Method for purifying silicon
AssigneeAstroPower, Inc.
InventorsRoger F. Clark, Michael G. Mauk, Robert B. Hall, Allen M. Barnett
Life of this patent
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Abstract
A method of purifying silicon, comprising feeding a sparging gas into a liquid melt [10] containing molten silicon and at least one impurity, in which the sparging gas is used to react with or move one or more impurity contained within the silicon. The products of such reaction or movement may be removed, e.g., by liquid-gas extraction, by liquid-liquid extraction or by liquid-solid extraction.
Claims23
A method of purifying silicon, comprising feeding a sparging gas into a liquid bath comprising silicon and at least one impurity, said liquid bath having an uppermost surface and a lowermost surface, said sparging gas being fed into said liquid bath at a location between said lowermost surface of said liquid bath and said uppermost surface of said liquid bath, and removing from said liquid bath at least a portion of said at least one impurity, said sparging gas further comprising solid silica.
A method of purifying silicon, comprising feeding a sparging gas through a tube having a sparging gas exit end from which said sparging gas exits said tube into a liquid bath comprising silicon and at least one impurity, said liquid bath having an uppermost surface, said sparging gas exit end of said tube being located below said uppermost surface of said liquid bath, and removing from said liquid bath at least a portion of said at least one impurity, said sparging gas further comprising solid silica.
A method of purifying silicon, comprising feeding a sparging gas through a tube having a sparging gas exit end from which said sparging gas exits said tube into a liquid bath comprising silicon and at least one impurity, said liquid bath having an uppermost surface, said sparging gas exit end of said tube being located below said uppermost surface of said liquid bath, and removing from said liquid bath at least a portion of said at least one impurity, said sparging gas moving in a direction which is substantially horizontal as it passes through said sparging gas exit end of said tube.
A method of purifying silicon, comprising feeding a sparging gas through a tube having a sparging gas exit end from which said sparging gas exits said tube into a liquid bath comprising silicon and at least one impurity, said liquid bath having an uppermost surface, said sparging gas exit end of said tube being located below said uppermost surface of said liquid bath, and removing from said liquid bath at least a portion of said at least one impurity, said liquid bath being within a container having at least one bottom surface and at least one sidewall, said tube projecting into said liquid bath from said at least one bottom surface.
A method of purifying silicon, comprising feeding a sparging gas through a tube having a sparging gas exit end from which said sparging gas exits said tube into a liquid bath comprising silicon and at least one impurity, said liquid bath having an uppermost surface, said sparging gas exit end of said tube being located below said uppermost surface of said liquid bath, and removing from said liquid bath at least a portion of said at least one impurity, and measuring pressure inside said tube.
A method of purifying silicon, comprising feeding a sparging gas into a liquid bath comprising silicon and at least one impurity, said liquid bath being within a container having at least one bottom surface and at least one sidewall, said sparging gas being fed into said bath through said sidewall, and removing from said liquid bath at least a portion of said at least one impurity, said sparging gas further comprising solid silica.
Dependencies are inferred from the claim text.