KR20220089725A - Container for storing high-purity hydrogen fluoride using a metal substrate having low corrosion resistance, and a method for manufacturing the same - Google Patents

Abstract

The present invention relates to _a container for storing high-purity hydrogen fluoride, using an inexpensive metal substrate such as carbon steel, adjusting the surface roughness Ra of the substrate to 0.5 μm or less, and plating the surface with nickel. It relates to a container for storing high-purity hydrogen fluoride, which is made to have sufficient corrosion resistance by increasing the density of the plating film.

Description

Container for storing high-purity hydrogen fluoride using a metal substrate having low corrosion resistance, and a method for manufacturing the same

The present invention relates to a container for storing high-purity hydrogen fluoride, using a metal substrate with weak corrosion resistance, and forming a nickel plating film after adjusting the surface roughness of the low corrosion resistance metal, thereby forming a nickel plating film and a fluoride passivation film By further improving efficiency and corrosion resistance, it relates to a container for storing high-purity hydrogen fluoride, which enables storage and transport of hydrogen fluoride, a corrosive gas, with high purity.

In the manufacturing process of semiconductor devices, MEMS (Micro Electro Mechanical Systems) devices, liquid crystal TFT (Thin Film Transistor) panels, solar cell panels, etc., depending on the process characteristics such as the etching process, the film formation process, and the cleaning process, nearly 150 kinds of gases are produced. is being used

For example, in the semiconductor manufacturing process, hydrogen chloride (HCl), boron trichloride (BCl ₃ ), fluorine (F ₂ ), nitrogen trifluoride (NF ₃ ), chlorine trifluoride (ClF ₃ ), hydrogen bromide (HBr), hydrogen fluoride A halogen-based special gas with strong reactivity and corrosive properties such as (HF) is used. In particular, hydrogen fluoride (HF) is used as a highly active corrosive gas in etching gas and cleaning processes, and the hydrogen fluoride is directly Ultra-high purity is required to minimize the defect rate due to the nature of the semiconductor process, which is gradually increasing.

However, hydrogen fluoride is a highly active corrosive gas, and it is easily hydrolyzed by moisture in the air and can very easily corrode metal materials or metal film structures constituting storage containers, valves, pipes, reaction chamfers, etc. that handle hydrogen fluoride. As a result, there are many difficulties in storing it in high purity without contamination due to corrosion.

In particular, substances such as impurities H ₂ and CH ₄ are formed by reacting with HF even in a vessel made of SUS316L, which has strong corrosion resistance, and the impurities increase over time, and semiconductor devices are manufactured using gases containing the generated impurities. Since it adversely affects semiconductor devices, it is necessary to use a material with strong corrosion resistance. In order to solve this problem, it is an alloy and metal film with excellent corrosion resistance that can handle hydrogen fluoride (2006.12.15), it is an alloy excellent in corrosion resistance and contains 4.0 to 5.0 mass% of Mg and 0.02 to 0.1 mass% of Cr, and each content of Si, Fe, Cu, Mn, Zn and Ni as impurities is 0.1 mass%, respectively. An aluminum alloy for a film forming treatment regulated below and the remainder being composed of Al and other impurities is known, and it is disclosed that the alloy and alloy material are suitable as materials for semiconductor manufacturing apparatuses. However, in the case of the prior literature, it is limited to an aluminum alloy, the manufacturing and refining process to have such a composition is complex, and when a scratch is formed by an external stimulus, there is a problem in that it is difficult to maintain corrosion resistance.

Therefore, it is generally developed to express very high corrosion resistance to corrosive gas by plating a metal substrate with a metal having corrosion resistance or by fluorination passivation.

The passivation layer using such a fluorine gas is not thick, so it is weak in scratches, etc., so Korean Patent No. 10-0308688 (Jan. 11.30, 2001) discloses a metal made of nickel or a nickel alloy to form a thick passivation layer. A technique for improving corrosion resistance by forming a fluoride layer on the surface of 1 μm or more by forcibly oxidizing the surface of the material or nickel or nickel alloy film and then passivating the forced oxidation layer using fluorine or the like However, in the case of the prior literature, as the surface of the nickel or nickel alloy film is forcibly oxidized, and the fluoride layer must also form a significant thickness of 1 μm or more, the process is complicated as well as the process between the fluoride layer and the base material. It is difficult to maintain the adhesion for a considerable period of time by improving the adhesion to a satisfactory level with the fluoride layer and abrasion resistance and durability.

In addition, Hastelloy, which is a nickel-based alloy with very strong corrosion resistance, and Inconel, which has excellent heat resistance and corrosion resistance with nickel as the main component and 15% chromium added, are considered as device materials for handling hydrogen fluoride. However, in the case of these alloys, since they are expensive and workability is not good, economical efficiency and process efficiency are reduced. It is developed to express high corrosion resistance.

Therefore, the present invention is devised to solve the above problems, and when the surface roughness of the metal substrate is adjusted in a certain range, the corrosion resistance of the metal substrate itself, adhesion to the coating film formed on the substrate, and the density of the coating film are improved. It has been found that it exhibits corrosion resistance even against strong acids such as hydrogen fluoride, thereby completing the present invention.

According to the present invention, low corrosion-resistant materials such as carbon steel, which easily react with oxygen and corrode, can also be applied as a metal substrate for a storage container for high-purity fluoride gas, particularly high-purity hydrogen fluoride for semiconductors, thereby improving economic efficiency.

Japanese Patent No. 3891815 (2006.12.15) Korean Patent Registration No. 10-0308688 (Jan. 11, 2001)

An object of the present invention is to provide a storage container for storing high-purity hydrogen fluoride using a low-cost, low-corrosion-resistant carbon steel-based metal.

In addition, the present invention makes it another solution to provide a method for manufacturing a container for storing high-purity hydrogen fluoride, using a metal such as carbon steel with low corrosion resistance at low cost.

In order to solve the above problems, the present invention provides a container for storing high-purity fluorinated gas, wherein the container includes a material in which a nickel plated film is plated on the surface of a metal substrate, and the nickel plated film is used as the inner surface of the container, The metal substrate provides a storage container for storing high-purity hydrogen fluoride, characterized in that the average centerline roughness (R _a ) of the surface roughness is 0.5 μm or less.

In an embodiment of the present invention, the metal substrate may be carbon steel, and a fluoride passivation film may be formed on the surface of the nickel plated film.

In one embodiment of the present invention, the thickness of the fluoride passivation film is characterized in that 0.1 ~ 1㎛.

In addition, the present invention is a method for manufacturing a container for storing high-purity fluorinated gas, (1) the metal substrate forming the inner surface of the storage container, the average roughness of the center line (R _a ) of the surface of the metal substrate is 0.5 ㎛ or less of the metal substrate. grinding; (2) plating nickel on the polished metal substrate to form a nickel plating film;

In one embodiment of the present invention, the metal substrate in step (1) may be carbon steel, and after step (2), (3) fluorination treatment of the nickel plating film to form a fluoride passivation film further comprising can do.

In one embodiment of the present invention, in the step of forming the fluoride passivation film of (3), the step of oxidizing the nickel plating film before fluorination treatment of the nickel plating film may be further included.

The present invention uses a low-cost metal as a metal substrate for a high-purity hydrogen fluoride storage container, while controlling the surface roughness of the metal substrate to improve the corrosion resistance of the substrate itself, as well as a nickel plating film formed on the metal substrate As the coating film stability and compactness are improved, carbon steel with strong corrosive properties can also be applied as a metal substrate, thereby improving economic efficiency and strength stability.

In addition, the present invention improves the corrosion resistance to hydrogen fluoride of the inner surface of the storage container by improving the adhesion and density of the fluoride passivation film as well as the nickel plating film by controlling the surface roughness of the metal substrate.

In addition, the present invention is a fluoride passivation treatment of not only the inner surface of the container but also the connected valve by charging the chemical substance having a fluoride group inside the container and then aging for a certain period of time and then removing it through the valve mounted on the container. By improving corrosion resistance, it is possible to maintain high purity of high-purity hydrogen fluoride stored inside the container.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In general, the nomenclature used herein is those well known and commonly used in the art.

When a part "includes" a component throughout this specification, this means that other components may be further included, rather than excluding other components, unless otherwise stated.

Hereinafter, the present invention will be described in detail.

High integration is progressing in the semiconductor and liquid crystal manufacturing fields, and ultra-fine pattern processing of 1 μm or less is required. In this ultra-LSI manufacturing process, a large amount of gas is used for microfabrication on the Si wafer, such as film formation and etching. In the semiconductor manufacturing process, even if minute dust or a trace amount of impurity gas adheres to and adsorbs on the wiring pattern, it can cause circuit failure. As a highly corrosive gas, it is easily hydrolyzed by moisture in the atmosphere to generate hydrofluoric acid. It becomes difficult to maintain high purity.

Therefore, Hastelloy as a nickel alloy, which is a corrosion-resistant metal strong against corrosive gases such as hydrogen fluoride, and Inconel with excellent heat resistance and corrosion resistance with nickel as the main component and 15% chromium added are sometimes used. , Since it is difficult to meet economic feasibility because the metal is expensive, it is necessary to develop a technology that can use a low-cost metal series such as carbon steel.

Accordingly, the present invention provides a container for storing high-purity fluorinated gas, wherein the container includes a material in which a nickel plated film is plated on the surface of a metal substrate, and the nickel plated film is used as the inner surface of the container, and the metal substrate has a surface roughness It provides a storage container for storing high-purity hydrogen fluoride, characterized in that the centerline average roughness (R _a ) is 0.5 μm or less.

In the present invention, the metal substrate is not particularly limited as long as it has stability and compactness usable as a container, but is preferably selected from carbon steel, aluminum, aluminum alloy, nickel, nickel alloy, copper, copper alloy, chromium and stainless steel. It may be any one that is, more preferably carbon steel, and the thickness of the metal substrate is in a range that meets the gas stability standard.

Carbon steel is an alloy steel of iron and carbon that contains 0.02 to 2.1% of carbon and may contain silicon, manganese, phosphorus, sulfur, etc. as impurities. When used as a substrate, the strength and economy of the container can be improved, but as it easily reacts with oxygen and corrodes, it is difficult to use as a container for strong acids such as hydrogen fluoride.

However, the container material of the present invention includes a nickel plating film and a fluoride passivation film having excellent acid resistance formed on the upper portion of the metal substrate together with the metal substrate, and by controlling the surface roughness of the metal substrate to a certain range, significantly improving corrosion resistance. , even if the metal substrate is carbon steel that is easily corroded, it can have corrosion resistance, especially corrosion resistance to hydrogen fluoride, so that inexpensive metal can be used as a material for a storage container of high purity hydrogen fluoride, thereby improving both economic efficiency, strength and corrosion resistance. can

The metal substrate of the present invention has a center line average roughness (R _a ) of 0.5 μm or less in surface roughness.

Surface roughness refers to the degree of fine irregularities that occur on the surface when finishing the metal surface. It can be defined as a maximum height (R _max ), a ten-point average roughness (R _z ) and a centerline average roughness (R _a ), which affects the physical and chemical properties of the contact part.

When R _a of the metal substrate exceeds 0.5 μm, oxygen, moisture, corrosive substances, etc. in the air have a sufficient contact area and angle to contact and react with the surface of the metal substrate, so that the surface of the metal substrate is easily On the other hand, corrosion resistance is significantly reduced due to oxidation or reactivity, whereas when Ra of _a metal substrate is 0.5 μm or less, the contact area of the metal substrate is minimized, which may exist on the surface of a metal substrate due to oxygen and moisture in the air. OH and oxygen are minimized, and furthermore, the formation of H ₂ , CH ₄ by the reaction of HF with this is suppressed. That is, the metal substrate in which the R _a is adjusted to 0.5 μm or less reduces the contact and reactivity with oxygen, moisture, and corrosive substances in the atmosphere by minimizing the contact area with the reactant, thereby suppressing the generation of impurities due to the reaction. It is possible to maintain the purity of the hydrogen fluoride gas.

In addition, when nickel plating is performed on a metal substrate in which Ra _is adjusted to 0.5 μm or less, particles generated in the nickel plating process generated when nickel plating is performed on a metal substrate in which Ra _is not adjusted are generated inside the container. There is no problem remaining in

If the inner surface of the container Ra is more than 0.5 ㎛ and the surface roughness is not good, the amount of metal eluted during nickel plating is relatively large, and the eluted metal material remains on the surface of the plating layer and remains as metal particles and reacts with hydrogen fluoride This adversely affects the formation of metal ions in hydrogen fluoride and maintaining high purity of hydrogen fluoride. Therefore, it is important to maintain the surface roughness of the metal substrate to 0.5 μm or less during plating.

In addition, when plating is performed on a metal substrate in which Ra _is adjusted to 0.5 μm or less, the quality of the surface roughness of the plating film is improved after nickel plating. When the plating film is fluorinated, it more stably forms a fluoride passivation film containing nickel fluoride, and as the formed fluoride passivation film also has compactness, corrosion resistance is improved and high purity hydrogen fluoride is contaminated by contamination. It can be stored without deterioration of purity.

The fluoride passivation film can be formed by fluorination treatment using a fluorinated gas, and the fluorinated gas used is fluorine (F ₂ ), hydrogen fluoride (HF), chlorine trifluoride (ClF ₃ ) and nitrogen fluoride (NF ₃ ), fluoride methane at least one gas selected from the group consisting of (CH ₃ F), or a gas obtained by diluting this gas with an inert gas.

Chlorine trifluoride is thermally decomposed at 60 ~ 100℃ to generate fluorine radicals, which can be used for fluorination reaction. In addition, nitrogen fluoride is decomposed by plasma energy to generate fluorine radicals, which can be used for fluorination reaction. As the diluting gas, an inert gas such as nitrogen or helium can be used, and nitrogen is preferable. When the fluorinated gas is diluted and used, the concentration can be appropriately set according to the reaction conditions. For example, in the case of fluorine, it is preferable to use it at a concentration of about 10% in consideration of cost.

The temperature during the fluorination treatment is 200 to 500 °C, preferably 200 to 390 °C, more preferably 250 to 380 °C. In addition, the time of fluorination treatment is 1 to 12 hours. After the fluorination treatment, heat treatment may be performed at a temperature of 100 to 300 °C, preferably 150 to 200 °C. This heat treatment is performed in an inert gas such as N ₂ , Ar, and He for 1 to 12 hours, thereby forming a solid and dense fluoride passivation film on the substrate.

In order to form _a non-fluoride passivation film by fluoridation treatment of the nickel plating film, the fluorination treatment may be performed immediately after formation of the plating film without any special pretreatment. may be implemented. By doing this, it is possible to improve the long-term durability of the fluoride passivation film by bringing the density and thickness of the fluoride passivation film generated by the fluoride treatment.

In the present invention, the surface roughness value _Ra of the metal substrate may be in the range of 0.5 μm or less, preferably 0.2 μm or less. The lower limit of R _a is not necessarily limited, but may be 0.1 μm. This is because, in the case of less than 0.1 μm, the effectiveness of the effect by improving corrosion resistance may be lowered compared to the effort required for the process to reduce surface roughness.

The surface roughness of the metal substrate may be achieved by physical polishing or chemical polishing. Physical polishing is commonly referred to as buffing, and refers to making a smooth surface by rubbing with an abrasive, and chemical polishing refers to a processing called electropolishing, generally in a phosphoric acid and sulfuric acid solution at 55 to 75°C. It is a method of polishing by passing a current of 12 to 15 V to the

In the present invention, both physical and chemical polishing methods can be used to control the surface roughness of the metal substrate, but in order to form Ra of the metal substrate to 0.5 μm or less, physical or chemical polishing _is performed, but the polishing time is 5 to 24 hours. . If the polishing time is less than 5 hours, the polishing is not sufficiently performed and the Ra of the metal substrate cannot be formed to 0.5 μm or less. Alternatively, damage such as cracks or pinholes may occur on the surface of the metal substrate due to excessive polishing, thereby reducing corrosion resistance.

In addition, when a metal substrate is polished by a physical polishing method, an abrasive having a particle size of 4 a.u or less is used. This is because, when the abrasive grain size exceeds 4 a.u, the smoothness of the metal substrate is reduced and the surface roughness is increased.

In the present invention, the nickel plating film is formed on a metal substrate having an average roughness of the center line of the surface, R _a of 0.5 μm or less as described above.

At this time, the nickel plating film is formed with a high Ni content of 85% or more, and 5 to 60 µm thick, preferably 30 to 40 µm, on the surface of the metal substrate. When the thickness of the nickel plating film is less than 5 μm, a sufficient nickel plating film cannot be formed on the surface of the metal substrate, so that corrosion resistance is reduced, and when it exceeds 60 μm, the nickel plating film is excessively thick. Although Ra _is adjusted to 0.5 μm or less to improve adhesion with the nickel coating film, the bonding stability between the nickel plating film and the substrate may be reduced.

In the present invention, the fluoride passivation film is formed to a thickness of 0.1 to 1 ㎛ by fluorination treatment on the nickel plating film, preferably the oxidized nickel plating film. The fluoride passivation film may be formed by fluorination treatment of a nickel plating film, but may be formed as a fluoride passivation film having enhanced acid resistance than when formed by fluorination treatment of an oxidized nickel plating film.

As described above, the container material of the present invention not only improves the corrosion resistance of the metal substrate itself by adjusting the surface roughness of the metal substrate, but also solves the problem that the particles generated in the plating process remain inside the container, By forming a nickel plating film with a thickness, it is possible to maintain the roughness quality of the surface after plating.

The present invention, (1) grinding the metal substrate forming the inner surface of the storage container so that the average roughness (R _a ) of the center line of the surface of the metal substrate is 0.5 ㎛ or less of the metal substrate; and (2) plating nickel on the polished metal substrate to form a nickel plating film;

The present invention also provides a method for manufacturing a container material for storing high-purity hydrogen fluoride, further comprising; (3) forming a fluoride passivation film by fluorination treatment of the nickel plating film after the step (2). The step of adjusting Ra to 0.5 μm or less by re-polishing the surface of the nickel plating film plated on the polished metal substrate of step (2) before the execution of step (3 ₎ may be further included.

First, in the present invention, the step of (1) grinding the metal substrate is a step of grinding the metal substrate so that the surface of the metal substrate has an average centerline roughness (R _a ) of 0.5 μm or less according to KS B 0161. Physical polishing ( Mechanical polishing) or chemical polishing (Electrical polishing) may be used, and the polishing time is 5 to 10 hours. If the polishing time _is less than 5 hours, the polishing _is not sufficiently performed and the Ra of the metal substrate cannot be formed to 0.5 μm or less. This is because damage such as cracks or pinholes may occur on the surface of the metal substrate due to reduced or excessive polishing, thereby reducing corrosion resistance.

In addition, when a metal substrate is polished by a physical polishing method, an abrasive having a particle size of 4 a.u or less is used. This is because, when the abrasive grain size exceeds 4 a.u, the smoothness of the metal substrate is reduced and the surface roughness is increased.

Preferably, the surface roughness value _Ra of the upper metal substrate may be in the range of 0.5 μm or less, preferably 0.2 μm or less. The lower limit of R _a is not necessarily limited, but may be 0.1 μm.

The metal substrate in step (1) is not particularly limited as long as it has stability and compactness usable as a container, but is preferably selected from among carbon steel, aluminum, aluminum alloy, nickel, nickel alloy, copper, copper alloy, chromium and stainless steel. It may be any one selected, and more preferably, by using carbon steel, in consideration of economic efficiency and strength along with corrosion resistance, carbon steel may be used as a metal substrate.

In the present invention, step (2) is a step of forming a nickel plating film by plating nickel on the polished metal substrate, wherein the Ni content _is 85% or more in the polished metal substrate to 0.5 μm or less. It is a step of plating the Ni content.

The formation of the nickel plating film may be performed by a general method such as electroplating or electroless plating, and thus the method is not limited, and thus a description thereof will be omitted.

In addition, before performing the step (2), if necessary, the polished metal substrate may be pre-treated to remove impurities present on the surface and not to form an unnecessary oxidizing atmosphere. The pretreatment method may be performed by generally known chemical cleaning, commercial degreasing, dry etching, and the like.

In the present invention, step (3) is a step of forming a fluoride passivation film, and the nickel plating film is fluorinated to form a fluoride passivation film.

As the nickel plated film formed in step (2) is dense and has excellent surface roughness quality, during the fluorination treatment in step (3), a fluoride passivation film containing nickel fluoride is more stably formed, and the formed fluoride passivation film also exhibits compactness. By having it, it is possible to improve scratch resistance as well as corrosion resistance.

However, in order to form a fluoride passivation film with more enhanced fluorination treatment efficiency and acid resistance, preferably, before the fluorination treatment, the nickel plating film is H ₂ O ₂ , O ₃ , O ₂ , Oxidizing substances of liquid or gas such as Air Oxidation treatment with fluoride and then fluoride treatment, in which case the fluoride treatment is a general method using chemicals containing fluoride groups, such as HF, F ₂ , NF ₃ , CIF ₃ , CH ₃ F can be carried out by The temperature of the oxidation treatment is carried out at a temperature of 200 to 500 ℃, for 2 to 24 hours. In addition, the fluorination treatment is 200 to 400 ℃, preferably 200 to 390 ℃, more preferably 250 to 380 ℃. In addition, the time of fluorination treatment is 1 to 12 hours. In this way, when high-temperature oxidation fluoride treatment is performed, a more dense fluoride passivation film may be formed on the nickel plating layer, and the fluoride passivation film includes nickel fluoride.

After the fluorination treatment, heat treatment may be performed at a temperature of 100 to 300 °C, preferably 150 to 250 °C. This heat treatment may be performed for 1 to 12 hours in an inert gas such as N ₂ , Ar, or He.

In addition, in the present invention, a fluorine passivation film is formed not only on the inner surface of the container, but also on the valve that inevitably comes into contact when the fluorine gas is discharged, so that contaminants are not generated from the valve when the hydrogen fluoride gas is discharged from the storage container. The formation of a fluoride passivation film on the valve is performed so that the chemical substance having a fluoride group is charged in the storage container and then aged for a certain period of time, so that the valve mounted on the storage container is also at the same aging temperature By slowly removing chemicals with fluoride groups through the valve in the state, not only the inner surface of the container but also the connected valves are fluoride passivated to improve corrosion resistance, so the purity of high-purity hydrogen fluoride stored inside the container can be maintained high. have.

Hereinafter, examples will be given for a more detailed description of the present invention. However, the following examples are only preferred examples of the present invention, and the present invention is not limited thereto.

<Example>

Example 1

The inner surface of the container made of carbon steel (Mn steel, standard 37Mn alloy) is polished so that the centerline average roughness (R _a ) of the surface of the carbon steel inside the container is 0.5 μm, and then the Ni content on the surface of the carbon steel is 85% A nickel plating film having a thickness of 30 to 40 μm was formed on the surface of the carbon steel substrate by electroless plating of the higher content of nickel.

Thereafter, in order to measure the corrosion resistance of the prepared storage container, it was filled with 99.99% pure hydrogen fluoride and left at room temperature for 60 days. Thereafter, some of the stored hydrogen fluoride was collected and the concentration of the hydrogen fluoride was measured using a gas analyzer, and the results are shown in Table 1 below.

Example 2

The results are shown in Table 1 in the same manner as in Example 1, except that in Example 1, the average roughness (R _a ) of the center line of the surface of the carbon steel inside the container was 0.2 μm.

Example 3

After nickel plating in Example 1, while supplying 20% O ₂ to the nickel plating film at 1 L/min, oxidizing the nickel plating film at 350° C. for 12 hours, and then a container filled with 20% F ₂ diluted with N ₂ fluoride treatment by aging at 200° C. for 12 hours. Accordingly, a fluoride passivation film was formed to a thickness of 300 nm on the nickel plating film.

Thereafter, in order to measure the corrosion resistance of the prepared storage container, it was filled with 99.99% pure hydrogen fluoride and left at room temperature for 60 days. Thereafter, some of the stored hydrogen fluoride was collected and the concentration of the hydrogen fluoride was measured using a gas analyzer, and the results are shown in Table 1 below.

Example 4

Table 1 shows the results of Example 3, except that oxidation fluorination treatment was performed at a high temperature at a fluorination temperature of 270°C.

Comparative Example 1

It was carried out in the same manner as in Example 1, except that the average roughness (Ra) of the center line of the surface of the carbon steel was 2 μm, and the results are shown in Table 1.

Comparative Example 2

It was carried out in the same manner as in Example 1, except that the average roughness (Ra) of the center line of the surface of the carbon steel was 1 μm, and the results are shown in Table 1.

Comparative Example 3

It was carried out in the same manner as in Example 1, except that stainless steel (SUS316L) was used instead of carbon steel in Example 1 and that nickel plating was not performed, and the results are shown in Table 1.

metal substrate metal substrate
Surface Ra (μm) Ni plating Fluorination temperature (℃) Hydrogen Fluoride Purity (%) Comparative Example 1 carbon steel 2 ○ - 98.89 Comparative Example 2 carbon steel One ○ - 99.25 Comparative Example 3 SUS316L 0.5 × - 99.93 Example 1 carbon steel 0.5 ○ - 99.97 Example 2 carbon steel 0.2 ○ - 99.98 Example 3 carbon steel 0.5 ○ 200 99.985 Example 4 carbon steel 0.5 ○ 270 99.99

According to Table 1, when _Ra of the carbon steel substrate was 0.5 μm or less, the purity of the stored hydrogen fluoride was high, and moreover, the purity of hydrogen fluoride was higher than that of SUS316L, which is known as a material with relatively strong corrosion resistance.

On the other hand, when the surface Ra of the metal substrate was 1 μm or more, the purity of storage hydrogen fluoride was lower than that of SUS316L of Comparative Example 3 despite nickel plating, and Comparative Example 1 having a larger Ra value appeared lower.

It is presumed that this is because the surface roughness of the metal substrate affects the quality of plating, and defects such as cracks or pinholes occur in the nickel plating film.

As described above, the present invention has been described with reference to the accompanying drawings and embodiments, but this is merely exemplary, and various modifications and equivalent other embodiments are possible by those skilled in the art. will understand Accordingly, the technical protection scope of the present invention should be defined by the following claims.

Claims (8)

As a container for storing high purity fluorinated gas,
The container includes a material in which a nickel plating film is plated on the surface of a metal substrate, and the nickel plating film is used as the inner surface of the container,
The metal substrate is a storage container for storing high-purity hydrogen fluoride, characterized in that the average roughness (R _a ) of the center line in the surface roughness is 0.5 μm or less.
The method of claim 1,
The metal substrate is a storage container for storing high-purity hydrogen fluoride, characterized in that the carbon steel.
The method of claim 1,
A storage container for storing high-purity hydrogen fluoride, characterized in that a fluoride passivation film is formed on the surface of the nickel plated film.
4. The method of claim 3,
A storage container for storing high-purity hydrogen fluoride, characterized in that the thickness of the fluoride passivation membrane is 0.1 ~ 1 ㎛.
A method for manufacturing a container for storing high-purity fluorinated gas, the method comprising:
(1) grinding the metal substrate forming the inner surface of the storage container so that the average roughness (R _a ) of the center line of the surface of the metal substrate is 0.5 μm or less;
(2) plating nickel on the polished metal substrate to form a nickel plating film;
6. The method of claim 5,
After step (2), (3) fluorination treatment of the nickel plating film, characterized in that it further comprises the step of forming a fluoride passivation film, a method of manufacturing a container for high-purity hydrogen fluoride storage.
6. The method of claim 5,
The method of manufacturing a container for storage of high purity hydrogen fluoride, characterized in that the metal substrate in step (1) is carbon steel.
6. The method of claim 5,
In the step of forming the fluoride passivation film of (3), before the fluorination treatment of the nickel plating film, the method of manufacturing a container for storage of high purity hydrogen fluoride, characterized in that it further comprises the step of oxidizing the nickel plating film.