Japan Super Quartz Corporation

Sumco Corporation

Mitsubishi Materials Quartz Corporation

Mitsubishi Material Quartz Corporation

Mitsubishi Materials Corporation

Mitsubishi Materials Silicon Corporation

Masanori Fukui

Hideki Watanabe

Yasunobu Shimizu

Toshiaki Sudo

Hiroshi Kishi

Masaki Morikawa

Eriko Kitahara

Takeshi Fujita

Yoshiyuki Tsuji

Ken Kitahara

Tomokazu Katano

Takahiro Satoh

Masaru Satoh

Ken-ichi Hiroshima

Keiichi Takanashi

Hisashi Furuya

Michio Kida

Hiroaki Taguchi

Takashi Atami

Minoru Kanda

Satoshi Kudo

Nobumitsu Takase

Koichi Suzuki

Minoru Shirakawa

Tadashi Nemoto

Tadashi Sato

Takahiro Sato

Hitoshi Kishi

An infrared transmissivity measurement method is for measuring an infrared transmissivity of a quartz glass crucible which includes a transparent layer made of quartz glass that does not contain bubbles, a bubble layer formed outside the transparent layer and made of quartz glass containing bubbles, and a semi-molten layer formed outside the bubble layer and made of raw material silica powder solidified in a semi-molten state. The infrared transmissivity measurement method includes processing an outer surface of the quartz glass crucible formed by the semi-molten layer to lower a surface roughness of the outer surface; and measuring an infrared transmissivity of the quartz glass crucible based on infrared light passing through the outer surface after processing the outer surface.

Infrared transmissivity measurement method of quartz glass crucible

An apparatus for manufacturing a silica glass crucible includes a rotating means for rotating a mold and a supply means for feeding a silica powder inside the mold, wherein the supply means has a feeding part for delivering the silica powder in a manner releasing it to fall to a position away from the inner wall surface of the mold inside the mold, and a dispersing part for changing, to one toward the inner wall surface side, at a fall position, the direction in which the silica powder fed from the feeding part moves, while also widening an angle at which the silica powder disperses toward the inner wall surface at the fall position. The apparatus is intended to allow a silica powder layer to be stably formed in the mold in a short period of time.

Apparatus and method for manufacturing silica glass crucible

A quartz glass cruciblehaving a cylindrical side wall portion, a bottom portion, and a corner portionincludes a transparent layeras an innermost layer made of quartz glass, a semi-molten layeras an outermost layer made of raw material silica powder solidified in a semi-molten state, and a bubble layermade of quartz glass interposed therebetween. An infrared transmissivity of the corner portionin a state where the semi-molten layeris removed is 25 to 51%, the infrared transmissivity of the corner portionin the state where the semi-molten layeris removed is lower than an infrared transmissivity of the side wall portion, and the infrared transmissivity of the side wall portionin the state where the semi-molten layeris removed is lower than an infrared transmissivity of the bottom portion

Quartz glass crucible, manufacturing method of silicon single crystal using the same, and infrared transmissivity measurement method and manufacturing method of quartz glass crucible

A measurement method and a measurement apparatus are capable of measuring the transmittance of a quartz crucible accurately. A measurement method includes: emitting a parallel light from a light source disposed on a side of one wall surface of a quartz crucible toward a predetermined measurement point of the quartz crucible; measuring reception levels of light transmitted through the quartz crucible at a plurality of positions by disposing a detector at the plurality of positions on a circle centered around an exit point of the parallel light on the other wall surface of the quartz crucible; and calculating a transmittance of the quartz crucible at the predetermined measurement point based on a plurality of the reception levels of the transmitted light measured at the plurality of positions.

Method and apparatus for measuring transmittance of quartz crucible

In an exemplary embodiment, a quartz glass crucibleincludes: a high-aluminum-content layerB which is made of quartz glass having a relatively high average aluminum concentration and is provided to form an outer surfaceof the quartz glass crucible; and a low-aluminum-content layerA which is made of quartz glass having a lower average aluminum concentration than that of the high-aluminum-content layerB and is provided on an inner side of the high-aluminum-content layerB, wherein the low-aluminum-content layerA includes an opaque layermade of quartz glass containing a large number of minute bubbles, and the high-aluminum-content layerB is made of transparent or translucent quartz glass having a lower bubble content than that of the opaque layer. The quartz glass crucible is capable of withstanding a single crystal pull-up step undertaken for a very long period of time.

Quartz glass crucible and manufacturing method thereof

Leakage of silicon melt is monitored and touch of a seed crystal at the silicon melt is detected, and in addition, reinforcement of a vitreous silica crucible to be endurable during pulling for a long time and decrease of impurity concentration of a silicon single crystal can be expected. A method for manufacturing a silicon single crystal is provided. The method includes: detecting touching status of a seed crystal at silicon melt by supplying voltage Vusing a crucible side as a negative electrode and a wire side as a positive electrode and by monitoring change of the voltage, when the seed crystal provided at a front end of the wire touches the silicon melt inside a vitreous silica crucible; devitrifying an inner surface of the vitreous silica crucible as supplying voltage Vusing the crucible side as a positive electrode and the wire side as a negative electrode during a temperature control period; and growing a silicon single crystal by slowly pulling the seed crystal as supplying voltage Vusing the crucible side as a negative electrode and the wire side as a positive electrode after the temperature control period.

Method of manufacturing silicon single crystal, apparatus for pulling silicon single crystal and vitreous silica crucible

A method of manufacturing a fused silica crucible by heating and melting a vitreous silica powder compact shaped into a mold using arc discharge of electrodes arranged around a rotation shaft of the mold, includes the steps of: arranging the electrodes in a ring shape, and setting a ratio W/R of a horizontal distance W between the electrode front end and the surface of the vitreous silica powder compact to a vitreous silica powder compact opening radius R, for at least a predetermined time during arc heating, to be in the range of 0.002 to 0.98.

Method and apparatus for manufacturing fused silica crucible, and the fused silica crucible

A silica glass crucible for pulling up a silicon single crystal including a wall part and a bottom part is provided with a natural silica glass layer which forms at least one part of a an inner surface of the bottom part, and a synthetic silica glass layer which forms at least an inner surface of the wall part, wherein a concentration of Ca included in the natural silica glass layer is 0.5 ppm or less.

Silica glass crucible for pulling up silicon single crystal, method for manufacturing thereof and method for manufacturing silicon single crystal

A carbon electrode grinding apparatus for shaping a front end of an arc discharge carbon electrode is provided with front end grinding blades configured to grind a front end surface of the carbon electrode, lateral surface grinding blades configured to grind a surface from the front end surface to a base end of the carbon electrode, and rotation means configured to rotate and drive the front end grinding blades and the lateral surface grinding blades around a rotation axis line coincident with an axis line of the carbon electrode.

Carbon electrode grinding apparatus

A silica glass crucible having a sidewall portion and a bottom portion is provided with a first synthetic silica glass layer constituting an inner layer at least in the sidewall portion, a second synthetic silica glass layer constituting an inner layer at least in a region including a center of the bottom portion, and a natural silica glass layer constituting an outer layer in the sidewall portion and the bottom portion. A melting rate of the second synthetic silica glass layer with respect to a silicon melt is higher than that of the first synthetic silica glass layer. An aluminum concentration of the second synthetic silica glass layer is higher than that of the first synthetic silica glass layer.

Silica glass crucible

An arc discharge method includes the steps of heating and melting a non-conductive object by arc discharge using a plurality of carbon electrodes in a output range of 300 to 12,000 kVA; and setting a ratio of the distance between a contact position at which the carbon electrodes come in contact with each other and a front end to the diameter of the carbon electrode during the start of the arc discharge to be in the range of 0.001 and 0.9.

Arc discharge method, arc discharge apparatus, and fused silica crucible manufacturing apparatus

A vitreous silica crucible manufacturing apparatus includes a plurality of carbon electrodes configured to heat and melt raw material powder by arc discharge, and a value of a ratio R/Rof a diameter Rof a front end of each of the carbon electrodes to a diameter Rof a base end is set in a range of 0.6 to 0.8. Each carbon electrode has a diameter reduction portion formed at a front end position and reduced in diameter from a diameter Rof a base end side to the diameter Rof the front end. When a length of the diameter reduction portion is L, the diameter of the front end is R, the diameter of the base end is R, an angle between the axis lines of the carbon electrodes is &#x3b8;, and X=(R&#x2212;R)/2, a value of L&#x2212;(X/tan(&#x3b8;/2)) is set in a range of 50 to 150 mm.

Vitreous silica crucible manufacturing apparatus

The arc discharge apparatus comprises a plurality of carbon electrodes connected to respective phases of a power supply for heating a silica powder and causing it to fuse by generating arc discharge between the carbon electrodes. All of the carbon electrodes have a density in a range from 1.30 g/cmto 1.80 g/cm, and variability in density among the carbon electrodes is 0.2 g/cmor less. The carbon particles that constitute the carbon electrodes preferably have a particle diameter of 0.3 mm or less.

Arc discharge apparatus, apparatus and method for manufacturing vitreous silica glass crucible, and method for pulling up silicon single crystal

A modification process of the synthetic quartz powder, which can make a quartz glass product hardly having bubbles at the time of fusing, is provided, along with a modification process of the synthetic quartz powder and a glass product using said modified quartz powder are provided, wherein the synthetic quartz powder is kept in helium atmosphere at least in the temperature falling process, when the amorphous synthetic quartz powder produced by the sol-gel method is carried out by heat treatment in a vacuum furnace at more than the degas temperature and less than the baking temperature, wherein the highest temperature in the helium atmosphere is preferably set to from more than 700&#xb0; C. to less than 1400&#xb0; C., and the helium atmosphere is kept to less than 400&#xb0; C.

Modification process of synthetic silica powder and its quartz glass product

A reforming process of a quartz glass crucible in which the quartz glass crucible is reformed by an arc discharge generated by electrodes positioned around a rotational axis and configured to heat an inside surface of the crucible while the crucible is rotated. The process includes arranging electrodes in an electrode structure such that neighboring electrodes are positioned at regular intervals in a ring-like configuration; forming a stable ring-like arc between the neighboring electrodes, without generating a continuous arc between electrodes facing each other across a central portion of the ring-like configuration; heating the inside surface of the crucible; and removing a foreign substance located on the inside surface of the crucible or a bubble located under the inside surface of the crucible.

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Akita, Japan

Masanori Fukui