High-purity tungsten hexafluoride steel bottle

Abstract

The utility model relates to the technical field of high-purity gas production, in particular to a high-purity tungsten hexafluoride steel bottle which comprises a base, a steel bottle body is mounted on the base and sleeved with a jacket, a gas phase valve is arranged at one end of the steel bottle body, and a liquid phase valve is arranged at the other end of the steel bottle body. The gas phase valve and the liquid phase valve are respectively covered with a bottle cap, the liquid phase valve is connected with a liquid phase guide pipe, the gas phase valve is connected with a gas phase guide pipe, and a platinum resistance guide pipe is arranged in the steel bottle. Therefore, the high-purity tungsten hexafluoride steel bottle can solve the problems that the flow of the steel bottle is limited at the normal temperature, the flow can be increased through heating, but the operation is complex, cooling is needed during filling so as to ensure tungsten hexafluoride liquefaction and increase the filling flow, the requirement of high-purity tungsten hexafluoride for the cleanliness of a system is extremely high, the treatment difficulty of the inner wall of the steel bottle is high, and the requirement for the polishing quality of the inner wall of a large-capacity steel bottle is high. And impurities are easily generated due to improper treatment, so that the shelf life of the product is influenced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high-purity gas production, more particularly to a high-purity tungsten hexafluoride cylinder. BACKGROUND

[0002] With the continuous advancement of 3D NAND technology, the demand for high-purity tungsten hexafluoride (WF6) in the semiconductor industry is increasing. As an important raw material, tungsten hexafluoride plays a key role in processes such as chemical vapor deposition (CVD). However, the commonly available tungsten hexafluoride cylinders on the market usually have a maximum volume of 40 liters, which is insufficient to meet the demand of large-scale production. Especially in high-demand production environments, smaller volume cylinders not only limit production efficiency, but also increase the frequency of cylinder replacement, affecting the continuity and stability of the production line.

[0003] In the practical application of CVD vapor deposition chambers, tungsten hexafluoride cylinders are usually used at room temperature. However, as the amount of tungsten hexafluoride increases, the flow rate of ordinary cylinders at room temperature often fails to meet production demands. In order to increase the flow rate, one effective method is to heat the cylinder to promote the discharge of tungsten hexafluoride. However, this method, while increasing the flow rate to some extent, may also bring additional energy consumption and temperature control problems.

[0004] On the other hand, during the filling of gaseous tungsten hexafluoride, the cylinder needs to be cooled. This is because tungsten hexafluoride is gaseous at room temperature and normal pressure, and cannot be effectively stored if directly introduced into the cylinder. Through cooling treatment, tungsten hexafluoride can be liquefied in the cylinder, thus achieving continuous and efficient filling. Cooling treatment also helps to increase the flow rate during filling, thereby shortening the filling time and improving production efficiency.

[0005] However, high-purity tungsten hexafluoride has very high cleanliness requirements for the system, and the total impurity content must be controlled below 1 ppm. In addition, tungsten hexafluoride is easily hydrolyzed by water to form hydrofluoric acid (HF), which not only affects the purity of the product, but also may cause corrosion of the inner wall of the cylinder. Therefore, the material, inner wall treatment, and sealing performance of the tungsten hexafluoride cylinder have very high requirements.

[0006] In particular, the roughness of the inner wall of the cylinder has a crucial impact on the storage and shelf life of tungsten hexafluoride. When the inner wall roughness of the cylinder is high, the inner wall surface is prone to adsorbing impurities such as oxygen, nitrogen, and water, leading to an increase in oxygen, nitrogen, and HF content during gas analysis. In addition, the corrosion problem of the inner wall of the cylinder cannot be ignored, because the metal particles produced by corrosion also contaminate tungsten hexafluoride, shortening its shelf life.

[0007] At present, the inner wall polishing quality of 40L tungsten hexafluoride steel cylinder has reached the standard of Ra=0.3 microns. However, with the research and application of large-capacity steel cylinders, the requirement for the inner wall polishing quality is also higher and higher. Because the inner wall area of the large-capacity steel cylinder is larger, the processing difficulty is also increased accordingly. If not handled properly, the impurities generated will seriously affect the purity and shelf life of tungsten hexafluoride, and then cause adverse effects at the customer end. Content of the utility model

[0008] Based on the above problems, the application provides a high-purity tungsten hexafluoride steel cylinder, which is used to solve the technical problems that the flow of the steel cylinder is limited at room temperature, the heating can improve the flow but the operation is complex, the temperature needs to be reduced during filling to ensure the liquefaction of tungsten hexafluoride, the high-purity tungsten hexafluoride has extremely high requirement for system cleanliness, the inner wall of the steel cylinder is difficult to process, and the polishing quality requirement of the inner wall of the large-capacity steel cylinder is high.

[0009] To solve the above technical problems, the technical scheme adopted by the utility model is:

[0010] A high-purity tungsten hexafluoride steel cylinder, comprising a base, a steel cylinder body is installed on the base, a jacket is arranged outside the steel cylinder body, a gas phase valve is arranged at one end of the steel cylinder body, a liquid phase valve is arranged at the other end of the steel cylinder body, a bottle cap is arranged on the gas phase valve and the liquid phase valve, a liquid phase conduit is connected to the liquid phase valve, a gas phase conduit is connected to the gas phase valve, and a platinum resistance conduit is arranged in the steel cylinder.

[0011] In a specific implementable scheme, the inner wall of the steel cylinder body is subjected to polishing treatment, and the polishing quality of the inner wall of the steel cylinder body reaches Ra≤0.1 microns.

[0012] In a specific implementable scheme, the nominal volume in the steel cylinder body is 0.5-5m 3 .

[0013] In a specific implementable scheme, a closed gap is arranged between the jacket and the steel cylinder body, and an inlet and an outlet are arranged on the jacket.

[0014] In a specific implementable scheme, one end of the liquid phase conduit is communicated with the liquid phase valve, the other end of the liquid phase conduit is bent towards the bottom of the steel cylinder body, one end of the gas phase conduit is communicated with the gas phase valve, and the other end of the gas phase conduit is bent towards the upper end of the steel cylinder body.

[0015] In a specific implementable scheme, the platinum resistance conduit is located between the gas phase conduit and the liquid phase conduit.

[0016] The positive effects of the utility model are as follows:

[0017] The design of the jacket allows the steel cylinder to be cooled during the filling process. By injecting a cooling medium into the jacket, the temperature of the steel cylinder body can be effectively reduced, so that the tungsten hexafluoride entering the steel cylinder can be liquefied, and the filling efficiency is improved.

[0018] The inner wall of the steel cylinder body is polished, and the polishing quality reaches the standard of Ra≤0.1 μm, which is much lower than the existing 40 liter steel cylinder standard of Ra=0.3 μm. This high-precision polishing process can significantly reduce the roughness of the inner wall surface, reduce the adsorption of impurities such as oxygen, nitrogen, and water, and thus meet the extremely high requirements of high-purity tungsten hexafluoride on system cleanliness.

[0019] By using high-precision polishing process and strict quality control, the polishing quality of the inner wall of the large-capacity steel cylinder is ensured to meet the requirements. This not only reduces the generation of impurities, but also prolongs the shelf life of tungsten hexafluoride, avoiding adverse effects at the customer end. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the drawings needed in the embodiment or prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the provided drawings.

[0021] Figure 1 The structure of the present application is shown in the schematic diagram.

[0022] BRIEF DESCRIPTION OF DRAWINGS

[0023] 1, liquid phase valve; 2, jacket; 3, platinum resistance guide pipe; 4, gas phase valve; 5, base; 6, bottle cap; 7, inlet; 8, outlet; 9, liquid phase guide pipe; 10, gas phase guide pipe. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0025] Embodiment 1

[0026] As Figure 1As shown, a high-purity tungsten hexafluoride cylinder includes a base 5 on which a cylinder body is mounted, the base 5 serving to fix the cylinder body, the inner wall of the cylinder body being subjected to polishing treatment, the polishing quality of the inner wall of the cylinder body reaching Ra≤0.1 μm, the nominal volume in the cylinder body being 0.5-5 m 3 .

[0027] The cylinder body is sleeved with a jacket 2, a closed gap being formed between the jacket 2 and the cylinder body, the jacket 2 being provided with an inlet 7 and an outlet 8, the jacket 2 being used for heating or cooling the cylinder.

[0028] One end of the cylinder body is provided with a gas-phase valve 4, the other end of the cylinder body is provided with a liquid-phase valve 1, the gas-phase valve 4 and the liquid-phase valve 1 are each covered with a cylinder cap 6, the liquid-phase valve 1 is connected with a liquid-phase conduit 9, the liquid-phase valve 1 being used for charging or discharging a liquid-phase component, the gas-phase valve is connected with a gas-phase conduit 10, one end of the liquid-phase conduit 9 communicates with the liquid-phase valve 1, the other end of the liquid-phase conduit 9 is bent towards the bottom of the cylinder body, one end of the gas-phase conduit 10 communicates with the gas-phase valve 4, the other end of the gas-phase conduit 10 is bent towards the upper end of the cylinder body.

[0029] The platinum resistance conduit 3 is located between the gas-phase conduit 10 and the liquid-phase conduit 9, the gas-phase valve 4 being used for charging or discharging a gas-phase component. The platinum resistance conduit 3 is arranged in the cylinder, the platinum resistance conduit being used for monitoring the temperature in the cylinder. The cylinder cap 6 is used for protecting the gas-phase valve 4 and the liquid-phase valve 1, so that they are not easily damaged during transportation. The inner wall of the cylinder is subjected to electrolytic polishing treatment, the shelf life of tungsten hexafluoride in the cylinder can reach 24 months.

[0030] Example 2

[0031] The cylinder body in this example is 0.5 m3. The gas-phase valve 4 is used for charging and discharging a gas-phase tungsten hexafluoride into the cylinder. The liquid-phase valve is connected with a conduit extending to the bottom of the cylinder body, which is used for discharging or charging a liquid-phase tungsten hexafluoride. The jacket 2 is wrapped around the cylinder body and the head, which is used for heating or cooling the cylinder. The platinum resistance conduit 3 is used for monitoring the temperature in the cylinder, which, in cooperation with the heating and cooling functions of the jacket 2, can control and adjust the speed of discharging and charging of the tungsten hexafluoride.

[0032] The temperature in the steel bottle body is raised to 40°C in 10 minutes, and the discharge rate of tungsten hexafluoride in the steel bottle is 20 kg / h. The polishing quality of the steel bottle body is Ra=0.1 μm. The gas in the bottle is analyzed when the steel bottle body is just filled with tungsten hexafluoride (detection time 0), the steel bottle body is placed at room temperature for 12 months (detection time 12 months), and the steel bottle body is placed at room temperature for 24 months (detection time 24 months), respectively. The qualified indicators and analysis results are shown in Table 1 and Table 2. The data in Table 1 and Table 2 show that when the steel bottle body of this embodiment stores tungsten hexafluoride for 24 months, the gas analysis and metal ion analysis results are still qualified.

[0033] Table 1 Analysis results of gas in bottle body of Example 2

[0034]

[0035]

[0036] Table 2 Analysis results of metal ions in bottle body of Example 2

[0037] Metal ion index 0 12 months 24 months Al / ppb W (< 5) 0 <0.000 <0.000 As / ppb W (< 5) 0.062 0.068 0.072 B / ppb W (< 5) 3.245 3.127 3.751 Ca / ppb W (< 5) 0.128 1.275 0.853 Cd / ppb W (< 2) 0.52 0.669 0.862 Cr / ppb W (< 5) 2.696 2.252 2.226 Fe / ppb W (< 5) 1.955 2.414 2.255 K / ppb W (< 5) 0.024 0.077 0.056 Mn / ppb W (< 5) 1.867 2.429 2.708 Na / ppb W (< 5) 0.027 0.033 0.042 Th / ppb W (< 0.1) 0.006 0.006 0.009 Ti / ppb W (< 5) 0.096 0.098 0.089 Li / ppb W (< 5) 1.378 2.444 3.128 U / ppb W (< 0.05) 0.006 0.009 0.009 Zn / ppb W (< 5) 0.338 0.447 0.426 Si / ppb W (< 5) 0.264 0.178 0.348 Pb / ppb W (< 5) 0.386 0.346 0.417 P / ppb W (< 2) 0.030 0.025 0.022 Mg / ppb W (< 5) 0.014 0.077 0.085 Ni / ppb W (< 10) 0.003 0.001 0.003 Cu / ppb W (< 5) 0.033 0.028 0.037 Mo / ppb W (< 10) 0.006 0.006 0.009

[0038] Example 3

[0039] In this embodiment, the volume of the bottle body of the high-purity tungsten hexafluoride steel bottle is increased to 3 m 3 . The heating in the bottle body to 50°C takes 30 minutes, and the discharge rate of tungsten hexafluoride in the bottle body is 40 kg / h. The polishing quality of the bottle body is Ra=0.05 μm, and the qualified indicators and analysis results are shown in Table 3 and Table 4. The data in Table 3 and Table 4 show that when the bottle body of this embodiment stores tungsten hexafluoride for 24 months, the gas analysis results are still qualified.

[0040] Table 3 Analysis results of gas in bottle body of Example 3

[0041]

[0042] Table 4 Analysis results of metal ions in bottle body of Example 3

[0043] Metal ion index 0 12 months 24 months Al / ppb W (< 5) 0.045 0.086 0.077 As / ppb W (< 5) 2.770 1.554 1.75 B / ppb W (< 5) 1.823 1.911 0.886 Ca / ppb W (< 5) 0.488 0.812 0.822 Cd / ppb W (< 2) <0.000 <0.000 <0.000 Cr / ppb W (< 5) <0.000 <0.000 <0.000 Fe / ppb W (< 5) 1.501 1.922 1.521 K / ppb W (< 5) 1.640 1.821 1.454 Mn / ppb W (< 5) 0.021 0.057 0.022 Na / ppb W (< 5) 0.501 1.254 1.145 Th / ppb W (< 0.1) 0.088 0.013 0.025 Ti / ppb W (< 5) 2.824 2.774 1.438 Li / ppb W (< 5) 0.009 0.012 0.013 U / ppb W (< 0.05) 0.009 0.011 0.013 Zn / ppb W (< 5) 0.35 0.213 0.105 Si / ppb W (< 5) 0.38 0.554 0.668 Pb / ppb W (< 5) 0.003 0.01 0.006 P / ppb W (< 2) 0.034 0.047 0.054 Mg / ppb W (< 5) 0.003 0.002 0.001 Ni / ppb W (< 10) 0.021 0.024 0.016 Cu / ppb W (< 5) 0.021 0.022 0.009 Mo / ppb W (< 10) 0.021 0.015 0.023

[0044] Example 4

[0045] In this embodiment, the volume of the bottle body of the high-purity tungsten hexafluoride steel bottle is increased to 5 m 3 . The heating in the bottle to 60°C takes 40 minutes, and the discharge rate of tungsten hexafluoride in the bottle body is 55 kg / h. The polishing quality of the bottle body is Ra=0.1 μm, and the qualified indicators and analysis results are shown in Table 5 and Table 6.

[0046] The data in Table 5 and Table 6 show that the gas analysis results are still qualified when the bottle body of the present example stores tungsten hexafluoride for 24 months.

[0047] Table 5 Gas analysis results in the bottle body of Example 4

[0048]

[0049] Table 6 Metal ion analysis results in the steel bottle of Example 4

[0050]

[0051]

[0052] Comparative Example

[0053] In the present example, the polishing quality of the inner wall of the steel bottle body is adjusted to Ra = 0.2 μm, and the steel bottle body is heated in the form of environmental warming. It takes 45 minutes to heat the steel bottle body to 40°C. The qualified indicators and analysis results are shown in Table 4. The data in Table 7 and Table 8 show that the gas analysis and metal ion analysis results are not qualified when the bottle body of the present comparative example stores tungsten hexafluoride for 12 months and 24 months. When the polishing quality of the inner wall of the steel bottle body is Ra = 0.2 μm, the shelf life of storing tungsten hexafluoride is less than 12 months.

[0054] Table 7 Gas analysis results in the bottle body of the comparative example

[0055]

[0056] Table 8 Metal ion analysis results in the bottle body of the comparative example

[0057] Al / ppb W (< 5) <0.000 <0.000 0.009 As / ppb W (< 5) 0.103 0.05 0.067 B / ppb W (< 5) Ca / ppb W (< 5) 0.24 0.322 1.571 Cd / ppb W (< 2) 0.45 0.57 0.484 Cr / ppb W (< 5) 18.897 9.056 22.245 Fe / ppb W (< 5) 14.552 10.045 18.324 K / ppb W (< 5) 1.039 1.451 1.648 Mn / ppb W (< 5) 0.374 0.44 1.37 Na / ppb W (< 5) 0.01 0.01 0.023 Th / ppb W (< 0.1) 0.012 0.011 0.020 Ti / ppb W (< 5) 0.051 0.124 0.227 Li / ppb W (< 5) 0.361 0.95 2.797 U / ppb W (< 0.05) 0.007 0.014 0.043 Zn / ppb W (< 5) 0.216 0.352 1.016 Si / ppb W (< 5) 0.087 0.065 0.116 Pb / ppb W (< 5) 0.217 0.308 0.638 P / ppb W (< 2) 0.687 0.329 0.193 Mg / ppb W (< 5) 0.02 0.046 0.226 Ni / ppb W (< 10) 12.258 13.544 13.756 Cu / ppb W (< 5) 0.005 0.008 0.015 Mo / ppb W (< 10) 18.251 17.315 20.575

[0058] Finally, it should be noted that the relational terms herein such as first and second and the like can merely be used to distinguish one entity or action from another, without necessarily requiring or implying that these entities or actions are in any way mutually exclusive or in any way arranged or ordered in succession or in sequence. Also, the terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by "comprises... a" does not, without more constraints, exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0059] The foregoing description of the disclosed embodiments enables a person skilled in the art to make or use the application. Modifications of these embodiments will occur to persons of skill in the art, and that the generic principles defined herein can be applied to other embodiments without departing from the spirit or scope of the application. Therefore, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A high purity tungsten hexafluoride cylinder characterized by, The utility model relates to a kind of gas cylinder, including base (5), the steel bottle body is installed on the base (5), the steel bottle body is equipped with jacket (2), one end of the steel bottle body is provided with gas phase valve (4), the other end of the steel bottle body is provided with liquid phase valve (1), the gas phase valve (4) and the liquid phase valve (1) are covered with bottle cap (6), the liquid phase valve (1) is connected with liquid phase conduit (9), the gas phase valve is connected with gas phase conduit (10), and the steel bottle is provided with platinum resistance conduit (3).

2. A high purity tungsten hexafluoride cylinder as claimed in claim 1, wherein, The inner wall of the steel bottle body is polished, and the polishing quality of the inner wall of the steel bottle body reaches Ra≤0.1 μm.

3. The high purity tungsten hexafluoride cylinder of claim 1 wherein, The nominal volume in the steel bottle body is 0.5-5m 3 .

4. The high purity tungsten hexafluoride cylinder of claim 1 wherein, A closed gap is formed between the jacket (2) and the steel bottle body, and the jacket (2) is provided with an inlet (7) and an outlet (8).

5. The high purity tungsten hexafluoride cylinder of claim 1 wherein, One end of the liquid phase conduit (9) communicates with the liquid phase valve (1), the other end of the liquid phase conduit (9) is bent towards the bottom of the steel bottle body, one end of the gas phase conduit (10) communicates with the gas phase valve (4), and the other end of the gas phase conduit (10) is bent towards the upper end of the steel bottle body.

6. The high purity tungsten hexafluoride cylinder of claim 1 wherein, The platinum resistance conduit (3) is located between the gas phase conduit (10) and the liquid phase conduit (9).

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