11 results about "Residual polarization" patented technology

This invention discloses a method and apparatus for awakening the polarization of a large-area ferroelectric capacitor at the wafer level. The wafer consists of a bottom electrode, a ferroelectric layer, and a patterned, independent top electrode array stacked sequentially from bottom to top. The bottom electrode is electrically connected to one end of a pulse voltage generator, and the conductive film on the surface of a flexible conductive roller is electrically connected to the other end of the pulse voltage generator. By controlling the horizontal movement of the wafer stage, the flexible conductive roller is driven to roll and contact the surface of the top electrode array; simultaneously, a preset pulse voltage is applied between the bottom electrode and the conductive film using the pulse voltage generator, increasing the ferroelectric remanent polarization intensity of the ferroelectric film covered by the top electrode in the contact area, thus achieving ferroelectric polarization awakening. This invention, after a high-temperature heat treatment at over 200°C, efficiently and over a large area awakens the polarization of the ferroelectric film corresponding to the top electrode array, ensuring high stability and consistency in its ferroelectric remanent polarization intensity.

The application provides a hafnium-based ferroelectric memristor, a preparation method and application thereof. The application relates to the application fields of ferroelectric memristors, neural networks and the like in microelectronic and thin film material science, and innovatively epitaxially grows a Y:HfO2 thin film on a single crystal 0.5%Nb:SrTiO3 (NSTO)<111> substrate. Yttrium doping can adjust the crystal phase structure of the hafnium oxide thin film, significantly increase the ferroelectricity of the thin film, reduce the leakage current, effectively improve the residual polarization intensity and stability of the device, and realize low power consumption, high durability, high ferroelectricity and stability. The application also designs a peripheral circuit based on the multi-resistance state stability characteristics of the HYO ferroelectric memristor to perform multiplication and addition reading operation on the memristor array, and innovatively designs a neural morphological computing system based on the HYO ferroelectric memristor, and applies the memristor neural network to the tracking work of an intelligent vehicle.

This invention discloses a ferroelectric thin-film transistor based on a multilayer structure of aluminum scandium nitride, aluminum nitride, and aluminum scandium nitride, and its fabrication method, relating to the fields of semiconductor devices and ferroelectric memories. The ferroelectric thin-film transistor based on the multilayer structure includes a multilayer ferroelectric gate stack structure and a channel layer that cooperates with the multilayer ferroelectric gate stack structure. The multilayer ferroelectric gate stack structure is a symmetrical stacked structure of aluminum scandium nitride / aluminum nitride / aluminum scandium nitride. This ferroelectric thin-film transistor based on the multilayer structure provides a structural basis for decoupling residual polarization and coercive field and mitigating the negative impact of depolarization field through the hierarchical cooperation of the stacked structure. It is also compatible with the assembly logic of conventional semiconductor devices, reserving structural space for subsequent performance optimization and material replacement.

The application discloses an artificial solid electrolyte interface layer and a preparation method thereof, and a preparation method of a composite piezoelectric film, and comprises the following steps: uniformly mixing an organic copolymer, an inorganic piezoelectric phase and a solvent to obtain a composite precursor solution, uniformly coating the composite precursor solution on an inert substrate, drying after coating is completed, and obtaining a composite film on the inert substrate; applying an electric field to the composite film, simultaneously, performing polarization treatment on the composite film, cooling to room temperature, and obtaining a composite piezoelectric film on the inert substrate. By constructing the composite piezoelectric film with residual polarization orientation on the surface of the negative electrode, the 'field-force coupling' response of the composite piezoelectric film under the action of the electric field and the stress is utilized, the dynamic negative feedback regulation of the lithium metal negative electrode interface electric field and the ion distribution is realized, and thus the dendrite growth is effectively inhibited, the deposition uniformity is improved, and the cycle stability is improved.

The present invention relates to a ferroelectric capacitor comprising a praseodymium oxide oxygen buffer layer. The ferroelectric capacitor of the present invention comprises a lower electrode, an upper electrode, a hafnium zirconium oxide ferroelectric layer disposed between the two electrodes, and a praseodymium oxide oxygen buffer layer disposed between the ferroelectric layer and the electrode. The above praseodymium oxide oxygen buffer layer has multivalent valence characteristics in which Pr3+ and Pr4+ already coexist in a significant proportion immediately after crystallization annealing, and has fluorite (111) crystal planes that are lattice-matched with the orthogonal (111) crystal planes of hafnium zirconium oxide. Accordingly, the oxygen buffer layer functions as a crystal nucleation template that induces orthogonal (111) preferential orientation for the ferroelectric layer, and at the same time functions as a bidirectional oxygen ion reservoir that absorbs oxygen vacancies generated during repeated switching and resupplies oxygen when returning to the initial state. The ferroelectric capacitor according to the present invention exhibits a residual polarization of 40 ÌC / cm² or more under low voltage conditions of an applied voltage of 1.3 V or less, and simultaneously satisfies repeatability of 10 or more cycles, wake-up free characteristics, and data retention characteristics equivalent to 10 years in an 85 ℃ environment. In addition, it can be formed within a post-processing thermal budget of 500 ℃ or less and can be conformally applied to a 3D trench structure and a 3D stacked memory array.

This invention provides a polyvinylidene fluoride-trifluoroethylene ferroelectric copolymer, its preparation method, and its applications, relating to the field of ferroelectric materials technology. The copolymer comprises repeating units derived from vinylidene fluoride and repeating units derived from trifluoroethylene, wherein the molar content of the trifluoroethylene units is 7%–19%; the copolymer has a sequence order defined by parameter S, where S ≥ 90%. This copolymer achieves high Curie temperature and high remanent polarization intensity at low trifluoroethylene content. This invention also provides a method for preparing the polyvinylidene fluoride-trifluoroethylene ferroelectric copolymer, as well as ferroelectric thin films and ferroelectric devices containing this copolymer. This invention overcomes the technical bottleneck of traditional ferroelectric polymers' difficulty in simultaneously achieving high polarization intensity and thermal stability, and can be widely applied in fields such as flexible sensors, non-volatile ferroelectric memories, and energy harvesters.

This invention discloses a method for preparing CeO2-HfO2 ferroelectric thin films based on cerium acetylacetone. The method includes: substrate pretreatment; preparation of a precursor solution: dissolving hafnium acetylacetone in glacial acetic acid, then sequentially adding cerium acetylacetone and acetylacetone, wherein the molar ratio of cerium ions to hafnium ions is 15:85, the total concentration is 0.1~0.2 mol / L, and the volume ratio of glacial acetic acid to acetylacetone is 3:2; coating to form a wet film, followed by drying and pyrolysis; repeating this process several times until the target thickness is reached; and annealing and crystallization. This invention utilizes the dual or multiple coordination ability of the acetylacetone ion in cerium acetylacetone to inhibit the aging of CeO2-HfO2 in the precursor. 3+ To Ce 4+ The valence state change of Ce causes the solution to undergo a 15-70 day aging period. 3+ With stable concentration, the oxygen vacancy concentration, ferroelectric orthorhombic phase ratio, and residual polarization intensity of the prepared CeO2-HfO2 ferroelectric thin film are all stable, which solves the technical problem of solution deterioration and ferroelectric performance degradation caused by nitrate oxidation of cerium nitrate source, and is suitable for large-scale preparation of ferroelectric storage devices.

This invention discloses a ferroelectric photovoltaic device and its fabrication method based on the shielding effect regulated by a dielectric insulating layer, belonging to the field of ferroelectric photovoltaic device technology. The ferroelectric photovoltaic device based on the shielding effect regulated by a dielectric insulating layer comprises, from bottom to top, a substrate, a bottom electrode layer, a dielectric insulating layer, a photoelectric ferroelectric functional layer, and a top electrode layer; the dielectric insulating layer is an Al2O3 layer; the photoelectric ferroelectric functional layer is a hexagonal LuMnO3 single crystal layer. This invention utilizes the high dielectric constant Al2O3 dielectric insulating layer to form a mirror shield against external free charges, weakening the compensation of interface induced charges on the ferroelectric residual polarization, thereby regulating the ferroelectric depolarization field and thus controlling the photovoltaic effect; simultaneously, the dielectric insulating layer can effectively block carrier injection, suppress leakage current, reduce dark current, and thus increase the photoelectric response of the device.

This invention relates to the field of piezoelectric materials and discloses a method for preparing a high-fatigue-resistant lead-free piezoelectric thin film. The method uses magnetron sputtering to directly prepare a lead-free piezoelectric thin film with a top electrode. The thin film layer of the lead-free piezoelectric thin film is a pure-phase potassium sodium niobate ceramic. An adhesive layer is disposed between the pure-phase potassium sodium niobate and the top electrode layer. The sputtering target for the adhesive layer is one or more of titanium, zirconium, ruthenium, titanium oxide, ruthenium oxide, and lanthanum nickelate. During the annealing process, the adhesive layer undergoes oxidation to form an oxide layer, which significantly improves the adhesion of the adhesive layer to the top electrode layer. The adhesive layer also significantly inhibits the volatilization of alkali metal elements in the thin film layer and significantly improves the fatigue resistance of the potassium sodium niobate thin film. The lead-free piezoelectric thin film prepared by this method exhibits high fatigue resistance at 10°C. 8 After the second electrical fatigue cycle, the residual polarization showed no significant decay.

The present application relates to a kind of BNT-based ferroelectric ceramics with ultra-high remanent polarization and excellent thermal stability, multilayer device and its preparation method and application.The chemical composition of the BNT-based ferroelectric ceramic is (1-x) Bi 0.5 Na 0.5 TiO3-xAgNbO3-ywt%MnCO3, wherein 0.01≤x≤0.10, 0.05≤y≤0.25; preferably, 0.01≤x≤0.05, 0.15≤y≤0.25.The BNT-based ferroelectric ceramic provided by the present application obtains 52.21 μC / cm 2 Ultra-high remanent polarization strength, breaks through the P r bottleneck of existing BNT-based ceramic modification.The ceramic multilayer device prepared based on the ceramic can realize 90A pulse current output, record-breaking pulse energy conversion efficiency.

This invention belongs to the field of microelectronic devices and functional thin film materials technology, and relates to a zirconium-rich hafnium oxide-based ferroelectric thin film capacitor based on atomic layer stacking. From bottom to top, it includes a substrate, a bottom electrode, a ferroelectric thin film, and a top electrode. The ferroelectric thin film is a bilayer structure composed of a HfO2 sublayer and a ZrO2 sublayer in direct contact. The thickness of the HfO2 sublayer is 1.5~2.5 nm, and the thickness of the ZrO2 sublayer is 3~12.5 nm, with a thickness ratio of 1:2~1:5 and an Hf:Zr atomic ratio of 1:4. After rapid thermal annealing, the volume fraction of the ferroelectric orthorhombic phase in the thin film is not less than 45%, exhibiting ferroelectricity in its initial, unawakened state. The fabrication method of the capacitor is also disclosed. This invention overcomes the technical bottleneck of traditional zirconium-rich compositions failing to achieve stable ferroelectricity. The fabrication process is compatible with CMOS, and the resulting capacitor has advantages such as high remanent polarization, excellent fatigue durability, and good high-temperature retention characteristics, showing broad application prospects.