Abstract: A device for separating mixtures of liquids not miscible with one another, especially of oil/water mixtures and with a filter medium of a viscose sponge layer which is capable of taking up oil and water is provided. The device is characterized in that, in the direction of flow of the liquid mixture to be separated after at least one viscose sponge layer (3), there is arranged at least one oil repellent viscose cloth (4). The device has the advantage that is allows in simple and certain fashion the separation of oil/water mixtures and an environmentally friendly disposal of the separated oil.

Abstract: Silicon wafers can be provided with a hydrophilic surface and/or freed of hering cement residues originating from the polishing operation with the aid of solutions adjusted to a pH of 8 to 14 with the aid of alkali-metal or alkaline-earth-metal compounds and containing hydrogen peroxide. These processes can even be carried out at room temperature and are remarkable for their low chemical consumption and easy manageability.

Abstract: A method is described according to which articles of quartz glass, particrly quartz crucibles for use in crucible pulling according to Czochralski of high-purity synthetic quartz glass can be produced. High-purity silicon tetrachloride is hydrolized with water. The hydrolysis product is separated, dried, shaped, sintered and superficially fused.

Abstract: A process for the removal of carbon- and iron-containing impurities from icon fragments which result when polycrystalline formed silicon bodies produced by vapor phase deposition undergo a crushing treatment. The removal is effected by several steps comprising nitrate treatment, annealing, acid and magnetic treatment, leaving the treated fragments in a state of highest purity that makes them particularly useful in the crucible-pulling process of Czochralski.

Abstract: Waste gases resulting from the production of silicon in connection with the ormation or decomposition of chlorosilanes, which gases always contain hydrogen chloride, can be worked up without removal of the hydrogen chloride. For this purpose, the waste gases which, after separation from the chlorosilanes, only contain hydrogen and hydrogen chloride, are subjected to combustion with addition of air and, after addition of silicon tetrachloride, the result being highly dispersed SiO.sub.2. The hydrogen chloride then remaining in the gaseous phase is returned to the process stream for production of trichlorosilane.

Abstract: The chlorosilanes contained in the residual gases obtained in the deposit of silicon and in the conversion of silicon tetrachloride are first condensed out in liquid form. The hydrogen chloride present in the residual gases is dissolved in the condensed silicon tetrachloride. The remaining, virtually pure hydrogen is passed back into the process. During the distillation of the condensate, the dissolved hydrogen chloride is removed and can be separated off and reused. The trichlorosilane obtained after the distillation and the silicon tetrachloride can also be reused in the deposition process or the conversion process, respectively.

Abstract: The invention relates to a method and device for making pure semiconductor aterial by thermal decomposition of compounds of the semiconductor material on suitable carrier elements. The quantity and quality of the obtained semiconductor material is increased in accordance with the invention by introducing the compounds to be decomposed into the reactor chamber in at least a partially liquid state through a nozzle having a plurality of discharge openings.

Abstract: In a device and process for the deposition of pure semiconductor materials, specially silicon, by thermal decomposition of gaseous compounds of said semiconductor materials on carrier bodies heated to decomposition temperatures, wherein the device consists of a metallic base plate, mounting means and electrical connections thereon for heating the carrier bodies, as well as pipe connections for supply and exhaust of said gaseous compounds, and a bell-shaped cover slipped onto the base plate and forming a gas-tight seal therewith, the improvement that the area of the bell-shaped cover facing the reaction space consists of silver or silverplated steel. A removable heating element is used to preheat the carrier bodies and a cylinder disposed about the bell forms therewith a closed annular cooling chamber.

Abstract: In a device and process for the deposition of pure semiconductor materials, specially silicon, by thermal decomposition of gaseous compounds of said semiconductor materials on carrier bodies heated to decomposition temperature, wherein the device consists of a silver plated base plate, mounting means and electrical connections thereon for heating the carrier bodies, as well as pipe connections for supply and exhaust of said gaseous compounds, and a bell-shaped cover slipped onto the base plate and forming a gas-tight seal therewith, the improvement that the area of the bell-shaped cover facing the reaction space consists of silver or silverplated steel.

Abstract: A process for deposition of polycrystalline silicon from the gas phase on ated carrier bodies of carbon, which comprises assembling the carrier bodies from extremely thin flexible graphite foils, heating the bodies to deposition temperature, while contacting them with a gaseous mixture containing a decomposable silicon compound and, if desired, hydrogen, and separating the deposited silicon from the carrier body, after termination of the deposition process, by mechanical means. The polycrystalline silicon can either be deposited in the form of shaped hollow bodies for use as laboratory equipment or in the semiconductor industries, or it may be processed to monocrystalline materials.

Abstract: Semi-conductor discs are cleaned, after being subjected to a polishing operation, by immersing the discs in a solution of about 30-100% by weight non-ionic or anionic surfactant and thereafter rinsing the discs with water.

Abstract: Process for producing large-size, self-supporting plates of silicon deposd from the gaseous phase on a substrate body, which comprises heating a graphite substrate to deposition temperature of silicon, which is deposited on the substrate from a gaseous compound to which a dopant has been added until a layer of about 200 to 650 .mu.m has formed, subsequently melting 40-100% of this layer from the free surface downward, resolidifying the molten silicon by adjustment of a temperature gradient from the substrate body upward, and finally separating the silicon therefrom. The plates so formed are used primarily for making solar cells.

Abstract: A process for producing large-size, substrate-based semiconductor material of silicon deposited on a substrate body from the gaseous phase, which comprises the steps of heating a substrate body by direct current passage to deposition temperature, contacting said body with a gaseous silicon-containing mixture to which a dopant has been added, until a deposit having a thickness from about 10 to 200 .mu.m has been formed, subsequently melting 80 to 100% of the deposited silicon layer from the free surface downward, and resolidifying the molten silicon by adjustment of a temperature gradient from the substrate body upward. Large-sized plates obtained by cutting up the semiconductor material are used as solar cells.

Abstract: Process for making haze-free surfaces of semiconductor bodies which comprs a first step of polishing the surface by means of a polishing agent containing at least one member of the group consisting of quartz, silica, silicates and fluosilicates, and a second step of polishing the surface by means of a polishing agent containing in addition to the above defined agents from 0.1 to 10% by weight calculated on the polishing agent of a nitrogen-free surfactant selected from the group consisting of anionic and non-ionic surfactants, and a mixture thereof.

Abstract: A process for the continuous production of silicon rods or tubes by the dsition of silicon from the gaseous phase on the inner wall of a carrier tube heated to the deposition temperature, in which a cooled, hollow metal cylinder is placed in a reactor having one open end, and a flexible band, substantially resistant to silicon at the deposition temperature, is continuously wound onto the cylinder in an overlapping manner at an angle of pitch from 5.degree. to 40.degree. so as to form the carrier tube for the silicon to be deposited; the tube is continuously drawn off the metal cylinder by a rotary traction movement and the portion of the tube adjacent the metal cylinder and still in the reactor is heated to the deposition temperature of about 1050.degree. to 1250.degree. C, while at the same time the gaseous mixture is passed for decomposition through the tube under a pressure exceeding the external atmospheric pressure by 0.

Abstract: A process for making hollow silicon bodies by decomposition from a gaseous ompound containing silicon and depositing said silicon on heated carrier bodies, which comprises assembling in a decomposition device a number of board-shaped members of silicon to form a hollow carrier body, heating said body to the decomposition temperature of the gaseous compound, introducing the gas into the device whereby it is thermally decomposed, causing the silicon released thereby to become inseparately united with the hollow carrier body, the hollow silicon body so formed being immediately available for use in the semiconductor industries. The invention also comprises the silicon bodies so made.