TW503218B - Tantalum sputtering target and method of manufacture - Google Patents

Abstract

Described is a method for producing high purity tantalum, the high purity tantalum so produced and sputtering targets of high purity tantalum. The method involves purifying starting materials followed by subsequent refining into high purity tantalum.

Description

503218 4888pif2.doc / 0 12-Printed A7 B7 by the Consumer Cooperatives of the Central Standards Bureau of the Ministry of Economic Affairs ___ V. Description of the Invention (/) The present invention relates to a method and device for manufacturing high-purity molybdenum, and formed by this method Extremely high purity. The present invention particularly relates to a method for manufacturing high-purity tantalum. BACKGROUND OF THE INVENTION In the electronics industry, the group has been widely used in manufacturing high-efficiency capacitors. This is mainly due to the strong and stable dielectric properties of the oxide film on the anodized metal. Therefore, processed fine foils and powders are often used to make main capacitors. In addition, thin film capacitors used in microcircuits are formed by anodized giant films, and anodized giant films are usually manufactured by sputtering. In new-generation wafers, tantalum sputtering can also be performed in an Ar-N2 environment to form an ultra-thin TaN layer as a barrier layer between the silicon substrate and the copper layer to ensure the cross-section of the interconnect. It is possible to take advantage of the high conductivity of copper. According to reports, the microstructure and surface texture of TaN films are not as sensitive to the deposition conditions as TiN. Therefore, for wafer processes using copper as the metallization process material, TaN is much better than ZN. For these thin film applications in the microelectronics industry, high-purity tantalum sputtering targets are needed. Most of the molybdenum metals produced in the world are derived from the sodium reduction reaction of K2TaF7. In addition, there are also some technologies that are not commercially adopted. These technologies include tantalum oxide (Ta205) and metal reducing agents such as calcium or aluminum, and non-metal reducing agents such as carbon and nitrogen carbide. Molybdenum pentachloride (TaCl5) performs reduction reaction with magnesium, sodium or hydrogen, and thermal dissociation reaction of tantalum pentachloride. 4 This paper size applies the Chinese National Standard (CNS) A4 specification (210X297 mm) 83. 3 ·! 0,000 (Please read the notes on the back before filling this page) C.-Order '503218 4888pif2.doc / 012 A7 B7 Standard local shell V. Description of the invention ()) The reduced giant system exists in the form of powder, lumps or monolithic metal. It often contains a considerable amount of oxygen and other impurities, including impurities such as reducing agents and impurities present in the molybdenum starting material. A common method to remove impurities in molybdenum is the electron beam melting method. This is because most of the metal impurities and the gas in the interstitial space are heated during the melting of the electron beam because of the high vapor pressure at the melting point of molybdenum (2996 degrees Celsius). Except for silver, cranes, pins, shafts, and agencies, basically all elements can be removed this way. When metal impurities and nitrogen are removed by direct evaporation, oxygen is also removed. The mechanism for removing oxygen includes the formation of carbon oxides, alumina, water, and other suboxides, which are then vaporized. The purity of molybdenum can be further improved by repeating the electron beam melting method. In other refining processes including vacuum arc melting, vacuum slag, molten salt electrorefining, and refining giant iodide, the refining of molybdenum iodide is the most reliable technique for removing molybdenum and tungsten. The above refining techniques are not effective in removing niobium from tantalum. This is because niobium and molybdenum are quite tightly bound in nature. Therefore, the removal of niobium is a critical step when preparing very high-purity tantalum. In order to separate tantalum from niobium, the method currently used is actually carried out by techniques such as solvent quenching, chlorination, and partial crystallization before performing the reduction reaction. The process steps of the giant target include forging the ingot into a strip, machining the surface of the bar tantalum, cutting the strip into a sheet, cold rolling the molybdenum sheet into the bull's eye, tempering the bull's eye, and finally Trim and combine with support plate. The paper size of the paper based on the fee-based cooperative system applies the Chinese National Standard (CMS) M specification (210 × 297 mm) 83. 3. 10,000 (please read the precautions on the back before filling out this page). 503218 4888pif2.doc / 012 A7 B7 _ V. Description of the Invention (Even) Invention Description The present invention provides a method and device for manufacturing a high-purity molybdenum sputtering target, and a high-purity molybdenum manufactured by this method. This method includes purifying K2TaF7, and reducing the purified K2TaF7 to make giant powder, and refining tantalum by reacting with iodine and finally performing an electron beam melting method to form a high-purity tantalum ingot. The starting material is the mass-produced heart salt, which is prepared by dissolving molybdenum ore in a mixture of hydrofluoric acid and sulfuric acid and then filtering, and quenching the solvent with methyl isobutyl ketone (MIBK). And K2TaF7 was crystallized. This step can be repeated several times to reduce the content of impurities, especially niobium. In the liquid-phase liquid-phase reduction distillation apparatus, the purified heart D &? 7 is subjected to sodium reduction reaction. In this distillation apparatus, K2TaF7 and the diluent (sodium chloride and potassium chloride) are heated to about 1000 degrees Celsius. degree. Next, molten sodium was poured into the still 'to cause it to react with K2TaF7. The reactants are stirred to accelerate the reduction reaction. After cooling, the material produced by the reaction is taken out of the evaporator, crushed, filtered, and washed to separate the molybdenum powder from the salt mixture. The saccharification step of Shendan is completed by iodization process or electron beam melting method. These two methods can be selected one by one or sequentially. However, the electron beam melting method is preferably the last step because the ingot produced is suitable for further physical metallurgical steps to achieve the purpose of manufacturing the target. The stomach is forged into a strip shape by an electron beam cast iron, and the surface is machined ', and the forged molybdenum strip is cut into flakes and further cold rolled into a leather core. Tempering in an inert atmosphere to form the microstructure after recrystallization. 6 This paper size applies to China National Standards (CNS) A4 specifications (210X297 mm) 83.3.10,000 (Please read the notes on the back before filling out this page)-Order printed by the Ministry of Economic Affairs Central Standards Bureau Consumer Consumption Cooperative 503218 4888pif2. doc / 012 A7 B7 V. Description of the invention (If) Next, the bulls eye is machined to complete its final form and combined with the support plate of copper or balu. Chemical analysis was performed to confirm the giants produced by this process. The method of obtaining the following chemical characteristics is to detect metal elements by glow discharge mass spectrometry (GDMS), and to detect non-metal elements by LECO gas phase analyzer. By weight, in the high-purity tantalum material of the present invention, all metal impurities are only 500 ppm, the oxygen content is less than about 100 ppm, the content of molybdenum and tungsten does not exceed 50 ppm, and the content of uranium and thorium does not exceed 10 ppb. It is also possible to make giants with a total content of molybdenum and tungsten of less than 5 ppm. Brief description of the drawings. Figure 1 is a schematic diagram of a liquid-liquid reactive distillation apparatus for K2TaF7 for sodium reduction reaction; Figure 2 is a schematic diagram of an iodination reaction tank; Figure 3 is a diagram of an iodization reaction tank with a distillation device Schematic diagrams; Figures 4A and 4B are the intentions of the group, and Figure 5 is a graph of the conductivity of the molybdenum rod versus the action time. Explanation of the reference numerals in the figure 1 ·· filled reactor 2: first tube column Tal5 condenser 3 ·· second tube column Nbl5 condenser 4: deposition reactor 5: iodine supply device 6: vacuum / circulation device 8 : Silk pole 12: Stirring device 14: Reactor 16: Cover (please read the precautions on the back before filling this page) The size of the paper is applicable to China National Standard (CNS) A4 (210X297 mm) 83. 3.! 〇, 〇〇〇〇503218 Printed by the Shelling Consumer Cooperative of the Central Standards Bureau of the Ministry of Economic Affairs 4888pif2.doc / 012 A7 V. Description of the invention (t) 18 Vacuum 20 Sodium input 22 Furnace tube 24 Molybdenum-lined reaction tank 26 Molybdenum charge 28 Molybdenum screen 30 Molybdenum wire 32 Lid 34 Electric feedthrough 36 Iodine supply device 42 Support plate of copper or aluminum 44 Bullseye Detailed description In nature, molybdenum is usually closely combined with niobium, tin and other elements. The most commonly used starting materials in giant processes are tantalite, tin-manganese-molybdenum, Micolite and niobium-yttrium. These minerals are concentrated by wet metering, magnetic or electrostatic methods. The concentrate was dissolved in a mixed solution of hydrofluoric acid and sulfuric acid. This solution 'is filtered and the niobium is then separated from the other impurities in a device that quenches the solvent. The concentrate of molybdenum will be transferred to an aqueous solution and precipitated with ammonia to form tantalic acid (T ^ 05 × Η20) ', which is calcined at high temperature to produce oxidized giants. Another method is to recrystallize tantalum to K2TaF7 by adding potassium fluoride and potassium chloride to a hot aqueous solution after quenching the solvent. The impure K2TaF7 obtained by these methods requires further purification before it can become a source of molybdenum used in the electronics industry. In general, H2 2 &? 7 can be purified by the following steps: Dissolve industrial grade K2TaF7 in hydrofluoric acid, where the hydrofluoric acid is, for example, a 49% hydrofluoric acid solution. Alternatively, a solution of hydrofluoric acid and sulfuric acid may be used for this dissolution step. The amount of K2TaF7 dissolved depends on the temperature and the concentration of hydrofluoric acid. In view of the very slow dissolution rate at room temperature, this paper size applies the Chinese National Standard (CNS) Α4 specification (210X29 * 7 mm) (Please read the precautions on the back before filling this page) -Packing · -Order 503218 4888pif2.doc / 012 A7 B7 Printed by the Shellfish Consumer Cooperative of the Bureau of Standards and Decisions of the Ministry of Economic Affairs. 5. Description of the Invention (G) The mixture is heated in a suitable container to, for example, 90 degrees Celsius. Cover the solution containing ITaF7 and keep stirring to avoid loss due to evaporation. The dissolution time is about 1 hour. Add potassium chloride chloride solution at 65 ° C to K ^ TaF? Solution, and stir the resulting solution until cooled to room temperature. Since the solubility of K2TaF7 is very low at room temperature, the giants in solution will precipitate out as K2TaF ?. The precipitate was filtered, washed and dried. At this point, some niobium, tungsten, molybdenum, zirconium, uranium, and tritium remain in the solution. For extremely high purity molybdenum, repeating this dissolution and precipitation step is quite useful. Elements such as niobium, tungsten, molybdenum, uranium, and thorium, which are difficult to remove by the electron beam melting method, can be easily removed by this method. K2TaF7 can be reduced to metallic molybdenum by molten salt electrolysis or sodium reduction. The rate of electrolytic reduction is very slow, so sodium reduction can be used to reduce a large amount of K2TaF7 to tantalum metal. The entire reduction reaction equation can be written as K2TaF7 + 5Na (/) = Ta〇s) + 2KF + 5NaF (1) Please refer to Figure 1, which shows a reduction furnace tube. This reduction reaction is carried out by putting K2TaF7 and diluted salts such as potassium chloride, sodium chloride, lithium chloride, thallium chloride and calcium chloride into a reactor 14 equipped with a stirring device 12. The reactor 14 is placed in a furnace tube and heated to a temperature above the melting point of the salt mixture, typically about 1000 degrees Celsius. On the one hand, the temperature was controlled, and on the other hand, molten sodium was injected into the reactor 14 and stirred. After cooling down, the reaction product will be removed from the reactor Η -------------- ^ ------ βΐ (Please read the precautions on the back before filling in this page) _ This paper size is in accordance with China National Standard (CNS) A4 (210X297 mm) 83. 3. 10,000 503218 4888pif2.doc / 012 A7 B7 V. Remove from the description of the invention (7), crush and filter with dilute acid to These powders are obtained by compressing and melting these powders in a tantalum metal powder furnace tube. Printed at the Central Bureau of Electron Beam Co., Ltd. 2) Iodization process Tantalum metal is produced by sodium reduction of a large amount of K2TaF7, which is similar to the Himter process used to make sponge giants. Most of the impurities in K2TaF7, such as iron, nickel, titanium, tungsten, and molybdenum, are still present in metals produced by sodium reduction reactions. This metal is in the form of powder and has a very high oxygen content. The method described herein can produce high-purity giants from fragments or impure giant metals. This step is based on a chemical conversion reaction. In this chemical conversion reaction, the impure tantalum metal reacts with iodine gas at a lower temperature to form molybdenum iodide (synthesis zone), and the iodine tantalum is then at a higher temperature Decomposes on the hot wire electrode to produce a very pure metal (deposition or thermal decomposition zone). Impure giants can be converted into gaseous substances in the synthesis zone according to the following reactions: Ta (s, impure) +5/2 I2 (g) = TaI5 (g) (synthetic reaction) (2) • Ta (s, impure ) + 5I (g) = Tal5 (g) (synthesis reaction) (3) Other tantalum iodine compounds such as Tal3 and Tal2 will also undergo similar reactions. According to the following reactions, these gaseous compounds of molybdenum will diffuse into the thermal decomposition zone and decompose to form pure tantalum metal: 10 This paper size applies the Chinese National Standard (CNS) A4 specification (210X297 mm) 83. 3.1〇, 〇〇0 Please read

Page I Order 503218 Printed by the Consumer Cooperatives of the Central Standards Bureau of the Ministry of Economic Affairs 4888pif2.doc / 0 I 2 V. Description of the Invention (s)

TaI5 (g) = Ta (s) + 5I (g) (Thermal decomposition reaction) The thermodynamic factor is very important in understanding and controlling this process. Therefore, in order to determine better operating conditions such as temperature and pressure in the synthesis zone and decomposition zone, some thermodynamic calculations need to be performed. The schematic diagram of the device is shown in Figure 2. The process device includes a reaction tank 24, a filament 30, and supplied materials, and is designed for batch operations. After each process, this process device is cooled to room temperature and disassembled. For the refining of tantalum, the preferred iodination reaction tank is an alloy 600 (Inconel) container covered with a metal. The metal covering the surface of this container is less reactive than tantalum in terms of electrochemical properties in the electro-chemical sequence of chlorine. For example, it is molybdenum (that is, the molybdenum-lined reaction tank 24 in FIG. 2), tungsten, or an alloy thereof. Since molybdenum and tungsten do not react with iodine at the operating temperature of the reaction tank 24, this layer of coating can avoid contamination of various components of the reaction tank 24 during refining. Alloy 600 vessels can also be used to refine metals such as titanium and zirconium, but they do not need to be covered because these metals are refined under different operating conditions. The filament 30 formed by a pure molybdenum rod was used as the decomposition surface. The filament 30 can be made into a U-shape or other shapes to increase its surface area. In addition, multiple filaments can be used to increase surface area and productivity of the reaction tank. The filament 30 can be heated by an external power source like a resistor. Since the filament temperature affects the rate of deposition, the current must be controlled to keep the temperature between 1000 and 1500 degrees Celsius. After that, tantalum crystals will be generated in the silk (please read the precautions on the back before filling out this page). • Loading ·, tr. This paper size applies the Chinese National Standard (CNS) A4 specification (210X297 mm) 83.3. 10,000 V. 4888pif2.d〇c / 〇1 2 A7 B7 Printed invention description printed on the Consumer Cooperatives of the Central Bureau of Standards (〒) on pole 30. A cylindrical molybdenum shield plate 28 is placed in the reaction tank 24 to provide an annular space 11 to 3 inches wide. The annular space may be filled with tantalum filling material 26 in the form of a sheet, a block, or a small ball. This arrangement allows a large surface area between the filling material 26 and the iodine gas in the reaction tank 24 to carry out the reaction. The untreated giant can also be compressed into a tadpole shape and placed in the reaction tank 24. Before placing the filling material 26 in the reaction tank 24, it must be washed with a cleaning agent. It is advantageous to use a better vacuum system when manufacturing low impurity tantalum. Therefore, the reaction tank 24 is connected to a vacuum system to generate a pressure of 10 · 6 Toπ * or lower. This reaction tank 24 was evacuated at room temperature and then heated to 800 to 1000 degrees Celsius under vacuum to remove all volatile impurities before adding iodine. The temperature in the synthesis zone affects the rate of the reaction. The temperature in the synthesis zone needs to be uniform and kept at a temperature higher than the melting point of Tal3. A special heater is placed on the lid 32 of the reaction tank 24 to keep its temperature at about 350 to 500 degrees Celsius. This temperature prevents the iodine under the lid 32 from condensing. Without the lid 32, iodine must be continuously added to the system. There are several sources of oxygen in tantalum from the precursor to the melting of the electron beam. A high concentration of oxygen is undesirable: it affects the resistance of the deposited tan film. Current technology cannot easily reduce the oxygen content below 30 ppm. Thermodynamic calculations and experimental results show that the metal oxides formed or present in the metal will not react with iodine and will not migrate to the decomposition zone. Therefore, this process can produce high purity tan with low oxygen content. The amount of oxygen in the gas in the reaction tank 24 can be obtained by the combination of oxygen and vacuum ^ ---------- (Please read the precautions on the back before filling this page) National Standard (CNS> A4 Specification (210X297 mm) 83.3.1, 〇00,503, 4888pif2.doc / 012 A7 B7 Printed by Shellfish Consumer Cooperative of the Standards Bureau of the Ministry of Economic Affairs. 5. The description of invention (p) is reduced. Nitrogen in europium-filled metals has oxygen-like properties, so the amount of nitrogen in giant rods will also be low. Electron beam melting is often used to refine molybdenum. However, electron beam melting does not remove things like tungsten and molybdenum. This is because these elements have a very low vapor pressure at the temperature of the melting point of tantalum. This process can reliably reduce the elements such as tungsten and molybdenum to a very low level. This process can remove the electron beam melting method cannot Removal of uranium and plutonium. The above-mentioned iodination process does not significantly remove the niobium content. Therefore, pure tantalum with low metal impurities can be obtained by modifying the previous process, where the metal impurities include niobium. In the process, tantalum fragments or native tantalum will The iodine gas reacts to form gaseous Tal5 and Nbl5. Since the two compounds have different boiling points, they can be separated in subsequent fractionation steps. The schematic diagram of the device is shown in Figure 3. Raw _ or fragments It can be placed in an upright tube made of Inconel and covered with molybdenum, tungsten, or an alloy thereof, and the upright tube can be placed in a furnace tube heated to 400 to 700 degrees Celsius to form a filling reactor 1. An eluent gas, such as clean argon or helium, is passed through the iodine supply device 5. The temperature of the iodine supply device 5 is adjusted to obtain a specific partial pressure of 12. The iodine gas will react with the tantalum fragments in the aeration reactor 1 To produce gaseous iodide and niobium iodide. The gas from the tritium-filled reactor 1 passes through the distillation columns 2 and 3, where the temperature of the first column 2 is maintained at a temperature just below the melting point of Tal5, To condense Tal5; the temperature of the second column 3 is maintained at a temperature low enough to condense Nbl5, but above the boiling point of 12. The iodine gas is circulated through the reuse step. It is located in the first column 2 and the tritium filling reactor Between 1 (please read the back first Please fill in this page again for the matters needing attention)-Installation ·-This paper size is applicable to Chinese National Standard (CNS) A4 specification (210X297 mm) 83. 3. 10,000 Printed by the China Standards Bureau of the Ministry of Economic Affairs, Peige Consumer Cooperative, India 503218 4888pif2.doc / 012 A7 B7 V. Description of the Invention Ul) The gas pipelines are all formed of molybdenum and maintained at a temperature higher than 600 degrees Celsius, while the other gas pipelines are maintained at a lower temperature. The liquid or solid pure Tal5 coming from the first column 2 is sent to the deposition reactor 4, and TaI5 will decompose on the hot surface and generate pure giant crystals. The tantalum produced by this process will be very pure and will not have all the impurities that cannot be removed by conventional methods. The pure molybdenum obtained by the modified iodination process is melted by an electron beam to produce a high-purity tantalum ingot. 3. Electron beam melting Electron beam melting is commonly used to melt and refine refractory metals. This process is based on the use of high-energy particle beams to impinge on the material, and the gravity energy is converted into thermal energy generated by the barrel heat. The easy control of the energy distribution makes it possible for speakers to use a variety of electron beam melting techniques for a variety of metals, such as spot, drip, wrought iron, and zone melting. Electron beam wrought furnace melting is already available for groups and superalloys. Electron beam dripping melting method can be used for refractory materials. The electron beam drip melting furnace tube includes a vertical rod feeder for primary raw materials. The rod feeder is equipped with a vacuum valve that allows the feed to be nearly continuous and melts the pre-compacted material. Refining of refractory materials is carried out by evaporation of secondary oxides, generation and removal of gases, carbon-oxygen reactions, and vaporization of metal impurities. In any of these mechanisms, most impurities are removed from tantalum. However, tungsten, molybdenum, niobium, uranium, and other elements are not easily removed by the electron beam melting method because the vapor pressure at the melting temperature is too low. Repeated melting steps may be required to obtain high purity materials. This paper size applies to China National Standard (CNS) A4 (210X297 mm)

--------- · Installation ------ IT ------ (Please read the precautions on the back before filling out this page) _I Printed by the Shellfish Consumer Cooperative of the Central Standards Bureau of the Ministry of Economic Affairs 503218 4888pif2.doc / 012 _B7__ V. Description of the invention (/ >) The tantalum fragments, impure molybdenum and giant powder produced by the electrolysis or reduction reaction of K2TaF7 are compressed and melted in the electron beam dripping melting furnace tube to obtain high Giant ingot of purity. 4. Manufacturing of the target The cast rod manufactured by the electron beam melting method is forged into a strip shape, and its surface is machined. After the surface is machined, the forged tantalum bar is cut into pieces and further cold rolled into a harrow core 44. Tempering this bulls-eye in an inert atmosphere to achieve the desired microstructure. Next, the bulls eye 44 is processed to the final shape and combined with the copper or aluminum support plate 42 as shown in FIGS. 4A and 4B. It is necessary to perform chemical analysis and characterization of the target by measuring the size and composition of the crystal grains. Chemical analysis methods that can describe chemical properties described herein include the analysis of metallic elements using glow discharge mass spectrometry and the analysis of non-metallic elements using a LECO gas analyzer. Interpolation can be used to determine the size of the grains, while XRD and EBSP can be used to obtain data about its structure. Example 1 Approximately 350 grams of K2TaF7 was added to a 595 ml Teflon beaker of hydrofluoric acid (49 percent). Heat the mixture to 90 ° C and continue to stir. Cover the beaker with a Teflon plate to avoid evaporation of the solution. This dissolution step is continued for approximately 1 hour. About 700 g of potassium chloride was added to 700 ml of distilled water and heated to 60 degrees Celsius. This potassium chloride solution was added to the K2TaF7 solution and the resulting solution was stirred for several minutes. The paper size of this solution is in accordance with China National Standards (CNS) A4 (210X297 mm) 83.3. 10,000 (please read the precautions on the back before filling this page). Order 503218 4888pif2.doc / 012 A7 B7 V. Description of the invention G?) But it reaches room temperature. Since the solubility of this compound is quite low at room temperature, the room temperature will cause the giant in the solution to precipitate out as K2TaF7. The precipitate was filtered and washed with potassium fluoride solution (100 g / liter H20) and distilled water. The powder was dried in a vacuum furnace tube at a temperature of 160 ° C, and the precipitate was then subjected to X-ray diffraction research to analyze its composition. Several samples can be formed according to the method described above, and these samples can be analyzed. After this first treatment, the niobium content in K2TaF7 was reduced by about 50%. The results are shown in Table 1. The data shown in Table 1 indicate that the niobium content of tantalum can be reduced in this way. After purification, @ K2TaF7 can be reduced with sodium. (Please read the precautions on the back before filling out this page) The first sample of K2TaF7 is printed on the first sheet of K2TaF7 after the first wash of K2TaF7 after the second wash of niobium 4.6 < 2.2 < 1 ____ Molybdenum 0.2 0.1 0.1 ___ Ore 4.8 1.1 < 1 __One Zirconium 0.52 0.14 0 · 1 丨 丨 One 钍 < 0.01 < 0.01 < 0.01 __- Uranium < 0.01 < 0.01 < 0.0 ! __ Monosodium 1100 130 50 ___ Iron 4.8 1.2 < 1 __ Aluminum 2.5 1.2 Sulfur 8.7 1.1 Standards are applicable to China National Standard (CNS) A4 specifications (210X297 mm) 83. 3.1〇, 〇〇〇503218 4888pif2.doc / 012 A7 B7 V. Description of the invention (I 浐) The data in Table 1 shows that the contents of niobium, molybdenum and tungsten have been greatly reduced by this method. These elements cannot be removed from the tantalum metal by the electron beam halogenation method. The removal of these three elements from tantalum can be of considerable benefit in purifying tantalum. Assuming that all the niobium, molybdenum, and tungsten in K2TaF7 are reduced together with the group at the stage of sodium reduction reaction, and the existence of other elements listed in Table 1 is ignored, the effect of the purification process of K2TaF7 on the purity of the metal can be simple Calculate to display. After 1000 grams of starting K2TaF7 has undergone a complete sodium reduction reaction 'will yield 461.7 grams of tantalum. These tantalums contain 9.6 mg of niobium, molybdenum and tungsten 'resulting in a metal purity of 99.9979 percent. When using K2TaF7 after two washing cycles, 461.7 g of giant will be generated through sodium reduction reaction. These molybdenum will contain 2.1 mg of niobium, molybdenum and tungsten, and the metal purity will reach 99.9995%. . Example 2 Please read

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The local manufacturer can use the iodization reaction tank to make the pure group from the fragments available on the market. This reaction tank is made of iron-iron alloy and lined with a pin inner for preliminary experiments. A molybdenum screen is placed in the reaction tank, and the gap between the screen and the wall of the reaction tank is filled with tantalum fragments. Leak test the reaction tank and evacuate to 10.5 torr. The reaction tank is heated to 850 ° C under vacuum to evaporate and remove some organics or other volatile compounds. Next, the reaction tank was cooled to room temperature and the precipitate on the lid was decanted. A pure giant filament was mounted on the lid of the reaction tank. After that, the reaction tank was sealed and evacuated again to about 10-5 Torr. The filling is heated to about 500 to 600 degrees Celsius' and the filament is heated to about Celsius 〖〇〇〇 装 83. 3.! 〇 ， 〇〇〇 This paper size applies the Chinese National Standard (CNS) A4 standard ( 21〇ΜΜ7mm) 503218 A7 4888pif2.doc / 012 _____B7_ One or five, the description of the invention (/ Π degrees to 1200 degrees. After the temperature of the filling and filaments stabilized, a certain amount of iodine crystals were added to the reaction tank. Continuously measure the current and voltage applied to the filament. From these data, the conductivity related to the diameter of the giant rod can be calculated. Control the temperature of the filling material, the temperature of the filament and the pressure of the container. The molybdenum rod can be used The growth of this method is smooth. The temperature and pressure of the filament and the filling have a significant effect on the deposition rate. The growth rate of the molybdenum rod is related to the conductivity of the tantalum rod. The correlation curve of conductivity and growth rate is plotted In Figure 5. It can be seen from Figure 5 that the tantalum rods formed by this method have a fast growth rate. Table 2 shows the results of chemical analysis of tantalum rods generated from different times of this method. Note that Is used in this experiment The fragments are not single-phase in composition. For tantalum hafnium fillings, please read the note above first.

The original composition is shown in Table 2. 1st 2nd 3rd 4th Time (hrs) 79 45 62 45 Weight (g) 5925 5043 7829 5969 Warp

Printed Elements (ppm) of the Central Bureau of Standards and Consumer Cooperatives Charging 1 and 2 1st 2nd Charging 3 and 4 3rd 4th Niobium 1200 900 505 90 185 230 Molybdenum 6 1.2 1.7 1.3 1.2 Tungsten 30,000 0.28 0.19 0.2 0.25 Oxygen 100 90 308 100 60 176 Nitrogen 100 < 10 3 100 6 4 This paper size applies Chinese National Standard (CNS) A4 specification (210 × 297 mm) 83. 3. 10,000 503218 4888pif2.doc / 012 A7 B7 V. Description of the invention (1 u) Example 3 The giant crystal rods formed through the process steps of different times are melted in an electron beam furnace tube. Table 3 shows the results of the analysis of the metal block and the molten molybdenum ingot. Table 3 Concentrations of elementary filling materials (average ppm) Concentration after melting (average ppm) Iron 344 1 Nickel 223 0.13 Chromium 205 0.19 Niobium 463 270 Oxygen 221 < 25 Example 4 Printed by the Shellfish Consumer Cooperative of the Central Standards Bureau of the Ministry of Economic Affairs (Please read the precautions on the back before filling out this page) The ingot formed by the electron beam melting method is cold-treated and tempered to make the bulls eye. The starting ingot is fractured by edge and forged casting. After surface machining, the forged ingot is cut into flakes and further cold rolled into a bull's eye. There are two types of rolling temperature: room temperature and the temperature of liquid nitrogen. The former is called cold rolling, while the latter is low temperature milk. The reduction reaction proceeds during the rolling process to an extent of between about 70 and 90 percent. The rolled bullseye is tempered in a blunt atmosphere or in a vacuum under different conditions to obtain the desired microstructure and surface texture. This paper size is applicable to China National Standard (CNS) A4 (210X297 mm) 83. 3. 10,000 503218 4888pif2.doc / 012 A7 B7 V. Description of the Invention (I?) Example 5 The surface texture of the bulls eye is machined to obtain the final shape and combined with a copper or aluminum support plate. Figures 4A and 4B are schematic diagrams of the target manufacturing process. In the above discussion, various changes and modifications can be made in the premise of the present invention. Accordingly, the scope of the present invention is limited by the scope of the attached patent application. (Please read the precautions on the back before filling out this page) -Installation-Printed by the Consumers' Cooperatives of the Central Bureau of Standards of the Ministry of Economy 20 This paper size applies to the Chinese National Standard (CNS) Α4 specification (210 × 297 mm) 83. 3. 10,000

Claims (1)

503218 Male 2: 1 * 18 8 8 off doc / 0 1 2 A8 B8 C8 D8 Correction charge M " domain—please .....—- ^ • one, one, six, patent scope 1. a high manufacturing A method for purifying molybdenum includes the following steps: Purifying K2TaF by a melting process "reacting the purified K2TaF7 with a reducing agent to produce a giant powder; and reacting the molybdenum powder with iodine in a container. 2. If applying for a patent The method of the first item, wherein tungsten and molybdenum in the K2TaF7 are reduced to less than 1 ppm by weight, and niobium and other metal impurities are reduced to less than 20 ppm by weight. 3. A method for manufacturing a high-purity giant, including: Reacting a feedstock with iodine gas in a vessel, the feedstock including tantalum and an impurity, and the impurity including at least one of tungsten and molybdenum; forming a reaction product including iodide of molybdenum; and Decompose the iodide of molybdenum on a filament to produce high-purity tantalum, which contains at least one of tungsten and molybdenum in a content lower than that of the feed. 4. Method as claimed in item 1 or 3 of the scope of patent application 'Where the container has Included in the electro-chlorine sequence is a reactant contact surface of a metal that is less reactive than tantalum. Printed by the Consumer Cooperative of the Central Standards Bureau of the Ministry of Economic Affairs (please read the precautions on the back before filling out this page). 5 The method of applying for item 4 of the patent, wherein the contact surface of the reactant includes one of molybdenum, tungsten, and an alloy of molybdenum and tungsten. 6. The method of applying for items 1 or 3 of the patent, wherein the high purity These include tungsten and molybdenum, each of which is less than 5 ppm by weight. 7. The method of item 1 or 3 of the patent application scope further includes melting the molybdenum with an electron beam to form a high-purity giant ingot. 8 · — ' A kind of high-purity sprinkler IG core 'The total gold paper size of this sprinkler palladium core is applicable to China National Standard (CNS) A4 specification (210X29 * 7 mm) 503218 A8 4888pif2.doc / 0 12 B8 C8 D8 The scope of patent application is that the weight of impurities is 500ppm, and the weight of tungsten or molybdenum is 50ppm. (Please read the precautions on the back before filling out this page) 9. The sputtered palladium core described in item 8 of the scope of patent application, where tungsten or Low weight of molybdenum 20ppm. 10. The sputtered palladium core as described in item 8 of the patent application, wherein the weight of tungsten and molybdenum is less than 5 ppm. 11. The shovel palladium core as described in item 8 of the patent application, where niobium, molybdenum and The total weight of tungsten is less than 20 ppm. 12. The sputtered palladium core as described in item 8 of the scope of patent application, wherein the total weight of niobium, molybdenum, and tin is less than 5 ppm. 13. A sputtering target, which is the first It consists of the sputtered palladium core according to item 8. 14. A method for manufacturing a high-purity group, comprising the steps of: reacting a material with iodine gas, the material including macro and at least one impurity; forming a reaction product including tantalum iodide and the at least one impurity Iodide; At least a portion of the iodide of molybdenum is separated from the reaction product by fractional distillation; and • The Consumer Cooperative of the Central Standards Bureau of the Ministry of Economic Affairs prints the iodide that decomposes the molybdenum on a filament. 15. The method according to item 14 of the patent application, wherein the so-called at least one impurity comprises niobium. 22 This paper size applies to China National Standard (CNS) A4 (210X297 mm)