JPH0149532B2 - - Google Patents
Info
- Publication number
- JPH0149532B2 JPH0149532B2 JP60277363A JP27736385A JPH0149532B2 JP H0149532 B2 JPH0149532 B2 JP H0149532B2 JP 60277363 A JP60277363 A JP 60277363A JP 27736385 A JP27736385 A JP 27736385A JP H0149532 B2 JPH0149532 B2 JP H0149532B2
- Authority
- JP
- Japan
- Prior art keywords
- gas
- exhaust gas
- dry etching
- gases
- 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.)
- Expired
Links
- 238000000034 method Methods 0.000 claims description 21
- 238000001312 dry etching Methods 0.000 claims description 16
- 239000007864 aqueous solution Substances 0.000 claims description 9
- 238000004140 cleaning Methods 0.000 claims description 8
- 239000001099 ammonium carbonate Substances 0.000 claims description 7
- ATRRKUHOCOJYRX-UHFFFAOYSA-N Ammonium bicarbonate Chemical compound [NH4+].OC([O-])=O ATRRKUHOCOJYRX-UHFFFAOYSA-N 0.000 claims description 6
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 claims description 6
- 229910052731 fluorine Inorganic materials 0.000 claims description 6
- 239000011737 fluorine Substances 0.000 claims description 6
- LSNNMFCWUKXFEE-UHFFFAOYSA-N Sulfurous acid Chemical compound OS(O)=O LSNNMFCWUKXFEE-UHFFFAOYSA-N 0.000 claims description 5
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 claims description 4
- 235000012501 ammonium carbonate Nutrition 0.000 claims description 4
- 235000012538 ammonium bicarbonate Nutrition 0.000 claims description 3
- 235000011114 ammonium hydroxide Nutrition 0.000 claims description 3
- 229910000013 Ammonium bicarbonate Inorganic materials 0.000 claims description 2
- 239000007789 gas Substances 0.000 description 50
- 230000001590 oxidative effect Effects 0.000 description 7
- 230000002378 acidificating effect Effects 0.000 description 5
- 238000006243 chemical reaction Methods 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 238000005406 washing Methods 0.000 description 4
- QGZKDVFQNNGYKY-UHFFFAOYSA-N ammonia Natural products N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 3
- 239000000243 solution Substances 0.000 description 3
- PQUCIEFHOVEZAU-UHFFFAOYSA-N Diammonium sulfite Chemical compound [NH4+].[NH4+].[O-]S([O-])=O PQUCIEFHOVEZAU-UHFFFAOYSA-N 0.000 description 2
- 229910004014 SiF4 Inorganic materials 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 2
- 239000003513 alkali Substances 0.000 description 2
- 229910052783 alkali metal Inorganic materials 0.000 description 2
- 150000001340 alkali metals Chemical class 0.000 description 2
- 229910052784 alkaline earth metal Inorganic materials 0.000 description 2
- 150000001342 alkaline earth metals Chemical class 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 2
- 238000006555 catalytic reaction Methods 0.000 description 2
- 238000005530 etching Methods 0.000 description 2
- ABTOQLMXBSRXSM-UHFFFAOYSA-N silicon tetrafluoride Chemical compound F[Si](F)(F)F ABTOQLMXBSRXSM-UHFFFAOYSA-N 0.000 description 2
- 238000001179 sorption measurement Methods 0.000 description 2
- LSNNMFCWUKXFEE-UHFFFAOYSA-L sulfite Chemical class [O-]S([O-])=O LSNNMFCWUKXFEE-UHFFFAOYSA-L 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 description 1
- BVKZGUZCCUSVTD-UHFFFAOYSA-M Bicarbonate Chemical compound OC([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-M 0.000 description 1
- 229910017855 NH 4 F Inorganic materials 0.000 description 1
- 239000005662 Paraffin oil Substances 0.000 description 1
- 229910004298 SiO 2 Inorganic materials 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- KYKAJFCTULSVSH-UHFFFAOYSA-N chloro(fluoro)methane Chemical compound F[C]Cl KYKAJFCTULSVSH-UHFFFAOYSA-N 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 239000012141 concentrate Substances 0.000 description 1
- 238000010790 dilution Methods 0.000 description 1
- 239000012895 dilution Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000003912 environmental pollution Methods 0.000 description 1
- 239000002360 explosive Substances 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 150000002823 nitrates Chemical class 0.000 description 1
- 239000010690 paraffinic oil Substances 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 231100000331 toxic Toxicity 0.000 description 1
- 230000002588 toxic effect Effects 0.000 description 1
- 239000002341 toxic gas Substances 0.000 description 1
- 231100000419 toxicity Toxicity 0.000 description 1
- 230000001988 toxicity Effects 0.000 description 1
- 238000001039 wet etching Methods 0.000 description 1
Landscapes
- Treating Waste Gases (AREA)
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は主としてフツ素系ガスを用いるドライ
エツチング排ガスの処理方法に関する。DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention mainly relates to a method for treating dry etching exhaust gas using fluorine-based gas.
近年集積回路の微細化の要求は高まるばかりで
そのエツチング工程はドライエツチング化の方向
にあり、半導体素子材料であるＰ−Si、Si3N4、
SiO2のエツチングも、HF、NH4F等の水溶液に
よるウエツトエツチングから、フツ素系ガスを用
いるドライエツチングが採用されるようになつて
きた。
In recent years, the demand for miniaturization of integrated circuits has only increased , and the etching process has been moving toward dry etching .
Etching of SiO 2 has changed from wet etching using an aqueous solution of HF, NH 4 F, etc. to dry etching using a fluorine-based gas.
ドライエツチングに用いられるフツ素系ガスと
しては、CF4、C2F6、C3F8、CClF3、CCl2F2、
CCl3F、CBrF3、SF6等があげられ、これらガス
は単独或いは二種以上の混合ガスとして用いられ
たり、さらにO2、H2、N2、Cl2等のガスを添加
した混合ガスとして用いられる。ドライエツチン
グに使用されたこれらのガスは、装置内でプラズ
マ化されるため化学反応によつて変化し、殆んど
の場合種々な毒性ガスおよび安全上問題となるガ
スを含んで排出される。 Fluorine gases used for dry etching include CF 4 , C 2 F 6 , C 3 F 8 , CClF 3 , CCl 2 F 2 ,
Examples include CCl 3 F, CBrF 3 , SF 6 , etc., and these gases can be used alone or as a mixture of two or more, or as a mixed gas with further gases such as O 2 , H 2 , N 2 , Cl 2 added. used as. These gases used for dry etching are converted into plasma within the apparatus and are changed by chemical reactions, and in most cases are emitted containing various toxic gases and gases that pose safety concerns.
これらガスとしては、F2、COF2、HF、SiF4、
SF4、NO、NO2、O3などがあり、このうち安全
上も問題となるガスとしては、プラスチツク材料
およびパラフイン系オイルと反応するNOx、O3、
F2等である。特にNOxはパラフイン系オイルと
反応して硝酸エステル等爆発性化合物を生成す
る。 These gases include F 2 , COF 2 , HF, SiF 4 ,
There are gases such as SF 4 , NO, NO 2 , O 3 , etc. Among these, the gases that pose safety issues are NO x , O 3 , and O 3 , which react with plastic materials and paraffin oil.
It is F2 grade. In particular, NO x reacts with paraffinic oil to produce explosive compounds such as nitrate esters.
しかし、従来上記排ガスの処理は、水洗浄によ
る除去が行なわれているのみで、排ガス成分に適
した効果的な処理法は全く検討されていないのが
実情である。 However, in the past, the above-mentioned exhaust gas has only been removed by washing with water, and the reality is that no effective treatment method suitable for the exhaust gas components has been studied at all.
除去を必要とする排ガス成分は、大別すると
HF、SiF4、COF2、SF4等の酸性ガスと、O3、
F2、NOx等の酸化性ガスとに分類され、その処
理法としては、吸着法、気相触媒反応法、湿式法
等がある。しかし、排ガス成分を考慮した場合、
吸着法は危険物質が濃縮されるため安全上採用し
難く、気相触媒反応法は費用がかかり経済性の面
で難点がある。
The exhaust gas components that require removal can be broadly classified into
Acid gas such as HF, SiF 4 , COF 2 , SF 4 and O 3 ,
It is classified into oxidizing gases such as F 2 and NO x , and treatment methods include adsorption methods, gas phase catalytic reaction methods, and wet methods. However, when considering exhaust gas components,
The adsorption method concentrates dangerous substances and is therefore difficult to adopt from a safety standpoint, while the gas phase catalytic reaction method is expensive and has disadvantages in terms of economic efficiency.
そのため、本発明者等は湿式法について鋭意研
究を重ねた結果、アルカリ洗浄または水洗浄によ
つては酸性ガスのみが除去され、酸化性ガスの効
果的な除去が行なわれないが、亜硫酸塩が酸化性
ガスの除去に極めて有効なことを知見した。 Therefore, as a result of intensive research into wet methods, the present inventors found that alkaline cleaning or water cleaning only removes acidic gases and does not effectively remove oxidizing gases, but sulfites It was found that this method is extremely effective in removing oxidizing gases.
本発明は上記の知見に基づいて開発されたもの
で、湿式法によつて酸性ガスおよび酸化性ガスを
共に除去するドライエツチング排ガスの処理方法
を提供することを目的とする。 The present invention was developed based on the above findings, and an object of the present invention is to provide a method for treating dry etching exhaust gas in which both acidic gas and oxidizing gas are removed by a wet method.
本発明は上記の目的を達成するためになされた
もので、その要旨は、フツ素系ガスを用いるドラ
イエツチング排ガスの処理方法において、ドライ
エツチング排ガスを亜硫酸塩水溶液にアンモニア
水、炭酸アンモニウム、重炭酸アンモニウムのう
ちの１種または２種以上を加えた混合水溶液で洗
浄するドライエツチング排ガスの処理方法にあ
る。
The present invention has been made to achieve the above object, and the gist thereof is to provide a method for treating dry etching exhaust gas using fluorine-based gas, in which dry etching exhaust gas is mixed with aqueous sulfite solution, aqueous ammonia, ammonium carbonate, and bicarbonate. The present invention provides a method for treating dry etching exhaust gas by cleaning it with a mixed aqueous solution containing one or more of ammonium.
以下本発明を詳細に説明する。 The present invention will be explained in detail below.
本発明の方法においては、洗浄液としてアルカ
リ水溶液と亜硫酸水溶液とを混合して用いるが、
半導体工場ではアルカリ金属、アルカリ土類金属
が忌避されるため、アルカリ源としてアンモニア
水または炭酸アンモニウムが使用される。また、
亜硫酸塩としては、アルカリ金属、アルカリ土類
金属以外の亜硫酸塩が用いられるが、特に亜硫酸
アンモニウムが好ましい。 In the method of the present invention, a mixture of an alkaline aqueous solution and a sulfite aqueous solution is used as the cleaning liquid.
Since alkali metals and alkaline earth metals are avoided in semiconductor factories, aqueous ammonia or ammonium carbonate is used as an alkali source. Also,
As the sulfite, sulfites other than those of alkali metals and alkaline earth metals are used, and ammonium sulfite is particularly preferred.
NH4OH、（NH4）2CO3、NH4HCO3を含んだ
（NH4）2SO3水溶液は、PH５以上、好ましくは７
〜９に調整される。濃度は排ガス成分によつて異
なり、条件によりSO3 --濃度：0.1〜2mol／、
CO3 --：0.1〜2mol／、NH4OH：0.1〜1mol／
の範囲に調整される。この範囲は厳密なもので
はないが、うすすぎると、吸収保有量が少な過
ぎ、濃過ぎると、吸収生成物の濃度が高くなり好
ましくない。また、洗浄温度は、低いと吸収反応
速度が遅く好ましくないが、室温以上であれば問
題はない。 The (NH 4 ) 2 SO 3 aqueous solution containing NH 4 OH, (NH 4 ) 2 CO 3 and NH 4 HCO 3 has a pH of 5 or higher, preferably 7.
Adjusted to ~9. The concentration varies depending on the exhaust gas components, and depending on the conditions, SO 3 --concentration : 0.1 to 2 mol/,
CO 3 -- : 0.1 to 2 mol/, NH 4 OH: 0.1 to 1 mol/
is adjusted to the range of This range is not strict, but if it is too dilute, the amount of absorption retained will be too small, and if it is too thick, the concentration of the absorbed product will be high, which is undesirable. Further, if the washing temperature is low, the absorption reaction rate is slow and undesirable, but there is no problem if the washing temperature is at room temperature or higher.
上記排ガス成分のうち酸性ガス、例えばHF、
SiF4、COF2、SF4、SOF等は混合洗浄液中のア
ルカリと(1)〜(5)に示す反応式に従つて反応除去さ
れる。 Among the above exhaust gas components, acidic gases, such as HF,
SiF 4 , COF 2 , SF 4 , SOF, etc. are removed by reaction with the alkali in the mixed cleaning solution according to reaction formulas (1) to (5).
（NH4）2CO3＋2HF→2NH4F＋H2CO3 ……(1)
２（NH4）2CO3＋3SiF4＋H2O→２（NH4）2SiF6＋
Si（OH）4＋2H2CO3 ……(2)
4NH4OH＋COF→（NH4）2CO3＋2NH4F＋
2H2O ……(3)
SF4＋（NH4）2CO3→2NH4F＋SOF2＋CO2 ……(4)
２（NH4）2CO3＋SOF2→（NH4）2SO3＋2NH4F＋
2CO2 ……(5)
また、酸化性ガス、例えばNOx、F2、O3等は
亜硫酸アンモニウムと(6)〜(8)に示す式に従つて反
応除去される。(NH 4 ) 2 CO 3 +2HF→2NH 4 F+H 2 CO 3 ...(1) 2(NH 4 ) 2 CO 3 +3SiF 4 +H 2 O→2(NH 4 ) 2 SiF 6 +
Si(OH) 4 +2H 2 CO 3 ...(2) 4NH 4 OH+COF→(NH 4 ) 2 CO 3 +2NH 4 F+
2H 2 O …(3) SF 4 +(NH 4 ) 2 CO 3 →2NH 4 F＋SOF 2 +CO 2 …(4) 2(NH 4 ) 2 CO 3 +SOF 2 →(NH 4 ) 2 SO 3 +2NH 4 F＋
2CO 2 ...(5) Further, oxidizing gases such as NO x , F 2 , O 3 and the like are removed by reaction with ammonium sulfite according to the formulas shown in (6) to (8).
２（NH4）2SO3＋NO23H2O→2NH（SO3NH4）2＋
３（NH4）2SO4＋4NH4OH ……(6)
（NH4）2SO3＋F2＋H2O→（NH4）2SO4＋2HF
……(7)
（NH4）2SO3＋O3→（NH4）2SO4＋O2 ……(8)
したがつて、アンモニア水、炭酸アンモニウ
ム、重炭酸アンモニウムの１種又は２種以上を含
む亜硫酸塩水溶液によつて洗浄することにより、
ドライエツチング排ガス中に含まれる酸性或いは
酸化性の毒性または安全上問題となるガス成分
が、一段の洗浄によつて除去することが出来る。2(NH 4 ) 2 SO 3 +NO 2 3H 2 O→2NH(SO 3 NH 4 ) 2 +
3 (NH 4 ) 2 SO 4 +4NH 4 OH ……(6) (NH 4 ) 2 SO 3 +F 2 +H 2 O→(NH 4 ) 2 SO 4 +2HF
...(7) (NH 4 ) 2 SO 3 +O 3 → (NH 4 ) 2 SO 4 +O 2 ...(8) Therefore, one or more of aqueous ammonia, ammonium carbonate, and ammonium bicarbonate By washing with an aqueous sulfite solution containing
Acidic or oxidizing toxic or safety-related gas components contained in the dry etching exhaust gas can be removed by one-stage cleaning.
次に実施例を示して本発明の方法を説明する。 Next, the method of the present invention will be explained with reference to Examples.
実施例 １
CF4：290ml／min、O2：240ml／min、N2：40
ml／minを供給しているドライエツチング装置よ
り排出されるガス組成を分析したところ、
NO2：1450ppm、O3：1300ppm、SiF4：
6500ppmであつた。ガスは、N2によつて希釈さ
れておりガス量は、2.5／minである。Example 1 CF 4 : 290ml/min, O 2 : 240ml/min, N 2 : 40
An analysis of the gas composition discharged from a dry etching device that supplies ml/min revealed that
NO2 : 1450ppm, O3 : 1300ppm, SiF4 :
It was 6500ppm. The gas is diluted with N 2 and the gas flow rate is 2.5/min.
このガスを、直径：150mm、高さ：600mmの充填
塔に導入し、塔頂より（NH4）2SO3：1mol／、
（NH4）2CO3：0.5mol／、PH：８の水溶液を５
／minの速度で供給して、向流によつて上記排
ガスを洗浄したところ、出口ガス中のNO2：
2ppm、O3：5ppm以下、SiF4：1ppm以下であつ
た。 This gas was introduced into a packed column with a diameter of 150 mm and a height of 600 mm, and from the top of the column (NH 4 ) 2 SO 3 : 1 mol/,
(NH 4 ) 2 CO 3 : 0.5 mol/, PH: 8 aqueous solution
When the above exhaust gas was washed by countercurrent by supplying at a rate of /min, NO 2 in the outlet gas:
2ppm, O 3 : 5ppm or less, and SiF 4 : 1ppm or less.
実施例 ２
CF4：150ml／min、O2：15ml／を供給して
いるドライエツチング装置より排出されるガス組
成を分析したところ、Fe：450ppm、O3：
500ppm、SiF：3400ppmであつた。ガス量はN2
によつて希釈されており２／minである。この
ガスを、径：150mm、高さ500mmの充填塔に導き塔
頂より（NH4）2SO3：1.5mol／、
（NH4）2CO3：0.5mol／、PH：７の水溶液を５
／minの速度で供給し、向流で洗浄したとこ
ろ、出口ガス中のF2：2ppm以下、O3：5ppm以
下、SiF4：1ppm以下であつた。Example 2 Analysis of the gas composition discharged from a dry etching device that supplies CF 4 : 150 ml/min and O 2 : 15 ml/min revealed that Fe: 450 ppm, O 3 :
It was 500ppm, SiF: 3400ppm. Gas amount is N2
The dilution rate is 2/min. This gas is led to a packed column with a diameter of 150 mm and a height of 500 mm, and from the top of the column (NH 4 ) 2 SO 3 : 1.5 mol/,
(NH 4 ) 2 CO 3 : 0.5 mol/, PH: 7 aqueous solution
When the gas was supplied at a rate of /min and washed in countercurrent, the outlet gas contained F2 : 2 ppm or less, O3 : 5 ppm or less, and SiF4 : 1 ppm or less.
以上述べたように本発明の方法は、フツ素系ガ
スを用いるドライエツチング排ガス中の毒性或い
は安全上問題となる酸性および酸化性ガスを、一
段の洗浄によつて除去することが出来るので、半
導体製造における環境汚染を、容易、かつ安価に
防止し得る優れた方法である。
As described above, the method of the present invention can remove acidic and oxidizing gases that cause toxicity or safety problems in the exhaust gas of dry etching using fluorine-based gases through one step of cleaning. This is an excellent method that can easily and inexpensively prevent environmental pollution during manufacturing.
Claims (1)
スの処理方法において、ドライエツチング排ガス
を亜硫酸塩水溶液にアンモニア水、炭酸アンモニ
ウム、重炭酸アンモニウムのうちの１種または２
種以上を加えた混合水溶液で洗浄することを特徴
とするドライエツチング排ガスの処理方法。1. In a method for treating dry etching exhaust gas using fluorine-based gas, one or two of ammonia water, ammonium carbonate, and ammonium bicarbonate are added to the dry etching exhaust gas in a sulfite aqueous solution.
A method for treating dry etching exhaust gas characterized by cleaning with a mixed aqueous solution containing at least one species.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60277363A JPS62136230A (en) | 1985-12-10 | 1985-12-10 | Treatment of dry etching exhaust gas |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60277363A JPS62136230A (en) | 1985-12-10 | 1985-12-10 | Treatment of dry etching exhaust gas |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62136230A JPS62136230A (en) | 1987-06-19 |
| JPH0149532B2 true JPH0149532B2 (en) | 1989-10-25 |
Family
ID=17582479
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP60277363A Granted JPS62136230A (en) | 1985-12-10 | 1985-12-10 | Treatment of dry etching exhaust gas |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS62136230A (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20010009652A1 (en) * | 1998-05-28 | 2001-07-26 | Jose I. Arno | Apparatus and method for point-of-use abatement of fluorocompounds |
| US6759018B1 (en) | 1997-05-16 | 2004-07-06 | Advanced Technology Materials, Inc. | Method for point-of-use treatment of effluent gas streams |
| AU2188900A (en) * | 1998-12-15 | 2000-07-03 | Advanced Technology Materials, Inc. | Apparatus and method for point-of-use treatment of effluent gas streams |
| FR2813205B1 (en) * | 2000-08-24 | 2003-07-25 | Picosil | PROCESS FOR THE PURIFICATION OF FLUORINATED GASEOUS EFFLUENTS |
-
1985
- 1985-12-10 JP JP60277363A patent/JPS62136230A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS62136230A (en) | 1987-06-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN1326767C (en) | Nox, Hg, and SO2 removal using ammonia | |
| EP1511554B1 (en) | PROCESS FOR REDUCING NOx IN WASTE GAS STREAMS USING CHLORINE D IOXIDE | |
| US6294139B1 (en) | Methods for wet cleaning or purifying gases or fumes to remove gaseous pollutants | |
| US6991771B2 (en) | NOx, Hg, and SO2 removal using ammonia | |
| KR20000005744A (en) | REMOVAL OF NOx AND SOx EMISSIONS FROM PICKLING LINES FOR METAL TREATMENT | |
| JPH0280310A (en) | Purifying method for gaseous nf3 | |
| US5637282A (en) | Nitrogen oxide scrubbing with alkaline peroxide solution | |
| JPH0149532B2 (en) | ||
| KR920007856B1 (en) | Method of removing gassy acidic halogen compound | |
| JP2663326B2 (en) | Dry etching exhaust gas treatment method | |
| JPH0938463A (en) | Semiconductor manufacturing exhaust gas treatment method | |
| JPH0356123A (en) | Method for removing mercury and NOx in gas | |
| JPH05293475A (en) | Treatment of acidic fluorine-containing water | |
| US20080307969A1 (en) | Method for Cleaning Exhaust Gases Containing Nitrous Gases | |
| JPS5855803B2 (en) | Denitration method | |
| JP2018061946A (en) | Method for treating exhaust gas and waste fluid | |
| JPS63162025A (en) | Removing method for arsine and phosphine | |
| JP2006231105A (en) | Removal method of oxidizing gas | |
| JPS6388023A (en) | Method for removing mercury from exhaust gas | |
| JPS5834174B2 (en) | Chitsusosankabutsunojiyokiyohouhou | |
| JPS6388024A (en) | Removal of mercury in exhaust gas | |
| JPS5861883A (en) | Treatment for waste liquid containing fluorine | |
| HK1078303B (en) | Nox, hg, and so2 removal using ammonia | |
| JP2005021785A (en) | Method for removing nitrogen compound | |
| KR20030053331A (en) | Wet Scrubbing method of dust, sulfur oxides and nitrogen oxides from flue gas |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| EXPY | Cancellation because of completion of term |