Abstract: A method for the generation of stacking-fault-induced damage on the back of emiconductor wafers is by treating the back with loose hard-material particles which are suspended in a liquid. The back of the semiconductor wafer is brought into contact with the suspended hard-material particles and the hard-material particles are propelled tangentially to the back, under which circumstances they exert on the back of the semiconductor wafer forces which have essentially only tangentially directed components.

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: 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: 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: 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: A process for the sawing of crystal rods or blocks into thin wafers by innal-hole saws is specified. In this process, the deviation of the saw blade from the intended cutting line, occurring in virtually every sawing operation, is countered by the force of a fluid being applied, at least periodically, to the side surfaces of the blade. This allows the force conditions in the saw cut and thus the deflection of the saw blade, to be influenced. This process results in an improved geometrical quality of the wafers obtained and in prolonged service life of the saw blades which have to be resharpened less often.

Abstract: Cutting-off tools whose cutting edge has a cutting layer with a bonded cutting grain are sharpened by sawing momentarily into a solid sharpening substance, in which case, in addition to a relative movement between cutting edge and solid material corresponding to the sawing operation, an oscillating relative movement transversely thereto is also performed. The process is used with particular advantage in combination with processes for the centerhole sawing of semiconductor or oxidic material.

Abstract: A process is provided for bilateral abrasive machining of wafer-like workpieces, especially semiconductor wafers. The process uses carrier disks in which the outer periphery on which the driving forces mesh, is made of a material having a tensile strength of at least 100 N/mm.sup.2, while in the area that comes into contact with the workpieces to be machined, there is provided a plastic material having an elasticity modulus of from 1.0 to 8.10.sup.4 N/mm.sup.2.