KR102223547B1 - Method for making noodles using dodam rice and konjac and noodles manufactured using the same - Google Patents

Abstract

The present invention relates to a method for surface treatment inside a high-purity hydrogen fluoride storage container, which comprises: a cylinder pretreatment step of removing moisture inside a cylinder; and a fluoride passivation film forming step of using anhydrous hydrofluoric acid to form a fluoride passivation film on an inner surface of the cylinder. It is possible to provide a method for surface treatment and a high-purity hydrogen fluoride storage container surface-treated according to the same method, capable of minimizing the generation of impurity gases such as hydrogen and oxygen even during long-term storage of high-purity hydrogen fluoride.

Description

Surface treatment method of high purity hydrogen fluoride storage container for semiconductor etching {Method for making noodles using dodam rice and konjac and noodles manufactured using the same}

The present invention relates to a high-purity hydrogen fluoride storage container for semiconductor etching, and more specifically, to a method for surface treatment of a storage container capable of reducing the amount of impurity gases such as hydrogen and oxygen even during long-term storage of high-purity hydrogen fluoride. .

Herein, background art related to the present disclosure is provided, and these do not necessarily mean known art.

Hydrogen fluoride is a strong oxidizing gas, and it is highly toxic and corrosive, so when stored in a container made of a general metal material, impurity gases such as hydrogen and oxygen may be generated, resulting in deterioration of quality.

To solve this problem, look at the example of Japanese Patent JP1996300342b2. After electrolytic polishing is performed on the surface of stainless steel to form a film of chromium-based oxide, it is heated at 400℃~500℃ for 1~3 hours to increase the concentration of the oxide film to prevent hydrogen fluoride. It has been reported to improve the corrosion resistance. However, since the high-purity hydrogen fluoride storage container for semiconductor etching is generally a cylinder type, it is difficult to put an electrode for electrolytic polishing inside the cylinder, making it difficult to uniformly coat the inside of the cylinder. In addition, in order to stabilize the passivation film produced by electrolytic polishing, high temperature treatment is performed at 400℃~500℃, which also increases the manufacturing cost of the storage container due to the occurrence of an additional process.

In the example of Korean patent KR100096658B1, a fluorinated passivation film is formed on the metal surface by performing _{F 2} treatment at a temperature of 150°C to 300°C for 2 hours using _{100% F 2 Gas.} In most cases, when 100% F ₂ gas is treated, environmental problems may occur due to the generation of _{substances (such as SF 6} ) with a high global warming potential (GWP). Also, the material inside the cylinder valve cannot be used at high temperatures. For this reason, when forming a fluoride passivation film, using 100% F ₂ Gas is difficult to commercially apply in view of environmental issues and the possibility of mass production.

1. Japanese registered patent JP 3194876 (2001.06.01) 2. Korean Patent Registration KR 0096658 (1996.03.06.)

The present invention provides a method for surface treatment inside a high-purity hydrogen fluoride storage container capable of minimizing the amount of _{H 2} generated when storing high-purity hydrogen fluoride by simply forming a fluoride passivation film inside a gas cylinder distributed on the market for easy commercial application. I want to provide.

However, the objects of the present invention are not limited to the above-mentioned objects, and other objects not mentioned will be clearly understood by those skilled in the art from the following description.

The present invention removes moisture from the inside of the cylinder, including a heating process for heating the entire cylinder to increase the cylinder temperature, a vacuum process for maintaining the inside of the cylinder in a vacuum state, and a pressurized exhaust process for repeatedly performing pressurization and exhaust using an inert gas. A cylinder pre-treatment step; And a fluorinated passivation film forming step of forming a fluoride passivation film on the inner surface of the cylinder using hydrofluoric acid anhydride.

In addition, the heating step is characterized in that the step of heating the cylinder to 100 to 150 ℃ to increase the temperature of the entire cylinder.

In addition, the vacuum process is characterized in that the degree of vacuum is 10 ^-3 torr to 10 ^-6 torr, and the vacuum time is 3 to 24 hours.

In addition, the pressurized exhaust process is characterized in that the process of pressurizing the pressure inside the cylinder with an inert gas to 40 psi to 60 psi, evacuating the inert gas, and then performing vacuum is repeated at least two or more times.

In addition, the step of forming the fluorinated passivation film is characterized in that the step of filling the cylinder in which the pretreatment has been completed is filled with hydrofluoric acid and storing the cylinder filled with the hydrofluoric acid in a space maintained at 70 to 90°C.

In addition, after the cylinder pre-treatment step, and before the fluorinated passivation film forming step, further comprising a step of measuring the moisture content in the cylinder for measuring the moisture content in the pre-treated cylinder, wherein when measuring the moisture in the cylinder, the moisture inside the cylinder is 1 ppm or less When measured as, characterized in that the fluorinated passivation layer forming step is performed.

In addition, the step of measuring the moisture in the cylinder is characterized in that the step of measuring whether or not the moisture in the cylinder is 1 ppm or less using an analysis device after pressurizing 40 psi to 60 psi using an inert gas inside the cylinder after the pretreatment.

In addition, the present invention is a storage container in which a fluorinated passivation film is formed using anhydrous hydrofluoric acid at 70 to 90°C on the inner surface of the pretreated container, and when high purity hydrogen fluoride is stored in the storage container for 30 days, _{the amount of H 2} generated is 100 ppm. It provides a high-purity hydrogen fluoride storage container, characterized in that the following.

The present invention forms a fluorinated passivation film by injecting hydrofluoric anhydride, which does not cause additional environmental pollution, into a gas cylinder circulated on the market for easy commercial application, so that the fluorinated passivation film formation temperature is relatively low (70 to 90°C). ), and in particular, when forming a fluorinated passivation film, a uniform fluoride passivation film can be formed without additional procedures by storing it in a room that maintains the relatively low temperature.

In addition, when storing high-purity hydrogen fluoride in a storage container with a surface treatment inside through the above invention, _{the amount of H 2} generated when stored for 30 days can be controlled to 100 ppm or less.

All technical and scientific terms used in this specification have the same meaning as commonly understood by those of ordinary skill in the art unless otherwise stated. Also throughout this specification and claims, unless otherwise stated, the term "comprise, comprising, comprising" means to include the recited object, step or group of objects, and steps, and any other It is not used in the sense of excluding an object, a step, or a group of objects or a group of steps.

Before describing the present invention in detail below, it is understood that the terms used in the present specification are for describing specific embodiments and are not intended to limit the scope of the present invention, which is limited only by the scope of the appended claims. shall.

On the other hand, various embodiments of the present invention may be combined with any other embodiments unless clearly indicated to the contrary. Any feature indicated to be particularly desirable or advantageous may be combined with any other feature and features indicated to be desirable or advantageous. Hereinafter, embodiments of the present invention and effects thereof will be described with reference to the accompanying drawings.

The present invention is a method for surface treatment inside a high-purity hydrogen fluoride storage container, and more specifically, a method for forming a corrosion-resistant fluoride passivation film by injecting anhydrous hydrofluoric acid into the high-purity hydrogen fluoride storage container for semiconductor etching. It is characterized by forming a fluorinated passivation film at a relatively low temperature for easy production.

The method for surface treatment inside a high-purity hydrogen fluoride storage container according to the present invention includes a cylinder pretreatment step and a fluoride passivation film formation step.

The cylinder pretreatment step is a step of removing moisture inside the cylinder, and a heating process of increasing the cylinder temperature by heating the entire cylinder, a vacuum process of maintaining the inside of the cylinder in a vacuum state, and pressurization and venting using an inert gas are repeated. It includes a pressurized exhaust process to be performed.

The cylinder is a cylinder made of steel, and it is preferable to use a cylinder made of metal steel or stainless steel, and more preferably, a cylinder made of stainless steel such as SUS304 or SUS316L is preferable.

The heating process is a process of heating the entire cylinder to increase the cylinder temperature, and is a process of heating the cylinder to 100 to 150°C to increase the temperature of the entire cylinder to the temperature, and preferably heating to 110 to 130°C to increase the temperature of the cylinder. It is good to raise it to the temperature.

The vacuum process is a process of maintaining the inside of the cylinder heated to the temperature in a vacuum state using a valve installed in the cylinder, the degree of vacuum is 10 ^-3 torr to 10 ^-6 torr, preferably 10 ^-4 torr to 10 ^-6 torr, most preferably 10 ^-5 torr to 10 ^-6 torr, and vacuum time is 3 hr to 24 hr, preferably 6 hr to 24 hr, and most preferably 12 hr to 24 hr.

The pressurized exhaust process is a process of repeatedly pressurizing and venting the inside of the cylinder using an inert gas, and pressurizing the pressure inside the cylinder to 40 psi to 60 psi with inert gases such _{as N 2, Ar, and} After evacuating, the process of performing vacuum (10 ^-5 torr to 10 ^-6 torr, holding for 100 to 150 minutes) is repeated at least two times or more. Preferably, it is good to repeat 3 to 4 times.

The fluorinated passivation film forming step is a step of forming a fluorinated passivation film inside a cylinder using anhydrous hydrogen fluoride, wherein hydrofluoric anhydride is filled in the pretreated cylinder, and the cylinder filled with hydrofluoric anhydride is 70 to 90. By storing in a room maintained at °C, a fluorinated passivation film is formed inside the cylinder.

The storage period is preferably 10 to 30 days, preferably 20 to 30 days, and most preferably 25 to 30 days. The longer the storage period, the thicker the fluorinated passive film is formed, but even if the fluorinated passive film is formed by storing it for more than 30 days, the effect of reducing the amount of impurity gas generated when storing hydrogen fluoride is insignificant compared to the storage period (formation period). It is of little significance.

On the other hand, the surface treatment method of the inside of the high purity hydrogen fluoride storage container according to the present invention further comprises the step of measuring the moisture content in the cylinder after the cylinder pretreatment step and before the fluorinated passivation film forming step. Can include.

The measuring of moisture in the cylinder is a step of measuring the moisture content in the cylinder after the pretreatment has been completed, and the moisture in the cylinder is 1 ppm or less using an analysis device after pressing 40 psi to 60 psi using an inert gas inside the pre-treated cylinder. This is a step of evacuating the inert gas present in the cylinder after measuring whether or not and performing a vacuum (10 ^-5 torr to 10 ^-6 torr, 100 to 150 minutes). If the moisture in the cylinder is less than 1 ppm, proceed to the next step. If the moisture in the cylinder is less than 1 ppm, pressurize 40 psi to 60 psi using an inert gas and then repeat the vacuum once to remove moisture. Proceed with the steps.

The present invention forms a fluorinated passivation film by injecting hydrofluoric anhydride, which does not cause additional environmental pollution, into a gas cylinder circulated on the market for easy commercial application, so that the fluorinated passivation film formation temperature is relatively low (70 to 90°C). ), and in particular, when forming a fluorinated passivation film, it is stored in a space maintaining the relatively low temperature to form a fluorinated passivation film without additional procedures.

According to the present invention, when high-purity hydrogen fluoride is stored for a long period in a cylinder-shaped storage container with a fluorinated passivation film formed therein, _{the amount of H 2} generated can be controlled up to 100 ppm or less.

Example

(1) cylinder pretreatment

First, cylinders made of Mn Steel, SUS-304 and SUS-316L were prepared, and valves were mounted on the top of the prepared cylinders, and then the entire cylinder was heated to 120°C. When the cylinder temperature rose to 120° C., vacuum inside the cylinder was applied. At this time, the degree of vacuum was 10 ^-6 torr, and the vacuum time was 20 hr.

Next, N ₂ was added to pressurize the inside of the cylinder to 50 psi, and _{after N 2} exhaust (Vent), vacuum was performed for 2 hours at a vacuum degree of ^{10 -6 torr.} Thereafter, pressurization, evacuation, and vacuum were repeatedly performed two more times under the same conditions as above to pretreat the cylinder.

(2) Measurement of moisture in the cylinder

After the pretreatment was completed, N ₂ was injected into the cylinder, pressurized to 50 psi, and moisture analysis was performed using FT-IR, and whether or not the moisture in the cylinder was 1 ppm or less was measured. All of the moisture in the cylinder manufactured as a specimen was measured to be 1 ppm or less, and after N ₂ purge, vacuum was performed for 2 hours at a vacuum degree of ^{10 -6 torr, and then the next step was carried out.}

(3) Fluoride passivation film formation

Hydrofluoric anhydride was filled into the cylinder in which the pretreatment and moisture measurement were completed. The cylinder filled with hydrofluoric acid was moved to the inside of the room maintained at 80℃ and stored so that a fluorinated passivation film was formed on the inner surface of the cylinder. The storage time was changed to 10, 20, and 30 days, respectively, so that a fluorinated passive film was formed on the inner surface of the cylinder.

Comparative example

In order to indirectly confirm the formation of the fluoride passivation film for each cylinder material, PFA (Daikin), which is inactive to hydrogen fluoride, was molded inside the Mn steel cylinder. More specifically, after preparing a cylinder molded with PFA, the cylinder pretreatment step and the fluorinated passivation film formation step were performed in the same manner. In the case of the comparative example, the storage time was 30 days to form a fluorinated passive film.

Experimental example

In the present invention, instead of cutting the cylinder to check the inside of the fluorinated passivation film to check whether or not the fluorinated passivation film is formed, high-purity hydrogen fluoride is added to the inside of the cylinder on which the fluoride passivation film is formed, and then H using GC-DID. _{2 The} generation amount was measured to indirectly measure the formation of a fluoride passivation film.

More specifically, according to the Examples and Comparative Examples, after vacuuming the inside of the cylinder on which the fluorinated passivation film was formed, high purity hydrogen fluoride gas was injected into each cylinder, and after storing each cylinder at the same room temperature for 30 days, the _{amount of H 2} increase was measured. It is shown in 1.

Fluoride passivation film formation time
(day) _{H 2} generation by cylinder material when stored for 30 days (ppm) Mn Steel Sus-304 Sus-316L PFA molding
-Mn Steel 10 1,500 950 720 - 20 1,120 410 230 - 30 880 280 80 42

As shown in Table 1, it can be seen that the amount of _{H 2} generated decreases as the fluorinated passivation passivation film formation time increases. In addition, it was confirmed that _{among the three cylinder materials, the amount of H 2} generated decreased in the order of Mn Steel>Sus-304> Sus-316L. In the case of the Mn steel cylinder, the _{reason for the high H 2} generation is that the fluorinated passivation film is not uniformly formed due to the poor roughness inside the cylinder due to the characteristics of the material.

The longer the fluorinated passivation film formation time was, the better, but _{it was confirmed that the H 2} generation amount dropped to 100 ppm or less when conducted for 30 days.

In forming a fluoride passivation film using hydrofluoric anhydride inside a commercially distributed gas cylinder, if the pretreatment according to the present invention is carried out, simply by storing it in a space maintained at a relatively low temperature, the fluoride passivation film is formed to the desired level. It was confirmed by the measurement result of _{H 2 generation.} It was confirmed that when Sus-316L was used as the most preferable cylinder material for the formation of a fluoride passivation film, even when high-purity hydrogen fluoride was stored for 30 days, H ₂ generation could be suppressed to 100 ppm or less.

Features, structures, effects, and the like illustrated in each of the above-described embodiments may be combined or modified for other embodiments by a person having ordinary knowledge in the field to which the embodiments belong. Therefore, contents related to such combinations and modifications should be construed as being included in the scope of the present invention.

Claims (8)

Cylinder pretreatment to remove moisture inside the cylinder, including a heating process that heats the entire cylinder to increase the cylinder temperature, a vacuum process that keeps the inside of the cylinder in a vacuum state, and a pressurized exhaust process that repeatedly pressurizes and exhausts the cylinder using an inert gas. step; And
Surface treatment method inside a high-purity hydrogen fluoride storage container comprising; forming a fluoride passivation film on the inner surface of the cylinder by using hydrofluoric acid anhydride.
The method of claim 1,
The heating process is a process of heating the cylinder to 100 to 150°C to increase the temperature of the entire cylinder.
The method of claim 1,
In the vacuum process, the degree of vacuum is 10 ^-3 torr to 10 ^-6 torr, and the vacuum time is 3 to 24 hours.
The method of claim 1,
The pressurized exhaust process is a process in which the pressure inside the cylinder is pressurized with an inert gas to 40 psi to 60 psi, and after evacuating the inert gas, a process of performing vacuum is repeated at least two or more times. Surface treatment method.
The method of claim 1,
The step of forming the fluoride passivation film is a process of filling the cylinder with the pretreatment completed with hydrofluoric acid and storing the cylinder filled with the hydrofluoric acid in a space maintained at 70 to 90°C. Surface treatment method inside the container.
The method of claim 1,
After the cylinder pretreatment step, and before the fluorinated passivation film forming step, further comprising the step of measuring the moisture in the cylinder by measuring the moisture content in the pretreated cylinder,
When measuring the moisture in the cylinder, when the moisture in the cylinder is measured to be 1 ppm or less, the step of forming the fluorinated passivation film is performed.
The method of claim 6,
In the step of measuring moisture in the cylinder, after pressurizing 40 psi to 60 psi using an inert gas inside the cylinder after the pretreatment is completed, the inert gas present in the cylinder is discharged after measuring whether the moisture in the cylinder is 1 ppm or less using an analysis device. And performing a vacuum surface treatment method inside a high-purity hydrogen fluoride storage container.
It is a storage container in which a fluoride passivation film is formed using hydrofluoric anhydride under conditions of 70 to 90°C on the inner surface of the container whose interior is pretreated
When storing high-purity hydrogen fluoride in the storage container for 30 days, _{the generation of H 2} is 100 ppm or less.