A method for preparing a silicon-molybdenum alloy target

Abstract

The application relates to the technical field of composite resin preparation, and discloses a silicon-molybdenum alloy target material preparation method, which comprises the following steps: raw material preparation, selecting molybdenum powder and silicon powder with a purity not less than 99.9%, mixing treatment, placing the raw material into a vacuum mixing machine, vacuumizing to 0.01-0.1 Pa, stirring for 1-5 hours, ultrasonic-assisted oxidation prevention with temperature control at 25-40 DEG C, forming process, loading the mixed powder into a detachable hard alloy mold coated with a 0.05-0.2 mm boron nitride coating, cold-pressing forming, keeping pressure for 5-20 minutes to obtain a green body, sintering process, loading the green body into a vacuum sintering furnace, microwave-assisted heating first, then heating to 1500-1800 DEG C, later controlling the structure by feeding trace argon, post-processing procedure, numerically controlling the sintered target material, chemical cleaning by using a mixed solution of hydrofluoric acid and nitric acid, then plasma treatment, and finally vacuum packaging with high-purity nitrogen. The raw material has high purity and good granularity; the mixture is uniform and oxidation is prevented; the forming and sintering are accurately controlled, the target material quality is guaranteed; the post-processing improves the surface performance, the packaging prevents oxygen and moisture, and the target material meets the needs of high-end industries.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of silicon-molybdenum alloy target material preparation, in particular to a silicon-molybdenum alloy target material preparation method. BACKGROUND

[0002] In today's era of rapid development of high-tech industries, the application of thin film materials is becoming more and more widespread. From semiconductor chip manufacturing, flat panel display to solar photovoltaic field, high-quality thin film deposition technology is indispensable, and the performance of target material as the key raw material for thin film deposition directly determines the quality of the thin film and the characteristics of the final product.

[0003] Silicon-molybdenum alloy target material has unique advantages in many frontier fields due to the combination of the characteristics of silicon and molybdenum. Silicon has good semiconductor properties and can provide precise electrical control for electronic devices. Molybdenum has high melting point, high hardness and excellent thermal conductivity, making the alloy target material stable and reliable under high temperature and high power working conditions. The silicon-molybdenum alloy target material formed by the combination of the two can meet the needs of special application scenarios such as high-temperature semiconductor devices and high-power electronic components.

[0004] However, the traditional silicon-molybdenum alloy target material preparation method has many drawbacks and cannot meet the requirements of modern industry for high-quality and high-precision target materials. In the raw material preparation stage, early methods often use conventional crushing and simple purification to obtain molybdenum powder and silicon powder, resulting in wide particle size distribution and limited purity, which seriously affects the density and electrical properties of the subsequent target material. For example, coarse particle size powder is prone to uneven porosity during forming, which can cause uneven film thickness and fluctuations in electrical properties during thin film deposition.

[0005] In terms of mixing process, past methods often rely on ordinary mechanical stirring, which has low mixing efficiency and poor uniformity, making it difficult to fully and uniformly disperse molybdenum powder and silicon powder. This can cause composition segregation, resulting in inconsistent performance of the target material, local defects during thin film deposition, and reduced product yield.

[0006] The forming and sintering process also faces challenges. Traditional cold pressing forming has rough pressure control, unreasonable die design, and difficulty in demolding, which can damage the green body and affect the size accuracy and surface quality of the target material. During the sintering process, the heating rate, holding time and atmosphere control lack precise regulation, making it difficult to achieve ideal microstructure, resulting in stress concentration and uneven grain size within the target material. This not only reduces the strength of the target material, but also can cause the target material to crack due to thermal stress release during use, shortening its service life.

[0007] The post-processing process also has defects, the machining precision is low, the chemical cleaning is not thorough, the packaging material is simple and cannot effectively isolate the external environment from erosion, so that the target material is easily contaminated and oxidized during storage and transportation, further reducing its performance. In summary, a new and all-round optimized silicon-molybdenum alloy target material preparation method is urgently needed to break through these bottlenecks and meet the growing industrial demand. SUMMARY

[0008] (I) Technical problems to be solved

[0009] In view of the defects of the prior art, the present application provides a silicon-molybdenum alloy target material preparation method.

[0010] (II) Technical solutions

[0011] A silicon-molybdenum alloy target material preparation method comprises the following steps:

[0012] S1, raw material preparation: selecting metal molybdenum powder with a purity of not less than 99.9%, a particle size of 1-10 μm, prepared by airflow crushing and grading screening technology, and silicon powder with a purity of not less than 99.9%, a particle size of 0.5-5 μm, prepared by chemical vapor deposition method, weighing according to the mass fraction of 10%-50% of the silicon content;

[0013] S2, mixing treatment: placing the weighed molybdenum powder and silicon powder in a vacuum mixer, vacuumizing to 0.01-0.1 Pa, stirring at a speed of 100-500 revolutions per minute for 1-5 hours, using ultrasonic assisted dispersion, the ultrasonic frequency is 20-60 kHz, and the ultrasonic generator has an intelligent frequency adjustment function, which is adjusted in real time according to the powder mixing state to make the powder fully mixed and uniform, and the inside of the mixer is provided with a temperature control system, the temperature is controlled at 25-40°C during mixing, the circulating water cooling system is used to accurately control the temperature to prevent the powder from being overheated and oxidized due to friction;

[0014] S3, forming process: the mixed powder is loaded into a mold, the inner wall of the mold is coated with a boron nitride coating with a thickness of 0.05-0.2 mm, prepared by thermal spraying process, the coating has strong bonding force, cold pressing under a pressure of 300 / 350 MPa, the pressure holding time is 5-20 minutes, the cold pressing equipment is provided with a pressure sensor and an automatic compensation system, a green body is obtained, the mold is of detachable structure, facilitating demolding, the mold material is hard alloy with a hardness of not less than HRA85, and the surface of the mold is treated by ion implantation;

[0015] S4, sintering process: the green body is placed in a vacuum sintering furnace, first heated to 1000-1200°C at a heating rate of 5-15°C / min, and then heated to 1500-1800°C at a heating rate of 2-8°C / min, and then heated for 2-6 hours, and the vacuum degree is maintained at 0.001-0.01 Pa during the whole sintering process, and then cooled in the furnace; the vacuum sintering furnace is equipped with an atmosphere control system, a small amount of argon gas can be introduced during the later stage of sintering, the argon gas flow is 1-5 ml / min, which is precisely controlled by a gas flow automatic regulating valve, and the internal structure of the target material is adjusted;

[0016] S5, post-processing step: the sintered target material is machined, the machining precision is controlled within ±0.05-±0.2mm, and the machining tool is selected as polycrystalline diamond tool, then chemical cleaning is carried out, a mixed solution of hydrofluoric acid and nitric acid is used, the concentration of hydrofluoric acid is 5%-15%, the concentration of nitric acid is 10%-25%, the cleaning time is 10-30 minutes, and the cleaning is carried out under the assistance of ultrasonic oscillation, the surface impurities are removed, and then plasma treatment is carried out, argon plasma is used, the power is 100-500W, the treatment time is 5-15 minutes, the plasma treatment equipment is equipped with a radio frequency matching network to automatically optimize the discharge parameters, and finally vacuum packaging is carried out, high-purity nitrogen gas is filled in the package, the purity of the nitrogen gas is not less than 99.99%, and a vacuum nitrogen filling packaging machine is used.

[0017] Further, the stirring paddle of the vacuum mixer adopts a special double-layer spiral structure, the inner paddle preliminarily mixes, and the outer paddle strengthens the dispersion effect, and the surface of the stirring paddle is coated with a ceramic wear-resistant coating with a thickness of 0.02-0.1mm, and the coating has self-lubricating properties.

[0018] Further, in the S3 step, the detachable structure of the cold pressing forming mold adopts a dovetail groove connection method, a demolding agent automatic spraying device is arranged in the mold, the demolding agent is uniformly sprayed before demolding, the demolding effect is further optimized, the demolding agent is selected as a high-temperature-resistant and pollution-free organic silicon demolding agent, and the spraying amount of the demolding agent can be accurately controlled through a numerical control system, and the spraying amount accuracy is controlled within ±0.1g / cm² according to the mold size and the powder characteristics.

[0019] Further, in the S4 step, the microwave-assisted heating system of the vacuum sintering furnace has a frequency of 2.45GHz, and the power is intelligently adjusted according to the size and material of the green body, in addition, during the microwave-assisted heating process, the sintering furnace is also equipped with a temperature field homogenization device, which is composed of multiple layers of metal reflecting plates and heat medium, and the device reflects and scatters microwaves to control the temperature field deviation in the furnace within ±2°C.

[0020] Further, in step S5, the target material after chemical cleaning is subjected to cold air drying treatment before entering the plasma processing equipment to remove the residual surface moisture. The cold air drying equipment adopts low-temperature cold air circulation technology, with the cold air temperature controlled at 5-15°C and the air speed at 2-5 m / s. Meanwhile, a humidity sensor is arranged inside the drying equipment to monitor the drying degree in real time, and the drying is automatically stopped when the humidity is lower than the set value of 10%.

[0021] Further, in step S5, the packaging material for vacuum packaging is a multi-layer composite aluminum foil bag with high barrier property and corrosion resistance. The inner layer of the multi-layer composite aluminum foil bag is attached to a slow-release oxygen scavenger film, which can slowly release the oxygen scavenger during storage, so that the oxygen content in the package is always maintained below 0.01%.

[0022] Further, after step S1 is completed, the mixed powder is subjected to pre-compaction treatment using low-frequency vibration compaction technology with a vibration frequency of 10-30 Hz, an amplitude of 0.5-2 mm, and a compaction time of 10-20 minutes. This makes the powder initially compact, reduces powder movement in the subsequent forming process, and improves the uniformity of the green body density.

[0023] Further, during the sintering process in step S4, hydrogen gas is intermittently introduced into the vacuum sintering furnace when the temperature rises to 1300-1500°C. The hydrogen flow is 0.5-2 ml / min, and each time the hydrogen is introduced for 2-5 minutes with an interval of 10-20 minutes. The reduction property of hydrogen is used to remove possible trace amounts of oxide impurities inside the target material, thereby improving the purity of the target material. At the same time, by controlling the hydrogen introduction time and interval, excessive reaction of hydrogen with molybdenum and silicon is avoided.

[0024] (Three) Beneficial technical effects

[0025] First, in terms of raw material processing, molybdenum powder is prepared by airflow crushing and classification screening technology, and silicon powder is prepared by chemical vapor deposition method, ensuring that the particle size of the raw materials is uniform and the purity is extremely high (both not less than 99.9%), laying a solid foundation for subsequent preparation of high-quality target materials, making the target material composition uniform, and the electrical performance stable and reliable.

[0026] In the mixing stage, the vacuum mixer combines intelligent frequency adjustment ultrasonic assisted dispersion and precise temperature control to allow the molybdenum powder and silicon powder to be fully and uniformly mixed, effectively avoiding composition segregation, greatly improving the mixing efficiency and uniformity, and thus ensuring that the performance of the target material is consistent everywhere, forming a uniform and high-quality film layer during film deposition, and improving the product yield.

[0027] In the forming process, the boron nitride coating mold prepared by thermal spraying and the precise cold pressing forming equipment not only facilitate demolding, but also ensure high dimensional accuracy and excellent surface quality of the green body, providing a good blank body for subsequent sintering and reducing the problem of performance degradation of the target material caused by forming defects.

[0028] The sintering process realizes ideal microstructure of the target material, uniform distribution of internal stress, small and uniform grains, greatly improves the strength of the target material, effectively prevents cracking during use, and prolongs the service life of the target material through microwave-assisted heating, precise heating rate and atmosphere control.

[0029] The post-processing process further guarantees the quality of the target material in all aspects. High-precision numerical control processing, thorough chemical cleaning and plasma treatment remove surface impurities and improve surface cleanliness. Vacuum packaging with multi-layer composite aluminum foil bag and oxygen scavenger slow-release film isolates external moisture and oxygen, maintains the stability of the target material performance, and keeps the target material in good condition during storage and transportation, meeting the stringent demands of high-tech industries for high-quality target materials. DETAILED DESCRIPTION

[0030] Example 1:

[0031] Raw material preparation:

[0032] Metallic molybdenum powder with a purity of 99.95% and a particle size of 3-7 μm is selected and prepared through advanced airflow crushing and fine classification screening technology to ensure high uniformity of particle size. Silicon powder with a purity of 99.93% and a particle size of 1-3 μm is prepared using an optimized chemical vapor deposition method. The silicon content is accurately weighed at a mass fraction of 30%.

[0033] Mixing process:

[0034] The molybdenum powder and silicon powder are placed in a mixer with high-precision vacuum (vacuumed to 0.05 Pa) and stirred at 300 revolutions per minute for 3 hours. During this period, ultrasonic dispersion is assisted, with the ultrasonic frequency dynamically adjusted between 30-50 kHz and intelligently adjusted according to the real-time mixing state of the powder. The internal temperature control system of the mixer uses high-precision temperature sensors and high-efficiency circulating water cooling to accurately maintain the temperature at 30°C, effectively preventing oxidation of the powder.

[0035] Forming process:

[0036] The mixed powder is loaded into a mold with a 0.1 mm boron nitride coating (prepared by thermal spraying process, coating bond strength exceeding 50 MPa) on the inner wall. The mold is a detachable hard alloy mold (hardness HRA88) connected by dovetail grooves, with the surface treated by ion implantation to improve wear resistance by 30%. Cold pressing is performed at a pressure of 350 MPa, with a pressure holding time of 12 minutes. The pressure sensor of the cold pressing equipment has an accuracy of ±0.5 MPa, and the automatic compensation system adjusts the pressure in real time.

[0037] Sintering process:

[0038] The green body is placed in a vacuum sintering furnace, first heated to 1100°C at a rate of 10°C / min, microwave-assisted heating (frequency 2.45GHz, power is intelligently adjusted according to the size of the green body), and held for 2 hours; then heated to 1650°C at a rate of 5°C / min, and held for 4 hours, the vacuum degree during the whole sintering process is 0.005Pa. In the later stage, 3ml / min of argon gas is introduced, and the microstructure of the target material is precisely controlled by using a high-precision gas flow automatic regulating valve.

[0039] Post-processing procedure:

[0040] After sintering, the target material is processed by high-precision numerical control machining equipment, the machining precision is controlled within ±0.1mm, and the sharpness retention of the cutting edge of the polycrystalline diamond cutter is improved by 20%. Chemical cleaning uses a mixed solution of 10% hydrofluoric acid and 18% nitric acid, and ultrasonic oscillation assisted cleaning for 20 minutes. Then plasma treatment (argon plasma, power 300W, radio frequency matching network optimized discharge parameters) for 5 minutes. Finally, vacuum packaging with multi-layer composite aluminum foil bag, filling pure nitrogen gas with a purity of 99.995% in the bag, and using an oxygen scavenger slow-release film in the inner layer to stabilize the oxygen content in the package below 0.005%.

[0041] After detection, the prepared silicon-molybdenum alloy target material has a density uniformity deviation of less than 0.5%, uniform grain size, an average particle size of 20μm, a film thickness uniformity deviation of less than 3% after thin film deposition, stable electrical performance, and meets the needs of high-end semiconductor chip manufacturing.

[0042] Example 2:

[0043] Raw material preparation:

[0044] Select molybdenum metal powder with a purity of 99.92% and a particle size of 2-8μm, and use airflow crushing combined with classification screening to ensure the particle size. Silicon powder with a purity of 99.94% and a particle size of 0.8-2μm is prepared by chemical vapor deposition method. Weigh according to the mass fraction of silicon content of 40%.

[0045] Mixing process:

[0046] Place in a vacuum mixer with a vacuum degree of 0.08Pa, stir at 250rpm for 4 hours, and intelligently adjust the ultrasonic frequency to 25-45kHz, with a temperature control of 35°C.

[0047] Forming process:

[0048] Load into a 0.15mm boron nitride coated mold (thermal spraying, combined strength exceeding 60MPa), a detachable dovetail slot hard alloy mold (hardness HRA86), and ion implantation treatment. Cold pressing at a pressure of 300MPa, holding pressure for 15 minutes, pressure sensor accuracy ±0.8MPa, and automatic compensation system calibration.

[0049] Sintering process:

[0050] The vacuum sintering furnace is first heated to 1050°C at a rate of 8°C / min, then microwave-assisted heating (frequency 2.45 GHz, power intelligently controlled) is applied for 2.5 hours; then it is heated to 1700°C at a rate of 4°C / min, and held for 5 hours at a vacuum degree of 0.008 Pa, and then 2 ml / min of argon gas is introduced for precise control.

[0051] Post-processing procedure:

[0052] The numerical control machining precision is ±0.15 mm, the chemical cleaning uses a mixed solution of 8% hydrofluoric acid and 22% nitric acid, ultrasonic oscillation is applied for 25 minutes, plasma treatment (power 400 W, 5 minutes) is applied, multi-layer composite aluminum foil bags are vacuum packaged, 99.992% pure nitrogen gas is filled, and the oxygen content is controlled to be less than 0.008% by the oxygen scavenger slow-release film.

[0053] Detection shows that the target material density uniformity deviation is less than 0.6%, the average grain size is 22 μm, and the film layer thickness uniformity deviation is less than 4%, which is suitable for high-performance flat panel display field.

[0054] Comparative example:

[0055] Traditional preparation method:

[0056] The raw materials are ordinary mechanical pulverized molybdenum powder (purity 99%, particle size 5-20 μm) and simply purified silicon powder (purity 99%, particle size 2-8 μm), and the silicon content is roughly weighed at 25%. The mixing uses ordinary mechanical stirring for 2 hours without vacuum and ultrasonic assistance, and the environmental temperature is uncontrollable. The molding uses a simple steel mold without coating, and is cold-pressed into shape at a pressure of 200 MPa, with a holding pressure of 10 minutes, and the ejection is difficult and the green body is damaged. The sintering is carried out in a simple electric furnace, the heating rate is randomly fluctuated at 3-8°C / min, there is no atmosphere control, and the holding time is inaccurate. The post-processing is manually polished and processed, the precision can only reach ±0.5 mm, the chemical cleaning uses a single acid solution for simple immersion for 10 minutes, and the ordinary plastic bag is used for packaging after natural air drying.

[0057] Comparative Example Example 1 Example 2 Comparative Example Metallic Mo powder purity 99.95% 99.92% 99% Metallic Mo powder particle size (μm) 3-7 2-8 5-20 Silicon powder purity 99.93% 99.94% 99% Silicon powder particle size (μm) 1-3 0.8-2 2-8 Mixing vacuum (Pa) 0.05 0.08 No Mixing ultrasonic frequency (kHz) 30-50 25-45 No Mixing temperature control (°C) 30 35 Uncontrollable Mold coating thickness (mm) 0.1 0.15 No Mold coating bonding strength (MPa) Over 50 Over 60 No Cold pressing forming pressure (MPa) 350 300 200 Cold pressing forming dwell time (min) 12 15 10 Sintering heating rate (°C / min) (early stage) 105 84 3-8 fluctuate randomly Sintering dwell time (hours) (early stage - late stage) 2-4 2.5-5 Inaccurate Sintering vacuum (Pa) 0.005 0.008 No control Sintering late stage argon flow (ml / min) 3 2 No Machining precision (mm) ±0.1 ±0.15 ±0.5 Chemical cleaning solution 10% hydrofluoric acid + 18% nitric acid 8% hydrofluoric acid + 22% nitric acid Single acid solution Chemical cleaning time (min) 20 25 10 Plasma processing power (W) 300 400 No Packaging nitrogen purity 99.995% 99.992% No high purity nitrogen Packaging oxygen content control 0.005% or less 0.008% or less No control Target density uniformity deviation Less than 0.5% Less than 0.6% More than 3% Grain average particle size (μm) 20 22 Size uneven, maximum over 50 Film thickness uniformity deviation Less than 3% Less than 4% More than 10% Electrical performance stability Stable Stable Large fluctuations

[0058] Performance test results:

[0059] The prepared target material density uniformity deviation is greater than 3%, the grain size is uneven, the maximum particle size is more than 50 μm, the film layer thickness uniformity deviation is greater than 10%, the electrical performance fluctuates greatly, and problems such as target cracking and film layer defects easily occur in use, which cannot meet the needs of high-end industries, and is in sharp contrast to Examples 1 and 2.

[0060] While embodiments of the application have been shown and described, it is to be understood that the embodiments described are merely exemplary of the principles and application of the present application. Numerous modifications and adaptions can be effected without departing from the spirit and scope of the present application, which is not limited to the exact construction and arrangement described. It is intended, therefore, to cover all modifications and adaptions that fall within the scope of the claims and their equivalents.

Claims

1. A method of preparing a silicon-molybdenum alloy target material, characterized by, The method comprises the following steps: S1, raw material preparation: selecting metal molybdenum powder with a purity of not less than 99.9% and a particle size of 1-10 μm, prepared by airflow crushing and grading screening technology, and silicon powder with a purity of not less than 99.9% and a particle size of 0.5-5 μm, prepared by chemical vapor deposition method, and weighing according to the mass fraction of 10%-50% of the silicon content; S2, mixing treatment: placing the weighed molybdenum powder and silicon powder in a vacuum mixer, vacuumizing to 0.01-0.1 Pa, stirring at a speed of 100-500 r / min for 1-5 hours, using ultrasonic assisted dispersion, the ultrasonic frequency is 20-60 kHz, and the ultrasonic generator has an intelligent frequency adjustment function, which is adjusted in real time according to the powder mixing state to make the powder fully mixed and uniform, and a temperature control system is arranged in the mixer, the temperature is controlled at 25-40°C during mixing, and a circulating water cooling system is used to accurately control the temperature to prevent the powder from being oxidized due to friction overheating; S3, forming process: the mixed powder is loaded into a mold, the inner wall of the mold is coated with a boron nitride coating with a thickness of 0.05-0.2 mm, which is prepared by thermal spraying process, and the coating has strong bonding force, and is cold-pressed into a green body under a pressure of 300 / 350 MPa, the pressure holding time is 5-20 minutes, the cold-pressing equipment is provided with a pressure sensor and an automatic compensation system, the mold is of a detachable structure for easy demolding, the mold material is hard alloy with a hardness of not less than HRA85, and the surface of the mold is treated by ion implantation; S4, sintering process: the green body is placed in a vacuum sintering furnace, first heated to 1000-1200°C at a heating rate of 5-15°C / min, and held for 1-3 hours, then heated to 1500-1800°C at a heating rate of 2-8°C / min, and held for 2-6 hours, the vacuum degree is maintained at 0.001-0.01 Pa during the whole sintering process, and then the furnace is cooled; the vacuum sintering furnace is provided with an atmosphere control system, a small amount of argon gas can be introduced during the later stage of sintering, the argon gas flow is 1-5 ml / min, and the gas flow automatic regulating valve is used for accurate control to adjust the internal structure of the target material; S5, post-processing process: the sintered target material is machined by numerical control machining equipment, the machining precision is controlled within ±0.05-±0.2 mm, and poly crystalline diamond tools are selected for machining, then chemical cleaning is carried out, a mixed solution of hydrofluoric acid and nitric acid is used, the concentration of hydrofluoric acid is 5%-15%, the concentration of nitric acid is 10%-25%, the cleaning time is 10-30 minutes, and the cleaning is carried out under ultrasonic oscillation assistance to remove surface impurities, after chemical cleaning, plasma treatment is also carried out, argon plasma is used, the power is 100-500 W, the treatment time is 5-15 minutes, the plasma treatment equipment is provided with a radio frequency matching network to automatically optimize discharge parameters, finally vacuum packaging is carried out, high-purity nitrogen gas is filled in the package, the purity of the nitrogen gas is not less than 99.99%, and a vacuum nitrogen filling packaging machine is used.

2. The method of claim 1, wherein: In S2, the stirring paddle of the vacuum mixer adopts a special double-layer spiral structure, the inner paddle for preliminary mixing and the outer paddle for enhanced dispersion effect, and the surface of the paddle is coated with a ceramic wear-resistant coating with a thickness of 0.02-0.1mm and self-lubricating property.

3. The method of claim 1, wherein: In S3, the detachable structure of the cold-press forming die adopts dovetail groove connection, the inside of the die is provided with an automatic release agent spraying device, and the release agent is uniformly sprayed before demolding to further optimize the demolding effect. The release agent is high-temperature resistant and pollution-free organic silicone release agent, and the spraying amount can be accurately controlled through the numerical control system, with an accuracy of ±0.1g / cm² according to the die size and powder characteristics.

4. The method of claim 1, wherein: In S4, the microwave-assisted heating system of the vacuum sintering furnace has a frequency of 2.45GHz, and the power is intelligently adjusted according to the size and material of the green body. In addition, during the microwave-assisted heating process, the sintering furnace is also equipped with a temperature field homogenization device composed of multiple layers of metal reflection plates and heat distribution media, which reflects and scatters microwaves to control the temperature field deviation within ±2°C.

5. The method of claim 1, wherein: In S5, the target material after chemical cleaning is first subjected to cold air drying treatment before entering the plasma treatment equipment to remove surface residual moisture. The cold air drying equipment adopts low-temperature cold air circulation technology, with a cold air temperature of 5-15°C and a wind speed of 2-5m / s. The drying equipment is equipped with a humidity sensor to monitor the drying degree in real time, and automatically stops drying when the humidity is lower than the set value of 10%.

6. The method of claim 1, wherein: In S5, the packaging material for vacuum packaging is a multi-layer composite aluminum foil bag with high barrier property and corrosion resistance. The inner layer of the multi-layer composite aluminum foil bag is attached to a layer of oxygen scavenger release film, which can slowly release oxygen scavenger during storage to keep the oxygen content in the package below 0.01%.

7. The method of claim 1, wherein: After S1, the mixed powder is subjected to pre-compaction treatment using low-frequency vibration compaction technology with a vibration frequency of 10-30Hz, an amplitude of 0.5-2mm, and a compaction time of 10-20 minutes to make the powder initially compact, reduce powder movement in subsequent forming processes, and improve the uniformity of the green body density.

8. The method of claim 1, wherein: During the sintering process in S4, hydrogen is intermittently introduced into the vacuum sintering furnace when the temperature rises to 1300-1500°C, with a hydrogen flow rate of 0.5-2ml / min and a duration of 2-5 minutes each time, and an interval of 10-20 minutes. The hydrogen gas is used to remove trace amounts of oxide impurities that may exist inside the target material, thereby improving the purity of the target material. By controlling the hydrogen introduction time and interval, excessive reaction of hydrogen with molybdenum and silicon is avoided.