Low-resistance LaNiO3 ceramic target material as well as preparation method and application thereof
The low-resistivity LaNiO3 ceramic target material was prepared by chemical synthesis, which solved the problem of high resistivity of existing LaNiO3 ceramic targets and realized the low-energy consumption and high-quality magnetron sputtering preparation of LaNiO3 thin films, which is suitable for electronic devices and sensors.
Patent Information
- Application Number
- CN202511343244.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-19
- Publication Date
- 2025-12-19
AI Technical Summary
The existing LaNiO3 ceramic target has high resistivity, which leads to high energy consumption during magnetron sputtering, and the target is prone to breakage, affecting its service life and film quality. In addition, traditional preparation methods are labor-intensive and easily introduce impurities.
Low-resistivity LaNiO3 ceramic targets were prepared by chemical synthesis. By controlling the ratio of lanthanum nitrate and nickel acetate, drying, heating and pressing were carried out, combined with low-temperature sintering, high-purity LaNiO3 ceramic targets were prepared for magnetron sputtering to prepare LaNiO3 thin films.
It significantly reduces energy consumption in the magnetron sputtering process, extends the lifespan of the target material, improves film quality, simplifies the preparation process, reduces costs, and is suitable for industrial mass production.
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Figure CN121159249A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of magnetron sputtering target material preparation, and particularly relates to a low-resistance LaNiO3 ceramic target material and a preparation method and application thereof. BACKGROUND
[0002] LaNiO3 is an important perovskite structure material, and has a wide application prospect in the fields of electronic devices and sensors due to its excellent physical and chemical properties. The magnetron sputtering technology is a commonly used thin film preparation method, and has the advantages of fast deposition rate and good film quality. However, the resistance of the LaNiO3 ceramic target material prepared from La2O3 and Ni2O3 powders is generally high, which leads to the need for a high power (more than 50 W) in the magnetron sputtering process. This not only increases the energy consumption, but also may affect the service life of the target material and the quality of the prepared thin film due to the high power. In addition, the traditional target material preparation technology is extremely labor-cost-consuming, and impurities are easily introduced in the human operation process, which affects the stability of the product. Therefore, it is of great practical significance to develop a low-resistance LaNiO3 ceramic target material. SUMMARY
[0003] The application aims to provide a low-resistance LaNiO3 ceramic target material and a preparation method and application thereof. The LaNiO3 ceramic target material prepared by the application has a same surface resistivity of less than 0.2 Ω·cm and a two-end resistivity of less than 0.3 Ω·cm, which can significantly reduce the energy consumption in the magnetron sputtering process, improve the service life of the target material and stabilize the quality of the prepared thin film.
[0004] To achieve the above-mentioned purpose, the application provides the following technical scheme.
[0005] One of the technical schemes of the application provides a preparation method of a low-resistance LaNiO3 ceramic target material, which comprises the following steps:
[0006] Lanthanum nitrate and nickel acetate are respectively dissolved in solvents according to a molar ratio of lanthanum to nickel of 1.05:1 to obtain a lanthanum nitrate solution and a nickel acetate solution, the lanthanum nitrate solution and the nickel acetate solution are mixed, and stirring is performed at 85-95 DEG C to obtain a mixed solution; the mixed solution is dried at a low temperature of 74-76 DEG C for 5.8-6.2 h to obtain a gelatinous substance; the gelatinous substance is heated at 179-181 DEG C for 2.8-3.2 h to obtain powder 1; the powder 1 is continuously heated at 349-351 DEG C for 2.0-2.2 h to obtain powder 2; and the powder 2 is used to press a target material, and the pressed target material is sintered to obtain the low-resistance LaNiO3 ceramic target material.
[0007] Preferably, the solvent is obtained by mixing ethylene glycol methyl ether, water, acetylacetone and acetic acid in a volume ratio of 4.8:1:1:0.2.
[0008] Preferably, the concentration of lanthanum in the lanthanum nitrate solution is 4.8-5.2 mol / L.
[0009] Preferably, the concentration of nickel in the nickel acetate solution is 4.8-5.2 mol / L.
[0010] Preferably, in the process of pressing the target material, the pressure program is 9.8-10.2 MPa for 30 min, and then 19.8-20.2 MPa for 30 min.
[0011] Preferably, the sintering process is heating at 500℃ for 6h, and then heating at 650℃ for 12h.
[0012] The second technical solution of the present application provides a low-resistance LaNiO3 ceramic target material prepared by the above method.
[0013] The third technical solution of the present application provides an application of the above low-resistance LaNiO3 ceramic target material in the preparation of LaNiO3 thin film by magnetron sputtering.
[0014] Preferably, in the process of magnetron sputtering, the power applied to the low-resistance LaNiO3 ceramic target material is 5W.
[0015] The fourth technical solution of the present application provides a method for preparing LaNiO3 thin film by magnetron sputtering, and the preparation process conditions are as follows: vacuum degree is less than 1×10 -6 Torr, substrate temperature is 600℃, Ar / O2 flow ratio is 3:1, total gas flow is not higher than 10sccm, working gas pressure is 2.99-3.01Pa, direct current power is 5W, after 29-31min of sputtering, in-situ annealing in 50Pa oxygen atmosphere for 29-31min (temperature 600℃), and the target material is the above low-resistance LaNiO3 ceramic target material.
[0016] The LaNiO3 thin film prepared by the present application has a same surface resistivity of 0.07-0.10Ω·cm, which belongs to high-quality LaNiO3 thin film.
[0017] The beneficial technical effects of the present application are as follows:
[0018] Compared with the traditional ball milling method for preparing the target material, the present application has a significant gain effect in the process of preparing the low-resistance LaNiO3 ceramic target material. Since the grinding process is not needed, the possibility of introducing impurities in the traditional physical preparation process is excluded, and the high purity, high uniformity and excellent performance of the target material are ensured by precisely controlling the proportioning of the chemical raw materials and the reaction conditions.
[0019] The preparation method of the present application also has the advantages of economic energy saving. In the traditional preparation process, it is usually necessary to use agate mortar to add grinding agent and to perform manual operation. However, the preparation method of the present application does not need additional granulation process and manual operation, simplifies the process flow, reduces the production cost, improves the production efficiency, and makes the method more suitable for industrial batch production.
[0020] In terms of the performance of the target material, the same surface resistivity of the target material prepared by the present application is less than 0.2Ω·cm, and the two-end resistivity is less than 0.3Ω·cm, which is significantly lower than the resistivity of the target material prepared by using the mixed oxide of La2O3 and Ni2O3 in the traditional preparation process. The low resistance characteristic makes the target material exhibit more excellent performance in the process of magnetron sputtering. In the process of preparing a thin film by magnetron sputtering, the traditional target material usually needs higher power and more gas flow to ignite, which not only increases the energy consumption, but also may cause the target material to overheat, affecting the service life of the target material and the quality of the thin film. In the present application, the low-resistance LaNiO3 ceramic target material only needs low power (such as 10sccm argon, 5W) to ignite to prepare a high-quality LaNiO3 thin film. This significantly reduces the energy consumption, while also prolongs the service life of the target material, improves the quality and performance of the thin film.
[0021] In summary, the low-resistance LaNiO3 ceramic target material and the preparation method thereof of the present application not only avoid the introduction of impurities in the preparation process, ensuring the high purity and excellent performance of the target material, but also have the characteristics of economic energy saving and being suitable for industrial batch production. At the same time, the low-power ignition characteristic of the target material in the process of magnetron sputtering further reduces the energy consumption, prolongs the service life of the target material, improves the quality and performance of the thin film, and provides a more reliable and efficient target material selection for the application of LaNiO3 thin film in the field of semiconductor such as electronic devices and sensors, which has a significant gain effect. BRIEF DESCRIPTION OF DRAWINGS
[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments. Obviously, the drawings described below are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without any creative labor on the basis of these drawings.
[0023] Figure 1A process flow chart for preparing the LaNiO3 thin film of the present application.
[0024] Figure 2 An XRD pattern of the low resistance LaNiO3 ceramic target prepared for Example 1.
[0025] Figure 3 An XRD pattern of the high quality LaNiO3 thin film prepared for Example 3.
[0026] Figure 4 An XRD pattern of the high quality LaNiO3 thin film prepared for Example 4. DETAILED DESCRIPTION
[0027] The detailed description set forth below is intended as a description of various example embodiments of the application and is not intended to represent the only embodiments in which the application can be practiced. The intent is to convey the principles and alternative implementations of the present application to those skilled in the art to enable one to practice the application.
[0028] It should be noted that the present application does not describe in detail the conventional operations in the art, and is not the focus of the present application.
[0029] In addition, for numerical ranges recited herein, every integer value within the range is specifically included. In any statement of a value or range of values, every intervening value between the lower and upper limit, inclusive, is specifically included. The upper and lower limits of these intervening values are also specifically included. These are also endpoints of the ranges.
[0030] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. Although preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present application.
[0031] As used herein, the terms "comprise", "comprising", "include", "including", "have", "having" and the like are open-ended terms that are intended to mean "including but not limited to".
[0032] A process flow chart for preparing the LaNiO3 thin film of the present application. Figure 1 .
[0033] Example 1
[0034] Preparation of the low resistance LaNiO3 ceramic target:
[0035] (1) Preparation of raw materials: La(NO3)3 and Ni(OAc)2 were weighed according to the molar ratio of La:Ni of 1.05:1.
[0036] (2) Preparation of single solution: La(NO3)3 and Ni(CH3COO)2 were dissolved in the solvent prepared by ethylene glycol methyl ether, water, acetylacetone and acetic acid with volume ratio of 4.8:1:1:0.2, and the concentration of the solution was 5 mol / L.
[0037] (3) Mixing and stirring: the two solutions were mixed and stirred on a magnetic stirrer for 30 min at a temperature of 90°C to obtain a clear turquoise solution.
[0038] (4) Drying: the above solution was dried in an oven at 75°C for 6 h to obtain a light green gum.
[0039] (5) Heat treatment: the light green gum was heated on a hot stage at 180°C for 3 h to obtain a white powder. The white powder was heated at a temperature of 350°C for 2 h to obtain a dark black powder.
[0040] (6) Pressing: the dark black powder was pressed at a pressure of 10 MPa for 30 min, and then the pressure was increased to 20 MPa for 30 min to obtain a circular target material with a diameter of 50.8 mm and a thickness of 2.0 mm.
[0041] (7) Sintering: the target material was placed in a muffle furnace and sintered at a temperature of 500°C for 6 h, and then sintered at a temperature of 650°C for 12 h. After cooling in the furnace, a low-resistance LaNiO3 ceramic target material with a diameter of 50.8 mm and a thickness of 2.0 mm was obtained.
[0042] The XRD pattern of the low-resistance LaNiO3 ceramic target material prepared in Example 1 is shown in Figure 2 The XRD results show that the composition of the obtained target material is completely consistent with PDF #34-1181. The target material is high-purity LaNiO3 rhombohedral phase, and there is no diffraction peak of any impurity phase.
[0043] The same surface resistivity of the target material is about 0.19 Ω·cm, and the two-end resistivity is about 0.29 Ω·cm, which is significantly lower than the resistivity of the traditional oxide La2O3 and Ni2O3 mixed target material. Using the target material for magnetron sputtering, the thin film can be prepared at low power (such as 10 sccm Ar, 5W).
[0044] Example 2
[0045] Preparation of LaNiO3 ceramic target material:
[0046] (1) Preparation of raw materials: La(NO3)3 and Ni(CH3COO)2 were weighed according to the molar ratio of La:Ni of 1.05:1.
[0047] (2) Preparation of single solution: lanthanum acetate and nickel acetate were dissolved in the solvent prepared from ethylene glycol methyl ether, water, acetylacetone and acetic acid in a volume ratio of 4.8:1:1:0.2, and the solution concentration was 5 mol / L.
[0048] (3) Mixing and stirring: the two solutions were mixed and stirred on a magnetic stirrer for 30 min at a temperature of 90°C to obtain a clear turquoise solution.
[0049] (4) Drying: the above solution was dried in an oven at 75°C for 6 h to obtain a light green gum.
[0050] (5) Heat treatment: the light green gum was heated on a hot stage at 180°C for 3 h to obtain a white powder. The white powder was heated at a temperature of 350°C for 2 h to obtain a dark black powder.
[0051] (6) Press forming: the dark black powder was pressed at a pressure of 10 MPa for 30 min, and then the pressure was increased to 20 MPa for 30 min to obtain a circular target material with a diameter of 50.8 mm and a thickness of 2.0 mm.
[0052] (7) Sintering: the target material was placed in a muffle furnace and sintered at a temperature of 500°C for 6 hours, and then sintered at a temperature of 650°C for 12 hours, and then taken out after furnace cooling to obtain a LaNiO3 ceramic target material with a diameter of 50.8 mm and a thickness of 2.0 mm.
[0053] The same surface resistivity of the target material was about 5.88 Ω·cm, and the two-end resistivity was about 24.53 Ω·cm. When the lanthanum salt and the nickel salt were a combination of non-lanthanum nitrate and nickel acetate, the resistivity of the prepared LaNiO3 ceramic target material was significantly increased.
[0054] Example 3
[0055] Preparation of LaNiO3 thin film:
[0056] The low-resistance LaNiO3 target material obtained in Example 1 was placed in a magnetron sputtering device, a vacuum pump was used to reduce the vacuum degree to less than 1×10 -6 Torr, the temperature of the LaAlO3 substrate was heated to 600°C, the Ar / O2 flow ratio was adjusted to 3:1, the total gas flow was maintained at 10 sccm, the working gas pressure was 3 Pa, the direct current power was 5 W, and after 30 min of sputtering, the obtained high-quality LaNiO3 thin film was annealed in situ for 30 min in an oxygen atmosphere of 50 Pa. The XRD of the obtained high-quality LaNiO3 thin film is shown in Figure 3 The same surface resistivity measured by a multimeter was 0.098 Ω·cm.
[0057] Example 4
[0058] Preparation of LaNiO3 thin film:
[0059] The low resistance LaNiO3 target obtained in Example 1 was placed in a magnetron sputtering device, and a vacuum pump was used to reduce the vacuum degree to less than 1 x 10 -6 Torr, and the temperature of the SrTiO3 substrate was heated to 600°C. The Ar / O2 flow ratio was adjusted to 3:1, the total gas flow was kept at 10 sccm, the working pressure was 3 Pa, the direct current power was 5 W, and after 30 min of sputtering, in-situ annealing was performed in an oxygen atmosphere of 50 Pa for 30 min. The XRD pattern of the obtained high-quality LaNiO3 thin film is shown in Figure 4 The same surface resistivity measured using a multimeter was 0.071 Ω·cm.
[0060] The above-described examples are merely to describe the preferred modes of the present application, and are not intended to limit the scope of the present application. Various modifications and improvements to the technical solutions of the present application made by those of ordinary skill in the art without departing from the design spirit of the present application shall fall within the scope of protection of the present application as defined by the claims.
Claims
1. A method for preparing a low-resistivity LaNiO3 ceramic target, characterized in that, Includes the following steps: Lanthanum nitrate and nickel acetate were dissolved separately in a solvent at a molar ratio of 1.05:1 to obtain lanthanum nitrate solution and nickel acetate solution, respectively. The lanthanum nitrate solution and nickel acetate solution were mixed and stirred at 85-95°C to obtain a mixed solution. The mixed solution was dried at a low temperature of 74-76°C for 5.8-6.2 hours to obtain a gel. The gel was heated at 179-181°C for 2.8-3.2 hours to obtain powder 1. Powder 1 was further heated at 349-351°C for 2.0-2.2 hours to obtain powder 2. Powder 2 was used to press a target material, and the pressed target material was sintered to obtain the low-resistivity LaNiO3 ceramic target material.
2. The method for preparing the low-resistivity LaNiO3 ceramic target according to claim 1, characterized in that, The solvent is obtained by mixing ethylene glycol methyl ether, water, acetylacetone and acetic acid in a volume ratio of 4.8:1:1:0.
2.
3. The method for preparing the low-resistivity LaNiO3 ceramic target according to claim 1, characterized in that, The concentration of lanthanum in the lanthanum nitrate solution is 4.8–5.2 mol / L.
4. The method for preparing the low-resistivity LaNiO3 ceramic target according to claim 1, characterized in that, The nickel concentration in the nickel acetate solution is 4.8–5.2 mol / L.
5. The method for preparing the low-resistivity LaNiO3 ceramic target according to claim 1, characterized in that, During the pressing of the target material, the pressure program is 9.8–10.2 MPa for 30 minutes, and then 19.8–20.2 MPa for 30 minutes.
6. The method for preparing the low-resistivity LaNiO3 ceramic target according to claim 1, characterized in that, The sintering process involves heating at 500°C for 6 hours, followed by further heating at 650°C for 12 hours.
7. A low-resistivity LaNiO3 ceramic target prepared by the method of preparing the low-resistivity LaNiO3 ceramic target according to any one of claims 1 to 6.
8. The application of the low-resistivity LaNiO3 ceramic target of claim 7 in the preparation of LaNiO3 thin films by magnetron sputtering.
9. The application according to claim 8, characterized in that, During magnetron sputtering, the power applied to the low-resistivity LaNiO3 ceramic target is 5W.
10. A method for preparing LaNiO3 thin films by magnetron sputtering, characterized in that, The preparation process conditions are: vacuum degree less than 1×10 -6 The substrate temperature is 600℃, the Ar / O2 flow ratio is 3:1, the total gas flow rate is not higher than 10 sccm, the working gas pressure is 2.99-3.01 Pa, the DC power is 5W, and after sputtering for 29-31 min, it is in-situ annealed in an oxygen atmosphere of 50 Pa for 29-31 min (temperature 600℃). The target material is the low-resistivity LaNiO3 ceramic target material as described in claim 7.