Abstract: A method produces semiconductor wafers of monocrystalline silicon. The method includes: pulling a cylindrical section of a single silicon crystal from a melt contained in a crucible, wherein the oxygen concentration in the cylindrical section is not more than 5×1017 atoms/cm3; subjecting the melt to a horizontal magnetic field; rotating the crucible at a rotational velocity and in a rotational direction during the pulling of the cylindrical section of the single crystal; and removing the semiconductor wafers of monocrystalline silicon from the cylindrical section of the single crystal. An amount of rotational velocity, averaged over time, is less than 1 rpm and the rotational direction is changed continually and the amplitude of the rotational velocity before and after the change in the rotational direction is not less than 0.5 rpm and not more than 3.0 rpm.

Abstract: A method produces semiconductor wafers of monocrystalline silicon. The method includes: pulling a cylindrical section of a single silicon crystal from a melt contained in a crucible, wherein the oxygen concentration in the cylindrical section is not more than 5×1017 atoms/cm3; subjecting the melt to a horizontal magnetic field; rotating the crucible at a rotational velocity and in a rotational direction during the pulling of the cylindrical section of the single crystal; and removing the semiconductor wafers of monocrystalline silicon from the cylindrical section of the single crystal. An amount of rotational velocity, averaged over time, is less than 1 rpm and the rotational direction is changed continually and the amplitude of the rotational velocity before and after the change in the rotational direction is not less than 0.5 rpm and not more than 3.0 rpm.

Abstract: Single silicon crystals having a resistivity of ?20 m?cm are pulled by the Czochralski process from a melt, by a method of pulling a first section of a neck at a first velocity whereby the diameter of a first section of the neck, with respect to the diameter of a seed crystal, tapers at a rate of ?0.3 mm per mm neck length to a diameter of not more than 5 mm; pulling a second section of the neck at a pulling velocity of <0.2 mm/min for not less than 3 min, without the diameter increasing to more than 5.5 mm; and pulling a third section of the neck at a third pulling velocity of >2 mm/min.

Abstract: Single crystal semiconductor ingots are pulled from a melt contained in a crucible by a method of controlling the pulling the single crystal in a phase in which an initial cone of the single crystal is grown until a phase in which the pulling of a cylindrical section of the single crystal is begun, by measuring the diameter Dcr of the initial cone of the single crystal and calculating the change in the diameter dDcr/dt; pulling the initial cone of the single crystal from the melt at a pulling rate vp(t) from a point in time t1 until a point in time t2, starting from which the pulling of the cylindrical section of the single crystal in conjunction with a target diameter Dcrs is begun, wherein the profile of the pulling rate vp(t) from the point in time t1 until the point in time t2 during the pulling of the initial cone is predetermined by means of an iterative computation process.

Abstract: A semiconductor wafer comprising single-crystal silicon has defined concentrations of oxygen, nitrogen and hydrogen; the semiconductor wafer further contains BMD seeds having a density averaged over the radius of not less than 1×105 cm?3 and not more than 1×107 cm?3; surface defects having a density averaged over the radius of not less than 1100 cm?2; and BMDs, whose density is not lower than a lower limit of 5×108/cm3. The semiconductor wafers are produced by a process which enables obtention of the required ranges of concentrations of oxygen, nitrogen, hydrogen, BMD seeds, and BMD's.

Abstract: Single crystal semiconductor wafers comprise oxygen and an n-type dopant, and are produced by a process comprising providing a silicon melt containing n-type dopant in a quartz crucible, the melt having an initial height hM; heating the melt from the side by selectively supplying heat to an upper volume of the melt having an initial height hm, wherein hm is smaller than hM; pulling a single crystal of silicon from the melt by the CZ method with a pulling velocity V; heating the melt from above in the region of a phase boundary between the growing single crystal and the melt; heating the melt from above in the region of a surface of the melt; subjecting the melt to a magnetic field; counterdoping the melt with p-type dopant; and separating the semiconductor wafer of single-crystal silicon from the single crystal. An apparatus for accomplishing the process is also disclosed.

Abstract: The invention relates to a silicon wafer having a radial variation of oxygen concentration of less than 7%, determined over the entire radius of the silicon wafer. The wafers are produced in the PV region with rotation of crystal and crucible in the same direction, and in the presence of a horizontal magnetic field of defined intensity.

Abstract: The invention relates to a silicon wafer having a radial variation of oxygen concentration of less than 7%, determined over the entire radius of the silicon wafer. The wafers are produced in the PV region with rotation of crystal and crucible in the same direction, and in the presence of a horizontal magnetic field of defined intensity.

Abstract: Single crystal semiconductor ingots are pulled from a melt contained in a crucible by a method of controlling the pulling the single crystal in a phase in which an initial cone of the single crystal is grown until a phase in which the pulling of a cylindrical section of the single crystal is begun, by measuring the diameter Dcr of the initial cone of the single crystal and calculating the change in the diameter dDcr/dt; pulling the initial cone of the single crystal from the melt at a pulling rate vp(t) from a point in time t1 until a point in time t2, starting from which the pulling of the cylindrical section of the single crystal in conjunction with a target diameter Dcrs is begun, wherein the profile of the pulling rate vp(t) from the point in time t1 until the point in time t2 during the pulling of the initial cone is predetermined by means of an iterative computation process.

Abstract: Single crystal semiconductor wafers comprise oxygen and an n-type dopant, and are produced by a process comprising providing a silicon melt containing n-type dopant in a quartz crucible, the melt having an initial height hM; heating the melt from the side by selectively supplying heat to an upper volume of the melt having an initial height hm, wherein hm is smaller than hM; pulling a single crystal of silicon from the melt by the CZ method with a pulling velocity V; heating the melt from above in the region of a phase boundary between the growing single crystal and the melt; heating the melt from above in the region of a surface of the melt; subjecting the melt to a magnetic field; counterdoping the melt with p-type dopant; and separating the semiconductor wafer of single-crystal silicon from the single crystal. An apparatus for accomplishing the process is also disclosed.

Abstract: A semiconductor wafer comprising single-crystal silicon has defined concentrations of oxygen, nitrogen and hydrogen; the semiconductor wafer further comprises: BMD seeds having a density averaged over the radius of not less than 1×105 cm?3 and not more than 1×107 cm?3; surface defects having a density averaged over the radius of not less than 1100 cm?2; and BMDs, whose density is not lower than a lower limit of 5×108/cm3. The semiconductor wafers are produced by a process which enables obtention of the required ranges of concentrations of oxygen, nitrogen, hydrogen, BMD seeds, and BMD's.

Abstract: Semiconductor wafers composed of monocrystalline silicon and doped with nitrogen contain an OSF region and a Pv region, wherein the OSF region extends from the center radially toward the edge of the wafer as far as the Pv region; the wafer has an OSF density of less than 10 cm?2, a BMD density in the bulk of at least 3.5×108 cm?3, and a radial distribution of the BMD density with a fluctuation range BMDmax/BMDmin of not more than 3. The wafers are produced by controlling initial nitrogen content and maintaining oxygen within a narrow window, followed by a heat treatment.

Abstract: Silicon semiconductor wafers are produced by: pulling a single crystal with a conical section and an adjoining cylindrical section having a diameter ?450 mm and a length of ?800 mm from a melt in a crucible, wherein in pulling the transition from the conical section to the cylindrical section, the pulling rate is at least 1.8 times higher than the average pulling rate during the pulling of the cylindrical section; cooling the growing single crystal with a cooling power of at least 20 kW; feeding heat from the side wall of the crucible to the single crystal, wherein a gap having a height of ?70 mm is present between a heat shield surrounding the single crystal and the melt surface.

Abstract: Silicon semiconductor wafers are produced by: pulling a single crystal with a conical section and an adjoining cylindrical section having a diameter ?450 mm and a length of ?800 mm from a melt in a crucible, wherein in pulling the transition from the conical section to the cylindrical section, the pulling rate is at least 1.8 times higher than the average pulling rate during the pulling of the cylindrical section; cooling the growing single crystal with a cooling power of at least 20 kW; feeding heat from the side wall of the crucible to the single crystal, wherein a gap having a height of ?70 mm is present between a heat shield surrounding the single crystal and the melt surface.

Abstract: Silicon semiconductor wafers are produced by: pulling a single crystal with a conical section and an adjoining cylindrical section having a diameter ?450 mm and a length of ?800 mm from a melt in a crucible, wherein in pulling the transition from the conical section to the cylindrical section, the pulling rate is at least 1.8 times higher than the average pulling rate during the pulling of the cylindrical section; cooling the growing single crystal with a cooling power of at least 20 kW; feeding heat from the side wall of the crucible to the single crystal, wherein a gap having a height of ?70 mm is present between a heat shield surrounding the single crystal and the melt surface.

Abstract: Semiconductor wafers composed of monocrystalline silicon and doped with nitrogen contain an OSF region and a PV region, wherein the OSF region extends from the center radially toward the edge of the wafer as far as the Pv region; the wafer has an OSF density of less than 10 cm?2, a BMD density in the bulk of at least 3.5×108 cm?3, and a radial distribution of the BMD density with a fluctuation range BMDmax/BMDmim of not more than 3. The wafers are produced by controlling initial nitrogen content and maintaining oxygen within a narrow window, followed by a heat treatment.