Abstract: A process for the wet-chemical surface treatment of semiconductor wafers in which aqueous phases containing one or more chemically active substances in solution act on the wafer surfaces, consisting of spraying a water mist over the wafer surfaces and then introducing chemically active substances in the gaseous state so that these gaseous substances combine with the water mist so that there is an interaction of the gas phase and the liquid phase taking place on the surface of the semiconductor wafer. Gases such as hydrogen fluoride, chlorine and ozonized oxygen or other halogen gases act on the wafer surfaces between rinsing steps so that when the wafers are dried, the surfaces achieve extremely high cleanliness levels.

Abstract: In the chemo-mechanical polishing, in particular, of semiconductor wafers, he abrasion and the geometrical quality of the wafers decreases with increasing service life of the polishing cloth. This can be prevented by treating the polishing cloth in each case after the polishing operation in a manner such that a pressure field is impressed, essentially without mechanical stress, on the polishing cloth, which pressure field causes a treatment liquid to flow through the interior of the polishing cloth and in this process the residues produced during polishing are rendered mobile and removed. A baseplate placed transversely across the polishing cloth and having a flat working surface provided with exit openings for the treatment liquid is suitable for carrying out the process. In the treatment, the treatment liquid is forced beneath the baseplate into the moving polishing cloth so that the latter is gradually traversed by the zone through which flow takes place.

Abstract: Semiconductor slices, in particular having the surface polished on both ss, can be provided with a surface which effects the formation of gettering centers. These centers include stacking faults and/or dislocation networks in subsequent thermal treatment steps by a pressure loading being exerted on them with the aid of an elastic pressure transmission medium which causes local pressure inhomogeneities. A material erosion, for example in the form of scratches, is not necessary in this process. Advantageously, the treatment is carried out during a template polishing step in which a suitable pressure transmission medium is in contact with the rear side of the slice. The process makes available semiconductor slices with gettering action on one side which have a high surface quality on both sides.

Abstract: The invention relates to an improved method for removing point defects and oint defect clusters from semiconductor discs, which defects impair the quality of electronic components or structural elements made from such discs. According to the invention, prior to polishing, the semiconductor discs are immersed in a bath containing grains moving in a streaming carrier medium of the bath. One side of the discs are then polished and thereafter the discs are subjected to oxidation processes whereby stacking faults are induced in the rear side of the discs. These stacking faults have an excellent gettering effect on the point defects.

Abstract: Semiconductor wafers, in particular, silicon wafers, with differently poled front and rear sides and high geometrical quality can be fabricated by double-sided polishing if the wafer surfaces are differently polarized during the polishing process. This can be achieved in a simple fashion, in that during polishing, an electric field is set up between the upper and lower polishing plates. This can be accomplished by providing the upper polishing plate between the plate surface and the polishing cloth with a thin conductive layer insulated with respect thereto, on which a voltage can be impressed, while both polishing plates are grounded to the frame.

Abstract: A device in which the wafers are moved with the aid of aqueous media, is posed for the transportation of semiconductor wafers and also for use in processes for the cleaning thereof, the device including a guideplate having a bottom plate with nozzle systems which are differently inclined in each case and independent of one another and through which the transportation fluid is, if necessary, forced into the transportation space, as a result of which the wafer can be loaded, retarded, caused to rotate and unloaded again. The devices can be combined to form treatment lines, different fluids being used in each case in the individual sections thereof, so that no mechanically moving parts act on the wafers during retardation and rotation and that no change of reagents has to be carried out inside a treatment station.

Abstract: A wafer holding device including a frame (2) which surrounds a wafer (1) ch is received without contact, which can be moved with the wafer having at least three holding elements (3) which are directed toward the outside circumference of the wafer and which can be changed from a holding position to a release position. The wafer can be supported in the holding device during many steps associated with movement in the production process so that a multiplicity of gripping and release operations which stress the wafer surface are unnecessary.

Abstract: Silicon ingots, in particular, with diameters of approximately 75 mm and greater, can be produced by zone pulling with an oxygen content comparable to crucible-pulled material if a flat quartz element is brought into contact with the molten cap during the pulling operation. A quartz ring which is arranged concentrically beneath the induction heating coil and can be lowered from a rest position into its working position on the molten cap is suitable as a flat element. The ingot material obtained in this manner and also the silicon wafers produced therefrom combine the purity advantages of zone-pulled silicon with the beneficial gettering and hardening action of the incorporated oxygen which otherwise distinguishes only crucible-pulled silicon.

Abstract: A process for removing contaminants, particularly dopant, from halosilane-containing carrier gases, such as those which are produced in the production of high-purity silicon. The process of the invention is perferably carried out with aid of zeolites which has a low proportion of aluminum and are used in the anhydrous state by bringing the zeolites into contact with the carrier gases. Zeolites, after use, can be regenerated and re-used by increasing the temperature and/or decreasing the pressure of the procedure.

Abstract: In the treatment of semiconductor slices, in particular silicon slices, w aqueous solutions containing hydrofluoric acid, a contamination of the slice surface with particles which interfere with the subsequent processes has been observed. This increase in particles can be markedly decreased by additionally adding to the solutions, organic ring molecules capable of forming inclusion compounds, such as, for instance, cyclodextrins, and/or acids with pKa below 3.14 which are incapable of oxidizing the semiconductor material. The actual treatment can be carried out in the usual way, for example, in immersion baths.

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: In a method and apparatus for monitoring the path of the cut in slicing wrs from non-magnetizble crystalline workpieces with a slicing tool which is moved through the workpiece, a measuring unit is disposed in a defined position with respect to the slicing tool and a constant magnetic field is established between the measuring unit and the slicing tool. The magnetic field during the slicing process passes at least partly through the wafer to be sliced off and varies with deviations of the slicing tool from the required line of cut established between the fixed measuring unit and the slicing tool. By measuring the change in the constant field caused by the deviation of the slicing tool, the slicing tool can be brought back into the required direction again by regulation so that wafers with excellent planarity are obtained.

Abstract: The invention is a method and apparatus for sawing bar-shaped workpieces o slices by means of an annular saw. The saw blade deviation, from its nominal position in the axial direction during the sawing operation, is compensated for. According to the invention, the deviation can be compensated for by the workpiece and the clamping system of the saw blade performing an appropriate relative translatory axial movement in accordance with the measured deviation. This movement is conveniently controlled by a computer, which compares the actual and nominal position of the saw blade with one another. The method can be used especially in the sawing of semiconductor bars.

Abstract: A process for preserving the surface of silicon wafers after the wafers are polished in a conventional polishing operation by converting the wafer surface to the hydrophobic state, in particular, by polishing, or with hydrofluoric acid and treating immediately afterwards with a reagent, e.g., alcohols, organosilanes or silanols and preferably in aqueous solution. The wafer becomes coated in this process with a protective layer which inhibits surface deterioration, and also permits long storage times.

Abstract: A process and apparatus for etching semiconductor surfaces, in particular, ilicon, with a mixture containing nitrogen-oxygen based compounds as oxidizing compounds, hydrofluoric acid as the component which dissolves the oxidation product, and sulfuric acid, optionally with phosphoric acid added, as a carrier medium. This mixture makes it possible to design the process as a cyclic process in which oxygen supplied to the system ultimately effects an oxidation of the material to be etched, and the product of its oxidation is removed from the circuit. The process is noteworthy for its low usage of reagents and because it is not harmful to the environment.

Abstract: A polishing process in which haze-free semiconductor wafers can be obtained in a single-stage process in which an initial phase of the polishing operation is carried out in the usual manner in the alkaline region. This initial stage is followed by a final phase in which polishing is carried out, at a pH of 3 to 7, in the presence of additives in the polishing agent which reduce the amount of material removed by polishing. Consequently, it may be possible to dispense with polishing agent components which act mechanically. Both phases can be carried out on one and the same equipment without interrupting the polishing operation.

Abstract: Silicon wafers and a process for the production thereof which produces was having intrinsic gettering action and on which thin oxide layers with high breakdown strength can be produced. During the production, the wafers are subjected to a treatment which smooths the wafer surface, for example, by repolishing, after the intrinsic getters have been produced in the interior of the wafer. Oxide layers subsequently deposited are outstanding for an increased breakdown strength compared with untreated wafers.

Abstract: A process and liquid preparation is disclosed for removing residues from ers sawn from crystalline rods. In sawing rod-shaped workpieces such as semiconductor rods, for example, into wafers, by means of an internal-hole saw, auxiliary sawing materials such as for example cutting strips are often attached to the rods. According to the present invention, the residues of such auxiliary sawing materials remaining on the wafers obtained after the sawing operation can be removed particularly easily by means of immersion in baths of aqueous carboxylic solutions and, in particular, aqueous formic acid.

Abstract: The liquid or gaseous substances, such as hydrogen or trichlorosilane, enntered in the gas-phase deposition of silicon may contain n-type doping impurities which can be removed by adduct formation with silicon, titanium or tin halides. The impurities can be liberated from the adducts by thermal treatment and finally removed. The halides left behind are capable of again forming adducts and are again used to remove the impurities. The process can consequently be operated cyclically and is remarkable for the low quantity of chemicals required and for its ecological harmlessness.

Abstract: A method to be used for adjusting the radial deviation from the true runn position of the internal cutting edge of annular saw blades and an apparatus for carrying out the method. For this purpose, the radial deviation or out-of-true is first measured as a function of position. Subsequently, the saw blade is stretched as a function of position in a defined manner in order to compensate for the deviations from the specified value of the radial out-of-true as a function of position. The measuring and tensioning cycles are continued until the deviation from the specified value no longer exceeds a predetermined tolerance limit. Saw blades adjusted in this manner are characterized by long service lives and high cutting accuracy.