[go: up one dir, main page]

CN120006238B - Dielectric film material for low and medium field application, capacitor and preparation method thereof - Google Patents

Dielectric film material for low and medium field application, capacitor and preparation method thereof

Info

Publication number
CN120006238B
CN120006238B CN202510502572.8A CN202510502572A CN120006238B CN 120006238 B CN120006238 B CN 120006238B CN 202510502572 A CN202510502572 A CN 202510502572A CN 120006238 B CN120006238 B CN 120006238B
Authority
CN
China
Prior art keywords
low
medium
thin film
dielectric
field
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202510502572.8A
Other languages
Chinese (zh)
Other versions
CN120006238A (en
Inventor
马春蕊
葛虎
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Xian Jiaotong University
Original Assignee
Xian Jiaotong University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Xian Jiaotong University filed Critical Xian Jiaotong University
Priority to CN202510502572.8A priority Critical patent/CN120006238B/en
Publication of CN120006238A publication Critical patent/CN120006238A/en
Application granted granted Critical
Publication of CN120006238B publication Critical patent/CN120006238B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
    • C23C14/22—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the process of coating
    • C23C14/34—Sputtering
    • C23C14/35—Sputtering by application of a magnetic field, e.g. magnetron sputtering
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
    • C04B35/46—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on titanium oxides or titanates
    • C04B35/462—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on titanium oxides or titanates based on titanates
    • C04B35/465—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on titanium oxides or titanates based on titanates based on alkaline earth metal titanates
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
    • C23C14/06—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the coating material
    • C23C14/08—Oxides
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
    • C23C14/22—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the process of coating
    • C23C14/34—Sputtering
    • C23C14/3407—Cathode assembly for sputtering apparatus, e.g. Target
    • C23C14/3414—Metallurgical or chemical aspects of target preparation, e.g. casting, powder metallurgy
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
    • C23C14/58—After-treatment
    • C23C14/5806—Thermal treatment
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G13/00—Apparatus specially adapted for manufacturing capacitors; Processes specially adapted for manufacturing capacitors not provided for in groups H01G4/00 - H01G11/00
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G4/00—Fixed capacitors; Processes of their manufacture
    • H01G4/33—Thin- or thick-film capacitors (thin- or thick-film circuits; capacitors without a potential-jump or surface barrier specially adapted for integrated circuits, details thereof, multistep manufacturing processes therefor)
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
    • C04B2235/3205—Alkaline earth oxides or oxide forming salts thereof, e.g. beryllium oxide
    • C04B2235/3206—Magnesium oxides or oxide-forming salts thereof
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
    • C04B2235/3205—Alkaline earth oxides or oxide forming salts thereof, e.g. beryllium oxide
    • C04B2235/3213—Strontium oxides or oxide-forming salts thereof
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
    • C04B2235/3231—Refractory metal oxides, their mixed metal oxides, or oxide-forming salts thereof
    • C04B2235/3251—Niobium oxides, niobates, tantalum oxides, tantalates, or oxide-forming salts thereof
    • C04B2235/3255—Niobates or tantalates, e.g. silver niobate
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
    • C04B2235/3298—Bismuth oxides, bismuthates or oxide forming salts thereof, e.g. zinc bismuthate
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/44—Metal salt constituents or additives chosen for the nature of the anions, e.g. hydrides or acetylacetonate
    • C04B2235/442—Carbonates

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Organic Chemistry (AREA)
  • Power Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Mechanical Engineering (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Manufacturing & Machinery (AREA)
  • Ceramic Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Structural Engineering (AREA)
  • Inorganic Insulating Materials (AREA)

Abstract

本发明属于电容器材料技术领域，具体涉及低、中场应用介电薄膜材料和电容器及其制备方法。本发明通过采用固相烧结法将SrTiO3与Bi(Mg2/3Ta1/3)O3复合，制成陶瓷靶材，然后将陶瓷靶材采用射频磁控溅射，于不同氧压下进行沉积，制得了低、中场应用介电薄膜材料。本发明通过将Bi(Mg2/3Ta1/3)O3引入至SrTiO3顺电体系材料的极化调控作用中，然后分别在不同氧压下进行物相沉积生长，沉积的氧压越低，低、中场应用介电薄膜材料内部的缺陷越多，以形成缺陷偶极的方式提高低、中场应用介电薄膜材料电阻率，增大其击穿场强，改善其漏电特性，同时提升其饱和极化强度。

The present invention belongs to the technical field of capacitor materials, and specifically relates to dielectric thin film materials and capacitors for low- and medium-range applications and methods for preparing the same. The present invention composites SrTiO 3 and Bi(Mg 2/3 Ta 1/3 )O 3 by a solid-phase sintering method to form a ceramic target, and then deposits the ceramic target by radio frequency magnetron sputtering at different oxygen pressures to obtain dielectric thin film materials for low- and medium-range applications. The present invention introduces Bi(Mg 2/3 Ta 1/3 )O 3 into the polarization regulation of SrTiO 3 paraelectric system materials, and then performs phase deposition growth at different oxygen pressures. The lower the deposited oxygen pressure, the more defects there are in the dielectric thin film materials for low- and medium-range applications, thereby increasing the resistivity of the dielectric thin film materials for low- and medium-range applications by forming defect dipoles, increasing their breakdown field strength, improving their leakage characteristics, and simultaneously improving their saturation polarization strength.

Description

Dielectric film material for low and medium field application, capacitor and preparation method thereof
Technical Field
The invention relates to the technical field of capacitor materials, in particular to a dielectric film material for low and medium fields, a capacitor and a preparation method thereof.
Background
The capacitor has the main function of energy storage, and unlike the battery type energy storage device, the capacitor can be charged and discharged rapidly, and the characteristic makes the capacitor play an important role in providing energy pulse, adjusting power of a power grid, maintaining stable frequency and improving electric energy quality. Along with the rapid development of the electronic industry, the requirements of power electronic devices on high energy storage capacity capacitors are increasingly larger, and particularly, the requirements of low-field and medium-field energy storage devices are increasingly higher, and the application fields of the low-field and the medium-field energy storage devices are 3-5 MV cm -1. For example, in wearable and portable devices, implantable hearing aids, and microelectromechanical systems applications, capacitors are required to have a sufficiently large energy storage density and sufficiently high energy efficiency while ensuring miniaturization due to the limitations of compact, lightweight designs of power supplies and devices. The capacitor has a great challenge in terms of how to achieve high energy storage density and energy efficiency in low and medium fields, and how to improve its energy storage characteristics under severe conditions.
SrTiO 3 is a leadless paraelectric system material, and has low leakage loss and high breakdown field strength due to the characteristic of no ferroelectric domain, and has stable energy storage performance in the temperature range of-100 ℃ to 300 ℃. The SrTiO 3 has extremely high energy efficiency in energy storage characteristic, and the high energy efficiency ensures that the capacitor has low energy loss during operation, can avoid the failure of devices caused by the fact that excessive heat is conducted to the periphery, and simultaneously caters to the development trend of solving the energy environment problem at present. However, in practical application, srTiO 3 has the defects of smaller saturated polarization intensity and lower energy storage density, and even though the energy storage efficiency is extremely high, the requirement of more scenes cannot be met in application, which greatly limits the energy storage application of SrTiO 3 as a dielectric material.
The weak coupling relaxation end member such as Bi (Mg 2/3Ta1/3)O3) can maintain higher saturated polarization intensity due to the existence of Bi element, but has smaller breakdown field intensity and lower energy efficiency due to self electric leakage characteristic, under the condition, the internal defect of the Bi (Mg 2/3Ta1/3)O3 film such as bismuth vacancy greatly deteriorates the energy storage characteristic, and the lower energy efficiency can not meet the practical application requirement.
Disclosure of Invention
In order to solve the defects in the prior art and widen the application field of the capacitor, the invention provides a dielectric film material for low and medium field application, the capacitor and a preparation method thereof. The invention adopts a solid phase sintering method to compound SrTiO 3 and Bi (Mg 2/3Ta1/3)O3) to prepare a ceramic target material, then adopts radio frequency magnetron sputtering to deposit the ceramic target material under different oxygen pressures to prepare the low-and medium-field application dielectric film material. The defect of the prior art in the application field of lower effective working voltage is overcome, the technical defects of SrTiO 3 and Bi (Mg 2/3Ta1/3)O3) are overcome, and the internal defect content of the dielectric film material for low and middle field application is regulated and controlled by regulating and controlling the growth oxygen compaction, so that the dielectric performance is improved, the use requirement of the dielectric film material for low and middle field application in a capacitor is met, and the obtained capacitor has high energy storage density, high energy efficiency and excellent wide-temperature stability.
The invention is realized by adopting the following technical scheme:
The first object of the invention is to provide a preparation method of a dielectric film material for low and medium field application, which comprises the following steps:
step 1, respectively weighing SrCO 3 with the purity of 99.95 percent and TiO 2、Bi2O3, mgO and Ta 2O5 with the purity of 99.99 percent according to the chemical component proportion of chemical formula 0.85SrTiO 3-0.15Bi(Mg2/3Ta1/3)O3, wherein the purpose of using high-purity raw materials is to avoid introducing other elements or impurities for standby, step 2, uniformly mixing SrCO 3、TiO2、Bi2O3, mgO and Ta 2O5, preparing a ceramic target by adopting a solid-phase sintering method, step 3, adopting radio-frequency magnetron sputtering, taking a conductive strontium titanate Nb: srTiO 3 substrate as a substrate, forming a dielectric film layer on the surface of the Nb: srTiO 3 substrate by the ceramic target, and cooling to room temperature after annealing treatment to obtain a low-field and medium-field application dielectric film material, wherein the oxygen pressure of radio-frequency magnetron sputtering is 0.04 mbar-0.23 mbar.
In order to form a dielectric film layer with uniform components on the surface of a Nb SrTiO 3 substrate, the technological parameters of radio frequency magnetron sputtering are that the distance between a ceramic target and the Nb SrTiO 3 substrate is 52-58 mm, the sputtering temperature is 650-750 ℃, and the sputtering atmosphere is a mixed gas of argon and oxygen in a volume ratio of 1:0.5-1.8.
In order to ensure that a dielectric film layer with uniform components, low defect concentration and high crystallization quality can be obtained, in the embodiment of the invention, the temperature of annealing treatment is 650-750 ℃ after radio frequency magnetron sputtering, the air pressure is 180-220 mbar, and the annealing time is 10-20 min. Meanwhile, the adopted Nb-SrTiO 3 substrate is a (00 l) -oriented single crystal substrate in consideration of the factors of crystallinity and stress state, so as to realize the purpose of high breakdown field strength.
In order to form a dielectric film layer with uniform components on the surface of a Nb:SrTiO 3 substrate, preparing a ceramic target material with uniform elements according to chemical composition, and then adopting radio frequency magnetron sputtering to form a uniform and compact dielectric film layer on the surface of a (00 l) -oriented Nb:SrTiO 3 substrate, the following steps are adopted to prepare the ceramic target material:
(1) The method comprises the steps of performing primary ball milling, namely uniformly mixing SrCO 3、TiO2、Bi2O3, mgO and Ta 2O5 to obtain mixed raw materials, weighing the mixed raw materials according to the mass ratio of alcohol to zirconium balls=1:1:2-3, placing the mixed raw materials into a ball milling tank, and performing ball milling for 3.5-6 hours at the rotating speed of 350-450 r/min to obtain a first-stage ball milling powder. (2) Presintering, namely after drying the ball-milling powder, presintering for 3.5-5 hours at 825-930 ℃ and removing impurity elements in the ball-milling powder to obtain presintering powder. (3) And performing secondary ball milling, namely weighing the presintered powder according to the mass ratio of alcohol to zirconium balls=1:1:2-3.5, placing the presintered powder into a ball milling tank, and performing ball milling for 3.5-6 hours at the rotating speed of 350-450 r/min to obtain the secondary ball milling powder. (4) And granulating, namely drying, grinding and dispersing the second-stage ball-milling powder, mixing the powder with a binder polyvinyl alcohol solution, wherein the mass of the binder accounts for 3% -10% of the total amount of the binder and the second-stage ball-milling powder, bonding the second-stage ball-milling powder by using the binder, and controlling the particle size by using a 60-mesh and 120-mesh screen to obtain uniform and fine particles. (5) Pressing, namely keeping the pressure of the powder particles at 10-20 MPa for 6-18 min to obtain a blank. (6) And (3) glue discharging, namely heat-preserving the blank body at 385-500 ℃ for 4-6 hours to volatilize and lose polyvinyl alcohol in the blank body, so that the phenomenon that the adhesive remains in the ceramic target material to influence the subsequent radio frequency magnetron sputtering process is avoided, and the precursor material is obtained. (7) And (3) solid-phase sintering, namely preserving the temperature of the precursor material at 900-1085 ℃ for 3.5-6 hours, and cooling to room temperature to obtain the ceramic target. The judgment standard of the sintering temperature of 900-1085 ℃ is less than T c -150 ℃, wherein T c is the ceramic forming temperature of the ceramic target.
The second object of the invention is to provide a low and middle field application dielectric film material which consists of a dielectric film layer and a conductive strontium titanate substrate, wherein the invention considers the low dielectric constant, high breakdown field strength and high dielectric constant and low breakdown field strength of Bi (Mg 2/3Ta1/3)O3 weak coupling relaxation end member) of SrTiO 3 along an electric system material, in order to simultaneously obtain the advantages of the two system materials, the invention combines SrTiO 3 and Bi (Mg 2/3Ta1/3)O3) by taking SrTiO 3 as a matrix to obtain the low and middle field application dielectric film material with the chemical formula of 0.85SrTiO 3-0.15Bi(Mg2/3Ta1/3)O3, namely 0.85SrTiO 3-0.15Bi(Mg2/3Ta1/3)O3 low and middle field application dielectric film material, realizes the regulation and control of the dielectric property of SrTiO 3 by the introduction of Bi (Mg 2/3Ta1/3)O3 end member), and simultaneously realizes high energy storage density, high energy efficiency and excellent wide temperature stability.
The invention researches the influence of different oxygen pressure conditions on the dielectric properties of the low-field and medium-field application dielectric film materials of 0.85SrTiO 3-0.15Bi(Mg2/3Ta1/3)O3, and discovers that when the low-field and medium-field application dielectric film materials grow under the oxygen pressure of 0.135mbar, the breakdown field intensity is smaller, when the oxygen pressure is increased to 0.205mbar, the breakdown field intensity is improved, but the energy storage property is still worse, and when the oxygen pressure is reduced to 0.065mbar, the breakdown field intensity is obviously improved, and the energy storage property is obviously improved. The invention realizes the regulation and control of the internal defect concentration by exploring and changing the oxygen pressure of the growth of the low-field and medium-field application dielectric film material, thereby improving the dielectric property. As a result, it was found that when the oxygen pressure for growing a dielectric thin film material is 0.065mbar in low and medium field applications, defects with different charging properties form defect dipoles due to the increased concentration of internal defects, and the dielectric constant and the breakdown field strength can be simultaneously increased.
Furthermore, the thickness of the dielectric film layer is 260-320 nm, and the thickness range ensures higher energy storage density and obtains larger breakdown field intensity.
The third object of the invention is to provide a capacitor which is made of low and medium field application dielectric film material and top electrode, and is prepared by the following steps:
S1, removing the dielectric film layer of the short side area of the low-field and medium-field application dielectric film material to expose the Nb SrTiO 3 substrate of the edge area, and serving as a bottom electrode. S2, a copper mesh mask plate method is adopted, a platinum target is subjected to radio frequency magnetron sputtering technology, a platinum electrode layer is formed above the dielectric film layer, and therefore a (00 l) -oriented Nb-SrTiO 3 substrate is used as a bottom electrode, the dielectric film layer is used as a functional layer, the platinum layer is used as a top electrode, and when in magnetron sputtering, the vacuum degree in a cavity is less than or equal to 6 multiplied by 10 - 3 Pa, the temperature is 280-320K, and the current is 17 mA-23 mA.
Compared with the prior art, the invention has the following beneficial effects:
1. The invention combines SrTiO 3 and Bi (Mg 2/3Ta1/3)O3) by adopting a solid-phase sintering method, introduces Bi (Mg 2/3Ta1/3)O3) into SrTiO 3 crystal lattice, converts a paraelectric system into relaxation-like ferroelectric in a solid solution mode, greatly improves the disadvantage of low energy storage density of SrTiO 3, can still maintain extremely high energy efficiency, can meet the energy supply at low and middle fields, simultaneously maintains higher energy efficiency, meets the requirements of the lower market on excellent energy storage characteristics and Gao Kuanwen stability materials in the application field of lower effective working voltage and the field of advanced electronic power systems, and simultaneously overcomes the technical defects of SrTiO 3 and Bi (Mg 2/ 3Ta1/3)O3).
The invention takes SrTiO 3 cis-electric system as matrix, combines SrTiO 3 with Bi (Mg 2/3Ta1/3)O3), realizes the dielectric regulation and control function on SrTiO 3 through Bi (Mg 2/ 3Ta1/3)O3 weak coupling relaxation end member, improves the internal defect concentration of the prepared low-field and medium-field application dielectric film material, improves the breakdown field strength in a mode of capturing carriers by defects and dipoles, greatly improves the saturation polarization strength of the low-field and medium-field application dielectric film material by introducing Bi (Mg 2/ 3Ta1/3)O3, and simultaneously enables the low-field and medium-field application dielectric film material to keep smaller residual polarization strength by high band gap metal oxide components.
2. The reason why Bi (Mg 2/3Ta1/3)O3 is used as an end member component is that the Mg-rich oxide system shows low electric leakage and high breakdown characteristics due to high band gap, the Bi-rich oxide system shows high dielectric constant, high saturation and high polarization intensity characteristics due to hybridization of Bi and O, ta forms defects in low-field and medium-field application dielectric film materials due to multivalent state, and the low-valence state shows the high dielectric constant, high saturation and high polarization intensity characteristics, and the defect concentration is excessively introduced to show the low electric leakage and high breakdown characteristics due to mutual coupling effect.
3. The capacitor prepared by the dielectric film material applied to low and middle fields has high energy storage density and high energy efficiency, and the prepared capacitor can obtain extremely high energy storage density and energy efficiency in the low and middle fields, thereby meeting the use requirement of the capacitor in the application field of lower effective working voltage and having excellent wide-temperature stability.
4. According to the invention, bi (Mg 2/3Ta1/3)O3 is introduced into the polarization regulation effect of the SrTiO 3 paraelectric system material to perform phase deposition growth under different oxygen pressures, and the lower the deposited oxygen pressure is, the more defects in the low-field and medium-field application dielectric film material are, the higher the resistivity of the low-field and medium-field application dielectric film material is in a defect dipole formation mode, so that the breakdown field intensity is increased, the leakage characteristic is improved, and the saturation polarization intensity and the breakdown field intensity are simultaneously improved.
Drawings
FIG. 1 shows XRD spectra of low and medium field applied dielectric thin film materials prepared in examples 1 to 3.
FIG. 2 shows the Phi-scan spectra of the low and medium field applied dielectric thin film materials prepared in examples 1-3.
FIG. 3 is a RSM chart of the (002) orientation of the low and medium field applied dielectric film material prepared in example 1.
Fig. 4 is an RSM plot of the orientation of the low and medium field applied dielectric film material (103) prepared in example 1.
FIG. 5 is a RSM plot of the (002) orientation of the low and medium field applied dielectric film material prepared in example 2.
Fig. 6 is an RSM plot of the orientation of the low and medium field applied dielectric film material (103) prepared in example 2.
FIG. 7 is a RSM chart of the (002) orientation of the low and medium field applied dielectric film material prepared in example 3.
Fig. 8 is an RSM plot of the orientation of the low and medium field applied dielectric film material (103) prepared in example 3.
FIG. 9 is a graph showing the dielectric constant of thin film capacitors prepared by using the low and medium field application dielectric thin film materials of examples 1 to 3 as a function of frequency.
FIG. 10 is a graph showing the dielectric constant of thin film capacitors prepared by using the low and medium field dielectric thin film materials of examples 1 to 3 as a function of temperature.
FIG. 11 is a graph of Wei-bull distribution data for thin film capacitors fabricated using the low and medium field applied dielectric thin film materials of examples 1-3.
Fig. 12 is a graph of bipolar hysteresis loops for thin film capacitors prepared using the low and medium field applied dielectric thin film materials of example 1 at different electric fields.
FIG. 13 is a graph of the unipolar hysteresis loop of a thin film capacitor prepared using the low and medium field applied dielectric thin film materials of examples 1-3 under an external field of 2.5MV cm -1.
FIG. 14 is a graph of the calculated maximum to remnant polarization ratio, energy storage density and energy efficiency for a film capacitor prepared using the low and medium field applied dielectric film materials of examples 1-3 at an external field of 2.5MV cm -1.
Fig. 15 is a graph of unipolar hysteresis loops for thin film capacitors prepared using the low and medium field applied dielectric thin film materials of example 1 under different external fields.
FIG. 16 is a graph of energy storage density and energy efficiency as a function of applied electric field for a thin film capacitor prepared using the low and medium field applied dielectric thin film materials of example 1.
FIG. 17 is a graph showing the energy storage density and energy efficiency as a function of charge and discharge cycles for a film capacitor prepared using the low and medium field applied dielectric film materials of example 1 and example 3 under an external field of 3MV cm -1.
FIG. 18 is a graph showing the energy storage density and energy efficiency as a function of charge and discharge cycles for a film capacitor prepared using the dielectric film material of example 1 in low and medium fields at an external field of 5MV cm -1.
FIG. 19 is a graph of unipolar hysteresis loops at-100, 0, 100, 200, and 300 ℃ for film capacitors prepared using the low and medium field applied dielectric film materials of example 1 under an external field of 5MV cm -1.
FIG. 20 is a graph showing the energy storage density and energy efficiency of a thin film capacitor prepared by using the dielectric thin film material of example 1 at-100-300 ℃ under the external field of 5MV cm -1.
FIG. 21 is a graph of hysteresis curves for different charge and discharge cycles at 300℃for a film capacitor prepared using the low and medium field applied dielectric film material of example 1 under an external field of 5MV cm -1.
FIG. 22 is a graph showing the energy storage density and energy efficiency as a function of charge and discharge cycles at 300℃for a film capacitor prepared using the dielectric film material of example 1 applied at low and medium fields at an external field of 5MV cm -1.
Fig. 23 is a graph showing ln (J) versus ln (E) characteristics of thin film capacitors prepared using the low and medium field applied dielectric thin film materials of examples 1 and 3.
Fig. 24 is a graph showing the change of the conduction mechanism of thin film capacitors prepared by using the dielectric thin film materials of examples 2 and 3 with respect to the applied electric field.
In FIG. 1 to FIG. 8, STO-BMT represents 0.85SrTiO 3-0.15Bi(Mg2/ 3Ta1/3)O3 low and medium field dielectric film materials prepared by the method, wherein 0.065mbar, 0135mbar and 0.205mbar represent oxygen pressures of the ceramic target materials in the radio frequency magnetron sputtering process of 0.065mbar, 0.135mbar and 0.205mbar respectively, namely examples 1 to 3. In fig. 9 to 24, unless otherwise specified, the temperature conditions for the test are room temperature.
Detailed Description
The following will describe the technical scheme of the present invention clearly and completely by using examples.
Example 1
A preparation method of a dielectric film material for low and medium fields comprises the following steps:
Step 1, weighing raw materials, namely weighing SrCO 3 with the purity of 99.95 percent and TiO 2、Bi2O3、MgO、Ta2O5 with the purity of 99.99 percent according to the chemical composition ratio of the SrTiO 3-0.15Bi(Mg2/3Ta1/3)O3 with the chemical formula of 0.85.
Step2, preparing a target material:
s1, weighing neutral Al 2O3 powder and alcohol according to the mass ratio of zirconium balls=1:1:2, placing the powder into a ball milling tank, and ball milling the powder in a planetary ball mill for 4 hours at a rotating speed of 400r/min to clean impurities in the ball milling tank.
S2, uniformly mixing the weighed Sr source, ti source, bi source, mg source and Ta source to obtain a mixed raw material, controlling the mass ratio of the mixed raw material to the alcohol to the zirconium ball=1:1:2, placing the mixed raw material into a ball milling tank, and ball milling the mixed raw material in a planetary ball mill for 4 hours at the rotating speed of 400r/min to obtain a section of ball milling powder.
S3, presintering, namely pouring a section of ball-milling powder into a cleaned culture dish, drying in an oven, placing in a muffle furnace after drying, presintering for 4 hours at 875 ℃ to obtain presintering powder, transferring the presintering powder into a cleaned ball-milling tank, placing in the ball-milling tank according to the mass ratio of presintering powder to alcohol to zirconium balls=1:1:2, and ball-milling in a planetary ball mill for 4 hours at a rotating speed of 400r/min to obtain a second section of ball-milling powder.
S4, drying the two-stage ball-milling powder, grinding into powder by an agate mortar, adding a polyvinyl alcohol solution with the mass fraction of 6% as a binder, and controlling the particle size by a screen with 60 meshes and 120 meshes to obtain fine powder particles with uniform size.
S5, pouring the powder particles into a cylindrical die with the diameter of 50mm for pressing, maintaining the pressure at 10MPa for 10min to obtain a blank, then placing the blank into a muffle furnace, and preserving heat for 4h at 400 ℃ to volatilize polyvinyl alcohol uniformly distributed in the blank, so as to realize glue discharge, and obtain the precursor material.
And S6, preserving the heat of the precursor material for 4 hours at 1025 ℃, slowly cooling the precursor material to room temperature along with a furnace, and taking out the precursor material to obtain the ceramic target.
And 3, performing magnetron sputtering and annealing treatment, namely adopting radio frequency magnetron sputtering, taking the ceramic target in the step 2 as a target of the radio frequency magnetron sputtering, taking a Nb SrTiO 3 substrate as a base, forming a dielectric film layer on the surface (conductive side surface) of the (00 l) oriented Nb SrTiO 3 substrate, completely annealing for 15min at 700 ℃ and 200mbar after the radio frequency magnetron sputtering process is finished, cooling the vacuum chamber to room temperature, and taking out to obtain the low-field and medium-field application dielectric film material. In the radio frequency magnetron sputtering process, the distance between the lower surface of the ceramic target and the upper surface of the Nb-SrTiO 3 substrate is controlled to be 55mm, the sputtering temperature is 700 ℃, the sputtering atmosphere is the mixed gas of argon and oxygen with the volume ratio of 1:1, and the oxygen pressure is 0.065mbar.
Example 2
The same procedure as in example 1 is followed, except that the growth oxygen pressure is replaced by 0.065mbar to 0.135mbar.
Example 3
The same procedure as in example 1 is followed, except that the growth oxygen pressure is replaced by 0.065mbar to 0.205mbar.
Example 4
A preparation method of a dielectric film material for low and medium fields comprises the following steps:
Step 1, weighing raw materials, namely weighing SrCO 3 with the purity of 99.95 percent and TiO 2、Bi2O3、MgO、Ta2O5 with the purity of 99.99 percent according to the chemical composition ratio of the SrTiO 3-0.15Bi(Mg2/3Ta1/3)O3 with the chemical formula of 0.85.
Step2, preparing a target material:
s1, weighing neutral Al 2O3 powder and alcohol according to the mass ratio of zirconium balls=1:1:2, placing the powder into a ball milling tank, and ball milling the powder in a planetary ball mill for 4 hours at a rotating speed of 400r/min to clean impurities in the ball milling tank.
S2, uniformly mixing the weighed Sr source, ti source, bi source, mg source and Ta source to obtain a mixed raw material, controlling the mass ratio of the mixed raw material to alcohol: zirconium ball=1:1:2.5, placing the mixed raw material into a ball milling tank, and ball milling the mixed raw material in a planetary ball mill for 6 hours at the rotating speed of 350r/min to obtain a first-stage ball milling powder.
S3, presintering, namely pouring a section of ball-milling powder into a cleaned culture dish, placing the culture dish into an oven for drying, placing the oven into a muffle furnace for presintering for 3.5 hours at 930 ℃ to obtain presintering powder, transferring the presintering powder into a cleaned ball-milling tank, placing the ball-milling tank into a planetary ball mill for ball-milling for 3.5 hours at the rotating speed of 450r/min according to the mass ratio of the presintering powder to the alcohol to the zirconium balls=1:1:3, and obtaining a second-section ball-milling powder.
S4, drying the two-stage ball-milling powder, grinding into powder by an agate mortar, adding 10% polyvinyl alcohol solution as a binder, and controlling the particle size by a 60-mesh and 120-mesh screen to obtain fine powder particles with uniform size.
S5, pouring the powder particles into a cylindrical die with the diameter of 50mm for pressing, maintaining the pressure at 15MPa for 20min to obtain a blank, then placing the blank into a muffle furnace, and preserving heat for 6h at 385 ℃ to volatilize polyvinyl alcohol uniformly distributed in the blank, so as to realize glue discharge, and obtain the precursor material.
And S6, preserving the heat of the precursor material for 6 hours at 900 ℃, slowly cooling the precursor material to room temperature along with a furnace, and taking out the precursor material to obtain the ceramic target.
And 3, performing magnetron sputtering and annealing treatment, namely adopting radio frequency magnetron sputtering, taking the ceramic target in the step 2 as a target of the radio frequency magnetron sputtering, taking a Nb:SrTiO 3 substrate as a base, forming a dielectric film layer on the surface of the (00 l) oriented Nb:SrTiO 3 substrate, after the radio frequency magnetron sputtering process is finished, performing complete annealing treatment for 10min at 750 ℃ and 180mbar, cooling the temperature of the vacuum cavity to room temperature, and taking out to obtain the low-field and medium-field application dielectric film material. In the radio frequency magnetron sputtering process, the distance between the lower surface of the ceramic target and the upper surface of the substrate is controlled to be 52mm, the sputtering temperature is 650 ℃, the sputtering atmosphere is the mixed gas of argon and oxygen with the volume ratio of 1:0.5, and the oxygen pressure is 0.23mbar.
Example 5
A preparation method of a dielectric film material for low and medium fields comprises the following steps:
Step 1, weighing raw materials, namely weighing SrCO 3 with the purity of 99.95 percent and TiO 2、Bi2O3、MgO、Ta2O5 with the purity of 99.99 percent according to the chemical composition ratio of the SrTiO 3-0.15Bi(Mg2/3Ta1/3)O3 with the chemical formula of 0.85.
Step2, preparing a target material:
s1, weighing neutral Al 2O3 powder and alcohol according to the mass ratio of zirconium balls=1:1:2, placing the powder into a ball milling tank, and ball milling the powder in a planetary ball mill for 4 hours at a rotating speed of 400r/min to clean impurities in the ball milling tank.
S2, uniformly mixing the weighed Sr source, ti source, bi source, mg source and Ta source to obtain a mixed raw material, controlling the mass ratio of the mixed raw material to alcohol to zirconium ball=1:1:3, placing the mixed raw material into a ball milling tank, and ball milling the mixed raw material in a planetary ball mill for 3.5 hours at the rotating speed of 450r/min to obtain a first-stage ball milling powder.
S3, presintering, namely pouring a section of ball-milling powder into a cleaned culture dish, placing the culture dish into an oven for drying, placing the oven into a muffle furnace for presintering for 5 hours at 825 ℃, obtaining presintering powder, then transferring the presintering powder into a cleaned ball-milling tank, placing the ball-milling tank into a planetary ball mill for ball-milling for 6 hours at a rotating speed of 350r/min according to the mass ratio of the presintering powder to the alcohol to the zirconium ball=1:1:3.5, and obtaining a second-section ball-milling powder.
S4, drying the two-stage ball-milling powder, grinding into powder by an agate mortar, adding a polyvinyl alcohol solution with the mass fraction of 3% as a binder, and controlling the particle size by a screen with 60 meshes and 120 meshes to obtain fine powder particles with uniform size.
S5, pouring the powder particles into a cylindrical die with the diameter of 50mm for pressing, maintaining the pressure at 20MPa for 6min to obtain a blank, then placing the blank into a muffle furnace, and preserving heat for 4h at 500 ℃ to volatilize polyvinyl alcohol uniformly distributed in the blank, so as to realize glue discharge, and obtain the precursor material.
And S6, preserving the heat of the precursor material for 3.5 hours at 1085 ℃, slowly cooling the precursor material to room temperature along with a furnace, and taking out the precursor material to obtain the ceramic target.
And 3, performing magnetron sputtering and annealing treatment, namely adopting radio frequency magnetron sputtering, taking the ceramic target in the step 2 as a target of the radio frequency magnetron sputtering, taking a Nb:SrTiO 3 substrate as a base, forming a dielectric film layer on the surface of the (00 l) oriented Nb:SrTiO 3 substrate, after the radio frequency magnetron sputtering process is finished, performing complete annealing treatment for 20min at 650 ℃ and 220mbar, cooling the temperature of the vacuum cavity to room temperature, and taking out to obtain the low-field and medium-field application dielectric film material. In the radio frequency magnetron sputtering process, the distance between the lower surface of the ceramic target and the upper surface of the substrate is controlled to be 58mm, the sputtering temperature is 750 ℃, the sputtering atmosphere is the mixed gas of argon and oxygen with the volume ratio of 1:1.8, and the oxygen pressure is 0.04mbar.
Taking the low-field and middle-field application dielectric film materials obtained in the embodiment 1-3 as examples, and preparing the film capacitor, the method comprises the following steps of firstly polishing short side edge regions of the low-field and middle-field application dielectric film materials in the embodiment 1-3 respectively by using sand paper to expose Nb SrTiO 3 substrates and serve as bottom electrodes, then sputtering a top electrode above a dielectric film layer by adopting a copper mesh mask plate method, wherein the sizes of copper mesh grids are 200 mu m multiplied by 200 mu m. A platinum (Pt) target is used as a sputtering electrode, the vacuum degree during sputtering is 5×10 -3 Pa, the temperature is 310K, and the current is 22mA, so that the film capacitor is obtained.
Experimental part:
(one) influence of different oxygen pressure growth conditions on the structure of low and medium field application dielectric film materials:
in the invention, the low-field and medium-field application dielectric film materials of examples 1-3 are taken as examples, the influence of different oxygen pressures on the structures of the low-field and medium-field application dielectric film materials in the radio frequency magnetron sputtering process is explored, and the test results are shown in figures 1-8 respectively.
FIG. 1 shows XRD spectra of low-and medium-field applied dielectric thin film materials of examples 1 to 3, in which the scanning mode is theta-2 theta scanning, and the relevant physical properties are determined by the position of characteristic peaks. Diffraction peaks of the low-and medium-field application dielectric film material and the Nb SrTiO 3 substrate (00 l) can be observed in a scanning range of 42-50 degrees, and l is a positive integer, and in the scanning range, the out-of-plane orientation of the low-and medium-field application dielectric film material and the Nb SrTiO 3 substrate only shows (002) orientation peaks. Furthermore, the SrTiO 3 -based modified low-field and medium-field application dielectric film material has the characteristic peak position very similar to that of the Nb SrTiO 3 substrate. Along with the reduction of the oxygen pressure for growing the low-field application dielectric film material and the medium-field application dielectric film material, the concentration of defects in the low-field application dielectric film material and the medium-field application dielectric film material is improved, and oxygen vacancies in the defects can expand crystal lattices in the low-field application dielectric film material and the medium-field application dielectric film material, so that characteristic peak positions in theta-2 theta scanning are shown to shift to low angles. It should be noted that the low and medium field dielectric thin film materials prepared in example 3 have a peak width at half height that is increased for the Nb SrTiO 3 substrate due to the closer characteristic peak positions to the Nb SrTiO 3 substrate.
Fig. 2 is a diagram of Phi-mode scanning results of low-and middle-field applied dielectric thin film materials in examples 1-3, wherein the analysis and judgment of characteristic peak angles of the low-and middle-field applied dielectric thin film materials show that three groups of low-and middle-field applied dielectric thin film materials have tetragonal symmetry in crystal structure, which indicates that the oxygen pressure and Bi (Mg 2/3Ta1/3)O3 solid solution end members are not significantly changed, and the symmetry characteristics of lattice tetragonal structure of the middle-field applied dielectric thin film materials are low, and 0.85SrTiO 3-0.15Bi(Mg2/3Ta1/3)O3 is still epitaxially grown on a Nb: srTiO 3 substrate in the tetragonal structure.
FIGS. 3 to 8 are graphs of the RSM scan results of the low and medium field applied dielectric thin film materials of examples 1 to 3, respectively, and the RSM scan results of the low and medium field applied dielectric thin film materials in the (002) direction under the conditions of 0.065mbar, 0.135mbar and 0.205mbar growth oxygen pressure, respectively, and the RSM scan results of the low and medium field applied dielectric thin film materials in the (103) direction under the conditions of 0.065mbar, 0.135mbar and 0.205mbar growth oxygen pressure, respectively. It is calculated that the in-plane lattice constant a of the low and middle field application dielectric film material of example 1 is 3.998, the in-plane lattice constant c is 3.966 and the c/a is 0.992, the in-plane lattice constant a of the low and middle field application dielectric film material of example 2 is 3.980, the in-plane lattice constant c is 3.932 and the c/a is 0.988, the in-plane lattice constant a of the low and middle field application dielectric film material of example 3 is 3.951, the in-plane lattice constant c is 3.931 and the c/a is 0.995, and the in-plane lattice parameter a of the Nb: srTiO 3 substrate is 3.908, and the out-of-plane lattice parameter c is 3.899 and the c/a is 0.998, which also provides support for RSM data accuracy of the low and middle field application dielectric film material.
(II) influence of different growth oxygen pressure conditions on the properties of dielectric film materials applied to low and medium fields:
(1) Dielectric properties and energy storage properties by taking the prepared film capacitor as an example, the invention explores the influence of different growth oxygen pressure conditions on the energy storage properties and dielectric properties of dielectric film materials applied to low and middle fields. As can be seen from the energy storage density formula, a high energy storage density requires a dielectric material with high saturation polarization, high breakdown field strength and low remnant polarization. Experimental research proves that the dielectric constant of the dielectric material is inversely proportional to the breakdown field strength, so that the dielectric material is difficult to obtain high saturation polarization strength and high breakdown field strength at the same time.
The invention tests the dielectric property of the film capacitor and calculates the dielectric constant epsilon r of the film capacitor by using a parallel plate capacitor model. The test characterization of the dielectric property comprises the change of the dielectric property along with frequency, the change of the dielectric property along with temperature, the change of the dielectric property along with voltage/electric field, namely dielectric spectrum, and the change of the dielectric property along with temperature, namely dielectric temperature spectrum. As a result of the dielectric spectrum analysis, as shown in fig. 9, the dielectric constants of the three groups of film capacitors all decrease with an increase in the external field frequency, because the dipoles inside the film capacitors cannot respond completely to the external field frequency change at high frequencies, thereby resulting in a decrease in polarization contribution. The thin film capacitor prepared under the condition of low oxygen pressure has higher dielectric constant, which indicates that the thin film capacitor can show higher saturated polarization intensity under the same electric field, and the prepared thin film capacitor has lower dielectric loss, which indicates that the thin film capacitor can bear larger applied voltage. The results of the dielectric temperature spectrum analysis are shown in fig. 10, and the three groups of film capacitors have relatively smooth curves except for relatively large differences in the values of dielectric constants, and have no obvious dielectric peaks, which indicates that no obvious phase change process exists in the temperature range.
According to the invention, breakdown field intensity is calculated for three groups of film capacitors through Wei-bull distribution, 13 pieces of test data are selected for each film capacitor for statistical analysis, and the total amount of test data is not excessively deviated from a reasonable interval range, so that randomness and accuracy of the calculated breakdown field intensity are ensured.
The Wei-bull distribution results of the film capacitor at room temperature are shown in FIG. 11, and the result shows that the breakdown field intensity of the film capacitor shows a tendency of increasing after decreasing along with the decrease of the oxygen pressure of growth, wherein the breakdown field intensity of the film capacitor prepared by using the dielectric film material with low and medium fields in the embodiment 1 is the highest and is 6.13MV cm -1. Compared with the film capacitor prepared by the low-field and medium-field application dielectric film material in the embodiment 3, the film capacitor prepared by the low-field and medium-field application dielectric film material in the embodiment 2 has higher breakdown field strength due to the increase of oxygen pressure and the improvement of crystallization quality of the film capacitor. Compared with the other two film capacitors, the film capacitor prepared by using the dielectric film material with low and medium fields in the embodiment 1 has the defect content in the film capacitor excessive due to the reduction of oxygen pressure, and defect dipoles are formed among defects with different charging properties. The defect dipoles have a remarkable contribution to high dielectric constant, have a certain capturing effect on internal carriers of the thin film capacitor, inhibit migration of the internal carriers, and further improve the dielectric constant and breakdown field strength of the thin film capacitor. In addition, the beta parameters of the Wei-bull distribution of the group of film capacitors are larger, which indicates that the fitting result is high in reliability.
Fig. 12 is a bipolar hysteresis loop of a thin film capacitor prepared using the low and medium field applied dielectric thin film materials of example 1 under different external fields, the thin film capacitor exhibiting a finer hysteresis loop over the range of breakdown field strengths, indicating that the thin film capacitor has no significant leakage behavior.
Fig. 13 shows the unipolar hysteresis loop of the film capacitor tested at 2.5MV cm -1 external field using the low-and mid-field applied dielectric film materials of examples 1-3, the film capacitors prepared using the low-and mid-field applied dielectric film materials of examples 1 and 3 exhibited elongated loop shapes with only slight differences in remnant polarization. Fig. 14 shows the parameters calculated from the monopolar electrode loop, namely the ratio P m/Pr of saturated polarization intensity to residual polarization intensity, the energy storage density W rec and the energy efficiency η, and the thin film capacitor prepared under the condition of low oxygen pressure shows more excellent energy storage characteristics in low field.
Fig. 15 shows unipolar hysteresis loops of different electric fields at breakdown field strengths for a thin film capacitor prepared using the low and medium field applied dielectric thin film materials of example 1, each exhibiting an elongated shape. FIG. 16 shows the parameters calculated from the monopole hysteresis loop, wherein the film capacitor can achieve an energy storage density of 97J cm 3 and an energy efficiency of 88% at maximum electric field. Namely, the thin film capacitor prepared under the condition of low oxygen pressure can simultaneously obtain higher energy storage density and higher energy efficiency, which is the result of introducing excessive defect regulation into the thin film capacitor.
Fig. 17 is a graph showing the comparison of energy storage density and energy efficiency at 3MV cm -1 external field and 10 6 charge-discharge cycles for the thin film capacitors prepared using the low and medium field applied dielectric thin film materials of example 1 and example 3, wherein the energy efficiency of the thin film capacitor prepared using the low and medium field applied dielectric thin film material of example 1 was maintained at almost 90%, whereas the energy storage efficiency of the thin film capacitor prepared using the low and medium field applied dielectric thin film material of example 3 was less than 80%. Fig. 18 shows the energy storage density and energy efficiency data of the thin film capacitor prepared by using the dielectric thin film material of example 1 in low and middle fields under the charge and discharge cycles of 5MV cm -1 and 10 6 in higher external fields, and the energy storage density of 70J cm 3 and the energy efficiency of approximately 90% can be still achieved, that is, the cycle characteristics of the thin film capacitor prepared under the condition of low oxygen pressure in the middle field can also reach the excellent level.
Fig. 19 shows the unipolar electric hysteresis loop of the thin film capacitor prepared by using the dielectric thin film material of example 1 in the wide temperature range of-100 ℃ to 300 ℃ in the external field of 5MV cm -1, and fig. 20 shows the wide temperature energy storage characteristic data calculated from the unipolar electric hysteresis loop. It is obtained that the film capacitor prepared by the dielectric film material applied to the low and middle fields in the embodiment 1 has stable and excellent low, normal and high temperature energy storage characteristics in the middle field, and can still keep the energy storage density of 69 J.cm 3 and the energy efficiency of 87 percent. Thermal breakdown is one of the main sources of film capacitors in practical application, and heating caused by heat loss cannot be avoided when the micro-devices of an electronic power system are applied. The heat can improve the mobility of carriers in the film capacitor, so that the probability of failure is greatly increased, and the high energy efficiency, namely low energy loss, is one of the most effective modes for avoiding the occurrence of thermal breakdown of the device. Fig. 21 shows unipolar hysteresis loops of a thin film capacitor prepared by using the dielectric thin film material of example 1 under the conditions of 5MV cm -1 external field, -100 ℃ to 300 ℃ wide temperature range and 10 6 charge-discharge cycles, and fig. 22 shows wide temperature fatigue characteristics calculated from the unipolar hysteresis loops. The film capacitor still maintains the energy storage density of 70J cm 3 and the energy efficiency of 83% under the condition, which shows that the film capacitor can still maintain excellent stability under the high-temperature condition.
(2) Leakage current characteristics taking the thin film capacitors prepared by using the low and medium field application dielectric thin film materials of example 1 and example 3 as examples, the influence of different growth oxygen pressures on the leakage current density of the low and medium field application dielectric thin film materials was investigated, and the conductive mechanisms thereof were analyzed, and the test results are shown in fig. 23 and 24, respectively. It should be noted that, the thin film capacitor prepared by using the dielectric thin film material applied in the low and middle fields of example 2 cannot be accurately fitted due to the small breakdown field strength, and the internal conductive mechanism is not compared here.
Fig. 23 is a graph showing ln (J) versus ln (E) characteristics of thin film capacitors prepared using the low and medium field applied dielectric thin film materials of examples 1 and 3, fitted using ohmic conduction, space charge confinement mechanism and high field conduction mechanism, as shown in the linear fitting portion of fig. 23, with a curve fitting slope of about 1, in which ohmic conduction is dominant, with a further increase in electric field, a fitting slope of 2-3, in which space charge confinement conduction is dominant, with a further increase in electric field, a sharp increase in leakage current density, and a fitting slope far greater than 2, indicating that other mechanisms are dominant at high fields, specifically PF emission & schottky conduction.
According to the above test results, the conductive mechanisms of the thin film capacitors prepared by using the low and medium field application dielectric thin film materials of example 1 and example 3 were arranged according to the change of the applied electric field intensity, as shown in fig. 24, as the oxygen pressure of the growth of the low and medium field application dielectric thin film materials was reduced, the initial voltage of each conductive mechanism of the thin film capacitor tended to increase, i.e. the higher field conductive mechanism was retarded due to the growth of the low oxygen pressure. This also illustrates that introducing excessive defects can improve the leakage behavior of the thin film capacitor by trapping carriers, thereby increasing the breakdown field strength of the thin film capacitor, i.e., this also explains the reason why the breakdown field strength of the thin film capacitor prepared using the low and medium field applied dielectric thin film material of example 1 is maximized.
In summary, the invention prepares the dielectric film material for low and middle fields of 0.85SrTiO 3-0.15Bi(Mg2/3Ta1/3)O3 with excellent energy storage property in low and middle fields on the Nb: STO substrate with the orientation of (00 l) through radio frequency magnetron sputtering. The defect concentration inside the low-field and medium-field application dielectric film material is regulated and controlled to form a defect dipole by changing the oxygen pressure, and the dielectric constant and the energy efficiency of the low-field and medium-field application dielectric film material are improved. By fitting analysis of leakage current mechanisms of dielectric film materials applied to low and medium fields, the initial voltage of each conduction mechanism is increased under the condition of low growth oxygen pressure. The thin film capacitor prepared by the dielectric thin film material with low and medium fields in the embodiment 1 has smaller leakage current and delayed higher field conduction mechanism, which shows that the defect dipole effectively improves the leakage behavior of the thin film capacitor. The film capacitor prepared by the dielectric film material applied to the low and middle fields grown under the condition of low oxygen pressure has optimal energy storage property, the normal temperature energy storage density is 97J cm -3, the energy efficiency is 88 percent, and the wide temperature and fatigue energy storage property are excellent, which also shows that the film capacitor prepared by the dielectric film material applied to the low and middle fields in the embodiment 1 has good energy storage property.
It should be apparent that the embodiments described above are only some, but not all, embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Claims (10)

1.低、中场应用介电薄膜材料的制备方法，其特征在于，包括如下步骤：1. A method for preparing dielectric thin film materials for low and medium field applications, comprising the following steps: 按照化学式0.85SrTiO3-0.15Bi(Mg2/3Ta1/3)O3的化学成分配比，分别称取SrCO3、TiO2、Bi2O3、MgO和Ta2O5；According to the chemical composition ratio of the chemical formula 0.85SrTiO 3 -0.15Bi(Mg 2/3 Ta 1/3 )O 3 , SrCO 3 , TiO 2 , Bi 2 O 3 , MgO and Ta 2 O 5 were weighed respectively; 将SrCO3、TiO2、Bi2O3、MgO和Ta2O5球磨混合后，进行预烧结，得到预烧结粉料；SrCO 3 , TiO 2 , Bi 2 O 3 , MgO and Ta 2 O 5 are ball-milled and mixed, and then pre-sintered to obtain pre-sintered powder; 将预烧结粉料球磨后与粘结剂混合，经压制成坯、烧结排胶，得到前驱体材料；The pre-sintered powder is ball-milled and mixed with a binder, pressed into a blank, and sintered to remove the binder to obtain a precursor material; 将前驱体材料采用固相烧结法制成陶瓷靶材；The precursor material is made into a ceramic target material by a solid phase sintering method; 采用射频磁控溅射，以导电钛酸锶为基底，将陶瓷靶材在基底的导电表面上形成介电薄膜层，在低于陶瓷靶材熔点温度下退火后，得到低、中场应用介电薄膜材料；Using radio frequency magnetron sputtering, with conductive strontium titanate as the substrate, a ceramic target is formed on the conductive surface of the substrate to form a dielectric film layer. After annealing at a temperature below the melting point of the ceramic target, a dielectric film material for low and medium field applications is obtained; 其中，射频磁控溅射的氧压为0.04mbar~0.23mbar。Among them, the oxygen pressure of RF magnetron sputtering is 0.04mbar~0.23mbar. 2.如权利要求1所述的低、中场应用介电薄膜材料的制备方法，其特征在于，固相烧结法的烧结温度小于Tc-150℃，其中，Tc为陶瓷靶材的成瓷温度。2. The method for preparing dielectric thin film materials for low- and medium-field applications according to claim 1, wherein the sintering temperature of the solid-phase sintering method is less than Tc -150°C, wherein Tc is the ceramic forming temperature of the ceramic target. 3.如权利要求2所述的低、中场应用介电薄膜材料的制备方法，其特征在于，固相烧结法的条件为：于900℃~1085℃下保温3.5h~6h。3. The method for preparing a dielectric thin film material for low- and medium-field applications as claimed in claim 2, wherein the solid-phase sintering method is carried out under the conditions of: keeping the temperature at 900°C to 1085°C for 3.5 hours to 6 hours. 4.如权利要求1所述的低、中场应用介电薄膜材料的制备方法，其特征在于，射频磁控溅射的工艺参数为：设置陶瓷靶材与导电钛酸锶的距离52mm~58mm，溅射温度650℃~750℃，溅射气氛为体积比1：0.5~1.8的氩气与氧气的混合气体。4. The method for preparing dielectric thin film materials for low- and medium-field applications as described in claim 1 is characterized in that the process parameters of RF magnetron sputtering are: setting a distance between the ceramic target and the conductive strontium titanate of 52 mm to 58 mm, a sputtering temperature of 650° C. to 750° C., and a sputtering atmosphere of a mixed gas of argon and oxygen in a volume ratio of 1:0.5 to 1.8. 5.如权利要求1所述的低、中场应用介电薄膜材料的制备方法，其特征在于，退火处理的温度为650℃~750℃，气压为180mbar~220mbar，退火时间为10min~20min。5. The method for preparing a dielectric thin film material for low- and medium-field applications according to claim 1, wherein the annealing temperature is 650°C to 750°C, the pressure is 180mbar to 220mbar, and the annealing time is 10min to 20min. 6.如权利要求1所述的低、中场应用介电薄膜材料的制备方法，其特征在于，预烧结的条件为：于825℃~930℃下预烧结3.5h~5h。6. The method for preparing a dielectric thin film material for low- and medium-field applications according to claim 1, wherein the pre-sintering conditions are: pre-sintering at 825°C to 930°C for 3.5 hours to 5 hours. 7.一种权利要求1~6任一项所述制备方法制得的低、中场应用介电薄膜材料，其特征在于，低、中场应用介电薄膜材料由介电薄膜层和导电钛酸锶基底组成，组成介电薄膜层的材料化学式为0.85SrTiO3-0.15Bi(Mg2/3Ta1/3)O3。7. A dielectric thin film material for low- and medium-range applications prepared by the preparation method according to any one of claims 1 to 6, characterized in that the dielectric thin film material for low- and medium-range applications comprises a dielectric thin film layer and a conductive strontium titanate substrate, and the chemical formula of the material constituting the dielectric thin film layer is 0.85SrTiO3-0.15Bi (Mg2 / 3Ta1/3 ) O3 . 8.如权利要求7所述的低、中场应用介电薄膜材料，其特征在于，介电薄膜层的厚度为260nm~320nm。8. The dielectric thin film material for low- and medium-field applications according to claim 7, wherein the thickness of the dielectric thin film layer is 260 nm to 320 nm. 9.一种电容器，其特征在于，由权利要求7所述的低、中场应用介电薄膜材料和顶电极制得。9. A capacitor, characterized in that it is made of the low- and medium-field application dielectric film material and a top electrode according to claim 7. 10.如权利要求9所述的电容器，其特征在于，电容器按照如下步骤制备：10. The capacitor according to claim 9, wherein the capacitor is prepared according to the following steps: 去除低、中场应用介电薄膜材料边缘区域的介电薄膜层，露出边缘区域的导电钛酸锶基底；Removing the dielectric film layer in the edge area of the dielectric film material for low and mid-field applications to expose the conductive strontium titanate substrate in the edge area; 采用铜网掩模板法，将铂靶采用磁控溅射技术，在介电薄膜层上方形成铂电极层，获得以导电钛酸锶基底为底电极，以介电薄膜层为电介质层，以铂层为顶电极的电容器。A copper mesh mask method is used and a platinum target is sputtered using magnetron sputtering technology to form a platinum electrode layer on top of the dielectric film layer, thereby obtaining a capacitor having a conductive strontium titanate substrate as a bottom electrode, a dielectric film layer as a dielectric layer, and a platinum layer as a top electrode.
CN202510502572.8A 2025-04-22 2025-04-22 Dielectric film material for low and medium field application, capacitor and preparation method thereof Active CN120006238B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202510502572.8A CN120006238B (en) 2025-04-22 2025-04-22 Dielectric film material for low and medium field application, capacitor and preparation method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202510502572.8A CN120006238B (en) 2025-04-22 2025-04-22 Dielectric film material for low and medium field application, capacitor and preparation method thereof

Publications (2)

Publication Number Publication Date
CN120006238A CN120006238A (en) 2025-05-16
CN120006238B true CN120006238B (en) 2025-08-01

Family

ID=95666474

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202510502572.8A Active CN120006238B (en) 2025-04-22 2025-04-22 Dielectric film material for low and medium field application, capacitor and preparation method thereof

Country Status (1)

Country Link
CN (1) CN120006238B (en)

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN118580065A (en) * 2024-05-21 2024-09-03 西安交通大学 A dielectric thin film material with adjustable properties and its preparation and application

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6774077B2 (en) * 2001-01-24 2004-08-10 Paratek Microwave, Inc. Electronically tunable, low-loss ceramic materials including a tunable dielectric phase and multiple metal oxide phases
US8609017B2 (en) * 2001-01-24 2013-12-17 Blackberry Limited Electronically tunable, low-loss ceramic materials including a tunable dielectric phase and multiple metal oxide phases
JP4190358B2 (en) * 2003-06-16 2008-12-03 富士通株式会社 Circuit board, passive component, electronic device, and circuit board manufacturing method
RU2422404C1 (en) * 2007-11-26 2011-06-27 Елизавета Аркадьевна Ненашева Ceramic ferroelectric composite material with low dielectric loss
CN113718330B (en) * 2021-07-26 2022-05-20 西安交通大学 Low-dielectric-constant high-entropy film and preparation method thereof

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN118580065A (en) * 2024-05-21 2024-09-03 西安交通大学 A dielectric thin film material with adjustable properties and its preparation and application

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
BaTiO3-BiMeO3基储能陶瓷的制备与性能研究;司峰;中国博士学位论文全文数据库（电子期刊），工程科技Ⅰ辑，B015-221;20210131;第五章小结部分 *

Also Published As

Publication number Publication date
CN120006238A (en) 2025-05-16

Similar Documents

Publication Publication Date Title
Wang et al. Optimizing the grain size and grain boundary morphology of (K, Na) NbO3-based ceramics: Paving the way for ultrahigh energy storage capacitors
CN110436920B (en) A kind of sodium bismuth titanate-sodium tantalate solid solution ceramic material and its preparation method and application
CN103922734B (en) A kind of wide temperature stablizes energy-storing dielectric ceramic and preparation method thereof
CN109942292B (en) A kind of sodium bismuth titanate-based transparent ceramic material and its preparation method and application
CN109161847B (en) Gallium-doped bismuth ferrite super-tetragonal phase epitaxial film and preparation method and application thereof
WO2018177019A1 (en) Bismuth ferrite-based dielectric thin film for high-density energy storage, preparation method therefor and use thereof
CN107253857A (en) A kind of unleaded high energy storage density ceramic material and preparation method thereof
CN107140974A (en) A kind of unleaded high energy storage density ST NBT ceramic materials of microwave sintering and preparation method thereof
CN104129988B (en) A kind of unleaded high energy storage density height energy storage efficiency ceramic medium material and preparation method thereof
Chen et al. Enhanced the energy storage performance of NBT-BY relaxor ferroelectric ceramics doped by STO
CN113666743A (en) A kind of KNN-based transparent energy storage ceramic material and preparation method thereof
CN109912304B (en) A kind of bismuth ferrite-based ternary solid solution dielectric film material and preparation method thereof
CN106699173A (en) Antiferroelectric high-energy-density ceramic material and preparation method thereof
Zhang et al. Linear dielectric ceramics for near-zero loss high-capacitance energy storage
JP2023020876A (en) Ceramic dielectric with high permittivity and low dielectric loss and preparation method therefor
CN108863348A (en) A kind of dielectric ceramic material and preparation method thereof of ultra-wide temperature stability
CN102060526A (en) Preparation method of manganese and yttrium double-doped barium strontium titanate ceramic material
CN120006238B (en) Dielectric film material for low and medium field application, capacitor and preparation method thereof
CN112500155B (en) Preparation method of lanthanum-doped barium titanate target
CN118580065B (en) A dielectric film material with adjustable properties and its preparation and application
CN116425536B (en) Ti-doped barium strontium gadolinium niobate ferroelectric ceramic material with non-axiom modulation structure and preparation method thereof
US11958781B2 (en) Potassium sodium bismuth niobate tantalate zirconate ferrite ceramics with non-stoichiometric Nb5+ and preparation method therefor
CN118405917A (en) A method for preparing high entropy ceramics by co-doping Sm and Ta to control oxygen vacancies and high entropy ceramics
CN115073168A (en) SBT-BNT-Mn ceramic material suitable for medium and low electric fields, preparation method and capacitor
CN119822811B (en) A compound-doped copper calcium titanate giant dielectric ceramic material and its preparation method

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant