Superconducting thin film based on ion irradiation and device thermal performance regulation and control method thereof

Abstract

The invention provides an ion irradiation-based superconducting thin film and a thermal property regulation and control method of a device thereof, which comprises the following steps of: S1, providing a substrate, and growing a superconducting thin film on the substrate; s2, preparing a superconducting device with a micron-scale or nano-scale line width structure; s3, performing ion implantation analog simulation on the superconducting thin film and the superconducting device by adopting SRIM software, and determining an ion type, incident energy, an incident angle and an ion implantation dose; s4, according to the data determined in the previous step, performing ion irradiation treatment on the superconducting thin film and the superconducting device by adopting ion injection equipment; and S5, testing the thermal properties of the superconducting thin film and the superconducting device after the ion radiation treatment. The thermal properties of the superconducting thin film and the device thereof can be accurately regulated and controlled without changing the chemical components of the material, the post-processing optimization can be realized, the sensitivity, the response speed and the working stability of the superconducting device can be accurately regulated and controlled, and the method has important scientific significance and application value.

Description

Technical Field

[0001] The present invention belongs to the technical field of superconducting devices, and particularly relates to a method for regulating the thermal performance of a superconducting thin film and its device based on ion irradiation. Background Art

[0002] Superconducting thin films and their devices play a crucial role in frontier scientific and technological 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 can achieve precise detection of single photons by utilizing the extremely high response sensitivity of superconducting materials to photons in a low-temperature environment. This property enables SNSPDs to exhibit excellent performance in applications such as quantum communication, quantum technology, laser ranging, and biological fluorescence spectroscopy detection, and has become an indispensable key device in related fields.

[0003] However, although superconducting thin films and their devices have significant performance advantages, how to effectively regulate 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 working stability of superconducting devices. Taking SNSPD as an example, its core working mechanism depends 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 ability of the nanowire material and the substrate. Specifically, the heat conduction efficiency between the nanowire and the substrate directly affects the relaxation time of the hot spot, and thus affects the sensitivity and detection wavelength range of the detector. Therefore, by regulating the thermal performance of the material, such as reducing the heat conduction ability between the nanowire and the substrate interface, the relaxation time of the hot spot can be extended, 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 a substrate material with high thermal conductivity (such as sapphire), optimizing the film preparation process (such as adjusting the thickness and geometric structure), and regulating the microstructure of the material (such as the grain state) during the preparation process. However, these traditional methods have certain limitations. First, they often rely on the selection of materials and the optimization of the preparation process. However, once the device is manufactured, it is difficult to further adjust or optimize the thermal performance of the device, that is, it is difficult to perform post-processing adjustment after the device is processed. Second, the regulation accuracy of these methods for thermal performance is limited and cannot meet the increasingly complex application requirements. In particular, how to achieve precise regulation of thermal performance without changing the chemical composition of the material remains an urgent technical bottleneck to be solved.

[0005] Therefore, it is necessary to develop a method that can precisely regulate 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 of the Invention

[0006] In view of the disadvantages of the prior art described above, the purpose of the present invention is to provide a method for regulating the thermal properties of superconducting thin films and their devices based on ion irradiation, which is used to solve the problems that the existing regulation methods are difficult to perform post-processing adjustment after the device processing is completed, and the regulation accuracy of the thermal properties of superconducting thin films and their devices is limited.

[0007] To achieve the above and other related purposes, the present invention provides a method for regulating the thermal properties of superconducting thin films and their devices based on ion irradiation. The regulation method includes the following steps:

[0008] S1. Provide a substrate and grow a superconducting thin film on the substrate;

[0009] S2. Fabricate a superconducting device with a micron or nanometer linewidth structure;

[0010] S3. Use SRIM software to perform ion implantation simulation and simulation on the superconducting thin film and the superconducting device respectively to determine 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, use an ion implantation device to perform ion irradiation treatment on the superconducting thin film and the superconducting device respectively;

[0012] S5. Test the thermal properties of the superconducting thin film and the superconducting device after ion radiation treatment to determine the regulation effect of the ion radiation treatment on the superconducting thin film and the superconducting device.

[0013] Preferably, in step S1, a superconducting thin film is grown on the substrate by magnetron sputtering.

[0014] Preferably, in step S1, the substrate includes 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 includes one of NbN, NbTiN, WSi, or MoGe.

[0016] Preferably, the method for fabricating a superconducting device with a micron or nanometer linewidth structure in step S2 includes the following steps:

[0017] Coat a photoresist on the superconducting thin film;

[0018] Use electron beam exposure to transfer the pattern to the photoresist. After development and fixing, etch and remove the excess photoresist to form a micron or nanometer linewidth structure.

[0019] Preferably, forming an electrode structure is further included in the steps of fabricating the superconducting device, and the fabrication process of the electrode structure includes the following steps:

[0020] Preparing a mask for the electrode pattern;

[0021] Coating a photoresist on the film forming the micron or nanometer linewidth structure, transferring the electrode pattern on the mask to the photoresist through ultraviolet exposure, and forming the electrode pattern after development, fixing, and etching treatments.

[0022] Preferably, the superconducting device prepared in step S2 is a superconducting nanowire single photon detector.

[0023] Preferably, the ion type in step S4 includes 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 ~1×10 17 ions / cm 2 .

[0027] Preferably, before performing 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 tolerance 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 the electron inelastic scattering rate; the thermal properties of the superconducting device include the boundary thermal conductance and the two-photon thermal relaxation time.

[0029] As described above, the method for regulating the thermal properties of the superconducting thin film and its device based on ion irradiation of the present invention has the following beneficial effects:

[0030] The present invention determines the ion type, incident energy, incident angle, and ion implantation dose during ion irradiation through SRIM simulation, and performs ion irradiation treatment on superconducting thin films and superconducting devices through an ion implantation device. During the ion irradiation process, by controlling the ion type, incident energy, incident angle, ion implantation dose, and implantation time, vacancy defects are introduced into the superconducting thin films and superconducting devices, thereby changing their thermal conductivity and microstructure, thus changing the inelastic scattering rate of the superconducting thin films and the boundary thermal conductance and two-photon thermal relaxation time of the superconducting devices; the thermal property regulation method in the present invention can accurately regulate the thermal properties of superconducting thin films or superconducting devices without changing the chemical composition of the material. Even after the device processing is completed, the post-processing optimization can still be achieved through the regulation method in the present invention, enabling the sensitivity, response speed, and working stability of the superconducting device to be accurately regulated, which has important scientific significance and application value; the thermal property regulation method in the present invention can not only provide a new technical path for improving the performance of superconducting devices, but also promote their wider applications in fields such as quantum technology and high-sensitivity detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 Shown is a process flow diagram of the thermal property regulation technology of a superconducting thin film and its device based on ion irradiation according to the present invention.

[0032] Figure 2 Shown is a conceptual diagram of the ion irradiation acting on a superconducting thin film in a specific embodiment of the present invention.

[0033] Figure 3a Shown is when performing SRIM simulation in a specific embodiment 1 of the present invention, the influence of bombarding a NbN superconducting thin film with different ions (He + , N + , Ar + ) at different energies on the position of the implanted ion distribution peak.

[0034] Figure 3b Shown is when performing SRIM simulation in a specific embodiment 1 of the present invention, the obtained distribution schematic diagram of He + ions.

[0035] Figure 3c Shown is when performing SRIM simulation in a specific embodiment 2 of the present invention, the change in the He + ion distribution concentration under different ion implantation doses.

[0036] Figure 3d Shown is when performing SRIM simulation in a specific embodiment 2 of the present invention, the DPA change under different ion implantation doses under the action of He + ions.

[0037] Figure 4a Shown is He in a specific embodiment 1 of the present invention+ Effect of ions on the number of defects in NbN superconducting thin films at different incident energies.

[0038] Figure 4b Shown is He in Specific Embodiment 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 Shown is the change in the electron inelastic scattering rate of the superconducting thin film before and after ion irradiation in Specific Embodiment 1 of the present invention.

[0040] Figure 6a Shown is the change in the boundary thermal conductance of the superconducting device before and after ion irradiation treatment in Specific Embodiment 2 of the present invention.

[0041] Figure 6b Shown is the change in the two-photon thermal relaxation time of the superconducting device before and after ion irradiation treatment in Specific Embodiment 2 of the present invention.

[0042] Description of component labels

[0043] 1 Si substrate

[0044] 2 Ta2O5 / SiO2 layer

[0045] 31 Ta2O5 layer

[0046] 32 SiO2 layer

[0047] 4 NbN thin film

[0048] 5 Vacancy defect Detailed implementation manners

[0049] The following uses specific specific examples to illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0050] Before further describing the specific implementation manners of the present invention, it should be understood that the protection scope of the present invention is not limited to the specific specific implementation manners described below; it should also be understood that the terms used in the embodiments of the present invention are for the purpose of describing specific specific implementation manners, rather than for limiting the protection scope of the present invention. The test methods without specific conditions noted in the following embodiments are usually carried out under conventional conditions or according to the conditions recommended by each manufacturer.

[0051] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise specified in the present invention, both endpoints of each numerical range and any value between the two endpoints can be selected. Unless otherwise defined, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the technical field to which the present invention pertains. In addition to the specific methods, devices, and materials used in the embodiments, according to the knowledge of those skilled in the technical field and the description of the present invention, any methods, devices, and materials similar to or equivalent to the methods, devices, and materials described in the embodiments of the present invention can also be used to implement the present invention.

[0052] Referring to Figure 1 , the present invention provides a method for regulating the thermal properties of a superconducting thin film and its device based on ion irradiation. The regulation method includes the following steps:

[0053] S1. Provide a substrate and grow a superconducting thin film on the substrate;

[0054] S2. Fabricate a superconducting device with a micron- or nanometer-scale linewidth structure;

[0055] S3. Use SRIM software to perform ion implantation simulation on the superconducting thin film and the superconducting device respectively to determine the ion type, incident energy, incident angle, and ion implantation dose;

[0056] S4. According to the ion type, incident energy, incident angle, and ion implantation dose determined in step S3, use an ion implantation device to perform ion irradiation on the superconducting thin film and the superconducting device respectively;

[0057] S5. Test the thermal properties of the superconducting thin film and the superconducting device after ion irradiation to determine the regulation effect of the ion irradiation on the superconducting thin film and the superconducting device.

[0058] Specifically, the equipment used in this thermal property regulation method includes a data processing module, an ion implantation device, and a testing device. The data processing module is used to analyze the simulation results of SRIM software and set the irradiation parameters. The ion implantation device includes ion implanters with different energies or different beam currents and is used to perform ion irradiation 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 (Physical Property Measurement System) is used to measure the magnetoresistance of the superconducting thin film to obtain the inelastic scattering time of the thin film, a 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 conductance of the superconducting device, and a built double-photon detection platform device is used to measure the two-photon thermal relaxation time of the superconducting device.

[0059] First, execute step S1 to provide a substrate and grow a superconducting thin film on the substrate.

[0060] As an example, in step S1, a superconducting thin film is grown on a substrate by magnetron sputtering.

[0061] Specifically, when preparing a superconducting thin film by magnetron sputtering, parameters such as the thickness, crystal structure of the superconducting thin film, and the substrate temperature, sputtering power, and gas pressure all have a significant impact on the superconducting properties of the grown superconducting thin film. By optimizing the process parameters, a high-quality superconducting thin film can be prepared to have a high critical current density and low resistance; preferably, the thickness of the superconducting thin film is 7 nm to 12 nm, and its crystal structure is mainly polycrystalline.

[0062] As an example, in step S1, the substrate 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 enables it to exhibit excellent superconducting properties 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 it is not overly restricted in the specific embodiments of the present invention; MoGe (molybdenum germanium alloy) has a relatively high superconducting transition temperature (Tc) that can reach 7 K.

[0065] In a specific embodiment, before growing the superconducting thin film, a DBR layer needs to be pre-formed on the substrate. The DBR layer includes multiple stacked Ta2O5 / SiO2 layers 2. Among them, each Ta2O5 / SiO2 layer 2 includes a Ta2O5 layer 31 and a SiO2 layer 32. Preferably, the DBR layer includes a total of 13 stacked Ta2O5 / SiO2 layers 2. The Ta2O5 / SiO2 layer 2 is used to improve the absorption of the superconducting thin film for 1550-nm light; during the ion irradiation process, 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, thereby changing its thermal conductivity and microstructure.

[0066] Then step S2 is executed to fabricate a superconducting device with a micron or nanometer linewidth structure.

[0067] Specifically, based on step S1, the fabrication of the superconducting device is carried out. As an example, the preparation method of the superconducting device with a micron or nanometer linewidth structure in step S2 includes the following steps:

[0068] S21. Coat a photoresist on the superconducting thin film;

[0069] S22. Transfer the pattern onto the photoresist by electron beam lithography. After development and fixing processes, etch and remove the excess photoresist to form a micron- or nanometer-scale linewidth structure.

[0070] Specifically, the thickness of the photoresist needs to be determined according to the device design requirements. After coating the photoresist, pre-baking is required, and then the pattern is transferred onto the photoresist by electron beam lithography. Post-baking is carried out after exposure, followed by cleaning after development and fixing processes. Then, etching is performed, where the etching includes reactive ion etching or ion beam etching, and the superconducting thin film not protected by the photoresist is etched away to form the desired micron- or nanometer-scale linewidth structure. In the method for preparing superconducting devices in the specific embodiments of the present invention, the exposure dose, development time, etching parameters, etc. need to be optimized, which will not be restricted here too much.

[0071] As an example, step S23 of forming an electrode structure is further included in the steps of preparing the superconducting device. The manufacturing process of the electrode structure includes the following steps:

[0072] S231. Prepare a mask for the electrode pattern

[0073] S232. Coat the photoresist on the thin film with the formed micron- or nanometer-scale linewidth structure, and transfer the electrode pattern on the mask onto the photoresist by ultraviolet exposure. After development, fixing, and etching processes, an electrode pattern is formed.

[0074] As an example, the superconducting device prepared in step S2 is a superconducting nanowire single-photon detector (SNSPD).

[0075] Specifically, 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", resulting in an instant increase in the resistance of the nanowire. This resistance change will trigger a measurable electrical signal, thus realizing the detection of a single photon.

[0076] Then, step S3 is executed. Use SRIM software to perform ion implantation simulation and simulation on 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 ions in the material. When using SRIM software for ion irradiation simulation, by inputting the ion type and the target material, the software can calculate the ion range at different incident energies, and then select the appropriate energy as needed; the incident angle can be selected according to the experimental design, preferably 0°, that is, 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 the peak concentration of the ion distribution; 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. After multiple simulations, the ion type, incident energy, incident angle, and ion implantation dose are determined.

[0078] Then, step S4 is executed. According to the ion type, incident energy, incident angle, and ion implantation dose determined in step S3, an ion implantation device is used to perform ion irradiation treatment on the superconducting thin film and the superconducting device respectively.

[0079] Specifically, refer to Figure 2 FIG. is a conceptual diagram of the ion irradiation acting on the superconducting device. The superconducting device includes a DBR high-contrast substrate. The DBR high-contrast substrate includes a Si substrate 1 (silicon wafer substrate) and an NbN thin film 4 with a nanoscale line width structure, and a DBR layer is also formed therebetween. The DBR layer includes a plurality of stacked Ta2O5 / SiO2 layers 2. Among them, each Ta2O5 / SiO2 layer 2 includes a Ta2O5 layer 31 and a SiO2 layer 32. Preferably, the DBR layer includes a total of 13 stacked Ta2O5 / SiO2 layers 2. The Ta2O5 / SiO2 layer 2 is used to improve the absorption of the NbN thin film 4 for 1550 nm light; during the ion implantation process, by controlling the ion type, incident energy, incident angle, ion implantation dose, and implantation time, vacancy defects 5 are introduced into the superconducting device, thereby changing 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 to 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° to 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 14~1×10 17 ions / cm 2 Specifically, the ion implantation dose may include 1×10 14 ions / cm 2 , 5×10 14 ions / cm 2 , 1×10 15 ions / cm 2 , 1×10 16 ions / cm 2 , 2×10 16 ions / cm 2 , 5×10 16 ions / cm 2 , 8×10 16 ions / cm 2 , 1×10 17 ions / cm 2 and so on.

[0084] As an example, before performing 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 tolerance 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 to 3 nm. Specifically, the AlN protective layer is deposited by magnetron sputtering, and the thickness of the protective layer may 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 executed to test the thermal properties of the superconducting thin film and the superconducting device after the ion radiation treatment to determine the regulation effect of the ion radiation 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 the electron inelastic scattering rate; the thermal properties of the superconducting device include the low-temperature boundary thermal conductance and the two-photon thermal relaxation time.

[0087] Specifically, the electron inelastic scattering rate is a rate that describes the energy loss when electrons 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] To better understand the method for regulating the thermal properties of a superconducting thin film and its device based on ion irradiation in the present invention, the following describes the method for regulating the thermal properties of a superconducting thin film and its device based on ion irradiation in the present invention with reference to specific embodiments. It should be noted that these embodiments are merely descriptive and do not limit the present invention in any way.

[0089] Example 1

[0090] This example provides a method for regulating the thermal properties of a superconducting thin film based on ion irradiation, including the following steps:

[0091] A1. Refer to Figure 2 , provide a DBR high-contrast substrate, which sequentially includes a Si substrate, 12 Ta2O5 / SiO2 layers, a Ta2O5 layer, and a SiO2 layer from bottom to top. Then, a NbN superconducting thin film with a thickness of 7 nm is grown on the substrate by magnetron sputtering;

[0092] A2. Use SRIM software to perform ion implantation simulation on the NbN superconducting thin film, select helium ions (He + ) as irradiation ions, and determine the ion type, incident energy, incident angle, and ion implantation dose;

[0093] A3. Use an ion implantation device to perform ion irradiation on the NbN superconducting thin film;

[0094] A4. Test the electron inelastic scattering rate of the NbN superconducting thin film after ion irradiation treatment through a PPMS system.

[0095] Refer to Figure 3a for the influence of bombarding the NbN superconducting thin film with different ions (He + , N + , Ar + ) at different energies on the position of the implanted ion distribution peak. As the incident energy increases, the position of the implanted ion distribution peak moves deeper; refer to Figure 3b for the schematic diagram of the distribution of He + ions obtained when simulating with helium ions (He + ) as irradiation ions, setting the incident energy to 30 KeV, and the ion implantation dose to 8×10 16 ions / cm 2 . The depth of the implanted ion distribution peak is calculated to be approximately 304 nm. +

[0096] Refer to Figure 4a for the influence of He + ions on the number of defects in the NbN superconducting thin film at different incident energies when the irradiation ion is helium ions (He + ), the incident angle is 0°, and the ion implantation dose is 8×10 16 ions / cm 2 . It can be seen from the figure that as the ion implantation dose increases, more He + ions +When ions enter the substrate, the number of defects caused to the superconducting thin film first decreases and then tends to be stable. The number of sputtered ions reflects the etching effect of the ions on the thin film. The larger the number of sputtered ions, the more obvious the etching. To study the influence of the number of thin film defects and the number of sputtered ions, any incident energy from 15 to 45 keV can be selected.

[0097] See Figure 4b using helium ions (He + ) as irradiation ions, with an incident energy of 30 keV and an ion implantation dose of 8×10 16 ions / cm 2 When, He + The influence of ions on the number of defects in the NbN superconducting thin film at different incident angles. The number of sputtered ions and the number of defects increase with the increase of the incident angle. When reaching a certain threshold (50°), the sputtering effect increases sharply, and the damage to the superconducting thin film is obvious. It is more appropriate to select an incident angle of 0 - 40°.

[0098] See Figure 5 This is the change in the electron inelastic scattering rate of the superconducting thin film before and after ion irradiation in this embodiment. The irradiated superconducting thin film may have vacancy defects introduced by irradiation, which affects the electro - phonon interaction time in the superconducting thin film, thus affecting the inelastic scattering time of the thin film. The electron inelastic scattering rate of the irradiated superconducting thin film is about 10% more than that before irradiation.

[0099] Example 2

[0100] This embodiment provides a method for regulating the thermal performance of a superconducting device based on ion irradiation. The difference from Example 1 is that the object of thermal performance regulation in this embodiment is a superconducting device, which is prepared on the basis of Example 1. Finally, the boundary thermal conductance and thermal relaxation time of the superconducting device after ion radiation treatment are measured. Other methods are the same as those in Example 1 and will not be elaborated here.

[0101] See Figure 3c using helium ions (He + ) as irradiation ions, the change in the distribution concentration of He + ions at different ion implantation doses, Figure 3d for the change in DPA under the action of He + ions at different ion implantation doses. DPA represents the average number of times each atom leaves its original position after being bombarded by particles at a given irradiation dose; according to the simulation results, due to the influence of the cumulative effect, with the increase of the ion implantation dose, the lattice in the target material may undergo local or global disorder. Due to the accumulation of defects and displacements, the lattice is more easily affected by ion implantation. Therefore, as the ion implantation dose increases, the DPA caused by ions also increases.

[0102] See Figure 6a Figure 6a shows the change in the interfacial thermal conductance of the superconducting device before and after ion irradiation treatment in this embodiment. It can be seen that the interfacial thermal conductance of the superconducting device decreases significantly after ion irradiation, and the influence of the ion implantation dose on the interfacial thermal conductance shows an approximately monotonic decreasing linear trend within the range of 0 - 9x10 16 ions / cm 2 , while it shows a saturation trend beyond this range. This result indicates that the interfacial thermal conductance of the thin film or device can be regulated by controlling the ion implantation dose.

[0103] See Figure 6b Figure 6b shows the change in the two - photon thermal relaxation time of the superconducting device before and after ion irradiation treatment in this embodiment. Before ion irradiation treatment, the two - photon thermal relaxation time of the superconducting device is 18 ps. After ion irradiation treatment, the two - photon thermal relaxation time of the superconducting device is 24 ps, and the two - photon thermal relaxation time of the superconducting device after ion irradiation treatment has increased by about 1 / 3.

[0104] In summary, in the present invention, the ion type, incident energy, incident angle, and ion implantation dose during ion radiation are determined through SRIM simulation. The superconducting thin film and superconducting device are subjected to ion irradiation treatment by an ion implantation device. During the ion irradiation process, by controlling the ion type, incident energy, incident angle, ion implantation dose, and implantation time, vacancy defects are introduced into the superconducting thin film and superconducting device, thereby changing their thermal conductivity and microstructure, thus changing the inelastic scattering rate of the superconducting thin film, and changing the interfacial thermal conductance and two - photon thermal relaxation time of the superconducting device; the thermal property regulation method in the present invention can precisely regulate the thermal properties of the superconducting thin film or superconducting device without changing the chemical composition of the material. Even after the device is processed, the post - treatment optimization can still be achieved through the regulation method in the present invention, enabling precise regulation of the sensitivity, response speed, and working stability of the superconducting device, which has important scientific significance and application value; the thermal property regulation method in the present invention can not only provide a new technical path for improving the performance of superconducting devices, but also promote their wider application in fields such as quantum technology and high - sensitivity detection. Therefore, the present invention effectively overcomes various drawbacks in the prior art and has high industrial utilization value.

[0105] The above embodiments are only illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A method for regulating the thermal properties of a superconducting film and its device based on ion irradiation, characterized in that: The control method comprises the following steps: S1. providing a substrate and growing a superconducting thin film on the substrate; S2. Preparation of superconducting devices with micrometer or nanometer line width structures; S3, using SRIM software to perform ion implantation simulation on the superconducting film and the superconducting device respectively, and determine the ion type, incident energy, incident angle and ion implantation dose; S4, using ion implantation equipment to perform ion irradiation treatment on the superconducting film and the superconducting device respectively according to the determined ion type, incident energy, incident angle and ion implantation dose; S5. Testing the thermal properties of the superconducting film and the superconducting device after the ion radiation treatment to determine the regulating effect of the ion radiation treatment on the superconducting film and the superconducting device.

2. The method for controlling thermal properties of superconducting thin films and devices based on ion irradiation according to claim 1, characterized in that: In step S1, a superconducting thin film is grown on the substrate by magnetron sputtering.

3. The method for controlling thermal properties of superconducting thin films and devices based on ion irradiation according to claim 1, characterized in that: The substrate in step S1 includes one of a distributed Bragg reflector (DBR) substrate, a sapphire substrate, a silicon wafer substrate, and a magnesium oxide substrate.

4. The method for controlling thermal properties of a superconducting film and its device based on ion irradiation according to claim 1, characterized in that: The material of the superconducting thin film in step S1 includes one of NbN, NbTiN, WSi or MoGe.

5. The method for controlling thermal properties of superconducting films and devices based on ion irradiation according to claim 1, characterized in that: The method for preparing a superconducting device with a micrometer or nanometer line width structure in step S2 comprises the following steps: coating a photoresist on the superconducting thin film; The pattern is transferred to the photoresist using electron beam exposure. After development and fixing, the excess photoresist is etched and removed to form a micron or nanometer line width structure.

6. The method for controlling thermal properties of superconducting thin films and devices based on ion irradiation according to claim 5, characterized in that: The step of preparing the superconducting device also includes forming an electrode structure, and the manufacturing process of the electrode structure includes the following steps: preparing a mask for electrode patterning; A photoresist is coated on the film forming the micrometer or nanometer line width structure, and the electrode pattern on the mask is transferred to the photoresist through ultraviolet exposure. After development, fixing and etching, the electrode pattern is formed.

7. The method for controlling thermal properties of a superconducting film and its device based on ion irradiation according to claim 1, characterized in that: The superconducting device prepared in step S2 is a superconducting nanowire single-photon detector.

8. The method for controlling thermal properties of superconducting thin films and devices based on ion irradiation according to claim 1, characterized in that: Step S4 includes one or a combination of the following conditions: The ion type includes one of helium ions, nitrogen ions, and argon ions; The incident energy is 15keV to 45keV; The incident angle is 0° to 40°; The ion implantation dose is 1×10 14 ~1×10 17 ions / cm 2 .

9. The method for controlling thermal properties of superconducting thin films and devices based on ion irradiation according to claim 1, characterized in that: Before performing the ion irradiation treatment in step S4, a protective layer needs to be deposited on the superconducting film and the superconducting device to improve the radiation tolerance of the superconducting 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.

10. The method for controlling thermal properties of superconducting thin films and devices thereof based on ion irradiation according to claim 1, characterized in that: The thermal properties of the superconducting film in step S5 include the electron inelastic scattering rate; the thermal properties of the superconducting device include boundary thermal conductivity and two-photon thermal relaxation time.

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