Abstract: Apparatus for machining workpieces by abrasion by means of an oscillating ltiple-blade tool, which is moved across the workpiece. The moved masses define an oscillatory system, as a result of which the energy can be stored in the reversal ranges by a buffer system. This apparatus, especially when designed as a lap-cutting machine for cutting semiconductor rods, is preferably driven by the oscillation of the masses to be moved, and is driven in the resonance range. The tool carriages are buffer loaded at each end and are oscillated at or near the natural resonance frequency of the moving masses.

Abstract: A process for the multiple lap cutting of solid materials, using a set of parallel, spaced apart blades mounted on the frame of a gang-saw for reciprocal movement over the solid materials to be cut, in a suspension of a lapping abrasive, wherein a pressure of from 100 to 1,000 gf per blade is exerted on the solid material, the free working length of the blades is held between 110 to 250 mm, and wherein the pressure applied to the blades is inversely proportional to the length of the blades, and the blades move through the solid material at a mean lateral speed of from 30 to 150 meters per minute.

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: The invention relates to a process and apparatus for manufacturing silicon astings or moldings, having a columnar structure of single-crystal regions of crystal with a preferential crystallographic orientation, and which can be manufactured cheaply and in large numbers in a semi-continuous mode of production. Liquid silicon is cast in a casting station, under an inert gas and preferably under reduced pressure, preferably in graphite molds which are exposed to a temperature gradient of 200.degree. to 1,000.degree. C. After cooling, the silicon is withdrawn automatically via a transport chamber connected to the casting station into special cooling stations, while the casting station is reloaded with an empty mold for repeating the process. The silicon blocks which have preferably been produced by this procedure are use as basic material for inexpensive solar cells having efficiencies of more than 10%, after they have been sawn into individual small wafers and have been doped and lead-bonded.

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: Lap cutting blades are provided which are useable for the multiple lap cung of solid materials, such as semiconductorrods. The blades each have a generally rectilinear cutting edge, the length of which is 1-75 times the thickness of the blade, as measured at its cutting edge. The cutting edge of each blade has rectilinear edge portions separated by a plurality of notched edge portions which, in turn, define a plurality of recesses which encompass 5 to 25% of the total blade length and 5 to 40% of the effective operating length of the blade. The notched blade edge portions define a notch angle of between 20 and 80 degrees, as measured between the tangent thereto at its point of intersection with the rectilinear cutting edge portion and a line perpendicular to the rectilinear cutting edge portion.

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: A stackable, tray-type packaging unit for semiconductor discs, having a lr portion accommodating the discs and a matching lid, comprising two upright, elongated side walls in the lower portion and two narrow end walls, all walls as well as the lid consisting of deep-drawn plastic material inert to the disc material. A plurality of ribs are formed opposite to each other on the side walls, serving as guide means for the discs during the loading of the unit, stabilizing ribs for accommodating the discs are provided in the base of the lower portion on the joining line between opposite guide ribs. The lower part of the side walls are curved inwardly at an angle of 30.degree. to 60.degree. with respect to the perpendicular upper part.

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 the manufacture of silicon of large surface area bonded to a substrate, which comprises depositing silicon to a thickness of from 30 to 500 .mu.m onto panel-shaped substrates of glassy carbon (a glass-like carbon obtained by carbonizing a spatially cross-linked synthetic resin) that are heated by direct passage of an electric current to temperatures above the melting point of silicon, and thereafter cooling the silicon to a temperature below its melting point in the direction from its free surface toward the substrate. The invention also comprises the silicon panels so made which are especially useful in the manufacture of solar cells.

Abstract: A process for the crucible-free zone pulling of a polycrystalline rod held ertically, together with a seed crystal fixed at its lower end, in which a melting zone is produced by means of an induction heating coil surrounding the rod, which zone, by means of relative movement of the coil and rod, traverses the entire length of the rod starting from the seed crystal, characterized in that after attaching the seed crystal to the rod, a support member is moved, below the induction heating coil, towards the rod, which support member rests gently against the rod and after being positioned, solidifies to form a firm support for the rod. A device for carrying out the process is also included.

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: Trichlorosilane or silicon tetrachloride is prepared by reacting metallic uminum-containing silicon in a reaction zone with hydrogen chloride or chlorine at a temperature between about 260.degree. and about 1200.degree. C, the reaction gas is then cooled to 40.degree. to 130.degree. in a cooling zone through which the velocity of flow is maintained at between 3 and 30 meters per second, and finally filtered.

Abstract: A process for producing gallium arsenide or phosphide at temperatures below he sublimation point of arsenic and red phosphorus, respectively, which consists of grinding and tempering a mixture of the constituent elements of the compound to be obtained in substantially stoichiometric amounts.

Abstract: A tool for the contact-free support of discs by gas streams impinging on discs when emerging from the supporting face of the tool at an acute angle to the disc surface, which comprises a body having a supporting face, bores within said body for connection with an extraneous gas reservoir, means in said body directed at an acute angle with respect to the supporting face for discharge of gas flowing from the reservoir, said flow-through means consisting of nozzles or recesses being position at equal distance from each other on the surface of a cone whose base is enclosed by a circle concentric with an imaginary circle on the supporting face, said circle having a diameter of 0.2-0.6 supporting face-diameters, the cone having an angle of 20.degree.-150.degree. at the apex, and wherein the distance of the flow-through means on the surface of the cone is from 2/3r.pi. to 0r, measured at the periphery of the circle, and the radial widths of the flow-through means in the supporting face are about 0.

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: Halogenosilanes and halogenogermanes which are contaminated by a boron-coining impurity are purified by treatment with an effective amount of a hydrated metal oxide or a hydrated silicate containing from about 3 to about 8% by weight of water, and then distilling the treated halogenosilane or halogenogermane at a temperature about 3.degree. to about 15.degree. C above its boiling temperature, and at atmosphere pressure.

Abstract: A process for making crucible-drawn silicon rods containing volatile doping gents, especially antimony, said rods having narrow resistance tolerances, which comprises drawing from a pre-doped silicon melt a monocrystalline rod while passing through the melt a current of inert gas either intermittently or continuously.

Abstract: Process for doping a semiconductor rod which comprises securing a semicontor rod containing a dopant and having a substantially smaller cross section than the rod to be doped against said rod, with the axes of the two rods substantially parallel to one another, both rods consisting of the same semiconductor material, fusing the two rods into a single rod and subjecting the rod so formed to a crucible zone melting process either subsequently or simultaneously.

Abstract: An etching agent for III/V semiconductor material consisting of(a) 1 to 30 percent by weight of hydrofluoric acid,(b) 2 to 30 percent by weight of hydrogen peroxide,(c) 1 to 75 percent by weight of sulfuric acid,(d) 15 to 95 percent by weight of water,Wherein the quantities by weight of the individual components are so chosen that they will add up to 100 percent by weight.