Apparatus for producing multicrystalline silicon ingots by induction method

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 ss of expanding the melting chamber is defined by the equation ss = arctg [2 (k - 1.35 10 3 b ) / d], where d is the dimension of the smaller side of the rectangle or of the side of the square of the cross-section of the melting chamber at the inducer level, b is the dimension of the adjoining side of the cross-section of the melting chamber at the inducer level, k is an empirical coefficient, which is 1.5 to 2. The apparatus makes it possible to decrease silicon melt spills and to increase the quality of multicrystalline silicon thus produced.

Description

Technical field [0001] The invention relates to an apparatus for producing polycrystalline silicon ingots by an induction method and which can be used in the manufacture of solar cells from polycrystalline silicon. Background technique [0002] Solar cells that generate electricity from sunlight are made of crystalline silicon. Monocrystalline silicon and polycrystalline silicon, that is, polycrystalline silicon containing large crystals, can be both. [0003] The interest in polycrystalline silicon has been growing because the efficiency of polycrystalline silicon solar cells is close to that of monocrystalline silicon solar cells, and the productivity of polycrystalline silicon growth equipment is many times that of monocrystalline silicon growth equipment. In other words, the growth of polysilicon is easier than the growth of single crystal silicon. [0004] There is an apparatus for producing polycrystalline silicon ingots by an induction method in the art. The apparatus include...

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Problems solved by technology

[0007] The disadvantage of this existing installation is that the quality of polycrystalline silicon ingots decreases and the productivity of producing polycrystalline silicon ingots decreases due to frequent spillage of silicon melt

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