Process and apparatus for producing a single crystal of semiconductor material
AssigneeWacker Siltronic AG
InventorWilfried Von Ammon
Life of this patent
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Abstract
A process for producing a single crystal of semiconductor material, in which fractions of a melt, are kept in liquid form by a pulling coil, solidify on a seed crystal to form the growing single crystal, and granules are melted in order to maintain the growth of the single crystal. The melting granules are passed to the melt after a delay. There is also an apparatus which is suitable for carrying out the process and has a device which delays mixing of the molten granules and of the melt.
Claims20
A process for producing a single crystal of semiconductor material, comprising
- maintaining fractions of a melt in a liquid state by a pulling coil;
- solidifying said liquid on a seed crystal to form a growing single crystal;
- melting granules of semiconductor material in order to maintain growth of the single crystal;
- and
- passing said melting granules to the melt after a delay.
An apparatus for producing a single crystal, comprising
- a vessel which is arranged above a growing single crystal;
- a conveyor device for feeding granules into the vessel;
- a melting coil for melting the granules;
- a pulling coil for maintaining a melt on the growing single crystal;
- the melting granules passing through openings in the vessel and the pulling coil to the melt, so as to form a melt neck, and solidifying fractions of the melt maintaining growth of the single crystal;
- and
- said vessel having a device which delays mixing of molten granules and of the melt.
A silicon single crystal comprising
- an oxygen concentration of 3-9*1017 atoms/cm3 and grown-in defects with a size of less than 60 nm.
Dependencies are inferred from the claim text.