In-situ field-induced rotating spray deposition device for thin film of ferrite and application thereof

Abstract

This invention discloses an in-situ magnetic field-induced spin-coating deposition apparatus for ferrite thin films and its application. The apparatus includes a spin-support and temperature control unit, comprising a heat-conducting disk and a temperature control layer, the temperature control layer being used to heat the heat-conducting disk; a dual-channel atomizing spray unit; an in-situ vertical magnetic field generating unit, comprising a lower coil disposed above the spin-support and temperature control unit and an upper coil disposed above the lower coil; and an iron outer shell disposed outside a reaction chamber. The reaction chamber is composed of the spin-support and temperature control unit, the dual-channel atomizing spray unit, and the in-situ vertical magnetic field generating unit. This invention enables the application of an in-situ DC vertical magnetic field in the film deposition space, enhancing orientation during nucleation and early growth stages, significantly improving the effective permeability of the film in the out-of-plane direction, while not obstructing the atomizing spray and spin-coating space, thus avoiding interference from external magnets on the spraying, spin-coating, and temperature control structures.

Description

Technical Field

[0001] This invention belongs to the field of magnetic thin film preparation technology, specifically relating to an in-situ magnetic field-induced rotary spray deposition apparatus for ferrite thin films and its application. Background Technology

[0002] With the development of RF front-ends, power management, and on-chip systems towards higher frequencies, smaller sizes, and higher integration, on-chip passive devices such as helical on-chip inductors and miniature transformers are widely used in impedance matching, filtering resonance, and DC-DC conversion. Helical on-chip inductors typically have a planar helical wire structure, with the operating magnetic flux exiting through the central region of the helical coil and closing in the vertical space. Therefore, a significant magnetic flux component perpendicular to the substrate exists in the magnetic circuit. To increase inductance density within a limited chip area, a ferrite core thin film is usually introduced near the helical wire to improve magnetic flux coupling and effective permeability, thereby increasing the equivalent inductance and reducing leakage flux.

[0003] However, ferrite thin films are typical two-dimensional thin-layer structures with a large demagnetization factor in the vertical direction. If the film lacks sufficient out-of-plane anisotropy, the magnetic moment is easily collapsed into the film surface under the action of the demagnetizing field, resulting in a low effective permeability of the film in the out-of-plane direction. This leads to insufficient coupling of the out-of-plane magnetic flux of the spiral-shaped on-chip inductor, limiting the inductance enhancement effect and making it difficult to guarantee consistency on large-area substrates.

[0004] On the other hand, spin coating deposition processes typically include atomized spraying, a rotating platform, and a temperature control structure, and apply an in-plane magnetic field parallel to the thin film plane using a permanent magnet. Chinese Patent CN 117966135A discloses a (222) low-temperature preparation method for oriented growth of nickel-zinc ferrite thin films, which discloses the preparation of Ni on a glass substrate by spin coating under an external magnetic field of 360 Oe. 0.27 Zn 0.1 Fe 2.63 O4 thin film, and the external permanent magnet or external electromagnet applies a parallel magnetic field from outside the cavity, which cannot meet the requirements of external magnetic field induction in the application of helical inductor. It is also prone to structural interference with nozzle, rotation, and temperature control space. In addition, the external magnetic field circuit is not closed, the distribution is divergent and affected by assembly deviation and temperature rise drift, making it difficult to achieve programmable and repeatable control of magnetic field strength and perpendicularity, which further limits the large-area orientation consistency and process window controllability.

[0005] Therefore, there is an urgent need to develop a device that is highly compatible with the rotary spraying space and can provide a stable, adjustable and reliable in-situ DC vertical magnetic field in the film formation space. This device enables ferrite films to achieve out-of-plane preferential orientation during the nucleation and early growth stages. The out-of-plane magnetic field induces vertical magnetic anisotropy, which matches the magnetization direction with the working magnetic flux (magnetic circuit) of the helical inductor, thereby reducing eddy current losses, increasing permeability and Q value, and significantly improving high-frequency performance, thus meeting the application requirements of on-chip helical inductor core films. Summary of the Invention

[0006] To address the shortcomings of existing technologies, an in-situ magnetic field-induced out-of-plane anisotropic rotary spray deposition apparatus for ferrite thin films and its application are provided.

[0007] The objective of this invention is achieved through the following technical solution: In a first aspect, the present invention provides an in-situ magnetic field-induced rotary spray deposition apparatus for ferrite thin films, comprising, A rotating bearing and temperature control unit includes a heat-conducting plate and a temperature control layer, wherein the temperature control layer is used to heat the heat-conducting plate; Dual-channel atomizing spray unit; The in-situ vertical magnetic field generating unit includes a lower coil disposed above the rotating bearing and temperature control unit and an upper coil disposed above the lower coil; An iron outer shell is located outside the reaction chamber, which is composed of a rotating bearing and temperature control unit, a dual-channel atomizing spray unit, and an in-situ vertical magnetic field generating unit. When energized, the upper and lower coils form a DC magnetic field perpendicular to the surface of the heat-conducting plate in their original positions.

[0008] In some specific embodiments of the present invention, the rotating bearing and temperature control unit further includes a Hall sensor, which is used to monitor the magnetic field strength generated by the in-situ vertical magnetic field generating unit in real time.

[0009] Secondly, the present invention provides an application of the rotary spray deposition apparatus described in the first aspect in the preparation of out-of-plane magnetic anisotropic ferrite thin films, the application including... The pretreated substrate is fixed on the heat transfer plate of the rotary spray deposition apparatus, and the rotation is started after the substrate is controlled at 90~150℃. The reduction reaction solution and the oxidation reaction solution are sprayed onto the substrate surface through a dual-channel atomization spray unit. A DC magnetic field is applied perpendicular to the substrate in situ through an in-situ vertical magnetic field generating unit to carry out the deposition reaction, thereby obtaining an out-of-plane magnetic anisotropic ferrite film.

[0010] In some specific embodiments of the present invention, the deposition reaction is carried out by applying a DC magnetic field perpendicular to the substrate in situ, wherein the time for applying the DC magnetic field in situ includes the first 30 to 90 seconds of the deposition reaction process and the entire deposition reaction process.

[0011] In some specific embodiments of the present invention, the magnetic field strength of the DC magnetic field is 20 to 200 Oe.

[0012] In some specific embodiments of the present invention, the substrate is controlled at 90~150°C and then the rotation is started, wherein the rotation speed is 90~300 rpm.

[0013] In some specific embodiments of the present invention, the reduction reaction solution and the oxidation reaction solution are sprayed onto the substrate surface through a dual-channel atomizing spray unit. The atomization method of the dual-channel atomizing spray unit includes one or more of ultrasonic atomization and pneumatic atomization.

[0014] In some specific embodiments of the present invention, the supply rate of the reduction reaction solution is 10-20 mL / min, and the supply rate of the oxidation reaction solution is 10-20 mL / min.

[0015] In some specific embodiments of the present invention, the median droplet size of the dual-channel atomizing spray unit is 20~80 μm, and the distance from the nozzle of the dual-channel atomizing spray unit to the substrate is 10~45 mm during spraying.

[0016] In some specific embodiments of the present invention, the ferrite includes one of nickel-zinc ferrite, nickel ferrite, and zinc ferrite.

[0017] The beneficial effects achieved by this invention are as follows: (1) The rotary spraying deposition apparatus provided by the present invention can apply a DC vertical magnetic field in situ in the film formation space through an in-situ vertical magnetic field generating unit. The structure configuration of the coil inside the cavity and the closed magnetic circuit outside the cavity can avoid obstructing the atomization spraying and rotation space, effectively avoiding interference between the external magnet or external electromagnet and the spraying, rotation and temperature control structure. Furthermore, the rotary spraying apparatus can make the magnetic field strength fluctuation and verticality deviation controllable through the closed-loop adjustment of the Hall sensor array and the controller, reducing the impact of temperature rise drift and assembly deviation on the consistency of film orientation, and can be applied to large-area substrates and batch process window curing.

[0018] (2) The rotary spraying deposition apparatus provided by the present invention can independently adjust the magnetic field strength, application timing, temperature, rotation and liquid supply parameters, which facilitates the rapid establishment of an optimal window for different ferrite systems and migration to on-chip device processes.

[0019] (3) The application of the rotary spraying deposition apparatus provided by the present invention in the preparation of out-of-plane magnetic anisotropic ferrite thin films can apply a DC magnetic field perpendicular to the substrate in situ during the preparation of out-of-plane magnetic anisotropic ferrite thin films, thereby strengthening the orientation in the nucleation and early growth stages, significantly improving the effective permeability of the out-of-plane direction of the ferrite thin film, which is beneficial to the out-of-plane magnetic flux of the coupled helical on-chip inductor, increasing the inductance density per unit area and reducing leakage flux. Attached Figure Description

[0020] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the overall structure of the rotary spray deposition apparatus of Embodiment 1 of the present invention.

[0022] Figure 2 This is a schematic diagram of the rotating bearing and temperature control unit in the rotary spraying deposition apparatus of Embodiment 1 of the present invention.

[0023] Figure 3 The images show the XRD patterns of the ferrite films prepared in Examples 2-4 and Comparative Example 1 of this invention.

[0024] Figure 4 The diagram shows a comparison of the hysteresis loops of the ferrite thin films prepared in Examples 2-4 and Comparative Example 1 of this invention.

[0025] Reference numerals: 1-Rotating bearing and temperature control unit, 101-Heat conduction plate, 102-Air path layer, 103-Temperature control layer, 104-Filling layer, 105-Base, 106-Opening, 107-Hall sensor, 108-Thermocouple temperature sensor, 2-Dual-channel atomizing spray unit, 3-In-situ vertical magnetic field generating unit, 301-Upper coil, 302-Lower coil, 4-Iron shell. Detailed Implementation

[0026] The present invention will be further described in detail below with reference to specific embodiments. The following embodiments are not intended to limit the present invention, but only to illustrate the present invention. Unless otherwise specified, the experimental methods used in the following embodiments are generally performed under conventional conditions. Unless otherwise specified, the materials and reagents used in the following embodiments are commercially available.

[0027] Example 1

[0028] This embodiment provides an in-situ magnetic field-induced out-of-plane anisotropic rotary spray deposition apparatus for ferrite thin films, specifically including... The rotating bearing and temperature control unit 1 includes a heat-conducting plate 101, an air passage layer 102, a temperature control layer 103, a filling layer 104, a base 105, an opening 106, a Hall sensor 107, and a thermocouple temperature sensor 108.

[0029] The heat-conducting plate 101 has vent holes 1011 on its surface, which are connected to the spiral air passage 1021 of the air passage layer 102 to provide vacuum adsorption force and fix the substrate to be deposited. The temperature control layer 103 is a temperature control component composed of mica heating elements. The filling layer 104 separates the temperature control layer 103 from the base 105 through the filler. The base 105 has a groove on the surface near the temperature control layer, in which the Hall sensor 107 and the thermocouple temperature sensor 108 are embedded. The base 105 has an opening 106 that passes through the base 105, the filling layer 104, the temperature control layer 103, and the air passage layer 102. The opening 106 is inserted into a rotary bearing, which includes wires and signal lines.

[0030] When powered on, the mica heating element in the temperature control layer 103 provides a stable heat source, the filling layer 104 provides insulation, and the opening 106 connects to a rotating bearing. The bearing integrates wires and signal lines, providing rotational power to the platform and transmitting signals from the Hall sensor 107 and thermocouple 108, thus achieving closed-loop control. The thermocouple temperature sensor 108 embedded in the base 105 monitors the temperature in real time. The controller precisely controls the surface temperature of the heat-conducting plate 101 based on the real-time monitoring value of the thermocouple temperature sensor 108, ensuring that the substrate temperature is maintained within the optimal range required for ferrite precursor solvent evaporation and film formation, avoiding excessively high or low temperatures.

[0031] The dual-channel atomizing spray unit 2 converts the ferrite precursor liquid into uniform droplets and delivers them to the rotating substrate surface. The atomized droplets have a uniform particle size, and with the centrifugal force of the rotating platform, the droplets will spread rapidly on the substrate surface to form a continuous, defect-free, and uniformly thick precursor film.

[0032] The in-situ vertical magnetic field generating unit 3 includes a lower coil 302 disposed above the rotating bearing and temperature control unit 1 and an upper coil 301 disposed above the lower coil.

[0033] When energized, the dual coils generate a uniform magnetic field perpendicular to the substrate surface. The Hall sensor 107, along with the controller, constant current drive power supply, and coil current, forms a closed-loop magnetic field control module: Hall sensor—controller—drive power supply—coil current. The controller adjusts the current of the upper coil 301 and lower coil 302 based on the real-time measurement value of the Hall sensor 107, thereby ensuring a uniform and stable magnetic field and avoiding orientation inhomogeneity caused by magnetic field fluctuations. Under the influence of this magnetic field, magnetic particles or ions in the ferrite precursor align oriented along the magnetic field direction. During subsequent thin film crystallization, the magnetocrystalline easy axis grows perpendicular to the film surface, forming out-of-plane magnetic anisotropy, thus significantly improving the magnetic properties of the ferrite thin film.

[0034] The iron outer shell 4 is located outside the reaction chamber, which is composed of a rotating bearing and temperature control unit 1, a dual-channel atomizing spray unit 2, and an in-situ vertical magnetic field generating unit 3.

[0035] Figure 1 This is a schematic diagram of the overall structure of the rotary spray deposition apparatus of Example 1.

[0036] Figure 2 This is a schematic diagram of the rotating bearing and temperature control unit in the rotary spraying deposition apparatus of Example 1. In this diagram, A is a cross-sectional view of the rotating bearing and temperature control unit 1, B is an enlarged view of the positional relationship of the temperature control layer 103, the filler layer 104, and the base 105 of the rotating bearing and temperature control unit, and C is an enlarged view of the positional relationship of the base 105, the Hall sensor 107, and the thermocouple temperature sensor 108.

[0037] Example 2

[0038] This embodiment uses the rotary spray deposition apparatus of Example 1 to prepare out-of-plane magnetic anisotropic ferrite thin films, specifically: (1) Substrate pretreatment and fixation: The glass substrate is ultrasonically cleaned sequentially with anhydrous ethanol and high-purity deionized water. The ultrasonic cleaning power is 100W and the cleaning time is 1min each time. The pretreated 4-inch glass substrate is fixed on the heat transfer plate of the rotary spray deposition device. The substrate temperature is controlled at 120℃ and then the rotation is started at 100 rpm. The temperature of the substrate can be controlled within the range of 120±1.0℃ through the rotation bearing and the temperature control layer in the temperature control unit. (2) Preparation of the precursor solution: Preparation of reduction reaction solution: Weigh 4.97g of FeCl2·4H2O, 0.95g of NiCl2·6H2O, and 0.27g of ZnCl2, and dissolve them sequentially in 200 mL of high-purity deionized water that has been pretreated with nitrogen to remove oxygen, to obtain the reduction reaction solution; Preparation of oxidation reaction solution: Weigh 0.345g of NaNO2 and 4.08g of CH3COONa·3H2O, and dissolve them in 200 mL of high-purity deionized water to obtain the oxidation reaction solution; (3) Rotary spraying deposition: The reduction reaction solution and oxidation reaction solution supplied in step (2) are delivered by two independent peristaltic pumps, and the reduction reaction solution and oxidation reaction solution are atomized and sprayed to the substrate surface by a dual-channel atomizing spray unit. At the beginning of the deposition reaction, a DC magnetic field with a magnetic field strength of 50 Oe is applied perpendicular to the substrate in situ for 60s, and then the deposition reaction continues for 14min to obtain the out-of-plane magnetic anisotropic ferrite film of this embodiment. The magnetic field strength can be controlled within the range of 50±1 Oe through the closed-loop control module of Hall sensor-controller-drive power supply-coil current. The supply rate of reduction reaction liquid is 12.0 mL / min, the supply rate of oxidation reaction liquid is 12.0 mL / min, and during spraying, the distance from the nozzle of the dual-channel atomizing spray unit to the substrate is 30 mm. The median volumetric particle size D50 of the droplets output by the dual-channel atomizing spray unit 2 is 20~80 μm. After deposition, the magnetic field is turned off after cooling to below 45℃.

[0039] Example 3

[0040] The difference between this embodiment and embodiment 2 is that the magnetic field strength of the DC magnetic field in step (3) is adjusted to 100 Oe, while the rest of the preparation methods are the same as in embodiment 2, thus obtaining the out-of-plane magnetic anisotropic ferrite thin film of this embodiment.

[0041] Example 4

[0042] The difference between this embodiment and embodiment 2 is that the magnetic field strength of the DC magnetic field in step (3) is adjusted to 150 Oe, while the rest of the preparation methods are the same as in embodiment 2, thus obtaining the out-of-plane magnetic anisotropic ferrite thin film of this embodiment.

[0043] Comparative Example 1

[0044] The difference between this comparative example and Example 2 is that the magnetic field strength of the DC magnetic field in step (3) is adjusted to 0Oe, while the rest of the preparation methods are the same as in Example 2, and the out-of-plane magnetic anisotropic ferrite film of this comparative example is obtained.

[0045] The XRD diffraction patterns of the ferrite films prepared in Examples 2-4 and Comparative Example 1 were tested, and the results are as follows: Figure 3 As shown.

[0046] contrast Figure 3The XRD patterns of ferrite films prepared under different in-situ vertical magnetic field intensities show that, compared to the case without a magnetic field, the relative intensity of the diffraction peaks related to the out-of-plane orientation is increased when the magnetic field intensity is 50 Oe. This indicates that the in-situ vertical magnetic field successfully induced the orientational growth of the crystal, successfully transforming the easy magnetization axis of the film from the in-plane direction to the out-of-plane direction, resulting in a ferrite film with significant out-of-plane magnetic anisotropy. With the continuous increase of the induced magnetic field intensity, the preferred orientation characteristics are further enhanced, while the grain orientation of the film in Comparative Example 1 is close to random.

[0047] The hysteresis loops of the ferrite thin films prepared in Examples 2-4 and Comparative Example 1 were tested, and the results are as follows: Figure 4 As shown.

[0048] Figure 4 The normalized out-of-plane hysteresis loop is shown after deducting the shape demagnetization factor. It can be seen that with the increase of the induced magnetic field, the opening of the out-of-plane hysteresis loop increases, and the out-of-plane remanence ratio and rectangularity improve, exhibiting excellent magnetic properties. Under small fields, the slope gradually increases and the remanence ratio... The increase indicates that the in-situ vertical magnetic field allows the film to form a stronger and more consistent out-of-plane easy axis during nucleation and early growth. Therefore, a small external field can pull the magnetic moment out of the plane more quickly, resulting in a larger initial slope. After the field is removed, the magnetic moment is also less likely to fall back into the plane. In contrast, the film prepared in Comparative Example 1 has a smaller opening and insufficient rectangularity of the out-of-plane magnetic hysteresis loop, showing a clear tendency for easy in-plane magnetization.

[0049] This is because the in-situ out-of-plane magnetic field applies a magnetic torque to the magnetic nuclei during the deposition nucleation and early growth stages, causing the easily magnetized direction of the nuclei to deflect statistically towards the vertical direction and reducing the probability of random orientation. As the magnetic field strength increases, the orientation-induced effect intensifies, thus enhancing the preferred orientation in XRD and improving the rectangularity of the out-of-plane hysteresis loop. Suppressing magnetic field drift and tilt through closed-loop magnetic field control can further improve the orientation consistency and batch stability of large-area substrates.

[0050] Example 5

[0051] The difference between this embodiment and embodiment 2 is that the magnetic field strength of the DC magnetic field in step (3) is adjusted to 200 Oe, while the rest of the preparation methods are the same as in embodiment 2, thus obtaining the out-of-plane magnetic anisotropic ferrite thin film of this embodiment.

[0052] The remanence ratio and permeability of the ferrite thin films prepared in Examples 1 to 5 and Comparative Example 1 were tested and calculated, and the results are shown in Table 1.

[0053] Table 1. Effect of different in-situ vertical magnetic field intensities on the magnetic properties of ferrite thin films.

[0054]

[0055] As can be seen from Table 1, compared with Comparative Example 1, the out-of-plane remanence ratio and permeability are improved at 200 Oe, but the magnetic properties of the ferrite film in Example 5 are similar to those in Example 4.

[0056] Example 6

[0057] The difference between this embodiment and embodiment 4 is that the temperature of the substrate in step (1) is adjusted from 120°C to 90°C and 150°C respectively. The rest of the preparation methods are the same as those in embodiment 4, and the ferrite film of this embodiment is obtained.

[0058] The results show that at 90℃, the ferrite film formation rate is slow, the deposition efficiency is low, and the magnetization is low; at 150℃, due to the high temperature of the liquid film, the reaction occurs not only at the interface between the substrate and the liquid film, but also within the liquid film, generating nanoparticles attached to the film surface, resulting in low film density.

[0059] Example 7

[0060] The difference between this embodiment and embodiment 2 is that a DC magnetic field with a magnetic field strength of 50 Oe is applied throughout the entire deposition reaction process in step (3), while the rest of the preparation methods are the same as in embodiment 2, resulting in an out-of-plane magnetic anisotropic ferrite film of this embodiment.

[0061] The results showed that, compared with the ferrite film of Example 2, the remanence ratio and preferred lattice orientation of the ferrite film of Example 7 were similar, and the anisotropy was not significantly improved. It can be seen that the optimal time for magnetic field induction is the early stage of nucleation of film deposition.

[0062] Comparative Example 2

[0063] The difference between this comparative example and Example 4 is that the distance from the nozzle to the substrate of the dual-channel atomizing spray unit in step (3) is adjusted from 30 mm to 5 mm and 50 mm respectively. The rest of the preparation methods are the same as those in Example 4, and the ferrite film of this comparative example is obtained.

[0064] The results showed that at a thickness of 50 mm, the ferrite film was porous, with poor crystallinity and weakened out-of-plane magnetic anisotropy. This was because the droplets had a longer mixing time in the air, and some oxidation reactions had already occurred before reaching the substrate, generating non-magnetic phase particles. At a thickness of 5 mm, the atomized droplets were not sufficiently dispersed and retained a large initial velocity, resulting in poor consistency of the prepared ferrite.

[0065] Comparative Example 3

[0066] The difference between this comparative example and Example 4 is that the supply rate of the reduction reaction solution and the oxidation reaction solution in step (3) is adjusted from 12 mL / min to 25 mL / min. The rest of the preparation methods are the same as in Example 4, and the ferrite film of this example is obtained.

[0067] The results show that excessive flow rate leads to excessive cooling effect of the liquid film, resulting in an excessively low critical surface temperature between the substrate and the liquid film, and a significant decrease in the film deposition rate, from 50 nm / min in Example 4 to 20 nm / min.

[0068] Comparative Example 4

[0069] The difference between this comparative example and Example 4 is that the supply rate of the reduction reaction solution and the oxidation reaction solution in step (3) is adjusted from 12 mL / min to 5 mL / min. The rest of the preparation methods are the same as in Example 4, and the ferrite film of this example is obtained.

[0070] The results showed that low flow rate made it difficult to form a uniform liquid film on a 4-inch substrate, resulting in poor thickness and performance consistency of the ferrite film.

[0071] In summary, to address the need for out-of-plane magnetic flux coupling in on-chip passive devices such as helical on-chip inductors, existing rotary spraying low-temperature deposition methods for ferrite thin films suffer from several problems: difficulty in achieving out-of-plane orientation, insufficient effective out-of-plane permeability, poor coupling between the applied magnetic field scheme and the process space, divergent magnetic field distribution, instability, and difficulty in ensuring large-area consistency. This invention provides an in-situ magnetic field-induced out-of-plane anisotropy rotary spraying deposition apparatus for ferrite thin films. This apparatus features stable magnetic field strength and reliable perpendicularity, with a magnetic field strength error of ≤2% within the film deposition space above the heat-conducting plate, successfully inducing out-of-plane magnetic anisotropy in the ferrite thin film. The rotary spraying apparatus incorporates upper and lower coaxial coils within the reaction chamber and a soft magnetic circuit outside the chamber to form a closed magnetic circuit, generating an adjustable DC vertical magnetic field within the substrate film deposition space. Combined with a Hall sensor and controller, closed-loop control is achieved, ensuring stable magnetic field strength and reliable perpendicularity.

[0072] This invention can apply a DC vertical magnetic field of 20-200 Oe in situ during the spin coating deposition process. This out-of-plane magnetic field induces ferrite nuclei to preferentially oriented out-of-plane during the nucleation and early growth stages at a low temperature of 90-150℃, thereby improving the out-of-plane permeability of the thin film and meeting the requirements of the core thin film of the spiral thin film inductor. It can be used for the preparation of on-chip inductor core thin films.

[0073] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A rotary spray deposition apparatus for in-situ magnetic field-induced ferrite thin film, characterized in that: include, The rotating bearing and temperature control unit (1) includes a heat-conducting plate (101) and a temperature control layer (103), wherein the temperature control layer (103) is used to heat the heat-conducting plate (101). Dual-channel atomizing spray unit (2); The in-situ vertical magnetic field generating unit (3) includes a lower coil (302) disposed above the rotating bearing and temperature control unit (1) and an upper coil (301) disposed above the lower coil. An iron outer shell (4) is set outside the reaction chamber, which is composed of a rotating bearing and temperature control unit (1), a dual-channel atomizing spray unit (2) and an in-situ vertical magnetic field generating unit (3); When energized, the upper coil (301) and the lower coil (302) form a DC magnetic field perpendicular to the surface of the heat-conducting plate (101) in their original positions.

2. The rotary spray deposition apparatus according to claim 1, characterized in that: The rotating bearing and temperature control unit (1) also includes a Hall sensor (107), which is used to monitor the magnetic field strength generated by the in-situ vertical magnetic field generating unit (3) in real time.

3. The application of the rotary spray deposition apparatus according to any one of claims 1 to 2 in the preparation of out-of-plane magnetic anisotropic ferrite thin films, characterized in that: include, The pretreated substrate is fixed on the heat transfer plate of the rotary spray deposition apparatus, and the rotation is started after the substrate is controlled at 90~150℃. The reduction reaction solution and the oxidation reaction solution are sprayed onto the substrate surface through a dual-channel atomization spray unit. A DC magnetic field is applied perpendicular to the substrate in situ through an in-situ vertical magnetic field generating unit to carry out the deposition reaction, thereby obtaining an out-of-plane magnetic anisotropic ferrite film.

4. The application according to claim 3, characterized in that: The deposition reaction is carried out by applying a DC magnetic field perpendicular to the substrate in situ. The time for applying the DC magnetic field in situ includes the first 30 to 90 seconds of the deposition reaction process and the entire deposition reaction process.

5. The application according to claim 4, characterized in that: The magnetic field strength of the DC magnetic field is 20–200 Oe.

6. The application according to claim 5, characterized in that: The substrate is controlled at 90~150℃ and then rotated, wherein the rotation speed is 90~300 rpm.

7. The application according to claim 6, characterized in that: The reduction reaction solution and the oxidation reaction solution are sprayed onto the substrate surface through a dual-channel atomization spray unit. The atomization method of the dual-channel atomizing spray unit includes one or more of ultrasonic atomization and pneumatic atomization.

8. The application according to claim 7, characterized in that: The supply rate of the reduction reaction solution is 10-20 mL / min, and the supply rate of the oxidation reaction solution is 10-20 mL / min.

9. The application according to claim 8, characterized in that: The median droplet size of the dual-channel atomizing spray unit is 20~80 μm, and the distance from the nozzle of the dual-channel atomizing spray unit to the substrate is 10~45 mm during spraying.

10. The application according to any one of claims 4 to 9, characterized in that: The ferrite includes one of nickel-zinc ferrite, nickel ferrite, and zinc ferrite.

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