Abstract: Accurate temperature measurement during manufacturing a vitreous silica crucible is enabled. The present invention provides an apparatus for manufacturing a vitreous silica crucible including: a mold for forming a silica powder layer by supplying silica powder therein; an arc discharge unit having carbon electrodes and a power supply unit and for heating and fusing the silica powder layer by arc discharge; and a temperature measurement unit for measuring temperature of a fused portion in the mold, wherein the temperature measurement unit is an radiation thermometer for measuring temperature by detecting radiation energy of a wavelength of 4.8 to 5.2 ?m.

Abstract: The present invention provides a method of manufacturing a vitreous silica crucible including: a silica powder supplying process of supplying a material silica powder into a mold for molding a crucible, to form a silica powder layer, and an arc fusing process of arc fusing the silica powder layer by arc discharge generated by carbon electrodes, wherein the arc fusing process includes processes of measuring a temperature of the silica powder layer, and controlling a vitreous silica fused state based on a reference temperature which is a temperature at a local maximum point which appears first in the arc fusing process.

Abstract: The present invention provides a method of manufacturing a vitreous silica crucible including: a silica powder supplying process of supplying a material silica powder into a mold for molding a vitreous silica crucible, to form a silica powder layer, and an arc fusing process of arc fusing the silica powder layer by arc discharge generated by carbon electrodes, wherein the arc fusing process includes processes of measuring temperatures at measuring points provided on different heights of an inner surface of the silica powder layer while rotating the mold, and controlling the arc discharge to enable detection, at each measuring point, of a local maximum point which appears first in the arc fusing process.

Abstract: The present invention provides a vitreous silica crucible which can suppress the sidewall lowering of the crucible under high temperature during pulling a silicon single crystal, and a method of manufacturing such a vitreous silica crucible. The vitreous silica crucible 10 includes an opaque vitreous silica layer 11 provided on the outer surface side of the crucible and containing numerous bubbles, and a transparent vitreous silica layer 12 provided on the inner surface side. The opaque vitreous silica layer 11 includes a first opaque vitreous silica portion 11a provided on the crucible upper portion, and a second opaque vitreous silica portion 11b provided on the crucible lower portion. The specific gravity of the second opaque vitreous silica portion 11b is 1.7 to 2.1, and the specific gravity of the first opaque vitreous silica portion 11a is 1.4 to 1.8, and smaller than that of the second opaque vitreous silica portion.

Abstract: The purpose of the present invention is to provide a crucible which has high viscosity at high temperature, and can be used for a long time, and can be manufactured at low cost, and a method of manufacturing the same. The composite crucible 10 is characterized in the use of mullite (3Al2O3.2SiO2) as the basic material of the crucible. The composite crucible 10 has the crucible body 11 made of mullite material whose main component is alumina and silica, and a transparent vitreous silica layer 12 formed on the inner surface of the crucible body 11. The thickness of the transparent vitreous silica layer 12 is smaller than that of the crucible body 11. The crucible body 11 can be formed by the slip casting method, and the transparent vitreous silica layer 12 can be formed by the thermal spraying method.

Abstract: The purpose of the present invention is to provide a crucible which has high viscosity at high temperature, can be used for a long time, and can be manufactured at low cost, and a method of manufacturing the crucible. The present invention provides a composite crucible including a vitreous silica crucible body having a sidewall portion and a bottom portion, and a reinforcement layer provided on an outer surface side of an upper end portion of the vitreous silica crucible body, wherein the reinforcement layer is made of mullite material whose main component is alumina and silica.

Abstract: The present invention provides a method of manufacturing a vitreous silica crucible having a transparent layer by use of waste vitreous silica, and silica powder suitable for the manufacturing. According to the present invention, there is provided a method of manufacturing granulated silica powder comprising a process for pulverizing waste vitreous silica generated in the manufacturing process of a crucible to form silica fine powder having an average particle diameter of 100 ?m or less, and a process for granulating the silica fine powder to obtain granulated silica powder having an average particle diameter of 50 ?m or more under helium atmosphere.

Abstract: There is provided a method of manufacturing a vitreous silica crucible having non-bubbles on the inner surface without necessitating new apparatuses for grinding and polishing and without damaging the productivity. According to the present invention, there is provided a method of manufacturing a vitreous silica crucible including the processes of: gathering a vitreous silica layer containing residual bubbles existing in a near-surface region of the transparent layer of the vitreous silica crucible by controlling the number of rotations applied to the vitreous silica crucible in a state that an inner surface side of the vitreous silica crucible is fused by arc heating; and moving a portion of a non-bubble layer in the surface of the transparent layer exposed by movement of the residual bubble-containing layer to cover a region in which bubbles have gathered with the non-bubble layer.

Abstract: Provided is a method for manufacturing a vitreous silica crucible and a manufacturing apparatus for the same, which can reduce the amount of bubbles and impurities of a crucible inner surface and enhance a crystallization yield of silicon single crystal. A method for manufacturing a vitreous silica crucible of the invention includes a silica powder supplying process of supplying silica powder in a rotating mold to form a silica powder layer; an arc fusing process of fusing the silica powder layer by arc discharge generated by carbon electrodes; and a fire polishing process of throwing an arc flame toward a target surface of the silica powder layer for surface removal, wherein, in the fire polishing process, the distances from the tips of the carbon electrodes to the target surface is set to be equal.

Abstract: There is provided a vitreous silica crucible whose strength at high temperature is high, and which allows easy taking-out from a susceptor after completion of pulling. The vitreous silica crucible 10 includes a vitreous silica outer layer 13a provided on the outer surface side of the crucible, a vitreous silica inner layer 13c provided on the inner surface side of the crucible, and an vitreous silica intermediate layer 13b provided between the vitreous silica outer layer 13a and the vitreous silica inner layer 13c. The vitreous silica outer layer 13a has a mineralizer concentration of 100 ppm or more, and the vitreous silica intermediate layer 13b and the vitreous silica inner layer 13c has a mineralizer concentration of 50 ppm or less. It is preferred that the vitreous silica outer layer 13a and the vitreous silica intermediate layer 13b are made of natural silica, and the vitreous silica inner layer 13c is made of high-purity natural silica or synthetic silica.

Abstract: The present invention provides a vitreous silica crucible which can suppress buckling and sidewall lowering of the crucible and the generation of cracks. According to the present invention, a vitreous silica crucible is provided for pulling a silicon single crystal having a wall, the wall including a non-doped inner surface layer made of natural vitreous silica or synthetic vitreous silica, a mineralizing element-maldistributed vitreous silica layer containing dispersed island regions each containing a mineralizing element, and wherein the vitreous silica of the island regions and the vitreous silica of a surrounding region of the island regions is a combination of mineralizing element-doped natural vitreous silica and non-doped synthetic vitreous silica, or a combination of mineralizing element-doped synthetic vitreous silica and non-doped natural vitreous silica, and the inner surface layer is made of vitreous silica of a different kind from that of the island region.

Abstract: Provided is a vitreous silica crucible, which is resistant to deformation and corrosion even when heated at high temperature for a long time. There is provided a vitreous silica crucible of the present invention including a substantially cylindrical straight body portion, a curved bottom portion, and a corner portion smoothly connecting the straight body portion and the bottom portion, wherein a wall of the vitreous silica crucible includes, from an inner surface side, a transparent layer and a bubble-containing layer, and a ratio of a thickness of the bubble-containing layer with respect to a thickness of the transparent layer at an intermediate position between an upper end and a lower end of the straight body portion is 0.7 to 1.4.

Abstract: Provided is an apparatus for manufacturing a vitreous silica crucible which has a structure which can reduce gaps between a partition wall and electrodes inserted into through-holes formed in the partition wall while enabling electrodes to move to adjust a heating temperature of arc discharge. A plate-shaped partition wall 15 is placed above the rotating mold 10. Electrodes 13 for heating and fusing are inserted into through-holes 16 penetrating in a thickness direction, and are directed toward the rotating mold 10. A rocking unit 40 is provided on an upper side of the partition wall 15 and rocks the electrodes 13 around virtual rocking axes P, and the virtual rocking axes P pass through the through-holes 16.

Abstract: The present invention provides a method of manufacturing a vitreous silica crucible having a transparent layer by use of waste vitreous silica. According to the present invention, there is provided a method of manufacturing a vitreous silica crucible for manufacturing a monocrystalline or polycrystalline silicon ingot, including a process of vitrifying a silica powder sintered body having a crucible shape in the whole or part of the thickness direction by arc fusing the silica powder sintered body from the inner surface side, wherein the method further includes at least one means of (1) depressurizing the silica powder sintered body from the outer surface side during the arc fusing, and (2) forming a synthetic vitreous silica layer on the inner surface by spraying synthetic silica powder onto the inner surface of the silica powder sintered body during the arc fusing.

Abstract: There are provided an apparatus and a method for manufacturing a vitreous silica crucible which can prevent the deterioration of the inner surface property in the manufacturing process of a vitreous silica crucible. The apparatus includes a mold defining an outer shape of a vitreous silica crucible, and an arc discharge unit having electrodes and a power-supply unit, wherein each of the electrodes includes a tip end directed to the mold, the other end opposite to the tip end, and a bent portion provided between the tip end and the other end.

Abstract: The present invention provides a vitreous silica crucible which can suppress buckling and sidewall lowering of the crucible without fear of mixing of impurities into silicon melt. According to the present invention, provided is a vitreous silica crucible for pulling a silicon single crystal, wherein a ratio I2/I1 is 0.67 to 1.17, where I1 and I2 are area intensities of the peaks at 492 cm?1 and 606 cm?1, respectively, in Raman spectrum of vitreous silica of the region having a thickness of 2 mm from an outer surface to an inner surface of a wall of the crucible.

Abstract: Provided is a vitreous silica crucible having a reference point, which is capable of accurately detecting the location of a defect in the vitreous silica crucible used for pulling silicon single crystal, determining a defect generating site of silicon single crystal, and investigating the cause of the defect. The reference point used for specifying the position relationship with respect to a particular part is formed in at least one site of an end portion, an inner wall and an outer wall of the crucible.

Abstract: The present invention provides a method of evaluating silica powder which, enables precise prediction of easiness of crystallization of a vitreous silica crucible. According to the present invention, provided is a method of evaluating silica powder including a sample preparation process for preparing a vitrified sample by fusing silica powder at a fusing temperature of 1700 to 1900 deg. C., followed by cooling; a sample heat treatment process for retaining the sample for 30 minutes or more at a temperature of 1400 to 1750 deg. C., followed by cooling; and a sample evaluation process for evaluating a state of opacification of the sample after the sample heat treatment process.

Abstract: The present invention provides a vitreous silica crucible which can suppress buckling and sidewall lowering of the crucible in multi-pulling. According to the present invention, provided is a vitreous silica crucible for pulling a silicon single crystal, comprising a mineralizer on an inner surface of the crucible, wherein the mineralizer contains at least one atoms selected from the group consisting of Ca, Sr, Ba, Ra, Ti, Zr, Cr, Mo, Fe, Co, Ni, Cu, and Ag, and the concentration of the mineralizer on the inner surface is 1.0×105 to 1.0×1017 atoms/cm2.

Abstract: The present invention provides a vitreous silica crucible which can restrain deterioration of crystallinity of a silicon ingot in multi-pulling. Provided is a vitreous silica crucible for pulling a silicon single crystal, the crucible has a wall having, from an inner surface toward an outer surface of the crucible, a synthetic vitreous silica layer, a natural vitreous silica layer, an impurity-containing vitreous silica layer and a natural vitreous silica layer.