Zirconium-lanthanum oxide film anti-ferroelectric capacitor with nonvolatile storage performance and implementation method of zirconium-lanthanum oxide film anti-ferroelectric capacitor

Abstract

The invention discloses a zirconium lanthanum oxide film anti-ferroelectric capacitor with nonvolatile storage performance and an implementation method thereof, the anti-ferroelectric capacitor adopts a metal-insulator-metal sandwich type capacitor structure, and is formed by stacking a silicon substrate, a bottom electrode, an anti-ferroelectric oxide layer and a top electrode. According to the invention, the top electrode material is selected to be aluminum, and a certain work function difference is kept between the top electrode material and the titanium nitride of the bottom electrode, so that lateral deviation of an anti-ferroelectric P-V curve is caused, and a nonvolatile storage function is realized. According to the design, the nonvolatile storage characteristic of the anti-ferroelectric capacitor can be effectively realized, and the process is relatively simple and convenient to realize.

Description

Technical Field

[0001] The invention belongs to the field of semiconductors and integrated circuits, and in particular relates to a zirconium lanthanum oxide thin film antiferroelectric capacitor with non-volatile storage performance and a realization method thereof. Background Art

[0002] Hafnium zirconium oxide (HZO) thin films have been widely used in the field of ferroelectric memory due to their high compatibility with standard CMOS processes and excellent miniaturization characteristics, including ferroelectric random access memory (FeRAM), ferroelectric field effect transistors (FeFET) and ferroelectric tunnel junctions (FTJ) and other devices. With the continuous advancement of semiconductor technology, the demand for high-performance memory is becoming increasingly urgent. HZO thin films have become the focus of research and development due to their excellent electrical properties and stability.

[0003] At present, the mainstream devices on the market are still ferroelectric capacitors. However, hafnium zirconium oxide antiferroelectric capacitors have recently set off a new wave. Although the spontaneous polarization of antiferroelectric materials is zero, antiferroelectric devices can also be used as memory under the action of an external electric field. This bias voltage can be an external electric field or caused by the work function difference between the upper and lower electrode materials. Compared with ferroelectric materials, antiferroelectric materials have a smaller coercive electric field when used as memory, which means that antiferroelectric devices require a lower operating voltage. The lower operating voltage not only makes antiferroelectric devices compatible with advanced CMOS processes, but also improves the reliability of the devices.

[0004] Another major advantage of antiferroelectric devices is their high durability. According to reports, the durability of antiferroelectric devices is as high as This makes them excellent in long-term stability and repeated use. In summary, hafnium zirconium oxide antiferroelectric capacitors not only inherit the advantages of HZO films, but also show significant progress in operating voltage and durability, providing new possibilities for future high-performance memory design.

[0005] However, despite the many advantages of antiferroelectric devices over ferroelectric devices, how to achieve non-volatility in antiferroelectric devices remains a key issue that needs to be addressed. Future research should focus on exploring more effective process improvements and protection measures to ensure the performance of antiferroelectric devices in practical applications. Summary of the invention

[0006] The purpose of the present invention is to provide a zirconium lanthanum oxide thin film antiferroelectric capacitor with non-volatile storage performance and a method for realizing the same, in view of the volatile storage characteristics of existing antiferroelectric devices.

[0007] The object of the present invention is achieved by the following technical solutions: A zirconium lanthanum oxide thin film antiferroelectric capacitor with non-volatile storage performance, which adopts a metal-insulator-metal sandwich-type capacitor structure and is stacked by a silicon substrate, a bottom electrode, an antiferroelectric oxide layer, and a top electrode; the bottom electrode is titanium nitride; the antiferroelectric oxide layer is a zirconium lanthanum oxide thin film layer; according to the work function differences between different metals, the top electrode metal is determined; the selected top electrode metal should be able to generate an additional electric field with the bottom electrode titanium nitride due to the work function difference to realize the shift of the polarization intensity-voltage P-V curve of the antiferroelectric capacitor, thereby realizing non-volatile storage performance.

[0008] Further, the top electrode is aluminum metal. The additional electric field generated by the work function difference between aluminum and titanium nitride can effectively realize the non-volatile characteristics of the antiferroelectric capacitor.

[0009] Further, when aluminum is in close contact with titanium nitride, due to the work function difference qV bias , where q is the electric charge carried by an electron, and the work function of aluminum is less than that of titanium nitride, electrons will flow from aluminum to titanium nitride, forming a built-in electric field V bias in the zirconium lanthanum oxide thin film, thereby realizing the non-volatile storage performance of the antiferroelectric capacitor.

[0010] Further, the antiferroelectric oxide layer is a zirconium lanthanum oxide thin film layer with a thickness of 8 nm deposited by atomic layer deposition, and the element ratio of zirconium to lanthanum is 20:1.

[0011] Further, by applying a triangular wave pulse signal to the zirconium lanthanum oxide thin film, an I-t curve graph of current-time is obtained, and then the polarization intensity P is obtained by integration; through the relationship between polarization intensity-time P-t and voltage-time V-t, a polarization intensity-voltage P-V curve is plotted; the window of the antiferroelectric capacitor device at 0 V can be obtained from the P-V curve.

[0012] The present invention also provides a method for realizing the above-mentioned zirconium lanthanum oxide thin film antiferroelectric capacitor with non-volatile storage performance, including:

[0013] Depositing titanium nitride on the silicon substrate by atomic layer deposition to form a bottom electrode;

[0014] Depositing a zirconium lanthanum oxide thin film layer on the bottom electrode by atomic layer deposition to form an antiferroelectric oxide layer;

[0015] Sputtering and depositing a tungsten electrode on the antiferroelectric oxide layer, and after rapid thermal annealing, removing the tungsten electrode;

[0016] Thermally evaporating and depositing a top electrode on the sample after removing the tungsten electrode, and performing top electrode patterning;

[0017] Growing a back electrode to complete the preparation of the antiferroelectric capacitor.

[0018] Further, the preparation of the bottom electrode is specifically as follows:

[0019] Deposit 10 nm thick titanium nitride (TiN) by atomic layer deposition. Titanium tetrachloride and ammonia are used as the precursor sources of Ti and N respectively, and nitrogen is used as the carrier gas and purge gas. The deposition temperature is 400 °C, the base pressure of the atomic layer deposition chamber for TiN is 100 Pa, and the deposition rate of TiN is 0.02 nm / cycle.

[0020] Further, the preparation of the zirconium lanthanum oxide thin film is specifically as follows:

[0021] Use lanthanum isopropyl cyclopentadienide and zirconium tetrakis(ethylmethylamido) as the precursor materials of LaO 2 and ZrO 2 respectively. Plasma oxygen is used as the reaction gas, and the overall deposition process is plasma-enhanced atomic layer deposition. The growth temperature is 280 °C, the base pressure of the atomic layer deposition chamber for the ZLO thin film is 30 Pa, the deposition rate of ZrO 2 is 0.1 nm / cycle, and the deposition rate of LaO 2 is 0.02 nm / cycle. By adjusting the cycle order and the number of cycles during the deposition of the ZLO thin film, alternate deposition of twenty layers of ZrO 2 and one layer of LaO 2 is achieved, and the total number of deposition times is 84 cycles.

[0022] Further, sputter deposit a tungsten electrode on the antiferroelectric oxide layer, and after rapid thermal annealing, remove the tungsten electrode, specifically as follows:

[0023] Deposit the tungsten electrode: Put the sample on which the zirconium lanthanum oxide thin film has been deposited into the physical vapor deposition chamber. After the chamber pressure is less than 5×10 -4 Pa, introduce argon to adjust the chamber pressure to about 0.5 Pa, and adjust the sputtering power so that tungsten is deposited on the sample at a rate of 2 nm / min. The thickness of the tungsten electrode is 100 nm to ensure that sufficient stress is provided to the ZLO thin film during the annealing crystallization process;

[0024] Rapid thermal annealing: Put the TiN / ZLO / W sample into the rapid thermal annealing chamber, evacuate to a chamber pressure less than 5×10 -2 Pa, then introduce nitrogen into the chamber at a rate of 1 L / min for 1 min, keep the nitrogen flow rate unchanged, quickly heat up to 500 °C, stabilize for 1 min, and then introduce nitrogen at a rate of 30 L / min to quickly cool the sample to 100 °C and then take it out. Vacuum rapid thermal annealing is used, and the vacuum environment can effectively protect the thin film and make the thin film crystallize to form an antiferroelectric phase;

[0025] Removing tungsten electrode: Immerse the sample in a mixed solution of hydrogen peroxide and ammonia water for 40 s, with the ratio of hydrogen peroxide to ammonia water being 20:1; remove the top metal tungsten in the annealed and crystallized Si / TiN / ZLO / W structure to expose the ZLO thin film.

[0026] Further, the deposition and patterning of the top electrode are specifically as follows:

[0027] Top electrode deposition: Deposit the top electrode aluminum by thermal evaporation. Put the sample after removing the tungsten electrode into the physical vapor deposition chamber. After the chamber pressure is less than 5×10 -4 Pa, turn on the thermal evaporation button, adjust the evaporation voltage, deposit aluminum on the sample at a rate of 0.6 nm / min for 30 nm first, and then deposit 100 nm on the sample at a rate of 2 nm / min. The thickness of the aluminum electrode is 130 nm;

[0028] Top electrode lithography: Spin-coat the photoresist AR-P 5350 at a rate of 4000 rpm / s. After spin-coating, pre-bake at 105 °C for 2 min, and then use a contact exposure lithography machine to closely attach the sample to the mask plate with a circular array layout of device patterns; use near-ultraviolet light to expose the area not blocked by the mask plate, dissolve the exposed part with the developer, rinse with deionized water, and dry with a nitrogen gun.

[0029] Etching: Adopt a wet etching process, use a mixed solution of developer and water as the etching solution, with an etching time of 3 min to ensure that the exposed aluminum electrode is completely etched. After etching, immerse the sample in acetone and ultrasonically treat it until the photoresist is completely dissolved, then ultrasonically treat it twice with deionized water to remove the excess acetone, and dry with a nitrogen gun.

[0030] The beneficial effects of the present invention are as follows: First, the present invention can achieve non-volatile storage of the antiferroelectric capacitor. Second, the process steps and device structure adopted by the present invention are simple and will not increase additional costs. Third, the working voltage of the present invention is smaller compared with that of the ferroelectric capacitor, and it has better compatibility with the standard CMOS process. Description of the Drawings

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0032] Figure 1 It is a schematic structural diagram of the zirconium lanthanum oxide thin film antiferroelectric capacitor device in the present invention;

[0033] Figure 2Process preparation flowchart of the zirconium-lanthanum oxide thin film antiferroelectric capacitor device in the present invention;

[0034] Figure 3 MIS structure diagram of aluminum-zirconium lanthanum oxide-titanium nitride in the present invention;

[0035] Figure 4 Graph of the current of the zirconium-lanthanum oxide thin film antiferroelectric capacitor changing with voltage in the present invention;

[0036] Figure 5 Graph of the polarization intensity of the zirconium-lanthanum oxide thin film antiferroelectric capacitor changing with voltage in the present invention. Specific embodiments

[0037] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0038] It should be clear that the described embodiments are only a part of the embodiments of the present application, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts belong to the scope of protection of the present application.

[0039] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the application. The singular forms "a", "the" and "said" used in the embodiments of the present application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0040] Figure 1Schematic diagram of a zirconium lanthanum oxide thin film antiferroelectric capacitor with non-volatile storage performance according to the present invention. A sandwich-type capacitor structure of Metal-insulator-Metal (MIM) is adopted, and this capacitor structure is stacked by a silicon substrate, a bottom electrode, an oxide layer, and a top electrode. In this capacitor structure, heavily doped P-type silicon with a (100) crystal orientation is selected as the substrate material, mainly considering the low resistivity (<0.001 Ω·cm) of heavily doped P-type silicon and its easy formation of ohmic contact with metals such as aluminum, which is convenient for subsequent wiring tests. The bottom electrode uses titanium nitride (TiN) deposited by atomic layer deposition (ALD). TiN can not only provide stress for the ZLO thin film during annealing but also act as a barrier layer to prevent external impurities from diffusing into the ZLO thin film. The oxide layer uses a zirconium lanthanum oxide thin film layer with a thickness of 8 nm deposited by ALD, and the element ratio of zirconium to lanthanum is 20:1; on the ZLO thin film, a tungsten electrode is sputter-deposited to provide sufficient stress for the ZLO thin film during the subsequent annealing crystallization process, improving the antiferroelectricity of the ZLO thin film; then rapid thermal annealing is carried out, and then the tungsten electrode is removed, and then a top electrode aluminum is thermally evaporated and deposited, and the top electrode is patterned.

[0041] Figure 2 The preparation process of a zirconium lanthanum oxide thin film antiferroelectric capacitor with non-volatile storage performance mainly includes the following steps:

[0042] (1) Bottom electrode deposition

[0043] Before depositing the bottom electrode, the silicon substrate is cleaned to remove residual organic substances, metal ions, etc. on the surface to improve the quality of subsequent thin film deposition. The cleaning steps are as follows:

[0044] a) Cleaning with acetone solution: Immerse the substrate in acetone solution at room temperature, ultrasonically clean for 5 min, and then rinse it clean with deionized water. Acetone can effectively remove organic substances on the substrate surface.

[0045] b) Cleaning with diluted hydrofluoric acid (HF) solution: Immerse the substrate in a 2% by volume HF solution for 1 min, and then rinse it clean with deionized water. This step is to remove the natural oxide layer on the silicon substrate surface.

[0046] c) Cleaning with SC-1 solution: Immerse the substrate that has undergone the above cleaning process in SC-1 solution (NH 4 OH:H 2 O 2 :H 2 O = 1:1:5) at 80 °C for 5 min, and then rinse it clean with deionized water. The SC-1 solution can effectively remove solid particles and organic substances on the substrate surface.

[0047] d) Cleaning with SC-2 solution: Immerse the substrate that has undergone the above cleaning process in an SC-2 solution (HCl:H 2 O 2 :H 2 O = 1:1:6) at 80 °C for 10 min, and then rinse it thoroughly with deionized water. This step is to remove ions and heavy metal particles on the surface of the silicon substrate.

[0048] After the cleaning is completed, dry the substrate with a nitrogen gun, and then prepare for the deposition of TiN. Deposit 10 nm thick TiN by ALD. Titanium tetrachloride (TiCl4) and ammonia are used as the precursor sources of Ti and N respectively, and nitrogen is used as the carrier gas and purge gas. The deposition temperature is about 400 °C, the base pressure of the ALD deposition chamber for TiN is 100 Pa, and the deposition rate of TiN is about 0.02 nm / cycle.

[0049] (2) Deposition of zirconium lanthanum oxide thin film

[0050] After depositing the bottom electrode TiN, deposit the ZLO thin film. Use isopropylcyclopentadienyl lanthanum and tetrakis(ethylmethylamino)zirconium as the precursor materials of LaO 2 and ZrO 2 respectively. Use plasma oxygen as the reaction gas. The overall deposition process is plasma-enhanced atomic layer deposition. The growth temperature is 280 °C, the base pressure of the ALD deposition chamber for ZLO thin film is 30 Pa, the deposition rate of ZrO 2 is 0.1 nm / cycle, and the deposition rate of LaO 2 is 0.02 nm / cycle; by adjusting the cycle order and the number of cycles during the deposition of the ZLO thin film, achieve the alternate deposition of twenty layers of ZrO 2 and one layer of LaO 2 with a total deposition number of 84 cycles.

[0051] (3) Deposition of electrode tungsten (W)

[0052] First, deposit the electrode W by sputtering. Put the sample on which the zirconium lanthanum oxide thin film has been deposited into the physical vapor deposition chamber. After the chamber pressure is less than 5×10 -4 Pa, introduce argon to adjust the chamber pressure to about 0.5 Pa, and adjust the sputtering power so that tungsten is deposited on the sample at a rate of 2 nm / min; the thickness of the tungsten electrode is 100 nm to ensure that sufficient stress is provided to the ZLO thin film during the annealing crystallization process.

[0053] (4) Rapid thermal annealing

[0054] Put the TiN / ZLO / W sample into the rapid thermal annealing chamber and evacuate it until the chamber pressure is less than 5×10-2 After reaching 1 Pa, nitrogen gas (N 2 ) is introduced into the cavity at a rate of 1 L / min for 1 min, and the N 2 flow rate is kept unchanged. Then, the temperature is rapidly raised to 500 °C, and after stabilizing for 1 min, nitrogen gas is introduced at a rate of 30 L / min to rapidly cool the sample to 100 °C, and then the sample is taken out.

[0055] (5) Removal of electrode W

[0056] The sample is immersed in a mixed solution of hydrogen peroxide and ammonia water for 40 s, and the ratio of hydrogen peroxide to ammonia water is 20:1. The top metal tungsten in the annealed and crystallized Si / TiN / ZLO / W structure is removed, and the ZLO thin film is exposed.

[0057] (6) Deposition of top electrode

[0058] For the top electrode aluminum, the thermal evaporation method is used. The sample after removing electrode W is placed in a physical vapor deposition cavity. After the cavity pressure is less than 5×10 -4 Pa, the thermal evaporation button is turned on, and the evaporation voltage is adjusted so that aluminum is first deposited on the sample at a rate of 0.6 nm / min for 30 nm, and then at a rate of 2 nm / min for 100 nm. The thickness of the aluminum electrode is 130 nm.

[0059] (7) Lithography of top electrode

[0060] Photoresist AR-P 5350 is spin-coated at a rate of 4000 rpm / s. After spin-coating, it is pre-baked at a temperature of 105 °C for 2 min. The purpose is to evaporate the solvent in the photoresist and improve the adhesion of the photoresist to the top electrode aluminum. Then, using a contact exposure photolithography machine, the sample is closely attached to a mask plate with a circular array layout of device patterns. The unmasked area is exposed using near-ultraviolet light, and the exposed part is dissolved using the prepared developer solution (AR 300-26:H 2 O = 1:7), rinsed with deionized water, and then dried with a nitrogen gun.

[0061] (8) Etching

[0062] The wet etching process is adopted. A mixed solution of developer AR-300-26 and water is used as the etching solution, and the ratio of developer to water is 1:16. The etching time is 3 min to ensure that the exposed part of the aluminum electrode is completely etched clean.

[0063] (9) Removing photoresist and depositing back electrode

[0064] After etching, the sample was immersed in acetone and ultrasonically treated until the photoresist was completely dissolved. Then it was ultrasonically treated twice with deionized water to remove the excess acetone and dried with a nitrogen gun. A layer of aluminum back electrode was deposited on the back of the silicon substrate by thermal evaporation to form a good ohmic contact.

[0065] Figure 3 This is the energy band structure diagram of the Al-ZrLa oxide-TiN MIM in the present invention, specifically:

[0066] The work function of a metal represents the minimum energy required for an electron with an initial energy equal to the Fermi level E F to escape from inside the metal to the vacuum. When aluminum and titanium nitride are in close contact, due to the work function difference qV bias (q is the electric charge carried by an electron) between aluminum and titanium nitride, and the work function of aluminum is less than that of titanium nitride, electrons will flow from aluminum to titanium nitride. Therefore, a built-in electric field V bias will be formed inside the ZLO film, thus enabling the non-volatile storage performance of the zirconium lanthanum oxide thin film antiferroelectric capacitor.

[0067] Figure 4 This is the graph of the current of the zirconium lanthanum oxide thin film antiferroelectric capacitor in the present invention changing with voltage. The data in the graph shows that compared with ordinary antiferroelectric capacitor devices, when the applied external electric field is removed, no depolarization current is generated, realizing the non-volatile storage function. It can be seen that the work function difference between the top electrode aluminum and the bottom electrode titanium nitride causes a built-in electric field inside the zirconium lanthanum oxide thin film layer, hindering its depolarization.

[0068] Figure 5 This is the graph of the polarization intensity of the zirconium lanthanum oxide thin film antiferroelectric capacitor in the present invention changing with voltage. During the test, by applying a triangular wave pulse signal to the zirconium lanthanum oxide thin film, an I-t curve graph was obtained, and then the polarization intensity P was obtained by integration. The formula is:

[0069]

[0070] where A is the area of the zirconium lanthanum oxide thin film antiferroelectric capacitor.

[0071] Next, through the relationship between polarization intensity - time (P-t) and voltage - time (V-t), a polarization intensity - voltage (P-V) curve can be plotted. It can be seen from the P-V curve that at 0V, this zirconium lanthanum oxide thin film antiferroelectric capacitor device has a window of nearly 20 μC / cm 2 and can realize the non-volatile storage function.

[0072] The above are only the preferred embodiments of one or more embodiments of this specification, and are not intended to limit one or more embodiments of this specification. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of one or more embodiments of this specification shall be included within the scope of protection of one or more embodiments of this specification.

Claims

1. A zirconium lanthanum oxide thin film antiferroelectric capacitor with non-volatile storage performance, characterized in that: A metal-insulator-metal sandwich capacitor structure is adopted, which is stacked by a silicon substrate, a bottom electrode, an antiferroelectric oxide layer, and a top electrode; the bottom electrode is titanium nitride; the antiferroelectric oxide layer is a zirconium lanthanum oxide thin film layer; the top electrode metal is determined according to the work function difference between different metals; The selected top electrode metal should be able to generate an additional electric field with the bottom electrode titanium nitride due to the work function difference, so as to achieve a shift in the polarization intensity-voltage PV curve of the antiferroelectric capacitor, thereby achieving non-volatile storage performance.

2. The zirconium lanthanum oxide thin film antiferroelectric capacitor according to claim 1, characterized in that: The top electrode is metal aluminum, and the additional electric field generated by the work function difference between aluminum and titanium nitride can effectively realize the non-volatile characteristics of the antiferroelectric capacitor.

3. The zirconium lanthanum oxide thin film antiferroelectric capacitor according to claim 2, characterized in that: When aluminum and titanium nitride are in close contact, due to the difference in work function qV between aluminum and titanium nitride, bias , q is the charge carried by an electron. The work function of aluminum is smaller than that of titanium nitride. Electrons will flow from aluminum to titanium nitride, forming a built-in electric field V in the zirconium lanthanum oxide film. bias , thereby achieving the non-volatile storage performance of antiferroelectric capacitors.

4. The zirconium lanthanum oxide thin film antiferroelectric capacitor according to claim 1, characterized in that: The antiferroelectric oxide layer is a zirconium lanthanum oxide thin film layer with a thickness of 8 nm deposited by atomic layer deposition, and the element ratio of zirconium to lanthanum is 20:

1.

5. The zirconium lanthanum oxide thin film antiferroelectric capacitor according to claim 1, characterized in that: By applying a triangular wave pulse signal to the zirconium lanthanum oxide film, the current-time It curve is obtained, and the polarization intensity P is obtained by integration; the polarization intensity-voltage PV curve is plotted through the relationship between the polarization intensity-time Pt ​​and the voltage-time Vt; the window of the antiferroelectric capacitor device at 0V can be obtained from the PV curve.

6. A method for realizing a zirconium lanthanum oxide thin film antiferroelectric capacitor with non-volatile storage performance according to any one of claims 1 to 5, characterized in that: include: A bottom electrode is formed on a silicon substrate by atomic layer deposition of titanium nitride; An antiferroelectric oxide layer is formed on the bottom electrode by atomic layer deposition of a zirconium lanthanum oxide thin film layer; sputtering a tungsten electrode on the antiferroelectric oxide layer, performing rapid thermal annealing, and then removing the tungsten electrode; Depositing a top electrode by thermal evaporation on the sample from which the tungsten electrode has been removed, and patterning the top electrode; Grow the back electrode to complete the preparation of the antiferroelectric capacitor.

7. The method for realizing the antiferroelectric capacitor of zirconium lanthanum oxide thin film according to claim 6, characterized in that: The preparation of the bottom electrode is specifically as follows: Atomic layer deposition of 10 nm thick titanium nitride TiN was used, titanium tetrachloride and ammonia were used as precursor sources of Ti and N respectively, and nitrogen was used as carrier gas and purge gas; the deposition temperature was 400°C, the base pressure of the atomic layer deposition chamber of TiN was 100 Pa, and the deposition rate of TiN was 0.02 nm / cycle.

8. The method for realizing the antiferroelectric capacitor of zirconium lanthanum oxide thin film according to claim 6, characterized in that: The preparation of the zirconium lanthanum oxide film is specifically as follows: Isopropylcyclopentadienyl lanthanum and tetrakis(ethylmethylamino)zirconium are used as precursor materials of LaO2 and ZrO2 respectively, plasma oxygen is used as reaction gas, the overall deposition process is plasma enhanced atomic layer deposition, the growth temperature is 280°C, the base pressure of the atomic layer deposition chamber of the ZLO film is 30Pa, the deposition rate of ZrO2 is 0.1nm / cycle, and the deposition rate of LaO2 is 0.02nm / cycle; by adjusting the cycle order and the number of cycles during the deposition of the ZLO film, twenty layers of ZrO2 and one layer of LaO2 are alternately deposited, and the total number of depositions is 84 cycles.

9. The method for realizing the antiferroelectric capacitor of zirconium lanthanum oxide thin film according to claim 6, characterized in that: The step of sputtering and depositing a tungsten electrode on the antiferroelectric oxide layer, performing rapid thermal annealing, and then removing the tungsten electrode is specifically as follows: Deposition of tungsten electrode: Place the sample with zirconium lanthanum oxide thin film deposition in the physical vapor deposition chamber and wait until the chamber pressure is less than 5×10 -4 After 0.5 Pa, argon gas was introduced to adjust the chamber pressure to about 0.5 Pa, and the sputtering power was adjusted to deposit tungsten on the sample at a rate of 2 nm / min; the thickness of the tungsten electrode was 100 nm to ensure that sufficient stress was provided to the ZLO film during the annealing crystallization process; Rapid thermal annealing: Place the TiN / ZLO / W sample in a rapid thermal annealing chamber and evacuate the chamber until the pressure is less than 5×10 - 2 After Pa, nitrogen was introduced into the chamber at a rate of 1 L / min for 1 min, the nitrogen flow rate was kept constant, and the temperature was quickly raised to 500 °C. After stabilization for 1 min, nitrogen was introduced at a rate of 30 L / min to quickly cool the sample to 100 °C before taking it out; Removing the tungsten electrode: Soak the sample in a mixture of hydrogen peroxide and ammonia for 40 seconds, with the ratio of hydrogen peroxide to ammonia being 20:1; remove the top metal tungsten in the annealed and crystallized Si / TiN / ZLO / W structure to expose the ZLO film.

10. The method for realizing the antiferroelectric capacitor of zirconium lanthanum oxide thin film according to claim 6, characterized in that: The deposition and patterning of the top electrode are specifically as follows: Top electrode deposition: The top electrode aluminum is deposited by thermal evaporation. The sample after removing the tungsten electrode is placed in the physical vapor deposition chamber. When the chamber pressure is less than 5×10 -4 After Pa, turn on the thermal evaporation button and adjust the evaporation voltage so that aluminum is first deposited on the sample at a rate of 0.6nm / min for 30nm, and then at a rate of 2nm / min for 100nm, and the thickness of the aluminum electrode is 130nm; Top electrode photolithography: Spin-coat photoresist AR-P 5350 at a rate of 4000 rpm / s. After spin coating, pre-bake at 105°C for 2 min. Then, use a contact exposure lithography machine to place the sample close to a mask plate with a circular array of device patterns. Use near-ultraviolet light to expose the area not blocked by the mask, use a developer to dissolve the exposed part, rinse with deionized water, and then use a nitrogen gun to blow dry; Etching: A wet etching process was used, using a mixed solution of developer and water as the etching solution. The etching time was 3 minutes to ensure that the exposed aluminum electrode was completely etched. After etching, the sample was immersed in acetone and ultrasonically treated until the photoresist was completely dissolved. Then, the sample was ultrasonically treated twice with deionized water to remove excess acetone, and then dried with a nitrogen gun.

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