JP3738494B2

JP3738494B2 - Single wafer heat treatment equipment

Info

Publication number: JP3738494B2
Application number: JP26777496A
Authority: JP
Inventors: 一二青木; 亘大加瀬; 雅昭長谷井
Original assignee: Tokyo Electron Ltd
Current assignee: Tokyo Electron Ltd
Priority date: 1996-09-18
Filing date: 1996-09-18
Publication date: 2006-01-25
Anticipated expiration: 2016-09-18
Also published as: JPH1092753A

Description

【０００１】
【発明の属する技術分野】
本発明は、半導体ウエハ等に対して成膜等の熱処理を施す枚葉式の熱処理装置に関する。
【０００２】
【従来の技術】
一般に、半導体集積回路の製造においては、半導体ウエハ表面に成膜や酸化・拡散を施す熱処理工程やパターンエッチングする工程を繰り返し行なう。従来、例えば８インチサイズのウエハを熱処理する場合には、一度に多数枚のウエハを熱処理できることから主に縦型のバッチ式の熱処理装置が使用されていた。この種の熱処理工程で重要な点は、製品回路の特性の均一性及び歩留まりの向上の観点より、熱処理時において、ウエハ面内の温度を均一性良く制御する点である。
【０００３】
【発明が解決しようとする課題】
ところで、回路の高集積化及び高微細化に伴って、ウエハサイズも大口径化され、例えば１２インチサイズのウエハの使用が検討されている。
このようにウエハサイズが８インチから１２インチ（略３０ｃｍ程度）に拡大すると、ウエハ自重が８インチサイズのウエハと比較して２．５〜３倍程度に増加し、しかも、ウエハ面内の均熱性を考慮すると、従来のバッチ式の縦型の熱処理装置では対応し難くなった。すなわち、ウエハ自重が上述のように数倍になった結果、多数のウエハを支持するウエハボートが強度上耐えられなくなったり、或いは、大口径化によりウエハ面積が大きくなったことから、所定のピッチで配列されたウエハの側方より加熱する方式ではウエハ面内の均一加熱を十分に行ない難くなった。
【０００４】
そこで、上記問題点を解決するために、ウエハを一枚ずつ処理する枚葉式の熱処理装置も種々提案されており、この装置ではウエハホルダの下方に配置したハロゲンランプや抵抗ヒータにより、ホルダ上に支持或いは載置したウエハを加熱するようになっている。しかしながら、従来の枚葉式の熱処理装置を用いた場合であっても、大口径化のウエハを面内温度の均一性良く加熱することは現状のヒータの単位面積当たりの発熱量を勘案すると、かなり難しく、従来装置で十分であるとは言えなかった。
本発明は、以上のような問題点に着目し、これを有効に解決すべく創案されたものである。本発明の目的は、被処理体の面内温度の均一性を向上させることができる枚葉式の熱処理装置を提供することにある。
【０００５】
【課題を解決するための手段】
本発明は、上記問題点を解決するために、処理容器内の被処理体ホルダに保持させた被処理体に対して所定の熱処理を施す枚葉式の熱処理装置において、前記被処理体ホルダの下方と上方に前記被処理体を加熱するために配置された加熱手段と、内部に前記加熱手段を収容して、前記処理容器内に対して気密状態で仕切るための加熱手段容器と、前記処理容器と前記加熱手段容器とに接続されて両容器内の圧力を所定の圧力範囲内に維持しつつガスを供給するガス供給系と、前記処理容器と前記加熱手段容器とに接続されて両容器内の圧力を所定の圧力範囲内に維持しつつ内部雰囲気を排出するガス排気系と、を備え、前記ガス供給系とガス排気系は、それぞれ前記各容器に共通に接続された共通ガス通路と、前記各容器に連結された通路に介設された固定ニードル弁とを有するように構成したものである。
【０００６】
このように、ホルダの上下に加熱手段を配置することにより、被処理体を両面から加熱でき、この面内温度の均一性を高めることが可能となる。また、加熱手段を処理容器に対して気密状態で仕切られた加熱手段容器内に収容して所定のガス供給系とガス排気系を設けることにより、処理容器内と加熱手段容器内の圧力差を常に少なくでき、その分、加熱手段容器の処理容器に対する区画壁を圧力差に耐え得る程度まで薄くして、加熱手段の熱効率を高めて面内温度の均一性の向上及び熱制御性の向上を図ることが可能となる。
上記のように両容器内の圧力差を所定の範囲内に設定するには、上記ガス供給系とガス排気系に、両容器に共通に接続された共通ガス通路を設け、各容器に連結された通路に固定ニードル弁を設け、これにより所定量ずつのガスを供給したり、或いは排気したりするように構成すればよい。
【０００７】
また、上記固定ニードル弁に代えて、流量制御弁を設け、差圧測定部により両容器内の圧力差を検出し、弁開度制御部がこの検出差圧に応じて上記流量制御弁の弁開度を制御して両容器内の差圧をコントロールするように制御してもよい。更には、被処理体ホルダの周辺部にリング状の均熱リング部材を設けることにより、この輻射熱によっても被処理体を加熱することができ、被処理体の面内温度の均一性を高めると同時に熱効率も向上させることができる。また、熱処理が成膜処理の場合には、均熱リング部材は、処理容器の側壁に対しては断熱材として機能して部分的なホットウォール構造となり、不要な反応生成物が処理容器側壁の代わりにメンテナンス容易な均熱リング部材に付着することになり、クリーニング等のメンテナンスを容易に行なうことが可能となる。
【０００８】
また、処理ガスを供給するガス供給ヘッドと、均熱リング部材と、被処理体ホルダと、処理容器内の雰囲気を排出するガス排気ヘッドを一体的に成形することにより、被処理体の部分のみに効率的に処理ガスを供給できるのみならず、メンテナンスも容易に行なうことが可能となる。
更に、加熱手段としてランプではなく、抵抗加熱ヒータを用いることにより、例えば１０００℃以上の高温の熱処理を行なうことが可能となる。
【０００９】
【発明の実施の形態】
以下に、本発明に係る枚葉式の熱処理装置の一実施例を添付図面に基づいて詳述する。
図１は本発明に係る枚葉式の熱処理装置を示す構成図、図２は加熱手段を示す平面図、図３は均熱リング部材を示す斜視図、図４はガス供給系とガス排気系を示す模式図である。
本実施例においては、熱処理装置として半導体ウエハ表面に成膜を施す成膜処理装置を例にとって説明する。
【００１０】
図示するようにこの熱処理装置２は、アルミニウム等により円筒体状に成形された処理容器４を有しており、この底部と天井部は、それぞれ開口されている。底部の開口には、例えば石英製の下側加熱手段容器６が、天井部の開口には同じく石英製の上側加熱手段容器８がそれぞれ処理容器４内に対して気密に区画されて密閉状態で設けられている。
上記下側加熱容器６は、処理容器４内に向けて凸状に挿入されて上端が平面状になされた薄板椀部６Ａと、この下端開口部を覆って設けられて外側が大気に晒される厚板蓋部６Ｂとにより構成され、Ｏリング等のシール部材１０を介して処理容器４の底部に気密に設けられる。
【００１１】
上記薄板椀部６Ａの厚さは例えば４ｍｍ程度と薄く設定され、この部分における熱ロスを抑制すると共に熱応答性を良好にしている。このように薄板椀部６Ａの厚みは薄いことから、後述するように処理容器４内の圧力変動に追従させてこの下側加熱手段容器６内の圧力も変動させて両容器内の差圧が薄板椀部６Ａの耐圧強度以下になるように設定している。また、厚板蓋部６Ｂの厚みは略大気圧に耐え得るような厚さ、例えば１５〜２０ｍｍ程度に設定される。
この下側加熱手段容器６の中央部には、磁性流体シール１２を介して上下方向に気密に貫通された例えば石英製の被処理体ホルダ１４の支持軸１５がウエハ均熱加熱のために回転可能に設けられており、ホルダ１４の上端には同一円周上に等間隔で配置された３つの爪部１４Ａが形成されて、この爪部１４Ａ上に被処理体である半導体ウエハＷの裏面周縁部を支持するようになっている。
【００１２】
ここで、薄板椀部６Ａは前述のように処理容器４内に凸部に挿入されて、できるだけ半導体ウエハＷの裏面に近付くように設定されており、この薄板椀部６Ａの上端平面部の内側に、下側の加熱手段として例えば抵抗加熱ヒータ１６が略全面に亘って設けられており、ウエハＷを下面側から加熱するようになっている。そして、ホルダ１４の支持軸１５の下部には、例えばモータの如き回転機構２２が設けられており、ウエハＷを回転しつつ加熱するようになっている。
厚板蓋部６Ｂには、下側加熱手段容器６内にＮ₂ガス等のパージガスを導入するパージガス導入口１８及び内部の雰囲気ガスを排気するパージガス排気口２０がそれぞれ設けられている。
【００１３】
一方、上記上側加熱手段容器８は、上記下側容器６と同様に、処理容器４内に向けて凸状に挿入されて下端が平面状になされた薄板椀部８Ａと、この上端開口部を覆って設けられて外側が大気に晒される厚板蓋部８Ｂとにより構成され、Ｏリング等のシール部材２４を介して処理容器４の天井部に気密に設けられる。
上記薄板椀部８Ａの厚さは例えば４ｍｍ程度と薄く設定され、この部分における熱ロスを抑制すると共に熱応答性を良好にしている。
このように薄板椀部８Ａの厚みも薄いことから、処理容器４内の圧力変動に追従させてこの上側加熱手段容器８内の圧力も変動させて両容器内の差圧が薄板椀部８Ａの耐圧強度以下になるように設定している。また、厚板蓋部８Ｂの厚みは略大気圧に耐え得るような厚さ、例えば１５〜２０ｍｍ程度に設定される。
【００１４】
この薄板椀部８Ａの下端平面部の内側に、上側の加熱手段として例えば抵抗加熱ヒータ２６が略全面に亘って設けられており、ウエハＷを上面側から加熱するようになっている。ここで、ウエハＷと上下の各抵抗加熱ヒータ２６、１６との間の距離は非常に小さく、例えばそれぞれ１０ｍｍ程度に設定されており、効率良くウエハＷを加熱するようになっている。
また、上側加熱手段容器８の下面側には、例えば石英製の容器状のシャワーヘッド構造になされたガス供給ヘッド２８が設けられており、これには処理ガスを導入する処理ガス導入管３０が接続されている。そして、この導入管３０より導入された処理ガスは、ガス供給ヘッド２８の下面全体に設けた多数の噴出孔３２よりウエハＷの上面全域に向けて処理ガスを噴出するようになっている。
厚板蓋部８Ｂには、ウエハ側加熱手段容器８内にＮ₂ガス等のパージガスを導入するパージガス導入口３６及び内部の雰囲気ガスを排気するパージガス排気口３８がそれぞれ設けられる。
【００１５】
一方、処理容器４の底部周縁部には、容器内の雰囲気を排気するために図示しない真空ポンプに接続されたガス排気口３４が設けられ、また、天井部には、Ｎ₂ガス等のパージガスを処理容器４内に導入するためのパージガス導入口４０が設けられている。尚、このパージガス導入口４０としてガス供給ヘッド２８を兼用するようにしてもよい。
また、処理容器４の側壁には、ウエハＷの搬入・搬出時に開閉されるゲートバルブ４０が設けられており、このゲートバルブ４０を介して例えばロードロック室４２を設けて、処理容器４内の真空を破ることなくウエハの搬入・搬出を行ない得るようになっている。そして、このロードロック室４２内には、ウエハを形成するために屈伸及び旋回可能になされた搬送アーム４４が設けられている。また、この搬送アーム４４のベースは、昇降可能なスライド機構４６に保持されており、アーム全体を昇降可能てしている。
【００１６】
一方、上記上側及び下側の抵抗加熱ヒータ２６、１６は図２に示すように同心円状に複数、例えば３つのゾーンに分割されており、電力供給部４８から各ゾーンに対して個別に供給電力を制御して電力を分配して供給できるようになっている。尚、ゾーン分割数は、３つに限定されず、２つ或いは４つ以上でもよい。
そして、処理容器４内の被処理体ホルダ１４の周辺部には、これに保持されたウエハＷの側部を覆うように例えば石英製の均熱リング部材５０（図３参照）が設けられており、これからの輻射熱によりウエハＷを加熱すると同時に、処理容器４の側壁に対しては断熱機能を発揮するようになっている。この均熱リング部材５０の一側には、すなわちゲートバルブ４０と対向する円弧状の部分は、シャッタ部５０Ａとして本体側から切断されて分離されており、このシャッタ部５０Ａには、処理容器４の底部を貫通させて設けたシャッタ棒５２が接続されている。そして、このシャッタ棒５２の貫通部には、気密性を保持しつつこの上下動を許容する金属性の伸縮可能なベローズ５４が設けられており、ウエハＷの搬入・搬出時に、図示しない昇降機構によりこのシャッタ部５０Ａを上下動させ得るようになっている。このシャッタ部５０Ａは、ゲートバルブ４０の開閉に同期して上下動される。
【００１７】
一方、上記処理容器４内、下側及び上側加熱手段容器６、８内の圧力を制御するガス供給系とガス排気系は図４に示すように構成される。すなわち、Ｎ₂ガス等のパージガスを供給するガス供給系５６は、各容器４、６、８のパージガス導入口４０、１８、３６に共通に接続される共通ガス通路５８を有しており、これより分岐した各分岐管６０を介して各パージガス導入口４０、１８、３６に接続される。そして、各分岐管６０には所定の差圧で開動作する供給側固定ニードル弁６２が介設されており、例えば大気圧復帰のためのＮ₂ガス供給時には、各容器内の差圧を過度に大きくすることなく、Ｎ₂ガスを供給し得るようになっている。
【００１８】
また、各容器内の雰囲気ガスを排出するガス排気系６４は処理容器４のガス排気孔３４及び下側及び上側加熱手段容器６、８のパージガス排気口２０、３８に共通に接続される共通ガス通路６６を有しており、これより分岐した各分岐管６８を介してガス排気孔３４及び各パージガス排気口２０、３８に接続される。そして、各分岐管６８には、所定差圧で開動作する排気側固定ニードル弁７０が介設されており、例えば処理容器内の真空引き時には他の容器内との差圧を過度に大きくすることなく雰囲気ガスを排気するようになっている。
そして、排気用の共通ガス通路６６には、排気時に一定量ずつのガスを排気するためのマスフローコントローラ７２及び真空ポンプ７４が介設されている。
【００１９】
次に、以上のように構成された本実施例の動作について説明する。
まず、ロードロック室４２の搬送アーム４４を伸長させることによってこれに保持した未処理の半導体ウエハＷを、開放されたゲートバルブ４０を介して処理容器４内に搬入し、アーム４４を微小距離だけ降下させてウエハＷを処理容器４内の被処理体ホルダ１４に受け渡す。そして、アーム４４を縮退させてゲートバルブ４０を閉じ、処理容器４内を密閉状態とする。
【００２０】
次に、処理容器４内を所定のプロセス圧力まで真空引きすると共にこの中に処理ガスをガス供給ヘッド２８からシャワー状に供給し、プロセス圧力を維持する。これと同時に、下側及び上側加熱手段容器６、８内に収容してある各抵抗加熱ヒータ１６、２６に電力を供給し、或いは供給電力を増大し、ホルダ１４に載置してあるウエハＷを上下の両面から加熱してこれをプロセス温度に維持し、所定の熱プロセスを行なう。この場合、上下の抵抗加熱ヒータ２６、１６は、ウエハ面内を均熱加熱するように各ゾーン毎に個別に投入電力を制御する。
熱処理として、例えばＣＶＤ（ＣｈｅｍｉｃａｌＶａｐｏｒＤｅｐｏｓｉｔｉｏｎ）を行なう場合には、処理ガスとして例えばシランと水素ガスの混合ガスを用い、キャリアガスとしてＡｒガスを流し、プロセス圧を０．５Ｔｏｒｒ程度、プロセス温度を１０５０℃程度に設定する。
【００２１】
ここでウエハＷを加熱するために、この上下に抵抗加熱ヒータ２６、１６を配置し、且つ、各ヒータ２６、１６をそれぞれ石英製の加熱手段容器８、６で密閉しているので、ウエハ汚染を引き起こすことなくウエハを両面から加熱することができる。従って、ウエハを高速で且つ面内温度の均一性良く加熱することが可能となる。特に、この実施例では、各加熱手段容器８、６の薄板椀部８Ａ、６Ａを処理容器４内に凹状に挿入させてそこに各ヒータ２６、１６を配置した結果、ウエハ面と各ヒータ面とを可能な限り近付けて両者間の距離を非常に小さく設定できるので、ウエハサイズが大きくても面内温度の均一性をより向上させることが可能となる。
また、石英製の各薄板椀部８Ａ、６Ａの厚みは、４ｍｍ程度と非常に薄く設定されているので、この部分における熱損失は少なく、しかも薄くて熱容量が小さいことから熱応答性に優れ、ウエハＷの温度を応答性良く制御することが可能となる。
【００２２】
また、各抵抗加熱ヒータ２６、１６は、図２に示すように同心円状に複数にゾーン分割されて、ゾーン毎に個別に供給電力を制御することができるので、ウエハ温度を細かくコントロールすることができる。
更には、ウエハＷの周辺部には、これを覆うように均熱リング部材５０を設けて、これからの輻射熱によってもウエハＷを加熱することができるので、ウエハ温度の面内均一性を一層向上させることができるのみならず、処理容器への熱の漏れも少なくなるので、その分、熱効率も向上させることができる。また、このように均熱リング部材５０を設けることにより、これに部分的にホットウォール機能を持たせることができ、従って、従来においては処理容器の内壁面に付着していた不要な成膜を、容器内壁面に付着させることなく着脱容易な均熱リング部材５０側に付着させることができるので、クリーニング等のメンテナンスを容易に行なうことができる。
更に、ここでは発熱量の大きな抵抗加熱ヒータ１６、２６を用いているので、１０００℃以上の高温にウエハを加熱することができる。尚、このヒータに代えて、ハロゲンランプを用いるようにしてもよい。
【００２３】
また、処理容器４内の圧力変化により、これと上側及び下側の加熱手段容器８、６内との間で過度の圧力差が生ずることが考えられるが、上側及び下側の加熱手段容器８、６内の圧力も処理容器４内の圧力に追従して変動させるようになっているので、両容器間の区画壁が破損することはない。これを図４を参照して説明する。
前述したように、ガス供給系５６及びガス排気系６４の各分岐管６０、６８にはそれぞれ固定ニードル弁６２、７０が設けられており、差圧により弁開度が自動的に変化するようになっている。
【００２４】
まず、真空引きする場合を説明すると、一般的に容量の異なる２つの容器から、同一流量で別個独立に真空引きすると、図５（Ａ）に示すように大容量の容器内の圧力は緩やかに低下するが、小容量の容器の圧力は急激に低下し、両容器間には大きな圧力差が生ずる。しかしながら、本発明のように分岐管６８に排気側固定ニードル弁７０を介設して、真空ポンプ７４によりマスフローコントローラ７２の制御下で一定の流量ずつ例えば毎分数リットルずつ排気すると、各固定ニードル弁７０の作用により、容量の小さな上側及び下側の加熱手段容器８、６内の雰囲気は小量ずつ排気されるのに対して、容量の大きな処理容器４内の雰囲気は大量に排気され、その結果、図５（Ｂ）に示すように加熱手段容器６、８内の圧力は処理容器４内の圧力に追従するように変動し、処理容器４と加熱手段容器６、８内の圧力差は常に少ない状態に維持されて真空引きされることになる。
このことは、各容器内を大気圧復帰させるためにＮ₂ガスをパージする場合も同様であり、図４に示すようにガス供給系５６の各分岐管６０にそれぞれ固定ニードル弁６２を介設した結果、Ｎ₂ガス供給時においても各容器間の圧力差が常に少ない状態に維持されてＮ₂ガスが供給されることになる。従って、処理容器４と両加熱手段容器６、８間の圧力差は常に少なく、例えば、１０Ｔｏｒｒ程度の差圧になっているので、両容器を区画する各薄板椀部６Ａ、８Ａは前述のように４ｍｍ程度の薄さで済ませることができ、熱損失の抑制や熱応答性の向上に寄与することができる。尚、大気圧に晒される両厚板蓋部６Ｂ、８Ｂは大気圧に耐え得るように肉厚に成形している。
【００２５】
次に、ウエハに対して片面加熱の場合と本発明のようにウエハの両面側に加熱手段を配置した両面加熱の場合のウエハ温度プロフィールをシミュレーションにより求めたので、その結果について説明する。
図６（Ａ）は従来の片面加熱の場合のウエハ温度プロフィールを示し、図６（Ｂ）は本発明のような両面加熱の場合のウエハ温度プロフィールを示す。それぞれ、ヒータのゾーンは２分割であり、設定温度は１０４０℃である。
図６（Ａ）に示すように片面加熱の場合は、ウエハの周辺部に行く程、少しずつ温度が低下して中心部との間で１０℃程度の温度差が生じ、面内温度の均一性がそれ程良好でなく、しかも、この時の外側ゾーンのヒータには定格の７ＫＷ以上の電力を投入しなければならなかった。これに対して、図６（Ｂ）に示す両面加熱の場合には、ウエハ中心部と周辺部との間にほとんど温度差はなく、面内温度の均一性を高く維持することができた。しかも、全体としての使用電力は片面加熱の場合よりも少し多くなったが、各ゾーン毎のヒータへの投入電力は全て定格値以下であった。
【００２６】
上記実施例においては、図３に示すように、ゲートバルブを熱から保護するために昇降可能なシャッタ部５０Ａを有する均熱リング部材５０を設けたが、これに代えて、図７（Ａ）に示すように均熱リング部材５０の一側面の中央に、ウエハＷを挿通し得る大きさのスリット状の開口５０Ｂを設けたものを用いるようにしてもよい。この場合には、ゲートバルブを熱から保護するために、回転可能とし、ウエハＷの搬入・搬出後、この均熱リング部材５０を略１８０度程度周方向へ回転させるようにすればよい。
また、上記構成に代えて、図７（Ｂ）に示すように均熱リング部材５０の一側面の下部に、ウエハＷを挿通し得る大きさの凹部状の切り欠き５０Ｃを設けたものを用いるようにしてもよい。この場合には、ゲートバルブを熱から保護するためにリング部材を回転可能、或いは昇降可能とし、ウエハＷの搬入・搬出後、この均熱リング部材５０を略１８０度程度周方向へ回転させるようにしてもよいし、或いは下方向へ移動させるとようにしてもよい。
また、ここではシャワーヘッド構造のガス供給ヘッド２８と、均熱リング部材５０と被処理体ホルダ１４を別個独立に設け、ガス排気孔３４は、処理容器４の底部周辺部に設けた構造としたが、これに代えて図８乃至図１０に示すようにガス排気孔をシャワーヘッド構造と同様な構造のガス排気ヘッド７６としてこれら全てを一体的に成形するようにしてもよい。すなわち、シャワーヘッド構造のガス供給ヘッド２８を図７（Ａ）に示すような構造の均熱リング部材５０と接合し、このリング部材５０の内壁面から中心に向けて３つの爪部１４Ａ付きの被処理体ホルダ１４を設ける。そして、ガス排気ヘッド７６は、上記ガス供給ヘッド２８と同様な構造のシャワーヘッド構造としてその上面にガスを吸入する多数の吸入孔７８を設け、ガス出口をガス排気孔３４に接続すればよい。これらは、例えば石英により一体的に形成することが可能である。
【００２７】
このように形成することにより、ガス供給ヘッド２８から下方のウエハＷ側へ供給された処理ガスは、この表面に接した後に横に流れて直ちにその下方のガス排気ヘッド７６内に吸引されるように流れる。従って、処理ガスが処理容器４内の周縁部に拡がって流れることがなく、効率的にウエハ面と接するように流れることとなり、処理ガスの使用効率を高めることが可能となる。
また、この一体構造物に不要な成膜が付着した場合には、この一体構造物のみをクリーニングすればよく、メンテナンス作業を効率的に行なうことが可能となる。
また、上記実施例では、図４に示すようにガス供給系５６とガス排気系６４に固定ニードル弁６２、７０を設けて各容器間の圧力差をコントロールしているが、これに限定されず、図１１に示すように構成してもよい。すなわち、ガス供給系５６及びガス排気系６４の各分岐管６０、６８の内、加熱手段容器６、８に連通される分岐管にはニードル弁に代えて弁開度を自由にコントロールすることができる流量制御弁８０Ａ、８０Ｂ、８２Ａ、８２Ｂを設け、処理容器４に連通される分岐管には、これらの弁を設けないようにする。そして、処理容器４と下側の加熱手段容器６内の圧力差を検出する第１の差圧測定部８４を設け、この検出値に基づいて第１の弁開度制御部８６が、下側加熱手段容器６の供給側或いは排気側の流量制御弁８０Ｂ、８２Ｂを制御する。
また、処理容器４と上側の加熱手段容器８内の圧力差を検出する第２の差圧測定部８８を設け、この検出値に基づいて第２の弁開度制御部９０が上側加熱手段容器８の供給側或いは排気側の流量制御弁８２Ａ、８２Ｂを制御する。
【００２８】
このような構成によれば、真空引き時には第１及び第２の弁開度制御部８６、９０は、各差圧測定部８４、８８の検出値が、薄板椀部６Ａ、８Ａの耐圧範囲内、例えば±１０Ｔｏｒｒ以内に維持されるように排気側の各流量制御弁８２Ａ、８２Ｂの弁開度を制御することになる。また、処理容器４内の大気圧復帰のためにＮ₂ガスをパージする場合には、同様に検出値が±１０Ｔｏｒｒ以内に維持されるように供給側の各流量制御弁８０Ａ、８０Ｂの弁開度が制御されることになる。従って、図４に示した構成と同様な作用効果を呈すことができる。
尚、本実施例においては、熱処理としてＣＶＤにより成膜処理を行なう場合を例にとって説明したが、これに限らず、酸化・拡散処理、アニール処理等の他の熱処理にも適用し得るのは勿論である。
また、ここでは処理容器４の一側にのみゲートバルブ４０を設けてこれよりウエハを搬入・搬出するようにしたが、これと対向する位置にもう１つのゲートバルブを設けて、ウエハの搬入口と搬出口とを別々に設けるようにしてもよい。この場合には、それに対応させて均熱リング部材５０のシャッタ部５０Ａ等も２つ設けるようにする。
更には、被処理体としては半導体ウエハに限定されず、ガラス基板、ＬＣＤ基板等にも適用することができる。
【００２９】
【発明の効果】
以上説明したように、本発明の枚葉式の熱処理装置によれば、次のように優れた作用効果を発揮することができる。
被処理体の両面側に加熱手段を配置して両面加熱するようにしたので、被処理体のサイズが大きくなってもこの面内温度の均一性を大幅に向上させることができる。
また、加熱手段を加熱手段容器内に収容して、内部を処理容器内の圧力変動に追従させて圧力変動させて両容器間の差圧を少なく維持することにより、両容器を区画する区画壁を薄くでき、その分、熱効率を高めて被処理体の面内温度の均一性を更に向上させることができるのみならず、熱応答性も良好にすることができる。
更に、被処理体の側部を均熱リング部材で覆うことにより、外部に放出される熱量を少なくして熱効率を高めることができると共に、その分、面内温度の均一性を向上させることができる。また、このリング部材により、部分的なホットウォール構造とすることができるので、処理容器側壁に不要な成膜が付着することを防止でき、メンテナンスも容易に行なうことができる。
また、ガス供給ヘッドと、均熱リング部材と、被処理体ホルダと、ガス排気ヘッドを一体構造化することにより、側部に漏れ出る処理ガスが少なくなり、処理ガスの使用効率を向上させることができるのみならず、メンテナンス作業も容易に行なうことができる。
【図面の簡単な説明】
【図１】本発明に係る枚葉式の熱処理装置を示す構成図である。
【図２】加熱手段を示す平面図である。
【図３】均熱リング部材を示す斜視図である。
【図４】ガス供給系とガス排気系を示す模式図である。
【図５】処理容器内と加熱手段容器内の圧力変化を示すグラフである。
【図６】従来の片面加熱と本発明の両面加熱の場合の被処理体の面内温度プロフィールを示すグラフである。
【図７】均熱リング部材の変形例を示す図である。
【図８】本発明の内部構造物を一体化した時の状態を示す断面図である。
【図９】図８に示す一体内部構造物の断面図である。
【図１０】図８に示す一体内部構造物の斜視模式図である。
【図１１】ガス供給系とガス排気系の変形例を示す図である。
【符号の説明】
２熱処理装置
４処理容器
６下側加熱手段容器
８上側加熱手段容器
１４被処理体ホルダ
１６下側の抵抗加熱ヒータ（加熱手段）
２６上側の抵抗加熱ヒータ（加熱手段）
２８ガス供給ヘッド
５０均熱リング部材
５０Ａシャッタ部材
５６ガス供給系
５８，６６共通ガス通路
６２供給側固定ニードル弁
６４ガス排気系
７０排気側固定ニードル弁
７６ガス排気ヘッド
８４，８８差圧測定部
８６，９０弁開度制御部
Ｗ半導体ウエハ（被処理体）[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a single wafer heat treatment apparatus for performing heat treatment such as film formation on a semiconductor wafer or the like.
[0002]
[Prior art]
In general, in the manufacture of a semiconductor integrated circuit, a heat treatment step for performing film formation, oxidation / diffusion on the surface of a semiconductor wafer, and a pattern etching step are repeatedly performed. Conventionally, when heat-treating, for example, an 8-inch wafer, a vertical batch-type heat treatment apparatus has been mainly used because a large number of wafers can be heat-treated at one time. An important point in this type of heat treatment step is that the temperature in the wafer surface is controlled with good uniformity during the heat treatment from the viewpoint of improving the uniformity of the characteristics of the product circuit and the yield.
[0003]
[Problems to be solved by the invention]
By the way, as the circuit is highly integrated and miniaturized, the wafer size is also increased. For example, the use of a wafer of 12 inch size is being studied.
When the wafer size is increased from 8 inches to 12 inches (about 30 cm) as described above, the weight of the wafer increases by about 2.5 to 3 times compared to an 8-inch wafer, and the average in the wafer surface is increased. Considering thermal properties, it has become difficult to cope with the conventional batch type vertical heat treatment apparatus. In other words, as a result of the fact that the weight of the wafer has increased several times as described above, the wafer boat that supports a large number of wafers cannot withstand the strength, or the wafer area has increased due to the increase in diameter, so that the predetermined pitch In the method of heating from the side of the wafers arranged in (1), uniform heating within the wafer surface becomes difficult.
[0004]
In order to solve the above problems, various single-wafer type heat treatment apparatuses for processing wafers one by one have been proposed. In this apparatus, a halogen lamp or a resistance heater disposed below the wafer holder is used to place the wafer on the holder. The wafer that is supported or placed is heated. However, even when using a conventional single wafer heat treatment apparatus, heating a large-diameter wafer with good in-plane temperature uniformity takes into account the amount of heat generated per unit area of the current heater, It was quite difficult and it could not be said that the conventional device was sufficient.
The present invention has been devised to pay attention to the above problems and to effectively solve them. An object of the present invention is to provide a single-wafer type heat treatment apparatus that can improve the uniformity of the in-plane temperature of the object to be processed.
[0005]
[Means for Solving the Problems]
In order to solve the above problems, the present invention provides a single wafer type heat treatment apparatus for performing a predetermined heat treatment on a target object held by a target object holder in a processing container. To heat the object to be processed downward and upward Arranged Heating means And a heating means container for accommodating the heating means therein and partitioning the processing container in an airtight state, and being connected to the processing container and the heating means container so that pressures in both containers are predetermined. A gas supply system for supplying gas while maintaining the pressure range, and the processing vessel and the heating means vessel connected to each other to discharge the internal atmosphere while maintaining the pressure in both vessels within a predetermined pressure range. A gas exhaust system, wherein the gas supply system and the gas exhaust system are respectively connected to a common gas passage commonly connected to the containers, and a fixed needle valve interposed in the passage connected to the containers. Have It is comprised as follows.
[0006]
Thus, by arranging the heating means above and below the holder, the object to be processed can be heated from both sides, and the uniformity of the in-plane temperature can be improved. In addition, the heating means is accommodated in a heating means container that is partitioned from the processing container in an airtight state, and a predetermined gas supply system and a gas exhaust system are provided to reduce the pressure difference between the processing container and the heating means container. It can always be reduced, and accordingly, the partition wall of the heating means container with respect to the processing container is made thin enough to withstand the pressure difference, and the heat efficiency of the heating means is improved to improve the uniformity of the in-plane temperature and the thermal controllability. It becomes possible to plan.
As described above, in order to set the pressure difference in both containers within a predetermined range, the gas supply system and the gas exhaust system are provided with a common gas passage commonly connected to both containers and connected to each container. A fixed needle valve may be provided in the passage so that a predetermined amount of gas is supplied or exhausted.
[0007]
Further, a flow rate control valve is provided in place of the fixed needle valve, the pressure difference in both the containers is detected by the differential pressure measuring unit, and the valve opening degree control unit detects the valve of the flow rate control valve according to the detected differential pressure. The opening degree may be controlled to control the differential pressure in both containers. Furthermore, by providing a ring-shaped soaking ring member around the workpiece holder, the workpiece can be heated by this radiant heat, and the uniformity of the in-plane temperature of the workpiece is improved. At the same time, the thermal efficiency can be improved. When the heat treatment is a film forming process, the soaking ring member functions as a heat insulating material on the side wall of the processing vessel to form a partial hot wall structure, and unnecessary reaction products are formed on the side wall of the processing vessel. Instead, it adheres to a soaking ring member that is easy to maintain, and maintenance such as cleaning can be easily performed.
[0008]
In addition, by integrally forming a gas supply head for supplying a processing gas, a soaking ring member, a processing object holder, and a gas exhaust head for discharging the atmosphere in the processing container, only a portion of the processing object is formed. In addition to being able to efficiently supply the processing gas, maintenance can be easily performed.
Further, by using a resistance heater instead of a lamp as a heating means, it becomes possible to perform a heat treatment at a high temperature of 1000 ° C. or higher, for example.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a single wafer heat treatment apparatus according to the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a block diagram showing a single wafer heat treatment apparatus according to the present invention, FIG. 2 is a plan view showing heating means, FIG. 3 is a perspective view showing a soaking ring member, and FIG. 4 is a gas supply system and a gas exhaust system. It is a schematic diagram which shows.
In this embodiment, a description will be given of a film forming apparatus that forms a film on the surface of a semiconductor wafer as a heat treatment apparatus.
[0010]
As shown in the figure, the heat treatment apparatus 2 has a processing container 4 formed into a cylindrical shape with aluminum or the like, and the bottom and the ceiling are respectively opened. The lower heating means container 6 made of, for example, quartz is formed in the opening at the bottom, and the upper heating means container 8 made of quartz, similarly, is formed in an airtight manner with respect to the inside of the processing container 4 in the opening at the ceiling. Is provided.
The lower heating vessel 6 is provided so as to cover the lower end opening portion and the outside is exposed to the atmosphere by being inserted into the processing vessel 4 so as to protrude into the processing vessel 4 and having a flat upper end. The thick plate lid portion 6B is airtightly provided at the bottom of the processing vessel 4 through a seal member 10 such as an O-ring.
[0011]
The thickness of the thin plate flange portion 6A is set to be as thin as, for example, about 4 mm, and heat loss in this portion is suppressed and thermal response is improved. Thus, since the thickness of the thin plate flange 6A is thin, the pressure in the lower heating means container 6 is also changed by following the pressure fluctuation in the processing container 4 as will be described later, so that the differential pressure in both containers is changed. It is set to be equal to or less than the pressure resistance of the thin plate flange portion 6A. Further, the thickness of the thick plate lid 6B is set to a thickness that can withstand substantially atmospheric pressure, for example, about 15 to 20 mm.
In the central portion of the lower heating means container 6, a support shaft 15 of a workpiece holder 14 made of quartz, for example, which is hermetically penetrated vertically through a magnetic fluid seal 12 is rotated for uniform heating of the wafer. The upper end of the holder 14 is formed with three claw portions 14A arranged at equal intervals on the same circumference, and the back surface of the semiconductor wafer W as the object to be processed is formed on the claw portions 14A. The peripheral edge is supported.
[0012]
Here, the thin plate flange 6A is inserted into the convex portion in the processing container 4 as described above, and is set as close to the back surface of the semiconductor wafer W as possible. Further, for example, a resistance heater 16 is provided over the entire surface as a lower heating means, and the wafer W is heated from the lower surface side. A rotating mechanism 22 such as a motor is provided below the support shaft 15 of the holder 14 to heat the wafer W while rotating it.
The thick plate lid 6B has N in the lower heating means container 6 ₂ A purge gas inlet 18 for introducing a purge gas such as a gas and a purge gas outlet 20 for exhausting the internal atmospheric gas are provided.
[0013]
On the other hand, the upper heating means container 8, similarly to the lower container 6, has a thin plate flange 8 </ b> A that is inserted into the processing container 4 in a convex shape and has a flat lower end, and an upper end opening. The thick plate lid portion 8B is provided so as to be covered and exposed to the atmosphere, and is airtightly provided on the ceiling portion of the processing container 4 via a seal member 24 such as an O-ring.
The thickness of the thin plate flange portion 8A is set to be as thin as, for example, about 4 mm, and the heat loss in this portion is suppressed and the thermal responsiveness is improved.
Thus, since the thickness of the thin plate flange 8A is thin, the pressure in the upper heating means vessel 8 is also changed by following the pressure fluctuation in the processing vessel 4 so that the differential pressure in both containers is reduced in the thin plate flange 8A. It is set to be less than the pressure strength. The thickness of the thick plate lid 8B is set to a thickness that can withstand substantially atmospheric pressure, for example, about 15 to 20 mm.
[0014]
For example, a resistance heater 26 is provided over the entire inner surface of the lower flat portion of the thin plate flange 8A as an upper heating means so as to heat the wafer W from the upper surface side. Here, the distance between the wafer W and the upper and lower resistance heaters 26 and 16 is very small, for example, set to about 10 mm, so that the wafer W is efficiently heated.
Further, a gas supply head 28 having a container-like shower head structure made of, for example, quartz is provided on the lower surface side of the upper heating means container 8, and a processing gas introduction pipe 30 for introducing a processing gas is provided therein. It is connected. The processing gas introduced from the introduction pipe 30 is ejected from the numerous ejection holes 32 provided on the entire lower surface of the gas supply head 28 toward the entire upper surface of the wafer W.
The thick plate lid 8B has N inside the wafer side heating means container 8. ₂ A purge gas introduction port 36 for introducing a purge gas such as a gas and a purge gas exhaust port 38 for exhausting the internal atmospheric gas are provided.
[0015]
On the other hand, a gas exhaust port 34 connected to a vacuum pump (not shown) for exhausting the atmosphere in the container is provided at the peripheral edge of the bottom of the processing container 4, and N ₂ A purge gas introduction port 40 for introducing a purge gas such as a gas into the processing container 4 is provided. Note that the gas supply head 28 may also be used as the purge gas introduction port 40.
A gate valve 40 that is opened and closed when the wafer W is loaded and unloaded is provided on the side wall of the processing container 4. A load lock chamber 42 is provided through the gate valve 40, for example. The wafer can be loaded and unloaded without breaking the vacuum. In the load lock chamber 42, there is provided a transfer arm 44 that can be bent and stretched and turned to form a wafer. The base of the transfer arm 44 is held by a slide mechanism 46 that can be raised and lowered, and the entire arm can be raised and lowered.
[0016]
On the other hand, the upper and lower resistance heaters 26 and 16 are concentrically divided into a plurality of, for example, three zones as shown in FIG. 2, and the power supplied from the power supply unit 48 to each zone individually. The power can be distributed and supplied by controlling. The number of zone divisions is not limited to three, but may be two or four or more.
A soaking ring member 50 (see FIG. 3) made of, for example, quartz is provided on the periphery of the workpiece holder 14 in the processing container 4 so as to cover the side portion of the wafer W held by the processing object holder 14. In addition, the wafer W is heated by the radiant heat from now on, and at the same time, a heat insulating function is exerted on the side wall of the processing container 4. On one side of the soaking ring member 50, that is, an arc-shaped portion facing the gate valve 40 is cut and separated from the main body side as a shutter portion 50A. A shutter rod 52 provided so as to penetrate through the bottom is connected. A metallic expandable / contractible bellows 54 that allows the vertical movement of the shutter bar 52 while maintaining airtightness is provided in the penetrating portion of the shutter bar 52. Thus, the shutter portion 50A can be moved up and down. The shutter portion 50A is moved up and down in synchronization with the opening and closing of the gate valve 40.
[0017]
On the other hand, the gas supply system and the gas exhaust system for controlling the pressure in the processing container 4, the lower and upper heating means containers 6 and 8 are configured as shown in FIG. That is, N ₂ A gas supply system 56 for supplying a purge gas such as a gas has a common gas passage 58 commonly connected to the purge gas inlets 40, 18, and 36 of the containers 4, 6, and 8. The purge gas inlets 40, 18, and 36 are connected to each other through the branch pipe 60. Each branch pipe 60 is provided with a supply-side fixed needle valve 62 that opens with a predetermined differential pressure. ₂ When supplying gas, N pressure is not increased without excessively increasing the differential pressure in each container. ₂ Gas can be supplied.
[0018]
The gas exhaust system 64 for discharging the atmospheric gas in each container is a common gas connected in common to the gas exhaust holes 34 of the processing container 4 and the purge gas exhaust ports 20 and 38 of the lower and upper heating means containers 6 and 8. It has a passage 66 and is connected to the gas exhaust hole 34 and the purge gas exhaust ports 20 and 38 via the branch pipes 68 branched therefrom. Each branch pipe 68 is provided with an exhaust-side fixed needle valve 70 that opens with a predetermined differential pressure. For example, when evacuating a processing container, the differential pressure with other containers is excessively increased. The atmosphere gas is exhausted without any trouble.
The exhaust common gas passage 66 is provided with a mass flow controller 72 and a vacuum pump 74 for exhausting a predetermined amount of gas during exhaust.
[0019]
Next, the operation of the present embodiment configured as described above will be described.
First, the unprocessed semiconductor wafer W held by extending the transfer arm 44 of the load lock chamber 42 is loaded into the processing container 4 through the opened gate valve 40, and the arm 44 is moved by a small distance. The wafer W is lowered and delivered to the object holder 14 in the processing container 4. Then, the arm 44 is retracted, the gate valve 40 is closed, and the inside of the processing container 4 is sealed.
[0020]
Next, the inside of the processing container 4 is evacuated to a predetermined process pressure, and a processing gas is supplied into the inside of the processing container 4 from the gas supply head 28 as a shower to maintain the process pressure. At the same time, power is supplied to the resistance heaters 16 and 26 accommodated in the lower and upper heating means containers 6 and 8, or the supplied power is increased and the wafer W placed on the holder 14. Is heated from both the upper and lower surfaces to maintain the temperature at the process temperature, and a predetermined thermal process is performed. In this case, the upper and lower resistance heaters 26 and 16 individually control the input electric power for each zone so as to heat the wafer in a uniform manner.
For example, when CVD (Chemical Vapor Deposition) is performed as the heat treatment, for example, a mixed gas of silane and hydrogen gas is used as a processing gas, Ar gas is flowed as a carrier gas, a process pressure is about 0.5 Torr, and a process temperature is 1050. Set to about ℃.
[0021]
Here, in order to heat the wafer W, resistance heaters 26 and 16 are disposed above and below, and the heaters 26 and 16 are sealed with quartz heating means containers 8 and 6, respectively. The wafer can be heated from both sides without causing any problems. Accordingly, it becomes possible to heat the wafer at high speed with good in-plane temperature uniformity. In particular, in this embodiment, the thin plate flanges 8A and 6A of the heating means containers 8 and 6 are inserted into the processing container 4 in a concave shape, and the heaters 26 and 16 are disposed therein. Since the distance between the two can be set to be extremely small, the uniformity of the in-plane temperature can be further improved even if the wafer size is large.
Moreover, since the thickness of each of the thin plate flanges 8A, 6A made of quartz is set to be very thin, about 4 mm, the heat loss in this portion is small, and since it is thin and has a small heat capacity, it has excellent thermal response. It becomes possible to control the temperature of the wafer W with good responsiveness.
[0022]
Further, each of the resistance heaters 26 and 16 is divided into a plurality of zones concentrically as shown in FIG. 2, and the supply power can be individually controlled for each zone, so that the wafer temperature can be finely controlled. it can.
Furthermore, a soaking ring member 50 is provided on the periphery of the wafer W so as to cover it, and the wafer W can be heated by radiant heat from now on, so that the in-plane uniformity of the wafer temperature is further improved. In addition, since heat leakage to the processing container is reduced, the thermal efficiency can be improved accordingly. Further, by providing the soaking ring member 50 in this way, it can be partially provided with a hot wall function, and therefore, unnecessary film formation which has been conventionally attached to the inner wall surface of the processing vessel can be performed. Further, since it can be attached to the heat equalizing ring member 50 side without being attached to the inner wall surface of the container, maintenance such as cleaning can be easily performed.
Further, since the resistance heaters 16 and 26 having a large calorific value are used here, the wafer can be heated to a high temperature of 1000 ° C. or higher. A halogen lamp may be used in place of this heater.
[0023]
Further, it is conceivable that an excessive pressure difference occurs between the inside of the processing container 4 and the inside of the upper and lower heating means containers 8, 6, but the upper and lower heating means containers 8. , 6 is also made to fluctuate following the pressure in the processing container 4, so that the partition wall between the two containers is not damaged. This will be described with reference to FIG.
As described above, the branch pipes 60 and 68 of the gas supply system 56 and the gas exhaust system 64 are provided with the fixed needle valves 62 and 70, respectively, so that the valve opening automatically changes depending on the differential pressure. It has become.
[0024]
First, the case of evacuation will be described. Generally, when two evacuated containers having different capacities are evacuated independently at the same flow rate, the pressure in the large-capacity container gradually decreases as shown in FIG. Although the pressure decreases, the pressure of the small-capacity container rapidly decreases, and a large pressure difference is generated between the two containers. However, when the exhaust side fixed needle valve 70 is provided in the branch pipe 68 as in the present invention, and each of the fixed needle valves is exhausted at a constant flow rate, for example, several liters per minute under the control of the mass flow controller 72 by the vacuum pump 74. 70, the atmosphere in the upper and lower heating means containers 8 and 6 having a small capacity is exhausted in small amounts, whereas the atmosphere in the processing container 4 having a large capacity is exhausted in large quantities. As a result, as shown in FIG. 5B, the pressure in the heating means containers 6 and 8 fluctuates so as to follow the pressure in the processing container 4, and the pressure difference between the processing container 4 and the heating means containers 6 and 8 is It is always kept in a small state and is evacuated.
This is because N in order to return the inside of each container to atmospheric pressure. ₂ The same applies to the case of purging the gas. As shown in FIG. 4, as a result of the fixed needle valve 62 interposed in each branch pipe 60 of the gas supply system 56, N ₂ Even during gas supply, the pressure difference between the containers is always kept small and N ₂ Gas will be supplied. Accordingly, the pressure difference between the processing container 4 and the two heating means containers 6 and 8 is always small, for example, a differential pressure of about 10 Torr. Therefore, each of the thin plate collars 6A and 8A that divide both containers is as described above. In addition, the thickness can be reduced to about 4 mm, which contributes to suppression of heat loss and improvement of thermal response. Both thick plate lid portions 6B and 8B that are exposed to atmospheric pressure are formed thick so that they can withstand atmospheric pressure.
[0025]
Next, the wafer temperature profile in the case of single-sided heating with respect to the wafer and in the case of double-sided heating in which heating means are arranged on both sides of the wafer as in the present invention were obtained by simulation, and the results will be described.
6A shows a wafer temperature profile in the case of conventional single-sided heating, and FIG. 6B shows a wafer temperature profile in the case of double-sided heating as in the present invention. Each of the heater zones is divided into two, and the set temperature is 1040 ° C.
As shown in FIG. 6A, in the case of single-sided heating, the temperature gradually decreases toward the periphery of the wafer, causing a temperature difference of about 10 ° C. from the central portion, and the in-plane temperature is uniform. In addition, the heater of the outer zone at this time had to be supplied with a power of 7 KW or more. On the other hand, in the case of the double-sided heating shown in FIG. 6B, there was almost no temperature difference between the wafer central portion and the peripheral portion, and the uniformity of the in-plane temperature could be maintained high. In addition, the power consumption as a whole was slightly higher than in the case of single-sided heating, but the power input to the heaters in each zone was all below the rated value.
[0026]
In the above embodiment, as shown in FIG. 3, the temperature equalizing ring member 50 having the shutter portion 50A that can be raised and lowered is provided to protect the gate valve from heat, but instead of this, FIG. As shown in FIG. 6, a member provided with a slit-like opening 50B having a size capable of inserting the wafer W at the center of one side surface of the soaking ring member 50 may be used. In this case, in order to protect the gate valve from heat, the gate valve can be rotated, and after the wafer W is loaded / unloaded, the heat equalizing ring member 50 is rotated approximately 180 degrees in the circumferential direction.
Further, in place of the above configuration, as shown in FIG. 7B, a recess-shaped notch 50C having a size capable of inserting the wafer W is provided at the lower part of one side surface of the soaking ring member 50. You may do it. In this case, in order to protect the gate valve from heat, the ring member can be rotated or moved up and down, and after the wafer W is loaded / unloaded, the heat equalizing ring member 50 is rotated approximately 180 degrees in the circumferential direction. Alternatively, it may be moved downward.
Here, the gas supply head 28 having a shower head structure, the heat equalizing ring member 50 and the object holder 14 are separately provided independently, and the gas exhaust holes 34 are provided in the periphery of the bottom of the processing container 4. However, instead of this, as shown in FIGS. 8 to 10, the gas exhaust holes may be integrally formed as a gas exhaust head 76 having a structure similar to the shower head structure. That is, the gas supply head 28 having a shower head structure is joined to a soaking ring member 50 having a structure as shown in FIG. 7A, and three claw portions 14A are attached from the inner wall surface of the ring member 50 toward the center. A workpiece holder 14 is provided. The gas exhaust head 76 has a shower head structure having a structure similar to that of the gas supply head 28 and is provided with a plurality of suction holes 78 for sucking gas on the upper surface thereof, and the gas outlet may be connected to the gas exhaust hole 34. These can be integrally formed of, for example, quartz.
[0027]
By forming in this way, the processing gas supplied from the gas supply head 28 to the lower wafer W side flows laterally after contacting the surface, and is immediately sucked into the lower gas exhaust head 76. Flowing into. Accordingly, the processing gas does not flow to the peripheral edge in the processing container 4 and flows so as to efficiently contact the wafer surface, and the use efficiency of the processing gas can be increased.
Further, when an unnecessary film is deposited on the integrated structure, it is only necessary to clean the integrated structure, and the maintenance work can be performed efficiently.
In the above embodiment, as shown in FIG. 4, the pressure supply between the containers is controlled by providing the fixed needle valves 62 and 70 in the gas supply system 56 and the gas exhaust system 64. However, the present invention is not limited to this. The configuration may be as shown in FIG. That is, of the branch pipes 60 and 68 of the gas supply system 56 and the gas exhaust system 64, the opening degree of the branch pipe communicating with the heating means containers 6 and 8 can be freely controlled instead of the needle valve. The flow control valves 80A, 80B, 82A, and 82B that can be provided are provided, and these valves are not provided in the branch pipe that communicates with the processing vessel 4. And the 1st differential pressure measurement part 84 which detects the pressure difference in the processing container 4 and the lower heating means container 6 is provided, Based on this detected value, the 1st valve opening degree control part 86 is lower side. The flow control valves 80B and 82B on the supply side or the exhaust side of the heating means container 6 are controlled.
Further, a second differential pressure measuring unit 88 for detecting a pressure difference between the processing container 4 and the upper heating means container 8 is provided, and the second valve opening degree control unit 90 is based on the detected value, and the upper heating means container is used. 8 control the flow control valves 82A and 82B on the supply side or the exhaust side.
[0028]
According to such a configuration, at the time of evacuation, the first and second valve opening degree control units 86 and 90 detect that the detected values of the differential pressure measuring units 84 and 88 are within the pressure resistance range of the thin plate flanges 6A and 8A. For example, the valve opening degree of each flow control valve 82A, 82B on the exhaust side is controlled so as to be maintained within ± 10 Torr. In order to return to the atmospheric pressure in the processing container 4, N ₂ When purging the gas, the valve opening degree of each of the flow rate control valves 80A and 80B on the supply side is controlled so that the detected value is maintained within ± 10 Torr. Therefore, the same effect as the configuration shown in FIG. 4 can be exhibited.
In this embodiment, the case where the film formation process is performed by CVD as an example of the heat treatment has been described as an example. However, the present invention is not limited to this, and can be applied to other heat treatments such as an oxidation / diffusion process and an annealing process. It is.
Further, here, the gate valve 40 is provided only on one side of the processing container 4 to carry in / out the wafer, but another gate valve is provided at a position opposite to the gate valve 40 to carry in the wafer loading port. And a carry-out port may be provided separately. In this case, two shutter portions 50A and the like of the soaking ring member 50 are also provided correspondingly.
Furthermore, the object to be processed is not limited to a semiconductor wafer, but can be applied to a glass substrate, an LCD substrate, and the like.
[0029]
【The invention's effect】
As described above, according to the single wafer type heat treatment apparatus of the present invention, the following excellent operational effects can be exhibited.
Since the heating means is arranged on both sides of the object to be processed and both surfaces are heated, the uniformity of the in-plane temperature can be greatly improved even if the size of the object to be processed is increased.
Moreover, the partition wall which divides both containers by accommodating a heating means in a heating means container, making the inside follow the pressure fluctuation in a processing container, and changing pressure, and maintaining the differential pressure | voltage between both containers small is maintained. Therefore, not only can the thermal efficiency be improved and the in-plane temperature uniformity of the object to be processed can be further improved, but also the thermal response can be improved.
Furthermore, by covering the side portion of the object to be processed with a soaking ring member, it is possible to increase the thermal efficiency by reducing the amount of heat released to the outside, and to improve the uniformity of the in-plane temperature accordingly. it can. Further, since this ring member can provide a partial hot wall structure, it is possible to prevent unnecessary film formation from adhering to the side wall of the processing vessel, and maintenance can be easily performed.
Also, by integrating the gas supply head, soaking ring member, workpiece holder, and gas exhaust head, the processing gas leaking to the side is reduced, and the use efficiency of the processing gas is improved. As well as being able to perform maintenance work can be easily performed.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing a single wafer heat treatment apparatus according to the present invention.
FIG. 2 is a plan view showing a heating means.
FIG. 3 is a perspective view showing a soaking ring member.
FIG. 4 is a schematic diagram showing a gas supply system and a gas exhaust system.
FIG. 5 is a graph showing pressure changes in the processing container and the heating means container.
FIG. 6 is a graph showing an in-plane temperature profile of an object to be processed in the case of conventional single-sided heating and double-sided heating of the present invention.
FIG. 7 is a view showing a modification of the soaking ring member.
FIG. 8 is a cross-sectional view showing a state when the internal structure of the present invention is integrated.
9 is a cross-sectional view of the integral internal structure shown in FIG.
10 is a schematic perspective view of the integral internal structure shown in FIG. 8. FIG.
FIG. 11 is a view showing a modification of the gas supply system and the gas exhaust system.
[Explanation of symbols]
2 Heat treatment equipment
4 processing containers
6 Lower heating means container
8 Upper heating means container
14 Object holder
16 Lower resistance heater (heating means)
26 Upper resistance heater (heating means)
28 Gas supply head
50 Soaking ring member
50A shutter member
56 Gas supply system
58,66 Common gas passage
62 Supply side fixed needle valve
64 Gas exhaust system
70 Exhaust side fixed needle valve
76 Gas exhaust head
84,88 Differential pressure measurement unit
86,90 Valve opening controller
W Semiconductor wafer (object to be processed)

Claims

In a single wafer type heat treatment apparatus that performs a predetermined heat treatment on a target object held by a target object holder in a processing container,
Heating means arranged to heat the object to be processed below and above the object holder;
A heating means container for accommodating the heating means therein and partitioning the processing container in an airtight state;
A gas supply system connected to the processing vessel and the heating means vessel to supply gas while maintaining the pressure in both vessels within a predetermined pressure range;
A gas exhaust system that is connected to the processing vessel and the heating means vessel and discharges the internal atmosphere while maintaining the pressure in both vessels within a predetermined pressure range, and
The gas supply system and the gas exhaust system each include a common gas passage commonly connected to the containers and a fixed needle valve interposed in the passage connected to the containers. Leaf heat treatment equipment.

In a single wafer type heat treatment apparatus that performs a predetermined heat treatment on a target object held by a target object holder in a processing container,
Heating means arranged to heat the object to be processed below and above the object holder;
A heating means container for accommodating the heating means therein and partitioning the processing container in an airtight state;
A gas supply system connected to the processing vessel and the heating means vessel to supply gas while maintaining the pressure in both vessels within a predetermined pressure range;
A gas exhaust system that is connected to the processing vessel and the heating means vessel and discharges the internal atmosphere while maintaining the pressure in both vessels within a predetermined pressure range, and
The gas supply system and gas exhaust system, a common gas passage which are respectively connected said commonly to each container, a flow control valve which said interposed in passage connected to each container, the pressure difference between the two container A single-wafer type comprising: a differential pressure measuring unit that detects the pressure difference; and a valve opening degree control unit that controls the valve opening degree of the flow rate control valve based on the differential pressure obtained from the differential pressure measuring unit. Heat treatment equipment.

In a single wafer type heat treatment apparatus that performs a predetermined heat treatment on a target object held by a target object holder in a processing container,
Heating means arranged to heat the object to be processed below and above the object holder;
A ring-shaped heat equalizing ring member provided in a peripheral portion of the object holder and covering a side portion of the object to be processed held by the object holder;
A gas supply head for introducing a processing gas into the processing container, the soaking ring member, the workpiece holder, and a gas exhaust head for discharging the atmosphere in the processing container are integrally formed. Single wafer heat treatment equipment.

In a single wafer type heat treatment apparatus that performs a predetermined heat treatment on a target object held by a target object holder in a processing container,
A heating means container having heating means for heating the object to be processed is disposed below and above the object holder;
The heating means container is provided in an airtight manner in the processing container, and the heating means container is provided with a thin plate portion provided to suppress heat loss toward the processing container and improve thermal response, and the thin plate. It is provided with a thick plate part that is provided so as to cover the part and the outside is exposed to the atmosphere,
In the processing container and the heating means container, a gas supply system that supplies gas while maintaining the pressure in both containers within a predetermined pressure range, and the pressure in both the containers is maintained in a predetermined pressure range. A gas exhaust system that exhausts the internal atmosphere is connected to the gas supply system, and the gas supply system and the gas exhaust system are connected to each container and a common gas passage that is connected to each container in common. A flow rate control valve interposed in the passage, a differential pressure measuring unit for detecting a pressure difference in the two containers, and a valve opening degree of the flow rate control valve based on the differential pressure obtained from the differential pressure measuring unit. single wafer type heat treatment apparatus characterized by having a valve opening control unit which controls.

Wherein the peripheral portion of the specimen holder, according to claim 4 Symbol mounting, characterized in that the ring-shaped soaking ring member is provided so as to cover the sides of the workpiece held by the holder Single wafer type heat treatment equipment.

A gas supply head for introducing a processing gas into the processing container, the soaking ring member, the workpiece holder, and a gas exhaust head for discharging the atmosphere in the processing container are integrally formed. The single wafer type heat treatment apparatus according to claim 5 .

It said heating means, single wafer type heat treatment apparatus according to any one of claims 1乃optimum 6, characterized in that the resistance heater which can issue hot.