Seed layer applied to preparation of preferred orientation crystal film and method for preparing crystal film

Abstract

The invention provides a seed layer for preparing a preferred orientation crystal film and the crystal film, lanthanide series metal salt is selected as an initial raw material of the seed layer, the initial raw material is adopted to prepare a solution, the prepared solution is filtered to obtain a seed layer solution, the seed layer solution is subjected to spin coating or ink jet printing on a substrate, and heat treatment is performed to obtain the seed layer. According to the seed layer for preparing the preferred orientation crystal film and the preferred orientation crystal film, the high-quality single crystal film is prepared under simple and convenient conditions, and the seed layer and the preferred orientation crystal film have wide application prospects in the fields of information storage, intelligent sensing, biomedical treatment, energy and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of functional materials for microelectronic devices, and in particular relates to a seed layer used for preparing a preferentially oriented crystal film and a method for preparing the crystal film. Background Art

[0002] Metal oxide crystal films have a series of electrical properties such as piezoelectricity, ferroelectricity, electro-optical effect, pyroelectric effect, etc., and are widely used in micro-electromechanical systems. As a functional layer, thin film materials are the core technology of optoelectronic devices and play an irreplaceable role. However, the performance of the film is strongly dependent on the microstructure of the film, and the preferred orientation of the film is an important feature of the film microstructure. Different preparation methods and preparation processes produce films with different orientations and large performance differences. For example, studies have shown that the piezoelectric performance of lead zirconate titanate film is relatively small when the preferred orientation is (111), and the piezoelectric performance is the best when the preferred orientation is (100), which is more suitable for use in MEMS actuators, as recorded in Integrated Ferroelectrics, 2011, 130, 1-11. However, in the development of crystal film material preparation, crystal films without preferred orientation are easier to prepare and are more widely used, but they often show disadvantages such as unstable performance, poor interface quality, and weak electrical / optical properties. Preferred orientation crystal films have improved the above shortcomings to a certain extent. However, how to prepare high-quality preferentially oriented crystal films and develop a method with a certain degree of universality is a major challenge in the current production process.

[0003] The performance of thin film materials is determined by the intrinsic crystallographic properties of the material and the physicochemical properties of the film microstructure. Since the atomic arrangement and coordination change with the change of crystallographic direction, the material will show anisotropic physical and chemical properties. Among optoelectronic functional thin film materials, epitaxial single crystal thin film is the most effective method to obtain the physicochemical properties on a specific crystal plane or crystal direction, but its preparation process is complicated and costly.

[0004] At present, most of the preferentially oriented thin film systems are based on the continuous interface formed between materials with the same crystal structure and lattice constant matching. In this way, the interface between the film and the substrate can achieve a coherent or semi-coherent relationship, thereby reducing interface defects and stress, and improving crystal quality and performance. However, during the growth process, it is difficult to achieve highly consistent crystal orientation of the film. In addition, the defects caused by internal stress during the film preparation process significantly affect the performance of the film. The growth and arrangement of crystals should be able to achieve consistency through precise control of conditions. However, in actual operation, due to weak intermolecular forces and external influences, such as substrate surface state, temperature, pressure, etc., it is difficult for crystals to maintain an ideal single-direction growth during growth. For example, in the solution method, the nucleation and growth of crystals are affected by many factors, such as solvent evaporation rate, solution concentration and external disturbances. These factors often lead to the formation of polycrystalline domains, and it is difficult to achieve large-area single crystal axis oriented single crystal film growth. The stress in the film usually originates from the mismatch between the lattice constant and thermal expansion coefficient between the film and the substrate. This internal stress will lead to the formation of defects such as dislocations and stacking faults in the film, thereby affecting its performance.

[0005] Therefore, how to control the high consistency of the crystal orientation of the thin film, solve the defects caused by stress during the growth process, and provide a method for preparing a preferentially oriented crystal film with a preferential orientation using a seed layer, so as to prepare high-quality preferentially oriented crystal films under simple conditions with a certain universality are technical problems that need to be urgently solved by technical personnel in this field. Summary of the invention

[0006] The first object of the present invention is to provide a seed layer for preparing a preferentially oriented crystal film in view of the problems in the prior art.

[0007] A seed layer for preparing a preferentially oriented crystal film, characterized in that: a lanthanide metal salt is selected as a starting material for the seed layer, a solution is prepared using the starting material, the solution concentration is 0.1-0.5 mol / L, the prepared solution is filtered to remove impurities and insoluble particles in the solution to obtain a seed layer solution, the seed layer solution is spin-coated on a substrate, an ultraviolet lamp with a mixed wavelength of 185nm and 254nm is used for irradiation, organic matter in the seed layer solution is decomposed at a temperature of 100°C, and the seed layer is obtained by heat treatment.

[0008] To this end, the above-mentioned purpose of the present invention is achieved through the following technical solutions:

[0009] While adopting the above technical solutions, the present invention may also adopt or combine the following technical solutions:

[0010] As a preferred technical solution of the present invention: the lanthanide metal salts include lanthanum nitrate, lanthanum acetate, praseodymium nitrate, and neodymium nitrate.

[0011] As a preferred technical solution of the present invention: lanthanide metal salt is used as the starting material of the seed layer, added into a solvent, and a seed layer solution is generated through stirring and filtering. The solvent includes ethylene glycol monomethyl ether, n-propanol or water, and the substrate includes Si, SiO2 substrate.

[0012] The second object of the present invention is to provide a type of seed layer for preparing a preferentially oriented crystal film in view of the problems in the prior art.

[0013] To this end, the above-mentioned purpose of the present invention is achieved through the following technical solutions:

[0014] A seed layer for preparing a preferentially oriented crystal film, characterized in that a seed layer solution is spin-coated on a substrate by a spin coating method, and the seed layer is formed by heat treatment.

[0015] The third object of the present invention is to provide a preferentially oriented crystal film to address the problems in the prior art.

[0016] To this end, the above-mentioned purpose of the present invention is achieved through the following technical solutions:

[0017] The method for preparing a preferentially oriented crystal film is characterized in that the preferentially oriented crystal film is prepared by a sol-gel method, a prepared metal oxide film precursor solution is spin-coated on the seed layer, and a preferentially oriented crystal film is prepared by heat treatment.

[0018] A fifth object of the present invention is to provide a crystal thin film to address the problems in the prior art.

[0019] To this end, the above-mentioned purpose of the present invention is achieved through the following technical solutions:

[0020] A preferentially oriented crystal film is prepared by a magnetron sputtering method: a substrate with a seed layer is placed on a sample stage of a magnetron sputtering instrument, a target material is selected, a corresponding metal oxide film is sputtered, and then a preferentially oriented crystal film is prepared through heat treatment.

[0021] While adopting the above technical solutions, the present invention may also adopt or combine the following technical solutions:

[0022] As a preferred technical solution of the present invention: the metal oxide precursor solution includes a lead zirconate titanate precursor solution, a barium titanate precursor solution or a barium strontium niobate precursor solution; the target material required for magnetron sputtering includes lead zirconate titanate, barium titanate or barium strontium niobate.

[0023] Compared with the prior art, a type of seed layer for preparing a preferentially oriented crystal film and a preferentially oriented crystal film of the present invention have the following beneficial effects: the seed layer provided by the present invention uses lanthanide metal salts as the starting material of the seed layer and is prepared into a seed layer film by spin coating, magnetron sputtering or inkjet printing; the lanthanide metal salts are easily soluble in water, and the crystallized salts contain crystal water, which is convenient for processing in a solvent and forming a coating. After being made into a film, the lanthanide metal salts have a good lattice match with the substrate and can provide an ordered crystal structure template. The similarity of lanthanide elements in crystal structure and the film formed on the substrate guide the growth direction and mode of the upper material, help control the orientation and crystal structure of the upper film, reduce the formation of defects, and improve the performance of the film; the lanthanide metal salts are relatively thin as the seed layer, with a thickness of 2 to 20 nm, and will not affect the mechanical and electrical properties of the film, and provide sufficient template effect; the seed layer achieves weaker light absorption characteristics through the lanthanide metal salts, and has good electrical properties without affecting light transmission. In the present invention, deep ultraviolet light (mixed wavelength of 185nm and 254nm) irradiation technology is used to decompose the organic matter of the seed layer at a relatively low temperature, thereby effectively reducing the defects caused by the decomposition of organic matter and solvent volatilization in the film layer at high temperature, ensuring the compactness of the film, and using ultraviolet irradiation technology to degrade the organic matter of the film under mild conditions, alleviate the defects such as holes and rough surfaces generated in the seed layer during rapid pyrolysis, and its lattice constant matches the crystal film more evenly, promoting the high-quality preferential orientation growth of the crystal film. Using the prepared seed layer film, a variety of highly preferentially oriented crystal films can be prepared through sol-gel method, magnetron sputtering method, etc.

[0024] The present invention can prepare a highly preferentially oriented crystal film by using a seed layer, and then prepare a variety of highly preferentially oriented crystal films by using a sol-gel method or a magnetron sputtering method. The invention of this method shows high superiority in preparing preferentially oriented crystal films: 1) the prepared crystal film has a high degree of preferential orientation and has certain universality; 2) the prepared crystal film has high quality; 3) the preparation process is relatively simple and the cost is low.

[0025] The present invention provides a seed layer for preparing a preferentially oriented crystal film and a preferentially oriented crystal film, which can prepare high-quality single crystal films under simple conditions and have broad application prospects in the fields of information storage, intelligent sensing, biomedicine, energy, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is the XRD pattern of the PZT film prepared by the method using seeds;

[0027] Figure 2 This is the XRD pattern of the SBN film prepared using seeds in this method;

[0028] Figure 3 This is the XRD pattern of BTO film prepared using seeds in this method. DETAILED DESCRIPTION

[0029] The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

[0030] The present invention aims at the shortcomings of the prior art and invents a method for preparing a preferentially oriented crystal film using a seed layer. The present invention uses lanthanide metal salts to prepare a seed layer film on a variety of substrates by spin coating, magnetron sputtering, inkjet printing, etc. The seed layer film is used to prepare a variety of highly preferentially oriented crystal films by sol-gel method, magnetron sputtering, etc.

[0031] To achieve the above object, the present invention provides the following technical solutions:

[0032] The method of preparing a preferentially oriented crystal film through a seed layer of the present invention comprises the following steps: 1) preparing the seed layer

[0033] Spin coating method: A certain amount of lanthanide metal salt is selected as the starting material of the seed layer, added to a certain volume of solvent, stirred, filtered, and impurities and insoluble particles in the solution are removed to form a seed layer solution with a certain concentration. The seed layer solution is spin-coated on the desired substrate by spin coating, irradiated with ultraviolet light, and heat treated to prepare the seed layer.

[0034] Magnetron sputtering method: Select a suitable target material and use the sputtering method to sputter lanthanum carbonate onto the desired substrate, and then form a seed layer after heat treatment.

[0035] Inkjet printing method: A certain amount of lanthanide metal salt is selected as the starting material of the seed layer, added to a certain volume of solvent, stirred, filtered, to form a seed layer solution with a certain concentration. The inkjet printing method is used to form a thin film, and then the seed layer is formed by heat treatment.

[0036] 2) Preparation of crystal thin films

[0037] Sol-gel method: The prepared metal oxide film precursor solution is spin-coated on the seed layer and then heat-treated to prepare a crystalline film with preferred orientation.

[0038] Magnetron sputtering method: Place the substrate with the seed layer on the sample stage of the magnetron sputtering instrument, select the required target material, sputter the corresponding metal oxide film, and then prepare it into a crystalline film with preferred orientation through heat treatment.

[0039] Preferably, in the preparation of the seed layer in step 1), the lanthanide metal salts mainly include lanthanum nitrate, lanthanum acetate, lanthanum carbonate and other similar lanthanide metal salts; the solvent includes ethylene glycol monomethyl ether, n-propanol, water, etc.; the substrate includes Si, SiO2 substrate, etc.

[0040] Preferably, the metal oxide precursor solution in step 2) includes lead zirconate titanate (PZT) precursor solution, barium titanate (BTO) precursor solution, barium strontium niobate (SBN) precursor solution, etc.; the target material required for magnetron sputtering includes lead zirconate titanate (PZT), barium titanate, barium strontium niobate, etc.

[0041] The present invention uses lanthanide metal salts to prepare seed layers on different substrates by spin coating, magnetron sputtering, inkjet printing and other methods, and then prepares a variety of preferentially oriented metal oxide crystal films by sol-gel method or magnetron sputtering method. The preparation process is simple, easy to operate, the raw materials are easily available, the cost of preparing the film is low, and high-quality single crystal films are prepared, which has certain universality.

[0042] Example 1

[0043] 1) Lanthanum (III) nitrate hydrate (0.649 g, 2.0 mmol) was dissolved in 20 mL of ethylene glycol monomethyl ether, stirred overnight at room temperature, and filtered to form a seed layer solution.

[0044] 2) Spin the above solution onto the Si substrate using a spin coating method at a spin coating speed of 3000 rpm for 30 seconds. Irradiate with a mixed wavelength of 185 nm and 254 nm UV light for 10 minutes at 100°C. Then place it on a hot plate and slowly heat it to 450°C for 10 minutes to form a seed layer film (the film thickness is about 10 nm as measured by SEM, and seed layer films of different thicknesses can be adjusted by changing the concentration of the seed layer solution and the spin coating speed).

[0045] 3) Using the sol-gel method, the prepared PZT precursor solution was spin-coated on the seed layer at a spin-coating speed of 3000rpm for 20s, and annealed at 600℃ for 10 minutes to prepare a PZT film. The preparation method of PZT is as follows: Take lead acetate trihydrate (12g, 31.63mmol), dissolve it in 6mL acetic acid, heat it to 110℃ and stir for 3 hours (distill to remove water), and then cool it to 90℃; add zirconium n-propoxide (6.41g, 13.71mmol, 70w%) to the above lead-acetic acid solution, and then add titanium isopropoxide (3.2g, 12.65mmol) and stir for 0.5 hours; cool it to room temperature, add 30mL acetic acid, stir overnight, filter, and obtain a clear and transparent solution, which is the PZT precursor solution.

[0046] 4) The PZT film prepared as above was characterized by XRD and SEM. The results showed that the PZT film prepared by this method had a higher preferred orientation.

[0047] The XRD pattern of the PZT film obtained in Example 1 is shown in Figure 1 .Depend on Figure 1 It can be seen that the PZT film has good crystallinity and has obvious (100) grain preferential orientation, which can indicate that the prepared PZT film has excellent performance. The diffraction angles 2θ=21.7° and 44.3° in the figure are the peaks of PZT (100) and (200), respectively.

[0048] Example 2

[0049] 1) Lanthanum acetate hydrate (0.668 g, 2.0 mmol) was dissolved in 20 mL of n-propanol, stirred overnight at room temperature, and filtered to form a seed layer solution.

[0050] 2) Spin the solution onto a Si substrate using a spin coating method at a speed of 3000 rpm for 30 seconds, and irradiate with a mixed wavelength of 185 nm and 254 nm UV light at 100° C. for 10 minutes. Slowly heat to 400° C. on a hot plate and maintain for 10 minutes to form a seed layer.

[0051] 3) PZT was sputtered onto the seed layer by magnetron sputtering, the sputtering atmosphere was Ar / O2=1:1, the gas pressure was 0.5 Pa, and the sputtering temperature was 25° C. After annealing at 600° C. for 10 minutes, a PZT crystal film was prepared.

[0052] 4) The PZT film prepared as above was characterized by XRD and SEM. The results showed that the PZT film prepared by this method had a high degree of preferential orientation.

[0053] The XRD of the PZT film prepared by this method is equivalent to that of Example 1.

[0054] Example 3

[0055] 1) Take lanthanum acetate hydrate (0.668 g, 2.0 mmol), dissolve it in 20 mL of water, stir it at room temperature overnight, and filter it to form a seed layer solution.

[0056] 2) Spin the above solution onto a SiO2 substrate using a spin coating method at a speed of 3000 rpm for 30 seconds. Irradiate with a mixed wavelength of 185 nm and 254 nm UV light at 100°C for 10 minutes. Slowly heat to 450°C on a hot plate and maintain for 10 minutes to form a seed layer.

[0057] 3) Using the sol-gel method, the prepared SBN precursor solution was spin-coated on the seed layer at a spin-coating speed of 3000 rpm for 20 seconds, and annealed at 900°C for 1.0 hour to prepare an SBN crystal film. The preparation method of the SBN precursor solution is as follows: take metal strontium (1.851 g, 9.0 mmol) and metal barium (1.532 g, 6.0 mmol), dissolve them in 20 mL of ethylene glycol monomethyl ether under nitrogen protection, heat to 120°C, stir and reflux for 12 hours; take ethanol niobium (9.546 g, 30.0 mmol), dissolve it in 10 mL of ethylene glycol monomethyl ether under nitrogen protection, heat to 120°C, stir and reflux for 12 hours, and cool; mix the two solutions in the above steps together, heat to 120°C, stir and reflux for 12 hours, cool, and filter to obtain an SBN precursor solution.

[0058] 4) The SBN film prepared as above was characterized by XRD and SEM. The results showed that the PZT film prepared by this method had a high degree of preferential orientation.

[0059] The XRD pattern of the SBN film obtained in Example 3 is shown in Figure 2 .Depend on Figure 2 It can be seen that the SBN film has good crystallinity and an obvious (100) preferred orientation, which can indicate that the prepared SBN film has excellent performance.

[0060] Example 4

[0061] 1) Lanthanum nitrate hexahydrate (0.866 g, 2.0 mmol) was dissolved in 20 mL of ethylene glycol monomethyl ether, stirred overnight at room temperature, and filtered to form a seed layer solution.

[0062] 2) Spin the above solution onto a Si substrate using a spin coating method at a speed of 3000 rpm for 30 seconds. Irradiate with a mixed wavelength of 185 nm and 254 nm ultraviolet light at 100°C for 10 minutes. Slowly heat to 450°C on a hot plate to form a seed layer.

[0063] 3) The prepared BTO precursor solution was spin-coated on the seed layer by a sol-gel method at a spin-coating speed of 3000 rpm for 20 s, and annealed at 700° C. for 0.5 hours to prepare a BTO film.

[0064] The BTO precursor solution was prepared as follows: tetrabutyl titanate (3.4 g, 10.0 mmol) was dissolved in 10 mL of acetic acid, 0.5 mL of acetylacetone was added, the mixture was heated to 60° C. and stirred for 0.5 hours, and the mixture was cooled; barium acetate (2.55 g, 10.0 mmol) was dissolved in 10 mL of acetic acid, 0.5 mL of acetylacetone was added, the mixture was heated to 80° C., stirred for 3 hours, and the mixture was cooled; the two solutions were mixed, stirred at room temperature for 12 hours, and filtered to obtain a BTO precursor solution.

[0065] 4) The BTO film prepared as above was characterized by XRD and SEM. The results showed that the BTO film prepared by this method had a high degree of preferential orientation.

[0066] The XRD pattern of the BTO film obtained in Example 4 is shown in Figure 3 .Depend on Figure 3 It can be seen that the BTO film has good crystallinity and has obvious (100) grain preferential orientation, which can indicate that the prepared BTO film has excellent performance.

[0067] Example 5

[0068] 1) Praseodymium (III) nitrate hexahydrate (0.870 g, 2.0 mmol) was dissolved in 20 mL of ethylene glycol monomethyl ether, stirred overnight at room temperature, and filtered to form a seed layer solution.

[0069] 2) Spin the above solution onto the Si substrate using a spin coating method at a spin coating speed of 3000 rpm for 30 seconds. Irradiate with a mixed wavelength of 185 nm and 254 nm UV light at 100°C for 10 minutes. Slowly heat to 450°C on a hot plate and keep for 10 minutes to form a seed layer film (the film thickness is about 10 nm as measured by SEM, and seed layer films of different thicknesses can be adjusted by changing the concentration of the seed layer solution and the spin coating speed).

[0070] 3) The prepared PZT precursor solution was spin-coated on the seed layer by the sol-gel method at a spin-coating speed of 3000 rpm for 20 seconds, and then annealed at 600°C for 10 minutes to prepare a PZT film. The preparation method of PZT is as follows: Take lead acetate trihydrate (12g, 31.63mmol), dissolve it in 6mL acetic acid, heat it to 110°C and stir for 3 hours (distill to remove water), and then cool it to 90°C; add zirconium n-propoxide (6.41g, 13.71mmol, 70w%) to the above lead-acetic acid solution, and then add titanium isopropoxide (3.2g, 12.65mmol) and stir for 0.5 hours; cool it to room temperature, add 30mL acetic acid, stir overnight, filter, and obtain a clear and transparent solution, which is the PZT precursor solution.

[0071] 4) The PZT film prepared as above was characterized by XRD and SEM. The results showed that the PZT film prepared by this method had a higher preferred orientation.

[0072] The XRD of the PZT film prepared by this method is equivalent to that of Example 1.

[0073] Example 6

[0074] 1) Neodymium (III) nitrate hexahydrate (0.876 g, 2.0 mmol) was dissolved in 20 mL of ethylene glycol monomethyl ether, stirred overnight at room temperature, and filtered to form a seed layer solution.

[0075] 2) Spin the solution onto a Si substrate using a spin coating method at a spin coating speed of 3000 rpm for 30 seconds, and irradiate with a mixed wavelength of 185 nm and 254 nm UV lamp at 100°C for 10 minutes. Slowly heat to 450°C on a hot plate and keep for 10 minutes to form a seed layer film (the film thickness is about 10 nm as measured by SEM, and seed layer films of different thicknesses can be adjusted by changing the concentration of the seed layer solution and the spin coating speed).

[0076] 3) Using the sol-gel method, the prepared PZT precursor solution was spin-coated on the seed layer at a spin-coating speed of 3000rpm for 20s, and annealed at 600℃ for 10 minutes to prepare a PZT film. The preparation method of PZT is as follows: Take lead acetate trihydrate (12g, 31.63mmol), dissolve it in 6mL acetic acid, heat it to 110℃ and stir for 3 hours (distill to remove water), and then cool it to 90℃; add zirconium n-propoxide (6.41g, 13.71mmol, 70w%) to the above lead-acetic acid solution, and then add titanium isopropoxide (3.2g, 12.65mmol) and stir for 0.5 hours; cool it to room temperature, add 30mL acetic acid, stir overnight, filter, and obtain a clear and transparent solution, which is the PZT precursor solution.

[0077] 4) The PZT film prepared as above was characterized by XRD and SEM. The results showed that the PZT film prepared by this method had a higher preferred orientation.

[0078] The XRD of the PZT film prepared by this method is equivalent to that of Example 1.

[0079] The above-mentioned specific implementation methods are used to explain the present invention and are only preferred embodiments of the present invention, rather than limiting the present invention. Any modifications, equivalent substitutions, improvements, etc. made to the present invention within the spirit of the present invention and the protection scope of the claims shall fall within the protection scope of the present invention.

Claims

1. A seed layer for preparing a preferentially oriented crystal film, characterized in that: A lanthanide metal salt is selected as the starting material for the seed layer, and a solution is prepared using the starting material, with the solution concentration being 0.1-0.5 mol / L. The prepared solution is filtered to remove impurities and insoluble particles in the solution to obtain a seed layer solution, and the seed layer solution is spin-coated on a substrate, and irradiated with an ultraviolet lamp with a mixed wavelength of 185 nm and 254 nm, and organic matter in the seed layer solution is decomposed at a temperature of 100°C, and the seed layer is obtained by heat treatment.

2. A seed layer for preparing a preferentially oriented crystal film according to claim 1, characterized in that: Lanthanide metal salts include lanthanum nitrate, lanthanum acetate, praseodymium nitrate, and neodymium nitrate.

3. A seed layer for preparing a preferentially oriented crystal film according to claim 1, characterized in that: Lanthanide metal salt is used as the starting material of the seed layer, added into a solvent, and a seed layer solution is generated through stirring and filtering. The solvent includes ethylene glycol monomethyl ether, n-propanol or water, and the substrate includes Si or SiO2 substrate.

4. A seed layer for preparing a preferentially oriented crystal film according to claim 1, characterized in that: The seed layer is formed by spin coating and heat treatment.

5. A method for preparing a crystal film using a seed layer for preparing a preferentially oriented crystal film according to any one of claims 1 to 4, characterized in that: The preferentially oriented crystal film is prepared by a sol-gel method, wherein a prepared metal oxide film precursor solution is spin-coated on the seed layer and subjected to heat treatment to prepare the preferentially oriented crystal film.

6. A method for preparing a crystal film using a seed layer for preparing a preferentially oriented crystal film according to any one of claims 1 to 4, characterized in that: The preferentially oriented crystal film is prepared by a magnetron sputtering method: a substrate with a seed layer is placed on a sample stage of a magnetron sputtering device, a target material is selected, a corresponding metal oxide film is sputtered, and then a preferentially oriented crystal film is prepared by heat treatment.

7. The method for preparing a crystal thin film according to claim 6, characterized in that: The metal oxide precursor solution includes a lead zirconate titanate precursor solution, a barium titanate precursor solution or a barium strontium niobate precursor solution; The target materials required for magnetron sputtering include lead zirconate titanate, barium titanate or barium strontium niobate.

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