CN113241407A - Preparation method and application of hafnium oxide-based nano ferroelectric film - Google Patents
Preparation method and application of hafnium oxide-based nano ferroelectric film Download PDFInfo
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- 229910000449 hafnium oxide Inorganic materials 0.000 title claims abstract description 61
- WIHZLLGSGQNAGK-UHFFFAOYSA-N hafnium(4+);oxygen(2-) Chemical compound [O-2].[O-2].[Hf+4] WIHZLLGSGQNAGK-UHFFFAOYSA-N 0.000 title claims abstract description 61
- 238000002360 preparation method Methods 0.000 title claims abstract description 20
- 239000010408 film Substances 0.000 claims abstract description 124
- 239000002243 precursor Substances 0.000 claims abstract description 66
- 238000004458 analytical method Methods 0.000 claims abstract description 40
- 239000010409 thin film Substances 0.000 claims abstract description 34
- 230000010287 polarization Effects 0.000 claims abstract description 17
- 238000001514 detection method Methods 0.000 claims abstract description 11
- 238000000034 method Methods 0.000 claims description 67
- 239000000463 material Substances 0.000 claims description 34
- CJNBYAVZURUTKZ-UHFFFAOYSA-N hafnium(IV) oxide Inorganic materials O=[Hf]=O CJNBYAVZURUTKZ-UHFFFAOYSA-N 0.000 claims description 33
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 30
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 30
- 239000002244 precipitate Substances 0.000 claims description 26
- 238000012360 testing method Methods 0.000 claims description 26
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 24
- 238000004528 spin coating Methods 0.000 claims description 20
- 230000005684 electric field Effects 0.000 claims description 18
- 239000000758 substrate Substances 0.000 claims description 18
- 238000002156 mixing Methods 0.000 claims description 17
- 230000008569 process Effects 0.000 claims description 16
- 239000000126 substance Substances 0.000 claims description 16
- 229910052786 argon Inorganic materials 0.000 claims description 15
- 229910052757 nitrogen Inorganic materials 0.000 claims description 15
- 238000004544 sputter deposition Methods 0.000 claims description 15
- MCMNRKCIXSYSNV-UHFFFAOYSA-N ZrO2 Inorganic materials O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 claims description 14
- 239000007772 electrode material Substances 0.000 claims description 14
- 229910001868 water Inorganic materials 0.000 claims description 14
- 239000003990 capacitor Substances 0.000 claims description 13
- 238000005119 centrifugation Methods 0.000 claims description 11
- 238000003760 magnetic stirring Methods 0.000 claims description 11
- 229910052751 metal Inorganic materials 0.000 claims description 11
- 239000002184 metal Substances 0.000 claims description 11
- NRTOMJZYCJJWKI-UHFFFAOYSA-N Titanium nitride Chemical compound [Ti]#N NRTOMJZYCJJWKI-UHFFFAOYSA-N 0.000 claims description 10
- 238000004833 X-ray photoelectron spectroscopy Methods 0.000 claims description 10
- 238000000137 annealing Methods 0.000 claims description 10
- 238000002425 crystallisation Methods 0.000 claims description 10
- 230000008025 crystallization Effects 0.000 claims description 10
- 239000008367 deionised water Substances 0.000 claims description 10
- 229910021641 deionized water Inorganic materials 0.000 claims description 10
- DFIPXJGORSQQQD-UHFFFAOYSA-N hafnium;tetrahydrate Chemical compound O.O.O.O.[Hf] DFIPXJGORSQQQD-UHFFFAOYSA-N 0.000 claims description 10
- 238000001755 magnetron sputter deposition Methods 0.000 claims description 10
- 239000004065 semiconductor Substances 0.000 claims description 10
- SQGYOTSLMSWVJD-UHFFFAOYSA-N silver(1+) nitrate Chemical compound [Ag+].[O-]N(=O)=O SQGYOTSLMSWVJD-UHFFFAOYSA-N 0.000 claims description 10
- 238000005406 washing Methods 0.000 claims description 9
- 238000010438 heat treatment Methods 0.000 claims description 7
- 230000015556 catabolic process Effects 0.000 claims description 6
- 125000004122 cyclic group Chemical group 0.000 claims description 6
- 238000011068 loading method Methods 0.000 claims description 6
- 229910052719 titanium Inorganic materials 0.000 claims description 6
- 239000010936 titanium Substances 0.000 claims description 6
- 238000004483 ATR-FTIR spectroscopy Methods 0.000 claims description 5
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 claims description 5
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 claims description 5
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 claims description 5
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 claims description 5
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 claims description 5
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims description 5
- 235000011114 ammonium hydroxide Nutrition 0.000 claims description 5
- 238000005102 attenuated total reflection Methods 0.000 claims description 5
- 238000005259 measurement Methods 0.000 claims description 5
- 229910017604 nitric acid Inorganic materials 0.000 claims description 5
- 230000010355 oscillation Effects 0.000 claims description 5
- 238000005086 pumping Methods 0.000 claims description 5
- 229910001961 silver nitrate Inorganic materials 0.000 claims description 5
- 239000002904 solvent Substances 0.000 claims description 5
- 239000006228 supernatant Substances 0.000 claims description 5
- 238000005033 Fourier transform infrared spectroscopy Methods 0.000 claims description 4
- 239000000084 colloidal system Substances 0.000 claims description 4
- 238000003756 stirring Methods 0.000 claims description 4
- 241000588731 Hafnia Species 0.000 claims 3
- 230000015654 memory Effects 0.000 abstract description 12
- 230000014759 maintenance of location Effects 0.000 abstract description 3
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- 230000007246 mechanism Effects 0.000 description 14
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- 238000001228 spectrum Methods 0.000 description 2
- 229910002902 BiFeO3 Inorganic materials 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- 230000002238 attenuated effect Effects 0.000 description 1
- 238000012512 characterization method Methods 0.000 description 1
- 238000000224 chemical solution deposition Methods 0.000 description 1
- 229910052681 coesite Inorganic materials 0.000 description 1
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- 229910052906 cristobalite Inorganic materials 0.000 description 1
- 238000013500 data storage Methods 0.000 description 1
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- 238000006731 degradation reaction Methods 0.000 description 1
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- 229910001385 heavy metal Inorganic materials 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
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- 230000007774 longterm Effects 0.000 description 1
- 230000028161 membrane depolarization Effects 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000003071 parasitic effect Effects 0.000 description 1
- 238000011056 performance test Methods 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 238000001055 reflectance spectroscopy Methods 0.000 description 1
- 230000001568 sexual effect Effects 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 230000005476 size effect Effects 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 229910052682 stishovite Inorganic materials 0.000 description 1
- 230000009897 systematic effect Effects 0.000 description 1
- 229910052905 tridymite Inorganic materials 0.000 description 1
- 229910052726 zirconium Inorganic materials 0.000 description 1
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Abstract
The invention discloses a preparation method and application of a hafnium oxide-based nano ferroelectric film, relating to the technical field of electric film preparation,including S1: preparation of a precursor solution I, S2: preparing a precursor solution III, and S3: preparing a hafnium oxide-based nano ferroelectric film, and S4: detection and analysis, HfO prepared by the invention2The novel ferroelectric thin film has simple unit oxide, easily controlled components, no pollution and higher remanent polarization strength, has the performance advantage of very low voltage in actual operation although the coercive field strength is slightly higher, and can greatly improve the storage density, prolong the memory retention time of the device and reduce the working voltage when being applied to a ferroelectric memory device.
Description
Technical Field
The invention relates to the technical field of electric film preparation, in particular to a preparation method and application of a hafnium oxide-based nano ferroelectric film.
Background
The hafnium oxide-based nano ferroelectric film has the advantages of lead-free, mature and various deposition technologies, high remanent polarization strength, high compressive strength and other processes and performance advantages, has great application value of the nonvolatile ferroelectric memory, and is expected to break through the material bottleneck of the nonvolatile ferroelectric memory and bring great opportunity for greatly improving the storage density and performance. The project adopts a chemical solution method to prepare Y-doped HfO2The nano film takes the classical thermodynamic theory of material phase change after surface energy is introduced for correction as guidance, and combines the microstructure test result to systematically research the influence rule of the process parameters such as doping amount, film thickness, deposition temperature and the like on the ferroelectric performance of the film, master the effective method of inhibiting paraelectric phase and improving ferroelectric volume fraction, and disclose the forming and stabilizing mechanism of the ferroelectric phase; and then, performing systematic electrical performance test on the film, combining the microstructure analysis result of the material, deeply researching the relation between the internal defect characteristic, the interface state, the phase structure and the polarization reversal characteristic of the film, analyzing the microscopic physical mechanism of various failure behaviors of the material, and providing an effective way for improving the failure. The research result of the project provides experimental basis and theoretical basis for optimizing the service performance of the novel ferroelectric film material device.
Years of practical experience shows that many intrinsic characteristics of traditional ferroelectric materials become key bottlenecks for restricting the development of ferroelectric memories, which are specifically shown as follows:
(1) the compatibility with the CMOS transistor integration process is poor, the mutual diffusion between the traditional multi-element oxide ferroelectric film and the Si substrate can form a complex interface state, and serious parasitic effects such as charge trapping are caused, so that the interface state density and the leakage current are increased. A dielectric buffer layer is required to be deposited between the ferroelectric film and the Si deposition, although the ferroelectric film and the Si substrate are effectively isolated, and the capacitance value of the buffer layer is increased, which is beneficial to the reduction of depolarization field intensity, the effective memory retention time is only a few weeks, and the use requirement of the ferroelectric memory device cannot be met;
(2) the traditional multi-element oxide electrode material and the corresponding electrode material contain heavy metal elements, which not only has destructive effect on the transistor performance, but also causes pollution;
(3) PZT requires a special oxide electrode to ensure the fatigue resistance of the device. Most BFO grows epitaxially, and the BFO also needs to grow on a special oxide electrode in order to obtain a crystal structure with higher remanent polarization;
(4) the traditional ferroelectric material has a high dielectric coefficient, so that the ferroelectric capacitance is overlarge, and even if a complex metal/ferroelectric/metal/insulating medium/metal/Si substrate (MFMIS) structure is adopted to adjust the capacitance area ratio, the polarization state can be effectively changed only by high working voltage;
(5) with the continuous increase of the integration of the memory device, the thickness of the ferroelectric film material is reduced, and the traditional ferroelectric material has the size effect, the ferroelectric property of the ferroelectric film is rapidly degraded after the thickness of the ferroelectric film is less than 100nm, and the root cause of the irreversible degradation is that the crystal structure of the ferroelectric film is changed from the ferroelectric phase to the paraelectric phase.
How to stabilize Y: HfO2The first key scientific problem to be solved by the project is that the ferroelectric phase of the base film inhibits the generation of paraelectric phase in the film and improves the volume fraction of the ferroelectric phase, and the existence of the paraelectric phase in the film can cause the reduction of residual polarization strength of an electric hysteresis loop and the conversion of the material from ferroelectric to paraelectric. The project adopts a chemical solution deposition method to prepare Y: HfO2Based on the nano film, the corresponding relation between the film components, the thickness, the annealing condition and the phase structure and the grain size is researched, the evolution rule of the volume fraction of the ferroelectric phase is determined, an experimental basis is provided for improving the ferroelectric property of the material, and how to improve Y: HfO2Ferroelectric thin filmEndurance is the second key scientific problem to be solved by the project, and the research on the fatigue property of the ferroelectric material is the key problem of the application research of the ferroelectric memory. In numerous studies, HfO has been used2The device structure taking the ferroelectric film as the core is mainly divided into two types: metal/oxide/semiconductor (MIS) structures and metal/oxide/metal (MIM) structures. In which, HfO of MIM structure2The ferroelectric device is the core part of a ferroelectric random access memory (FeRAM), and the core part of a ferroelectric field effect transistor (FeFET) is a MIS structure capacitor device. The term will be directed to Y: HfO of two different capacitor structures2The fatigue characteristics of the ferroelectric film are researched and compared, the corresponding relation between the preparation process and the testing electric field and the fatigue state of the film is proved, and the effective means for improving the fatigue state of the film is mastered, so that the material meets the requirement of long-term service of ferroelectric capacitors with different structures in the application of ferroelectric memory devices.
Disclosure of Invention
In order to solve the technical problems, the invention provides a preparation method and application of a hafnium oxide-based nano ferroelectric film.
The technical scheme of the invention is as follows: a preparation method of a hafnium oxide based nano ferroelectric film comprises the following steps:
s1: preparing HfO by chemical solution method2The nano ferroelectric film is prepared by a water-based method to prepare a precursor solution I, and comprises the following steps:
s11: the HfOCl with the purity of more than 98 percent2·8H2Dissolving O in deionized water to form a solution with the Hf concentration of 0.12mol/L and the volume of 20 mL;
s12: adding 6.7mL of 1mol/L ammonia water solution into the solution to ensure that the pH value of the solution is 8.5 so as to form hafnium hydroxide precipitate, and stirring by magnetic force to fully react;
s13: centrifuging and washing the obtained white precipitate for 5-8 times to remove ammonium and chloride ions, and performing ultrasonic oscillation on the white precipitate for 4-10min before centrifuging each time to uniformly disperse the white precipitate;
s14: collecting supernatant after centrifugal washing, dripping silver nitrate solution, and observing no precipitateAfter the reaction is finished, 5mL of hydrogen peroxide solution with the concentration of 10mol/L and 1.4mL of nitric acid solution with the concentration of 2mol/L are added into the hafnium hydroxide precipitate to form a precursor solution [ Hf ] with the colloid diameter less than 2nm4(OH)12(O2)2·(y-4)H2O]m(aq)；
S15: magnetically stirring at room temperature for 10-20h to obtain clear HfO2/ZrO2Precursor solution one, the pH of the solution is 1.2 at this time, HfO2/ZrO2The shelf life of the precursor solution I is 1 year at room temperature;
s2: mixing Y (NO) with purity of 99.9%3)3·6H2Dissolving O in deionized water to form a precursor solution II with the Y concentration of 0.1mol/L, and then mixing with HfO2/ZrO2Mixing the precursor solution I to obtain a precursor solution III with the required doping concentration;
s3: the method for preparing the hafnium oxide-based nano ferroelectric film by adopting the spin coating method comprises the following steps:
s31: placing a Si substrate on a spin coater, taking three drops of precursor solution on the substrate, and then performing low-speed spin coating at 500rpm/5s and high-speed spin coating at 3000rpm/30 s;
s32: placing the sample on a hot plate at 140-160 ℃ and heating for 1-2min to evaporate the solvent;
s33: repeating the steps to obtain samples with different thicknesses;
s34: after the spin coating is finished, placing the sample in an annealing furnace for heat treatment to obtain a hafnium oxide based nano ferroelectric film;
s4: detecting and analyzing the obtained hafnium oxide-based nano ferroelectric film, wherein the detecting and analyzing comprise microstructure and crystallization behavior analysis and HfO2Fatigue characteristic analysis of ferroelectric thin film
Further, before the detection and analysis of the hafnium oxide-based nano ferroelectric thin film in S4, an electrode material is prepared on the surface of the hafnium oxide-based nano ferroelectric thin film to form a metal-insulating layer-semiconductor measurement structure, and specifically, a titanium nitride thin film electrode is prepared by a direct current magnetron sputtering method as an electrode material required for the electrical detection of the hafnium oxide-based nano ferroelectric thin film in a manner of a metal mask.
Further, the preparation method of the titanium nitride membrane electrode comprises the following steps:
s41: putting the cleaned Si substrate or the hafnium oxide-based nano ferroelectric film into a vacuum chamber of high-vacuum magnetron sputtering equipment, then roughly pumping by using a mechanical pump, and opening a molecular pump when the air pressure in the vacuum chamber is lower than 0.5 Pa;
s42: when the background vacuum reaches 5X 10-4After Pa, opening a thermocouple to heat the sample to 330-380 ℃, and keeping the temperature for 8-20 min;
s43: introducing nitrogen and argon into the vacuum chamber, wherein the flow of the nitrogen is 2.4-2.6sccm, the flow of the argon is 29-31sccm, then adjusting the air pressure of the vacuum chamber to be 0.2-0.4Pa, the sputtering power is 156W, the target base distance is 92-94mm, and pre-sputtering for 4-6min to remove an oxide layer on the surface of the titanium target;
s44: sputtering for 4-5min to obtain electrode with thickness of 70nm and resistivity lower than 7.5 × 10-7Ω·m。
Further, the purity of the nitrogen and the argon introduced in the step S43 is 99.99%.
Further, in the S13, the centrifugal speed is 9000rpm, and the centrifugal time is 8 min.
Further, the magnetic stirring speed in the step S12 is 80 r/min.
Further, when the precursor solution i and the precursor solution ii are prepared into the precursor solution three in the step S2, the preparation mixing ratio of the precursor solution i and the precursor solution ii is determined according to the finally required doping amount of the hafnium oxide based nano ferroelectric thin film Y.
Further, the microstructure and crystallization behavior analysis method in step S5 includes: characterizing components and chemical bond structures of the film by using X-ray photoelectron spectroscopy XPS and attenuated total reflection Fourier transform infrared spectroscopy ATR-FTIR, and determining Y doping amount and chemical environment of the film; the thickness of the film is accurately measured through X-ray reflection XRR and a step instrument; analyzing the crystal structure of the film by adopting grazing incidence X-ray diffraction GIXRD and a high-resolution transmission electron microscope HRTEM to determine the phase structure and the grain size of the film; judging whether ferroelectric properties exist or not according to the electric hysteresis loop test result, and determining the change of the ferroelectric properties according to the change of the residual polarization intensity; and (3) the relationship between the stability of the ferroelectric phase and the Y doping amount, the film thickness, the annealing condition and the grain size is proved by combining the microstructure analysis and the macroscopic electrical property test result, and the stable microscopic mechanism of the ferroelectric phase is mastered.
Further, the Y is HfO2The fatigue characteristic analysis method of the ferroelectric film comprises the following steps: HfO and MIS structures prepared according to different process parameters2The ferroelectric film capacitor is used for carrying out fatigue characteristic test of electric field cyclic loading, the frequency of an electric field is 10kHz-1MHz, the amplitude is 50-90% of breakdown field intensity, the relation between the residual polarization intensity and the frequency, amplitude and cycle frequency of the test electric field is analyzed, and the existing traditional ferroelectric material fatigue theory is verified or a new fatigue theory model is proposed; analyzing the influence mechanism of a non-ferroelectric interface layer (layer) on fatigue characteristics by comparing the test results of MIS and MIM capacitors with different structures; the method comprises the steps of carrying out fatigue test analysis on films prepared by different process parameters, researching the influence rule of a microstructure on fatigue characteristics by combining a microstructure analysis result system, exploring a micro physical mechanism generated by failure, carrying out summary analysis on a fatigue model, and mastering an effective means for improving the endurance of the material.
The application of the hafnium oxide-based nano ferroelectric film prepared by the method is to apply the hafnium oxide-based nano ferroelectric film to a ferroelectric memory device.
The invention has the beneficial effects that:
HfO, relative to conventional multi-component oxide ferroelectric materials2The novel ferroelectric film has the following remarkable advantages:
(1) has good compatibility of CMOS integration process and can replace the traditional SiO2Has been applied to large-scale industrial technology production practice by the semiconductor industry;
(2) simple unit oxide, easy control of components and no pollution;
(3) the electrode material has no special requirement, and the most common TiN material in the semiconductor industry at the present stage can be used;
(4) the remanent polarization is higher;
(5) although the coercive field strength is slightly high, the physical film is extremely thin, so the actual working voltage is very low;
(6) when the physical film thickness is extremely thin (<10nm), the ferroelectric property is still remarkable, and the size requirement of the ultrahigh-integration memory device can be met.
Based on the above advantages, HfO2The novel ferroelectric film is expected to bring a new opportunity for the ferroelectric memory to break through the material bottleneck and go out of the development dilemma. We can expect that: after the ferroelectric phase change machine and the electrical properties are comprehensively mastered, the ferroelectric phase change machine is applied to a ferroelectric memory device, so that the memory density is greatly improved, the memory retention time of the device is prolonged, and the working voltage is reduced.
Drawings
FIG. 1 is a flow chart of the manufacturing process of the present invention.
FIG. 2 shows HfO with different Y doping concentrations according to the present invention2XRD spectrum of the film.
Detailed Description
Example 1:
as shown in fig. 1, a method for preparing a hafnium oxide-based nano ferroelectric thin film comprises the following steps:
s1: preparing HfO by chemical solution method2The nano ferroelectric film is prepared by a water-based method to prepare a precursor solution I, and comprises the following steps:
s11: HfOCl with purity of 98%2·8H2Dissolving O in deionized water to form a solution with the Hf concentration of 0.12mol/L and the volume of 20 mL;
s12: adding 6.7mL of 1mol/L ammonia water solution into the solution to ensure that the pH value of the solution is 8.5 to form hafnium hydroxide precipitate, and fully performing the reaction by magnetic stirring at the magnetic stirring speed of 80 r/min;
s13: centrifuging and washing the obtained white precipitate with water for 8 times to remove ammonium and chloride ions, wherein the centrifugation speed is 9000rpm, the centrifugation time is 8min, and the white precipitate needs to be subjected to ultrasonic oscillation for 10min before each centrifugation to be uniformly dispersed;
s14: taking supernatant after centrifugal washing, dripping silver nitrate solution, observing that no precipitate is generated, adding 5mL of hydrogen peroxide solution with the concentration of 10mol/L and 1.4mL of nitric acid solution with the concentration of 2mol/L into the hafnium hydroxide precipitate to form precursor solution [ Hf ] with the colloid diameter less than 2nm4(OH)12(O2)2·(y-4)H2O]m(aq)；
S15: magnetic stirring at room temperature for 20h to obtain clear HfO2/ZrO2Precursor solution one, the pH of the solution is 1.2 at this time, HfO2/ZrO2The shelf life of the precursor solution I is 1 year at room temperature;
s2: mixing Y (NO) with purity of 99.9%3)3·6H2Dissolving O in deionized water to form a precursor solution II with the Y concentration of 0.1mol/L, and then mixing with HfO2/ZrO2After the precursor solution I is mixed, obtaining a precursor solution III with the required doping concentration, and when the precursor solution I and the precursor solution II are prepared into the precursor solution III, determining that the volume ratio of the precursor solution I to the precursor solution II is 1:7 for mixing and preparation according to the finally required hafnium oxide-based nano ferroelectric film Y doping amount of 0.7 mol%;
s3: the method for preparing the hafnium oxide-based nano ferroelectric film by adopting the spin coating method comprises the following steps:
s31: placing a Si substrate on a spin coater, taking three drops of precursor solution on the substrate, and then performing low-speed spin coating at 500rpm/5s and high-speed spin coating at 3000rpm/30 s;
s32: the sample was placed on a hot plate at 160 ℃ and heated for 2min to evaporate the solvent;
s33: repeating the steps to obtain samples with different thicknesses;
s34: after the spin coating is finished, placing the sample in an annealing furnace for heat treatment to obtain a hafnium oxide based nano ferroelectric film;
s4: the obtained hafnium oxide based nano ferroelectric film is subjected to microstructure and crystallization behavior analysis and Y: HfO2Fatigue characteristics of ferroelectric thin filmPerforming sexual analysis; the analysis method of the medium microstructure and the crystallization behavior comprises the following steps: characterizing components and chemical bond structures of the film by using X-ray photoelectron spectroscopy XPS and attenuated total reflection Fourier transform infrared spectroscopy ATR-FTIR, and determining Y doping amount and chemical environment of the film; the thickness of the film is accurately measured through X-ray reflection XRR and a step instrument; analyzing the crystal structure of the film by adopting grazing incidence X-ray diffraction GIXRD and a high-resolution transmission electron microscope HRTEM to determine the phase structure and the grain size of the film; judging whether ferroelectric properties exist or not according to the electric hysteresis loop test result, and determining the change of the ferroelectric properties according to the change of the residual polarization intensity; the relationship between the stability of the ferroelectric phase and the Y doping amount, the film thickness, the annealing condition and the grain size is proved by combining the microstructure analysis and the macroscopic electrical property test results, and the stable microscopic mechanism of the ferroelectric phase is mastered; y is HfO2The fatigue characteristic analysis method of the ferroelectric film comprises the following steps: HfO and MIS structures prepared according to different process parameters2The ferroelectric film capacitor is used for carrying out fatigue characteristic test of electric field cyclic loading, the frequency of an electric field is 1MHz, the amplitude is 90 percent of breakdown field intensity, the relation between the residual polarization intensity and the frequency, the amplitude and the cycle number of the test electric field is analyzed, and the existing traditional ferroelectric material fatigue theory is verified or a new fatigue theory model is put forward; analyzing the influence mechanism of a non-ferroelectric interface layer (layer) on fatigue characteristics by comparing the test results of MIS and MIM capacitors with different structures; the method comprises the steps of carrying out fatigue test analysis on films prepared by different process parameters, researching the influence rule of a microstructure on fatigue characteristics by combining a microstructure analysis result system, exploring a micro physical mechanism generated by failure, carrying out summary analysis on a fatigue model, and mastering an effective means for improving the endurance of the material.
Before the detection and analysis of the hafnium oxide-based nano ferroelectric thin film in the S4, an electrode material is prepared on the surface of the hafnium oxide-based nano ferroelectric thin film to form a metal-insulating layer-semiconductor measurement structure, specifically, a titanium nitride thin film electrode is prepared by a direct current magnetron sputtering method in a metal mask manner as an electrode material required by the electrical detection of the hafnium oxide-based nano ferroelectric thin film.
The preparation method of the titanium nitride membrane electrode comprises the following steps:
s41: putting the cleaned Si substrate or the hafnium oxide-based nano ferroelectric film into a vacuum chamber of high-vacuum magnetron sputtering equipment, then roughly pumping by using a mechanical pump, and opening a molecular pump when the air pressure in the vacuum chamber is 0.3 Pa;
s42: when the background vacuum reaches 5X 10-4After Pa, the thermocouple was turned on to heat the sample to 380 ℃ and held at this temperature for 20 min;
s43: introducing nitrogen and argon into the vacuum chamber, wherein the nitrogen flow is 2.6sccm, the purities of the nitrogen and the argon are 99.99%, the argon flow is 31sccm, then adjusting the air pressure of the vacuum chamber to be 0.4Pa, the sputtering power to be 156W, the target base distance to be 94mm, and pre-sputtering for 6min to remove an oxide layer on the surface of the titanium target;
s44: sputtering for 5min to obtain electrode with thickness of 70nm and resistivity of 5.5 × 10-7Ω·m。
The application of the hafnium oxide-based nano ferroelectric film prepared by the method applies the hafnium oxide-based nano ferroelectric film to a ferroelectric memory device.
Example 2:
as shown in fig. 1, a method for preparing a hafnium oxide-based nano ferroelectric thin film comprises the following steps:
s1: preparing HfO by chemical solution method2The nano ferroelectric film is prepared by a water-based method to prepare a precursor solution I, and comprises the following steps:
s11: HfOCl with purity of 98%2·8H2Dissolving O in deionized water to form a solution with the Hf concentration of 0.12mol/L and the volume of 20 mL;
s12: adding 6.7mL of 1mol/L ammonia water solution into the solution to ensure that the pH value of the solution is 8.5 to form hafnium hydroxide precipitate, and fully performing the reaction by magnetic stirring at the magnetic stirring speed of 80 r/min;
s13: centrifuging and washing the obtained white precipitate with water for 5 times to remove ammonium and chloride ions, wherein the centrifugation speed is 9000rpm, the centrifugation time is 8min, and the white precipitate needs to be subjected to ultrasonic oscillation for 4min before each centrifugation to be uniformly dispersed;
s14: taking supernatant after centrifugal washing, dripping silver nitrate solution, observing that no precipitate is generated, adding 5mL of hydrogen peroxide solution with the concentration of 10mol/L and 1.4mL of nitric acid solution with the concentration of 2mol/L into the hafnium hydroxide precipitate to form precursor solution [ Hf ] with the colloid diameter less than 2nm4(OH)12(O2)2·(y-4)H2O]m(aq)；
S15: magnetic stirring at room temperature for 10h to obtain clear HfO2/ZrO2Precursor solution one, the pH of the solution is 1.2 at this time, HfO2/ZrO2The shelf life of the precursor solution I is 1 year at room temperature;
s2: mixing Y (NO) with purity of 99.9%3)3·6H2Dissolving O in deionized water to form a precursor solution II with the Y concentration of 0.1mol/L, and then mixing with HfO2/ZrO2After the precursor solution I is mixed, obtaining a precursor solution III with the required doping concentration, and when the precursor solution I and the precursor solution II are prepared into the precursor solution III, determining that the volume ratio of the precursor solution I to the precursor solution II is 1:6 for mixing and preparation according to the finally required hafnium oxide-based nano ferroelectric film Y doping amount of 0.6 mol%;
s3: the method for preparing the hafnium oxide-based nano ferroelectric film by adopting the spin coating method comprises the following steps:
s31: placing a Si substrate on a spin coater, taking three drops of precursor solution on the substrate, and then performing low-speed spin coating at 500rpm/5s and high-speed spin coating at 3000rpm/30 s;
s32: the sample was placed on a hot plate at 140 ℃ and heated for 1min to evaporate the solvent;
s33: repeating the steps to obtain samples with different thicknesses;
s34: after the spin coating is finished, placing the sample in an annealing furnace for heat treatment to obtain a hafnium oxide based nano ferroelectric film;
s4: the obtained hafnium oxide based nano ferroelectric film is subjected to microstructure and crystallization behavior analysis and Y: HfO2Analyzing the fatigue characteristics of the ferroelectric film; the analysis method of the medium microstructure and the crystallization behavior comprises the following steps:characterizing components and chemical bond structures of the film by using X-ray photoelectron spectroscopy XPS and attenuated total reflection Fourier transform infrared spectroscopy ATR-FTIR, and determining Y doping amount and chemical environment of the film; the thickness of the film is accurately measured through X-ray reflection XRR and a step instrument; analyzing the crystal structure of the film by adopting grazing incidence X-ray diffraction GIXRD and a high-resolution transmission electron microscope HRTEM to determine the phase structure and the grain size of the film; judging whether ferroelectric properties exist or not according to the electric hysteresis loop test result, and determining the change of the ferroelectric properties according to the change of the residual polarization intensity; the relationship between the stability of the ferroelectric phase and the Y doping amount, the film thickness, the annealing condition and the grain size is proved by combining the microstructure analysis and the macroscopic electrical property test results, and the stable microscopic mechanism of the ferroelectric phase is mastered; y is HfO2The fatigue characteristic analysis method of the ferroelectric film comprises the following steps: HfO and MIS structures prepared according to different process parameters2The ferroelectric film capacitor is used for carrying out fatigue characteristic test of electric field cyclic loading, the frequency of an electric field is 10kHz, the amplitude is 50 percent of breakdown field intensity, the relation between the residual polarization intensity and the frequency, amplitude and cycle frequency of the test electric field is analyzed, and the existing traditional ferroelectric material fatigue theory is verified or a new fatigue theory model is put forward; analyzing the influence mechanism of a non-ferroelectric interface layer (layer) on fatigue characteristics by comparing the test results of MIS and MIM capacitors with different structures; the method comprises the steps of carrying out fatigue test analysis on films prepared by different process parameters, researching the influence rule of a microstructure on fatigue characteristics by combining a microstructure analysis result system, exploring a micro physical mechanism generated by failure, carrying out summary analysis on a fatigue model, and mastering an effective means for improving the endurance of the material.
Before the detection and analysis of the hafnium oxide-based nano ferroelectric thin film in the S4, an electrode material is prepared on the surface of the hafnium oxide-based nano ferroelectric thin film to form a metal-insulating layer-semiconductor measurement structure, specifically, a titanium nitride thin film electrode is prepared by a direct current magnetron sputtering method in a metal mask manner as an electrode material required by the electrical detection of the hafnium oxide-based nano ferroelectric thin film.
The preparation method of the titanium nitride membrane electrode comprises the following steps:
s41: putting the cleaned Si substrate or the hafnium oxide-based nano ferroelectric film into a vacuum chamber of high-vacuum magnetron sputtering equipment, then roughly pumping by using a mechanical pump, and opening a molecular pump when the air pressure in the vacuum chamber is 0.3 Pa;
s42: when the background vacuum reaches 5X 10-4After Pa, the thermocouple was turned on to heat the sample to 330 ℃ and held at this temperature for 8 min;
s43: introducing nitrogen and argon into the vacuum chamber, wherein the nitrogen flow is 2.4sccm, the purities of the nitrogen and the argon are 99.99%, the argon flow is 29sccm, then adjusting the air pressure of the vacuum chamber to be 0.2Pa, the sputtering power to be 156W, the target base distance to be 92mm, and pre-sputtering for 4min to remove an oxide layer on the surface of the titanium target;
s44: sputtering for 4min to obtain electrode with thickness of 70nm and resistivity of 6.5 × 10-7Ω·m。
The application of the hafnium oxide-based nano ferroelectric film prepared by the method applies the hafnium oxide-based nano ferroelectric film to a ferroelectric memory device.
Example 3:
as shown in fig. 1, a method for preparing a hafnium oxide-based nano ferroelectric thin film comprises the following steps:
s1: preparing HfO by chemical solution method2The nano ferroelectric film is prepared by a water-based method to prepare a precursor solution I, and comprises the following steps:
s11: HfOCl with purity of 99 percent2·8H2Dissolving O in deionized water to form a solution with the Hf concentration of 0.12mol/L and the volume of 20 mL;
s12: adding 6.7mL of 1mol/L ammonia water solution into the solution to ensure that the pH value of the solution is 8.5 to form hafnium hydroxide precipitate, and fully performing the reaction by magnetic stirring at the magnetic stirring speed of 80 r/min;
s13: centrifuging and washing the obtained white precipitate with water for 6 times to remove ammonium and chloride ions, wherein the centrifugation speed is 9000rpm, the centrifugation time is 8min, and the white precipitate needs to be subjected to ultrasonic oscillation for 5min before each centrifugation to be uniformly dispersed;
s14: taking centrifugal water for washingDripping silver nitrate solution into the supernatant, observing no precipitate, adding 5mL hydrogen peroxide solution with concentration of 10mol/L and 1.4mL nitric acid solution with concentration of 2mol/L into the hafnium hydroxide precipitate to form precursor solution [ Hf ] with colloidal diameter less than 2nm4(OH)12(O2)2·(y-4)H2O]m(aq)；
S15: magnetic stirring at room temperature for 12h to obtain clear HfO2/ZrO2Precursor solution one, the pH of the solution is 1.2 at this time, HfO2/ZrO2The shelf life of the precursor solution I is 1 year at room temperature;
s2: mixing Y (NO) with purity of 99.9%3)3·6H2Dissolving O in deionized water to form a precursor solution II with the Y concentration of 0.1mol/L, and then mixing with HfO2/ZrO2After the precursor solution I is mixed, obtaining a precursor solution III with the required doping concentration, and when the precursor solution I and the precursor solution II are prepared into the precursor solution III, determining that the volume ratio of the precursor solution I to the precursor solution II is 1:5 for mixing and preparation according to the finally required hafnium oxide-based nano ferroelectric film Y doping amount of 0.5 mol%;
s3: the method for preparing the hafnium oxide-based nano ferroelectric film by adopting the spin coating method comprises the following steps:
s31: placing a Si substrate on a spin coater, taking three drops of precursor solution on the substrate, and then performing low-speed spin coating at 500rpm/5s and high-speed spin coating at 3000rpm/30 s;
s32: the sample was placed on a hot plate at 150 ℃ and heated for 1min to evaporate the solvent;
s33: repeating the steps to obtain samples with different thicknesses;
s34: after the spin coating is finished, placing the sample in an annealing furnace for heat treatment to obtain a hafnium oxide based nano ferroelectric film;
s4: the obtained hafnium oxide based nano ferroelectric film is subjected to microstructure and crystallization behavior analysis and Y: HfO2Analyzing the fatigue characteristics of the ferroelectric film; the analysis method of the medium microstructure and the crystallization behavior comprises the following steps: using X-ray photoelectron spectroscopy XPS and attenuated total reflection Fourier transformThe method comprises the following steps of (1) performing characterization on components and a chemical bond structure of a film by ATR-FTIR (attenuated reflectance spectroscopy) to determine Y doping amount and chemical environment of the film; the thickness of the film is accurately measured through X-ray reflection XRR and a step instrument; analyzing the crystal structure of the film by adopting grazing incidence X-ray diffraction GIXRD and a high-resolution transmission electron microscope HRTEM to determine the phase structure and the grain size of the film; judging whether ferroelectric properties exist or not according to the electric hysteresis loop test result, and determining the change of the ferroelectric properties according to the change of the residual polarization intensity; the relationship between the stability of the ferroelectric phase and the Y doping amount, the film thickness, the annealing condition and the grain size is proved by combining the microstructure analysis and the macroscopic electrical property test results, and the stable microscopic mechanism of the ferroelectric phase is mastered; y is HfO2The fatigue characteristic analysis method of the ferroelectric film comprises the following steps: HfO and MIS structures prepared according to different process parameters2Performing fatigue characteristic test of electric field cyclic loading on the ferroelectric film capacitor, wherein the frequency of an electric field is 20kHz, the amplitude is 80 percent of breakdown field intensity, analyzing the relation between the residual polarization intensity and the frequency, amplitude and cycle times of the test electric field, and verifying the existing traditional ferroelectric material fatigue theory or providing a new fatigue theory model; analyzing the influence mechanism of a non-ferroelectric interface layer (layer) on fatigue characteristics by comparing the test results of MIS and MIM capacitors with different structures; the method comprises the steps of carrying out fatigue test analysis on films prepared by different process parameters, researching the influence rule of a microstructure on fatigue characteristics by combining a microstructure analysis result system, exploring a micro physical mechanism generated by failure, carrying out summary analysis on a fatigue model, and mastering an effective means for improving the endurance of the material.
Before the detection and analysis of the hafnium oxide-based nano ferroelectric thin film in the S4, an electrode material is prepared on the surface of the hafnium oxide-based nano ferroelectric thin film to form a metal-insulating layer-semiconductor measurement structure, specifically, a titanium nitride thin film electrode is prepared by a direct current magnetron sputtering method in a metal mask manner as an electrode material required by the electrical detection of the hafnium oxide-based nano ferroelectric thin film.
The preparation method of the titanium nitride membrane electrode comprises the following steps:
s41: putting the cleaned Si substrate or the hafnium oxide-based nano ferroelectric film into a vacuum chamber of high-vacuum magnetron sputtering equipment, then roughly pumping by using a mechanical pump, and opening a molecular pump when the air pressure in the vacuum chamber is 0.4 Pa;
s42: when the background vacuum reaches 5X 10-4After Pa, the thermocouple is turned on to heat the sample to 350 ℃ and the temperature is kept for 10 min;
s43: introducing nitrogen and argon into the vacuum chamber, wherein the nitrogen flow is 2.5sccm, the purities of the nitrogen and the argon are 99.99%, the argon flow is 30sccm, then adjusting the air pressure of the vacuum chamber to be 0.3Pa, the sputtering power to be 156W, the target base distance to be 93mm, and pre-sputtering for 5min to remove an oxide layer on the surface of the titanium target;
s44: sputtering for 5min to obtain electrode with thickness of 70nm and resistivity of 7.4 × 10-7Ω·m。
The application of the hafnium oxide-based nano ferroelectric film prepared by the method applies the hafnium oxide-based nano ferroelectric film to a ferroelectric memory device.
In the above examples, the hafnium oxide based nano ferroelectric thin film produced in example 3 has the best quality.
The hafnium oxide based nano ferroelectric film has the application value that:
as an important functional thin film material, a ferroelectric thin film material is a leading edge and a hot spot of the current high and new technology research field because: firstly, the structure of the ferroelectric film determines that the ferroelectric film has dielectricity, ferroelectric switch effect, piezoelectric effect, pyroelectric effect, photoelectric effect, acousto-optic effect, photorefractive effect and nonlinear optical effect, and various functional devices, integrated devices or smart devices can be manufactured based on the effects; secondly, the development of the film preparation technology enables the ferroelectric film process technology to be compatible with the semiconductor process technology, so that a new scientific branch-integrated ferroelectric electricity appears, namely, the traditional dielectric material, device and physics are combined with the semiconductor material; finally, due to the development of microelectronics, optoelectronics, and sensor technologies, the development of ferroelectric materials toward small size, light weight, and integratability has been promoted, so that a large number of novel ferroelectric thin film devices have been developed. Therefore, the research and application of ferroelectric thin film materials are receiving attention from researchers in physics, material science and engineering, microelectronics and optoelectronics, etc.
With the rapid development of internet of things networks in recent years, ferroelectric memory devices represented by ferroelectric random access memories (ferams), ferroelectric field effect transistors (FeFETs), and Ferroelectric Tunnel Junctions (FTJs) have attracted much attention. As a typical representative of integrated circuit devices, ferroelectric memories have many advantages such as non-volatility of data storage at the time of power-off, lower power consumption, higher number of times of erasing and writing, very large scale integration, and high read and write speeds comparable to those of DRAMs. At present, Pb (Zr, Ti) O with perovskite structure is mainly selected in the research and actual industrial production of ferroelectric memories3(PZT)，SrBi2Ta2O9(SBT) and BiFeO3(BFO) and the like.
The performance ratio of the hafnium oxide-based nano ferroelectric thin film produced in this example to the ferroelectric memory made of conventional electrode material is shown in table 1.
Table 1: conventional ferroelectric material and HfO for ferroelectric memory2Comparison of properties of novel ferroelectric thin film materials
HfO of different Y doping concentrations produced according to the above examples2The XRD spectrum of the film is shown in figure 2.
Claims (10)
1. A preparation method of a hafnium oxide based nano ferroelectric film is characterized by comprising the following steps:
s1: preparing HfO by chemical solution method2The nano ferroelectric film is prepared by a water-based method to prepare a precursor solution I, and comprises the following steps:
s11: the HfOCl with the purity of more than 98 percent2·8H2Dissolving O in deionized water to form a solution with the Hf concentration of 0.12mol/L and the volume of 20 mL;
s12: adding 6.7mL of 1mol/L ammonia water solution into the solution to ensure that the pH value of the solution is 8.5 so as to form hafnium hydroxide precipitate, and stirring by magnetic force to fully react;
s13: centrifuging and washing the obtained white precipitate for 5-8 times to remove ammonium and chloride ions, and performing ultrasonic oscillation on the white precipitate for 4-10min before centrifuging each time to uniformly disperse the white precipitate;
s14: taking supernatant after centrifugal washing, dripping silver nitrate solution, observing that no precipitate is generated, adding 5mL of hydrogen peroxide solution with the concentration of 10mol/L and 1.4mL of nitric acid solution with the concentration of 2mol/L into the hafnium hydroxide precipitate to form precursor solution [ Hf ] with the colloid diameter less than 2nm4(OH)12(O2)2·(y-4)H2O]m(aq)；
S15: magnetically stirring at room temperature for 10-20h to obtain clear HfO2/ZrO2The pH value of the precursor solution I is 1.2;
s2: mixing Y (NO) with purity of 99.9%3)3·6H2Dissolving O in deionized water to form a precursor solution II with the Y concentration of 0.1mol/L, and then mixing with HfO2/ZrO2Mixing the precursor solution I to obtain a precursor solution III with the required doping concentration;
s3: the method for preparing the hafnium oxide-based nano ferroelectric film by adopting the spin coating method comprises the following steps:
s31: placing a Si substrate on a spin coater, taking three drops of precursor solution on the substrate, and then performing low-speed spin coating at 500rpm/5s and high-speed spin coating at 3000rpm/30 s;
s32: placing the sample on a hot plate at 140-160 ℃ and heating for 1-2min to evaporate the solvent;
s33: repeating the steps to obtain samples with different thicknesses;
s34: after the spin coating is finished, placing the sample in an annealing furnace for heat treatment to obtain a hafnium oxide based nano ferroelectric film;
s4: detecting and analyzing the obtained hafnium oxide-based nano ferroelectric film, wherein the detecting and analyzing comprise microstructure and crystallization behavior analysis and HfO2And analyzing the fatigue characteristics of the ferroelectric film.
2. The method of claim 1, wherein before the detection and analysis of the hafnia-based nano ferroelectric thin film in S4, an electrode material is prepared on the surface of the hafnia-based nano ferroelectric thin film to form a metal-insulator-semiconductor measurement structure, and specifically, a titanium nitride thin film electrode is prepared by a dc magnetron sputtering method as an electrode material required for the electrical detection of the hafnia-based nano ferroelectric thin film in a manner of a metal mask.
3. The method for preparing a hafnium oxide-based nano ferroelectric film according to claim 2, wherein the method for preparing a titanium nitride film electrode comprises the following steps:
s41: putting the cleaned Si substrate or the hafnium oxide-based nano ferroelectric film into a vacuum chamber of high-vacuum magnetron sputtering equipment, then roughly pumping by using a mechanical pump, and opening a molecular pump when the air pressure in the vacuum chamber is lower than 0.5 Pa;
s42: when the background vacuum reaches 5X 10-4After Pa, opening a thermocouple to heat the sample to 330-380 ℃, and keeping the temperature for 8-20 min;
s43: introducing nitrogen and argon into the vacuum chamber, wherein the flow of the nitrogen is 2.4-2.6sccm, the flow of the argon is 29-31sccm, then adjusting the air pressure of the vacuum chamber to be 0.2-0.4Pa, the sputtering power is 156W, the target base distance is 92-94mm, and pre-sputtering for 4-6min to remove an oxide layer on the surface of the titanium target;
s44: sputtering for 4-5min to obtain electrode with thickness of 70nm and resistivity lower than 7.5 × 10-7Ω·m。
4. The method of claim 3, wherein the purity of the nitrogen and argon introduced in step S43 is 99.99%.
5. The method of claim 1, wherein the centrifugation speed in S13 is 9000rpm, and the centrifugation time is 8 min.
6. The method of claim 1, wherein the magnetic stirring speed in step S12 is 80 r/min.
7. The method according to claim 1, wherein in step S2, when the first precursor solution and the second precursor solution are prepared into the third precursor solution, the mixing ratio of the first precursor solution and the second precursor solution is determined according to the final doping amount of the hafnium oxide-based nano ferroelectric thin film Y.
8. The method of claim 1, wherein the method for analyzing microstructure and crystallization behavior in step S5 comprises: and characterizing the components and the chemical bond structure of the film by using X-ray photoelectron spectroscopy XPS and attenuated total reflection Fourier transform infrared spectroscopy ATR-FTIR, and determining the Y doping amount and the chemical environment of the film.
9. The method of claim 1, wherein Y is HfO2The fatigue characteristic analysis method of the ferroelectric film comprises the following steps: HfO and MIS structures prepared according to different process parameters2The ferroelectric film capacitor is used for carrying out fatigue characteristic test of electric field cyclic loading, the frequency of an electric field is 10kHz-1MHz, the amplitude is 50-90% of breakdown field intensity, the relation between the remanent polarization and the frequency, amplitude and cycle frequency of the test electric field is analyzed, and the existing traditional ferroelectric material fatigue theory is verified or a new fatigue theory model is provided.
10. The method of claim 1, wherein Y is HfO2The fatigue characteristic analysis method of the ferroelectric film comprises the following steps: MIS structure and MIM structure Y H prepared for different process parametersfO2The ferroelectric film capacitor is used for carrying out fatigue characteristic test of electric field cyclic loading, analyzing the relation between the residual polarization strength and the frequency, amplitude and cycle number of a test electric field, and verifying the existing traditional ferroelectric material fatigue theory or providing a new fatigue theory model.
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