Abstract: A method for the production of a single crystal has the single crystal crystallizing from a melt and being subjected to a rotation with an alternating rotation direction. The single crystal is periodically rotated through a sequence of rotation angles, and the rotation direction is changed after each rotation through a rotation angle of the sequence, with a change of the rotation direction defining an inversion point on the circumference of the single crystal. There is at least one recurring pattern of inversion points created, in which the inversion points lie distributed on straight lines that are aligned parallel with the z-axis and are spaced apart uniformly from one another.

Abstract: A semiconductor wafer is made of a silicon substrate wafer and an epitaxial silicon layer deposited thereon. The substrate wafer has a specific resistance of 0.1 to 50 &OHgr;cm, an oxygen concentration of less than 7.5*1017 atcm−3 and a nitrogen concentration of 1*1013 to 5*1015 atcm−3. The epitaxial layer is 0.2 to 1.0 &mgr;m thick and has a surface on which fewer than 30 LLS (localized light scattering) defects which are greater in size than 0.085 &mgr;m can be detected. A method for producing the semiconductor wafer has a sequence of steps for providing the substrate wafer with the aforementioned features; heating the substrate wafer in a deposition reactor to a deposition temperature of at least 1120° C.; and depositing the epitaxial layer thereon with a thickness of 0.2 to 1.0 &mgr;m, immediately after the deposition temperature has been reached.

Abstract: A method for doping a melt with a dopant has the melt being provided in a crucible. The dopant is introduced into a vessel and the vessel is immersed in the melt, the dopant being transferred into the melt through an opening which forms in the vessel. There is also an apparatus which comprises a vessel containing the dopant and a device which is connected to the vessel, for lowering the vessel into a melt and for lifting the vessel out of the melt, the vessel being provided with an opening which is blocked by a closure piece which is of the same type of material as the melt and melts when it is brought into contact with the melt.

Abstract: A process for producing semiconductor wafers by double-sided polishing between two rotating, upper and lower polishing plates, which are covered with polishing cloth, while an alkaline polishing abrasive with colloidal solid fractions is being supplied, the semiconductor wafers being guided by carriers which have circumferential gear teeth and are set in rotation by complementary outer gear teeth and inner gear teeth of the polishing machine, which is distinguished by the following process steps: (a) at least one of the two sets of gear teeth of the polishing machine is at least from time to time sprayed with a liquid which substantially comprises water, (b) the alkaline polishing abrasive is fed continuously to the semiconductor wafers in a closed supply device. There is also a device which is suitable for carrying out the process.

Abstract: A method for separating slices from a hard brittle workpiece involves subjecting the workpiece to an advancing movement and pressing it onto wires of a wire web of a wire saw, the wires being under a defined wire tension and making contact with the workpiece over a cutting depth along a cutting contour. The wires are lifted off the cutting contour an number of times while the wire tension is kept substantially unchanged, with the aid of rolls of a roll system. The roll system comprises at least one roll that is moved onto the wire web and back, the roll system comprising at least two moveable rolls which flank the workpiece. A wire saw is suitable for carrying out the method.

Abstract: A method for the production of a semiconductor wafer having a front and a back and an epitaxial layer of semiconductor material deposited on the front, includes the following process steps: (a) preparing a substrate wafer having a polished front and a specific thickness; (b) pretreating the front of the substrate wafer in the presence of HCl gas and a silane source at a temperature of from 950 to 1250 degrees Celsius in an epitaxy reactor, the thickness of the substrate wafer remaining substantially unchanged; and (c) depositing the epitaxial layer on the front of the pretreated substrate wafer.

Abstract: A silicon semiconductor substrate which realises a defect-free region of void type crystals to a greater depth and allows the duration of production to be decreased and a method for the production thereof are provided.

Abstract: A process for producing a multiplicity of semiconductor wafers, which includes the following individual steps: (a) simultaneous polishing a front side and a back side of each semiconductor wafer between rotating polishing plates with a polishing fluid being supplied, the semiconductor wafer in each case resting in a cutout in a carrier and being kept on a specific geometric path, and all semiconductor wafers having a thickness t1 following the polishing; (b) assessment of each semiconductor wafer with regard to quality features which are stipulated for further processing; (c) further simultaneous polishing a front side and a back side of each of those semiconductor wafers which, according to quality inspection (b), do not satisfy the stipulated quality features, these semiconductor wafers having a thickness t2 following the further polishing; and (d) further assessment of each of those semiconductor wafers which were fed to step (c) with regard to quality features stipulated for further processing.

Abstract: A semiconductor substrate after heat-treatment in a non-oxidising atmosphere has the characteristics that the depth of the denuded zone may be greater than 12 &mgr;m or the defect-free depth of the void type defect is greater than 12 &mgr;m and the substrate has a locally densified portion produced by nitrogen segregation and exhibiting a signal strength two or more times the average signal strength at the depth of 12 &mgr;m or more below the surface thereof when measuring the concentration of nitrogen by using secondary ion mass-spectroscopy, and the density of the crystal defect of oxygen precipitates is 5×108/cm3 or more, and the said substrate is produced by heat-treating for at least one hour at the temperature of 1200° C. or more in a non-oxidising atmosphere.

Abstract: A sawing wire is for the simultaneous cutting and lapping of a multiplicity of wafers from a hard brittle workpiece. The sawing wire exhibits torsion. There is also a method for cutting and lapping using the sawing wire.

Abstract: A silicon semiconductor substrate has a structure possessing oxygen precipitate defects fated to form gettering sites in a high density directly below the defect-free region of void type crystals. The silicon semiconductor substrate is formed by heat-treating a silicon semiconductor substrate derived from a silicon single crystal grown by the Czochralski method or the magnetic field-applied Czochralski method and characterized by satisfying the relational expression (Oi DZ)−(COP DZ)≦10 &mgr;m wherein Oi DZ denotes a defect-free zone of oxygen precipitate crystal defects and COP DZ denotes a region devoid of a void type defect measuring not less than 0.11 &mgr;m in size, and having not less than 5×108 oxygen precipitate crystal defects per cm3.

Abstract: A process for producing semiconductor wafers comprises simultaneous grinding of both sides of the semiconductor wafers in a single step, 1S-DDG, wherein this grinding is the only material-removing mechanical machining step which is used to machine the surfaces of the semiconductor wafers. This process produces semiconductor wafers with improved geometry and nanotopology.

Abstract: A process is for material-removing machining, on both sides simultaneously, of semiconductor wafers having a front surface and a back surface, the semiconductor wafers resting in carriers which are set in rotation by means of an annular outer drive ring and an annular inner drive ring and being moved between two oppositely rotating working disks in a manner which can be described by means of in each case one path curve relative to the upper working disk and one path curve relative to the lower working disk, wherein the two path curves after six loops around the center have the appearance of still being open, and at each point have a radius of curvature which is at least as great as the radius of the inner drive ring.

Abstract: A process for the surface polishing of a silicon wafer, includes the successive polishing of the silicon wafer on at least two different polishing plates covered with polishing cloth, with a continuous supply of alkaline polishing abrasive with SiO2 constituents, an amount of silicon removed during the polishing on a first polishing plate being significantly higher than on a second polishing plate, with the overall amount of silicon removed not exceeding 1.5 &mgr;m. A polishing abrasive (1a), then a mixture of a polishing abrasive (1b) and at least one alcohol, and finally ultrapure water (1c) are added to the first polishing plate, and a mixture of a polishing abrasive (2a) and at least one alcohol and then ultrapure water (2b) are added to the second plate.

Abstract: A process for the wet-chemical surface treatment of a semiconductor wafer following a mechanical surface treatment, in particular following a mechanical surface treatment in a lapping machine, includes a sequence of treatment steps. The process essentially includes a wet-chemical surface cleaning, preferably for neutralizing and eliminating the lapping slurry, an acid etching treatment, preferably for eliminating the mechanically imposed damage and for surface smoothing and removal of metals. There is a final step of drying and rendering the cleaned and etched surface hydrophilic.

Abstract: A semiconductor wafer has a front surface and a back surface and flatness values based on partial areas of a surface grid on the front surface of the semiconductor wafer, which has a maximum local flatness value SFQRmax of less than or equal to 0.13 &mgr;m and individual SFQR values which in a peripheral area of the semiconductor wafer do not differ significantly from those in a central area of the semiconductor wafer. There is also a process for producing this semiconductor wafer, wherein the starting thickness of the semiconductor wafer is 20 to 200 &mgr;m greater than the thickness of the carrier and the semiconductor wafer is polished until the end thickness of the semiconductor wafer is 2 to 20 &mgr;m greater than the thickness of the carrier.

Abstract: A method and device for producing an adhesive-bonded join between a semiconductor wafer and a carrier plate, the semiconductor wafer being held at a distance above the carrier plate and being convexly deformed by an elastic wall of an inflatable pressure chamber, then being laid onto the carrier plate, enclosing an adhesive substance, and is joined in a nonpositively locking manner to the carrier plate. An edge region of the semiconductor wafer is sucked up and held above the carrier plate, the suction is ended and the semiconductor wafer is allowed to drop in a convexly deformed state onto the carrier plate, and only a central area of the semiconductor wafer is pressed onto the carrier plate by the elastic wall of the pressure chamber.

Abstract: A method for separating slices from a hard brittle workpiece involves subjecting the workpiece to an advancing movement and pressing it onto wires of a wire web of a wire saw, the wires being under a defined wire tension and making contact with the workpiece over a cutting depth along a cutting contour. The wires are lifted off the cutting contour an number of times while the wire tension is kept substantially unchanged, with the aid of rolls of a roll system. The roll system comprises at least one roll that is moved onto the wire web and back, the roll system comprising at least two moveable rolls which flank the workpiece. A wire saw is suitable for carrying out the method.

Abstract: A silicon single crystal is produced by crucible-free float zone pulling, has a diameter of at least 200 mm over a length of at least 200 mm and is free of dislocations in the region of this length. A silicon wafer is separated from the silicon single crystal by a process for producing the silicon single crystal. The silicon single crystal is produced by crucible-free float zone pulling in a receptacle, in which an atmosphere of inert gas and nitrogen exerts a pressure of 1.5-2.2 bar, the atmosphere being continuously exchanged, with the volume of the receptacle being exchanged at least twice per hour. A flat coil with an external diameter of at least 220 mm is inserted in order to melt a stock ingot. The single crystal is pulled at a rate in a range from 1.4-2.2 mm/min and is periodically rotated through a sequence of rotation angles.

Abstract: A method for the production of a single crystal has the single crystal crystallizing from a melt and being subjected to a rotation with an alternating rotation direction. The single crystal is periodically rotated through a sequence of rotation angles, and the rotation direction is changed after each rotation through a rotation angle of the sequence, with a change of the rotation direction defining an inversion point on the circumference of the single crystal. There is at least one recurring pattern of inversion points created, in which the inversion points lie distributed on straight lines that are aligned parallel with the z-axis and are spaced apart uniformly from one another.