JP7298406B2

JP7298406B2 - Method and apparatus for regenerating members in silicon single crystal pulling apparatus, and method for manufacturing silicon single crystal using regenerated members

Info

Publication number: JP7298406B2
Application number: JP2019165790A
Authority: JP
Inventors: 憲哉鈴木; 敏明琴岡; 賢二宗実; 剛中村; 良太末若
Original assignee: Sumco Corp
Current assignee: Sumco Corp
Priority date: 2019-09-12
Filing date: 2019-09-12
Publication date: 2023-06-27
Anticipated expiration: 2039-09-12
Also published as: JP2021042103A

Description

本発明は、シリコン単結晶引上げ装置内に設けられた表面にＳｉＯｘ及び／又は金属シリコンが付着した部材からＳｉＯｘ及び／又は金属シリコンを除去して部材を再生する方法及び再生装置並びに再生された部材を用いるシリコン単結晶の製造方法に関する。 The present invention provides a method and apparatus for removing SiOx and/or metal silicon from a member having SiOx and/or metal silicon adhered to the surface provided in a silicon single crystal pulling apparatus, and the regenerated member. It relates to a method for producing a silicon single crystal using

従来、チョクラルスキー法でシリコン単結晶を引上げる装置内では、シリコン融液表面からＳｉＯ、ＳｉＯ_２等のＳｉＯｘ及び／又は金属シリコン（以下、単に「シリコン等」ということもある。）が蒸発し、このシリコン等は引上げ装置内に設けられた熱遮蔽部材、整流筒等の各種部材表面に付着し、徐々に固化していく。こうして付着し固化したシリコン等は、引上げ装置内を流れる不活性ガスの流速の変化や、シリコン等が付着した部材の熱膨張の変化などによって部材表面から剥離し、シリコン融液に落下する場合があった。落下したシリコン等はシリコン融液の不純物となり、引上げられるシリコン単結晶の品質を悪化させる要因になっていた。引上げ装置内に設けられた整流筒が石英製である場合、整流筒の石英表面にシリコン等が付着し、徐々に茶色に変色していった。石英製の整流筒を通して炉内の観察を行っている場合には、シリコン等の付着により、炉内観察ができなくなる不具合を生じていた。 Conventionally, in an apparatus for pulling a silicon single crystal by the Czochralski method, SiOx such as SiO, _SiO2 , and/or metal silicon (hereinafter sometimes simply referred to as "silicon, etc.") evaporates from the silicon melt surface. However, this silicon or the like adheres to the surfaces of various members such as heat shielding members and rectifying tubes provided in the pulling apparatus, and gradually solidifies. The silicon, etc. adhered and solidified in this way may peel off from the member surface and fall into the silicon melt due to changes in the flow velocity of the inert gas flowing through the pulling apparatus or changes in the thermal expansion of the member to which the silicon, etc. adheres. there were. The fallen silicon or the like becomes an impurity in the silicon melt, and becomes a factor of degrading the quality of the silicon single crystal to be pulled. When the rectifying tube provided in the pulling apparatus was made of quartz, silicon or the like adhered to the quartz surface of the rectifying tube, gradually discoloring it to brown. When observing the inside of the furnace through a straightening cylinder made of quartz, there has been a problem that the inside of the furnace cannot be observed due to adhesion of silicon or the like.

この問題を解決するため、本出願人は、ＳｉＯｘ及び／又は金属シリコンが表面に付着した黒鉛部材からなる熱遮蔽部材、石英部材からなる整流筒等の部材を不活性ガス雰囲気下、２．６７ｋＰａ以下の圧力下、上記部材の表面温度が表面に付着したＳｉＯｘ及び／又は金属シリコンの昇華を開始する温度以上でかつ上記部材が熱変形及び／又は熱変質を開始する温度未満の温度で少なくとも２時間熱処理して上記部材の表面に付着したシリコン等を昇華し除去するシリコン単結晶引上げ装置内の部材の再生方法を提案した（特許文献１、請求項１、段落[００３２]～段落[００３９]、図１参照。）。 In order to solve this problem, the present applicant has developed heat shielding members made of graphite members with SiOx and/or metal silicon attached to their surfaces, rectifying tubes made of quartz members, etc., under an inert gas atmosphere at 2.67 kPa. Under the following pressure, the surface temperature of the member is equal to or higher than the temperature at which sublimation of SiOx and/or metal silicon adhered to the surface starts and is lower than the temperature at which the member starts thermal deformation and/or thermal alteration for at least 2 We have proposed a method for regenerating members in a silicon single crystal pulling apparatus by sublimating and removing silicon and the like adhering to the surface of the members by time heat treatment (Patent document 1, claim 1, paragraphs [0032] to [0039]). , see FIG. 1).

この部材の再生方法は、具体的には、図９に示される部材の再生装置を用いて再生する。この部材の再生装置１０は、シリコン単結晶を引上げる装置を利用したもので、上部は径が小さく下部は径が大きな外部雰囲気から密閉されたチャンバ１１内に、筒状のヒータ１２と、保温筒１３と、黒鉛坩堝１４、坩堝受け１５等が収容される。チャンバ１１の上端には、円筒状のケーシング１６が設けられる。このケーシング１６には、チャンバ内部に不活性ガスを導入する不活性ガス導入口１７が設けられ、その上端にはケーシング１６内を外気雰囲気から遮断する閉止板１８が設けられる。チャンバ１１の下部には、リング状のボトムヒータ１９と不活性ガスの排出口２０が設けられる。排出口２０は、図示しない排気管路を介して真空ポンプに接続される。再生を必要とする部材として、黒鉛部材からなる熱遮蔽部材２１がチャンバ１１内の保温筒１３の上部に設けられた支持部材２２に取付けられる。 Specifically, in this member recycling method, a member recycling apparatus shown in FIG. 9 is used. The regenerating device 10 for this member utilizes a device for pulling up silicon single crystals. A cylinder 13, a graphite crucible 14, a crucible receiver 15 and the like are accommodated. A cylindrical casing 16 is provided at the upper end of the chamber 11 . The casing 16 is provided with an inert gas introduction port 17 for introducing inert gas into the chamber, and a closing plate 18 is provided at the upper end of the casing 16 for isolating the inside of the casing 16 from the external atmosphere. A ring-shaped bottom heater 19 and an inert gas outlet 20 are provided in the lower part of the chamber 11 . The exhaust port 20 is connected to a vacuum pump via an exhaust line (not shown). As a member requiring regeneration, a heat shield member 21 made of graphite is attached to a support member 22 provided on the top of the heat insulating cylinder 13 inside the chamber 11 .

部材の再生装置１０では、チャンバ内に不活性ガスを導入し、チャンバ内を減圧して、筒状のヒータ１２及びリング状のボトムヒータ１９（以下、双方のヒータ１２、１９又は筒状のヒータ１２のみを、単にヒータということもある。）により上記の所定の圧力下、上記の所定の温度で上記所定の時間、熱遮蔽部材２１を熱処理する。熱遮蔽部材２１の熱処理中及び冷却中、不活性ガス導入口から導入した不活性ガスの流れに随伴して、昇華したシリコン等は不活性ガスの排出口２０から再生装置１０の外部に排出される。熱遮蔽部材２１を冷却後、再生装置１０から熱遮蔽部材２１を取り出せば、シリコン等を完全に除去した再生された熱遮蔽部材が得られる。 In the member recycling apparatus 10, an inert gas is introduced into the chamber, the pressure in the chamber is reduced, and the cylindrical heater 12 and the ring-shaped bottom heater 19 (hereinafter referred to as both heaters 12 and 19 or the cylindrical heater 12 The heat shield member 21 is heat-treated under the predetermined pressure and at the predetermined temperature for the predetermined time. During the heat treatment and cooling of the heat shield member 21, the sublimated silicon or the like is discharged from the inert gas outlet 20 to the outside of the regenerator 10 along with the flow of the inert gas introduced from the inert gas inlet. be. After the heat shielding member 21 is cooled, the heat shielding member 21 is removed from the regenerating apparatus 10 to obtain a regenerated heat shielding member from which silicon and the like are completely removed.

特開２０１７－０１４０７２号公報JP 2017-014072 A

しかしながら、特許文献１の再生方法では、所定の温度で所定の時間、筒状のヒータ１２及びリング状のボトムヒータ１９に印加する電圧を高めてチャンバ１１とケーシング１６を加熱するため、加熱する空間及び加熱される面積が広大で、シリコン単結晶を引上げる以上の多大のヒータ電力を必要とした。この結果、ヒータ電極と黒鉛坩堝の間でグロー放電を生じることがあった。グロー放電を生じると放電部位が損傷するため、従来の再生方法にはまだ解決すべき課題があった。 However, in the regeneration method of Patent Document 1, the chamber 11 and the casing 16 are heated by increasing the voltage applied to the cylindrical heater 12 and the ring-shaped bottom heater 19 at a predetermined temperature for a predetermined time. The area to be heated was vast, and a large amount of heater power was required, more than that for pulling up a silicon single crystal. As a result, glow discharge sometimes occurred between the heater electrode and the graphite crucible. Since glow discharge damages the discharge site, conventional regeneration methods still have problems to be solved.

本発明の第１の目的は、上記課題を解決するもので、シリコン単結晶引上げ装置内のシリコン等が付着する部材を再生する際に、ヒータに印加する電圧を高めることなく引上げ装置内のグロー放電を防止するとともに、電力消費量を低減して部材を再生する再生方法及び再生装置を提供することにある。本発明の第２の目的は、再生された部材を用いて高品質のシリコン単結晶を製造する方法を提供することにある。 SUMMARY OF THE INVENTION A first object of the present invention is to solve the above-mentioned problems. An object of the present invention is to provide a regenerating method and a regenerating apparatus for regenerating a member while preventing discharge and reducing power consumption. A second object of the present invention is to provide a method for producing high-quality silicon single crystals using regenerated members.

本発明の第１の観点は、密閉されたチャンバと、前記チャンバ内に設けられた保温筒と、前記保温筒の内側に設けられた筒状のヒータとを備えたシリコン単結晶引上げ装置の前記筒状のヒータの内側に、ＳｉＯ_ｘ及び／又は金属シリコンが付着した部材を配置して、不活性ガス雰囲気下、熱処理することにより、前記部材を再生する方法において、前記筒状のヒータの内側に配置した部材の上方を覆う断熱板が前記チャンバ内に設けられ、前記断熱板が被覆材により被覆された断熱材で構成され、前記断熱材の熱伝導率が５Ｗ／（ｍ／℃）以下であり、前記断熱板に前記不活性ガスが流通するための１又は２以上の貫通孔が設けられ、前記被覆材が黒鉛、表面にＳｉＣがコーティングされた黒鉛、又はＭｏ（モリブデン）であり、前記貫通孔の孔面積は、前記断熱板の覆う部分を１００とするときに、２．５以上５以下である、ことを特徴とする。 A first aspect of the present invention is a silicon single crystal pulling apparatus comprising a sealed chamber, a heat insulating tube provided in the chamber, and a cylindrical heater provided inside the heat insulating tube. A method for regenerating a member by arranging a member to which SiO _x and/or metal silicon is attached inside a cylindrical heater and heat-treating the member in an inert gas atmosphere, wherein A heat insulating plate is provided in the chamber to cover the upper part of the member placed in the chamber, the heat insulating plate is composed of a heat insulating material covered with a covering material, and the heat insulating material has a thermal conductivity of 5 W / (m / ° C.) or less wherein the heat insulating plate is provided with one or more through-holes for the inert gas to flow, and the coating material is graphite, graphite whose surface is coated with SiC, or Mo (molybdenum), A hole area of the through hole is 2.5 or more and 5 or less when the portion covered by the heat insulating plate is 100.

本発明の第２の観点は、第１の観点の発明であって、前記断熱板の周縁が前記保温筒の上端に載置されたことを特徴とする。 A second aspect of the present invention is the invention according to the first aspect, and is characterized in that the peripheral edge of the heat insulating plate is placed on the upper end of the heat insulating cylinder.

本発明の第３の観点は、第１又は２の観点のうち、いずれかの観点の発明であって、前記シリコン単結晶引上げ装置が複数のヒータを備えたことを特徴とする。 A third aspect of the present invention is the invention according to either the first aspect or the second aspect, and is characterized in that the silicon single crystal pulling apparatus includes a plurality of heaters.

本発明の第４の観点は、密閉されたチャンバと、前記チャンバ内に設けられた保温筒と、前記保温筒の内側に設けられた筒状のヒータとを備えたシリコン単結晶引上げ装置の前記筒状のヒータの内側に、ＳｉＯ_ｘ及び／又は金属シリコンが付着した部材を配置して、不活性ガス雰囲気下、熱処理することにより、前記部材を再生する装置において、前記筒状のヒータの内側に配置した部材の上方を覆う断熱板が前記チャンバ内に設けられ、前記断熱板が被覆材により被覆された断熱材で構成され、前記断熱材の熱伝導率が５Ｗ／（ｍ／℃）以下であり、前記断熱板に前記不活性ガスが流通するための１又は２以上の貫通孔が設けられ、前記被覆材が黒鉛、表面にＳｉＣがコーティングされた黒鉛、又はＭｏ（モリブデン）であり、前記貫通孔の孔面積は、前記断熱板の覆う部分を１００とするときに、２．５以上５以下である、ことを特徴とする。 A fourth aspect of the present invention is a silicon single crystal pulling apparatus comprising a sealed chamber, a heat insulating tube provided in the chamber, and a cylindrical heater provided inside the heat insulating tube. An apparatus for regenerating a member by arranging a member to which SiO _x and/or metal silicon is attached inside a tubular heater and performing heat treatment in an inert gas atmosphere, wherein the member is regenerated inside the tubular heater. A heat insulating plate is provided in the chamber to cover the upper part of the member placed in the chamber, the heat insulating plate is made of a heat insulating material covered with a covering material, and the heat insulating material has a thermal conductivity of 5 W/(m/°C) or less. wherein the heat insulating plate is provided with one or more through-holes for the inert gas to flow, and the coating material is graphite, graphite whose surface is coated with SiC, or Mo (molybdenum), A hole area of the through hole is 2.5 or more and 5 or less when the portion covered by the heat insulating plate is 100.

本発明の第５の観点は、第４の観点の発明であって、前記断熱板の周縁が前記保温筒の上端に載置されたことを特徴とする。 A fifth aspect of the present invention is the invention according to the fourth aspect, characterized in that the peripheral edge of the heat insulating plate is placed on the upper end of the heat insulating cylinder.

本発明の第６の観点は、第４又は５の観点のうち、いずれかの観点の発明であって、前記シリコン単結晶引上げ装置が複数のヒータを備えたことを特徴とする。 A sixth aspect of the present invention is the invention according to either the fourth or fifth aspect, wherein the silicon single crystal pulling apparatus is provided with a plurality of heaters.

本発明の第７の観点は、第１ないし第３の観点のうち、いずれかの観点に記載された方法又は第４ないし第６のうち、いずれかの観点に記載された装置で再生された部材を用いて、シリコン単結晶を製造する方法である。 A seventh aspect of the present invention is reproduced by the method described in any one of the first to third aspects or the apparatus described in any one of the fourth to sixth aspects. A method of manufacturing a silicon single crystal using a member.

本発明の再生方法及び再生装置では、特許文献１の再生方法と異なり、筒状のヒータの内側に配置した部材の上方を覆う断熱板がチャンバ内に設けられたことにより、部材を加熱するためのヒータに印加する電圧を高めることなく引上げ装置内のグロー放電を防止することができる。また再生に要する電力消費量を低減することができる。 In the regeneration method and the regeneration apparatus of the present invention, unlike the regeneration method of Patent Document 1, a heat insulating plate is provided in the chamber to cover the upper part of the member arranged inside the cylindrical heater, so that the member is removed. Glow discharge in the pulling apparatus can be prevented without increasing the voltage applied to the heater for heating. In addition, power consumption required for reproduction can be reduced.

本発明の再生方法及び再生装置では、断熱板に不活性ガスが流通するための１又は２以上の貫通孔を設けることにより、不活性ガス導入口から導入された不活性ガスが貫通孔を通過して、部材の表面に流れ込み、部材から昇華したシリコン等が不活性ガスの流れに随伴して、不活性ガスの排出口から排出され、部材の再生をより確実にすることができる。 In the regeneration method and regeneration apparatus of the present invention, the inert gas introduced from the inert gas inlet penetrates through the insulating plate by providing one or two or more through-holes for the inert gas to flow through. Silicon or the like that passes through the holes and flows onto the surface of the member and is sublimated from the member is accompanied by the flow of the inert gas and is discharged from the inert gas outlet, so that the member can be regenerated more reliably. .

本発明の再生方法及び再生装置では、断熱板の周縁が保温筒の上端に載置されて、断熱板がチャンバ内に設けられるため、断熱板の取付け、取外しを容易にすることができる。 In the regenerating method and regenerating apparatus of the present invention, the peripheral edge of the heat insulating plate is placed on the upper end of the heat insulating cylinder and the heat insulating plate is provided in the chamber, so that the heat insulating plate can be easily attached and removed. can.

本発明の再生方法及び再生装置では、断熱板が黒鉛により被覆された断熱材で構成されているため、断熱板に一定の強度を持たせることができる。 In the recycling method and the recycling apparatus of the present invention, since the insulating board is made of a heat insulating material coated with graphite, the insulating board can have a certain strength.

本発明の再生方法及び再生装置では、シリコン単結晶引上げ装置が複数のヒータを備えるため、各々のヒータに印加する電圧を低減させることができ、結果として引上げ装置内のグロー放電をより一層防止することができる。 In the regenerating method and regenerating apparatus of the present invention, since the silicon single crystal pulling apparatus is provided with a plurality of heaters, the voltage applied to each heater can be reduced. This can be further prevented.

本発明の再生された部材を用いてシリコン単結晶を製造する方法は、高品質のシリコン単結晶を製造することができる。 The method of manufacturing silicon single crystals using the regenerated member of the present invention can manufacture high-quality silicon single crystals.

本実施形態に係る部材が熱遮蔽部材であって断熱板を有する再生装置の構成図である。FIG. 2 is a configuration diagram of a regeneration device in which the member according to the present embodiment is a heat shield member and has a heat insulating plate. 図１に示す断熱板の平面図である。FIG. 2 is a plan view of the heat insulating plate shown in FIG. 1; 本実施形態に係る部材の再生装置の別の形態の断熱板の平面図である。FIG. 5 is a plan view of another form of the heat insulating plate of the member recycling apparatus according to the present embodiment. 本実施形態に係る部材の再生装置の更に別の形態の断熱板の平面図である。FIG. 11 is a plan view of still another heat insulating plate of the member recycling apparatus according to the present embodiment. 図１に示す断熱板の断面を示す斜視図である。It is a perspective view which shows the cross section of the heat insulating board shown in FIG. 本実施形態に係る部材が整流筒である再生装置の構成図である。1 is a configuration diagram of a reproducing device in which a member according to the present embodiment is a rectifying cylinder; FIG. 熱遮蔽部材を再生する際に、断熱板の有無による熱遮蔽部材の温度変化の違いを示す図である。FIG. 7 is a diagram showing a difference in temperature change of the heat shielding member depending on the presence or absence of the heat insulating plate when regenerating the heat shielding member. 熱遮蔽部材を再生する際に、断熱板の有無による熱遮蔽部材の温度をＳｉＯ融点以上にするためのヒータ電力量の違いを示す図である。変化の違いを示す図である。FIG. 7 is a diagram showing a difference in heater electric energy for making the temperature of the heat shielding member equal to or higher than the melting point of SiO depending on the presence or absence of the heat insulating plate when the heat shielding member is regenerated. It is a figure which shows the difference of a change. 従来の部材が熱遮蔽部材であって断熱板を有しない再生装置の構成図である。FIG. 4 is a configuration diagram of a regeneration device in which a conventional member is a heat shield member and does not have a heat insulating plate.

次に本発明を実施するための形態を図面を参照して説明する。図１は、本実施形態に係るシリコン単結晶引上げ装置内の部材である熱遮蔽部材２１を再生する装置３０の構成図である。この再生装置３０は、チョクラルスキー法でシリコン単結晶を引上げる装置を利用している。図１において、各構成要素の符号は、前述した図９の各構成符号に対応する。この実施の形態では、再生装置３０は、チャンバ１１と、筒状のヒータ１２と、保温筒１３と、黒鉛坩堝１４、坩堝受け１５を備える。筒状のヒータ１２は保温筒１３の内側に設けられ、黒鉛坩堝１４は坩堝受け１５に支持されて筒状のヒータ１２の内側に設けられる。 Next, a mode for carrying out the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of an apparatus 30 for regenerating a heat shield member 21, which is a member in a silicon single crystal pulling apparatus according to this embodiment. This regeneration device 30 utilizes a device for pulling a silicon single crystal by the Czochralski method. In FIG. 1, the code|symbol of each component corresponds to each component code|symbol of FIG. 9 mentioned above. In this embodiment, the regeneration device 30 includes a chamber 11 , a cylindrical heater 12 , a heat retaining cylinder 13 , a graphite crucible 14 and a crucible receiver 15 . A cylindrical heater 12 is provided inside a heat insulating cylinder 13 , and a graphite crucible 14 is supported by a crucible holder 15 and provided inside the cylindrical heater 12 .

チャンバ１１の上端には、チャンバと連通する円筒状のケーシング１６が設けられる。このケーシング１６には、チャンバ内部に不活性ガスを導入する不活性ガス導入口１７が設けられ、その上端にはケーシング１６内を外気雰囲気から遮断する閉止板１８が設けられる。チャンバ１１の下部には、リング状のボトムヒータ１９及び不活性ガスの排出口２０が設けられる。即ち、本実施形態のシリコン単結晶引上げ装置は、筒状のヒータ１２とリング状のボトムヒータ１９のように、複数のヒータを備える。排出口２０は、図示しない排気管路を介して真空ポンプに接続される。この実施の形態では、再生を必要とする部材は、熱遮蔽部材２１であって、チャンバ１１内の保温筒１３の上部に設けられた支持部材２２に取付けられる。符号１はシリコン単結晶引上げ時に使用する石英坩堝であり、符号２は引上げワイヤであり、符号３は石英坩堝１内に貯えるシリコン融液であり、部材の再生時には存在しないため、破線で示している。 A cylindrical casing 16 communicating with the chamber is provided at the upper end of the chamber 11 . The casing 16 is provided with an inert gas introduction port 17 for introducing inert gas into the chamber, and a closing plate 18 is provided at the upper end of the casing 16 for isolating the inside of the casing 16 from the external atmosphere. A ring-shaped bottom heater 19 and an inert gas outlet 20 are provided in the lower part of the chamber 11 . That is, the silicon single crystal pulling apparatus of this embodiment includes a plurality of heaters such as the tubular heater 12 and the ring-shaped bottom heater 19 . The exhaust port 20 is connected to a vacuum pump via an exhaust line (not shown). In this embodiment, the member requiring regeneration is a heat shield member 21 attached to a support member 22 provided on top of the heat insulating tube 13 inside the chamber 11 . Reference numeral 1 denotes a quartz crucible used when pulling a silicon single crystal, reference numeral 2 denotes a pulling wire, and reference numeral 3 denotes a silicon melt stored in the quartz crucible 1. Since they do not exist when the member is regenerated, they are indicated by broken lines. there is

熱遮蔽部材２１としては、基材が黒鉛製でその表面にＳｉＣ被覆がなされた部材、基材が黒鉛製でその表面に炭素（Ｃ）膜が被覆された部材又は基材が黒鉛製でその表面にＳｉＣも炭素膜も被覆されていない部材等が例示される。熱遮蔽部材２１は、シリコン単結晶を引上げる際に、単結晶が石英坩堝１６内のシリコン融液３から受ける輻射熱を抑制するために設けられ、円錐台の筒状であって下方に向けて径が狭まるテーパー形状を有し、その下端部は、シリコン単結晶の引上げ時において、シリコン融液３表面の近傍に延びる。このため、熱遮蔽部材２１はシリコン融液３からの蒸発物であるシリコン等が比較的多く付着する。 As the heat shielding member 21, a member having a base material made of graphite and having a surface coated with SiC, a member having a base material made from graphite and having a carbon (C) film coated on the surface, or a member having a base material made of graphite and having its surface coated with a carbon (C) film can be used. A member whose surface is coated with neither SiC nor a carbon film is exemplified. The heat shield member 21 is provided to suppress the radiation heat received by the silicon single crystal from the silicon melt 3 in the quartz crucible 16 when the silicon single crystal is pulled up. It has a tapered shape with a narrower diameter, and its lower end extends near the surface of the silicon melt 3 when the silicon single crystal is pulled. For this reason, a relatively large amount of silicon or the like, which is an evaporated product from the silicon melt 3, adheres to the heat shielding member 21 .

この実施の形態の特徴ある構成は、筒状のヒータ１２の内側に配置した部材である熱遮蔽部材２１の上方を覆う断熱板２６がチャンバ１１内に設けられたことにある。具体的には、断熱板２６は、図２に示すように、円板状であって、その中央には単一の円孔の貫通孔２６ａが形成される。断熱板２６は、保温筒１３の上部に設けられた支持部材２２上にその周縁が位置するように、また貫通孔２６ａが黒鉛坩堝１４の中心位置になるようにして、載置される。断熱板２６を特別な工具を用いて支持部材２２に取付ける必要はない。このため断熱板２６の取付け及び取外しが容易である。断熱板２６は、図５に示すように、例えば断熱材２６ｂと断熱材２６ｂを被包する被覆材２６ｃとを有することが好ましい。断熱材２６ａは、カーボン繊維からなるフェルト材又はアルミナ等であって、熱伝導率が５Ｗ／（ｍ・℃）以下であることが好ましい。また被覆材２６ｃは、一定の強度を有する材料で構成され、熱的に安定で高純度の黒鉛、表面にＳｉＣがコーティングされた黒鉛、又は表面輻射率が低くかつ熱的に安定なＭｏ（モリブデン）等の材料を使うことができる。 A characteristic configuration of this embodiment is that a heat insulating plate 26 is provided in the chamber 11 to cover the heat shielding member 21 which is a member arranged inside the tubular heater 12 . Specifically, as shown in FIG. 2, the heat insulating plate 26 is disc-shaped and has a single circular through hole 26a formed in its center. The heat insulating plate 26 is placed on the support member 22 provided at the top of the heat insulating cylinder 13 so that the peripheral edge thereof is located and the through hole 26 a is positioned at the center of the graphite crucible 14 . It is not necessary to attach the insulating plate 26 to the support member 22 using special tools. Therefore, the heat insulating plate 26 can be easily attached and detached. As shown in FIG. 5, the heat insulating plate 26 preferably has, for example, a heat insulating material 26b and a covering material 26c covering the heat insulating material 26b. The heat insulating material 26a is a felt material made of carbon fiber, alumina, or the like, and preferably has a thermal conductivity of 5 W/(m·° C.) or less. The coating material 26c is made of a material having a certain strength, such as thermally stable and high-purity graphite, SiC-coated graphite, or Mo (molybdenum), which has a low surface emissivity and is thermally stable. ) can be used.

円板状の断熱板２６は、図２に示す単一の円孔の貫通孔２６ａが形成される以外に、図３に示すように、複数の円孔の貫通孔２７ａが同心円状に等間隔に形成された円板状の断熱板２７、或いは図４に示すように、複数の矩形状又はスリット状の貫通孔２８ａが９０度間隔で形成された円板状の断熱板２８でもよい。貫通孔の数又は形状は、上記に限らない。貫通孔２６ａ、２７ａ、２８ａは、図１に示すように、再生時に不活性ガスが流通するようになっている。貫通孔２６ａ、２７ａ、２８ａの孔面積は、再生する必要のある部材である熱遮蔽部材２１の上方を覆う断熱板２６、２７、２８の覆う部分を１００とするときに、２．５以上５以下であることが好ましい。２．８以上４以下であることが更に好ましい。２．５未満であると、再生時に不活性ガスが流通する量が少な過ぎて、熱遮蔽部材２１から昇華したシリコン等が排出されにくい。また、５を超えると、熱遮蔽部材２１に向けられた熱が貫通孔からチャンバ１１やケーシング１６に向かって拡散し本発明の目的を達成しにくい。 The disk-shaped heat insulating plate 26 has a single circular through-hole 26a shown in FIG. or a disk-shaped heat insulating plate 28 having a plurality of rectangular or slit-shaped through holes 28a formed at intervals of 90 degrees as shown in FIG. The number or shape of through-holes is not limited to the above. As shown in FIG. 1, the through holes 26a, 27a, and 28a allow inert gas to flow during regeneration. The hole area of the through holes 26a, 27a, 28a is 2.5 or more and 5 when the portion covered by the heat insulating plates 26, 27, 28 that cover the heat shield member 21, which is a member that needs to be regenerated, is taken as 100. The following are preferable. It is more preferably 2.8 or more and 4 or less. If it is less than 2.5, the amount of inert gas flowing during regeneration is too small, and sublimated silicon or the like is difficult to discharge from the heat shield member 21 . On the other hand, if it exceeds 5, the heat directed to the heat shield member 21 diffuses from the through holes toward the chamber 11 and the casing 16, making it difficult to achieve the object of the present invention.

再生を必要とする部材として、熱遮蔽部材２１を挙げたが、図６に示すように、整流筒２９、図１及び図６に示した支持部材２２、図示しない黒鉛製シードチャック、図示しない黒鉛製排気管等でもよい。整流筒２９としては、石英製、黒鉛製又は基材が黒鉛製でその表面にＳｉＣ又は炭素膜が被覆された部材が例示される。この整流筒２５は、図６に示すように、再生装置内では平坦な坩堝受け１５の上に載置されて再生される。 Although the heat shielding member 21 is mentioned as a member requiring regeneration, as shown in FIG. 6, the straightening cylinder 29, the support member 22 shown in FIGS. A manufactured exhaust pipe or the like may also be used. Examples of the rectifying tube 29 include a member made of quartz, graphite, or a member whose base material is made of graphite and whose surface is coated with a SiC or carbon film. As shown in FIG. 6, the rectifying cylinder 25 is placed on a flat crucible holder 15 in the regenerating apparatus and regenerated.

整流筒２９は円筒形の部材であり、単結晶引き上げ時には、図示しないが、チャンバ１１の径の小さい上部からシリコン融液の表面近傍まで延びていて、引上げられる単結晶がこの整流筒２９内部を通るように配置される。また、上述の不活性ガス導入口１７から流入された不活性ガスは、この整流筒２９の内部を通過して、シリコン融液３の表面に導かれる。このため、整流筒２９にもシリコン融液からの蒸発物であるシリコン等が比較的多く付着する。 The rectifying cylinder 29 is a cylindrical member, and when the single crystal is pulled, it extends from the small-diameter upper part of the chamber 11 to the vicinity of the surface of the silicon melt (not shown). arranged to pass. Also, the inert gas introduced from the inert gas introduction port 17 is guided to the surface of the silicon melt 3 through the inside of the straightening tube 29 . For this reason, a relatively large amount of silicon or the like, which is an evaporated product from the silicon melt, adheres to the straightening tube 29 as well.

次に、この再生装置３０を用いて、シリコン等が付着し固化した熱遮蔽部材２１を再生する方法を説明する。まず上述したように、支持部材２２にシリコン等が付着し固化した熱遮蔽部材２１を取付ける。次いで、単一の円孔の貫通孔２６ａを有する円板状の断熱板２６を、貫通孔２６ａが黒鉛坩堝１４の中心位置になるようにして、支持部材２２上に載置する。不活性ガス導入口１７から不活性ガスをケーシング１６及びチャンバ１１内に導入するとともに、図示しない真空ポンプを作動してケーシング１６及びチャンバ１１内の圧力を低くする。この不活性ガスの導入とケーシング・チャンバ内の減圧と同時に筒状のヒータ１２及びボトムヒータ１９により熱遮蔽部材２１を加熱する。 Next, a method for regenerating the heat shielding member 21 to which silicon or the like is adhered and solidified by using the regenerating apparatus 30 will be described. First, as described above, the heat shield member 21 to which silicon or the like is attached and solidified is attached to the support member 22 . Next, a disk-shaped heat insulating plate 26 having a single circular through-hole 26 a is placed on the support member 22 so that the through-hole 26 a is positioned at the center of the graphite crucible 14 . An inert gas is introduced into the casing 16 and the chamber 11 through the inert gas inlet 17, and a vacuum pump (not shown) is operated to reduce the pressure in the casing 16 and the chamber 11. FIG. The thermal shield member 21 is heated by the cylindrical heater 12 and the bottom heater 19 at the same time as the inert gas is introduced and the pressure in the casing chamber is reduced.

この熱遮蔽部材２１の熱処理は、不活性ガス雰囲気下、２．６７ｋＰａ（２０ｔｏｒｒ）以下の圧力下で行うことが好ましく、熱遮蔽部材の表面温度が１７００℃以上でかつ熱遮蔽部材が熱変形及び／又は熱変質を開始する温度未満の温度で少なくとも２時間行われることが好ましい。熱遮蔽部材２１の基材が黒鉛製でその表面にＳｉＣ被覆がなされた部材又は基材が黒鉛製でその表面に炭素（Ｃ）膜が被覆された部材である場合には、ＳｉＣ又は炭素膜の昇華を未然に防ぐために、熱遮蔽部材２１の表面温度の上限値を２５００℃以下の温度にすることが好ましい。熱遮蔽部材２１の表面温度が１０００℃以上になると、シリコン等の昇華が始まるが、この温度を１７００℃以上にすることにより、シリコン等の融点以上にしてシリコン等を完全に除去させることが容易になる。熱エネルギー消費量を節約する観点からより好ましい温度は１７００～１８００℃である。 The heat treatment of the heat shield member 21 is preferably performed in an inert gas atmosphere under a pressure of 2.67 kPa (20 torr) or less, and the surface temperature of the heat shield member is 1700° C. or higher, and the heat shield member is thermally deformed and deformed. / or preferably at a temperature below the temperature at which thermal alteration is initiated for at least 2 hours. In the case where the base material of the heat shield member 21 is made of graphite and its surface is coated with SiC, or the base material is made of graphite and its surface is coated with a carbon (C) film, SiC or carbon film In order to prevent the sublimation of , it is preferable to set the upper limit of the surface temperature of the heat shield member 21 to 2500° C. or lower. When the surface temperature of the heat shielding member 21 reaches 1000° C. or higher, sublimation of silicon or the like begins. By raising the temperature to 1700° C. or higher, the temperature rises above the melting point of silicon or the like, making it easy to completely remove the silicon or the like. become. A more preferable temperature is 1700 to 1800° C. from the viewpoint of saving thermal energy consumption.

熱遮蔽部材の表面温度が１７００℃未満の場合には、不活性ガス雰囲気下であっても熱遮蔽部材の表面に付着したシリコン等の昇華が促進されにくく、完全にシリコン等を除去しにくい。また熱遮蔽部材がＳｉＣ被覆されている場合又は炭素（Ｃ）膜により被覆されている場合、２５００℃を超えて再生処理を行うと、ＳｉＣ被膜又は炭素膜が昇華反応によりその膜厚が薄くなり易く、ＳｉＣ被膜又は炭素膜が剥がれてしまうおそれがある。 If the surface temperature of the heat shielding member is less than 1700° C., sublimation of silicon adhered to the surface of the heat shielding member is less likely to be promoted even in an inert gas atmosphere, making it difficult to remove silicon completely. In addition, when the heat shield member is coated with SiC or is coated with a carbon (C) film, if the regeneration treatment is performed at a temperature exceeding 2500° C., the film thickness of the SiC coating or carbon film becomes thinner due to a sublimation reaction. There is a risk that the SiC coating or carbon film will peel off.

またケーシング１６及びチャンバ１１内の圧力を２．６７ｋＰａ以下の減圧にすると、熱遮蔽部材２１の表面に付着したシリコン等の昇華をより早まり、シリコン等をより均一に除去し易くなる。より好ましい圧力は１．３３ｋＰａ（１０ｔｏｒｒ）以下である。２．６７ｋＰａを超える圧力では、熱遮蔽部材表面に付着したシリコン等の昇華が促進されにくく、完全にシリコン等を除去しにくい。熱遮蔽部材２１の表面温度が上記温度に達してからその温度に保持する時間は少なくとも２時間することが好ましい。２時間未満では、シリコン等を熱遮蔽部材２１から完全に除去させることが困難となる。熱エネルギー消費量を節約する観点からより好ましい保持時間は３～６時間である。熱遮蔽部材２１の熱処理中及び冷却中、不活性ガス導入口１７から導入した不活性ガスは、断熱板２６の貫通孔２６を通って、熱遮蔽部材２１の表面に到達し、昇華したシリコン等は不活性ガスの流れに随伴して、排出口２０から再生装置３０の外部に排出される。 When the pressure in the casing 16 and the chamber 11 is reduced to 2.67 kPa or less, the sublimation of silicon adhered to the surface of the heat shield member 21 is accelerated, and the silicon and the like can be removed more uniformly. A more preferable pressure is 1.33 kPa (10 torr) or less. At a pressure exceeding 2.67 kPa, it is difficult to promote the sublimation of silicon adhered to the surface of the heat shield member, and it is difficult to completely remove the silicon. After the surface temperature of the heat shielding member 21 reaches the above temperature, it is preferable to maintain the temperature for at least two hours. If the time is less than 2 hours, it becomes difficult to completely remove the silicon or the like from the heat shield member 21 . A more preferable retention time is 3 to 6 hours from the viewpoint of saving thermal energy consumption. During the heat treatment and cooling of the heat shield member 21, the inert gas introduced from the inert gas inlet 17 reaches the surface of the heat shield member 21 through the through holes 26 of the heat insulating plate 26, and sublimates silicon or the like. is discharged from the discharge port 20 to the outside of the regenerator 30 along with the flow of the inert gas.

熱処理した後、熱遮蔽部材２１の熱膨張率とシリコン等の熱膨張率の差を大きくして、シリコン等を熱遮蔽部材２１から剥離しやすくするため、熱遮蔽部材２１を熱処理温度から３～１５℃／分の速度で室温まで冷却することが好ましい。３℃／分未満では熱遮蔽部材２１の熱膨張率とシリコン等の熱膨張率の差が大きくなく、シリコン等が熱遮蔽部材２１から剥離しにくい。また２０℃／分を超えると、熱遮蔽部材にクラックが入るおそれがある。熱遮蔽部材２１を冷却後、再生装置３０から熱遮蔽部材２１を取り出せば、シリコン等を完全に除去した再生された熱遮蔽部材が得られる。再生した熱遮蔽部材の品質をより高めるために、熱遮蔽部材の表面にブロアで空気を吹き付けるか、或いは熱遮蔽部材の表面をブラシや布で清掃することが好ましい。 After the heat treatment, the difference between the coefficient of thermal expansion of the heat shielding member 21 and the coefficient of thermal expansion of silicon or the like is increased so that the silicon or the like can be easily separated from the heat shielding member 21. Cooling to room temperature at a rate of 15° C./min is preferred. If the heating rate is less than 3° C./min, the difference between the coefficient of thermal expansion of the heat shielding member 21 and the coefficient of thermal expansion of silicon or the like is not large, and the silicon or the like is difficult to separate from the heat shielding member 21 . On the other hand, if it exceeds 20° C./min, cracks may occur in the heat shielding member. After the heat shielding member 21 is cooled, the heat shielding member 21 is removed from the regenerating device 30 to obtain a regenerated heat shielding member from which silicon and the like are completely removed. In order to further improve the quality of the recycled heat shielding member, it is preferable to blow air onto the surface of the heat shielding member with a blower or clean the surface of the heat shielding member with a brush or cloth.

再生を必要とする部材が図６に示す整流筒２９である場合には、この整流筒２５の熱処理は、不活性ガス雰囲気下、２．６７ｋＰａ（２０ｔｏｒｒ）以下の圧力下で１４００℃以上２５００℃以下の温度で行われることが好ましい。整流筒２９が石英ガラス材料から形成されている場合には、整流筒２９の熱変形を未然に防ぐために、整流筒２９の表面温度の上限値を１７００℃以下の温度にすることが好ましい。また整流筒２９が黒鉛製である場合には、表面被膜を保護するために、整流筒２９の表面温度の上限値を２５００℃以下の温度にすることが好ましい。整流筒２９の表面温度が１０００℃以上になると、シリコン等の昇華が始まるが、この温度を１４００℃以上にすることにより、シリコン等の融点以上にしてシリコン等を完全に除去させることが容易になる。熱エネルギー消費量を節約する観点からより好ましい温度は１７００～１８００℃である。 When the member requiring regeneration is the rectifying cylinder 29 shown in FIG. 6, the heat treatment of this rectifying cylinder 25 is performed at 1400° C. or more and 2500° C. under a pressure of 2.67 kPa (20 torr) or less in an inert gas atmosphere. It is preferably carried out at the following temperatures. When the rectifying tube 29 is made of a quartz glass material, it is preferable to set the upper limit of the surface temperature of the rectifying tube 29 to 1700° C. or less in order to prevent thermal deformation of the rectifying tube 29 . In addition, when the rectifying cylinder 29 is made of graphite, it is preferable to set the upper limit of the surface temperature of the rectifying cylinder 29 to 2500° C. or less in order to protect the surface coating. When the surface temperature of the rectifying tube 29 reaches 1000° C. or higher, sublimation of silicon or the like begins. By raising this temperature to 1400° C. or higher, the melting point of silicon or the like is reached, and the silicon or the like can be easily removed completely. Become. A more preferable temperature is 1700 to 1800° C. from the viewpoint of saving thermal energy consumption.

次に本発明の実施例を比較例とともに詳しく説明する。 Next, examples of the present invention will be described in detail together with comparative examples.

＜実施例１＞
特定の引上げ装置に基材が黒鉛製でその表面にＳｉＣ被覆がなされた熱遮蔽部材を取付け、シリコン単結晶を１０回引上げ、この熱遮蔽部材の表面にシリコン等を付着させた。付着量が比較的多い１０箇所の平均付着厚さは６１０μｍであった。図１に示す再生装置３０の支持部材２２にシリコン等が付着した上記熱遮蔽部材２１を取付け、単一の円孔の貫通孔２６ａを有する直径が約１０４０ｍｍ、厚さが約９０ｍｍ円板状の断熱板２６を、貫通孔２６ａが黒鉛坩堝１４の中心位置になるようにして、支持部材２２上に載置した。断熱板２６はカーボン繊維からなるフェルト材の断熱材２６ｂと断熱材２６ｂを被包する黒鉛からなる被覆材２６ｃとにより構成されていた。貫通孔２６ａの孔面積は、再生する必要のある部材である熱遮蔽部材２１の上方を覆う断熱板２６の覆う部分を１００とするときに２．８であった。 <Example 1>
A heat shielding member having a base material made of graphite and a surface coated with SiC was attached to a specific pulling apparatus, and a silicon single crystal was pulled up 10 times to adhere silicon or the like to the surface of the heat shielding member. The average deposition thickness at 10 locations where the deposition amount was relatively large was 610 μm. The heat shielding member 21 to which silicon or the like is adhered is attached to the supporting member 22 of the reproducing apparatus 30 shown in FIG. The heat insulating plate 26 was placed on the support member 22 so that the through hole 26 a was positioned at the center of the graphite crucible 14 . The heat insulating plate 26 is composed of a felt heat insulating material 26b made of carbon fiber and a graphite covering material 26c covering the heat insulating material 26b. The hole area of the through hole 26a was 2.8 when the portion covered by the heat insulating plate 26 covering the upper part of the heat shield member 21, which is a member that needs to be regenerated, was taken as 100.

不活性ガス導入口１７からアルゴンガスを導入し、チャンバ１１内をアルゴン雰囲気下にした。また真空ポンプを作動してチャンバ１１内の圧力を１．３３ｋＰａにした。この状態で熱遮蔽部材２１の表面温度が１７００℃になるまで筒状のヒータ１２に２７．０Ｖの電圧を印加し、リング状のボトムヒータ１９に２５．６Ｖの電圧を印加した。１７５０℃で８時間維持した後、筒状のヒータ１２を切電して室温まで、冷却した。冷却速度は４．０℃／分であった。筒状のヒータ１２の消費電力は９０ｋＷであり、リング状のボトムヒータ１９の消費電力は２５ｋＷであった。 Argon gas was introduced from the inert gas inlet 17 to create an argon atmosphere in the chamber 11 . Also, the vacuum pump was operated to set the pressure in the chamber 11 to 1.33 kPa. In this state, a voltage of 27.0 V was applied to the cylindrical heater 12 and a voltage of 25.6 V was applied to the ring-shaped bottom heater 19 until the surface temperature of the heat shield member 21 reached 1700.degree. After maintaining the temperature at 1750° C. for 8 hours, the cylindrical heater 12 was turned off and cooled to room temperature. The cooling rate was 4.0°C/min. The power consumption of the cylindrical heater 12 was 90 kW, and the power consumption of the ring-shaped bottom heater 19 was 25 kW.

＜実施例２＞
実施例１と同一のシリコン等の付着量が同じ熱遮蔽部材２１を図１に示す再生装置３０の支持部材２２に取付け、実施例１と同じ断熱板２６を実施例１と同様に支持部材２２の上に載置した。筒状のヒータ１２に印加する電圧を２７．７Ｖにし、リング状のボトムヒータ１９に印加する電圧を２３．０Ｖにすることにより、筒状のヒータ１２の消費電力を９５ｋＷにし、リング状のボトムヒータ１９の消費電力を２０ｋＷにした以外、実施例１と同様にして、熱遮蔽部材２１を熱処理し、冷却した。 <Example 2>
A heat shielding member 21 having the same adhesion amount of silicon or the like as in Example 1 is attached to a support member 22 of a regeneration device 30 shown in FIG. placed on top of. By setting the voltage applied to the cylindrical heater 12 to 27.7 V and the voltage applied to the ring-shaped bottom heater 19 to 23.0 V, the power consumption of the cylindrical heater 12 is set to 95 kW, and the ring-shaped bottom heater 19 The heat shield member 21 was heat-treated and cooled in the same manner as in Example 1, except that the power consumption was changed to 20 kW.

＜実施例３＞
実施例１と同一のシリコン等の付着量が同じ熱遮蔽部材２１を図１と同じ再生装置３０の支持部材２２に取付け、実施例１と同じ断熱板２６を実施例１と同様に支持部材２２の上に載置した後、筒状のヒータ１２にのみ３０．１Ｖの電圧を印加し、リング状のボトムヒータ１９には、電圧を印加しなかった。筒状のヒータ１２の消費電力を１１１ｋＷにした。それ以外、実施例１と同様にして、熱遮蔽部材２１を熱処理し、冷却した。 <Example 3>
A heat shielding member 21 having the same adhesion amount of silicon or the like as in Example 1 is attached to a supporting member 22 of the same regenerating device 30 as in FIG. After being placed on the substrate, a voltage of 30.1 V was applied only to the cylindrical heater 12 and no voltage was applied to the ring-shaped bottom heater 19 . The power consumption of the cylindrical heater 12 was set to 111 kW. Otherwise, the heat shield member 21 was heat-treated and cooled in the same manner as in Example 1.

＜比較例１＞
実施例１と同一のシリコン等の付着量が同じ熱遮蔽部材２１を図９に示す再生装置１０の支持部材２２に取付けた。実施例１で用いた断熱板２６は用いなかった。筒状のヒータ１２に印加する電圧を２９．２Ｖにし、リング状のボトムヒータ１９に印加する電圧を３２．３Ｖにすることにより、筒状のヒータ１２の消費電力を１０５ｋＷにし、リング状のボトムヒータ１９の消費電力を３８ｋＷにした以外、実施例１と同様にして、熱遮蔽部材２１を熱処理し、冷却した。 <Comparative Example 1>
A heat shielding member 21 having the same adhesion amount of silicon or the like as in Example 1 was attached to a supporting member 22 of the reproducing apparatus 10 shown in FIG. The heat insulating plate 26 used in Example 1 was not used. By setting the voltage applied to the cylindrical heater 12 to 29.2 V and the voltage applied to the ring-shaped bottom heater 19 to 32.3 V, the power consumption of the cylindrical heater 12 is set to 105 kW, and the ring-shaped bottom heater 19 The heat shield member 21 was heat-treated and cooled in the same manner as in Example 1, except that the power consumption was changed to 38 kW.

＜比較例２＞
実施例１と同一のシリコン等の付着量が同じ熱遮蔽部材２１を図９に示す再生装置１０の支持部材２２に取付けた。実施例１で用いた断熱板２６は用いなかった。筒状のヒータ１２に印加する電圧を３２．８Ｖにし、リング状のボトムヒータ１９に印加する電圧を２４．５Ｖにすることにより、筒状のヒータ１２の消費電力を１３０ｋＷにし、リング状のボトムヒータ１９の消費電力を２３ｋＷにした以外、実施例１と同様にして、熱遮蔽部材２１を熱処理し、冷却した。 <Comparative Example 2>
A heat shielding member 21 having the same adhesion amount of silicon or the like as in Example 1 was attached to a supporting member 22 of the reproducing apparatus 10 shown in FIG. The heat insulating plate 26 used in Example 1 was not used. By setting the voltage applied to the cylindrical heater 12 to 32.8 V and the voltage applied to the ring-shaped bottom heater 19 to 24.5 V, the power consumption of the cylindrical heater 12 is set to 130 kW, and the ring-shaped bottom heater 19 The heat shield member 21 was heat-treated and cooled in the same manner as in Example 1, except that the power consumption was changed to 23 kW.

＜比較試験その１と評価＞
実施例１～３及び比較例１～２で用いた熱遮蔽部材の部材について、再生後におけるシリコン等の付着状況、再生後における部材表面の劣化又は疵の有無及び筒状のヒータ電極と黒鉛坩堝の間のグロー放電の発生の有無を調べた。再生後におけるシリコン等の付着状況、部材表面の劣化又は疵の有無、及びグロー放電の発生の有無は、それぞれ目視により判定した。これらの結果を表１に示す。 <Comparative test 1 and evaluation>
Regarding the members of the heat shield members used in Examples 1 to 3 and Comparative Examples 1 and 2, the state of adhesion of silicon etc. after regeneration, the presence or absence of deterioration or scratches on the surface of the member after regeneration, and the cylindrical heater electrode and graphite crucible The presence or absence of glow discharge during the period was examined. The state of adhesion of silicon or the like after regeneration, the presence or absence of deterioration or flaws on the surface of the member, and the presence or absence of glow discharge were each determined visually. These results are shown in Table 1.

表１から明らかなように、筒状のヒータ１２の消費電力を１０５ｋＷにし、リング状のボトムヒータ１９の消費電力を３８ｋＷにした比較例１では、再生後における熱遮蔽部材表面の劣化又は疵は無かったが、再生後の熱遮蔽部材表面にはシリコン等がまだ付着しており、グロー放電も生じていた。また筒状のヒータ１２の消費電力を１３０ｋＷにし、リング状のボトムヒータ１９の消費電力を２３ｋＷにした比較例２では、再生後の熱遮蔽部材表面にはシリコン等が付着しておらず、再生後における熱遮蔽部材表面の劣化又は疵は無かったが、ヒータ電極と黒鉛坩堝の間でグロー放電が生じた。 As is clear from Table 1, in Comparative Example 1 in which the power consumption of the cylindrical heater 12 was 105 kW and the power consumption of the ring-shaped bottom heater 19 was 38 kW, there was no deterioration or flaw on the surface of the heat shielding member after regeneration. However, silicon or the like still adhered to the surface of the heat shield member after regeneration, and glow discharge was also generated. In Comparative Example 2, in which the power consumption of the cylindrical heater 12 was 130 kW and the power consumption of the ring-shaped bottom heater 19 was 23 kW, silicon or the like did not adhere to the surface of the heat shield member after regeneration. There was no deterioration or flaws on the surface of the heat shielding member at the time, but glow discharge occurred between the heater electrode and the graphite crucible.

これに対して、実施例１～３で再生した熱遮蔽部材は、再生処理後にシリコン等が全く付着しておらず、肉厚変化や熱変形は全くなく、被膜剥離や部材表面の疵は全く生じなかった。またグロー放電も起こらなかった。特に、実施例１及び２のように、筒状のヒータとリング状のボトムヒータの２つのヒータに電圧を印加することにより、各ヒータの電圧を、比較例１及び２のヒータ電圧よりも、それぞれ低減して、グロー放電の危険性を下げることができる。このため、複数のヒータを同時に用いることが好ましいことがわかった。また、実施例１～３の評価結果から明かなように、断熱板２６を用いることにより、各々のヒータに印加する電圧を３０．１Ｖ以下に低くすることができ、グロー放電が生じることはなかった。 On the other hand, the heat shield members regenerated in Examples 1 to 3 had no adhesion of silicon or the like after the reclaim treatment, and there was no change in wall thickness or thermal deformation, and no peeling of the film or flaws on the surface of the member. did not occur. Also, no glow discharge occurred. In particular, as in Examples 1 and 2, by applying a voltage to the two heaters of the cylindrical heater and the ring-shaped bottom heater, the voltage of each heater is lower than the heater voltage of Comparative Examples 1 and 2, respectively. can be reduced to reduce the risk of glow discharge. Therefore, it has been found that it is preferable to use a plurality of heaters at the same time. Moreover, as is clear from the evaluation results of Examples 1 to 3, the use of the heat insulating plate 26 made it possible to lower the voltage applied to each heater to 30.1 V or less, and no glow discharge occurred. rice field.

＜比較試験その２と評価＞
同一機種の再生装置を２台選び、それぞれの再生装置に再生を必要とする同じ使用履歴のあるシリコン等が付着した熱遮蔽部材２１を取付けた。１台の再生装置３０には、図１に示すように断熱板２６を設けた。もう１台の再生装置１０には、図９に示すように、断熱板を設けなかった。筒状のヒータ１２の温度を２１７０Ｋに設定したときの、熱遮蔽部材２１の上端からの距離における温度分布をシミュレーションにより求めた。その結果を図７に示す。 <Comparative test 2 and evaluation>
Two regenerating devices of the same model were selected, and the heat shield member 21 attached with silicon or the like having the same history of use requiring regenerating was attached to each of the regenerating devices. A heat insulating plate 26 was provided in one regeneration device 30 as shown in FIG. As shown in FIG. 9, the other regeneration device 10 was not provided with a heat insulating plate. The temperature distribution in the distance from the upper end of the heat shield member 21 when the temperature of the cylindrical heater 12 was set to 2170K was obtained by simulation. The results are shown in FIG.

図７から明らかなように、断熱材を設けなかった再生装置１０における熱遮蔽部材２１上端近傍の温度は１５００Ｋ～１６００Ｋの間にあり、ＳｉＯ融点である１９７５．２Ｋ以下になっていた。これに対して断熱材２６を設けた再生装置３０における熱遮蔽部材２１上端近傍の温度は２０００Ｋを超え、ＳｉＯ融点である１９７５．２Ｋを上回り、ＳｉＯを除去するのに十分な温度を確保していることがわかった。 As is clear from FIG. 7, the temperature near the upper end of the heat shielding member 21 in the regenerating apparatus 10 not provided with the heat insulating material was between 1500K and 1600K, and was below the SiO melting point of 1975.2K. On the other hand, the temperature near the upper end of the heat shielding member 21 in the regeneration device 30 provided with the heat insulating material 26 exceeds 2000 K, exceeding the SiO melting point of 1975.2 K, ensuring a temperature sufficient to remove SiO. It turns out that there is

＜比較試験その３と評価＞
同一機種の再生装置を２台選び、それぞれの再生装置に再生を必要とする同じ使用履歴のあるシリコン等が付着した熱遮蔽部材２１を取付けた。１台の再生装置３０には、図１に示すように断熱板２６を設けた。もう１台の再生装置１０には、図９に示すように、断熱板を設けなかった。熱遮蔽部材２１を再生するために、再生装置３０及び再生装置１０において、筒状のヒータ１２とリング状のボトムヒータ１９の双方にそれぞれ電圧を印加した。それぞれの熱遮蔽部材２１の温度をＳｉＯ融点（１９７５．２Ｋ）以上にするための必要なヒータ電力量を求めた。その結果を図８に示す。 <Comparative test 3 and evaluation>
Two regenerating devices of the same model were selected, and the heat shield member 21 attached with silicon or the like having the same history of use requiring regenerating was attached to each of the regenerating devices. A heat insulating plate 26 was provided in one regeneration device 30 as shown in FIG. As shown in FIG. 9, the other regeneration device 10 was not provided with a heat insulating plate. In order to regenerate the heat shielding member 21, a voltage was applied to both the tubular heater 12 and the ring-shaped bottom heater 19 in the regenerating device 30 and the regenerating device 10, respectively. The amount of heater electric power required to raise the temperature of each heat shield member 21 to the SiO melting point (1975.2 K) or higher was determined. The results are shown in FIG.

図８から明らかなように、断熱板２６を設けた場合には、筒状のヒータへの印加電圧が２１．８Ｖ、リング状のボトムヒータへの印加電圧が１８．５Ｖであり、ヒータ電力量は６４．８ｋＷ（筒状のヒータ：５３．５ｋＷ、リング状のボトムヒータ：１１．３ｋＷ）であった。これに対して、断熱板を設けなかった場合には、筒状のヒータへの印加電圧が４７．２Ｖ、リング状のボトムヒータへの印加電圧が３７．８Ｖであり、ヒータ電力量は２７９．２ｋＷ（筒状のヒータ：２３０．６ｋＷ、リング状のボトムヒータ：４８．６ｋＷ）であった。即ち断熱板２６を設けた場合には、設けなかった場合よりも、印加電圧を２分の１以下、またヒータ電力量を４分の１以下に抑えられることがわかった。 As is clear from FIG. 8, when the heat insulating plate 26 is provided, the applied voltage to the cylindrical heater is 21.8 V, the applied voltage to the ring-shaped bottom heater is 18.5 V, and the heater power consumption is It was 64.8 kW (cylindrical heater: 53.5 kW, ring-shaped bottom heater: 11.3 kW). On the other hand, when the heat insulating plate was not provided, the applied voltage to the cylindrical heater was 47.2 V, the applied voltage to the ring-shaped bottom heater was 37.8 V, and the heater power amount was 279.2 kW. (cylindrical heater: 230.6 kW, ring-shaped bottom heater: 48.6 kW). That is, it was found that when the heat insulating plate 26 is provided, the applied voltage can be reduced to 1/2 or less, and the heater power consumption can be reduced to 1/4 or less, as compared with the case where the heat insulating plate 26 is not provided.

本発明の再生方法は、シリコン単結晶引上げ装置内のシリコン等が付着する部材からシリコン等を昇華除去して再生するのに用いられる。 The regenerating method of the present invention is used for sublimating and regenerating silicon and the like from members to which silicon and the like adhere in a silicon single crystal pulling apparatus.

１０，３０引上げ装置
１１チャンバ
１２筒状のヒータ
１３保温筒
１４黒鉛坩堝
１５坩堝受け
１６ケーシング
１７不活性ガス導入口
１９リング状のボトムヒータ
２０不活性ガス排出口
２１熱遮蔽部材（再生を必要とする部材）
２２支持部材
２６，２７，２８断熱板
２６ａ，２７ａ，２８ａ断熱板の貫通孔
２９整流筒 REFERENCE SIGNS LIST 10, 30 Pulling device 11 Chamber 12 Cylindrical heater 13 Thermal insulation cylinder 14 Graphite crucible 15 Crucible receiver 16 Casing 17 Inert gas inlet 19 Ring-shaped bottom heater 20 Inert gas outlet 21 Heat shield member (requires regeneration) Element)
22 Supporting member 26, 27, 28 Heat insulating plate 26a, 27a, 28a Through hole of heat insulating plate 29 Rectifying tube

Claims

A silicon single crystal pulling apparatus comprising a sealed chamber, a heat insulating cylinder provided in the chamber, and a cylindrical heater provided inside the heat insulating cylinder. In a method of regenerating a member by arranging the member to which _x and/or metal silicon is attached and heat-treating the member in an inert gas atmosphere,
A heat insulating plate is provided in the chamber to cover the upper part of the member arranged inside the cylindrical heater,
The heat insulating plate is made of a heat insulating material covered with a covering material,
The thermal conductivity of the heat insulating material is 5 W / (m / ° C.) or less,
1 or 2 or more through-holes are provided in the heat insulating plate for the inert gas to flow,
The coating material is graphite, graphite coated with SiC on the surface, or molybdenum,
The hole area of the through-hole is 2.5 or more and 5 or less when the portion covered by the heat insulating plate is 100.
A method of recycling a member, characterized by:

2. The method of regenerating a member according to claim 1 , wherein the peripheral edge of said heat insulating plate is placed on the upper end of said heat insulating cylinder.

3. The method of regenerating a member according to claim 1, wherein said silicon single crystal pulling apparatus comprises a plurality of heaters.

A silicon single crystal pulling apparatus comprising a sealed chamber, a heat insulating cylinder provided in the chamber, and a cylindrical heater provided inside the heat insulating cylinder. In an apparatus for regenerating a member by arranging a member to which _x and/or metal silicon is attached and heat-treating the member in an inert gas atmosphere,
A heat insulating plate is provided in the chamber to cover the upper part of the member arranged inside the cylindrical heater,
The heat insulating plate is made of a heat insulating material covered with a covering material,
The thermal conductivity of the heat insulating material is 5 W / (m / ° C.) or less,
1 or 2 or more through-holes are provided in the heat insulating plate for the inert gas to flow,
The coating material is graphite, graphite coated with SiC on the surface, or molybdenum,
The hole area of the through-hole is 2.5 or more and 5 or less when the portion covered by the heat insulating plate is 100.
A member recycling device characterized by:

5. The member recycling apparatus according to claim 4 , wherein the peripheral edge of said heat insulating plate is placed on the upper end of said heat insulating cylinder.

6. The apparatus for regenerating a member according to claim 4, wherein said silicon single crystal pulling apparatus comprises a plurality of heaters.

A method for producing a silicon single crystal using a member regenerated by the method according to any one of claims 1 to 3 or the apparatus according to any one of claims 4 to 6 .