Abstract: A silicon wafer produced from a silicon single crystal ingot grown by Czochralski process is subjected to rapid heating/cooling thermal process at a maximum temperature (T1) of 1300° C. or more, but less than 1380° C. in an oxidizing gas atmosphere having an oxygen partial pressure of 20% or more, but less than 100%. The silicon wafer according to the invention has, in a defect-free region (DZ layer) including at least a device active region of the silicon wafer, a high oxygen concentration region having a concentration of oxygen solid solution of 0.7×1018 atoms/cm3 or more and at the same time, the defect-free region contains interstitial silicon in supersaturated state.

Abstract: A quartz crucible retaining silicon melt is rotated at a prescribed rotating speed, and a silicon single crystal bar pulled from the quartz crucible is rotated at a prescribed rotating speed. A first coil and a second coil having the rotating center of the crucible at the center are arranged in a vertical direction at a prescribed interval, and currents of the same direction are permitted to flow in the first and the second coils to generate a magnetic field. The first coil is arranged outside a chamber, and the second coil is arranged inside the chamber. An intermediate position of the prescribed interval between the first and the second coils is controlled to be at a surface of the silicon melt or below so that a distance between the intermediate position and the surface of the silicon melt is 0 mm or more but not more than 10,000 mm.

Abstract: In appropriate setting of magnetic field applied to a molten silicon 12 stored in a cylindrical quartz crucible 11, the maximum value B0 of magnetic flux density on a vertical symmetric axis 17 as a cylindrical axis of the quartz crucible 11 in horizontal magnetic field generated by a pair of exciting coils 13 and 14 calls B0. On circle at which horizontally symmetric plane 18 traversing and perpendicular to a vertically symmetric axis 17 becoming magnetic flux B0 crosses an inner diameter of the quartz crucible 11, the minimum value of magnetic flux density calls Bmin, and the maximum value of magnetic flux density calls Bmax. Those magnetic flux densities B0, Bmin and Bmax are adjusted to be given ranges, and upward flow and temperature of a molten silicon 12 at the lower part of a solid-liquid interface 15a are appropriately controlled.

Abstract: A silicon wafer produced from a silicon single crystal ingot grown by Czochralski process is subjected to rapid heating/cooling thermal process at a maximum temperature (T1) of 1300° C. or more, but less than 1380° C. in an oxidizing gas atmosphere having an oxygen partial pressure of 20% or more, but less than 100%. The silicon wafer according to the invention has, in a defect-free region (DZ layer) including at least a device active region of the silicon wafer, a high oxygen concentration region having a concentration of oxygen solid solution of 0.7×1018 atoms/cm3 or more and at the same time, the defect-free region contains interstitial silicon in supersaturated state.

Abstract: The axial temperature gradient G at the vicinity of the solid-liquid interface 24 in an ingot is calculated in consideration of the heating value of a heater 18, the dimensions and physical property values of furnace inside components and the convection of the melt 12 before pulling up the single crystal ingot 15 by a puller 10 by use of a numerical simulation of synthetic heater transfers and a numerical simulation of melt convection. Then, the pulling velocity V of the single crystal ingot is determined from an value experienced of the ratio C=V/G of the pulling velocity V and the axial temperature gradient G of the single crystal ingot at which the single crystal ingot becomes defect-free, obtained when the single crystal ingot was pulled up by a same type puller as the puller in the past, and the axial temperature gradient G calculated by use of the simulations.

Abstract: A heat shielding member is provided in a device pulling up a silicon single crystal rod from a silicon melt stored in a quartz crucible, and equipped with a tube portion which shields radiant heat from the heater surrounding the outer peripheral face of the silicon single crystal rod, a swelling portion provided at the lower portion of the tube portion, and a ring-shape heat accumulating portion provided at the inside of the swelling portion. The heat accumulating portion is a thermal conductivity of 5 W/(m·° C.) or less, its inner peripheral face is a height (H1) of 10 mm or more and d/2 or less when the diameter of the silicon single crystal rod is referred to as d and the minimum distance (W1) between the outer peripheral face of the silicon single crystal rod and the inner peripheral face of the heat accumulating portion is formed so as to be 10 mm or more and 0.

Abstract: [Problem] A silicon single crystal ingot in which point defect agglomerates do not exist over a substantially entire length thereof is manufactured without reducing a pure margin. [Solving Means] A heat shielding member 36 comprises a bulge portion 41 which is provided to bulge in an in-cylinder direction at a lower portion of a cylindrical portion 37 and has a heat storage member 47 provided therein. A flow quantity of an inert gas flowing down between the bulge portion 41 in the heat shielding member 36 and an ingot 25 when pulling up a top-side ingot 25a of the silicon single crystal ingot 25 is set larger than a flow quantity of the inert gas flowing down between the bulge portion 41 and the ingot 25 when pulling up a bottom-side ingot 25b of the silicon single crystal ingot 25, thereby pulling up the ingot 25.

Abstract: [Problem] A silicon single crystal ingot in which point defect agglomerates do not exist over a substantially entire length thereof is manufactured without reducing a pure margin. [Solving Means] A heat shielding member 36 comprises a bulge portion 41 which is provided to bulge in an in-cylinder direction at a lower portion of a cylindrical portion 37 and has a heat storage member 47 provided therein. A flow quantity of an inert gas flowing down between the bulge portion 41 in the heat shielding member 36 and an ingot 25 when pulling up a top-side ingot 25a of the silicon single crystal ingot 25 is set larger than a flow quantity of the inert gas flowing down between the bulge portion 41 and the ingot 25 when pulling up a bottom-side ingot 25b of the silicon single crystal ingot 25, thereby pulling up the ingot 25.

Abstract: The axial temperature gradient G at the vicinity of the solid-liquid interface 24 in an ingot is calculated in consideration of the heating value of a heater 18, the dimensions and physical property values of furnace inside components and the convection of the melt 12 before pulling up the single crystal ingot 15 by a puller 10 by use of a numerical simulation of synthetic heater transfers and a numerical simulation of melt convection. Then, the pulling velocity V of the single crystal ingot is determined from an value experienced of the ratio C=V/G of the pulling velocity V and the axial temperature gradient G of the single crystal ingot at which the single crystal ingot becomes defect-free, obtained when the single crystal ingot was pulled up by a same type puller as the puller in the past, and the axial temperature gradient G calculated by use of the simulations.

Abstract: A heat shielding member is provided in a device pulling up a silicon single crystal rod from a silicon melt stored in a quartz crucible, and equipped with a tube portion which shields radiant heat from the heater surrounding the outer peripheral face of the silicon single crystal rod, a swelling portion provided at the lower portion of the tube portion, and a ring-shape heat accumulating portion provided at the inside of the swelling portion. The heat accumulating portion is a thermal conductivity of 5 W/(m·° C.) or less, its inner peripheral face is a height (H1) of 10 mm or more and d/2 or less when the diameter of the silicon single crystal rod is referred to as d and the minimum distance (W1) between the outer peripheral face of the silicon single crystal rod and the inner peripheral face of the heat accumulating portion is formed so as to be 10 mm or more and 0.

Abstract: A thermal shield device is equipped in a crystal-pulling apparatus for pulling a silicon monocrystal ingot from a silicon melt reserved in a quartz crucible having an outer peripheral surface encircled with a heater. The thermal shield device has a tubular part to be used for surrounding a silicon monocrystal ingot being pulled and grown in an upward direction to prevent radiant heat from the heater toward the silicon monocrystal ingot. The tubular part has a lower end positioned above a surface of the silicon melt with a predetermined spacing therebetween. A protruding part is formed on a lower portion of the tubular part and filled with a thermal-insulating member. The protruding part extends to the inside of the tubular part and has a bottom wall, a vertical wall, and a top wall. The bottom wall is shaped like a ring having an outer edge connected to a lower edge of the tubular part and extends to the proximity of an outer peripheral surface of the silicon monocrystal ingot.