Hafnium-based ferroelectric capacitor based on island-like metal layer and method of manufacturing the same
By introducing an island-shaped metal layer structure into hafnium-based ferroelectric capacitors, the performance deficiencies of hafnium-based ferroelectric materials are solved, achieving a more stable polarization state and faster polarization reversal, thereby improving the data retention capability and durability of ferroelectric capacitors.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- FUDAN UNIVERSITY
- Filing Date
- 2026-01-27
- Publication Date
- 2026-06-02
AI Technical Summary
Existing ferroelectric capacitors based on hafnium-based ferroelectric materials suffer from insufficient retention characteristics, high operating voltage, durability degradation, and randomness in polarization domain nucleation and growth. Existing solutions have limited effectiveness.
The structure adopts an island-shaped metal layer design, which includes forming discontinuous island-shaped metal layers between hafnium-based ferroelectric layers, and crystallizing the material through rapid thermal annealing to form a five-layer superlattice capacitor structure.
It effectively shields the depolarization electric field, enhances the stability of the polarization state, prolongs the data retention time, reduces the polarization reversal energy barrier, and improves the ferroelectric domain reversal speed and durability.
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Figure CN122138427A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of semiconductor device technology, and in particular to a hafnium-based ferroelectric capacitor based on an island-shaped metal layer, its preparation method, and a ferroelectric random access memory. Background Technology
[0002] Ferroelectric random access memory (FRAM) is widely used in various small devices due to its advantages such as non-volatility, high-speed read / write, and low power consumption. Among them, hafnium-based ferroelectric materials, represented by hafnium oxide doping, have become a research hotspot in the field of FRAM due to their excellent compatibility with CMOS technology.
[0003] However, ferroelectric capacitors based on hafnium-based ferroelectric materials still face several key challenges in practical applications: ferroelectric capacitors based on hafnium-based ferroelectric materials have insufficient retention characteristics due to internal depolarization fields and external disturbances, and the high operating voltage is caused by high coercivity fields; moreover, ferroelectric capacitors based on hafnium-based ferroelectric materials experience durability degradation after repeated read-write cycles; in addition, the nucleation and growth process of polarization domains in ferroelectric capacitors is random, leading to bottlenecks in switching speed and other issues.
[0004] Currently, to address the aforementioned shortcomings of ferroelectric capacitors based on hafnium-based ferroelectric materials, the focus is typically on intrinsic material doping optimization or interface engineering. However, existing solutions have limited effectiveness in improving the performance of ferroelectric capacitors based on hafnium-based ferroelectric materials, thus limiting their application. Summary of the Invention
[0005] The purpose of this invention is to provide a hafnium-based ferroelectric capacitor based on an island-shaped metal layer, a method for its preparation, and a ferroelectric random access memory, in order to solve the problem of how to improve the performance of ferroelectric capacitors based on hafnium-based ferroelectric materials.
[0006] To address the aforementioned technical problems, this invention provides a method for fabricating a hafnium-based ferroelectric capacitor based on an island-shaped metal layer, comprising: Provide substrate; A lower electrode is formed on the substrate; A first hafnium-based ferroelectric layer is formed on the lower electrode; An island-shaped metal layer is formed on the first hafnium-based ferroelectric layer, the island-shaped metal layer comprising multiple discontinuous island-shaped metal structures; A second hafnium-based ferroelectric layer is formed on the island-shaped metal layer; An upper electrode is formed on the second hafnium-based ferroelectric layer; Rapid thermal annealing is performed to allow the hafnium-based ferroelectric material in the first and second hafnium-based ferroelectric layers to crystallize.
[0007] Optionally, in the method for fabricating the hafnium-based ferroelectric capacitor based on the island-shaped metal layer, the material of the lower electrode is one or more of TiN, W, Ru, and Pt, and the thickness of the lower electrode is not less than 3 nm; the material of the upper electrode is one or more of TiN, W, Ru, and Pt, and the thickness of the upper electrode is not less than 3 nm.
[0008] Optionally, in the method for fabricating the hafnium-based ferroelectric capacitor based on the island-shaped metal layer, the method for forming the first hafnium-based ferroelectric layer on the lower electrode includes: Hafnium-based ferroelectric materials were deposited using atomic layer deposition (ALD) to form the first hafnium-based ferroelectric layer. The ALD temperature was 250°C to 350°C and the atmosphere was nitrogen.
[0009] Optionally, in the method for preparing the hafnium-based ferroelectric capacitor based on the island-shaped metal layer, the material of the first hafnium-based ferroelectric layer is Zr-doped HfO2, Si-doped HfO2, Al-doped HfO2, or La-doped HfO2; the thickness of the first hafnium-based ferroelectric layer is 3 nm to 10 nm.
[0010] Optionally, in the method for fabricating the hafnium-based ferroelectric capacitor based on the island-shaped metal layer, the method for forming the island-shaped metal layer on the first hafnium-based ferroelectric layer includes: A metallic precursor is formed on the first hafnium-based ferroelectric layer using atomic layer deposition or physical vapor deposition. Rapid thermal annealing or laser annealing is performed to dewetting and agglomerate the metal precursor, forming a discontinuous island-like metal structure, thus obtaining an island-like metal layer.
[0011] Optionally, in the method for preparing the hafnium-based ferroelectric capacitor based on the island-shaped metal layer, the metal precursor is made of metal, metal oxide or metal nitride, and the thickness of the metal precursor is 0.2 nm to 1.5 nm.
[0012] Optionally, in the method for preparing the hafnium-based ferroelectric capacitor based on the island-shaped metal layer, the rapid thermal annealing temperature for forming the discontinuous island-shaped metal structure is 300℃~400℃, the time is 5s~120s, and the atmosphere is an oxygen-containing gas or an inert gas.
[0013] Optionally, in the method for fabricating the hafnium-based ferroelectric capacitor based on the island-shaped metal layer, the method for forming a second hafnium-based ferroelectric layer on the island-shaped metal layer includes: Hafnium-based ferroelectric materials were deposited using atomic layer deposition (ALD) to form a second hafnium-based ferroelectric layer. The ALD temperature was 250°C to 350°C and the atmosphere was nitrogen.
[0014] Optionally, in the method for preparing the hafnium-based ferroelectric capacitor based on the island-shaped metal layer, the material of the second hafnium-based ferroelectric layer is Zr-doped HfO2, Si-doped HfO2, Al-doped HfO2, or La-doped HfO2; the thickness of the second hafnium-based ferroelectric layer is 3 nm to 10 nm.
[0015] Optionally, in the method for preparing the hafnium-based ferroelectric capacitor based on the island-shaped metal layer, the rapid thermal annealing temperature for crystallizing the hafnium-based ferroelectric material in the first and second hafnium-based ferroelectric layers is 500℃~700℃, and the time is 30s~120s.
[0016] To solve the above-mentioned technical problems, the present invention also provides a hafnium-based ferroelectric capacitor based on an island-shaped metal layer, which is manufactured using the preparation method of a hafnium-based ferroelectric capacitor based on an island-shaped metal layer as described in any of the above claims. The hafnium-based ferroelectric capacitor based on an island-shaped metal layer includes a substrate, a lower electrode, a first hafnium-based ferroelectric layer, an island-shaped metal layer, a second hafnium-based ferroelectric layer, and an upper electrode arranged sequentially from bottom to top.
[0017] To address the aforementioned technical problems, the present invention also provides a ferroelectric random access memory, including a hafnium-based ferroelectric capacitor based on an island-shaped metal layer as described above.
[0018] This invention provides a hafnium-based ferroelectric capacitor based on island-shaped metal layers, its fabrication method, and a ferroelectric random access memory, comprising: providing a substrate; forming a lower electrode on the substrate; forming a first hafnium-based ferroelectric layer on the lower electrode; forming an island-shaped metal layer on the first hafnium-based ferroelectric layer, the island-shaped metal layer comprising multiple discontinuous island-shaped metal structures; forming a second hafnium-based ferroelectric layer on the island-shaped metal layer; forming an upper electrode on the second hafnium-based ferroelectric layer; and performing rapid thermal annealing to crystallize the hafnium-based ferroelectric material in the first and second hafnium-based ferroelectric layers. By forming island-shaped metal layers to constitute a five-layer superlattice capacitor structure, not only can the depolarization electric field inside the ferroelectric layer be effectively shielded, enhancing the stability of the polarization state and extending the data retention time, but the nucleation energy barrier of ferroelectric domains can also be significantly reduced, and polarization reversal can be completed rapidly under a lower applied electric field, thus solving the problem of how to improve the performance of ferroelectric capacitors based on hafnium-based ferroelectric materials. Attached Figure Description
[0019] Figure 1 A flowchart illustrating the fabrication method of the hafnium-based ferroelectric capacitor based on an island-shaped metal layer provided in this embodiment; Figures 2(A) to 2(G) are schematic diagrams of the capacitor structure in each step of the preparation method of the hafnium-based ferroelectric capacitor based on the island metal layer provided in this embodiment; Figure 3This is a schematic diagram of the structure of a hafnium-based ferroelectric capacitor based on an island-shaped metal layer provided in this embodiment; The labels in the accompanying drawings are explained as follows: 100 - Substrate; 110 - Lower electrode; 120 - First hafnium-based ferroelectric layer; 130 - Metal precursor; 140 - Island metal layer; 141 - Island metal structure; 150 - Second hafnium-based ferroelectric layer; 160 - Upper electrode. Detailed Implementation
[0020] The following detailed description, in conjunction with the accompanying drawings and specific embodiments, provides a further detailed account of the hafnium-based ferroelectric capacitor based on an island-shaped metal layer, its fabrication method, and the ferroelectric random access memory proposed in this invention. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, intended only to facilitate and clarify the illustration of the embodiments of the present invention. Furthermore, the structures shown in the drawings are often part of the actual structures. In particular, different proportions may be used in different drawings to emphasize different aspects.
[0021] 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.
[0022] This embodiment provides a method for fabricating a hafnium-based ferroelectric capacitor based on an island-shaped metal layer, such as... Figure 1 As shown, it includes: S1 provides the substrate; S2, forming the lower electrode on the substrate; S3, forming a first hafnium-based ferroelectric layer on the lower electrode; S4, forming an island-shaped metal layer on the first hafnium-based ferroelectric layer, the island-shaped metal layer comprising a plurality of discontinuous island-shaped metal structures; S5, a second hafnium-based ferroelectric layer is formed on the island-shaped metal layer; S6, an upper electrode is formed on the second hafnium-based ferroelectric layer; S7, rapid thermal annealing is performed to crystallize the hafnium-based ferroelectric material in the first and second hafnium-based ferroelectric layers.
[0023] The method for fabricating a hafnium-based ferroelectric capacitor based on island-shaped metal layers provided in this embodiment forms a five-layer superlattice capacitor structure by creating island-shaped metal layers. This not only effectively shields the depolarization electric field inside the ferroelectric layer, enhancing the stability of the polarization state and extending the data retention time, but also significantly reduces the nucleation energy barrier of ferroelectric domains. Polarization reversal can be completed quickly under a lower applied electric field, thus solving the problem of how to improve the performance of ferroelectric capacitors based on hafnium-based ferroelectric materials.
[0024] The following uses a planar capacitor as an example to illustrate the specific implementation of the method for fabricating a hafnium-based ferroelectric capacitor based on an island-shaped metal layer provided in this embodiment.
[0025] Specifically, in this embodiment, step S1 involves providing a substrate.
[0026] In practical applications, as shown in Figure 2(A), a substrate 100 is provided. The substrate 100 can specifically be a silicon substrate, etc., and this application does not limit this. Furthermore, other structures and circuits can also be formed in the substrate 100, and this application also does not limit this.
[0027] Furthermore, in this embodiment, step S2 involves forming a lower electrode on the substrate.
[0028] In practical applications, as shown in Figure 2(B), a lower electrode 110 can be formed on the substrate 100 using processes such as atomic layer deposition. The material of the lower electrode 110 is one or more of TiN, W, Ru, and Pt, and the thickness of the lower electrode 110 is not less than 3 nm, for example, 10 nm.
[0029] The specific implementation process for forming the lower electrode 110 can use the existing process for forming the lower electrode of a capacitor, which will not be described in detail here.
[0030] Furthermore, in this embodiment, step S3 involves forming a first hafnium-based ferroelectric layer on the lower electrode.
[0031] Specifically, in this embodiment, as shown in FIG2(C), an atomic layer deposition process is used to deposit hafnium-based ferroelectric material on the lower electrode 110 to form a first hafnium-based ferroelectric layer 120, wherein the atomic layer deposition temperature is 250℃~350℃ and the atmosphere is nitrogen.
[0032] In practical applications, the hafnium-based ferroelectric material, namely the first hafnium-based ferroelectric layer 120, can be made of Zr-doped HfO2, Si-doped HfO2, Al-doped HfO2, or La-doped HfO2. The thickness of the first hafnium-based ferroelectric layer 120 is 3 nm to 10 nm.
[0033] In one specific embodiment, when the material of the first hafnium-based ferroelectric layer 120 is Zr-doped HfO2, the Zr doping concentration can be approximately 50%, for example, 40% to 60%; when the material of the first hafnium-based ferroelectric layer 120 is Si or Al-doped HfO2, the Si or Al doping concentration can be approximately 3%, for example, 2.4% to 3.6%; when the material of the first hafnium-based ferroelectric layer 120 is La-doped HfO2, the La doping concentration can be approximately 10%, for example, 8% to 12%.
[0034] Furthermore, in this embodiment, in step S4, an island-shaped metal layer is formed on the first hafnium-based ferroelectric layer, the island-shaped metal layer comprising a plurality of discontinuous island-shaped metal structures.
[0035] Specifically, in this embodiment, firstly, as shown in Figure 2(D), an atomic layer deposition (ALD) or physical vapor deposition (PVD) process is used to form a metal precursor 130 on the first hafnium-based ferroelectric layer 120. In practical applications, the metal used for deposition can be materials such as Pt, Ru, or Ir. Using ALD or PVD, a metal precursor 130 with a sub-nanometer thickness is formed, for example, a thickness of 0.2 nm to 1.5 nm. Depending on the atmosphere used in the deposition process, the material of the formed metal precursor 130 can be a metal, a metal oxide, or a metal nitride.
[0036] Then, as shown in Figure 2(E), a rapid thermal annealing process is performed to dewetting and agglomerate the metal precursor 130, forming a discontinuous island-like metal structure 141, resulting in an island-like metal layer 140. In practical applications, the rapid thermal annealing temperature in this step is 300℃~400℃, the time is 5s~120s, and the atmosphere is an oxygen-containing gas or an inert gas. Of course, in other embodiments, laser annealing can be used instead of rapid thermal annealing.
[0037] Furthermore, in this embodiment, step S5 involves forming a second hafnium-based ferroelectric layer on the island-shaped metal layer.
[0038] Specifically, in this embodiment, as shown in Figure 2(F), an atomic layer deposition process is used to deposit hafnium-based ferroelectric material on the island-shaped metal layer 140 to form a second hafnium-based ferroelectric layer 150. The atomic layer deposition temperature is 250°C to 350°C, and the atmosphere is nitrogen.
[0039] In practical applications, the hafnium-based ferroelectric material, i.e., the second hafnium-based ferroelectric layer 150, can be made of Zr-doped HfO2, Si-doped HfO2, Al-doped HfO2, or La-doped HfO2. The thickness of the second hafnium-based ferroelectric layer 150 is 3 nm to 10 nm.
[0040] In one specific embodiment, when the material of the second hafnium-based ferroelectric layer 150 is Zr-doped HfO2, the Zr doping concentration can be approximately 50%, for example, 40% to 60%; when the material of the first hafnium-based ferroelectric layer 120 is Si or Al-doped HfO2, the Si or Al doping concentration can be approximately 3%, for example, 2.4% to 3.6%; when the material of the first hafnium-based ferroelectric layer 120 is La-doped HfO2, the La doping concentration can be approximately 10%, for example, 8% to 12%.
[0041] Preferably, in order to simplify the process, reduce the process complexity, and improve the process yield and manufacturing efficiency, in this embodiment, the material and thickness of the second hafnium-based ferroelectric layer 150 are the same as those of the first hafnium-based ferroelectric layer 120, so that the second hafnium-based ferroelectric layer 150 can be prepared using the manufacturing process adopted by the first hafnium-based ferroelectric layer 120.
[0042] Furthermore, in this embodiment, step S6 involves forming an upper electrode on the second hafnium-based ferroelectric layer.
[0043] Specifically, in this embodiment, as shown in FIG2(G), an upper electrode 160 can be formed on the second hafnium-based ferroelectric layer 150 using processes such as atomic layer deposition. The upper electrode 160 is made of one or more of TiN, W, Ru, and Pt, and the thickness of the upper electrode 160 is not less than 3 nm, for example, 10 nm.
[0044] The specific implementation process for forming the upper electrode 160 can use the existing process for forming the upper electrode of a capacitor, which will not be described in detail here.
[0045] Preferably, in order to simplify the process, reduce the process complexity, and improve the process yield and manufacturing efficiency, in this embodiment, the material and thickness of the upper electrode 160 are the same as those of the lower electrode 110, so that the upper electrode 160 can be prepared using the manufacturing process adopted by the lower electrode 110.
[0046] Furthermore, in this embodiment, step S7 involves performing rapid thermal annealing to crystallize the hafnium-based ferroelectric material in the first and second hafnium-based ferroelectric layers.
[0047] Specifically, in this embodiment, the rapid thermal annealing temperature is 500℃~700℃, and the time is 30s~120s, to ensure the crystallization of the hafnium-based ferroelectric material in the first hafnium-based ferroelectric layer 120 and the second hafnium-based ferroelectric layer 150.
[0048] Of course, those skilled in the art can learn, based on the above-described planar capacitor preparation method, how to manufacture capacitors with other structures such as three-dimensional columnar capacitors or three-dimensional trench capacitors using the hafnium-based ferroelectric capacitor preparation method based on island metal layers provided in this application. This application will not elaborate further on this.
[0049] The method for fabricating a hafnium-based ferroelectric capacitor based on an island-shaped metal layer provided in this embodiment utilizes a discontinuous island-shaped metal structure as an intermediate metal layer. This island-shaped metal structure acts as a nano-floating gate, thereby using electrostatic induction to store mirror charges opposite to the polarization charges of adjacent ferroelectric layers. This effectively shields the depolarization electric field within the ferroelectric layer, enhancing the stability of the polarization state and extending data retention time. Simultaneously, the edges of the island-shaped metal structure exhibit an electric field enhancement effect. Under an applied voltage, this is equivalent to pre-implanting numerous high-field "trigger points" within the ferroelectric layer, which not only lowers the nucleation energy barrier of the ferroelectric domains... The polarization reversal is significantly reduced, enabling it to occur under lower applied electric fields. Furthermore, the high local electric field accelerates domain wall movement, shortening the polarization reversal switching time. The island-like metal structure provides a deterministic nucleation and growth path for ferroelectric domain reversals, ensuring that each reversal preferentially begins at a fixed position on the edge of the island-like metal structure and extends along a defined direction, avoiding the accumulation of lattice damage caused by random nucleation. Additionally, the large interfacial dipole formed at the interface between the island-like metal structure and the ferroelectric material contributes additional polarizability under alternating electric fields, increasing the overall effective dielectric constant of the capacitor. Thus, the data retention characteristics of ferroelectric capacitors are significantly improved, their coercive electric field is reduced, their durability is enhanced, and their ferroelectric reversal speed is accelerated.
[0050] This embodiment also provides a hafnium-based ferroelectric capacitor based on an island-shaped metal layer, which is manufactured using the method described above for preparing a hafnium-based ferroelectric capacitor based on an island-shaped metal layer. Figure 3 As shown, the hafnium-based ferroelectric capacitor based on the island metal layer includes a substrate 100, a lower electrode 110, a first hafnium-based ferroelectric layer 120, an island metal layer 140, a second hafnium-based ferroelectric layer 150, and an upper electrode 160 arranged sequentially from bottom to top.
[0051] Specifically, in this embodiment, the lower electrode 110 is made of one or more of TiN, W, Ru, and Pt; the thickness of the lower electrode 110 is not less than 3 nm. The first hafnium-based ferroelectric layer 120 is made of Zr-doped HfO2, Si-doped HfO2, Al-doped HfO2, or La-doped HfO2; the thickness of the first hafnium-based ferroelectric layer 120 is 3 nm to 10 nm. The island-shaped metal layer 140 is made of metal, metal oxide, or metal nitride. The second hafnium-based ferroelectric layer 150 is made of Zr-doped HfO2, Si-doped HfO2, Al-doped HfO2, or La-doped HfO2; the thickness of the second hafnium-based ferroelectric layer 150 is 3 nm to 10 nm. The upper electrode 160 is made of one or more of TiN, W, Ru, and Pt, and the thickness of the upper electrode 160 is not less than 3 nm.
[0052] Preferably, in this embodiment, the material and thickness of the lower electrode 110 are the same as those of the upper electrode 160. The material and thickness of the first hafnium-based ferroelectric layer 120 are the same as those of the second hafnium-based ferroelectric layer 150.
[0053] Furthermore, this embodiment also provides a ferroelectric random access memory, including the hafnium-based ferroelectric capacitor based on the island metal layer as described above.
[0054] 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.
[0055] This embodiment provides a hafnium-based ferroelectric capacitor based on island-shaped metal layers, its fabrication method, and a ferroelectric random access memory, comprising: providing a substrate; forming a lower electrode on the substrate; forming a first hafnium-based ferroelectric layer on the lower electrode; forming an island-shaped metal layer on the first hafnium-based ferroelectric layer, the island-shaped metal layer comprising multiple discontinuous island-shaped metal structures; forming a second hafnium-based ferroelectric layer on the island-shaped metal layer; forming an upper electrode on the second hafnium-based ferroelectric layer; and performing rapid thermal annealing to crystallize the hafnium-based ferroelectric material in the first and second hafnium-based ferroelectric layers. By forming island-shaped metal layers to constitute a five-layer superlattice capacitor structure, not only can the depolarization electric field inside the ferroelectric layer be effectively shielded, enhancing the stability of the polarization state and extending the data retention time, but the nucleation energy barrier of ferroelectric domains can also be significantly reduced, and polarization reversal can be completed rapidly under a lower applied electric field, solving the problem of how to improve the performance of ferroelectric capacitors based on hafnium-based ferroelectric materials.
[0056] 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 method for fabricating a hafnium-based ferroelectric capacitor based on an island-shaped metal layer, characterized in that, include: Provide substrate; A lower electrode is formed on the substrate; A first hafnium-based ferroelectric layer is formed on the lower electrode; An island-shaped metal layer is formed on the first hafnium-based ferroelectric layer, the island-shaped metal layer comprising multiple discontinuous island-shaped metal structures; A second hafnium-based ferroelectric layer is formed on the island-shaped metal layer; An upper electrode is formed on the second hafnium-based ferroelectric layer; Rapid thermal annealing is performed to allow the hafnium-based ferroelectric material in the first and second hafnium-based ferroelectric layers to crystallize.
2. The method for preparing a hafnium-based ferroelectric capacitor based on an island-shaped metal layer according to claim 1, characterized in that, The lower electrode is made of one or more of TiN, W, Ru, and Pt, and its thickness is not less than 3 nm; the upper electrode is made of one or more of TiN, W, Ru, and Pt, and its thickness is not less than 3 nm.
3. The method for preparing a hafnium-based ferroelectric capacitor based on an island-shaped metal layer according to claim 1, characterized in that, The method for forming a first hafnium-based ferroelectric layer on the lower electrode includes: Hafnium-based ferroelectric materials were deposited using atomic layer deposition (ALD) to form the first hafnium-based ferroelectric layer. The ALD temperature was 250°C to 350°C and the atmosphere was nitrogen.
4. The method for preparing a hafnium-based ferroelectric capacitor based on an island-shaped metal layer according to claim 1, characterized in that, The first hafnium-based ferroelectric layer is made of Zr-doped HfO2, Si-doped HfO2, Al-doped HfO2, or La-doped HfO2; the thickness of the first hafnium-based ferroelectric layer is 3 nm to 10 nm.
5. The method for preparing a hafnium-based ferroelectric capacitor based on an island-shaped metal layer according to claim 1, characterized in that, The method for forming an island-shaped metal layer on the first hafnium-based ferroelectric layer includes: A metallic precursor is formed on the first hafnium-based ferroelectric layer using atomic layer deposition or physical vapor deposition. Rapid thermal annealing or laser annealing is performed to dewetting and agglomerate the metal precursor, forming a discontinuous island-like metal structure, thus obtaining an island-like metal layer.
6. The method for preparing a hafnium-based ferroelectric capacitor based on an island-shaped metal layer according to claim 5, characterized in that, The metal precursor is made of metal, metal oxide, or metal nitride, and the thickness of the metal precursor is 0.2 nm to 1.5 nm.
7. The method for preparing a hafnium-based ferroelectric capacitor based on an island-shaped metal layer according to claim 5, characterized in that, The rapid thermal annealing used to form discontinuous island-like metal structures is performed at a temperature of 300℃~400℃ for 5s~120s in an atmosphere containing oxygen or an inert gas.
8. The method for preparing a hafnium-based ferroelectric capacitor based on an island-shaped metal layer according to claim 1, characterized in that, The method for forming a second hafnium-based ferroelectric layer on an island-shaped metal layer includes: Hafnium-based ferroelectric materials were deposited using atomic layer deposition (ALD) to form a second hafnium-based ferroelectric layer. The ALD temperature was 250°C to 350°C and the atmosphere was nitrogen.
9. The method for preparing a hafnium-based ferroelectric capacitor based on an island-shaped metal layer according to claim 1, characterized in that, The material of the second hafnium-based ferroelectric layer is Zr-doped HfO2, Si-doped HfO2, Al-doped HfO2, or La-doped HfO2; the thickness of the second hafnium-based ferroelectric layer is 3 nm to 10 nm.
10. The method for preparing a hafnium-based ferroelectric capacitor based on an island-shaped metal layer according to claim 1, characterized in that, The rapid thermal annealing temperature for crystallizing the hafnium-based ferroelectric material in the first and second hafnium-based ferroelectric layers is 500℃~700℃, and the time is 30s~120s.
11. A hafnium-based ferroelectric capacitor based on an island-shaped metal layer, manufactured using the method for preparing a hafnium-based ferroelectric capacitor based on an island-shaped metal layer as described in any one of claims 1 to 10, characterized in that, The hafnium-based ferroelectric capacitor based on an island metal layer includes, from bottom to top, a substrate, a lower electrode, a first hafnium-based ferroelectric layer, an island metal layer, a second hafnium-based ferroelectric layer, and an upper electrode.
12. A ferroelectric random access memory, characterized in that, Including the hafnium-based ferroelectric capacitor based on an island-shaped metal layer as described in claim 11.