Wacker Chemie Ag

Siltronic Ag

Walter Haeckl

Wilfried Von Ammon

Martin Weber

Hanns Wochner

Uwe Paetzold

Andreas Sattler

Herbert Schmidt

Barbara Mueller

Andreas Huber

Ulrich Lambert

Robert Ring

Karl Hesse

Natalia Sofina

Reinhard Wolf

Jan Prochaska

Norbert Ellinger

Wolfgang Stoiber

Andreas Hirschmann

Thorsten Goebel

Wolfgang Muenzer

Wilhelm Hoebold

Markus Kahler

The composition of a gas or gas stream containing AlClin a chemical reactor is measured by removing AlClfrom the gas and analyzing the gas by gas chromatography or spectroscopy. Chlorosilanes may be prepared in a fluidized bed reactor having a reactor height H0, in which supplied HCl reacts with silicon, wherein a temperature profile in the fluidized bed reactor is greater than S1(H/H0)=(a1&#x2212;b1)*(1/(1+exp(&#x2212;c1((H/H0)&#x2212;d1))))+b1 and less than S2(H/H0)=(a2&#x2212;b2)*(1/(1+exp(&#x2212;c2((H/H0)&#x2212;d2))))+b2, where a1=100&#xb0; C., a2=300&#xb0; C., b1=300&#xb0; C., b2=400&#xb0; C., c1=50, c2=20, d1=0.2, and d2=0.8.

Compositional analysis of a gas or gas stream in a chemical reactor and method for preparing chlorosilanes in a fluidized bed reactor

A process for producing polysilicon, includes a) depositing polycrystalline silicon on filaments using reaction gas containing silicon-containing component (SCC) containing trichlorosilane, and hydrogen, wherein molar saturation of SCC based on hydrogen is at least 25%; b) feeding offgas from the deposition into a cooling apparatus, i) wherein condensed offgas components containing SiClare conducted to an apparatus which enables distillative purification of the condensate, and ii) non-condensing components are conducted to an adsorption or desorption unit; c) obtaining a first stream of non-condensing components purified by adsorption and containing hydrogen; and d) obtaining, during adsorption unit regeneration, a second stream of non-condensing components, containing SiClwhich is then preferably supplied to a converter for conversion of SiClto trichlorosilane. A process for depositing polysilicon on filaments with a reaction gas includes a SCC and hydrogen, wherein molar saturation of SCC based on hydrogen is at least 25%.

Process for producing polysilicon

Installation of a shield around a Siemens reactor prior to harvesting polysilicon rods produced therein allows the upper, bell jar-like shell to be removed for cleaning, while protecting the polysilicon rods from contamination and increasing safety of nearby personnel. The polysilicon rods are harvested while the shield is present.

Process for producing polycrystalline silicon

The invention provides a process for endothermic gas phase reaction in a reactor, in which reactant gases are introduced into the reactor via a gas inlet apparatus and distributed homogeneously into a heating zone by means of a gas distribution apparatus, wherein the reactant gases are heated in the heating zone to a mean temperature of 500-1500&#xb0; C. by means of heating elements and then conducted into a reaction zone, the reactant gases reacting in the reaction zone to give a product gas which is conducted out of the reactor via a gas outlet apparatus. Further subject matter of the invention relates to a process for endothermic gas phase reaction in a reactor, wherein the heating of the heating elements is controlled by temperature measurements in the reaction zone, at least two temperature sensors being present in the reaction zone for this purpose, and reactor for performance of the process.

Reactor and process for endothermic gas phase reaction in a reactor

The invention relates to a process for purifying chlorosilanes by distillation, which includes providing a boron-containing mixture of chlorosilanes containing TCS, DCS and STC and purifying the mixture of chlorosilanes by distillation in a plurality of distillation columns, wherein low-boiling boron compounds are branched off from the distillation columns by overhead streams containing boron-enriched DCS and high-boiling boron compounds are branched off by a boron-enriched bottom stream containing high boilers.

Process for purifying chlorosilanes by distillation

The invention provides a process for producing polycrystalline silicon, by introducing reaction gases containing a silicon-containing component and hydrogen into reactors to deposit silicon, wherein a purified condensate from a first deposition process in a first reactor is supplied to a second reactor, and is used in a second deposition process in that second reactor.

Semiconductor wafers of silicon are produced by pulling a single crystal growing on a phase boundary from a melt contained in a crucible and cutting of semiconductor wafers therefrom, wherein during pulling of the single crystal, heat is delivered to a center of the phase boundary and a radial profile of a ratio V/G from the center to an edge of the phase boundary is controlled, G being the temperature gradient perpendicular to the phase boundary and V being the pull rate. The radial profile of the ratio V/G is controlled so that the effect of thermomechanical stress in the single crystal adjoining the phase boundary, is compensated with respect to creation of intrinsic point defects. The invention also relates to defect-free semiconductor wafers of silicon, which can be produced economically by this method.

Semiconductor wafers of silicon and method for their production

In a process for producing silicon semiconductor wafers, a silicon single crystal is pulled using the Czochralski method and is processed to form semiconductor wafers, a ratio V/G of pulling rate V and axial temperature gradient G at a growth front during the pulling of the single crystal being controlled in such a manner that agglomerated vacancy defects above a critical size are formed in the single crystal, the agglomerated vacancy defects, in a region of the semiconductor wafer that is of relevance to electronic components, shrinking during production of the components such that the size in this region no longer exceeds the critical size. Silicon semiconductor wafers with agglomerated vacancy defects in the relevant device region preferably contain agglomerated vacancy defects having an inner surface which is at least partially free of an oxide layer and a size of less than 50 nm.

Growing community of inventors

Zeilarn, Germany

Walter Haeckl