Wacker Chemie Ag

Wacker-chemie Gmbh

Wacker Siltronic Gesellschaft Fur Halbleitermaterialien Ag

Hanns Wochner

Christian Gossmann

Reiner Pech

Theresia Bauer

Werner Ott

Wilhelm Schmidbauer

Susanne Weizbauer

Herbert Lindner

Robert Baumann

Josef Dietl

Laszlo Fabry

Dieter Seifert

Walter Haeckl

Peter Gruebl

Bruno Lichtenegger

Marcus Schaefer

Matthaeus Schantz

Wolfgang Stoiber

Herbert Pichler

Alfred Bergler

Reiner Peach

Thomas Gailer

Rudolf Kellner

Andreas Killinger

Marcus Schäfer

The invention provides a process for determining surface contamination of polycrystalline silicon, including the steps of: a) providing two polycrystalline silicon rods by deposition in a Siemens reactor; b) determining contaminants in the first of the two rods immediately after the deposition; c) conducting the second rod through one or more systems in which polycrystalline silicon rods are processed further to give rod pieces or polysilicon fragments, optionally cleaned, stored or packed; d) then determining contaminants in the second rod; wherein the difference in the contaminants determined in the first and second rods gives surface contamination of polycrystalline silicon resulting from systems and the system environment.

Process for determining surface contamination of polycrystalline silicon

Polycrystalline silicon with low contamination by impurities, especially boron and phosphorus, is manufactured by the Siemens process or by the fluidized bed process, in which deposition of polycrystalline silicon takes place in a reactor maintained within a clean room of the 1 to 100,000 class, and air entering the facility enclosing the reactors is filtered by a multiple stage filtration system wherein coarse and fine filter elements contain less than 0.1% by weight of boron and phosphorus and less than 0.01% by weight of arsenic and aluminum. Following production of the polycrystalline silicon, the polycrystalline silicon may be further treated by steps such as comminution, classifying, wet-chemical treatment, and packing, all these further steps also preferably taking place within a clean room of the 1 to 100,000 class.

Process for producing polycrystalline silicon

A bag contains polysilicon, has been welded and includes at least one weld seam and a polyethylene film having: a thickness of 150-900 &#x3bc;m; a stiffness at a flexural modulus Fof 300-2000 mN and Fof 100-1300 mN; a fracture force F determined by dynamic penetration testing of 200-1500 N; a fracture energy Ws of 2-30 J; a penetration energy Wof 2.2-30 J; a film tensile stress at 15% longitudinal and transverse elongation of 9-50 MPa; an Elmendorf longitudinal film tear resistance of 10-60 cN; an Elmendorf transverse film tear resistance of 18-60 cN; a longitudinal film elongation at break of 300-2000%; a transverse film elongation at break of 450-3000%; and a weld seam strength of 25-150 N/15 mm. A method includes filling a bag with polysilicon, and welding by pulse sealing with contact pressure greater than 0.01 N/mmto obtain a 25-150 N/15 mm weld seam strength.

Packing of polysilicon

Polysilicon fragments are purified to remove metal contaminates by contacting the fragments with a purifying liquid at a flow rate &#x3e;100 mm/sec. Effective removal without abrasion is accomplished.

Method for purifying polycrystalline silicon

Polysilicon rods from the Siemens process are crushed into fragments and further processed to fragments having very low metal contamination in an economical manner by purposefully fabricating parts contacting the polysilicon from materials which cause high metal contamination, and removing the metal contamination by a cleaning bath or baths tailored to the particular metal contamination. By this process, economical materials previously scrupulously avoided, such as low alloy steel, can be used for crushers, conveyors, and other polysilicon-contacting parts of the crushing and classifying system.

Method and device for producing classified high-purity polycrystalline silicon fragments

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

Disclosed is a process for cleaning polycrystalline silicon chunks in an acidic cleaning bath, wherein: (a) the cleaning includes several cleaning cycles, (b) a particular amount of acid is consumed in each cycle, (c) a computer-controlled dosage system integrator adds up those amounts of acid consumed in each cycle to give a current total consumption of acid in the bath, and (d) on attainment of a total consumption of acid in the bath corresponding to an optimal dosage of the dosage system, the dosage system supplies this optimal dosage of unconsumed acid withdrawn from a reservoir vessel to the bath. Another process for cleaning polycrystalline silicon chunks in an acidic cleaning bath includes an acid circuit in which acid is circulated, wherein the ratio of amount of acid circulated in liters to the mass of polysilicon chunks present in the bath in kg is greater than 10.

Process for cleaning polycrystalline silicon chunks

The invention provides a polycrystalline silicon chunk having a concentration of 1-50 ppta of boron and 1-50 ppta of phosphorus at the surface.

Low-dopant polycrystalline silicon chunk

An automated filling system for introducing crushed polysilicon fragments into shipping bags without significant contamination positions a freely suspended energy absorber into a freely suspended bag of non-contaminating material prior to filling, and following filling, the energy absorber is removed, and the bag is sealed. The system can replace manual packaging which has been required for semiconductor applications.

Method and device for packaging polycrystalline bulk silicon

A breathable polyethylene glove as an overglove, over a cut- and puncture-resistant and nonfuzzing underglove, is useful for the non-contaminating packing of high-purity silicon, such as chunk polysilicon and silicon wafers.

Breathable glove for use in packing and sorting high-purity silicon

In a method for recovering acid from an aqueous etching mixture containing HF, HNO, HSiFand HNOwhich has been used for purifying polycrystalline silicon, the used etching mixture is distilled progressively so that approximately from 20 to 50 wt. % of the mixture is distilled off as dilute acid containing more than 90 wt. % of the silicon dissolved as hexafluorosilicic acid in a first fraction, and the water contained in the used etching mixture having been reduced by approximately 10-30 wt. %, this water-depleted mixture is then concentrated by evaporation to a residue of about 1 to 5 wt. % of the initial amount of used etching mixture during which a second fraction is distilled off, and the residue is disposed of.

Method for processing an etching mixture which is formed during the production of highly pure silicon

The present invention relates to a method for cleaning polycrystalline silicon fragments to a metal content of &#x3c;100 ppbw, wherein a polysilicon fraction is added to an aqueous cleaning solution containing HF and HO, this aqueous cleaning solution is removed and the polycrystalline fraction thereby obtained is washed with highly pure water and subsequently dried.

Method for cleaning a polysilicon fraction

A mechanical crushing apparatus for comminuting a polycrystalline silicon ingot, has a base and opposed comminuting and mating chisels, the chisels having longitudinal axises oriented at right angles to a longitudinal axis of the base and parallel to the surface of the base, and being movable in such a manner that a silicon ingot to be comminuted and which rests on the surface of the base can be positioned between the chisels such that all the chisels in the region of the silicon ingot are in contact with the silicon ingot, and comminution chisels in front of and behind the silicon ingot can be moved in the direction of their longitudinal axis to within a safety distance of the respective mating chisel, and the comminution chisels act on and break up the silicon ingot by means of sudden movement(s) in the direction of their longitudinal axes.

Apparatus and method for the mechanical comminution of semiconductor materials

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&times;10,g/cm,. 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.

Method for producing a semiconductor material

A method and apparatus for drying semiconductor fragment material, has at least one vacuum-tight chamber with at least one receiving means for semiconductor fragment material, and there is a means for maintaining a vacuum in the apparatus.

Growing community of inventors

Burghausen, Germany

Hanns Wochner