JP3973848B2

JP3973848B2 - Cylindrical glassy carbon member

Info

Publication number: JP3973848B2
Application number: JP2001056439A
Authority: JP
Inventors: 祐史田中; 幹治杉原
Original assignee: Tokai Carbon Co Ltd
Current assignee: Tokai Carbon Co Ltd
Priority date: 2001-03-01
Filing date: 2001-03-01
Publication date: 2007-09-12
Anticipated expiration: 2021-03-01
Also published as: JP2002261080A

Description

【０００１】
【発明の属する技術分野】
本発明は、例えばシリコンウエハのプラズマエッチング装置やプラズマＣＶＤ装置等のプラズマ処理装置の保護部材等として有用な円筒状ガラス状カーボン部材に関する。
【０００２】
【従来の技術】
プラズマエッチング装置やプラズマＣＶＤ装置等のプラズマ処理を行う半導体製造装置の部材には、ＣＦ₄、ＣＨＦ₃、ＳｉＨ₄等とＡｒ、Ｏ₂等を混合した反応性ガスのガスプラズマに曝されるので、耐プラズマ性に優れ、ガスプラズマにより損傷し難い材質特性が要求される。
【０００３】
例えば、平行平板型リアクティブイオンエッチング（ＲＩＥ）装置は、一対の平行平面電極を上下に設置したエッチング装置内に、上部電極の細孔から反応性ガス（Ｃ、Ｈ、Ｆ、Ｏ等の原子含有ガス）を導入しながら、上下両電極間に印加した高周波電圧により放電させて、発生したプラズマにより下部電極上に置いたシリコンウエハ等のプラズマ被処理物のエッチング加工を行って、高精度で微細な高密度回路パターンを形成するものである。
【０００４】
このプラズマ処理装置において、例えば、反応チャンバーの内壁部は常時反応性ガスのガスプラズマに曝されるのでエッチングにより壁面が損傷され易く、内壁面が損傷するとプラズマ状態が変動し、プラズマ処理条件が変化するので製造される半導体の特性を劣化させることとなる。更に、内壁面がエッチングにより損傷するとパーティクル（ダスト）が発生し、このパーティクルがウエハ面上に付着すると品質が劣化して不良品となり、製品デバイスの歩留りが低下することとなる。したがって、反応チャンバー内壁部の寿命も短いものとなる。
【０００５】
従来から反応チャンバーの内壁部はアルミニウムやその表面を酸化処理したアルミニウム材料が使用されているが、耐プラズマ性が充分でないために内壁面が損傷して、製品歩留りが低下し、また使用寿命が短縮化する難点がある。そこでプラズマ処理を行う反応チャンバー内にプラズマを囲包するように、チャンバー内壁部に沿って内壁保護部材を着脱可能な状態に配設して、チャンバー内壁面をプラズマによる損耗から防御する手段が採られている。
【０００６】
この反応チャンバーの内壁部等を保護するプラズマ処理装置用保護部材には、耐プラズマ性に優れ、プラズマガスに曝されても安定で損傷せず、また、高純度で強度、耐熱性、耐蝕性等の材質性状に優れていることが必要であり、このような材質性状を満たすものとしてガラス状カーボン材が有用されている。
【０００７】
例えば、特開平９−２８９１９８号公報には、プラズマ処理室内の電極以外のプラズマに曝される部分の少なくとも表面をガラス状カーボンにて形成したことを特徴とするプラズマ処理装置、及び、プラズマ処理装置用保護部材において、この保護部材の少なくともプラズマ領域側表面をガラス状カーボンにて形成したことを特徴とするプラズマ処理装置用保護部材が提案されている。これは、プラズマに曝される部分をガラス状カーボンで形成することにより、プラズマによる浸食、損傷が少なくなり、長寿命でパーティクル（ダスト）の発生も少なく、パーティクルによる被処理物の汚染の防止を図るものである。
【０００８】
ガラス状カーボン材は、熱硬化性樹脂を非酸化性雰囲気下で加熱し、焼成炭化して得られる、巨視的に無孔組織の三次元網目構造を呈するガラス質の緻密な硬質炭素物質であり、強度が高く、化学的安定性、ガス不透過性に優れ、また耐摩耗性や堅牢性にも優れており、プラズマ処理中に微小なパーティクルが組織から離脱し難い利点がある。
【０００９】
しかしながら、近時、ＬＳＩの高集積化が進み、要求されるプラズマ処理精度が高くなるに伴って、プラズマ処理を行う反応チャンバーの内壁部もより苛酷なプラズマ雰囲気に曝されることとなり、内壁保護部材にも耐プラズマ性により一層優れた材質性状が必要となってきた。ガラス状カーボン材の耐プラズマ性はガラス状カーボンの材質性状によって異なるため、保護部材として好適な性能を発揮するためには適切な材質設定が重要となる。
【００１０】
【発明が解決しようとする課題】
一般に、プラズマ処理装置の保護部材には、形状精度の高い円筒形状のガラス状カーボン材が好適に用いられるが、円筒状ガラス状カーボン材は熱硬化性樹脂を円筒形状に成形したのち、熱硬化及び焼成炭化して作製され、次いで、内外両面層を研削や切削等の機械加工により加工して径精度の高い保護部材が製造される。
【００１１】
この機械加工時に、円筒状のガラス状カーボン材には内部歪みが発生して蓄積されるため、僅かな機械的衝撃や熱的衝撃により亀裂が発生し易く、割損する問題がある。すなわち、円筒状ガラス状カーボン材は焼成炭化時に焼き締まるため応力が内在し、機械加工時に内面層と外面層において応力のバランスが崩れるため、比較的僅かな機械的衝撃や熱的衝撃により亀裂や割れが発生し易い問題点がある。
【００１２】
本発明者らは、上記問題点を解消するために鋭意研究を行い、円筒状ガラス状カーボン材の内在応力は、円筒の内面と外面におけるガラス状カーボンの結晶性に影響され、そして、円筒の内面層と外面層における炭素結晶子Ｌc(002)の大きさ、特にその比が大きく影響することを見出した。
【００１３】
本発明は上記の知見に基づいて完成したもので、その目的は、例えば、優れた耐プラズマ性を備えるとともに機械的衝撃や熱的衝撃に強く、プラズマ処理装置の内壁部等を保護し、また内壁部の損耗によるパーティクルの発生を抑制し、長期に亘って安定したプラズマ処理が可能なプラズマ処理装置の保護部材等として有用な円筒状ガラス状カーボン部材を提供することにある。
【００１４】
【課題を解決するための手段】
上記の目的を達成するための本発明の円筒状ガラス状カーボン部材は、円筒の内外両面層を異なる研削条件で機械加工したガラス状カーボンからなる円筒体であって、内径が３００ｍｍ以上、厚さが４ｍｍ以上の形状を有し、円筒の内面層と外面層におけるガラス状カーボン材の炭素結晶子Ｌｃ(002)の大きさの比Ｒ（＝内面層Ｌｃ／外面層Ｌｃ）の値が、０．６８≦Ｒ≦１．４７の関係を満たす結晶性状を備えることを構成上の特徴とする。
【００１５】
【発明の実施の形態】
ガラス状カーボン材は熱硬化性樹脂を焼成炭化して得られる無定形で均質緻密な組織を備える高強度の炭素質材料で、黒鉛のようなカーボン粉末の集合体からなる材料とは全く異質の素材である。したがって、プラズマによるスパッタリングやエッチングを受けた場合に、黒鉛材では構成粉末の離脱が起こるが、ガラス状カーボン材では粉末離脱を生じることがない。
【００１６】
このガラス状カーボン材を円筒形状に加工し、例えばプラズマ処理装置の保護部材等を構成する場合、その厚さは強度特性を維持する上から重要であり、本発明においては、円筒体の内径を３００mm以上とするとともに、構造的強度を維持するためにその厚さは４mm以上に設定される。
【００１７】
本発明は、上記の円筒状のガラス状カーボン材において、円筒の内面層の炭素結晶子の大きさＬc(002)と外面層の炭素結晶子の大きさＬc(002)との比Ｒ（＝内面層Ｌc ／外面層Ｌc ）の値を、０．６８≦Ｒ≦１．４７の範囲に結晶性状を設定することを特徴とする。
【００１８】
円筒状ガラス状カーボン材は、熱硬化性樹脂を円筒形状に成形したのち熱硬化及び焼成炭化して作製され、次いで、円筒の内外両面層を研削や切削等により機械加工して径精度の高い円筒状部材が製造される。この機械加工時の、例えば、研削代、研削速度、研削工具の応圧度合い等の研削条件によっては結晶性状が変化することとなり、円筒状ガラス状カーボン材の内部に歪み応力の蓄積を助長する一要因となる。
【００１９】
本発明で定義した円筒の内面層の炭素結晶子の大きさＬc(002)と外面層の炭素結晶子の大きさＬc(002)との比Ｒ（＝内面層Ｌc ／外面層Ｌc ）の値を、０．６８≦Ｒ≦１．４７の関係を満たす結晶性状に制御することにより、機械加工時の機械的衝撃や熱的衝撃による亀裂や割れ発生を低減化することが可能となる。
【００２０】
すなわち、Ｒの値が、Ｒ＜０．６８の場合には円筒体を縮める方向に歪み応力が蓄積されることになり、また、１．４７＜Ｒの場合には円筒体を拡げる方向に歪み応力が蓄積されることとなり、いずれの場合も亀裂や割れ発生の頻度が増大するとになる。なお、炭素結晶子Ｌc(002)の大きさは、常法であるＸ線回折により黒鉛六角網面層の回折ピークから測定される。
【００２１】
本発明の円筒状ガラス状カーボン部材は、次の方法により製造することができる。原料樹脂としては常用されるフェノール系、フラン系、ポリイミド系等の熱硬化性樹脂を用い、モールド成形、射出成形、注型成形、遠心成形等の適宜な成形法により、円筒形状に成形する。成形体は、大気中で９０〜２５０℃の温度で加熱硬化したのち、非酸化性雰囲気中で１０００〜２３００℃の温度で焼成炭化する。なお、焼成炭化の際に生じる線収縮率を考慮して、例えば円筒状成形体の肉厚は６mm以上に成形することが望ましい。次いで、常法であるハロゲン系の高純度ガス中で加熱して高純度化処理が施される。
【００２２】
このようにして得られる円筒状のガラス状カーボン成形体は、その両端部をダイヤモンドホイール等で端面を平行となるように調整したのち、例えば研削工具を備えた旋盤等で内面層及び外面層を研削して所定形状に加工する。この際に、研削代や研削速度等の研削条件を変えて、内面層と外面層の炭素結晶子Ｌc(002)の大きさを調整することにより、Ｒの値を０．６８≦Ｒ≦１．４７に制御する。なお、研削時に付着した油脂分、微粉等は、高純水中での超音波洗浄、酸洗浄、有機溶媒洗浄などにより除去する。このようにして、本発明の円筒状ガラス状カーボン部材が製造される。
【００２３】
【実施例】
以下、本発明の実施例を比較例と対比して具体的に説明する。
【００２４】
実施例１〜５、比較例１〜２
精製処理した残炭率が５０％のフェノール樹脂初期縮合物を外枠と内枠を有する有底の枠体に注入して、内径５２０mm、外径５３６mm、高さ２２０mmの円筒形状に成形した。成形体を大気中１５０℃の温度に１０時間保持して熱硬化したのち、電気炉に入れ、窒素雰囲気中で１０００℃に加熱、昇温して焼成炭化した。次いで、雰囲気置換可能な電気炉に入れて高純度塩素ガスを流しながら２０００℃の温度に加熱して、高純度化処理を行った。このようにして、内径３９８mm、外径４１０mm、高さ１６８mmの円筒状ガラス状カーボン部材（肉厚６mm）を作製した。
【００２５】
次いで、両端部をダイヤモンドホイールで両端面を研削し平行とした後、ダイヤモンド砥粒を含有する回転ツールを備えた旋盤により円筒の内面層及び外面層を研削加工した。この旋盤加工の際、内面層及び外面層の研削量（研削厚さ）を変えて行い、円筒状ガラス状カーボン材の内面層と外面層の炭素結晶子Ｌc(002)の大きさの異なる試料を作製した。なお、炭素結晶子Ｌc(002)の測定は、円筒状ガラス状カーボンより厚さ１mmの内面層および外面層を採取し、粉砕した後、日本学術振興会第１１７委員会作成の「人造黒鉛の格子定数および結晶子の大きさ測定法」により行った。
【００２６】
これらの試料から高さ５０mmの輪切りサンプルを切り出し、耐荷重を潰し荷重により測定し、割れ難さを評価、比較した。なお、潰し荷重は、図１に示したオートグラフＡＧ−１０ＴＢ（島津製作所製）を用いて測定した。図１において、台座２と押し板３の間に厚紙（例えば官製はがき）４を介して輪切りサンプル１を置き、押し板３をヘッドスピード０．５mm／秒の速度で荷重を加えていき、輪切りサンプル１に割れを生じた時の荷重（kg）を測定して潰し荷重とした。得られた結果を、表１に示した。
【００２７】
【表１】

【００２８】
表１から、本発明の条件を満たす実施例１〜５の円筒状ガラス状カーボン部材は潰し荷重が高く、Ｒの値が本発明の条件を外れる比較例１〜２の円筒状ガラス状カーボン材に比べて１．５倍以上の強度を示し、割損し難いことが判る。
【００２９】
実施例６〜１０、比較例３〜４
実施例１〜５、比較例１〜２と同じ方法で作製した試料から高さ１５０mmのサンプルを切り出し、これらの各サンプルに、回転テーブルを備えたＮＣ加工機により電着ダイヤツールを用いてプラズマ処理装置のウエハ出し入れ用の窓、及び覗き窓を加工取り付けた。この機械加工時の割れの状況を観察し、加工時の割損の比率（加工不良率）を求めた。得られた結果を表２に示した。
【００３０】
【表２】

【００３１】
表２から、本発明の条件を満たす実施例６〜１０の円筒状ガラス状カーボン部材は、Ｒ値が外れる比較例３〜４の円筒状ガラス状カーボン部材に比較して、ウエハ出し入れ用の窓や覗き窓のような複雑な機械加工を行っても割れが発生することなく、極めて高い加工歩留りで製品加工できることが判る。
【００３２】
【発明の効果】
以上のとおり、本発明の円筒状ガラス状カーボン部材によれば、円筒体の内面層と外面層におけるガラス状カーボン材の結晶性状を特定し、内面層と外面層におけるガラス状カーボン材の炭素結晶子Ｌc(002)の大きさの比Ｒ（＝内面層Ｌc ／外面層Ｌc ）の値を、０．６８≦Ｒ≦１．４７の関係を満たす結晶性状に設定することにより、機械加工時の機械的衝撃や熱的衝撃による亀裂や割れ発生を低減することが可能となる。したがって、優れた耐プラズマ性を備えるとともに機械的衝撃や熱的衝撃に強く、例えば、プラズマ処理装置の内壁部等を保護し、また内壁部の損耗によるパーティクルの発生を抑制し、長期に亘って安定したプラズマ処理が可能なプラズマ処理装置の保護部材等として有用な円筒状ガラス状カーボン部材を提供することができる。
【図面の簡単な説明】
【図１】潰し荷重の測定装置を示した断面略図である。
【符号の説明】
１輪切りサンプル
２台座
３押し板
４厚紙[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cylindrical glassy carbon member useful as a protective member of a plasma processing apparatus such as a silicon wafer plasma etching apparatus or a plasma CVD apparatus.
[0002]
[Prior art]
Since members of semiconductor manufacturing apparatuses that perform plasma processing such as plasma etching apparatuses and plasma CVD apparatuses are exposed to gas plasma of a reactive gas in which CF ₄ , CHF ₃ , SiH _4, etc. and Ar, O _2, etc. are mixed. The material properties are required to be excellent in plasma resistance and hard to be damaged by gas plasma.
[0003]
For example, in a parallel plate type reactive ion etching (RIE) apparatus, a reactive gas (atom such as C, H, F, O, etc.) is generated from the pores of the upper electrode in an etching apparatus in which a pair of parallel plane electrodes are installed one above the other. The plasma processing object such as a silicon wafer placed on the lower electrode is etched with high accuracy by discharging with a high-frequency voltage applied between the upper and lower electrodes while introducing a gas). A fine high-density circuit pattern is formed.
[0004]
In this plasma processing apparatus, for example, the inner wall portion of the reaction chamber is constantly exposed to reactive gas plasma, so the wall surface is easily damaged by etching, and the plasma state fluctuates and the plasma processing conditions change when the inner wall surface is damaged. Therefore, the characteristics of the manufactured semiconductor are deteriorated. Further, if the inner wall surface is damaged by etching, particles (dust) are generated. If these particles adhere to the wafer surface, the quality deteriorates and becomes a defective product, and the yield of product devices decreases. Therefore, the lifetime of the inner wall of the reaction chamber is also shortened.
[0005]
Conventionally, the inner wall of the reaction chamber has been made of aluminum or an aluminum material whose surface has been oxidized. However, because the plasma resistance is not sufficient, the inner wall is damaged, the product yield is reduced, and the service life is shortened. There is a difficulty to shorten. Therefore, a means for protecting the inner wall surface of the chamber from wear due to plasma is provided by detachably placing an inner wall protection member along the inner wall portion of the chamber so as to surround the plasma in the reaction chamber for plasma treatment. It has been.
[0006]
This protective member for plasma processing equipment that protects the inner wall of the reaction chamber has excellent plasma resistance, is stable and not damaged even when exposed to plasma gas, and has high purity, strength, heat resistance, and corrosion resistance. It is necessary to have excellent material properties such as, and a glassy carbon material is useful for satisfying such material properties.
[0007]
For example, Japanese Patent Laid-Open No. 9-289198 discloses a plasma processing apparatus and a plasma processing apparatus characterized in that at least the surface of a portion exposed to plasma other than the electrode in the plasma processing chamber is formed of glassy carbon. In the protective member for plasma, a protective member for a plasma processing apparatus has been proposed in which at least the plasma region side surface of the protective member is formed of glassy carbon. This is because the part exposed to plasma is made of glassy carbon, which reduces erosion and damage due to plasma, has a long life and generates less particles (dust), and prevents contamination of the workpiece by particles. It is intended.
[0008]
A glassy carbon material is a vitreous dense hard carbon material that exhibits a macroscopically non-porous three-dimensional network structure obtained by heating and carbonizing a thermosetting resin in a non-oxidizing atmosphere. It has high strength, excellent chemical stability and gas impermeability, and also has excellent wear resistance and fastness, and has the advantage that minute particles are not easily detached from the tissue during plasma processing.
[0009]
However, recently, with the progress of higher integration of LSI and higher required plasma processing accuracy, the inner wall of the reaction chamber for plasma processing is also exposed to a harsher plasma atmosphere. The members also have to have better material properties due to plasma resistance. Since the plasma resistance of the glassy carbon material varies depending on the material properties of the glassy carbon, it is important to set an appropriate material in order to exhibit suitable performance as a protective member.
[0010]
[Problems to be solved by the invention]
In general, a cylindrical glassy carbon material with high shape accuracy is suitably used as a protective member of a plasma processing apparatus. However, a cylindrical glassy carbon material is formed by thermosetting resin after it is formed into a cylindrical shape. Then, the protective member with high diameter accuracy is manufactured by processing the inner and outer double-sided layers by machining such as grinding or cutting.
[0011]
During this machining, the cylindrical glassy carbon material is internally strained and accumulated, so that there is a problem that cracks are likely to occur due to slight mechanical and thermal shocks and breakage. That is, since the cylindrical glassy carbon material is squeezed during firing and carbonization, stress is inherent, and the balance of stress is lost in the inner surface layer and outer surface layer during machining. There is a problem that cracks are likely to occur.
[0012]
The present inventors have intensively studied to solve the above problems, and the internal stress of the cylindrical glassy carbon material is influenced by the crystallinity of the glassy carbon on the inner and outer surfaces of the cylinder, and It has been found that the size of carbon crystallite Lc (002) in the inner surface layer and the outer surface layer, particularly the ratio thereof, has a great influence.
[0013]
The present invention has been completed on the basis of the above knowledge, and its purpose is, for example, to have excellent plasma resistance and to be resistant to mechanical shock and thermal shock, to protect the inner wall of the plasma processing apparatus, etc. An object of the present invention is to provide a cylindrical glassy carbon member useful as a protective member of a plasma processing apparatus capable of suppressing generation of particles due to wear of an inner wall portion and performing stable plasma processing over a long period of time.
[0014]
[Means for Solving the Problems]
The cylindrical glassy carbon member of the present invention for achieving the above object is a cylindrical body made of glassy carbon obtained by machining the inner and outer double-sided layers of the cylinder under different grinding conditions, and has an inner diameter of 300 mm or more and a thickness. Has a shape of 4 mm or more, and the ratio R (= inner surface layer Lc / outer surface layer Lc) of the size of carbon crystallite Lc (002) of the glassy carbon material between the inner surface layer and the outer surface layer of the cylinder is 0. It is a structural feature that it has crystal properties satisfying the relationship of .68 ≦ R ≦ 1.47.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Glassy carbon material is a high-strength carbonaceous material with an amorphous, homogeneous and dense structure obtained by calcining a thermosetting resin. It is completely different from a material consisting of an aggregate of carbon powders such as graphite. It is a material. Therefore, when subjected to sputtering or etching by plasma, the constituent powder is detached from the graphite material, but the powder is not detached from the glassy carbon material.
[0016]
When this glassy carbon material is processed into a cylindrical shape, for example, when forming a protective member of a plasma processing apparatus, the thickness is important from the standpoint of maintaining strength characteristics. In the present invention, the inner diameter of the cylindrical body is reduced. The thickness is set to 300 mm or more, and the thickness is set to 4 mm or more in order to maintain the structural strength.
[0017]
In the present invention, in the above-described cylindrical glassy carbon material, the ratio R (=) of the carbon crystallite size Lc (002) of the inner surface layer of the cylinder to the carbon crystallite size Lc (002) of the outer surface layer. The crystal property is set so that the value of the inner surface layer Lc / outer surface layer Lc) is in the range of 0.68 ≦ R ≦ 1.47.
[0018]
The cylindrical glassy carbon material is produced by molding a thermosetting resin into a cylindrical shape and then thermosetting and firing carbonization, and then machining the inner and outer double-sided layers of the cylinder by grinding, cutting, or the like to provide high diameter accuracy. A cylindrical member is manufactured. During this machining process, for example, the crystallinity changes depending on the grinding conditions such as the grinding allowance, grinding speed, and the degree of pressure applied to the grinding tool, which promotes the accumulation of strain stress inside the cylindrical glassy carbon material. One factor.
[0019]
The ratio R (= inner surface layer Lc / outer surface layer Lc) of the carbon crystallite size Lc (002) of the inner surface layer of the cylinder defined in the present invention and the carbon crystallite size Lc (002) of the outer surface layer. Is controlled to a crystal property satisfying the relationship of 0.68 ≦ R ≦ 1.47, it is possible to reduce the occurrence of cracks and cracks due to mechanical shock and thermal shock during machining.
[0020]
That is, when the value of R is R <0.68, strain stress is accumulated in the direction of shrinking the cylindrical body, and when 1.47 <R, the strain is expanded in the direction of expanding the cylindrical body. Stress is accumulated, and in any case, the frequency of occurrence of cracks and cracks increases. The size of the carbon crystallite Lc (002) is measured from the diffraction peak of the graphite hexagonal network layer by X-ray diffraction as usual.
[0021]
The cylindrical glassy carbon member of the present invention can be produced by the following method. As a raw material resin, a thermosetting resin such as phenol, furan or polyimide that is commonly used is used, and is molded into a cylindrical shape by an appropriate molding method such as molding, injection molding, cast molding, or centrifugal molding. The molded body is heat-cured at a temperature of 90 to 250 ° C. in the air, and then calcined and carbonized at a temperature of 1000 to 2300 ° C. in a non-oxidizing atmosphere. In consideration of the linear shrinkage rate that occurs during firing carbonization, for example, it is desirable that the cylindrical molded body has a thickness of 6 mm or more. Next, a high-purity treatment is performed by heating in a halogen-based high-purity gas, which is a conventional method.
[0022]
After the cylindrical glassy carbon molded body thus obtained is adjusted so that both end portions thereof are parallel to each other with a diamond wheel or the like, the inner layer and the outer layer are formed on a lathe equipped with a grinding tool, for example. Grind and process into a predetermined shape. At this time, the value of R is set to 0.68 ≦ R ≦ 1 by changing the grinding conditions such as the grinding allowance and the grinding speed and adjusting the size of the carbon crystallite Lc (002) of the inner surface layer and the outer surface layer. .47. Oils and fats, fine powder, etc. adhering during grinding are removed by ultrasonic cleaning, acid cleaning, organic solvent cleaning or the like in high purity water. Thus, the cylindrical glassy carbon member of the present invention is manufactured.
[0023]
【Example】
Examples of the present invention will be specifically described below in comparison with comparative examples.
[0024]
Examples 1-5, Comparative Examples 1-2
The refined phenol resin initial condensate with a residual carbon ratio of 50% was poured into a bottomed frame having an outer frame and an inner frame, and formed into a cylindrical shape having an inner diameter of 520 mm, an outer diameter of 536 mm, and a height of 220 mm. The molded body was kept at a temperature of 150 ° C. in the atmosphere for 10 hours and thermally cured, and then placed in an electric furnace, heated to 1000 ° C. in a nitrogen atmosphere, heated and calcined. Subsequently, it was placed in an electric furnace capable of atmosphere substitution and heated to a temperature of 2000 ° C. while flowing high-purity chlorine gas to perform a purification process. Thus, a cylindrical glassy carbon member (thickness 6 mm) having an inner diameter of 398 mm, an outer diameter of 410 mm, and a height of 168 mm was produced.
[0025]
Next, both end portions were ground with a diamond wheel so as to be parallel, and then the cylindrical inner surface layer and outer surface layer were ground by a lathe equipped with a rotary tool containing diamond abrasive grains. In this lathe process, the grinding amount (grinding thickness) of the inner surface layer and the outer surface layer is changed, and samples having different sizes of carbon crystallites Lc (002) of the inner surface layer and the outer surface layer of the cylindrical glassy carbon material are used. Was made. The carbon crystallite Lc (002) was measured by collecting and grinding an inner surface layer and an outer surface layer having a thickness of 1 mm from cylindrical glassy carbon, and then preparing “artificial graphite of artificial graphite prepared by the Japan Society for the Promotion of Science 117”. It was carried out by “Lattice constant and crystallite size measurement method”.
[0026]
From these samples, 50 mm-high round slice samples were cut out, the load resistance was crushed and measured by the load, and the difficulty of cracking was evaluated and compared. The crushing load was measured using the autograph AG-10TB (manufactured by Shimadzu Corporation) shown in FIG. In FIG. 1, a sliced sample 1 is placed between a pedestal 2 and a pressing plate 3 via a thick paper (for example, a public postcard) 4, and a load is applied to the pressing plate 3 at a head speed of 0.5 mm / second. The load (kg) when the sample 1 was cracked was measured to obtain a crushing load. The obtained results are shown in Table 1.
[0027]
[Table 1]

[0028]
From Table 1, the cylindrical glassy carbon members of Examples 1 to 5 that satisfy the conditions of the present invention have a high crushing load, and the cylindrical glassy carbon material of Comparative Examples 1 and 2 whose R value deviates from the conditions of the present invention. Compared to the above, the strength is 1.5 times or more, and it is difficult to break.
[0029]
Examples 6-10, Comparative Examples 3-4
Samples having a height of 150 mm were cut out from the samples prepared in the same manner as in Examples 1 to 5 and Comparative Examples 1 and 2, and plasma was generated on each of these samples using an electrodeposition diamond tool by an NC processing machine equipped with a rotary table. A processing window and a view window for processing the wafer were taken in and attached. The state of cracks during machining was observed, and the ratio of breakage during machining (machining defect rate) was determined. The obtained results are shown in Table 2.
[0030]
[Table 2]

[0031]
From Table 2, the cylindrical glassy carbon members of Examples 6 to 10 satisfying the conditions of the present invention have a window for taking in and out of the wafer as compared with the cylindrical glassy carbon members of Comparative Examples 3 to 4 in which the R value deviates. It can be seen that the product can be processed with a very high processing yield without causing cracks even when complicated machining such as a viewing window is performed.
[0032]
【The invention's effect】
As described above, according to the cylindrical glassy carbon member of the present invention, the crystallinity of the glassy carbon material in the inner surface layer and the outer surface layer of the cylindrical body is specified, and the carbon crystal of the glassy carbon material in the inner surface layer and the outer surface layer is specified. By setting the value of the ratio R (= inner surface layer Lc / outer surface layer Lc) of the child Lc (002) to a crystalline property satisfying the relationship of 0.68 ≦ R ≦ 1.47, It becomes possible to reduce the occurrence of cracks and cracks due to mechanical shocks and thermal shocks. Therefore, it has excellent plasma resistance and is resistant to mechanical shock and thermal shock.For example, it protects the inner wall and the like of the plasma processing apparatus, and suppresses the generation of particles due to wear of the inner wall. A cylindrical glassy carbon member useful as a protective member of a plasma processing apparatus capable of stable plasma processing can be provided.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing a crushing load measuring device.
[Explanation of symbols]
1 Round slice sample 2 Pedestal 3 Press plate 4 Cardboard

Claims

A cylindrical body made of glassy carbon obtained by machining the inner and outer double-sided layers of the cylinder under different grinding conditions, and has a shape with an inner diameter of 300 mm or more and a thickness of 4 mm or more. The ratio R (= inner surface layer Lc / outer surface layer Lc) of the size ratio of carbon crystallites Lc (002) of the carbon material has crystal properties satisfying the relationship of 0.68 ≦ R ≦ 1.47. A cylindrical glassy carbon member.