A method for the production of a metal chloride

Abstract

This application provides a method for preparing metal chlorides. This method and apparatus solve the problem of inaccurate flow metering of chlorides as reactants in existing chemical vapor deposition (CVD) processes. The method includes: installing a dedicated chlorine flow meter at the inlet of a chlorine gas inlet pipe; adding bulk metal to a reaction vessel and sealing the vessel; purging the reaction vessel containing the bulk metal with an inert protective gas, heating to remove water and oxygen; heating to a specified temperature, shutting off the inert protective gas, and starting the chlorine gas reaction. This invention precisely controls the flow rate of the chlorine gas to generate a fixed amount of metal chloride. Under the action of a reducing gas, a uniformly deposited, high-strength metal / carbide coating is obtained on the substrate surface. This coating is virtually free of impurities, and the deposited substrate can be used in industries such as semiconductors and medicine. This method is low-cost, produces stable products, and is easy to scale up.

Description

Technical Field

[0001] This application relates to the field of chemical vapor deposition technology, and in particular to a method for preparing metal chlorides. Background Technology

[0002] Chemical vapor deposition (CVD) technology, as a core method in the field of materials preparation, is widely used in the production of high-end products such as semiconductor chips, optical thin films, and functional ceramics. This technology involves the chemical reaction and deposition of gaseous raw materials on a substrate surface to form thin films or coatings with specific structures and properties. Its core lies in the precise control of the type, concentration, and flow rate of the gaseous raw materials. The accuracy of the raw material metering directly determines the compositional uniformity, thickness accuracy, and mechanical / electrical properties of the deposited product, and is crucial for ensuring process stability and product yield.

[0003] Among numerous CVD raw materials, metal chlorides are widely used in the preparation of metal-based thin films such as silicon and titanium due to their moderate reactivity and controllable deposition rate. For example, silicon chloride (SiCl4) can be used to deposit silicon thin films, and titanium chloride (TiCl4) can be used to prepare titanium-based coatings. These chlorides react with hydrogen gas at high temperatures to ultimately form the target material on the substrate surface. However, when using pre-prepared chlorides as raw materials in traditional processes, a persistent technical bottleneck remains: the challenge of vaporizing and metering solid chlorides.

[0004] Most metal chlorides (such as TaCl5 and WCl6) are solid at room temperature and have high melting and boiling points (e.g., TaCl5 melting point 221℃, boiling point 242℃, WCl6 melting point 275℃, boiling point 346℃). They need to be vaporized by heating before they can be used as gaseous feedstocks for CVD reactions. In this process, the vaporization efficiency of solid chlorides is greatly affected by factors such as temperature, heating rate, and container sealing. If the temperature is too low, vaporization will be incomplete and may easily clog the ventilation pipes and cause an explosion risk, resulting in unstable feedstock supply. If the temperature is too high, it may cause chloride decomposition or impurity volatilization, introducing side reactions. Even if the vaporization conditions are stable, the solid feedstock may still experience "caking" or "bridging" phenomena due to local overheating during the heating process, causing fluctuations in the vaporization rate and directly resulting in unstable flow of gaseous feedstocks.

[0005] Because tantalum pentachloride has a boiling point of 242℃ and there are currently no high-temperature flow meters, it is impossible to directly measure tantalum pentachloride using a flow meter. The only method is to indirectly measure it by allowing chlorine gas to react completely with tantalum and then completely introduce the tantalum pentachloride into the vapor deposition chamber. More importantly, the accuracy of the vaporized chloride measurement is difficult to guarantee. In existing technologies, it is difficult to find high-temperature flow meters above 300℃, and even with custom manufacturing, the cost remains high and they are prone to damage. Furthermore, the following drawbacks exist: Chloride gases are highly corrosive and can erode the sensing elements of flow meters (such as the heating wire of thermal flow meters and the vibrating tube of Coriolis flow meters), causing the measurement accuracy to drop sharply over time, shortening the equipment lifespan, and resulting in high maintenance costs. Chloride gas is prone to condensation in pipelines due to temperature fluctuations (especially in metering areas far from the heating source), forming droplets or solid particles, causing flow meter readings to be distorted, or even clogging the pipeline, leading to process interruption, or even the risk of physical explosion. Some easily hydrolyzable chlorides (such as TaCl5) can still react with trace amounts of moisture in the air after vaporization to form solid impurities (such as Ta2O5), which adhere to the inner wall of the flow meter, further aggravating measurement errors and equipment wear.

[0006] To address these issues, the industry has attempted various optimization solutions: for example, using a constant-temperature heating jacket to insulate the chloride storage container, delivery pipeline, and flow meter as a whole to reduce condensation. However, this requires a complex temperature control system and cannot completely prevent uneven vaporization caused by local temperature differences. Another approach is to use high-pressure inert gas to pressurize molten chloride into the vaporization chamber in an attempt to stabilize the vaporization rate. However, this method is prone to flow fluctuations due to changes in the viscosity of the molten chloride, and the corrosiveness of chloride is stronger under high pressure, making equipment sealing extremely difficult.

[0007] In addition, pre-prepared chloride raw materials have inherent defects during storage and transportation: solid chlorides are prone to moisture absorption and deterioration (such as WCl6 reacting with water to generate HCl and tungsten oxide), affecting the purity of the raw materials; liquid chlorides (such as TiCl4) are prone to volatilization at room temperature, which not only wastes raw materials, but also endangers the safety of operators due to the toxicity of the volatilized gases, increasing the safety management cost of the production environment.

[0008] In summary, the inherent instability of the vaporization process and the high precision required for metering after vaporization in traditional CVD processes using pre-prepared solid chlorides as raw materials present an irreconcilable contradiction, becoming a key bottleneck restricting the development of CVD technology towards higher precision and stability. Therefore, developing a new technology that can circumvent the challenges of solid chloride vaporization and achieve precise raw material metering is of great significance for improving the reliability and economy of chemical vapor deposition processes. Summary of the Invention

[0009] The purpose of this invention is to solve the above-mentioned problems by providing a method for preparing metal chlorides.

[0010] The technical solution of this application is implemented as follows: This application provides a method for preparing metal chlorides. The preparation method is implemented through a first reaction chamber, which includes a chlorination chamber, a first heating unit for heating the chlorination chamber, a chlorine gas inlet pipe connected to the chlorination chamber, an inert gas inlet pipe, and a dedicated flow meter installed in the chlorine gas inlet pipe. The preparation method includes the following steps: S101. Add block metal to the chlorination chamber and seal the chlorination chamber. Then purge with inert protective gas and heat up through the heating unit to remove water and oxygen. S102. Further heat to the specified temperature, turn off the inert protective gas, and turn on the chlorine gas to carry out the reaction. The step of turning on the chlorine gas to carry out the reaction specifically includes: by measuring the amount of chlorine gas introduced, combined with the chemical reaction stoichiometry, the amount of metal chloride generated can be indirectly and precisely controlled, and finally the precise control of the metal chloride raw material in the subsequent chemical vapor deposition reaction can be achieved.

[0011] The advantages or beneficial effects of the above technical solutions include at least the following: This method utilizes the direct reaction of chlorine gas with metals within a reaction system to generate chlorides, while indirectly controlling the amount of chloride generated by precisely metering the chlorine gas flow. Compared to traditional methods using pre-prepared chlorides, this approach offers significant advantages: It avoids the problem of solid chloride gasification: there is no need to heat and gasify the pre-prepared chloride. It directly generates gaseous chloride through the reaction of chlorine with metal, which completely eliminates the problem of unstable raw material supply caused by factors such as temperature fluctuation, agglomeration, and condensation during the gasification process. Higher and more stable metering accuracy: As a gaseous raw material, the flow rate of chlorine can be accurately measured by mature corrosion-resistant mass flow meters (such as flow meters made of Hastelloy or Inconel alloy). Moreover, under normal temperature and waterless environment, the chemical properties of chlorine are relatively stable (it does not react with the pipe material before the reaction), resulting in a long lifespan of metering equipment and slow accuracy decay. Raw material purity is easier to guarantee: Metal raw materials (such as bulk metals tantalum and tungsten) are highly pure and not easily deteriorated. Chlorine can be purified to remove impurities. The chloride produced by the reaction of the two is much purer than the pre-made chloride that is easy to absorb moisture and decompose during storage. The system integration is simpler: there is no need for a complicated heating and insulation system and chloride storage device. The chloride generated in the reaction can directly enter the CVD chamber to participate in the reaction, which simplifies the equipment structure and reduces system complexity and maintenance costs. Superior safety: Reduces the toxicity risks from the storage and volatilization of pre-prepared chlorine, and chlorine can be precisely controlled through a closed-loop control system, resulting in a lower risk of leakage. Attached Figure Description

[0012] The accompanying drawings illustrate exemplary embodiments of the present application and, together with the description thereof, serve to explain the principles of the present application. These drawings are included to provide a further understanding of the present application and are incorporated in and constitute a part of this specification.

[0013] Figure 1 A first schematic diagram of a first reaction chamber according to an embodiment of the invention is shown; Figure 2 A cross-sectional schematic diagram of the chlorination chamber according to an embodiment of the invention is shown.

[0014] Reference numerals: 1. First reaction chamber; 2. Second reaction chamber; 31. First heating unit; 32. Second heating unit; 4. Matrix; 5. Chlorine gas inlet pipe; 6. Inert gas inlet pipe; 71. Hydrogen gas inlet pipe; 8. Inert protective gas inlet pipe; 9. Exhaust pipe; 10. Dedicated flow meter; 12. Block metal; 13. Quartz sieve plate; 14. Chlorination chamber. Detailed Implementation

[0015] Embodiments of this application will now be described in more detail with reference to the accompanying drawings. While some embodiments of this application are shown in the drawings, it should be understood that this application can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this application. It should be understood that the drawings and embodiments of this application are for illustrative purposes only and are not intended to limit the scope of protection of this application.

[0016] It should be noted that, where there is no conflict, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0017] It should be understood that the term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". Definitions of other terms will be given in the following description. It should be noted that the concepts of "first", "second", etc., mentioned in this application are used only to distinguish different devices, modules, or units, and are not intended to limit the order of functions performed by these devices, modules, or units or their interdependencies.

[0018] It should be noted that the terms "one" and "more" used in this application are illustrative rather than restrictive, and those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0019] The names of the messages or information exchanged between multiple devices in the embodiments of this application are for illustrative purposes only and are not intended to limit the scope of these messages or information.

[0020] Please see Figure 1-2 As shown, this embodiment of the invention provides a method for preparing metal chlorides. The preparation method is implemented through a reaction apparatus, which includes a first reaction chamber 1, which includes a chlorination chamber, a first heating unit 31 for heating the chlorination chamber, a chlorine gas inlet pipe 5 connected to the chlorination chamber, and an inert gas inlet pipe 6. The reaction apparatus also includes a gas input pipe 8, which leads into the chlorination chamber. The chlorine gas inlet pipe 5 and the inert gas inlet pipe 6 are connected to the gas input pipe 8. A dedicated flow meter 10 is installed in the chlorine gas inlet pipe 5, and an exhaust pipe 9 is installed at the bottom. In other embodiments, the reaction apparatus may further include a hydrogen input pipe 71, which is used to input hydrogen into the reaction apparatus. The hydrogen input pipe 71 is equipped with a hydrogen meter to measure the amount of hydrogen input.

[0021] The preparation method includes the following steps: S101. Add bulk metal 12 to the chlorination chamber. The bulk metal 12 is placed on a quartz sieve plate 13 (the quartz sieve plate 13 has gaps to allow gas to pass through). Seal the chlorination chamber, then purge with inert protective gas, and heat through the first heating unit 31 to remove water and oxygen. Specifically, the step of heating through the first heating unit 31 to remove water and oxygen includes: heating to 80~120℃ through the first heating unit 31 and holding at that temperature for 0.5~1 hour.

[0022] S102. Further heat to the specified temperature, turn off the inert protective gas, and turn on the chlorine gas to carry out the reaction. The step of turning on the chlorine gas to carry out the reaction specifically includes: indirectly calculating the amount of chloride generated by the metered chlorine gas flow rate and the chemical reaction stoichiometric ratio, thereby achieving precise control of the chloride raw material in the chemical vapor deposition reaction. As a further improvement, in other embodiments, the bulk metal 12 includes at least one of tantalum, niobium, tungsten, molybdenum, and corresponding alloys. In one embodiment, to improve reaction efficiency, the surface of the bulk metal 12 can be pretreated. Specifically, a porous nanocone array (cone height 100-200 μm, spacing 50 μm) can be sputtered onto the metal surface by introducing hydrogen-argon plasma (power 300 W, H2:Ar=1:3), thereby increasing the specific surface area by more than 100 times (BET test from 0.1m). 2 / g→10 m 2 / g), thus greatly shortening the time.

[0023] As a further improvement, in other embodiments, the chlorine inlet pipe 5 is at least one of polytetrafluoroethylene (PTFE), high-density polyethylene (HDPE), copper, and titanium. The core function of the chlorine inlet pipe 5 is to stably and safely transport highly corrosive chlorine gas, requiring it to meet the requirements of "chlorine corrosion resistance, adaptability to operating conditions (temperature / pressure), and no impurity release"; avoiding corrosion and leakage problems during chlorine transport and ensuring metering accuracy. It is understood that a corrosion-resistant plastic coating or metal passivation layer can also be applied to the chlorination chamber or rotating mechanism to prevent chlorine gas from corroding it.

[0024] Preferably, the chlorination chamber is made of quartz. Quartz (SiO2) does not react with bulk metal 12 (bulk metal 12 includes at least one of tantalum, niobium, tungsten, molybdenum and corresponding alloys), chlorine gas, or the generated metal chlorides (such as TaCl5 and NbCl5) at high temperatures, thus avoiding corrosion of the reaction vessel (as metal chlorides do not corrode quartz) and preventing the release of impurities (such as metal ions and oxides) that could contaminate the product, ensuring the purity of the chloride (which directly affects the quality of the subsequent CVD film). Furthermore, the smooth surface of quartz makes it difficult to adsorb moisture, oxygen, or reaction byproducts from the air, facilitating the thoroughness of the initial "dehydration and deoxygenation" steps, reducing product residue after the reaction, and facilitating cleaning.

[0025] The thermocouple is at least one of type K, type E, type R, and type S. The inert protective gas is at least one of high-purity argon, high-purity helium, and high-purity nitrogen.

[0026] The chlorine-specific flow meter 10 includes at least one of the following: rotor flow meter, turbine flow meter, and mass flow meter. For example, Alicat MCS series (Hastelloy C-22 material); Brooks SLA5850 series (Inconel alloy, corrosion resistant); Horiba Z500 series (chlorine-specific version), etc., are not limited here.

[0027] In step 102, the specified temperature is 500℃~800℃, preferably 630~680℃. In other embodiments, the specified temperature is 630℃, 635℃, 640℃, 645℃, 650℃, 655℃, 660℃, 665℃, 670℃, 675℃, or 680℃.

[0028] The embodiments of the present invention further provide a method for preparing a porous metal coating by chemical vapor deposition, the preparation method being based on the above-mentioned method for preparing metal chlorides, as detailed below.

[0029] The preparation method is implemented through a second reaction chamber 2, which includes a deposition chamber, a chlorination chamber disposed in the deposition chamber, a reaction vessel disposed opposite the chlorination chamber, a second heating unit 32 for heating the chlorination chamber and the deposition chamber, a chlorine gas inlet pipe 5 connecting the chlorination chamber and an inert gas inlet pipe 6, a dedicated flow meter 10 disposed in the chlorine gas inlet pipe 5, and a hydrogen gas inlet pipe connecting the deposition chamber.

[0030] The preparation method includes the following steps: S201. Add bulk metal 12 to the chlorination chamber and add the reaction vessel to the substrate 4 to be deposited, and seal the deposition chamber. Then, purge with inert protective gas and heat up through the second heating unit 32 to remove water and oxygen.

[0031] S202. Further heat to the specified temperature, turn off the inert protective gas, and turn on the chlorine gas to carry out the reaction. The step of turning on the chlorine gas to carry out the reaction specifically includes: by measuring the amount of chlorine gas introduced, combined with the chemical reaction stoichiometry, the amount of metal chloride generated can be indirectly and precisely controlled.

[0032] S203, the temperature of the deposition chamber is raised to 1000℃-1200℃, and high-purity hydrogen is introduced according to the stoichiometric ratio. The hydrogen reacts with the chloride generated in the chlorination chamber 14 in a redox reaction, and the reduced metal atoms are deposited on the substrate 4 in the form of a thin film.

[0033] With the widespread application of chemical vapor deposition (CVD) technology in materials preparation, precise control of raw materials has become a key factor determining the quality and performance of deposited films. Tantalum pentachloride (TaCl5), a commonly used tantalum source in CVD, is significantly affected by its metering method. Traditional direct metering of tantalum pentachloride has revealed limitations in long-term application, while a newly proposed method of generating a quantitative amount of tantalum pentachloride through the reaction of chlorine gas with tantalum metal offers a new approach to solving these problems. This study aims to compare the differences between these two metering methods in terms of deposition rate, film quality, and cost-effectiveness during CVD through examples and comparative examples, providing a scientific basis for selecting a superior metering method in actual production.

[0034] As shown in the table below, numbers 1-5 represent the measurement methods of this application, and numbers 6-10 represent traditional measurement methods: Table 1

[0035] Table 2

[0036] The chlorine flow rate is strictly controlled by a dedicated chlorine flow meter 10, with the flow rate range set between 50 and 200 mL / min. Preferably, the chlorine flow rate is 80 to 150 mL / min. More preferably, the chlorine flow rate is 100 to 120 mL / min. Experiments have shown that when the chlorine flow rate is too high, it leads to uneven metal deposition, unstable grain size, and the inability to maintain good flatness on the film surface. However, when the chlorine flow rate is low, the deposition rate is slow. Tantalum metal is placed on a specially designed heating support within the first reaction chamber 11. The use of a support with good thermal conductivity ensures that the tantalum metal is heated uniformly.

[0037] Tantalum metal is heated to 500-800℃ using a heating device, allowing it to fully react with the introduced chlorine gas to produce tantalum pentachloride, chemical formula: 2Ta + 10Cl2 = 2TaCl5.

[0038] The carrier gas hydrogen flow rate was also set to 100–600 m³ / min to ensure that the reaction gas could be uniformly distributed in the reaction chamber. The temperature, pressure, and deposition time of the vapor deposition chamber were kept consistent with the traditional metering method, namely 1000–1200 °C, slightly positive pressure, and 1–4 hours, for comparative analysis.

[0039] The deposition rate was also calculated by measuring the film thickness. The results showed that the deposition rate increased with increasing chlorine flow rate. In experiment 3, with a chlorine flow rate of 100 mL / min, a reaction temperature of 1100℃, and a deposition time of 3 hours, corresponding to a tantalum mass of 0.3222 g, the deposition rate reached 20 μm / h. Compared to traditional metering methods under the same temperature, pressure, and deposition time conditions, the metering method of this application achieved a slightly higher deposition rate at higher chlorine flow rates. For example, in experiment 8 of Table 2, the traditional metering method resulted in a deposition rate of 15-18 μm / h, which was unstable due to the influence of various factors such as temperature and pressure. This is mainly because chlorine reacts in situ with tantalum metal in the second reaction chamber 2 to generate tantalum pentachloride, reducing losses during transport and ensuring a more sufficient supply of active material for the deposition reaction, thereby increasing the deposition rate.

[0040] The deposition rate is calculated as follows: chlorine flow rate is 100 mL / min, which is 0.268 mol / h; tantalum metal consumption is 0.1072 mol / h; tantalum pentachloride / tantalum metal utilization rate is approximately 19-20%; therefore, the usable tantalum mass per hour is 3.782 g (tantalum pentachloride utilization rate is taken as 19.5%), and its volume is 0.2266 cm3. Assuming the substrate size is a D60 sphere with a surface area of ​​113.04 cm2, 0.2266 / 113.04 = 0.002 cm, which is 20 μm.

[0041] Under different chlorine flow rates, the microstructure of the film surface became more uniform. Even at a higher chlorine flow rate (80 mL / min), the film surface maintained good flatness, the grain size remained relatively stable with an average grain size of approximately 75 μm, and the grains were uniformly distributed without obvious agglomeration. This indicates that the metering method described in this application can better control the film growth process, contributing to a more uniform and dense film structure, thereby improving the film's performance.

[0042] Chlorine gas has relatively low procurement costs and is widely available and easily accessible. Although tantalum metal is required, it can be recycled to some extent, requiring only the replenishment of a small amount lost during the reaction. Furthermore, the equipment for transporting and controlling the flow of chlorine gas is relatively simple, with lower requirements for equipment materials compared to TaCl5, thus reducing equipment and maintenance costs. Considering the costs of raw material procurement, equipment purchase, and maintenance, the metering method proposed in this application has a significant cost advantage in long-term operation, effectively reducing production costs and improving production efficiency.

[0043] Comparative examples (please refer to numbers 6-10 in the table): TaCl5 was placed in a heating vaporization apparatus, with temperature fluctuations controlled within ±0.5℃. The TaCl5 vapor flow rate was precisely controlled using a mass flow meter, and it was mixed with a carrier gas (H2) with a stable flow rate of 500 mL / min before being introduced into the reaction chamber. During the experiment, the TaCl5 vapor flow rate was precisely adjusted within the range of 10-50 mL / min according to different experimental requirements.

[0044] The reaction chamber temperature was maintained at 1000-1200℃, and a high-precision temperature control system was used to ensure temperature stability. A silicon substrate was placed in a specific position in the reaction chamber for chemical vapor deposition, and the deposition time was set to 1-4 hours to investigate the effect of different deposition times on the film performance.

[0045] The film thickness deposited on silicon wafers under different experimental conditions was accurately measured using a film thickness gauge, and the deposition rate was precisely calculated using the deposition time. Experimental results show that the deposition rate gradually increases with the increase of TaCl5 flow rate.

[0046] In experiment 8, the deposition rate reached its maximum of 15 μm / h when the TaCl5 flow rate was 40 mL / min, the reaction temperature was 1100 °C, and the deposition time was 3 hours. However, when the TaCl5 flow rate was further increased, the film quality decreased significantly, and the surface roughness increased significantly. This may be because the reaction was too vigorous, causing an imbalance between nucleation and growth processes, resulting in the inability to form a uniform film structure.

[0047] At lower TaCl5 flow rates (e.g., experiments 6 and 7), the film surface was relatively smooth with relatively uniform grain size, averaging approximately 8 μm. However, with increasing TaCl5 flow rates (experiments 9 and 10), significant particle agglomeration appeared on the film surface, the grain size distribution became more widespread, and larger grains, reaching up to 160 μm, appeared in some areas. This non-uniform microstructure may adversely affect the electrical and mechanical properties of the film, reducing its overall quality.

[0048] TaCl5, a commonly used feedstock for chemical vapor deposition, has a relatively high procurement cost. Due to its strong corrosiveness, TaCl5 places stringent requirements on the materials used in pipelines and vaporization devices, necessitating the use of corrosion-resistant special materials. This significantly increases both the purchase and maintenance costs of the equipment. Furthermore, to precisely control the flow rate of TaCl5, high-precision liquid vaporization and flow control equipment is required, further increasing costs. Over the long term, these cost factors will significantly increase production costs.

[0049] In other embodiments, a detection device may be further included for detecting the content of metal chlorides in the exhaust gas generated by the reaction apparatus. By detecting the content of metal chlorides, the chlorine gas flow rate can be adjusted in real time to ensure a complete reaction and prevent excessive chloride release, thereby improving raw material utilization and reducing environmental pollution.

[0050] In summary, through detailed examples and comparative studies of the traditional metering method (direct metering of tantalum pentachloride) and the metering method of this application (metering the reaction of chlorine gas with tantalum metal to generate tantalum pentachloride), the following conclusions are drawn: 1. Regarding the deposition rate, the metering method of this application is slightly higher than that of the traditional metering method under higher flow conditions, and the change in deposition rate is more stable throughout the entire flow range, which is conducive to achieving a more stable deposition process.

[0051] 2. In terms of film quality, the film microstructure obtained by the metrology method of this application is more uniform and dense, the crystal structure is purer, and the preferred orientation is more stable. The quality and performance of the film are significantly better than those of the traditional metrology method, which can meet the application scenarios with high requirements for film quality.

[0052] 3. Cost analysis shows that the measurement method proposed in this application has lower procurement costs, equipment costs, and maintenance costs, and has significant economic advantages in long-term application. It can effectively reduce production costs and improve the market competitiveness of enterprises.

[0053] In summary, the novel metrological method for generating tantalum pentachloride through the reaction of chlorine with tantalum metal demonstrates superior performance and cost-effectiveness in chemical vapor deposition (CVD), showing broad application prospects and the potential to gradually replace traditional metrological methods in related fields. However, in practical applications, further optimization of reaction conditions is needed, such as precise control of the reaction process between tantalum metal and chlorine, to fully leverage the advantages of this metrological method and address potential issues, such as the handling of reaction byproducts, thus providing stronger technical support for its large-scale industrial application.

[0054] The present invention also provides a porous metal coating composite material, wherein the porous metal coating is formed by reducing metal onto a porous carbon substrate using the above-mentioned chemical vapor deposition method to form a porous metal coating carbon-based composite material.

[0055] The porous metal-coated carbon-based composite material can be applied to artificial bones. The porous metal-coated carbon-based composite material has a porosity of 85%, a pore size of 150μm-600μm, and a yield strength of 0.1MPa-0.07MPa; the porous carbon substrate has an open porosity of over 85%, an average pore size of approximately 500μm (40-60ppi), a yield strength of 0.05-0.1MPa, and a deposited metal thickness of approximately 60-80μm.

[0056] In summary, the novel metrological method for generating tantalum pentachloride through the reaction of chlorine with tantalum metal demonstrates superior performance and cost-effectiveness in chemical vapor deposition (CVD), showing broad application prospects and the potential to gradually replace traditional metrological methods in related fields. However, in practical applications, further optimization of reaction conditions is needed, such as precise control of the reaction process between tantalum metal and chlorine, to fully leverage the advantages of this metrological method and address potential issues, such as the handling of reaction byproducts, thus providing stronger technical support for its large-scale industrial application.

[0057] In the description of this application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0058] Those skilled in the art should understand that the above embodiments are merely for illustrative purposes and are not intended to limit the scope of this application. Those skilled in the art can make other changes or modifications based on the above disclosure, and these changes or modifications still fall within the scope of this application.

Claims

1. A method for preparing a metal chloride, characterized in that: The preparation method is implemented through a first reaction chamber, which includes a chlorination chamber, a first heating unit for heating the chlorination chamber, a chlorine gas inlet pipe connected to the chlorination chamber, an inert gas inlet pipe, and a dedicated flow meter installed in the chlorine gas inlet pipe. The preparation method includes the following steps: S101. Add block metal to the chlorination chamber and seal the chlorination chamber. Then purge with inert protective gas and heat up through the heating unit to remove water and oxygen. S102. Further heat to the specified temperature, turn off the inert protective gas, and turn on the chlorine gas to carry out the reaction. The step of turning on the chlorine gas to carry out the reaction specifically includes: by measuring the amount of chlorine gas introduced, combined with the chemical reaction stoichiometry, the amount of metal chloride generated can be indirectly and precisely controlled, and finally the precise control of the metal chloride raw material in the subsequent chemical vapor deposition reaction can be achieved.

2. The method for preparing metal chlorides according to claim 1, characterized in that: The bulk metal includes at least one of tantalum, niobium, tungsten, molybdenum, and corresponding alloys.

3. The method for preparing metal chlorides according to claim 2, characterized in that: In step S101, the chlorine gas inlet pipe is at least one of polytetrafluoroethylene pipe, high-density polyethylene pipe, copper pipe, and titanium pipe.

4. The method for preparing metal chlorides according to claim 3, characterized in that: In step 101, the inert protective gas is at least one of high-purity argon, high-purity helium, and high-purity nitrogen.

5. The method for preparing metal chlorides according to claim 4, characterized in that: The specified temperature in step 102 is 500℃~800℃.

6. The method for preparing metal chlorides according to claim 5, characterized in that: The specified temperature in step 102 is 630~680℃.

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