Abstract: The invention provides chunk polycrystalline silicon having a concentration of carbon at the surface of 0.5-35 ppbw. A process for cleaning polycrystalline silicon chunks having carbon contaminations at the surface, includes a thermal treatment of the polycrystalline silicon chunks in a reactor at a temperature of 350 to 600° C., the polycrystalline silicon chunks being present in an inert gas atmosphere during the thermal treatment, and the polycrystalline silicon chunks after the thermal treatment having a concentration of carbon at the surface of 0.5-35 ppbw.

Abstract: The invention provides chunk polycrystalline silicon having a concentration of carbon at the surface of 0.5-35 ppbw. A process for cleaning polycrystalline silicon chunks having carbon contaminations at the surface, includes a thermal treatment of the polycrystalline silicon chunks in a reactor at a temperature of 350 to 600° C., the polycrystalline silicon chunks being present in an inert gas atmosphere during the thermal treatment, and the polycrystalline silicon chunks after the thermal treatment having a concentration of carbon at the surface of 0.5-35 ppbw.

Abstract: Polycrystalline silicon in the form of chunks packed in plastic bags containing a mass of at least 5 kg, including chunks of size from 20 to 200 mm, wherein any fines fraction in the plastic bag is less than 900 ppmw, preferably less than 300 ppmw, more preferably less than 10 ppmw. The polycrystalline silicon, after comminution of a silicon rod obtained by CVD (Siemens process), is sorted and classified, optionally dedusted and then metered and packed. Metering and packing units include elements for removing fines or small particles during metering and during packing. The packing unit includes an energy absorber or a reservoir vessel which enables sliding or slipping of the silicon chunks into the plastic bag. Gas flow generated within the plastic bag after the bag has been filled transports the dust or small particles out of the bag, and these are sucked out with a suction device.

Abstract: The invention provides a polycrystalline silicon chunk having a concentration of 1-50 ppta of boron and 1-50 ppta of phosphorus at the surface.

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: An automated filling system for introducing crushed polysilicon fragments into shipping bags without significant contamination positions a freely suspended energy absorber into a freely suspended bag of non-contaminating material prior to filling, and following filling, the energy absorber is removed, and the bag is sealed. The system can replace manual packaging which has been required for semiconductor applications.

Abstract: The present invention relates to a method for packing polysilicon in the form of chunks by introducing the chunks into a first plastic bag, the first plastic bag being introduced into a second plastic bag after the introduction of the chunks, or the first plastic bag already having been inserted into the second plastic bag prior to the introduction of the chunks into the first plastic bag, as a result of which the chunks are present in a double bag which is sealed, wherein the air present in the two plastic bags in the double bag after the introduction of the chunks is removed before the sealing of the double bag such that the total volume of the double bag relative to the volume of the chunks is 2.4 to 3.0.

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: Polycrystalline silicon in the form of chunks packed in plastic bags containing a mass of at least 5 kg, including chunks of size from 20 to 200 mm, wherein any fines fraction in the plastic bag is less than 900 ppmw, preferably less than 300 ppmw, more preferably less than 10 ppmw. The polycrystalline silicon, after comminution of a silicon rod obtained by CVD (Siemens process), is sorted and classified, optionally dedusted and then metered and packed. Metering and packing units include elements for removing fines or small particles during metering and during packing. The packing unit includes an energy absorber or a reservoir vessel which enables sliding or slipping of the silicon chunks into the plastic bag. Gas flow generated within the plastic bag after the bag has been filled transports the dust or small particles out of the bag, and these are sucked out with a suction device.

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: The invention relates to a device for comminuting and sorting polycrystalline silicon, comprising an instrument for feeding a coarse polysilicon fraction into a crushing system, the crushing system associated with a sorting system for classifying the polysilicon fraction, wherein the device is provided with a controller which allows variable adjustment of at least one crushing parameter in the crushing system and/or at least one sorting parameter in the sorting system.

Abstract: An automated filling system for introducing crushed polysilicon fragments into shipping bags without significant contamination positions a freely suspended energy absorber into a freely suspended bag of non-contaminating material prior to filling, and following filling, the energy absorber is removed, and the bag is sealed. The system can replace manual packaging which has been required for semiconductor applications.

Abstract: Polysilicon rods from the Siemens process are crushed into fragments and further processed to fragments having very low metal contamination in an economical manner by purposefully fabricating parts contacting the polysilicon from materials which cause high metal contamination, and removing the metal contamination by a cleaning bath or baths tailored to the particular metal contamination. By this process, economical materials previously scrupulously avoided, such as low alloy steel, can be used for crushers, conveyors, and other polysilicon-contacting parts of the crushing and classifying system.

Abstract: Polycrystalline silicon fragments are sorted into defined particle fractions in a flexible manner independent of initial particle size distribution and desired fraction size by a first mechanical screening into a fine fraction and residual fraction, followed by optoelectronic sorting of the residual fraction.

Abstract: The invention relates to a device for comminuting and sorting polycrystalline silicon, comprising an instrument for feeding a coarse polysilicon fraction into a crushing system, the crushing system associated with a sorting system for classifying the polysilicon fraction, wherein the device is provided with a controller which allows variable adjustment of at least one crushing parameter in the crushing system and/or at least one sorting parameter in the sorting system.