HZO ferroelectric film with controllable coercive field, ferroelectric capacitor and preparation method of HZO ferroelectric film

Abstract

The invention relates to an HZO ferroelectric film with a controllable coercive field, a ferroelectric capacitor and a preparation method of the ferroelectric capacitor. The HZO ferroelectric film is provided with at least one microbeam gallium ion implantation region; and the gallium ion injection amount of each micro-beam gallium ion injection region is 1.3 * 10 < 14 >-5.2 * 10 < 14 > ion / cm < 2 >. According to the HZO ferroelectric film with the controllable coercive field provided by the invention, the coercive field of the HZO ferroelectric film can be accurately regulated and controlled by adjusting the gallium ion injection amount in the micro-beam gallium ion injection region, and meanwhile, the high polarization intensity, the structural uniformity and the electrical stability of the ferroelectric film can be maintained. Moreover, different injection amounts of gallium ions are injected into different regions of the HZO ferroelectric film, different coercive fields can be shown in different regions, the HZO ferroelectric film can be applied to a multi-valued memory, and the storage density is greatly improved.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductors, and in particular relates to a HZO ferroelectric film with controllable coercive electric field, a ferroelectric capacitor and a preparation method thereof. Background Art

[0002] With the rapid development of high-tech technologies such as artificial intelligence and the Internet of Things, higher requirements have been placed on the performance, size, and integration of microelectronic devices. In particular, in the face of massive data in the information age, new challenges have been brought to the real-time transmission, storage, and processing of information. Ferroelectric materials are crucial to the development of low-power, high-security, and high-capacity memory due to their unique bistable electric polarization characteristics and excellent properties such as radiation resistance, low power consumption, and fast response speed. In recent years, they have attracted much attention from academia and industry.

[0003] Compared with traditional perovskite ferroelectric materials, the new hafnium oxide-based ferroelectric film not only exhibits an inverse size effect (i.e., the ferroelectric performance increases with decreasing size), but is also perfectly compatible with the existing Si-based standard CMOS process. The unique microscopic isolation band structure ensures ultrafast polarization response speed, showing great application potential in the next generation of non-volatile memory. However, compared with traditional ferroelectric materials, the coercive electric field of hafnium oxide-based ferroelectric films is significantly higher, which brings many challenges to practical applications: first, the high coercive electric field means that the device requires a higher operating voltage, which is easy to cause breakdown failure; second, long-term operation under high electric fields can easily lead to the accumulation of material structural defects, causing the leakage current to increase rapidly, thereby reducing the performance reliability of the device.

[0004] The existing technology can reduce the coercive electric field to a certain extent by conventional doping in hafnium oxide-based ferroelectric films, but it often also weakens the polarization strength. The commonly used Zr-doped hafnium oxide-based ferroelectric films show high residual polarization strength when the doping concentration is about 50%, but they also have the problem of high coercive electric field. Therefore, how to accurately control the coercive electric field of hafnium oxide ferroelectric films while ensuring the stability of ferroelectric properties has become a key scientific and engineering issue to promote the large-scale application of hafnium oxide-based ferroelectric memory. Summary of the invention

[0005] In order to solve the above problems existing in the prior art, the present invention provides a HZO ferroelectric film with controllable coercive electric field, a ferroelectric capacitor and a preparation method thereof. The technical problem to be solved by the present invention is achieved by the following technical solutions:

[0006] A first aspect of the present invention provides a HZO ferroelectric film with controllable coercive electric field, wherein the HZO ferroelectric film has at least one microbeam gallium ion implantation region;

[0007] The gallium ion implantation amount in each microbeam gallium ion implantation area is 1.3×10 14 ~5.2×10 14 ion / cm 2 .

[0008] In an achievable manner, the HZO ferroelectric thin film has a plurality of micro-beam gallium ion implantation regions, and at least two micro-beam gallium ion implantation regions have different gallium ion implantation amounts.

[0009] In an achievable manner, the surface size of each microbeam gallium ion implantation region is less than or equal to 1 mm×1 mm;

[0010] The depth of each microbeam gallium ion implantation region is equal to the thickness of the HZO ferroelectric film.

[0011] In one possible implementation, the HZO ferroelectric thin film includes a plurality of hafnium oxide layers and zirconium oxide layers which are alternated in sequence.

[0012] The second aspect of the present invention provides a HZO ferroelectric capacitor with controllable coercive electric field, comprising a substrate, a first electrode layer, the HZO ferroelectric film provided by the first aspect of the present invention, and a second electrode layer arranged in sequence from bottom to top.

[0013] In one achievable manner, the second electrode layer includes a plurality of sub-electrodes uniformly distributed on the upper surface of the HZO ferroelectric thin film.

[0014] In one achievable manner, the material of the first electrode layer and the second electrode layer includes: one of TiN, TaN, and W.

[0015] A third aspect of the present invention provides a method for preparing a HZO ferroelectric capacitor with a controllable coercive electric field, comprising the following steps:

[0016] S1: preparing a first electrode layer on the upper surface of the substrate;

[0017] S2: preparing a HZO ferroelectric thin film on the upper surface of the first electrode layer;

[0018] S3: Micro-beam gallium ion implantation is performed in the HZO ferroelectric film using a micro-beam gallium ion implantation process to form several micro-beam gallium ion implantation areas; the implantation amount is 1.3×10 14 ~5.2×10 14 ion / cm 2 , and the gallium ion implantation amounts of at least two microbeam gallium ion implantation regions are different;

[0019] S4: preparing a second electrode layer on the upper surface of the HZO ferroelectric thin film.

[0020] In one possible implementation, S2 includes:

[0021] S201: depositing a hafnium oxide layer and a zirconium oxide layer in sequence on the upper surface of the first electrode layer;

[0022] S202: Repeat S201 several times to obtain the HZO ferroelectric thin film.

[0023] In one achievable manner, step S4 further includes step S5:

[0024] The sample obtained in S4 is placed in a rapid annealing furnace and subjected to rapid thermal annealing at a temperature of 400 to 650°C.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The present invention provides a HZO ferroelectric film with controllable coercive electric field. The coercive electric field of the HZO ferroelectric film can be precisely controlled by adjusting the amount of gallium ion implantation in a microbeam gallium ion implantation area. At the same time, the high polarization strength, structural uniformity and electrical stability of the ferroelectric film can be maintained. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic structural diagram of a HZO ferroelectric thin film with controllable coercive electric field provided by an embodiment of the present invention;

[0028] Figure 2 1 is a schematic structural diagram of a HZO ferroelectric capacitor with controllable coercive electric field provided by an embodiment of the present invention;

[0029] Figure 3 It is a process flow chart of a method for preparing a HZO ferroelectric capacitor with controllable coercive electric field provided by an embodiment of the present invention;

[0030] Figure 4 is the hysteresis loop of the HZO ferroelectric capacitor provided in Example 2 measured at a frequency of 1 kHz and a voltage of 3 V;

[0031] Figure 5 is the hysteresis loop of the HZO ferroelectric capacitor provided in Example 3 measured at a frequency of 1 kHz and a voltage of 3 V;

[0032] Figure 6 is the hysteresis loop of the HZO ferroelectric capacitor provided in Example 4 measured at a frequency of 1 kHz and a voltage of 3 V;

[0033] Figure 7 is the hysteresis loop of the HZO ferroelectric capacitor provided in Example 5 measured at a frequency of 1 kHz and a voltage of 3 V;

[0034] Figure 8It is a bar graph of the residual polarization intensity and coercive electric field of the HZO ferroelectric capacitor provided in Example 2, Example 3, Example 4 and Example 5 measured at a frequency of 1 kHz and a voltage of 3 V.

[0035] Reference numerals:

[0036] 1: substrate; 2: first electrode layer; 3: HZO ferroelectric thin film; 4: second electrode layer. DETAILED DESCRIPTION

[0037] The present invention is further described in detail below with reference to specific embodiments, but the embodiments of the present invention are not limited thereto.

[0038] Embodiment 1

[0039] See also Figure 1 , Figure 1 It is a schematic structural diagram of a HZO ferroelectric film with controllable coercive electric field provided in an embodiment of the present invention.

[0040] The first aspect of the present embodiment provides a HZO ferroelectric film with controllable coercive electric field. The HZO ferroelectric film 3 has at least one micro-beam gallium ion implantation region. The gallium ion implantation amount of each micro-beam gallium ion implantation region is 1.3×10 14 ~5.2×10 14 ion / cm 2 .

[0041] In an achievable manner, the HZO ferroelectric thin film 3 has a plurality of micro-beam gallium ion implantation regions, and the gallium ion implantation amounts of at least two micro-beam gallium ion implantation regions are different.

[0042] Specifically, by adjusting the amount of gallium ions injected in the microbeam gallium ion injection area, the coercive electric field of the HZO ferroelectric film can be precisely controlled, and at the same time, the high polarization strength, structural uniformity and electrical stability of the ferroelectric film can be maintained. Through microbeam Ga ion injection, positive ions can be enriched in the HZO film, resulting in lattice distortion and large stress in the film; in addition, the injected Ga ions are easily oxidized during the annealing process to produce charged oxygen vacancies, thereby inducing the generation of a ferroelectric phase and achieving high residual polarization strength and low coercive electric field. When the amount of gallium ions injected is less than 1.3×10 14 ion / cm 2 When the dose is too small, the effect on the film performance is minimal; however, when the gallium ion implantation amount exceeds 5.2×10 14 ion / cm 2Furthermore, according to application requirements, different gallium ion implantation in different regions of the HZO ferroelectric film can show different coercive electric fields in different regions, which can be applied to multi-valued memory, where each region corresponds to a different storage unit window, thereby greatly improving storage density.

[0043] In this embodiment, the surface size of each microbeam gallium ion implantation area is less than or equal to 1mm×1mm. The depth of each microbeam gallium ion implantation area is equal to the thickness of the HZO ferroelectric film. The adjustable range of the coercive electric field of the HZO ferroelectric film 3 is 1.08 to 1.28MV / cm. The HZO ferroelectric film 3 includes a plurality of layers of hafnium oxide layers and zirconium oxide layers that alternate in sequence. In an achievable manner, the gallium ion implantation amounts of multiple microbeam gallium ion implantation areas are different. The number of hafnium oxide layers and zirconium oxide layers is 50 to 70 layers.

[0044] See also Figure 2 , Figure 2 The second aspect of the present embodiment provides a HZO ferroelectric capacitor with a controllable coercive electric field, comprising a substrate 1, a first electrode layer 2, a HZO ferroelectric film 3 provided in the first aspect of the present embodiment, and a second electrode layer 4, which are sequentially arranged from bottom to top.

[0045] In this embodiment, the material of the substrate 1 includes: one of silicon, germanium, gallium oxide, gallium nitride, and gallium arsenide. The material of the first electrode layer 2 and the second electrode layer 4 includes: one of TiN, TaN, and W. The thickness of the first electrode layer 2 is 30 to 50 nm. The second electrode layer 4 includes a plurality of sub-electrodes uniformly distributed on the upper surface of the HZO ferroelectric thin film 3, and the thickness of the second electrode layer 4 is 20 to 40 nm.

[0046] See also Figure 3 , Figure 3 It is a process flow chart of a method for preparing a HZO ferroelectric capacitor with controllable coercive electric field provided in an embodiment of the present invention.

[0047] A third aspect of the present embodiment provides a method for preparing a HZO ferroelectric capacitor with a controllable coercive electric field, comprising the following steps:

[0048] S1: preparing a first electrode layer 2 on the upper surface of the substrate 1.

[0049] Specifically, the material of substrate 1 is one of silicon, germanium, gallium oxide, gallium nitride, and gallium arsenide, preferably a silicon substrate. The substrate 1 is placed in a mixed solution of concentrated sulfuric acid and hydrogen peroxide for cleaning for 10 to 30 minutes to remove metal particles and organic pollutants on the surface of the substrate 1, and then placed in ultrapure water and hydrofluoric acid with a concentration of 0.5 to 1.5% for cleaning for 10 to 30 minutes, and the above operation is repeated 2 to 3 times to avoid defects and impurities as much as possible. On the upper surface of the cleaned substrate 1, a first electrode layer 2 is prepared by magnetron sputtering.

[0050] Furthermore, the substrate 1 is placed in a magnetron sputtering chamber, the chamber is closed, and the chamber is evacuated to a vacuum level less than or equal to 1×10 -8 Torr, set the power of magnetron sputtering deposition to 80-140W, grow 30-50nm thick electrode metal, after the growth is completed, fill to atmospheric pressure, open the chamber, and obtain the first electrode layer 2. In this embodiment, the electrode metal is TiN, TaN or W, preferably W.

[0051] S2 : preparing a HZO ferroelectric thin film 3 on the upper surface of the first electrode layer 2 .

[0052] Specifically, the HZO ferroelectric thin film 3 with a thickness of 9-12 nm is prepared on the upper surface of the first electrode layer 2 by atomic layer deposition.

[0053] In this embodiment, S2 includes:

[0054] S201 : depositing a hafnium oxide layer and a zirconium oxide layer in sequence on the upper surface of the first electrode layer 2 .

[0055] Specifically, the sample obtained in S1 is placed in an atomic layer deposition chamber, the temperature of the atomic layer deposition chamber is set to 250-300° C., and after the temperature parameter reaches a preset value, a hafnium oxide layer and a zirconium oxide layer are sequentially deposited on the upper surface of the first electrode layer 2 .

[0056] S202: Repeat S201 several times to obtain the HZO ferroelectric thin film 3.

[0057] In a feasible manner, S202 is repeated 50 to 70 times to obtain the HZO ferroelectric thin film 3, that is, the HZO ferroelectric thin film 3 is composed of 50 to 70 hafnium oxide layers and 50 to 70 zirconium oxide layers alternately in sequence.

[0058] S3: Using the micro-beam gallium ion implantation process, micro-beam gallium ion implantation is performed in the HZO ferroelectric thin film 3 to form a plurality of micro-beam gallium ion implantation areas; wherein the implantation amount is 1.3×10 14 ~5.2×10 14 ion / cm 2 , and the gallium ion implantation amounts of at least two microbeam gallium ion implantation regions are different.

[0059] Specifically, the upper surface of the HZO ferroelectric film 3 is processed with a metal mask according to the requirements, and several micro-beam gallium ion implantation areas are delineated. Then, the film is placed in the chamber of the gallium ion beam implantation system and evacuated to a vacuum degree of 1×10 -4 ~1×10 - 6 Pa, use electron beam imaging to observe the sample surface, determine the specific location and direction where ion implantation is required, start the ion source, and after the ion source in the system generates a gallium ion beam, it is accelerated and focused by a series of electromagnetic lenses, and the diameter of the gallium ion beam can be focused to the nanometer level; at the same time, the deflection system can accurately guide the gallium ion beam to scan the sample surface by adjusting the voltage or current on the deflection plate, so that the gallium ion beam can be positioned to a specific selected area; the gallium ion beam with adjusted parameters is focused to the selected area, and ion implantation is performed according to the set scanning mode and dose. After completion, it is inflated to atmospheric pressure, the chamber is opened, and the sample after ion implantation is taken out. In this embodiment, the injection amount is 1.3×10 14 ~5.2×10 14 ion / cm 2 The surface size of each micro-beam gallium ion implantation region is less than or equal to 1 mm×1 mm. The depth of each micro-beam gallium ion implantation region is equal to the thickness of the HZO ferroelectric film 3, and the gallium ion implantation amounts of at least two micro-beam gallium ion implantation regions are different.

[0060] S4: preparing a second electrode layer 4 on the upper surface of the HZO ferroelectric thin film 3 .

[0061] Specifically, the sample obtained in S3 was placed in a magnetron sputtering chamber, the chamber was closed, and the vacuum was evacuated to a vacuum degree less than or equal to 1×10 -8 Torr, set the power of magnetron sputtering deposition to 80-140W, grow electrode metal with a thickness of 20-40nm, and after the growth is completed, fill it to atmospheric pressure, open the chamber, and obtain the second electrode layer 4. In this embodiment, the electrode metal is TiN, TaN or W, preferably W.

[0062] In this embodiment, step S4 further includes S5: rapid thermal annealing treatment.

[0063] Specifically, the sample obtained in S4 is placed in a rapid annealing furnace, high-purity nitrogen with a purity of 99.999% is introduced, and rapid thermal annealing is performed, with the temperature rising from room temperature to 400-650°C at a heating rate of 10-30°C / s, and then the temperature is cooled to room temperature at a cooling rate of 100-200°C / s after being kept for 30-180s, to obtain a HZO ferroelectric capacitor.

[0064] Embodiment 2

[0065] Based on the first embodiment, this embodiment provides a HZO ferroelectric film with controllable coercive electric field, a ferroelectric capacitor and a preparation method thereof. In this embodiment, the Ga ion implantation amount of the HZO ferroelectric film is 1.3×10 14 ion / cm 2 The substrate 1 is made of silicon, and the first electrode layer 2 and the second electrode layer 4 are both made of W.

[0066] The method for preparing the ferroelectric capacitor provided in this embodiment includes:

[0067] Step 1: Select silicon as substrate 1 and clean substrate 1. Specifically, place substrate 1 in a mixed solution of concentrated sulfuric acid and hydrogen peroxide for 20 minutes to remove metal particles and organic pollutants on the surface of substrate 1, and then place it in ultrapure water and 1.0% hydrofluoric acid for 20 minutes, and repeat the above operation 3 times. Deposit W on the cleaned substrate 1 by magnetron sputtering to obtain a first electrode layer 2 with a thickness of 40nm, and the power of magnetron sputtering deposition is 100W.

[0068] Step 2: Deposit a HZO ferroelectric thin film 3 on the first electrode layer 2 by atomic layer deposition, with a thickness of 12 nm and a deposition chamber temperature of 270° C.

[0069] Step 3: Cover the HZO ferroelectric film 3 with a metal mask and perform microbeam gallium ion implantation with an implantation volume of 1.3×10 14 ion / cm 2 .

[0070] Step 4: After the ion implantation, W is deposited on the HZO ferroelectric thin film 3 by magnetron sputtering to obtain a second electrode layer 4 with a thickness of 30 nm. The power of the magnetron sputtering deposition is 100 W.

[0071] Step 5: Place the sample obtained in step 4 into a rapid annealing furnace, introduce high-purity nitrogen with a purity of 99.999%, and perform rapid thermal annealing, heating the temperature from room temperature to 550°C at a heating rate of 20°C / s, and then cool it to room temperature at a cooling rate of 150°C / s after keeping it for 30s to obtain a HZO ferroelectric capacitor.

[0072] Embodiment 3

[0073] Based on the second embodiment, this embodiment provides a HZO ferroelectric film with controllable coercive electric field, a ferroelectric capacitor and a preparation method thereof. The difference between this embodiment and the second embodiment is that the Ga ion implantation amount of the HZO ferroelectric film is 2.6×10 14 ion / cm 2 The ferroelectric capacitor and its preparation method are the same as those in the second embodiment and will not be described in detail here.

[0074] Embodiment 4

[0075] Based on the second embodiment, this embodiment provides a HZO ferroelectric film with controllable coercive electric field, a ferroelectric capacitor and a preparation method thereof. The difference between this embodiment and the second embodiment is that the Ga ion implantation amount of the HZO ferroelectric film is 3.9×10 14 ion / cm 2 The ferroelectric capacitor and its preparation method are the same as those in the second embodiment and will not be described in detail here.

[0076] Embodiment 5

[0077] Based on the second embodiment, this embodiment provides a HZO ferroelectric film with controllable coercive electric field, a ferroelectric capacitor and a preparation method thereof. The difference between this embodiment and the second embodiment is that the Ga ion implantation amount of the HZO ferroelectric film is 5.2×10 14 ion / cm 2 The ferroelectric capacitor and its preparation method are the same as those in the second embodiment and will not be described in detail here.

[0078] Embodiment 6

[0079] Based on the second embodiment, this embodiment provides a HZO ferroelectric film with controllable coercive electric field, a ferroelectric capacitor and a preparation method thereof. The difference between this embodiment and the second embodiment is that the Ga ion implantation amount of the HZO ferroelectric film is 3.0×10 14 ion / cm 2 .

[0080] The method for preparing the ferroelectric capacitor provided in this embodiment includes:

[0081] Step 1: Select silicon as substrate 1 and clean substrate 1. Specifically, place substrate 1 in a mixed solution of concentrated sulfuric acid and hydrogen peroxide for 10 minutes to remove metal particles and organic pollutants on the surface of substrate 1, and then place it in ultrapure water and 0.5% hydrofluoric acid for 30 minutes, and repeat the above operation twice. Deposit W on the cleaned substrate 1 by magnetron sputtering to obtain a first electrode layer 2 with a thickness of 30nm, and the power of magnetron sputtering deposition is 80W.

[0082] Step 2: Deposit a HZO ferroelectric thin film 3 on the first electrode layer 2 by atomic layer deposition, with a thickness of 9 nm and a deposition chamber temperature of 250° C.

[0083] Step 3: Cover the HZO ferroelectric film 3 with a metal mask and perform microbeam gallium ion implantation with an implantation volume of 3.0×10 14 ion / cm 2 .

[0084] Step 4: After the ion implantation, W is deposited on the HZO ferroelectric thin film 3 by magnetron sputtering to obtain a second electrode layer 4 with a thickness of 20 nm. The power of the magnetron sputtering deposition is 80W.

[0085] Step 5: Place the sample obtained in step 4 into a rapid annealing furnace, introduce high-purity nitrogen with a purity of 99.999%, and perform rapid thermal annealing, heating from room temperature to 400°C at a heating rate of 10°C / s, keeping the temperature for 90s, and then cooling to room temperature at a cooling rate of 100°C / s to obtain a HZO ferroelectric capacitor.

[0086] Embodiment 7

[0087] Based on the second embodiment, this embodiment provides a HZO ferroelectric film with controllable coercive electric field, a ferroelectric capacitor and a preparation method thereof. The difference between this embodiment and the second embodiment is that the Ga ion implantation amount of the HZO ferroelectric film is 4.4×10 14 ion / cm 2 .

[0088] The method for preparing the ferroelectric capacitor provided in this embodiment includes:

[0089] Step 1: Select silicon as substrate 1 and clean substrate 1. Specifically, place substrate 1 in a mixed solution of concentrated sulfuric acid and hydrogen peroxide for 30 minutes to remove metal particles and organic pollutants on the surface of substrate 1, and then place it in ultrapure water and 1.5% hydrofluoric acid for 10 minutes, and repeat the above operation 3 times. Deposit W on the cleaned substrate 1 by magnetron sputtering to obtain a first electrode layer 2 with a thickness of 50nm, and the power of magnetron sputtering deposition is 140W.

[0090] Step 2: Deposit the HZO ferroelectric thin film 3 on the first electrode layer 2 by atomic layer deposition, with a thickness of 10 nm and a deposition chamber temperature of 300° C.

[0091] Step 3: Cover the HZO ferroelectric film 3 with a metal mask and perform microbeam gallium ion implantation with an implantation volume of 4.4×10 14 ion / cm 2 .

[0092] Step 4: After the ion implantation, W is deposited on the HZO ferroelectric thin film 3 by magnetron sputtering to obtain a second electrode layer 4 with a thickness of 40 nm. The power of the magnetron sputtering deposition is 140W.

[0093] Step 5: Place the sample obtained in step 4 into a rapid annealing furnace, introduce high-purity nitrogen with a purity of 99.999%, and perform rapid thermal annealing, heating from room temperature to 650°C at a heating rate of 30°C / s, keeping the temperature for 180s, and then cooling to room temperature at a cooling rate of 200°C / s to obtain a HZO ferroelectric capacitor.

[0094] The hysteresis loops of the HZO ferroelectric capacitors of the second, third, fourth and fifth embodiments were tested using a ferroelectric analyzer. The test results are shown in FIG. Figures 4 to 8 As shown, the 2Pr (residual polarization intensity) of the HZO ferroelectric capacitors of Example 2, Example 3, Example 4 and Example 5 tested at 1kHz and 3V voltage is 44-48μC / cm 2 , Ec (coercive electric field) is 1.08~1.28MV / cm; while the 2Pr=42μC / cm of HZO ferroelectric film capacitors reported in the prior art tested at 1kHz and 3V voltage 2 , Ec = 1.4MV / cm. Figure 8 It can be seen that the electrical properties of the HZO ferroelectric film capacitor can be precisely controlled according to the injection amount of micro-beam gallium ions. The HZO ferroelectric capacitor after micro-beam gallium ion injection not only has a large polarization strength, but also the coercive electric field can be precisely controlled with the ion injection dose. The HZO ferroelectric film provided by the present invention can achieve precise control of the coercive electric field according to the injection dose of gallium ions while ensuring a large residual polarization strength. When the Ga injection amount is 1.3 to 5.2×10 14 ion / cm 2 When the coercive electric field is 1.08-1.28 MV / cm, the coercive electric field of the HZO ferroelectric film can be adjusted by adjusting the Ga injection amount. It should be noted that in order to meet the test requirements, the HZO ferroelectric film in the embodiment of the present invention has only one micro-beam gallium ion injection area. The test results of the second, third, fourth and fifth embodiments can prove that when the Ga injection amount is 1.3-5.2×10 14 ion / cm 2 When the residual polarization intensity is large, it can be ensured that the coercive electric field decreases with the increase of the gallium ion injection amount. Therefore, by preparing multiple micro-beam gallium ion injection areas with different injection amounts in the HZO ferroelectric film, the multiple micro-beam gallium ion injection areas with different injection amounts in the HZO ferroelectric film can exhibit different coercive electric fields, thereby realizing the performance regulation of different areas of the same ferroelectric film. Different coercive electric fields can be exhibited in different areas, which can be applied to multi-valued memories, thereby greatly improving the storage density, and can be applied to electronic devices such as artificial synapses and neuron devices.

[0095] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. A HZO ferroelectric thin film with controllable coercive electric field, characterized in that: The HZO ferroelectric film has at least one microbeam gallium ion implantation region; The gallium ion implantation amount in each microbeam gallium ion implantation area is 1.3×10 14 ~5.2×10 14 ion / cm 2 .

2. The HZO ferroelectric thin film with controllable coercive electric field according to claim 1, characterized in that: The HZO ferroelectric film has a plurality of micro-beam gallium ion implantation regions, and at least two micro-beam gallium ion implantation regions have different gallium ion implantation amounts.

3. The HZO ferroelectric thin film with controllable coercive electric field according to claim 1, characterized in that: The surface size of each microbeam gallium ion implantation area is less than or equal to 1 mm×1 mm; The depth of each microbeam gallium ion implantation region is equal to the thickness of the HZO ferroelectric film.

4. The HZO ferroelectric thin film with controllable coercive electric field according to claim 1, characterized in that: The HZO ferroelectric film includes a plurality of hafnium oxide layers and zirconium oxide layers which are alternated in sequence.

5. A HZO ferroelectric capacitor with controllable coercive electric field, characterized in that: The invention comprises a substrate, a first electrode layer, the HZO ferroelectric thin film according to any one of claims 1 to 4, and a second electrode layer which are arranged in sequence from bottom to top.

6. The HZO ferroelectric capacitor with controllable coercive electric field according to claim 5, characterized in that: The second electrode layer includes a plurality of sub-electrodes uniformly distributed on the upper surface of the HZO ferroelectric thin film.

7. The HZO ferroelectric capacitor with controllable coercive electric field according to claim 5, characterized in that: The material of the first electrode layer and the second electrode layer includes: one of TiN, TaN, and W.

8. A method for preparing a HZO ferroelectric capacitor with controllable coercive electric field, characterized in that: The following steps are involved: S1: preparing a first electrode layer on the upper surface of the substrate; S2: preparing a HZO ferroelectric thin film on the upper surface of the first electrode layer; S3: Micro-beam gallium ion implantation is performed in the HZO ferroelectric film using a micro-beam gallium ion implantation process to form several micro-beam gallium ion implantation areas; the implantation amount is 1.3×10 14 ~5.2×10 14 ion / cm 2 , and the gallium ion implantation amounts of at least two microbeam gallium ion implantation regions are different; S4: preparing a second electrode layer on the upper surface of the HZO ferroelectric thin film.

9. The method for preparing a HZO ferroelectric capacitor with controllable coercive electric field according to claim 8, characterized in that S2 include: S201: depositing a hafnium oxide layer and a zirconium oxide layer in sequence on the upper surface of the first electrode layer; S202: Repeat S201 several times to obtain the HZO ferroelectric thin film.

10. The method for preparing a HZO ferroelectric capacitor with controllable coercive electric field according to claim 8, characterized in that: S4 also includes step S5: The sample obtained in S4 is placed in a rapid annealing furnace and subjected to rapid thermal annealing at a temperature of 400 to 650°C.

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