Wacker Chemie Ag

Wacker-chemitronic Gesellschaft Fur Elektronik-grundstoffe Mbh

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Wacker Siltronic Gesellschaft Fur Halbleitermaterialien

Laszlo Fabry

Michael Stepp

Reiner Pech

Peter John

Gerhard Traunspurger

Manfred Grundner

Christian Huber

Heinz Kraus

Hanns Wochner

Uwe Paetzold

Anton Schnegg

Thomas Altmann

Mikhail Sofin

Peter Gruebl

Barbara Mueller

Uwe Pätzold

Susanne Bauer-Mayer

Andreas Ehlert

Dieter Graef

Wolfgang Feichtner

Bernd Passer

Gabriele Lechner

Dieter Graefg

Rosemarie Winklharrer

Edeltraud Steiger

Peter Grübl

Barbara Muller

Barbara MÜLLER

The invention provides chunk polycrystalline silicon having a concentration of carbon at the surface of 0.5-35 ppbw. A process for cleaning polycrystalline silicon chunks having carbon contaminations at the surface, includes a thermal treatment of the polycrystalline silicon chunks in a reactor at a temperature of 350 to 600&#xb0; C., the polycrystalline silicon chunks being present in an inert gas atmosphere during the thermal treatment, and the polycrystalline silicon chunks after the thermal treatment having a concentration of carbon at the surface of 0.5-35 ppbw.

Chunk polycrystalline silicon and process for cleaning polycrystalline silicon chunks

The content of phosphorus in polycrystalline silicon prepared by the Siemens process is reduced by treating phosphorus-containing steel surfaces with an &#x3b1;-amino-functional alkoxysilane. The treated surface exhibits less corrosion in an atmosphere of moist hydrogen chloride, and less loss of phosphorus as a result.

Treatment of steel surfaces

The present invention relates to polycrystalline silicon chunks which are cubic and have a metal content of less than 200 pptw and a dopant content of less than 50 ppta. Methods for producing polycrystalline silicon chunks, include the steps of providing a polycrystalline silicon rod, comminuting the polycrystalline silicon rod into cubic chunks, and cleaning the polycrystalline silicon chunks, wherein comminution takes place using a spiked-roll crusher having at least one spiked roll, the spiked roll including WC phases or WC phases with 0.1-10% of a metal carbide selected from the group consisting of titanium carbide, chromium carbide, molybdenum carbide, vanadium carbide, and nickel carbide or consisting of steel with 1-25% W.

Polycrystalline silicon chunks and method for producing them

The invention relates to a polycrystalline silicon portion having at least one fracture surface or cut surface, which includes metal contamination of from 0.07 ng/cmto 1 ng/cm. The invention also relates to a method for breaking a silicon body, preferably a rod of polycrystalline silicon, including the steps: a) determining the lowest natural bending frequency of the silicon body; b) exciting the silicon body in its lowest natural bending frequency by means of an oscillation generator, the excitation being carried out at an excitation point of the silicon body such that the silicon body breaks at the excitation point; so that a silicon portion having a fracture surface results which includes metal contamination of from 0.07 ng/cmto 1 ng/cm.

Polycrystalline silicon portion and method for breaking a silicon body

Trichlorosilane production is increased while simultaneously lowering environmental burden due to destruction and disposition of high boilers by feeding high boilers from trichlorosilane production or from polycrystalline silicon production into a fluidized bed for production of trichlorosilane from metallic silicon and hydrogen chloride.

Recycling of high-boiling compounds within an integrated chlorosilane system

A process is for producing a semiconductor wafer with a front surface and a back surface, in which the semiconductor wafer is subjected to two-sided polishing. The process includes the following: (a) producing a hydrophobic surface on the semiconductor wafer by treating the semiconductor wafer with an aqueous HF solution; (b) simultaneous polishing of the front surface and the back surface of the semiconductor wafer with a surface which has been rendered hydrophobic, with an alkaline polishing abrasive being continuously supplied between two rotating upper and lower polishing plates, which are both covered with a polishing cloth, the pH of the polishing abrasive being from pH 8.5 to pH 12.5; (c) after an intended polishing abrasion has been reached, supplying a stopping agent to the semiconductor wafer; and (d) removing the semiconductor wafer from the polishing plates. There is also a carrier for the double-side polishing of at least one semiconductor wafer, having a cutout for holding the semiconductor wafer which is lined with a shaped part made from plastic. The shaped part is constructed in such a manner that it divides a free space between an edge of the semiconductor wafer and the carrier into a plurality of separate empty spaces.

Process for producing a semiconductor wafer

A method is provided to remove crystal regions from silicon wafers which are damaged as a consequence of mechanical machining of the silicon wafers. The silicon wafers are pretreated with an aqueous solution containing hydrogen fluoride. Then the wafers are etched in an aqueous solution exposed to ultrasound and containing alkali metal hydroxide at temperatures from 55.degree. C. to 95.degree. C.

Method of removing damaged crystal regions from silicon wafers

A process for producing silicon wafers which have a storage-stable surface and which can be thermally oxidized directly, that is to say, without a prior HF immersion bath, and without the addition of halogen-containing gases, it being possible to achieve an equal or better oxidation result than that achieved by including these measures.

Process for producing storage-stable silicon wafer surfaces having

Silicon wafers are first subjected to an oxidative treatment and subsequey to exposure to organosilicon compounds which contain at least one radical in the molecule which is hydrolyzably bound to the silicon and at least one radical in the molecule having hydrophilic properties. Depending on the compound selected, more or less strongly hydrophilic or hydrophobic properties of the silicon surface can consequently be established under mild conditions. The wafers treated in such a manner have a high storage stability and retain their surface nature even under difficult climatic circumstances. The surface nature present after the oxidative treatment can then be restored particularly easily by hydrolysis.

Process for producing storage-stable surfaces of polished silicon wafers

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Burghausen, Germany

Laszlo Fabry