CN117915666A - Hfo free of substrate and electrode self-supporting structures2Preparation method of ferroelectric thin film - Google Patents
Hfo free of substrate and electrode self-supporting structures2Preparation method of ferroelectric thin film Download PDFInfo
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- 229910000449 hafnium oxide Inorganic materials 0.000 description 1
- WIHZLLGSGQNAGK-UHFFFAOYSA-N hafnium(4+);oxygen(2-) Chemical compound [O-2].[O-2].[Hf+4] WIHZLLGSGQNAGK-UHFFFAOYSA-N 0.000 description 1
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- VSZWPYCFIRKVQL-UHFFFAOYSA-N selanylidenegallium;selenium Chemical compound [Se].[Se]=[Ga].[Se]=[Ga] VSZWPYCFIRKVQL-UHFFFAOYSA-N 0.000 description 1
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Classifications
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/50—Manufacturing or production processes characterised by the final manufactured product
Abstract
The invention discloses a preparation method of a HfO 2 -based ferroelectric film without a substrate and an electrode self-supporting structure, belonging to the field of film preparation, comprising the following steps: depositing a bottom electrode on a silicon substrate with a SiO 2 layer; depositing an HfO 2 -based ferroelectric film on the surface of the bottom electrode; depositing a top electrode on the surface of the HfO 2 -based ferroelectric film; performing heat treatment crystallization on the obtained HfO 2 -based ferroelectric film with the SiO 2 layer silicon substrate; taking the SiO 2 layer as a sacrificial layer, dissolving the SiO 2 sacrificial layer by using alkali solution to obtain an HfO 2 -based ferroelectric film with the SiO 2 sacrificial layer silicon substrate removed; and dissolving the electrode to obtain the HfO 2 -based ferroelectric film without the substrate and the electrode constraint self-supporting structure. The preparation method overcomes the constraint of the substrate and the electrode on the film, and SiO 2 serving as a sacrificial layer also reduces the influence on the electrical property and the crystal structure of the HfO 2 -based ferroelectric film, so that the preparation method is low in cost, simple and feasible.
Description
Technical Field
The invention relates to the field of film preparation, in particular to a preparation method of an HfO 2 -based ferroelectric film without a substrate and an electrode self-supporting structure.
Background
In recent years, great attention is paid to the novel hafnium oxide-based ferroelectric film (hereinafter referred to as HfO 2 -based ferroelectric film) material, which has the advantages of compatibility with a CMOS process, high reading and writing speed, high storage density, no toxicity, no pollution and the like, and is one of the most potential novel semiconductor memory materials.
However, since the film is usually deposited on a substrate material in the film preparation process, and the purpose of depositing the top and bottom electrodes in the preparation of the HfO 2 -based ferroelectric film is to provide a certain clamping stress for the film to induce stronger ferroelectric performance, so that the film is bound, the development and application of the film to the fields of flexible electronics and the like are hindered, and meanwhile, the phenomenon that the HfO 2 -based ferroelectric film with the substrate and the electrodes is directly prepared into a TEM plane sample, the HfO 2 -based ferroelectric film overlaps with the electrode and the substrate lattice in the vertical direction, so that the crystal phase information of the HfO 2 -based ferroelectric film cannot be effectively represented, and the research on relevant microscopic representation along the horizontal direction of the HfO 2 -based film is seriously hindered.
Disclosure of Invention
The invention aims to overcome the defects of the prior art, and provides a preparation method of an HfO 2-based ferroelectric film without a substrate and electrode self-supporting structure, which can prepare the self-supporting structure HfO 2 -based ferroelectric film without the constraint of the substrate and the electrode, thereby reducing the possibility of introducing other stress and the influence on the electrical property and the crystal structure of the HfO 2 -based ferroelectric film. Meanwhile, the preparation process is simple, the cost is low, the efficiency is high, and the method has a very good application prospect.
The invention aims at realizing the following scheme:
A preparation method of an HfO 2 -based ferroelectric film without a substrate and an electrode self-supporting structure comprises the following steps:
S1, depositing a bottom electrode on a silicon substrate with a SiO 2 layer;
S2, depositing an HfO 2 -based ferroelectric film on the surface of the bottom electrode;
s3, depositing a top electrode on the surface of the HfO 2 -based ferroelectric film;
s4, performing heat treatment annealing on the HfO 2 -based ferroelectric film with the SiO 2 -layer silicon substrate obtained in the step S3 to crystallize the film;
S5, taking the SiO 2 layer as a sacrificial layer, and using an alkali solution to heat and react to dissolve the SiO 2 sacrificial layer so as to obtain the HfO 2 -based ferroelectric film with the SiO 2 sacrificial layer silicon substrate removed;
S6, dissolving the bottom electrode and the top electrode to obtain the HfO 2 -based ferroelectric film without a substrate and an electrode constraint self-supporting structure.
Further, in step S1, the depositing a bottom electrode specifically includes: the W/TiN/Ni bottom electrode is deposited by magnetron sputtering.
Further, in step S2, the deposited HfO 2 -based ferroelectric thin film is specifically prepared by an atomic layer deposition method.
Further, in step S3, the depositing a top electrode specifically includes: and a magnetron sputtering method is adopted to deposit the W/TiN/Ni top electrode.
Further, in step S3, the top electrode may obtain a point electrode or a surface electrode with or without a mask during the deposition process.
Further, in step S4, the integral thin film formed by annealing the silicon substrate with the SiO 2 layer is annealed by heat treatment to change the amorphous state into the crystalline state.
Further, in step S5, the alkali solution includes a KOH solution.
Further, in step S6, the dissolving-out metal electrode specifically includes: and (3) preparing an SC-1 solution of a mixed solution of ammonia water NH 4 OH, hydrogen peroxide H 2O2 and deionized water H 2 O, and carrying out heating reaction to dissolve the metal electrode.
Further, in step S1, the depositing a bottom electrode on the silicon substrate with the SiO 2 layer includes the sub-steps of: depositing metal Au/Pt on the surface of the SiO 2 sacrificial layer by adopting an ion sputtering instrument to serve as a bottom electrode;
in step S3, the depositing a top electrode on the surface of the HfO 2 -based ferroelectric film includes the following substeps: and depositing metal Au/Pt on the surface of the HfO 2 -based ferroelectric film by adopting an ion sputtering instrument as a top electrode.
Further, in step S2, the depositing the HfO 2 -based ferroelectric thin film on the bottom electrode surface specifically includes the following sub-steps: the HfO 2 -based ferroelectric film is prepared by adopting a pulse laser deposition method PLD/Sol-Gel method Sol-Gel/magnetron sputtering PVD/molecular beam epitaxy MBE/electron beam evaporation coating EBE deposition.
The beneficial effects of the invention include:
According to the invention, the self-supporting structure HfO 2 -based ferroelectric film without substrate and electrode constraint can be prepared, the SiO 2 layer obtained after the silicon substrate is directly oxidized is used as a sacrificial layer, and compared with other sacrificial layer materials, the SiO 2 -based ferroelectric film has higher lattice matching degree and smaller thermal expansion coefficient difference with the substrate, reduces the possibility of introducing other stresses, and reduces the influence on the electrical property and crystal structure of the HfO 2 -based ferroelectric film. Meanwhile, the preparation process is simple, the cost is low, and the efficiency is high. The self-supporting structure HfO 2 -based ferroelectric film without substrate and electrode constraint has great application prospect in the fields of novel HfO 2 -based flexible electronics, TEM microcosmic phase structural characterization and the like.
The preparation method of the self-supporting structure HfO 2 -based ferroelectric film overcomes the constraint effect of a substrate and an electrode on the film, provides a new preparation method for scientific research of a novel HfO 2 -based ferroelectric film, improves the development and application fields of the film, and can be used as a Transmission Electron Microscope (TEM) plane sample when being transferred onto a copper mesh.
The SiO 2 sacrificial layer adopted by the invention has better lattice matching degree with the silicon substrate and smaller thermal expansion coefficient difference, reduces the possibility of introducing other strains, and reduces the influence on the performance and the crystal structure of the HfO 2 -based ferroelectric film to the minimum extent. Meanwhile, the complexity of the process is reduced, the cost is reduced, and the efficiency of the process flow is improved. Meanwhile, siO 2 can be directly obtained by oxidizing Si sheets, and the cost is low.
The invention adopts alkali solution as the dissolvent of the SiO 2 sacrificial layer, and the temperature is controlled to be about 100 ℃ and the alkali solution can not react with the HfO 2 ferroelectric film under heating.
The invention adopts the SC-1 solution after adjustment and optimization as the dissolvent of the bottom electrode and the top electrode, has fast etching dissolution speed, but very slow reaction with the HfO 2 -based ferroelectric film, and can greatly reduce the influence on the HfO 2 -based ferroelectric film, thereby protecting the HfO 2 -based ferroelectric film.
Drawings
In order to more clearly illustrate the embodiments of the invention or the technical solutions of the prior art, the drawings which are used in the description of the embodiments or the prior art will be briefly described, it being obvious that the drawings in the description below are only some embodiments of the invention, and that other drawings can be obtained according to these drawings without inventive faculty for a person skilled in the art.
FIG. 1 is a flow chart showing the steps of a method for preparing an embodiment of the present invention;
FIG. 2 is a view of a HfO 2 based ferroelectric thin film without removal of the silicon substrate and electrodes with the sacrificial layer of SiO 2;
FIG. 3 is a view of removing the HfO 2 based ferroelectric thin film with the SiO 2 sacrificial layer silicon substrate;
FIG. 4 is a view of a free-substrate and electrode-confined self-supporting structure HfO 2 -based ferroelectric thin film;
FIG. 5 is a graph of the PV dynamic hysteresis loop of FIG. 2 after wake-up of the film;
In fig. 2 to 5, the reference numerals in fig. 2 to 4 are as follows, when the scheme of the present invention is understood: 1-a silicon substrate; a 2-SiO2 layer; 3-a bottom electrode; 4-HfO 2 -based ferroelectric thin film; 5-top electrode.
Detailed Description
All of the features disclosed in all of the embodiments of this specification, or all of the steps in any method or process disclosed implicitly, except for the mutually exclusive features and/or steps, may be combined and/or expanded and substituted in any way.
In order to solve the problems in the background, the inventors of the present invention have continuously sought solutions aimed at preparing HfO 2 -based ferroelectric thin films of self-supporting structures that meet the current research requirements. At present, the inventor of the invention finds that in the research of domestic and foreign researchers aiming at a self-supporting ferroelectric film, firstly, a mixed solution of HCL and KI is introduced on a SrTiO 3 substrate with LSMO to sacrifice the LSMO layer to prepare the HfO 2 -based ferroelectric film with a self-supporting structure; secondly, introducing an anode Al 2O3 substrate with a barrier layer by an electrochemical oxidation-anodic oxidation method, and enabling the anode Al 2O3 substrate to react with an alkali solution to peel off the self-supporting PZT ferroelectric film; secondly, a water-soluble Sr 3Al2O6 blocking sacrificial layer is introduced to prepare the flexible self-supporting structure BaTiO 3 ferroelectric film. The above research preliminarily solves a part of problems, and the self-supporting structure ferroelectric film which can be used for various researches is successfully prepared. However, after further inventive thought, the inventors of the present invention considered that: in the prior art solutions reported at present, the implementation operation steps are mostly complex, and the anode Al 2O3 substrate with the barrier layer can be obtained only after the steps of high-temperature chemical polishing pretreatment, anodic oxidation and chemical replacement reaction for removing the back aluminum are required, or other extra steps are required for obtaining the sacrificial layer, so that the whole substrate preparation process has high cost, takes a long time and is easier to introduce other organic impurities, and the performance parameters of the electrode and the PZT ferroelectric film deposited in the next step are affected. In short, the prior art increases the uncontrollable factors of the preparation process due to the complexity of the operating steps. Meanwhile, as the high-quality HfO 2 -based ferroelectric film with better compatibility with the CMOS process is mostly prepared by deposition on a monocrystalline silicon substrate with higher process compatibility, the lattice matching degree and the thermal expansion coefficient of the Al 2O3 substrate with the blocking layer and the SrTiO 3 substrate with the LSMO layer are greatly different from those of the HfO 2 -based ferroelectric film, and the problem that the performance of the HfO 2 -based ferroelectric film is changed due to the introduction of substrate stress can be caused.
In the invention, the invention particularly provides a preparation method of a novel self-supporting structure HfO 2 -based ferroelectric film without a substrate and an electrode, in the concrete implementation, a self-supporting structure HfO 2 -based ferroelectric film with an electrode is formed by stripping a silicon substrate from SiO 2 with a certain thickness and KOH solution under the heating reaction condition of about 100 ℃, and then the self-supporting structure HfO 2 -based ferroelectric film without the substrate and the electrode can be obtained by heating and reacting with a mixed solution (SC-1 solution) of ammonia water (NH 4 OH), hydrogen peroxide (H 2O2) and deionized water (H 2 O) which are configured in a certain proportion in a water bath at 50-80 ℃ to remove the electrode. Fig. 1 shows the technical solution of the present invention, comprising the following steps:
A first step of depositing a bottom electrode 3 on a silicon substrate 1 with a SiO 2 layer 2;
Secondly, depositing an HfO 2 -based ferroelectric film 4 on the surface of the bottom electrode;
Thirdly, depositing a top electrode 5 on the surface of the HfO 2 -based ferroelectric film, and obtaining the HfO 2 -based ferroelectric film with the structure shown in figure 2 and without removing the silicon substrate with the SiO 2 sacrificial layer and the electrode;
Fourthly, performing heat treatment annealing on the HfO 2 -based ferroelectric film with the SiO 2 sacrificial layer silicon substrate and the electrode which are not removed and obtained in the third step, which is of the structure shown in fig. 2, so that the HfO 2 -based ferroelectric film is changed from an amorphous state to a crystalline state;
Fifthly, heating and reacting by using alkali solution to dissolve the SiO 2 sacrificial layer, so as to obtain the HfO 2 -based ferroelectric film with the structure shown in FIG. 3 and the silicon substrate with the SiO 2 sacrificial layer removed;
And sixthly, preparing a mixed solution (SC-1 solution) of ammonia water (NH 4 OH), hydrogen peroxide (H 2O2) and deionized water (H 2 O) according to a mature process proportion, and heating and reacting to dissolve out the metal electrode to obtain the HfO 2 -based ferroelectric film without the substrate and the electrode constraint self-supporting structure shown in figure 4.
Further, in the present inventive concept, the following improvement points are included:
1) SiO 2 obtained by directly oxidizing on a silicon wafer substrate is used as a sacrificial layer in the preparation process of the HfO 2 -based ferroelectric thin without a substrate and an electrode constraint self-supporting structure. Compared with other sacrificial layers such as water-soluble Sr 3Al2O6 or LSMO in the prior art, the SiO 2 sacrificial layer 2 has the advantages that the lattice matching degree of SiO 2 obtained by directly oxidizing on a silicon wafer substrate is better, the difference value of thermal expansion coefficients is smaller, and other stress changes introduced in the deposition preparation process are smaller, so that the influence on the performance and the crystal structure of the HfO 2 ferroelectric film 4 is smaller, and the silicon substrate is more compatible with the silicon substrate, the operation is simple, the cost is low, the time consumption is short, and the like;
2) The SC-1 solution after adjustment and optimization is used as a dissolving agent of a metal electrode: the volume ratio of ammonia water (NH 4 OH), hydrogen peroxide (H 2O2) and deionized water (H 2 O) in the SC-1 solution for dissolving the W/TiN electrode is 2:3:15-1:2:5, heating and reacting for a certain time according to the thickness of the electrode at 50-80 ℃;
3) The alkali solution does not react with the HfO 2 -based ferroelectric film (4) under the heating condition of about 100 ℃, so that 1mol/L alkali solution is used as a dissolvent of the SiO 2 sacrificial layer;
4) The HfO 2 -based ferroelectric film (4) comprises a HfO 2 -based ferroelectric film doped with various elements such as zirconium (Zr), aluminum (Al), titanium (Ti), lanthanum (La), cerium (Ce), silicon (Si) and the like, and the deposition preparation method comprises Atomic Layer Deposition (ALD), pulse Laser Deposition (PLD), sol-Gel method (Sol-Gel), magnetron sputtering (PVD), molecular Beam Epitaxy (MBE), electron beam evaporation coating (EBE) and other methods.
It should be noted that, within the scope of protection defined in the claims of the present invention, the following embodiments may be combined and/or expanded, and replaced in any manner that is logical from the above specific embodiments, such as the disclosed technical principles, the disclosed technical features or the implicitly disclosed technical features, etc.
Example 1
In this embodiment, the preparation process of the self-supporting structure HfO 2 -based ferroelectric thin film without substrate and electrode constraint mainly comprises three processes. Firstly, an integral film with a structure shown in fig. 2 is prepared, and a PV dynamic hysteresis loop after wake-up is shown in fig. 5, so that the film prepared by the method of fig. 2 has excellent ferroelectric property, good linearity, good rectangularity, and high residual polarization value (Pr) and saturated polarization value (Ps). And preparing the HfO 2 -based ferroelectric film shown in FIG. 3, which is obtained by removing the silicon substrate with the SiO 2 sacrificial layer, and finally preparing the novel self-supporting structure HfO 2 -based ferroelectric film without substrate and electrode constraint of the structure shown in FIG. 4. The method comprises the following specific steps:
step (1), depositing a tungsten (W)/titanium nitride (TiN) bottom electrode 3 with a certain thickness on a purchased silicon substrate 1 with a SiO 2 sacrificial layer with a certain thickness through magnetron sputtering (PVD);
Step (2), preparing an HfO 2 -based ferroelectric film 4 on the surface of the bottom electrode 3 obtained in the step (1) by adopting an Atomic Layer Deposition (ALD);
And (3) depositing a tungsten (W)/titanium nitride (TiN) top electrode 5 with a certain thickness on the surface of the HfO 2 base ferroelectric film 4 obtained in the step (2) by adopting magnetron sputtering (PVD), and obtaining the W (TiN)/HfO 2 base ferroelectric layer/W (TiN)/SiO 2/Si integral film shown in figure 2. The top electrode 5 can be added or not added with a mask plate in the deposition process to obtain a point electrode or a surface electrode;
Step (4), carrying out heat treatment annealing crystallization on the obtained W (TiN)/HfO 2 -based ferroelectric layer/W (TiN)/SiO 2/Si integral film;
Step (5), putting the obtained W (TiN)/HfO 2 -based ferroelectric layer/W (TiN)/SiO 2/Si integral film into 1mol/L alkali solution, heating and reacting for a certain time according to the thickness of the SiO 2 sacrificial layer at about 100 ℃, reacting the SiO 2 sacrificial layer with the alkali solution to generate silicate and water, and taking out a reaction product to obtain a W (TiN)/HfO 2 -based ferroelectric layer/W (TiN) structural film shown in figure 3;
And (6) putting the W (TiN)/HfO 2 -based ferroelectric layer/W (TiN) structural film obtained in the step (4) into a mixed solution (SC-1 solution) prepared by using a mature technology in a specific proportion and prepared with ammonia water (NH 4 OH), hydrogen peroxide (H 2O2) and deionized water (H 2 O) for 50-80 ℃ water bath heating reaction to dissolve a metal electrode, and then taking out and transferring a reaction product to obtain the HfO 2 -based ferroelectric film without a substrate and an electrode constraint self-supporting structure shown in figure 4. Wherein, the volume ratio range of ammonia water (NH 4 OH), hydrogen peroxide (H 2O2) and deionized water (H 2 O) in the SC-1 solution of the dissolved electrode is 2:3:15-1:2: and 5, heating and reacting for a certain time according to the thickness of the electrode at 50-80 ℃.
Example 2
In this embodiment, the preparation method of the HfO 2 -based ferroelectric film without the substrate and the electrode constraint self-supporting structure is basically the same as that in example 1, except that in steps (1) and (3), a small ion sputtering apparatus is used to deposit metal Au/Pt on the surfaces of the SiO 2 sacrificial layer 2 and the HfO 2 -based ferroelectric film 4 as the bottom electrode 3 and the top electrode 5, respectively, in step (2), a Pulse Laser Deposition (PLD)/Sol-Gel method (Sol-Gel)/magnetron sputtering (PVD)/Molecular Beam Epitaxy (MBE)/electron beam evaporation coating (EBE) deposition is used to prepare the HfO 2 -based ferroelectric film 4, and the other steps (4) and (5) are the same as in example 1, except that a certain adjustment is required for the reaction parameters of the Au/Pt metal electrode to be dissolved with the SC-1 solution, so as to obtain the HfO 2 -based ferroelectric film without the substrate and the electrode constraint self-supporting structure shown in fig. 4.
While the foregoing embodiments have been described in some detail by way of illustration of the invention, it should be understood that this invention is not limited to particular embodiments of the invention, but is intended to cover modifications, additions and substitutions of the like within the spirit and scope of the invention.
Claims (10)
1. The preparation method of the HfO 2 -based ferroelectric film without the substrate and the electrode self-supporting structure is characterized by comprising the following steps of:
S1, depositing a bottom electrode (3) on a silicon substrate (1) with a SiO 2 layer (2);
s2, depositing an HfO 2 -based ferroelectric film (4) on the surface of the bottom electrode (3);
s3, depositing a top electrode (5) on the surface of the HfO 2 -based ferroelectric film (4);
s4, performing heat treatment annealing on the HfO 2 -based ferroelectric film with the SiO 2 -layer silicon substrate obtained in the step S3 to crystallize the film;
S5, taking the SiO 2 layer (2) as a sacrificial layer, and using an alkali solution to heat and react to dissolve the SiO 2 sacrificial layer to obtain the HfO 2 -based ferroelectric film with the SiO 2 sacrificial layer silicon substrate removed;
S6, dissolving the bottom electrode (3) and the top electrode (5) to obtain the HfO 2 -based ferroelectric film without a substrate and an electrode constraint self-supporting structure.
2. The method for preparing a HfO 2 -based ferroelectric thin film without a substrate and an electrode self-supporting structure according to claim 1, wherein in step S1, the depositing a bottom electrode specifically comprises: the W/TiN/Ni bottom electrode is deposited by magnetron sputtering.
3. The method for preparing a HfO 2 -based ferroelectric thin film without a substrate and an electrode self-supporting structure according to claim 1, wherein in step S2, the deposited HfO 2 -based ferroelectric thin film (4) is prepared specifically by an atomic layer deposition method.
4. The method for preparing a HfO 2 -based ferroelectric thin film without a substrate and an electrode self-supporting structure according to claim 1, wherein in step S3, the deposition top electrode (5) specifically comprises: and a magnetron sputtering method is adopted to deposit the W/TiN/Ni top electrode.
5. The method for preparing a HfO 2 -based ferroelectric thin film without a substrate and an electrode self-supporting structure according to claim 1, characterized in that in step S3, the top electrode (5) is a point electrode or a surface electrode with or without a mask plate added during the deposition process.
6. The method for preparing a HfO 2 -based ferroelectric thin film without a substrate and an electrode self-supporting structure according to claim 1, wherein in step S4, the annealing for heat treatment is performed to heat treat the monolithic thin film with SiO 2 layer silicon substrate to convert it from amorphous state to crystalline state.
7. The method for preparing a HfO 2 based ferroelectric thin film without a substrate and an electrode self-supporting structure according to claim 1, wherein in step S5, the alkali solution comprises KOH solution.
8. The method for preparing a HfO 2-based ferroelectric thin film without a substrate and an electrode self-supporting structure according to claim 1, wherein in step S6, the dissolving-out of the metal electrode specifically comprises: and (3) preparing an SC-1 solution of a mixed solution of ammonia water NH 4 OH, hydrogen peroxide H 2O2 and deionized water H 2 O, and carrying out heating reaction to dissolve the metal electrode.
9. The method for preparing a HfO 2 -based ferroelectric thin film without a substrate and electrode self-supporting structure according to claim 1, characterized in that in step S1, the deposition of the bottom electrode (3) on the silicon substrate (1) with the SiO 2 layer (2) comprises the sub-steps of: depositing metal Au/Pt on the surface of the SiO 2 sacrificial layer by adopting an ion sputtering instrument to serve as a bottom electrode (3);
In step S3, the depositing of the top electrode (5) on the surface of the HfO 2 -based ferroelectric film includes the sub-steps of: and depositing metal Au/Pt on the surface of the HfO 2 -based ferroelectric film (4) by adopting an ion sputtering instrument to serve as a top electrode (5).
10. The method for preparing the HfO 2 -based ferroelectric thin film without the substrate and the electrode self-supporting structure according to claim 9, wherein in step S2, the HfO 2 -based ferroelectric thin film (4) is deposited on the surface of the bottom electrode (3), specifically comprising the sub-steps of: the HfO 2 -based ferroelectric film is prepared by adopting a pulse laser deposition method PLD/Sol-Gel method Sol-Gel/magnetron sputtering PVD/molecular beam epitaxy MBE/electron beam evaporation coating EBE deposition.
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