Abstract: The bulk polysilicon deposition rate of a Siemens method CVD reactor system having a power supply configured for deposition on a solid rod silicon filament of a specified diameter and length is increased by installing a high surface area silicon filament in the CVD reactor in lieu of the specified solid rod filament, the high surface area filament being dimensionally configured such that it can be used in place of the solid rod filament without reconfiguring or replacing the reactor power supply. The high surface area filament can be tubular, flat, or shaped with radial fins. Existing reactors thereby require only adaptation or replacement of filament supports to be adapted for use of the high surface area filament. The high surface area filament can be grown from silicon melt using the EFG method, so as to maintain a cross-sectional shape within a tolerance of +/?10%.

Abstract: A method and process for the production of bulk polysilicon by chemical vapor deposition (CVD) where conventional silicon “slim rods” commonly used in Siemens-type reactors are replaced with shaped silicon filaments of similar electrical properties but larger surface areas, such as silicon tubes, ribbons, and other shaped cross sections. Silicon containing gases, such as chlorosilane or silane, are decomposed and form a silicon deposit on the hot surfaces of the filaments The larger starting surface areas of these filaments ensures a higher production rate without changing the reactor size, and without increasing the number and length of the filaments. Existing reactors need only the adaptation or replacement of filament supports to use the new filaments. The filaments are grown from silicon melt by Edge-defined, Film-fed Growth (EFG) method. This also enables the doping of the filaments and simplification of power supplies for new reactors.

Abstract: A method for preventing molten material breach in a crystal growth apparatus includes providing a chamber of the crystal growth apparatus which is coated with a ceramic material. The chamber can be coated on an interior surface to prevent damage to the chamber itself, which is made of steel, and to prevent steam explosions in the water-cooled chamber. Ceramic blanket layers also can be provided over the coated interior surface of the chamber. As a result, it is possible to produce high quality crystalline products while minimizing the hazards and costs in the event of a spill of molten material.

Abstract: A furnace for growing sapphire crystal in which the furnace comprises a furnace housing; a hot zone which comprises insulation and a heater which are both accommodated within the furnace housing; a crucible located within the hot zone and the crucible has an opening. Either a crucible lid covers the opening of the crucible, and the crucible lid has a first conduit which extends therefrom or a crucible enclosure surrounds at least a side wall and a top portion of the crucible and the crucible enclosure is impermeable to at least carbon preventing carbon contamination of a melt contained within the crucible.

Abstract: A method for making a large surface area silicon filament for production of bulk polysilicon by chemical vapor deposition (CVD) includes melting silicon and growing the filament from the melted silicon by an EFG method using a shaping die. The cross sectional shape of the silicon filament is constant over its axial length to within a tolerance of 10%. In embodiments, a plurality of identical and/or dissimilar filaments are grown simultaneously using a plurality of shaping dies. The filaments can be tubular. Filament cross sections can be annular and/or can include outwardly extending fins, with wall and/or fin thicknesses constant to within 10%. Filaments can be doped with at least one element from groups 3 and 5 of the Periodic Table. The filament can have a length equal to a length of a specified slim rod filament, and a total impedance not greater than the slim rod impedance.

Abstract: To reduce the heat input to the bottom of the crucible and to control heat extraction independently of heat input, a shield can be raised between a heating element and a crucible at a controlled speed as the crystal grows. Other steps could include moving the crucible, but this process can avoid having to move the crucible. A temperature gradient is produced by shielding only a portion of the heating element; for example, the bottom portion of a cylindrical element can be shielded to cause heat transfer to be less in the bottom of the crucible than at the top, thereby causing a stabilizing temperature gradient in the crucible.

Abstract: A method for preventing molten material breach in a crystal growth apparatus includes providing a chamber of the crystal growth apparatus which is coated with a ceramic material. The chamber can be coated on an interior surface to prevent damage to the chamber itself, which is made of steel, and to prevent steam explosions in the water-cooled chamber. Ceramic blanket layers also can be provided over the coated interior surface of the chamber. As a result, it is possible to produce high quality crystalline products while minimizing the hazards and costs in the event of a spill of molten material.

Abstract: A method for producing growth-axis oriented single crystal sapphire cores or near-net cores is provided. According to the method, a boule is grown on a desired growth axis having a first axial end and a second axial end. An orientation of a plane normal to the desired growth axis with respect to the boule is determined. The boule is then cored in a direction perpendicular to the plane to produce at least one growth-axis oriented single crystal sapphire core, or the boule is outer-diameter-grinded the boule to form a single crystal sapphire near-net core.

Abstract: A method for making a large surface area silicon filament for production of bulk polysilicon by chemical vapor deposition (CVD) includes melting silicon and growing the filament from the melted silicon by an EFG method using a shaping die. The cross sectional shape of the silicon filament is constant over its axial length to within a tolerance of 10%. In embodiments, a plurality of identical and/or dissimilar filaments are grown simultaneously using a plurality of shaping dies. The filaments can be tubular. Filament cross sections can be annular and/or can include outwardly extending fins, with wall and/or fin thicknesses constant to within 10%. Filaments can be doped with at least one element from groups 3 and 5 of the Periodic Table. The filament can have a length equal to a length of a specified slim rod filament, and a total impedance not greater than the slim rod impedance.

Abstract: Systems and methods are provided for producing monocrystalline materials such as silicon, the monocrystalline materials being usable in semiconductor and photovoltaic applications. A crucible (50) is received in a furnace (10) for growing a monocrystalline ingot, the crucible (50) initially containing a single seed crystal (20) and feedstock material (90), where the seed crystal (20) is at least partially melted, and the feedstock material (90) is completely melted in the crucible (50), which is followed by a growth and solidification process. Growth of monocrystalline materials such as silicon ingots is achieved by directional solidification, in which heat extraction during growth phases is achieved using insulation (14) that is movable relative to a crucible (50) containing feedstock (90). A heat exchanger (200) also is provided to control heat extraction from the crucible (50) during the growth and solidification process to achieve monocrystalline growth.

Abstract: Provided is a system and method for growing crystals. The method includes substantially fully covering a seed crystal in a charge material, using a heat source to melt the charge material, cooling the seed crystal to keep the seed crystal at least partially intact as the charge material melts, allowing at least a portion of the seed crystal to melt into the molten charge material, and continually growing the crystal by reducing the temperature of the heat source, moving the molten charge material and seed crystal from the heat source, and increasing a rate of cooling of the seed crystal.

Abstract: Systems and methods for arranging a heating element in a crystal growth apparatus include connecting elements such as heater clips used to interconnect one or more heating components of the heating element, and to connect at least one of the heating components with the crystal growth apparatus. The heating components can be electrically and thermally coupled, and can be connected via the same circuit, in order to simplify control of the heating element.

Abstract: To reduce the heat input to the bottom of the crucible and to control heat extraction independently of heat input, a shield can be raised between a heating element and a crucible at a controlled speed as the crystal grows. Other steps could include moving the crucible, but this process can avoid having to move the crucible. A temperature gradient is produced by shielding only a portion of the heating element; for example, the bottom portion of a cylindrical element can be shielded to cause heat transfer to be less in the bottom of the crucible than at the top, thereby causing a stabilizing temperature gradient in the crucible.

Abstract: A method for using substantial quantities of silicon powders as charge and processing it to produce a high quality silicon ingots suitable for photovoltaic use is disclosed. In a fused silica crucible, silicon feedstock containing more than about 5% by weight silicon powder is charged. The crucible with the charged silicon feedstock is placed into a furnace chamber and a vacuum is drawn to remove air. The vacuum is applied slowly. Then, the furnace chamber is backfilled with argon gas and heated to form molten silicon. Afterward, the molten silicon is solidified and annealed to form a multicrystalline silicon ingot.

Abstract: To reduce the heat input to the bottom of the crucible and to control heat extraction independently of heat input, a shield can be raised between a heating element and a crucible at a controlled speed as the crystal grows. Other steps could include moving the crucible, but this process can avoid having to move the crucible. A temperature gradient is produced by shielding only a portion of the heating element; for example, the bottom portion of a cylindrical element can be shielded to cause heat transfer to be less in the bottom of the crucible than at the top, thereby causing a stabilizing temperature gradient in the crucible.

Abstract: A method for using substantial quantities of silicon powders as charge and processing it to produce a high quality silicon ingots suitable for photovoltaic use is disclosed. In a fused silica crucible, silicon feedstock containing more than about 5% by weight silicon powder is charged. The crucible with the charged silicon feedstock is placed into a furnace chamber and a vacuum is drawn to remove air. The vacuum is applied slowly. Then, the furnace chamber is backfilled with argon gas and heated to form molten silicon. Afterward, the molten silicon is solidified and annealed to form a multicrystalline silicon ingot.

Abstract: To reduce the heat input to the bottom of the crucible and to control heat extraction independently of heat input, a shield can be raised between a heating element and a crucible at a controlled speed as the crystal grows. Other steps could include moving the crucible, but this process can avoid having to move the crucible. A temperature gradient is produced by shielding only a portion of the heating element; for example, the bottom portion of a cylindrical element can be shielded to cause heat transfer to be less in the bottom of the crucible than at the top, thereby causing a stabilizing temperature gradient in the crucible.

Abstract: A silicon nitride crucible is coated with a crucible release coating for use in directional solidification of multicrystalline silicon ingots. The crucible preferably includes reaction bonded silicon nitride crucible. After removing the silicon ingot, the release coating is easily removed and the crucible can be repeatedly recoated and reused.

Abstract: A cutting machine has a blade mounted for reciprocating movement. A workpiece is rotated while the blade is reciprocated, and then the workpiece is rotated through smaller angles to complete the cut. A holder is attached to partially cut slices of the workpiece.

Abstract: A cutting machine has a blade mounted for reciprocating movement. A workpiece is rotated while the blade is reciprocated, and then the workpiece is rotated through smaller angles to complete the cut. A holder is attached to partially cut slices of the workpiece.