Patent classifications
C30B30/04
Method for producing semiconductor wafers of monocrystalline silicon by pulling a single silicon crystal from a melt contained in a crucible and continually changing the rotational direction of the crucible
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 510.sup.17 atoms/cm.sup.3; 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.
Method for producing semiconductor wafers of monocrystalline silicon by pulling a single silicon crystal from a melt contained in a crucible and continually changing the rotational direction of the crucible
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 510.sup.17 atoms/cm.sup.3; 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.
Process for preparing ingot having reduced distortion at late body length
A method for growing a single crystal silicon ingot by the Czochralski method having reduced deviation in diameter is disclosed.
Process for preparing ingot having reduced distortion at late body length
A method for growing a single crystal silicon ingot by the Czochralski method having reduced deviation in diameter is disclosed.
Methods directed to crystalline biomolecules
Disclosed herein are methods of preparing a composition comprising crystalline biomolecules, for example, crystalline antibodies. In exemplary embodiments, the method comprises forming a fluidized bed of crystalline biomolecules using, for example, a counter-flow centrifuge to exchange buffer and/or to concentrate the crystalline biomolecules in a solution. Also provided are methods of detecting crystalline biomolecules and/or amorphous biomolecules in a sample.
Methods directed to crystalline biomolecules
Disclosed herein are methods of preparing a composition comprising crystalline biomolecules, for example, crystalline antibodies. In exemplary embodiments, the method comprises forming a fluidized bed of crystalline biomolecules using, for example, a counter-flow centrifuge to exchange buffer and/or to concentrate the crystalline biomolecules in a solution. Also provided are methods of detecting crystalline biomolecules and/or amorphous biomolecules in a sample.
FURNACE FOR SEEDED SUBLIMATION OF WIDE BAND GAP CRYSTALS
An apparatus for physical vapor transport growth of semiconductor crystals having a cylindrical vacuum enclosure defining an axis of symmetry; a reaction-cell support for supporting a reaction cell inside the vacuum enclosure; a cylindrical reaction cell made of material that is transparent to RF energy and having a height Hcell defined along the axis of symmetry; an RF coil provided around exterior of the vacuum enclosure and axially centered about the axis of symmetry, wherein the RF coil is configured to generate a uniform RF field along at least the height Hcell; and, an insulation configured for generating thermal gradient inside the reaction cell along the axis of symmetry. The ratio of height of the RF induction coil, measured along the axis of symmetry, to the height Hcell may range from 2.5 to 4.0 or from 2.8 to 4.0.
FURNACE FOR SEEDED SUBLIMATION OF WIDE BAND GAP CRYSTALS
An apparatus for physical vapor transport growth of semiconductor crystals having a cylindrical vacuum enclosure defining an axis of symmetry; a reaction-cell support for supporting a reaction cell inside the vacuum enclosure; a cylindrical reaction cell made of material that is transparent to RF energy and having a height Hcell defined along the axis of symmetry; an RF coil provided around exterior of the vacuum enclosure and axially centered about the axis of symmetry, wherein the RF coil is configured to generate a uniform RF field along at least the height Hcell; and, an insulation configured for generating thermal gradient inside the reaction cell along the axis of symmetry. The ratio of height of the RF induction coil, measured along the axis of symmetry, to the height Hcell may range from 2.5 to 4.0 or from 2.8 to 4.0.
Apparatus for growing single crystalline ingot and method for growing same
The present invention relates to an apparatus for growing a single crystal ingot capable of uniformly controlling an oxygen concentration in a longitudinal direction and a radial direction of a single crystal ingot by uniformly maintaining a convection pattern on a silicon melt interface, and a method for growing the same. In an apparatus for growing a single crystal ingot and a method for growing the same according to the present invention, a horizontal magnet is positioned to be movable up and down by a magnet moving unit around a crucible, so that a maximum gauss position (MGP) is positioned to be higher than the silicon melt interface and simultaneously, a rate of increase in the MGP is controlled to 3.5 mm/hr to 6.5 mm/hr, and thus it possible to secure simplicity and symmetry of convection on the silicon melt interface. Accordingly, in the present invention, it is possible to reduce an Oi deviation and a BMD deviation in a longitudinal direction and a radial direction of a single crystal ingot, thereby improving quality.
Apparatus for growing single crystalline ingot and method for growing same
The present invention relates to an apparatus for growing a single crystal ingot capable of uniformly controlling an oxygen concentration in a longitudinal direction and a radial direction of a single crystal ingot by uniformly maintaining a convection pattern on a silicon melt interface, and a method for growing the same. In an apparatus for growing a single crystal ingot and a method for growing the same according to the present invention, a horizontal magnet is positioned to be movable up and down by a magnet moving unit around a crucible, so that a maximum gauss position (MGP) is positioned to be higher than the silicon melt interface and simultaneously, a rate of increase in the MGP is controlled to 3.5 mm/hr to 6.5 mm/hr, and thus it possible to secure simplicity and symmetry of convection on the silicon melt interface. Accordingly, in the present invention, it is possible to reduce an Oi deviation and a BMD deviation in a longitudinal direction and a radial direction of a single crystal ingot, thereby improving quality.