JP3860404B2

JP3860404B2 - Heat treatment equipment

Info

Publication number: JP3860404B2
Application number: JP2000296430A
Authority: JP
Inventors: 英夫西原; 俊幸小林; 康裕芝
Original assignee: Screen Holdings Co Ltd; Dainippon Screen Manufacturing Co Ltd
Current assignee: Screen Holdings Co Ltd; Dainippon Screen Manufacturing Co Ltd
Priority date: 2000-09-28
Filing date: 2000-09-28
Publication date: 2006-12-20
Anticipated expiration: 2020-09-28
Also published as: JP2002110583A

Description

【０００１】
【発明の属する技術分野】
本発明は、半導体ウエハ、液晶表示装置用ガラス基板、フォトマスク用ガラス基板、光ディスク用基板等の薄板状精密基板（以下、単に「基板」という。）に熱処理を施す熱処理装置に関する。
【０００２】
【従来の技術】
従来、加熱光源が基板の上面に対向するように配置された片面加熱のランプアニール等の熱処理装置が知られている。かかる熱処理装置においては基板の全面を均一に加熱するために、基板の外周部に厚みが１ｍｍ程度のセラミックス製のリング部材を設けている。また、熱処理を行うための加熱手段として、基板のみならず、リング部材をも加熱することができるように加熱光源が配置されている。
【０００３】
そして、基板に対する加熱処理を行う際には、主として基板を加熱するために設けられた加熱光源は複数ゾーンに分割され、それぞれのゾーンごとに制御を行うことで基板に対する熱処理の均一性を向上させている。
【０００４】
【発明が解決しようとする課題】
しかしながら、従来の熱処理装置では、主としてリング部材を加熱するために設けられた加熱光源が全体的に統一されて制御されること、及びリング部材の外側には水冷されたチャンバ壁が存在すること等が要因となって、基板外周部に設けられたリング部材の内周側と外周側とで温度勾配が発生していた。すなわち、リング部材の外周側の温度が内周側の温度よりも低くなるという現象が生じていたのである。
【０００５】
このようなリング部材における内周側と外周側との温度差は、熱処理過程を通して最大で約２４３℃にも達し、内周側に圧縮応力を、外周側に引っ張り応力を発生させて最終的にリング部材を破損させる結果を招くことになる。
【０００６】
そこで、本発明は、上記課題に鑑みてなされたものであって、熱処理におけるリング部材の温度均一性を図り、リング部材を破損することのない熱処理装置を提供することを目的とする。
【０００７】
【課題を解決するための手段】
上記目的を達成するために、請求項１に記載の発明は、基板を処理室に収容して熱処理を施す熱処理装置であって、基板の外周部に配置され、基板の温度均一性を向上させる温度補償部材と、主として前記温度補償部材を加熱するために設けられ、前記温度補償部材の内周側と外周側とを別のゾーンに分割したときの前記内周側のゾーンとして、主として前記温度補償部材における基板近傍領域を加熱する第１の温度補償部材加熱手段と、主として前記温度補償部材を加熱するために設けられ、前記外周側のゾーンとして、主として前記温度補償部材における基板遠隔領域を加熱する第２の温度補償部材加熱手段と、基板に対して熱処理を施す際に、主として基板を加熱するために設けられた基板加熱手段を制御するとともに、前記第１の温度補償部材加熱手段と前記第２の温度補償部材加熱手段とを個別に制御する制御手段と、を備え、前記制御手段は、前記第１の温度補償部材加熱手段への電力供給量よりも、前記第２の温度補償部材加熱手段への電力供給量を大きくして、前記温度補償部材の前記基板近傍領域と前記基板遠隔領域との温度差を低減する。
【０００８】
請求項２に記載の発明は、請求項１に記載の熱処理装置において、前記温度補償部材が、基板の周縁部を支持する支持手段としても機能することを特徴としている。
【０００９】
請求項３に記載の発明は、請求項１又は２に記載の熱処理装置において、前記温度補償部材がリング状部材であることを特徴としている。
請求項４に記載の発明は、請求項１ないし３のいずれかに記載の熱処理装置において、前記第１の温度補償部材加熱手段と前記第２の温度補償部材加熱手段との双方が、少なくとも一部が鉛直方向において前記温度補償部材と重なることを特徴としている。
請求項５に記載の発明は、請求項１ないし３のいずれかに記載の熱処理装置において、前記第１の温度補償部材加熱手段と前記第２の温度補償部材加熱手段との双方が、前記温度補償部材の外形サイズに対応して設けられていることを特徴としている。
請求項６に記載の発明は、請求項１ないし５のいずれかに記載の熱処理装置において、前記制御手段が、前記第１の温度補償部材加熱手段と前記第２の温度補償部材加熱手段とを含む主として前記温度補償部材を加熱するための加熱手段を、３ゾーン以上に分割してそれぞれのゾーンを個別に制御することを特徴としている。
【００１０】
【発明の実施の形態】
以下、本発明の実施の形態について図面を参照しつつ詳細に説明する。
【００１１】
＜１．熱処理装置＞
図１は、本実施形態にかかる熱処理装置１を示す断面図である。図１に示すように、熱処理装置１はチャンバ壁２と開閉扉３と石英窓４とリング部材５とリフタ６と加熱手段７と制御部８とを備えて構成される。
【００１２】
チャンバ壁２は水冷機構を備え、チャンバ壁２と開閉扉３と石英窓４とで基板Ｗを熱処理する際の処理室９を形成する。開閉扉３は基板Ｗの搬送時に搬送口９ａを開放し、外部に設けられる搬送ロボット等が処理室９内にアクセス可能な状態とする。
【００１３】
処理室９内に基板Ｗを搬送する際には、図１に２点鎖線で示すように処理室９の下部から昇降自在に設けられたリフタ６が上昇し、搬送ロボット等との基板Ｗの受け渡しを行う。その後、リフタ６は下降し、図１に実線で示すように基板Ｗをリング部材５に載置して処理室９内から退避する。
【００１４】
リング部材５は、基板Ｗに対する熱処理する際に、基板Ｗの全面において温度の均一性を向上させるために設けられたものであり、リング形状の内縁部５ａで基板Ｗを支持することによって基板Ｗの外形サイズを擬似的に大型化し、その大型化された加熱領域に対して熱処理を施すことで加熱領域の中央部分に存在する基板Ｗの均一性を高めるものである。このことから、リング部材５は基板Ｗの外周部に配置されて基板Ｗの温度均一性を向上させる温度補償部材として機能するとともに、基板Ｗを支持する支持手段としても機能することになる。
【００１５】
このリング部材５は、焼結ＳｉＣ等のセラミックス材料で形成され、チャンバ壁２に設けられる支持部９ｂによって処理室９内に配置され、熱処理を行う際に内縁部５ａで支持する基板Ｗが処理室９内の最適な処理位置に配置されるようになっている。なお、リング部材５を処理室９内に設ける構造は他の構造であってもよい。
【００１６】
加熱手段７は石英窓４の上方側に配置されており、複数の直管状加熱光源１０が上下２段で井桁状に配列されて構成される。この直管状加熱光源１０として例えばハロゲンランプ等が使用できる。各直管状加熱光源１０は制御部８から電力供給を受けることにより、放射エネルギーを放出するように構成される。そして各直管状加熱光源１０から放射される放射エネルギーは石英窓４を介して処理室９に導かれ、処理室９内の基板Ｗ及びリング部材５を加熱させる。
【００１７】
図２は加熱手段７と基板Ｗとリング部材５との位置関係を示す概念図であり、熱処理装置１の上方側からみた図である。図２に示すように、本実施形態においては加熱手段７として直管状加熱光源１０が合計３２本設けられており、１６本ずつの上下２段構成で井桁状に配列されている。
【００１８】
複数の直管状加熱光源１０のうちの下段中央の１０本及び上段中央の１０本は基板Ｗの外形サイズをカバーするように設けられており、直下に位置する基板Ｗを主として加熱するための基板加熱手段７１として機能する。一方、複数の直管状加熱光源１０のうちの下段両外側の６本及び上段両外側の６本はリング部材５の外形サイズに対応して設けられており、直下に位置するリング部材５を主として加熱するためのリング部材加熱手段（温度補償部材加熱手段）７２として機能する。
【００１９】
ただし、各直管状加熱光源１０からの放射エネルギーは直下方向にのみ放射されるものではないため、基板加熱手段７１として機能する直管状加熱光源１０からの放射エネルギーの一部がリング部材５を加熱するように作用し、リング部材加熱手段７２として機能する直管状加熱光源１０からの放射エネルギーの一部が基板Ｗを加熱するように作用することは勿論である。
【００２０】
図３は、制御部８による制御形態を示すブロック図である。制御部８はリング加熱制御部８１と基板加熱制御部８２とを備えており、リング加熱制御部８１はリング部材加熱手段７２を構成する下段両外側の６本及び上段両外側の６本の直管状加熱光源１０を制御し、基板加熱制御部８２は基板加熱手段７１を構成する下段中央の１０本及び上段中央の１０本の直管状加熱光源１０を制御する。
【００２１】
基板加熱制御部８２は、基板加熱手段７１を構成する上下段それぞれの１０本の直管状加熱光源１０うちの中央２本（上下段合わせて４本）を中央部、その両外側２本を合わせた４本（上下段合わせて８本）を中間部、さらにその両外側２本を合わせた４本（上下段合わせて８本）を外周部として３ゾーンに分割し、ゾーン毎に個別に加熱制御を行う。すなわち、基板加熱制御部８２は中央部加熱制御部８２ａと中間部加熱制御部８２ｂと外周部加熱制御部８２ｃとを備えており、中央部加熱制御部８２ａが中央部に配置されている直管状加熱光源１０を制御し、中間部加熱制御部８２ｂが中間部に配置されている直管状加熱光源１０を制御し、外周部加熱制御部８２ｃが外周部に配置されている直管状加熱光源１０を制御する。各制御部８２ａ〜８２ｃは基板Ｗに対する熱処理過程において基板Ｗの全面が均一な状態で昇温・保温・降温されるように、直管状加熱光源１０に対して供給する電力を調整する。
【００２２】
なお、基板加熱制御部８２は、基板Ｗの全面に対して均一な温度状態での熱処理を実現するために、処理室９には図示しない温度計測手段が設けられ、その温度計測手段からの計測温度に基づいて昇温・保温・降温の各段階で各制御部８２ａ〜８２ｃが個別にフィードバック制御を行うように構成されている。
【００２３】
また、リング加熱制御部８１は、リング部材加熱手段７２を構成する上下段それぞれの６本のうちのリング部材５における基板Ｗの近傍領域を加熱する内側２本（上下段合わせて４本）をリング部材５の内周側加熱手段（第１の温度補償部材加熱手段）とし、リング部材５における基板Ｗの遠隔領域を加熱する外側４本（上下段合わせて８本）をリング部材５の外周側加熱手段（第２の温度補償部材加熱手段）として、リング部材５の内周側と外周側との２ゾーンに分割し、ゾーン毎に個別に加熱制御を行うように構成されている。
【００２４】
すなわち、リング加熱制御部８１は内周側加熱制御部８１ａと外周側加熱制御部８１ｂとを備えており、内周側加熱制御部８１ａが主としてリング部材５の内周側を加熱するための直管状加熱光源１０を制御し、外周側加熱制御部８１ｂが主としてリング部材５の外周側を加熱するための直管状加熱光源１０を制御する。各制御部８１ａ，８１ｂは、基板Ｗに対して熱処理を行う際に、リング部材５が均一な状態で昇温・保温・降温されるように制御する。
【００２５】
具体的には、昇温段階・保温段階・降温段階の各段階ごとに予め内周側と外周側との電力供給比を設定しておき、実際の基板Ｗに対する熱処理の際には各制御部８１ａ，８１ｂが予め設定された比率で直管状加熱光源１０に電力供給を行うことにより、熱処理中におけるリング部材５の温度均一性を向上させている。例えば、内周側よりも外周側の電力供給量が大きくなるように各段階についての電力供給比を予め設定しておくことで、熱処理中に外周部の温度が内周部よりも著しく低くなることを防止することができる。
【００２６】
なお、図３では上段と下段とのそれぞれにリング加熱制御部８１及び基板加熱制御部８２を設ける構成例を示しているが、これに限定されるものではなく、上段と下段とで１個のリング加熱制御部８１及び１個の基板加熱制御部８２を共有するように構成してもよい。むしろ、そのように構成する方が装置構成を簡単化できるので好ましい。
【００２７】
本実施形態における熱処理装置１は上記のように構成されており、リング部材５の上方位置に配置され、直管状加熱光源１０によって構成されるリング部材加熱手段７２を内周側と外周側とに分割し、内周側と外周側とを個別に制御して各直管状加熱光源１０からの放射エネルギーの出力調整を行うことができるように構成されているため、熱処理の際にリング部材５の内周側と外周側とに発生する温度勾配を低減することが可能になる。
【００２８】
＜２．実験例＞
次に、上記のような構成の場合と従来の構成の場合との比較を行った実験例について説明する。
【００２９】
本実験例において、加熱光源は定格２ＫＷで発光長３００ｍｍの直管状ハロゲンランプを使用し、リング部材５は幅４３ｍｍの焼結ＳｉＣで形成されたものを使用する。
【００３０】
また、基板Ｗの加熱手順は次のように実施する。加熱当初は基板温度を測定しているパイロメータの測定下限よりも基板温度が高くなるまで適当な大きさの定電力を加熱光源に与え、基板Ｗとリング部材５とを加熱していく。そして、基板Ｗの温度がパイロメータによって測定可能な状態となってから、基板Ｗの温度をフィードバック信号としてフィードバック制御に切り換え、目標温度に到達して所定時間が経過すれば、加熱光源による加熱を終了する。
【００３１】
本実験では、目標温度を１１００℃、昇温過程における昇温レートを１２０℃／ｓとした加熱条件において基板Ｗに対する加熱処理を行うこととし、その熱処理過程でのリング部材５の各部での温度を測定する。
【００３２】
図４は、本実験でのリング部材５の温度計測点を示す図である。図４に示すように、本実験ではリング部材５の外周端部から約２ｍｍ内側の点Ｐ１と、基板Ｗをリング部材５に載置した状態での基板Ｗの端部から約２ｍｍ外側の点Ｐ５と、点Ｐ１と点Ｐ５との間に等間隔で設けられた３点（Ｐ２，Ｐ３，Ｐ４）との合計５点に熱電対を設置し、リング部材５の温度を測定した。
【００３３】
なお、この熱電対は実験のためのものであり、熱処理装置１として必須のものではない。
【００３４】
従来の構成で本実験を行うと、上述のように、リング部材５を加熱するための加熱光源が１ゾーンとされているとともに、リング部材５の外側に水冷されるチャンバ壁２の影響を受けるため、リング部材５の内側と外側との温度差は昇温過程から目標温度保持状態に移り変わる時点で最大の約２４３℃に達する。
【００３５】
一般に、内周側の温度をＴ１、外周側の温度をＴ２、内周側半径をａ、外周側半径ｂ、ヤング率をＥ、リング部材を形成する材料の線膨張係数をα、とすると、任意の半径ｒにおける円周方向の応力 θは、次式
【００３６】
【数１】

【００３７】
で求めることができる。ただし、Ｋは外周側半径ｂと内周側半径ａとの比であり、Ｋ＝ｂ／ａである。数１より、内径側と外径側との温度差が直接応力に結びつくことが分かる。
【００３８】
したがって、従来の構成において約２４３℃の温度差が生じている状態では、数１の計算から内部応力が約４５７Ｍｐａとなり、焼結ＳｉＣの応力破壊限界の約５１０Ｍｐａに近い値となっている。この数値は上記の数値条件のみを考慮したものであり、実際の装置においては他の詳細部分において条件が異なってくることから、従来の構成では応力破壊限界に対して余裕のない装置構成となっている。
【００３９】
これに対し、上述した本実施形態の熱処理装置１の構成では、予め設定される内周側と外周側との電力供給比に基づいてリング部材５の内周側と外周側との出力調整を行いつつ加熱処理を行うことで、リング部材５の内周側と外周側との温度差は最大でも約１８０℃に低減することができた。そして、この熱処理装置１のリング部材５に発生する円周方向の応力は数１の計算から約３７０Ｍｐａとなり、応力破壊限界に対して充分な余裕を含ませることができるので、リング部材５の破壊を防止することができる。
【００４０】
＜３．変形例＞
以上、本発明の実施の形態について説明したが、本発明は上記の内容に限定されるものではない。
【００４１】
例えば、上記において加熱手段７が直管状加熱光源である場合について説明したがこれに限定されるものではなく、シングルエンド型の加熱光源等のように任意の加熱光源であってもよい。また、ランプ等のような光源である必要もない。さらに、上記説明においては、加熱手段７が基板Ｗ及びリング部材５の上方側に配置される例について示したがこれに限定されるものでもなく、また、加熱手段７の配置形態も井桁状であることに限定されない。
【００４２】
また、上記において基板Ｗの外周部に配置され、基板Ｗの温度均一性を向上させる温度補償部材の一例として一体化されたリング部材５を例示したが、温度補償部材はリング部材５が複数の分離された部材によって形成されて、処理室９内に設置されたときに複数の部材が組み合わされて全体として略リング形状をなすようにしてもよい。
【００４３】
また、上記説明では基板Ｗとして半導体ウエハを想定しているため、温度補償部材はリング形状である例を示しているが、基板Ｗが半導体ウエハでない場合には他の形状の方が好ましい場合もある。また、温度補償部材を形成する材料も任意である。
【００４４】
また、上記においてリング部材５は熱処理時に基板Ｗを支持する支持手段としても機能する例について示したが、熱処理時において基板Ｗを支持するために、リング部材５とは別個独立した支持手段を設けてもよい。この場合、リング部材５は温度補償部材としてのみ機能することになる。
【００４５】
さらに、上記においては主としてリング部材５を加熱するための加熱手段を内周側と外周側との２ゾーンに分割し、その２ゾーンを加熱過程において個別に制御する構成例について示したが、３ゾーン以上に分割してそれぞれのゾーンを個別に制御するように構成してもよい。この場合であっても、リング部材５における基板近傍領域を加熱する第１の温度補償部材加熱手段と、基板遠隔領域を加熱する第２の温度補償部材加熱手段とは少なくとも存在することになる。
【００４６】
【発明の効果】
以上説明したように、請求項１ないし請求項６に記載の発明によれば、基板に対して熱処理を施す際に、温度補償部材における基板近傍領域を加熱する第１の温度補償部材加熱手段と、温度補償部材における基板遠隔領域を加熱する第２の温度補償部材加熱手段とを個別に制御するように構成されているため、熱処理過程での温度補償部材の基板近傍領域側と基板遠隔領域側との温度差を低減することができ、温度補償部材の温度均一性が向上する。
【００４７】
請求項２に記載の発明によれば、温度補償部材が基板の周縁部を支持する支持手段としても機能するため、別途支持手段を設ける必要がない。
【００４８】
請求項３に記載の発明によれば、温度補償部材がリング状部材であるため、基板が特に半導体ウエハである場合に、基板の温度均一性を良好に向上させる。
【図面の簡単な説明】
【図１】熱処理装置を示す断面図である。
【図２】加熱手段と基板とリング部材との位置関係を示す概念図である。
【図３】制御部による制御形態を示すブロック図である。
【図４】実験例でのリング部材の温度計測点を示す図である。
【符号の説明】
１熱処理装置
５リング部材（温度補償部材）
７加熱手段
８制御部（制御手段）
１０直管状加熱光源
７１基板加熱手段
７２リング部材加熱手段（第１及び第２の温度補償部材加熱手段）
８１リング加熱制御部
８１ａ内周側加熱制御部
８１ｂ外周側加熱制御部
８２基板加熱制御部
８２ａ中央部加熱制御部
８２ｂ中間部加熱制御部
８２ｃ外周部加熱制御部
Ｗ基板[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a heat treatment apparatus for performing heat treatment on a thin precision substrate (hereinafter simply referred to as “substrate”) such as a semiconductor wafer, a glass substrate for a liquid crystal display device, a glass substrate for a photomask, and an optical disk substrate.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a heat treatment apparatus such as single-side heating lamp annealing in which a heating light source is disposed so as to face an upper surface of a substrate is known. In such a heat treatment apparatus, in order to uniformly heat the entire surface of the substrate, a ceramic ring member having a thickness of about 1 mm is provided on the outer peripheral portion of the substrate. Further, as a heating means for performing the heat treatment, a heating light source is arranged so that not only the substrate but also the ring member can be heated.
[0003]
When performing heat treatment on the substrate, the heating light source provided mainly for heating the substrate is divided into a plurality of zones, and the uniformity of heat treatment on the substrate is improved by controlling each zone. ing.
[0004]
[Problems to be solved by the invention]
However, in the conventional heat treatment apparatus, the heating light source provided mainly for heating the ring member is controlled in a unified manner, and there is a water-cooled chamber wall outside the ring member. As a result, a temperature gradient was generated between the inner peripheral side and the outer peripheral side of the ring member provided on the outer peripheral portion of the substrate. That is, a phenomenon has occurred in which the temperature on the outer peripheral side of the ring member is lower than the temperature on the inner peripheral side.
[0005]
The temperature difference between the inner peripheral side and the outer peripheral side of such a ring member reaches a maximum of about 243 ° C. throughout the heat treatment process, and finally generates compressive stress on the inner peripheral side and tensile stress on the outer peripheral side. As a result, the ring member is damaged.
[0006]
Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a heat treatment apparatus that achieves temperature uniformity of the ring member in heat treatment and does not damage the ring member.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the invention described in claim 1 is a heat treatment apparatus for performing heat treatment by accommodating a substrate in a treatment chamber, and is disposed on an outer peripheral portion of the substrate to improve temperature uniformity of the substrate. The temperature compensation member is provided mainly for heating the temperature compensation member, and the temperature is mainly used as the inner circumference side zone when the inner circumference side and the outer circumference side of the temperature compensation member are divided into different zones. First temperature compensation member heating means for heating a region in the vicinity of the substrate in the compensation member, and mainly for heating the temperature compensation member , and mainly heating the remote region in the temperature compensation member as the outer peripheral zone. The second temperature compensation member heating means and the substrate heating means provided mainly for heating the substrate when the substrate is subjected to heat treatment, and the first temperature compensation member heating means. And a control means for individually controlling the compensation member heating means and said second temperature compensating member heating means, said control means, than the electric power supplied to the first temperature compensation member heating means, wherein A power supply amount to the second temperature compensation member heating means is increased to reduce a temperature difference between the substrate vicinity region and the substrate remote region of the temperature compensation member .
[0008]
According to a second aspect of the present invention, in the heat treatment apparatus according to the first aspect, the temperature compensation member also functions as a support means for supporting a peripheral portion of the substrate.
[0009]
According to a third aspect of the present invention, in the heat treatment apparatus according to the first or second aspect, the temperature compensation member is a ring-shaped member.
According to a fourth aspect of the present invention, in the heat treatment apparatus according to any one of the first to third aspects, at least one of the first temperature compensation member heating means and the second temperature compensation member heating means is at least one. The portion overlaps with the temperature compensation member in the vertical direction.
The invention according to claim 5 is the heat treatment apparatus according to any one of claims 1 to 3, wherein both the first temperature compensation member heating means and the second temperature compensation member heating means are the temperature. It is characterized by being provided corresponding to the outer size of the compensation member .
According to a sixth aspect of the present invention, in the heat treatment apparatus according to any one of the first to fifth aspects, the control means includes the first temperature compensation member heating means and the second temperature compensation member heating means. The heating means for mainly heating the temperature compensating member is divided into three or more zones and each zone is individually controlled.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0011]
<1. Heat treatment equipment>
FIG. 1 is a cross-sectional view showing a heat treatment apparatus 1 according to the present embodiment. As shown in FIG. 1, the heat treatment apparatus 1 includes a chamber wall 2, an opening / closing door 3, a quartz window 4, a ring member 5, a lifter 6, a heating unit 7, and a control unit 8.
[0012]
The chamber wall 2 includes a water cooling mechanism, and the chamber wall 2, the opening / closing door 3, and the quartz window 4 form a processing chamber 9 for heat-treating the substrate W. The open / close door 3 opens the transfer port 9a when the substrate W is transferred so that an external transfer robot or the like can access the processing chamber 9.
[0013]
When transporting the substrate W into the processing chamber 9, the lifter 6 provided so as to be lifted and lowered from the lower portion of the processing chamber 9 as shown by a two-dot chain line in FIG. Deliver. Thereafter, the lifter 6 is lowered, and the substrate W is placed on the ring member 5 and retracted from the processing chamber 9 as indicated by a solid line in FIG.
[0014]
The ring member 5 is provided in order to improve temperature uniformity over the entire surface of the substrate W when heat treatment is performed on the substrate W, and the substrate W is supported by supporting the substrate W with the ring-shaped inner edge portion 5a. The external size of the substrate is increased in size, and the heat treatment is performed on the enlarged heating region, thereby improving the uniformity of the substrate W existing in the central portion of the heating region. For this reason, the ring member 5 is disposed on the outer peripheral portion of the substrate W and functions as a temperature compensation member that improves the temperature uniformity of the substrate W, and also functions as a support unit that supports the substrate W.
[0015]
The ring member 5 is formed of a ceramic material such as sintered SiC, and is disposed in the processing chamber 9 by a support portion 9b provided on the chamber wall 2, and the substrate W supported by the inner edge portion 5a when the heat treatment is performed is processed. It is arranged at an optimum processing position in the chamber 9. Note that the structure in which the ring member 5 is provided in the processing chamber 9 may be another structure.
[0016]
The heating means 7 is disposed on the upper side of the quartz window 4 and is configured by arranging a plurality of straight tubular heating light sources 10 in two rows in a vertical direction. For example, a halogen lamp can be used as the straight tubular heating light source 10. Each straight tubular heating light source 10 is configured to emit radiant energy upon receiving power supply from the control unit 8. And the radiant energy radiated | emitted from each straight tubular heating light source 10 is guide | induced to the process chamber 9 through the quartz window 4, and the board | substrate W and the ring member 5 in the process chamber 9 are heated.
[0017]
FIG. 2 is a conceptual diagram showing the positional relationship among the heating means 7, the substrate W, and the ring member 5, as viewed from above the heat treatment apparatus 1. As shown in FIG. 2, in the present embodiment, a total of 32 straight tubular heating light sources 10 are provided as the heating means 7 and are arranged in a grid pattern with 16 upper and lower two-stage configurations.
[0018]
Of the plurality of straight tubular

heating light sources

10, 10 in the lower center and 10 in the upper center are provided so as to cover the outer size of the substrate W, and a substrate for mainly heating the substrate W located immediately below. It functions as the heating means 71. On the other hand, among the plurality of straight tubular heating light sources 10, six on the lower outer sides and six on the upper outer sides are provided corresponding to the outer size of the ring member 5, and the ring member 5 positioned directly below is mainly used. It functions as a ring member heating means (temperature compensation member heating means) 72 for heating.
[0019]
However, since the radiant energy from each straight tube heating light source 10 is not radiated only in the downward direction, a part of the radiant energy from the straight tube heating light source 10 functioning as the substrate heating means 71 heats the ring member 5. Of course, part of the radiant energy from the straight tubular heating light source 10 that functions as the ring member heating means 72 acts to heat the substrate W.
[0020]
FIG. 3 is a block diagram showing a control form by the control unit 8. The control unit 8 includes a ring heating control unit 81 and a substrate heating control unit 82, and the ring heating control unit 81 directly includes the six lower outer sides and the six upper outer sides of the ring member heating unit 72. The tubular heating light source 10 is controlled, and the substrate heating control section 82 controls the lower central 10 and the upper central 10 straight tubular heating light sources 10 constituting the substrate heating means 71.
[0021]
The substrate heating control unit 82 combines the center of the 10 straight tubular heating light sources 10 in the upper and lower stages constituting the substrate heating means 71 (four in total in the upper and lower stages) and the two on the outer sides thereof. 4 zones (8 in the upper and lower stages) are divided into 3 zones, with the middle part and the 4 outer sides (8 in the upper and lower stages) as the outer circumference. Take control. That is, the substrate heating control unit 82 includes a central heating control unit 82a, an intermediate heating control unit 82b, and an outer peripheral heating control unit 82c, and the central heating control unit 82a is disposed in the central part. The heating light source 10 is controlled, the intermediate heating control unit 82b controls the straight tubular heating light source 10 disposed in the intermediate portion, and the outer peripheral heating control unit 82c is disposed in the outer peripheral portion. Control. Each control part 82a-82c adjusts the electric power supplied with respect to the straight tube | pipe heating light source 10 so that the whole surface of the board | substrate W may be heated up / warmed / cooled in a uniform state in the heat treatment process for the substrate W.
[0022]
The substrate heating control unit 82 is provided with a temperature measuring unit (not shown) in the processing chamber 9 in order to realize a heat treatment in a uniform temperature state on the entire surface of the substrate W, and the measurement from the temperature measuring unit is performed. Each control unit 82a to 82c is configured to individually perform feedback control at each stage of temperature increase, temperature retention, and temperature decrease based on the temperature.
[0023]
Further, the ring heating control unit 81 has two inner heating units (four in total in the upper and lower stages) for heating the vicinity of the substrate W in the ring member 5 out of the six upper and lower stages constituting the ring member heating means 72. The outer peripheral side heating means (first temperature compensation member heating means) of the ring member 5 is used, and the outer four sides (eight in total in the upper and lower steps) for heating the remote area of the substrate W in the ring member 5 are the outer circumference of the ring member 5. As the side heating means (second temperature compensation member heating means), the ring member 5 is divided into two zones, an inner peripheral side and an outer peripheral side, and heating control is performed individually for each zone.
[0024]
That is, the ring heating control unit 81 includes an inner peripheral side heating control unit 81a and an outer peripheral side heating control unit 81b, and the inner peripheral side heating control unit 81a is a direct unit for heating mainly the inner peripheral side of the ring member 5. The tubular heating light source 10 is controlled, and the outer peripheral heating control unit 81b mainly controls the straight tubular heating light source 10 for heating the outer peripheral side of the ring member 5. When the heat treatment is performed on the substrate W, the

control units

81a and 81b perform control so that the ring member 5 is heated, kept warm, and cooled in a uniform state.
[0025]
Specifically, a power supply ratio between the inner peripheral side and the outer peripheral side is set in advance for each stage of the temperature raising stage, the heat retaining stage, and the temperature lowering stage, and each control unit is set in the heat treatment for the actual substrate W. By supplying power to the straight tubular heating light source 10 at a preset ratio of 81a and 81b, the temperature uniformity of the ring member 5 during the heat treatment is improved. For example, by setting the power supply ratio for each stage in advance so that the power supply amount on the outer peripheral side is larger than the inner peripheral side, the temperature of the outer peripheral portion becomes significantly lower than that of the inner peripheral portion during the heat treatment. This can be prevented.
[0026]
FIG. 3 shows a configuration example in which the ring heating control unit 81 and the substrate heating control unit 82 are provided in each of the upper stage and the lower stage, but the present invention is not limited to this, and one piece is provided in the upper stage and the lower stage. The ring heating control unit 81 and the single substrate heating control unit 82 may be shared. Rather, such a configuration is preferable because the device configuration can be simplified.
[0027]
The heat treatment apparatus 1 in the present embodiment is configured as described above, and the ring member heating means 72 that is disposed above the ring member 5 and includes the straight tubular heating light source 10 is arranged on the inner peripheral side and the outer peripheral side. The ring member 5 is configured so as to be capable of adjusting the output of the radiant energy from each straight tubular heating light source 10 by separately controlling the inner peripheral side and the outer peripheral side. It becomes possible to reduce the temperature gradient generated on the inner peripheral side and the outer peripheral side.
[0028]
<2. Experimental example>
Next, an experimental example in which the case of the above configuration is compared with the case of the conventional configuration will be described.
[0029]
In this experimental example, a heating light source uses a straight tubular halogen lamp with a rating of 2 KW and a light emission length of 300 mm, and the ring member 5 is made of sintered SiC having a width of 43 mm.
[0030]
The heating procedure for the substrate W is performed as follows. At the beginning of heating, the substrate W and the ring member 5 are heated by applying a constant power of an appropriate magnitude to the heating light source until the substrate temperature becomes higher than the measurement lower limit of the pyrometer that measures the substrate temperature. Then, after the temperature of the substrate W becomes measurable by the pyrometer, the temperature of the substrate W is switched to feedback control as a feedback signal. When the target temperature is reached and a predetermined time elapses, heating by the heating light source is terminated. To do.
[0031]
In this experiment, the substrate W is subjected to the heat treatment under the heating conditions in which the target temperature is 1100 ° C. and the temperature increase rate in the temperature increase process is 120 ° C./s. Measure.
[0032]
FIG. 4 is a diagram showing temperature measurement points of the ring member 5 in this experiment. As shown in FIG. 4, in this experiment, a point P1 that is about 2 mm inside from the outer peripheral end of the ring member 5 and a point that is about 2 mm outside from the end of the substrate W when the substrate W is placed on the ring member 5. Thermocouples were installed at a total of five points including P5 and three points (P2, P3, P4) provided at equal intervals between the points P1 and P5, and the temperature of the ring member 5 was measured.
[0033]
This thermocouple is for experiments and is not essential for the heat treatment apparatus 1.
[0034]
When this experiment is performed with the conventional configuration, as described above, the heating light source for heating the ring member 5 is set to one zone, and is affected by the chamber wall 2 that is water-cooled outside the ring member 5. Therefore, the temperature difference between the inner side and the outer side of the ring member 5 reaches a maximum of about 243 ° C. when the temperature is changed from the temperature raising process to the target temperature holding state.
[0035]
In general, assuming that the temperature on the inner peripheral side is T1, the temperature on the outer peripheral side is T2, the inner radius is a, the outer radius is b, the Young's modulus is E, and the linear expansion coefficient of the material forming the ring member is α, The circumferential stress θ at an arbitrary radius r is given by
[Expression 1]

[0037]
Can be obtained. However, K is a ratio of the outer radius b and the inner radius a, and K = b / a. From Equation 1, it can be seen that the temperature difference between the inner diameter side and the outer diameter side is directly related to the stress.
[0038]
Therefore, in a state where a temperature difference of about 243 ° C. occurs in the conventional configuration, the internal stress is about 457 Mpa from the calculation of Equation 1, which is a value close to the stress fracture limit of sintered SiC of about 510 Mpa. This numerical value considers only the above numerical conditions, and in the actual apparatus, the conditions differ in other detailed portions. Therefore, the conventional configuration has a device configuration with no margin for the stress fracture limit. ing.
[0039]
On the other hand, in the configuration of the heat treatment apparatus 1 of the present embodiment described above, output adjustment between the inner peripheral side and the outer peripheral side of the ring member 5 is performed based on a preset power supply ratio between the inner peripheral side and the outer peripheral side. By performing the heat treatment while performing, the temperature difference between the inner peripheral side and the outer peripheral side of the ring member 5 could be reduced to about 180 ° C. at the maximum. The circumferential stress generated in the ring member 5 of the heat treatment apparatus 1 is about 370 Mpa based on the calculation of Formula 1, and a sufficient margin can be included with respect to the stress failure limit. Can be prevented.
[0040]
<3. Modification>
Although the embodiments of the present invention have been described above, the present invention is not limited to the above contents.
[0041]
For example, although the case where the heating means 7 is a straight tubular heating light source has been described above, the present invention is not limited to this, and an arbitrary heating light source such as a single-ended heating light source may be used. Further, the light source such as a lamp need not be used. Furthermore, in the above description, the example in which the heating means 7 is arranged above the substrate W and the ring member 5 is shown, but the present invention is not limited to this, and the arrangement form of the heating means 7 is also in a cross-beam shape. It is not limited to being.
[0042]
In the above description, the ring member 5 that is disposed on the outer peripheral portion of the substrate W and is integrated as an example of the temperature compensation member that improves the temperature uniformity of the substrate W is illustrated. However, the temperature compensation member includes a plurality of ring members 5. A plurality of members may be combined to form a substantially ring shape as a whole when formed by separated members and installed in the processing chamber 9.
[0043]
In the above description, since a semiconductor wafer is assumed as the substrate W, the temperature compensation member is shown in a ring shape. However, when the substrate W is not a semiconductor wafer, other shapes may be preferable. is there. Moreover, the material which forms a temperature compensation member is also arbitrary.
[0044]
In the above description, the ring member 5 has also been described as an example of functioning as a support means for supporting the substrate W during the heat treatment. However, in order to support the substrate W during the heat treatment, a support means independent of the ring member 5 is provided. May be. In this case, the ring member 5 functions only as a temperature compensation member.
[0045]
Further, in the above description, the heating means for mainly heating the ring member 5 is divided into two zones of the inner peripheral side and the outer peripheral side, and the two zones are individually controlled in the heating process. It may be configured such that each zone is individually controlled by being divided into zones or more. Even in this case, at least the first temperature compensation member heating means for heating the region near the substrate in the ring member 5 and the second temperature compensation member heating means for heating the substrate remote region are present.
[0046]
【The invention's effect】
As described above, according to the first to sixth aspects of the invention, the first temperature compensation member heating unit that heats the region in the vicinity of the substrate of the temperature compensation member when the substrate is subjected to heat treatment. Since the second temperature compensation member heating means for heating the substrate remote region in the temperature compensation member is individually controlled, the substrate vicinity region side and the substrate remote region side of the temperature compensation member in the heat treatment process And the temperature uniformity of the temperature compensation member is improved.
[0047]
According to the second aspect of the invention, since the temperature compensation member also functions as a support means for supporting the peripheral edge portion of the substrate, it is not necessary to provide a separate support means.
[0048]
According to the third aspect of the present invention, since the temperature compensation member is a ring-shaped member, the temperature uniformity of the substrate is improved satisfactorily when the substrate is a semiconductor wafer.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a heat treatment apparatus.
FIG. 2 is a conceptual diagram showing a positional relationship among heating means, a substrate, and a ring member.
FIG. 3 is a block diagram showing a control form by a control unit.
FIG. 4 is a diagram showing temperature measurement points of a ring member in an experimental example.
[Explanation of symbols]
1 Heat treatment device 5 Ring member (temperature compensation member)
7 Heating means 8 Control section (control means)
DESCRIPTION OF SYMBOLS 10 Straight tubular heating light source 71 Substrate heating means 72 Ring member heating means (1st and 2nd temperature compensation member heating means)
81 Ring heating control unit 81a Inner peripheral side heating control unit 81b Outer peripheral side heating control unit 82 Substrate heating control unit 82a Central heating control unit 82b Intermediate heating control unit 82c Outer peripheral heating control unit W Substrate

Claims

A heat treatment apparatus for accommodating a substrate in a processing chamber and performing a heat treatment,
A temperature compensation member disposed on the outer periphery of the substrate and improving the temperature uniformity of the substrate;
Provided mainly for heating the temperature compensation member, and as a zone on the inner circumference side when the inner circumference side and the outer circumference side of the temperature compensation member are divided into different zones, mainly near the substrate in the temperature compensation member First temperature compensation member heating means for heating the region;
A second temperature compensation member heating means which is provided mainly for heating the temperature compensation member and mainly heats a remote area of the substrate in the temperature compensation member as the outer peripheral zone ;
When heat-treating the substrate, the substrate heating means provided mainly for heating the substrate is controlled, and the first temperature compensation member heating means and the second temperature compensation member heating means are individually provided. Control means to control,
Equipped with a,
The control means increases the power supply amount to the second temperature compensation member heating means to be larger than the power supply amount to the first temperature compensation member heating means, so that the substrate vicinity region of the temperature compensation member And a temperature difference between the remote region of the substrate and the heat treatment apparatus.

The heat treatment apparatus according to claim 1,
The temperature compensation member also functions as a support means for supporting the peripheral edge of the substrate.

In the heat treatment apparatus according to claim 1 or 2,
The heat treatment apparatus, wherein the temperature compensation member is a ring-shaped member.

The heat treatment apparatus according to any one of claims 1 to 3,
Both the first temperature compensation member heating means and the second temperature compensation member heating means are at least partially overlapped with the temperature compensation member in the vertical direction.

The heat treatment apparatus according to any one of claims 1 to 3,
Both the first temperature compensation member heating means and the second temperature compensation member heating means are provided corresponding to the outer size of the temperature compensation member.

In the heat treatment apparatus according to any one of claims 1 to 5,
The control means mainly divides the heating means for heating the temperature compensation member including the first temperature compensation member heating means and the second temperature compensation member heating means into three or more zones, respectively. The heat processing apparatus characterized by controlling a zone separately .