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

Abstract: 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.

Abstract: The present invention relates to a method for cleaning polycrystalline silicon fragments to a metal content of <100 ppbw, wherein a polysilicon fraction is added to an aqueous cleaning solution containing HF and H2O2, this aqueous cleaning solution is removed and the polycrystalline fraction thereby obtained is washed with highly pure water and subsequently dried.

Abstract: 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.

Abstract: 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.

Abstract: In a method for recovering acid from an aqueous etching mixture containing HF, HNO3, H2SiF6 and HNO2 which 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.

Abstract: The present invention relates to a method for cleaning polycrystalline silicon fragments to a metal content of <100 ppbw, wherein a polysilicon fraction is added to an aqueous cleaning solution containing HF and H2O2, this aqueous cleaning solution is removed and the polycrystalline fraction thereby obtained is washed with highly pure water and subsequently dried.

Abstract: A mechanical crushing apparatus for comminuting a polycrystalline silicon ingot, comprises a base and opposed comminution and mating chisels, the comminution chisels and mating 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.

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: 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.

Abstract: A process is taught for etching semiconductor wafers with an etching mixture comprising nitric and hydrofluoric acids and optionally a surfactant. To this mixture are added either more hydrofluoric acid, or more hydrofluoric and nitric acids, with the added acids having concentrations of at least 70% by weight. The use of concentrated acids reduces the loss of substrate material and extends etching bath life.