Method and apparatus for producing a single crystal
AssigneeTopsil Simiconductor Materials A/S
InventorsPer Vaabengaard, Anne Nielsen, Theis Leth Larsen, Jan Eyving Petersen, Leif Jensen
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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.
Claims21
-24. (canceled)
A method for producing a single crystal comprising the steps of:
- passing a polycrystalline rod through a heating region to create a molten zone;
- applying a magnetic field to the molten zone;
- and
- inducing formation and growth of a single crystal upon solidification of the molten material on a single crystal seed;
- wherein the growing single crystal is rotated in a pattern alternating between clockwise and counter-clockwise rotational directions.
An apparatus for producing a single crystal, comprising a heater for creating a molten zone in a polycrystalline rod, a current conductor arranged as a coil surrounding the heater, an upper shaft for suspending the polycrystalline rod, and a lower shaft for supporting the growing single crystal, wherein the lower shaft are capable of conveying to the growing single crystal a clockwise rotational direction in a first time period and a counter-clockwise rotational direction in a second time period.
Dependencies are inferred from the claim text.