JP3574973B2

JP3574973B2 - Method and apparatus for removing harmful components in exhaust gas discharged from semiconductor manufacturing plants and liquid crystal manufacturing plants

Info

Publication number: JP3574973B2
Application number: JP2001323236A
Authority: JP
Inventors: 由章杉森; 修康富田; 昭彦新田; 修一小関; 大貴万行; 宏之小野; 宏増崎
Original assignee: Taiyo Nippon Sanso Corp
Current assignee: Taiyo Nippon Sanso Corp
Priority date: 2001-10-22
Filing date: 2001-10-22
Publication date: 2004-10-06
Anticipated expiration: 2021-10-22
Also published as: JP2003126647A

Description

【０００１】
【発明の属する技術分野】
本発明は、有害成分である揮発性無機水素化物，揮発性無機ハロゲン化物，有機金属化合物を除去する方法及び装置に関し、詳しくは、有害成分として揮発性無機水素化物，揮発性無機ハロゲン化物，有機金属化合物を含む半導体製造工場や液晶製造工場から排出される排ガス中の有害成分の除去方法及び除去装置に関する。
【０００２】
【従来の技術】
半導体製造工程において使用されるガスには、シラン、アルシン、ホスフィン等の金属水素化物やジクロルシラン、三フッ化ホウ素等の金属ハロゲン化物のように人体に対して有毒なガスや空気中で自然発火する性質を持つガス等、空気中にそのまま排出すると安全上、重大な危険をもたらす特殊ガスが多く使用されている。したがって、これらの特殊ガスを使用した後は、安全に処理して許容濃度未満まで除害してから廃棄する必要がある。
【０００３】
これらの特殊ガスを処理する方法は、いくつか実用化されているが、近年最も多用されているのは、除害剤と呼ばれる固形物を使用して特殊ガスを除去する方法であり、これは乾式法との別称がある。最近、この除害剤として、金属水酸化物系の除害剤、特に水酸化第二銅（水酸化銅（ＩＩ））、中でも結晶性水酸化第二銅を主成分とする除害剤が、従来の金属酸化物系の除害剤に比べて反応熱が小さく、除害反応時の発熱が低いこと、剤の処理能力が大きいこと、水素還元し難いことなどを理由に着目されている。
【０００４】
【発明が解決しようとする課題】
しかし、一般的に市販されている工業用の水酸化第二銅は、不純物を数％、例えば５％以上含んでおり、このような不純物を多量に含む水酸化第二銅をそのまま前記除害剤として用いると、含有する不純物の種類によっては、除害反応時の発熱が高くなったり、嵩密度が小さくて単位体積当たりの除害剤の充填量が小さくなるなどの不都合が一部に発生するときがあった。さらに、不純物、特に、リン酸、硫酸、塩酸等の鉱酸成分及びリチウム、ナトリウム、カリウム等のアルカリ金属成分を多く含んでいる水酸化第二銅は、高温になると化学的に不安定となり、経時的に劣化してしまうことがある。
【０００５】
また、半導体製造工程から排出される排ガスには様々な成分が混在しており、成分や流量が変化するのが一般的である。前記水酸化第二銅を除害剤として使用した場合、設計値に対して排ガス中の特殊ガス濃度が高くなったり、空塔速度が速くなったりすると、特殊ガスに対する除害能力が若干低下するなどの不都合が発生してしまうことがある。
【０００６】
そこで本発明は、半導体製造工場、液晶製造工場等から排出される排ガス中の有害成分である揮発性無機ハロゲン化物，有機金属化合物を効率よく除害処理することができ、かつ、除害剤の性能向上を図りつつ、暴走反応（除害剤が被処理ガス中の水素と反応して高温の発熱を起こす反応）を抑制することができる半導体製造工場や液晶製造工場から排出される排ガス中の有害成分の除去方法及び除去装置を提供することを目的としている。
【０００７】
【課題を解決するための手段】
上記目的を達成するため、本発明の半導体製造工場や液晶製造工場から排出される排ガス中の有害成分である揮発性無機水素化物，揮発性無機ハロゲン化物，有機金属化合物の除去方法は、該排ガスを、水酸化第二銅を主成分とし、不純物成分として、リン酸、硫酸、塩酸の鉱酸成分及びリチウム、ナトリウム、カリウムのアルカリ金属成分が含まれ、かつ水酸化第二銅中の不純物成分の含有率が、１つの不純物成分あたり単位換算で０．５重量％以下である高純度水酸化第二銅を主成分とする第１除害剤に接触させた後、金属酸化物、金属酸化水酸化物、金属炭酸塩、塩基性金属炭酸塩のうち少なくとも１つの化合物を主成分とする第２除害剤に接触させることを特徴としている。
【０００８】
本発明で除害対象となる特殊ガスは、前述の通り、半導体製造工場、液晶製造工場等から排出される排ガス中に含まれている有害成分ガスであって、例えば化合物半導体製造工程やＭＯＣＶＤ装置、液晶製造装置で使用されて排出される排ガス中の有害成分である。具体的には、揮発性無機水素化物，揮発性無機ハロゲン化物，有機金属化合物等であって、前記揮発性無機水素化物としては、シラン，ジシラン，アルシン，ホスフィン，ジボラン，ゲルマン，アンモニア，硫化水素，セレン化水素等を挙げることができ、また、揮発性無機ハロゲン化物としては、三フッ化ホウ素，三塩化ホウ素，四フッ化ケイ素，ジクロルシラン，トリクロルシラン，四塩化ケイ素，トリクロルアルシン，六フッ化タングステン，四フッ化ゲルマン，三フッ化リン，四塩化チタン，フッ素，塩素，フッ化水素，塩化水素，臭化水素，ヨウ化水素等、ハロゲンガスも含む各種ガスを挙げることができる。
【０００９】
さらに、有機金属化合物としては、アルキル基を含むものとして、ジメチル亜鉛，ジメチルカドミウム，ジメチルテルル，ジエチル亜鉛，トリメチルアルミニウム，トリメチルガリウム，トリメチルインジウム，トリメチルアルシン，トリメチルボロン，トリエチルボロン，トリエチルアルミニウム，トリエチルガリウム，トリエチルインジウム，トリエチルアルシン，テトラメチル錫，テトラエチル錫，ターシャリーブチルホスフィン，ターシャリーブチルアルシン等を、アルコキシド基を含むものとして、ジメトキシ亜鉛，トリブトキシガリウム，トリメトキシボロン，トリエトキシボロン，テトラメトキシシラン，テトラエトキシシラン，テトラメトキシゲルマン，テトラエトキシゲルマン，テトラターシャリーブトキシ錫，トリメトキシホスフィン，トリエトキシホスフィン，トリメトキシアルシン，トリエトキシアルシン，テトラエトキシセレン，テトラメトキシチタン，テトラエトキシチタン，テトライソプロポキシチタン，テトライソプロポキシジルコニウム，テトラターシャリーブトキシジルコニウム，ペンタメトキシタンタル，ペンタエトキシタンタル等をそれぞれ挙げることができる。
【００１０】
これらの有害な特殊ガスを除害するための第１除害剤として、本発明では、不純物の成分毎濃度がそれぞれ０．５重量％以下の高純度水酸化第二銅であって、好ましくは不純物の総量が５重量％以下、特に好ましくは、除害性能や水酸化第二銅の安定性に大きな影響を与えるリン酸、硫酸、塩酸等の鉱酸成分及びナトリウム、カリウム等のアルカリ金属成分の各成分含有量を、それぞれ０．２重量％以下にした高純度水酸化第二銅を使用する。
【００１１】
このように、不純物含有量が少ない高純度水酸化第二銅を第１除害剤の主成分とすることにより、例えばシランを除害処理する場合は、一般的な工業用水酸化第二銅に比べて処理能力を６倍程度にまで高めることができる。また、ホスフィンを除害処理する場合には発熱温度を低くすることができる。なお、不純物を低減するための水酸化第二銅の精製処理は、任意の方法で行うことができ、特に限定されるものではない。
【００１２】
さらに、高純度水酸化第二銅として、結晶性の水酸化第二銅を使用することにより、非晶質のものに比べて温度に対する安定性を高めることができるので、有害成分の濃度が高く、反応熱が高い場合にも安定的に使用できる。これにより、除害処理を行うカラム等に特別な冷却構造を採用しなくても、安定した除害処理を行うことができる。
【００１３】
また、このように不純物を少なくした高純度水酸化第二銅は、銅含有量が６０％以上と、水酸化第二銅の一般品（銅含有量５５〜５８％程度）に比べて高く、タップ密度も一般品の０．４〜０．５程度から０．８以上と高くなっている。これにより、除害剤として使用したときの単位量当たりの水酸化第二銅量が十％程度増大し、充填密度が２０〜３０％向上し、圧壊強度も数十％向上する。したがって、除害剤としての処理性能向上が図れるとともに、取扱性も向上する。
【００１４】
一方、前記第２除害剤は、前述の通り、金属酸化物、金属酸化水酸化物、金属炭酸塩、塩基性金属炭酸塩のいずれか少なくとも一つの化合物を主成分としている。金属酸化物としては、酸化第一銅、酸化第二銅、酸化マグネシウム、酸化カルシウム、二酸化チタン、酸化クロム、二酸化マンガン、三酸化二マンガン、酸化第一鉄、酸化ニッケル、酸化亜鉛、酸化アルミニウム、二酸化ケイ素、酸化ルテニウム、酸化銀、酸化セリウム、酸化オスミウム等の多くの金属酸化物が使用できる。また、金属酸化水酸化物としては、酸化水酸化マンガン、酸化水酸化鉄、酸化水酸化鉛、酸化水酸化モリブデン等を上げることができ、塩基性金属炭酸塩としては、炭酸二水酸化二銅（塩基性炭酸銅）、塩基性炭酸鉛、塩基性炭酸ニッケル、塩基性炭酸ベリリウム、炭酸マンガン等を挙げることができる。
【００１５】
これらの金属酸化物、金属酸化水酸化物、金属炭酸塩、塩基性金属炭酸塩は、それぞれ単独で使用することもできるし、混合して使用することもでき、さらに、複数の層に積層して使用することもできる。例えば、三酸化二マンガンや塩基性炭酸銅と二酸化マンガンや酸化第二銅とを混合したり、三酸化二マンガンや塩基性炭酸銅の充填層の下流側に酸化第二銅や二酸化マンガンの充填層を配置したりすることができる。
【００１６】
前記第１除害剤や第２除害剤は、これらを粉末のまま、あるいは適当な形状に成形してそのまま用いることもできるが、適宜な担体、例えば、シリカゲル，アルミナ，珪藻土等の担体に担持させて使用することが好ましい。なお、塩基性金属炭酸塩は、排ガス中に水素が大量に含まれている場合であっても還元されにくいので、水素含有排ガスを処理する場合の第２除害剤として非常に有効である。特に、塩基性炭酸銅が最適である。
【００１７】
このように、高純度水酸化第二銅を主成分とする第１除害剤に接触させた後、続いて金属酸化物、金属酸化水酸化物、金属炭酸塩、塩基性金属炭酸塩を主成分とする第２除害剤に接触させることにより、排ガス中の揮発性無機水素化物，揮発性無機ハロゲン化物，有機金属化合物に対する除害処理能力が格段に向上するとともに、両剤の劣化を抑制することができ、長時間にわたって効率の良い除害処理が可能となる。
【００１８】
このようにして排ガスの除害処理を行う際に、揮発性無機水素化物，揮発性無機ハロゲン化物，有機金属化合物の種類や第２除害剤の種類によっては、上流側の第１除害剤と排ガス中の有害成分ガスとが接触反応して発生した水分により、下流側の第２除害剤が劣化することがある。特に、特殊ガスを使用する最近のプロセスでは、特殊ガスを大量に、しかも長時間流すケースが増えてきているので、第１除害剤と特殊ガスとの反応で発生する水分は常時発生していることになり、下流側の第２除害剤の表面が水分を多量に吸着して反応効率を損なうことがある。
【００１９】
このような場合、第１除害剤との接触により発生した水分を、シリカゲル、アルミナ、ゼオライト等の脱水剤に接触させて除去してから第２除害剤に接触させることにより、水分によって第２除害剤が劣化することを防止でき、より安定した状態の除害処理を効率よく長時間継続させることができる。このとき、前記第１除害剤に接触した後の排ガスを脱水剤に接触させてから第２除害剤に接触させるようにしてもよく、脱水剤を第１除害剤や第２除害剤に添加混合して共存状態にしたり、高純度水酸化第二銅等の除害剤成分の担体として使用したりすることもできる。
【００２０】
さらに、前記高純度水酸化第二銅を、ベリリウム、マグネシウム、バナジウム、モリブデン、コバルト、ニッケル、銅、亜鉛、ホウ素、アルミニウム、ケイ素、鉛、アンチモン、ビスマスの元素の群より選ばれた少なくとも１種の単体、または該元素の酸化物、水酸化物（水酸化銅を除く）、炭酸塩、炭酸水素塩、塩基性炭酸塩、酸化水酸化物、過酸化物、カルボン酸塩、オキシ酸塩の少なくとも一種からなる安定化剤、具体的には、マグネシウム、酸化マグネシウム、水酸化マグネシウム、塩基性炭酸マグネシウム、アルミニウム、ケイ素、水酸化ニッケル、亜鉛、一酸化鉛、酸化アンチモン、酸化ビスマス、炭酸コバルト、酸化ホウ素、ホウ酸等の安定化剤と共存させることにより、高純度水酸化第二銅の劣化や熱分解反応を抑制して初期性能を長時間維持することができ、安定した除害処理を行うことができる。
【００２１】
高純度水酸化第二銅への安定化剤の添加量は、安定化剤の種類によって多少異なるが、通常は、高純度水酸化第二銅に対して０．０１〜１０重量％程度が適当であり、添加量が多すぎると水酸化第二銅の除害能力を損なうことがあり、少なすぎると十分な安定化効果を得ることができなくなる。なお、この安定化剤は、前記脱水剤と共に高純度水酸化第二銅中に共存していてもよい。
【００２２】
【発明の実施の形態】
図１乃至図３は、本発明装置の各形態例を示す概略系統図である。まず、図１に示す第１形態例は、有害成分として揮発性無機水素化物，揮発性無機ハロゲン化物，有機金属化合物を含む排ガスが導入されるガス導入口１１と、処理ガスが導出されるガス導出口１２とを有するカラム１３内に、前記導入口側に前記高純度水酸化第二銅を主成分とする前記第１除害剤１４を充填するとともに、前記導出口側に前記第２除害剤１５を充填したものである。
【００２３】
図２に示す第２形態例は、前記カラム１３における第１除害剤１４と第２除害剤１５との間に脱水剤１６を充填したものである。また、図３に示す第３形態例は、前記カラム１３における前記導入口側に前記高純度水酸化第二銅を主成分とする第１除害剤１４と脱水剤とを共存させた処理剤１７を充填したものである。
【００２４】
前記第１除害剤は、前述のように、高純度水酸化第二銅と安定化剤とが共存しているものであってもよく、高純度水酸化第二銅と脱水剤及び安定化剤とが共存しているものであってもよい。また、各形態例では、一つのカラムに第１除害剤や第２除害剤を層状に充填したが、第１除害剤と第２除害剤、あるいは、第１除害剤と脱水剤と第２除害剤とを別のカラムに充填して配管で接続するようにしてもよい。
【００２５】
このように形成した有害成分の除去装置は、前記導入口１１からカラム１３内に特殊ガスを含む排ガスを導入することにより、排ガス中の有害成分ガスを上流側の高純度水酸化第二銅を主成分とする第１除害剤で処理した後、下流側の第２除害剤で仕上げ処理を行うので、有害成分を十分に処理したガスを前記導出口１２から導出することができる。
【００２６】
【実施例】
実施例１
まず、第１除害剤、第２除害剤、脱水剤及び有害成分ガスとして下記のものを用意した。なお、成形品とは、転動造粒機で直径３ｍｍの大きさに造粒したものである。また、処理後のガス中に含まれる有害成分ガス量が各ガスの許容濃度に達するまでの試験ガスの導入量から剤１ｋｇ当たりの有害成分ガス処理量［Ｌ／ｋｇ］を算出し、これを処理能力とした。
【００２７】
前記第１除害剤としては、比較として市販の水酸化第二銅の成型品（Ａ）、不純物の成分毎濃度がそれぞれ０．５重量％以下になるように精製した高純度結晶性水酸化第二銅の成形品（Ｂ）、第２除害剤として酸化第二銅の成形品（Ｃ）、脱水剤としてシリカゲル（Ｓ）をそれぞれ用意した。また、有害成分ガスには、シラン（許容濃度５ｐｐｍ）、アルシン（許容濃度０．０５ｐｐｍ）、ホスフィン（許容濃度０．３ｐｐｍ）及びターシャリーブチルアルシン（ＴＢＡ：許容濃度０．０２５ｐｐｍ（含有する砒素の許容濃度からの換算値））をそれぞれ用意した。
【００２８】
除害処理を行うときの試験ガスとしては、窒素ベースで前記有害ガス成分濃度１％、流量１リットル／分とした第１試験ガス（Ｇ１）と、窒素ベースで前記有害ガス成分濃度５％、流量５リットル／分とした第２試験ガス（Ｇ２）とを調製した。また、第１除害剤等を充填するカラムには内径４３ｍｍのものを用意した。
【００２９】
カラム内に、市販の水酸化第二銅（Ａ）（充填高さ２５０ｍｍ）と酸化第二銅（Ｃ）（充填高さ５０ｍｍ）とを層状に充填したもの（図１参照）、高純度結晶性水酸化第二銅（Ｂ）（充填高さ２５０ｍｍ）と酸化第二銅（Ｃ）（充填高さ５０ｍｍ）とを層状に充填したもの（図１参照）、高純度結晶性水酸化第二銅（Ｂ）（充填高さ２１５ｍｍ）と脱水剤（Ｓ）（充填高さ４２．５ｍｍ）と酸化第二銅（Ｃ）（充填高さ４２．５ｍｍ）とを層状に充填したもの（図２参照）の３種について、両試験ガスを用いて各有害成分ガスに対する処理能力を測定した。その結果を表１に示す。
【００３０】
【表１】

【００３１】
実施例２
実施例１と同様にして第１除害剤（Ｂ）を高さ２５０ｍｍで充填したカラムの下流側に、表２に示すように、金属酸化物、金属酸化水酸化物、金属炭酸塩、塩基性金属炭酸塩等の第２除害剤を高さ５０ｍｍで充填し、ここに第２試験ガス（Ｇ２）の条件でシランを含むガスを導入し、各処理能力を測定した。その結果を表２に示す。
【００３２】
【表２】

【００３３】
実施例３
高純度結晶性水酸化第二銅（Ｂ）に、表３に示す各種物質と水とを加えてよく混合した後、転動造粒機にて直径３ｍｍの大きさに造粒し、高純度結晶性水酸化第二銅と各種物質とが共存した状態の第１除害剤を作成した。なお、特記した以外の各物質の添加量は０．５重量％である。得られた各第１除害剤を１００℃に保持して青色から黒色への変色状態を調べた。なお、水酸化第二銅自体は青色であるが、高温下では徐々に酸化銅に変化して黒色となる。変色時間の測定結果を表３に示す。
【００３４】
【表３】

【００３５】
【発明の効果】
以上説明したように、本発明は、あらかじめ高純度な水酸化第二銅を主成分とする第１除害剤に有害成分として揮発性無機水素化物，揮発性無機ハロゲン化物，有機金属化合物を含む排ガスを接触させて前処理的に該有害成分の除害処理を行い、ある程度有害成分が低減したガスを、金属酸化物、金属酸化水酸化物、金属炭酸塩、塩基性金属炭酸塩を主成分とする第２除害剤に接触させて仕上げ処理を行うようにしたので、単独でこれらの剤を使用する場合と比較して長時間使用することが可能となる。そして使用条件によって第１除害剤で十分に除害処理を行うことができなかった場合でも、下流側の第２除害剤によって確実に特殊ガス成分を極微量にまで処理することができる。したがって、有害成分を含む排ガス、特に半導体製造工場から排出されるアルシン、ホスフィン、シラン、ジクロルシラン、ターシャリーブチルアルシン等の特殊ガス成分を含む排ガスを効率よく除害処理することができる。
【図面の簡単な説明】
【図１】本発明の有害成分の除去装置の第１形態例を示す概略系統図である。
【図２】本発明の有害成分の除去装置の第２形態例を示す概略系統図である。
【図３】本発明の有害成分の除去装置の第３形態例を示す概略系統図である。
【符号の説明】
１１…ガス導入口、１２…ガス導出口、１３…カラム、１４…第１除害剤、１５…第２除害剤、１６…脱水剤、１７…処理剤[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method and an apparatus for removing volatile inorganic hydrides, volatile inorganic halides and organometallic compounds which are harmful components. More specifically, the present invention relates to volatile inorganic hydrides, volatile inorganic halides, and organic compounds as harmful components. relates to the removal method and apparatus for removing harmful components in exhaust gas discharged from a semiconductor manufacturing plant or a liquid crystal manufacturing plant comprising a metal compound.
[0002]
[Prior art]
Gases used in the semiconductor manufacturing process, such as metal hydrides such as silane, arsine, and phosphine, and metal halides such as dichlorosilane and boron trifluoride, ignite spontaneously in gases and air toxic to the human body. Special gases, such as gases having properties, which pose a serious danger in terms of safety when discharged directly into the air, are often used. Therefore, after using these special gases, it is necessary to dispose them safely after treating them to a level lower than the allowable concentration.
[0003]
Several methods of treating these special gases have been put to practical use, but the most frequently used method in recent years is a method of removing special gases using solid substances called abatement agents. There is another name for the dry method. Recently, metal hydroxide-based scavengers, particularly cupric hydroxide (copper (II) hydroxide), especially scavengers mainly composed of crystalline cupric hydroxide, have been known as such scavengers. , Compared to conventional metal oxide-based abatement agents, the heat of reaction is small, the heat generated during the abatement reaction is low, the agent's processing capacity is large, and it is noted that hydrogen reduction is difficult. .
[0004]
[Problems to be solved by the invention]
However, commercially available industrial cupric hydroxide contains several percent, for example, 5% or more of impurities, and the cupric hydroxide containing a large amount of such impurities is harmless as described above. When used as an agent, depending on the type of impurities contained, some inconveniences such as increased heat generation during the abatement reaction and small filling density of the abatement agent per unit volume due to low bulk density occur There was time to do. Furthermore, impurities, especially phosphoric acid, sulfuric acid, cupric hydroxide containing a large amount of mineral acid components such as hydrochloric acid and alkali metal components such as lithium, sodium and potassium become chemically unstable at high temperatures, It may deteriorate with time.
[0005]
Further, various components are mixed in the exhaust gas discharged from the semiconductor manufacturing process, and the components and the flow rates are generally changed. When the cupric hydroxide is used as a harm-removing agent, when the special gas concentration in the exhaust gas is higher than the design value or when the superficial velocity is high, the harm-removing ability for the special gas is slightly reduced. Inconveniences such as this may occur.
[0006]
Therefore, the present invention can efficiently remove harmful components such as volatile inorganic halides and organometallic compounds in exhaust gas discharged from a semiconductor manufacturing plant, a liquid crystal manufacturing plant, and the like. while achieving improved performance, runaway reaction in an exhaust gas discharged from a semiconductor manufacturing plant or a liquid crystal manufacturing factory can be suppressed (detoxifying agent react to cause heating of the high temperature to react with hydrogen in the process gas) and its object is to provide a removal method and apparatus for removing harmful components.
[0007]
[Means for Solving the Problems]
To achieve the above object, a method of removing a semiconductor manufacturing plant or a harmful components volatile inorganic hydrides in an exhaust gas discharged from a liquid crystal manufacturing plant, volatile inorganic halides, organometallic compounds of the present invention, the exhaust gas Contains cupric hydroxide as a main component, and contains, as impurity components, mineral acid components of phosphoric acid, sulfuric acid, and hydrochloric acid, and alkali metal components of lithium, sodium, and potassium , and an impurity component in cupric hydroxide. Is contacted with a first abatement agent containing high-purity cupric hydroxide as a main component, the content of which is 0.5% by weight or less in terms of a unit per one impurity component. It is characterized in that it is brought into contact with a second abatement agent containing at least one compound of a hydroxide, a metal carbonate and a basic metal carbonate as a main component.
[0008]
As described above, the special gas to be abated in the present invention is a harmful component gas contained in exhaust gas discharged from a semiconductor manufacturing plant, a liquid crystal manufacturing plant, etc., for example, a compound semiconductor manufacturing process or a MOCVD device. And harmful components in the exhaust gas discharged from the liquid crystal manufacturing apparatus. Specifically, it is a volatile inorganic hydride, a volatile inorganic halide, an organometallic compound, or the like. Examples of the volatile inorganic hydride include silane, disilane, arsine, phosphine, diborane, germane, ammonia, and hydrogen sulfide. , Hydrogen selenide, etc., and the volatile inorganic halides include boron trifluoride, boron trichloride, silicon tetrafluoride, dichlorosilane, trichlorosilane, silicon tetrachloride, trichloroarsine, hexafluoride. Various gases including halogen gas such as tungsten, germane tetrafluoride, phosphorus trifluoride, titanium tetrachloride, fluorine, chlorine, hydrogen fluoride, hydrogen chloride, hydrogen bromide, and hydrogen iodide can be given.
[0009]
Further, as the organometallic compounds, those containing an alkyl group include dimethylzinc, dimethylcadmium, dimethyltellurium, diethylzinc, trimethylaluminum, trimethylgallium, trimethylindium, trimethylarsine, trimethylboron, triethylboron, triethylaluminum, triethylgallium , Triethylindium, triethylarsine, tetramethyltin, tetraethyltin, tertiary butyl phosphine, tertiary butyl arsine, and the like containing an alkoxide group as dimethoxy zinc, tributoxy gallium, trimethoxy boron, triethoxy boron, tetramethoxy Silane, tetraethoxysilane, tetramethoxygermane, tetraethoxygermane, tetratertiarybutoxytin, trimet Cyphosphine, triethoxyphosphine, trimethoxyarsine, triethoxyarsine, tetraethoxyselenium, tetramethoxytitanium, tetraethoxytitanium, tetraisopropoxytitanium, tetraisopropoxyzirconium, tetratertiarybutoxyzirconium, pentamethoxytantalum, pentaethoxytantalum And the like.
[0010]
In the present invention, as a first abatement agent for removing these harmful special gases, high-purity cupric hydroxide having a concentration of 0.5% by weight or less for each component of impurities is preferably used. The total amount of impurities is 5% by weight or less, and particularly preferably, mineral acid components such as phosphoric acid, sulfuric acid, and hydrochloric acid, and alkali metal components such as sodium and potassium, which greatly affect the abatement performance and the stability of cupric hydroxide. , High-purity cupric hydroxide having a content of each component of 0.2% by weight or less is used.
[0011]
As described above, by using high-purity cupric hydroxide having a small impurity content as a main component of the first abatement agent, for example, when removing silanes, it is possible to use a general industrial cupric hydroxide. In comparison, the processing capacity can be increased up to about six times. In addition, when the phosphine is subjected to the detoxification treatment, the heat generation temperature can be lowered. The purification treatment of cupric hydroxide to reduce impurities can be performed by any method, and is not particularly limited.
[0012]
Furthermore, by using crystalline cupric hydroxide as high-purity cupric hydroxide, the stability with respect to temperature can be increased as compared with amorphous one, so that the concentration of harmful components is high. It can be used stably even when the reaction heat is high. Thereby, stable detoxification processing can be performed without employing a special cooling structure in a column or the like for performing detoxification processing.
[0013]
In addition, the high-purity cupric hydroxide thus reduced in impurities has a copper content of 60% or more, which is higher than a general product of cupric hydroxide (copper content of about 55 to 58%), The tap density also increases from about 0.4 to 0.5 of general products to 0.8 or more. Thereby, the amount of cupric hydroxide per unit amount when used as an abatement agent is increased by about 10%, the packing density is improved by 20 to 30%, and the crushing strength is also improved by several tens%. Therefore, the processing performance as an abatement agent can be improved, and the handleability can be improved.
[0014]
On the other hand, as described above, the second abatement agent contains, as a main component, at least one compound of a metal oxide, a metal oxide hydroxide, a metal carbonate, and a basic metal carbonate. Metal oxides include cuprous oxide, cupric oxide, magnesium oxide, calcium oxide, titanium dioxide, chromium oxide, manganese dioxide, dimanganese trioxide, ferrous oxide, nickel oxide, zinc oxide, aluminum oxide, Many metal oxides such as silicon dioxide, ruthenium oxide, silver oxide, cerium oxide, osmium oxide and the like can be used. Examples of the metal oxide hydroxide include manganese oxide hydroxide, iron oxide hydroxide, lead oxide hydroxide, and molybdenum hydroxide hydroxide. As the basic metal carbonate, dicobium dihydroxide (Basic copper carbonate), basic lead carbonate, basic nickel carbonate, basic beryllium carbonate, manganese carbonate and the like.
[0015]
These metal oxides, metal oxide hydroxides, metal carbonates, and basic metal carbonates can be used alone, or can be used as a mixture. Can also be used. For example, mixing manganese trioxide or basic copper carbonate with manganese dioxide or cupric oxide, or filling cupric oxide or manganese dioxide on the downstream side of a packed layer of dimanganese trioxide or basic copper carbonate Or layers can be arranged.
[0016]
The first and second abatement agents can be used as they are in a powder form or in an appropriate shape and used as they are. However, they can be applied to an appropriate carrier such as a carrier such as silica gel, alumina and diatomaceous earth. It is preferable to use it supported. The basic metal carbonate is very difficult to be reduced even when the exhaust gas contains a large amount of hydrogen, and is therefore very effective as a second abatement agent when treating a hydrogen-containing exhaust gas. In particular, basic copper carbonate is most suitable.
[0017]
As described above, after contact with the first abatement agent containing high-purity cupric hydroxide as a main component, subsequently, a metal oxide, a metal oxide hydroxide, a metal carbonate, and a basic metal carbonate are mainly used. By contacting with a second abatement agent as a component, the ability to remove a volatile inorganic hydride, a volatile inorganic halide and an organometallic compound in exhaust gas is remarkably improved, and the deterioration of both agents is suppressed. This enables efficient abatement treatment for a long time.
[0018]
When performing the abatement treatment of the exhaust gas in this way, depending on the type of the volatile inorganic hydride, the volatile inorganic halide, the organometallic compound or the type of the second abatement agent, the first abatement agent on the upstream side. The second abatement agent on the downstream side may be deteriorated by moisture generated by the contact reaction between the gas and the harmful component gas in the exhaust gas. In particular, in recent processes using special gases, the number of cases where special gases are flowed in large amounts for a long time has increased, and the moisture generated by the reaction between the first abatement agent and the special gases is constantly generated. As a result, the surface of the second abatement agent on the downstream side may adsorb a large amount of water, thereby impairing the reaction efficiency.
[0019]
In such a case, the water generated by the contact with the first abatement agent is removed by contacting with a dehydrating agent such as silica gel, alumina, zeolite or the like, and then is brought into contact with the second abatement agent. (2) Deterioration of the abatement agent can be prevented, and a more stable abatement process can be efficiently continued for a long time. At this time, the exhaust gas after contacting the first abatement agent may be brought into contact with the dehydration agent before being brought into contact with the second abatement agent. It can also be added to and mixed with an agent to make it coexist, or used as a carrier for a scavenger component such as high-purity cupric hydroxide.
[0020]
Further, the high-purity cupric hydroxide is at least one selected from the group consisting of beryllium, magnesium, vanadium, molybdenum, cobalt, nickel, copper, zinc, boron, aluminum, silicon, lead, antimony, and bismuth. Of the element or oxides, hydroxides (excluding copper hydroxide), carbonates, bicarbonates, basic carbonates, hydroxides, peroxides, carboxylates, oxyacids of the element At least one stabilizer, specifically, magnesium, magnesium oxide, magnesium hydroxide, basic magnesium carbonate, aluminum, silicon, nickel hydroxide, zinc, lead monoxide, antimony oxide, bismuth oxide, cobalt carbonate, By coexisting with stabilizing agents such as boron oxide and boric acid, the degradation and thermal decomposition reaction of high-purity cupric hydroxide can be suppressed for the first time. Can be maintained for a long time performance, it is possible to perform a stable abatement process.
[0021]
The amount of the stabilizer to be added to the high-purity cupric hydroxide varies somewhat depending on the type of the stabilizer, but usually about 0.01 to 10% by weight based on the high-purity cupric hydroxide is appropriate. If the amount is too large, the ability to remove copper (II) hydroxide may be impaired. If the amount is too small, a sufficient stabilizing effect cannot be obtained. The stabilizer may be present together with the dehydrating agent in high-purity cupric hydroxide.
[0022]
BEST MODE FOR CARRYING OUT THE INVENTION
FIGS. 1 to 3 are schematic system diagrams showing each embodiment of the device of the present invention. First, a first embodiment shown in FIG. 1 has a gas inlet 11 into which exhaust gas containing volatile inorganic hydride, volatile inorganic halide, and organometallic compound as harmful components is introduced, and a gas from which a processing gas is led out. Into a column 13 having an outlet 12, the inlet is filled with the first harm-removing agent 14 containing high-purity cupric hydroxide as a main component, and the second eliminator 14 is provided on the outlet. It is filled with the harmful agent 15.
[0023]
In the second embodiment shown in FIG. 2, a dehydrating agent 16 is filled between the first abatement agent 14 and the second abatement agent 15 in the column 13. Further, a third embodiment shown in FIG. 3 is a treating agent in which a first abatement agent 14 containing high-purity cupric hydroxide as a main component and a dehydrating agent coexist on the inlet side of the column 13. 17 is filled.
[0024]
As described above, the first abatement agent may be one in which high-purity cupric hydroxide and a stabilizer coexist, and may be high-purity cupric hydroxide, a dehydrating agent, and a stabilizing agent. An agent may coexist. Also, in each embodiment, one column is packed with the first abatement agent and the second abatement agent in layers, but the first abatement agent and the second abatement agent or the first abatement agent and the The agent and the second abatement agent may be filled in another column and connected by piping.
[0025]
The harmful component removing device formed as described above introduces an exhaust gas containing a special gas into the column 13 from the inlet port 11 to convert the harmful component gas in the exhaust gas into high-purity cupric hydroxide on the upstream side. After the treatment with the first abatement agent as the main component, the finishing treatment is carried out with the second abatement agent on the downstream side, so that the gas sufficiently treated with the harmful component can be led out from the outlet 12.
[0026]
【Example】
Example 1
First, the following were prepared as a 1st abatement agent, a 2nd abatement agent, a dehydrating agent, and a harmful component gas. In addition, a molded article is what was granulated to the size of 3 mm in diameter with a rolling granulator. Further, a harmful component gas treatment amount [L / kg] per 1 kg of the agent is calculated from the amount of the test gas introduced until the amount of the harmful component gas contained in the treated gas reaches the allowable concentration of each gas. Processing capacity.
[0027]
Examples of the first abatement agent include a commercially available molded product of cupric hydroxide (A) and a high-purity crystalline hydroxide purified so that the concentration of each impurity component is 0.5% by weight or less. A cupric molded article (B), a cupric oxide molded article (C) as a second detoxifying agent, and silica gel (S) as a dehydrating agent were prepared. In addition, harmful component gases include silane (allowable concentration 5 ppm), arsine (allowable concentration 0.05 ppm), phosphine (allowable concentration 0.3 ppm) and tertiary butyl arsine (TBA: allowable concentration 0.025 ppm (of arsenic contained). Conversion values from the allowable concentration)) were prepared.
[0028]
As the test gas when performing the detoxification treatment, a first test gas (G1) having a harmful gas component concentration of 1% on a nitrogen basis and a flow rate of 1 liter / min, a harmful gas component concentration of 5% on a nitrogen basis, A second test gas (G2) having a flow rate of 5 L / min was prepared. A column filled with the first abatement agent or the like had an inner diameter of 43 mm.
[0029]
A column filled with commercially available cupric hydroxide (A) (filling height 250 mm) and cupric oxide (C) (filling height 50 mm) in a layer (see FIG. 1), high-purity crystals Cupric hydroxide (B) (filling height 250 mm) and cupric oxide (C) (filling height 50 mm) packed in layers (see FIG. 1); Copper (B) (filling height 215 mm), dehydrating agent (S) (filling height 42.5 mm), and cupric oxide (C) (filling height 42.5 mm) filled in layers (FIG. 2) ), The processing capacity for each harmful component gas was measured using both test gases. Table 1 shows the results.
[0030]
[Table 1]

[0031]
Example 2
As shown in Table 2, a metal oxide, a metal oxide hydroxide, a metal carbonate, and a base were placed downstream of the column packed with the first abatement agent (B) at a height of 250 mm in the same manner as in Example 1. A second harm-removing agent such as a neutral metal carbonate was filled at a height of 50 mm, and a gas containing silane was introduced therein under the condition of the second test gas (G2), and the respective treatment capacities were measured. Table 2 shows the results.
[0032]
[Table 2]

[0033]
Example 3
After adding various substances shown in Table 3 and water to high-purity crystalline cupric hydroxide (B) and mixing well, the mixture is granulated to a size of 3 mm in diameter by a tumbling granulator to obtain high purity. A first abatement agent in a state where crystalline cupric hydroxide and various substances coexist was prepared. The amount of each substance other than those specified is 0.5% by weight. Each of the obtained first abatement agents was kept at 100 ° C., and the discoloration state from blue to black was examined. The cupric hydroxide itself is blue, but gradually changes to copper oxide and turns black at high temperatures. Table 3 shows the measurement results of the discoloration time.
[0034]
[Table 3]

[0035]
【The invention's effect】
As described above, the present invention includes a volatile inorganic hydride, a volatile inorganic halide, and an organometallic compound as a harmful component in the first abatement agent containing high-purity cupric hydroxide as a main component in advance. The exhaust gas is contacted to pre-treat the harmful components in a pretreatment manner, and the gas with reduced harmful components to some extent is converted to a metal oxide, a metal oxide hydroxide, a metal carbonate, or a basic metal carbonate. Since the finishing treatment is performed by contacting the second abatement agent, the agent can be used for a longer time than when these agents are used alone. Then, even if the first detoxifying agent cannot sufficiently perform the detoxification treatment depending on the use conditions, the special gas component can be surely processed to an extremely small amount by the second detoxification agent on the downstream side. Therefore, the exhaust gas containing harmful components , particularly, the exhaust gas containing special gas components such as arsine, phosphine, silane, dichlorosilane, tertiary butyl arsine and the like discharged from a semiconductor manufacturing plant can be efficiently removed.
[Brief description of the drawings]
FIG. 1 is a schematic system diagram showing a first embodiment of an apparatus for removing harmful components according to the present invention.
FIG. 2 is a schematic system diagram showing a second embodiment of the harmful component removing device of the present invention.
FIG. 3 is a schematic system diagram showing a third embodiment of the harmful component removing device of the present invention.
[Explanation of symbols]
11 gas inlet, 12 gas outlet, 13 column, 14 first abatement agent, 15 second abatement agent, 16 dehydrating agent, 17 treatment agent

Claims

Volatile inorganic hydrides as harmful components, volatile inorganic halides, a semiconductor manufacturing factories and exhaust gases that will be discharged from the liquid crystal manufacturing plant comprising an organometallic compound, as a main component cupric hydroxide, as an impurity component, phosphorus Contains mineral acid components such as acid, sulfuric acid and hydrochloric acid and alkali metal components such as lithium, sodium and potassium , and the content of the impurity component in cupric hydroxide is 0.5 wt. % Or less of a high-purity cupric hydroxide as a main component, and then contacted with at least one of a metal oxide, a metal oxide hydroxide, a metal carbonate, and a basic metal carbonate. A method for removing harmful components in exhaust gas discharged from a semiconductor manufacturing plant or a liquid crystal manufacturing plant, wherein the method is brought into contact with a second abatement agent containing two compounds as main components .

The exhaust gas is discharged from a semiconductor manufacturing plant or a liquid crystal manufacturing plant according to claim 1, wherein the exhaust gas is brought into contact with a first detoxifying agent, then with a dehydrating agent, and then with the second detoxifying agent. Of harmful components in waste gas.

The first abatement agent, the high-purity cupric hydroxide and beryllium, magnesium, vanadium, molybdenum, cobalt, nickel, copper, zinc, boron, aluminum, silicon, lead, antimony, bismuth At least one element selected, or an oxide, hydroxide (excluding copper hydroxide), carbonate, hydrogencarbonate, basic carbonate, oxide hydroxide, peroxide, carboxylic acid of the element 2. The method for removing harmful components in exhaust gas discharged from a semiconductor manufacturing plant or a liquid crystal manufacturing plant according to claim 1, wherein a stabilizer comprising at least one of a salt and an oxyacid salt is present.

The first Jogaizai is detrimental in an exhaust gas discharged from a semiconductor manufacturing plant or a liquid crystal manufacturing plant according to claim 1, wherein the said high purity cupric hydroxide and dehydrating agent coexist How to remove components .

The first abatement agent, beryllium, magnesium, vanadium, molybdenum, cobalt, nickel, copper, zinc, boron, aluminum, silicon, lead, antimony, at least one element selected from the group of bismuth, or It consists of at least one of oxides, hydroxides (excluding copper hydroxide), carbonates, bicarbonates, basic carbonates, hydroxides, peroxides, carboxylates and oxyacids of the element. 5. The method for removing harmful components in exhaust gas discharged from a semiconductor manufacturing plant or a liquid crystal manufacturing plant according to claim 4 , wherein a stabilizing agent coexists.

The high-purity cupric hydroxide has a concentration of each of the mineral acid components of phosphoric acid, sulfuric acid, and hydrochloric acid and the alkali metal components of lithium, sodium, and potassium in cupric hydroxide of 0.2% by weight or less. 2. The method for removing harmful components in exhaust gas discharged from a semiconductor manufacturing plant or a liquid crystal manufacturing plant according to claim 1.

The method for removing harmful components in exhaust gas discharged from a semiconductor manufacturing plant or a liquid crystal manufacturing plant according to claim 1, wherein the high-purity cupric hydroxide is crystalline cupric hydroxide.

Volatile inorganic hydrides as harmful components, volatile inorganic halides, and inlet exhaust gas that will be discharged from a semiconductor manufacturing plant or a liquid crystal manufacturing plant comprising an organic metal compound is introduced, and electrical outlet process gas is derived In the column having, on the inlet side the main component is cupric hydroxide, and as the impurity components, phosphoric acid, sulfuric acid, a mineral acid component of hydrochloric acid and an alkali metal component of lithium, sodium and potassium are contained, and The first abatement agent containing high-purity cupric hydroxide as a main component, in which the content of the impurity component in cupric hydroxide is 0.5% by weight or less per unit of one impurity component , is filled. In addition, the outlet port side is filled with a second harm-removing agent containing at least one compound of a metal oxide, a metal oxide hydroxide, a metal carbonate, and a basic metal carbonate as a main component. Semiconductor manufacturing plant Apparatus for removing harmful components in exhaust gas discharged from a liquid crystal manufacturing plant.

Between the second detoxifying agents and the first detoxifying agents, harmful in the exhaust gas dehydrating agent is discharged from a semiconductor manufacturing plant or a liquid crystal manufacturing plant according to claim 8, characterized in that it is filled Component removal device.

The first abatement agent, the high-purity cupric hydroxide and beryllium, magnesium, vanadium, molybdenum, cobalt, nickel, copper, zinc, boron, aluminum, silicon, lead, antimony, bismuth At least one element selected, or an oxide, hydroxide (excluding copper hydroxide), carbonate, hydrogencarbonate, basic carbonate, oxide hydroxide, peroxide, carboxylic acid of the element 9. The apparatus for removing harmful components in exhaust gas discharged from a semiconductor manufacturing plant or a liquid crystal manufacturing plant according to claim 8, wherein a stabilizer comprising at least one of a salt and an oxyacid salt coexists.

The first Jogaizai is detrimental in an exhaust gas discharged from a semiconductor manufacturing plant or a liquid crystal manufacturing plant according to claim 8, wherein the said high purity cupric hydroxide and dehydrating agent coexist Component removal device.