Abstract: A quartz glass crucible which has a non-transparent outer layer formed through melting a natural silica powder and a transparent layer formed in the inside of the outer layer, wherein the transparent layer comprises a natural quartz layer having a thickness of 0.4 to 5.0 mm transparent layer comprising a synthetic quarts glass is formed thereon in the inside of the crucible in the range of 0.15 to 0.55 L relative to L, which is the distance from the center of the bottom of the inner surface of the quartz glass crucible to the upper end thereof along the inner surface thereof. The quartz glass crucible can be suitably used for suppressing the occurrence of vibration and reducing the generation of roughened face in the surface of a crucible, and thus for pulling up a silicon single crystal with enhanced stability.

Abstract: An upper heater for use in the production of a single crystal, the upper heater having electrodes to which a current is supplied and a heat generating section which generates heat by resistance heating are provided, the upper heater being used when a single crystal is produced by a Czochralski method, the upper heater being placed above a graphite heater which is placed so as to surround a crucible containing silicon melt, wherein the heat generating section is ring-shaped and is placed so as to surround the crucible, and has slits formed from the inside and the outside of the heat generating section in a horizontal direction. As a result, the upper heater controls a crystal defect of the single crystal efficiently and improves the oxygen concentration controllability.

Abstract: A single-crystal manufacturing apparatus comprising at least: a main chamber configured to accommodate a crucible; a pulling chamber continuously provided above the main chamber, the pulling chamber into which a grown single crystal is pulled and accommodated; a gas inlet provided in the pulling chamber; a gas flow-guide cylinder downwardly extending from a ceiling of the main chamber; and a heat-insulating ring upwardly extending from a lower end portion of the gas flow-guide cylinder with a diameter of the heat-insulating ring increased so as to surround an outside of the gas flow-guide cylinder, wherein at least one window is provided in a region between 50 and 200 mm from a lower end of the gas flow-guide cylinder, and an opening area of the window accounts for 50% or more of a surface area of the region between 50 and 200 mm from the lower end of the gas flow-guide cylinder.

Abstract: A method and apparatus for growing a semiconductor crystal include pulling the semiconductor crystal from melt at a pull speed and modulating the pull speed by combining a periodic pull speed with an average speed. The modulation of the pull speed allows in-situ determination of characteristic temperature gradients in the melt and in the crystal during crystal formation. The temperature gradients may be used to control relevant process parameters that affect morphological stability or intrinsic material properties in the finished crystal such as for instance the target pull speed of the crystal or the melt gap, which determines the thermal gradient in the crystal during growth.

Abstract: Disclosed is a sapphire single crystal growing apparatus using the Kyropoulos method, and more particularly, is a Kyropoulos sapphire single crystal growing apparatus using an elliptic crucible, which can increase the recovery rate by the elliptic crucible and anisotropic heating.

Abstract: A process for producing a single crystal of semiconductor material, in which fractions of a melt, are kept in liquid form by a pulling coil, solidify on a seed crystal to form the growing single crystal, and granules are melted in order to maintain the growth of the single crystal. The melting granules are passed to the melt after a delay. There is also an apparatus which Is suitable for carrying out the process and has a device which delays mixing of the molten granules and of the melt.

Abstract: A method and apparatus for growing a semiconductor crystal include pulling the semiconductor crystal from melt at a pull speed and modulating the pull speed by combining a periodic pull speed with an average speed. The modulation of the pull speed allows in-situ determination of characteristic temperature gradients in the melt and in the crystal during crystal formation. The temperature gradients may be used to control relevant process parameters that affect morphological stability or intrinsic material properties in the finished crystal such as for instance the target pull speed of the crystal or the melt gap, which determines the thermal gradient in the crystal during growth.

Abstract: A Czochralski single crystal manufacturing apparatus uses multiple heaters to improve the controllability of crystal diameter. The power supplied to the multiple heaters is controlled so as to bring the pulling up speed close to a predetermined speed set value, and so as to bring the heater temperatures close to predetermined target temperature values. The ratio of electrical power between the heaters is controlled to agree with a predetermined power ratio set value which varies according to the crystal pulling up length, and the heater temperatures change along with this change, which causes disturbance to the diameter control. To compensate for this, heater temperature changes along with the power ratio set value change are taken into account in advance in the temperature set values. Accordingly, along with change of the power ratio set value, the temperature set values change to values appropriate for the current power ratio set value.

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: A method for producing thin silicon rods using a floating zone crystallization process includes supplying high frequency (HF) current to a flat induction coil having a central opening, a plurality of draw openings and a plate with a slot as a current supply of the HF current so as to provide a circumfluent current to the central opening. An upper end of a raw silicon rod is heated by induction using the flat induction coil so as to form a melt pool. A thin silicon rod is drawn upwards through each of the plurality of draw openings in the flat induction coil from the melt pool without drawing a thin silicon rod through the central opening having the circumfluent current.

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: 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: 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: 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: A high-purity vitreous silica crucible used for pulling a large-diameter single-crystal silicon ingot, includes a double layered structure constituted by an outer layer composed of high-purity amorphous vitreous silica with a bubble content of 1 to 10% and a purity of 99.99% or higher, and an inner layer composed of high-purity amorphous vitreous silica s with a bubble content of 0.6% or less and a purity of 99.99% or higher, wherein, at least for an inner surface of the vitreous silica crucible between ingot-pulling start line and ingot-pulling end line of a silicon melt surface, a longitudinal section of the inner surface is shaped into a waveform, and depth and width of the ring grooves constituting the multi ring-groove patterned face are set in the range of 0.5 to 2 mm and 10 to 100 mm, respectively.

Abstract: Semiconductor wafers of silicon are produced by pulling a single crystal from a melt contained in a crucible and slicing semiconductor wafers from the pulled single crystal, heat being delivered to a center of the growing single crystal at the boundary with the melt during the pulling of the single crystal, a CUSP magnetic field applied such that a neutral surface of the CUSP magnetic field intersects a pulling axis of the single crystal at a distance of at least 50 mm from a surface of the melt. An apparatus suitable therefore contains a CUSP field positioned such that a neutral field intersects the axis of the crystal in the crucible 50 mm or more from the melt surface.

Abstract: PROBLEM To provide a seed crystal axis for solution growth of single crystal able to prevent or suppress formation of polycrystals due to the liquid phase technique and grow a single crystal with a high growth rate.

Abstract: A crucible and method for the crystallization of silicon utilize release coatings. The crucible is used in the handling of molten materials that are solidified in the crucible and then removed as ingots. The crucible does not require the preparation of a very thick coating at the end user facilities, is faster and cheaper to produce, presents an improved release effect and allows the production of silicon ingot without cracks. The crucible includes a base body, a substrate layer containing silicon nitride, an intermediate layer containing silica, and a surface layer containing silicon nitride, silicon dioxide and silicon.

Abstract: A crystal puller for growing monocrystalline ingots includes a side heater adjacent a crucible for heating the crucible and a melt heat exchanger sized and shaped for surrounding the ingot and disposed adjacent a surface of the melt. The heat exchanger includes a heat source having an area for radiating heat to the melt for controlling heat transfer at the upper surface of the melt. The melt heat exchanger is adapted to reduce heat loss at the exposed upper surface portion. Methods for growing single crystal silicon crystals having desired defect characteristics are disclosed.

Abstract: 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.

Abstract: A crucible for producing a silicon suitable for producing a semiconductor includes a plurality of components and at least one unclosed joint gap.

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: A single crystal pull apparatus has a multilayer crucible wherein the crucible has an outer crucible, an insertable layer intimately fitted thereon, and a wire frame positioned between the insertable layer and an inner crucible. The insertable layer, wire frame and inner crucible are preferably composed of platinum. Furthermore the insertable layers have thin walls and the frame has a small diameter such that they can be easily reshaped after any deformation occurring as a result of the single crystal growth process.

Abstract: A lid for a crystal growth chamber crucible is constructed by forming arcuate sector-shaped portions and coupling them in abutting relationship, for example by welding, to form an annular profile fabricated lid. The arcuate sector-shaped portions may be formed and removed from a lid fabrication blank with less waste than when unitary annular lids are formed and removed from a similarly sized fabrication blank. For example, the sector-shaped portions may be arrayed in an undulating pattern on the fabrication sheet.

Abstract: Using a pulling-up apparatus, an oxygen concentration of the monocrystal at a predetermined position in a pulling-up direction is controlled based on a relationship in which the oxygen concentration of the monocrystal is decreased as a flow rate of the inactive gas at a position directly above a free surface of the dopant-added melt is increased when the monocrystal is manufactured with a gas flow volume in the chamber being in the range of 40 L/min to 400 L/min and an inner pressure in the chamber being in the range of 5332 Pa to 79980 Pa. Based on the relationship, oxygen concentration is elevated to manufacture the monocrystal having a desirable oxygen concentration. Because the oxygen concentration is controlled under a condition corresponding to a condition where the gas flow rate is rather slow, the difference between a desirable oxygen concentration profile of the monocrystal and an actual oxygen concentration profile is reduced.

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 invention provides a quartz glass crucible for pulling up single-crystal silicon, and a method for producing single-crystal silicon by using it. The quartz glass crucible is characterized by having a crystallization promoter-containing layer as the inner surface thereof and is characterized in that, when single-crystal silicon is pulled up, macular crystallized regions are formed in the inner surface thereof by the action of the crystallization promoter.

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.

Abstract: Provided is a vitreous silica crucible which can suppress inward sagging and buckling of the sidewall effectively even when time for pulling silicon ingots is extremely long. According to the present invention, provided is a vitreous silica crucible for pulling a silicon single crystal, wherein the crucible has a wall comprising, from an inner surface toward an outer surface of the crucible, a transparent vitreous silica layer having a bubble content rate of less than 0.5%, a bubble-containing vitreous silica layer having a bubble content rate of 1% or more and less than 50%, a semi-transparent vitreous silica layer having a bubble content rate of 0.5% or more and less than 1.0% and having an OH group concentration of 35 ppm or more and less than 300 ppm.

Abstract: In an apparatus for the production of a silica crucible comprising a carbon mold suitable for producing the silica crucible by the rotating mold method, the carbon mold has a thermal conductivity of not more than 125 W/(m·K).

Abstract: The liquid surface position of the melt in the crucible in the silicon single crystal growth process utilizing the Czochralski method is monitored using the melt surface position on the occasion of seeding as a reference position and an estimated melt surface position can be calculated according to every situation, so that the distance between the melt and the thermal shield or water-cooling structure can be controlled with high precision. When the estimated melt surface position passes a preset upper limit and approaches the thermal shield, an alarm goes off and, further, when the melt comes into contact with the thermal shield or approaches the water-cooling structure, an alarm goes off if desired and, at the same time, the crucible is forcedly stopped from moving, so that a serious accident such as steam-incurred explosion resulting from the melt coming into contact with the water-cooling structure can be prevented.

Abstract: To provide a crystal growing apparatus and a crystal growing method capable of enabling use of a quartz crucible for a longer period of time and improving operation rate. A crystal growing apparatus according to the invention includes a crystal growing furnace equipped with a quartz crucible, a raw material melting furnace, and a supply unit for repeatedly supplying a molten raw material from the raw material melting furnace to the quartz crucible. The crystal growing furnace may include a supply port for allowing supply of the molten raw material therethrough, and the supply port may be configured to be movable close to or away from the raw material melting furnace. A plurality of the crystal growing furnaces may be disposed around the raw material melting furnace. The raw material melting furnace may include an insoluble material separating unit. A crystal growing method according to the invention includes supplying a molten raw material melted in advance to a quartz crucible.

Abstract: A graphite crucible for silicon single crystal manufacturing by the Czochralski method, having a long life cycle, contains at least one gas venting hole provided in a corner portion of the crucible. Gas generated by reaction between the graphite crucible and a quartz crucible is released to the outside through the gas venting hole, and formation of SiC on the surface of the graphite crucible and deformation of the quartz crucible caused by the pressure of the generated gas are prevented.

Abstract: Provided are a quartz crucible and a method of manufacturing the quartz crucible. The quartz crucible is used in a single crystal growth apparatus. The quartz crucible comprises an inner layer including silica, and an outer layer including silica disposed outside the inner layer to surround the inner layer, wherein nitrogen is added in the silica of the outer layer.

Abstract: The present invention provides a silica glass crucible for manufacturing a silicon single crystal, in which melt vibration can be controlled more certainly and a high yield of single crystal can be realized. A first substantially bubble-free layer 10a having a thickness of 100 ?m-450 ?m is formed on the inner periphery side of an initial melt line zone 10 which has a height of 10 mm-30 mm, of a transparent layer, a bubble-containing layer 10b having a thickness of 100 ?m or more and bubbles with an average diameter of 20 ?m-60 ?m is formed outside the above-mentioned first substantially bubble-free layer 10a, and a second substantially bubble-free layer 10c having a thickness of 300 ?m or more is formed on the inner periphery side in the whole region lower than the above-mentioned initial melt line zone 10.

Abstract: The present invention is a single-crystal manufacturing apparatus based on the Czochralski method having a main chamber configured to accommodate hot zone components including a crucible, and a pull chamber configured to accommodate and take out a single crystal pulled from a raw material melt, the apparatus further comprising a multipurpose chamber interchangeable with the pull chamber, wherein a heating means for heating a raw material charged into the crucible and a cooling means for cooling the hot zone components after pulling the single crystal are placeable in the multipurpose chamber respectively. As a result, there is provided a single-crystal manufacturing apparatus that enables, in manufacture of a single crystal of a large diameter, e.g., approximately 200 mm or more, an operating rate of the single-crystal manufacturing apparatus and productivity of the single crystal to be improved.

Abstract: Provided is a vitreous silica crucible for pulling a silicon single crystal, having an inner surface layer which is excellent in uniformity and has a low bubble content rate, and a method of manufacturing the same. Provided is a method of manufacturing a vitreous silica crucible for pulling a silicon single crystal comprising the step of forming an inner surface layer 30 made of synthetic silica powder, wherein the inner surface layer 30 comprises an inner side portion 31 of the inner surface layer 30, the inner side portion 31 made of a first synthetic silica powder; and a surface side portion 32 of the inner surface layer 30, the surface side portion made of a second synthetic silica powder having a smaller average particle size than that of the first synthetic silica powder.

Abstract: Disclosed is a silicon single crystal pull-up apparatus that can grow a silicon single crystal having a desired electrical resistivity, to which a sublimable dopant has been reliably added, regardless of the length of the time necessary for the formation of a first half part of a straight body part in a silicon single crystal. Also disclosed is a process for producing a silicon single crystal. The silicon single crystal pull-up apparatus pulls up a silicon single crystal from a melt by a Czochralski method. The silicon single crystal pull-up apparatus comprises a pull-up furnace, a sample chamber that is externally mounted on the pull-up furnace and houses a sublimable dopant, a shielding mechanism that thermally shields the pull-up furnace and the sample chamber, and supply means that, after the release of shielding of the shielding mechanism, supplies the sublimable dopant into the melt.

Abstract: Provided are a vitreous silica crucible which enables, during pulling, crystallization promotion of the inner surface and retention of the crucible strength, and a method of manufacturing the same. The vitreous silica crucible 10 has, in at least a portion of a straight body section 10, a region between 0.3 mm and 3 mm from the crucible inner surface has an OH group concentration and an OH group concentration gradient which increase as a distance from the inner surface decreases, and decrease as a distance from the inner surface increases. The vitreous silica crucible can be manufactured by a process comprising the step of heating and melting silica powder deposited on an inner surface of a rotating mold to vitrify the silica powder, wherein vapor-containing air is introduced during or right after the melting, or the crucible is reheated, after the melting and cooling, under a vapor-containing environment.

Abstract: An apparatus for producing group III nitride crystals includes a pressure container, a reaction vessel positioned in the pressure container, a supplier for supplying an interior of the pressure container with nitrogen gas and nitrogen mixed gas at 1 to 20 MPa, a heater for heating the reaction vessel in the pressure container to at least 700° C., a power unit, a seed crystal arrangement for holding a plurality of seed crystal substrates, a dry box part disposed outside the pressure container, and raising/lowering and rotational axes disposed outside the pressure container.

Abstract: There is provided a silica crucible for pulling a silicon single crystal, comprising silica glass and having a two-layer structure of an outer layer and an inner layer, wherein the inner layer, in a sectional side view of the crucible, has a wavy inner surface shape having mountain parts and valley parts at least between a start position and an end position for the pulling of a silicon single crystal in a silicon melt surface, and when a distance from an upper opening end of the crucible to the start position for the pulling of the silicon single crystal is 100, only a crucible portion from the upper opening end to a position within a range of 40 to 100 is crystalline.

Abstract: A vitreous silica crucible for pulling single-crystal silicon, in which the vibration of a melt surface at the initial stage of the pulling of single-crystal silicon can be suppressed, a shoulder portion of single-crystal silicon can be stably formed, and a high yield of single-crystal silicon can be achieved.

Abstract: A pulling apparatus and a method with which especially heavy crystals (5) can be pulled using the Czochralski method utilizing the pulling apparatus. For this purpose the neck (4) of the crystal (5) has an enlargement (10) beneath which extends the support device. This device includes latches (7), which are moved from a resting position into an operating position in which the latches (7) extend beneath the enlargement (10). Each latch (7) is supported on the base body such that it is swivellable about a pivot axis (8) and can assume two stable positions, namely the resting position and the operating position. Each of these positions is defined by a stop on the base body. When the latch rests on the one stop, its center of gravity, viewed from the neck (4), is located on the other side of the pivot axis (8). When the latch rests on the other stop, the center of gravity is located on this side of the pivot axis (8).

Abstract: An apparatus for supporting a single crystal during Czochralski crystal pulling below a thickened crystal neck has lower bearing surface(s) with a central opening inscribable with a horizontal circle of diameter D1, centered on a vertical axis, the bearing surface(s) connected by connecting element(s) to minimally one securing element for securing to a crystal pulling lifting device, the connecting elements arranged to provide a clear-space in the region above the bearing surface(s) in which a circle of diameter D2 centered on the vertical axis (D2>D1) is inscribable over a length of the vertical axis. The unitary apparatus is useful for crystal ingot growth by immersion into the semiconductor melt prior to growth of a Dash neck and a thickening of the Dash neck. The apparatus is then raised to support the crystal by bearing against the bottom of the thickening.

Abstract: 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 ?m is 10% or more and less than 30%, the content of bubbles having a diameter of 40 ?m or more and less than 90 ?m is 40% or more and less than 80%, and the content of bubbles having a diameter equal to or more than 90 ?m is 10% or more and less than 30%.

Abstract: In order to provide a vitreous silica crucible which does not employ a crystallization accelerator but is difficult to deform during its use even under high temperature, and is easily manufactured, there is provided a vitreous silica crucible for pulling single-crystal silicon wherein the outer surface layer is formed of a bubble-containing vitreous silica layer, the inner surface layer is formed of a vitreous silica layer whose bubbles are invisible to the naked eye, a surface of the outer surface layer includes an unmelted or half-melted silica layer (abbreviated as a half-melted silica layer), and the center line average roughness (Ra) of the half-melted silica layer is 50 to 200 ?m, also preferably, and the thickness of the half-melted silica layer is 0.5 to 2.0 mm.

Abstract: A closure for silica glass crucible to be mounted on an opening portion of a silica glass crucible is provided with a peripheral edge mounting portion closely adhered to an inner peripheral end of the opening portion.

Abstract: Methods of recycling excess semiconductor material removed from an unshaped semiconductor boule are disclosed. Excess semiconductor material is cut from an semiconductor unshaped boule thereby generating a shaped semiconductor boule. The excess semiconductor material is removed in the form of large pieces that can easily be cleaned and retrieved for reuse.