Abstract: A crystal growth furnace comprising a crucible containing at least feedstock material and a liquid-cooled heat exchanger that is vertically movable beneath the crucible to extract heat from it to promote the growth of a crystalline ingot is disclosed. The liquid-cooled heat exchanger comprises a heat extraction bulb made of high thermal conductivity material that is vertically movable into thermal communication with the crucible to extract heat from the crucible using a liquid coolant. A liquid-cooled heat exchanger enclosed in a sealed tubular outer jacket is also disclosed as is a method for producing a crystalline ingot using a vertically movable liquid-cooled heat exchanger.

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 crystal growth furnace comprising a crucible containing at least feedstock material and a liquid-cooled heat exchanger that is vertically movable beneath the crucible to extract heat from it to promote the growth of a crystalline ingot is disclosed. The liquid-cooled heat exchanger comprises a heat extraction bulb made of high thermal conductivity material that is vertically movable into thermal communication with the crucible to extract heat from the crucible using a liquid coolant. A liquid-cooled heat exchanger enclosed in a sealed tubular outer jacket is also disclosed as is a method for producing a crystalline ingot using a vertically movable liquid-cooled heat exchanger.

Abstract: Systems and methods are provided to promote uniform thermal environment to feedstock material (e.g., silicon) in a crucible of a crystal growth apparatus are provided herein. More specifically, a heating system may be arranged in the crystal growth apparatus so as to include at least a first and second heating element which are configured to distribute heat axisymmetrically to the feedstock material and the second heating element that is configured to distribute heat symmetrically to the feedstock material to thereby provide uniform heat distribution to the feedstock material in the crucible to allow for increased consistency in crystal ingot quality.

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 to promote uniform thermal environment to feedstock material (e.g., silicon) in a crucible of a crystal growth apparatus are provided herein. More specifically, a heating system may be arranged in the crystal growth apparatus so as to include at least a first and second heating element which are configured to distribute heat axisymmetrically to the feedstock material and the second heating element that is configured to distribute heat symmetrically to the feedstock material to thereby provide uniform heat distribution to the feedstock material in the crucible to allow for increased consistency in crystal ingot quality.

Abstract: A crystal growth apparatus is disclosed comprising a crucible, optionally contained within a crucible box, on a crucible support block, wherein the bottom of the crucible, the bottom plate of the crucible box, if used, and/or the crucible support block comprise at least one cavity configured to circulate at least one coolant therein. Also disclosed is a method of preparing a crystalline material using the disclosed crystal growth apparatus as well as the resulting crystalline material, having larger overall grain sizes.

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 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: A chemical vapor deposition reactor system includes one or more tube filaments connected to a bridge, each tube filament being connected to a chuck. The chuck-to-filament connection can include a seed formed on an end of the tube filament, the seed being connected to a protrusion of the chuck, or the filament may be formed directly onto the chuck. For the bridge-to-filament connection, a flat cross bridge or a rectangular bridge is connected with corresponding openings in the filament. Use of these connections can maintain electrical connectivity and thus resistive heating of the tube filaments during operation of the reactor system.

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: A process for making silicon ingots using a multi-part, reusable, graphite crucible of at least two mold pieces configured for assembly into an open top mold having an interior surface functional as a mold cavity for receiving molten silicon; removing or reducing a prior applied release coating from the interior surface until a uniformly smooth finish is achieved; coating the interior surface with a first layer of release coating comprising silicon nitride; coating the interior surface with a second layer of release coat comprising silica suspended in water; coating the interior surface with a third layer of release coat comprising silicon nitride; curing the release coat on said crucible; casting a silicon ingot in the crucible; and then repeating the prior steps multiple times.

Abstract: A process for making silicon ingots using a multi-part, reusable, graphite crucible of at least two mold pieces configured for assembly into an open top mold having an interior surface functional as a mold cavity for receiving molten silicon; removing or reducing a prior applied release coating from the interior surface until a uniformly smooth finish is achieved; coating the interior surface with a first layer of release coating comprising silicon nitride; coating the interior surface with a second layer of release coat comprising silica suspended in water; coating the interior surface with a third layer of release coat comprising silicon nitride; curing the release coat on said crucible; casting a silicon ingot in the crucible; and then repeating the prior steps multiple times.

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 process for making silicon ingots using a multi-part, reusable, graphite crucible of at least two mold pieces configured for assembly into an open top mold having an interior surface functional as a mold cavity for receiving molten silicon; removing or reducing a prior applied release coating from the interior surface until a uniformly smooth finish is achieved; coating the interior surface with a first layer of release coating comprising silicon nitride; coating the interior surface with a second layer of release coat comprising silica suspended in water; coating the interior surface with a third layer of release coat comprising silicon nitride; curing the release coat on said crucible; casting a silicon ingot in the crucible; and then repeating the prior steps multiple times.

Abstract: A method for making ingots, and devices for making ingots are provided. Crucibles are provided that are reusable for forming multicrystalline silicon ingots. Crucibles are provided with features such as multiple components, coefficients of thermal expansion, and coatings that enhance a release of the ingots from the crucibles after cooling. Coatings on crucibles are provided that reduce or eliminate contamination of silicon ingots during formation. Methods of forming composite wafers are provided that produce a low cost wafer without sacrificing performance.