[0081] As an example, the incident energy in step S4 is 15 keV-45 keV. Specifically, the incident energy can include 15 keV, 20 keV, 25 keV, 30 keV, 35 keV, 40 keV, 45 keV, etc.
[0082] As an example, the incident angle in step S4 is 0°-40°. Specifically, the incident angle can include 0°, 1°, 5°, 10°, 20°, 30°, 35°, 40°, etc.
[0083] As an example, the ion implantation dose in step S4 is 1×10 14~1x10 17 ions / cm 2 Specifically, the ion implantation dose can include 1x10 14 ions / cm 2 , 5x10 14 ions / cm 2 , 1x10 15 ions / cm 2 , 1x10 16 ions / cm 2 , 2x10 16 ions / cm 2 , 5x10 16 ions / cm 2 , 8x10 16 ions / cm 2 , 1x10 17 ions / cm 2 , etc.
[0084] As an example, before the ion irradiation treatment in step S4, a protective layer is deposited on the superconducting thin film and the superconducting device to improve the irradiation resistance of the superconducting thin film and the superconducting device; wherein the material of the protective layer is AlN (aluminum nitride), and the thickness of the protective layer is 1-3 nm. Specifically, the AlN protective layer is deposited by a magnetron sputtering method, and the thickness of the protective layer can include any value within the range of 1 nm, 1.5 nm, 2 nm, 2.5 nm, 3 nm, etc.
[0085] Finally, step S5 is performed to test the thermal properties of the superconducting thin film and the superconducting device after the ion irradiation treatment, so as to determine the regulation effect of the ion irradiation treatment on the superconducting thin film and the superconducting device.
[0086] As an example, the thermal properties of the superconducting thin film in step S5 include electron inelastic scattering rate; and the thermal properties of the superconducting device include low-temperature boundary thermal conductivity and two-photon thermal relaxation time.
[0087] Specifically, the electron inelastic scattering rate is the rate of energy loss of electrons when they interact with lattice vibrations (phonons) or other electrons in a material. By measuring the electron inelastic scattering rate, the thermal conductivity, electrical conductivity and superconducting properties of the material can be obtained.
[0088] In order to better understand the ion irradiation-based superconducting thin film and its device thermal property regulation method in the present application, the ion irradiation-based superconducting thin film and its device thermal property regulation method in the present application will be described below with reference to specific embodiments. It should be noted that these embodiments are merely descriptive and do not limit the present application in any way.
[0089] Embodiment 1
[0090] The embodiment provides an ion irradiation-based superconducting thin film thermal performance regulation method, which comprises the following steps:
[0091] A1, refer to Figure 2 , a DBR high-contrast substrate is provided, which comprises, from bottom to top, a Si substrate, 12 layers of Ta2O5 / SiO2 layers, a Ta2O5 layer and a SiO2 layer, and then a NbN superconducting thin film with a thickness of 7 nm is grown on the substrate by using a magnetron sputtering method;
[0092] A2, SRIM software is used to simulate ion implantation of the NbN superconducting thin film, helium ions (He + ) are selected as irradiation ions, and the ion type, incident energy, incident angle and ion implantation dose are determined;
[0093] A3, an ion implantation device is used to perform ion irradiation treatment on the NbN superconducting thin film;
[0094] A4, the electronic inelastic scattering rate of the NbN superconducting thin film after ion irradiation treatment is tested by using a PPMS system.
[0095] refer to Figure 3a , the influence of different ions (He + , N + , Ar + ) on the peak position of the implanted ion distribution when the NbN superconducting thin film is bombarded at different energies, as the incident energy increases, the peak position of the implanted ion distribution is deeper, refer to Figure 3b , helium ions (He + ) are used as irradiation ions, the incident energy is set to 30 KeV, the ion implantation dose is 8×10 16 ions / cm 2 , and the distribution diagram of He + ions obtained when simulation is performed, and the calculated implanted ion distribution peak depth is about 304 nm.
[0096] refer to Figure 4a , helium ions (He + ) are used as irradiation ions, the incident angle is 0°, and the ion implantation dose is 8×10 16 ions / cm 2 , the influence of He + ions on the defect number of the NbN superconducting thin film under different incident energies, as can be seen from the figure, as the ion implantation dose increases, more He +The number of defects caused by the ions entering the substrate to the superconducting thin film first decreases and then tends to be stable, the sputtering ion number reflects the etching effect of the ions on the thin film, the greater the sputtering ion number, the more obvious the etching, in order to affect the number of defects of the thin film and the sputtering ion number, the incident energy of 15-45 keV can be selected.
[0097] Referring to Figure 4b He ions (He + ) are used as irradiation ions, the incident energy is 30 KeV, and the ion implantation dose is 8*10 16 ions / cm 2 , the influence of He + ions on the number of defects of the NbN superconducting thin film at different incident angles, the sputtering ion number and the number of defects increase with the increase of the incident angle, when a certain threshold (50°) is reached, the influence of sputtering increases sharply, and the damage to the superconducting thin film is obvious, and the incident angle of 0-40° is more appropriate.
[0098] Referring to Figure 5 The electron inelastic scattering rate of the superconducting thin film before and after ion irradiation in this embodiment changes, the irradiated superconducting thin film may be due to the vacancy defects introduced by irradiation, which affects the electron-phonon interaction time of the superconducting thin film, thereby affecting the inelastic scattering time of the thin film, and the electron inelastic scattering rate of the irradiated superconducting thin film is about 10% more than that before irradiation.
[0099] Embodiment 2
[0100] The embodiment provides a method for controlling the thermal performance of a superconducting device based on ion irradiation, which is different from embodiment 1 in that the object of the thermal performance control in the embodiment is a superconducting device, which is prepared on the basis of embodiment 1, and the final measurement is the boundary thermal conductivity and thermal relaxation time of the superconducting device after ion irradiation treatment, and other methods are the same as in embodiment 1 and will not be repeated here.
[0101] Referring to Figure 3c He ions (He + ) are used as irradiation ions, the He + ion distribution concentration changes under different ion implantation doses, Figure 3d DPA changes under the action of He + ions under different ion implantation doses, DPA represents the number of times that each atom is hit by a particle and leaves the original position under a given irradiation dose; according to the simulation results, due to the influence of the cumulative effect, the lattice in the target material may be locally or globally disordered with the increase of the ion implantation dose, and the lattice is more easily affected by ion implantation due to the accumulation of defects and displacement, therefore, with the increase of the ion implantation dose, the DPA caused by the ions also increases.
[0102] Referring to Figure 6a For the change of the boundary thermal conductance of the superconducting device before and after ion irradiation treatment in the embodiment, it can be seen that the boundary thermal conductance of the superconducting device after ion irradiation treatment is significantly reduced, and the ion implantation dose in the range of 0-9x10 16 ions / cm 2 has an approximate linear trend of monotonous decrease on the boundary thermal conductance, and exceeds the high range to show a saturated trend, which shows that the boundary thermal conductance of the thin film or the device can be regulated by controlling ion implantation.
[0103] Referring to Figure 6b For the change of the two-photon thermal relaxation time of the superconducting device before and after ion irradiation treatment in the embodiment, the two-photon thermal relaxation time of the superconducting device is 18ps before ion irradiation treatment, and the two-photon thermal relaxation time of the superconducting device is 24ps after ion irradiation treatment, and the two-photon thermal relaxation time of the superconducting device after ion irradiation treatment is increased by about 1 / 3.
[0104] In summary, the type of ions, the incident energy, the incident angle and the ion implantation dose during ion irradiation are determined by SRIM simulation, the superconducting thin film and the superconducting device are treated by ion irradiation by the ion implantation equipment, in the ion irradiation process, by controlling the type of ions, the incident energy, the incident angle, the ion implantation dose and the implantation time, vacancies are introduced in the superconducting thin film and the superconducting device, so as to change the thermal conductivity and the microstructure, so as to change the inelastic scattering rate of the superconducting thin film, the boundary thermal conductance and the two-photon thermal relaxation time of the superconducting device; the thermal performance regulation method in the embodiment can accurately regulate the thermal performance of the superconducting thin film or the superconducting device without changing the chemical composition of the material, even after the device is processed, the regulation method in the embodiment can still be used for post-processing optimization, so that the sensitivity, response speed and working stability of the superconducting device can be accurately regulated, which has important scientific significance and application value; the thermal performance regulation method in the embodiment not only provides a new technical path for improving the performance of the superconducting device, but also promotes its wider application in the fields of quantum technology and high-sensitivity detection. Therefore, the present application effectively overcomes the shortcomings of the prior art and has high industrial utilization value.
[0105] The above embodiments only exemplarily illustrate the principles and effects of the present application, and are not used to limit the present application. Any person skilled in the art can modify or change the above embodiments without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or changes completed by those skilled in the art without departing from the spirit and technical thought disclosed by the present application should be covered by the claims of the present application.
Claims
1. A method for thermal performance regulation based on ion irradiation, characterized in that, The method is used for superconducting thin film and its device, comprising the following steps: S1, providing a substrate and growing a superconducting thin film on the substrate; the substrate comprises a distributed Bragg reflector (DBR) substrate, and the DBR substrate comprises a Si substrate and a plurality of Ta2O5 / SiO2 layers stacked on the Si substrate; S2, preparing a superconducting device with a micron or nanometer level line width structure; S3, using SRIM software to respectively simulate ion implantation of the superconducting thin film and the superconducting device, and determining ion type, incident energy, incident angle and ion implantation dose; S4, according to the determined ion type, incident energy, incident angle and ion implantation dose, using an ion implantation device to respectively perform ion irradiation treatment on the superconducting thin film and the superconducting device; S5, testing thermal properties of the superconducting thin film and the superconducting device after ion irradiation treatment, so as to determine the regulation effect of the ion irradiation treatment on the superconducting thin film and the superconducting device; the thermal properties of the superconducting thin film in step S5 include electron inelastic scattering rate; the thermal properties of the superconducting device include boundary thermal conductivity and two-photon thermal relaxation time.
2. The ion irradiation based thermal property modulation method of claim 1, wherein: In step S1, the superconducting thin film is grown on the substrate by using a magnetron sputtering method.
3. The ion irradiation based thermal property modulation method of claim 1, wherein: In step S1, the material of the superconducting thin film comprises one of NbN, NbTiN, WSi or MoGe.
4. The ion irradiation based thermal property modulation method of claim 1, wherein: In step S2, the preparation method of the superconducting device with a micron or nanometer level line width structure comprises the following steps: coating photoresist on the superconducting thin film; using electron beam exposure to transfer a pattern to the photoresist, after development and fixing treatment, etching and removing excess photoresist to form a micron or nanometer level line width structure.
5. The ion irradiation based thermal property modulation method of claim 4, wherein: In the step of preparing the superconducting device, an electrode structure is further formed, and the manufacturing process of the electrode structure comprises the following steps: preparing a mask for an electrode pattern; coating photoresist on the thin film forming the micron or nanometer level line width structure, transferring the electrode pattern on the mask to the photoresist by ultraviolet exposure, and forming an electrode pattern after development, fixing and etching treatment.
6. The ion irradiation based thermal property modulation method of claim 1, wherein: The superconducting device prepared in step S2 is a superconducting nanowire single-photon detector.
7. The ion irradiation based thermal property modulation method of claim 1, wherein: In step S4, one or a combination of the following conditions is included: the ion type comprises one of helium ion, nitrogen ion and argon ion; the incident energy is 15 keV to 45 keV; the incident angle is 0° to 40°; The ion implantation dose is 1 x 10 14 ~1 x 10 17 ions / cm 2 .
8. The ion irradiation based thermal property modulation method of claim 1, wherein: Before the ion irradiation treatment in step S4, a protective layer needs to be deposited on the superconducting thin film and the superconducting device to improve the irradiation resistance of the superconducting thin film and the superconducting device; wherein the material of the protective layer is AlN, and the thickness of the protective layer is 1 to 3 nm.