摘要:
Provided is a vitreous silica crucible for pulling silicon single crystals, which can melt a silicon raw material in a short time and improve production yield of silicon single crystals by temporal change of an opaque vitreous silica layer. The vitreous silica crucible includes an opaque vitreous silica layer(11) provided on an outer surface thereof and containing plural bubbles, and a transparent vitreous silica layer(12) provided on an inner surface and not containing bubbles substantially. The opaque vitreous silica layer(11) has a bubble diameter distribution in which the content of bubbles having a diameter of less than 40 μm is 10% or more and less than 30%, the content of bubbles having a diameter of 40 μm or more and less than 90 μm is 40% or more and less than 80%, and the content of bubbles having a diameter equal to or more than 90 μm is 10% or more and less than 30%. Relatively small bubbles contained in the opaque vitreous silica layer(11) contribute to the thermal conductivity of a crucible at an initial pulling stage, and relatively large bubbles contained in the opaque vitreous silica layer are expanded through a long-term pulling process to thereby largely contribute to the warmth retaining property of the crucible at a later pulling stage.
摘要:
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. The particle size distribution of the material silica powder for the first opaque vitreous silica portion 11a is wider than that of the second opaque vitreous silica portion 11b, and the material silica powder for the first opaque vitreous silica portion 11a includes more fine powder than that for the second opaque vitreous silica portion 11b.
摘要:
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. The particle size distribution of the material silica powder for the first opaque vitreous silica portion 11a is wider than that of the second opaque vitreous silica portion 11b, and the material silica powder for the first opaque vitreous silica portion 11a includes more fine powder than that for the second opaque vitreous silica portion 11b.
摘要:
Provided is a vitreous silica crucible which has a special region for suppressing vibration of melt surface during pulling of a silicon single crystal and at the same time, a marking capable of accurately monitoring a changed position of the melt surface when passing through the special region. The special region for preventing sloshing of silicon melt is provided on an inner wall of a straight body portion, and the marking is provided at least at an upper end and a lower end of the special region.
摘要:
Provided is a vitreous silica crucible which has a special region for suppressing vibration of melt surface during pulling of a silicon single crystal and at the same time, a marking capable of accurately monitoring a changed position of the melt surface when passing through the special region. The special region for preventing sloshing of silicon melt is provided on an inner wall of a straight body portion, and the marking is provided at least at an upper end and a lower end of the special region.
摘要:
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.
摘要:
A vitreous silica crucible for pulling single-crystal silicon, which is formed of vitreous silica and has a bottomed cylindrical shape, wherein, in a liquid-level movement range in the inner surface of the crucible, ranging from a position corresponding to the liquid surface level of a silicon melt at the time of stating the pulling of single-crystal silicon to a position corresponding to the liquid surface level of a silicon melt at the time of finishing the pulling of single-crystal silicon, the concentration of an OH group included in the vitreous silica is higher in an erosion thickness portion of the inner surface of the crucible than that in the range lower than the liquid surface level which is positioned below the liquid-level movement range.
摘要:
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.
摘要:
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.
摘要:
A method of producing a quartz glass crucible by arc melting a quartz powder molded product loaded on the inner side of a mold while performing vacuum suction, includes initiating the melting of quartz powder from the rim edge of a quartz powder molded product, subsequently lowering the arc electrode or raising the mold to heat and melt the sections on the downside of the rim edge. The method is preferably carried out such that the inner surface of the crucible is sealed within a time corresponding to 10% of the total arc time starting from the initiation of arc melting, and the seal thickness is 3 mm or less. The quartz glass crucible thus produced is useful for the pulling up of silicon single crystals and has a uniform glass layer with fewer internal bubbles.