A locally modulated antiferroelectric capacitor, its fabrication method, and electronic devices thereof.

Abstract

This invention provides a locally modulated antiferroelectric capacitor, its fabrication method, and an electronic device, comprising a bottom electrode layer, a dielectric layer, and a top electrode layer sequentially disposed on a substrate from bottom to top; the dielectric layer includes an antiferroelectric thin film layer and a locally modulated layer located within the antiferroelectric thin film layer; the locally modulated layer is used to synchronously introduce lattice distortion, oxygen defect redistribution, and local potential changes locally within the antiferroelectric thin film layer by utilizing differences in ionic radius, valence state, and / or bonding characteristics with ions in the antiferroelectric thin film layer, thereby synergistically controlling the stress state, defect distribution, and built-in electric field of the antiferroelectric thin film layer, thus optimizing phase stability, phase transition barrier, and breakdown behavior, improving the energy storage density, energy storage efficiency, and device reliability of the antiferroelectric capacitor, and solving the problem of how to maintain a high antiferroelectric polarization capability of the antiferroelectric capacitor while increasing the breakdown field strength.

Description

Technical Field

[0001] This invention relates to the field of electronic device technology, and in particular to a locally modulated antiferroelectric capacitor, its preparation method, and electronic devices. Background Technology

[0002] With the rapid development of integrated circuits, microelectronic systems, and high-speed communication technologies, on-chip energy storage devices are facing increasingly stringent requirements for high power density, high charge / discharge rates, high cycle stability, and high-temperature reliability. Among existing energy storage devices, lithium-ion batteries and electrochemical supercapacitors primarily rely on ion migration for energy storage, which suffers from slow charge / discharge rates, limited cycle life, and insufficient high-temperature stability. In contrast, dielectric capacitors utilize electronic polarization for energy storage, offering advantages such as fast charge / discharge rates, high power density, long cycle life, and ease of integration, making them more suitable for on-chip energy storage applications.

[0003] Among existing dielectric energy storage materials, antiferroelectric materials, due to their electric field-induced phase transition characteristics, can simultaneously achieve high polarization intensity and low remanent polarization, thus becoming an important research direction for high-performance energy storage capacitors. In recent years, fluorite-structured antiferroelectric thin films based on HfO2 and ZrO2 have attracted widespread attention due to their high breakdown field strength, good dimensional stability, and compatibility with complementary metal-oxide-semiconductor (CMOS) processes.

[0004] However, existing antiferroelectric energy storage films still face the challenge of simultaneously improving energy density, energy storage efficiency, and device reliability. Typically, increasing the film polarization intensity leads to increased residual polarization and leakage current, thus reducing energy storage efficiency; while increasing insulation and breakdown field strength tends to suppress antiferroelectric phase transition behavior, resulting in a decrease in polarization response. Therefore, how to maintain high antiferroelectric polarization capability while increasing breakdown field strength is a crucial problem that needs to be solved in the field of antiferroelectric energy storage. Summary of the Invention

[0005] The purpose of this invention is to provide a locally modulated antiferroelectric capacitor, its preparation method, and electronic devices, in order to solve the problem of how to maintain the high antiferroelectric polarization capability of the antiferroelectric capacitor while increasing the breakdown field strength.

[0006] To address the aforementioned technical problems, this invention provides a locally modulated antiferroelectric capacitor, comprising a bottom electrode layer, a dielectric layer, and a top electrode layer sequentially disposed on a substrate from bottom to top; the dielectric layer includes an antiferroelectric thin film layer and a locally modulated layer located within the antiferroelectric thin film layer; the locally modulated layer is used to synchronously introduce lattice distortion, oxygen defect redistribution, and local potential changes locally within the antiferroelectric thin film layer by utilizing differences in ionic radius, valence state, and / or bonding characteristics between the layer and ions in the antiferroelectric thin film layer, thereby coordinating the control of the stress state, defect distribution, and built-in electric field of the antiferroelectric thin film layer.

[0007] Optionally, in the locally modulated antiferroelectric capacitor, an insulating layer is further provided between the substrate and the bottom electrode layer.

[0008] Optionally, in the locally modulated antiferroelectric capacitor, the bottom electrode layer is made of one or more of TiN, W, Mo, Ni, and Ru; the top electrode layer is made of one or more of TiN, W, Mo, Ni, and Ru.

[0009] Optionally, in the locally modulated antiferroelectric capacitor, the antiferroelectric thin film layer is made of ZrO2; the locally modulated layer is made of one or more of SrO, TiO2, SnO2, In2O3, Ga2O3, ZnO, MgO, Ta2O5, Y2O3, and Al2O3.

[0010] Optionally, in the locally modulated antiferroelectric capacitor, the thickness of the antiferroelectric thin film layer is 5~30nm; the thickness of the bottom electrode layer is 30~150nm; and the thickness of the top electrode layer is 30~150nm.

[0011] Optionally, in the locally modulated antiferroelectric capacitor, the locally modulated layer is discontinuously inserted into the antiferroelectric thin film layer.

[0012] To address the aforementioned technical problems, the present invention also provides a method for fabricating a locally modulated antiferroelectric capacitor, used to manufacture a locally modulated antiferroelectric capacitor as described in any of the preceding claims, the method comprising: Provide substrate; A bottom electrode layer is formed on the substrate surface; A dielectric layer is formed on the surface of the bottom electrode layer using atomic layer deposition technology; A top electrode layer is formed on the surface of the dielectric layer; Annealing is performed to obtain a locally modulated antiferroelectric capacitor.

[0013] Optionally, in the method for fabricating the locally modulated antiferroelectric capacitor, before forming the bottom electrode layer on the substrate surface, the fabrication method further includes: An insulating layer is formed on the substrate surface.

[0014] Optionally, in the method for fabricating the locally modulated antiferroelectric capacitor, the method of forming a dielectric layer on the surface of the bottom electrode layer using atomic layer deposition includes: The cycle ratio and sequence of the atomic layer deposition process are determined based on the target location and local target concentration of the local modulation layer. Following a defined cycle ratio and sequence, an antiferroelectric thin film layer and a localized modulation layer are prepared using atomic layer deposition (ALD) to obtain a dielectric layer.

[0015] Optionally, in the method for preparing the locally modulated antiferroelectric capacitor, the annealing temperature is 350~650℃, the atmosphere is oxygen, nitrogen or a mixture of nitrogen and hydrogen, and the time is 1~60min.

[0016] To address the aforementioned technical problems, the present invention also provides an electronic device comprising a locally modulated antiferroelectric capacitor as described in any of the preceding claims.

[0017] The present invention provides a locally modulated antiferroelectric capacitor, its fabrication method, and an electronic device, comprising a bottom electrode layer, a dielectric layer, and a top electrode layer sequentially disposed from bottom to top on a substrate; the dielectric layer includes an antiferroelectric thin film layer and a locally modulated layer located within the antiferroelectric thin film layer; the locally modulated layer is used to synchronously introduce lattice distortion, oxygen defect redistribution, and local potential changes locally in the antiferroelectric thin film layer by utilizing the differences in ionic radius, valence state, and / or bonding characteristics between the ions and ions in the antiferroelectric thin film layer, so as to synergistically regulate the stress state, defect distribution, and built-in electric field of the antiferroelectric thin film layer, thereby optimizing phase stability, phase transition barrier, and breakdown behavior, improving the energy storage density, energy storage efficiency, and device reliability of the antiferroelectric capacitor, and solving the problem of how to maintain a high antiferroelectric polarization capability of the antiferroelectric capacitor while increasing the breakdown field strength. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the basic device structure of the locally modulated antiferroelectric capacitor provided in this embodiment. Figure 2 This is a schematic diagram of the device structure of the locally modulated antiferroelectric capacitor provided in this embodiment; Figure 3 A flowchart illustrating the fabrication method of the locally modulated antiferroelectric capacitor provided in this embodiment; Figures 4(A) to 4(E) are schematic diagrams of the device structure of the locally modulated antiferroelectric capacitor provided in this embodiment at each step; Figure 5This is a schematic diagram illustrating the setting of the cycle ratio and sequence of the atomic layer deposition process provided in this embodiment; The labels in the accompanying drawings are explained as follows: 100 - Substrate; 110 - Insulating layer; 200 - Bottom electrode layer; 300 - Dielectric layer; 310 - Antiferroelectric thin film layer; 320 - Localized modulation layer; 400 - Top electrode layer. Detailed Implementation

[0019] The following detailed description, in conjunction with the accompanying drawings and specific embodiments, provides a further detailed account of the locally modulated antiferroelectric capacitor, its fabrication method, and electronic devices proposed in this invention. It should be noted that the drawings are all in a very simplified form and use non-precise scales, intended only to facilitate and clarify the illustration of the embodiments of this invention. Furthermore, the structures shown in the drawings are often part of the actual structures. In particular, different figures may emphasize different aspects and sometimes use different scales.

[0020] It should be noted that the terms "first," "second," etc., used in the specification, claims, and drawings of this invention are used to distinguish similar objects in order to describe embodiments of the invention, and are not used to describe a specific order or sequence. It should be understood that such uses of terminology are interchangeable where appropriate. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0021] To improve the breakdown field strength while maintaining high antiferroelectric polarization capability in antiferroelectric capacitors, existing technologies mainly employ methods such as uniform elemental doping, solid solution modulation, or continuous interface layer construction to enhance the performance of antiferroelectric thin films. For example, the crystal phase composition is controlled by doping with elements such as Hf, Al, Si, and La, or the interface quality is improved by introducing a buffer layer. However, traditional uniform doping methods tend to lead to a decrease in polarization capability and are difficult to effectively control the distribution of local defects; continuous interface layers tend to form low dielectric layers and hinder continuous grain growth, thus affecting the antiferroelectric phase transition behavior and energy storage performance. Furthermore, most existing technologies focus on controlling the overall crystal phase ratio or average defect concentration, with limited research on the synergistic control of local stress distribution, local defect state, and spatial electric field distribution.

[0022] Therefore, this embodiment provides a locally modulated antiferroelectric capacitor, such as... Figure 1As shown, the substrate 100 includes a bottom electrode layer 200, a dielectric layer 300, and a top electrode layer 400 disposed sequentially from bottom to top. The dielectric layer 300 includes an antiferroelectric thin film layer 310 and a local modulation layer 320 located in the antiferroelectric thin film layer 310. The local modulation layer 320 is used to synchronously introduce lattice distortion, oxygen defect redistribution, and local potential changes in the local area of ​​the antiferroelectric thin film layer 310 by utilizing the differences in ionic radius, valence state, and / or bonding characteristics between the ions in the antiferroelectric thin film layer 310 and the ions in the antiferroelectric thin film layer 310, so as to coordinately control the stress state, defect distribution, and built-in electric field of the antiferroelectric thin film layer 310.

[0023] The locally modulated antiferroelectric capacitor provided in this embodiment introduces a local modulation layer into the antiferroelectric thin film layer. By utilizing the differences in ionic radius, valence state, and / or bonding characteristics between ions in the local modulation layer and the antiferroelectric thin film layer, lattice distortion, oxygen defect redistribution, and local potential changes are synchronously introduced locally into the antiferroelectric thin film layer. This allows for the coordinated control of the stress state, defect distribution, and built-in electric field of the antiferroelectric thin film layer, thereby optimizing phase stability, phase transition barrier, and breakdown behavior. This improves the energy storage density, energy storage efficiency, and device reliability of the antiferroelectric capacitor, solving the problem of how to maintain a high antiferroelectric polarization capability of the antiferroelectric capacitor while increasing the breakdown field strength.

[0024] Preferably, to prevent the bottom electrode material from diffusing into the substrate due to contact between the bottom electrode layer 200 and the substrate 100, thereby causing a short circuit, in this embodiment, such as Figure 2 As shown, an insulating layer 110 is also provided between the substrate 100 and the bottom electrode layer 200.

[0025] Specifically, in practical applications, the substrate 100 can be a silicon substrate, and other device structures can also be formed in the substrate 100; this application does not impose any restrictions on this.

[0026] Furthermore, the bottom electrode layer 200 is made of one or more of TiN, W, Mo, Ni, and Ru to ensure good conductivity, thermal stability, and thin film deposition compatibility, enabling it to form a stable interfacial contact with the antiferroelectric dielectric. When the bottom electrode layer 200 is made of multiple materials, the differential work function and thermal expansion coefficient between different electrode materials can be utilized to introduce controllable in-plane stress within the dielectric layer 300 during subsequent annealing through the thermal mismatch effect, thereby adjusting the relative stability between the antiferroelectric phase and the linear phase. In practical applications, the material of the bottom electrode layer 200 can be rationally selected according to actual needs to further control the interfacial oxygen diffusion behavior and local oxygen defect distribution, synergistically improving the thin film insulation performance, breakdown field strength, and cycle reliability.

[0027] Based on the aforementioned substrate 100 material and bottom electrode layer 200 material, in this embodiment, the insulating layer 110 is made of SiO2 with a thickness of 100~500nm, thereby effectively preventing the bottom electrode layer 200 material from diffusing into the substrate 100, thus ensuring that the device will not short-circuit and guaranteeing the reliability of the device performance.

[0028] Furthermore, in this embodiment, the top electrode layer 400 is made of one or more of TiN, W, Mo, Ni, and Ru. In practical applications, the material of the top electrode layer 400 can be the same as or different from that of the bottom electrode layer 200, thus resulting in different capacitor performances. The top electrode layer 400 also needs to have good conductivity, thermal stability, and thin film deposition compatibility, and can form a stable interface contact with the antiferroelectric. The top electrode layer 400 works in conjunction with the bottom electrode layer 200 to flexibly control the interfacial oxygen diffusion behavior and local oxygen defect distribution, synergistically improving the thin film insulation performance, breakdown field strength, and cycle reliability.

[0029] Furthermore, in this embodiment, the antiferroelectric thin film layer 310 is made of ZrO2; the local modulation layer 320 is made of one or more of SrO, TiO2, SnO2, In2O3, Ga2O3, ZnO, MgO, Ta2O5, Y2O3, and Al2O3.

[0030] Using ZrO2 thin film as the antiferroelectric thin film layer 310, antiferroelectric properties can be exhibited through the reversible transition between the tetragonal and orthorhombic phases, and it still has high energy storage potential at the nanoscale. At the same time, by utilizing the differences in ionic radius, valence state, and bonding characteristics between the oxide cations in the local modulation layer 320 and the Zr ions in the antiferroelectric thin film layer 310, lattice distortion, oxygen defect redistribution, and local potential changes are simultaneously introduced in the local region, thereby achieving synergistic control of stress state, defect distribution, and built-in electric field.

[0031] Specifically, local lattice distortion can regulate the relative stability between tetragonal, orthorhombic, and cubic phases, thereby controlling the proportion of antiferroelectric phases and phase transition behavior; local oxygen defect redistribution can improve the insulation performance of the thin film and increase the breakdown field strength; at the same time, by adjusting the distribution position, local concentration, and spatial spacing of the local modulation layer 320 in the antiferroelectric thin film layer 310, a non-uniform local potential distribution and built-in electric field can be further formed to control the phase transition barrier and polarization reversal process, thereby reducing leakage loss and improving energy storage efficiency.

[0032] In this embodiment, the thickness of the antiferroelectric thin film layer 310 is 5-30 nm; the thickness of the bottom electrode layer 200 is 30-150 nm; and the thickness of the top electrode layer 400 is 30-150 nm. In practical applications, the thickness of the antiferroelectric thin film layer 310 refers to the sum of the thicknesses of all antiferroelectric thin film layers 310 in the dielectric layer 300. Furthermore, the thickness of the bottom electrode layer 200 may be the same as or different from the thickness of the top electrode layer 400.

[0033] Furthermore, in this embodiment, the localized modulation layers 320 are inserted discontinuously into the antiferroelectric thin film layer 310. That is, the thickness, concentration, and / or material of the localized modulation layers 320 at different locations within the antiferroelectric thin film layer 310 are inconsistent, and / or the thickness of the antiferroelectric thin film layers 310 above and below the localized modulation layers 320 is inconsistent after insertion. This avoids the disruption to continuous grain growth and antiferroelectric phase continuity caused by traditional continuous intercalation or uniform doping. It maintains a stable antiferroelectric response while improving breakdown reliability and cycle stability, achieving a synergistic improvement in energy storage density, energy storage efficiency, and device reliability.

[0034] This embodiment also provides a method for preparing a locally modulated antiferroelectric capacitor, used to manufacture the locally modulated antiferroelectric capacitor as described above, such as... Figure 3 As shown, the preparation method includes: S1 provides the substrate; S2, forming a bottom electrode layer on the substrate surface; S3 uses atomic layer deposition to form a dielectric layer on the surface of the bottom electrode layer; S4, forming a top electrode layer on the surface of the dielectric layer; S5, Annealing, to obtain a locally modulated antiferroelectric capacitor.

[0035] The method for fabricating a locally modulated antiferroelectric capacitor provided in this embodiment uses atomic layer deposition (ALD) or plasma-enhanced atomic layer deposition (PEALD) to form the dielectric layer. This method not only enables precise deposition of the dielectric layer at the sub-nanometer scale, but also allows for easy control of the thickness and distribution of the antiferroelectric thin film layer and the locally modulated layer. Furthermore, it is compatible with integrated circuit manufacturing processes and is suitable for on-chip integration of highly integrated nanoscale energy storage capacitors. Moreover, the atomic layer deposition (ALD) process allows for flexible adjustment of the position, concentration, and distribution period of the locally modulated layer in the antiferroelectric thin film layer, enabling fine control of the energy storage density, energy storage efficiency, and device reliability of the antiferroelectric capacitor.

[0036] Specifically, in this embodiment, step S1, as shown in FIG4(A), involves providing a substrate 100.

[0037] In practical applications, the substrate 100 can be a silicon substrate, and other device structures can also be formed in the substrate 100. This application does not impose any restrictions on this.

[0038] Preferably, in order to prevent the bottom electrode material from diffusing into the substrate due to contact between the bottom electrode layer 200 and the substrate 100, thereby causing a short circuit, in this embodiment, as shown in FIG4(B), an insulating layer 110 is formed on the surface of the substrate 100.

[0039] In practical applications, insulating layers 110 can be fabricated on the surface of substrate 100 using processes such as wet oxidation, dry oxidation, rapid thermal oxidation (RTO), chemical vapor deposition (CVD), or physical vapor deposition (PVD). The insulating layer 110 is made of SiO2 and has a thickness of 100-500 nm, effectively preventing the diffusion of the bottom electrode layer 200 material into the substrate 100, thus ensuring that the device will not experience short circuits and guaranteeing device reliability.

[0040] In one specific embodiment, a 300 nm SiO2 insulating layer 110 is prepared on the surface of substrate 100 by wet oxidation. The oxidation temperature is 950 °C, the oxidants are H2O and O2, the O2 flow rate is 50 L / min, the H2O is sufficient, and the thermal oxidation is carried out for 2 h to obtain a SiO2 insulating layer 110 with a thickness of 300 nm.

[0041] Furthermore, in this embodiment, step S2 involves forming a bottom electrode layer on the substrate surface. Specifically, in this embodiment, as shown in FIG4(C), a bottom electrode layer 200 is formed on the surface of the insulating layer 110.

[0042] In practical applications, thin film preparation processes such as physical vapor deposition (PVD) or atomic layer deposition (ALD) can be used to prepare a bottom electrode layer 200 with a thickness of 30~150 nm. The bottom electrode layer 200 is made of one or more of TiN, W, Mo, Ni and Ru to ensure that the bottom electrode layer 200 has good conductivity, thermal stability and thin film deposition compatibility, and can form a stable interface contact with antiferroelectric materials.

[0043] In one specific embodiment, a W bottom electrode layer 200 is deposited on the insulating layer 110 using a PVD process. The process atmosphere is Ar, the sputtering power is 100W, and the sputtering time is 1800s to obtain a W bottom electrode layer 200 with a thickness of 100nm.

[0044] Furthermore, in this embodiment, step S3 involves forming a dielectric layer on the surface of the bottom electrode layer using an atomic layer deposition process.

[0045] Specifically, in this embodiment, firstly, the cycle ratio and sequence of the atomic layer deposition process are determined based on the target location and local target concentration of the local modulation layer 320; then, according to the determined cycle ratio and sequence, the antiferroelectric thin film layer 310 and the local modulation layer 320 are prepared using the atomic layer deposition process to obtain the dielectric layer 300, as shown in Figure 4(D). By adjusting the position, concentration, and distribution period of the local modulation layer 320, the energy storage performance of the antiferroelectric capacitor can be precisely controlled.

[0046] In practical applications, the antiferroelectric thin film layer 310 is made of ZrO2; the local modulation layer 320 is made of one or more of SrO, TiO2, SnO2, In2O3, Ga2O3, ZnO, MgO, Ta2O5, Y2O3, and Al2O3.

[0047] Taking the antiferroelectric thin film layer 310 as being made of ZrO2 and the localized modulation layer 320 as being made of SrO as an example, the cycle ratio and sequence of the atomic layer deposition process are explained: (e.g.) Figure 5 As shown, firstly, an antiferroelectric ZrO2 thin film layer 310 is deposited for n cycles using atomic layer deposition, then an SrO localization modulation layer 320 is deposited for x cycles, and then an antiferroelectric ZrO2 thin film layer 310 is deposited for m cycles, thereby obtaining a dielectric layer 300. Here, n and m are integers greater than or equal to 0, and x is an integer greater than or equal to 1 and less than or equal to 3.

[0048] In one specific embodiment, a ZrO2 antiferroelectric thin film layer 310 and an SrO localization modulation layer 320 are deposited on the bottom electrode layer 200 using an ALD process. The SrO localization modulation layer 320 is located in the ZrO2 antiferroelectric thin film layer 310 at a position approximately 1 / 10 of the thickness of the bottom electrode layer 200. The precursor for the ZrO2 antiferroelectric thin film layer 310 is TDMAZr at a temperature of 65°C, and the precursor for the SrO localization modulation layer 320 is Sr(iPr3Cp)2 at a temperature of 140°C. The carrier gas is nitrogen at a flow rate of 120 sccm. The pulse duration for the ZrO2 antiferroelectric thin film layer 310 is 0.5 s, the pulse duration for the SrO localization modulation layer 320 is 1 s, and the purge time is 10 s. O2 plasma was used as the oxygen source and Ar gas was used as the carrier gas to transport it to the deposition chamber. The plasma generator power was 2000W, the O2 flow rate was 100sccm, the pulse time was 15s, and the purging time was 10s.

[0049] Under these parameters, 10 cycles of ZrO2 antiferroelectric thin film layers 310 are first deposited, followed by 1 cycle of SrO localization modulation layer 320. This is then repeated for 90 cycles of ZrO2 antiferroelectric thin film layers 310, i.e., n=10, x=1, m=90, ultimately yielding a dielectric layer 300 with a thickness of 10 nm. The SrO localization modulation layer 320 is distributed discontinuously within the ZrO2 antiferroelectric thin film layers 310, used to synchronously modulate local lattice stress, oxygen defect distribution, and built-in electric field, thereby improving the energy storage performance and breakdown reliability of the antiferroelectric thin film.

[0050] In another embodiment, the antiferroelectric thin film layer 310 is made of ZrO2, and the local modulation layer 320 is made of SnO2. The SnO2 local modulation layer 320 is located in the ZrO2 antiferroelectric thin film layer 310 at a position approximately half the thickness of the bottom electrode layer 200, that is, the thickness ratio of the ZrO2 antiferroelectric thin film layer 310 above and below the SnO2 local modulation layer 320 is 1:1. The precursor for the ZrO2 antiferroelectric thin film layer 310 is TDMAZr at a temperature of 65°C, the precursor for the SnO2 local modulation layer 320 is TDMASn at a temperature of 55°C, the carrier gas is nitrogen at a flow rate of 120 sccm, the pulse duration for the ZrO2 antiferroelectric thin film layer 310 is 0.5 s, the pulse duration for the SnO2 local modulation layer 320 is 0.8 s, and the purge time is 10 s. O2 plasma was used as the oxygen source and Ar gas was used as the carrier gas to transport it to the deposition chamber. The plasma generator power was 2000W, the O2 flow rate was 100sccm, the pulse time was 15s, and the purging time was 10s.

[0051] Under these parameters, 50 cycles of ZrO2 antiferroelectric thin film layers 310 are first deposited, followed by one cycle of SnO2 localization modulation layer 320. This process is repeated for another 50 cycles of ZrO2 antiferroelectric thin film layers 310, ultimately yielding a dielectric layer 300 with a thickness of 10 nm. The SnO2 localization modulation layer 320 is distributed discontinuously within the ZrO2 antiferroelectric thin film layer 310, serving to simultaneously modulate local lattice stress, oxygen defect distribution, and built-in electric field, thereby improving the energy storage performance and breakdown reliability of the antiferroelectric thin film.

[0052] Of course, those skilled in the art can learn from the above examples how to obtain the dielectric layer 300 in other materials, and this application will not elaborate on this further.

[0053] Furthermore, in this embodiment, step S4, as shown in FIG4(E), involves forming a top electrode layer 400 on the surface of the dielectric layer 300.

[0054] Specifically, in practical applications, thin film preparation processes such as physical vapor deposition (PVD) or atomic layer deposition (ALD) can be used to prepare a top electrode layer 400 with a thickness of 30~150 nm. The top electrode layer 400 is made of one or more of TiN, W, Mo, Ni and Ru to ensure that the top electrode layer 400 has good conductivity, thermal stability and thin film deposition compatibility, and can form a stable interface contact with antiferroelectric materials.

[0055] In one specific embodiment, a W top electrode layer 400 is deposited on the dielectric layer 300 using a PVD process. The process atmosphere is Ar, the sputtering power is 100W, and the sputtering time is 1800s to obtain a W top electrode layer 400 with a thickness of 100nm.

[0056] Furthermore, in this embodiment, an electrode pattern can be formed on the top electrode layer 400 using photolithography, and the top electrode layer 400 outside the pattern can be etched away by wet or dry etching. Subsequently, the device is subjected to a resist removal process to obtain a single independent device with a patterned top electrode layer.

[0057] In one specific embodiment, when etching using photolithography, the W top electrode layer is etched using a mixed gas of SF6 and Ar with a power of 300W, an SF6 flow rate of 15sccm, and an Ar flow rate of 9sccm; the related dielectric materials are etched using a mixed gas of BCl3 and Ar with a power of 300W, a BCl3 flow rate of 15sccm, and an Ar flow rate of 9sccm.

[0058] The specific implementation of the graphical top electrode layer 400 is well known to those skilled in the art, and will not be described in detail here.

[0059] Furthermore, in this embodiment, step S5 involves annealing to obtain a locally modulated antiferroelectric capacitor.

[0060] Specifically, in this embodiment, the annealing temperature is 350~650℃, the atmosphere is oxygen, nitrogen or a mixture of nitrogen and hydrogen, and the time is 1~60min.

[0061] In one specific embodiment, the annealing temperature is 450°C, the annealing atmosphere is a mixture of N2 and H2, and the annealing time is 30 min.

[0062] The method for fabricating a locally modulated antiferroelectric capacitor provided in this embodiment achieves coordinated control of local stress, defect distribution, and built-in electric field by constructing a local modulation layer of discontinuous oxides inside the antiferroelectric thin film layer, thereby improving the energy storage density, energy storage efficiency, and device reliability of the antiferroelectric capacitor.

[0063] Furthermore, this embodiment also provides an electronic device, including the antiferroelectric capacitor described above.

[0064] In practical applications, this electronic device can specifically be an on-chip energy storage capacitor. Furthermore, it can be used in wireless sensor networks, biomedical electronics, embedded microsystems, and more.

[0065] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Similar or identical parts between embodiments can be referred to mutually. In addition, different parts between embodiments can also be combined with each other, and this invention does not limit this.

[0066] The locally modulated antiferroelectric capacitor, its fabrication method, and electronic device provided in this embodiment include a bottom electrode layer, a dielectric layer, and a top electrode layer sequentially disposed on a substrate from bottom to top. The dielectric layer includes an antiferroelectric thin film layer and a locally modulated layer located within the antiferroelectric thin film layer. The locally modulated layer is used to synchronously introduce lattice distortion, oxygen defect redistribution, and local potential changes in the local area of ​​the antiferroelectric thin film layer by utilizing the differences in ionic radius, valence state, and / or bonding characteristics between the ions and the ions in the antiferroelectric thin film layer. This allows for the coordinated control of the stress state, defect distribution, and built-in electric field of the antiferroelectric thin film layer, thereby optimizing phase stability, phase transition barrier, and breakdown behavior, improving the energy storage density, energy storage efficiency, and device reliability of the antiferroelectric capacitor, and solving the problem of how to maintain a high antiferroelectric polarization capability of the antiferroelectric capacitor while increasing the breakdown field strength.

[0067] The above description is merely a description of preferred embodiments of the present invention and is not intended to limit the scope of the present invention in any way. Any changes or modifications made by those skilled in the art based on the above disclosure shall fall within the protection scope of the claims.

Claims

1. A locally modulated antiferroelectric capacitor, characterized in that, The substrate comprises a bottom electrode layer, a dielectric layer, and a top electrode layer disposed sequentially from bottom to top on a substrate; the dielectric layer includes an antiferroelectric thin film layer and a local modulation layer located in the antiferroelectric thin film layer; the local modulation layer is used to synchronously introduce lattice distortion, oxygen defect redistribution, and local potential changes in the local area of ​​the antiferroelectric thin film layer by utilizing the differences in ionic radius, valence state, and / or bonding characteristics between the ions and the ions in the antiferroelectric thin film layer, so as to coordinately regulate the stress state, defect distribution, and built-in electric field of the antiferroelectric thin film layer.

2. The locally modulated antiferroelectric capacitor according to claim 1, characterized in that, An insulating layer is also provided between the substrate and the bottom electrode layer.

3. The locally modulated antiferroelectric capacitor according to claim 1, characterized in that, The bottom electrode layer is made of one or more of TiN, W, Mo, Ni, and Ru; the top electrode layer is made of one or more of TiN, W, Mo, Ni, and Ru.

4. The locally modulated antiferroelectric capacitor according to claim 1, characterized in that, The antiferroelectric thin film layer is made of ZrO2; the local modulation layer is made of one or more of SrO, TiO2, SnO2, In2O3, Ga2O3, ZnO, MgO, Ta2O5, Y2O3, and Al2O3.

5. The locally modulated antiferroelectric capacitor according to claim 1, characterized in that, The thickness of the antiferroelectric thin film layer is 5~30nm; the thickness of the bottom electrode layer is 30~150nm; and the thickness of the top electrode layer is 30~150nm.

6. The locally modulated antiferroelectric capacitor according to claim 1, characterized in that, The localized modulation layers are discontinuously inserted into the antiferroelectric thin film layer.

7. A method for preparing a locally modulated antiferroelectric capacitor, used to manufacture the locally modulated antiferroelectric capacitor as described in any one of claims 1 to 6, characterized in that, The preparation method includes: Provide substrate; A bottom electrode layer is formed on the substrate surface; A dielectric layer is formed on the surface of the bottom electrode layer using atomic layer deposition technology; A top electrode layer is formed on the surface of the dielectric layer; Annealing is performed to obtain a locally modulated antiferroelectric capacitor.

8. The method for preparing a locally modulated antiferroelectric capacitor according to claim 7, characterized in that, Before forming the bottom electrode layer on the substrate surface, the fabrication method further includes: An insulating layer is formed on the substrate surface.

9. The method for preparing a locally modulated antiferroelectric capacitor according to claim 7, characterized in that, The method for forming a dielectric layer on the surface of the bottom electrode layer using atomic layer deposition includes: The cycle ratio and sequence of the atomic layer deposition process are determined based on the target location and local target concentration of the local modulation layer. Following a defined cycle ratio and sequence, an antiferroelectric thin film layer and a localized modulation layer are prepared using atomic layer deposition (ALD) to obtain a dielectric layer.

10. The method for preparing a locally modulated antiferroelectric capacitor according to claim 7, characterized in that, The annealing temperature is 350~650℃, the atmosphere is oxygen, nitrogen or a mixture of nitrogen and hydrogen, and the time is 1~60min.

11. An electronic device, characterized in that, Including the locally modulated antiferroelectric capacitor as described in any one of claims 1 to 6.

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