Abstract: A fluidized bed reactor and a Siemens reactor are used to produce polycrystalline silicon. The process includes feeding the vent gas from the Siemens reactor as a feed gas to the fluidized bed reactor.

Abstract: Provided are photoluminescence spectroscopy systems and methods for identifying and quantifying impurities in a semiconductor sample. In some embodiments, the systems and methods comprise a defocused collimated laser beam illuminating a first sample surface, and collection by a collection lens of photoluminescence from a sample edge at the intersection of the first surface with a substantially orthogonal second surface, wherein the first sample surface is oriented from about 0° to 90° with respect to a position parallel to the collection lens.

Abstract: A method for quantitatively monitoring gas phase materials in a chemical process is provided and includes, providing a gaseous feed stream containing one or more reactant gases of interest; exposing the gaseous feed stream to coherent radiation from a Raman spectroscopic device; acquiring a Raman spectroscopic signal from each of the gaseous components in the feed stream; analyzing the spectroscopic signal to determine the presence and concentration of each of the gaseous components; and displaying the results of the analysis. In one embodiment, the method is useful for quantitatively monitoring gas phase materials in a process for making high purity silicon.

Abstract: A method for recharging a crucible with polycrystalline silicon comprises adding flowable chips to a crucible used in a Czochralski-type process. Flowable chips are polycrystalline silicon particles made from polycrystalline silicon prepared by a chemical vapor deposition process, and flowable chips have a controlled particle size distribution, generally nonspherical morphology, low levels of bulk impurities, and low levels of surface impurities. Flowable chips can be added to the crucible using conventional feeder equipment, such as vibration feeder systems and canister feeder systems.

Abstract: A fluidized bed reactor and a Siemens reactor are used to produce polycrystalline silicon. The process includes feeding the vent gas from the Siemens reactor as a feed gas to the fluidized bed reactor.

Abstract: Silicon deposits are suppressed at the wall of a fluidized bed reactor by a process in which an etching gas is fed near the wall of the reactor. The etching gas includes tetrachlorosilane. A Siemens reactor may be integrated into the process such that the vent gas from the Siemens reactor is used to form a feed gas and/or etching gas fed to the fluidized bed reactor.

Abstract: A method for processing polycrystalline silicon workpieces to form size distributions of polycrystalline silicon pieces suitable for use in a Czochralski-type process includes: (1) preparing a polycrystalline silicon workpiece by a chemical vapor deposition process; (2) fracturing the polycrystalline silicon workpiece into a mixture of polycrystalline silicon pieces, where the polycrystalline silicon pieces have varying sizes; and (3) sorting the mixture of polycrystalline silicon pieces into at least two size distributions. Step (2) may be carried out by a thermal shock process. Step (3) may be carried out using a rotary indent classifier.

Abstract: A process forms a single crystal silicon ingot from varying sized pieces of polycrystalline silicon source material according to the Czochralski method. The process comprises placing into a crucible on the bottom a generally polygonal-shaped concentric array of rod-shaped polycrystalline silicon pieces having obliquely cut ends. The method of stacking the polycrystalline silicon pieces in the crucible allows for a denser packing of silicon in the crucible, can be accomplished in a quicker time then conventional packing methods, and has the potential for less damage to the crucible bottom, when comparing to standard packing methods using a size assortment of irregular shaped silicon pieces.

Abstract: The present invention is an improved susceptor for a float-zone apparatus for the float-zone processing of silicon elements. The susceptor is of a cylindrical design which allows the susceptor to be positioned around a free end of a silicon element to heat the free end of the silicon element to facilitate inductive coupling of the free end of the silicon element with an RF induction coil heater. In a preferred embodiment of the present invention, the susceptor is formed from tantalum.

Abstract: The present invention is a reactor for the hydrogenation of chlorosilanes at temperatures above about 600.degree. C. The reactor comprises one or more of the following improvements: (1) a reaction chamber formed from a silicon carbide coated carbon fiber composite, (2) a heating element formed from a silicon carbide coated carbon fiber composite, and (3) one or more silicon nitride insulators electrically insulating the heating element.

Abstract: A method for removing metal surface contaminants from silicon metalloid. The method comprises sequentially contacting the silicon with gaseous hydrogen fluoride and then with an aqueous solution comprising at least one-half weight percent hydrogen peroxide. The method is especially useful as a means for recovering metal surface contaminants on semiconductor grade silicon for analysis of surface contamination of the silicon by such metals. The method is useful for recovering copper from the surface of semiconductor grade silicon in an aqueous solution which can be analyzed directly to determine the amount of copper contamination of the surface of the silicon.

Abstract: A process for determining the organoamines concentrations in chlorosilane. The process comprises separating a mixture comprising as a major portion a chlorosilane and as minor portion an organoamine having a boiling point less than or about the boiling point of the chlorosilane, where the organoamine is complexed in situ in the chlorosilane to form an organoamine complex which vaporizes at a temperature greater than the boiling point temperature of the chlorosilane, into a vapor phase comprising the chlorosilane and a solid phase comprising the organoamine complex. An aqueous solution of the solid phase is formed and analyzed by ion exchange chromatography for organoamine content. The present invention is particularly useful for analyzing chlorosilanes for dimethylamine and trimethylamine where the chlorosilane or residual hydrogen chloride in the chlorosilane serves to complex the organoamine.

Abstract: An improved process for contacting hydrogen gas and tetrachlorosilane in a reactor comprising a pressurizable shell having located therein a reaction vessel forming a substantially closed inner chamber for reacting the hydrogen gas with the tetrachlorosilane. The improvement comprises feeding to an outer chamber between the pressurizable shell and the reaction vessel a gas or gaseous mixture having a chlorine to silicon molar ratio greater than about 3.5. The improvement reduces the concentration of hydrogen and tetrachlorosilane in the outer chamber that results from leakage of these gases from the substantially closed inner chamber and the detrimental reactions associated with such leakage on structural elements and performance of the reactor.

Abstract: A process for recovering chlorine present in a gaseous vent stream. The process comprises contacting a gaseous vent gas comprising hydrogen chloride and a hydrosilane with a chlorination catalyst to form a more chlorinated silane. The chlorination of the hydrosilane captures the chlorine of the hydrogen chloride as a substituent of the resulting chlorosilane and provides for a readily condensable chlorosilane.

Abstract: The present invention is a method for analyzing irregular-shaped chunked silicon for low-level contaminates. The method comprises selecting a zonable-chunk of silicon and float-zoning the chunk of silicon to effect a distribution of surface contaminates into the bulk of a monocrystal of silicon. The float-zoned monocrystalline silicon is then processed into a wafer suitable for analysis for low-level contaminates.

Abstract: The present invention relates to a method for the purification of tetrachlorosilane used for the manufacture of electronic grade silicon and, more particularly, to a method for removing trace impurities of phosphorus. The method involves contacting liquid tetrachlorosilane with activated charcoal. The process is effective in reducing the phosphorus levels in the tetrachlorosilane to the parts per trillion range. The process can be run as a continuous or batch process with easy separation of the activated charcoal. containing the phosphorus contaminate from the tetrachlorosilane.

Abstract: The present invention is a device for separating semiconductor grade silicon pieces into desired size ranges, while minimizing contact contamination of the separated pieces. The device employs a rotatable cylindrical screen, with contact surfaces of semiconductor grade silicon. In a preferred embodiment, the cylindrical screen consists of parallel rods of semiconductor grade silicon separated by semiconductor grade silicon, internal, spacers. In addition, external spacers of semiconductor grade silicon are arranged along the length of the parallel rods to further define the exclusion characteristics of the cylindrical screen.

Abstract: The present invention relates to an insulation system for a high temperature reactor in which chlorosilanes and hydrogen gases are present. The system described comprises an inner graphite radiant heat shield and an outer carbon-based, rigid, felt insulation of high density. The inner radient heat shield provides increased chemical stability at the hot face in a chlorosilane and hydrogen reactor. Also, the inner radient heat shield reduces the temperature at the interface with the carbon-based rigid felt, thereby reducing the reactivity of the chlorosilanes with the carbon-based rigid felt. The high density of the carbon-based rigid belt further reduces radiant heat loss. More importantly, the high density of the carbon-based rigid felt excludes the highly heat conductive hydrogen gas from the voids of the flet. The insulation system, as described, allows reactors containing chlorosilanes and hydrogen gases to be operated at higher and more efficient temperatures for longer periods of time.

Abstract: A process for the deposition of pure semiconductor silicon by reductive chemical vapor decomposition of a precursor silane, the process comprising: (1) forming and depositing semiconductor silicon on a heated substrate; (2) separating a mixture enriched in lower-boiling silanes from the effluent gases from the decomposition/deposition reactor; (3) combining the mixture enriched in lower-boiling silanes with additional tetrachlorosilane, so that there is present in the combination less than about 1.0 mole hydrogen bonded to silicon per mole of total silicon; (4) passing the combination through a bed of a solid disproportionation catalyst to facilitate disproportionation of hydrogen-containing silanes and chlorine-containing silanes to produce a stream that is reduced in content of silane, chlorosilane, and dichlorosilane and increased in content of trichlorosilane; and (5) isolating and separating the trichlorosilane.

Abstract: The present invention is a process for separating particulate silicon from a liquid by-product stream containing silanes. The liquid by-product stream comprising silanes and particulate silicon is atomized into a heated zone to effect vaporization of the liquid silanes, thus drying the particulate silicon. The dried particulate silicon is separated from the gaseous silanes by filtration or other suitable means. The separated solid and gaseous phases may be used as feed to the process generating the by-product stream or as a feed for other processes.