JP2013134057A - Method for determining three-dimensional distribution of bubble distribution of silica glass crucible, and method for manufacturing silicon monocrystal - Google Patents

Method for determining three-dimensional distribution of bubble distribution of silica glass crucible, and method for manufacturing silicon monocrystal Download PDF

Info

Publication number
JP2013134057A
JP2013134057A JP2011282409A JP2011282409A JP2013134057A JP 2013134057 A JP2013134057 A JP 2013134057A JP 2011282409 A JP2011282409 A JP 2011282409A JP 2011282409 A JP2011282409 A JP 2011282409A JP 2013134057 A JP2013134057 A JP 2013134057A
Authority
JP
Japan
Prior art keywords
crucible
silica glass
distribution
measuring unit
distance measuring
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP2011282409A
Other languages
Japanese (ja)
Other versions
JP5818675B2 (en
Inventor
Toshiaki Sudo
俊明 須藤
Tadahiro Sato
忠広 佐藤
Masaru Kitahara
賢 北原
Eriko Suzuki
江梨子 鈴木
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Japan Super Quartz Corp
Original Assignee
Japan Super Quartz Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to JP2011282409A priority Critical patent/JP5818675B2/en
Application filed by Japan Super Quartz Corp filed Critical Japan Super Quartz Corp
Priority to US14/365,523 priority patent/US9809902B2/en
Priority to EP12859405.8A priority patent/EP2796595B1/en
Priority to CN201280063279.7A priority patent/CN104145051B/en
Priority to PCT/JP2012/078260 priority patent/WO2013094318A1/en
Priority to KR1020147020091A priority patent/KR101638584B1/en
Priority to TW101140627A priority patent/TWI480505B/en
Publication of JP2013134057A publication Critical patent/JP2013134057A/en
Application granted granted Critical
Publication of JP5818675B2 publication Critical patent/JP5818675B2/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P40/00—Technologies relating to the processing of minerals
    • Y02P40/50—Glass production, e.g. reusing waste heat during processing or shaping
    • Y02P40/57—Improving the yield, e-g- reduction of reject rates

Abstract

PROBLEM TO BE SOLVED: To provide a method for determining a three-dimensional distribution of a bubble distribution of a silica glass crucible with high precision.SOLUTION: According to the present invention, there is provided a method for determining three-dimensional distribution of a bubble distribution of a silica glass crucible including the steps of: moving an inner distance-measuring part along an inner surface of a silica glass crucible having a transparent silica glass layer on an inner surface side and a bubble-containing silica glass layer on an outer surface side, in a noncontact manner; at a plurality of measuring points in a moving path, irradiating the inner surface of the silica glass crucible with laser light obliquely thereto from the inner distance-measuring part and detecting inner surface reflected light from the inner surface to measure an inner surface distance between the inner distance-measuring part and the inner surface; calculating a three-dimensional shape of the inner surface of the silica glass crucible by associating a three-dimensional coordinate of each measuring point with the inner surface distance; and determining a three-dimensional distribution of the bubble distribution by measuring, at a plurality of measuring points on the three-dimensional shape, bubble distribution at a position of a wall of the crucible corresponding to each measuring point.

Description

本発明は、シリカガラスルツボの気泡分布の三次元分布の決定方法、及びシリコン単結晶の製造方法に関する。   The present invention relates to a method for determining a three-dimensional distribution of bubble distribution in a silica glass crucible and a method for producing a silicon single crystal.

シリコン単結晶の製造にはシリカガラスルツボを用いたチョクラルスキー法（ＣＺ法）が採用されている。具体的には、シリカガラスルツボの内部にシリコン多結晶原料を熔融したシリコン融液を貯留し、シリコン単結晶の種結晶を接触させ、回転させながら徐々に引き上げ、シリコン単結晶の種結晶を核として成長させてシリコン単結晶を製造する。   A Czochralski method (CZ method) using a silica glass crucible is employed for producing a silicon single crystal. Specifically, a silicon melt obtained by melting a silicon polycrystal raw material is stored inside a silica glass crucible, and a silicon single crystal seed crystal is brought into contact with the silicon crystal crucible and is gradually pulled up to rotate the silicon single crystal seed crystal as a nucleus. To produce a silicon single crystal.

シリコン単結晶引き上げに用いるルツボは、一般に、回転モールドの内表面に平均粒径３００μｍ程度のシリカ粉を堆積させてシリカ粉層を形成するシリカ粉層形成工程と、モールド側からシリカ粉層を減圧しながら、シリカ粉層をアーク熔融させることによってシリカガラス層を形成するアーク熔融工程を備える（この方法を「回転モールド法」と称する）。   A crucible used for pulling a silicon single crystal is generally a silica powder layer forming step of forming a silica powder layer by depositing silica powder having an average particle size of about 300 μm on the inner surface of a rotary mold, and reducing the silica powder layer from the mold side. However, an arc melting step of forming a silica glass layer by arc melting the silica powder layer is provided (this method is referred to as “rotary molding method”).

アーク熔融工程の初期にはシリカ粉層を強く減圧することによって気泡を除去して透明シリカガラス層（以下、「透明層」と称する。）を形成し、その後、減圧を弱くすることによって気泡が残留した気泡含有シリカガラス層（以下、「気泡含有層」と称する。）を形成することによって、内表面側に透明層を有し、外表面側に気泡含有層を有する二層構造のシリカガラスルツボを形成することができる。   At the initial stage of the arc melting process, the silica powder layer is strongly depressurized to remove bubbles to form a transparent silica glass layer (hereinafter referred to as “transparent layer”). By forming a residual bubble-containing silica glass layer (hereinafter referred to as “bubble-containing layer”), a two-layered silica glass having a transparent layer on the inner surface side and a bubble-containing layer on the outer surface side A crucible can be formed.

ルツボの製造に使用されるシリカ粉には、天然石英を粉砕して製造される天然シリカ粉や化学合成によって製造される合成シリカ粉があるが、特に天然シリカ粉は、天然物を原料としているので、物性・形状・サイズがばらつきやすい。物性・形状・サイズが変化すると、シリカ粉の溶融状態が変化するので、同じ条件でアーク熔融を行っても、製造されるルツボの気泡分布（サイズ毎の気泡数の分布）は、ルツボ毎に異なり、又は各ルツボにおいても部位毎に気泡分布が異なる場合がある。   Silica powder used for crucible production includes natural silica powder produced by pulverizing natural quartz and synthetic silica powder produced by chemical synthesis, but natural silica powder is made from natural products. Therefore, physical properties, shapes, and sizes tend to vary. As the physical properties, shape, and size change, the melting state of the silica powder changes, so even if arc melting is performed under the same conditions, the bubble distribution of the produced crucible (the distribution of the number of bubbles for each size) There are cases where the bubble distribution is different from site to site in each crucible.

ルツボ内表面は、シリコン融液と接触する部分であり、ルツボ内表面の近傍に存在している気泡はシリコン単結晶の単結晶収率に与える影響が大きい。また、気泡含有層は、ルツボ周囲に配置されたカーボンヒーターからの熱を均一にシリコン融液に伝える機能を有しており、シリコン単結晶引き上げ時の熱環境に与える影響が大きい。   The inner surface of the crucible is a portion in contact with the silicon melt, and bubbles existing in the vicinity of the inner surface of the crucible have a large influence on the single crystal yield of the silicon single crystal. In addition, the bubble-containing layer has a function of uniformly transferring heat from the carbon heater disposed around the crucible to the silicon melt, and has a great influence on the thermal environment when pulling up the silicon single crystal.

特許文献１では、気泡径の分布を規定の範囲内にすることによってシリコン単結晶の製造歩留まりを向上させることができる点が記載されている。また、側壁部、湾曲部、及び底部における気泡径の分布を適切に設定する点についても記載されている。   Patent Document 1 describes that the production yield of a silicon single crystal can be improved by keeping the distribution of bubble diameters within a specified range. Moreover, it is described also about the point which sets distribution of the bubble diameter in a side wall part, a curved part, and a bottom part appropriately.

特開２０１０−２４１６２３号公報JP 2010-241623 A

しかし、特許文献１の方法では、気泡径分布の大まかな傾向が分かるのみであり、ルツボの特定部位での気泡分布がどうなっているのかが分からず、また特許文献１の方法では、ルツボの気泡分布の三次元分布を高精度に決定することは極めて困難である。   However, the method of Patent Document 1 only shows a general tendency of the bubble diameter distribution, and does not know what the bubble distribution is at a specific part of the crucible. It is extremely difficult to determine the three-dimensional distribution of the bubble distribution with high accuracy.

本発明はこのような事情に鑑みてなされたものであり、シリカガラスルツボの気泡分布の三次元分布を高精度に決定する方法を提供するものである。   This invention is made | formed in view of such a situation, and provides the method of determining the three-dimensional distribution of the bubble distribution of a silica glass crucible with high precision.

本発明によれば、内表面側に透明シリカガラス層と、外表面側に気泡含有シリカガラス層を有するシリカガラスルツボの内表面に沿って非接触で内部測距部を移動させ、移動経路上の複数の測定点において、内部測距部から前記シリカガラスルツボの内表面に対して斜め方向にレーザー光を照射し、前記内表面からの内表面反射光を検出することによって、内部測距部と前記内表面の間の内表面距離を測定し、各測定点の三次元座標と、前記内表面距離を関連付けることによって、前記シリカガラスルツボの内表面の三次元形状を求め、この三次元形状上の複数の測定点において、各測定点に対応した位置のルツボの壁での気泡分布を測定することによって、前記気泡分布の三次元分布を決定する工程を備えるシリカガラスルツボの気泡分布の三次元分布の決定方法が提供される。   According to the present invention, the internal distance measuring unit is moved in a non-contact manner along the inner surface of the silica glass crucible having the transparent silica glass layer on the inner surface side and the bubble-containing silica glass layer on the outer surface side. The internal distance measuring unit is configured to irradiate laser light obliquely to the inner surface of the silica glass crucible from the inner distance measuring unit and detect the inner surface reflected light from the inner surface. And measuring the inner surface distance between the inner surface and the three-dimensional coordinates of each measuring point and the inner surface distance to obtain the three-dimensional shape of the inner surface of the silica glass crucible, The bubble distribution of the silica glass crucible comprising the step of determining the three-dimensional distribution of the bubble distribution by measuring the bubble distribution at the crucible wall at the position corresponding to each measurement point at the plurality of measurement points above. Method of determining the three-dimensional distribution is provided.

上記の通り、ルツボの気泡分布は、シリコン単結晶の単結晶収率やシリコン単結晶引き上げ時の熱環境に大きな影響を与えるものである。本発明では、以下の方法によって、この気泡分布の三次元分布を高精度に決定することを可能にしている。   As described above, the bubble distribution in the crucible greatly affects the single crystal yield of the silicon single crystal and the thermal environment during the pulling of the silicon single crystal. In the present invention, the three-dimensional distribution of the bubble distribution can be determined with high accuracy by the following method.

本発明者らは、内表面の三次元形状を最初に特定して、その三次元形状上に複数の測定点において各測定点に対応した位置のルツボの壁での気泡分布を測定することによって気泡分布の三次元分布を決定しようとしたが、通常の三次元レーザースキャナを用いて、内表面の三次元形状を特定しようとしたところ、ルツボが透明体であるので、測定はうまくいかなかった。ルツボ内表面に光を照射して画像を取得し、その画像を解析する方法も試してみたが、この方法では、画像の解析に非常に長い時間がかかるため、ルツボの内表面全体の三次元形状の測定には到底使えるものではなかった。   The inventors first identify the three-dimensional shape of the inner surface, and measure the bubble distribution at the crucible wall at the position corresponding to each measurement point at a plurality of measurement points on the three-dimensional shape. I tried to determine the three-dimensional distribution of the bubble distribution, but when I tried to identify the three-dimensional shape of the inner surface using a normal three-dimensional laser scanner, the measurement was not successful because the crucible was transparent. . I tried to illuminate the inner surface of the crucible to acquire an image and analyze the image, but this method takes a very long time to analyze the image. It could not be used to measure the shape.

このような状況において、本発明者らは、ルツボの内表面に対して斜め方向からレーザー光を照射したところ、ルツボ内表面からの反射光（内表面反射光）の検出が可能であり、この反射光に基づいて内部測距部と内表面の間の内表面距離が測定可能であることを見出した。   In such a situation, the present inventors can detect the reflected light (inner surface reflected light) from the inner surface of the crucible when the inner surface of the crucible is irradiated with laser light from an oblique direction. It was found that the inner surface distance between the inner distance measuring unit and the inner surface can be measured based on the reflected light.

また、ルツボの内表面に沿った複数の測定点において測定が行われるが、各測定点での内部測距部の座標と内表面距離を関連付けることによって、各測定点に対応するルツボ内表面座標が得られる。   In addition, the measurement is performed at a plurality of measurement points along the inner surface of the crucible. By associating the inner surface distance with the coordinates of the internal distance measuring unit at each measurement point, the inner surface coordinates of the crucible corresponding to each measurement point. Is obtained.

そして、ルツボの内表面に沿って、メッシュ状に多数の測定点を配置して測定を行うことによって、メッシュ状の内表面座標が得られ、これによって、ルツボの内表面の三次元形状を求めることができる。
この方法が優れているのは、画像解析による方法に比べて、データのサンプリングレートが格段に大きいことであり、予備実験によると、直径１ｍのルツボで１０万点の測定をする場合であっても、１０分程度で内表面全体の三次元形状の測定を終えることができた。 Then, by arranging and measuring a large number of measurement points in a mesh shape along the inner surface of the crucible, mesh-like inner surface coordinates are obtained, thereby obtaining the three-dimensional shape of the inner surface of the crucible. be able to.
The superiority of this method is that the data sampling rate is much higher than that of the image analysis method. According to a preliminary experiment, 100,000 points are measured with a 1 m diameter crucible. However, the measurement of the three-dimensional shape of the entire inner surface was completed in about 10 minutes.

ルツボの内表面の三次元形状が求まった後は、この三次元形状上の複数の測定点で各測定点に対応した位置のルツボの壁での気泡分布を測定を測定することによって、ルツボの気泡分布の三次元分布を決定する。気泡分布とは、狭い測定範囲内でどのような大きさの気泡がどれくらい存在しているのかを示す尺度であり、局所的な気泡の分布を示す尺度である。一方、気泡分布の三次元分布とは、気泡分布がルツボ全体においてどのように変化しているのかを示す尺度である。従って、本発明では、局所的な気泡の分布と、ルツボ全体での気泡の分布を高精度に決定することができる。
本発明の方法が優れている点は、気泡分布の三次元分布が非破壊で決定できるため、実際の製品の気泡分布の三次元分布が分かることである。従来は、ルツボを切断してサンプルを作成し、このサンプルの気泡分布を測定していたが、この方法では、実際の製品のデータが取得できないこと、サンプル作成に時間とコストがかかるという問題があるので、本発明は、実際の製品の気泡分布を低コストで測定できる点で利点が大きい。また、本発明は、外径２８インチ以上の大型ルツボや、４０インチ以上の超大型ルツボにおいて特に利点がある。なぜなら、このようなルツボにおいては、サンプル作成にかかる時間とコストが小型ルツボに比べて非常に大きいからである。 After the three-dimensional shape of the inner surface of the crucible is obtained, the measurement of the bubble distribution on the crucible wall at the position corresponding to each measurement point at a plurality of measurement points on this three-dimensional shape is performed, thereby measuring the crucible's inner surface. Determine the three-dimensional distribution of the bubble distribution. The bubble distribution is a scale indicating how many bubbles exist in a narrow measurement range, and is a scale indicating a local bubble distribution. On the other hand, the three-dimensional distribution of the bubble distribution is a scale indicating how the bubble distribution changes in the entire crucible. Therefore, in the present invention, the local bubble distribution and the bubble distribution in the entire crucible can be determined with high accuracy.
The advantage of the method of the present invention is that the three-dimensional distribution of the bubble distribution of the actual product can be known because the three-dimensional distribution of the bubble distribution can be determined nondestructively. In the past, a crucible was cut to create a sample, and the bubble distribution of this sample was measured. However, this method has the problems that actual product data cannot be obtained and that sample preparation takes time and costs. Therefore, the present invention has a great advantage in that the bubble distribution of an actual product can be measured at low cost. The present invention is particularly advantageous in a large crucible having an outer diameter of 28 inches or more and a super large crucible having a diameter of 40 inches or more. This is because, in such a crucible, the time and cost required for sample preparation are very large compared to a small crucible.

ルツボの気泡分布の三次元分布が決定されれば、この分布に基づいてルツボの品質検査を行うことができる。例えば、各部位の気泡分布が規定の範囲内に入っているかどうかだけではなく、そのバラツキが規定の範囲内に入っているかどうかに従って品質検査を行うことができ、規定の範囲外である場合には出荷せずにＮＧ品とする等によって、規格外の製品が出荷されるのを防ぐことができる。   If the three-dimensional distribution of the bubble distribution of the crucible is determined, the quality inspection of the crucible can be performed based on this distribution. For example, quality inspection can be performed not only according to whether the bubble distribution of each part is within the specified range, but also whether the variation is within the specified range. For example, it is possible to prevent non-standard products from being shipped by, for example, making an NG product without shipping.

また、シリコン単結晶の引き上げ条件を設定する際に、ルツボの気泡分布の三次元分布を考慮して条件設定を行うことができ、シリコン単結晶の引き上げを高精度に行うことができる。   Further, when setting the pulling conditions for the silicon single crystal, the conditions can be set in consideration of the three-dimensional distribution of the bubble distribution of the crucible, and the pulling of the silicon single crystal can be performed with high accuracy.

さらに、ルツボの使用前にルツボの気泡分布の三次元分布を決定しておくことによって、万が一、シリコン単結晶の引き上げがうまく行かなかった場合、その原因追求を行うことが容易になる。   Furthermore, by determining the three-dimensional distribution of the bubble distribution of the crucible before using the crucible, if the silicon single crystal cannot be pulled up by any chance, the cause can be easily pursued.

以下、本発明の種々の実施形態を例示する。以下の実施形態は、互いに組み合わせ可能である。
好ましくは、前記気泡含有率は、共焦点顕微鏡を用いて測定される。 Hereinafter, various embodiments of the present invention will be exemplified. The following embodiments can be combined with each other.
Preferably, the bubble content is measured using a confocal microscope.

好ましくは、前記内部測距部からのレーザー光は、前記内表面に対して３０〜６０度の入射角で照射される。   Preferably, the laser beam from the internal distance measuring unit is irradiated at an incident angle of 30 to 60 degrees with respect to the inner surface.

好ましくは、前記内部測距部は、前記内部測距部を三次元的に移動させることができるように構成された内部ロボットアームに固定され、前記シリカガラスルツボは、前記内部ロボットアームを覆うように配置される。   Preferably, the internal distance measuring unit is fixed to an internal robot arm configured to be able to move the internal distance measuring unit three-dimensionally, and the silica glass crucible covers the internal robot arm. Placed in.

好ましくは、前記外部測距部は、前記外部測距部を三次元的に移動させることができるように構成された外部ロボットアームに固定される。   Preferably, the external distance measuring unit is fixed to an external robot arm configured to be able to move the external distance measuring unit three-dimensionally.

好ましくは、前記シリカガラスルツボ内に保持されたシリコン融液からシリコン単結晶を引き上げる工程を備え、前記シリコン単結晶の引き上げ条件が、前記シリカガラスルツボの気泡分布の三次元分布に基づいて決定され、前記気泡分布の三次元分布は、上記方法によって決定される、シリコン単結晶の製造方法である。   Preferably, the method includes a step of pulling up the silicon single crystal from the silicon melt held in the silica glass crucible, and the pulling condition of the silicon single crystal is determined based on the three-dimensional distribution of the bubble distribution of the silica glass crucible. The three-dimensional distribution of the bubble distribution is a method for producing a silicon single crystal determined by the above method.

図１は、シリカガラスルツボの三次元形状測定方法の説明図である。FIG. 1 is an explanatory diagram of a method for measuring the three-dimensional shape of a silica glass crucible. 図２は、図１の内部測距部及びその近傍のシリカガラスルツボの拡大図である。FIG. 2 is an enlarged view of the internal distance measuring unit of FIG. 1 and a silica glass crucible in the vicinity thereof. 図３は、図１の内部測距部の測定結果を示す。FIG. 3 shows a measurement result of the internal distance measuring unit of FIG. 図４は、図１の外部測距部の測定結果を示す。FIG. 4 shows a measurement result of the external distance measuring unit in FIG. 図５は、共焦点顕微鏡を用いて取得した気泡の画像を示す。FIG. 5 shows an image of bubbles acquired using a confocal microscope.

以下、図１〜図５を用いて、本発明の一実施形態のシリカガラスルツボの気泡分布の三次元分布の決定方法を説明する。   Hereinafter, the determination method of the three-dimensional distribution of the bubble distribution of the silica glass crucible of one embodiment of the present invention will be described with reference to FIGS.

＜１．シリカガラスルツボ＞
本実施形態で使用されるシリカガラスルツボ１１は、一例では、回転モールドの内表面に平均粒径３００μｍ程度のシリカ粉を堆積させてシリカ粉層を形成するシリカ粉層形成工程と、モールド側からシリカ粉層を減圧しながら、シリカ粉層をアーク熔融させることによってシリカガラス層を形成するアーク熔融工程を備える（この方法を「回転モールド法」と称する）方法によって製造される。 <1. Silica glass crucible>
In one example, the silica glass crucible 11 used in the present embodiment is a silica powder layer forming step of forming a silica powder layer by depositing silica powder having an average particle size of about 300 μm on the inner surface of the rotary mold, and from the mold side. The silica powder layer is manufactured by a method including an arc melting step of forming a silica glass layer by arc melting the silica powder layer while reducing the pressure of the silica powder layer (this method is referred to as “rotary molding method”).

アーク熔融工程の初期にはシリカ粉層を強く減圧することによって気泡を除去して透明シリカガラス層（以下、「透明層」と称する。）１３を形成し、その後、減圧を弱くすることによって気泡が残留した気泡含有シリカガラス層（以下、「気泡含有層」と称する。）１５を形成することによって、内表面側に透明層１３を有し、外表面側に気泡含有層１５を有する二層構造のシリカガラスルツボを形成することができる。   At the initial stage of the arc melting process, the silica powder layer is strongly decompressed to remove bubbles to form a transparent silica glass layer (hereinafter referred to as “transparent layer”) 13, and then the decompression is weakened to reduce the bubbles. Forming a bubble-containing silica glass layer 15 (hereinafter referred to as “bubble-containing layer”) 15, thereby having two layers having a transparent layer 13 on the inner surface side and a bubble-containing layer 15 on the outer surface side. A structured silica glass crucible can be formed.

ルツボの製造に使用されるシリカ粉には、天然石英を粉砕して製造される天然シリカ粉や化学合成によって製造される合成シリカ粉があるが、特に天然シリカ粉は、天然物を原料としているので、物性・形状・サイズがばらつきやすい。物性・形状・サイズが変化すると、シリカ粉の溶融状態が変化するので、同じ条件でアーク熔融を行っても、製造されるルツボの気泡分布は、ルツボ毎にばらついてしまい、また同じルツボ内においても部位毎にばらついてしまう。従って、製造したルツボの一つ一つについて、気泡分布の三次元分布を決定する必要がある。   Silica powder used for crucible production includes natural silica powder produced by pulverizing natural quartz and synthetic silica powder produced by chemical synthesis, but natural silica powder is made from natural products. Therefore, physical properties, shapes, and sizes tend to vary. As the physical properties, shape, and size change, the melting state of the silica powder changes, so even if arc melting is performed under the same conditions, the bubble distribution of the produced crucible varies from crucible to crucible. Will also vary from site to site. Therefore, it is necessary to determine the three-dimensional distribution of the bubble distribution for each manufactured crucible.

シリカガラスルツボ１１は、円筒状の側壁部１１ａと、湾曲した底部１１ｃと、側壁部１１ａと底部１１ｃを連結し且つ底部１１ｃよりも曲率が大きいコーナー部１１ｂを備える。本発明において、コーナー部１１ｂとは、側壁部１１ａと底部１１ｃを連接する部分で、コーナー部の曲線の接線がシリカガラスルツボの側壁部１１ａと重なる点から、底部１１ｃと共通接線を有する点までの部分のことを意味する。言い換えると、シリカガラスルツボ１１の側壁部１１ａが曲がり始める点が側壁部１１ａとコーナー部１１ｂの境界である。さらに、ルツボの底の曲率が一定の部分が底部１１ｃであり、ルツボの底の中心からの距離が増したときに曲率が変化し始める点が底部１１ｃとコーナー部１１ｂとの境界である。   The silica glass crucible 11 includes a cylindrical side wall part 11a, a curved bottom part 11c, and a corner part 11b that connects the side wall part 11a and the bottom part 11c and has a larger curvature than the bottom part 11c. In the present invention, the corner portion 11b is a portion connecting the side wall portion 11a and the bottom portion 11c, from a point where the tangent line of the corner portion curve overlaps the side wall portion 11a of the silica glass crucible to a point having a common tangent line with the bottom portion 11c. Means the part. In other words, the point where the side wall portion 11a of the silica glass crucible 11 begins to bend is the boundary between the side wall portion 11a and the corner portion 11b. Further, the portion where the curvature of the bottom of the crucible is constant is the bottom portion 11c, and the point where the curvature starts to change when the distance from the center of the bottom of the crucible increases is the boundary between the bottom portion 11c and the corner portion 11b.

＜２．ルツボの内表面の三次元形状の測定方法＞
以下、図１〜図４を用いて、ルツボの内表面の三次元形状の測定方法について説明する。本実施形態では、レーザー変位計などからなる内部測距部１７をルツボ内表面に沿って非接触で移動させ、移動経路上の複数の測定点において、ルツボ内表面に対してレーザー光を斜め方向に照射し、その反射光を検出することによって、ルツボの内表面の三次元形状を測定する。以下、詳細に説明する。また、内表面形状を測定する際に、透明層１３と気泡含有層１５の界面の三次元形状も同時に測定することができ、また、内部測距部１９を用いることによってルツボの外表面の三次元形状も測定することができるので、これらの点についても合わせて説明する。 <2. Method for measuring the 3D shape of the inner surface of the crucible>
Hereinafter, a method for measuring the three-dimensional shape of the inner surface of the crucible will be described with reference to FIGS. In the present embodiment, the internal distance measuring unit 17 including a laser displacement meter is moved in a non-contact manner along the inner surface of the crucible, and laser light is obliquely directed to the inner surface of the crucible at a plurality of measurement points on the movement path. And measuring the three-dimensional shape of the inner surface of the crucible by detecting the reflected light. Details will be described below. Further, when measuring the inner surface shape, the three-dimensional shape of the interface between the transparent layer 13 and the bubble-containing layer 15 can also be measured at the same time. Since the original shape can also be measured, these points will be described together.

＜２−１．シリカガラスルツボの設置、内部ロボットアーム、内部測距部＞
測定対象であるシリカガラスルツボ１１は、開口部が下向きになるように回転可能な回転台９上に載置されている。ルツボ１１に覆われる位置に設けられた基台１上には、内部ロボットアーム５が設置されている。内部ロボットアーム５は、複数のアーム５ａと、これらのアーム５ａを回転可能に支持する複数のジョイント５ｂと、本体部５ｃを備える。本体部５ｃには図示しない外部端子が設けられており、外部とのデータ交換が可能になっている。内部ロボットアーム５の先端にはルツボ１１の内表面形状の測定を行う内部測距部１７が設けられている。内部測距部１７は、ルツボ１１の内表面に対してレーザー光を照射し、内表面からの反射光を検出することによって内部測距部１７からルツボ１１の内表面までの距離を測定する。本体部５ｃ内には、ジョイント５ｂ及び内部測距部１７の制御を行う制御部が設けられている。制御部は、本体部５ｃ設けられたプログラム又は外部入力信号に基づいてジョイント５ｂを回転させてアーム５を動かすことによって、内部測距部１７を任意の三次元位置に移動させる。具体的には、内部測距部１７をルツボ内表面に沿って非接触で移動させる。従って、制御部には、ルツボ内表面の大まかな形状データを与え、そのデータに従って、内部測距部１７の位置を移動させる。より具体的には、例えば、図１（ａ）に示すようなルツボ１１の開口部近傍に近い位置から測定を開始し、図１（ｂ）に示すように、ルツボ１１の底部１１ｃに向かって内部測距部１７を移動させ、移動経路上の複数の測定点において測定を行う。測定間隔は、例えば、１〜５ｍｍであり、例えば２ｍｍである。測定は、予め内部測距部１７内に記憶されたタイミングで行うか、又は外部トリガに従って行う。測定結果は、内部測距部１７内の記憶部に格納されて、測定終了後にまとめて本体部５ｃに送られるか、又は測定の度に、逐次本体部５ｃに送られるようにする。内部測距部１７は、本体部５ｃとは別に設けられた制御部によって制御するように構成してもよい。 <2-1. Installation of silica glass crucible, internal robot arm, internal distance measuring section>
The silica glass crucible 11 to be measured is placed on a turntable 9 that can be rotated so that the opening is directed downward. On the base 1 provided at a position covered with the crucible 11, an internal robot arm 5 is installed. The internal robot arm 5 includes a plurality of arms 5a, a plurality of joints 5b that rotatably support these arms 5a, and a main body 5c. The main body 5c is provided with an external terminal (not shown) so that data exchange with the outside is possible. An internal distance measuring unit 17 for measuring the inner surface shape of the crucible 11 is provided at the tip of the internal robot arm 5. The internal distance measuring unit 17 measures the distance from the internal distance measuring unit 17 to the inner surface of the crucible 11 by irradiating the inner surface of the crucible 11 with laser light and detecting reflected light from the inner surface. A control unit that controls the joint 5b and the internal distance measuring unit 17 is provided in the main body 5c. The control unit moves the internal distance measuring unit 17 to an arbitrary three-dimensional position by rotating the joint 5b and moving the arm 5 based on a program provided in the main body 5c or an external input signal. Specifically, the internal distance measuring unit 17 is moved in a non-contact manner along the inner surface of the crucible. Therefore, rough shape data of the inner surface of the crucible is given to the control unit, and the position of the internal distance measuring unit 17 is moved according to the data. More specifically, for example, the measurement is started from a position near the opening of the crucible 11 as shown in FIG. 1A, and toward the bottom 11c of the crucible 11 as shown in FIG. The internal distance measuring unit 17 is moved to perform measurement at a plurality of measurement points on the movement path. The measurement interval is, for example, 1 to 5 mm, for example, 2 mm. The measurement is performed at a timing stored in the internal distance measuring unit 17 in advance or according to an external trigger. The measurement results are stored in the storage unit in the internal distance measuring unit 17, and are sent to the main body unit 5c collectively after the measurement is completed, or are sequentially sent to the main body unit 5c for each measurement. The internal distance measuring unit 17 may be configured to be controlled by a control unit provided separately from the main body 5c.

ルツボの開口部から底部１１ｃまでの測定が終わると、回転台９を少し回転させ、同様の測定行う。この測定は、底部１１ｃから開口部に向かって行ってもよい。回転台９の回転角は、精度と測定時間との考慮して決定されるが、例えば、２〜１０度である。回転角が大きすぎると測定精度が十分でなく、小さすぎると測定時間が掛かりすぎる。回転台９の回転は、内蔵プログラム又は外部入力信号に基づいて制御される。回転台９の回転角は、ロータリーエンコーダ等によって検出可能である。回転台９の回転は、内部測距部１７及び後述する外部測距部１９の移動と連動してすることが好ましく、これによって、内部測距部１７及び外部測距部１９の３次元座標の算出が容易になる。   When the measurement from the opening of the crucible to the bottom 11c is completed, the turntable 9 is slightly rotated and the same measurement is performed. This measurement may be performed from the bottom 11c toward the opening. The rotation angle of the turntable 9 is determined in consideration of accuracy and measurement time, and is, for example, 2 to 10 degrees. If the rotation angle is too large, the measurement accuracy is not sufficient, and if it is too small, it takes too much measurement time. The rotation of the turntable 9 is controlled based on a built-in program or an external input signal. The rotation angle of the turntable 9 can be detected by a rotary encoder or the like. It is preferable that the rotation of the turntable 9 be interlocked with the movement of the internal distance measuring unit 17 and the external distance measuring unit 19 which will be described later, whereby the three-dimensional coordinates of the internal distance measuring unit 17 and the external distance measuring unit 19 are changed. Calculation becomes easy.

後述するが、内部測距部１７は、内部測距部１７から内表面までの距離（内表面距離）、及び内部測距部１７から透明層１３と気泡含有層１５の界面までの距離（界面距離）の両方を測定することができる。ジョイント５ｂの角度はジョイント５ｂに設けられたロータリーエンコーダ等によって既知であるので、各測定点での内部測距部１７の位置の三次元座標及び方向が既知になるので、内表面距離及び界面距離が求まれば、内表面での三次元座標、及び界面での三次元座標が既知となる。そして、ルツボ１１の開口部から底部１１ｃまでの測定が、ルツボ１１の全周に渡って行われるので、ルツボ１１の内表面の三次元形状、及び界面の三次元形状が既知になる。また、内表面と界面の間の距離が既知になるので、透明層１３の厚さも既知になり、透明層の厚さの三次元分布が求められる。   As will be described later, the internal distance measuring unit 17 includes a distance from the internal distance measuring unit 17 to the inner surface (inner surface distance) and a distance from the inner distance measuring unit 17 to the interface between the transparent layer 13 and the bubble-containing layer 15 (interface). Both distances can be measured. Since the angle of the joint 5b is known by a rotary encoder or the like provided in the joint 5b, the three-dimensional coordinates and direction of the position of the internal distance measuring unit 17 at each measurement point are known. Is obtained, the three-dimensional coordinates on the inner surface and the three-dimensional coordinates on the interface are known. And since the measurement from the opening part of the crucible 11 to the bottom part 11c is performed over the perimeter of the crucible 11, the three-dimensional shape of the inner surface of the crucible 11 and the three-dimensional shape of the interface become known. Further, since the distance between the inner surface and the interface is known, the thickness of the transparent layer 13 is also known, and a three-dimensional distribution of the thickness of the transparent layer is obtained.

＜２−２．外部ロボットアーム、外部測距部＞
ルツボ１１の外部に設けられた基台３上には、外部ロボットアーム７が設置されている。外部ロボットアーム７は、複数のアーム７ａと、これらのアームを回転可能に支持する複数のジョイント７ｂと、本体部７ｃを備える。本体部７ｃには図示しない外部端子が設けられており、外部とのデータ交換が可能になっている。外部ロボットアーム７の先端にはルツボ１１の外表面形状の測定を行う外部測距部１９が設けられている。外部測距部１９は、ルツボ１１の外表面に対してレーザー光を照射し、外表面からの反射光を検出することによって外部測距部１９からルツボ１１の外表面までの距離を測定する。本体部７ｃ内には、ジョイント７ｂ及び外部測距部１９の制御を行う制御部が設けられている。制御部は、本体部７ｃ設けられたプログラム又は外部入力信号に基づいてジョイント７ｂを回転させてアーム７を動かすことによって、外部測距部１９を任意の三次元位置に移動させる。具体的には、外部測距部１９をルツボ外表面に沿って非接触で移動させる。従って、制御部には、ルツボ外表面の大まかな形状データを与え、そのデータに従って、外部測距部１９の位置を移動させる。より具体的には、例えば、図１（ａ）に示すようなルツボ１１の開口部近傍に近い位置から測定を開始し、図１（ｂ）に示すように、ルツボ１１の底部１１ｃに向かって外部測距部１９を移動させ、移動経路上の複数の測定点において測定を行う。測定間隔は、例えば、１〜５ｍｍであり、例えば２ｍｍである。測定は、予め外部測距部１９内に記憶されたタイミングで行うか、又は外部トリガに従って行う。測定結果は、外部測距分１９内の記憶部に格納されて、測定終了後にまとめて本体部７ｃに送られるか、又は測定の度に、逐次本体部７ｃに送られるようにする。外部測距部１９は、本体部７ｃとは別に設けられた制御部によって制御するように構成してもよい。 <2-2. External robot arm, external distance measuring unit>
An external robot arm 7 is installed on a base 3 provided outside the crucible 11. The external robot arm 7 includes a plurality of arms 7a, a plurality of joints 7b that rotatably support these arms, and a main body portion 7c. The main body 7c is provided with an external terminal (not shown) so that data exchange with the outside is possible. An external distance measuring unit 19 that measures the outer surface shape of the crucible 11 is provided at the tip of the external robot arm 7. The external distance measuring unit 19 measures the distance from the external distance measuring unit 19 to the outer surface of the crucible 11 by irradiating the outer surface of the crucible 11 with laser light and detecting the reflected light from the outer surface. A control unit that controls the joint 7b and the external distance measuring unit 19 is provided in the main body 7c. The control unit moves the external distance measuring unit 19 to an arbitrary three-dimensional position by rotating the joint 7b and moving the arm 7 based on a program provided in the main body unit 7c or an external input signal. Specifically, the external distance measuring unit 19 is moved in a non-contact manner along the outer surface of the crucible. Therefore, rough shape data of the outer surface of the crucible is given to the control unit, and the position of the external distance measuring unit 19 is moved according to the data. More specifically, for example, the measurement is started from a position near the opening of the crucible 11 as shown in FIG. 1A, and toward the bottom 11c of the crucible 11 as shown in FIG. The external distance measuring unit 19 is moved to perform measurement at a plurality of measurement points on the movement path. The measurement interval is, for example, 1 to 5 mm, for example, 2 mm. The measurement is performed at a timing stored in advance in the external distance measuring unit 19 or according to an external trigger. The measurement results are stored in the storage unit in the external distance measuring unit 19 and are collectively sent to the main unit 7c after the measurement is completed, or are sequentially sent to the main unit 7c every measurement. The external distance measuring unit 19 may be configured to be controlled by a control unit provided separately from the main body unit 7c.

内部測距部１７と外部測距部１９は、同期させて移動させてもよいが、内表面形状の測定と外表面形状の測定は独立して行われるので、必ずしも同期させる必要はない。   The internal distance measuring unit 17 and the external distance measuring unit 19 may be moved in synchronization. However, since the measurement of the inner surface shape and the measurement of the outer surface shape are performed independently, it is not always necessary to synchronize.

外部測距部１９は、外部測距部１９から外表面までの距離（外表面距離）を測定することができる。ジョイント７ｂの角度はジョイント７ｂに設けられたロータリーエンコーダ等によって既知であるので、外部測距部１９の位置の三次元座標及び方向が既知になるので、外表面距離が求まれば、外表面での三次元座標が既知となる。そして、ルツボ１１の開口部から底部１１ｃまでの測定が、ルツボ１１の全周に渡って行われるので、ルツボ１１の外表面の三次元形状が既知になる。
以上より、ルツボの内表面及び外表面の三次元形状が既知になるので、ルツボの壁厚の三次元分布が求められる。 The external distance measuring unit 19 can measure the distance (outer surface distance) from the external distance measuring unit 19 to the outer surface. Since the angle of the joint 7b is known by a rotary encoder or the like provided in the joint 7b, the three-dimensional coordinates and direction of the position of the external distance measuring unit 19 are known. The three-dimensional coordinates are known. And since the measurement from the opening part of the crucible 11 to the bottom part 11c is performed over the perimeter of the crucible 11, the three-dimensional shape of the outer surface of the crucible 11 becomes known.
From the above, since the three-dimensional shape of the inner surface and the outer surface of the crucible becomes known, a three-dimensional distribution of the wall thickness of the crucible is obtained.

＜２−３．距離測定の詳細＞
次に、図２を用いて、内部測距部１７及び外部測距部１９による距離測定の詳細を説明する。
図２に示すように、内部測距部１７は、ルツボ１１の内表面側（透明層１３側）に配置され、外部測距部１９は、ルツボ１１の外表面側（気泡含有層１５側）に配置される。内部測距部１７は、出射部１７ａ及び検出部１７ｂを備える。外部測距部１９は、出射部１９ａ及び検出部１９ｂを備える。また、内部測距部１７及び外部測距部１９は、図示しない制御部及び外部端子を備える。出射部１７ａ及び１９ａは、レーザー光を出射するものであり、例えば、半導体レーザーを備えるものである。出射されるレーザー光の波長は、特に限定されないが、例えば、波長６００〜７００ｎｍの赤色レーザー光である。検出部１７ｂ及び１９ｂは、例えばＣＣＤで構成され、光が当たった位置に基づいて三角測量法の原理に基づいてターゲットまでの距離が決定される。 <2-3. Details of distance measurement>
Next, details of distance measurement by the internal distance measuring unit 17 and the external distance measuring unit 19 will be described with reference to FIG.
As shown in FIG. 2, the internal distance measuring unit 17 is arranged on the inner surface side (transparent layer 13 side) of the crucible 11, and the external distance measuring unit 19 is arranged on the outer surface side (bubble-containing layer 15 side) of the crucible 11. Placed in. The internal distance measuring unit 17 includes an emitting unit 17a and a detecting unit 17b. The external distance measuring unit 19 includes an emitting unit 19a and a detecting unit 19b. The internal distance measuring unit 17 and the external distance measuring unit 19 include a control unit and an external terminal (not shown). The emitting portions 17a and 19a emit laser light, and include, for example, a semiconductor laser. The wavelength of the emitted laser light is not particularly limited, but is, for example, red laser light having a wavelength of 600 to 700 nm. The detectors 17b and 19b are composed of, for example, a CCD, and the distance to the target is determined based on the principle of triangulation based on the position where the light hits.

内部測距部１７の出射部１７ａから出射されたレーザー光は、一部が内表面（透明層１３の表面）で反射し、一部が透明層１３と気泡含有層１５の界面で反射し、これらの反射光（内表面反射光、界面反射光）が検出部１７ｂに当たって検出される。図２から明らかなように、内表面反射光と界面反射光は、検出部１７ｂの異なる位置に当たっており、この位置の違いによって、内部測距部１７から内表面までの距離（内表面距離）及び界面までの距離（界面距離）がそれぞれ決定される。好適な入射角θは、内表面の状態、透明層１３の厚さ、気泡含有層１５の状態等によって、変化しうるが例えば３０〜６０度である。   A part of the laser light emitted from the emitting part 17a of the internal distance measuring part 17 is reflected by the inner surface (the surface of the transparent layer 13), and partly reflected by the interface between the transparent layer 13 and the bubble-containing layer 15, These reflected lights (inner surface reflected light and interface reflected light) strike the detection unit 17b and are detected. As is clear from FIG. 2, the inner surface reflected light and the interface reflected light hit different positions of the detection unit 17b, and due to this position difference, the distance from the inner distance measuring unit 17 to the inner surface (inner surface distance) and The distance to the interface (interface distance) is determined. A suitable incident angle θ may vary depending on the state of the inner surface, the thickness of the transparent layer 13, the state of the bubble-containing layer 15, etc., but is, for example, 30 to 60 degrees.

図３は、市販のレーザー変位計を用いて測定された実際の測定結果を示す。図３に示すように、２つのピークが観察されており、内表面側のピークが内表面反射光によるピークであり、外表面側のピークが界面反射光によるピークに対応する。このように、透明層１３と気泡含有層１５の界面からの反射光によるピークもクリアに検出されている。従来は、このような方法で界面の特定がなされたことがなく、この結果は非常に斬新である。   FIG. 3 shows the actual measurement results measured using a commercially available laser displacement meter. As shown in FIG. 3, two peaks are observed, the peak on the inner surface side corresponds to the peak due to the inner surface reflected light, and the peak on the outer surface side corresponds to the peak due to the interface reflected light. Thus, the peak due to the reflected light from the interface between the transparent layer 13 and the bubble-containing layer 15 is also clearly detected. Conventionally, the interface has not been specified in this way, and this result is very novel.

内部測距部１７から内表面までの距離が遠すぎる場合や、内表面又は界面が局所的に傾いている場合には、２つのピークが観測されない場合がある。その場合には、内部測距部１７を内表面に近づけたり、内部測距部１７の傾けてレーザー光の出射方向を変化させて、２つのピークが観測される位置及び角度を探索することが好ましい。また、２つのピークが同時に観測されなくても、ある位置及び角度において内表面反射光によるピークを観測し、別の位置及び角度において界面反射光によるピークを観測するようにしてもよい。また、内部測距部１７が内表面に接触することを避けるために、最大近接位置を設定しておいて、ピークが観測されない場合でも、その位置よりも内表面に近づけないようにすることが好ましい。
また、透明層１３中に独立した気泡が存在する場合、この気泡からの反射光を内部測距部１７が検出してしまい、透明層１３と気泡含有層１５の界面を適切に検出できない場合がある。従って、ある測定点Ａで測定された界面の位置が前後の測定点で測定された界面の位置から大きく（所定の基準値を超えて）ずれている場合には、測定点Ａでのデータを除外してもよい。また、その場合、測定点Ａからわずかにずれた位置で再度測定を行って、得られたデータを採用してもよい。 If the distance from the internal distance measuring unit 17 to the inner surface is too far, or if the inner surface or interface is locally inclined, two peaks may not be observed. In this case, the position and angle at which two peaks are observed can be searched by moving the internal distance measuring unit 17 closer to the inner surface or by tilting the internal distance measuring unit 17 to change the laser beam emission direction. preferable. Further, even if the two peaks are not observed simultaneously, the peak due to the inner surface reflected light may be observed at a certain position and angle, and the peak due to the interface reflected light may be observed at another position and angle. In order to prevent the internal distance measuring unit 17 from coming into contact with the inner surface, a maximum proximity position is set so that even if no peak is observed, the inner distance measuring unit 17 cannot be closer to the inner surface than that position. preferable.
In addition, when there are independent bubbles in the transparent layer 13, the internal distance measuring unit 17 may detect the reflected light from the bubbles, and the interface between the transparent layer 13 and the bubble-containing layer 15 may not be detected properly. is there. Therefore, when the position of the interface measured at a certain measurement point A is greatly deviated (exceeding a predetermined reference value) from the position of the interface measured at the preceding and following measurement points, the data at the measurement point A is It may be excluded. In that case, data obtained by performing measurement again at a position slightly deviated from the measurement point A may be employed.

また、外部測距部１９の出射部１９ａから出射されたレーザー光は、外表面（気泡含有層１５）の表面で反射し、その反射光（外表面反射光）が検出部１９ｂに当たって検出され、検出部１９ｂ上での検出位置に基づいて外部測距部１９と外表面の間の距離が決定される。図４は、市販のレーザー変位計を用いて測定された実際の測定結果を示す。図４に示すように、１つのピークのみが観察される。ピークが観測されない場合には、外部測距部１９を内表面に近づけたり、外部測距部１９の傾けてレーザー光の出射方向を変化させて、ピークが観測される位置及び角度を探索することが好ましい。   The laser light emitted from the emitting portion 19a of the external distance measuring section 19 is reflected by the surface of the outer surface (bubble-containing layer 15), and the reflected light (outer surface reflected light) strikes the detecting portion 19b and is detected. The distance between the external distance measuring unit 19 and the outer surface is determined based on the detection position on the detection unit 19b. FIG. 4 shows the actual measurement results measured using a commercially available laser displacement meter. As shown in FIG. 4, only one peak is observed. When the peak is not observed, the external distance measuring unit 19 is brought closer to the inner surface, or the external distance measuring unit 19 is tilted to change the emission direction of the laser light to search for the position and angle at which the peak is observed. Is preferred.

＜３．ルツボの気泡分布の三次元分布の決定方法＞
ルツボの内表面の三次元形状が求まった後は、この三次元形状上の複数の測定点において、各測定点に対応した位置のルツボの壁での気泡分布を測定することによって、前記気泡分布の三次元分布を決定する。 <3. Method for determining three-dimensional distribution of bubble distribution in crucible>
After the three-dimensional shape of the inner surface of the crucible is obtained, the bubble distribution is measured by measuring the bubble distribution at the crucible wall at the position corresponding to each measurement point at a plurality of measurement points on the three-dimensional shape. Determine the three-dimensional distribution of.

各測定点でのルツボの壁での気泡分布の測定方法は、非接触式であれば特に限定されないが、焦点が合った面からの情報を選択的に取得することができる共焦点顕微鏡を用いれば、図５に示すような気泡の位置が明確に分かるクリアな画像が取得できるので、高精度な測定が可能である。また、焦点位置をずらしながら各焦点位置の面において図５のような画像を取得して合成することによって気泡の三次元配置が分かり、各気泡のサイズが分かるので、気泡分布を求めることができる。焦点位置を移動させる方法としては、（１）ルツボを移動させたり、（２）プローブを移動させたり、（３）プローブの対物レンズを移動させたりする方法がある。   The method of measuring the bubble distribution at the crucible wall at each measurement point is not particularly limited as long as it is a non-contact type, but a confocal microscope that can selectively acquire information from the focused surface is used. For example, a clear image that clearly shows the position of the bubble as shown in FIG. 5 can be acquired, so that highly accurate measurement is possible. Further, by acquiring and synthesizing an image as shown in FIG. 5 on the plane of each focal position while shifting the focal position, the three-dimensional arrangement of the bubbles is known and the size of each bubble is known, so that the bubble distribution can be obtained. . Methods for moving the focal position include (1) moving the crucible, (2) moving the probe, and (3) moving the objective lens of the probe.

測定点の配置は、特に限定されないが、例えば、ルツボの開口部から底部に向かう方向には５〜２０ｍｍ間隔で配置し、円周方向には例えば１０〜６０度間隔である。   The arrangement of the measurement points is not particularly limited. For example, the measurement points are arranged at intervals of 5 to 20 mm in the direction from the opening to the bottom of the crucible, and at intervals of 10 to 60 degrees in the circumferential direction, for example.

具体的な測定は、例えば、共焦点顕微鏡用プローブを内部ロボットアーム５の先端に取り付け、内部測距部１７と同様の方法で、非接触で内表面に沿って移動させる。内部測距部１７を移動させる際には、内表面の大雑把な三次元形状が分かっているだけで内表面の正確な三次元形状は分かっていなかったので、その大雑把な三次元形状に基づいて内部測距部１７を移動させていたが、気泡分布の測定時には、内表面の正確な三次元形状が分かっているので、共焦点顕微鏡用プローブを移動させる際に、内表面とプローブとの距離を高精度に制御することが可能である。   Specifically, for example, a confocal microscope probe is attached to the tip of the internal robot arm 5 and moved along the inner surface in a non-contact manner in the same manner as the internal distance measuring unit 17. When the internal distance measuring unit 17 is moved, only the rough three-dimensional shape of the inner surface is known, but the exact three-dimensional shape of the inner surface is not known. Therefore, based on the rough three-dimensional shape. Although the internal distance measuring unit 17 has been moved, since the accurate three-dimensional shape of the inner surface is known when measuring the bubble distribution, the distance between the inner surface and the probe when moving the confocal microscope probe is measured. Can be controlled with high accuracy.

共焦点顕微鏡用プローブをルツボの開口部から底部まで移動させ、その移動経路上の複数点で気泡分布を測定した後は、回転台９を回転させて、ルツボ１１の別の部位の気泡分布の測定を行う。
このような方法でルツボの内表面全体に渡って気泡分布を測定することができ、その測定結果により、ルツボの気泡分布の三次元分布を決定することができる。 After the confocal microscope probe is moved from the opening to the bottom of the crucible and the bubble distribution is measured at a plurality of points on the moving path, the turntable 9 is rotated to change the bubble distribution in another part of the crucible 11. Measure.
With such a method, the bubble distribution can be measured over the entire inner surface of the crucible, and the three-dimensional distribution of the crucible bubble distribution can be determined based on the measurement result.

Claims (6)

内表面側に透明シリカガラス層と、外表面側に気泡含有シリカガラス層を有するシリカガラスルツボの内表面に沿って非接触で内部測距部を移動させ、
移動経路上の複数の測定点において、内部測距部から前記シリカガラスルツボの内表面に対して斜め方向にレーザー光を照射し、前記内表面からの内表面反射光を検出することによって、内部測距部と前記内表面の間の内表面距離を測定し、
各測定点の三次元座標と、前記内表面距離を関連付けることによって、前記シリカガラスルツボの内表面の三次元形状を求め、
この三次元形状上の複数の測定点において、各測定点に対応した位置のルツボの壁での気泡分布を測定することによって、前記気泡分布の三次元分布を決定する工程を備えるシリカガラスルツボの気泡分布の三次元分布の決定方法。 Move the internal distance measuring unit in a non-contact manner along the inner surface of the silica glass crucible having the transparent silica glass layer on the inner surface side and the bubble-containing silica glass layer on the outer surface side,
By irradiating laser light obliquely to the inner surface of the silica glass crucible from the internal distance measuring unit at a plurality of measurement points on the moving path, and detecting the inner surface reflected light from the inner surface, Measure the inner surface distance between the distance measuring unit and the inner surface,
By associating the three-dimensional coordinates of each measurement point with the inner surface distance, the three-dimensional shape of the inner surface of the silica glass crucible is obtained,
A silica glass crucible comprising a step of determining the three-dimensional distribution of the bubble distribution by measuring the bubble distribution at the crucible wall at a position corresponding to each measurement point at a plurality of measurement points on the three-dimensional shape. A method for determining the three-dimensional distribution of bubble distribution. 前記気泡含有率は、共焦点顕微鏡を用いて測定される、請求項１に記載の方法。 The method of claim 1, wherein the bubble content is measured using a confocal microscope. 前記内部測距部からのレーザー光は、前記内表面に対して３０〜６０度の入射角で照射される、請求項１又は２に記載の方法。 The method according to claim 1 or 2, wherein the laser beam from the internal distance measuring unit is irradiated at an incident angle of 30 to 60 degrees with respect to the inner surface. 前記内部測距部は、前記内部測距部を三次元的に移動させることができるように構成された内部ロボットアームに固定され、
前記シリカガラスルツボは、前記内部ロボットアームを覆うように配置される、請求項１〜３の何れか１つに記載の方法。 The internal distance measuring unit is fixed to an internal robot arm configured to be able to move the internal distance measuring unit three-dimensionally,
The method according to claim 1, wherein the silica glass crucible is arranged so as to cover the internal robot arm. 前記外部測距部は、前記外部測距部を三次元的に移動させることができるように構成された外部ロボットアームに固定される、請求項１〜４の何れか１つに記載の方法。 The method according to claim 1, wherein the external distance measuring unit is fixed to an external robot arm configured to be able to move the external distance measuring unit three-dimensionally. 前記シリカガラスルツボ内に保持されたシリコン融液からシリコン単結晶を引き上げる工程を備え、
前記シリコン単結晶の引き上げ条件が、前記シリカガラスルツボの気泡分布の三次元分布に基づいて決定され、
前記気泡分布の三次元分布は、請求項１〜５の何れか１つに記載の方法によって決定される、シリコン単結晶の製造方法。 A step of pulling up the silicon single crystal from the silicon melt held in the silica glass crucible,
The pulling condition of the silicon single crystal is determined based on the three-dimensional distribution of the bubble distribution of the silica glass crucible,
The method for producing a silicon single crystal, wherein the three-dimensional distribution of the bubble distribution is determined by the method according to claim 1.
JP2011282409A 2011-12-22 2011-12-22 Method for determining three-dimensional distribution of bubble distribution in silica glass crucible, method for producing silicon single crystal Active JP5818675B2 (en)

Priority Applications (7)

Application Number Priority Date Filing Date Title
JP2011282409A JP5818675B2 (en) 2011-12-22 2011-12-22 Method for determining three-dimensional distribution of bubble distribution in silica glass crucible, method for producing silicon single crystal
EP12859405.8A EP2796595B1 (en) 2011-12-22 2012-10-31 Method for evaluating silica glass crucible, method for producing silicon single crystals
CN201280063279.7A CN104145051B (en) 2011-12-22 2012-10-31 The evaluation method of silica glass crucible, the manufacturing method of monocrystalline silicon
PCT/JP2012/078260 WO2013094318A1 (en) 2011-12-22 2012-10-31 Method for evaluating silica glass crucible, method for producing silicon single crystals
US14/365,523 US9809902B2 (en) 2011-12-22 2012-10-31 Method for evaluating silica glass crucible, method for producing silicon single crystals
KR1020147020091A KR101638584B1 (en) 2011-12-22 2012-10-31 Method for evaluating silica glass crucible, method for producing silicon single crystals
TW101140627A TWI480505B (en) 2011-12-22 2012-11-01 Evaluation method of silica glass crucible and manufacture method of silicon single crystal

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2011282409A JP5818675B2 (en) 2011-12-22 2011-12-22 Method for determining three-dimensional distribution of bubble distribution in silica glass crucible, method for producing silicon single crystal

Related Child Applications (1)

Application Number Title Priority Date Filing Date
JP2015191007A Division JP6114795B2 (en) 2015-09-29 2015-09-29 Method for determining three-dimensional distribution of bubble distribution in silica glass crucible, method for producing silicon single crystal

Publications (2)

Publication Number Publication Date
JP2013134057A true JP2013134057A (en) 2013-07-08
JP5818675B2 JP5818675B2 (en) 2015-11-18

Family

ID=48910863

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2011282409A Active JP5818675B2 (en) 2011-12-22 2011-12-22 Method for determining three-dimensional distribution of bubble distribution in silica glass crucible, method for producing silicon single crystal

Country Status (1)

Country Link
JP (1) JP5818675B2 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2013139354A (en) * 2011-12-29 2013-07-18 Sumco Corp Mehtod for determining silica powder suitable for producing silica glass crucible for pulling up silicon single crystal
KR101856091B1 (en) 2013-12-28 2018-05-09 가부시키가이샤 섬코 Quartz glass crucible and strain measurement device therefor

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0386249A (en) * 1989-08-30 1991-04-11 Mitsubishi Materials Corp Method and device for optical non-destructive inspection of quartz crucible
JPH0392712A (en) * 1989-09-05 1991-04-17 Fanuc Ltd Three-dimensional position recognition by use of image processing device and distance measuring sensor
JPH08208376A (en) * 1995-02-06 1996-08-13 Mitsubishi Materials Corp Method for measuring crucible
JPH11171571A (en) * 1997-12-05 1999-06-29 Toshiba Ceramics Co Ltd Quartz glass crucible and production thereof
JPH11228283A (en) * 1998-02-16 1999-08-24 Mitsubishi Materials Corp Optical nondestructive inspection of quartz crucible and apparatus therefor
JP2003106995A (en) * 2001-09-28 2003-04-09 Takai Seisakusho:Kk Quality determining method for gel forming food
JP2006096618A (en) * 2004-09-29 2006-04-13 Toshiba Ceramics Co Ltd Apparatus for removing object to be removed in quartz glass crucible
JP2009002823A (en) * 2007-06-22 2009-01-08 Bridgestone Corp Three-dimensional shape measuring system and three-dimensional shape measuring method
JP2010030884A (en) * 2008-06-30 2010-02-12 Japan Siper Quarts Corp Quartz glass crucible and method for pulling silicon single crystal with quartz glass crucible

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0386249A (en) * 1989-08-30 1991-04-11 Mitsubishi Materials Corp Method and device for optical non-destructive inspection of quartz crucible
JPH0392712A (en) * 1989-09-05 1991-04-17 Fanuc Ltd Three-dimensional position recognition by use of image processing device and distance measuring sensor
JPH08208376A (en) * 1995-02-06 1996-08-13 Mitsubishi Materials Corp Method for measuring crucible
JPH11171571A (en) * 1997-12-05 1999-06-29 Toshiba Ceramics Co Ltd Quartz glass crucible and production thereof
JPH11228283A (en) * 1998-02-16 1999-08-24 Mitsubishi Materials Corp Optical nondestructive inspection of quartz crucible and apparatus therefor
JP2003106995A (en) * 2001-09-28 2003-04-09 Takai Seisakusho:Kk Quality determining method for gel forming food
JP2006096618A (en) * 2004-09-29 2006-04-13 Toshiba Ceramics Co Ltd Apparatus for removing object to be removed in quartz glass crucible
JP2009002823A (en) * 2007-06-22 2009-01-08 Bridgestone Corp Three-dimensional shape measuring system and three-dimensional shape measuring method
JP2010030884A (en) * 2008-06-30 2010-02-12 Japan Siper Quarts Corp Quartz glass crucible and method for pulling silicon single crystal with quartz glass crucible

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2013139354A (en) * 2011-12-29 2013-07-18 Sumco Corp Mehtod for determining silica powder suitable for producing silica glass crucible for pulling up silicon single crystal
KR101856091B1 (en) 2013-12-28 2018-05-09 가부시키가이샤 섬코 Quartz glass crucible and strain measurement device therefor

Also Published As

Publication number Publication date
JP5818675B2 (en) 2015-11-18

Similar Documents

Publication Publication Date Title
JP6123001B2 (en) Method for evaluating silica glass crucible, method for producing silicon single crystal
JP5749151B2 (en) Method for measuring the three-dimensional shape of the Raman spectrum of silica glass crucibles
JP5773866B2 (en) Apparatus for supporting setting of manufacturing conditions of silica glass crucible, simulation data generating apparatus, and improved mold design data generating apparatus
JP5818675B2 (en) Method for determining three-dimensional distribution of bubble distribution in silica glass crucible, method for producing silicon single crystal
JP6114795B2 (en) Method for determining three-dimensional distribution of bubble distribution in silica glass crucible, method for producing silicon single crystal
JP5773865B2 (en) Apparatus for supporting setting of manufacturing conditions for silica glass crucible, simulation data generating apparatus, and improved manufacturing condition data generating apparatus
JP6123000B2 (en) Method for evaluating silica glass crucible, method for producing silicon single crystal
JP5749149B2 (en) Method for measuring three-dimensional shape of silica glass crucible
JP5946561B2 (en) Method for determining three-dimensional distribution of surface roughness of silica glass crucible, method for producing silicon single crystal
JP5946560B2 (en) Method for determining three-dimensional distribution of Raman spectrum of silica glass crucible, method for producing silicon single crystal
JP6162848B2 (en) Method for producing silicon single crystal
JP2017138322A (en) Method for determining three-dimensional arrangement of air bubble of silica grass crucible and method for evaluating silica glass crucible
JP6162847B2 (en) Method for determining three-dimensional distribution of infrared absorption spectrum of silica glass crucible and method for producing silicon single crystal
JP5749152B2 (en) Method for measuring three-dimensional shape of surface roughness of silica glass crucible
JP5923644B2 (en) Method for determining three-dimensional distribution of infrared absorption spectrum of silica glass crucible, method for producing silicon single crystal
JP6162870B2 (en) Method for producing silica glass crucible
JP5749150B2 (en) Method for determining three-dimensional distribution of infrared absorption spectrum of silica glass crucible, method for producing silicon single crystal
JP5996718B2 (en) Method for measuring three-dimensional shape of silica glass crucible, method for producing silicon single crystal
JP5709737B2 (en) Method for producing silicon single crystal
JP2017215325A (en) Measuring method of silica glass crucible
JP6301531B2 (en) Method for producing silica glass crucible
JP6142052B2 (en) Method for producing silica glass crucible
JP5968505B2 (en) Equipment that supports setting of manufacturing conditions for silica glass crucible
JP5925348B2 (en) Method for producing silicon single crystal
JP5968506B2 (en) Apparatus for supporting setting of manufacturing conditions of mold for manufacturing silica glass crucible

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20131213

A711 Notification of change in applicant

Free format text: JAPANESE INTERMEDIATE CODE: A712

Effective date: 20131213

RD04 Notification of resignation of power of attorney

Free format text: JAPANESE INTERMEDIATE CODE: A7424

Effective date: 20141027

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20141104

RD02 Notification of acceptance of power of attorney

Free format text: JAPANESE INTERMEDIATE CODE: A7422

Effective date: 20141121

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20150105

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20150414

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20150423

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20150911

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20150929

R150 Certificate of patent or registration of utility model

Ref document number: 5818675

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R150

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250