A rare earth aluminum alloy target material and a method of manufacturing the same

Abstract

The application discloses a rare earth aluminum alloy target material and a preparation method thereof, which comprises rare earth elements RE, metal elements M, Al elements and other impurities, wherein the rare earth elements RE comprise at least one of neodymium, praseodymium and cerium, and the metal elements M comprise at least one of copper, silver, magnesium and zinc; the normal section of a sputtering surface of the rare earth aluminum alloy target material is trisected, and the rare earth element composition deviation is controlled within ±0.3wt%. The prepared rare earth aluminum alloy target material improves the composition, grain and phase uniformity of the normal section of the sputtering surface, and reduces the number of microcracks in the target material; sputtering is performed by using the alloy target material, and a gate electrode with more excellent performance can be obtained, thereby providing a support material for the development of a new display field.

Description

Technical Field

[0001] This invention relates to the field of rare earth aluminum alloy technology, specifically to a rare earth aluminum alloy target and its preparation method. Background Technology

[0002] Aluminum-neodymium (ANd) thin films prepared by sputtering high-purity ANd alloy targets are a key material for liquid crystal display panels due to their excellent electrical conductivity and high-temperature hill-forming resistance. In large-scale industrial production, to pursue efficiency and product stability, the sputtering process on the sputtering substrate is generally fixed. Under these conditions, the quality of the alloy target becomes a crucial factor affecting the stability of the coating quality and determines the final product yield. As the target is consumed, sputtered atoms are stripped away, continuously exposing new sputtered surfaces. However, current reports on ANd alloy targets mainly focus on their macroscopic dimensions and composition, with insufficient attention paid to the uniformity of the target in specific directions and microcracks. This lack of understanding prevents the development of effective improvement strategies. Furthermore, microcracks within the target cause uneven energy distribution during sputtering. This energy gradient affects the intensity and uniformity of the ignition phenomenon, thus impacting the film quality. Summary of the Invention

[0003] (I) Purpose of the Invention

[0004] The purpose of this invention is to provide a rare earth aluminum alloy sputtering target and its preparation method. This invention can significantly improve the uniformity of composition, grain size and phase in the normal direction of the sputtering surface of the target, and reduce the number of microcracks inside the target. Using this alloy target for sputtering can obtain gate electrodes with better performance, providing supporting materials for the development of new display fields.

[0005] (II) Technical Solution

[0006] To address the aforementioned problems, a first aspect of the present invention provides a rare-earth aluminum alloy sputtering target with a purity ≥99.95%, comprising: rare-earth element RE, metallic element M, Al element, and other impurities. The rare-earth element RE includes at least one of neodymium, praseodymium, and cerium, and the metallic element M includes at least one of copper, silver, magnesium, and zinc. The normal cross-section of the sputtering surface of the rare-earth aluminum alloy sputtering target is divided into three equal parts, and the deviation of the rare-earth element composition is controlled within ±0.3 wt%. Preferably, the rare-earth element RE includes at least one of neodymium and praseodymium, and the metallic element M includes at least one of copper and silver.

[0007] Furthermore, the average grain size on the normal section of the sputtering surface of the rare earth aluminum alloy target is ≤50μm, and the standard deviation of the grain size is ≤7.5%.

[0008] Furthermore, the rare-earth aluminum alloy target sputtering surface contains dispersed α-Al atoms on its normal cross-section. 11Nd3 crystals with a phase size ≤30μm.

[0009] Furthermore, the number of microcracks with a length greater than 300 μm inside the rare earth aluminum alloy target is 0.

[0010] Furthermore, the number of microcracks with a length of 100–299 μm per cubic millimeter inside the rare earth aluminum alloy target is less than 10.

[0011] Furthermore, the number of microcracks with a length of 10–99 μm per cubic millimeter inside the rare earth aluminum alloy target is <120.

[0012] Further, the content of the rare earth element RE is 0.5–5.5 wt%, the content of the metallic element M is 0.1–1.5 wt%, and the content of Al is ≥92.95 wt%. Preferably, the RE content is 2–3 wt%, the M content is 0.5–1 wt%, and the Al content is 96–97.5 wt%.

[0013] Further, the rare earth aluminum alloy target material has an oxygen content of <350ppm, a carbon content of <200ppm, a total impurity content of Li, Na, and K of <10ppm, and a total impurity content of Ti, Ta, Cr, Mn, and Pb of <50ppm. Preferably, the rare earth aluminum alloy target material has a purity of ≥99.98%, an oxygen content of <150ppm, a carbon content of <100ppm, a total impurity content of Li, Na, and K of <5ppm, and a total impurity content of Ti, Ta, Cr, Mn, and Pb of <30ppm.

[0014] Furthermore, a second aspect of the present invention provides a method for preparing a rare earth aluminum alloy target as described above, comprising the following steps:

[0015] S1: Using high-purity rare earth aluminum alloy ingots as raw materials, immerse them in a cooling medium for cooling time ≥20min;

[0016] S2: The cooled high-purity rare earth aluminum alloy ingot is rolled using an asynchronous rolling process, with the reduction (deformation) per pass controlled at 3-20%. The resulting rare earth aluminum alloy target rough is then placed in a cooling medium for cooling for ≥10 minutes.

[0017] S3: Repeat step S2 until the thickness reduction of the rare earth aluminum alloy target rough material reaches 1 / 2 of the target reduction amount, and then perform intermediate annealing.

[0018] S4: Repeat step S2 on the crude rare earth aluminum alloy sputtering material after intermediate annealing until the target reduction amount is reached. Then, perform final heat treatment and machine it into a rare earth aluminum alloy sputtering material.

[0019] Furthermore, the target reduction (total deformation) is 60-95%, and the asynchronous ratio of the mill in the asynchronous rolling process is 1-1.5.

[0020] Furthermore, the intermediate annealing temperature is 200℃~400℃, and the annealing time is 1~4h.

[0021] Furthermore, the cooling medium has a cooling temperature of -50℃ to -268.9℃, and the cooling medium includes liquid nitrogen, liquid helium, liquid hydrogen, dry ice, liquid ammonia, liquid oxygen or liquid neon, preferably liquid nitrogen or dry ice.

[0022] Furthermore, in step S4, the heat treatment temperature is 220–450°C, and the heat treatment time is 2–6 hours.

[0023] Furthermore, in step S4, the final heat treatment temperature is 220–450°C, and the final heat treatment time is 2–6 hours.

[0024] (III) Beneficial Effects

[0025] The above-mentioned technical solution of the present invention has the following beneficial technical effects: The present invention provides a rare earth aluminum alloy target and its preparation method. The rare earth aluminum alloy target includes rare earth elements RE, metallic elements M and Al elements. The rare earth elements RE include at least one of neodymium, praseodymium and cerium. By introducing praseodymium and cerium, which have similar physical and chemical properties and relatively lower costs, to replace part of neodymium, the cost can be reduced and the cost-effectiveness of the target can be improved. The metallic elements M include at least one of copper, silver, magnesium and zinc. By introducing copper, silver, magnesium and zinc, which have low resistivity and high solid solubility with aluminum, the film hardness is increased while ensuring excellent conductivity, thereby better suppressing the formation of "hills". The overall performance of sputtering film is better than that of aluminum-neodymium alloy target. In addition, the present invention, by adjusting the alloy composition and ratio, integrates the advantages of other metallic elements while maintaining the unique properties of rare earth elements, thereby creating better electrical properties. This invention focuses on the normal uniformity of the sputtering surface of the target material. This is achieved by dividing the normal section of the rare-earth aluminum alloy target sputtering surface into three equal parts and controlling the rare-earth element composition deviation within ±0.3wt%. Furthermore, it also addresses the uniformity of the normal grain size and α-Al content. 11 The size distribution of the Nd3 phase is clearly defined. The preparation method of this invention can ensure the improvement of the uniformity of composition, grains and phases in the normal direction of the sputtering surface of the target material, and reduce the number of microcracks. Sputtering with this alloy target material can obtain gate electrodes with better performance, providing supporting materials for the development of new display fields. Moreover, it is simple to operate and has the advantage of large-scale production. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concepts of the invention.

[0027] The first aspect of this invention provides a rare-earth aluminum alloy target material, comprising: rare-earth element RE, metallic element M, Al element, and other impurities. The rare-earth element RE includes at least one of neodymium, praseodymium, and cerium. This invention introduces praseodymium and cerium rare-earth elements, which are close to neodymium in the periodic table and have similar physical properties. Both praseodymium and neodymium can form α-Al and α-Al with Al. 11 RE3 phase, and slightly cheaper than neodymium, offers high cost-effectiveness; the metal element M includes at least one of copper, silver, magnesium, and zinc. By introducing non-rare earth elements such as copper, silver, magnesium, and zinc, the resistivity of these metals is relatively low, and trace amounts will not cause a rapid increase in the resistivity of the alloy target, ensuring excellent conductivity. Secondly, copper, silver, magnesium, and zinc have high solid solubility with aluminum, resulting in high hardness of the sputtered film, effectively suppressing the formation of "hills," and their work function is close to that of aluminum, ensuring low leakage current and electrostatic loss in the device.

[0028] The rare earth element RE has a content of 0.5–5.5 wt%, the metallic element M has a content of 0.1–1.5 wt%, and the Al content is ≥92.95 wt%. Preferably, the RE content is 2–3 wt%, the M content is 0.5–1 wt%, and the Al content is 96–97.5 wt%. Selecting this composition range ensures that the sputtered alloy film possesses both excellent electrical conductivity and excellent high-temperature hill-forming resistance, meeting the requirements for the gate electrode of thin-film transistors in the display field. The rare earth element RE is preferably at least one of neodymium and praseodymium. Praseodymium and neodymium are adjacent in the periodic table, have very similar physicochemical properties, and form a similar phase structure to aluminum. Secondly, praseodymium (68 × 10⁻⁶) is preferred. -4 Ω·cm) and neodymium (64×10 -4 The resistivity (Ω·cm) is also very similar. The preferred metallic element M is at least one of copper and silver. Both copper and silver have lower resistivity than aluminum. The addition of trace amounts of copper or silver, or their substitution for rare earth elements, ensures a low overall resistivity of the alloy. Furthermore, copper, silver, and aluminum have high solid solubility, ensuring greater hardness of the deposited film and thus excellent high-temperature resistance to hillock formation. Additionally, the work functions of copper, silver, and aluminum are similar, so their introduction will not significantly affect leakage current and electrostatic losses.

[0029] The rare-earth aluminum alloy target sputtering surface exhibits highly uniform composition, grain size, and phase distribution across its normal cross-section. The normal cross-section is divided into three equal parts, and the rare-earth element composition deviation is controlled within ±0.3 wt%. For example, the rare-earth element composition deviation at at least three equidistant points (top, middle, and bottom) on the normal cross-section is controlled to be ±0.3 wt%. The average grain size on the normal cross-section of the rare-earth aluminum alloy target sputtering surface is ≤50 μm, and the standard deviation of the grain size is ≤7.5%. The normal cross-section of the rare-earth aluminum alloy target sputtering surface contains dispersed α-Al. 11 The Nd3 crystal has a phase size ≤30μm. Furthermore, microcracks within the target material cause uneven energy distribution during sputtering. This energy gradient affects the intensity and uniformity of the ignition phenomenon, influencing surface energy and ignition tendency. Crack formation increases the material's surface area, thus increasing the total surface energy. Increased surface energy affects material stability, making localized ignition phenomena more likely, thereby impacting film quality. Therefore, controlling the number of microcracks is crucial. The rare-earth aluminum alloy target material has zero microcracks longer than 300μm, <10 microcracks per cubic millimeter with a length between 100 and 299μm, and <120 microcracks per cubic millimeter with a length between 10 and 99μm. Controlling the number of cracks makes the energy distribution and ignition threshold of the entire target material more uniform.

[0030] The rare earth aluminum alloy target material has a purity ≥99.95%, an oxygen content <350ppm, a carbon content <200ppm, a total impurity content of Li, Na, and K <10ppm, and a total impurity content of Ti, Ta, Cr, Mn, and Pb <50ppm. Preferably, the rare earth aluminum alloy target material has a purity ≥99.98%, an oxygen content <150ppm, a carbon content <100ppm, a total impurity content of Li, Na, and K <5ppm, and a total impurity content of Ti, Ta, Cr, Mn, and Pb <30ppm. Oxygen and carbon impurities readily react with aluminum and rare earth elements to form metal oxides and carbides. These metal oxides and carbides have high resistivity, and as they are deposited into the final thin film during the sputtering process, they cause the film resistivity to increase. Therefore, the rare earth aluminum alloy target material provided by this invention has a low content of oxygen and carbon impurities. Secondly, the work functions of metal impurities Li, Na, and K are relatively small, which will increase the leakage current and electrostatic loss of the thin film. Metal impurities Ti, Ta, Cr, Mn, and Pb have relatively high resistivity. When their content is high, they will increase the overall resistivity of the alloy. Therefore, this invention controls the above-mentioned metal impurities.

[0031] A second aspect of the present invention provides a method for preparing a rare earth aluminum alloy target as described above, comprising the following steps:

[0032] S1: Using high-purity rare-earth aluminum alloy ingots as raw materials, the ingots are immersed in a cooling medium for cooling for ≥20 minutes. The high-purity rare-earth aluminum alloy ingots obtained after multiple vacuum induction melting processes have a purity of ≥99.95%. The cooling medium has a cooling temperature of -50℃ to -268.9℃. Cooling media include liquid nitrogen, liquid helium, liquid hydrogen, dry ice, liquid ammonia, liquid oxygen, or liquid neon. The purpose of low-temperature rolling is to suppress dynamic recrystallization of the rare-earth aluminum alloy target material during rolling, allowing more dislocation energy to be stored within the grains, thus refining the grains. Liquid nitrogen and dry ice are preferred cooling media because they offer superior performance and lower cost, resulting in a high cost-effectiveness ratio.

[0033] S2: The cooled high-purity rare-earth aluminum alloy ingot is rolled using an asynchronous rolling process, with a reduction per pass controlled at 3-20%. The resulting rough rare-earth aluminum alloy target material is then cooled again in a cooling medium for ≥10 minutes. The asynchronous ratio of the mill in the asynchronous rolling process is 1-1.5. The rolling effect of asynchronous rolling refines the grains and homogenizes the composition of the normal cross-section of the target sputtering surface. Cryogenic rolling can control oxygen impurity oxidation contamination. Setting the asynchronous ratio utilizes the shear force of the asynchronous rolling process, which on the one hand breaks up the phase in the normal direction of the target sputtering surface and redistributes it, and on the other hand refines the grains and makes the grain size distribution more uniform. S3: Repeat step S2 until the thickness reduction of the rough rare-earth aluminum alloy target material reaches 1 / 2 of the target reduction, and then perform intermediate annealing. The intermediate annealing temperature is 200℃-400℃, and the annealing time is 1-4 hours. The intermediate annealing step is set up to close the micro-cracks generated in the target material during the rolling process, remove internal stress, and improve the quality of the target material.

[0034] S4: Repeat step S2 on the intermediate annealed rare earth aluminum alloy sputtering material until the target reduction is achieved. Then, perform final heat treatment and machine it into a rare earth aluminum alloy sputtering material. The target reduction is 60-95%. The final heat treatment temperature is 220-450℃, and the heat treatment time (holding time) is 2-6 hours. The heat treatment process allows for more uniform component diffusion.

[0035] Example 1

[0036] High-purity rare-earth aluminum alloy ingots (Nd: 3wt%, Ag: 1wt%, Al: 95.993wt%) with a purity of 99.99% or higher were subjected to low-temperature rolling. Before rolling, the samples were placed in liquid nitrogen for 30 minutes to cool, and then rolled and deformed by a rolling mill. The deformation per pass (reduction per pass) was 10%. After each pass, the resulting rough rare-earth aluminum alloy target material was placed in liquid nitrogen for 10 minutes to cool. The asynchronous ratio was selected as 1.1. When the total deformation reached 40%, intermediate annealing was performed to eliminate microcracks and internal stress. The material was then held at 250°C for 2 hours in an argon atmosphere. The above steps were repeated to roll the material at low temperature until the total deformation reached 80% (the target reduction in this example was 80%). Finally, the sample was heat-treated in an argon atmosphere and machined into a rare-earth aluminum alloy target material. The heat treatment temperature was 350°C and the heat treatment time was 4.5 hours. Testing revealed that the alloy target material has a purity of 99.99% (excluding gaseous impurities), an oxygen content of 110 ppm, a carbon content of 50 ppm, a total impurity content of 5 ppm for Li, Na, and K, and a total impurity content of 40 ppm for Ti, Ta, Cr, Mn, and Pb. The rare earth element composition deviation at more than three equidistant points (top, middle, and bottom) on the normal cross-section of the target sputtering surface is -0.3 wt%. The average grain size of the normal cross-section is 50 μm, with a standard deviation of 7%. The normal cross-section α-Al... 11 The Nd3 phase is 20 μm in size, dispersed, and contains no microcracks with a maximum length greater than 300 μm. The maximum length of the microcracks is 100–299 μm, and the number of microcracks per mm is 100–299 μm. 3 <10 microcracks, with a maximum length of 10–99 μm; number of microcracks / mm 3 With fewer than 120 sputtering targets, a coating experiment was conducted on the target material, which sputtered to obtain a thin film with uniform thickness (thickness uniformity of 2.4%), excellent conductivity (resistivity 5.1 μΩ·cm) and resistance to hillocks. Table 1 shows the composition of the high-purity rare-earth aluminum alloy raw materials for each embodiment, Table 2 shows the rare-earth aluminum alloy targets prepared for each embodiment, Table 3 shows the process conditions corresponding to each embodiment in Table 2, and Table 4 shows the performance test results of the gate electrode thin film prepared for each embodiment.

[0037] Comparative Example 1-1

[0038] The rare earth aluminum alloy target of Comparative Example 1-1 has the same composition and preparation steps as Example 1. The normal composition of the sputtering surface, grain size and phase size, and the number of microcracks inside the target are similar to those of Example 1 (see Tables 1 and 2 for details). The difference is that the purity of the rare earth aluminum alloy ingot is lower. After testing, the purity of the alloy target is 99.5% (excluding gaseous impurities), oxygen content is 1000ppm, carbon content is 600ppm, the total amount of Li, Na, and K impurities is 70ppm, and the total amount of Ti, Ta, Cr, Mn, and Pb impurities is 200ppm. The target was subjected to a coating experiment, and the test showed that the film thickness uniformity was poor (7.3%), the resistivity was high (10.5μΩ·cm), and the resistance to "hills" was poor, which did not meet the requirements for actual use.

[0039] Comparative Examples 1-2

[0040] The rare earth aluminum alloy sputtering targets of Comparative Examples 1-2 had the same composition, purity, and key impurity content as those of Example 1. The difference was that Comparative Examples 1-2 did not undergo low-temperature asynchronous rolling; instead, they used ordinary room-temperature synchronous rolling, and the intermediate annealing process was omitted. The remaining preparation steps were the same as those of Example 1. Testing revealed that dynamic recrystallization occurred during the room-temperature rolling process. After the same heat treatment process, the grain size of the normal cross-section of the sputtering surface was relatively large (150 μm). Without asynchronous rolling, the α-Al grain size of the normal cross-section of the sputtering surface was significantly larger. 11 The Nd3 phase exhibits coarse dendritic structures with uneven distribution. Without intermediate annealing, numerous microcracks exceeding the length specified in the claims are generated inside the target material. Coating experiments were conducted on this target material, revealing poor uniformity of film thickness (10.2%), high resistivity (12.1 μΩ·cm), and poor resistance to hillock formation.

[0041] Example 2

[0042] High-purity rare-earth aluminum alloy ingots (Pr: 0.5wt%, Cu: 0.1wt%, Al: 99.352wt%) with a purity of 99.99% or higher were subjected to low-temperature rolling. Before rolling, the samples were placed in liquid oxygen for 35 minutes to cool, and then rolled and deformed by a rolling mill with a reduction of 15% per pass. After each pass, the resulting rare-earth aluminum alloy target rough was placed in liquid oxygen for 15 minutes to cool. The asynchronous ratio was selected as 1.15. When the total deformation reached 47%, intermediate annealing was performed to eliminate microcracks and internal stress. The sample was then held at 200°C for 4 hours in an argon atmosphere. The above steps were repeated to achieve a total deformation of 94% (the target reduction in this example was 94%). Finally, the sample was heat-treated in an argon atmosphere and machined into a rare-earth aluminum alloy target. The heat treatment temperature was 220°C and the heat treatment time was 6 hours. Testing revealed that the alloy target material has a purity of 99.95% (excluding gaseous impurities), an oxygen content of 120 ppm, a carbon content of 60 ppm, a total impurity content of 6 ppm for Li, Na, and K, and a total impurity content of 20 ppm for Ti, Ta, Cr, Mn, and Pb. The rare earth element composition deviation at more than three equidistant points (top, middle, and bottom) on the normal cross-section of the target sputtering surface is 0.25 wt%. The average grain size of the normal cross-section is 35 μm, the standard deviation of the grain size is 7.5, and the normal cross-section α-Al... 11 The Nd3 phase is 30 μm in size, dispersed, and contains no microcracks with a maximum length greater than 300 μm. The maximum length of the microcracks is 100–299 μm, and the number of microcracks per mm is 100–299 μm. 3 <10 microcracks, with a maximum length of 10–99 μm; number of microcracks / mm 3 With fewer than 120 targets, the film coating experiment showed that a thin film with uniform thickness (thickness uniformity of 3.1%) could be sputtered, exhibiting excellent conductivity (resistivity of 5.8 μΩ·cm) and resistance to hillocks.

[0043] Comparative Example 2-1

[0044] The preparation steps of the rare earth aluminum alloy target material in Comparative Example 2-1 are the same as those in Example 2. The difference is that the composition of the rare earth aluminum alloy target material in Comparative Example 2 is different (Pr: 13wt%, Cu: 2wt%, Al: 84.95wt%). The purity and content of key impurities are basically the same. Due to the high content of rare earth, there is a lot of brittle second phase. The ingot cracks severely during low-temperature rolling, and the alloy target material cannot be successfully prepared, so the coating evaluation cannot be carried out.

[0045] The process preparation conditions and test results of Examples 3-9 are shown in Tables 1-4, and the other conditions are the same as those of Example 1.

[0046] Table 1. Composition of high-purity rare earth aluminum alloy raw materials in each embodiment.

[0047]

[0048]

[0049] Table 2. Rare earth aluminum alloy sputtering targets prepared in each example (including comparative examples).

[0050]

[0051]

[0052]

[0053] Table 3. Preparation process parameters for each embodiment

[0054]

[0055]

[0056] Table 4. Properties of gate electrode films prepared using rare earth aluminum alloy targets.

[0057]

[0058]

[0059] This invention provides a rare-earth aluminum alloy sputtering target and its preparation method, focusing on the uniformity of the target's sputtering surface in the normal direction, and addressing compositional deviations, grain size, and α-Al content. 11 The size distribution of the Nd3 phase is clearly defined, and specific requirements are set for the number of microcracks in the sputtering target. Furthermore, by adjusting the alloy composition and proportions, the unique properties of rare earth elements are maintained while incorporating the advantages of other metallic elements, thereby creating superior electrical properties. This invention imposes strict control on the oxygen content and key metallic impurities in rare earth aluminum alloy sputtering targets, and proposes a simple and easy-to-implement method for preparing rare earth aluminum alloy sputtering targets. This method ensures improved uniformity of composition, grain size, and phase in the normal direction of the sputtering surface, and reduces the number of microcracks. This invention has the following advantages:

[0060] (1) This invention provides a rare earth aluminum alloy sputtering target with highly uniform composition, grain size and phase size in the sputtering surface normal direction. By introducing praseodymium and cerium with similar physical and chemical properties and relatively lower cost to replace part of neodymium, the cost can be reduced and the cost-effectiveness of the target can be improved. By introducing copper, silver, magnesium and zinc with low resistivity and high solid solubility with aluminum, the film hardness is increased while ensuring excellent conductivity, thereby better suppressing the formation of "hills". The overall performance of sputtering film is better than that of aluminum-neodymium alloy target.

[0061] (2) The purity, key impurities and microcracks in the rare earth aluminum alloy target material were effectively controlled, and the thin film prepared using the alloy target material had better electrical properties.

[0062] (3) A low-temperature rolling technology suitable for rare earth aluminum alloy target material was proposed. It does not require structural modification of the existing rolling mill, is simple to operate, and has the advantage of large-scale production.

[0063] Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention. As those skilled in the art will understand, the present invention can be implemented without following these specific details. It should be understood that the above specific embodiments of the present invention are merely illustrative or explanatory of the principles of the present invention and do not constitute a limitation thereof. Therefore, any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and scope of the present invention should be included within the scope of protection of the present invention. Furthermore, the appended claims are intended to cover all variations and modifications falling within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries. The present invention has been described above with reference to embodiments thereof. However, these embodiments are merely for illustrative purposes and are not intended to limit the scope of the present invention. The scope of the present invention is defined by the appended claims and their equivalents. Those skilled in the art can make various substitutions and modifications without departing from the scope of the present invention, and these substitutions and modifications should all fall within the scope of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. However, any obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A rare earth aluminum alloy target material, characterized in that, The rare earth aluminum alloy target has a purity of ≥99.95% and includes: rare earth element RE, metallic element M, Al element and other impurities. The rare earth element RE includes at least one of neodymium, praseodymium and cerium, and the metallic element M includes at least one of copper, silver, magnesium and zinc. The normal section of the sputtering surface of the rare earth aluminum alloy target is divided into three equal parts and the deviation of the rare earth element composition is controlled within ±0.3wt%.

2. The rare earth aluminum alloy target material according to claim 1, characterized in that, The average grain size on the normal section of the sputtering surface of the rare earth aluminum alloy target is ≤50μm, and the standard deviation of the grain size is ≤7.5%.

3. The rare earth aluminum alloy target material according to claim 1 or 2, characterized in that, The rare-earth aluminum alloy target sputtering surface contains dispersed α-Al on its normal cross-section. 11 Nd3 crystals with a phase size ≤30μm.

4. The rare earth aluminum alloy target material according to claim 3, characterized in that, The number of microcracks with a length greater than 300 μm inside the rare earth aluminum alloy target is 0.

5. The rare earth aluminum alloy target material according to claim 1, 2, or 4, characterized in that, The number of microcracks with a length of 100-299 μm per cubic millimeter inside the rare earth aluminum alloy target is <10.

6. The rare earth aluminum alloy target material according to claim 5, characterized in that, The number of microcracks with a length of 10-99 μm per cubic millimeter inside the rare earth aluminum alloy target is <120.

7. The rare earth aluminum alloy target material according to claim 1, 2, 4 or 6, characterized in that, The content of rare earth element RE is 0.5-5.5 wt%, the content of metallic element M is 0.1-1.5 wt%, and the content of Al element is ≥92.95 wt%.

8. The rare earth aluminum alloy target material according to claim 7, characterized in that, The rare earth aluminum alloy target material has an oxygen content of <350ppm, a carbon content of <200ppm, a total amount of Li, Na, and K impurities of <10ppm, and a total amount of Ti, Ta, Cr, Mn, and Pb impurities of <50ppm.

9. A method for preparing a rare earth aluminum alloy target material as described in any one of claims 1-8, characterized in that, Includes the following steps: S1: Using high-purity rare earth aluminum alloy ingots as raw materials, immerse them in a cooling medium for cooling time ≥20min; S2: The cooled high-purity rare earth aluminum alloy ingot is rolled using an asynchronous rolling process, with the reduction per pass controlled at 3-20%. The resulting rare earth aluminum alloy target rough is then placed in a cooling medium for cooling for ≥10 minutes. S3: Repeat step S2 until the thickness reduction of the rare earth aluminum alloy target rough material reaches 1 / 2 of the target reduction amount, and then perform intermediate annealing. S4: Repeat step S2 on the crude rare earth aluminum alloy sputtering material after intermediate annealing until the target reduction amount is reached. Then, perform final heat treatment and machine it into a rare earth aluminum alloy sputtering material.

10. The method for preparing the rare earth aluminum alloy target material according to claim 9, characterized in that, The target reduction is 60-95%.

11. The method for preparing the rare earth aluminum alloy target material according to claim 9 or 10, characterized in that, In step S4, the intermediate annealing temperature is controlled at 200℃~400℃, and the annealing time is 1~4h.

12. The method for preparing the rare earth aluminum alloy target material according to claim 11, characterized in that, The final heat treatment temperature in step S4 is 220–450°C, and the final heat treatment time is 2–6 hours.

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