KR20130003432U - Fluorine gas plant - Google Patents

Abstract

A fluorine generating unit 1 connected to a fluorine supply line 2 having several further processing steps such as feedstock, F ₂ -purification steps and off-gas reduction system; And a permanent fluorine storage unit 4 connected to the supply line, wherein the fluorine storage unit comprises a plurality of hollow bodies.

Description

Fluorine gas plant {FLUORINE GAS PLANT}

The invention relates to a fluorine gas plant and a fluorine gas supply method, claiming the priority of European Patent Application No. 1077206.9, filed September 16, 2010, which is hereby incorporated by reference in its entirety.

Fluorine gases such as molecular fluorine (F ₂ ), and mixtures of molecular fluorine and especially inert gases (eg N ₂ or Ar) are useful as cleaning gases for process chambers, for example, in semiconductor manufacturing.

Patent document WO 2006 / 067364-A1 (corresponding to US 2006/0130929) provides high purity fluorine to a fixed storage unit using an on-site fluorine generator, and supplies high purity fluorine from the storage unit to a processing system, thereby treating high purity fluorine. A method of delivering to a system is disclosed. To provide a backup for the fluorine generator, high purity fluorine is also provided in a transportable gas storage container, for example, a relatively low pressure multi-cylinder pack, typically less than 35 psig. Since the amount of fluorine in the storage unit is required to be maintained at a desired level, the transportable storage container is optionally connected to a fixed storage unit.

We have now found a fluorine gas plant that can provide a stable and economical supply of fluorine requirements to the site while minimizing the safety risks associated with the presence of F ₂ .

Accordingly, the present invention relates to a fluorine gas plant comprising a fluorine generating unit 1 connected to a fluorine supply system 2 having a fluorine application 3 and a permanent fluorine storage unit 4 connectable to the fluorine supply system. The fluorine storage unit comprises a plurality of hollow bodies 5.

1 is a schematic illustration of a fluorine gas plant according to the invention connected to a fluorine supply system and for example a fluorine gas storage unit with six hollow bodies.

It is to be understood that "fluorine gas" specifically refers to molecular fluorine (F ₂ ) and mixtures thereof, especially mixtures with inert gases. The inert gas can for example be selected from argon and nitrogen. Preferred fluorine gas consists of or consists essentially of F ₂ .

It is to be understood that "permanent fluorine storage unit" specifically refers to a fluorine storage unit integrated in a fluorine plant. For example, the fluorine storage unit may be a transportable unit that is permanently present near the fluorine supply system throughout the operation of the fluorine plant. Preferably, the fluorine storage unit may be a transportable unit that is permanently present near the fluorine supply system throughout the operation of the fluorine plant. Thus, while the fluorine plant is running, the permanent fluorine storage unit will be permanently near the fluorine supply system; Since the permanent fluorine storage unit is connectable to the supply system, the permanent fluorine storage unit can be separated from the fluorine plant during times when the fluorine plant is not in operation. Therefore, the permanent fluorine storage unit can be disconnected during the downtime of the fluorine plant. If necessary, for example, in the event of a problem with each hollow body, it is possible to close each valve or individual valves of the permanent fluorine supply system and to disconnect one or more of the hollow bodies without shutting down the fluorine plant. Thus, the permanent fluorine storage unit allows the plant to continue running even if one or more of the hollow bodies fails.

Preferably, the permanent fluorine storage unit is adapted to store more than 90%, more preferably more than 95%, most preferably about 100% by weight of fluorine gas based on the total weight of fluorine gas stored in the plant. Is designed. Thus, no additional storage tank is needed.

A "fluorine supply system" is specifically understood to represent a member that can store fluorine and can deliver fluorine from the fluorine generating unit to the point of use. Possible components of the fluorine supply system include, but are not limited to, a supply line, a compressor, a mixer and a buffer tank.

“Connectable” is specifically understood to indicate that the permanent fluorine storage unit is provided to be connected to one component of the fluorine supply system. Preferably, the permanent fluorine storage unit is provided to be connected to the fluorine supply line. According to one preferred aspect, the fluorine storage unit is connected to one component of the fluorine supply system, specifically one fluorine supply line, throughout the operation of the fluorine plant. According to another preferred aspect, the fluorine storage unit is directly connected to one component of the fluorine supply system.

Equipment suitable for connecting the fluorine storage unit to one component of the fluorine supply system comprises a manifold 6 connected via a line to each hollow body 5 of the fluorine storage unit, preferably shut within each line. The provision of an off valve 7 makes it possible to isolate each hollow body individually. The manifold is also connected to one component of the fluorine supply system.

In the plant according to the invention, plant components intended to be in contact with gas, such as the hollow bodies, valves and lines for filling and / or discharging gas, if applicable, are made of a material which is resistant to molecular fluorine or It is appropriate to be coated. Examples of such materials are monel metal, stainless steel, copper, and preferably nickel.

In the plant according to the invention, the fluorine storage unit preferably comprises 4 to 25 hollow bodies, more preferably 5 to 8 hollow bodies. Preferably these hollow bodies have substantially the same shape and dimensions. The individual hollow bodies preferably have a deviation of up to ± 5% of the average volume of each of the hollow bodies; Preferably, the interior volume of each hollow body is about the same. Cylindrical hollow bodies are preferred.

Appropriate frames can be used to fix the hollow bodies of the fluorine storage unit as appropriate. Specific geometric shapes for such frames include triangular, square, and rectangular geometric shapes.

Preferably, each of the hollow bodies has a single coupled inlet / outlet, through which F ₂ is fed into the hollow body and F ₂ is discharged from the hollow body.

In the fluorine gas plant according to the invention, the fluorine storage unit may or may store fluorine gas generally at a pressure of at least 25 psig. Often this pressure is at least 35 psig, preferably at least 40 psig. In the plant according to the invention, the fluorine storage unit can or can store fluorine gas generally at a pressure of 400 psig or less, usually 75 psig or less. Often this pressure is below 65 psig, preferably below 60 psig. Preferably the fluorine storage unit can store or store fluorine gas at a pressure of 25 to 75 psig, more preferably the fluorine storage unit can store fluorine gas at a pressure of 35 to 65 psig, particularly preferably 40 to 60 psig. Or keep it.

Preferably, the internal volume of at least one of the hollow bodies is at least 50 liters. The volume of one or more of the hollow bodies may be less than 50 liters, but this storage volume is too small for practical use. More preferably, the internal volume of at least one of the hollow bodies is at least 100 liters. Even more preferably, the internal volume of each hollow body is at least 100 liters. Especially preferably, the internal volume of each of the hollow bodies is at least 500 liters. Most preferably, the interior volume of each hollow body is at least 1000 liters (1000 liters = 1 m ³ ).

Preferably, the internal volume of each of the hollow bodies is no greater than 5000 liters, more preferably no greater than 3000 liters.

Thus, the preferred internal volume range of each hollow body is 100 to 5000 liters, more preferably 100 to 3000 liters, most preferably 500 to 3000 liters, particularly preferably 1000 to 3000 liters.

The fluorine storage unit is generally capable of or stores fluorine gas at a pressure of at least 25 psig, and preferably has an internal volume of at least 100 liters of each hollow body. It is even more preferred that the fluorine storage unit is capable of or stores fluorine gas generally at a pressure of at least 35 psig, with an internal volume of at least 500 liters of each hollow body.

It is preferred that the fluorine storage unit can store or store fluorine gas at a pressure of generally 400 psig or less, usually 75 psig or less, with the internal volume of each of the hollow bodies being 3000 liters or less.

It is most preferred that the fluorine storage unit can or store fluorine gas at a pressure of 35 to 65 psig, with an internal volume of 500 to 3000 liters of each of the hollow bodies.

It is to be understood that the hollow body of the fluorine storage unit can or will generally store fluorine gas at the pressures mentioned above. It is particularly preferable for the hollow body to store fluorine at the pressure mentioned above.

In the fluorine gas plant according to the invention, the ratio of molecular fluorine (F ₂ ) stored in the fluorine storage means to the molecular fluorine (F ₂ ) daily production capacity of the fluorine gas plant is generally 0.1 to 1, preferably 0.1 To 0.25.

In the fluorine gas plant according to the invention, the fluorine production unit generally comprises an electrolysis device for producing molecular fluorine by electrolysis of molten electrolytes, preferably KF and HF-containing molten electrolytes.

In the fluorine gas plant according to the invention, the fluorine storage unit is preferably mounted on a skid.

In the fluorine gas plant according to the invention, the place of use can be connected to another manufacturing plant, for example a chemical plant or, in particular, a plant using fluorine for surface treatment. The use is often connected to a micro-electromechanical system manufacturing plant, preferably a semiconductor manufacturing plant, particularly preferably a photovoltaic device or flat panel display manufacturing plant.

In a preferred embodiment of the fluorine gas plant according to the invention, the fluorine storage unit is contained in the enclosed space 8. Particularly preferably, the fluorine storage unit is contained in the enclosed space 8, and the fluorine storage unit is mounted on the skid. The enclosed space is generally equipped with a fluorine detector which can trigger the connection of the enclosed space to the fluorine decomposition system 9. Suitably, the confined space is connected to the fluorine decomposition system via a suction line 10, where the suction line is connected to a fan 11 operable to move gas from the confined space to the fluorine decomposition system.

The fluorine decomposition system is preferably a scrubber. Suitably the scrubber contains an alkaline aqueous solution, for example a KOH solution, and optionally a reducing agent such as for example sodium thiosulfate or potassium thiosulfate.

In general, fluorine decomposition systems can decompose fluorine stored in one or two hollow bodies. Preferably, the fluorine decomposition system can decompose fluorine stored in about one hollow body.

In another embodiment, the fluorine gas plant according to the invention further comprises a mixer 12, preferably a stationary mixer, which mixer is preferably capable of receiving fluorine from the fluorine generating unit 1 and inert gas. It is possible to receive an inert gas, preferably argon and / or nitrogen, from the feed line 13.

The invention also relates to a fluorine gas supply method comprising using the fluorine gas plant according to the invention to supply fluorine gas to a place of use.

1 shows an example of a preferred fluorine plant of the present invention.

The fluorine generation unit 1 is connected to a fluorine supply system 2 comprising a fluorine supply line connected to a place of use 3, where the place of use is connected to a semiconductor manufacturing plant. According to one optional embodiment, the pressure control loop 14 adjusts and generally reduces the pressure of fluorine supplied to the point of use to a desired value. According to an optional embodiment, the fluorine supply line is connected to the mixer 12 which is also connected to the inert gas supply line 13, and another fluorine supply line connects the mixer 12 to the point of use 3. The fluorine supply system 2 is also connected to the fluorine storage unit 4 via a manifold 6 which is connected via a line to each hollow body 5 of the fluorine storage unit, preferably each F ₂ −. The storage container is provided with a shut-off valve 7. The fluorine supply unit is housed in an enclosed space 8, which typically contains a fluorine detector which can cause a connection of the enclosed space to the fluorine decomposition system 9. The enclosed space is connected to the fluorine decomposition system via a suction line 10, where the suction line is connected to a fan 11 operable to move gas from the enclosed space to the fluorine decomposition system 9.

Wherever the disclosure of all patents, patent applications, and publications incorporated herein by reference is inconsistent with the present disclosure, the present disclosure shall prevail.

Example

In a fluorine plant according to the basic design of FIG. 1 (without mixer and inert gas supply), the fluorine generating unit 1 produces F ₂ of about 415 kg / day via HF electrolysis in molten KFx2HF electrolyte. F ₂ is delivered to the point of use 3 through the fluorine supply system 2 and supplied to a flat panel display manufacturing plant using F ₂ for chamber cleaning. F ₂ is supplied to the customer as required.

By regulating the F ₂ production of the F ₂ generation unit, the fluorine pressure in the fluorine supply system 2 and the F ₂ storage unit 4 is maintained at 3.5 barg. The F ₂ storage unit 4 comprises six identical cylindrical containers each having an internal volume of 1.3 m ³ . The pressure control loop 14 is used to lower the fluorine pressure at the point of use 3 to 1.5 barg.

In normal operation, the shut-off valve 7 is open, and the pressure difference between the F ₂ storage unit 4 and the place of use 3 is dependent on various consumption patterns at the place of use or the manufacturing process of the fluorine generating unit. Even in the event of an interruption, a buffer is provided that allows smooth control of the delivered fluorine flow.

If a leak occurs in one of the hollow bodies, the fluorine is detected by a fluorine detector in the confined space, and the fan 11 is operated to draw fluorine-containing gas from the confined space via the suction line 10, KOH. It transfers to the fluorine decomposition system 9 which is a scrubber containing aqueous solution. The scrubber can handle 15 kg of F ₂ .

The fluorine plant according to the invention and the process according to the invention enable a stable and economical fluorine gas supply, especially for semiconductor applications such as chamber cleaning and etching. In particular, the fluorine storage system and the selective fluorine decomposition system are very efficient, thus achieving supply stability and high plant safety.

Claims (16)

A fluorine generating unit 1 connected to the fluorine supply system 2 having a fluorine use point 3, and a permanent fluorine storage unit 4 connectable to the fluorine supply system,
The fluorine storage unit comprises a plurality of hollow bodies (5), wherein the internal volume of at least one of the hollow bodies is at least 50 liters, preferably at least 100 liters. The fluorine gas plant according to claim 1, wherein the fluorine storage unit comprises 4 to 25 hollow bodies, preferably 5 to 8 hollow bodies. The fluorine gas plant of claim 1, wherein the fluorine storage unit is capable of or stores fluorine gas at a pressure of 25 to 75 psig. 4. The fluorine gas plant of claim 3 wherein the fluorine storage unit is capable of or stores fluorine gas at a pressure of 35 to 65 psig, preferably 40 to 60 psig. The fluorine gas plant according to claim 1, wherein the fluorine storage unit is connected directly to the fluorine supply line. 6. The fluorine gas plant according to any one of claims 1 to 5, which is capable of delivering to the place of use a fluorine gas consisting essentially of molecular fluorine. 6. The fluorine gas plant according to any one of claims 1 to 5, wherein the fluorine gas plant is capable of delivering fluorine gas consisting essentially of a mixture of molecular fluorine and an inert gas, preferably a mixture of inert gases selected from nitrogen and argon. 8. The mixer according to claim 7, further comprising a mixer (12), preferably a stationary mixer, wherein the mixer is preferably capable of receiving fluorine from the fluorine generating unit (1) and from the inert gas supply line (13). The fluorine gas plant will be delivered. 9. The fluorine generating unit according to claim 1, wherein the fluorine generating unit comprises an electrolysis device for producing molecular fluorine by electrolysis of a molten electrolyte, preferably KF and HF-containing molten electrolyte. Fluorine gas plant. 10. The fluorine gas plant according to claim 1, wherein the fluorine storage unit is contained in an enclosed space (8) and the fluorine storage unit is preferably mounted on a skid. 11. The fluorine gas plant according to claim 10, wherein the enclosed space (8) is equipped with a fluorine detector which can cause the connection of the enclosed space to the fluorine decomposition system (9), preferably the scrubber. The fluorine gas plant of claim 11 wherein the fluorine decomposition system is capable of decomposing fluorine stored in one or two hollow bodies. 13. The fluorine of claim 12 wherein the ratio of molecular fluorine (F ₂ ) stored in the fluorine storage unit to the molecular fluorine (F ₂ ) daily production capacity of the fluorine gas plant is between 0.1 and 1, preferably between 0.1 and 0.25. gasworks. The fluorine gas plant according to claim 1, wherein the use is connected to a semiconductor fabrication plant, preferably a photovoltaic device or a flat panel display fabrication plant. The fluorine gas plant according to claim 1, wherein the fluorine storage unit is capable of storing or storing fluorine gas at a pressure of 35 to 65 psig, wherein the internal volume of each hollow body is 500 to 3000 liters. A fluorine gas supply method comprising using the fluorine gas factory according to any one of claims 1 to 15 to supply fluorine gas to a place of use.

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