Abstract: Epitaxially coated semiconductor wafers are prepared by a process in which a semiconductor wafer polished at least on its front side is placed on a susceptor in a single-wafer epitaxy reactor and epitaxially coated on its polished front side at temperatures of 1000-1200° C., wherein, after coating, the semiconductor wafer is cooled in the temperature range from 1200° C. to 900° C. at a rate of less than 5° C. per second. In a second method for producing an epitaxially coated wafer, the wafer is placed on a susceptor in the epitaxy reactor and epitaxially coated on its polished front side at a deposition temperature of 1000-1200° C., and after coating, and while still at the deposition temperature, the wafer is raised for 1-60 seconds to break connections between susceptor and wafer produced by deposited semiconductor material before the wafer is cooled.

Abstract: Monocrystalline silicon semiconductor wafers have a front side and a rear side, and a denuded zone which extends from the front side to the rear side as far as a depth which between a center and an edge of the semiconductor wafer on average is not less than 8 ?m and not more than 18 ?m, and having a region adjoining the denuded zone having BMDs whose density at a distance of 30 ?m from the front side is not less than 2×109 cm?3. The semiconductor wafers are produced by a method comprising providing a substrate wafer of monocrystalline silicon and an RTA treating the substrate wafer, the treatment subdivided into a first thermal treatment of the substrate wafer in an atmosphere consisting of argon and into a second thermal treatment of the substrate wafer in an atmosphere consisting of argon and ammonia.

Abstract: Semiconductor wafers are cleaned, dried, and hydrophilized the following steps in the order stated: a) treating the semiconductor wafer with a liquid aqueous solution containing hydrogen fluoride, the semiconductor wafer rotating about its center axis at least occasionally, and b) drying the semiconductor wafer by rotation of the semiconductor wafer about its center axis at a rotational speed of 1000 to 5000 revolutions per minute in an ozone-containing atmosphere, the liquid aqueous solution containing hydrogen fluoride flowing away from the semiconductor wafer on account of the centrifugal force generated by the rotation, and the surface of the semiconductor wafer being hydrophilized by ozone.

Abstract: A method of polishing a semiconductor wafer includes simultaneous double-side polishing the wafer in a gap of a polishing device between a lower polishing plate covered with a lower polishing pad and upper polishing plate covered with an upper polishing pad while supplying a polishing agent. A first of the upper and lower polishing pads is dressed using a dressing tool. The dressing tool is mounted in the gap so that it extends from the inner edge to the outer edge of the first polishing pad. The distance between the dressing tool and a second of the upper and lower polishing pads at the inner edge of the second polishing pad differs from a corresponding distance at the outer edge of the second polishing pad. After the dressing, the at least one semiconductor wafer in the gap is polished.

Abstract: Both sides of a large diameter semiconductor wafer are polished by the following ordered steps: a) polishing the wafer backside on a polishing pad containing a fixed abrasive, a polishing agent solution free of solids being introduced between the wafer backside and the polishing pad; b) stock polishing the wafer frontside on a polishing pad which contains a fixed abrasive, a polishing agent solution free of solids being introduced between the wafer frontside of and the polishing pad; c) removing microroughness and microdamage from the wafer frontside by polishing the frontside on a polishing pad, a polishing agent solution containing abrasives being introduced between the wafer frontside and the polishing pad; and d) final polishing of the wafer frontside by polishing the frontside on a polishing pad containing no fixed abrasive, a polishing agent solution containing abrasives being introduced between the wafer frontside and the polishing pad during the polishing step.

Abstract: A multiplicity of wafer-type workpieces are buffer stored in a device having, a frame, at least two transport elements which each circulate in a vertical direction around an upper and a lower deflection device connected to the frame and are provided, at uniform intervals, with a multiplicity of bearing areas for the horizontal mounting of workpieces, wherein at least one of the deflection devices of each transport element is driven and a free space is situated between the transport elements, a loading position between the upper deflection devices at which a workpiece can be placed onto corresponding bearing areas, and a stationary removal device below the loading position, comprising a horizontal transport device, the first end of which lies within the free space between the transport elements. The invention also relates to a method for buffer-storing a multiplicity of wafer-type workpieces using the abovementioned device.

Abstract: A method for polishing at least one semiconductor wafer while supplying a polishing agent includes performing a first simultaneous double-side polishing of the front side and the back side of the at least one semiconductor wafer with first upper and lower polishing pads, edge-notch polishing the surface of the at least one semiconductor wafer, performing a second simultaneous double-side polishing of the front side and the back side of the at least on semiconductor wafer with second upper and lower polishing pads, where the upper and lower polishing pads for the first simultaneous double-side polishing are harder and less compressible than the upper and lower polishing pads for the second simultaneous double-side polishing and performing single-side polishing of the front side of the at least one semiconductor wafer.

Abstract: A method for simultaneously slicing a multiplicity of wafers from a substantially circular-cylindrical workpiece that is connected to a sawing strip includes executing a relative movement between the workpiece and a wire gang of a wire saw with the aid of a forward feed device with a defined forward feed rate so as to slice the wafers. The forward feed rate is varied through the course of the method and includes being set to a value v1 at a cutting depth of 50% of the workpiece diameter. Subsequently, the forward feed rate is to a value v2>1.15×v1 as the forward feed rate passes through a local maximum. The forward feed rate is set to a value v3<v1 when the wire gang first comes into contact with the sawing strip. The forward feed rate is increased to a value v5>v3.

Abstract: Uniformity of vapor deposited coatings on semiconductor wafers is improved by employing an apparatus having a gas distributor head below a susceptor onto which the wafer is placed, the gas distributor head directing a fan of cooling gas at the rear side of the susceptor. The ratio of the diameter of the cooled section of the susceptor to the diameter D of the wafer is preferably from 0.1 to 0.4.

Abstract: A semiconductor wafer contains the following layers in the given order: a monocrystalline substrate wafer (1) consisting predominantly of silicon and having a (111) surface orientation, a monocrystalline layer (3) of Sc2O3 having a (111) surface orientation, a monocrystalline layer (4) of ScN having a (111) surface orientation, and a monocrystalline layer (6) of AlzGa1-zN with 0?z?1 having a (0001) surface orientation, the semiconductor wafers are produced by appropriate deposition of the respective layers.

Abstract: An induction heating coil melts granules composed of semiconductor material on a plate with an outlet tube. The induction heating coil has a coil body provided with current-guiding slots, the coil body having an upper side and a lower side and having a passage opening for granules in a region of the coil body that lies outside the center of the coil, and current-carrying segments which project from the center of the lower side of the coil body and which are electrically conductively connected by a web at a lower end.

Abstract: A method for cutting a workpiece with a wire saw includes running at least one saw wire in a lateral direction. A first abrasive grain slurry is supplied to the saw wire on two points that are separated by a predetermined distance in a lateral direction. Cutting of the workpiece is started by moving at least one of the workpiece and the saw wire relative to the other and bringing the workpiece into contact with the saw wire from above at a location between the two points on the saw wire where the first abrasive grain slurry is supplied. A second abrasive grain slurry is supplied to a part of an area where the saw wire meshes with the workpiece.

Abstract: A method for slicing wafers from a workpiece includes providing wire guide rolls that each have a grooved coating with a specific thickness, providing a fixed bearing respectively associated with each wire guide roll and providing a sawing wire including wire sections disposed in a parallel fashion. The wire sections are tensioned between the wire guide rolls and are moved relative to the workpiece so as to perform a sawing operation. The wire guide rolls cooled and the fixed bearings are cooled independently of the wire guide rolls.

Abstract: Silicon single crystals having suppressed deformation and dislocations and the successful omission of the tail section are produced by growing the straight-body section of the silicon single crystal under the influence of a horizontal magnetic field with a magnetic flux density at its magnetic center being ?1000 Gauss, and ?2000 Gauss, reducing the lifting speed of the silicon single crystal relative to the surface of the melt to 0 mm/minute, maintaining a static state until there is a decrease in the apparent weight of the silicon single crystal, then further maintaining the static state so that the entire growth front of the silicon single crystal forms a convex shape protruding in a direction opposite to the lifting direction of the silicon single crystal, and separating the silicon single crystal from the melt.

Abstract: A layer is deposited onto a semiconductor wafer by CVD in a process chamber having upper and lower covers, wherein the wafer front side temperature is measured; the wafer is heated to deposition temperature; the temperature of the upper process chamber cover is controlled to a target temperature by measuring the temperature of the center of the outer surface of the upper cover as the value of a controlled variable of an upper cover temperature control loop; a gas flow rate of process gas for depositing the layer is set; and a layer is deposited on the heated wafer front side during control of the upper cover temperature to the target temperature. A process chamber suitable therefor has a sensor for measuring the upper cover outer surface center temperature and a controller for controlling this temperature to a predetermined value.

Abstract: A trimming apparatus for trimming two working layers, including bonded abrasive applied on mutually facing sides of an upper and a lower working disk of a grinding apparatus configured for simultaneous double-side processing of flat workpieces includes a trimming disk, a plurality of trimming bodies and an outer toothing, where the trimming bodies are configured to release abrasive substances upon contract with the working layers so as to effect material removal from the working layers. At least 80% of the area of the trimming bodies configured to come into contact with the working layers is arranged within a ring-shaped region on the trimming disk. The width of the ring-shaped region is between 1-25% of the diameter of the trimming disk and the area of the trimming bodies which comes into contact with the working layers occupies 20-90% of the total area of the ring-shaped region.

Abstract: Silicon wafers having an oxygen concentration of 5·1017 to 7.5·1017 cm?3 have the following BMD densities after the following thermal processes, carried out alternatively: a BMD density of at most 1·108 cm?3 after a treatment for three hours at 780° C. and subsequently for 16 hours at 1000° C., and a BMD density of at least 1·109 cm?3 after heating of the silicon wafer at a heating rate of 1 K/min from a start temperature of 500° C. to a target temperature of 1000° C. and subsequent holding at 1000° C. for 16 hours. The wafers are prepared by a method of irradiation of a heated wafer with flashlamp which delivers energy which is from 50 to 100% of the energy density necessary for melting the wafer surface.

Abstract: A graphite crucible for silicon single crystal manufacturing by the Czochralski method, having a long life cycle, contains at least one gas venting hole provided in a corner portion of the crucible. Gas generated by reaction between the graphite crucible and a quartz crucible is released to the outside through the gas venting hole, and formation of SiC on the surface of the graphite crucible and deformation of the quartz crucible caused by the pressure of the generated gas are prevented.

Abstract: A method for simultaneously cutting a multiplicity of wafers from a cylindrical workpiece having an axis and a notch applied parallel to the axis in a lateral surface of the workpiece includes applying a cut-in beam on the workpiece where the cut-in beam has a head end and a foot end. The head end is inserted into the notch of the workpiece. The workpiece is held with a feed device so as to position an axis of the work piece parallel to the axes of cylindrical wire guide rollers of a wire saw. The cut-in beam is moved through a planar wire web, where the planar wire web has sections of wire arranged parallel to one another and perpendicular to the axes of the wire guide roller. The wire sections are moved the longitudinal wire direction in the presence of abrasives.

Abstract: A method for trimming two working layers including bonded abrasive applied on mutually facing sides of an upper and a lower working disk of a grinding apparatus configured for simultaneous double-side processing of flat workpiece includes providing at least one trimming apparatus including a trimming disk, a plurality of trimming bodies and an outer toothing. The upper and lower working disks are rotated. The trimming apparatus is moved between the rotating working disks using a rolling apparatus and the outer toothing on cycloidal paths relative to working layers of the working disks. The working layers and the trimming body are brought into contact so as to release abrasive substances from the trimming bodies and so as to effect material removal from the working layers. The direction of the drives of the grinding apparatus is changed at least twice during trimming.