BZT laminated dielectric film with low loss and high tuning rate and preparation method thereof
By depositing zinc niobate-based microwave dielectric ceramic thin film layers on BZT thin films to form heterostructured BZT stacked dielectric thin films, the problems of high dielectric loss and limited tuning rate of traditional BZT materials are solved, and the effect of low loss and high tuning rate is achieved.
Patent Information
- Application Number
- CN202511375266.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-25
- Publication Date
- 2026-02-03
AI Technical Summary
Traditional BZT-based dielectric materials suffer from high dielectric loss and limited tuning rate, which restricts their application in high-performance devices.
A heterostructure of BZT thin film layer and zinc niobate-based microwave dielectric ceramic thin film layer is adopted. BZT thin film and zinc niobate thin film are deposited on the substrate by magnetron sputtering technology to form a low-loss and high-tunability BZT stacked dielectric thin film.
It significantly reduces dielectric loss, improves tuning performance, and achieves the best balance between high tunability and low loss, resulting in improved tuning performance, reduced dielectric loss, and optimized frequency characteristics.
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Figure CN121451118A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of dielectric materials technology, specifically to a low-loss, high-tunability BZT laminated dielectric thin film and its preparation method. Background Technology
[0002] With the rapid development of technologies such as microwave communication, tunable filters, and phased array radar, dielectric tunable materials have attracted much attention due to their dielectric response characteristics under electric field modulation. Among many dielectric tunable materials, perovskite-structured barium strontium titanate (BaSrTiO3, BST) and barium zirconium titanate (BaZr) stand out. x Ti1-xO3 (BZT) has become a research hotspot due to its excellent ferroelectricity and dielectric tunability. BZT is a lead-free ferroelectric material with excellent dielectric properties, and its tuning performance has important applications in microwave communication and electronic devices. Studies on the dielectric properties and tuning mechanisms of BZT-based dielectric materials show that this material can effectively reduce dielectric loss while maintaining a certain tuning rate. Furthermore, BZT films typically have a high dielectric constant, and their dielectric properties exhibit weak frequency dependence. These characteristics enable BZT films to exhibit low conductivity and excellent and stable dielectric properties at room temperature.
[0003] However, traditional BZT-based materials suffer from high dielectric loss and limited tuning rate, hindering their application in high-performance devices. This patent selects BZT-based dielectric films as the research object, designing stacked films and constructing heterostructures by combining other materials with BZT films. The aim is to combine the high dielectric constant of BZT with its low-loss characteristics, hoping to achieve a synergistic effect of high tuning rate and low loss. Therefore, it is necessary to design a low-loss, high-tunability BZT stacked dielectric film and its preparation method to solve the above problems. Summary of the Invention
[0004] The present invention aims to provide a low-loss, high-tunability BZT laminated dielectric thin film and its preparation method to solve at least one technical problem existing in the prior art.
[0005] To achieve the above objectives, the present invention adopts the following technical solution:
[0006] A low-loss, high-tunability BZT laminated dielectric thin film, comprising a substrate;
[0007] A BZT thin film layer formed on the substrate; and a zinc niobate-based microwave dielectric ceramic thin film layer formed on the BZT thin film layer;
[0008] The general chemical formula of the zinc niobate-based microwave dielectric ceramic thin film layer is:
[0009] Zn[(Ge 0.5 Mo 0.5 ) x Nb 1-x ]2O6, wherein 0 < x < 1.
[0010] Preferably, the chemical formula of the zinc-niobate-based microwave dielectric ceramic thin film layer is Zn[(Ge 0.5 Mo 0.5 ) 0.05 Nb 0.95 ]2O6, wherein x = 0.05.
[0011] Preferably, the chemical composition of the BZT thin film layer is BaZr x Ti 1-x O3, wherein 0 < x < 1; the thickness of the BZT thin film layer is 150-250 nm, and the thickness of the zinc-niobate-based microwave dielectric ceramic thin film layer is 50-150 nm.
[0012] Preferably, the thickness of the BZT thin film layer is 200 nm, and the thickness of the zinc-niobate-based microwave dielectric ceramic thin film layer is 50 nm, 100 nm or 150 nm.
[0013] Preferably, the substrate is a fluorine-doped tin oxide conductive glass.
[0014] A method for preparing a BZT laminated dielectric thin film with low loss and high tuning rate, comprising the following steps:
[0015] S1: preparing a BZT ceramic target and a zinc-niobate-based microwave dielectric ceramic target respectively by a solid phase reaction method;
[0016] S2: providing a substrate, depositing a BZT thin film layer on the substrate by a magnetron sputtering double-layer coating technology using the BZT ceramic target;
[0017] S3: depositing a zinc-niobate-based microwave dielectric ceramic thin film layer on the BZT thin film layer obtained in S2 by a magnetron sputtering technology using the zinc-niobate-based microwave dielectric ceramic target, thereby obtaining the laminated dielectric thin film.
[0018] Preferably, the process parameters of the magnetron sputtering in S2 are as follows: the sputtering atmosphere is a mixed gas of argon and oxygen, the sputtering power is 150-200 W, and the substrate temperature is 650-750°C.
[0019] Preferably, the flow ratio of argon and oxygen in S2 is (85-95):(5-15), preferably 90:10 (sccm); the sputtering power is 180 W, the substrate temperature is 700°C, and the sputtering time is set to 3 hours.
[0020] Preferably, the process parameters for magnetron sputtering in S3 are: the sputtering atmosphere is a mixture of argon and oxygen, the sputtering power is 70-90W, and the substrate temperature is 600-700℃.
[0021] Preferably, the flow rate ratio of argon to oxygen in S3 is (85-95):(5-15), more preferably 90:10 (sccm); the sputtering power is 80W, and the substrate temperature is 650℃.
[0022] Compared with the prior art, the present invention provides a low-loss, high-tunability BZT laminated dielectric thin film and its preparation method, which have the following advantages:
[0023] 1. A heterostructure of BZT-based dielectric and zinc niobate film was successfully prepared using magnetron sputtering. XRD showed that the BZT-based dielectric exhibited a typical perovskite structure, while the zinc niobate film had a columbite structure. No obvious impurity phases were observed at the interface, and elemental diffusion was effectively controlled.
[0024] 2. Optimized frequency characteristics. The introduction of zinc niobate film significantly improves the frequency characteristics of BZT dielectric. The dielectric losses of BZTZ50, BZTZ100, and BZTZ150 are all lower than those of pure BZT film, i.e., BZT200.
[0025] 3. Improved tuning performance. The introduction of zinc niobate film significantly improves tunability and reduces dielectric loss by enhancing interfacial polarization and optimizing electric field distribution. At a test frequency of 100kHz, the tunability of BZTZ50 reaches 41.89%, higher than that of BZT200, and the maximum quality factor (FOM) is 36.77, significantly higher than that of BZT200, achieving the best balance between high tunability and low loss. Attached Figure Description
[0026] Figure 1 Flowchart of a method for preparing low-loss, high-tunability BZT laminated dielectric films;
[0027] Figure 2 Pre-sintering, debinding, and sintering time curves for BaZr0.2Ti0.8O3 samples: (a) Pre-sintering time curve; (b) Debinding time curve; (c) Sintering time curve;
[0028] Figure 3 Pre-sintering and sintering time curves for Zn[(Ge0.5Mo0.5)xNb1-x]2O6 microwave dielectric ceramic: (a) Pre-sintering time curve; (b) Sintering time curve;
[0029] Figure 4 Zn[(Ge 0.5 Mo 0.5 )0.05 Nb 0.95 Schematic diagram of the process of depositing 2O6 thin film on BZT dielectric;
[0030] Figure 5 The following are graphs showing the dielectric constant and dielectric loss of BZT200, BZTZ50, BZTZ100, and BZTZ150 as a function of frequency: (a) ε r (a) Frequency variation curve; (b) tanδ as a function of frequency;
[0031] Figure 6 The following are graphs showing the dielectric constant and tuning rate of BZT200, BZTZ50, BZTZ100 and BZTZ150 as a function of electric field: (a) ε r (b)n curves showing the variation with bias electric field; r Curve showing the variation with bias electric field;
[0032] Figure 7 The following are graphs showing the dielectric loss and FOM values of BZT200, BZTZ50, BZTZ100 and BZTZ150 as a function of electric field: (a) tanδ as a function of bias electric field; (b) FOM as a function of bias electric field. Detailed Implementation
[0033] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.
[0034] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.
[0035] Please see the appendix Figures 1-7 As shown, this embodiment provides a low-loss, high-tunability BZT stacked dielectric thin film, including a substrate; a BZT thin film layer formed on the substrate; and a zinc niobate-based microwave dielectric ceramic thin film layer formed on the BZT thin film layer.
[0036] The general chemical formula of the zinc niobate-based microwave dielectric ceramic thin film layer is:
[0037] Zn[(Ge 0.5 Mo 0.5 ) x Nb1-x 2O6, where 0 < x < 1.
[0038] In the chemical general formula of the zinc niobate-based microwave dielectric ceramic thin film layer, x = 0.05, that is, Zn[(Ge 0.5 Mo 0.5 ) 0.05 Nb 0.95 2O6.
[0039] The chemical composition of the BZT thin film layer is BaZr x Ti 1-x O3, where 0 < x < 1; the thickness of the BZT thin film layer is 150 - 250 nm, and the thickness of the zinc niobate-based microwave dielectric ceramic thin film layer is 50 - 150 nm.
[0040] The thickness of the BZT thin film layer is 200 nm, and the thickness of the zinc niobate-based microwave dielectric ceramic thin film layer is 50 nm, 100 nm or 150 nm.
[0041] The substrate is fluorine-doped tin oxide conductive glass.
[0042] In this embodiment, fluorine-doped tin oxide (FTO) conductive glass is used as the substrate, and a 200-nanometer-thick BZT (BaZr 0.2 Ti 0.8 O3) thin film is coated as the sample dielectric layer, and then a layer of Zn[(Ge 0.5 Mo 0.5 ) 0.05 Nb 0.95 2O6 film with a thickness of 50 / 100 / 150 nm is coated to prepare a Zn[(Ge 0.5 Mo 0.5 ) 0.05 Nb 0.95 2O6 / BaZr 0.2 Ti 0.8 O3 laminated film. Both Zn[(Ge 0.5 Mo 0.5 ) 0.05 Nb 0.95 2O6 and BaZr 0.2 Ti 0.8 [[ID=
[0044] (2) The mixed powder was placed in a ball mill jar and ball-milled for 6 hours. The ball milling medium was deionized water, and the grinding balls were zirconium oxide. Planetary ball milling was used, with a nylon ball mill jar capacity of 500 ml and a ball milling speed of 350 rad / min.
[0045] (3) The ball-milled mixed powder is placed in a 120℃ electric heating constant temperature blower drying oven to dry, then ground, and sieved through an 80-mesh nylon sieve.
[0046] (4) Collect the sieved mixed powder and pre-sinter it. The pre-sintering temperature is generally about 200°C lower than the sintering temperature. In this patent, the pre-sintering temperature is 1000°C, the heating rate is 5°C / min, and the holding time is 3h.
[0047] (5) Weigh the pre-sintered powder, add 2 wt.% PVA as a binder for granulation, and then put the powder into a ball mill jar for secondary ball milling. The secondary ball milling time is 6 hours and the ball milling speed is 350 rad / min.
[0048] (6) Place the ball-milled mixed powder in a 120℃ electric heating constant temperature drying oven to dry it, then grind it and sieve it through a 120-mesh nylon sieve.
[0049] (7) Take out the above ceramic powder as raw material and press it into a cylindrical ceramic body with a diameter of 50 mm and a thickness of 4 mm using a powder press. The pressing pressure is 20 MPa and the holding time is 1 min.
[0050] (8) The pressed ceramic green body was placed in a box-type resistance furnace for degreasing and sintering. In this project, the optimal degreasing curve was set as follows: heating to 200℃ for 40 minutes to remove moisture, and then slowly heating to 800℃ over 4 hours to remove organic impurities such as PVA. After degreasing, the body was left in the resistance furnace until the temperature dropped to room temperature before sintering. The temperature was increased to 1200℃ at a rate of 5℃ / min and held for 6 hours to obtain BaZr. 0.2 Ti 0.8 O3 sample.
[0051] A method for preparing low-loss, high-tunability BZT laminated dielectric thin films includes the following steps:
[0052] S1: BZT ceramic targets and zinc niobate-based microwave dielectric ceramic targets were prepared by solid-state reaction method.
[0053] S2: Provide a substrate, and using the BZT ceramic target, deposit a BZT thin film layer on the substrate by magnetron sputtering double-layer deposition technology;
[0054] S3: Using the zinc niobate-based microwave dielectric ceramic target, a zinc niobate-based microwave dielectric ceramic thin film layer is deposited on the BZT thin film layer obtained in S2 by magnetron sputtering technology, thereby obtaining the stacked dielectric thin film.
[0055] The process parameters for magnetron sputtering in S2 are as follows: the sputtering atmosphere is a mixture of argon and oxygen, the sputtering power is 150-200W, and the substrate temperature is 650-750℃.
[0056] The flow rate ratio of argon to oxygen in S2 is (85-95):(5-15), preferably 90:10 (sccm); the sputtering power is 180W, the substrate temperature is 700℃, and the sputtering time is set to 3 hours.
[0057] The process parameters for magnetron sputtering in S3 are as follows: the sputtering atmosphere is a mixture of argon and oxygen, the sputtering power is 70-90W, and the substrate temperature is 600-700℃.
[0058] The flow rate ratio of argon to oxygen in S3 is (85-95):(5-15), preferably 90:10 (sccm); the sputtering power is 80W, and the substrate temperature is 650℃.
[0059] In this embodiment, magnetron sputtering double-layer coating technology is used to coat Zn[(Ge)] 0.5 Mo 0.5 ) 0.05 Nb 0.95 A Zn[(Ge)]2O6 film was deposited on a BZT dielectric. After setting the sputtering conditions, the film thickness was measured using a profilometer. The deposition rate of the BZT dielectric film was approximately 66.7 nm / h. 0.5 Mo 0.5 ) 0.05 Nb 0.95 The 2O6 film has a flow rate of approximately 50 nm / h. For example... Figure 4 As shown, its preparation process is as follows:
[0060] (1) Deposition of BZT dielectric film.
[0061] Place a clean FTO glass plate on the sample plate and use the prepared BaZr... 0.2 Ti 0.8 O3 was used to sputter the FTO surface. The gas flow rates of argon and oxygen in the gas chamber were 90 sccm and 10 sccm, respectively. The sputtering power was 180 W, the sputtering ambient temperature was maintained at 700℃, and the sputtering time was set to 3 hours. After sputtering and cooling, the film was removed, yielding a 200 nm BZT thin film deposited on the FTO glass, which will be abbreviated as BZT200 below.
[0062] (2) Deposition of Zn[(Ge] 0.5 Mo0.5 ) 0.05 Nb 0.95 ]2O6 thin film.
[0063] The BZT membrane sample prepared in (1) was placed on a sample plate, and the prepared Zn[(Ge)] membrane was used. 0.5 Mo 0.5 ) 0.05 Nb 0.95 The BZT film surface was sputtered with 2O6. The gas flow rates of argon and oxygen in the gas chamber were 90 sccm and 10 sccm, respectively. The sputtering power was 80 W, the sputtering ambient temperature was maintained at 650℃, and the sputtering times were set to 0.5 h, 1 h, and 1.5 h based on the previously explored deposition rates. After sputtering and cooling, the film was removed to obtain Zn[(Ge]2O6]2O6. 0.5 Mo 0.5 ) 0.05 Nb 0.95 ]2O6 thin films with thicknesses of 50 nm, 100 nm, and 150 nm were deposited on a 200 nm BZT thin film. These are hereinafter referred to as BZTZ50, BZTZ100, and BZTZ150.
[0064] Combination Figure 5 As shown, the dielectric constant and dielectric loss are compared intuitively. Compared with BZT200, the dielectric loss of BZTZ50, BZTZ100 and BZTZ150 decreases more significantly with decreasing frequency, thereby reducing dielectric loss and improving frequency characteristics.
[0065] like Figure 6 As shown, at each bias voltage, the tuning rate of sample BZTZ50 is slightly higher than that of the other three samples, reaching the highest tuning rate.
[0066] like Figure 7 The sample coated with a zinc niobate film showed lower dielectric loss under zero electric field than BZT200 without the zinc niobate film coating, indicating that the bilayer structure coated with zinc niobate can effectively reduce the dielectric loss of BZT. Under various bias voltages, the FOM value of BZTZ50 was slightly higher than that of the other three groups of samples, and it had the highest FOM value.
[0067] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.
Claims
1. A low-loss, high-tunability BZT laminated dielectric thin film, characterized in that: Including substrate; A BZT thin film layer formed on the substrate; And a zinc niobate-based microwave dielectric ceramic thin film layer formed on the BZT thin film layer; The general chemical formula of the zinc niobate-based microwave dielectric ceramic thin film layer is: Zn[(Ge 0.5 Mo 0.5 ) x Nb 1-x ]2O6, of which 0 <x<1。 2. The low-loss, high-tunability BZT laminated dielectric film according to claim 1, characterized in that: In the general chemical formula of the zinc niobate-based microwave dielectric ceramic thin film layer, x = 0.05, which is Zn[(Ge 0.5 Mo 0.5 ) 0.05 Nb 0.95 ]2O6.
3. The low-loss, high-tunability BZT laminated dielectric film according to claim 1, characterized in that: The chemical composition of the BZT thin film layer is BaZr x Ti 1-x O3, where 0 < x < 1; the thickness of the BZT thin film layer is 150 - 250 nm, and the thickness of the zinc niobate-based microwave dielectric ceramic thin film layer is 50 - 150 nm.
4. The low-loss, high-tunability BZT laminated dielectric film according to claim 1, characterized in that: The thickness of the BZT thin film layer is 200 nm, and the thickness of the zinc niobate-based microwave dielectric ceramic thin film layer is 50 nm, 100 nm, or 150 nm.
5. The low-loss, high-tunability BZT laminated dielectric film according to claim 1, characterized in that: The substrate is fluorine-doped tin oxide conductive glass.
6. A method for preparing a low-loss, high-tunability BZT laminated dielectric thin film as described in any one of claims 1-5, characterized in that, Includes the following steps: S1: BZT ceramic targets and zinc niobate-based microwave dielectric ceramic targets were prepared by solid-state reaction method. S2: Provide a substrate, and using the BZT ceramic target, deposit a BZT thin film layer on the substrate by magnetron sputtering double-layer deposition technology; S3: Using the zinc niobate-based microwave dielectric ceramic target, a zinc niobate-based microwave dielectric ceramic thin film layer is deposited on the BZT thin film layer obtained in S2 by magnetron sputtering technology, thereby obtaining the stacked dielectric thin film.
7. The method for producing low-loss, high-tunability BZT laminated dielectric thin films according to claim 6, characterized in that: The process parameters for magnetron sputtering in S2 are as follows: the sputtering atmosphere is a mixture of argon and oxygen, the sputtering power is 150-200W, and the substrate temperature is 650-750℃.
8. The method for producing low-loss, high-tunability BZT laminated dielectric thin films according to claim 7, characterized in that: The flow rate ratio of argon to oxygen in S2 is (85-95):(5-15), preferably 90:10 (sccm); the sputtering power is 180W, the substrate temperature is 700℃, and the sputtering time is set to 3 hours.
9. The method for producing low-loss, high-tunability BZT laminated dielectric thin films according to claim 6, characterized in that: The process parameters for magnetron sputtering in S3 are as follows: the sputtering atmosphere is a mixture of argon and oxygen, the sputtering power is 70-90W, and the substrate temperature is 600-700℃.
10. The method for producing low-loss, high-tunability BZT laminated dielectric thin films according to claim 9, characterized in that: The flow rate ratio of argon to oxygen in S3 is (85-95):(5-15), preferably 90:10 (sccm); the sputtering power is 80W, and the substrate temperature is 650℃.