Abstract: An apparatus for producing multicrystalline silicon ingots by the induction method comprises an enclosure, which includes means for start-up heating of silicon and a cooled crucible enveloped by an inductor. The crucible has a movable bottom and four walls consisting of sections spaced apart by vertically extending slots, means for moving the movable bottom, and a controlled cooling compartment arranged under the cooled crucible. The inside face of the crucible defines a melting chamber of a rectangular or square cross-section. The walls of the cooled crucible extend outwards at least from the inductor toward the lowest portion of the cooled crucible to thereby expand the melting chamber, and the angle ? of expanding the melting chamber is defined by the equation ?=arctg[2·(k?1.

Abstract: Methods and systems are provided for monitoring a solid-liquid interface, including providing a vessel configured to contain an at least partially melted material; detecting radiation reflected from a surface of a liquid portion of the at least partially melted material that is parallel with the liquid surface; measuring a disturbance on the surface; calculating at least one frequency associated with the disturbance; and determining a thickness of the liquid portion based on the at least one frequency, wherein the thickness is calculated based on L = f 2 ? w 2 g , where g is the gravitational constant, w is the horizontal width of the liquid, and f is the at least one frequency.

Abstract: A method is disclosed for producing a single crystal comprising passing a polycrystalline rod through a heating region to create a molten zone, applying a magnetic field to the molten zone, and inducing growth of a single crystal upon solidification of the molten material on a single crystal seed. The growing single crystal is rotated in a pattern alternating between clockwise and counter-clockwise rotational directions. The method is useful for producing silicon single crystals having uniform electrical characteristics. Also disclosed is an apparatus for performing said method.

Abstract: A doped semiconductor wafer of float zone-pulled semiconductor material contains a dopant added to a molten material and has a radial macroscopic resistance distribution of less than 12% and striations of ?10% to +10%. There is also a process for producing a doped semiconductor wafer by float zone pulling of a single crystal and dividing up the single crystal, in which process, during the float zone pulling, a molten material which is produced using an induction coil is doped with a dopant. It is exposed to at least one rotating magnetic field and is solidified. The single crystal which is formed during the solidification of the molten material is rotated. The single crystal and the magnetic field are rotated with opposite directions of rotation and the magnetic field has a frequency of 400 to 700 Hz.

Abstract: The method of protectively coating metallic uranium which comprises dipping the metallic uranium in a molten alloy comprising about 20-75% of copper and about 80-25% of tin, dipping the coated uranium promptly into molten tin, withdrawing it from the molten tin and removing excess molten metal, thereupon dipping it into a molten metal bath comprising aluminum until it is coated with this metal, then promptly withdrawing it from the bath.

Abstract: A method and apparatus for locally and successively melting a material by induction heating using a horizontal floating-zone crucible to refine and/or analyze the material. An electromagnetic field is generated to create a localized molten zone within the material that is at least partially levitated within the crucible. The crucible has an upper peripheral opening so that an upper portion of the molten zone is generally at a higher temperature than the lower portion of the molten zone adjacent the crucible wall. As a result, insoluble inclusions within the material separate and float to the upper portion of the molten zone. The molten zone may be translated longitudinally through the material to drive the inclusions toward one end of the material. The process can be carried out to refine or characterize the material, or to determine the solidus and liquidus temperatures of the material.

Abstract: A method of producing a silicon single crystal by the floating-zone method, comprising the steps of: providing a polysilicon rod having an average grain length of 10 to 1000 .mu.m; heating a portion of the polysilicon rod to form a molten zone while applying a magnetic field of 300 to 1000 gauss to the molten zone; and passing the molten zone through the length of the polysilicon rod thereby the polysilicon rod is converted into a silicon single crystal ingot through a one-pass zoning of the floating zone method. An apparatus for reducing the method into practice is also described. The growing single crystal ingot is post-heated by a heat reflector near the molten zone.

Abstract: Proposed is a low-cost method for the preparation of a wire-formed crystal of silicon having a diameter of 1 mm or smaller, in which a vertically held starting rod of silicon is melted at one end portion by high-frequency induction heating, a seed crystal is brought into contact with the molten portion and then the seed crystal and the starting silicon rod are pulled apart in the vertical direction at a controlled velocity with a controlled high-frequency power input so that the melt of silicon drawn by the seed crystal is solidified and crystallized into the form of a wire.

Abstract: A method of producing a silicon single crystal by the floating-zone method, comprising the steps of: providing a polysilicon rod having an average grain length of 10 to 1000 .mu.m; heating a portion of the polysilicon rod to form a molten zone while applying a magnetic field of 300 to 1000 gauss to the molten zone; and passing the molten zone through the length of the polysilicon rod thereby the polysilicon rod is converted into a silicon single crystal ingot through a one-pass zoning of the floating zone method. An apparatus for reducing the method into practice is also described.