Method for regulating and controlling ferroelectric property of AlScN film

Abstract

The invention relates to the technical field of ferroelectric material preparation, in particular to a method for regulating and controlling the ferroelectric property of an AlScN film. Comprising the following steps that an n-type single crystal substrate serves as a base, AlScN grows on the surface of the n-type single crystal substrate through a magnetron sputtering method, and the magnetron sputtering conditions are that the magnetron sputtering power is 400-500 W, and the growth temperature is 500-600 DEG C; the irreversible Rayleigh coefficient representing the domain wall density in the initial deposition state of the AlScN film is made to be larger than or equal to 0.3 through magnetron sputtering, and the ferroelectric property of the AlScN film is improved; and the n-type single crystal substrate is an nGaN substrate. The improvement of the ferroelectric property of the AlScN thin film comprises the reduction of the coercive field of the AlScN thin film or / and the inhibition of the awakening behavior of the AlScN thin film. The method has the advantages that the nitridation process of the substrate and the AlScN interface is regulated and controlled by reducing the growth temperature and improving the sputtering power, the polarity is regulated and controlled, and the AlScN film coercive field and the awakening behavior are effectively reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of ferroelectric material preparation, and particularly to a method for regulating the ferroelectric properties of AlScN thin films. Background Art

[0002] Aluminum scandium nitride (AlScN) thin film is a ferroelectric material, which has large remanent polarization, high Curie temperature, and remarkable piezoelectric, linear and nonlinear optical properties, and can be compatible with mainstream semiconductor manufacturing processes, and has broad application prospects in the manufacture of transistors, memristors, sensors, actuators, quantum switches, transducers, etc. Magnetron sputtering technology is a commonly used physical vapor deposition (PVD) method, which has the advantages of high sputtering rate, simple operation, low cost, and suitability for large-area growth. It is the most widely used technology in the current preparation of AlScN thin films and is considered to be one of the most promising methods for growing high-quality and large-size AlScN thin films. Its working principle is that under the condition of high vacuum, incident ions bombard the target under the action of electric and magnetic fields, so that the atoms on the surface of the target obtain sufficient kinetic energy to break away from the surface of the target and deposit on the surface of the substrate to form a thin film. Among them, temperature and sputtering power are important factors affecting the deposition rate and quality of the thin film. The crystal quality and ferroelectric properties of the AlScN thin film grown by magnetron sputtering technology are largely regulated by the growth conditions.

[0003] As is well known, for traditional oxide ferroelectric materials, their polarization reversal only involves single-atom movement. However, for wurtzite nitride ferroelectrics represented by AlScN, the polarization direction is determined by the stacking order of metal atoms and nitrogen atoms. Its polarization reversal involves the simultaneous movement of metal and nitrogen atoms. This complex long-range lattice inversion makes the domain dynamics of nitrides more complex, facing a larger polarization reversal barrier, resulting in a higher coercive field, and even wake-up behavior may occur under certain growth conditions, that is, the polarization-electric field hysteresis loop gradually opens in the initial cycle, so that the AlScN thin film experiences a process of gradually increasing the remanent polarization amplitude during cycling. The wake-up behavior will lead to unstable device performance and affect its reliability and service life. Therefore, suppressing the wake-up behavior is a key issue in the application of AlScN ferroelectric materials. The above situation poses challenges to the development of low-energy, high-stability, and scalable nitride ferroelectric devices, restricting the commercial application of this ferroelectric material. Therefore, it is necessary to clarify the domain dynamics mechanism of AlScN and study methods for reducing the coercive field of AlScN thin films and suppressing the wake-up behavior. Summary of the Invention

[0004] In order to solve the above problems, the present invention provides a method for regulating the ferroelectric properties of AlScN thin films.

[0005] The first object of the present invention is to provide a method for regulating the ferroelectric properties of AlScN thin films, which includes the following steps: using an n-type single crystal substrate as the base, growing AlScN on the surface of the n-type single crystal substrate by magnetron sputtering, and the conditions of magnetron sputtering are: the magnetron sputtering power is 400-500 W, and the growth temperature is 500-600 °C; by magnetron sputtering, the irreversible Rayleigh coefficient α of the AlScN thin film in the initial deposition state is ≥0.3, so as to improve the ferroelectric properties of the AlScN thin film.

[0006] Preferably, the magnetron sputtering power is 500 W, and the growth temperature is 500 °C.

[0007] Preferably, the n-type single crystal substrate is an n-GaN substrate.

[0008] Preferably, the gas atmosphere of magnetron sputtering is high-purity nitrogen, and the flow rate is 60-100 sccm; the sputtering pressure is 0.1-0.2 Pa.

[0009] Preferably, the flow rate of high-purity nitrogen is 70 sccm; the sputtering pressure is 0.15 Pa.

[0010] Preferably, the magnetron sputtering power is 400 W, and the growth temperature is 500 °C.

[0011] Preferably, improving the ferroelectric properties of the AlScN thin film includes reducing the coercive field of the AlScN thin film and / or suppressing the wake-up behavior of the AlScN thin film.

[0012] The second object of the present invention is to provide an AlScN thin film. During the preparation of the AlScN thin film, the method for regulating the ferroelectric properties of the AlScN thin film is used for regulation, so that the irreversible Rayleigh coefficient α of the AlScN thin film in the initial deposition state is ≥0.3.

[0013] Compared with the prior art, the present invention can achieve the following beneficial effects: (1) Suppressing the wake-up behavior: By reducing the growth temperature and increasing the sputtering power, increasing the initial domain wall density and optimizing the film quality, the wake-up behavior of the AlScN thin film is significantly suppressed; (2) Improving the stability of ferroelectric properties: Reducing the coercive field of the prepared thin film and improving the stability of the remanent polarization, which is suitable for high-performance ferroelectric devices; (3) Simple and easy to implement: It can be achieved by regulating the growth conditions (temperature, power, etc.), without complex processes; In summary, the present invention regulates the nitridation process at the interface between the substrate and AlScN by means of reducing the growth temperature and increasing the sputtering power, thereby regulating the polarity of AlScN, increasing the domain wall density in the initial deposition state, realizing the growth of AlScN with mixed polarity throughout the film, and promoting the lateral movement of domain walls. Since the lateral movement of domain walls has a relatively small energy barrier, the coercive field of the AlScN film is reduced and the wake-up behavior is inhibited. Through ferroelectric testing, Rayleigh testing, wet etching and other related characterizations as well as theoretical calculation simulations, it is confirmed that reducing the growth temperature and increasing the sputtering power can effectively reduce the coercive field and wake-up behavior of the AlScN film. Description of the Drawings

[0014] Figure 1 is the ferroelectric test curve of the AlScN film provided by the embodiment of the present invention.

[0015] Figure 2 is the fitting curve of the Rayleigh behavior of the AlScN film provided by the embodiment of the present invention.

[0016] Figure 3 is the SEM image of the wet-etched AlScN film provided by the embodiment of the present invention.

[0017] Figure 4 is the curve of the change in the remanent polarization and the dielectric constant of the AlScN film provided by the embodiment of the present invention with the cycle.

[0018] Figure 5 is the model of the polarization reversal process of the AlScN film provided by the embodiment of the present invention.

[0019] Figure 6 is the energy state of the microscopic structure corresponding to different stages when the domain wall moves along the c-axis direction of the AlScN film in the theoretical calculation simulation provided by the embodiment of the present invention. Detailed Embodiments

[0020] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same modules are denoted by the same reference numerals. In the case of the same reference numerals, their names and functions are also the same. Therefore, their detailed descriptions will not be repeated.

[0021] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not constitute a limitation to the present invention.

[0022] The present invention provides a method for regulating the ferroelectric properties of AlScN thin films, including: using an n-type single crystal substrate as a base, growing an AlScN target on the surface of the n-type single crystal substrate by magnetron sputtering. The conditions for magnetron sputtering are: the magnetron sputtering power is 400 - 500 W, and the growth temperature is 500 - 600 °C; by magnetron sputtering, the domain wall density in the initial deposition state of the AlScN thin film is ≥ 0.3, so as to improve the ferroelectric properties of the AlScN thin film.

[0023] Specifically, the n-type single crystal substrate is an nGaN substrate; using an n-type single crystal substrate (such as nGaN) can ensure the lattice matching between the thin film and the substrate, which is beneficial to improving the crystallization quality of the thin film, reducing defects and residual stress, and suppressing the wake-up behavior.

[0024] Specifically, the gas atmosphere for magnetron sputtering is high-purity nitrogen (N2), and the flow rate is 60 - 100 sccm; the sputtering pressure is 0.1 - 0.2 Pa; preferably, the nitrogen flow rate is 70 sccm; the sputtering pressure is 0.15 Pa; Specifically, the magnetron sputtering power is 500 W and the growth temperature is 500 °C; or the magnetron sputtering power is 400 W and the growth temperature is 500 °C; Specifically, by magnetron sputtering, the domain wall density in the initial deposition state of the AlScN thin film is > 0.3; improving the ferroelectric properties of the AlScN thin film includes reducing the coercive field of the AlScN thin film and / or suppressing the wake-up behavior of the AlScN thin film.

[0025] Example 1 This example provides a method for regulating the ferroelectric properties of AlScN thin films, including the following steps: S1. Select an nGaN substrate grown by MOCVD as the single crystal substrate material with metal polarity; S2. Grow an AlScN target on the surface of the nGaN substrate by magnetron sputtering. The conditions for magnetron sputtering are: the magnetron sputtering power is 400 W, the growth temperature is 600 °C; the gas atmosphere for magnetron sputtering is high-purity nitrogen (N2), the nitrogen flow rate is 70 sccm; the sputtering pressure is 0.15 Pa; prepare the AlScN thin film under the above conditions.

[0026] Example 2 This example provides a method for regulating the ferroelectric properties of AlScN thin films, including the following steps: S1. Select an nGaN substrate grown by MOCVD as the single crystal substrate material with metal polarity; S2. Grow an AlScN target on the surface of an nGaN substrate by magnetron sputtering. The conditions for magnetron sputtering are as follows: the magnetron sputtering power is 400 W, and the growth temperature is 500 °C; the gas atmosphere for magnetron sputtering is high-purity nitrogen (N2), and the nitrogen flow rate is 70 sccm; the sputtering pressure is 0.15 Pa; prepare an AlScN thin film under the above conditions.

[0027] The difference between Example 2 and Example 1 lies in the different growth temperatures. The nGaN substrate grown by MOCVD is a metal-polarity single-crystal material. Ideally, AlScN should grow according to the metal polarity. However, during the magnetron sputtering process, nitrogen ions in the cavity will nitride the nGaN substrate with a certain probability, thereby affecting the initial nucleation process of the AlScN material and generating a mixed polarity. When the temperature is too high, the nitrogen-polarity AlScN will transform back to the metal polarity driven by thermal energy. Therefore, when growing an AlScN thin film on an nGaN substrate at a higher temperature, it is more conducive to growing a thin film with a relatively single metal polarity and a low domain wall density. When the growth temperature is reduced, it is more conducive to the generation of a mixed polarity.

[0028] Example 3 This example provides a method for regulating the ferroelectric properties of an AlScN thin film, including the following steps: S1. Select an nGaN substrate grown by MOCVD as a metal-polarity single-crystal substrate material; S2. Grow an AlScN target on the surface of an nGaN substrate by magnetron sputtering. The conditions for magnetron sputtering are as follows: the magnetron sputtering power is 500 W, and the growth temperature is 500 °C; the gas atmosphere for magnetron sputtering is high-purity nitrogen (N2), and the nitrogen flow rate is 70 sccm; the sputtering pressure is 0.15 Pa; prepare an AlScN thin film under the above conditions.

[0029] The difference between Example 3 and Example 2 lies in the different magnetron sputtering powers. The nGaN substrate grown by MOCVD is a metal-polarity single-crystal material. Therefore, when growing an AlScN thin film on an nGaN substrate, it is easier to deposit a single-polarity thin film under the restraint of the metal polarity. However, during the magnetron sputtering process, nitrogen ions in the cavity will nitride the nGaN substrate with a certain probability, thereby affecting the initial nucleation process of the AlScN material and generating a mixed polarity. Increasing the sputtering power increases the concentration of nitrogen ions in the cavity, further increasing the probability of nitriding the nGaN substrate, and it is easier to grow a mixed-polarity AlScN thin film with a through-domain structure.

[0030] Test the ferroelectric properties of the AlScN thin films prepared in Examples 1 to 3. The test result curves are shown in Figure 1 . Figure 1Figure (a) shows a series of polarization - electric field (P - E) hysteresis loops of the sample grown at 600 °C during the wake - up process. The initial loop shows a remanent polarization value of 43 μC / cm² in polarization. When cycling under the same field, the loop gradually opens until the remanent polarization reaches 120 μC / cm² 2 , presenting an increment of more than 70 μC / cm² 2 . Similarly, the peak value of the current density - electric field (J–E) curve also shows a corresponding degree of increase, as shown in 2 Figure (d). The results show that the sample grown at 600 °C has a large coercive field and obvious wake - up behavior. The P - E hysteresis loop gradually opens during cycling, resulting in a gradual increase in the remanent polarization amplitude during cycling. Figure 1 Figure (b) and (e) show the P - E and J–E characteristic loop curves of the sample grown at 500 °C during the wake - up process. After reducing the growth temperature to 500 °C, the coercive field decreases by 0.5 MV / cm compared to 600 °C. The wake - up amplitude of the P - E hysteresis loop and J–E curve during cycling is significantly reduced, and the remanent polarization only presents an increment of 35 μC / cm² Figure 1 . Under the growth condition of a growth temperature of 500 °C, when the sputtering power is set to 500 W, the test curves are shown in 2 Figure (c) and (f). The figure shows the P - E and J–E characteristic loop curves of the sample grown at 500 W during the wake - up process. The results show that after increasing the sputtering power to 500 W, the coercive field decreases to 4 MV / cm, and almost no wake - up behavior occurs in the P - E hysteresis loop during cycling. The results show that by reducing the growth temperature and increasing the sputtering power, the coercive field and wake - up behavior of the AlScN thin film are effectively reduced. Figure 1

[0031] Since the wake - up behavior of the AlScN ferroelectric material is related to the domain - wall density in the initial state, the film grown with a single polarity will be more likely to show wake - up than the film grown with a mixed polarity. The formation of through - domains will promote the lateral movement of domain walls with a smaller energy barrier, thus significantly reducing the coercive field of the thin film and suppressing the wake - up behavior. An important method to quantify the domain - wall density or domain - wall movement is to use Rayleigh behavior for characterization, and another important method is to use wet etching for characterization. The improvement of ferroelectric properties such as the coercive field and wake - up behavior is characterized by the hysteresis loop.

[0032] Rayleigh behavior is widely used in the characterization of domain - wall density. Generally, Rayleigh behavior can be expressed as: ; where: ε r is the relative permittivity; E AC is the alternating - current electric field; ε init ​is the reversible Rayleigh coefficient, representing the reversible motion of lattice vibrations and domain walls; α is the irreversible Rayleigh coefficient, representing irreversible domain wall migration, i.e., the domain wall mobility. The larger the irreversible Rayleigh coefficient, the greater the domain wall density; conversely, the smaller the domain wall density.

[0033] As Figure 2 shown, the differences in domain wall density of the AlScN films grown under the conditions of Examples 1 - 3 in the initial state and during 40 cycles are characterized by Rayleigh behavior. From the curve slopes of the dielectric constant and the alternating current electric field in the figure, it can be known that the values of the irreversible Rayleigh coefficients of the samples grown under the conditions of Examples 1 - 3 are 0.06, 0.18, and 0.45 respectively. The irreversible Rayleigh coefficient (α) characterizes the magnitude of the domain wall density. The smaller the irreversible Rayleigh coefficient, the lower the domain wall density. This trend indicates that the sample grown under the conditions of Example 1 has a relatively single polarity, corresponding to a smaller domain wall density, while conversely, the sample under the conditions of Example 3 has a larger domain wall density. The results show that by reducing the growth temperature and increasing the sputtering power, the domain wall density in the initial deposition state is effectively increased.

[0034] To evaluate the magnitude of the domain wall density in the initial state, a 25% KOH solution was used to wet - etch the deposited AlScN film. Usually, the KOH solution etches the nitrogen polarity faster than the metal polarity. A scanning electron microscope (SEM) was used to characterize the etching morphology at the polarization boundary, intuitively showing the differences in domain wall density. The results are shown in Figure 3 . To evaluate the domain wall density in the initial state from a microscopic perspective, a 100 - nm Ni mask was covered by photolithography, and then wet - etched with a 25% KOH solution, which is known to etch the nitrogen polarity faster than the metal polarity. SEM was used to characterize the etching morphology at the polarization boundary. Figure 3 shows the results. The sample grown under the conditions of Example 1 was hardly etched at all. On the contrary, the sample grown under the conditions of Example 2 was etched away almost 100 nm of the deposited film, and there were residual unetched metal - polarity grains. The sample grown under the conditions of Example 3 was etched away the entire 280 - nm deposited film, leaving unetched pyramid - shaped metal - polarity grains that penetrated the 280 - nm thin film. The results show that the sample grown under the conditions of Example 3 has a larger domain wall density in the initial state and there are more through - domains, with the best technical effect.

[0035] For the AlScN films prepared in Examples 1 - 3, under the excitation field with a DC bias voltage 10 V higher than the coercive voltage, the statistical curves of the remanent polarization and the irreversible Rayleigh coefficient changing with the cycle period are as Figure 4As shown; as shown in (a) and (b) of the figure, compared with the sample prepared in Example 1, the sample prepared in Example 2 has a smaller coercive field, a smaller amplitude of wake-up behavior, and a smaller domain wall density in the initial deposition state; similarly, compared with the sample prepared in Example 2, the sample prepared in Example 3 has a coercive field as low as 4 MV / cm, almost no wake-up behavior, and the largest domain wall density in the initial deposition state. The results show that reducing the growth temperature and increasing the sputtering power can increase the domain wall density in the initial deposition state, especially promoting the formation of through-domains, thereby reducing the coercive field and wake-up behavior of the AlScN thin film. Further, in the growth temperature range of 500 - 600 °C and the sputtering power range of 400 - 500 W, the domain wall density is regulated, and the variation relationships of the remanent polarization and coercive field with the domain wall density are shown in Figure 4 as shown in (c) and (d). Taking the irreversible Rayleigh coefficient α = 0.3 as the threshold, an irreversible Rayleigh coefficient exceeding 0.3 that characterizes the domain wall density in the initial deposition state will significantly reduce the coercive field and inhibit the generation of wake-up behavior.

[0036] Based on the above results, a model of the polarization reversal process of the AlScN thin film is proposed, as shown in Figure 5 as shown. It is assumed that stable AlScN reverse domains are generated starting from the initial cycle, but their volume fraction is very small, showing a small remanent polarization. In subsequent cycles, new reverse domains are continuously generated, accompanied by the growth, expansion, and merger of reverse domains. In this way, the ferroelectric hysteresis loop gradually opens, and the increase in Pr (total reversed charge) reflects the increase in the volume of reversed domains caused by the continuous polarization reversal process until the polarization saturation state is achieved. At the same time, the influence of the domain wall density in the initial deposition state on the coercive field and wake-up behavior occurs in this form. Combining Figure 5 as shown in (a), the polarization directions of the samples prepared in Example 1 in the initial state are unified, with a low domain wall density. During the field cycle, nucleation of reversed domains needs to occur first, and after the reversed domains grow longitudinally to a certain extent, further lateral expansion of the domain walls can be achieved until the entire thin film layer is finally switched. As shown in Figure 5 as shown in (b), compared with the sample prepared in Example 1, the sample prepared in Example 2 with a larger domain wall density in the initial deposition state only requires half of the cycle period to complete a larger volume of polarization reversal, while the sample prepared in Example 3 with the largest domain wall density and more through-domains relies more on the lateral expansion movement of reverse domains for polarization reversal and can reach an almost polarization saturation state within only one cycle period, as shown in Figure 5 as shown in (c).

[0037] Samples with a large domain wall density have more reverse domains in the initial state. Therefore, during the polarization reversal process, they rely more on the lateral expansion movement of the reverse domains (running perpendicular to the c-axis direction). For samples with a small domain wall density in the initial deposition state, during the polarization reversal process, reverse domain nucleation needs to be achieved at more sites first. After the reverse domains grow longitudinally (move along the c-axis direction) to a certain extent, the lateral expansion of the domain walls can be further realized. Therefore, to further explore the influence mechanism of the domain wall density on the coercive field and wake-up behavior of AlScN, the atomic-scale dynamic processes during polarization reversal along the c-axis and perpendicular to the c-axis were simulated by molecular dynamics simulation and first-principles calculation. Figure 6 Figure (a) shows the energy states of various microstructures of the AlScN thin film corresponding to the occurrence of domain wall movement perpendicular to the c-axis direction. Among them, the boundary region between the metal polarity and the N polarity is the domain wall, as shown by the elliptical marked area. Due to sufficient energy supply during the growth process, the atomic structure of the thin film in the initial deposition state will maintain the existence of the domain wall in some regions, as shown in Figure image-0. When a sufficient external electric field is applied, as the polarization reversal is completed, the domain wall structure will gradually move until it disappears. Among them, taking the movement of a one-atomic-layer domain wall as an example, during the evolution from image-0 to image-6, the atomic structure continuously twists, breaks, and reconstructs. When the domain wall gradually moves until it completely disappears, it will maintain the single-metal-polarity state shown in image-6. Here, the relative energy represents the energy of the atomic structure remaining in the current state after the change. The difference of 0.0018 eV is the energy barrier for the domain wall movement. Similarly, Figure 6 Figure (b) shows the energy states of the corresponding microstructures at different stages during the occurrence of domain wall movement along the c-axis direction. When the domain wall moves from image-0 to the state shown in image-7, the energy barrier to be crossed is 50 times that of the lateral expansion shown in Figure (a) of 6. Therefore, a larger number of times or a longer time of applying the excitation voltage is required to achieve complete polarization reversal. This theoretical calculation result is consistent with the model of the polarization reversal process of the AlScN thin film proposed above. Thin films with a large domain wall density in the initial deposition state are more inclined to achieve polarization reversal through lateral expansion and require a smaller energy barrier to cross. However, thin films with a small domain wall density also require more reverse domain nucleation and longitudinal growth. The energy barrier that the domain wall movement needs to cross is larger, and the result is reflected in a larger coercive field and the phenomenon that the residual polarization amplitude increases with the increase of the number of cycles during the polarization reversal process, that is, the wake-up behavior occurs.

[0038] It should be understood that the various forms of processes shown above can be used, with steps reordered, added or deleted. For example, the steps described in the disclosure of the present invention can be executed in parallel, sequentially or in a different order, as long as the desired results of the technical solution disclosed in the present invention can be achieved, and no limitation is imposed herein.

[0039] The above specific embodiments do not constitute a limitation on the protection scope of the present invention. Those skilled in the art should understand that various modifications, combinations, sub - combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for regulating the ferroelectric properties of an AlScN thin film, characterized in that: The method comprises the following steps: taking an n-type single crystal substrate as a base, growing AlScN on the surface of the n-type single crystal substrate by magnetron sputtering, wherein the magnetron sputtering conditions are: the magnetron sputtering power is 400-500W, and the growth temperature is 500-600°C; and the irreversible Rayleigh coefficient α of the AlScN film in the initial deposition state is made ≥0.3 by magnetron sputtering, thereby improving the ferroelectric properties of the AlScN film.

2. The method for regulating the ferroelectric properties of an AlScN thin film according to claim 1, characterized in that: The magnetron sputtering power is 500W, and the growth temperature is 500°C.

3. The method for regulating the ferroelectric properties of an AlScN thin film according to claim 1, characterized in that: The n-type single crystal substrate is an nGaN substrate.

4. The method for regulating the ferroelectric properties of an AlScN thin film according to claim 1, characterized in that: The gas atmosphere of the magnetron sputtering is high-purity nitrogen with a flow rate of 60-100 sccm; the sputtering pressure is 0.1-0.2 Pa.

5. The method for regulating the ferroelectric properties of an AlScN thin film according to claim 4, characterized in that: The flow rate of the high-purity nitrogen gas is 70 sccm; the sputtering pressure is 0.15 Pa.

6. The method for regulating the ferroelectric properties of an AlScN thin film according to claim 1, characterized in that: The magnetron sputtering power is 400W, and the growth temperature is 500°C.

7. A method for regulating the ferroelectric properties of an AlScN thin film according to any one of claims 1 to 6, characterized in that: The method of improving the ferroelectric properties of the AlScN film includes reducing the coercive field of the AlScN film and / or inhibiting the awakening behavior of the AlScN film.

8. An AlScN film, characterized in that: In the process of preparing the AlScN film, the method for regulating the ferroelectric properties of the AlScN film according to any one of claims 1 to 7 is used to regulate the irreversible Rayleigh coefficient α of the AlScN film in the initial deposition state ≥ 0.3.

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