265 results about "Ferroelectric thin films" patented technology

The invention discloses a high-durability superlattice wurtzite ferroelectric material and preparation and application thereof.The high-durability superlattice wurtzite ferroelectric material is of a stacked structure composed of wurtzite ferroelectric films and AlN films alternately, and the total layer number of the stacked structure is larger than two. The first layer and the last layer of the stacked structure are wurtzite ferroelectric films. The preparation method comprises the following steps: depositing a layer of wurtzite ferroelectric film on the substrate; depositing a layer of AlN thin film on the obtained wurtzite ferroelectric thin film; a layer of wurtzite ferroelectric film is deposited on the obtained AlN film; the steps are repeated until a required stacked structure is formed, and the material can be used for a ferroelectric memory. The AlN thin film with good lattice matching performance with the wurtzite ferroelectric thin film is inserted into the wurtzite ferroelectric thin film, so that the durability of the thin film is improved, the superlattice structure shows excellent performance of low defect, low electric leakage, high durability and the like, and the breakdown resistance and durability of the ferroelectric memory are improved when the superlattice structure is applied to the ferroelectric memory.

The present disclosure relates to a ferroelectric thin film transistor and may include: a substrate; a gate electrode layer formed on the substrate; a ferroelectric layer formed on the gate electrode layer, including a hafnium-based oxide, and including an uneven portion having at least one or more step that is formed on the gate electrode layer; a semiconductor channel layer formed on the ferroelectric layer and including an oxide semiconductor; a drain electrode layer connected to the semiconductor channel layer at one side of the gate electrode layer; and a source electrode layer connected to the semiconductor channel layer at the other side of the gate electrode layer.

The invention belongs to the field of microelectronics, and particularly relates to a preparation method and application of a ferroelectric diode based on a scandium-doped aluminum nitride thin film, and the ferroelectric diode is prepared through the following steps: S1, growing an adhesion layer on a substrate through magnetron sputtering; s2, growing a bottom electrode on the adhesion layer through magnetron sputtering; s3, growing a ferroelectric film on the bottom electrode through magnetron co-sputtering at room temperature; s4, coating photoresist on the ferroelectric film, and exposing and developing; s5, growing a top electrode on the exposed and developed ferroelectric film through magnetron sputtering; and S6, stripping to obtain the ferroelectric diode. Compared with the prior art, the method has the advantages that the problems of high preparation temperature of the Al1-xScxN layer and large thickness of the Al1-xScxN layer in the prior art are solved, the ferroelectric diode memory of the scandium-doped aluminum nitride film is prepared at room temperature for the first time, and compatibility with a CMOS (complementary metal oxide semiconductor) process is better realized.

In accordance with some embodiments of the present disclosure, a memory device is provided. The memory device may include a first electrode, a ferroelectric layer fabricated on the first electrode, and a second electrode fabricated on the ferroelectric layer. The ferroelectric layer includes a plurality of ferroelectric films and a plurality of interface layers stacked alternately. Each of the ferroelectric films comprises at least one ferroelectric material, such as hafnium oxide (HfO2), zirconium oxide (ZrO2), zirconium-doped hafnium oxide (Hf1-xZrxO2), scandium-doped aluminum nitride (Al1-xScxN), titanates (BaTiO3), niobates (LiNbO3), tantalates (NaTaO3), etc. Each of the interface layers comprises at least one dielectric material that is more chemically stable than the ferroelectric material, such as aluminum oxide.

The invention provides a hafnium oxide-based ferroelectric film annealing process with a low thermal budget and a hafnium oxide-based ferroelectric film, and relates to the field of ferroelectric films, the hafnium oxide-based ferroelectric film is subjected to multiple low-temperature rapid annealing cycles, and the hafnium oxide-based ferroelectric film annealing process comprises the following steps: heating to an annealing temperature of 400 DEG C at a heating rate of 10-80K / s, keeping the temperature for 15-120s, and cooling at a cooling rate of not less than 10K / s, and after cooling to room temperature, carrying out next annealing cycle. The internal defect distribution of the thin film is changed through repeated rapid annealing circulation; and multiple times of rapid cooling are introduced, so that multiple times of enhanced stress is generated in the thin film, the hafnium oxide phase change potential barrier is cooperatively regulated and controlled, conversion from a non-ferroelectric high-temperature tetragonal phase to a ferroelectric orthogonal phase is promoted, and the requirement for the high annealing temperature is avoided.

The invention discloses a strontium-doped bismuth titanate-based ferroelectric film and a preparation method thereof, and belongs to the technical field of dielectric energy storage materials. The chemical composition of the film is Ba < 1-x > Sr < x > Bi < 4 > Ti < 4 > O < 15 >, wherein x ranges from 0.025 to 0.1. The preparation method comprises the following steps: mixing ethylene glycol monomethyl ether and ethylene glycol, adding bismuth nitrate, barium acetate, strontium acetate and butyl titanate, fully stirring and filtering to obtain a precursor solution, aging, dripping to the center of a substrate for spin coating, heating a spin-coated sample to obtain a dry film, and annealing to obtain the ferroelectric film. The method is low in technological condition requirement, and the thin film obtains the optimal energy storage density by changing the doping proportion of Sr. According to the ferroelectric film, when x is equal to 0.075, the leakage current density of Ba0. 925Sr0. 075Bi4Ti4O15 (BBST75) is only 1.59 * 10 <-7 > A / cm < 2 >, the breakdown field strength is as high as 3.22 MV / cm, and at the moment, the film has the energy storage density of 28.2 J / cm < 3 > and the energy storage efficiency of 80.36%.

The invention discloses a method for improving the performance of an HZO ferroelectric capacitor through plasma interface treatment. The method comprises the following steps: forming a TiN bottom electrode on a Si substrate material through deposition; zrO2 and HfO2 are deposited on the TiN bottom electrode through an atomic layer to form an HZO ferroelectric medium layer; performing plasma treatment on the upper surface of the HZO ferroelectric dielectric layer; after processing, a TiN top electrode is formed on the upper surface of the HZO ferroelectric dielectric layer through deposition; carrying out rapid thermal annealing treatment in an N2 atmosphere; according to the method, plasma is adopted to process the upper surface of the ferroelectric film, and the oxygen vacancy distribution uniformity of the upper surface of the HZO film can be optimized, so that the wake-up effect is inhibited, and the performance of the ferroelectric film is improved; plasma is adopted to process the upper surface of the ferroelectric film, and generation of oxygen vacancies on the upper surface of the HZO film can be inhibited, so that electric leakage is reduced, the fatigue effect and the imprinting effect are inhibited, and the performance of the ferroelectric film is improved.

The invention belongs to the field of microelectronics, and particularly relates to a ferroelectric capacitor, a preparation method thereof and a three-dimensional ferroelectric memory array, and the ferroelectric capacitor comprises a substrate, a bottom electrode, a ferroelectric dielectric layer, a deoxidizing layer and a top electrode which are sequentially arranged from bottom to top; the ferroelectric medium layer is an Hf < 1-x > Zr < x > O < 2 > layer, 0 lt; xlt; the Hf-rich composition is realized by controlling the Hf: Zr super-cycle ratio of atomic layer deposition; the thickness of the ferroelectric medium layer is 1-6 nm, and the thickness of the bottom electrode is 0.1-5 nm. Compared with the prior art, the problems of polarization characteristic degradation caused by thinning of the ferroelectric layer in the hafnium-based ferroelectric capacitor and crosstalk in the FeRAM in the prior art are solved. According to the scheme, the oxygen vacancy concentration is accurately adjusted to inhibit the formation of a non-ferroelectric phase, so that the ultra-thin ferroelectric film can still maintain relatively high remanent polarization while the size is reduced, a storage window is effectively improved, and the wake-up requirement is reduced.

The invention discloses a dynamic light field regulation and control method based on a ferroelectric topological domain structure, and the method comprises the steps: selecting the ferroelectric topological domain structure formed in a ferroelectric film material as a light field regulation and control medium, and the ferroelectric topological domain structure is provided with dipole arrangement in spatial distribution; the ferroelectric topological domain structure is used for carrying out linear or nonlinear conversion on a light field of incident fundamental waves to generate a vortex light field or a vector light field, and domain distribution and dipole arrangement of the ferroelectric topological domain structure are adjusted in real time through external field driving modes such as a thermal field, an electric field or a pulse light field. And dynamically changing the phase, the amplitude and the polarization state of the vortex light field or the vector light field to realize real-time correlation response of the light field parameters and the topological domain structure. According to the method, the topological domain structure in the ferroelectric material is utilized, multi-dimensional regulation and control of the light field are achieved through rich dipole arrangement, and the method can also be applied to the fields of high-integration photonic circuits and reconfigurable high-capacity optical communication.

The invention relates to an HZO ferroelectric film with a controllable coercive field, a ferroelectric capacitor and a preparation method of the ferroelectric capacitor. The HZO ferroelectric film is provided with at least one microbeam gallium ion implantation region; and the gallium ion injection amount of each micro-beam gallium ion injection region is 1.3 * 10 < 14 >-5.2 * 10 < 14 > ion / cm < 2 >. According to the HZO ferroelectric film with the controllable coercive field provided by the invention, the coercive field of the HZO ferroelectric film can be accurately regulated and controlled by adjusting the gallium ion injection amount in the micro-beam gallium ion injection region, and meanwhile, the high polarization intensity, the structural uniformity and the electrical stability of the ferroelectric film can be maintained. Moreover, different injection amounts of gallium ions are injected into different regions of the HZO ferroelectric film, different coercive fields can be shown in different regions, the HZO ferroelectric film can be applied to a multi-valued memory, and the storage density is greatly improved.

The invention discloses a phase field simulation and analysis method for an anisotropic domain wall of a hafnium oxide-based ferroelectric film, and solves the problems that an existing method is difficult to reflect the influence of the anisotropy of the domain wall on domain evolution and polarization overturning dynamics and is associated with macroscopic electrical properties. Comprising the following steps: 1) determining a total energy equation and correlation coefficients; 2) establishing a gradient energy density equation based on domain wall anisotropy; 3) constructing and solving a control equation; 4) visualizing a simulation result; and 5) domain evolution and polarization flipping characteristics under different voltages are analyzed. According to the method, accurate simulation of the anisotropic domain wall and quantitative analysis of the migration behavior of the domain wall are realized, guidance is provided for experimenters to understand the influence rule of the anisotropic domain wall on the domain overturning characteristic and the macroscopic electrical property, the experiment cost is reduced, and the experiment efficiency is improved.

The present invention relates to a display pixel circuit using ferroelectric thin-film transistors and a method of driving the same. More particularly, the present invention relates to a display pixel circuit in which a volatile switch function and a non-volatile memory function are selectively applied by using a plurality of ferroelectric thin-film transistors including a ferroelectric gate-insulating film having a high dielectric constant (high-k) and a method of driving the display pixel circuit.

A method for manufacturing a piezoelectric film deposition substrate (100) according to this present invention includes forming a piezoelectric film (3) on or above the lower electrode (2) with the mask (5) being attached on or above the lower electrode; forming an upper electrode (4) on the piezoelectric film with the mask being attached on or above the lower electrode; forming a the lower-electrode-exposed part (2a) by detaching the mask from the lower electrode; and subjecting the piezoelectric film to polarization by applying a voltage between the lower-electrode-exposed part and the upper electrode.

The present application discloses a phase field analysis method based on the influence of oxygen vacancies on hafnium oxide-based ferroelectric films, including: considering the influence of oxygen vacancy concentration on hafnium oxide-based ferroelectric films, determining the total energy equation; establishing the constitutive equations of various physical fields based on the influence of oxygen vacancies through the energy equation; determining the control equations of various physical fields; solving through the finite element method, deriving the weak form of the control equations of various physical fields based on the influence of oxygen vacancies, and establishing a phase field calculation model based on the influence of oxygen vacancies for hafnium oxide-based ferroelectric films according to the weak form of the equations, so as to simulate the domain structure cloud diagram and its phase transition law of polymorphic coexistence of hafnium oxide-based ferroelectric films under different oxygen vacancy concentrations. The present application can provide theoretical guidance on the influence of oxygen vacancies for experimenters during the experiment through the establishment of a calculation model, thereby effectively reducing the experimental cost, and having a preset range control value for the oxygen vacancy concentration used in the experiment.

The invention belongs to the field of semiconductors, and discloses a novel ferroelectric memcapacitor based on an MFIS structure and a preparation method thereof, a substrate of the novel ferroelectric memcapacitor comprises a first doped region and a second doped region, and the doping type of the first doped region is p-type; the insulating layer, the ferroelectric layer and the top electrode layer are arranged on the substrate from bottom to top and cover the first doped region of the substrate; an uncovered area on the surface of the substrate is a second doped area, and the doping type of the second doped area is n type; the bottom electrode layer is located in the second doped region of the substrate and is far away from the first doped region; the channel is located in the second doped region of the substrate and is close to the first doped region; the invention also provides a corresponding preparation method, according to the ferroelectric memcapacitor prepared by using the method, because the semiconductor layer has a PN junction depletion region, the ferroelectric film can be fully overturned by using a band-to-band tunneling mechanism without large voltage, and meanwhile, the capacitance of the depletion region of the PN junction on one side of the semiconductor is adjusted, so that a relatively high capacitance-to-switch ratio is obtained while low power consumption is ensured.

The invention provides a Bi < 1.8 > Sm < 0.2 > O < 3 > ferroelectric film as well as a preparation method and application thereof. The preparation method comprises the following steps: taking sapphire subjected to annealing treatment at the temperature of 1100-1300 DEG C as a substrate, bombarding a bismuth oxide samarium target material in a chamber by adopting pulse laser, and depositing on the substrate at the temperature of 450-600 DEG C to form the Bi1. 8Sm0. 2O3 ferroelectric film. The preparation method of the Bi1. 8Sm0. 2O3 ferroelectric film provided by the invention is simple to operate, the production cost of the ferroelectric film is low, a brand new method and thought are provided for the preparation of the Bi1. 8Sm0. 2O3 ferroelectric epitaxial film, and the prepared Bi1. 8Sm0. 2O3 ferroelectric epitaxial film has excellent crystallinity and ferroelectric property.

The embodiment of the invention discloses a hafnium oxide-based ferroelectric film doped in a calcium gap position and a preparation method. The method comprises the following steps: preparing a target material: mixing hafnium oxide and calcium oxide according to a set ratio, and grinding to obtain mixed raw material powder; calcining the mixed raw material powder for the first time; grinding the mixed raw material powder calcined for the first time, and performing compression molding to obtain a target material biscuit; calcining the target material biscuit for the second time to obtain the hafnium oxide-based ceramic target material doped in the calcium gap position; a commercial bottom electrode La0. 7Sr0. 3MnO3 target material is used as a first sputtering target, sputtering is carried out under a first set condition, and an LSMO bottom electrode thin film is obtained; taking the calcium gap position doped hafnium oxide-based ceramic target material as a second sputtering target, sputtering under a second set condition, and epitaxially growing on the LSMO bottom electrode film to form a calcium gap position doped hafnium oxide-based ferroelectric film; the chemical composition of the hafnium oxide-based ferroelectric film doped in the calcium gap position is CaxHf (1-x) O (2-x), x is 0.01-0.05, and calcium ions occupy the gap position of a hafnium oxide crystal lattice.

The invention provides a method for recovering a hafnium oxide-based ferroelectric erasing and writing mark phenomenon, which relates to the field of ferroelectric films, and comprises the step of applying bipolar electric pulses or unipolar electric pulses with the polarization direction opposite to that of data erasing and writing electric pulses to a hafnium oxide-based ferroelectric film device which is subjected to data erasing and writing after the electric pulses are applied to the hafnium oxide-based ferroelectric film device. By means of the method, the imprint offset field caused by data erasing and writing can be effectively recovered.

This invention discloses an electrode-free constrained annealed hafnium oxide-based ferroelectric thin film, its preparation method, and its application. The method employs ALD technology to alternately deposit a predetermined number of hafnium oxide layers on a substrate. 0.5 Zr 0.5 O2 thin film and a layer of Al2O3 thin film were used to obtain Al with different doping concentrations. x -(Hf) 0.5 Zr 0.5 O2) y Ferroelectric thin films, where x represents the number of Al2O3 layers deposited using ALD, and y represents the number of Hf layers deposited using ALD. 0.5 Zr 0.5 The number of O2 layers; for the obtained Al x -(Hf) 0.5 Zr 0.5 O2) y Ferroelectric thin films are subjected to high-temperature annealing to obtain Al. x -(Hf) 0.5 Zr 0.5 O2) y Ferroelectric thin film samples; for the obtained Al x -(Hf) 0.5 Zr 0.5 O2) y A hafnium oxide-based ferroelectric thin film was obtained by depositing a top electrode and a bottom electrode onto a ferroelectric thin film sample. This invention improves the performance of annealed ferroelectric thin films without electrode constraint, deepens the understanding of the ferroelectric principle of HfO2 thin films, and promotes the development of the field of novel practical ferroelectric thin films.

The present invention relates to a ferroelectric thin film transistor and a method of manufacturing the same. According to an example embodiment of the present invention, a ferroelectric thin film transistor may include: a ferroelectric layer formed by depositing a ferroelectric material on a buffer layer provided on a substrate, a semiconductor layer formed by depositing an oxide on the ferroelectric layer and doping an upper region thereof through plasma treatment, a gate insulating layer formed by depositing a dielectric material on the semiconductor layer, a gate electrode formed by depositing a metal material on the gate insulating layer and performing a gate patterning process, an interlayer formed on the gate electrode and the semiconductor layer, and a source electrode and a drain electrode formed by patterning the interlayer and depositing a metal material.

The phase structure evolution phase field analysis method in the annealing and crystallization process of the amorphous hafnium oxide-based ferroelectric film comprises the following steps: S1, setting a sequence parameter xi according to the evolution process from an amorphous phase to a crystal phase in the annealing process, and setting a sequence parameter eta according to the process of the crystal phase and the crystal phase; s2, a phase field theoretical model is established, the total free energy is the sum of the free energy of the sequence parameter xi and the free energy of the sequence parameter eta, and the free density in the free energy of the sequence parameter eta is obtained through coupling of the sequence parameter xi and the sequence parameter eta; s3, deducing a weak form of the control equation; and S4, compiling the weak form equation into COMSOL finite element software, solving and analyzing the phase structure in the annealing crystallization process of the thin film. According to the method, the sequence parameter xi representing the transformation process from the amorphous phase to the crystalline phase is introduced and coupled with the sequence parameter eta to construct a new free energy equation and a new control equation, the weak form of the control equation is deduced, and the phase structure and the evolution rule of the hafnium oxide-based ferroelectric film at different annealing moments can be dynamically reproduced.

The application provides a ferroelectric thin film with a two-dimensional layered electrode and a preparation method thereof. The ferroelectric thin film comprises a ferroelectric hafnium oxide thin film and a two-dimensional layered calcium nitride electrode arranged on the ferroelectric hafnium oxide thin film. The calcium nitride of the application has excellent in-plane lattice matching with hafnium oxide (111), and the lattice mismatch degree is extremely low, which is beneficial to realize high-quality epitaxial growth of the heterostructure and provides a structural basis for device manufacturing. The calcium nitride of the application can form stable chemical bonds (such as Hf-N and O-Ca) with hafnium oxide at the interface, can effectively enhance the interface bonding force, and improve the structural stability of the device. The calcium nitride of the application can significantly inhibit the depolarization field in the hafnium oxide thin film, restore and exceed the ferroelectric polarization intensity of the hafnium oxide bulk, and significantly improve the ferroelectric performance of the hafnium oxide.

The embodiment of the invention discloses a donor-receptor complementary co-doped hafnium oxide-based ferroelectric film material and a preparation method thereof. The method comprises the following steps: according to the composition of the donor-receptor complementary co-doped hafnium oxide-based ceramic target material, mixing raw material powder to obtain mixed raw material powder; calcining the mixed raw material powder under a preset condition; pressing and molding the calcined product into a target material green body; and sintering the target material green body to obtain the donor-receptor complementary co-doped hafnium oxide-based ceramic target material. Wherein the composition of the donor-acceptor complementary co-doped hafnium oxide-based ceramic target material is expressed as AxByHf (1-x-y) O2, A is a donor and comprises elements niobium and tan, and B is an acceptor and comprises elements yttrium and lanthanum; x is more than 0.01 and less than 0.05, and y is more than 0.01 and less than 0.05; the raw material powder containing the donor comprises niobium oxide and tantalum oxide, and the raw material powder containing the acceptor comprises yttrium oxide and lanthanum oxide; and taking the donor-acceptor complementary co-doped hafnium oxide-based ceramic target material as a sputtering target, and obtaining the donor-acceptor complementary co-doped hafnium oxide-based ferroelectric material film by using a pulse laser deposition method.

The self-driven sensor and bearing slip rate in-situ monitoring method disclosed by the specification relates to the technical field of bearing detection and comprises a ferroelectric PVDF film, an upper flexible electrode, a lower flexible electrode and a spacer. The ferroelectric PVDF film is bonded to the Cu electrode area on the upper surface of the lower flexible electrode. The spacer is arranged on the two sides of the ferroelectric PVDF film in the horizontal direction. The upper flexible electrode is bonded to the spacer. When subjected to external pressure, the upper flexible electrode is deformed to contact the ferroelectric PVDF film. The self-driven sensor and bearing slip rate in-situ monitoring method provided by the present application meets the requirements of non-interference, easy integration, self-power supply and high-precision monitoring for bearing slip rate monitoring, and realizes precise wireless in-situ monitoring of bearing slip rate.

The invention discloses a high-linearity AlGaN / GaN device based on a ferroelectric medium, a conductor layer and an AlGaN layer are arranged on a GaN layer, a barrier layer is formed, a ferroelectric film is arranged between a grid electrode and the barrier layer, and the high-linearity AlGaN / GaN device based on the ferroelectric medium is obtained. In the prior art, the linearity of a device is improved to a certain extent, but the complexity of the device is increased due to higher design requirements on a process and an epitaxial material. According to the invention, a layer of ferroelectric medium is introduced under the gate, and polarization regulation and control of the AlGaN / GaN HEMT are realized by utilizing the characteristic that the polarization intensity of the ferroelectric medium can be modulated by an external electric field and an extremely high dielectric constant, so that relatively flat transconductance is obtained. According to the high-linearity AlGaN / GaN HEMT device, the ferroelectric material is introduced and the parameters of the ferroelectric material are optimized, so that the electrical characteristics of the AlGaN / GaN HEMT device are successfully regulated and controlled, the peak transconductance is broadened, and the high-linearity AlGaN / GaN HEMT device based on the ferroelectric gate medium is realized. Therefore, an important theoretical and experimental basis is provided for further improving the performance of the device and expanding the application field.

A superconducting circuit element includes a piezoelectric or ferroelectric thin film formed on a rigid substrate. The piezoelectric or ferroelectric thin film has one or more circuit element openings and an under compression room temperature superconductor material disposed within the one or more circuit element openings. Actuation of the thin film applies a compressive stress on the under compression room temperature superconductor material such that a room temperature superconducting circuit element is formed on the rigid substrate.

The present invention belongs to the field of NEMS micro-pressure sensitive sensor design, specifically a PZT-based graphene composite pressure-sensitive thin film structure based on the flexoelectric polarization-enhanced force-electric coupling mechanism, which includes a Si / SiO2 substrate. A back cavity is provided on the Si / SiO2 substrate. A metal layer of pt / Ti is sputtered on the front surface of the Si / SiO2 substrate. A PZT ferroelectric thin film is sputtered on the metal layer of pt / Ti. A graphene thin film is on the PZT ferroelectric thin film. Metal electrodes are sputtered on both sides of the graphene thin film. A packaging substrate is on the back surface of the Si / SiO2 substrate. The present invention regulates the graphene thin film through the polarization voltage generated by the bending of the PZT ferroelectric thin film, applies a bias voltage to the graphene thin film, indirectly characterizes the transport of graphene carriers through the output current of the circuit, and further characterizes the change in the energy band of the graphene thin film, completing the exploration of the mechanism of regulating the energy band structure and electrical transport of graphene by PZT flexoelectric polarization, and completing the design of a high-sensitivity force-electric coupling PZT-based graphene composite pressure-sensitive thin film structure.

The application discloses a lead lanthanum zirconium tin-based antiferroelectric film prepared through doping regulation, a preparation method and application thereof, and relates to the technical field of antiferroelectric films. The lead lanthanum zirconium tin-based antiferroelectric film is prepared through the following steps. First, a mixed solution is prepared by mixing lead acetate trihydrate, dibutyl tin diacetate, lanthanum nitrate hexahydrate, manganese acetate tetrahydrate and glacial acetic acid. Then, the mixed solution is heated and stirred and cooled. Subsequently, polyethylene glycol and acetylacetone are added in sequence and stirred at room temperature. Then, zirconium n-propylate, ethylene glycol methyl ether and deionized water are added and stirred at room temperature. Finally, lactic acid is added and stirred at room temperature. After standing, a precursor solution is obtained through filtration. The precursor solution is prepared on a Pt(111) / Ti / SiO2 / Si(004) substrate through spin coating. Then, the precursor solution is subjected to drying treatment and pyrolysis treatment. The thin film of the first layer and the tenth layer is subjected to annealing treatment in an air atmosphere, so that the lead lanthanum zirconium tin-based antiferroelectric film is obtained. While realizing a larger refrigeration temperature change value, the electric refrigerator refrigeration effect is also expanded to a low-temperature region, and the antiferroelectric performance is more excellent.

This invention discloses a phase-field method for multi-topological domain cyclic transformation in lead titanate (PTO) ferroelectric thin films. A computational model of the PTO ferroelectric thin film is established, defining polarization, potential, displacement, and oxygen vacancy concentration as field variables. Based on Ginzburg-Landau theory, a total free energy expression for the PTO ferroelectric thin film is established, incorporating oxygen vacancy transport processes and the coupling between oxygen vacancies and the electrostatic field. Combining time-correlated Ginzburg-Landau kinetic equations, mechanical equilibrium equations, electrostatic equilibrium equations, and Nernst-Planck equations, a phase-field model of the PTO ferroelectric thin film coupled with multiple physics fields is established. A stable initial skyrmion domain structure is constructed, and a preset uniform electric field sequence is applied to simulate the cyclic transformation process between skyrmions and flux-closed domains and / or stripe domains. This method can analyze the evolution path, transformation threshold, oxygen vacancy distribution, and cyclic stability of topological domains in PTO ferroelectric thin films under the synergistic effect of an applied electric field and oxygen vacancies, providing a theoretical basis for the design of ferroelectric topological domain multi-state storage devices.

The invention relates to the field of semiconductor devices, in particular to an ultra-low sub-threshold swing transistor based on a hafnium-aluminum-oxygen ultra-thin matching layer film and a preparation method of the ultra-low sub-threshold swing transistor based on the hafnium-aluminum-oxygen ultra-thin matching layer film. And the driving capability and switching speed of the device are further improved. On the premise of ensuring stable characteristics of the ferroelectric film, a proper matching layer medium is introduced to achieve the purpose of reducing clockwise hysteresis caused by an interface state so as to further reduce total hysteresis, the introduced new matching layer Hf1-aAlaOb is compared with a common Al2O3 matching layer, nitridation process research is carried out, a capacitance matching medium most suitable for Zr1-xAlxOy is explored, and the performance of the ferroelectric film is improved. And the driving capability and switching speed of the device are further improved.