Abstract: An apparatus for pulling up a single crystal according to Czochralski method is provided with a cylindrical first screen and a second screen. The first screen is arranged in the periphery of the zone of pulling up the single crystal, said screen being constituted by a heat absorbing body at the side facing a quartz crucible and by a heat insulator at the other side and being provided with respective outward and inward annular rims at the upper and lower ends thereof, the corner of said screen facing the crucible being formed in a curved or polygonal structure, and said annular rim at the lower end being positioned in the vicinity of filling the melt in the crucible. The second screen forming a parabolic shape in the section opening at its center while enclosing the crystal pulling-up zone and being provided at its upper end with an outward annular rim.

Abstract: A method of producing a silicon single crystal, in which a cylindrical partition is immersed in a molten pure silicon liquid or molten silicon liquid containing a Sb dopant within a crucible and the molten liquid inside the partition is pulled up from the crucible to produce the silicon single crystal, wherein an interval between a lower end of the partition and a crucible bottom is changed to control an oxygen concentration in the pulling-up silicon single crystal. The interval is reduced in the case where the oxygen concentration in the pulling-up silicon single crystal is to be increased while the interval is increased in the case where the oxygen concentration is to be reduced.

Abstract: An apparatus for growing a single crystal having a crucible, two heaters arranged at the outside of the crucible and along the vertical direction, a heat shield placed at the outside of the heaters, a radiation shield for shielding the single crystal from the radiation heat, and an upper heat shield for preventing the upward heat, transfer of the heaters. In the apparatus, a melted layer and solid layer of raw material are formed in the upper and lower portions of the crucible, respectively. While melting the solid layer, the single crystal is pulled up. The lower portion of the heat shield is thinner than the upper portion. The ratio of the height to the diameter of the crucible is 0.85 or more. The melting amount of the solid layer is controlled in the pulling process according to the non-segregation condition in the variable-thickness melted layer method.

Abstract: There is disclosed a method for growing single crystal material, particularly silicon, in modified Czochralski process furnaces and chambers. The Czochralski process equipment is modified to permit continuous addition of polycrystalline material, preferably in dry powdered form to a molten bath of the material that is maintained at a constant shallow depth. For this purpose, a circular baffle is placed within the crucible containing the molten bath of the material, dividing the crucible into an annular feed zone and a central crystal growth zone. A cylindrical boule is withdrawn from the central crystal growth zone. The surrounding walls of the crucible, and graphite cup that supports the crucible, provide a heating and annealing zone in which the boule is continuously annealed as it is withdrawn from the molten pool. Dopants are also introduced into the annular feed zone, either separately or admixed with the polycrystalline material.