JP6659408B2 - Method for producing silica glass crucible for pulling silicon single crystal - Google Patents

Method for producing silica glass crucible for pulling silicon single crystal Download PDF

Info

Publication number
JP6659408B2
JP6659408B2 JP2016043396A JP2016043396A JP6659408B2 JP 6659408 B2 JP6659408 B2 JP 6659408B2 JP 2016043396 A JP2016043396 A JP 2016043396A JP 2016043396 A JP2016043396 A JP 2016043396A JP 6659408 B2 JP6659408 B2 JP 6659408B2
Authority
JP
Japan
Prior art keywords
crucible
oxygen
silica glass
silica
glass crucible
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.)
Active
Application number
JP2016043396A
Other languages
Japanese (ja)
Other versions
JP2017160063A (en
Inventor
綾平 斎藤
綾平 斎藤
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.)
Coorstek KK
Original Assignee
Coorstek KK
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
Application filed by Coorstek KK filed Critical Coorstek KK
Priority to JP2016043396A priority Critical patent/JP6659408B2/en
Publication of JP2017160063A publication Critical patent/JP2017160063A/en
Application granted granted Critical
Publication of JP6659408B2 publication Critical patent/JP6659408B2/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • YGENERAL 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
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02PCLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P40/00Technologies relating to the processing of minerals
    • Y02P40/50Glass production, e.g. reusing waste heat during processing or shaping
    • Y02P40/57Improving the yield, e-g- reduction of reject rates

Landscapes

  • Crucibles And Fluidized-Bed Furnaces (AREA)
  • Glass Melting And Manufacturing (AREA)
  • Crystals, And After-Treatments Of Crystals (AREA)

Description

本発明は、シリコン単結晶引上げ用シリカガラスルツボの製造方法に関し、より詳しくは、シリコン単結晶を引上げる際に発生するルツボ内層の気泡発生および膨張を抑制した、シリコン単結晶引上げ用シリカガラスルツボの製造方法に関する。   The present invention relates to a method for producing a silica glass crucible for pulling a silicon single crystal, and more particularly, to suppressing a bubble generation and expansion of a crucible inner layer generated when pulling a silicon single crystal, and a silica glass crucible for pulling a silicon single crystal. And a method for producing the same.

シリコン単結晶の製造においては、チョクラルスキー法(CZ法)が広く用いられている。この方法は、ルツボ内に収容された原料シリコン融液の表面に種結晶を接触させ、ルツボを回転させるとともに、前記種結晶を反対方向に回転させながら上方へ引上げることにより、種結晶の下端に単結晶インゴットを育成していくものである。   In the production of silicon single crystals, the Czochralski method (CZ method) is widely used. In this method, the seed crystal is brought into contact with the surface of the raw material silicon melt accommodated in the crucible, and the crucible is rotated, and the seed crystal is pulled upward while rotating the seed crystal in the opposite direction. A single crystal ingot is to be grown.

上記方法において、原料シリコン融液を収容するためのルツボには、シリカガラスルツボが用いられる。このシリカガラスルツボは、一般に2層構造であり、内層が透明層、外層が不透明層である。
前記内層の透明層は、引上げられるシリコン単結晶インゴットに対する不純物汚染の抑制のため、高純度の合成シリカ原料により形成され、また前記単結晶インゴットの結晶化率の向上等の観点から、ルツボ内表面は平滑に形成されている。
一方、前記外層の不透明層は、合成シリカガラスに比べて、純度は低いものの、耐熱性に優れた天然シリカ原料により形成され、多数の気泡を含有している。
In the above method, a silica glass crucible is used as a crucible for containing the raw material silicon melt. This silica glass crucible generally has a two-layer structure, in which the inner layer is a transparent layer and the outer layer is an opaque layer.
The transparent layer of the inner layer is formed of a high-purity synthetic silica raw material in order to suppress impurity contamination of the pulled silicon single crystal ingot, and from the viewpoint of improving the crystallization rate of the single crystal ingot, the crucible inner surface. Are formed smoothly.
On the other hand, the opaque layer of the outer layer is formed of a natural silica raw material having a low purity but excellent heat resistance as compared with synthetic silica glass, and contains many bubbles.

ところで、前記内層はシリコン単結晶引上げ開始前において実質的に無気泡の透明層であるが、シリコン単結晶引上げのために減圧、高温に曝されると気泡が生じるという問題があった。
更に言えば、前記気泡が膨張することによりルツボ内表面が剥離する、もしくは気泡内部のガスがガス泡となって原料シリコン融液内に放出されるという問題があった。また、前記剥離片やガス泡が原料シリコン融液の対流によりシリコン単結晶の成長界面に到達し、取り込まれるとシリコン単結晶の品質を低下させるという問題があった。
By the way, the inner layer is a substantially bubble-free transparent layer before the start of pulling the silicon single crystal, but there is a problem that bubbles are generated when the inner layer is exposed to reduced pressure and high temperature for pulling the silicon single crystal.
In addition, there is a problem that the inner surface of the crucible is peeled off due to the expansion of the bubble, or the gas inside the bubble is released as a gas bubble into the raw silicon melt. Further, there is a problem that the quality of the silicon single crystal is degraded when the peeled pieces and gas bubbles reach the growth interface of the silicon single crystal by convection of the raw silicon melt and are taken in.

上記問題を解決するため、例えば、特許文献1では、所定の水素圧下で加熱し、水素ドープシリカ粉により透明石英ガラス層を形成する、石英ガラスルツボの製造方法が開示されている。
また、特許文献2では、アーク放電によるルツボの加熱溶融の際に、ルツボ内表面に沿って水素を供給することにより、ルツボの酸素過剰欠陥を低減させる、シリカガラスルツボの製造方法が開示されている。
In order to solve the above problem, for example, Patent Document 1 discloses a method for manufacturing a quartz glass crucible in which heating is performed under a predetermined hydrogen pressure to form a transparent quartz glass layer using hydrogen-doped silica powder.
Further, Patent Document 2 discloses a method for producing a silica glass crucible in which hydrogen is supplied along the inner surface of the crucible during heating and melting of the crucible by arc discharge, thereby reducing oxygen excess defects in the crucible. I have.

特開2007−326780号公報JP 2007-326780 A 特開2014−065622号公報JP 2014-065622A

前記したように、特許文献1,2に示されたルツボの製造方法にあっては、アーク溶融によるルツボ成形体の加熱溶融を水素雰囲気で行うことにより、内層の気泡を抑制している。即ち、前記加熱溶融が水素雰囲気中でなされることにより、シリカガラス構造体内への酸素の取り込みが抑制される。その結果、酸素過剰欠陥が抑制され、気泡の発生が抑制される。   As described above, in the crucible manufacturing methods disclosed in Patent Literatures 1 and 2, the crucible formed body is heated and melted by arc melting in a hydrogen atmosphere to suppress bubbles in the inner layer. That is, by performing the heating and melting in a hydrogen atmosphere, the incorporation of oxygen into the silica glass structure is suppressed. As a result, oxygen excess defects are suppressed, and generation of bubbles is suppressed.

しかしながら、ルツボの内層表面から内部に行くにしたがって、水素雰囲気による、酸素過剰欠陥を低減する効果が薄れ、シリカガラス構造体内の酸素過剰欠陥が残存し、気泡の発生を抑制できないという技術的課題があった。
更に言えば、特許文献1,2に示されたルツボの製造方法であっても、シリカガラスルツボが減圧、高温に曝されるとルツボの内層表面から略2mmを越える深部に気泡が発生、膨張することがあり、前記気泡の膨張によりルツボ内表面が剥離する、もしくは気泡内部のガスがガス泡となって原料シリコン融液内に放出されることがあった。
However, as the crucible goes from the inner layer surface to the inside, the effect of reducing the excess oxygen defects due to the hydrogen atmosphere diminishes, and the excess oxygen defects in the silica glass structure remain, which makes it difficult to suppress the generation of bubbles. there were.
In addition, even in the crucible manufacturing methods disclosed in Patent Documents 1 and 2, when the silica glass crucible is exposed to reduced pressure and high temperature, bubbles are generated and expanded at a depth of more than about 2 mm from the inner layer surface of the crucible. In some cases, the inner surface of the crucible peels off due to the expansion of the bubbles, or the gas inside the bubbles becomes gas bubbles and is released into the raw silicon melt.

この技術的課題を解決するために、より酸素濃度を低くした水素雰囲気で、アーク溶融によるルツボ成形体の加熱溶融を実行することが考えられる。
しかしながら、前記雰囲気内でアーク溶融した際、アーク溶融に用いられるカーボン電極のカーボン粒子が完全に燃焼しない場合があり、加熱溶融中に前記カーボン粒子がルツボ内周面に落下、付着し、この付着したカーボン粒子によってルツボ内表面に泡を発生させる虞がある。
In order to solve this technical problem, it is conceivable to perform heating and melting of a crucible formed by arc melting in a hydrogen atmosphere having a lower oxygen concentration.
However, when the arc is melted in the atmosphere, the carbon particles of the carbon electrode used for the arc melting may not completely burn, and the carbon particles fall and adhere to the inner peripheral surface of the crucible during the heating and melting. There is a possibility that bubbles may be generated on the inner surface of the crucible due to the carbon particles.

本発明者は、酸素濃度をより低くなすことにより、シリカガラス構造体内の酸素過剰欠陥を抑制し、一方において、酸素濃度をより低くなすことによって生じる前記カーボン粒子の落下の抑制という、二律背反の問題を鋭意研究した。
即ち、本発明者は、内層における酸素過剰欠陥を抑制しつつ、前記カーボン粒子の落下を抑制し、内層表面の気泡、内層中の気泡の発生、及び膨張を抑制することを鋭意研究し、アーク溶融中の雰囲気の酸素濃度が所定の範囲内にある場合に、内層表面の気泡、内層中の気泡の発生及び膨張を抑制することを知見し、本発明を想到するに至り、本発明を完成した。
The inventor of the present invention suppressed the excess oxygen defect in the silica glass structure by lowering the oxygen concentration, while suppressing the drop of the carbon particles caused by lowering the oxygen concentration. Studied diligently.
That is, the present inventor has studied diligently to suppress the carbon particles from falling while suppressing the oxygen excess defect in the inner layer, to suppress the bubbles on the inner layer surface, the generation of bubbles in the inner layer, and to suppress the expansion. When the oxygen concentration of the atmosphere during the melting is within a predetermined range, it has been found that bubbles on the inner layer surface, generation and expansion of bubbles in the inner layer are suppressed, and the present invention has been conceived, and the present invention has been completed. did.

本発明の目的は、上記したように、シリカガラスルツボの内層表面の気泡、内層中の気泡の発生及び膨張を抑制した、シリコン単結晶引上げ用シリカガラスルツボの製造方法を提供することにある。   An object of the present invention is to provide a method for producing a silica glass crucible for pulling a silicon single crystal, which suppresses generation and expansion of bubbles on the inner layer surface of the silica glass crucible and bubbles in the inner layer as described above.

上記技術的課題を解決するためになされた、本発明にかかるシリコン単結晶引上げ用シリカガラスルツボの製造方法は、石英原料粉末を成形型内に供給して直胴部、コーナー部および底部を有するシリカ粉成形体を形成し、このシリカ粉成形体をアーク放電により加熱溶融してルツボを製造する、シリコン単結晶引上げ用シリカガラスルツボの製造方法であって、アーク放電による加熱溶融中の雰囲気の酸素体積濃度が、30%以上、35%以下であることを特徴としている。 The method for producing a silica glass crucible for pulling a silicon single crystal according to the present invention, which has been made to solve the above technical problem, has a straight body portion, a corner portion, and a bottom portion by supplying a quartz raw material powder into a molding die. A method for manufacturing a silica glass crucible for pulling a silicon single crystal, which comprises forming a silica powder molded body, and melting and heating the silica powder molded body by arc discharge to produce a crucible. It is characterized in that the oxygen volume concentration is 30% or more and 35% or less .

このシリコン単結晶引上げ用シリカガラスルツボの製造方法によれば、アーク放電による加熱溶融中の雰囲気の酸素体積濃度が、30%以上、35%以下であるため、シリカガラスルツボの内層表面の気泡、内層中の気泡の発生及び膨張を抑制することができる。
ここで、アーク溶融中の雰囲気の酸素体積濃度が30%未満の場合は、炉内の酸素が少なく、カーボン電極のカーボン粒子が完全に燃焼し終えず、加熱溶融中にカーボン粒子が落下し、内層表面に表面泡が発生するため、好ましくない。
一方、アーク溶融中の雰囲気の酸素体積濃度が35%を超える場合は、酸素過剰供給による酸素過剰欠陥が発生し、内層に気泡が発生し、また前記気泡が膨張するため、好ましくない。
According to the method for producing a silica glass crucible for pulling a silicon single crystal, since the oxygen volume concentration in the atmosphere during heating and melting by arc discharge is 30% or more and 35% or less , bubbles on the inner layer surface of the silica glass crucible, Generation and expansion of bubbles in the inner layer can be suppressed.
Here, when the oxygen volume concentration of the atmosphere during the arc melting is less than 30% , the oxygen in the furnace is small, the carbon particles of the carbon electrode do not completely burn, and the carbon particles fall during the heating and melting, This is not preferable because surface bubbles are generated on the inner layer surface.
On the other hand, if the oxygen volume concentration in the atmosphere during arc melting exceeds 35%, excess oxygen defects due to excessive oxygen supply occur, bubbles are generated in the inner layer, and the bubbles expand, which is not preferable.

また、前記雰囲気は、アルゴン、水素、窒素のいずれかのキャリアガスと酸素とが混合したガスであることが望ましい。
このように、前記雰囲気を、アルゴン、水素、窒素のいずれかのキャリアガスと酸素とを混合したガスとし、前記酸素の分圧を調整することで、酸素体積濃度が所定濃度の雰囲気とすることができる。
Preferably, the atmosphere is a gas in which a carrier gas of any of argon, hydrogen and nitrogen and oxygen are mixed.
As described above, the atmosphere is a gas obtained by mixing oxygen and a carrier gas of any of argon, hydrogen, and nitrogen, and the partial pressure of the oxygen is adjusted so that the oxygen volume concentration is an atmosphere having a predetermined concentration. Can be.

本発明によれば、シリカガラスルツボの内層表面の気泡、内層中の気泡の発生及び膨張を抑制した、シリコン単結晶引上げ用シリカガラスルツボの製造方法を得ることができる。   ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the silica glass crucible for pulling a silicon single crystal which suppressed generation | occurrence | production of the bubble of the inner layer surface of a silica glass crucible, and the bubble in an inner layer, and expansion can be obtained.

図1は、本発明の製造方法に用いられる石英ガラスルツボの製造装置の概略断面図である。FIG. 1 is a schematic sectional view of an apparatus for manufacturing a quartz glass crucible used in the manufacturing method of the present invention. 図2は、実施例、比較例の測定点示すルツボの概略図である。FIG. 2 is a schematic diagram of a crucible showing measurement points of an example and a comparative example. 図3は、実施例及び比較例の酸素濃度に対する肉中気泡密度(pcs/mm3)を示したグラフである。FIG. 3 is a graph showing the air bubble density (pcs / mm 3 ) in the meat with respect to the oxygen concentration in Examples and Comparative Examples. 図4は、実施例及び参考例の酸素濃度に対するルツボ内層表面の表面泡(個/10cm2)を示したグラフである。FIG. 4 is a graph showing surface foam (cells / 10 cm 2 ) on the inner layer surface of the crucible with respect to oxygen concentration in Examples and Reference Examples.

本発明にかかるシリコン単結晶引上げ用シリカガラスルツボの製造方法にあっては、まず、石英原料粉末を成形型内に供給して直胴部、コーナー部および底部を有するシリカ粉成形体を形成する。そして、雰囲気の酸素体積濃度を、30%以上、35%以下とし、前記雰囲気中で、シリカ粉成形体をアーク放電により加熱溶融して、ルツボを製造するものである。 In the method for producing a silica glass crucible for pulling a silicon single crystal according to the present invention, first, a silica raw material powder is supplied into a molding die to form a silica powder molded body having a straight body, a corner and a bottom. . Then, the oxygen volume concentration of the atmosphere is set to 30% or more and 35% or less, and the silica powder molded body is heated and melted by arc discharge in the atmosphere to produce a crucible.

このシリコン単結晶引上げ用シリカガラスルツボの製造方法は、図1に示すような回転モールド法を採用した石英ガラスルツボ製造装置10を用いることによってなされる。
前記石英ガラスルツボ製造装置10のルツボ成形用型11は、例えば複数の貫通孔を穿設した金型、もしくは高純化処理した多孔質カーボン型などのガス透過性部材で構成されている内側部材12と、その外周に通気部13を設けて、内側部材12を保持する保持体14とから構成されている。
The method for manufacturing a silica glass crucible for pulling a silicon single crystal is performed by using a quartz glass crucible manufacturing apparatus 10 employing a rotary molding method as shown in FIG.
The crucible forming mold 11 of the quartz glass crucible manufacturing apparatus 10 includes an inner member 12 made of a gas permeable member such as a mold having a plurality of through holes or a highly purified porous carbon mold. And a holding body 14 provided with a ventilation portion 13 on the outer periphery thereof to hold the inner member 12.

また、保持体14の下部には、図示しない回転手段と連結されている回転軸15が固着されていて、ルツボ成形用型11を回転可能に支持している。通気部13は、保持体14の下部に設けられた開口部16を介して、回転軸15の中央に設けられた排気口17と連結されており、この通気部13は、減圧機構18と連結されている。
このように石英ガラスルツボ製造装置10は、前記減圧機構18を動作させることにより、内側部材12内部の雰囲気を内周面から吸引するように構成されている。
A rotating shaft 15 connected to rotating means (not shown) is fixed to a lower portion of the holding body 14 and rotatably supports the crucible-forming mold 11. The ventilation portion 13 is connected to an exhaust port 17 provided at the center of the rotating shaft 15 through an opening 16 provided at a lower portion of the holder 14, and the ventilation portion 13 is connected to a pressure reducing mechanism 18. Have been.
As described above, the quartz glass crucible manufacturing apparatus 10 is configured to operate the pressure reducing mechanism 18 to suck the atmosphere inside the inner member 12 from the inner peripheral surface.

シリカガラスルツボを製造するには、前記シリカガラスルツボ製造装置10を用いて、図1に示すようなシリカ粉成形体を形成する。
このシリカ粉成形体を製造するには、図示しない回転駆動源を稼働して回転軸15を矢印の方向に、ルツボ成形用型11を高速で回転させつつ、ルツボ成形用型11内の上部の原料粉供給ノズル21から天然シリカ原料粉末を装填し、さらにその内表面に合成シリカ原料粉末を装填する。
In order to manufacture a silica glass crucible, the silica glass crucible manufacturing apparatus 10 is used to form a silica powder molded body as shown in FIG.
In order to manufacture this silica powder molded body, a rotating drive source (not shown) is operated to rotate the rotating shaft 15 in the direction of the arrow and rotate the crucible molding die 11 at a high speed. A natural silica raw material powder is loaded from the raw material powder supply nozzle 21, and a synthetic silica raw material powder is further loaded on the inner surface thereof.

初めに供給された天然シリカ原料粉末は、遠心力によってルツボ成形用型11の内側部材12に押圧され、一つの天然シリカ原料粉末層1bが形成される。
そして、この天然シリカ原料粉末に続いて、合成シリカ原料粉末がルツボ成形用型11内に供給され、合成シリカ原料粉末は、遠心力によって天然シリカ原料粉末の層に押圧され一つの合成シリカ原料粉末層1aが形成され、全体としてルツボ形状の2層のシリカ粉成形体1が形成される。
The natural silica raw material powder supplied first is pressed against the inner member 12 of the crucible molding die 11 by centrifugal force to form one natural silica raw material powder layer 1b.
Then, following the natural silica raw material powder, the synthetic silica raw material powder is supplied into the crucible molding die 11, and the synthetic silica raw material powder is pressed against the layer of the natural silica raw material powder by centrifugal force. The layer 1a is formed, and a two-layer silica powder compact 1 having a crucible shape as a whole is formed.

その後、減圧機構18を作動させることにより、内側部材12に形成された貫通穴(図示せず)、通気部13、開口部16、排気口17を介して、減圧機構18を動作させることにより、内側部材3内部の雰囲気を内周面から吸引し、減圧する。
一方、ガス供給ノズル20から、アルゴン、水素、窒素のいずれかのキャリアガスと酸素とが混合したガス(酸素体積濃度が20%を超え40%未満)を供給し、炉内の雰囲気の酸素体積濃度を、20%を超え40%未満になす。
このとき、減圧機構18の作動により減圧するため、合成シリカ原料粉末層1aの内部、天然シリカ原料粉末層1bの内部は、大気から前記酸素体積濃度が20%を超えかつ40%未満の雰囲気に置換される。
Thereafter, by operating the pressure reducing mechanism 18, the pressure reducing mechanism 18 is operated through a through hole (not shown) formed in the inner member 12, the ventilation part 13, the opening 16, and the exhaust port 17, The atmosphere inside the inner member 3 is sucked from the inner peripheral surface and decompressed.
On the other hand, a gas (oxygen volume concentration is more than 20% and less than 40%) in which oxygen is mixed with a carrier gas of any of argon, hydrogen and nitrogen is supplied from the gas supply nozzle 20, and the oxygen volume of the atmosphere in the furnace is increased. The concentration is greater than 20% and less than 40%.
At this time, since the pressure is reduced by the operation of the pressure reducing mechanism 18, the inside of the synthetic silica raw material powder layer 1a and the inside of the natural silica raw material powder layer 1b are changed from the atmosphere to an atmosphere in which the oxygen volume concentration exceeds 20% and is less than 40%. Will be replaced.

続いて、ガス供給ノズル20から、アルゴン、水素、窒素のいずれかのキャリアガスと酸素とが混合したガス(酸素体積濃度が20%を超えかつ40%未満)を供給しながら、カーボン電極19に通電してシリカ粉成形体1の内側から加熱し、シリカ粉成形体1を内側から順次溶融する。   Subsequently, a gas (oxygen volume concentration exceeds 20% and less than 40%) in which oxygen is mixed with a carrier gas of any of argon, hydrogen and nitrogen is supplied from the gas supply nozzle 20 to the carbon electrode 19. Electric power is applied to heat the silica powder molded body 1 from the inside, and the silica powder molded body 1 is sequentially melted from the inside.

ここで、ガス供給ノズル20から、アルゴン、水素、窒素のいずれかのキャリアガスと酸素とが混合したガスを供給するのは、前記酸素の分圧を調整することで、酸素体積濃度が所定濃度の雰囲気とすることができるためである。   Here, a gas in which a carrier gas of any of argon, hydrogen, and nitrogen and oxygen are supplied from the gas supply nozzle 20 is supplied by adjusting the partial pressure of the oxygen so that the oxygen volume concentration becomes a predetermined concentration. This is because the atmosphere can be set to the above.

前記アーク溶融中の雰囲気の酸素体積濃度は、20%を超え40%未満になされる。酸素体積濃度が20%以下の場合は、炉内の酸素が少なく、カーボン電極のカーボン粒子が完全に燃焼し終えず、加熱溶融中にカーボン粒子が落下し、内層表面に表面泡が発生するため、好ましくない。尚、前記酸素体積濃度は、30%以上がより好ましい。
一方、前記酸素体積濃度が40%以上の場合は、酸素過剰供給による酸素過剰欠陥が発生し、内層に気泡が発生するため、好ましくない。尚、酸素体積濃度35%以下がより好ましい。
したがってアーク溶融中の雰囲気の酸素体積濃度が、30%以上、35%以下であることがより好ましい。
The oxygen volume concentration of the atmosphere during the arc melting is made more than 20% and less than 40%. When the oxygen volume concentration is 20% or less, the amount of oxygen in the furnace is small, the carbon particles of the carbon electrode do not completely burn, and the carbon particles drop during heating and melting, and surface bubbles are generated on the inner layer surface. Is not preferred. The oxygen volume concentration is more preferably 30% or more.
On the other hand, when the oxygen volume concentration is 40% or more, an excess oxygen defect due to excess oxygen supply occurs, and bubbles are generated in the inner layer, which is not preferable. The oxygen volume concentration is preferably 35% or less.
Therefore, the oxygen volume concentration in the atmosphere during the arc melting is more preferably 30% or more and 35% or less.

また、特許文献2に記載されているように、アーク放電によるルツボの加熱溶融の際に、ルツボ内表面に沿って水素を供給することにより、ルツボの酸素過剰欠陥を低減させる方法を併用しても良い。
即ち、ガス供給ノズル20から、アルゴン、水素、窒素のいずれかのキャリアガスと酸素とが混合したガス(酸素体積濃度が20%を超えかつ40%未満)を供給すると共に、他のノズル(図示せず)から水素ガスをルツボ内表面に沿って供給しながら、カーボン電極19に通電してシリカ粉成形体1の内側から加熱し、シリカ粉成形体1を内側から順次溶融しても良い。
Further, as described in Patent Document 2, when heating and melting a crucible by arc discharge, hydrogen is supplied along the inner surface of the crucible, thereby simultaneously using a method of reducing oxygen excess defects in the crucible. Is also good.
That is, a gas (oxygen volume concentration exceeds 20% and less than 40%) in which oxygen is mixed with a carrier gas of any of argon, hydrogen, and nitrogen is supplied from the gas supply nozzle 20, and another nozzle (FIG. While not supplying hydrogen gas along the inner surface of the crucible (not shown), the carbon electrode 19 may be energized and heated from the inside of the silica powder molded body 1 to melt the silica powder molded body 1 sequentially from the inside.

そして、前記アーク溶融終了後、冷却することにより、図2に示すような形状のシリカガラスルツボ2が製造される。
即ち、内面側には実質的に無気泡化状態で酸素過剰欠陥が抑制された透明シリカガラス層2aが形成され、外表側には多数の気泡が存在する不透明シリカガラス層2bが形成された、2重層構造のシリカガラスルツボ2が製造される。
After the completion of the arc melting, cooling is performed to produce a silica glass crucible 2 having a shape as shown in FIG.
That is, a transparent silica glass layer 2a in which oxygen excess defects were suppressed in a substantially bubble-free state was formed on the inner surface side, and an opaque silica glass layer 2b having a large number of bubbles was formed on the outer surface side. A silica glass crucible 2 having a double layer structure is manufactured.

以下、本発明を実施例に基づきさらに具体的に説明するが、本発明は下記の実施例により制限されるものではない。   Hereinafter, the present invention will be described more specifically with reference to Examples, but the present invention is not limited to the following Examples.

(実施例1,2、比較例1〜4)
前述の回転モールド法により、外径725mm、高さ500mmのシリカ粉成形体を成形した。外層には粒径300μmの天然シリカ粉末を用い、肉厚を30mmとなるように天然シリカ原料粉末層を形成した。
また内層には粒径300μmの高純度合成シリカを用い、肉厚を5mmとなるように合成シリカ原料粉末層を形成した。
(Examples 1 and 2, Comparative Examples 1 to 4)
A silica powder molded body having an outer diameter of 725 mm and a height of 500 mm was formed by the above-mentioned rotary molding method. As the outer layer, a natural silica powder having a particle diameter of 300 μm was used, and a natural silica raw material powder layer was formed so as to have a thickness of 30 mm.
A high purity synthetic silica having a particle diameter of 300 μm was used for the inner layer, and a synthetic silica raw material powder layer was formed so as to have a thickness of 5 mm.

その後、大気雰囲気において減圧機構の作動により、内側部材表面の圧力100kPaを、20kPaまで減圧した。
一方、キャリアガスとして窒素を用い、ガス供給ノズルから前記キャリアガスと酸素とが混合したガス(実施例1:酸素体積濃度35%)を3分間供給し、合成シリカ原料粉末層の内部、天然シリカ原料粉末層の内部を、大気から前記ガスに置換した。
Thereafter, the pressure of the inner member surface was reduced from 100 kPa to 20 kPa by operating a pressure reducing mechanism in an air atmosphere.
On the other hand, using nitrogen as a carrier gas, a mixed gas of the carrier gas and oxygen (Example 1: oxygen volume concentration of 35%) was supplied from a gas supply nozzle for 3 minutes, and the inside of the synthetic silica raw material powder layer and the natural silica The inside of the raw material powder layer was replaced with the above gas from the atmosphere.

そして、前記減圧下であって、かつ前記キャリアガスと酸素とを混合したガスを1000L/min供給しつつ、カーボン電極に通電してシリカ粉成形体の内側から2000℃で、20min加熱し、シリカ粉成形体を内側から順次溶融した。
その後、冷却することにより、図2に示すような形状のシリカガラスルツボを製造した。
Then, while supplying a gas obtained by mixing the carrier gas and oxygen at 1000 L / min under the reduced pressure, the carbon electrode is energized and heated from the inside of the silica powder molded body at 2000 ° C. for 20 minutes, and the silica is heated. The powder compacts were sequentially melted from the inside.
Thereafter, by cooling, a silica glass crucible having a shape as shown in FIG. 2 was manufactured.

そして、シリカガラスルツボの底部(図2に示す測定点A)、コーナー部(図2に示す測定点B)、側壁部(図2に示す測定点C)について、CCDカメラを用いて、肉中気泡密度を測定した。
肉中気泡密度の測定は、製造したシリカガラスルツボを、1600℃、0.1Torr、5hで熱処理を行い、ルツボ横断面を厚さ1mmに切断し、ルツボ内表面から2mmピッチで、CCDカメラを用いて測定した。尚、肉中気泡密度の単位は個/mmであり、pcs/mmで表記した。尚、肉中とは、無泡領域である内表面から約2mmの深さから、不透明層領域境界までを領域をいう。
その測定結果を表1、図3に示す。
また、内面からの目視による外観検査によって表面泡を測定した。その測定結果を表1、図4に示す。
Then, the bottom (measurement point A shown in FIG. 2), the corner (measurement point B shown in FIG. 2), and the side wall (measurement point C shown in FIG. 2) of the silica glass crucible are measured in the meat using a CCD camera. The bubble density was measured.
The measurement of the bubble density in the meat is performed by heat-treating the manufactured silica glass crucible at 1600 ° C. and 0.1 Torr for 5 hours, cutting the crucible cross section to a thickness of 1 mm, and setting the CCD camera at a pitch of 2 mm from the inner surface of the crucible. It measured using. The unit of the density of cells in the meat is unit / mm 3, which is represented by pcs / mm 3 . The inside of the meat refers to a region from a depth of about 2 mm from the inner surface which is a bubble-free region to a boundary of the opaque layer region.
The measurement results are shown in Table 1 and FIG.
Surface bubbles were measured by visual inspection from the inside. The measurement results are shown in Table 1 and FIG.

(実施例2)
実施例2は、前記ガスの酸素体積濃度を30%とした以外は、実施例1と同一条件で、シリカガラスルツボを製造した。そして、測定結果を表1、図3、図4に示す。
(Example 2)
In Example 2, a silica glass crucible was manufactured under the same conditions as in Example 1 except that the oxygen volume concentration of the gas was 30%. The measurement results are shown in Table 1, FIG. 3, and FIG.

(比較例1〜4)
比較例1〜4は、前記ガスの酸素体積濃度を50%(比較例1)、40%(比較例2)、20%(比較例3)、10%(比較例4)とした以外は、実施例1と同一条件で、シリカガラスルツボを製造した。そして、測定結果を表1、図3、図4に示す。
(Comparative Examples 1-4)
Comparative Examples 1 to 4 were the same except that the oxygen volume concentration of the gas was 50% (Comparative Example 1), 40% (Comparative Example 2), 20% (Comparative Example 3), and 10% (Comparative Example 4). Under the same conditions as in Example 1, a silica glass crucible was manufactured. The measurement results are shown in Table 1, FIG. 3, and FIG.

Figure 0006659408
Figure 0006659408

表1及び図4からわかるように、酸素体積濃度が20%から表面泡が増加した。したがって、表面泡の発生を抑制する観点から酸素体積濃度が20%を超えていることが望ましく、より好ましくは酸素体積濃度が30%以上である。   As can be seen from Table 1 and FIG. 4, the surface bubbles increased from the oxygen volume concentration of 20%. Therefore, from the viewpoint of suppressing the generation of surface bubbles, the oxygen volume concentration is desirably more than 20%, and more preferably the oxygen volume concentration is 30% or more.

また、比較例2に見られるように、酸素体積濃度が40%の場合には底部の気泡密度が小さく、気泡の発生の抑制効果が認められるが、コーナー部、側壁部は、1pcs/mm以上であり、底部の気泡密度が大きい。また、肉中泡は酸素体積濃度が40%から急激に上昇する傾向が見られる。このことから、酸素体積濃度が40%を未満であることが好ましい。
また、酸素体積濃度が35%以下の場合には、底部、コーナー部、側壁部の気泡密度が小さく、ルツボ全体にわたって気泡の発生の抑制効果が認められるため、酸素体積濃度は35%以下であることがより好ましい。
Further, as seen in Comparative Example 2, when the oxygen volume concentration was 40%, the bubble density at the bottom was small and the effect of suppressing the generation of bubbles was recognized, but the corners and the side walls were 1 pcs / mm 3. As described above, the bubble density at the bottom is large. Further, the foam in the meat tends to have a sharp increase in the oxygen volume concentration from 40%. For this reason, the oxygen volume concentration is preferably less than 40%.
When the oxygen volume concentration is 35% or less, the bubble density at the bottom, corners and side walls is small, and the effect of suppressing the generation of bubbles over the entire crucible is recognized. Therefore, the oxygen volume concentration is 35% or less. Is more preferable.

以上のように、アーク放電による加熱溶融中の雰囲気の酸素体積濃度が、20%を超え、かつ40%未満であることが望ましく、酸素体積濃度が30%以上、35%以下であることが、より好ましい。
尚、泡の大きさは、直胴部、コーナー部および底部における平均で、酸素濃度50%の場合に対し、酸素濃度30%で15%縮小した。同様に、酸素濃度50%の場合に対し、酸素濃度40%では泡の大きさは10%縮小し、酸素濃度20%では泡の大きさは20%縮小した。
As described above, it is desirable that the oxygen volume concentration of the atmosphere during heating and melting by arc discharge is more than 20% and less than 40%, and the oxygen volume concentration is 30% or more and 35% or less. More preferred.
In addition, the size of the bubbles was reduced by 15% at an oxygen concentration of 30% as compared with the case of an oxygen concentration of 50% on average at the straight body, the corner and the bottom. Similarly, when the oxygen concentration was 50%, the bubble size was reduced by 10% when the oxygen concentration was 40%, and the bubble size was reduced by 20% when the oxygen concentration was 20%.

1 シリカ粉成形体
1a 合成シリカ原料粉末層
1b 天然シリカ原料粉末層
2 シリカガラスルツボ
2a 透明シリカガラス層(内層)
2b 不透明シリカガラス層(外層)
10 石英ガラスルツボ製造装置
11 ルツボ成形用型
12 内側部材
13 通気部
14 保持体
15 回転軸
16 開口部
17 排気口
18 減圧機構
19 カーボン電極
20 ガス供給ノズル
21 原料粉末供給ノズル
Reference Signs List 1 silica powder compact 1a synthetic silica raw material powder layer 1b natural silica raw material powder layer 2 silica glass crucible 2a transparent silica glass layer (inner layer)
2b Opaque silica glass layer (outer layer)
DESCRIPTION OF SYMBOLS 10 Quartz glass crucible manufacturing apparatus 11 Crucible forming die 12 Inner member 13 Ventilation part 14 Holder 15 Rotating shaft 16 Opening 17 Exhaust port 18 Decompression mechanism 19 Carbon electrode 20 Gas supply nozzle 21 Raw material powder supply nozzle

Claims (2)

石英原料粉末を成形型内に供給して直胴部、コーナー部および底部を有するシリカ粉成形体を形成し、このシリカ粉成形体をアーク放電により加熱溶融してルツボを製造する、シリコン単結晶引上げ用シリカガラスルツボの製造方法であって、
アーク放電による加熱溶融中の雰囲気の酸素体積濃度が、30%以上、35%以下であることを特徴とするシリコン単結晶引上げ用シリカガラスルツボの製造方法。
A silicon single crystal is manufactured by supplying a quartz raw material powder into a mold to form a silica powder compact having a straight body, a corner and a bottom, and heating and melting the silica powder compact by arc discharge. A method for producing a silica glass crucible for pulling,
A method for producing a silica glass crucible for pulling a silicon single crystal, wherein an oxygen volume concentration in an atmosphere during heating and melting by arc discharge is 30% or more and 35% or less.
前記雰囲気は、アルゴン、水素、窒素のいずれかのキャリアガスと酸素とが混合したガスであることを特徴とする請求項1記載のシリコン単結晶引上げ用シリカガラスルツボの製造方法。
の製造方法。
2. The method for producing a silica glass crucible for pulling a silicon single crystal according to claim 1, wherein the atmosphere is a mixture of oxygen and a carrier gas selected from argon, hydrogen and nitrogen.
Manufacturing method.
JP2016043396A 2016-03-07 2016-03-07 Method for producing silica glass crucible for pulling silicon single crystal Active JP6659408B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2016043396A JP6659408B2 (en) 2016-03-07 2016-03-07 Method for producing silica glass crucible for pulling silicon single crystal

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2016043396A JP6659408B2 (en) 2016-03-07 2016-03-07 Method for producing silica glass crucible for pulling silicon single crystal

Publications (2)

Publication Number Publication Date
JP2017160063A JP2017160063A (en) 2017-09-14
JP6659408B2 true JP6659408B2 (en) 2020-03-04

Family

ID=59853504

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2016043396A Active JP6659408B2 (en) 2016-03-07 2016-03-07 Method for producing silica glass crucible for pulling silicon single crystal

Country Status (1)

Country Link
JP (1) JP6659408B2 (en)

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000103694A (en) * 1998-09-29 2000-04-11 Sumitomo Metal Ind Ltd Quartz glass crucible and its production
JP4951040B2 (en) * 2009-08-05 2012-06-13 信越石英株式会社 Silica container and method for producing the same
JP4969632B2 (en) * 2009-10-14 2012-07-04 信越石英株式会社 Silica powder and silica container and method for producing them
US8281620B1 (en) * 2011-04-27 2012-10-09 Japan Super Quartz Corporation Apparatus for manufacturing vitreous silica crucible

Also Published As

Publication number Publication date
JP2017160063A (en) 2017-09-14

Similar Documents

Publication Publication Date Title
US6553787B1 (en) Method for manufacturing quartz glass crucible
JP4702898B2 (en) Method for producing quartz glass crucible for pulling silicon single crystal
JP5462423B1 (en) Silica container for pulling single crystal silicon and manufacturing method thereof
JP4398527B2 (en) Silica glass crucible for pulling silicon single crystals
JP5459004B2 (en) Method for producing sapphire single crystal
JP4789437B2 (en) Silica glass crucible for pulling silicon single crystal and method for producing the same
EP2067883A2 (en) Vitreous silica crucible
JP2010155762A (en) Method of producing silicon single crystal
JP2018104248A (en) Quartz glass crucible for pulling silicon single crystal
JP4803784B2 (en) Method for producing quartz glass crucible for pulling silicon single crystal
JP2008297154A (en) Quartz glass crucible for pulling silicon single crystal and method for manufacturing the same
JP6659408B2 (en) Method for producing silica glass crucible for pulling silicon single crystal
WO2013171955A1 (en) Silica vessel for drawing up monocrystalline silicon and method for producing same
JP4549008B2 (en) Hydrogen-doped silica powder and quartz glass crucible for pulling silicon single crystal using the same
JP6855358B2 (en) Quartz glass crucible for pulling silicon single crystal
JP5685894B2 (en) Quartz glass crucible, method for producing the same, and method for producing silicon single crystal
JP5941384B2 (en) Method for producing silica glass crucible for pulling silicon single crystal
JP2017031007A (en) Method for storing hydrogen doped silica powder and method for manufacturing quartz glass crucible for pulling silicon single crystal
JP6812176B2 (en) Quartz glass crucible
JP2016033093A (en) Quartz glass crucible for lifting single crystal silicon, and method of manufacturing the same
JP6713382B2 (en) Quartz glass crucible manufacturing method and quartz glass crucible
JP6795461B2 (en) Manufacturing method of quartz glass crucible
JP4482567B2 (en) Method for producing quartz glass crucible for pulling silicon single crystal
JP2011184213A (en) Method for producing silicon single crystal
JP2020097512A (en) Silica glass crucible

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20180608

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20190219

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20190225

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20190422

A02 Decision of refusal

Free format text: JAPANESE INTERMEDIATE CODE: A02

Effective date: 20190823

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20191122

A911 Transfer to examiner for re-examination before appeal (zenchi)

Free format text: JAPANESE INTERMEDIATE CODE: A911

Effective date: 20191129

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: 20200114

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20200206

R150 Certificate of patent or registration of utility model

Ref document number: 6659408

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R150

S111 Request for change of ownership or part of ownership

Free format text: JAPANESE INTERMEDIATE CODE: R313111

R350 Written notification of registration of transfer

Free format text: JAPANESE INTERMEDIATE CODE: R350

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250