Abstract: There are disclosed a silicon seed crystal which is composed of silicon single crystal and used for the Czochralski method, wherein oxygen concentration in the seed crystal is 15 ppma (JEIDA) or less, a silicon seed crystal which is used for the Czochralski method, wherein the silicon seed crystal does not have a straight body, and a method for producing a silicon single crystal by the Czochralski method comprising using said seed crystal, bringing a tip end of the seed crystal into contact with a silicon melt to melt the tip end of the seed crystal, with or without performing necking operation, and growing a silicon single crystal.

Abstract: There are disclosed a silicon seed crystal which is composed of silicon single crystal and used for the Czochralski method, wherein oxygen concentration in the seed crystal is 15 ppma (JEIDA) or less, a silicon seed crystal which is used for the Czochralski method, wherein the silicon seed crystal does not have a straight body, and a method for producing a silicon single crystal by the Czochralski method comprising using said seed crystal, bringing a tip end of the seed crystal into contact with a silicon melt to melt the tip end of the seed crystal, with or without performing necking operation, and growing a silicon single crystal. The method is capable of improving the rate of success in making crystals dislocation-free and the productivity of single crystal rods regardless of the use of necking operation.

Abstract: There are disclosed a silicon seed crystal which is composed of silicon single crystal and used for the Czochralski method, wherein oxygen concentration in the seed crystal is 15 ppma (JEIDA) or less, a silicon seed crystal which is used for the Czochralski method, wherein the silicon seed crystal does not have a straight body, and a method for producing a silicon single crystal by the Czochralski method comprising using said seed crystal, bringing a tip end of the seed crystal into contact with a silicon melt to melt the tip end of the seed crystal, with or without performing necking operation, and growing a silicon single crystal.

Abstract: In a method for producing a silicon single crystal by growing a single crystal ingot while a magnetic field perpendicular to a crystal growth axis is applied to a silicon melt contained in a quartz crucible during pulling of the single crystal from the melt contained in the quartz crucible, the crystal growth is performed so that one of a low temperature region and a high temperature region generated at a surface of the silicon melt contained in the crucible should always cover a solid-liquid interface of the crystal growth, or a ratio of vertical magnetic field component to horizontal magnetic field component for magnetic field strength at the crystal center of the surface of the silicon melt contained in the quartz crucible is controlled to be 0.3 or more and 0.5 or less.

Abstract: In method for manufacturing a silicon single crystal in accordance with a Czochralski method, during the growth of the silicon single crystal, pulling is performed such that a solid-liquid interface in the crystal, excluding a peripheral 5 mm-width portion, exists within a range of an average vertical position of the solid-liquid interface ±5 mm. There is also disclosed a method for manufacturing a silicon single crystal in accordance with the Czochralski method, wherein during the growth of a silicon single crystal, a furnace temperature is controlled such that a temperature gradient difference &Dgr;G (=Ge−Gc) is not greater than 5° C./cm, where Ge is a temperature gradient (° C./cm) at a peripheral portion of the crystal, and Gc is a temperature gradient (° C./cm) at a central portion of the crystal, both in an in-crystal descending temperature zone between 1420° C. and 1350° C. or between a melting point of silicon and 1400° C.

Abstract: A method for producing a silicon single crystal in accordance with the Czochralski method. The single crystal is grown in an N2(V) region where a large amount of precipitated oxygen and which is located within an N region located outside an OSF ring region, or is grown in a region including the OSF ring region, N1(V) and N2(V) regions located inside and outside the OSF ring region, in a defect distribution chart which shows a defect distribution in which the horizontal axis represents a radial distance D (mm) from the center of the crystal and the vertical axis represents a value of F/G (mm2/° C.·min), where F is a pulling rate (mm/min) of the single crystal, and G is an average intra-crystal temperature gradient (° C./mm) along the pulling direction within a temperature range of the melting point of silicon to 1400° C.

Abstract: A method for producing a single crystal by pulling the single crystal with a wire according to the Czochralski method, wherein temperature around an end of joint part of the wire and a seed crystal holder is controlled so as not to exceed 1200° C., preferably 800° C., at any time, and material of the wire is one selected from tungsten, stainless steel and molybdenum, and a pulling apparatus therefor. According to the present invention, there can be provided a method in which temperature around an end of joint part of a wire and a seed crystal holder is controlled so as not to exceed a temperature at which material degradation of the wire begins during the period of from seeding to an early stage of the pulling, and a pulling apparatus therefor.

Abstract: There is disclosed a method of producing a silicon monocrystal which comprises preparing a silicon seed crystal having a sharp tip end, and melting down a part of the silicon seed crystal from a tip end to a position having a predetermined thickness, followed by performing a necking operation to form a tapered necking part and a neck portion, and subsequently pulling a monocrystal ingot after increasing a diameter, wherein said part to be melted down is a part from a tip end to a position in which a thickness is twice as large as the diameter of the neck portion to be formed or more; said necking operation is performed in such a way that a tapered necking part is formed at an early stage by pulling a crystal with gradually decreasing the diameter to a minimum diameter of 5 mm or more, and then a neck portion is formed, subsequently the monocrystal ingot is pulled with increasing a diameter.

Abstract: There is provided a seed crystal having a strength that the seed crystal is not broken even when the heavy single crystal is produced. The seed crystal is a seed crystal used for producing a single crystal according to Czochralski method wherein a relation between a sectional area of the seed crystal S (mm2) and a weight W (kg) of the single crystal to be pulled is represented by the formula: S>W. The single crystal is produced using the seed crystal. Furthermore, the single crystal is pulled with conforming a sectional area S (mm2) of a seed crystal and a weight W (kg) of a single crystal to be pulled to the formula: S>W.

Abstract: In a method of manufacturing a silicon monocrystalline ingot using the Czochralski (CZ) method, there is used a seed crystal whose tip end has a sharp-pointed shape or a truncation thereof, and the maximum apex angle is not less than 3° but not greater than 28°. In this case, a monocrystal having an etched tip end portion or a monocrystalline ingot manufactured in accordance with the CZ method and having a tail portion is used as the seed crystal. Further, there may be used a silicon seed crystal having a tapered tip end portion of a conical or pyramidal shape, a straight body portion of a cylindrical columnar or rectangular columnar shape, and an intermediate portion located between the tip end portion and the straight body portion and having a truncated conical or pyramidal shape formed by a curved outer surface. A silicon monocrystalline ingot having a desired diameter is grown through use of such a seed crystal without performance of necking.

Abstract: In a method for producing a silicon single crystal, a silicon seed crystal having a sharp tip end is prepared, and a part of the silicon seed crystal is melted down from a tip end to a position having a predetermined thickness. This is followed by performing a necking operation to form a tapered necking part and a neck portion, and by subsequently pulling a single crystal ingot after increasing a diameter. The part to be melted down is a part from a tip end to a position in which a thickness is 1.1 to 2 times the diameter of the neck portion to be formed. The necking operation is then performed in such a way that a tapered necking part in the shape of a cone is formed at an early stage thereof by pulling a crystal with gradually decreasing a diameter to a minimum diameter of 5 mm or more, then forming a neck portion. Subsequently, the single crystal ingot is pulled after being increased in diameter.

Abstract: A method for producing a silicon single crystal by a Czochralski method comprises bringing a seed crystal into contact with a melt, performing a necking operation, and growing a single crystal ingot, wherein concentration of interstitial oxygen incorporated during the necking operation is 1 ppma (JEIDA) or more. The rate of success in making dislocation-free crystals is improved in a seeding method in which a necking operation is performed.

Abstract: There is disclosed a method of producing a silicon monocrystal using a Czochralski method in which a sharp tip end of a seed crystal is brought into contact with silicon melt and is melted, and the seed crystal is then pulled, without performance of a necking operation, in order to grow a silicon monocrystalline ingot below the seed crystal. The operation of melting the seed crystal into the silicon melt is performed in a state in which a temperature in the vicinity of the surface of the silicon melt is set in a range between a temperature 25.degree. C. higher than the melting point of silicon and a temperature 45.degree. C. higher than the melting point of silicon. The operation of growing the monocrystal is started within 0 to 10 minutes after completion of the operation of melting the sharp tip end of the seed crystal into the silicon melt. The monocrystal is grown at a rate in a range of 0.3 to 0.7 mm/min when growth of the monocrystal is started after completion of the melting operation.

Abstract: Apparatus for measuring the mechanical strength of a neck portion of a silicon seed crystal used for growing a silicon crystal by the Czochralski method includes a seed chuck for holding the seed crystal of a test sample and an end of a wire hung from an upper hook. A crystal holder which holds the other end part of the test sample from below is tied to a lower hook with another wire to support the holder. The apparatus includes means for pulling the hook at a given rate, and measuring means for continuously measuring tensile load. Such apparatus and the method thereby provide accurate measurement of mechanical strength of the neck portion of the silicon seed crystal with good precision and reproducibility. A single crystal ingot is grown under conditions affording good balance of productivity and safety.

Abstract: In method for manufacturing a silicon single crystal in accordance with a Czochralski method, during the growth of the silicon single crystal, pulling is performed such that a solid-liquid interface in the crystal, excluding a peripheral 5 mm-width portion, exists within a range of an average vertical position of the solid-liquid interface.+-. 5 mm. There is also disclosed a method for manufacturing a silicon single crystal in accordance with the Czochralski method, wherein during the growth of a silicon single crystal, a furnace temperature is controlled such that a temperature gradient difference .DELTA.G (=Ge-Gc) is not greater than 5.degree. C./cm, where Ge is a temperature gradient (.degree. C./cm) at a peripheral portion of the crystal, and Gc is a temperature gradient (.degree. C./cm) at a central portion of the crystal, both in an in-crystal descending temperature zone between 1420.degree. C. and 1350.degree. C. or between a melting point of silicon and 1400.degree. C.

Abstract: A silicon single-crystal wafer having a diameter of 6 inches or larger and improved in the dielectric breakdown strength of oxide film especially in a peripheral part thereof is provided to thereby heighten the yield of device chips produced per wafer. This wafer has no crystal defects with regard to the dielectric breakdown strength of oxide film in its peripheral region which extends from the circumference and accounts for up to 50% of the total area, in particular which extends from the circumference to a circle 30 mm apart from the circumference. A process for producing a silicon single crystal for easily producing, by the Czochralski method, a silicon single-crystal wafer improved in the dielectric breakdown strength of oxide film especially in a peripheral part thereof without considerably lowering the production efficiency is provided.

Abstract: A single crystal is grown in accordance with a Czochralski method such that the time for passing through a temperature zone of 1150-1080.degree. C. is 20 minutes or less, or such that the length of a portion of the single crystal corresponding to the temperature zone of 1150-1080.degree. C. in the temperature distribution is 2.0 cm or less. Alternatively, the single crystal is grown such that the time for passing through a temperature zone of 1250-1200.degree. C. is 20 minutes or less, or such that the length of a portion of the single crystal corresponding to the temperature zone of 1250-1200.degree. C. in the temperature distribution is 2.0 cm or less. This method decreases both the density and size of so-called grown-in defects such as FPD (100 defects/cm.sup.2 or less), LSTD, and COP (10 defects/cm.sup.2 or less) to thereby enable efficient production of a single crystal having an excellent good chip yield (80% or greater) in terms of oxide dielectric breakdown voltage characteristics.

Abstract: In a method for producing a silicon single crystal wafer, a silicon single crystal is grown in accordance with the Czochralski method such that the F/G value becomes 0.112-0.142 mm.sup.2 /.degree. C..multidot.min at the center of the crystal, where F is a pulling rate (mm/min) of the single crystal, and G is an average intra-crystal temperature gradient (.degree. C./mm) along the pulling direction within a temperature range of the melting point of silicon to 1400.degree. C. Additionally, the single crystal is pulled such that the interstitial oxygen concentration becomes less than 24 ppma, or the time required to pass through a temperature zone of 1050-850.degree. C. within the crystal is controlled to become 140 minutes or less. The method allows production of silicon single crystal wafers in which neither FPDs nor L/D defects exist on the wafer surface, which therefore has an extremely low defect density, and whose entire surface is usable.

Abstract: A method and apparatus for growing and manufacturing a single crystal according to a so-called Czochralski (CZ) method. A seed crystal 12 is connected to a tip end of a wire 41a as a hanging member 41 to pull and form a single crystal part 15, arm-shaped members 44a of a lifting jig 44 are engaged in a recess 16 of a corrugated portion 14 formed on the single crystal part 15 during the pulling operation, the pulling speeds of both of the arm-shaped members 44a and wire 41a are synchronously controlled to provide smooth transfer between the arm-shaped members 44a and wire 41a, whereby the single crystal part 15 is pulled always at a constant pulling speed. In particular, a heavy-weight single crystal can be safely pulled and formed without any dislocation therein while minimizing an impact force applied to the crystal.

Abstract: In a method for producing a silicon single crystal wafer, a silicon single crystal is grown in accordance with the Czochralski method such that the F/G value becomes 0.112-0.142 mm.sup.2 /.degree.C.multidot.min at the center of the crystal, where F is a pulling rate (mm/min) of the single crystal, and G is an average intra-crystal temperature gradient (.degree.C/mm) along the pulling direction within a temperature range of the melting point of silicon to 1400.degree. C. Additionally, the single crystal is pulled such that the interstitial oxygen concentration becomes less than 24 ppma , or the time required to pass through a temperature zone of 1050-850.degree. C. within the crystal is controlled to become 140 minutes or less. The method allows production of silicon single crystal wafers in which neither FPDs nor L/D defects exist on the wafer surface, which therefore has an extremely low defect density, and whose entire surface is usable.