Abstract: A method for producing a silicon monocrystal has a growing monocrystal kept for a specified dwell time in the specified temperature range of from 850.degree. C. to 1100.degree. C. This dwell time for the growing monocrystal in the chosen temperature range is either greater than 250 min or less than 80 min. A device and a method, in which the cooling rate of the growing monocrystal is to be influenced, has a heat shield which is subdivided into adjacent annular zones between a lower rim and an upper rim. These adjacent zones differ in regard to each's thermal conduction and transparency to heat radiation.

Abstract: A sawing suspension composition is composed of an essentially nonaqueous or anhydrous organic liquid in which hard-material particles are dispersed. The liquid is selected from a group of compounds which comprises low molecular weight polyglycols and any desired mixture of these polyglycols. The sawing suspension is used in conjunction with a wire saw for cutting wafers from a crystal of a brittle and hard material.

Abstract: A process for producing silicon wafers with low defect density is one wherein a) a silicon single crystal having an oxygen doping concentration of at least 4*10.sup.17 /cm.sup.3 is produced by molten material being solidified to form a single crystal and is then cooled, and the holding time of the single crystal during cooling in the temperature range of from 850.degree. C. to 1100.degree. C. is less than 80 minutes; b) the single crystal is processed to form silicon wafers; and c) the silicon wafers are annealed at a temperature of at least 1000.degree. C. for at least one hour. Also, it is possible to prepare a silicon single crystal based upon having an oxygen doping concentration of at least 4*10.sup.17 /cm.sup.3 and a nitrogen doping concentration of at least 1*10.sup.14 /cm.sup.3 for (a) above.

Abstract: A carrier for a semiconductor wafer has at least three protrusions on which he edge of the semiconductor wafer is supported so that the semiconductor wafer is positioned essentially horizontal. The carrier does not make contact with the front side and the rear side of the semiconductor wafer. The protrusions are shaped so that the edge of the semiconductor wafer is supported exclusively below an imaginary central plane in the center between the front side and the rear side of the semiconductor wafer. The carrier is preferably used in the treatment of semiconductor wafers at temperatures of at least 200.degree. C.

Abstract: A process and an apparatus control the growth of a crystal, which growth is governed by a set of measurable and non-measurable variables. The process includes establishing an on-line simulation software working with a reduced number of variables, the reduction of variables being performed by using a projection algorithm; speeding up the on-line simulation software by generating data banks in which values of off-line precalculated variables are stored; tuning the on-line simulation software by adjusting the results predicted by on-line simulations to the results obtained by off-line simulations and by measurements; and establishing a control loop and controlling at least one of the variables in real time, the control loop using the speeded up and tuned on-line simulation software as an on-line observer.

Abstract: A wire saw for, and a method of, cutting off slices from a workpiece. The re saw has a cutting head, which contains a plurality of wire guide rollers and around which a multiplicity of wire sections lying parallel to one another and forming plane wire webs are moved, a holding arm which carries the workpiece, and a feed, by means of which the wire sections of one of the wire frames cut through the workpiece while an auxiliary sawing medium is supplied. In one embodiment of the wire saw, the feed guide is arranged at the side of the cutting head and the holding arm can be swivelled parallel to the wire web. In another embodiment, holding arm is swivellable parallel to the wire web and the feed has a feed guide which guides the cutting head with the wire web toward the workpiece.

Abstract: A method and an apparatus for pulling a silicon monocrystal from a melt iudes the pulling of a conical portion in each case at the beginning and at the end of the monocrystal and the pulling of a cylindrical portion between the conical portions. In this method, the surface of the conical portion at the beginning of the monocrystal is shielded by a shielding means spaced apart from the monocrystal.

Abstract: A method and a device is provided for determining the diameter of a monocrystal growing at a crystallization boundary during the pulling of the monocrystal from a melt. The method includes imaging a part of the crystallization boundary on at least one mirror, observing the mirror image and determining the diameter of the monocrystal from the observed relative position of the crystallization boundary on the mirror image.

Abstract: A method and an apparatus are for machining semiconductor material with a inding tool while feeding a liquid cleaning agent to the working surface of the grinding tool, has the cleaning agent being exposed to sound waves having a specific frequency and having a specific intensity. In one embodiment of the method, the cleaning agent is exposed to sound waves in at least one nozzle and then the cleaning agent is directed against the working surface of the grinding tool. In another embodiment, the cleaning agent is guided through at least two cleaning agent jets against the working surface of the grinding tool, which cleaning agent jets differ from each other in that they are exposed to sound waves of different frequencies.

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: Apparatus for preparing a single crystal made of silicon is according to Czochralski method, which includes a tubular to the conical body which shields the growing single crystal and divides the receiver chamber above the melt into an inner portion and an outer portion, the body having at least one orifice through which inert gas which is conducted into the inner portion of the receiver chamber is able to pass directly into the outer portion of the receiver chamber. The method for preparing a single crystal made of silicon is in accordance with the Czochralski method, wherein a portion of an inert gas stream is conducted through at least one orifice in the tubular to conical body from the inner portion into the outer portion of the receiver chamber.

Abstract: Apparatus for producing a single crystal of semiconductor material in accance with the Czochralski method, has a cooling means which cools the growing single crystal and is constructed in two parts, The first is an upper part duct system through which a liquid coolant flows. The second is a lower part which is a heat-conducting cooling body.