Abstract: The invention provides a polycrystalline silicon rod having a total diameter of at least 150 mm, including a core A having a porosity of 0 to less than 0.01 around a thin rod, and at least two subsequent regions B and C which differ in porosity by a factor of 1.7 to 23, the outer region C being less porous than region B.

Abstract: Polycrystalline silicon rods produced by the Siemens process produce a higher yield of CZ crystals when the process parameters are modified in a second stage of deposition such that an outer layer of larger crystallites having a mean swize >20 ?m is produced. Harvesting of these polycrystalline rods and conventional rods by enclosing them in a plastic bag or sheath prior to removal from the reactor also surprisingly increase the yield of CZ crystals grown from a melt containing the sheathed rods.

Abstract: The invention provides a polycrystalline silicon rod having a total diameter of at least 150 mm, including a core A having a porosity of 0 to less than 0.01 around a thin rod, and at least two subsequent regions B and C which differ in porosity by a factor of 1.7 to 23, the outer region C being less porous than region B.

Abstract: The invention provides a polycrystalline silicon rod having a total diameter of at least 150 mm, including a core A having a porosity of 0 to less than 0.01 around a thin rod, and at least two subsequent regions B and C which differ in porosity by a factor of 1.7 to 23, the outer region C being less porous than region B.

Abstract: Polycrystalline silicon rods produced by the Siemens process produce a higher yield of CZ crystals when the process parameters are modified in a second stage of deposition such that an outer layer of larger crystallites having a mean swize>20 ?m is produced. Harvesting of these polycrystalline rods and conventional rods by enclosing them in a plastic bag or sheath prior to removal from the reactor also surprisingly increase the yield of CZ crystals grown from a melt containing the sheathed rods.

Abstract: Polycrystalline silicon of the invention contains: (a) polycrystalline silicon fragments, wherein at least 90% of the fragments have a size from 10 to 40 mm, (b) <15 ppmw of silicon dust particles having particle sizes <400 ?m; (c) <14 ppmw of silicon dust particles having particle sizes <50 ?m; (d) <10 ppmw of silicon dust particles having particle sizes <10 ?m; (e) <3 ppmw of silicon dust particles having particle sizes <1 ?m; and (f) surface metal impurities in an amount ?0.1 ppbw and ?100 ppbw. A polycrystalline silicon production method of the invention includes fracturing polycrystalline silicon deposited on thin rods in a Siemens reactor into fragments; classifying the fragments by size; and treating the fragments with compressed air or dry ice to remove silicon dust from the fragments without wet chemical cleaning.

Abstract: The invention provides a polycrystalline silicon rod having a total diameter of at least 150 mm, including a core A having a porosity of 0 to less than 0.01 around a thin rod, and at least two subsequent regions B and C which differ in porosity by a factor of 1.7 to 23, the outer region C being less porous than region B.

Abstract: Polycrystalline silicon of the invention contains: (a) polycrystalline silicon fragments, wherein at least 90% of the fragments have a size from 10 to 40 mm, (b) <15 ppmw of silicon dust particles having particle sizes <400 ?m; (c) <14 ppmw of silicon dust particles having particle sizes <50 ?m; (d) <10 ppmw of silicon dust particles having particle sizes <10 ?m; (e) <3 ppmw of silicon dust particles having particle sizes <1 ?m; and (f) surface metal impurities in an amount ?0.1 ppbw and ?100 ppbw. A polycrystalline silicon production method of the invention includes fracturing polycrystalline silicon deposited on thin rods in a Siemens reactor into fragments; classifying the fragments by size; and treating the fragments with compressed air or dry ice to remove silicon dust from the fragments without wet chemical cleaning.

Abstract: A method for pulling a single crystal has a monocrystalline seed crystal being brought into contact with molten material and an interface being formed between solid and molten material, and molten material being caused to solidify with the formation of a thin-necked crystal and a cylindrical single crystal. The method is one wherein, during the pulling of the thin-necked crystal, it is ensured that the ratio V/G(r) is above a constant Ccrit having the value 1.3*10−3 cm2/Kmin, with V being the pulling rate, with G(r) being the axial temperature gradient at the interface and r being the radial distance from the center of the thin-necked crystal.

Abstract: Device for pulling a silicon single crystal 1 includes an element 5 which annularly surrounds the single crystal growing at a crystallization boundary; and the element has a face 6 directed at the single crystal. The element surrounds the single crystal substantially level with the crystallization boundary 2 and has the property of reflecting heat radiation radiated by the single crystal and the similar melt or of generating and radiating heat radiation back to the lower part of the crystal close to the crystallization boundary. There is also a method for pulling a silicon single crystal, in which the single crystal is thermally affected using the element surrounding it.

Abstract: A method and an apparatus for pulling a silicon monocrystal from a melt iudes the pulling of a conical portion in each case at the beginning and at the end of the monocrystal and the pulling of a cylindrical portion between the conical portions. In this method, the surface of the conical portion at the beginning of the monocrystal is shielded by a shielding means spaced apart from the monocrystal.

Abstract: A method for producing a silicon monocrystal has a growing monocrystal kept for a specified dwell time in the specified temperature range of from 850.degree. C. to 1100.degree. C. This dwell time for the growing monocrystal in the chosen temperature range is either greater than 250 min or less than 80 min. A device and a method, in which the cooling rate of the growing monocrystal is to be influenced, has a heat shield which is subdivided into adjacent annular zones between a lower rim and an upper rim. These adjacent zones differ in regard to each's thermal conduction and transparency to heat radiation.

Abstract: A process and an apparatus control the growth of a crystal, which growth is governed by a set of measurable and non-measurable variables. The process includes establishing an on-line simulation software working with a reduced number of variables, the reduction of variables being performed by using a projection algorithm; speeding up the on-line simulation software by generating data banks in which values of off-line precalculated variables are stored; tuning the on-line simulation software by adjusting the results predicted by on-line simulations to the results obtained by off-line simulations and by measurements; and establishing a control loop and controlling at least one of the variables in real time, the control loop using the speeded up and tuned on-line simulation software as an on-line observer.

Abstract: A method and an apparatus for pulling a silicon monocrystal from a melt iudes the pulling of a conical portion in each case at the beginning and at the end of the monocrystal and the pulling of a cylindrical portion between the conical portions. In this method, the surface of the conical portion at the beginning of the monocrystal is shielded by a shielding means spaced apart from the monocrystal.

Abstract: Apparatus for producing a single crystal of semiconductor material in accance with the Czochralski method, has a cooling means which cools the growing single crystal and is constructed in two parts, The first is an upper part duct system through which a liquid coolant flows. The second is a lower part which is a heat-conducting cooling body.

Abstract: A method for pulling a silicon single crystal has the single crystal being pulled at a speed defined as maximum pulling speed in the vertical direction with respect to a silicon melt held in a crucible. The value of the maximum pulling speed is approximately proportional to the axial temperature gradient in the growing single crystal.