Abstract: A method that decomposes monosilane wherein a monosilane-containing gas stream is circulated in a circuit system including a reactor that decomposes the monosilane, the method including injecting a monosilane-containing gas stream into the reactor, bringing the gas stream into contact with a heated surface inside the reactor at which surface a portion of the monosilane in the gas stream is decomposed to deposit a solid silicon layer on the surface so that the concentration of the monosilane in the gas stream decreases, discharging the gas stream from the reactor, reprocessing the gas stream including at least partially compensating the decrease in the monosilane concentration resulting from the decomposition by addition of monosilane, and reinjecting the reprocessed, monosilane-containing gas stream into the reactor, wherein during deposition an operating pressure of 2.5 to 10 bar is established and the gas stream enters the reactor at a velocity of less than 7.5 m/s.

Abstract: A column includes a column head, a column sump and a tube-shaped column shell disposed therebetween, two or more reaction zones lying above each other which each accommodate a catalyst bed, in which catalyst beds chlorosilanes disproportionate into low-boiling silanes, which form an ascending stream of gas, and also into high-boiling silanes which form a downwardly directed stream of liquid, within the column shell and along the column axis, two or more rectificative separation zones, the reaction zones and the separation zones alternate along the column axis, the separation zones are configured such that the stream of gas and the stream of liquid meet in the separation zones, and the reaction zones are configured such that the downwardly directed stream of liquid is led through the catalyst beds, whereas the upwardly directed stream of gas passes the catalyst beds in spatial separation from the stream of liquid.

Abstract: A plant for preparing monosilane (SiH4) by catalytic disproportionation of trichlorosilane (SiHCl3) includes a reaction column having a feed line for trichlorosilane and a discharge line for silicon tetrachloride (SiCl4) formed, and at least one condenser via which monosilane produced can be discharged from the reaction column, wherein the reaction column has at least two reactive/distillative reaction regions operated at different temperatures and containing different catalytically active solids, at least one of the reaction regions containing a catalytically active solid based on vinylpyridine, and at least one of the reaction regions containing a catalytically active solid based on styrene.

Abstract: A reactor that produces polycrystalline silicon using a monosilane process includes a reactor base plate having a multiplicity of nozzles formed therein through which a silicon-containing gas flows, a plurality of filament rods mounted on the reactor base plate, and a gas outlet opening located at a selected distance from the nozzles to feed used monosilane to an enrichment and/or treatment stage, wherein the gas outlet opening is formed at a free end of an inner tube, the inner tube is conducted through the reactor base plate, and the inner tube has an outer wall and an inner wall and thus forms an intermediate space in which at least one cooling water circuit is conducted.

Abstract: A process for preparing high-purity silicon by thermal decomposition of a silicon compound includes decomposing the silicon compound by mixing with a carrier gas at a temperature at which the silicon compound is thermally decomposed.

Abstract: A method of producing a crystalline semiconductor material includes feeding particles of the semiconductor material and/or a precursor compound of the semiconductor material into a gas flow, wherein the gas flow has a sufficiently high temperature to convert the particles of the semiconductor material from a solid into a liquid and/or gaseous state and/or to thermally decompose the precursor compound, condensing out and/or separating the liquid semiconductor material from the gas flow, and converting the liquid semiconductor material to a solid state with formation of mono- or polycrystalline crystal properties.

Abstract: A method of producing a monocrystalline semiconductor material includes providing a starting material composed of the semiconductor material, transferring the starting material into a heating zone in which a melt composed of the semiconductor material is fed with the starting material, and lowering the melt from the heating zone and/or raising the heating zone such that, at a lower end portion of the melt, a solidification front forms along which the semiconductor material crystallizes in a desired structure, wherein the starting material composed of the semiconductor material is provided in liquid form and fed into the melt in liquid form.

Abstract: A process of producing high-purity silicon includes providing silicon-containing powder, feeding the silicon-containing powder into a gas stream, where the gas has a temperature sufficiently high to convert particles of metallic silicon from a solid state into a liquid and/or gaseous state, collecting and, optionally, condensing the liquid and/or gaseous silicon formed, and cooling the collected liquid and/or condensed silicon in a casting mold,

Abstract: A plant for preparing monosilane (SiH4) by catalytic disproportionation of trichlorosilane (SiHCl3) includes a reaction column having a feed line for trichlorosilane and a discharge line for silicon tetrachloride (SiCl4) formed, and at least one condenser via which monosilane produced can be discharged from the reaction column, wherein the reaction column has at least two reactive/distillative reaction regions operated at different temperatures and containing different catalytically active solids, at least one of the reaction regions containing a catalytically active solid based on vinylpyridine, and at least one of the reaction regions containing a catalytically active solid based on styrene.

Abstract: A process for preparing trichlorosilane includes reacting silicon particles with tetrachlorosilane and hydrogen and optionally with hydrogen chloride in a fluidized-bed reactor to form a trichlorosilane-containing product gas stream, where the trichlorosilane-containing product gas stream is discharged from the reactor via an outlet preceded by at least one particle separator which selectively allows only silicon particles up to a particular maximum size to pass through and silicon particles are discharged from the reactor at preferably regular intervals or continuously via at least one further outlet without such a particle separator.

Abstract: A plant and a process prepare monosilane (SiH4) by catalytically disproportionating trichlorosilane (SiHCl3). The trichlorosilane is converted in a reaction column over a catalyst and then purified in a rectification column. Between a reactive/distillative reaction region in the reaction column and the rectification column are arranged one or more condensers in which monosilane-containing reaction product from the reaction column is partly condensed. However, these are exclusively condensers which are operated at a temperature above ?40° C.

Abstract: A process for preparing high-purity silicon by thermal decomposition of a silicon compound includes decomposing the silicon compound by mixing with a carrier gas at a temperature at which the silicon compound is thermally decomposed.

Abstract: A reactor that produces polycrystalline silicon using a monosilane process includes a reactor base plate having a multiplicity of nozzles formed therein through which a silicon-containing gas flows, a plurality of filament rods mounted on the reactor base plate, and a gas outlet opening located at a selected distance from the nozzles to feed used monosilane to an enrichment and/or treatment stage, wherein the gas outlet opening is formed at a free end of an inner tube, the inner tube is conducted through the reactor base plate, and the inner tube has an outer wall and an inner wall and thus forms an intermediate space in which at least one cooling water circuit is conducted.

Abstract: A process for producing high-purity silicon includes (1) preparing trichlorosilane by reacting silicon with hydrogen chloride in at least one hydrochlorination process; (2) preparing monosilane by disproportionation of the trichlorosilane to provide a monosilane-containing reaction mixture containing silicon tetrachloride as a by-product; (3) in parallel to (1), reacting silicon tetrachloride obtained as the by-product in (2) with silicon and hydrogen in at least one converting process to produce a trichlorosilane-containing reaction mixture; and (4) thermally decomposing the monosilane into silicon and hydrogen.