An ultra-thin YBCO nanostructure IV characteristic regulation method based on an LSAT substrate

Abstract

This invention provides a method for controlling the IV properties of ultrathin YBCO nanostructures based on LSAT substrates, belonging to the field of single-photon detection technology. This method combines the unique modulation effect of the LSAT substrate / interface on hydrogen ion transport behavior with a partially reversible control mechanism that combines low-energy hydrogen ion implantation provided by an ICP-RIE device with subsequent thermal treatment. This allows for the control of ultrathin YBCO nanostructures while maintaining the integrity of the nanostructure's geometry and crystal structure. I - V Characteristics and critical current I c Its controllable, continuous, and repeatable adjustment is suitable for the parameter matching requirements of superconducting detector threshold design and superconducting array integration.

Description

Technical Field

[0001] This invention belongs to the field of single-photon detection technology, specifically relating to a method for controlling the IV properties of an ultrathin YBCO nanostructure based on an LSAT substrate. Background Technology

[0002] YBa2Cu3O 7-δ (YBCO) has a high critical temperature (T) c YBCO nanofilms, with their advantages of high K density (92K), large-area epitaxial growth capability, and shorter electroacoustic relaxation time, stand out among various superconducting materials and have broad application prospects in superconducting electronics, high-sensitivity detection, and other fields. With the development of thin-film epitaxial growth and micro / nano fabrication technologies, YBCO ultrathin films and their nanostructures (such as nanowires, nanobridges, and nanopores) have gradually become research hotspots. Compared to bulk materials or thick-film structures, the superconducting properties of ultrathin YBCO nanostructures are more easily affected by geometric scale, interface state, and defect distribution, leading to significant changes in superconducting transition and current-carrying capacity. This influence is usually directly reflected in the current-voltage (IV) characteristics and critical current (Ic). c The changes in IV characteristics are related to those of I. c It can be used as a core parameter for evaluating its superconducting performance, operating window, and stability.

[0003] In practical applications, the critical current I c This directly limits the operating current range, trigger threshold, and dynamic response sensitivity of the device. For example, for devices such as superconducting detectors and Josephson junctions, appropriately reducing I... c Stable operation can be achieved at lower bias currents, thereby reducing power consumption and improving response to weak disturbances (such as light, magnetism, heat, or electromagnetic pulses); for superconducting device arrays and integrated circuits, I c The consistency and designability of the components determine the degree of matching between devices, the operating margin, and the system-level stability. Therefore, achieving the design of ultrathin YBCO nanostructures... c Controllable regulation is a key technical problem that urgently needs to be solved in the process of promoting the engineering and large-scale integration of YBCO nanodevices.

[0004] In existing technologies, the methods for controlling the critical current of ultrathin YBCO nanostructures mainly include geometric and structural design, oxygen content (vacancy) control, and ion implantation / irradiation modification. Ion implantation typically introduces defect centers of a certain density and distribution within the material, modulating the continuity of current-carrying channels and superconducting coherence, thereby achieving control over local structure and electrical transport properties. Because this method is compatible with micro / nano fabrication processes and possesses spatial selectivity and integrability, it has been widely used for performance modification of superconducting thin films and nanodevices.

[0005] However, for ultrathin YBCO nanostructures with thicknesses on the nanometer scale, traditional ion implantation / irradiation still has the following limitations: On the one hand, the incident particles provided by ion implanters or irradiation equipment usually have high energy, the energy deposition process of ions in ultrathin films is relatively intense, and the defect generation caused by some ions is highly localized, making the device performance highly sensitive to the implantation / irradiation dose. Often, only within a narrow dose range can the desired ion density be achieved. c The relatively effective regulation is achieved; however, when the dosage is slightly low, the regulation effect is not obvious, while when the dosage is slightly high, it is easy to cause excessive accumulation of defects, aggravated lattice damage, and excessive degradation of superconductivity, thereby reducing IT. c It is difficult to achieve continuous and precise controllable adjustment. On the one hand, due to the limited film thickness, the scattering and energy loss of ions at the film / substrate interface have a more significant impact on the depth and lateral distribution of defect formation, making the defect distribution susceptible to fluctuations in process and interface conditions, thereby increasing the uncertainty of the control results and reducing the repeatability of the adjustment and the consistency between devices.

[0006] Therefore, there is an urgent need to propose a control scheme for ultrathin YBCO nanostructures, which can achieve the control of IV and I properties without damaging the main structure of the device and the basic superconducting properties. c The continuous, precise, and repeatable adjustment of the operating threshold and consistency is met in applications such as superconducting detectors and superconducting array integration. Summary of the Invention

[0007] To address the problems existing in the background technology, the present invention aims to provide a method for controlling the IV properties of ultrathin YBCO nanostructures based on LSAT substrates. This method combines the unique modulation effect of the LSAT substrate / interface on hydrogen ion transport behavior with a partially reversible control mechanism that combines low-energy hydrogen ion implantation provided by an ICP-RIE device with subsequent heat treatment. While maintaining the geometry of the nanostructure, this method achieves control over the IV properties and critical current I of ultrathin YBCO nanostructures. c Its controllable, continuous, and repeatable adjustment is suitable for the parameter matching requirements of superconducting detector threshold design and superconducting array integration.

[0008] To achieve the above objectives, the technical solution of the present invention is as follows:

[0009] A method for controlling the IV properties of ultrathin YBCO nanostructures based on LSAT substrates includes the following steps:

[0010] Step 1: Growth of YBCO thin film and in-situ amorphous YBCO protective layer:

[0011] (LaAlO3) was selected. 0.3 (Sr2TaAlO6) 0.7(LSAT) substrate, YBCO thin film is epitaxially grown on the substrate surface, and then an amorphous YBCO protective layer is grown in situ on the YBCO thin film surface to isolate the atmospheric environment and suppress film degradation and oxygen content drift.

[0012] Step 2: Prepare the metal electrode:

[0013] An electrode pattern mask is attached to the sample surface obtained in step 1, and then a metal electrode is prepared by electron beam evaporation. After the evaporation is completed, the mask is removed.

[0014] Step 3: Growing an alumina protective layer:

[0015] A dense alumina protective layer was deposited on the sample surface obtained in step 2 using plasma-enhanced atomic layer deposition (PEALD) to further improve the chemical stability and degradation resistance in subsequent processes.

[0016] Step 4: Prepare YBCO microstructures to obtain the localization region:

[0017] YBCO microwire devices were fabricated using ultraviolet lithography combined with low-temperature inductively coupled plasma reactive ion etching (ICP-RIE) technology to locate the regions of the nanostructures to be fabricated;

[0018] Step 5: Preparation of YBCO nanostructures:

[0019] In the pre-defined region, the desired nanostructure is fabricated using electron beam lithography combined with low-temperature inductively coupled plasma reactive ion etching (ICP-RIE) technology.

[0020] Step 6: Perform low-energy hydrogen ion implantation on the YBCO nanostructure obtained in Step 5. The hydrogen ion energy is 200eV-350eV and the treatment time is 30-120s.

[0021] Step 7: Perform a thermal post-treatment on the sample after Step 6 at a temperature of 100-150℃ for 10-20 minutes. This is to accelerate the evolution of hydrogen-related processes and defect / oxygen-related states, promote the redistribution and rebalancing of the aforementioned non-equilibrium states, reduce the effects of random fluctuations and excessive damage, and solidify the transient changes induced by implantation into stable and repeatable IV characteristics and critical current I. c Results of regulation.

[0022] Furthermore, in step 1, the thickness of the YBCO thin film is 5-10 nm; the thickness of the amorphous YBCO protective layer is 6-10 nm; and the preferred growth method is DC magnetron sputtering.

[0023] Furthermore, in step 2, the vacuum level of the electron beam evaporation system cavity is lower than 5 × 10⁻⁶. -6mbar, evaporation rate of 0.5-2 Å / s.

[0024] Furthermore, in step 4, the specific process of ultraviolet lithography includes: cleaning the sample surface, spin-coating photoresist and baking the photoresist, performing ultraviolet exposure and development, etching to obtain the micron-line region of the nanostructure to be made connected to the electrode channel, and removing the photoresist.

[0025] Furthermore, in steps 4 and 5, the parameters for low-temperature inductively coupled plasma reactive ion etching are as follows: sample stage temperature is -20 to 10°C, process gas is CHF3 / Ar mixed gas with a flow rate ratio of 10 / 10 sccm, ICP power is 800-1200W, RF power is 80-120W, and etching gas pressure is 1-3 mTorr.

[0026] Furthermore, in step 5, the specific process of electron beam lithography includes: cleaning the sample surface, spin-coating electron beam photoresist and baking the photoresist, then spin-coating conductive carbon photoresist and baking the photoresist again; subsequently, electron beam exposure of the nanostructure pattern, rinsing to remove the conductive carbon photoresist, developing and etching, and finally removing the photoresist to complete the preparation of the nanostructure.

[0027] Furthermore, in step 7, the heat post-treatment equipment can be a hot stage, a heatable sample stage (such as a probe station), or a constant temperature oven.

[0028] The mechanism of this invention is as follows:

[0029] The ultrathin YBCO nanostructure based on LSAT substrate exhibits IV characteristics and critical current I under the combined effects of hydrogen ion implantation and subsequent thermal post-treatment. cThe regulation of the superconducting properties is not caused by a single defect effect, but is determined by the synergistic effect of three factors: defect reconstruction under interface constraints, hydrogen-related chemical interactions, and post-processing-driven redistribution / rebalancing. The LSAT substrate not only provides epitaxial support for ultrathin YBCO, but also, due to its lattice constraints, thermal boundary conditions, and interface blocking characteristics, significantly affects the energy deposition of implanted particles in the ultrathin YBCO film, the spatial distribution of defects, and the retention and migration behavior of hydrogen-related components near the film / substrate interface. Therefore, the substrate does not merely serve a mechanical support function, but is a crucial boundary condition for the controllable regulation of this invention. Furthermore, compared to traditional high-energy ion implantation or irradiation methods, this scheme uses lower-energy hydrogen ion implantation, resulting in a gentler process and higher controllability of process parameters such as implantation intensity and treatment time. This makes it more suitable for achieving shallow, gradual, and precise performance regulation of ultrathin YBCO nanostructures, avoiding the deep damage, excessive defect accumulation, and abrupt degradation of superconducting performance problems easily caused by high-energy particle implantation. Specifically, during hydrogen ion implantation, on the one hand, hydrogen ion bombardment introduces microscopic damage, mainly point defects, into the ultrathin YBCO nanostructure, altering the local lattice order, the superconducting coherence length-related region, and the continuity of the current-carrying channels, thereby reducing the critical current I. c Due to the low energy of the incident ions, the introduction of defects is mainly concentrated near the film surface and sensitive regions of the local interface. The defect formation process is more tunable and less structurally destructive, thus facilitating more refined control over the degree of perturbation of the superconducting channel. On the other hand, hydrogen entering the material surface and near the interface also participates in oxygen-related chemical processes, including inducing oxygen migration, changing the local oxygen occupancy state, affecting the Cu-O chain / oxygen order, and further altering the spatial distribution of carrier concentration and local superconductivity. In other words, hydrogen ion implantation not only brings defect control in the sense of "physical damage" but also introduces chemical regulation in the sense of "hydrogen-oxygen coupling." These two types of effects jointly determine the final electrical transport characteristics.

[0030] Because the device is an ultrathin YBCO nanostructure based on a LSAT substrate, the film thickness is close to the scale range dominated by interface effects. Hydrogen ions and their induced defects, as well as hydrogen-related components, are more likely to accumulate, reflect, scatter, redistribute, and couple near the YBCO / LSAT interface. This interface constraint prevents the implantation effect from manifesting as a simple, unidirectional performance degradation, but rather enables I… c The IV characteristics have a two-way adjustment space: under different injection parameters, if defect modulation is dominant, the superconducting channel is suppressed, and the I... c Lowering (i.e., "leftward adjustment"); if hydrogen-related chemical interactions have a more significant impact on oxygen order, local carrier distribution, and weakly connected states, it may rebalance the original non-uniform region, thereby achieving I cThe improvement (i.e., "right-hand adjustment") is achieved. Furthermore, after hydrogen ion implantation, the ultrathin YBCO nanostructure remains in a non-equilibrium state; hydrogen-related components, implantation-induced defects, and oxygen-related structures are not yet stable. Post-thermal treatment can promote the redistribution and rebalancing of these non-equilibrium states, reducing the effects of random fluctuations and excessive damage, and solidifying the implantation-induced transient changes into stable, repeatable IV characteristics and a critical current Ic. c Adjustment results. In other words, the reason this scheme can achieve both "left-hand adjustment" and "right-hand adjustment" is not because there are two independent methods, but because the defect effect and the hydrogen-oxidation chemical effect have a competitive and coupled relationship in the ultrathin interface system. By changing the injection intensity, time, and post-processing conditions, the relative weights of the two can be adjusted, thereby allowing I... c The IV characteristics evolve continuously in different directions and remain within a preset range.

[0031] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0032] The method of this invention employs low-energy, controllable hydrogen ion implantation to mildly modify ultrathin YBCO nanostructures, thereby achieving improvements in the device's IV characteristics and critical current Ic. c Effective regulation. Test results show that I c The method exhibits a clear linear relationship with changes in RF power and injection time, indicating that it possesses a quantifiable, calibrable, and predictable process control window. This invention can achieve I... c Bidirectional regulation, of which I c It can improve performance by up to 19% and reduce performance by up to 60%, thus enabling the designable adjustment of different target thresholds while ensuring the integrity of the device structure and the usability of the basic superconducting performance. Furthermore, by accelerating and solidifying the hydrogen-related interaction process through post-implantation heat treatment, parameter drift caused by LSAT interface scattering, reflection, and subsequent back diffusion can be suppressed, allowing the electrical parameters to reach a stable state more quickly. This improves the stability and repeatability of the control results, making it suitable for array and integrated applications. Attached Figure Description

[0033] Figure 1 The image shows a scanning electron microscope (SEM) image of the YBCO nanostructure prepared in Example 1.

[0034] (a) is the overall SEM image, and (b) is the local SEM image.

[0035] Figure 2 This is a schematic diagram comparing the IV properties of the YBCO nanostructure in Example 1 at different treatment stages (before hydrogen ion implantation, after implantation, and after thermal post-treatment).

[0036] Figure 3This is a schematic diagram comparing the IV properties of the YBCO nanostructure in Example 2 at different treatment stages (before hydrogen ion implantation, after implantation, and after thermal post-treatment).

[0037] Figure 4 The YBCO nanostructure in Example 1 underwent different treatment stages (before hydrogen ion implantation, after implantation, after thermal post-treatment, and after a period of time). c Comparison diagram;

[0038] Figure 5 The image shows the IV characteristics of the YBCO nanostructure in Comparative Example 1 after hydrogen ion implantation (without thermal post-treatment).

[0039] Wherein, (a) is the IV characteristic graph as a function of placement time, and (b) is the I characteristic graph as a function of placement time. c Evolution diagram.

[0040] Figure 6 The critical current change ΔI of the YBCO nanostructure in Example 3. c (%) Schematic diagram showing the relationship between the process parameters of hydrogen ion implantation and the changes in process parameters;

[0041] (a) is a schematic diagram showing the relationship between the processing time and the radio frequency power under a fixed processing time; (b) is a schematic diagram showing the relationship between the processing time and the radio frequency power under a fixed processing time.

[0042] Figure 7 The image shows the IV characteristics of the YBCO nanostructure in Comparative Example 2 at different treatment stages (before hydrogen ion implantation, after implantation, and after thermal post-treatment). Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings.

[0044] Example 1

[0045] A method for controlling the IV properties of ultrathin YBCO nanostructures based on LSAT substrates includes the following steps:

[0046] Step 1: Select an LSAT substrate and clean it. After cleaning, grow an 8 nm thick YBCO thin film on the substrate surface using DC magnetron sputtering. The cavity contains an O2:Ar = 1:3 mixed gas at a pressure of 30 Pa, a sputtering power of 125 W, and a cavity temperature of 802 °C. After the film growth is complete, wait for the cavity to cool to room temperature, and then grow a 10 nm thick amorphous YBCO protective layer on the YBCO thin film under the same gas conditions and sputtering power.

[0047] Step 2: A stainless steel mask with an electrode pattern is attached to the sample surface, and then metal electrodes (Ag / Au: 20nm / 20nm) are prepared by electron beam evaporation, with a cavity vacuum degree of less than 5×10⁻⁶. -6 mbar, evaporation rate 1 Å / s;

[0048] Step 3: After the electrode fabrication is completed, the mask is removed, and then a dense 10nm alumina protective layer is grown on the entire device surface using plasma-enhanced atomic layer deposition (PEALD) to further isolate the external environment;

[0049] Step 4: Perform UV lithography on the sample obtained in Step 3: First, clean the surface of the sample obtained in Step 3 (acetone megasonic 5 min, isoacetone megasonic 5 min, isopropanol rinsing, N2 drying); then place it on a 110℃ hot plate for pre-baking for 1 min; spin-coat AZ5214 photoresist (6000 rpm, 60 s); bake the photoresist on a 110℃ hot plate for 1 min; after UV exposure, develop with ZX238 for 45 s to locate the micron region of the nanostructure to be formed and connected to the electrode channel; use inductively coupled plasma reactive ion etching (ICP-IR) to obtain a 30 μm micron-line device: using a mixed gas (Ar / CHF3: 10 / 10 sccm), ICP power of 1000 W, RF power of 100 W, processing pressure of 1 mTorr, and maintaining the sample stage temperature at -20℃ to prevent thermal damage during the etching process; the photoresist removal process involves acetone soaking for 10 min, megasonic 20 min, isopropanol rinsing, and N2 drying.

[0050] Step 5: Perform electron beam lithography on the sample obtained in Step 4: First, clean the surface of the sample obtained in Step 4, then pre-bake it on a 180℃ hot plate for 1 min; spin-coat ZEP-520A electron beam photoresist (7000 rpm, 60 s), and bake it on a 180℃ hot plate for 3 min; spin-coat conductive carbon adhesive (4000 rpm, 60 s), and bake it on a 110℃ hot plate for 2 min; with an accelerating voltage of 20 kV and an exposure dose of 30 uC / cm... 2 Electron beam lithography was used to pattern the defined nanostructure (porous nanowires: nanowires with a uniformly distributed array of pores, with a pore size of 80 nm and a linewidth of 1 μm). The conductive carbon resist was removed by rinsing with deionized water, dried with N2, and then developed with ZED-N50 developer at room temperature for 3 min. Afterward, the nanowires were fixed by immersion in isopropanol for 15 s, rinsed with deionized water, and dried with a nitrogen gun. The electron beam-lithographic sample was then subjected to inductively coupled plasma reactive ion etching (ICP-RI) to obtain the desired porous nanowires. The resist removal process involved UV light treatment for 5 min, acetone immersion for 10 min, megasonic etching for 20 min, rinsing with isopropanol, and drying with N2. The obtained porous nanowires were placed on a temperature-controlled DC probe station and subjected to IV testing at a low temperature of 4 K.

[0051] Step 6: Low-energy hydrogen plasma was generated using an inductively coupled plasma reactive ion etching (ICP-RI) machine, and hydrogen ion implantation was performed on the YBCO porous nanowires obtained in Step 5. The implantation parameters were as follows: stage temperature -20℃, process gas set to H2, gas flow rate 10 sccm, ICP power 1000W, processing gas pressure 1 mTorr, RF power 100W, corresponding bias voltage 300V, and implantation time 60s. The obtained porous nanowires were placed in a temperature-controlled DC probe station and IV tests were performed at a low temperature of 4K.

[0052] Step 7: Place the YBCO porous nanowires obtained in Step 6 on a hot stage for post-processing at a temperature of 150°C for 10 minutes; place the obtained porous nanowires on a temperature-controlled DC probe station and perform IV testing at a low temperature of 4K.

[0053] Example 2

[0054] YBCO porous nanowires were prepared according to the steps of Example 1, except that step 1 was adjusted to: using an LSAT substrate, cleaning it, and then growing a 10 nm thick YBCO film on the substrate surface by DC magnetron sputtering.

[0055] The hydrogen ion implantation process in step 6 was adjusted to have an RF power of 40W and a corresponding bias voltage of 150V.

[0056] Example 3

[0057] YBCO porous nanowires were prepared according to the steps in Example 1, except that the hydrogen ion implantation process in step 6 was adjusted to have RF powers of 40W, 60W, 80W and 120W and implantation times of 30s, 60s and 120s respectively.

[0058] Comparative Example 1

[0059] YBCO porous nanowires were prepared according to the steps in Example 1, except that step 7 was omitted, while the other steps remained unchanged.

[0060] Comparative Example 2

[0061] YBCO porous nanowires were prepared according to the steps in Example 1, except that the hydrogen ion implantation process in step 6 was adjusted to: RF power of 100W, corresponding bias voltage of 300V, and implantation time of 120s.

[0062] like Figure 1 As shown, the ultrathin YBCO porous nanowires prepared on LSAT substrates by this invention have a uniformly distributed pore array structure with a pore size of approximately 80 nm. The constructed nanostructure morphology is controllable and has good reproducibility.

[0063] In Example 1, the IV curves of the same device at 4K before hydrogen ion implantation, after implantation, and after heat treatment at 150°C for 10 min are compared. Figure 2 As shown in the figure, it can be seen that the hydrogen ion implantation heating post-treatment method of the present invention can achieve I c And the hysteresis window is significantly reduced, I c The current decreased from 0.707 mA to 0.379 mA, as shown in Example 1. c The "leftward adjustment". And the IV characteristics at different treatment stages in Example 2 (before hydrogen ion implantation, after implantation, and after thermal post-treatment) are as follows: Figure 3 As shown, hydrogen ion implantation followed by heating can achieve I c With the increase of the hysteresis window, I c The current increased from 1.159 mA to 1.378 mA, an improvement of approximately 19%. Example 2 is I. c The "rightward adjustment".

[0064] Figure 4 Example 1: I before hydrogen ion implantation, after implantation, after heat treatment, and after different placement times c Comparing the schematic diagrams, it can be seen from the figures that the effect of the control method of the present invention does not change with the storage time, exhibiting good stability. In contrast, Comparative Example 1 only underwent hydrogen ion implantation without subsequent heat treatment, and its IV characteristics showed a significant evolution with storage time, such as... Figure 5 As shown in (a). Its I c As the number of days the object is left to stand varies, significant drift still exists even after two weeks, such as... Figure 5 As shown in (b). Comparison Figure 4 and Figure 5 It is known that post-thermal treatment can significantly accelerate and solidify the hydrogen-related interaction process, significantly reduce the time-varying drift of the device's electrical characteristics after implantation, and promote the rapid stabilization of the modulation results after implantation; otherwise, the device performance will remain in the process of time evolution for a long time, which is very unfavorable for practical applications.

[0065] Example 3 achieved different levels of I by changing the RF power and processing time in step 6. c Regulation, its statistical relationship is as follows Figure 6 As shown: Under a fixed processing time, ΔI c The variation with RF power is regular; under fixed RF power conditions, ΔI c The changes also show a regular pattern with processing time, indicating that I c There is a linear relationship between the modulation effect and the hydrogen ion implantation parameters, meaning that the IV and I properties of YBCO porous nanowires can be controlled by adjusting the hydrogen ion implantation parameters. cContinuous, precise, and controllable regulation can provide a clear process window for the parameters of the target device.

[0066] Furthermore, when the RF power or processing time exceeds a suitable range, the device's IV hysteresis will significantly weaken or even disappear; excessive processing may even lead to device performance degradation or damage. For example... Figure 7 As shown in Comparative Example 2, the porous nanowires I before treatment c The hysteresis of the porous nanowires disappeared when the RF power was 0.678 mA, the processing time was increased to 2 min, and the RF power was 100 W. Therefore, the injection parameters of this invention are specific to ensure a balance between device control effect and device integrity, and to provide a reasonable process window for the target device parameters.

[0067] The above description is merely a specific embodiment of the present invention. Any feature disclosed in this specification may be replaced by other equivalent or similar features unless otherwise specified. All disclosed features, or steps in all methods or processes, may be combined in any way except for mutually exclusive features and / or steps.

Claims

1. A method for controlling the IV properties of ultrathin YBCO nanostructures based on LSAT substrates, characterized in that, Includes the following steps: Step 1: Grow YBCO thin films and in-situ amorphous YBCO protective layers on LSAT substrates; Step 2: Fabricate a metal electrode on the surface of the amorphous YBCO protective layer; Step 3: Grow an alumina protective layer on the surface of the amorphous YBCO protective layer; Step 4: Prepare YBCO microstructures to obtain the localization region; Step 5: Prepare YBCO nanostructures in the pre-positioned region; Step 6: Perform low-energy hydrogen ion implantation on the YBCO nanostructure obtained in Step 5. The hydrogen ion energy is 200-350 eV and the treatment time is 30-120 s. Step 7: Perform post-heat treatment on the sample after step 6. The treatment temperature is 100-150℃ and the treatment time is 10-20min.

2. The method for regulating the IV properties of ultrathin YBCO nanostructures as described in claim 1, characterized in that, In step 1, the thickness of the YBCO thin film is 5-10 nm; the thickness of the amorphous YBCO protective layer is 6-10 nm; and the growth method is DC magnetron sputtering.

3. The method for regulating the IV properties of ultrathin YBCO nanostructures as described in claim 1, characterized in that, In step 2, the vacuum level of the electron beam evaporation system cavity is lower than 5 × 10⁻⁶. -6 mbar, evaporation rate of 0.5-2 Å / s.

4. The method for controlling the IV properties of ultrathin YBCO nanostructures as described in claim 1, characterized in that, In step 4, YBCO microstructures are prepared by combining ultraviolet lithography with low-temperature inductively coupled plasma reactive ion etching. The specific process of ultraviolet lithography includes: cleaning the sample surface, spin-coating photoresist and baking the photoresist, performing ultraviolet exposure and development, etching to obtain the micron-line region to be made of nanowires connected to the electrode channel, and removing the photoresist.

5. The method for regulating the IV properties of ultrathin YBCO nanostructures as described in claim 1, characterized in that, In step 5, YBCO nanostructures are prepared using electron beam lithography combined with low-temperature inductively coupled plasma reactive ion etching (ICP-IR). The parameters for ICP-IR are as follows: stage temperature -20 to 10°C, process gas CHF3 / Ar mixed gas with a flow rate ratio of 10 / 10 sccm, ICP power 800-1200 W, RF power 80-120 W, and etching pressure 1-3 mTorr.

6. The method for regulating the IV properties of ultrathin YBCO nanostructures as described in claim 5, characterized in that, In step 5, the specific process of electron beam lithography includes: cleaning the sample surface, spin-coating electron beam photoresist and baking the photoresist, then spin-coating conductive carbon photoresist and baking the photoresist again; subsequently, electron beam exposure of the nanostructure pattern, rinsing to remove the conductive carbon photoresist, developing and etching, and finally removing the photoresist to complete the preparation of the nanostructure.

7. The method for controlling the IV properties of ultrathin YBCO nanostructures as described in claim 1, characterized in that, In step 7, the heat post-treatment equipment is a hot table, a heatable probe station, or a constant temperature oven.

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