Thin film and preparation method thereof, electronic device and electronic equipment

Abstract

The embodiment of the invention provides a thin film and a preparation method thereof, an electronic device and electronic equipment, relates to the technical field of communication, and aims to reduce the preparation temperature of the thin film so as to reduce the preparation temperature and the preparation cost of the thin film. The preparation method of the film comprises the following steps: preparing a precursor solution; preparing a dry film by using the precursor solution; and carrying out annealing treatment on the dry film under the conditions that the pressure intensity is greater than or equal to 1.5 MPa and the temperature is less than or equal to 450 DEG C to form the thin film. The film is applied to the electronic equipment, and the performance of the electronic equipment is improved.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a thin film and its preparation method, electronic devices, and electronic equipment. Background Technology

[0002] Lead zirconate titanate (PZT), barium strontium niobate (SBN), barium titanate (BTO), and lanthanum-modified lead zirconate titanate (PLZT) are all multifunctional materials with large piezoelectric and electro-optic coefficients, high dielectric constants, and significant remanent polarization, demonstrating their excellent piezoelectric, electro-optic, and pyroelectric properties. Therefore, lead zirconate titanate films, barium strontium niobate films, barium titanate films, and lanthanum-modified lead zirconate titanate films have wide applications in microelectronics, optoelectronics, and microelectro-mechanical systems (MEMS).

[0003] Currently, although there are many methods for preparing the aforementioned thin films, the preparation temperatures of these methods are all relatively high, making the preparation of thin films difficult and costly. Summary of the Invention

[0004] This application provides a thin film and its preparation method, electronic device and electronic device, which are used to reduce the preparation temperature of the thin film, thereby reducing the preparation difficulty and cost of the thin film.

[0005] To achieve the above objectives, the embodiments of this application adopt the following technical solutions:

[0006] In a first aspect, a method for preparing a thin film is provided, the method comprising: preparing a precursor solution; preparing a dry film using the precursor solution; and annealing the dry film under conditions of pressure greater than or equal to 1.5 MPa and temperature less than or equal to 450°C to form a thin film.

[0007] This application utilizes the sol-gel method, first preparing a precursor solution, then using the precursor solution to prepare a dry film, and finally subjecting the dry film to high-pressure, low-temperature annealing to obtain a thin film. Compared with related technologies, the thin film preparation method provided in this application involves a higher pressure during the annealing process (i.e., pressure greater than or equal to 1.5 MPa), which reduces the energy required for film crystallization, allowing for a lower annealing temperature. This, in turn, helps to reduce the difficulty and cost of thin film preparation.

[0008] Meanwhile, the annealing temperature in the fabrication method provided in this application is less than or equal to 450°C, which is less than or equal to the highest temperature that silicon-based CMOS circuits can withstand. This allows the thin film to be applied to silicon-based complementary metal-oxide-semiconductor (CMOS) circuits, improving the film's applicability.

[0009] In some embodiments, the preparation of the precursor solution includes the preparation of Pb x Zr y Ti 1-y O3 precursor solution; where 1≤x≤1.3, 0.51≤y≤0.53.

[0010] In some embodiments, the preparation of Pb x Zr y Ti 1-y The O3 precursor solution comprises: adding zirconium oxynitrate, tetraethyl titanate, lead nitrate, and acetylacetone to ethylene glycol monomethyl ether to obtain the Pb. x Zr y Ti 1-y O3 precursor solution.

[0011] Zirconium oxynitrate, tetraethyl titanate, and lead nitrate were used as raw materials, ethylene glycol monomethyl ether as a solvent, and acetylacetone as a stabilizer. Acetylacetone, as a stabilizer, helps to stabilize the Pb obtained during preparation. x Zr y Ti 1-y The stability of the O3 precursor solution is greatly improved, which makes Pb x Zr y Ti 1-y O3 precursor solutions can be stored stably for a relatively long time.

[0012] In some embodiments, the preparation of Pb x Zr y Ti 1-y The O3 precursor solution comprises: adding zirconium oxynitrate and tetraethyl titanate to glacial acetic acid, followed by the addition of lead acetate to obtain the Pb. x Zr y Ti 1-y O3 precursor solution.

[0013] In some embodiments, the preparation of a dry film using the precursor solution includes: spin-coating the precursor solution onto a substrate to form a wet film; and drying the wet film to form a dry film.

[0014] In some embodiments, the drying process of the wet film to form a dry film includes: drying the wet film under vacuum conditions to form a dry film. This helps to improve the uniformity of the dry film and reduce defects on the film surface.

[0015] In some embodiments, the drying process is performed at a temperature greater than or equal to 100°C and less than or equal to 300°C.

[0016] In some embodiments, after preparing a dry film using the precursor solution, the preparation method further includes pyrolyzing the dry film. This can reduce defects on the film surface, such as cracks or point defects.

[0017] In some embodiments, the pyrolysis temperature is greater than or equal to 100°C and less than or equal to 450°C. This ensures that the pyrolysis temperature is not too low, which is beneficial for the decomposition of the raw materials in the dry film; and that the pyrolysis temperature is not too high, which helps to maintain a low temperature throughout the film preparation process, reducing the difficulty and cost of film preparation, ensuring that the film can be applied to CMOS circuits, and improving the applicability of the film.

[0018] In some embodiments, the annealing treatment of the dry film to form a thin film under conditions of pressure greater than or equal to 1.5 MPa and temperature less than or equal to 450°C includes: placing the dry film in a high-pressure reactor, maintaining the pressure at 2 ± 0.5 MPa in an oxygen atmosphere, raising the temperature from room temperature to 445 ± 5°C and holding it for 1 ± 0.5 hours, and then lowering the temperature to room temperature to obtain the thin film.

[0019] In this way, the annealing temperature is lower, the pressure is lower, and the annealing time is shorter, which helps to reduce the difficulty of annealing, improve the annealing efficiency, and thus help to reduce the difficulty of film preparation and improve the film preparation efficiency.

[0020] In some embodiments, the annealing treatment of the dry film to form a thin film under conditions of pressure greater than or equal to 1.5 MPa and temperature less than or equal to 450°C includes: placing the dry film in a high-pressure reactor, maintaining the pressure at 2±0.5 MPa in an oxygen atmosphere, raising the temperature from room temperature to 400±10°C and holding it for 10±1 hours, and then lowering the temperature to room temperature to obtain the thin film.

[0021] In this way, the annealing temperature can be lower, the thin film preparation is easier, and the preparation cost is lower. When the thin film is applied to silicon-based CMOS circuits, the thin film preparation process is less likely to damage the silicon-based CMOS device.

[0022] In some embodiments, the annealing treatment of the dry film to form a thin film under conditions of pressure greater than or equal to 1.5 MPa and temperature less than or equal to 450°C includes: placing the dry film in a high-pressure reactor, maintaining the pressure at 2 ± 0.5 MPa in an oxygen atmosphere, raising the temperature from room temperature to 300 ± 10°C and holding it for 30 ± 5 minutes, then raising the temperature to 445 ± 5°C and holding it for 1 ± 0.5 hours, and finally lowering the temperature to room temperature to obtain the thin film.

[0023] In this way, on the one hand, the raw materials in the dry film can be fully decomposed and react with each other, and on the other hand, it is beneficial to transform the film from a polycrystalline phase to a single crystal phase.

[0024] In some embodiments, the annealing treatment of the dry film to form a thin film under conditions of pressure greater than or equal to 1.5 MPa and temperature less than or equal to 450°C includes: placing the dry film in a high-pressure reactor, maintaining the pressure at 2±0.5 MPa in an oxygen atmosphere, raising the temperature from room temperature to 300±10°C and holding it for 30±5 minutes, then raising the temperature to 400±10°C and holding it for 10±1 hours, and finally lowering the temperature to room temperature to obtain the thin film.

[0025] At this point, the annealing temperature can be lower, the pressure lower, and the film preparation conditions simpler. Simultaneously, the annealing time is longer, which helps ensure the film's crystallization effect.

[0026] In some embodiments, annealing the dry film to form a thin film under conditions of pressure greater than or equal to 1.5 MPa and temperature less than or equal to 450°C includes: placing the dry film in a high-pressure reactor, maintaining the pressure at 4 ± 0.5 MPa in an oxygen atmosphere, raising the temperature from room temperature to 300 ± 10°C and holding it for 30 ± 5 minutes, then raising the temperature to 445 ± 5°C and holding it for 30 ± 5 minutes, and finally lowering the temperature to room temperature to obtain the thin film. This method requires a lower annealing temperature and shorter time, thereby improving the efficiency of thin film preparation.

[0027] Secondly, a thin film is provided. The thin film is prepared by the preparation method described in any of the above embodiments.

[0028] Thirdly, an electronic device is provided. The electronic device includes a metal oxide layer and a plurality of electrodes. The metal oxide layer includes the thin film provided in any of the above embodiments. The plurality of electrodes are located on the same side of the metal oxide layer, or the metal oxide layer is located between the plurality of electrodes.

[0029] Fourthly, an electronic device is provided. The electronic device includes a circuit board and an electronic component as described in any of the above embodiments, the electronic component being located on the circuit board and electrically connected to the circuit board.

[0030] The technical effects of any of the design methods in the second to fourth aspects can be found in the technical effects of different design methods in the first aspect, and will not be repeated here. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in this application, the accompanying drawings used in some embodiments of this application will be briefly described below. Obviously, the drawings described below are only drawings of some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings. In addition, the drawings described below can be regarded as schematic diagrams and are not intended to limit the actual size of the product, the actual flow of the method, the actual timing of the signals, etc. involved in the embodiments of this application.

[0032] Figure 1 A schematic flowchart illustrating a method for preparing a thin film according to an embodiment of this application;

[0033] Figure 2 A schematic flowchart illustrating another method for preparing a thin film provided in this application embodiment;

[0034] Figure 3 A schematic flowchart illustrating another method for preparing a thin film provided in this application embodiment;

[0035] Figure 4 A schematic flowchart illustrating another method for preparing a thin film provided in this application embodiment;

[0036] Figure 5 A schematic flowchart illustrating another method for preparing a thin film provided in this application embodiment;

[0037] Figure 6 A schematic flowchart illustrating another method for preparing a thin film provided in this application embodiment;

[0038] Figure 7 A schematic flowchart illustrating another method for preparing a thin film provided in this application embodiment;

[0039] Figure 8 A Pb provided for embodiments of this application x Zr y Ti 1-y Physical image of the O3 precursor solution;

[0040] Figure 9 A physical image of a lead zirconate titanate thin film provided for an embodiment of this application;

[0041] Figure 10 An X-ray diffraction pattern of a lead zirconate titanate thin film provided in an embodiment of this application;

[0042] Figure 11 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application;

[0043] Figure 12 This is a schematic diagram of the structure of another electronic device provided in an embodiment of this application;

[0044] Figure 13 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0045] The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0046] In this application, unless the context otherwise requires, the term "comprising" is interpreted as open-ended and encompassing, meaning "including, but not limited to," throughout the specification and claims. In the description, terms such as "one embodiment," "some embodiments," "exemplary embodiment," "exemplary," or "some examples" are intended to indicate that a particular feature, structure, material, or characteristic associated with that embodiment or example is included in at least one embodiment or example of this disclosure. The illustrative representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics mentioned may be included in any suitable manner in any one or more embodiments or examples.

[0047] Metal oxide thin films such as lead zirconate titanate, barium strontium niobate, barium titanate, and lanthanum lead zirconate titanate all possess excellent piezoelectric, ferroelectric, dielectric, and electro-optic properties, and are therefore widely used in microelectronics, optoelectronics, and microelectromechanical systems. Currently, although there are numerous methods for preparing these metal oxide thin films, the preparation temperatures are generally high, making the film preparation process challenging and costly.

[0048] For example, the numerous methods for preparing lead zirconate titanate (PZT) thin films can be broadly categorized into two types: physical vapor deposition (PVD) and chemical deposition (CSD). PVD requires temperatures of 550–600°C to prepare high-performance PZT films, while CSD requires temperatures of 650–750°C.

[0049] In addition to affecting the difficulty and cost of thin film fabrication, higher fabrication temperatures also impact the application scenarios of thin films. For example, the highest temperature that silicon-based CMOS devices can currently withstand is 450℃. When integrating PZT thin films into silicon-based CMOS devices using physical vapor deposition or chemical deposition methods, the high fabrication temperature of PZT thin films can severely damage the silicon-based CMOS devices, making it difficult to apply PZT thin films to CMOS devices.

[0050] Based on this, embodiments of this application provide a method for preparing a thin film. For example... Figure 1 As shown, the preparation method includes steps S100 to S300.

[0051] S100, Prepare the precursor solution.

[0052] The aforementioned precursor solution can be a lead zirconate titanate precursor solution, a barium strontium niobate precursor solution, a barium titanate precursor solution, or a lead zirconate titanate lanthanum precursor solution.

[0053] In some embodiments, such as Figure 2 As shown, step S100 may include step S110.

[0054] S110, Preparation of Pb x Zr y Ti 1-y O3 precursor solution. Where 1≤x≤1.3, 0.51≤y≤0.53.

[0055] For example, Pb x Zr y Ti 1-y O3 precursor solutions may include Pb1Zr 0.52 Ti 0.48 O3, Pb1Zr 0.51 Ti 0.49 O3, Pb1Zr 0.53 Ti 0.47 O3, Pb 1.1 Zr 0.51 Ti 0.49 O3, Pb 1.1 Zr 0.52 Ti 0.48 O3, Pb 1.1 Zr 0.53 Ti 0.47 O3, Pb 1.2 Zr 0.51 Ti 0.49 O3, Pb 1.2 Zr 0.52 Ti 0.48 O3, Pb 1.2 Zr 0.53 Ti0.47 O3, Pb 1.3 Zr 0.51 Ti 0.49 O3, Pb 1.3 Zr 0.52 Ti 0.48 O3 or Pb 1.3 Zr 0.53 Ti 0.47 O3.

[0056] In some examples, such as Figure 3 As shown, step S110 may include step S111.

[0057] S111. Zirconium oxynitrate, tetraethyl titanate, lead nitrate, and acetylacetone are added to ethylene glycol monomethyl ether to obtain Pb. x Zr y Ti 1-y O3 precursor solution.

[0058] Zirconium oxynitrate, tetraethyl titanate, and lead nitrate are used as raw materials, ethylene glycol monomethyl ether is used as a solvent, and acetylacetone is used as a stabilizer (or chelating agent).

[0059] Acetylacetone, as a stabilizer, can stabilize the prepared Pb x Zr y Ti 1-y The stability of the O3 precursor solution is greatly improved, which makes Pb x Zr y Ti 1-y O3 precursor solutions are stable for a relatively long time, for example, up to two months. Of course, besides acetylacetone, stabilizers can also be formamide or glycerol, etc.

[0060] For example, after adding zirconium oxynitrate, tetraethyl titanate, lead nitrate, and acetylacetone to ethylene glycol monomethyl ether, Pb can be obtained by heating, stirring, cooling, and filtering. x Zr y Ti 1-y O3 precursor solution. The heating temperature can be 100℃~150℃, for example, 110℃, 120℃, 130℃, 140℃, 150℃, etc. The stirring time can be 1 hour~5 hours, for example, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, etc.

[0061] It is understandable that the molar ratio of zirconium oxynitrate, tetraethyl titanate, and lead nitrate can be determined based on Pb. x Zr y Ti 1-y The proportions of Pb, Zr, and Ti in O3 are adjusted. For example, in Pb x Zry Ti 1-y The O3 precursor solution is Pb 1.2 Zr 0.52 Ti 0.48 In the case of O3 solution, 4.0 mmol of zirconium oxynitrate, 3.7 mmol of tetraethyl titanate, 9.24 mmol of lead nitrate and 1.0 mL of acetylacetone can be added to ethylene glycol monomethyl ether.

[0062] In some examples, zirconium oxynitrate, tetraethyl titanate, lead nitrate, and acetylacetone can be added to ethylene glycol monomethyl ether under nitrogen protection.

[0063] The Pb prepared using the above steps is described in this embodiment. x Zr y Ti 1-y The O3 precursor solution can be a stable, orange-yellow, transparent solution. "Stable" means that Pb remains stable after standing for 1 to 2 days. x Zr y Ti 1-y The O3 precursor solution will not settle or separate into layers.

[0064] In other examples, such as Figure 4 As shown, step S110 may include step S112.

[0065] S112. Zirconium oxynitrate and tetraethyl titanate were added to glacial acetic acid, followed by the addition of lead acetate to obtain Pb. x Zr y Ti 1-y O3 precursor solution.

[0066] Zirconium oxynitrate, tetraethyl titanate, and lead acetate were used as raw materials, and glacial acetic acid was used as a solvent. The Pb prepared using the above steps in the embodiments of this application... x Zr y Ti 1-y The O3 precursor solution can be a stable, clear, and transparent solution.

[0067] In some examples, after adding zirconium oxynitrate and tetraethyl titanate to glacial acetic acid, the resulting solution can be heated and stirred. The heating temperature can be 100℃–150℃, and the stirring time can be 1–5 hours. For example, the heating temperature can be 110℃, 120℃, 130℃, 140℃, or 150℃, and the stirring time can be 1 hour, 2 hours, 3 hours, 4 hours, or 5 hours.

[0068] In some examples, the resulting solution can be stirred after the addition of lead acetate. The stirring time can be 1 to 5 hours. For example, the stirring time can be 1 hour, 2 hours, 3 hours, 4 hours, or 5 hours, etc.

[0069] In some examples, in Pb x Zr y Ti 1-y The O3 precursor solution is Pb 1.2 Zr 0.52 Ti 0.48 In the presence of O3 solution, 4.0 mmol of zirconium oxynitrate and 3.7 mmol of tetraethyl titanate can be added to 20 ml of glacial acetic acid, heated and stirred, followed by the addition of 9.24 mmol of lead acetate. After stirring and filtration, Pb is obtained. 1.2 Zr 0.52 Ti 0.48 O3 solution.

[0070] In other examples, in Pb x Zr y Ti 1-y The O3 precursor solution is Pb1Zr 0.52 Ti 0.48 In the presence of O3 solution, 4.0 mmol of zirconium oxynitrate and 3.7 mmol of tetraethyl titanate can be added to 20 ml of glacial acetic acid, heated and stirred, followed by the addition of 7.7 mmol of lead acetate. After stirring and filtration, Pb1Zr can be obtained. 0.52 Ti 0.48 O3 solution.

[0071] It is understood that the embodiments of this application are in the preparation of Pb x Zr y Ti 1-y When preparing the O3 precursor solution, the raw materials used are not limited to zirconium oxynitrate, tetraethyl titanate, lead nitrate, or lead acetate, and the solutions used are not limited to ethylene glycol monomethyl ether and glacial acetic acid. Furthermore, the preparation of Pb... x Zr y Ti 1-y When using O3 precursor solutions, the amounts of raw materials and solvents are not limited to the examples above.

[0072] S200, Dry film is prepared using precursor solution.

[0073] In some embodiments, such as Figure 5 As shown, step S200 may include steps S210 and S220.

[0074] S210. Spin-coat the precursor solution onto the substrate to form a wet film.

[0075] In some examples, the substrate material can be monocrystalline silicon, sapphire, silicon dioxide, or metal, etc. The substrate can be a single-layer structure or a multi-layer structure.

[0076] In some examples, the substrate can be cleaned and dried before spin-coating the precursor solution onto it to remove organic and inorganic impurities from its surface. This helps ensure both the composition of the film formed on the substrate and the quality of the film.

[0077] For example, a spin coater can be used to spin-coat the precursor solution onto the substrate. The spin coater speed can be 2000 rpm to 4000 rpm, and the spin coat time can be 5 seconds to 40 seconds. For instance, the spin coater speed can be 2000 rpm, 2500 rpm, 3000 rpm, 3500 rpm, or 4000 rpm, and the spin coat time can be 5 seconds, 10 seconds, 15 seconds, 20 seconds, 25 seconds, 30 seconds, 35 seconds, or 40 seconds.

[0078] The rotation speed of the spin coater affects the continuous distribution and thickness uniformity of the film on the substrate surface. Excessive spin coater speed can easily lead to discontinuous wet film distribution and severe edge divergence. Furthermore, a high spin coater speed results in a thinner wet film, increasing the number of coating and heat treatment (drying or annealing) cycles and making the film prone to cracking. Conversely, a low spin coater speed makes it difficult for the precursor solution to spread evenly on the substrate, hindering uniform film distribution and also making the film prone to cracking during heat treatment. In the embodiments of this application, the spin coater rotation speed is 2000 Rpm to 4000 Rpm. This ensures that when the precursor solution is spin-coated onto the substrate to form a wet film, the wet film can be continuously distributed on the substrate surface with uniform thickness.

[0079] S220. The wet film is dried to form a dry film.

[0080] For example, the drying temperature can be greater than or equal to 100°C and less than or equal to 300°C. For instance, the drying temperature can be 100°C, 150°C, 200°C, 250°C, or 300°C.

[0081] For example, the drying time can be from 5 minutes to 20 minutes. For instance, the drying time can be 5 minutes, 10 minutes, 15 minutes, 20 minutes, etc. It is understood that the drying temperature and time are not limited to these and can be adjusted according to actual needs.

[0082] In some examples, such as Figure 6 As shown, step S220 may include step S221.

[0083] S221. The wet film is dried in a vacuum environment to form a dry film. This helps improve the uniformity of the dry film and reduce defects on the film surface. For example, the wet film can be placed in a vacuum drying oven for drying.

[0084] S300: Under conditions of pressure greater than or equal to 1.5 MPa and temperature less than or equal to 450°C, the dry film is annealed to form a thin film.

[0085] For example, the annealing pressure can be 1.5MPa, 2MPa, 3MPa, 4MPa, 5MPa, etc., and the temperature can be 300℃, 350℃, 400℃, 450℃, etc.

[0086] In some examples, the dry film can be placed in a high-pressure reactor under an oxygen atmosphere, with the pressure maintained at 2±0.5 MPa. The temperature is then raised from room temperature to 445±5℃ and held for 1±0.5 hours, before being lowered back to room temperature to obtain the film. This method involves lower annealing temperatures, lower pressures, and shorter annealing times, which helps reduce the difficulty of annealing, improves annealing efficiency, and consequently reduces the difficulty and efficiency of film preparation.

[0087] In other examples, the dry film can be placed in a high-pressure reactor under an oxygen atmosphere, with the pressure maintained at 2±0.5 MPa. The temperature is then raised from room temperature to 400±10℃ and held for 10±1 hours, before being lowered back to room temperature to obtain the thin film. This allows for lower annealing temperatures, easier film fabrication, and lower costs. Furthermore, when applying the thin film to silicon-based CMOS circuits, the fabrication process is less likely to damage the silicon-based CMOS circuits.

[0088] In other examples, the dry film can be placed in a high-pressure reactor under an oxygen atmosphere, with the pressure maintained at 2±0.5 MPa. The temperature is then raised from room temperature to 300±10℃ and held for 30±5 minutes, followed by raising the temperature to 445±5℃ and holding for 1±0.5 hours. Finally, the temperature is lowered to room temperature to obtain the thin film. This process allows the raw materials in the dry film to fully decompose and react with each other, and also facilitates the transformation of the film from a polycrystalline phase to a single-crystalline phase.

[0089] In other examples, the dry film can be placed in a high-pressure reactor under an oxygen atmosphere, with the pressure maintained at 2±0.5 MPa. The temperature is then raised from room temperature to 300±10℃ and held for 30±5 minutes, followed by raising the temperature to 400±10℃ and holding for 10±1 hours. Finally, the temperature is lowered to room temperature to obtain the film. In this case, the annealing temperature can be lower, the pressure is lower, and the film preparation conditions are simpler. At the same time, the longer annealing time helps to ensure the crystallization effect of the film.

[0090] In other examples, the dry film can be placed in a high-pressure reactor under an oxygen atmosphere, with the pressure maintained at 4±0.5 MPa. The temperature is then raised from room temperature to 300±10℃ and held for 30±5 minutes, followed by raising the temperature to 445±5℃ and holding for another 30±5 minutes. Finally, the temperature is lowered to room temperature to obtain the film. This method requires a lower annealing temperature and shorter time, thus improving the film preparation efficiency.

[0091] In this embodiment, there are no restrictions on the heating and cooling rates during the annealing process; the design can be tailored to actual needs.

[0092] It is understandable that when the required film thickness is large, steps S100 to S300 can be repeated multiple times.

[0093] This application utilizes the sol-gel method, first preparing a precursor solution, then using the precursor solution to prepare a dry film, and finally subjecting the dry film to high-pressure, low-temperature annealing to obtain a thin film. Compared with related technologies, the lead zirconate titanate thin film preparation method provided in this application involves higher pressure during the annealing process, thereby reducing the energy required for film crystallization and allowing for a lower annealing temperature. This, in turn, helps to reduce the difficulty and cost of thin film preparation.

[0094] Furthermore, the annealing temperature in the preparation method provided in this application is less than or equal to 450°C, which is less than or equal to the highest temperature that silicon-based CMOS circuits can withstand. This allows the thin film to be applied to CMOS circuits, improving its applicability.

[0095] In some embodiments, such as Figure 7 As shown, after step S200 and before step S300, the preparation method may also include step S400.

[0096] S400: Pyrolyze the dry film. This reduces surface defects such as cracks or point defects.

[0097] For example, the dry film can be placed on a hot plate for pyrolysis.

[0098] For example, the pyrolysis temperature can be greater than or equal to 100°C and less than or equal to 450°C. For instance, the pyrolysis temperature can be 100°C, 200°C, 250°C, 300°C, 400°C, 450°C, etc. The pyrolysis time can be greater than or equal to 5 minutes and less than or equal to 60 minutes. For instance, the pyrolysis time can be 5 minutes, 10 minutes, 20 minutes, 30 minutes, 40 minutes, 50 minutes, 60 minutes, etc.

[0099] In this way, on the one hand, the pyrolysis temperature will not be too low, which is conducive to the decomposition of raw materials in the dry film; on the other hand, the pyrolysis temperature will not be too high, which is conducive to ensuring that the temperature is low throughout the film preparation process, reducing the difficulty and cost of film preparation, ensuring that the film can be applied to CMOS circuits, and improving the applicability of the film.

[0100] Below, taking lead zirconate titanate thin film as an example, the preparation method of the thin film provided in this application will be described in detail through five embodiments.

[0101] Example 1

[0102] Under nitrogen protection, 4.0 mmol of zirconium oxynitrate, 3.7 mmol of tetraethyl titanate, 9.24 mmol of lead nitrate, and 1.0 mL of acetylacetone were added to ethylene glycol monomethyl ether, heated to 120 °C, and stirred for 3 hours. After cooling and filtration, the following product was obtained: Figure 8 The stable, orange-yellow transparent Pb shown x Zr y Ti 1-y O3 precursor solution.

[0103] Pb was coated using a spin coating method and a spin coater. x Zr y Ti 1-y The O3 precursor solution was spin-coated onto the substrate to form a wet film. The spin coater was set at a speed of 3000 rpm for 20 seconds.

[0104] The wet film is placed in a vacuum drying oven to dry it, forming a dry film. The drying temperature is 150℃, and the time is 10 minutes.

[0105] The dry film was placed on a hot plate for pyrolysis at a temperature of 250°C.

[0106] The pyrolyzed dry film was placed in a high-pressure reactor, and the pressure was maintained at 2 MPa. Under an oxygen atmosphere, the temperature was slowly raised from room temperature to 450°C and held for 1 hour. Then, the temperature was slowly lowered to room temperature to prepare a high-quality, preferentially oriented PZT film. By repeating the above steps multiple times, PZT films of different thicknesses can be obtained.

[0107] Figure 9 This is a photograph of a lead zirconate titanate thin film prepared using the preparation method provided in the embodiments of this application. Figure 9 As can be seen, the lead zirconate titanate film prepared by the preparation method provided in the embodiments of this application has a smooth surface and is free of point defects and line defects, indicating that the lead zirconate titanate film has a high quality.

[0108] Figure 10This image shows the X-ray diffraction (XRD) pattern of the lead zirconate titanate thin film prepared using the method provided in the embodiments of this application. The horizontal axis represents 2theta, the diffraction angle, in degrees (°). The diffraction angle is the angle between the incident X-ray and the diffracted line; theta is called the half-angle of diffraction, which is the angle between the incident X-ray and the crystal plane that meets the diffraction conditions. The vertical axis represents the intensity, i.e., the intensity after X-ray diffraction. The unit of the vertical axis is au (arbitrary unit).

[0109] pass Figure 10 It can be seen that the diffraction peaks corresponding to crystal planes (100) and (200) are relatively high, while the diffraction peaks corresponding to other crystal planes are relatively small or even non-existent. Therefore, it can be determined that the lead zirconate titanate film prepared using the preparation method provided in this application not only has a preferred orientation of the (100) crystal plane but also possesses a single phase. Furthermore, the XRD pattern shows that the diffraction peaks corresponding to crystal planes (100) and (200) are relatively small, indicating that the lead zirconate titanate film prepared using the preparation method provided in this application has good crystallinity.

[0110] Lead zirconate titanate films possess a preferred orientation of the (100) crystal plane, which enables them to exhibit not only piezoelectric, ferroelectric, and dielectric properties, but also good electro-optic properties. This allows lead zirconate titanate films to be applied in fields such as optical communication, optical information storage, and terahertz systems. For example, tests have shown that the electro-optic coefficient of lead zirconate titanate films can reach 100 pm / V, and the piezoelectric coefficient can reach 250 pm / V.

[0111] Example 2

[0112] Under nitrogen protection, 4.0 mmol of zirconium oxynitrate and 3.7 mmol of tetraethyl titanate were added to 20 mL of glacial acetic acid, heated to 120 °C, and stirred for 2 hours.

[0113] Add 9.24 mmol of lead acetate, stir for 2 hours, and filter to obtain clear and transparent Pb. x Zr y Ti 1-y O3 precursor solution.

[0114] Pb was coated using a spin coating method and a spin coater. x Zr y Ti 1-y The O3 precursor solution was spin-coated onto the substrate to form a wet film. The spin coater was set at a speed of 3000 rpm for 20 seconds.

[0115] The wet film is placed in a vacuum drying oven to dry it, forming a dry film. The drying temperature is 150℃, and the time is 10 minutes.

[0116] The dry film was placed in a high-pressure reactor and maintained at a pressure of 2 MPa. Under an oxygen atmosphere, the temperature was slowly increased from room temperature to 300°C and held for 30 minutes. Then, the temperature was slowly increased to 450°C and held for 1 hour. Finally, the temperature was slowly reduced to room temperature to prepare the PZT film. By repeating the above steps multiple times, PZT films of different thicknesses can be obtained.

[0117] Example 3

[0118] Under nitrogen protection, 4.0 mmol of zirconium oxynitrate and 3.7 mmol of tetraethyl titanate were added to 20 mL of glacial acetic acid, heated to 120 °C, and stirred for 2 hours.

[0119] Add 7.7 mmol of lead acetate, stir for 2 hours, and filter to obtain clear and transparent Pb. x Zr y Ti 1-y O3 precursor solution.

[0120] Pb was coated using a spin coating method and a spin coater. x Zr y Ti 1-y The O3 precursor solution was spin-coated onto the substrate to form a wet film. The spin coater was set at a speed of 3000 rpm for 20 seconds.

[0121] The wet film is placed in a vacuum drying oven to dry it, forming a dry film. The drying temperature is 150℃, and the time is 10 minutes.

[0122] The dry film was placed in a high-pressure reactor and maintained at a pressure of 2 MPa. Under an oxygen atmosphere, the temperature was raised from room temperature to 300°C and held for 30 minutes. Then, the temperature was slowly raised to 400°C and held for 10 hours. Finally, the temperature was slowly lowered to room temperature to prepare the PZT film. By repeating the above steps multiple times, PZT films of different thicknesses can be obtained.

[0123] Example 4

[0124] Under nitrogen protection, 4.0 mmol of zirconium oxynitrate, 3.7 mmol of tetraethyl titanate, 9.24 mmol of lead nitrate, and 1.0 mL of acetylacetone were added to ethylene glycol monomethyl ether, and the mixture was heated to 120 °C and stirred for 3 hours. After cooling and filtration, a stable, orange-yellow, transparent Pb was obtained. x Zr y Ti 1-y O3 precursor solution.

[0125] Pb was coated using a spin coating method and a spin coater. x Zr y Ti 1-y The O3 precursor solution was spin-coated onto the substrate to form a wet film. The spin coater was set at a speed of 3000 rpm for 20 seconds.

[0126] The wet film is placed in a vacuum drying oven to dry it, forming a dry film. The drying temperature is 150℃, and the time is 10 minutes.

[0127] The dry film was placed in a high-pressure reactor and kept at a pressure of 2.0 MPa. Under an oxygen atmosphere, the temperature was slowly increased from room temperature to 400°C and maintained for 10 hours. Finally, the temperature was slowly reduced to room temperature to prepare a PZT film. By repeating the above steps multiple times, PZT films of different thicknesses can be obtained.

[0128] Example 5

[0129] Preparation of PZT precursor solution:

[0130] Under nitrogen protection, 4.0 mmol of zirconium oxynitrate, 3.7 mmol of tetraethyl titanate, 9.24 mmol of lead nitrate, and 1.0 mL of acetylacetone were added to ethylene glycol monomethyl ether, and the mixture was heated to 120 °C and stirred for 3 hours. After cooling and filtration, a stable, orange-yellow, transparent Pb was obtained. x Zr y Ti 1-y O3 precursor solution.

[0131] Pb was coated using a spin coating method and a spin coater. x Zr y Ti 1-y The O3 precursor solution was spin-coated onto the substrate to form a wet film. The spin coater was set at a speed of 3000 rpm for 20 seconds.

[0132] The wet film is placed in a vacuum drying oven to dry it, forming a dry film. The drying temperature is 150℃, and the time is 10 minutes.

[0133] The dry film was placed in a high-pressure reactor and maintained at a pressure of 4 MPa. Under an oxygen atmosphere, the temperature was raised from room temperature to 300°C and held for 30 minutes. Then, the temperature was slowly raised to 450°C and held for 0.5 hours. Finally, the temperature was slowly lowered to room temperature to prepare the PZT film. By repeating the above steps multiple times, PZT films of different thicknesses can be obtained.

[0134] This application provides a thin film. The thin film is prepared by the method described in the above embodiments.

[0135] In some embodiments, the aforementioned film is a lead zirconate titanate film. The lead zirconate titanate film can be a single-crystal film.

[0136] In some examples, the lead zirconate titanate film has a preferred orientation of the (100) crystal plane. This allows the lead zirconate titanate film to possess good electro-optic properties, enabling its application in optical communication and increasing its applicability.

[0137] In some embodiments, the thickness of the lead zirconate titanate film is greater than or equal to 10 nanometers and less than or equal to 1 millimeter. For example, the thickness of the lead zirconate titanate film can be 10 nanometers, 100 nanometers, 500 nanometers, 1 micrometer, 100 micrometers, 500 micrometers, 1 millimeter, etc. This provides a wide range of lead zirconate titanate film thicknesses, satisfying not only the requirements of the optical field (i.e., 400 nm to 600 nm) but also the requirements of the acoustic field (800 nm to 1200 nm), thus facilitating further expansion of the application scope of lead zirconate titanate films.

[0138] This application provides an electronic device. For example... Figure 11 and Figure 12 As shown, the electronic device 100 may include a metal oxide layer 10 and a plurality of electrodes 20. The metal oxide layer 10 includes the thin film provided in any of the above embodiments. The plurality of electrodes 20 may be located on the same side of the metal oxide layer 10, or the metal oxide layer 10 may be located between the plurality of electrodes 20.

[0139] In some embodiments, the electronic device 100 may be an optical device. The optical device referred to herein may be an electro-optic modulator, an acousto-optic modulator, a photodetector, or other device that uses optical materials as a key technology.

[0140] Figure 11 The following diagram illustrates the use of electronic device 100 as an electro-optic modulator. Figure 11 As shown, in addition to the metal oxide layer 10 and the plurality of electrodes 20, the electronic device 100 may also include a substrate 30. The metal oxide layer 10 and the plurality of electrodes 20 are both located on the substrate 10, with a portion of the metal oxide layer 10 located between two adjacent electrodes 20.

[0141] In some examples, the material of electrode 20 may include metals such as gold, silver, copper, and aluminum. The material of substrate 30 may include silicon. The number of electrodes 20 in the electronic device 100 in this embodiment is not limited and can be designed according to actual needs. Figure 11 The following is an illustration of an electronic device 100 that includes two electrodes 20.

[0142] The metal oxide layer 10 comprises the thin film provided in any of the above embodiments, and therefore the metal oxide layer 10 exhibits electro-optic properties, with its refractive index varying with the applied electric field. The metal oxide layer 10 serves as an optical waveguide for transmitting optical signals. Multiple electrodes 20 located on both sides of the metal oxide layer 10 can modulate the optical signals within the metal oxide layer 10 based on the received electrical signals.

[0143] In some examples, such as Figure 11 As shown, the metal oxide layer 10 may include a first branch 101 and a second branch 102, with the input terminals of the first branch 101 and the second branch 102 connected together, and the output terminals of the first branch 101 and the second branch 102 connected together. In this case, the electronic device 100 may be a Mach-Zehnder modulator.

[0144] When the metal oxide layer 10 includes a first branch 101 and a second branch 102, it can be as follows: Figure 11 The first branch 101 shown is located between two adjacent electrodes 20. Alternatively, a portion of the second branch 102 may be located between two adjacent electrodes 20. Or, a portion of the first branch 101 may be located between two adjacent electrodes 20, and a portion of the second branch 102 may be located between two other adjacent electrodes 20.

[0145] When a portion of the first branch 101 is located between two adjacent electrodes 20, the electric field formed between the two electrodes 20 can modulate the optical signal transmitted in the first branch 101. When a portion of the second branch 102 is located between two adjacent electrodes 20, the electric field formed between the two electrodes 20 can modulate the optical signal transmitted in the second branch 102. When a portion of the first branch 101 is located between two adjacent electrodes 20, and a portion of the second branch 102 is located between two other adjacent electrodes 20, the electrodes 20 located on both sides of the first branch 101 can modulate the optical signal transmitted in the first branch 101, and the electrodes 20 located on both sides of the second branch 102 can modulate the optical signal transmitted in the second branch 102.

[0146] In other embodiments, the electronic device 100 may be an acoustic device. The acoustic device referred to herein may include surface acoustic wave devices (e.g., surface acoustic wave sensors, surface acoustic wave filters, etc.), bulk acoustic wave devices, and other devices that use piezoelectric materials as a key technology.

[0147] Figure 12 The following diagram illustrates the use of electronic device 100 as a surface acoustic wave filter. Figure 12As shown, the electronic device 100 may include a metal oxide layer 10 and four electrodes 20. All four electrodes 20 are located on the metal oxide layer 10. All four electrodes 20 are comb-shaped electrodes, and the four electrodes 20 can form two interdigital transducers (IDTs).

[0148] One interdigital transducer can convert an electrical signal into a sound wave based on the inverse piezoelectric effect, and the sound wave propagates on the surface of the metal oxide layer. The other interdigital transducer can convert the received sound wave into an electrical signal output based on the piezoelectric effect, thereby achieving filtering.

[0149] It is understood that, in addition to being used as optical and acoustic devices as described above, electronic devices can also be applied to other fields. The electronic devices provided in the embodiments of this application can be used as standalone components or integrated into silicon-based CMOS circuits. The silicon-based CMOS circuits can be, for example, a central processing unit (CPU) or a graphics processing unit (GPU).

[0150] This application provides an electronic device. This electronic device can be, for example, a consumer electronics product, a home electronics product, an in-vehicle electronics product, a financial terminal product, or a communication electronics product. Consumer electronics products include mobile phones, tablets, laptops, e-readers, personal computers (PCs), personal digital assistants (PDAs), desktop monitors, smart wearable products (e.g., smartwatches, smart bracelets), virtual reality (VR) terminal devices, augmented reality (AR) terminal devices, drones, etc. Home electronics products include smart door locks, televisions, remote controls, refrigerators, and rechargeable small household appliances (e.g., soymilk makers, robot vacuum cleaners), etc. In-vehicle electronics products include in-vehicle navigation systems, in-vehicle high-density digital video discs (DVDs), etc. Financial terminal products include automated teller machines (ATMs), self-service terminals, etc. This electronic device can also be, for example, a server, a switch, a fiber optic network card, and a fiber optic transceiver.

[0151] For ease of explanation, the following example uses a mobile phone as an example. Figure 13As shown, the electronic device 200 mainly includes a cover plate 11, a display screen 12, a middle frame 13, and a rear shell 14. The rear shell 14 and the display screen 12 are located on both sides of the middle frame 13, and the middle frame 13 and the display screen 12 are disposed inside the rear shell 14. The cover plate 11 is disposed on the side of the display screen 12 away from the middle frame 13, and the display surface of the display screen 12 faces the cover plate 11.

[0152] The aforementioned display screen 12 can be a liquid crystal display (LCD). In this case, the LCD includes a liquid crystal display panel and a backlight module. The liquid crystal display panel is disposed between the cover plate 11 and the backlight module, and the backlight module provides a light source for the liquid crystal display panel. Alternatively, the aforementioned display screen 12 can be an organic light-emitting diode (OLED) display. Since OLED displays are self-emissive, a backlight module is not required.

[0153] The aforementioned middle frame 13 includes a support plate 131 and a frame 132 surrounding the support plate 131. The aforementioned electronic device 100 may also include electronic components such as batteries and cameras, which may be mounted on the support plate 131.

[0154] The electronic device may include electronic components and a circuit board, with the electronic components located on and electrically connected to the circuit board. The electronic component is the electronic component 100 provided in any of the above embodiments. The circuit board may be a printed circuit board (PCB). The circuit board may be located on a carrier board 131.

[0155] In the description of this specification, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0156] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method of producing a thin film, characterized by, The method comprises the following steps: preparing a precursor solution; preparing a dry film by using the precursor solution; annealing the dry film under a pressure greater than or equal to 1.5 MPa and a temperature less than or equal to 450 ℃ to form a thin film.

2. The production method according to claim 1, characterized by, The method of preparing the precursor solution comprises: Pb x Zr y Ti 1-y O3 precursor solution; wherein 1 < x < 1.3, 0.51 < y < 0.

53.

3. The preparation method according to claim 2, characterized in that, The preparation of Pb x Zr y Ti 1-y O3 precursor solution comprises: Zirconyl nitrate, tetraethyl titanate, lead nitrate and acetylacetone were added to ethylene glycol monomethyl ether to obtain the Pb x Zr y Ti 1-y O3 precursor solution.

4. The preparation method according to claim 2, characterized in that, The preparation of Pb x Zr y Ti 1-y O3 precursor solution comprises: Zirconyl nitrate and tetraethyl titanate were added to glacial acetic acid, followed by the addition of lead acetate to obtain the Pb x Zr y Ti 1-y O3 precursor solution.

5. The production method according to any one of claims 1 to 4, characterized by, The method of preparing the dry film by using the precursor solution comprises: spinning the precursor solution on a substrate to form a wet film; drying the wet film to form a dry film.

6. The production method according to claim 5, wherein The method of drying the wet film to form a dry film comprises: drying the wet film in a vacuum environment to form a dry film.

7. The production method according to claim 5 or 6, characterized by, The drying temperature is greater than or equal to 100 ℃ and less than or equal to 300 ℃.

8. The production method according to any one of claims 1 to 7, characterized by, After the dry film is prepared by using the precursor solution, the preparation method further comprises: pyrolyzing the dry film.

9. The production method according to claim 8, characterized by, The pyrolysis temperature is greater than or equal to 100 ℃ and less than or equal to 450 ℃.

10. The production method according to any one of claims 1 to 9, characterized by, The annealing of the dry film under a pressure greater than or equal to 1.5 MPa and a temperature less than or equal to 450 ℃ to form a thin film comprises: placing the dry film in a high-pressure reaction kettle, maintaining the pressure at 2±0.5 MPa in an oxygen atmosphere, increasing the temperature from room temperature to 445±5 ℃ and maintaining for 1±0.5 hours, and then decreasing the temperature to room temperature to obtain a thin film.

11. The production method according to any one of claims 1 to 9, characterized by, The annealing of the dry film under a pressure greater than or equal to 1.5 MPa and a temperature less than or equal to 450 ℃ to form a thin film comprises: placing the dry film in a high-pressure reaction kettle, maintaining the pressure at 2±0.5 MPa in an oxygen atmosphere, increasing the temperature from room temperature to 400±10 ℃ and maintaining for 10±1 hours, and then decreasing the temperature to room temperature to obtain a thin film.

12. The production method according to any one of claims 1 to 9, characterized by, The annealing of the dry film under a pressure greater than or equal to 1.5 MPa and a temperature less than or equal to 450 ℃ to form a thin film comprises: placing the dry film in a high-pressure reaction kettle, maintaining the pressure at 2±0.5 MPa in an oxygen atmosphere, increasing the temperature from room temperature to 300±10 ℃ and maintaining for 30±5 minutes, then increasing the temperature to 445±5 ℃ and maintaining for 1±0.5 hours, and finally decreasing the temperature to room temperature to obtain a thin film.

13. The production method according to any one of claims 1 to 9, characterized by, The annealing of the dry film under a pressure greater than or equal to 1.5 MPa and a temperature less than or equal to 450 ℃ to form a thin film comprises: placing the dry film in a high-pressure reaction kettle, maintaining the pressure at 2±0.5 MPa in an oxygen atmosphere, increasing the temperature from room temperature to 300±10 ℃ and maintaining for 30±5 minutes, then increasing the temperature to 400±10 ℃ and maintaining for 10±1 hours, and finally decreasing the temperature to room temperature to obtain a thin film.

14. The production method according to any one of claims 1 to 9, characterized by, The annealing of the dry film under a pressure greater than or equal to 1.5 MPa and a temperature less than or equal to 450 ℃ to form a thin film comprises: placing the dry film in a high-pressure reaction kettle, maintaining the pressure at 4±0.5 MPa in an oxygen atmosphere, increasing the temperature from room temperature to 300±10 ℃ and maintaining for 30±5 minutes, then increasing the temperature to 445±5 ℃ and maintaining for 30±5 minutes, and finally decreasing the temperature to room temperature to obtain a thin film.

15. A film, characterized by, The thin film is produced by the production method according to any one of claims 1 to 14.

16. An electronic device, characterized by Comprising: a metal oxide layer, comprising the thin film according to claim 15; a plurality of electrodes, which are located on the same side of the metal oxide layer, or the metal oxide layer is located between the plurality of electrodes.

17. An electronic device, comprising: Comprising: the electronic device according to claim 16; a circuit board, on which the electronic device is located, and is electrically connected with the circuit board.

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