Abstract: Gas distribution units of fluidized bed reactors are configured to direct thermally decomposable compounds to the center portion of the reactor and away from the reactor wall to prevent deposition of material on the reactor wall and process for producing polycrystalline silicon product in a reactor that reduce the amount of silicon which deposits on the reactor wall.

Abstract: Gas distribution units of fluidized bed reactors are configured to direct thermally decomposable compounds to the center portion of the reactor and away from the reactor wall to prevent deposition of material on the reactor wall and process for producing polycrystalline silicon product in a reactor that reduce the amount of silicon which deposits on the reactor wall.

Abstract: Gas distribution units of fluidized bed reactors are configured to direct thermally decomposable compounds to the center portion of the reactor and away from the reactor wall to prevent deposition of material on the reactor wall and process for producing polycrystalline silicon product in a reactor that reduce the amount of silicon which deposits on the reactor wall.

Abstract: Gas distribution units of fluidized bed reactors are configured to direct thermally decomposable compounds to the center portion of the reactor and away from the reactor wall to prevent deposition of material on the reactor wall and process for producing polycrystalline silicon product in a reactor that reduce the amount of silicon which deposits on the reactor wall.

Abstract: Gas distribution units of fluidized bed reactors are configured to direct thermally decomposable compounds to the center portion of the reactor and away from the reactor wall to prevent deposition of material on the reactor wall and process for producing polycrystalline silicon product in a reactor that reduce the amount of silicon which deposits on the reactor wall.

Abstract: Processes for purifying silicon tetrafluoride source gas by subjecting the source gas to one or more purification processes including: contacting the silicon tetrafluoride source gas with an ion exchange resin to remove acidic contaminants, contacting the silicon tetrafluoride source gas with a catalyst to remove carbon monoxide, by removal of carbon dioxide by use of an absorption liquid, and by removal of inert compounds by cryogenic distillation; catalysts suitable for removal of carbon monoxide from silicon tetrafluoride source gas and processes for producing such catalysts.

Abstract: The present invention is directed to a method for treatment of a gas stream comprising silicon tetrafluoride and hydrogen chloride. For example, the present invention is directed to a method for treatment of such a gas stream that involves contacting the gas stream with a metal that reacts with the hydrogen chloride to provide a treated gas stream having reduced hydrogen chloride content. The present invention is further directed to methods for subjecting silicon tetrafluoride and hydrogen chloride-containing gas streams to elevated pressure to provide gas streams suitable for transport.

Abstract: The present invention is directed to a method for treatment of a gas stream comprising silicon tetrafluoride and hydrogen chloride. For example, the present invention is directed to a method for treatment of such a gas stream that involves contacting the gas stream with a metal that reacts with the hydrogen chloride to provide a treated gas stream having reduced hydrogen chloride content. The present invention is further directed to methods for subjecting silicon tetrafluoride and hydrogen chloride-containing gas streams to elevated pressure to provide gas streams suitable for transport.

Abstract: Processes for purifying silicon tetrafluoride source gas by subjecting the source gas to one or more purification processes including: contacting the silicon tetrafluoride source gas with an ion exchange resin to remove acidic contaminants, contacting the silicon tetrafluoride source gas with a catalyst to remove carbon monoxide, by removal of carbon dioxide by use of an absorption liquid, and by removal of inert compounds by cryogenic distillation; catalysts suitable for removal of carbon monoxide from silicon tetrafluoride source gas and processes for producing such catalysts.

Abstract: Processes for purifying silicon tetrafluoride source gas by subjecting the source gas to one or more purification processes including: contacting the silicon tetrafluoride source gas with an ion exchange resin to remove acidic contaminants, contacting the silicon tetrafluoride source gas with a catalyst to remove carbon monoxide, by removal of carbon dioxide by use of an absorption liquid, and by removal of inert compounds by cryogenic distillation; catalysts suitable for removal of carbon monoxide from silicon tetrafluoride source gas and processes for producing such catalysts.

Abstract: Gas distribution units of fluidized bed reactors are configured to direct thermally decomposable compounds to the center portion of the reactor and away from the reactor wall to prevent deposition of material on the reactor wall and process for producing polycrystalline silicon product in a reactor that reduce the amount of silicon which deposits on the reactor wall.

Abstract: Processes for producing polycrystalline silicon include contacting silicon particles with a thermally decomposable silicon compound in a reaction chamber. A portion of the silicon decomposable compound decomposes to produce silicon dust which is discharged from and reintroduced into the reaction chamber. The discharged silicon dust agglomerates with the silicon particles.

Abstract: Processes for purifying silicon tetrafluoride source gas by subjecting the source gas to one or more purification processes including: contacting the silicon tetrafluoride source gas with an ion exchange resin to remove acidic contaminants, contacting the silicon tetrafluoride source gas with a catalyst to remove carbon monoxide, by removal of carbon dioxide by use of an absorption liquid, and by removal of inert compounds by cryogenic distillation; catalysts suitable for removal of carbon monoxide from silicon tetrafluoride source gas and processes for producing such catalysts.

Abstract: The present invention is directed to a method for treatment of a gas stream comprising silicon tetrafluoride and hydrogen chloride. For example, the present invention is directed to a method for treatment of such a gas stream that involves contacting the gas stream with a metal that reacts with the hydrogen chloride to provide a treated gas stream having reduced hydrogen chloride content. The present invention is further directed to methods for subjecting silicon tetrafluoride and hydrogen chloride-containing gas streams to elevated pressure to provide gas streams suitable for transport.

Abstract: A high-purity semiconductor grade granular silicon composition, which can be produced in commercial quantities, is disclosed. In one embodiment the composition comprises a plurality of free-flowing particles having a total weight of at least about 300 kg and an average transition metal concentration of less than 0.2 ppba. In another embodiment the composition comprises a plurality of free-flowing silicon particles having a total weight of at least about 300 kg and at least 99 percent of the particles are between about 250 and 3500 microns in size.

Abstract: A high-purity semiconductor grade granular silicon composition and methods for making the same are disclosed. Commercial quantities of the granular silicon can be produced by depositing silicon on silicon seeds in a first chemical vapor deposition (CVD)reactor, thereby growing the seeds into larger secondary seeds. Additional silicon is deposited on the secondary seeds in a second CVD reactor. Dust is reduced in a third reactor. The methods disclosed herein can be used to achieve higher throughput and better yield than conventional practices.

Abstract: This invention relates to an improved process for the thermal dehydrogenation of polysilicon granules in a fluidized bed reactor, the improvement which comprises introducing a varying electromagnetic field into the reactor whereby reactor walls are coated with silicon during the dehydrogenation.

Abstract: This invention relates to a process for etching a silicon coat on the inside wall of a tube. The tube may be a product discharge tube associated with a fluidized bed reactor used in the thermal production of silicon from a silicon containing compound, e.g., silane. The process features: a) heating the silicon coat to a temperature within the range of from about 500.degree. to about 750.degree. C., such heating occurring principally with radiant heat from a heating means inserted within the interior of the tube; and (b) contacting the heated silicon coat with a mineral acid which etches the heated silicon coat.

Abstract: A product withdrawal tube for use in a fluidized bed reactor is disclosed. The tube features a plurality of elongated tubular segments which are fitted together to obtain flexible and sealing engagement between the segments whereby the tube is durable despite the vibrations and shocks experienced by it due to the operation of the fluidized bed reactor.

Abstract: Boron particles in bead-like form suitable for use in the preparation of doped, single crystal silicon can be prepared using a fluidized bed technique for chemical vapor deposition of a boron hydride, such as diborane or decaborane.