Abstract: A single-crystal pulling apparatus includes: a pulling furnace having a heater and crucible; and a magnetic field generation device having superconducting coils, the device having four of the superconducting coils, two of the superconducting coils are in each of two regions divided by a cross section that includes an X axis being a direction of magnetic force lines at the central axis in the horizontal plane including all the coil axes of the four superconducting coils, and includes the pulling furnace central axis having line symmetry about the cross section, the four superconducting coils are all arranged so that the coil axes have an angle of more than ?30° and less than 30° relative to a Y axis, the direction of the magnetic force lines thereof have line symmetry about the cross section, and in each of the regions, the two superconducting coils generate magnetic force lines in opposite directions.

Abstract: A single-crystal pulling apparatus including: a pulling furnace having a central axis; and a magnetic field generation device arranged around the pulling furnace and having superconducting coils, the apparatus applying a horizontal magnetic field to the molten semiconductor raw material, two coil axes in the two pairs of the superconducting coils are included in a single horizontal plane, and when a direction of lines of magnetic force at the central axis of the pulling furnace in the horizontal plane is determined as an X axis, a center angle ? having the X axis between the two coil axes is 100 degrees or more and 120 degrees or less. This makes it possible to reduce the height of the coils, to raise the magnetic field center close to the melt surface of the semiconductor raw material, and to obtain a single crystal having a lower oxygen concentration than conventional single crystals.

Abstract: The present invention is a single crystal pulling apparatus which includes a pulling furnace having a central axis and a magnetic field generating apparatus having coils, and applies a horizontal magnetic field to a molten semiconductor raw material, wherein the coils are saddle-shaped, two pairs of the coils are provided with the coils of each pair arranged facing each other, two coil axes in the two pairs of coils are included in the same horizontal plane, when a magnetic force line direction on the central axis of the pulling furnace in the horizontal plane is defined as a X-axis, and a direction perpendicular to the X-axis in the horizontal plane is defined as a Y-axis, a center angle ? between the two coil axes sandwiching the X-axis is 90 degrees or less and an inter-coil angle ? between adjacent superconducting coils sandwiching the Y-axis is 20 degrees or less.

Abstract: A single crystal pulling apparatus includes: a pulling furnace having a central axis; and magnetic field generating apparatus around the pulling furnace and having coils, for applying a horizontal magnetic field to molten semiconductor raw material to suppress convection in crucible, in which, main coils and sub-coils are provided, as the main coils, two pairs of coils arranged facing each other are provided, two coil axes thereof are included in the same horizontal plane, a center angle ? between the two coil axes sandwiching the X-axis, which is a magnetic force line direction on the central axis in the horizontal plane, is 100 degrees or more and 120 degrees or less, as the sub-coils, a pair of superconducting coils arranged to face each other is provided and its one coil axis is aligned with the X-axis, and current values of the main coils and the sub-coils can be set independently.

Abstract: A single crystal manufacturing including: main chamber; pulling chamber; thermal shield member provided so as to face a silicon melt; rectifying cylinder provided on the thermal shield member so as to enclose the silicon single crystal being pulled up; cooling cylinder provided so as to encircle the silicon single crystal being pulled up and including an extending portion extending toward the silicon melt; and cooling auxiliary cylinder fitted to inside of the cooling cylinder. The extending portion of the cooling cylinder includes a bottom surface facing the silicon melt. The cooling auxiliary cylinder includes at least a first portion surrounding the bottom surface of the cooling cylinder and a second portion surrounding an upper end portion of the rectifying cylinder. This enables provision of the apparatus capable of manufacturing a single crystal with a carbon concentration lower than that according to the conventional technologies.

Abstract: The present invention is a single-crystal pulling apparatus including: a pulling furnace which has a heater and a crucible arranged and which has a central axis; and a magnetic field generation device having superconducting coils, where the magnetic field generation device has four of the superconducting coils, two of the superconducting coils are arranged in each of two regions divided by a cross section that includes an X axis, the X axis being a direction of lines of magnetic force at the central axis in the horizontal plane including all the coil axes of the four superconducting coils, and includes the central axis of the pulling furnace so as to have line symmetry about the cross section, the four superconducting coils are all arranged so that the coil axes have an angle within a range of more than ?30° and less than 30° relative to a Y axis, the direction of the lines of magnetic force thereof have line symmetry about the cross section, and in each of the regions, the two superconducting coils generate

Abstract: A single-crystal pulling apparatus including: a pulling furnace having a central axis; and a magnetic field generation device arranged around the pulling furnace and having superconducting coils, the apparatus applying a horizontal magnetic field to the molten semiconductor raw material, two coil axes in the two pairs of the superconducting coils are included in a single horizontal plane, and when a direction of lines of magnetic force at the central axis of the pulling furnace in the horizontal plane is determined as an X axis, a center angle ? having the X axis between the two coil axes is 100 degrees or more and 120 degrees or less. This makes it possible to reduce the height of the coils, to raise the magnetic field center close to the melt surface of the semiconductor raw material, and to obtain a single crystal having a lower oxygen concentration than conventional single crystals.

Abstract: A method controls a resistivity of a grown silicon single crystal by using a dopant when the silicon single crystal is grown by CZ method, including the steps of initially doping with a primary dopant such that the silicon single crystal has a predetermined conductive type and additionally doping with a secondary dopant having a conductive type opposite to that of the primary dopant continuously or intermittently, according to a solidification rate expressed by (crystalized weight)/(initial weight of silicon raw material) while growing the silicon single crystal, wherein in the additional doping step, the additional doping with the secondary dopant is carried out when the solidification rate is a predetermined value ? or more, while the crystal is not doped with the secondary dopant until the solidification rate reaches the predetermined value ?.

Abstract: A single-crystal pulling apparatus including a pulling furnace containing a crucible containing molten single crystal material, and a magnetic field generation device that is arranged around the furnace, has superconducting coils, and generates a magnetic field distribution. A magnetic flux density distribution on an X axis, which is a direction of magnetic force lines at the central axis in a horizontal plane, is a convex upward distribution, and a magnetic flux density on the X axis becomes 80% or less of a magnetic flux density set value at a crucible wall. Simultaneously, a magnetic flux density distribution on a Y axis, orthogonal to the X axis, is a convex downward distribution, and a magnetic flux density on the Y axis becomes 140% or more of the set value at the crucible wall when the magnetic flux density at the central axis in the horizontal plane is the set value.

Abstract: A single-crystal pulling apparatus including a pulling furnace containing a crucible containing molten single crystal material, and a magnetic field generation device that is arranged around the furnace, has superconducting coils, and generates a magnetic field distribution. A magnetic flux density distribution on an X axis, which is a direction of magnetic force lines at the central axis in a horizontal plane, is a convex upward distribution, and a magnetic flux density on the X axis becomes 80% or less of a magnetic flux density set value at a crucible wall. Simultaneously, a magnetic flux density distribution on a Y axis, orthogonal to the X axis, is a convex downward distribution, and a magnetic flux density on the Y axis becomes 140% or more of the set value at the crucible wall when the magnetic flux density at the central axis in the horizontal plane is the set value.

Abstract: A method controls a resistivity of a grown silicon single crystal by using a dopant when the silicon single crystal is grown by CZ method, including the steps of initially doping with a primary dopant such that the silicon single crystal has a predetermined conductive type and additionally doping with a secondary dopant having a conductive type opposite to that of the primary dopant continuously or intermittently, according to a solidification rate expressed by (crystalized weight)/(initial weight of silicon raw material) while growing the silicon single crystal, wherein in the additional doping step, the additional doping with the secondary dopant is carried out when the solidification rate is a predetermined value ? or more, while the crystal is not doped with the secondary dopant until the solidification rate reaches the predetermined value ?.

Abstract: There is provided a method for manufacturing a silicon single crystal, the method includes: a raw material melting step of melting polycrystalline silicon accommodated in a crucible to obtain a silicon melt; and bringing a seed crystal into contact with the silicon melt and pulling up the seed crystal to grow the silicon single crystal, wherein, after the raw material melting step and before the pulling step, there are performed: a cristobalitizing step of leaving the silicon melt at a predetermined number of rotations of the crucible with a predetermined gas flow rate and a predetermined furnace pressure to generate cristobalite while applying a magnetic field; and a dissolving step of partially dissolving the cristobalite by carrying out any one of an increase in number of rotations of the crucible, an increase in gas flow rate, and a reduction in furnace pressure beyond counterpart figures in the cristobalitizing step.

Abstract: The present invention is an apparatus for producing a single crystal, growing the single crystal by the Czochralski method and comprising at least: a main chamber in which a crucible for accommodating a raw material melt and a heater for heating the raw material melt are arranged; a pulling chamber into which the grown single crystal is pulled and accommodated, the pulling chamber being continuously provided above the main chamber; and a cooling cylinder extending at least from a ceiling of the main chamber toward a surface of the raw material melt so as to surround the single crystal during pulling, the cooling cylinder being forcibly cooled with a cooling medium. As a result, there is provided an apparatus for producing a single crystal that can increase the growth rate of the single crystal by efficiently cooling the single crystal during the growth.

Abstract: The present invention provides an apparatus for producing single crystals according to the Czochralski method, the apparatus including a chamber that can be divided into a plurality of chambers; at least one of the plurality of divided chambers having a circulating coolant passage in which a circulating coolant for cooling the chamber circulates; and measuring means that respectively measure an inlet temperature, an outlet temperature, and a circulating coolant flow rate of the circulating coolant in the circulating coolant passage; the apparatus further including a calculating means that calculates a quantity of heat removed from the chamber and/or a proportion of the quantity of removed heat, from the measured values of the inlet temperature, outlet temperature, and circulating coolant flow rate; and a pulling rate control means that controls a pulling rate of the single crystal based on the resulting quantity of removed heat and/or the resulting proportion of the quantity of removed heat.

Abstract: There is provided a method for manufacturing a silicon single crystal, the method includes: a raw material melting step of melting polycrystalline silicon accommodated in a crucible to obtain a silicon melt; and bringing a seed crystal into contact with the silicon melt and pulling up the seed crystal to grow the silicon single crystal, wherein, after the raw material melting step and before the pulling step, there are performed: a cristobalitizing step of leaving the silicon melt at a predetermined number of rotations of the crucible with a predetermined gas flow rate and a predetermined furnace pressure to generate cristobalite while applying a magnetic field; and a dissolving step of partially dissolving the cristobalite by carrying out any one of an increase in number of rotations of the crucible, an increase in gas flow rate, and a reduction in furnace pressure beyond counterpart figures in the cristobalitizing step.

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: The present invention is directed to an upper heater for use in the production of a single crystal, the upper heater in which at least 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 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.

Abstract: The present invention is an apparatus for producing a single crystal, growing the single crystal by the Czochralski method and comprising at least: a main chamber in which a crucible for accommodating a raw material melt and a heater for heating the raw material melt are arranged; a pulling chamber into which the grown single crystal is pulled and accommodated, the pulling chamber being continuously provided above the main chamber; and a cooling cylinder extending at least from a ceiling of the main chamber toward a surface of the raw material melt so as to surround the single crystal during pulling, the cooling cylinder being forcibly cooled with a cooling medium. As a result, there is provided an apparatus for producing a single crystal that can increase the growth rate of the single crystal by efficiently cooling the single crystal during the growth.

Abstract: The present invention provides an apparatus for producing single crystals according to the Czochralski method, the apparatus including a chamber that can be divided into a plurality of chambers; at least one of the plurality of divided chambers having a circulating coolant passage in which a circulating coolant for cooling the chamber circulates; and measuring means that respectively measure an inlet temperature, an outlet temperature, and a circulating coolant flow rate of the circulating coolant in the circulating coolant passage; the apparatus further including a calculating means that calculates a quantity of heat removed from the chamber and/or a proportion of the quantity of removed heat, from the measured values of the inlet temperature, outlet temperature, and circulating coolant flow rate; and a pulling rate control means that controls a pulling rate of the single crystal based on the resulting quantity of removed heat and/or the resulting proportion of the quantity of removed heat.

Abstract: The present invention provides a method of producing an SOI wafer, comprising at least steps of forming an oxygen ion-implanted layer by implanting oxygen ions into a silicon wafer from one main surface thereof, subjecting the silicon wafer to oxide film-forming heat treatment to convert the oxygen ion-implanted layer into a buried oxide film, and thereby producing an SOI wafer having an SOI layer on the buried oxide film, wherein when the buried oxide film is formed in the silicon wafer, the buried oxide film is formed so that a thickness thereof is thicker than a thickness of the buried oxide film which the SOI wafer to be produced has, and thereafter the silicon wafer in which the thicker buried oxide film is formed is subjected to a heat treatment to reduce the thickness of the buried oxide film.