Abstract: Provided is a production method for producing a solid product by a reaction of gaseous raw materials with a plurality of components including a step of conducting the reaction using a reactor disposed in a vertical direction; a step of feeding the gaseous raw materials with a plurality of components from the upper part of the reactor; a step of, in the lower part of the reactor, forming a seal gas layer composed of a gas having a high density and fed continuously from the lower part of the reactor; a step of discharging an exhaust gas containing a by-product gas generated by the reaction and unreacted gaseous raw materials from somewhere in the upper part of the formed seal gas layer; and a step of accommodating a solid product in the seal gas layer of the lower part.

Abstract: The present invention relates to a method for producing highly pure, granular silicon with a narrow particle-size distribution by decomposing silanes or halosilanes in a fluidised bed and epitaxially growing silicon on silicon seed particles, which method is characterised in that the gas containing silicon is supplied to the reaction chamber in an upward flow and the contents of the fluidised bed are separated in a continuous or discontinuous manner, whereby a particle stream from the fluidised bed is supplied to a separator mounted outside the fluidised bed, particles of the desired size are separated and undersized particles are returned to the fluidised bed. The invention also relates to a device and the use thereof for carrying out said method.

Abstract: The present invention provides a method for producing polycrystalline silicon. The method for producing polycrystalline silicon comprises the steps of (A), (B), and (C), (A) reducing a chlorosilane represented by the formula (1) with a metal at a temperature Ti to obtain a silicon compound; SiHnCl4-n??(1) wherein n is an integer of 0 to 3, (B) transferring the silicon compound to a zone having a temperature T2, wherein T1>T2; and (C) depositing polycrystalline silicon in the zone having a temperature T2, wherein the temperature T1 is not less than 1.29 times of a melting point (Kelvin unit) of the metal, and the temperature T2 is higher than a sublimation point or boiling point of the chloride of the metal.

Abstract: The present invention provides a method for producing high purity silicon. The method for producing high purity silicon comprises a step of reducing halogenated silicon represented by the following formula (1) with aluminum, wherein the aluminum used as a reductant has a purity of not less than 99.9% by weight, SiHnX4-n??(1) wherein n is an integer of 0 to 3, X is at least one halogen selected from the group consisting of F, Cl, Br and I; and the purity of the aluminum is the balance obtained by deducting the total % by weight of iron, copper, gallium, titanium, nickel, sodium, magnesium and zinc contained in the aluminum from 100% by weight.

Abstract: There is provided a silicon production method which comprises producing semiconductor grade silicon while producing solar grade silicon by converting a portion of trichlorosilane into silicon for solar cells. There is also provided an industrially advantageous method that removes contaminants from a chlorosilane circulating system which produces trichlorosilane in producing silicon from trichlorosilane by a vapor deposition method.

Abstract: Embodiments of the present invention relate to a process for obtaining silicon crystals from silicon. The method includes contacting silicon powder with a solvent metal to provide a mixture containing silicon, melting the silicon under submersion to provide a first molten liquid, contacting the first molten liquid with a first gas to provide dross and a second molten liquid, separating the dross and the second molten liquid, cooling the second molten liquid to form first silicon crystals and a first mother liquid and separating the first silicon crystals and the first mother liquid.

Abstract: A clean bench comprising a worktable on which polycrystalline silicon is placed, a box part which includes side plates to surround three sides except a front face of a working space above the worktable, and a ceiling plate which covers an upper side of the working space. Supplying holes are formed in the ceiling plate of the box part, which supply clean air onto an upper surface of the worktable. An ionizer is provided, which ionizes the clean air supplied from the supplying holes to the working space and removes static electricity on the worktable. Suction holes are formed in the side plate of the box part, which suction air from the working space.

Abstract: An exemplary method of production of solar grade silicon is disclosed. The method comprises melting the silicon and directionally solidifying the melt. The method additionally comprises forming a crystallization front during the directional solidification, the front having the shape of at least a section of a spherical surface. Also disclosed are a silicon wafer and a solar cell in accordance with an exemplary embodiment of the present invention.

Abstract: A production method of nano-sized silicon crystal particles comprising the step of allowing monosilane to be oxidized in a liquid phase.

Abstract: A method for the mass production of nanostructures is provided. The method comprises introducing metal catalyst nanoparticles into a plurality of uniformly sized pores of mesoporous templates, distributing the templates containing the metal catalyst nanoparticles in a three-dimensional manner, and introducing a nanowire source into the pores of the templates to grow the nanowire source into nanowires along the length of the pores. Further provided are nanostructures produced by the method. The nanostructures have a uniform thickness. In addition, the nanostructures may have various shapes and can be controllably doped. The nanostructures can be applied to a variety of devices, including electronic devices, e.g., field effect transistors (FETs) and light-emitting diodes (LEDs), photodetectors, nano-analyzers, and high-sensitivity signal detectors for various applications, e.g., cancer diagnosis.

Abstract: This invention relates to a method and reactor for continuous production of semiconductor grade silicon by decomposition of a silicon containing gas of ultra-high purity to particulate silicon and other decomposition products in a free-space reactor and in which the gaseous stream of decomposition gas is set into a swirl motion. Optionally the method and reactor also includes means for melting the formed particulate silicon to obtain a continuous phase of elementary silicon, and then casting the liquid silicon to form solid objects of semiconductor grade silicon.

Abstract: A process for production of Si, characterized by adding an oxide, hydroxide, carbonate or fluoride of an alkali metal element, or an oxide, hydroxide, carbonate or fluoride of an alkaline earth metal element, or two or more of such compounds, to solid SiO in a total molar amount of from 1/20 to 1000 times with respect to the moles of solid SiO, heating the mixture at between the melting point of Si and 2000° C. to induce a chemical reaction which produces Si and separating and recovering the Si from the reaction by-product, for the purpose of inexpensively and efficiently producing Si from various forms of solid SiO with no industrial value produced from Si production steps and the like.

Abstract: The invention relates to a method for producing a great deal of inexpensive high purity silicon useful in a solar battery. Disclosed is a method for producing high purity silicon by removing boron from silicon by oxidization including commencing an oxidization reaction between an oxidizing agent and molten silicon, and cooling at least part of the oxidizing agent during the reaction.

Abstract: A container for forming an electrode that can be used in electric reduction furnaces. The container comprises a cylindrical casing. Within the cylindrical casing is a plurality of ribs attached along the inner surface of the casing lengthwise of the cylindrical casing. At least one of the ribs in the container is made of a material comprising copper.

Abstract: A process and apparatus for purifying low-purity silicon material and obtaining a higher-purity silicon material is provided. The process includes providing a melting apparatus equipped with an oxy-fuel burner, and melting the low-purity silicon material in the melting apparatus to obtain a melt of higher-purity silicon material. The melting apparatus may include a rotary drum furnace and the melting of the low-purity silicon material may be carried out at a temperature in the range from 1410° C. to 1700° C. under an oxidizing or reducing atmosphere. A synthetic slag may be added to the molten material during melting. The melt of higher-purity silicon material may be separated from a slag by outpouring into a mould having an open top and insulated bottom and side walls. Once in the mould, the melt of higher-purity silicon material can undergo controlled unidirectional solidification to obtain a solid polycrystalline silicon of an even higher purity.

Abstract: An apparatus for manufacturing a high purity polycrystalline silicon is characterized by comprising: a vaporizer 8 of silicon chloride; a fusing evaporator 5 of zinc; a vertical reactor 1 provided with a heating means on the peripheral face thereof; a silicon chloride gas supply nozzle 2 disposed to connect the vaporizer 8 of silicon chloride and the vertical reactor 1 and for supplying a silicon chloride gas supplied from the vaporizer 8 of silicon chloride into the vertical reactor 1; a zinc gas supply nozzle 3 disposed to connect the fusing evaporator 5 of zinc and the vertical reactor 1 and for supplying a zinc gas supplied from the fusing evaporator 5 of zinc into the vertical reactor 1; and an exhaust gas vent pipe 4 connected to the vertical reactor 1, the fusing evaporator 5 of zinc, further comprising: a zinc evaporator 24; a main vertical cylinder part 28 connected to the upper part of the zinc evaporator 24; a solid trapping pipe 32 inserted into the main vertical cylinder part 28; a zinc introduci

Abstract: A method of fabricating silicon parts are provided herein. The method includes growing a silicon sample, machining the sample to form a part, and annealing the part by exposing the part sequentially to one or more gases. Process conditions during silicon growth and post-machining anneal are designed to provide silicon parts that are particularly suited for use in corrosive environments.

Abstract: To provide a method for producing polycrystalline silicon at relatively low cost, wherein the amount of waste generated is reduced by decreasing the amount of waste generated in producing polycrystalline silicon from silicon chloride by a method of reduction and increasing the amount of reused auxiliary raw materials. In the production of polycrystalline silicon using a gas phase reaction of a silicon chloride gas and a reducing agent gas, a chlorine gas is blown into an exhaust gas discharged from a reaction device to initiate a reaction, an unreacted reducing agent and silicon particles contained in the exhaust gas are chlorinated, and then a reducing agent chloride contained in the exhaust gas is separated from the other impurities and recovered.

Abstract: Provided is a production method and a production apparatus using a method for producing a solid product by a reaction of gaseous raw materials with a plurality of components including a step of conducting the reaction using a reactor disposed in a vertical direction; a step of feeding the gaseous raw materials with a plurality of components from the upper part of the reactor; a step of, in the lower part of the reactor, forming a seal gas layer composed of a gas having a high density and fed continuously from the lower part of the reactor; a step of discharging an exhaust gas containing a by-product gas generated by the reaction and unreacted gaseous raw materials from somewhere in the upper part of the formed seal gas layer; and a step of accommodating a solid product in the seal gas layer of the lower part.

Abstract: A silicon production reactor including a reaction vessel and heating element, the reaction vessel has a vertically extending wall and a space surrounded by the wall, the heating element being capable of heating at least a part, including lower end portion, of the wall's surface facing the space to a temperature of not lower than the melting point of silicon, the silicon production reactor being adapted to flow raw gas for silicon deposition from an upper part of the space of the reaction vessel toward a lower part thereof, characterized in that the space of the reaction vessel is of slit form in cross-sectional view. This silicon production reactor is capable of attaining improvement with respect to problems encountered at apparatus scale-up, such as decrease of reactivity of raw gas and generation of by-products, thereby accomplishing a striking enhancement of production efficiency.

Abstract: The invention relates to the manufacture of high purity silicon as a base material for the production of e.g. crystalline silicon solar cells. SiCU is converted to Si metal by contacting gaseous SiCU with liquid Zn, thereby obtaining a Si-bearing alloy and Zn-chloride, which is separated. The Si-bearing alloy is then purified at a temperature above the boiling point of Zn. This process does not require complicated technologies and preserves the high purity of the SiCU towards the end product, as the only reactant is Zn, which can be obtained in very high purity grades and continuously recycled.

Abstract: The invention concerns a method for producing a medium purity silicon comprising: preparing, by carbothermic reduction of silica in a submerged arc-furnace a silicon with low boron content; refining the liquid silicon with oxygen or chlorine; treating the refined silicon under reduced pressure from 10 to 100 Pa with neutral gas injection; segregated solidification. The invention also concerns a medium purity silicon designed to serve as raw material for making silicon of electronic or voltaic quality, and having (in weight fractions): a total of impurities ranging between 100 and 400 ppm, with the content in metallic elements ranging between 30 and 300 ppm; a boron content from 1 to 10 ppm; a phosphorus/boron ratio ranging between 0.5 and 1.5.

Abstract: In a reactor for the decomposition of a silicon-containing gas, provision is made, to avoid silicon deposition on an inner wall of a reactor vessel, for at least one catalytically active mesh to be provided within a reaction chamber between at least one gas feed line and the inner wall (4). The mesh accelerates the thermal decomposition of the gas and reduces the deposition of silicon on the inner wall. Also described is a process for the preparation of silicon using the reactor according to the invention and the use in photovoltaics of the silicon prepared.

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: Chlorosilanes are continuously removed from a gas stream in an apparatus in which the gas stream is treated in a first stage with water vapor in the gas phase, and in a second stage with a liquid, aqueous phase.

Abstract: The invention relates to a method for producing granular silicon by thermal decomposition of a gas containing silicon in a fluidized bed, said decomposition occurring in the presence of free-flowing mobile elements. Preferably, said free-flowing mobile elements become devoid of silicon in a separate procedural step, said silicon being deposited during decomposition of gas containing silicon, by reacting with hydrogen halides, halogens, alkyl halogenides, aryl halogenides or combinations of halogen and/or hydrogen halide and/or oxidized mineral acids and/or by thermal treatment of said elements.

Abstract: A silicon production process which improves the production efficiency of trichlorosilane while an industrially advantageous output is ensured and the amount of the by-produced tetrachlorosilane is suppressed. This process does not require a bulky reduction apparatus for the by-produced tetrachlorosilane, can construct a closed system, which is a self-supporting silicon production process, can easily control the amount of the by-produced tetrachlorosilane and therefore can adjust the amount of tetrachlorosilane to be supplied to a tetrachlorosilane treating system when the tetrachlorosilane treating system is used. This process comprises a silicon deposition step for forming silicon by reacting trichlorosilane with hydrogen at a temperature of 1,300° C.

Abstract: The invention relates to a method for purification of metallurgical grade silicon where a calcium containing compound is added to molten silicon prior to or after the silicon is tapped from the furnace. The silicon is cast and solidified at a relatively high cooling rate and the solidified silicon is crushed and subjected to a purification process consisting of two leaching steps. In the first leaching step the silicon is treated with an aqueous solution of FeCl3 or FeCl3 and HCl which causes disintegration of the silicon, and in the second leaching step the silicon is treated with an aqueous solution of HF or HF/HNO3. Calcium-containing compound is added to the molten silicon in an amount necessary to provide between 0.3 and 0.95% by weight of calcium in the molten silicon and the weight ratio between Al and Fe in the molten silicon is regulated to between 0.5 and 2.0 by addition of aluminum to the molten silicon.

Abstract: The invention relates to a method for producing hyper-pure, granular silicon by decomposing a gas containing silicon in a reactor consisting of a silicon carbide-based, carbon-fiber reinforced material; to a corresponding reactor; and to the use of said reactor for producing silicon.

Abstract: A process for producing hexachlorodisilane comprising, condensing an exhaust gas discharged from a reactor for producing polycrystalline silicon from a chlorosilane and hydrogen to separate the hydrogen, distilling the resultant condensate to separate the unreacted chlorosilane and by-product silicon tetrachloride, and then further distilling to recover hexachlorodisilane, wherein tetrachlorodisilane can be recovered together with the hexachlorodisilane, and the hexachlorodisilane and tetrachlorodisilane recovered have a far higher purity than the conventional ones produced from metallic silicon.

Abstract: In an optical element which includes a single crystal having at least one flat light-transmitting end surface, the at least one light-transmitting end surface is inclined at at least 0.5 degrees relative to a plane perpendicular to one of an a-axis and a c-axis of the single crystal. In a process of producing such an optical element, a single crystal is cut out so that the single crystal has at least one surface which is inclined at at least 0.5 degrees relative to a plane perpendicular to one of an a-axis and a c-axis of the single crystal, and then the at least one surface is polished into at least one light-transmitting end surface.

Abstract: A process for preparing polycrystalline silicon comprising the steps of (A) reacting trichlorosilane with hydrogen thereby forming silicon and an effluent mixture comprising tetrachlorosilane and disilane described by formula HnCl6—NSi2 where n is a value of 0 to 6 and (B) co-feeding the effluent mixture and hydrogen to a reactor at a temperature within a range of about 600° C. to 1200° C. thereby effecting hydrogenation of the tetrachlorosilane and conversion of the disilane to monosilanes.

Abstract: Disclosed are processes and reactor apparatus for rapidly producing large diameter, high-purity polycrystalline silicon rods for semiconductor applications. A.C. current, having a fixed or variable high frequency in the range of about 2 kHz to 800 kHz, is provided to concentrate at least 70% of the current in an annular region that is the outer 15% of a growing rod due to the “skin effect.

Abstract: A silicon production process which improves the production efficiency of trichlorosilane while an industrially advantageous output is ensured and the amount of the by-produced tetrachlorosilane is suppressed. This process does not require a bulky reduction apparatus for the by-produced tetrachlorosilane, can construct a closed system, which is a self-supporting silicon production process, can easily control the amount of the by-produced tetrachlorosilane and therefore can adjust the amount of tetrachlorosilane to be supplied to a tetrachlorosilane treating system when the tetrachlorosilane treating system is used.

Abstract: There are disclosed a silicon seed crystal which is composed of silicon single crystal and used for the Czochralski method, wherein oxygen concentration in the seed crystal is 15 ppma (JEIDA) or less, a silicon seed crystal which is used for the Czochralski method, wherein the silicon seed crystal does not have a straight body, and a method for producing a silicon single crystal by the Czochralski method comprising using said seed crystal, bringing a tip end of the seed crystal into contact with a silicon melt to melt the tip end of the seed crystal, with or without performing necking operation, and growing a silicon single crystal. The method is capable of improving the rate of success in making crystals dislocation-free and the productivity of single crystal rods regardless of the use of necking operation.

Abstract: A method of purifying silicon, comprising feeding a sparging gas into a liquid melt [10] containing molten silicon and at least one impurity, in which the sparging gas is used to react with or move one or more impurity contained within the silicon. The products of such reaction or movement may be removed, e.g., by liquid-gas extraction, by liquid-liquid extraction or by liquid-solid extraction.

Abstract: In producing rod-form high-purity polycrystalline silicon by depositing silicon on a silicon core by the thermal decomposition of a silane gas, the occurrence of defects near the interface of the silicon core and polycrystalline silicon newly deposited thereon is prevented. A silicon core before depositing silicon thereon is subjected to a hydrogen treatment. In this case, the treatment temperature and the treatment time are controlled according to the dew point of the hydrogen gas. After the hydrogen treatment, the hydrogen gas in a reactor may be replaced with a high-purity hydrogen gas, followed by producing a polycrystalline silicon by a silane gas.

Abstract: A process for preparing polycrystalline silicon comprising the steps of (A) reacting trichlorosilane with hydrogen thereby forming silicon and an effluent mixture comprising tetrachlorosilane and disilane described by formula HnCl6−nSi2 where n is a value of 0 to 6 and (B) co-feeding the effluent mixture and hydrogen to a reactor at a temperature within a range of about 600° C. to 1200° C. thereby effecting hydrogenation of the tetrachlorosilane and conversion of the disilane to monosilanes.

Abstract: It is possible to produce high purity Si by heating solid SiO at a temperature of at least 1000° C. and lower than 1730° C., for a disproportionation reaction in which the SiO solid is decomposed to liquid or solid Si and solid SiO2, and the produced Si is separated from the SiO2 and/or SiO. The SiO solid can be obtained by a process whereby a starting mixture of carbon C, silicon Si or ferrosilicon, or a combination thereof, with SiO2 is heated to generate SiO gas-containing gas, and the SiO-containing gas is cooled to produce SiO solid.

Abstract: The disclosure describes a process for the production of polycrystalline silicon by a thermal decomposition or hydrogen reduction of a reaction gas consisting of silane gas, which comprises additionally introducing hydrogen chloride into the reaction gas and utilizing the reaction heat generated from the reaction between hydrogen chloride and silicon on the inside of the reactor as an additional heat source.

Abstract: A Method for Improving the efficiency of a silicon purification process is by controlling the temperature and composition of the effluent to a feedstock recovery composition and temperature, rapidly quenching the effluent at or near the recovery composition, separating the gases from the liquids, sending the gases to conventional hydrogen recovery and recycle facilities, separating the hydrohalosilanes from silicon tetrahalide, returning the hydrohalosilanes to the inlet of the deposition reactor, using all or some of the silicon tetrahalide to control the composition and temperature of the effluent and separately heating the hydrogen and any silicon tetrahalide returned to the decomposition reactor to a temperature greater than 400 C. and separately injecting them into the decomposition reactor.

Abstract: Semiconductor material has a low metal concentration at the surface. The semiconductor material has an iron content and/or chromium content on the surface of less than 6.66×10−11 g/cm2. A method for producing this semiconductor material includes a preliminary cleaning, a main cleaning and hydrophilization. A device for use in this method has a container with pyramid-shaped recesses at the bottom.

Abstract: There is disclosed a method for heat treatment of a silicon wafer performed in a reducing atmosphere containing hydrogen by utilizing a rapid thermal annealer, wherein the heat treatment comprises a plurality of steps each of which is performed with a differently defined heat treatment condition. In this method, the heat treatment comprising a plurality of steps may be continuously performed without taking out the wafer from an RTA apparatus. The method of the present invention can, in particular, reduce COP density of the silicon wafer surface, reduce its microroughness and haze, and thus improve electric characteristics such as oxide dielectric breakdown voltage and mobility of carriers.

Abstract: Method for producing highly purified silicon for use in solar cells by a single solidification purification, pouring silicon into a mold and gradually fractionally solidifying it while solidifying the liquid surface, followed by purifying the solidified silicon by zone melting or continuous casting using an electromagnetic mold, or by zone melting in combination with continuous casting, and optionally causing directional solidification to concentrate impurities, leaching and recycling.

Abstract: A system for the water vapor reforming of a hydrocarbon includes an evaporator, a prereforming unit, a main reformer, a CO removal unit and at least one catalytic burner unit. A first burner unit is in a thermal contact with the evaporator and a second burner unit is in a thermal contact with the main reformer, and the prereforming unit is in a thermal contact with the CO removal unit by way of one heat conducting separating medium. In addition, the outlet of the CO removal unit is connected with the inlet of the at least one burner unit. During a cold start, a heating-up operation is carried out during which first the two burner units are activated with an external feeding of hydrogen or hydrocarbon, and the reforming operation is started with a hydrocarbon fraction that is lower than in the normal operation. The resulting reformate gas, instead of the externally fed hydrogen or hydrocarbon, is introduced as fuel into the burner units.

Abstract: The present invention relates to directionally solidified, arsenic- and/or antimony-containing, multicrystalline silicon, a process for the production thereof and its use, and to solar cells containing this silicon and a process for the production thereof.

Abstract: A polycrystal silicon rod characterized in that it has a half value width of a peak indicative of crystal orientation (111) of an X-ray diffraction pattern, of 0.3.degree. or less, an internal strain rate in a radial direction of less than 5.0.times.10.sup.-5 cm.sup.-1 and an internal iron concentration of 0.5 ppba or less. The above polycrystal silicon rod having high crystallinity, high purity and low internal strain is produced by heating a core material in a gaseous atmosphere comprising trichlorosilane and hydrogen to deposit silicon on the silicon core material to produce a polycrystal silicon rod, and subjecting the polycrystal silicon rod to a heat treatment without allowing it to contact with the air, to remove strain contained therein.

Abstract: Silicon thin films of superior resistivity useful for, e.g., semiconductor elements in solar cells, are formed by coating and drying silicon vaporized in the presence of hydrogen alone or hydrogen and an inert gas, followed by contacting the thus produced silicon particles with solvent to form a silicon colloid. Preferably, the silicon colloid is produced by a process which comprises vaporizing silicon in an atmosphere consisting essentially of hydrogen and up to 10 mol of an inert gas per mol of hydrogen; condensing silicon vaporized in the first step to form fine silicon particles; bringing the silicon particles into contact with a solvent to cover the silicon particles with solvent, and collecting the solvent covered silicon particles to obtain the silicon colloid.

Abstract: Metallic magnesium and pure magnesium oxide are produced by carbothermal reduction of starting materials such as magnesium oxide containing minor amounts of oxides of Fe, Si, Ca and Al, and/or magnesium silicate minerals, such as olivine, at subatmospheric pressure. Metallic magnesium is evaporated from a reduction zone and pure metallic magnesium and pure magnesium oxide are precipitated in a second condensation zone. Si is partly evaporated as SiO which is precipitated in a first condensation zone upstream the second condensation zone, partly converted to SiC and an alloy of Si and Fe in the reaction mixture. The starting materials may also be processed by a method wherein their magnesium component is converted to magnesium oxide in the reaction mixture, while the remaining components are converted to SiC and an alloy of Si and Fe. Au and valuable siderophilic elements may be recovered by leaching the alloy of Si and Fe.

Abstract: Methods for quantifying, in near real-time, the amount of silicon oxide (SiO) volatilized from a pool of molten silicon such as a Czochralski silicon melt and present in the atmosphere over the melt are disclosed. A preferred method includes reacting a gas sample containing SiO withdrawn from the atmosphere over the molten silicon with a reactant to form a detectable reaction product, determining the amount of reaction product formed, and correlating the determined amount of reaction product to the amount of SiO present in the atmosphere. The quantification of SiO is used for monitoring and/or controlling the amount of oxygen in the molten silicon or the oxygen content in single crystal silicon being drawn from the molten silicon. A SiO reaction probe and a system using the probe for monitoring and/or controlling oxygen are also disclosed.