Ferroelectric structure based on amorphous oxide semiconductor / AlScN and preparation method and application thereof

Abstract

The invention provides a ferroelectric structure based on an amorphous oxide semiconductor / AlScN and a preparation method and application thereof. The ferroelectric structure comprises a substrate and an AlScN thin film epitaxially grown on the substrate, the substrate comprises an amorphous oxide semiconductor material, and a bonding interface of the substrate and the AlScN thin film is the amorphous oxide semiconductor material. The AlScN thin film has good ferroelectricity and high remanent polarization, and a ferroelectric field effect transistor with a top gate structure can be prepared by integrating the AlScN thin film on an amorphous oxide semiconductor, so that the AlScN thin film can be applied to the field of high-density and nonvolatile storage and the field of neuromorphic chips.

Description

Technical Field

[0001] The present invention belongs to the technical field of ferroelectric materials, and particularly relates to a ferroelectric structure based on amorphous oxide semiconductor / AlScN, a preparation method thereof, and an application thereof. Background Art

[0002] With the rapid development of emerging information technology industries such as big data and artificial intelligence, higher requirements are put forward for the efficiency and energy consumption of data processing. However, due to the physical separation of the logic unit and the storage unit in the traditional von Neumann architecture-based computing system, it leads to high latency and high energy consumption problems in data transmission. For example, although artificial intelligence applications such as ChatGPT have powerful computing capabilities, their computing power depends on a large number of high-performance GPUs and has extremely high energy consumption, making it difficult to meet the sustainable development requirements. Therefore, academia and industry are exploring new computing architectures, especially the in-memory computing architecture inspired by the principles of human brain neuromorphic computing, aiming to overcome the von Neumann bottleneck by integrating storage and computing functions to achieve higher computing efficiency and lower energy consumption.

[0003] Currently, the implementation of the in-memory computing architecture mainly focuses on the component layer or the chip layer. For example, through the through-silicon via technology, the storage units are three-dimensionally stacked on top of the logic unit layer. However, this three-dimensional integration method brings new problems, such as a sharp increase in the test volume, output constraints, and thermal crosstalk problems. To achieve true in-memory computing, it is necessary to integrate storage and computing at the same device level. Traditional CMOS devices are difficult to meet this requirement due to their volatility. Utilizing the physical properties of new non-volatile memory devices for information storage and in-situ computing is a very promising in-memory computing technology route. Among them, ferroelectric field-effect transistors have attracted much attention due to their same scalability as advanced logic transistors, extremely low-power write operations, and non-destructive reading, etc.

[0004] Although traditional perovskite-based ferroelectric materials (such as BaTiO3, Pb[ZrxTi1−x]O3, etc.) have a high remanent polarization intensity, which is beneficial to the realization of multi-value storage ferroelectric field-effect transistors, they have many limitations in practical applications, such as weak thickness scaling ability, low coercive field, high annealing temperature, complex etching process, and diffusion problems of elements such as Pb, which limit their compatibility with CMOS processes. Although doped hafnium-based ferroelectric materials exhibit some unique advantages, such as good ferroelectric properties at the nanoscale, good compatibility with silicon-based CMOS processes, low dielectric constant, and large coercive electric field, etc., there are also problems such as a small remanent polarization value and the existence of multiple metastable phases that require an accurate post-annealing process to optimize.

[0005] Research findings show that aluminum scandium nitride (AlScN) has ferroelectric properties superior to those of hafnium-based ferroelectric materials, such as high remanent polarization values, compatibility with CMOS processes, extremely high thermal stability, a single crystal phase, and the absence of the need for a post-annealing process. Based on these advantages, research on the growth and application of AlScN has been carried out. Currently, it mainly focuses on the growth of AlScN on metal substrates (such as Mo, Pt, TiN, etc.). This is because these metal thin films with preferred orientation growth can promote the preferred orientation growth of AlScN, resulting in high crystal quality and ensuring its ferroelectricity. However, this also limits the structure to be only applicable to back-gate ferroelectric field-effect transistor devices, thus restricting the storage density of memory chips.

[0006] Amorphous semiconductors have excellent electrical properties, large-area uniformity, and simple preparation characteristics. However, the existing methods for growing AlScN on metal-based substrates are not fully applicable to amorphous oxide semiconductor substrates. Growing AlScN thin films on amorphous oxide semiconductor substrates faces the problem of poor crystal quality caused by lattice mismatch. Summary of the Invention

[0007] To solve all or part of the above technical problems, the present invention provides the following technical solutions: One of the objectives of the present invention is to provide a ferroelectric structure based on amorphous oxide semiconductor / AlScN. The ferroelectric structure includes a substrate and an AlScN thin film epitaxially grown on the substrate. The substrate includes an amorphous oxide semiconductor material, and the bonding interface between the substrate and the AlScN thin film is the amorphous oxide semiconductor material.

[0008] In some embodiments, the amorphous oxide semiconductor material includes at least one of indium gallium zinc oxide and indium tin zinc oxide.

[0009] In some embodiments, the thickness of the AlScN thin film is 10 - 100 nm.

[0010] In some embodiments, the AlScN thin film has a hexagonal (002) preferred orientation and a wurtzite structure, where the content of Sc / (Sc + Al) is 15% - 30%.

[0011] Another objective of the present invention is to provide a method for preparing a ferroelectric structure based on amorphous oxide semiconductor / AlScN, including: Providing a substrate, at least one surface of which is an amorphous oxide semiconductor material; Growing an AlScN thin film on the amorphous oxide semiconductor material by physical deposition to obtain a ferroelectric structure.

[0012] The ferroelectric structure based on amorphous oxide semiconductor / AlScN prepared by the above method can be used to fabricate a top-gate ferroelectric field-effect transistor.

[0013] In some embodiments, the amorphous oxide semiconductor material includes at least one of indium gallium zinc oxide and indium tin zinc oxide.

[0014] In some embodiments, the physical deposition method includes at least one of the second pulsed laser deposition method and the second magnetron sputtering deposition method.

[0015] In some embodiments, the method includes: growing an AlScN thin film by the second pulsed laser deposition method and performing an annealing treatment to obtain the ferroelectric structure.

[0016] In some embodiments, the second pulsed laser deposition method specifically includes: setting the substrate temperature to 100-400 °C, the growth atmosphere to a nitrogen atmosphere with a pressure of 0.5-3 Pa, the laser energy to 250-400 mJ, and the laser frequency to 1-3 Hz. Under the process parameter conditions of this pulsed laser deposition, an AlScN thin film with a wurtzite structure and good ferroelectric properties can be prepared.

[0017] Furthermore, the target used in the second pulsed laser deposition method includes an Al 1-x Sc x target or an Al 1-x Sc x N target, or an Al target and a Sc target are used.

[0018] Furthermore, an excimer laser can be used in the second pulsed laser deposition method.

[0019] In some embodiments, the annealing treatment temperature is 100-450 °C, the annealing atmosphere is a nitrogen atmosphere with a pressure of 0.5-3 mTorr, and the annealing time is 30-90 min to obtain the ferroelectric structure.

[0020] Furthermore, the annealing treatment can be, for example, an in-situ annealing treatment.

[0021] In some embodiments, the AlScN thin film is grown by the second magnetron sputtering deposition method to obtain the ferroelectric structure.

[0022] Furthermore, the process conditions of the second magnetron sputtering deposition method include: using an Al 1-x Sc x target, setting the sputtering power to 10-15 kW, the substrate temperature to 200 °C, the atmosphere to a mixed atmosphere containing argon and nitrogen with a pressure of 1-5 mTorr, the argon flow rate in the mixed atmosphere to 20 sccm, and the nitrogen flow rate to 80-120 sccm.

[0023] Further, the process conditions of the second magnetron sputtering deposition method include: using an Al target and a Sc target, the sputtering power of the Al target is 600 - 800 W, the sputtering power of the Sc target is 300 W, the substrate temperature is 400 °C, the atmosphere is a mixed atmosphere containing argon and nitrogen and the pressure is 1 - 5 mTorr, the argon flow rate in the mixed atmosphere is 15 sccm, and the nitrogen flow rate is 35 sccm.

[0024] The present invention can prepare an AlScN thin film with a wurtzite structure, high crystal quality, and good ferroelectric properties on an amorphous oxide semiconductor substrate by optimizing the above-mentioned magnetron sputtering parameters.

[0025] In some preferred embodiments, the method specifically includes: First, grow an AlScN seed layer on the amorphous oxide semiconductor material; Then, use the physical deposition method to epitaxially grow an AlScN thin film on the AlScN seed layer, thereby obtaining the ferroelectric structure.

[0026] Due to the problem of lattice mismatch between the amorphous oxide semiconductor and AlScN, it is technically difficult to grow an AlScN thin film with preferred orientation and high crystal quality on the amorphous oxide semiconductor. In the basic solution of the present invention, an AlScN thin film that can basically meet the requirements of ferroelectric devices is prepared by optimizing the magnetron sputtering and pulsed deposition processes. To further optimize the quality of the AlScN thin film, the present invention first forms an AlScN seed layer on the amorphous oxide semiconductor, and uses the AlScN seed layer to promote the preferred growth of AlScN, so that the AlScN thin film has a hexagonal (002) preferred orientation, thereby further improving the crystal quality, obtaining an AlScN thin film with better ferroelectricity and high remanent polarization intensity, that is, providing a more excellent ferroelectric structure based on amorphous oxide semiconductor / AlScN, which can be used to prepare top-gate ferroelectric field-effect transistors.

[0027] In some embodiments, use the first magnetron sputtering deposition method to grow an AlScN seed layer on the amorphous oxide semiconductor material. The process conditions of the first magnetron sputtering deposition method include: the sputtering power is 3 kW, the working gas is a nitrogen atmosphere and the flow rate is 100 sccm, the deposition time is 10 s, and the substrate temperature is 200 °C.

[0028] In some embodiments, use the first pulsed laser deposition method to grow an AlScN seed layer on the amorphous oxide semiconductor material. The process conditions of the first pulsed laser deposition method include: the laser energy is 200 mJ, the laser frequency is 5 Hz, the deposition time is 2 min, the atmosphere is a nitrogen atmosphere and the pressure is 0.5 Pa, and the substrate temperature is 400 °C.

[0029] In some embodiments, the thickness of the AlScN seed layer is 3 nm.

[0030] A third object of the present invention is to provide a ferroelectric structure based on amorphous oxide semiconductor / AlScN, which is prepared by the method described in any one of the above.

[0031] A fourth object of the present invention is to provide the application of the ferroelectric structure based on amorphous oxide semiconductor / AlScN in the preparation of ferroelectric devices.

[0032] A fifth object of the present invention is to provide a top-gate ferroelectric field-effect transistor, and the top-gate ferroelectric field-effect transistor includes the ferroelectric structure based on amorphous oxide semiconductor / AlScN described in any one of the above.

[0033] The method provided by the present invention successfully grows an AlScN thin film with a hexagonal (002) preferred orientation and a wurtzite structure on an amorphous semiconductor, making it suitable for the preparation of top-gate ferroelectric field-effect transistor devices, and thus can be applied to high storage density chips.

[0034] Compared with the prior art, the present invention has at least the following technical effects: (1) By optimizing the process parameters of pulsed laser deposition and magnetron sputtering deposition, the present invention grows an AlScN thin film with ferroelectricity on an amorphous oxide semiconductor.

[0035] (2) The method provided by the present invention first grows an AlScN seed layer on an amorphous oxide semiconductor, and uses the AlScN seed layer to promote the preferred growth of AlScN, so as to grow an AlScN thin film with a hexagonal (002) preferred orientation and a wurtzite structure on the amorphous oxide semiconductor, further improving the crystallization quality of the AlScN thin film, making it have good ferroelectricity and a high remanent polarization intensity, and solving the problem of poor crystallization quality caused by lattice mismatch when growing the AlScN thin film on an amorphous substrate.

[0036] (3) The ferroelectric structure based on amorphous oxide semiconductor and AlScN thin film can be applied to the preparation of top-gate ferroelectric field-effect transistors, and thus can be applied to the fields of high-density, non-volatile storage and neuromorphic chips, solving the limitation that the AlScN-based structure in the prior art is only applied to back-gate ferroelectric field-effect transistor devices. Description of the Drawings

[0037] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the accompanying drawings required for the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only some embodiments recorded in the present application. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can also be obtained based on these drawings.

[0038] Figure 1 is the XRD pattern of the AlScN thin film (before and after annealing) prepared in Example 1; Figure 2 is the C-V test chart of the AlScN thin film prepared in Example 1; Figure 3 is the P-E test chart of the AlScN thin film prepared in Example 1. Detailed Embodiments

[0039] The following will detail the technical solutions of the present invention in combination with specific embodiments, so that those skilled in the art can better understand and implement the technical solutions of the present invention. The specific functional details disclosed herein should not be construed as restrictive, but only as the basis of the claims and as a representative basis for teaching those skilled in the art to adopt the present invention in any appropriate detailed embodiment in different ways.

[0040] In addition, unless otherwise specified, various raw materials used in the following embodiments can be obtained from the market or other channels, various production and testing equipment used are also known equipment in the art, and the testing methods used are also conventional methods in the art.

[0041] Example 1 This example provides a method for growing an AlScN thin film on an indium gallium zinc oxide (IGZO) semiconductor material, which specifically includes the following steps: (1) Using IGZO as the substrate, an AlScN thin film is grown on IGZO by magnetron sputtering: Using an Al 1-x Sc x target, setting the sputtering power to 10 kW, the substrate temperature to 200 °C, the atmosphere to a mixed atmosphere of argon and nitrogen with a pressure of 3 mTorr, the argon flow rate in the mixed atmosphere to 20 sccm, the nitrogen flow rate to 100 sccm, and the deposition time to 2 min, to form an AlScN thin film with a thickness of 160 nm.

[0042] (2) In-situ annealing is performed on the AlScN thin film obtained in step (1). The in-situ annealing temperature is 200 °C, the annealing atmosphere is a nitrogen atmosphere with 3 Pa, and the annealing time is 1 h, to obtain the AlScN thin film grown on IGZO, that is, a ferroelectric structure is obtained.

[0043] Figure 1 XRD pattern of the AlScN thin film prepared in this example (the black line is the XRD pattern before annealing, and the red line is the XRD pattern after annealing). The results show that under this growth condition, the AlScN thin film grows with a preferred orientation of the (002) crystal plane on the IGZO substrate and has a high crystal quality. Figure 2 is the C-V test chart of the AlScN thin film, Figure 3 is the P-E test chart of the AlScN thin film, which proves that the AlScN thin film has good ferroelectricity.

[0044] Example 2 This example provides a method for growing an AlScN thin film on an indium gallium zinc oxide (IGZO) semiconductor material, which specifically includes the following steps: Use magnetron sputtering to grow an AlScN seed layer on IGZO. The specific steps are as follows: Set the substrate temperature to 200 °C, the sputtering power to 3 kW, the working gas to nitrogen with a gas flow rate of 100 sccm, and the deposition time to 10 s to form a seed layer with a thickness of 3 nm, obtaining an intermediate structure; Using the intermediate structure obtained in step (1) as the substrate, grow an AlScN thin film on the AlScN seed layer by magnetron sputtering: Use an Al 1-x Sc x target, set the sputtering power to 10 kW, the substrate temperature to 200 °C, the atmosphere to a mixed atmosphere of argon and nitrogen with a pressure of 3 mTorr, the argon flow rate in the mixed atmosphere to 20 sccm, the nitrogen flow rate to 100 sccm, and the deposition time to 2 min to form an AlScN thin film.

[0045] (3) Perform in-situ annealing on the structure obtained in step (2). The in-situ annealing temperature is 200 °C, the annealing atmosphere is a nitrogen atmosphere with a pressure of 3 mTorr, and the annealing time is 1 h to obtain an AlScN thin film grown on IGZO, that is, a ferroelectric structure is obtained.

[0046] First, form an AlScN seed layer on the amorphous oxide semiconductor. Use the AlScN seed layer to promote the preferred growth of AlScN, so that the AlScN thin film has a hexagonal (002) preferred orientation, thereby further improving the crystal quality and obtaining an AlScN thin film with better ferroelectricity and high remanent polarization intensity.

[0047] Example 3 This example provides a method for growing an AlScN thin film on an indium gallium zinc oxide (IGZO) semiconductor material, which specifically includes the following steps: (1) A layer of AlScN seed layer is grown on IGZO by magnetron sputtering. The specific steps are as follows: Set the substrate temperature at 200 °C, the sputtering power at 3 kW, the working gas as nitrogen with a gas flow rate of 100 sccm, and the deposition time at 10 s to form a seed layer with a thickness of 3 nm, obtaining an intermediate structure; (2) Using the intermediate structure obtained in step (1) as the substrate, an AlScN thin film is grown on the AlScN seed layer by magnetron sputtering: Use an Al target and a Sc target. The sputtering power of the Al target is 600 W, and the sputtering power of the Sc target is 300 W. The substrate temperature is 400 °C, the atmosphere is a mixed atmosphere of argon and nitrogen with a pressure of 3 mttor, the argon flow rate in the mixed atmosphere is 15 sccm, and the nitrogen flow rate is 35 sccm to form an AlScN thin film with a thickness of 100 nm.

[0048] (3) The structure obtained in step (2) is subjected to in-situ annealing. The in-situ annealing temperature is 100 °C, the annealing atmosphere is a nitrogen atmosphere with a pressure of 3 Pa, and the annealing time is 1 h to obtain an AlScN thin film grown on IGZO, that is, a ferroelectric structure is obtained.

[0049] Example 4 This example provides a method for growing an AlScN thin film on an indium tin zinc oxide (ITZO) semiconductor material, which specifically includes the following steps: (1) A layer of AlScN seed layer is grown on IGZO by magnetron sputtering. The specific steps are as follows: Set the substrate temperature at 200 °C, the sputtering power at 3 kW, the working gas as nitrogen with a gas flow rate of 100 sccm, and the deposition time at 10 s to form a seed layer with a thickness of 3 nm, obtaining an intermediate structure; (2) Using the intermediate structure obtained in step (1) as the substrate, an AlScN thin film is grown on the AlScN seed layer by magnetron sputtering: Use an Al 1~x Sc x target, set the sputtering power at 10 kW, the substrate temperature at 200 °C, the atmosphere as a mixed atmosphere of argon and nitrogen with a pressure of 3 mttor, the argon flow rate in the mixed atmosphere is 20 sccm, and the nitrogen flow rate is 100 sccm, and the deposition time is 2 min to form an AlScN thin film with a thickness of 10 nm.

[0050] (3) The structure obtained in step (2) is subjected to in-situ annealing. The in-situ annealing temperature is 450 °C, the annealing atmosphere is a nitrogen atmosphere with a pressure of 0.5 Pa, and the annealing time is 1 h to obtain an AlScN thin film grown on ITZO, that is, a ferroelectric structure is obtained.

[0051] Example 5 This embodiment provides a method for growing an AlScN thin film on an indium gallium zinc oxide (IGZO) semiconductor material, specifically including the following steps: (1) Using IGZO as a substrate, grow an AlScN thin film on the IGZO by pulsed laser deposition. Set the substrate temperature to 100 °C, the growth atmosphere to a nitrogen atmosphere with a pressure of 0.5 Pa, use an excimer laser, with a laser energy of 250 mJ and a laser frequency of 1 Hz.

[0052] (2) Perform in-situ annealing on the structure obtained in step (1). The in-situ annealing temperature is 100 °C, the annealing atmosphere is a nitrogen atmosphere with a pressure of 0.5 Pa, and the annealing time is 1 h, to obtain an AlScN thin film grown on the IGZO, that is, a ferroelectric structure is obtained.

[0053] Example 6 This embodiment provides a method for growing an AlScN thin film on an indium gallium zinc oxide (IGZO) semiconductor material, specifically including the following steps: (1) Grow a layer of AlScN seed layer on the IGZO by pulsed laser deposition. Set the laser energy to 200 mJ, the laser frequency to 5 Hz, the deposition time to 2 min, the atmosphere to a nitrogen atmosphere with a pressure of 0.5 Pa, and the substrate temperature to 400 °C; (2) Using the intermediate structure obtained in step (1) as a substrate, grow an AlScN thin film on the AlScN seed layer by pulsed laser deposition. Set the substrate temperature to 100 °C, the growth atmosphere to a nitrogen atmosphere with a pressure of 0.5 Pa, use an excimer laser, with a laser energy of 250 mJ and a laser frequency of 1 Hz.

[0054] (3) Perform in-situ annealing on the structure obtained in step (2). The in-situ annealing temperature is 100 °C, the annealing atmosphere is a nitrogen atmosphere with a pressure of 0.5 Pa, and the annealing time is 1 h, to obtain an AlScN thin film grown on the IGZO, that is, a ferroelectric structure is obtained.

[0055] First, form a layer of AlScN seed layer on the amorphous oxide semiconductor, and use the AlScN seed layer to promote the preferential growth of AlScN, so that the AlScN thin film has a hexagonal (002) preferential orientation, thereby further improving the crystallization quality and obtaining an AlScN thin film with better ferroelectricity and high remanent polarization intensity.

[0056] Example 7 This embodiment provides a method for growing an AlScN thin film on an indium gallium zinc oxide (IGZO) semiconductor material, specifically including the following steps: (1) A layer of AlScN seed layer was grown on IGZO by pulsed laser deposition. The laser energy was set to 200 mJ, the laser frequency was 5 Hz, the deposition time was 2 min, the atmosphere was nitrogen atmosphere with a pressure of 0.5 Pa, and the substrate temperature was 400 °C; (2) Using the intermediate structure obtained in step (1) as the substrate, an AlScN thin film was grown on the AlScN seed layer by pulsed laser deposition. The substrate temperature was set to 400 °C, the growth atmosphere was nitrogen atmosphere with a pressure of 3 Pa, an excimer laser was used, the laser energy was 400 mJ, and the laser frequency was 3 Hz.

[0057] (3) The structure obtained in step (2) was subjected to in-situ annealing. The in-situ annealing temperature was 450 °C, the annealing atmosphere was nitrogen atmosphere with a pressure of 3 Pa, and the annealing time was 1 h, obtaining an AlScN thin film grown on IGZO, that is, a ferroelectric structure was obtained.

[0058] Example 8 This example provides a method for growing an AlScN thin film on an indium tin zinc oxide (ITZO) semiconductor material, specifically including the following steps: (1) A layer of AlScN seed layer was grown on ITZO by pulsed laser deposition. The laser energy was set to 200 mJ, the laser frequency was 5 Hz, the deposition time was 2 min, the atmosphere was nitrogen atmosphere with a pressure of 0.5 Pa, and the substrate temperature was 400 °C; (2) Using the intermediate structure obtained in step (1) as the substrate, an AlScN thin film was grown on the AlScN seed layer by pulsed laser deposition. The substrate temperature was set to 300 °C, the growth atmosphere was nitrogen atmosphere with a pressure of 2 Pa, an excimer laser was used, the laser energy was 300 mJ, and the laser frequency was 2 Hz.

[0059] (3) The structure obtained in step (2) was subjected to in-situ annealing. The in-situ annealing temperature was 300 °C, the annealing atmosphere was nitrogen atmosphere with a pressure of 2 Pa, and the annealing time was 1 h, obtaining an AlScN thin film grown on ITZO, that is, a ferroelectric structure was obtained.

[0060] All aspects, embodiments, features, and examples of the present invention should be considered illustrative in all respects and are not intended to limit the present invention. The scope of the present invention is only defined by the claims. Without departing from the spirit and scope of the claimed present invention, those skilled in the art will understand other embodiments, modifications, and uses.

[0061] In addition, the inventors of this case also referred to the foregoing embodiments and conducted tests with other raw materials, process operations, and process conditions described in this specification, and all obtained relatively ideal results.

[0062] Although the present invention has been described with reference to illustrative embodiments, those skilled in the art will understand that various other changes, omissions and / or additions can be made without departing from the spirit and scope of the present invention and elements of the embodiments can be replaced with substantially equivalent ones. Additionally, many modifications can be made to adapt a particular situation or material to the teachings of the present invention without departing from the scope of the present invention. Accordingly, it is not intended that the present invention be limited to the particular embodiments disclosed for carrying out the present invention, but rather that the present invention will include all embodiments falling within the scope of the appended claims. Further, unless specifically stated, any use of the terms first, second, etc. does not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another.

Claims

1. A ferroelectric structure based on amorphous oxide semiconductor / AlScN, characterized in that: The ferroelectric structure includes a substrate and an AlScN thin film epitaxially grown on the substrate. The substrate includes an amorphous oxide semiconductor material, and the bonding interface between the substrate and the AlScN thin film is the amorphous oxide semiconductor material; Preferably, the amorphous oxide semiconductor material includes at least one of indium gallium zinc oxide and indium tin zinc oxide; Preferably, the thickness of the AlScN thin film is 10~100nm; Preferably, the AlScN thin film has a hexagonal (002) preferred orientation and a wurtzite structure, and the content of Sc / (Sc+Al) is 15%~30%.

2. A preparation method of a ferroelectric structure based on amorphous oxide semiconductor / AlScN, characterized in that, It includes: Providing a substrate, at least one surface of which is an amorphous oxide semiconductor material; Growing an AlScN thin film on the amorphous oxide semiconductor material by physical deposition to obtain a ferroelectric structure.

3. The preparation method according to claim 2, characterized in that, Specifically, it includes: First, growing an AlScN seed layer on the amorphous oxide semiconductor material; Then, epitaxially growing an AlScN thin film on the AlScN seed layer by physical deposition to obtain the ferroelectric structure.

4. The preparation method according to claim 3, characterized in that, Growing an AlScN seed layer on the amorphous oxide semiconductor material by the first magnetron sputtering deposition method. The process conditions of the first magnetron sputtering deposition method include: sputtering power of 3kw, working gas of nitrogen atmosphere and flow rate of 100sccm, deposition time of 10s, and substrate temperature of 200°C; And / or, growing an AlScN seed layer on the amorphous oxide semiconductor material by the first pulsed laser deposition method. The process conditions of the first pulsed laser deposition method include: laser energy of 200 mJ, laser frequency of 5Hz, deposition time of 2min, atmosphere of nitrogen atmosphere and pressure of 0.5Pa, and substrate temperature of 400°C; And / or, the thickness of the AlScN seed layer is 3nm.

5. The preparation method according to claim 2 or 3, characterized in that: The amorphous oxide semiconductor material includes at least one of indium gallium zinc oxide and indium tin zinc oxide; And / or, the physical deposition method includes at least one of the second pulsed laser deposition method and the second magnetron sputtering deposition method.

6. The preparation method according to claim 5, characterized in that: Growing an AlScN thin film by the second pulsed laser deposition method and performing annealing treatment to obtain the ferroelectric structure; Preferably, the process conditions of the second pulsed laser deposition method include: substrate temperature of 100~400°C, growth atmosphere of nitrogen atmosphere and pressure of 0.5~3Pa, laser energy of 250~400mJ, and laser frequency of 1~3Hz; Preferably, the target used in the second pulsed laser deposition method includes Al 1-x Sc x target or Al 1-x Sc x N target, or an Al target and a Sc target are used; Preferably, the annealing temperature is 100~450°C, the annealing atmosphere is nitrogen atmosphere and pressure of 0.5~3mttor, and the annealing time is 30-90min.

7. The preparation method according to claim 5, characterized in that, Specifically, it includes: Growing the AlScN thin film by the second magnetron sputtering deposition method to obtain the ferroelectric structure; The process conditions of the second magnetron sputtering deposition method include: using an Al 1-x Sc x target, setting the sputtering power to 10 - 15 kW, the substrate temperature to 200 °C, the atmosphere to a mixed atmosphere containing argon and nitrogen with a pressure of 1 - 5 mTorr, the argon flow rate in the mixed atmosphere to 20 sccm, and the nitrogen flow rate to 80 - 120 sccm; Alternatively, the process conditions of the second magnetron sputtering deposition method include: using an Al target and a Sc target, the sputtering power of the Al target is 600 - 800 W, the sputtering power of the Sc target is 300 W, the substrate temperature is 400 °C, the atmosphere is a mixed atmosphere containing argon and nitrogen and the pressure is 1 - 5 mTorr, the argon flow rate in the mixed atmosphere is 15 sccm, and the nitrogen flow rate is 35 sccm.

8. A ferroelectric structure based on amorphous oxide semiconductor / AlScN, characterized in that, It is prepared by the preparation method described in any one of claims 2 - 7.

9. Use of the ferroelectric structure based on amorphous oxide semiconductor / AlScN described in claim 1 or 8 in the preparation of ferroelectric devices.

10. A top-gate ferroelectric field-effect transistor, characterized in that, It includes the ferroelectric structure based on amorphous oxide semiconductor / AlScN described in claim 1 or 8.

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