Functional thin film material based on high-flux component gradient screening and preparation method thereof

Abstract

The application discloses a functional thin film material based on high-flux component gradient screening and a preparation method thereof, and belongs to the fields of antiferroelectric materials and pulsed laser deposition. The functional thin film material comprises a substrate layer, a bottom electrode layer and a functional layer which are stacked in sequence, and the component of the functional layer is Pb(Zr 1‑x Sn x )O3, wherein Pb(Zr 1‑x Sn x )O3 is composed of PbZrO3 and SnO2 which is solid-solved in the PbZrO3, and x=0.012-0.020. The functional thin film material has excellent and stable antiferroelectric performance, and the electric hysteresis loop presents a "full" double-loop shape. The functional layer of the functional thin film material is mainly composed of common PbZrO3, the amount of SnO2 is very small, and expensive Sr-containing substances or Sr-containing targets do not need to be used, so that the preparation cost of the functional thin film material can be effectively reduced.

Description

Technical Field

[0001] This invention relates to a functional thin film material and its preparation method, and more particularly to a functional thin film material based on high-throughput composition gradient screening and its preparation method, belonging to the fields of anti-electro-electric materials and pulsed laser deposition. Background Technology

[0002] Functional oxide thin films have attracted much attention due to their unique ferroelectric, magnetic, and dielectric properties, which make them suitable for a wide range of applications in memory, sensors, and energy storage devices. These properties are fundamentally determined by the phase structure of the functional thin film materials. Extensive research has been conducted on phase modulation of complex-composition oxide thin films, such as Ba... 1-x Sr x TiO3, PbZr x Ti 1-x O3 and (Pb,La)(Zr,Sn,Ti)O3 thin films, where 0 < x < 1. Therefore, constructing accurate phase diagrams is crucial for guiding the design and application of functional thin films. Currently, phase diagram construction mainly relies on theoretical simulations, such as density functional theory and phase-field modeling. While these methods provide valuable insights, they are inherently limited by computational methods, including assumptions about equilibrium conditions and ideal defect-free structures. Traditional experimental methods typically rely on iterative processes, including independent sample preparation and continuous tuning of experimental parameters, which inevitably introduces uncertainties.

[0003] High-throughput fabrication methods enable parallel experiments under single parameters, offering significant advantages in efficiency and systematicity. In fact, high-throughput strategies have been used to optimize various parameters affecting the properties of functional oxide thin films, including thickness tuning and critical thickness screening, orientation and strain engineering, and systematic screening of growth atmospheres (see CN116121704A, CN115763074A). Despite these advances, achieving precise compositional gradient control or screening in complex oxide thin films remains challenging. Conventional deposition techniques, such as pulsed laser deposition, magnetron sputtering deposition, and chemical vapor deposition, typically rely on a single target source, limiting the ability to achieve continuous and fine compositional variations on the substrate. This limitation hinders systematic studies of composition-dependent phase behavior.

[0004] Chinese invention patent application CN117986016A discloses a method for preparing an antiferroelectric thin film, which involves the following steps: A (001) oriented SrTiO3 substrate is fixed on a heating pad; the heating pad is placed into the cavity of a pulsed laser deposition equipment, the vacuum is reduced to below 10 Pa, the temperature is raised to 680-720℃, a strontium ruthenium target is switched, and deposition is performed for 2 minutes in an oxygen atmosphere; subsequently, the temperature is lowered to 580-620℃, the oxygen pressure is adjusted to 8-12 Pa, a strontium lead zirconate target is switched, and deposition is performed for 20 minutes in an oxygen atmosphere; finally, the temperature is lowered and annealed in an oxygen atmosphere; wherein the strontium lead zirconate target is an antiferroelectric material (Pb). 1- x Sr x ZrO3 (where 0.4 ≤ x ≤ 0.6). The high Sr content in the antiferroelectric material of this patent application can easily lead to increased costs. Furthermore, this patent application relies on a single lead-strontium zirconate target to prepare Pb with different compositions via pulsed laser deposition. 1-x Sr x ZrO3 thin films are time-consuming and labor-intensive, and may also result in compositional differences during growth due to the fact that they are not prepared simultaneously.

[0005] Chinese invention patent application CN115763074A discloses a high-throughput antiferroelectric-dielectric energy storage solid solution film, comprising: a substrate, and a bottom electrode layer and an antiferroelectric-dielectric layer sequentially grown on the substrate; the substrate is a rigid SrTiO3 substrate; the bottom electrode layer is an SrRuO3 film; the antiferroelectric-dielectric layer is a solid solution film consisting of alternating PbZrO3 antiferroelectric layers and SrTiO3 dielectric layers; the composition of the PbZrO3 antiferroelectric layer decreases stepwise along the horizontal direction, while the composition of the SrTiO3 dielectric layer increases stepwise along the horizontal direction. This patent application optimizes the antiferroelectric properties of the high-throughput film by changing the laser emission ratio and cycle period of PbZrO3 and SrTiO3, thereby achieving lower leakage current density and better performance. However, the remanent polarization intensity of this high-throughput antiferroelectric-dielectric energy storage solid solution film is as high as 11 μC / cm. 2 This is detrimental to improving its antiferroelectric properties; furthermore, the high SrTiO3 content (up to 50 mol%) in the antiferroelectric-dielectric layer also leads to high film preparation costs. Additionally, the wide range of SrTiO3 proportions used in this patent application makes it easy to miss the optimal composition range for performance control of this solid solution film. Moreover, SrTiO3 has disadvantages in stabilizing the antiferroelectric phase. Summary of the Invention

[0006] In view of the shortcomings of the prior art, one of the objectives of the present invention is to provide a functional thin film material with excellent antiferroelectric properties; another objective of the present invention is to provide a method for preparing the functional thin film material.

[0007] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows: A functional thin film material based on high-throughput composition gradient screening includes a substrate layer, a bottom electrode layer, and a functional layer stacked sequentially, wherein the functional layer is composed of Pb(Zr) 1-x Sn x )O3, of which Pb(Zr 1-x Sn x The O3 is composed of PbZrO3 and SnO2 dissolved in the PbZrO3, with x = 0.012~0.020.

[0008] Furthermore, x = 0.014~0.018, such as 0.015, 0.016, or 0.017.

[0009] This invention has found that incorporating SnO2 into PbZrO3 in a solid solution form and controlling the value of x (i.e., the proportion of SnO2 in the functional layer) within a specific range helps the functional thin film material exhibit superior and stable antiferroelectric properties.

[0010] Furthermore, the thickness of the functional layer is 200-240 nm, such as 205, 210, 215, 220, 225, or 230 nm. Preferably, it is 220-225 nm. This invention has found that controlling the thickness of the functional layer helps the functional thin film material exhibit superior antiferroelectric properties.

[0011] Furthermore, the thickness of the bottom electrode layer is 20-35 nm, and even further, 28-32 nm.

[0012] Furthermore, the substrate layer is an SrTiO3 substrate (rigid substrate), and the SrTiO3 orientation is

[111] ; the bottom electrode layer is an SrRuO3 layer and La 0.67 Sr 0.33 One of the following layers is selected: MnO3 layer, TiN layer, and ITO layer, preferably SrRuO3 layer. The crystal structure of SrRuO3 is more compatible with the crystal structure of the functional layer, which helps to deposit and grow a functional layer with higher quality and better performance.

[0013] Optionally, the area of ​​the substrate layer is 1-2cm × 1-2cm.

[0014] Optionally, the substrate layer is square.

[0015] In this invention, Sn doping is achieved by dissolving SnO2 in PbZrO3, thereby introducing local lattice distortion into the functional layer. This effectively enhances the local polarizability and flipping synergy of the dipoles while maintaining long-range antiferroelectric order, thus increasing the saturation polarization intensity and current of the functional thin film material. Further investigation revealed that the saturation polarization intensity and current first increase and then decrease with increasing Sn doping concentration. This may be due to the different roles Sn plays in the lattice. More specifically, when the Sn content in the functional layer is relatively low, a small amount of Sn doping enters the lattice as isolated point defects, leading to Sn... 4+ The ionic radius (0.69 Å) is smaller than that of Zr. 4+ (0.72Å) generates a local strain field with symmetry breaking around it, reducing the oxygen octahedral rotation barrier and enhancing the local polarizability. When the Sn content in the functional layer increases to the critical range, the local strain fields begin to overlap, forming a pathway through the film. At this time, a dynamic metastable polar nanoregion is established inside the material, the synergy of polarization reversal reaches its best, the saturation polarization intensity reaches its peak, and the hysteresis loop exhibits the most "full" double-ring morphology. When the Sn content in the functional layer is too high, excessive Sn doping leads to excessively high lattice distortion density, generating a strong random internal stress field and chemical disorder. The excessive random field breaks and fragments the originally connected pathways, and the high concentration of defects increases the barrier for the overall reversal of the dipoles. The synergy of polarization reversal is destroyed, the reversal becomes incomplete and requires a higher electric field, resulting in a decrease in saturation polarization intensity, and the hysteresis loop may become narrower or exhibit irregular characteristics.

[0016] Based on the same inventive concept, the present invention also provides a method for preparing the functional thin film material as described above, comprising the following steps: S1, Provide a substrate layer; S2. A bottom electrode layer is deposited on the substrate layer using a pulsed laser deposition process; S3. A functional layer is deposited on the bottom electrode layer using a pulsed laser deposition process; S4. Perform cooling post-processing to obtain functional thin film material.

[0017] Furthermore, in S2, the specific parameters of the pulsed laser deposition process are as follows: the vacuum level of the deposition cavity is 6 × 10⁻⁶. -7 ~9×10 -7 Pa, preferably 7 × 10 -7 ~8×10 -7Pa; the deposition temperature is 610~625℃, preferably 618~622℃; the oxygen partial pressure (i.e., the partial pressure of oxygen) is 90~105mTorr, preferably 98~102mTorr; the laser energy is 330~360mJ, preferably 349~351mJ; the pulsed laser frequency is 8~10Hz, preferably 8.5-9.5Hz; the rate of heating to the deposition temperature is 18~21℃ / min, preferably 19~20℃ / min; the laser focal length is -10~+20mm, preferably +5~+15mm, at which point the deposition rate is approximately 2~17nm / min, preferably 10~12nm / min.

[0018] Furthermore, in S3, the number of laser pulses (i.e., the number of laser pulses) is 34,000 to 37,000, preferably 35,000 to 36,000, and more preferably 36,000.

[0019] Furthermore, in S3, the specific steps of the pulsed laser deposition process include: a. Place the PbZrO3 target and the SnO2 target on two adjacent target sites respectively; b. The substrate layer is bonded and then placed directly above the main target on the substrate stage in the deposition chamber. The distance between the substrate layer and the target is 46~52cm, preferably 48~50cm. c. Move the substrate stage to a safe height; d. Move the substrate stage and mask to their initial positions, then lower the substrate stage to the deposition position. Switch the main target to a PbZrO3 target. Set the specific parameters for the pulsed laser deposition process as follows: vacuum level of the deposition chamber is 6 × 10⁻⁶. -7 ~9×10 -7 Pa, preferably 7 × 10 -7 ~8×10 -7 Pa; deposition temperature is 580~610℃, preferably 595~605℃; oxygen partial pressure is 90~105mTorr, preferably 97~103mTorr; heating rate to deposition temperature is 20~25℃ / min, preferably 22~24℃ / min; laser energy is 330~360mJ, preferably 348~352 mJ; pulsed laser frequency is 8~10Hz, preferably 9~10Hz; laser firing rate is 1362~3128, preferably 1640~1660; laser focal length is -15~+30mm, preferably +13~+17mm; target rotation speed is 18~21°, preferably 20°; at this time, deposition rate is 3~15nm / min, preferably 14nm / min; The mask has through holes that match the shape and size of the functional layer; when the substrate stage and the mask are in the initial position, the orthographic projection of the through holes on the substrate stage coincides with the area where the functional layer is located. e. Switch the main target to SnO2 target and set the specific parameters for the pulsed laser deposition process as follows: vacuum level of the deposition chamber is 6 × 10⁻⁶. -7 ~9×10 -7 Pa, preferably 7 × 10 -7 ~8×10 -7 Pa; deposition temperature is 580~610℃, preferably 595~605℃; oxygen partial pressure is 90~105mTorr, preferably 97~103mTorr; heating rate to deposition temperature is 20~25℃ / min, preferably 22~24℃ / min; laser energy is 330~360mJ, preferably 349~351mJ; pulsed laser frequency is 8~10Hz, preferably 10Hz; number of laser shots is 118~272, preferably 140~150; laser focal length is -10~+20mm; target rotation speed is 15~22°, preferably 20°; at this time, deposition rate is 3~15 nm / min, preferably 14 nm / min. nm / min; the number of laser shots in step e is much smaller than the number of laser shots in step d. During each deposition, the thickness of the SnO2 layer is much smaller than the thickness of the PbZrO3 layer. In the end, SnO2 is dissolved in PbZrO3, and finally, a functional layer with uniform composition is formed. f. Move the substrate stage to a safe height to complete one deposition cycle; g. Repeat steps d to f 10 to 25 times.

[0020] Further, in step d, the number of laser shots is 1640-1660; in step e, the number of laser shots is 140-150; in step g, the process of steps d-f is repeated 18-22 times, preferably 20 times.

[0021] Furthermore, in S4, during the cooling post-treatment, the sample is first placed in an atmosphere of 580~610℃ and 90~105mTorr oxygen partial pressure for 4~8 minutes, preferably 6~7 minutes; then cooled to room temperature at a rate of 1~7℃ / min, preferably 2~4℃ / min.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The functional thin film material of the present invention exhibits excellent and stable antiferroelectric properties, with a saturation polarization intensity reaching 57 μC / cm. 2 When the current value reaches 0.45mA or more, the hysteresis loop exhibits a "full" double-loop shape.

[0023] (2) The functional layer of the functional thin film material of the present invention is mainly composed of common PbZrO3, with a very small amount of SnO2, and does not require expensive Sr-containing substances or Sr-containing targets, which can effectively reduce the preparation cost of functional thin film materials and help promote their application. Attached Figure Description

[0024] To more clearly illustrate the technical methods in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art methods will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0025] Figure 1 The polarization intensity-voltage diagrams are for the antiferroelectric thin film materials in Comparative Examples 1-4.

[0026] Figure 2 The polarization intensity-voltage diagrams are shown for the x=0 region in the functional layer of the functional thin film materials in Examples 1-4.

[0027] Figure 3 The polarization intensity-voltage diagrams are for the x=0 region in the functional thin film materials of Examples 3, 5-7.

[0028] Figure 4 This is a schematic diagram of a functional thin film material with a high-throughput composition gradient prepared by a high-throughput experimental method.

[0029] Figure 5 This is a compositional distribution diagram of the functional layer along the X-direction in Example 3, and an enlarged X-ray photoelectron spectrum of each segment along the X-direction.

[0030] Figure 6 Zr 3d in each segment of the functional layer of the functional thin film material in Example 3 5 / 2 and Sn 3d 5 / 2 The graph shows how the binding energy changes with increasing Sn content.

[0031] Figure 7 The image (a) shows a cross-section (perpendicular to the X direction) of the functional thin film material of Example 3, along with the corresponding elemental distribution map for energy dispersive spectroscopy analysis. Here, b is the elemental distribution map of Ti, c is the elemental distribution map of Ru, d is the elemental distribution map of Pb, e is the elemental distribution map of Zr, and f is the elemental distribution map of Sn.

[0032] Figure 8The polarization intensity-voltage diagram and current-voltage diagram of the functional thin film material in Example 3 are shown in different Sn element content ranges (0.01≤x≤0.08). Among them, a corresponds to the polarization intensity-voltage diagram and current-voltage diagram of the segment with x of 0.01~0.04, and b corresponds to the polarization intensity-voltage diagram and current-voltage diagram of the segment with x of 0.05~0.08.

[0033] Figure 9 The polarization intensity-voltage diagram and current-voltage diagram of the functional thin film material in Example 8 are shown for different Sn element content ranges (0.004≤x≤0.036). Among them, a corresponds to the polarization intensity-voltage diagram and current-voltage diagram for the segment with x of 0.004~0.020, and b corresponds to the polarization intensity-voltage diagram and current-voltage diagram for the segment with x of 0.024~0.036.

[0034] Figure 10 The saturation polarization intensity and current values ​​of the functional thin film material in Example 8 are measured in different Sn element content ranges (0.004≤x≤0.036).

[0035] Figure 11 The polarization intensity-voltage diagram is shown for the functional thin film material of Example 8 under temperature dependence (175℃~275℃) in different Sn element content ranges (0.004≤x≤0.020).

[0036] Figure 12 The polarization intensity-voltage diagram is shown for the functional thin film material of Example 8 under temperature dependence (175℃~275℃) in different Sn element content ranges (0.024≤x≤0.036).

[0037] In the figure, 1-substrate layer, 2-bottom electrode layer, 3-functional layer. Detailed Implementation

[0038] The present invention will be described in detail below with reference to embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other. For ease of description, the words "upper," "lower," "left," and "right" appearing below only indicate that they are consistent with the upper, lower, left, and right directions of the drawings themselves, and do not limit the structure.

[0039] To improve efficiency and screening accuracy, a functional layer with varying compositional gradients is prepared on a substrate using a high-throughput experimental method, thereby obtaining a functional thin film material with a high-throughput compositional gradient. Then, by measuring the electrical properties of segments of the functional thin film material with different Sn contents, segments of the functional layer with excellent antiferroelectric properties are screened out. Finally, the functional thin film material of the present invention is obtained based on high-throughput compositional gradient screening.

[0040] Specifically, the preparation method of the above-mentioned functional thin film material with high-throughput composition gradient includes the following steps: S1, Provide a substrate layer; S2. A bottom electrode layer is deposited on the substrate layer using a pulsed laser deposition process; S3. A functional layer is deposited on the bottom electrode layer using a high-throughput pulsed laser deposition process; S4. Perform cooling post-processing to obtain a functional thin film material with a high-flux composition gradient (see...). Figure 4 ).

[0041] More specifically, in S2, the specific parameters of the pulsed laser deposition process are: the vacuum degree of the deposition chamber is 6 × 10⁻⁶. -7 ~9×10 -7 Pa, preferably 7 × 10 -7 ~8×10 -7 Pa; the deposition temperature is 610~625℃, preferably 618~622℃; the oxygen partial pressure (i.e., the partial pressure of oxygen) is 90~105mTorr, preferably 98~102mTorr; the laser energy is 330~360mJ, preferably 349~351mJ; the pulsed laser frequency is 8~10Hz, preferably 8.5-9.5Hz; the rate of heating to the deposition temperature is 18~21℃ / min, preferably 19~20℃ / min; the laser focal length is -10~+20mm, preferably +5~+15mm, at which point the deposition rate is 2~17nm / min, preferably 10~12nm / min.

[0042] More specifically, in S3, the number of laser shots is 34,000 to 37,000, preferably 35,000 to 36,000, and more preferably 36,000.

[0043] More specifically, in S3, the specific steps of the pulsed laser deposition process include: a. Place the PbZrO3 target and the SnO2 target on two adjacent target sites respectively; b. The substrate layer is bonded and then placed directly above the main target on the substrate stage in the deposition chamber. The distance between the substrate layer and the target is 46~52cm, preferably 48~50cm. c. Move the substrate stage to a safe height; d. First layer gradient: Move the substrate stage and mask to their initial positions, then lower the substrate stage to the deposition position. Switch the main target to a PbZrO3 target. Set the specific parameters for the pulsed laser deposition process as follows: vacuum level of the deposition chamber is 6 × 10⁻⁶. -7 ~9×10 -7 Pa, preferably 7 × 10-7 ~8×10 -7 Pa; deposition temperature is 580~610℃, preferably 595~605℃; oxygen partial pressure is 90~105 mTorr, preferably 97~103 mTorr; heating rate to deposition temperature is 20~25℃ / min, preferably 22~24℃ / min; laser energy is 330~360 mJ, preferably 348~352 mJ; pulsed laser frequency is 8~10 Hz, preferably 9~10 Hz; laser firing rate is 1362~3128 firings. The laser has a maximum firing rate of 1640-1660 shots; a laser focal length of -15-+30mm, preferably +13-+17mm; a target rotation speed of 18-21°, preferably 20°; and a mask moving at a speed of 0.11-0.17mm / s along the X-direction, preferably 0.15mm / s. At this speed, the deposition rate is 3-15nm / min, preferably 14nm / min. Therefore, the thickness of the deposited PbZrO3 layer gradually decreases along the direction of mask movement. The mask has through holes that match the shape and size of the functional layer. The mask can move along the X direction, which is parallel to the horizontal plane. When the substrate stage and the mask are in the initial position, the orthographic projection of the through holes on the substrate stage partially coincides with the area where the functional layer is located. Optionally, the size of the overlapping area in the X direction is 1-2 mm, preferably 1.2-1.6 mm. e. Second gradient: Raise the substrate stage to a safe height, then rotate the substrate stage 180° and move the mask to the initial position; then lower the substrate stage to the deposition position, switch the main target to the SnO2 target, and set the specific parameters of the pulsed laser deposition process as follows: the vacuum degree of the deposition chamber is 6×10⁻⁶. -7 ~9×10 -7 Pa, preferably 7 × 10 -7 ~8×10 -7 Pa; the deposition temperature is 580~610℃, preferably 595~605℃; the oxygen partial pressure is 90~105mTorr, preferably 97~103mTorr; the heating rate to the deposition temperature is 20~25℃ / min, preferably 22~24℃ / min; the laser energy is 330~360mJ, preferably 349~351mJ; the pulsed laser frequency is 8~10Hz, preferably 10Hz; the number of laser shots is 118~272, preferably 140~150; the laser focal length is -10~+20mm; the target rotation speed is 15~22°, preferably 20°; the speed at which the mask moves along the X direction is 0.16~0.22mm / s, preferably 0.20mm / s, at which point the deposition rate is 3~15 nm / min, preferably 14 nm / min; thus, the thickness of the deposited SnO2 layer gradually increases along the direction of mask movement; The number of laser shots in step e is much smaller than the number of laser shots in step d, and the thickness of the SnO2 layer is much smaller than the thickness of the PbZrO3 layer. In the end, SnO2 is dissolved in PbZrO3. f. Move the mask along the X direction to the initial position, move the substrate stage to a safe height, and complete one deposition. g. Repeat steps d to f 10 to 25 times; In steps d and e, the mask moves in opposite directions during pulsed laser deposition, which ultimately causes the SnO2 content in the functional layer to gradually increase along the X direction.

[0044] More specifically, in step d, the number of laser shots is 1640-1660; in step e, the number of laser shots is 140-150; in step g, the process of steps d-f is repeated 18-22 times, preferably 20 times.

[0045] More specifically, in S4, during the cooling post-treatment, the sample is first placed in an oxygen partial pressure atmosphere of 580~610℃ and 90~105mTorr for 4~8 minutes, preferably 6~7 minutes; then cooled to room temperature at a rate of 1~7℃ / min, preferably 2~4℃ / min.

[0046] Example 1 A functional thin film material with a high-throughput composition gradient includes a substrate layer, a bottom electrode layer, and a functional layer stacked sequentially, wherein the composition of the functional layer is Pb(Zr) 1-x Sn x )O3, of which Pb(Zr 1-x Sn x The PbZrO3 layer consists of PbZrO3 and SnO2 dissolved in the PbZrO3 layer, with x = 0~0.08. The functional layer is a solid solution film with alternating growth of PbZrO3 layer (antiferroelectric layer) and SnO2 layer. In the functional layer, the content of PbZrO3 gradually decreases in the horizontal direction, and the content of SnO2 gradually increases in the same direction (i.e., x gradually increases from 0 to 0.08 in this direction).

[0047] The substrate is a rigid substrate (SrTiO3) with an orientation of

[111] and an area of ​​1.5cm × 1.5cm.

[0048] The bottom electrode layer is a SrRuO3 thin film with a thickness of 20 nm.

[0049] The thickness of the functional layer is 205±5nm.

[0050] This embodiment also provides a method for preparing the functional thin film material, which specifically includes the following steps: 1) The substrate layer is bonded and then placed directly above the main target on the substrate stage in the deposition chamber of the pulsed laser deposition equipment, with the distance between the substrate layer and the target material controlled to be 46cm; 2) A bottom electrode layer is grown on the substrate using pulsed laser deposition. 3) A functional layer is grown on the bottom electrode layer using a high-throughput pulsed laser deposition process; 4) Perform cooling post-treatment to obtain functional thin film materials with high-throughput composition gradient.

[0051] In step 2), the specific parameters of the pulsed laser deposition process are: the vacuum degree of the deposition cavity is 6 × 10⁻⁶. -7 With a deposition temperature of 610 °C, an oxygen partial pressure of 90 mTorr, a laser energy of 330 mJ, a pulsed laser frequency of 8 Hz, a heating rate to the deposition temperature of 18 °C / min, and a laser focal length of -10 mm, the deposition rate is approximately 2 nm / min.

[0052] In step 3), the specific steps of the high-throughput pulsed laser deposition process are as follows: a. Place the PbZrO3 target and the SnO2 target on two adjacent target sites respectively; b. Set the relevant parameters as follows: Vacuum degree of deposition chamber is 6×10 -7 Pa, deposition temperature 580 ℃, oxygen partial pressure 90 mTorr, heating rate to deposition temperature 20℃ / min, deposition rate at this point approximately 3 nm / min; total laser firing rate 34000 shots; c. Move the substrate stage to a safe height; d. First layer gradient: Move the substrate stage and mask to the initial position at speeds of 3 mm / s and 4 mm / s, respectively. Then lower the substrate stage to the deposition position and switch the main target to PbZrO3. Set the specific parameters of the high-throughput pulsed laser deposition process as follows: laser energy of 330 mJ, pulsed laser frequency of 8 Hz, number of laser shots of 3128, laser focal length of -15 mm, target rotation speed of 18°, and mask moving speed along the X direction of 0.11 mm / s. The mask has through holes (square holes) that match the shape and size of the functional layer. The mask can move along the X direction, which is parallel to the horizontal plane. When the substrate stage and the mask are in the initial position, the orthographic projection of the through holes on the substrate stage partially coincides with the area where the functional layer is located. The size of the overlapping area in the X direction is 1.5 mm. e. Second gradient: Raise the substrate stage to a safe height, then rotate the substrate stage 180°, and move the mask to the initial position at a moving speed of 4 mm / s; then lower the substrate stage to the deposition position, switch the main target to the SnO2 target, and set the specific parameters of the pulsed laser deposition process as follows: laser energy of 330mJ, pulsed laser frequency of 8Hz, number of laser shots of 272, laser focal length of -10mm, target rotation speed of 15°, and mask moving speed along the X direction of 0.16mm / s; f. Move the mask along the X direction to the initial position, move the substrate stage to a safe height, and complete one deposition. g. Repeat steps d to f 10 times; In steps d and e, the mask moves in opposite directions during pulsed laser deposition.

[0053] In step 4), the specific steps of the cooling post-treatment are as follows: place it in an atmosphere of 580 °C and 90 mTorr oxygen partial pressure for 4 min; then cool it to room temperature at a cooling rate of 1 °C / min.

[0054] Example 2 A functional thin film material with a high-throughput composition gradient includes a substrate layer, a bottom electrode layer, and a functional layer stacked sequentially, wherein the composition of the functional layer is Pb(Zr) 1-x Sn x )O3, of which Pb(Zr 1-x Sn x The PbZrO3 layer consists of PbZrO3 and SnO2 dissolved in the PbZrO3 layer, with x = 0~0.08. The functional layer is a solid solution film with alternating growth of PbZrO3 layer (antiferroelectric layer) and SnO2 layer. In the functional layer, the content of PbZrO3 gradually decreases in the horizontal direction, and the content of SnO2 gradually increases in the same direction (i.e., x gradually increases from 0 to 0.08 in this direction).

[0055] The substrate is a rigid substrate (SrTiO3) with an orientation of

[111] and an area of ​​1.5cm × 1.5cm.

[0056] The bottom electrode layer is a SrRuO3 thin film with a thickness of 25 nm.

[0057] The thickness of the functional layer is 215±5nm.

[0058] This embodiment also provides a method for preparing the functional thin film material, which specifically includes the following steps: 1) The substrate is bonded and then placed directly above the main target on the substrate stage in the deposition chamber of the pulsed laser deposition equipment, with the distance between the substrate and the target controlled to be 48cm. 2) A bottom electrode layer is grown on the substrate using pulsed laser deposition. 3) A functional layer is grown on the bottom electrode layer using a high-throughput pulsed laser deposition process; 4) Perform cooling post-treatment to obtain functional thin film materials with high-throughput composition gradient.

[0059] In step 2), the specific parameters of the pulsed laser deposition process are: the vacuum degree of the deposition chamber is 7 × 10⁻⁶. -7 At a given temperature of 615 °C, an oxygen partial pressure of 95 mTorr, a laser energy of 340 mJ, a pulsed laser frequency of 9 Hz, a heating rate to the deposition temperature of 19 °C / min, and a laser focal length of 0 mm, the deposition rate is approximately 7 nm / min.

[0060] In step 3), the specific steps of the high-throughput pulsed laser deposition process are as follows: a. Place the PbZrO3 target and the SnO2 target on two adjacent target sites respectively; b. Set the relevant parameters as follows: Vacuum degree of deposition chamber is 7×10 -7 Pa, deposition temperature 590℃, oxygen partial pressure 95mTorr, heating rate to deposition temperature 22℃ / min, deposition rate at this point approximately 8 nm / min; total laser firing rate 35000 shots; c. Move the substrate stage to a safe height; d. First layer gradient: Move the substrate stage and mask to the initial position at moving speeds of 4 mm / s and 5 mm / s respectively. Then lower the substrate stage to the deposition position and switch the main target to PbZrO3 target. Set the specific parameters of the high-throughput pulsed laser deposition process as follows: laser energy of 340 mJ, pulsed laser frequency of 9 Hz, number of laser shots of 2146, laser focal length of 0 mm, target rotation speed of 19°, and mask moving speed along the X direction of 0.13 mm / s. The mask has through holes (square holes) that match the shape and size of the functional layer. The mask can move along the X direction, which is parallel to the horizontal plane. When the substrate stage and the mask are in the initial position, the orthographic projection of the through holes on the substrate stage partially coincides with the area where the functional layer is located. The size of the overlapping area in the X direction is 1.5 mm. e. Second gradient: Move the substrate stage to a safe height, then rotate the substrate stage 180°, and move the mask to the initial position at a speed of 5 mm / s; then lower the substrate stage to the deposition position, switch the main target to SnO2 target, and set the specific parameters of the high-throughput pulsed laser deposition process as follows: laser energy of 340 mJ, pulsed laser frequency of 9 Hz, number of laser shots of 187, laser focal length of 0 mm, target rotation speed of 18°, and mask moving speed along the X direction of 0.18 mm / s; f. Move the mask along the X direction to the initial position, move the substrate stage to a safe height, and complete one deposition. g. Repeat steps d to f 15 times; In steps d and e, the mask moves in opposite directions during pulsed laser deposition.

[0061] In step 4), the specific steps of the cooling post-treatment are as follows: place it in an atmosphere of 590℃ and 95mTorr oxygen partial pressure for 5 minutes; then cool it to room temperature at a cooling rate of 3℃ / min.

[0062] Example 3 A functional thin film material with a high-throughput composition gradient includes a substrate layer, a bottom electrode layer, and a functional layer stacked sequentially, wherein the composition of the functional layer is Pb(Zr) 1-x Sn x )O3, of which Pb(Zr 1-x Sn x The PbZrO3 layer consists of PbZrO3 and SnO2 dissolved in the PbZrO3 layer, with x = 0~0.08. The functional layer is a solid solution film with alternating growth of PbZrO3 layer (antiferroelectric layer) and SnO2 layer. In the functional layer, the content of PbZrO3 gradually decreases in the horizontal direction, and the content of SnO2 gradually increases in the same direction (i.e., x gradually increases from 0 to 0.08 in this direction).

[0063] The substrate is a rigid substrate (SrTiO3) with an orientation of

[111] and an area of ​​1.5cm × 1.5cm.

[0064] The bottom electrode layer is a SrRuO3 thin film with a thickness of 30 nm.

[0065] The thickness of the functional layer is 225±5nm.

[0066] This embodiment also provides a method for preparing the functional thin film material, which specifically includes the following steps: 1) The substrate is bonded and then placed directly above the main target on the substrate stage in the deposition chamber of the pulsed laser deposition equipment, with the distance between the substrate and the target material controlled to be 50cm. 2) A bottom electrode layer is grown on the substrate using pulsed laser deposition. 3) A functional layer is grown on the bottom electrode layer using a high-throughput pulsed laser deposition process; 4) Perform cooling post-treatment to obtain functional thin film materials with high-throughput composition gradient.

[0067] In step 2), the specific parameters of the pulsed laser deposition process are as follows: the vacuum degree of the deposition cavity is 8 × 10⁻⁶. -7 With a deposition temperature of 620℃, an oxygen partial pressure of 100 mTorr, a laser energy of 350 mJ, a pulsed laser frequency of 10 Hz, a heating rate to the deposition temperature of 20℃ / min, and a laser focal length of +10 mm, the deposition rate is approximately 12 nm / min.

[0068] In step 3), the specific steps of the high-throughput pulsed laser deposition process are as follows: a. Place the PbZrO3 target and the SnO2 target on two adjacent target sites respectively; b. Set the relevant parameters as follows: Vacuum degree of deposition chamber is 8×10 -7 Pa, deposition temperature 600℃, oxygen partial pressure 100mTorr, heating rate to deposition temperature 24℃ / min, deposition rate at this point approximately 14nm / min; total laser firing rate 36000 shots; c. Move the substrate stage to a safe height; d. First layer gradient: Move the substrate stage and mask to the initial position at moving speeds of 5 mm / s and 6 mm / s, respectively. Then lower the substrate stage to the deposition position and switch the main target to PbZrO3 target. Set the specific parameters of the high-throughput pulsed laser deposition process as follows: laser energy of 350 mJ, pulsed laser frequency of 10 Hz, number of laser shots of 1656, laser focal length of +15 mm, target rotation speed of 20°, and mask moving speed along the X direction of 0.15 mm / s. The mask has through holes (square holes) that match the shape and size of the functional layer. The mask can move along the X direction, which is parallel to the horizontal plane. When the substrate stage and the mask are in the initial position, the orthographic projection of the through holes on the substrate stage partially coincides with the area where the functional layer is located. The size of the overlapping area in the X direction is 1.5 mm. e. Second gradient: Move the substrate stage to a safe height, then rotate the substrate stage 180°, and move the mask to the initial position at a speed of 6 mm / s; then lower the substrate stage to the deposition position, switch the main target to SnO2 target, and set the specific parameters of the high-throughput pulsed laser deposition process as follows: laser energy of 350 mJ, pulsed laser frequency of 10 Hz, number of laser shots of 144, laser focal length of +10 mm, target rotation speed of 20°, and mask moving speed along the X direction of 0.20 mm / s; f. Move the mask along the X direction to the initial position, move the substrate stage to a safe height, and complete one deposition. g. Repeat steps d to f 20 times; In steps d and e, the mask moves in opposite directions during pulsed laser deposition.

[0069] In step 4), the specific steps of the cooling post-treatment are as follows: place it in an atmosphere of 600℃ and 100mTorr oxygen partial pressure for 7 minutes; then cool it to room temperature at a cooling rate of 4℃ / min.

[0070] Example 4 A functional thin film material with a high-throughput composition gradient includes a substrate layer, a bottom electrode layer, and a functional layer stacked sequentially, wherein the composition of the functional layer is Pb(Zr) 1-x Sn x )O3, of which Pb(Zr 1-x Sn x The PbZrO3 layer consists of PbZrO3 and SnO2 dissolved in the PbZrO3 layer, with x = 0~0.08. The functional layer is a solid solution film with alternating growth of PbZrO3 layer (antiferroelectric layer) and SnO2 layer. In the functional layer, the content of PbZrO3 gradually decreases in the horizontal direction, and the content of SnO2 gradually increases in the same direction (i.e., x gradually increases from 0 to 0.08 in this direction).

[0071] The substrate is a rigid substrate (SrTiO3) with an orientation of

[111] and an area of ​​1.5cm × 1.5cm.

[0072] The bottom electrode layer is a SrRuO3 thin film with a thickness of 35 nm.

[0073] The thickness of the functional layer is 235±5nm.

[0074] This embodiment also provides a method for preparing the functional thin film material, which specifically includes the following steps: 1) The substrate layer is bonded and then placed directly above the main target on the substrate stage in the deposition chamber of the pulsed laser deposition equipment, with the distance between the substrate layer and the target material controlled to be 52cm; 2) A bottom electrode layer is grown on the substrate using pulsed laser deposition. 3) A functional layer is grown on the bottom electrode layer using a high-throughput pulsed laser deposition process; 4) Perform cooling post-treatment to obtain functional thin film materials.

[0075] In step 2), the specific parameters of the high-throughput pulsed laser deposition process are: the vacuum degree of the deposition cavity is 9 × 10⁻⁶. -7 With a deposition temperature of 625 °C, an oxygen partial pressure of 105 mTorr, a laser energy of 360 mJ, a pulsed laser frequency of 10 Hz, a heating rate to the deposition temperature of 21 °C / min, and a laser focal length of +20 mm, the deposition rate is approximately 17 nm / min.

[0076] In step 3), the specific steps of the high-throughput pulsed laser deposition process are as follows: a. Place the PbZrO3 target and the SnO2 target on two adjacent target sites respectively; b. Set the relevant parameters as follows: Vacuum degree of the deposition chamber is 9×10 -7 Pa, deposition temperature 610 ℃, oxygen partial pressure 105 mTorr, heating rate to deposition temperature 25℃ / min, deposition rate at this point approximately 15 nm / min; total laser firing rate 37,000 shots; c. Move the substrate stage to a safe height; d. First layer gradient: Move the substrate stage and mask to the initial position at speeds of 6 mm / s and 7 mm / s, respectively; then lower the substrate stage to the deposition position, switch the main target to PbZrO3 target, and set the specific parameters of the high-throughput pulsed laser deposition process as follows: laser energy of 360 mJ, pulsed laser frequency of 10 Hz, number of laser shots of 1362, laser focal length of +30 mm, target rotation speed of 21°, and mask moving speed along the X direction of 0.17 mm / s; The mask has through holes (square holes) that match the shape and size of the functional layer. The mask can move along the X direction, which is parallel to the horizontal plane. When the substrate stage and the mask are in the initial position, the orthographic projection of the through holes on the substrate stage partially coincides with the area where the functional layer is located. The size of the overlapping area in the X direction is 1 mm. e. Second gradient: Move the substrate stage to a safe height, then rotate the substrate stage 180°, and move the mask to the initial position at a speed of 7 mm / s; then lower the substrate stage to the deposition position, switch the main target to SnO2 target, and set the specific parameters of the high-throughput pulsed laser deposition process as follows: laser energy of 360 mJ, pulsed laser frequency of 10 Hz, number of laser shots of 118, laser focal length of +20 mm, target rotation speed of 22°, and mask moving speed along the X direction of 0.22 mm / s; f. Move the mask along the X direction to the initial position, move the substrate stage to a safe height, and complete one deposition. g. Repeat steps d to f 25 times; In steps d and e, the mask moves in opposite directions during pulsed laser deposition.

[0077] In step 4), the specific steps of the cooling post-treatment are as follows: place it in an atmosphere of 610℃ and 105mTorr oxygen partial pressure for 8 minutes; then cool it to room temperature at a cooling rate of 7℃ / min.

[0078] Comparative Example 1 An antiferroelectric thin film material includes: a substrate layer, and a bottom electrode layer and an antiferroelectric layer sequentially grown on the substrate layer; the antiferroelectric layer is composed of PbZrO3.

[0079] The substrate is a rigid substrate (SrTiO3) with an orientation of

[111] and an area of ​​1.5cm × 1.5cm.

[0080] This comparative example also provides a method for preparing the antiferroelectric thin film material, specifically including: 1) The substrate is bonded and then placed directly above the main target on the substrate stage in the deposition chamber of the pulsed laser deposition equipment, with the distance between the substrate and the target controlled to be 40cm. 2) A bottom electrode layer (SrRuO3 thin film with a thickness of 32nm) is grown on the substrate using pulsed laser deposition. 3) An antiferroelectric layer is grown on the bottom electrode layer using pulsed laser deposition. 4) Perform cooling post-treatment to obtain antiferroelectric thin film material.

[0081] In step 2), the specific parameters of the pulsed laser deposition process are as follows: the target material is SrRuO3; the vacuum degree of the deposition cavity is ≤2×10⁻⁶. -7At a given temperature of 580℃, an oxygen partial pressure of 60 mTorr, a laser energy of 290 mJ, a pulsed laser frequency of 6 Hz, a heating rate to the deposition temperature of 16℃ / min, a laser focal length of -10 mm, and 2500 laser shots, the deposition rate is approximately 8 nm / min.

[0082] In step 3), the specific parameters of the pulsed laser deposition process are as follows: the target material is PbZrO3; the vacuum degree of the deposition cavity is ≤2×10⁻⁶. -7 The deposition temperature is 500 ℃, the oxygen partial pressure is 80 mTorr, the laser energy is 290 mJ, the pulsed laser frequency is 6 Hz, the deposition rate is 20 ℃ / min, the laser focal length is -5 mm, the deposition rate is approximately 10 nm / min, the number of laser shots is 36,000, and the target rotation speed is 16°.

[0083] Step 4) The specific steps of the cooling post-treatment are as follows: place it in an atmosphere of 500℃ and 80mTorr oxygen partial pressure for 5 minutes; then cool it to room temperature at a cooling rate of 2℃ / min.

[0084] Comparative Example 2 An antiferroelectric thin film material includes: a substrate layer, and a bottom electrode layer and an antiferroelectric layer sequentially grown on the substrate layer; the antiferroelectric layer is composed of PbZrO3.

[0085] The substrate is a rigid substrate (SrTiO3) with an orientation of

[111] and an area of ​​1.5cm × 1.5cm.

[0086] This comparative example also provides a method for preparing the antiferroelectric thin film, which specifically includes the following steps: 1) The substrate is bonded and then placed directly above the main target on the substrate stage in the deposition chamber of the pulsed laser deposition equipment, with the distance between the substrate and the target controlled to be 45cm. 2) A bottom electrode layer (SrRuO3 thin film with a thickness of 32 mm) is grown on the substrate using pulsed laser deposition. 3) An antiferroelectric layer is grown on the bottom electrode layer using pulsed laser deposition. 4) Perform cooling post-treatment to obtain antiferroelectric thin film material.

[0087] In step 2), the specific parameters of the pulsed laser deposition process are as follows: the target material is SrRuO3; the vacuum degree of the deposition cavity is ≤4×10⁻⁶. -7At a given temperature of 600℃, an oxygen partial pressure of 80 mTorr, a laser energy of 320 mJ, a pulsed laser frequency of 8 Hz, a heating rate to the deposition temperature of 18℃ / min, a laser focal length of 0 mm, and 2500 laser shots, the deposition rate is approximately 10 nm / min.

[0088] In step 3), the specific parameters of the pulsed laser deposition process are as follows: the target material is a PbZrO3 target; the vacuum degree of the deposition cavity is ≤4×10⁻⁶. -7 The deposition temperature is 550 °C, the oxygen partial pressure is 90 mTorr, the laser energy is 320 mJ, the pulsed laser frequency is 8 Hz, the heating rate to the deposition temperature is 22 °C / min, the laser focal length is +5 mm, the deposition rate is approximately 12 nm / min, the number of laser shots is 36,000, and the target rotation speed is 18°.

[0089] In step 4), the specific steps of the cooling post-treatment are as follows: place it in an atmosphere of 550℃ and 90mTorr oxygen partial pressure for 6 minutes; then cool it to room temperature at a cooling rate of 3℃ / min.

[0090] Comparative Example 3 An antiferroelectric thin film material includes: a substrate layer, and a bottom electrode layer and an antiferroelectric layer sequentially grown on the substrate layer; the antiferroelectric layer is a thin film grown from PbZrO3.

[0091] The substrate is a rigid substrate (SrTiO3) with an orientation of

[111] and an area of ​​1.5cm × 1.5cm.

[0092] This comparative example also provides a method for preparing the antiferroelectric thin film, which specifically includes the following steps: 1) The substrate is bonded and then placed directly above the main target on the substrate stage in the deposition chamber of the pulsed laser deposition equipment, with the distance between the substrate and the target material controlled to be 50cm. 2) A bottom electrode layer (SrRuO3 thin film with a thickness of 32nm) is grown on the substrate using pulsed laser deposition. 3) An antiferroelectric layer is grown on the bottom electrode layer using pulsed laser deposition. 4) Perform cooling post-treatment to obtain antiferroelectric thin film material.

[0093] In step 2), the specific parameters of the pulsed laser deposition process are as follows: the target material is SrRuO3; the vacuum degree of the deposition cavity is ≤6×10⁻⁶. -7With a deposition temperature of 620℃, an oxygen partial pressure of 100 mTorr, a laser energy of 350 mJ, a pulsed laser frequency of 10 Hz, a heating rate to the deposition temperature of 20℃ / min, a laser focal length of +10 mm, and 2500 laser shots, the deposition rate is approximately 12 nm / min.

[0094] In step 3), the specific parameters of the pulsed laser deposition process are as follows: the target material is a PbZrO3 target; the vacuum degree of the deposition cavity is ≤6×10⁻⁶. -7 The deposition temperature is 600 ℃, the oxygen partial pressure is 100 mTorr, the laser energy is 350 mJ, the pulsed laser frequency is 10 Hz, the heating rate to the deposition temperature is 24 ℃ / min, the laser focal length is +15 mm, the deposition rate is approximately 14 nm / min, the number of laser shots is 36,000, and the target rotation speed is 20°.

[0095] In step 4), the specific steps of the cooling post-treatment are as follows: place it in an atmosphere of 600℃ and 100mTorr oxygen partial pressure for 7 minutes; then cool it to room temperature at a cooling rate of 4℃ / min.

[0096] Comparative Example 4 An antiferroelectric thin film includes: a substrate layer, and a bottom electrode layer and an antiferroelectric layer sequentially grown on the substrate layer; the antiferroelectric layer is composed of PbZrO3.

[0097] The substrate is a rigid substrate (SrTiO3) with an orientation of

[111] and an area of ​​1.5cm × 1.5cm.

[0098] This comparative example also provides a method for preparing the antiferroelectric thin film material, which specifically includes the following steps: 1) The substrate is bonded and then placed directly above the main target on the substrate stage in the deposition chamber of the pulsed laser deposition equipment, with the distance between the substrate and the target controlled to be 55cm. 2) A bottom electrode layer (SrRuO3 thin film with a thickness of 32nm) is grown on the substrate using pulsed laser deposition. 3) An antiferroelectric layer is grown on the bottom electrode layer using pulsed laser deposition. 4) Perform cooling post-treatment to obtain antiferroelectric thin film material.

[0099] In step 2), the specific parameters of the pulsed laser deposition process are as follows: the target material is SrRuO3; the vacuum degree of the deposition cavity is ≤8×10⁻⁶. -7At a given temperature of 640℃, oxygen partial pressure of 120 mTorr, laser energy of 380 mJ, pulsed laser frequency of 10 Hz, heating rate to deposition temperature of 22℃ / min, laser focal length of +20 mm, and laser firing rate of 2500, the deposition rate is approximately 14 nm / min.

[0100] In step 3), the specific parameters of the pulsed laser deposition process are as follows: the target material is a PbZrO3 target; the vacuum degree of the deposition cavity is ≤8×10⁻⁶. -7 The deposition temperature is 650℃, the oxygen partial pressure is 110mTorr, the laser energy is 380mJ, the pulsed laser frequency is 10Hz, the heating rate to the deposition temperature is 26℃ / min, the laser focal length is +25mm, the deposition rate is approximately 16nm / min, the number of laser shots is 36000, and the target rotation speed is 22°.

[0101] In step 4), the specific steps of the cooling post-treatment are as follows: place it in an oxygen partial pressure atmosphere of 110 mTorr at 650℃ for 8 minutes; then cool it to room temperature at a cooling rate of 5℃ / min.

[0102] After Au electrode layers were prepared on the top surface of each antiferroelectric thin film material and functional thin film material using a thin film sputtering instrument, the antiferroelectric properties of the target section of the functional thin film material and the antiferroelectric thin film material were measured using a ferroelectric analyzer.

[0103] Figure 1 This shows the polarization intensity-voltage diagrams for the antiferroelectric thin film materials in Comparative Examples 1-4. Figure 1 As can be seen, the antiferroelectric thin film materials in Comparative Examples 1 to 4 all exhibit typical antiferroelectric properties. Among them, the antiferroelectric thin film material in Comparative Example 3 has superior electrical properties and also possesses a high saturation polarization intensity (approximately 48 μC / cm). 2 and a low remanent polarization intensity (approximately 5 μC / cm). 2 Therefore, the preparation process parameters of the functional thin film materials in Examples 1-4 were obtained by optimizing the process parameters of Comparative Example 3.

[0104] Figure 2 The figures show the polarization intensity-voltage diagrams for the x=0 region in the functional layers of the functional thin film materials of Examples 1-4. As can be seen from the figures, the functional thin film materials of Examples 1-4 all exhibit typical antiferroelectric properties. The functional thin film material of Example 3 has a higher saturation polarization value (approximately 52 μC / cm²) compared to Examples 1, 2, and 4. 2 and a lower remanent polarization (approximately 1 μC / cm). 2 ).

[0105] Example 5 Example 3 was repeated, with the only difference being that the number of laser shots in step d was 1288, and the number of laser shots in step e was 112. Thus, a functional thin film material with a functional layer thickness of approximately 200-210 nm was obtained.

[0106] Example 6 Example 3 was repeated, with the only difference being that the number of laser shots in step d was 1472, and the number of laser shots in step e was 128. Thus, a functional thin film material with a functional layer thickness of approximately 210-220 nm was obtained.

[0107] Example 7 Example 3 was repeated, except that the number of laser shots in step d was 1840 and the number of laser shots in step e was 160. Thus, a functional thin film material with a functional layer thickness of approximately 230-240 nm was obtained.

[0108] Figure 3 The graphs show the polarization intensity-voltage distribution in the x=0 region of the functional thin film materials in Examples 3 and 5-7. As can be seen from the graphs, the saturation polarization intensity of the resulting functional thin film materials first increases and then decreases with increasing functional layer thickness. The saturation polarization intensity reaches its maximum value when the functional layer thickness is 220~230 nm (i.e., 225±5 nm, Example 3). This indicates that controlling the functional layer thickness within a suitable range helps to obtain superior antiferroelectric properties.

[0109] Figure 4 This is a schematic diagram of a functional thin film material with a high-throughput composition gradient prepared by a high-throughput experimental method. First, a bottom electrode layer is prepared on a substrate. Then, a mask is moved along the X-direction to prepare a functional layer with a gradually changing composition gradient, which can be used to more accurately screen functional thin film materials with excellent antiferroelectric properties.

[0110] Figure 5 This is a compositional distribution diagram of the functional layer along the X-direction in Example 3, and magnified X-ray photoelectron spectroscopy (XPS) of each segment along the X-direction. In the segment where x=0, no Sn was detected in the XPS spectrum. 4+ The relevant signals confirmed the absence of Sn doping in this region. Furthermore, binding energies at approximately 181.6 eV and 183.9 eV clearly identified the corresponding Zr 3d... 5 / 2 and Zr3d 3 / 2 Characteristic peaks. In the x=0.01 region, two new characteristic peaks appear, with binding energies of approximately 486.7 eV and 494.3 eV, respectively. These characteristic peaks are attributed to the 3d... 5 / 2 and 3D 3 / 2 Orbit. In each segment of the functional layer, as the Sn element content increases from x=0 to x=0.08, Sn 3d 5 / 2and Sn 3d 3 / 2 The peak intensity gradually increased, thus confirming the successful preparation of the functional layer with compositional gradient changes.

[0111] Figure 6 Zr 3d in each segment of the functional layer of the functional thin film material in Example 3 5 / 2 and Sn 3d 5 / 2 The graph shows the change in Sn peak height with increasing Sn content. It can be seen that the Sn peak height increases as the Zr peak height decreases, further confirming the successful preparation of the functional layer with compositional gradient variation.

[0112] Figure 7 The images show a transmission electron microscope (TEM) image (perpendicular to the X-direction) of the functional thin film material in Example 3, along with the corresponding energy dispersive spectroscopy (EDS) elemental distribution map. The images clearly demonstrate the high-quality epitaxial growth of the functional thin film material, with sharp and clear interfaces between the substrate layer and the bottom electrode layer, and between the bottom electrode layer and the functional layer. The thickness of the functional layer is approximately 224.3 nm. Furthermore, the EDS elemental distribution map reveals the uniform distribution of Ti, Ru, Pb, Zr, and Sn in their respective layers, without significant separation or phase separation.

[0113] Example 8 Example 3 was repeated, except that the number of laser shots in step d was 1735 and the number of laser shots in step e was 65. Thus, in the functional layer of the obtained functional thin film material, the content of PbZrO3 gradually decreases horizontally, while the content of SnO2 gradually increases in the same direction (i.e., x gradually increases from 0 to 0.036 along this direction).

[0114] Figure 8 and Figure 9 The polarization-voltage and current-voltage diagrams for the functional thin film materials of Examples 3 and 8 are shown for different Sn element content ranges (x = 0.01~0.08 and x = 0.004~0.036), respectively. After two sets of precise high-throughput component screening, the high-throughput component gradient Pb(Zr) was determined. 1-x Sn xThe compositional window for stable antiferroelectricity in O3 thin films was determined. Based on data from x to 0.08, a "full" double-ring hysteresis loop was observed, with the x=0.02 segment exhibiting more stable antiferroelectricity. Further analysis of the compositional range from x to 0.004 to 0.036 revealed that the x=0.012~0.020 segment exhibited a superior double-ring hysteresis loop and a quadruple switching peak. The polarization intensity and current value initially increased and then decreased with increasing Sn content, ultimately showing the most significant stability of antiferroelectricity at x=0.016. Furthermore, the remanent polarization value in the x=0.016 segment was also relatively low, only about 1.3 μC / cm. 2 .

[0115] Figure 10 The saturation polarization intensity and current values ​​of the functional thin film material in Example 8 are shown in the range of different Sn element contents (x = 0.004~0.036). It can be seen that when x = 0.016, the functional thin film material has a larger saturation polarization intensity (approximately 57 μC / cm). 2 ) and current value (approximately 0.45mA).

[0116] Figure 11 and Figure 12 The figure shows the polarization intensity-voltage diagram of the functional thin film material in Example 8 under temperature dependence (175℃~275℃) in different Sn element content ranges (0.004≤x≤0.036). As can be seen from the figure, for the undoped region (x=0), the characteristic double hysteresis curve gradually evolves into a finer relaxation-type antiferroelectric loop with increasing temperature. This corresponds to the phase transition film from the antiferroelectric phase to an intermediate phase with mixed antiferroelectric and positive electrical properties. When x ≤ 0.004≤x≤0.016, the transition temperature from the antiferroelectric phase to positive electrical properties of the functional thin film material is around 235℃, demonstrating that the antiferroelectricity maintains relatively good stability within this range. When x ≥ 0.020, the transition temperature from the antiferroelectric phase to positive electrical properties of the functional thin film material decreases significantly due to the influence of Sn element content (from 235℃ to 225℃ or even 215℃), which will lead to increased instability of the antiferroelectric phase. It is evident that when x = 0.012~0.016, the thin film exhibits both a relatively high phase transition temperature and superior antiferroelectric properties. These results demonstrate that the functional thin film of this invention possesses good high-temperature resistance and can still maintain excellent antiferroelectric properties under high temperature conditions.

[0117] In summary, the functional thin film material based on high-throughput component gradient screening of the present invention has excellent antiferroelectric properties.

[0118] The above embodiments should be understood as being used only to illustrate the present invention more clearly, and not to limit the scope of the present invention. After reading the present invention, any modifications of the present invention in various equivalent forms by those skilled in the art fall within the scope defined by the appended claims.

Claims

1. A functional thin film material based on high-throughput composition gradient screening, comprising a substrate layer, a bottom electrode layer, and a functional layer stacked sequentially, characterized in that, The functional layer is composed of Pb(Zr) 1-x Sn x )O3, of which, Pb(Zr 1-x Sn x The O3 is composed of PbZrO3 and SnO2 dissolved in the PbZrO3, x=0.012~0.016; the thickness of the functional layer is 220-230nm; the substrate is an SrTiO3 substrate, and the SrTiO3 orientation is [111]; the bottom electrode layer is an SrRuO3 layer.

2. The functional thin film material according to claim 1, characterized in that, x=0.014~0.016。 3. The functional thin film material according to any one of claims 1-2, characterized in that, The thickness of the bottom electrode layer is 20~35nm.

4. The method for preparing the functional thin film material according to any one of claims 1-3, characterized in that, Includes the following steps: S1, Provide a substrate layer; S2. A bottom electrode layer is deposited on the substrate layer using a pulsed laser deposition process; S3. A functional layer is deposited on the bottom electrode layer using a pulsed laser deposition process; S4. Perform cooling post-processing to obtain functional thin film material.

5. The method for preparing the functional thin film material according to claim 4, characterized in that, In S2, the specific parameters for the pulsed laser deposition process are: the vacuum level of the deposition cavity is 6 × 10⁻⁶. -7 ~9×10 -7 Pa, deposition temperature of 610~625℃, oxygen partial pressure of 90~105mTorr, laser energy of 330~360mJ, pulsed laser frequency of 8~10Hz, laser focal length of -10~+20mm, and laser firing rate of 2000~3000 shots.

6. The method for preparing the functional thin film material according to claim 4, characterized in that, In S3, the specific steps of the pulsed laser deposition process include: a. Place the PbZrO3 target and the SnO2 target on two adjacent target sites respectively; b. Bond the substrate layer and then place it directly above the main target position on the substrate stage in the deposition chamber. The distance between the substrate layer and the target is 46~52cm. c. Move the substrate stage to a safe height; d. Move the substrate stage and mask to their initial positions, then lower the substrate stage to the deposition position. Switch the main target to a PbZrO3 target. Set the specific parameters for the pulsed laser deposition process as follows: vacuum level of the deposition chamber is 6 × 10⁻⁶. -7 ~9×10 -7 Pa, deposition temperature of 580~610℃, oxygen partial pressure of 90~105mTorr, laser energy of 330~360mJ, pulsed laser frequency of 8~10Hz, number of laser shots of 1362~3128, laser focal length of -15~+30mm, and target rotation speed of 18~21°. The mask has through holes that match the shape and size of the functional layer; when the substrate stage and the mask are in the initial position, the orthographic projection of the through holes on the substrate stage coincides with the area where the functional layer is located. e. Switch the main target to SnO2 target and set the specific parameters for the pulsed laser deposition process as follows: vacuum level of the deposition chamber is 6 × 10⁻⁶. -7 ~9×10 -7 Pa, deposition temperature of 580~610℃, oxygen partial pressure of 90~105mTorr, laser energy of 330~360mJ, pulsed laser frequency of 8~10Hz, number of laser shots of 118~272, laser focal length of -10~+20mm, and target rotation speed of 15~22°. f. Move the substrate stage to a safe height to complete one deposition cycle; g. Repeat steps d to f 10 to 25 times.

7. The method for preparing the functional thin film material according to claim 6, characterized in that, In step d, the number of laser shots is 1640-1660; in step e, the number of laser shots is 140-150; in step g, the process of steps d-f is repeated 18-22 times.

8. The method for preparing the functional thin film material according to claim 4, characterized in that, In S4, during the post-cooling treatment, the sample is first placed at 580~610℃ and 90~105mTorr oxygen partial pressure for 4~8 min; then cooled to room temperature at a rate of 1~7℃ / min.

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