Apparatus for growing tubular crystalline bodies

Claim 2

Apparatus for use in growing thin-walled hollow tubular crystalline bodies from the melt employing a hollow elongate tubular seed, said apparatus comprising in combination: a crucible suitable for containing a melt; a capillary die at least partially disposed within said crucible, said capillary die having an end face in the form of a closed plane geometric figure and capillary means for feeding melt from said crucible to said end face; means for (a) holding an elongate hollow tubular seed of predetermined cross-sectional configuration in contact with a film of melt on said end face, and (b) moving said seed vertically away from said end face; an inner radiation shield disposed interior to said capillary die end face and supported so as to be clear of and confront any melt in said crucible, said inner radiation shield having a central aperture; and a hollow tubular inner after heater dimensioned to be wholly contained within said tubular seed when said seed is in contact with a film of melt on said end face, said inner after heater being supported on said inner radiation shield and having an interior in communication with said crucible through said aperture in said inner radiation shield; and a hollow tubular outer after heater surrounding and spaced from said inner after heater, said outer after heater being dimensioned so as to surround said seed when said seed is in contact with said film of melt.

Claim 3

Apparatus according to claim 1 wherein said inner after heater is supported on said inner radiation shield by way of a hollow conical frustum, the smaller diameter of said frustum being connected to said inner radiation shield.

Claim 4

Apparatus according to claim 1 wherein said inner radiation shield is supported by said crucible and is formed of a plurality of plates held together in parallel spaced apart opposing relationship.

Claim 5

Apparatus according to claim 1 for growing silicon bodies wherein said inner radiations shield is made of graphite.

Claim 6

Apparatus according to claim 1 wherein said inner after heater includes a top plate distal said central aperture.

Claim 7

Apparatus according to claim 5 wherein said inner after heater is made of graphite.

Claim 8

Apparatus accoring to claim 5 wherin an insulating pad overlies said top plate.

Claim 9

Apparatus according to claim 7 wherein said insulating pad is a carbon felt.

Claim 10

Apparatus for use in growing thin-walled hollow tubular crystalline bodies of silicon from the melt comprising in combination: a crucible suitable for containing a melt of silicon; a capillary die positioned at the upper end of said crucible, said capillary die having an end face with an annular configuration; an inner radiation shield formed of a plurality of graphite plates held together in parallel spaced apart opposing relationship and having a central through aperture, said inner radiation shield being disposed interior to said end face clear of any melt in said crucible; an elongate hollow tubular inner after heater, said inner after heater having an open end and a closed end and being supported on said inner radiation shield substantially concentrically within said capillary die, with said open end of said after heater directed toward said crucible, said inner after heater having a section substantially in the form of a hollow conical frustum connecting with said inner radiation shield, with the smaller diameter of said frustum substantially concentric and coplanar with said aperture, so that the interior of said inner after heater is in communication with the interior of said crucible through said aperture; an elongate hollow tubular outer after heater surrounding and spaced from said inner after heater, said outer after heater being concentric with said end face; an insulating pad of similar shape but smaller internal dimension than the transverse cross section of said inner after heater, said insulating pad being disposed substantially centrally said closed end of said inner after heater; and means for supporting an elongate hollow seed in contact with said die end face and in confronting, spaced apart substantially coaxial relationship with said inner after heater and said outer after heater, said means for supporting including means for translating said seed substantially coaxially with said inner and outer after heaters.

Claim 11

Apparatus for use in growing thin-walled hollow tubular crystalline bodies of silicon from the melt comprising in combination: a crucible suitable for containing a melt of silicon; a capillary die positioned at the upper end of said crucible, said capillary die having an end face with an annular configuration; an inner radiation shield formed of a plurality of graphite plates held together in parallel spaced apart opposing relationship and having a central through aperture, said inner radiation shield being disposed interior to said end face clear of any melt in said crucible; an elongate hollow tubular inner after heater, said inner after heater having an open end and a closed end and being supported on said inner radiation shield substantially concentrically within said capillary die, with said open end of said after heater directed toward said crucible, said inner after heater having a section substantially in the form of a hollow conical frustum connecting with said inner radiation shield, with the smaller diameter of said frustum substantially concentric and coplanar with said aperture, so that the interior of said inner after heater is in communication with the interior of said crucible through said aperture; an elongate hollow tubular outer after heater surrounding and spaced from said inner after heater, said outer after heater being concentric with said end face; an insulating pad of similar shape but smaller internal dimension than the transverse cross section of said inner after heater, said insulating pad being disposed substantially centrally said closed end of said inner after heater; and means for supporting an elongate hollow seed in contact with said die end face and in confronting, spaced apart substantially coaxial relationship with said inner after heater and said outer after heater, said means for supporting including means for translating said seed substantially coaxially with said inner and outer after heaters.

Claim 12

Apparatus for use in growing thin-walled hollow tubular crystalline bodies from a melt of a selected material employing a hollow elongate tubular seed, said apparatus comprising in combination a crucible suitable for containing a melt of a selected material; a capillary die having an end face defining an annular geometric shape and capillary means for feeding melt from said crucible to said end face; a hollow tubular inner after heater; an elongate, hollow, generally tubular seed having a cross-sectional configuration similar to said annular geometric shape; said seed having a length greater than said inner after heater; pulling means including seed holding means for (a) holding said elongate hollow seed, (b) positioning said seed adjacent said end face, and (c) pulling said seed vertically away from said end face; a radiation shield disposed interior to said end face and confronting the interior of said crucible, said radiation shield having a central aperture; said hollow tubular inner after heater supported by said radiation shield, said inner after heater being sized so as to be surrounded by said elongate hollow seed when said seed is positioned adjacent to said end face; and a hollow tubular outer after heater concentric with and surrounding said first after heater, said after heater being supported by said crucible.

Claim 13

Apparatus for use in growing thin-walled hollow tubular crystalline bodies from a melt of a selected material employing a hollow elongate tubular seed, said apparatus comprising in combination a crucible suitable for containing a melt of a selected material; a capillary die having an end face defining an annular geometric shape and capillary means for feeding melt from said crucible to said end face; a hollow tubular inner after heater; an elongate, hollow, generally tubular seed having a cross-sectional configuration similar to said annular geometric shape; said seed having a length greater than said inner after heater; pulling means including seed holding means for (a) holding said elongate hollow seed, (b) positioning said seed adjacent said end face, and (c) pulling said seed vertically away from said end face; a radiation shield disposed interior to said end face and confronting the interior of said crucible, said radiation shield having a central aperture; said hollow tubular inner after heater supported by said radiation shield, said inner after heater being sized so as to be surrounded by said elongate hollow seed when said seed is positioned adjacent to said end face; and a hollow tubular outer after heater concentric with and surrounding said first after heater, said after heater being supported by said crucible.

Claim 14

Apparatus according to claim 10 further including an outer radiation shield surrounding said end face of said die and located below said outer after heater.

Claim 15

Apparatus according to claim 11 wherein said outer radiation shield is supported by susceptor means surrounding said crucible.

Claim 16

Apparatus according to claim 12 wherein said seed is in the form of a plurality of substantially flat plates held in abutting relationship with one another and arranged in a circular array.