Ultrahigh-purity silver target material and preparation method thereof

Abstract

The invention relates to an ultra-high-purity silver target material and a preparation method thereof, and belongs to the field of target materials, and the ultra-high-purity silver target material comprises the following raw materials in percentage by weight: 99.99% of high-purity silver, 0.05%-0.15% of palladium, 0.025%-0.075% of iridium, 0.1%-0.3% of neodymium and 0.1%-0.3% of praseodymium. According to the ultra-high-purity silver target material and the preparation method thereof, 5N-grade high-purity silver is adopted as a base material, trace palladium, iridium, neodymium, praseodymium and other elements are accurately added, the purity of the target material is remarkably improved and exceeds the purity range in the prior art, the hardness, strength and abrasion resistance of the target material are optimized through the innovative material design, and the service life of the target material is prolonged. The compact uniformity of the material is effectively improved and the internal stress is eliminated through grain refinement and multi-stage heat treatment, in addition, the isotropy of the target material is enhanced through the multi-directional forging process, the consistency of the performance in different directions is ensured, the mechanical performance of the target material is remarkably improved through the improvements, the target material can better adapt to the application environment with the high wear resistance requirement, and the service life of the target material is prolonged. And meanwhile, the conductivity, the reflectivity and the uniformity of a thin film prepared by using the target material are improved.

Description

Technical Field

[0001] The invention relates to the technical field of target materials, and in particular to an ultra-high purity silver target material and a preparation method thereof. Background Art

[0002] Target material is the basic consumable in the magnetron sputtering process. Not only is it used in large quantities, but the quality of the target material also plays a crucial and decisive role in the performance of the thin film. Target materials have a wide range of applications, mainly including optical targets, targets for display films, targets for semiconductors, targets for recording media, superconducting targets, etc. Among them, targets for semiconductors, targets for displays and targets for recording media are the three most widely used target materials. Silver target is one of the target materials. High-purity silver target is widely used in industry due to its good performance.

[0003] As disclosed in Chinese Patent Publication No. (CN115141952A), a high-purity silver target material and a processing method thereof are prepared from a silver raw material with a purity of 99%. The purity of the prepared high-purity silver target material is 3N to 6N, and the microstructure of the high-purity silver target is fine and uniform grains with an average grain size of ≤40μm. The invention provides a high-purity silver target material and a processing method thereof. 1. The high-purity silver target material and the processing method thereof provided by the invention are prepared by forming and heat treatment to obtain a high-purity silver target material having the characteristics of fine grain size, uniform grain distribution, uniform composition and high density, thereby ensuring the quality and quality of the high-purity silver target material. The high-purity silver target material produced by the invention and the method is made uniform in composition, uniform in grain distribution and refined in grain by combining forging, rolling and annealing heat treatment. The internal stress of the silver target material is eliminated by heat treatment of the silver target material, thereby improving the density and uniformity of the silver target material.

[0004] However, in the prior art such as the above-mentioned patent, there are still problems such as single material selection for ultra-high purity silver target and lack of applicability in different environments. This is because the prior art uses high-purity silver as raw material for preparation, and silver is a relatively soft metal. Its hardness is not enough to cope with some applications with high wear resistance requirements. It is easy to deform or wear during physical vapor deposition. At the same time, the tensile strength of silver is relatively low, which may lead to cracks or breakage during the preparation or use of the target. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention provides an ultra-high purity silver target material and a preparation method thereof, which has the advantages of ultra-high purity and wide applicability, and solves the problems in the prior art of single material selection for ultra-high purity silver target materials and lack of applicability in different environments.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solution: an ultra-high purity silver target, comprising the following raw materials in weight fraction ratio: 99.99% high purity silver, 0.05%-0.15% palladium, 0.025%-0.075% iridium, 0.1%-0.3% neodymium, and 0.1%-0.3% praseodymium.

[0007] Furthermore, the ultra-high purity silver target also includes the following raw materials in a weight fraction ratio: 99.99% high purity silver, 0.05% palladium, 0.025% iridium, 0.1% neodymium, and 0.1% praseodymium.

[0008] Furthermore, the ultra-high purity silver target material also includes the following raw materials in a weight fraction ratio: 99.99% high purity silver, 0.1% palladium, 0.05% iridium, 0.2% neodymium, and 0.2% praseodymium.

[0009] Furthermore, the ultra-high purity silver target also includes the following raw materials in a weight fraction ratio: 99.99% high purity silver, 0.15% palladium, 0.075% iridium, 0.3% neodymium, and 0.3% praseodymium.

[0010] Furthermore, the high-purity silver is the main raw material, and the purity of the high-purity silver is 5N.

[0011] The present application further proposes a method for preparing an ultra-high purity silver target material, including the ultra-high purity silver target material, characterized in that it comprises the following steps:

[0012] S1 Raw material preparation: Select high-purity silver with a purity of 5N as the base material, and prepare trace amounts of palladium, iridium, neodymium and praseodymium as alloy elements in proportion;

[0013] S2 uses induction melting technology to melt the base materials and alloy elements into a uniform alloy under vacuum;

[0014] S3 slowly cools the smelted alloy liquid in an inert atmosphere to form an ingot;

[0015] S4 performs high temperature annealing on the ingot to eliminate casting stress and microsegregation;

[0016] S5 forges the ingot multiple times in different directions to refine the grains and improve the isotropy of the material;

[0017] S6 cold-rolls the forged silver ingot at room temperature to further refine the grains and increase the density of the material;

[0018] S7 performs intermediate annealing to restore the plasticity of the material and eliminate the internal stress generated during the cold rolling process;

[0019] S8 uses precision rolling technology to roll the material into silver targets of the required thickness;

[0020] S9 performs final annealing on the precision rolled silver target to obtain a fine and uniform grain structure;

[0021] S10 polishes the surface of the silver target to ensure the flatness and cleanliness of the target surface.

[0022] Furthermore, in the raw material preparation stage in step S1, high-precision weighing equipment is used to ensure accurate addition of trace elements, and before smelting, the trace elements are pre-mixed with the base material to promote initial mixing between the elements.

[0023] Furthermore, the vacuum environment in step S2 adopts vacuum induction melting, and the melting is performed multiple times, and the molten alloy is thoroughly stirred after each melting to ensure uniform distribution of elements.

[0024] Furthermore, the annealing treatment in step S4 is a homogenization annealing treatment of the ingot at 1100°C, and the holding time is 2 hours. Step S5 includes multi-directional forging, and the deformation of each forging is controlled within 20%, and the forging temperature is 700°C. Step S6 includes cold rolling the forged silver ingot at room temperature, and the deformation is controlled within 60%.

[0025] Furthermore, in step S7, an intermediate annealing treatment is performed, the annealing temperature is controlled to be 600° C., and the holding time is 1 hour. In step S8, precision rolling technology is used to roll the material into a 0.5 mm thick silver target. In step S9, the silver target is finally annealed at 500° C. and the holding time is 2 hours.

[0026] Compared with the prior art, the technical solution of this application has the following beneficial effects:

[0027] 1. The ultra-high purity silver target material and its preparation method, by using 5N grade high purity silver as the base material and accurately adding trace amounts of elements such as palladium, iridium, neodymium and praseodymium, achieve a significant improvement in the purity of the target material, surpassing the purity range of the existing technology. The innovative material design not only optimizes the hardness, strength and wear resistance of the target material, but also effectively improves the density and uniformity of the material and eliminates internal stress through grain refinement and multi-stage heat treatment. In addition, the multi-directional forging process enhances the isotropy of the target material and ensures the consistency of performance in different directions. These improvements significantly improve the mechanical properties of the target material, making it more adaptable to application environments with high wear resistance requirements, while also improving the conductivity, reflectivity and uniformity of the film prepared using the target material.

[0028] 2. The ultra-high purity silver target material and its preparation method have enhanced environmental adaptability through alloying and the addition of rare earth elements, and strict quality control throughout the preparation process ensures the consistency and reliability of the product. While maintaining high purity and high performance, the present invention also achieves a balance between cost and benefit, meeting the urgent demand for high-performance target materials in the field of high-end technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The figure is a flowchart of the method of the present invention. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] Embodiment 1:

[0032] See also Figure 1 An ultra-high purity silver target material in this embodiment includes the following raw materials in a weight fraction ratio: 99.99% high purity silver, 0.05% palladium, 0.025% iridium, 0.1% neodymium, and 0.1% praseodymium.

[0033] In this embodiment, high-purity silver is the main raw material, and the purity of the high-purity silver is 5N.

[0034] It should be noted that high-purity silver with a purity of 5N is selected as the base material to ensure the high purity of the target material.

[0035] The present application further proposes a method for preparing an ultra-high purity silver target, comprising the following steps:

[0036] S1 Raw material preparation: Select high-purity silver with a purity of 5N as the base material, and prepare trace amounts of palladium, iridium, neodymium and praseodymium as alloy elements in proportion;

[0037] S2 uses induction melting technology to melt the base materials and alloy elements into a uniform alloy under vacuum;

[0038] S3 slowly cools the smelted alloy liquid in an inert atmosphere to form an ingot;

[0039] S4 performs high temperature annealing on the ingot to eliminate casting stress and microsegregation;

[0040] S5 forges the ingot multiple times in different directions to refine the grains and improve the isotropy of the material;

[0041] S6 cold-rolls the forged silver ingot at room temperature to further refine the grains and increase the density of the material;

[0042] S7 performs intermediate annealing to restore the plasticity of the material and eliminate the internal stress generated during the cold rolling process;

[0043] S8 uses precision rolling technology to roll the material into silver targets of the required thickness;

[0044] S9 performs final annealing on the precision rolled silver target to obtain a fine and uniform grain structure;

[0045] S10 polishes the surface of the silver target to ensure the flatness and cleanliness of the target surface.

[0046] In the raw material preparation stage in step S1 of this embodiment, high-precision weighing equipment is used to ensure accurate addition of trace elements, and before smelting, the trace elements are pre-mixed with the base material to promote preliminary mixing between the elements.

[0047] It should be noted that trace amounts of palladium and iridium are added as alloying elements to enhance the strength and wear resistance of the target material, and trace amounts of rare earth elements such as neodymium and praseodymium are introduced to refine the grains and improve the microstructural uniformity of the target material.

[0048] In this embodiment, the vacuum environment in step S2 adopts vacuum induction melting, and multiple meltings are performed. After each melting, the molten alloy is thoroughly stirred to make the elements evenly distributed.

[0049] In this embodiment, the annealing treatment in step S4 is to perform homogenization annealing treatment on the ingot at 1100°C, and the holding time is 2 hours. The smelted alloy liquid is slowly cooled in an inert atmosphere to form an ingot to reduce the incorporation of gas and impurities, and the cooling rate is controlled to avoid internal stress and abnormal grain growth. Step S5 includes multi-directional forging, and the deformation amount of each forging is controlled within 20%. The forging temperature is 700°C. After each forging, the temperature and deformation are monitored to ensure the consistency of material properties. Step S6 includes cold rolling the forged silver ingot at room temperature, and the deformation amount is controlled at 60%. The forged silver ingot is cold rolled at room temperature to further refine the grains and increase the density of the material. The deformation amount and rate of cold rolling are controlled to avoid excessive hardening of the material.

[0050] In this embodiment, an intermediate annealing treatment is performed in step S7, and the annealing temperature is controlled to be 600°C and the holding time is 1 hour. In step S8, precision rolling technology is used to roll the material into a 0.5 mm thick silver target. In step S9, the silver target is subjected to a final annealing treatment, and the annealing temperature is 500°C and the holding time is 2 hours. The silver target after precision rolling is subjected to a final annealing treatment to obtain a fine and uniform grain structure. After annealing, the grain size and distribution are tested to ensure that the technical requirements are met.

[0051] It should be noted that the surface of the silver target is polished to ensure the flatness and cleanliness of the target surface. Surface analysis technology is used to detect the surface roughness through white light interferometry to ensure that high standards are met. The prepared silver target is subjected to comprehensive quality inspection, including chemical composition analysis, microstructure analysis, physical property testing, etc. Quality assessment is carried out based on the test results to ensure that the target meets the requirements of ultra-high purity and high performance.

[0052] Embodiment 2:

[0053] See also Figure 1 An ultra-high purity silver target material in this embodiment includes the following raw materials in a weight fraction ratio: 99.99% high purity silver, 0.1% palladium, 0.05% iridium, 0.2% neodymium, and 0.2% praseodymium.

[0054] In this embodiment, high-purity silver is the main raw material, and the purity of the high-purity silver is 5N.

[0055] It should be noted that high-purity silver with a purity of 5N is selected as the base material to ensure the high purity of the target material.

[0056] The present application further proposes a method for preparing an ultra-high purity silver target, comprising the following steps:

[0057] S1 Raw material preparation: Select high-purity silver with a purity of 5N as the base material, and prepare trace amounts of palladium, iridium, neodymium and praseodymium as alloy elements in proportion;

[0058] S2 uses induction melting technology to melt the base materials and alloy elements into a uniform alloy under vacuum;

[0059] S3 slowly cools the smelted alloy liquid in an inert atmosphere to form an ingot;

[0060] S4 performs high temperature annealing on the ingot to eliminate casting stress and microsegregation;

[0061] S5 forges the ingot multiple times in different directions to refine the grains and improve the isotropy of the material;

[0062] S6 cold-rolls the forged silver ingot at room temperature to further refine the grains and increase the density of the material;

[0063] S7 performs intermediate annealing to restore the plasticity of the material and eliminate the internal stress generated during the cold rolling process;

[0064] S8 uses precision rolling technology to roll the material into silver targets of the required thickness;

[0065] S9 performs final annealing on the precision rolled silver target to obtain a fine and uniform grain structure;

[0066] S10 polishes the surface of the silver target to ensure the flatness and cleanliness of the target surface.

[0067] In the raw material preparation stage in step S1 of this embodiment, high-precision weighing equipment is used to ensure accurate addition of trace elements, and before smelting, the trace elements are pre-mixed with the base material to promote preliminary mixing between the elements.

[0068] It should be noted that trace amounts of palladium and iridium are added as alloying elements to enhance the strength and wear resistance of the target material, and trace amounts of rare earth elements such as neodymium and praseodymium are introduced to refine the grains and improve the microstructural uniformity of the target material.

[0069] In this embodiment, the vacuum environment in step S2 adopts vacuum induction melting, and multiple meltings are performed. After each melting, the molten alloy is thoroughly stirred to make the elements evenly distributed.

[0070] In this embodiment, the annealing treatment in step S4 is to perform homogenization annealing treatment on the ingot at 1100°C, and the holding time is 2 hours. The smelted alloy liquid is slowly cooled in an inert atmosphere to form an ingot to reduce the incorporation of gas and impurities, and the cooling rate is controlled to avoid internal stress and abnormal grain growth. Step S5 includes multi-directional forging, and the deformation amount of each forging is controlled within 20%. The forging temperature is 700°C. After each forging, the temperature and deformation are monitored to ensure the consistency of material properties. Step S6 includes cold rolling the forged silver ingot at room temperature, and the deformation amount is controlled at 60%. The forged silver ingot is cold rolled at room temperature to further refine the grains and increase the density of the material. The deformation amount and rate of cold rolling are controlled to avoid excessive hardening of the material.

[0071] In this embodiment, an intermediate annealing treatment is performed in step S7, and the annealing temperature is controlled to be 600°C, and the holding time is 1 hour. In step S8, precision rolling technology is used to roll the material into a 0.5 mm thick silver target. The density and uniformity of the material are effectively improved by grain refinement and multi-stage heat treatment, and internal stress is eliminated. In addition, the multi-directional forging process enhances the isotropy of the target material and ensures the consistency of performance in different directions. In step S9, the silver target material is finally annealed at a temperature of 500°C and a holding time of 2 hours. The silver target material after precision rolling is finally annealed to obtain a fine and uniform grain structure. After annealing, the grain size and distribution are tested to ensure that the technical requirements are met.

[0072] It should be noted that the surface of the silver target is polished to ensure the flatness and cleanliness of the target surface. Surface analysis technology is used to detect the surface roughness through white light interferometry to ensure that high standards are met. The prepared silver target is subjected to comprehensive quality inspection, including chemical composition analysis, microstructure analysis, physical property testing, etc. Quality assessment is carried out based on the test results to ensure that the target meets the requirements of ultra-high purity and high performance.

[0073] Embodiment three:

[0074] See also Figure 1 An ultra-high purity silver target material in this embodiment includes the following raw materials in a weight fraction ratio: 99.99% high purity silver, 0.15% palladium, 0.075% iridium, 0.3% neodymium, and 0.3% praseodymium.

[0075] In this embodiment, high-purity silver is the main raw material, and the purity of the high-purity silver is 5N.

[0076] It should be noted that high-purity silver with a purity of 5N is selected as the base material to ensure the high purity of the target material.

[0077] The present application further proposes a method for preparing an ultra-high purity silver target, comprising the following steps:

[0078] S1 Raw material preparation: Select high-purity silver with a purity of 5N as the base material, and prepare trace amounts of palladium, iridium, neodymium and praseodymium as alloy elements in proportion;

[0079] S2 uses induction melting technology to melt the base materials and alloy elements into a uniform alloy under vacuum;

[0080] S3 slowly cools the smelted alloy liquid in an inert atmosphere to form an ingot;

[0081] S4 performs high temperature annealing on the ingot to eliminate casting stress and microsegregation;

[0082] S5 forges the ingot multiple times in different directions to refine the grains and improve the isotropy of the material;

[0083] S6 cold-rolls the forged silver ingot at room temperature to further refine the grains and increase the density of the material;

[0084] S7 performs intermediate annealing to restore the plasticity of the material and eliminate the internal stress generated during the cold rolling process;

[0085] S8 uses precision rolling technology to roll the material into silver targets of the required thickness;

[0086] S9 performs final annealing on the precision rolled silver target to obtain a fine and uniform grain structure;

[0087] S10 polishes the surface of the silver target to ensure the flatness and cleanliness of the target surface.

[0088] In the raw material preparation stage in step S1 of this embodiment, high-precision weighing equipment is used to ensure accurate addition of trace elements, and before smelting, the trace elements are pre-mixed with the base material to promote preliminary mixing between the elements.

[0089] It should be noted that trace amounts of palladium and iridium are added as alloying elements to enhance the strength and wear resistance of the target material, and trace amounts of rare earth elements such as neodymium and praseodymium are introduced to refine the grains and improve the microstructural uniformity of the target material.

[0090] In this embodiment, the vacuum environment in step S2 adopts vacuum induction melting, and multiple meltings are performed. After each melting, the molten alloy is thoroughly stirred to make the elements evenly distributed.

[0091] In this embodiment, the annealing treatment in step S4 is to perform homogenization annealing treatment on the ingot at 1100°C, and the holding time is 2 hours. The smelted alloy liquid is slowly cooled in an inert atmosphere to form an ingot to reduce the incorporation of gas and impurities, and the cooling rate is controlled to avoid internal stress and abnormal grain growth. Step S5 includes multi-directional forging, and the deformation amount of each forging is controlled within 20%. The forging temperature is 700°C. After each forging, the temperature and deformation are monitored to ensure the consistency of material properties. Step S6 includes cold rolling the forged silver ingot at room temperature, and the deformation amount is controlled at 60%. The forged silver ingot is cold rolled at room temperature to further refine the grains and increase the density of the material. The deformation amount and rate of cold rolling are controlled to avoid excessive hardening of the material.

[0092] In this embodiment, an intermediate annealing treatment is performed in step S7, and the annealing temperature is controlled to be 600°C and the holding time is 1 hour. In step S8, precision rolling technology is used to roll the material into a 0.5 mm thick silver target. In step S9, the silver target is subjected to a final annealing treatment, and the annealing temperature is 500°C and the holding time is 2 hours. The silver target after precision rolling is subjected to a final annealing treatment to obtain a fine and uniform grain structure. After annealing, the grain size and distribution are tested to ensure that the technical requirements are met.

[0093] It should be noted that the surface of the silver target is polished to ensure the flatness and cleanliness of the target surface. Surface analysis technology is used to detect the surface roughness through white light interferometry to ensure that high standards are met. The prepared silver target is subjected to comprehensive quality inspection, including chemical composition analysis, microstructure analysis, physical property testing, etc. Quality assessment is carried out based on the test results to ensure that the target meets the requirements of ultra-high purity and high performance.

[0094] The beneficial effects of the above embodiments are:

[0095] The ultra-high purity silver target material and its preparation method, by adopting 5N grade high purity silver as the base material and accurately adding trace amounts of elements such as palladium, iridium, neodymium and praseodymium, achieve a significant improvement in the purity of the target material, surpassing the purity range of the existing technology. This innovative material design not only optimizes the hardness, strength and wear resistance of the target material, but also effectively improves the density and uniformity of the material through grain refinement and multi-stage heat treatment, and eliminates internal stress. In addition, the multi-directional forging process enhances the isotropy of the target material and ensures the consistency of performance in different directions. These improvements significantly improve the mechanical properties of the target material, making it more adaptable to application environments with high wear resistance requirements, while also improving the conductivity, reflectivity and uniformity of the film prepared using the target material.

[0096] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0097] While the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that many changes, modifications, substitutions and variations can be made to the embodiments without departing from the principles and spirit of the invention.

Claims

1. An ultra-high purity silver target, characterized in that: The invention comprises the following raw materials in weight fraction ratio: 99.99% of high-purity silver, 0.05%-0.15% of palladium, 0.025%-0.075% of iridium, 0.1%-0.3% of neodymium, and 0.1%-0.3% of praseodymium.

2. The ultra-high purity silver target according to claim 1, characterized in that: The ultra-high purity silver target material also includes the following raw materials in weight fraction ratio: 99.99% high purity silver, 0.05% palladium, 0.025% iridium, 0.1% neodymium, and 0.1% praseodymium.

3. The ultra-high purity silver target according to claim 1, characterized in that: The ultra-high purity silver target material also includes the following raw materials in weight fraction ratio: 99.99% high purity silver, 0.1% palladium, 0.05% iridium, 0.2% neodymium, and 0.2% praseodymium.

4. The ultra-high purity silver target according to claim 1, characterized in that: The ultra-high purity silver target material also includes the following raw materials in weight fraction ratio: 99.99% high purity silver, 0.15% palladium, 0.075% iridium, 0.3% neodymium, and 0.3% praseodymium.

5. The ultra-high purity silver target according to claim 1, characterized in that: The high-purity silver is the main raw material, and the purity of the high-purity silver is 5N.

6. A method for preparing an ultra-high purity silver target, comprising the ultra-high purity silver target according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1 Raw material preparation: Select high-purity silver with a purity of 5N as the base material, and prepare trace amounts of palladium, iridium, neodymium and praseodymium as alloy elements in proportion; S2 uses induction melting technology to melt the base materials and alloy elements into a uniform alloy under vacuum; S3 slowly cools the smelted alloy liquid in an inert atmosphere to form an ingot; S4 performs high temperature annealing on the ingot to eliminate casting stress and microsegregation; S5 forges the ingot multiple times in different directions to refine the grains and improve the isotropy of the material; S6 cold-rolls the forged silver ingot at room temperature to further refine the grains and increase the density of the material; S7 performs intermediate annealing to restore the plasticity of the material and eliminate the internal stress generated during the cold rolling process; S8 uses precision rolling technology to roll the material into silver targets of the required thickness; S9 performs final annealing on the precision rolled silver target to obtain a fine and uniform grain structure; S10 polishes the surface of the silver target to ensure the flatness and cleanliness of the target surface.

7. The method for preparing an ultra-high purity silver target according to claim 6, characterized in that: In the raw material preparation stage in step S1, high-precision weighing equipment is used to ensure accurate addition of trace elements, and before smelting, the trace elements are pre-mixed with the base material to promote preliminary mixing between the elements.

8. The method for preparing an ultra-high purity silver target according to claim 6, characterized in that: The vacuum environment in step S2 adopts vacuum induction melting, and the melting is performed multiple times. After each melting, the molten alloy is thoroughly stirred to make the elements evenly distributed.

9. The method for preparing an ultra-high purity silver target according to claim 6, characterized in that: The annealing treatment in step S4 is a homogenization annealing treatment of the ingot at 1100°C, and the holding time is 2 hours. The step S5 includes multi-directional forging, and the deformation of each forging is controlled within 20%, and the forging temperature is 700°C. The step S6 includes cold rolling the forged silver ingot at room temperature, and the deformation is controlled within 60%.

10. The method for preparing an ultra-high purity silver target according to claim 6, characterized in that: In the step S7, an intermediate annealing treatment is performed, the annealing temperature is controlled at 600° C., and the holding time is 1 hour. In the step S8, precision rolling technology is used to roll the material into a 0.5 mm thick silver target. In the step S9, the silver target is finally annealed at 500° C. and the holding time is 2 hours.

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