JP2002068716A - Method of refining high purity nf3 gas - Google Patents
Method of refining high purity nf3 gasInfo
- Publication number
- JP2002068716A JP2002068716A JP2000257968A JP2000257968A JP2002068716A JP 2002068716 A JP2002068716 A JP 2002068716A JP 2000257968 A JP2000257968 A JP 2000257968A JP 2000257968 A JP2000257968 A JP 2000257968A JP 2002068716 A JP2002068716 A JP 2002068716A
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- JP
- Japan
- Prior art keywords
- gas
- crude
- water
- refrigerant
- aqueous solution
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Links
Classifications
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/10—Greenhouse gas [GHG] capture, material saving, heat recovery or other energy efficient measures, e.g. motor control, characterised by manufacturing processes, e.g. for rolling metal or metal working
Landscapes
- Gas Separation By Absorption (AREA)
- Vaporization, Distillation, Condensation, Sublimation, And Cold Traps (AREA)
Abstract
Description
【0001】[0001]
【発明の属する技術分野】本発明はNF3ガスの精製方
法、特にNF3ガス中の水分除去方法に関する。The present invention relates to a method for purifying NF 3 gas, and more particularly to a method for removing water from NF 3 gas.
【0002】[0002]
【従来の技術】NF3ガスは、電子材料向け、特にCV
D装置のクリーニングガスとして、また半導体のドライ
エッチング剤やTFT液晶分野における枚葉式装置のク
リーニング用として近年注目され、その生産量は著しく
伸びている。そして、これらの用途に使用されるNF3
ガスは、益々高純度のものが要求されて来ている。2. Description of the Related Art NF 3 gas is used for electronic materials, especially for CV.
In recent years, it has attracted attention as a cleaning gas for D devices and as a cleaning agent for semiconductor dry etching and for cleaning single-wafer devices in the field of TFT liquid crystals. And NF 3 used for these applications
Gases are increasingly required to be of high purity.
【0003】NF3ガスの製造法は、NH4F・χHF
(χ=1〜2)を電解液として、これを電気分解する直
接電解法と、HFを電解液とする電気分解で得られるF
2ガスにNH3を接触させる間接電解法がある。これらの
いずれの方法でも、得られたNF3中には、HF、O
F2、N2F2、N 2F4、CO2、N2Oなどの不純物が含
まれている。これらの不純物のうち、HF、OF2、C
O2をアルカリ水溶液を用いて除去する方法や、N2Oを
チオ硫酸ナトリウム水溶液などを用いて除去する方法
(「フッ素化学と工業、進歩と応用」渡辺信淳編:化学
工業社刊(1973)208頁)等が知られている。[0003] NFThreeThe gas production method is NHFourF ・ χHF
(Χ = 1 to 2) is used as an electrolytic solution.
F obtained by electrolysis and electrolysis using HF as an electrolyte
TwoNH in gasThreeThere is an indirect electrolysis method of contacting with. these
In either method, the obtained NFThreeSome are HF, O
FTwo, NTwoFTwo, N TwoFFour, COTwo, NTwoContains impurities such as O
It is rare. Of these impurities, HF, OFTwo, C
OTwoRemoval using an aqueous alkaline solution,TwoO
Removal method using aqueous sodium thiosulfate solution
("Fluorine Chemistry and Industry, Progress and Applications", edited by Shinjun Watanabe: Chemistry
Published by Kogyosha (1973), p. 208).
【0004】しかし、これらの方法で洗浄処理されたN
F3ガスは、いずれも水分を含む結果となる。従って、
通常は洗浄の後工程に、液体窒素や液体炭酸ガス等の冷
媒を使用し、水分を液化もしくは固化させて分離するこ
とや、吸着剤を使用して、これらの不純物を吸着除去
(米国特許第4156598号)する精製法が行われて
いる。コールドトラップによる精製方法において、NF
3より低沸点の冷媒である液体窒素(b.p:-196℃)を使
用して、これらの分離、精製操作を行うと、NF3(b.
p:-129℃)自身が液化するため、系内の圧力バランス
に変調を来し運転継続が困難になる。[0004] However, the N 2 which has been cleaned by these methods is used.
Each of the F 3 gases results in containing moisture. Therefore,
Usually, in the post-washing step, a refrigerant such as liquid nitrogen or liquid carbon dioxide is used to liquefy or solidify the water to separate it, or an adsorbent is used to adsorb and remove these impurities (US Patent No. No. 4,156,598). In a purification method using a cold trap, NF
When these separation and purification operations are performed using liquid nitrogen (bp: -196 ° C), which is a refrigerant having a boiling point lower than 3 , NF 3 (b.
(p: -129 ° C) Because it liquefies itself, the pressure balance in the system is modulated, making it difficult to continue operation.
【0005】また、NF3を液化させないように、冷媒
を液体炭酸ガス(b.p:-79℃)等沸点の高いものを使
用するか又は冷却温度を制御すると、ガス露点を十分に
下げることが出来ず、水分の分離が不十分となり製品純
度が低下したり、精製装置の能力不足等の問題が生じて
いた。In order to prevent NF 3 from being liquefied, if a refrigerant having a high boiling point such as liquid carbon dioxide (bp: -79 ° C.) is used or the cooling temperature is controlled, the gas dew point can be sufficiently lowered. However, the separation of water is insufficient and the purity of the product is reduced, and there are problems such as insufficient capacity of the purification device.
【0006】[0006]
【発明が解決しようとする課題】本発明の目的は、上記
精製装置の欠点を解消し、高純度NF3ガスを安定的に
製造することにある。SUMMARY OF THE INVENTION An object of the present invention is to eliminate the drawbacks of the above-mentioned refining apparatus and to stably produce high-purity NF 3 gas.
【0007】[0007]
【課題を解決するための手段】本発明者らは、NF3ガ
スを安定的に高純度に精製する方法について鋭意検討を
重ねた結果、洗浄処理された後の水分を含む粗NF3ガ
ス中の水分を、液化もしくは固化させて、分離、精製を
行う方法において、冷媒として液化NF3を用いること
により、従来困難であった製品であるNF3の精製装置
中での液化を防止して、安定した連続運転を可能にする
と共に、高純度化のニーズに対応出来ることを見出し、
本発明を完成するに至った。Means for Solving the Problems The present inventors have conducted intensive studies on a method for stably purifying NF 3 gas to a high purity, and as a result, it has been found that crude NF 3 gas containing water after being subjected to cleaning treatment is used. In the method of liquefying or solidifying, separating and refining, by using liquefied NF 3 as a refrigerant, it is possible to prevent liquefaction of a conventionally difficult product NF 3 in a purification device, It has been found that it enables stable continuous operation and can meet the needs of high purity.
The present invention has been completed.
【0008】すなわち、本発明はHF、CO2、N2O等
の不純物を含む粗NF3ガスを、水及び/又はアルカリ
水溶液及び/又は還元性水溶液を用い、洗浄で除去した
後、水分を含む粗NF3ガス中の水分を液化もしくは固
化させて、これらの不純物の分離、精製を行う方法にお
いて、冷媒として液化NF3を用いることにより、従来
困難であった、製品であるNF3の液化を防止し、安定
した連続運転を可能にする高純度NF3ガスの精製方法
である。That is, in the present invention, after removing crude NF 3 gas containing impurities such as HF, CO 2 and N 2 O by washing with water and / or an alkaline aqueous solution and / or a reducing aqueous solution, water is removed. and the water of the crude NF 3 gas is liquefied or solidified, including the separation of these impurities, a method of performing purification by using a liquefied NF 3 as the refrigerant, which has heretofore been difficult, liquefaction of NF 3 as a product This is a method for purifying high-purity NF 3 gas that prevents the occurrence of NF 3 gas and enables stable continuous operation.
【0009】[0009]
【発明の実施の形態】以下、本発明を更に詳細に説明す
る。HF、CO2、N2O等の不純物を含む粗NF3ガス
を、アルカリ水溶液及び/又は還元性水溶液を用いて除
去する方法としては、ガススクラバーを使用して、上記
の水溶液を循環させながら、粗NF3ガスを通気させる
方法が好適に使用される。BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. As a method for removing the crude NF 3 gas containing impurities such as HF, CO 2 and N 2 O using an alkaline aqueous solution and / or a reducing aqueous solution, a gas scrubber is used to circulate the above aqueous solution. A method of passing a crude NF 3 gas is preferably used.
【0010】本発明に用いるアルカリ水溶液としては、
アルカリ金属、アルカリ土類金属群の水酸化物の水溶液
が使用される。また、還元性水溶液としは、KI、H
I、Na2S、Na2S2O3、Na2SO3から選ばれた少
なくとも1種の水溶液が用いられる。このアルカリ水溶
液及び/又は還元性水溶液を用いたガススクラバーによ
り洗浄されたNF3ガスは、水溶液の温度やガススクラ
バーの構造等で異なるが、数十〜数千ppmの水分含ん
だ粗NF3ガスとしてスクラバーより排出される。そこ
で、この水分を含む粗NF3ガスを、冷媒に液化NF3を
用いた熱交換式の精製装置を用いて精製を行う。The alkaline aqueous solution used in the present invention includes:
An aqueous solution of a hydroxide of an alkali metal or alkaline earth metal group is used. KI, H
At least one aqueous solution selected from the group consisting of I, Na 2 S, Na 2 S 2 O 3 and Na 2 SO 3 is used. The NF 3 gas cleaned by the gas scrubber using the alkaline aqueous solution and / or the reducing aqueous solution varies depending on the temperature of the aqueous solution, the structure of the gas scrubber, and the like, but the crude NF 3 gas containing tens to thousands of ppm of water. As discharged from the scrubber. Therefore, the crude NF 3 gas containing water is purified using a heat exchange type purification device using liquefied NF 3 as a refrigerant.
【0011】本発明において使用する熱交換式の精製装
置の構造は、特に限定されるものではなく、一般的な二
重管式,多管式,コイル式等を用いられ、材質としては
低温脆性等を考慮した材質であれば、特に限定されるも
のではないが通常SUS製のものを使用する。The structure of the heat exchange type refining apparatus used in the present invention is not particularly limited, and a general double tube type, multi-tube type, coil type, or the like is used. Although it is not particularly limited as long as it is a material in consideration of the above, a material made of SUS is usually used.
【0012】次に、本発明を図1を参照して説明する。
アルカリ洗浄塔等で洗浄された粗NF3ガスは、粗NF3
導管より精製装置内に入り、NF3貯蔵タンクよ
り供給される冷媒用液化NF3(b.p:-129℃)にて冷
却されて、水分は精製装置内で、凝縮、又は固化分離
される。精製されたNF3は、精製NF3導管を経てN
F3貯蔵タンクへ導かれ、貯蔵され製品となると共
に、冷媒として利用される。NF3の貯蔵タンクで
の冷却には液体窒素等を使用する。Next, the present invention will be described with reference to FIG.
Crude NF 3 gas is washed with an alkaline washing tower or the like, the crude NF 3
The water enters the purifier through a conduit, is cooled by liquefied refrigerant NF 3 (bp: -129 ° C.) supplied from the NF 3 storage tank, and water is condensed or solidified and separated in the purifier. The purified NF 3 is passed through a purified NF 3 conduit
It led to F 3 storage tank, with a stored product is used as a refrigerant. Liquid nitrogen or the like is used to cool the NF 3 in the storage tank.
【0013】一定期間運転した精製装置内には、固結
又は凝結した水分が蓄積するため、精製装置は、通常複
数基設置し定期的に切り替える方式を用いる。精製装置
を切り替えた後、冷媒に代えて加熱窒素を流し、氷結
した水分を融解後系外へ排出して、次の運転に備える。Since the condensed or condensed water accumulates in the refining apparatus which has been operated for a certain period of time, a plurality of refining apparatuses are usually installed and periodically switched. After switching the purifier, heated nitrogen is flowed in place of the refrigerant, and the frozen water is thawed and discharged outside the system to prepare for the next operation.
【0014】[0014]
【実施例】以下、本発明を実施例及び比較例をもって説
明する。尚、以下、%は重量基準、ppmは容量基準で
表す。The present invention will be described below with reference to examples and comparative examples. Hereinafter,% is represented by weight and ppm is represented by volume.
【0015】実施例1 NF4F・1.7HFの電解液を用い、これを電気分解
して陽極より粗NF3ガスを発生させた。この粗NF3ガ
スを2段のガススクラバーを用い、1段目では3%のチ
オ硫酸ナトリム水溶液と接触させOF2並びに他の酸化
性ガス成分を除去し、2段目では10%の水酸化ナトリ
ウム水溶液を用いCO2を除去した。この2段目のガス
スクラバーの出口ガスをガスクロマトグラフィ及び/又
はFT−IR、水分計等にて分析したところ水分が6%
含まれていた。この水分を含む粗NF3ガスを、図1に
示す精製装置に導き、冷媒用液化NF3量を循環し、粗
NF 3の精製を行った。通気して24Hr後、精製NF3
導管出口にて露点計(日本パナメトリック社:SER
I−ES35)で水分を分析したところ、1ppm以下
に減少していた。この状態で連続7日運転を実施した
が、期間中NF3の液化による系内の圧変動等で運転に
支障を来すようなことは無く、安定した運転が出来た。Embodiment 1 NFFourElectrolysis using an electrolytic solution of F1.7 HF
NFThreeGas was evolved. This crude NFThreeMoth
Using a two-stage gas scrubber, the first stage has a 3%
Contact with aqueous sodium osulphate solutionTwoAs well as other oxidation
In the second stage, 10% sodium hydroxide is removed.
COTwoWas removed. This second stage gas
The gas at the outlet of the scrubber is analyzed by gas chromatography and / or
Is 6% when analyzed by FT-IR, moisture meter, etc.
Was included. Crude NF containing this waterThreeThe gas in Figure 1
Liquefied NF for refrigerantThreeCirculating quantity and coarse
NF ThreeWas purified. 24 hours after aeration, purified NFThree
Dew point gauge at conduit outlet (Panametric Japan: SER
When the water content was analyzed by I-ES35), it was 1 ppm or less.
Was decreasing. In this state, operation was performed for 7 consecutive days.
But during the period NFThreeOperation due to pressure fluctuations in the system due to liquefaction
There was no trouble and stable operation was possible.
【0016】比較例1 実施例1と同様にして得られた粗NF3ガスを、冷媒を
冷却用液化NF3から液体窒素に代えて、図1に示す精
製装置へ導き、冷媒用液体窒素を循環して、粗NF3の
精製を行った。通気して10Hr後、精製装置内での粗
NF3ガスの凝縮と思われる現象により系内に圧変動が
生じ運転が停止した。Comparative Example 1 The crude NF 3 gas obtained in the same manner as in Example 1 was introduced into the purification apparatus shown in FIG. 1 by changing the refrigerant from liquid liquefied NF 3 for cooling to liquid nitrogen, and the liquid nitrogen for refrigerant was obtained. The crude NF 3 was purified by circulation. After 10 hours of aeration, the pressure was fluctuated in the system due to a phenomenon considered to be condensation of the crude NF 3 gas in the purification device, and the operation was stopped.
【0017】比較例2 実施例1と同様にして得られた粗NF3ガスを、冷媒を
冷却用液化NF3から液体炭酸ガスに代えて、図1に示
す精製装置へ導き、冷媒用液体炭酸ガスを循環して、粗
NF3の精製を行った。通気して24Hr後、精製NF3
導管出口にて露点計(日本パナメトリック社:SER
I−ES35)で水分を分析したところ、6ppmと規
格(1ppm)を大きく逸脱していたため、運転を停止
した。[0017] The crude NF 3 gas obtained in the same manner as in Comparative Example 2 Example 1, in place of the coolant from the cooling liquefied NF 3 in the liquid carbon dioxide, leads to purification device shown in FIG. 1, liquid carbon refrigerant The gas was circulated to purify the crude NF 3 . After 24 hours of aeration, purified NF 3
Dew point gauge at conduit outlet (Panametric Japan: SER
When the water content was analyzed by I-ES35), the operation was stopped because it was 6 ppm, which greatly deviated from the standard (1 ppm).
【0018】[0018]
【発明の効果】本発明は、粗NF3ガス中のHF、O
F2、N2F2、N2F4、CO2などの不純物を、洗浄塔等
で取り除いた後の水分を含むNF3ガスの水分除去を行
う方法である。この方法により、従来の脱水工程で生じ
ていた粗NF3の凝縮による、系内の圧変動を防止し長
期に渡り安定した運転が出来るNF3製造プロセスが実
現出来、その産業上の効果は非常に大きい。According to the present invention, HF and O in crude NF 3 gas are used.
This is a method of removing moisture of NF 3 gas including moisture after removing impurities such as F 2 , N 2 F 2 , N 2 F 4 and CO 2 by a washing tower or the like. By this method, it is possible to realize a NF 3 production process that can prevent pressure fluctuation in the system due to condensation of crude NF 3 generated in the conventional dehydration step and can operate stably for a long period of time. Big.
【図1】精製装置のフローを示す図である。FIG. 1 is a diagram showing a flow of a purification device.
1 精製装置 2 NF3貯蔵タンク 3 粗NF3導管 4 精製NF3導管 5 冷媒用液化NF3 6 不純物排出弁 7 液化NF3 8 液体窒素 9 加熱窒素入口 10 加熱窒素出口 11 冷媒用液体窒素又は液体炭酸ガス入口 12 冷媒用液体窒素又は液体炭酸ガス出口1 purifier 2 NF 3 storage tank 3 crude NF 3 conduit 4 purified NF 3 conduit 5 refrigerant liquefied NF 3 6 impurity exhaust valve 7 liquefied NF 3 8 liquid nitrogen 9 heated nitrogen inlet 10 heated nitrogen outlet 11 coolant liquid nitrogen or liquid Carbon dioxide inlet 12 Liquid nitrogen or refrigerant carbon dioxide outlet for refrigerant
フロントページの続き (72)発明者 林田 博巳 山口県下関市彦島迫町七丁目1番1号 三 井化学株式会社内 Fターム(参考) 4D020 AA03 AA05 AA10 BA01 BA07 BA08 BA10 BA23 BB03 4D076 AA15 BE00 FA02 FA15 HA12 JA02 Continued on the front page (72) Inventor Hiromi Hayashida 7-1-1, Hikoshimasako-cho, Shimonoseki-shi, Yamaguchi Prefecture F-term in Mitsui Chemicals Co., Ltd. HA12 JA02
Claims (1)
スを、水及び/又はアルカリ水溶液及び/又は還元性水
溶液を用いて洗浄、除去した後、この水分を含む三弗化
窒素ガスを熱交換式の精製装置を用いて、水分を液化も
しくは固化して除去、精製する方法に於いて、冷媒に液
体NF3を用いることを特徴とする高純度NF3ガスの精
製方法。1. A method for cleaning and removing a crude nitrogen trifluoride (NF 3 ) gas containing impurities using water and / or an alkaline aqueous solution and / or a reducing aqueous solution, and then removing the nitrogen trifluoride gas containing the water. via the use of an apparatus for purifying the heat exchange type, remove liquefied or solidified water, in the method for purifying a high-purity NF 3 purification process of the gas, which comprises using a liquid NF 3 into the refrigerant.
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WO2010050342A1 (en) * | 2008-10-28 | 2010-05-06 | セントラル硝子株式会社 | Method and system for purifying nitrogen trifluoride containing halogen or halogen compound as impurity |
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Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
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KR100428905B1 (en) * | 2001-09-07 | 2004-04-28 | 주식회사 소디프신소재 | A process for preparing highly pure potassium fluoride from nitrogen trifluoride composite gas |
WO2010050342A1 (en) * | 2008-10-28 | 2010-05-06 | セントラル硝子株式会社 | Method and system for purifying nitrogen trifluoride containing halogen or halogen compound as impurity |
JP2013539717A (en) * | 2010-09-15 | 2013-10-28 | ソルヴェイ(ソシエテ アノニム) | Method of removing F2 and / or OF2 from gas |
KR101320794B1 (en) * | 2012-12-28 | 2013-10-23 | 오씨아이머티리얼즈 주식회사 | Apparatus and method for recovering hydrogen fluoride generated from anode/cathode in process of nitrogen trifluoride gas |
CN111039266A (en) * | 2019-12-29 | 2020-04-21 | 中船重工(邯郸)派瑞特种气体有限公司 | Device and method for removing nitrous oxide in nitrogen trifluoride |
CN112742158A (en) * | 2020-12-30 | 2021-05-04 | 中船重工(邯郸)派瑞特种气体有限公司 | Hydrogen fluoride waste gas treatment system and method in nitrogen trifluoride electrolysis preparation process |
CN113606820A (en) * | 2021-08-27 | 2021-11-05 | 中船重工(邯郸)派瑞特种气体有限公司 | Direct and indirect refrigeration combined nitrogen trifluoride electrolysis gas ultralow temperature cold trap device |
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