Abstract: Electrode assemblies useful, inter alia, for mounting thin rods in Siemens reactors for manufacture of polysilicon, have a base segment which receives a holder segment, and an insert, interfacial surface(s) of which have depressions and/or elevations which reduce contact surface area, allowing the holder, base segment, insert, and optional intermediate segments to be constructed of materials having different thermal conductivities.

Abstract: Method for producing polycrystalline silicon by inducing reaction gas, which in addition to hydrogen contains silane and/or at least one halosilane, into a reaction space of a vapour deposition reactor. The reaction space comprises at least one filament rod heated by the passage of current and on which by means of deposition silicon is deposited to form a polycrystalline silicon rod. A determination of morphology of the silicon rod during deposition at a rod temperature a first resistance R1 of the silicon rod is determined by R 1 = U I where U is a voltage between two ends of the silicon rod and I is a current strength, and a second resistance R2 is determined by R 2 = ? ? L A were ? is a resistivity of silicon, L is a length of the silicon rod and A is a cross-sectional area of the silicon rod. A morphology index M is calculated from the ratio R1/R2.

Abstract: A method for producing polycrystalline silicon includes introducing a reaction gas, which in addition to hydrogen contains silane and/or at least one halosilane, into a reaction space of a gas phase deposition reactor. The reaction space includes at least one heated filament rod upon which by deposition silicon is deposited to form a polycrystalline silicon rod. During the deposition, the the morphology of the silicon rod is determined.

Abstract: Electrode assemblies useful, inter alia, for mounting thin rods in Siemens reactors for manufacture of polysilicon, have a base segment which receives a holder segment, and an insert, interfacial surface(s) of which have depressions and/or elevations which reduce contact surface area, allowing the holder, base segment, insert, and optional intermediate segments to be constructed of materials having different thermal conductivities.

Abstract: Silicon single crystals are grown from the melt by providing the melt in a crucible; imposing a horizontal magnetic field on the melt; directing a gas between the single crystal and a heat shield to a melt free surface, and controlling the gas to flow over a region of the melt free surface extending in a direction substantially perpendicular to the magnetic induction. A suitable apparatus has a crucible for holding the melt; a heat shield surrounding the silicon single crystal having a lower end which is connected to a bottom cover facing a melt free surface and a non-axisymmetric shape with respect to a crucible axis, such that gas which is directed between the crystal and the heat shield to the melt free surface is forced to flow over a region of the melt which extends substantially perpendicular to the magnetic induction.

Abstract: Silicon semiconductor wafers are produced by pulling a single crystal at a seed crystal from a melt heated in a crucible; supplying heat to the center of the crucible bottom with a heating power which, in the course of the growth of a cylindrical section of the single crystal, is increased at least once to not less than 2 kW and is then decreased again; and slicing semiconductor wafers from the pulled single crystal.

Abstract: Silicon single crystals are grown from the melt by providing the melt in a crucible; imposing a horizontal magnetic field on the melt; directing a gas between the single crystal and a heat shield to a melt free surface, and controlling the gas to flow over a region of the melt free surface extending in a direction substantially perpendicular to the magnetic induction. A suitable apparatus has a crucible for holding the melt; a heat shield surrounding the silicon single crystal having a lower end which is connected to a bottom cover facing a melt free surface and a non-axisymmetric shape with respect to a crucible axis, such that gas which is directed between the crystal and the heat shield to the melt free surface is forced to flow over a region of the melt which extends substantially perpendicular to the magnetic induction.

Abstract: Silicon semiconductor wafers are produced by pulling a single crystal at a seed crystal from a melt heated in a crucible; supplying heat to the center of the crucible bottom with a heating power which, in the course of the growth of a cylindrical section of the single crystal, is increased at least once to not less than 2 kW and is then decreased again; and slicing semiconductor wafers from the pulled single crystal.

Abstract: Silicon single crystals are grown from the melt by providing the melt in a crucible; imposing a horizontal magnetic field on the melt; directing a gas between the single crystal and a heat shield to a melt free surface, and controlling the gas to flow over a region of the melt free surface extending in a direction substantially perpendicular to the magnetic induction. A suitable apparatus has a crucible for holding the melt; a heat shield surrounding the silicon single crystal having a lower end which is connected to a bottom cover facing a melt free surface and a non-axisymmetric shape with respect to a crucible axis, such that gas which is directed between the crystal and the heat shield to the melt free surface is forced to flow over a region of the melt which extends substantially perpendicular to the magnetic induction.