Controllable preparation method and application of high-resistance superconducting nitride film

Abstract

The invention discloses a controllable preparation method and application of a high-resistance superconducting nitride film, and the method comprises the steps: firstly, drawing a distribution phase diagram of a magnetron sputtering mode of the nitride film along with the change of sputtering current and argon-nitrogen ratio, and according to the change trend of sputtering voltage along with the sputtering current; a magnetron sputtering mode is divided into a metal mode, a competition mode and a poisoning mode; then selecting a magnetron sputtering volt-ampere curve in the phase diagram, and growing a nitride film under typical working conditions in different magnetron sputtering modes; the crystal phase and the electrical property distribution of the nitride film are observed, and a basic working mode for preparing the high-resistance superconducting nitride film is determined; and finally, growing the high-resistance superconducting nitride film according to the boundary condition of the basic working mode. According to the universal method for preparing the high-resistance superconducting nitride thin film, the prepared high-resistance superconducting niobium nitride thin film has the electrical resistivity obviously higher than that of an existing niobium nitride thin film material, and a favorable guarantee is provided for preparing SNSPD detection with high saturation quantum efficiency.

Description

Technical Field

[0001] The present invention relates to a method for preparing a superconducting film and its application, and in particular to a controllable method for preparing a high-resistance superconducting nitride film and its application. Background Art

[0002] Superconducting materials have important technical significance due to their zero resistance characteristics at the superconducting transition temperature and their complete anti-magnetism. Various superconducting devices based on superconducting materials play an important role in quantum computing, encrypted communications, and wide-spectrum astronomical detection. Niobium nitride (NbN) is widely used as the main material for various superconducting devices such as superconducting nanowires single photon detector (SNSPD), superconducting quantum interference device (SQUID), and Josephson junction (JJ) due to its strong structural stability, high superconducting transition temperature (17K), and can operate at a temperature higher than 2.3K. It is widely used in wide-spectrum detection from terahertz to infrared bands. The quality of NbN thin films plays a vital role in the performance of devices. Different device application scenarios have different requirements for the material characteristics of NbN (superconducting transition temperature, current density, disorder, and conductivity).

[0003] However, due to the lack of repeatable control of material parameters such as film thickness, uniformity, resistivity, etc. during the NbN growth process, the yield and size of devices made of such films are greatly limited. For example, in order to achieve thousands of photon number recognition and GHz-level photon detection rates, the number of device pixels needs to be expanded on a large scale. The low uniformity of thin NbN films or the limited area of ​​the superconducting active region of the film lead to extremely low multi-pixel SNSPD yield and pixel scale.

[0004] At the same time, different types of magnetron sputtering systems have large differences in internal cavity structure, sputtering target size, etc., and the sputtering process parameters between different equipment do not have direct reference value. Therefore, the mature and stable niobium nitride film sputtering system is difficult to be reproducible. This means that the development of a new niobium nitride sputtering system requires trying to jointly select multiple working parameters such as sputtering gas pressure, argon nitrogen ratio, sputtering power, and target substrate distance, as well as measuring the superconducting properties of a large number of films, which consumes huge manpower, material resources and time costs. This seriously limits the expansion of the research scale of niobium nitride and other similar materials. Summary of the invention

[0005] Purpose of the invention: The purpose of the present invention is to provide a controllable preparation method of high-resistance superconducting nitride thin films that is not dependent on a specific magnetron sputtering system and has universal applicability;

[0006] The second object of the present invention is to provide the application of the high-resistance superconducting nitride film prepared by the above method in a superconducting single-photon detector.

[0007] Technical solution: The controllable preparation method of the superconducting nitride film of the present invention comprises the following steps:

[0008] (1) Draw a distribution phase diagram of the magnetron sputtering mode of nitride film as the sputtering current and argon-nitrogen ratio change, and divide the magnetron sputtering mode into metal mode, competitive mode and poisoning mode according to the variation trend of sputtering voltage with sputtering current;

[0009] (2) Select a magnetron sputtering voltammetric curve in the phase diagram and grow nitride films under typical working conditions under different magnetron sputtering modes; observe the crystal phase and electrical property distribution of the nitride film, and determine the basic working mode for preparing high-resistance superconducting nitride films from the three magnetron sputtering modes;

[0010] (3) Grow high-resistance superconducting nitride films based on the boundary conditions of the basic working mode.

[0011] Furthermore, in step (1), under the condition of fixed discharge gas pressure, a distribution phase diagram of the magnetron sputtering mode as the sputtering current and the argon-nitrogen ratio change is drawn.

[0012] Furthermore, in step (1), when drawing the phase diagram, the process conditions of magnetron sputtering are: target substrate distance is 30-80 mm, gas pressure is 0.5-8 mTorr, argon flow rate is 30-120 sccm, nitrogen flow rate is 2-40 sccm, and the current of the DC power supply is 0.1-3 A; record the discharge voltage under the working conditions; the step length is 0.5 A; wait for each working condition to stabilize for 10-30 seconds, and record the discharge voltage after stabilization.

[0013] Further, in step (1), the poisoning mode is at a sputtering current of 0.2-0.6A in the phase diagram, the competitive mode is at a sputtering current of 0.6-1.15A in the phase diagram, and the metal mode is at a sputtering current of 1.15-3A in the phase diagram.

[0014] Furthermore, the nitride is one of niobium nitride, aluminum nitride or tungsten nitride.

[0015] Furthermore, when the nitride is niobium nitride, the basic working mode for preparing the niobium nitride film is the region where the competition mode in the phase diagram is close to the poisoning mode, wherein the nitride film focusing on metallic properties selects the metallic mode region, and the nitride film focusing on non-metallic properties selects the poisoning mode region.

[0016] Furthermore, the niobium nitride film is grown by selecting a poisoning mode / competition mode boundary condition at a low sputtering power through a phase diagram.

[0017] Among them, in step (2), the conditions for selecting the basic working mode are: the thickness of the nitride film is 4-10nm, the superconducting transition temperature is 3-15K, and the resistivity is not less than 300μΩcm; for the nitride film with a thickness of 8nm and above, the superconducting transition temperature is not less than 7K; when using a silicon-based substrate, the superconducting transition temperature of the nitride film of 10nm and below does not exceed 10K.

[0018] Furthermore, in step (2), typical working conditions are: target substrate distance is 30-80 mm, total gas pressure is 1-6 mTorr, argon flow rate is 50-100 sccm, nitrogen flow rate is 2-10 sccm, and DC power supply current is 0.2-2.4 A.

[0019] Furthermore, in step (2), the typical operating currents in different sputtering modes are: 0.2A and 0.4A in poisoning mode, 0.6A, 0.8A, 0.9A and 1.1A in competition mode, and 1.2A, 1.4A and 1.65A in metal mode.

[0020] Furthermore, in step (2), when growing the nitride film, the substrate is ultrasonically cleaned in acetone, ethanol, and deionized water for a period of time to remove surface impurities, and the ultrasonic power is preferably 80W.

[0021] Furthermore, in step (2), when growing the nitride film, the growth time under different working conditions is controlled to be 27.8 min, 11.1 min, 5.95 min, 3.8 min, 2.9 min, 2 min, 1.8 min, 98 s, and 77 s; a film with a thickness of 100 nm is obtained under each condition.

[0022] Furthermore, in step (2), after growing the nitride film, a four-probe method is used to obtain the resistivity distribution of the nitride film in the three modes; liquid helium and a GM refrigerator are used to obtain the resistance change trend of the nitride film and the distribution of the superconducting transition temperature in the three modes.

[0023] Furthermore, in step (2), when growing the nitride film, the sputtering rate under different working conditions is calibrated, which specifically includes the following steps:

[0024] (S1) applying photoresist to a part of the surface of the substrate and drying;

[0025] (S2) Growth under different working conditions;

[0026] (S3) placing the substrate on which the thin film is grown in acetone, ethanol and deionized water for a period of time to remove the photoresist and the upper thin film to form a step;

[0027] (S4) Scanning the step height of the film using a step meter.

[0028] Furthermore, in step (S1), the photoresist is az1500, which is dried at 100°C for 2 minutes; and in step (S2), the growth time is controlled to be 5-30 minutes.

[0029] Furthermore, in step (S4), the scanning distance is 0.5 mm and the scanning speed is 0.02 mm / s; the obtained film growth rates are 0.06 nm / s, 0.15 nm / s, 0.28 nm / s, 0.44 nm / s, 0.57 nm / s, 0.8 nm / s, 0.92 nm / s, 1.02 nm / s, and 1.3 nm / s, respectively.

[0030] Furthermore, in step (3), the process parameters of the boundary conditions are: target substrate distance is 30-80 mm, total gas pressure is 2-5 mTorr, argon flow rate is 50-100 sccm, nitrogen flow rate is 2-10 sccm, DC power supply current is 0.2-1.6 A, discharge voltage is 322-433 V, sputtering rate is 0.05-0.5 nm / s; growth time is controlled to be 20-200 s, and thickness of the grown nitride film is 4-10 nm; wherein, the DC power supply current is more preferably 0.2-0.6 A, the discharge voltage is more preferably 362-433 V, and the growth time is more preferably 20-45 s.

[0031] The present invention provides the application of the high-resistance superconducting nitride film prepared by the above method in a superconducting single-photon detector.

[0032] Beneficial effects: Compared with the prior art, the present invention achieves the following significant effects:

[0033] (1) The present invention provides a universal method for preparing high-resistance superconducting NbN and similar nitride films. The method establishes a corresponding relationship between the specific sputtering state inside the magnetron sputtering and the structure and material properties of the nitride film such as resistivity and superconducting transition temperature through the magnetron volt-ampere characteristic curve, that is, obtains the structural phase diagram of the nitride film, and then uses the structural phase diagram model of the nitride film in combination with the principle of glow discharge to infer the sputtering mode of the magnetron sputtering instrument under specific conditions. In the phase diagram, according to the variation trend of the sputtering voltage with the sputtering current, the magnetron sputtering mode is divided into a poisoning mode, a competitive mode and a metal mode; then, by adjusting the argon-nitrogen ratio, the discharge pressure, the target-substrate distance and other parameters, the desired sputtering mode is set to a process parameter that meets the power requirement, that is, the sputtering mode that can make the nitride film have a high resistance and a high superconducting transition temperature is selected as the basic working mode, and finally, a nitride film with a high resistance and a high superconducting transition temperature can be grown under the boundary conditions of the basic working mode.

[0034] (2) For the preparation of superconducting niobium nitride films, by selecting the working point at the boundary of the poisoning mode and the competition mode under low power, a high-resistance superconducting niobium nitride film can be grown. The resistivity of the niobium nitride film is significantly higher than that of the current niobium nitride film materials, which provides a favorable guarantee for the preparation of SNSPD detection with high saturation quantum efficiency.

[0035] (3) The phase diagram construction method used in the present invention can be widely used in the efficient development and maintenance of growth systems of aluminum nitride, tungsten nitride and other materials similar to niobium nitride, and has general applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 Phase diagram of the magnetron sputtering mode constructed in step 1 of Example 1;

[0037] Figure 2 A schematic diagram of a magnetron sputtering mode constructed for the present invention;

[0038] Figure 3 The voltammetric curve diagram of the specific conditions in step 2 of Example 1;

[0039] Figure 4 The material characteristic mode distribution diagram of niobium nitride thin film constructed in step 3 of Example 1;

[0040] Figure 5 The temperature variation curve of the niobium nitride film resistance in step 4 of Example 1;

[0041] Figure 6 The high resistance niobium nitride obtained in step 6 of Example 1 is compared with the current resistance result of niobium nitride. DETAILED DESCRIPTION

[0042] The present invention is described in further detail below.

[0043] Example 1

[0044] A method for preparing a high-resistance superconducting niobium nitride film comprises the following steps:

[0045] Step 1: Collect the magnetron voltammetric characteristics under different argon-nitrogen ratio conditions and draw the model phase diagram of niobium nitride film:

[0046] The discharge pressure was fixed to be 2 mTorr for the total pressure of argon and nitrogen, and the target-substrate distance was fixed to be 70 mm; the argon flow rate was 100 sccm, the nitrogen flow rate was 2-20 sccm, the step length was 0.25 sccm, the DC power supply current was 0.2-3 A, and the step length was 0.5 A; each working condition was waited for about 15 seconds to stabilize, the discharge voltage after stabilization was recorded, and the sputtering mode phase diagram of the niobium nitride film was drawn. The phase diagram is shown in FIG. Figure 1 shown.

[0047] Step 2: Classify sputtering modes by volt-ampere characteristics:

[0048] The magnetron sputtering mode phase diagram obtained in step 1 includes the following three modes: a poisoning mode in which the target surface is completely covered with NbN compounds, a competitive mode in which the target surface is partially covered with NbN compounds, and a metal mode in which Nb atoms are completely sputtered. Specifically:

[0049] Combination Figure 2 Initial stage: the current range is 0.2-0.6A. The higher discharge voltage in the initial stage reflects the relatively low conductivity of the target surface. This result is due to the fact that the metal Nb atoms on the target surface combine faster with the reaction gas N2 molecules than the discharge gas Ar. + The rate of Nb atoms sputtering from the bombarded target material is caused by the complete coverage of the metal Nb target surface by NbN with a higher secondary electron emission coefficient, which corresponds to the magnetron sputtering poisoning mode; the intermediate stage: the current range is 0.6-1.15A, and the discharge voltage in the intermediate stage shows an abnormal negative growth trend. This result is caused by the gradual increase in the sputtering rate of Nb atoms, the gradual decrease in the target surface area covered by NbN, and the increase in the overall conductivity of the target surface, which corresponds to the competition mode; the third stage: the current range is 1.15-3A, and the discharge voltage growth trend in the third stage is consistent with the trend of pure argon glow discharge. Nb atomic sputtering dominates the sputtering process, and the sputtering area of ​​the target surface is not covered by NbN, which corresponds to the metal mode.

[0050] By observing the phase diagram distribution of step one, it can be concluded that increasing the nitrogen flow rate can improve the growth competitiveness of NbN on the Nb target surface and significantly extend the negative resistance region.

[0051] Step 3: Select one of the magnetron sputtering voltammetry curves in the phase diagram obtained in step 1, take typical working conditions under different sputtering modes, and grow a 100-nanometer thick film; specifically, the following steps are included:

[0052] (3-1) Si / SiO2 substrate treatment: A two-inch double-sided polished Si / SiO2 substrate was ultrasonically cleaned in acetone, ethanol, and deionized water for 5 min each, with an ultrasonic power of 80 W to remove surface impurities. Finally, the substrate was blown dry with a nitrogen gun and set aside for later use;

[0053] (3-2) Step pretreatment: Apply az1500 photoresist to the treated surface of the substrate and dry at 100°C for 2 min;

[0054] (3-3) Niobium nitride film growth: The treated substrate was placed in a magnetron sputtering chamber and evacuated to 8×10 - 4 Pa. The specific process parameters of magnetron sputtering are: target-substrate distance is 70mm, total gas pressure is 2mTorr, argon gas flow rate is 100sccm, nitrogen gas flow rate is 6.5sccm; the typical working currents in different sputtering modes are: 0.2A and 0.4A in poisoning mode, 0.6A, 0.8A, 0.9A, 1.1A in competition mode, and 1.2A, 1.4A, 1.65A in metal mode; and the growth time is controlled to be 30min;

[0055] (3-4) Step preparation: The substrate with the grown film was ultrasonically treated in acetone, ethanol and deionized water for 5 min each, with an ultrasonic power of 80 W, to remove the az1500 photoresist and the upper film to form a step, and then dried with a nitrogen gun and waited for the step test;

[0056] (3-5) Growth rate measurement: The step height of the film was scanned using a step profiler with a scanning distance of 0.5 mm and a scanning speed of 0.02 mm / s. The film growth rates obtained were 0.06 nm / s, 0.15 nm / s, 0.28 nm / s, 0.44 nm / s, 0.57 nm / s, 0.8 nm / s, 0.92 nm / s, 1.02 nm / s, and 1.3 nm / s, respectively.

[0057] (3-6) Growth of 100-nanometer niobium nitride film: The magnetron sputtering process parameters are the same as in step (3-3), and the growth time under different working conditions is controlled to be 27.8 min, 11.1 min, 5.95 min, 3.8 min, 2.9 min, 2 min, 1.8 min, 98 s, and 77 s; a 100 nm thick film is obtained under each condition.

[0058] Step 4: Testing the electrical properties of the 100 nm thick niobium nitride film grown under various conditions in step 3, specifically including the following steps:

[0059] (4-1) Resistivity measurement: The resistance of the niobium nitride film grown on a two-inch Si / SiO2 substrate was measured using the Keithlay 2450 analyzer four-probe method, and the sheet resistance of the film was obtained by multiplying the two-inch corresponding coefficient 4.478. The sheet resistance was then multiplied by the actual film thickness to obtain the film resistivity. Figure 4 As shown, the film resistivity remains relatively highest in the poisoning mode and rapidly decreases to a relatively lowest level in the competition mode. Compared with the poisoning mode, the resistivity decreases by about 50%, and gradually increases as it approaches the metal mode and finally rapidly decreases in the metal mode.

[0060] (4-2) Measurement of superconducting transition temperature: Place the sample wire in a liquid helium tank, use a Keithlay 2450 analyzer to give a 10μA bias current, and record the film bias voltage at the same time to calculate the film resistance. The film temperature change is read through the serial port. The superconducting transition temperature is the temperature at which the sample resistance reaches 10%. Record the superconducting transition temperature of the film under various conditions. Figure 3 As shown, the competition mode has the highest superconducting transition temperature, which is about 25% higher than the superconducting transition temperature of the film grown in the poisoning mode. In the metallic mode, the superconducting transition temperature of the film will rapidly decrease to below 2.3K.

[0061] Combining the above results, we can draw the following conclusions: NbN film has the highest superconducting transition temperature in the competitive mode, and is the basic choice mode for preparing high-performance superconducting devices. However, this does not mean that other modes have no application scenarios, and they can be selected according to needs.

[0062] Step 5: Experimental results verification

[0063] The temperature curves of NbN thin film resistance at sputtering currents of 0.2A, 0.8A, and 1.1A are normalized to the resistance at 300K, as shown in Figure 5 As shown, the ratios of the film resistance at 20K to the resistance at room temperature at 300K are 1.257, 1.082, and 1.009, respectively. The negative growth rate of the film resistivity gradually returns to zero from the poisoning mode to the metal mode as the temperature decreases, indicating that the metal phase in the film is gradually strengthening, which is consistent with the expectations of the actual sputtering mode inside the magnetron in step one.

[0064] Step 6: Prepare nanoscale high-resistance NbN film and measure the electrical properties of the film: specifically including the following steps:

[0065] (6-1) Selection of working point for high-resistance superconducting NbN film: As shown in the results of step 4, the competitive mode is the primary region for preparing superconducting films. Under the premise of keeping the superconducting properties unchanged, the NbN film grown at the working point at the boundary between the poisoning mode and the competitive mode has both good superconducting properties and high resistivity. In addition, the sputtering rate needs to be reduced to ensure the controllable growth of nano-scale films, and a smaller sputtering current needs to be selected to meet the low sputtering rate requirement. Since the boundary between the poisoning mode and the competitive mode will move toward a small sputtering current as the argon gas flow rate decreases, increasing the gas pressure can inhibit the decomposition of the NbN film during the growth process and improve the film growth quality. Therefore, the selected working conditions for the high-resistance superconducting NbN are: target-substrate distance of 70 mm, total gas pressure of 4.25 mTorr, argon gas flow rate of 100 sccm, nitrogen gas flow rate of 4 sccm, DC power supply current of 0.5 A, discharge voltage of 382 V, and sputtering rate of 0.2 nm / s.

[0066] (6-2) Growth of high-resistance superconducting NbN thin film: The substrate is treated according to the substrate treatment method of step 3, and growth is carried out according to the magnetron sputtering process parameters determined in step (6-1), and the growth time is controlled to be 20s-45s, and the step length is 5s, to grow high-resistance niobium nitride thin films with thicknesses of 4nm, 5nm, 6nm, 7nm, 8nm, and 9nm, respectively.

[0067] (6-3) Measurement of electrical properties of high resistance superconducting NbN thin films: The resistivity and superconducting transition temperature of the six thin films obtained in step (6-2) were measured using the same measurement method as in step 4. The measurement results are shown in Table 1.

[0068] Example 2

[0069] On the basis of Example 1, different from Example 1, in step (6-2), the magnetron sputtering process parameters for the growth of the NbN film are: the total gas pressure during the sputtering process is 2 mTorr, the argon gas flow rate is 100 sccm, the nitrogen gas flow rate is 2.5 sccm, the current of the DC power supply is 0.25 A, the discharge voltage is 334 V, the sputtering rate is 0.093 nm / s, the growth time is controlled to be 80 s, and the thickness of the grown niobium nitride film is 8.2 nm. The electrical properties of the film are measured as shown in Table 1.

[0070] Example 3

[0071] On the basis of Example 1, different from Example 1, in step (6-2), the magnetron sputtering process parameters for the growth of the NbN film are: the total gas pressure during the sputtering process is 4.25 mTorr, the argon gas flow rate is 100 sccm, the nitrogen gas flow rate is 10 sccm, the current of the DC power supply is 1.2 A, the discharge voltage is 420 V, the sputtering rate is 0.48 nm / s, the growth time is controlled to be 16.6 s, and the thickness of the grown niobium nitride film is 8.1 nm. The electrical properties of the film are measured as shown in Table 1.

[0072] Comparative Example 1

[0073] On the basis of Example 1, different from Example 1, in step (6-1), the selected NbN working conditions are: selecting the working point in the competition mode; in step (6-2), the magnetron sputtering process conditions for the growth of the NbN film are: the total gas pressure of the sputtering process is 4.25mTorr, the argon gas flow rate is 100sccm, the nitrogen gas flow rate is 4sccm, the current of the DC power supply is 1A, the discharge voltage is 368V, the sputtering rate is 0.513nm / s, the growth time is controlled to be 17s, and the thickness of the grown niobium nitride film is 8.4nm. The electrical properties of the film are measured as shown in Table 1.

[0074] Table 1 Low temperature measurement data of niobium nitride films prepared in Examples 1-3 and Comparative Example 1

[0075]

[0076]

[0077] As shown in Table 1, the sputtering rate of Example 2 is reduced by about 1 times compared with that of Example 1. However, due to the lower working gas pressure, the NbN film may be decomposed during the growth process, and the superconducting transition temperature and resistivity of the prepared 8nm film are lower than those of Example 1.

[0078] The working gas pressure of Example 3 is the same as that of Example 1, but due to the higher nitrogen flow rate, the poisoning mode and the competition mode have a higher sputtering power, and the sputtering rate is increased by about 1.5 times compared with Example 1. The superconducting transition temperature and resistivity of the prepared 8nm film are lower than those of Example 1.

[0079] The working gas pressure of Comparative Example 1 is the same as that of Example 1, but the working point in the competitive mode is selected. The sputtering rate is increased by about 1.5 times compared with Example 1, the superconducting transition temperature of the prepared 8nm film is increased by 0.17K compared with the 8nm film of Example 1, and the resistivity is reduced by about 1 times compared with Example 1.

[0080] The test results shown in Table 1 indicate that the magnetron sputtering process parameters determined in Example 1 are the optimal conditions for low-rate sputtering of high-resistance superconducting niobium nitride films. Figure 6 As shown, the resistivity of the grown high-resistance superconducting niobium nitride film is significantly higher than the current resistivity of niobium nitride films.

Claims

1. A controllable preparation method of a high-resistance superconducting nitride film, characterized in that: The following steps are involved: (1) Draw a distribution phase diagram of the magnetron sputtering mode of nitride film as the sputtering current and argon-nitrogen ratio change, and divide the magnetron sputtering mode into metal mode, competitive mode and poisoning mode according to the variation trend of sputtering voltage with sputtering current; (2) Select a magnetron sputtering voltammetric curve in the phase diagram and grow nitride films under typical working conditions under different magnetron sputtering modes; observe the crystal phase and electrical property distribution of the nitride film, and determine the basic working mode for preparing high-resistance superconducting nitride films from the three magnetron sputtering modes; (3) Grow high-resistance superconducting nitride films based on the boundary conditions of the basic working mode.

2. The controllable preparation method of high-resistance superconducting nitride thin film according to claim 1, characterized in that: In step (2), the conditions for selecting the basic working mode are: the thickness of the nitride film is 4-10 nm, the superconducting transition temperature is 3-15 K, and the resistivity is not less than 300 μΩcm.

3. The controllable preparation method of high-resistance superconducting nitride thin film according to claim 1, characterized in that: In step (1), when drawing the phase diagram, the process conditions of magnetron sputtering are: target substrate distance is 30-80 mm, gas pressure is 0.5-8 mTorr, argon flow rate is 30-120 sccm, nitrogen flow rate is 2-40 sccm, and the current of the DC power supply is 0.1-3 A; record the discharge voltage under the working conditions.

4. The controllable preparation method of high-resistance superconducting nitride thin film according to claim 1, characterized in that: In step (2), typical working conditions are: target-substrate distance of 30-80 mm, total gas pressure of 1-6 mTorr, argon flow rate of 50-100 sccm, nitrogen flow rate of 2-10 sccm, and DC power supply current of 0.2-2.4 A.

5. The controllable preparation method of high-resistance superconducting nitride thin film according to claim 1, characterized in that: The nitride is one of niobium nitride, aluminum nitride or tungsten nitride.

6. The controllable preparation method of high-resistance superconducting nitride thin film according to claim 1, characterized in that: The nitride is niobium nitride, and the basic working mode for preparing niobium nitride film is the area where the competition mode is close to the poisoning mode in the phase diagram, wherein the nitride film focusing on metallic properties selects the metal mode area, and the nitride film focusing on non-metallic properties selects the poisoning mode area.

7. The controllable preparation method of high-resistance superconducting nitride thin film according to claim 6, characterized in that: The niobium nitride film was grown under the poisoning mode / competition mode boundary condition at low sputtering power through phase diagram selection.

8. The controllable preparation method of high-resistance superconducting nitride thin film according to claim 7, characterized in that: The process parameters of the boundary conditions are: target-substrate distance is 30-80mm, total gas pressure is 2-5mTorr, argon flow rate is 50-100sccm, nitrogen flow rate is 2-10sccm, DC power supply current is 0.2-1.6A, discharge voltage is 322-433V, sputtering rate is 0.05-0.5nm / s; the growth time is controlled to be 20-200s, and the thickness of the grown nitride film is 4-10nm.

9. The controllable preparation method of high-resistance superconducting nitride thin film according to claim 6, characterized in that: In step (1), the poisoning mode is within the sputtering current of 0.2-0.6A in the phase diagram, the competitive mode is within the sputtering current of 0.6-1.15A in the phase diagram, and the metal mode is within the sputtering current of 1.15-3A in the phase diagram.

10. Use of the high-resistance superconducting nitride film prepared by the method according to claim 1 in a superconducting single-photon detector.

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