Abstract: Apparatus and method for a crucible-less production of silicon ingots, including a support with a seed layer and a liquid layer is gradually lowered in a temperature field with a vertical gradient to solidify the liquid layer in a controlled way.

Abstract: Apparatus and method for a crucible-less production of silicon ingots, wherein a support with a seed layer and a liquid layer is gradually lowered in a temperature field with a vertical gradient to solidify the liquid layer in a controlled way.

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: 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: Single crystal composed of silicon with a section having a diameter that remains constant, are pulled by a method wherein the single crystal is pulled with a predefined pulling rate vp having the units [mm/min]; and the diameter of the single crystal in the section having a diameter that remains constant is regulated to the predefined diameter by regulating the heating power of a first heating source which supplies heat to the single crystal and to a region of the melt that adjoins the single crystal and is arranged above the melt, such that diameter fluctuations are corrected with a period duration T that is not longer than (2·18 mm)/vp.

Abstract: Silicon single crystals are grown by a method of remelting silicon granules, by crystallizing a conically extended section of the single crystal with the aid of an induction heating coil arranged below a rotating plate composed of silicon; feeding inductively melted silicon through a conical tube in the plate, the tube enclosing a central opening of the plate and extending below the plate, to a melt situated on the conically extended section of the single crystal in contact with a tube end of the conical tube, wherein by means of the induction heating coil below the plate, sufficient energy is provided to ensure that the external diameter of the tube end is not smaller than 15 mm as long as the conically extended section of the single crystal has a diameter of 15 to 30 mm.

Abstract: A single crystal of semiconductor material is produced by a method of melting semiconductor material granules by means of a first induction heating coil on a dish with a run-off tube consisting of the semiconductor material, forming a melt of molten granules which extends from the run-off tube in the form of a melt neck and a melt waist to a phase boundary, delivering heat to the melt by means of a second induction heating coil which has an opening through which the melt neck passes, crystallizing the melt at the phase boundary, and delivering a cooling gas to the run-off tube and to the melt neck in order to control the axial position of an interface between the run-off tube and the melt neck.

Abstract: A single crystal of semiconductor material is produced by a method of melting semiconductor material granules by means of a first induction heating coil on a dish with a run-off tube consisting of the semiconductor material, forming a melt of molten granules which extends from the run-off tube in the form of a melt neck and a melt waist to a phase boundary, delivering heat to the melt by means of a second induction heating coil which has an opening through which the melt neck passes, crystallizing the melt at the phase boundary, and delivering a cooling gas to the run-off tube and to the melt neck in order to control the axial position of an interface between the run-off tube and the melt neck.

Abstract: Silicon single crystals are prepared from molten granules, by producing a first volume of molten silicon between a growing single crystal and the lower end of a silicon conical tube which is closed at its lower end, and encloses a central opening of a rotating silicon plate below which the tube extends, by means of a first induction heating coil arranged below the plate; producing a second volume of molten silicon by a second induction heating coil arranged above the plate; melting the lower end of the tube to form a passage for the second volume of molten silicon, the passage produced at a point in time when the second volume is not yet present or is less than double the volume of the first volume; and crystallizing monocrystalline silicon on the growing single crystal with consumption of molten silicon from the first and the second volume.

Abstract: The epitaxial layer defects generated from voids of a silicon substrate wafer containing added hydrogen are suppressed by a method for producing an epitaxial wafer by: growing a silicon crystal by the Czochralski method comprising adding hydrogen and nitrogen to a silicon melt and growing from the silicon melt a silicon crystal having a nitrogen concentration of from 3×1013 cm?3 to 3×1014 cm?3, preparing a silicon substrate by machining the silicon crystal, and forming an epitaxial layer at the surface of the silicon substrate.

Abstract: Semiconductor wafers of silicon are produced by pulling a single crystal growing on a phase boundary from a melt contained in a crucible and cutting of semiconductor wafers therefrom, wherein during pulling of the single crystal, heat is delivered to a center of the phase boundary and a radial profile of a ratio V/G from the center to an edge of the phase boundary is controlled, G being the temperature gradient perpendicular to the phase boundary and V being the pull rate. The radial profile of the ratio V/G is controlled so that the effect of thermomechanical stress in the single crystal adjoining the phase boundary, is compensated with respect to creation of intrinsic point defects. The invention also relates to defect-free semiconductor wafers of silicon, which can be produced economically by this method.

Abstract: A process for producing a single crystal of semiconductor material, in which fractions of a melt, are kept in liquid form by a pulling coil, solidify on a seed crystal to form the growing single crystal, and granules are melted in order to maintain the growth of the single crystal. The melting granules are passed to the melt after a delay. There is also an apparatus which Is suitable for carrying out the process and has a device which delays mixing of the molten granules and of the melt.

Abstract: Silicon wafers having a density of BMDs with sizes between 20 to 40 nm at positions ?20 ?m below the wafer surface in the range of 5×1011/cm3, and a density of BMDs with sizes of ?300 nm?1×107/cm3, exhibit reduced slip dislocation and warpage. The wafers are sliced from a crystal grown under specific conditions and then subjected to both low temperature heat-treatment and high temperature anneal.

Abstract: Semiconductor wafers of silicon are produced by pulling a single crystal from a melt contained in a crucible and slicing semiconductor wafers from the pulled single crystal, heat being delivered to a center of the growing single crystal at the boundary with the melt during the pulling of the single crystal, a CUSP magnetic field applied such that a neutral surface of the CUSP magnetic field intersects a pulling axis of the single crystal at a distance of at least 50 mm from a surface of the melt. An apparatus suitable therefore contains a CUSP field positioned such that a neutral field intersects the axis of the crystal in the crucible 50 mm or more from the melt surface.

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: Semiconductor wafers of silicon are produced by pulling a single crystal growing on a phase boundary from a melt contained in a crucible and cutting of semiconductor wafers therefrom, wherein during pulling of the single crystal, heat is delivered to a center of the phase boundary and a radial profile of a ratio V/G from the center to an edge of the phase boundary is controlled, G being the temperature gradient perpendicular to the phase boundary and V being the pull rate. The radial profile of the ratio V/G is controlled so that the effect of thermomechanical stress in the single crystal adjoining the phase boundary, is compensated with respect to creation of intrinsic point defects. The invention also relates to defect-free semiconductor wafers of silicon, which can be produced economically by this method.

Abstract: Semiconductor wafers of silicon are produced by pulling a single crystal growing on a phase boundary from a melt contained in a crucible and cutting of semiconductor wafers therefrom, wherein during pulling of the single crystal, heat is delivered to a center of the phase boundary and a radial profile of a ratio V/G from the center to an edge of the phase boundary is controlled, G being the temperature gradient perpendicular to the phase boundary and V being the pull rate. The radial profile of the ratio V/G is controlled so that the effect of thermomechanical stress in the single crystal adjoining the phase boundary, is compensated with respect to creation of intrinsic point defects. The invention also relates to defect-free semiconductor wafers of silicon, which can be produced economically by this method.

Abstract: Hetero-semiconductor structures possessing an SOI structure containing a silicon-germanium mixed crystal are produced at a low cost and high productivity. The semiconductor substrates comprise a first layer formed of silicon having germanium added thereto, a second layer formed of an oxide and adjoined to the first layer, and a third layer derived from the same source as the first layer, but having an enriched content of germanium as a result of thermal oxidation and thinning of the third layer.

Abstract: Silicon single crystals are prepared from molten granules, by producing a first volume of molten silicon between a growing single crystal and the lower end of a silicon conical tube which is closed at its lower end, and encloses a central opening of a rotating silicon plate below which the tube extends, by means of a first induction heating coil arranged below the plate; producing a second volume of molten silicon by a second induction heating coil arranged above the plate; melting the lower end of the tube to form a passage for the second volume of molten silicon, the passage produced at a point in time when the second volume is not yet present or is less than double the volume of the first volume; and crystallizing monocrystalline silicon on the growing single crystal with consumption of molten silicon from the first and the second volume.

Abstract: Single crystal composed of silicon with a section having a diameter that remains constant, are pulled by a method wherein the single crystal is pulled with a predefined pulling rate vp having the units [mm/min]; and the diameter of the single crystal in the section having a diameter that remains constant is regulated to the predefined diameter by regulating the heating power of a first heating source which supplies heat to the single crystal and to a region of the melt that adjoins the single crystal and is arranged above the melt, such that diameter fluctuations are corrected with a period duration T that is not longer than (2·18 mm)/vp.