Abstract: A process and apparatus for the manufacture of silicon rods having a colur structure comprising monocrystalline crystal zones with a crystallographic preferred orientation. Molten silicon is transferred from a silicon reservoir into a crystallization chamber which is formed by rollers arranged in a leak-proof manner in the shape of the desired rod cross-section. There the silicon first forms a stable outer shell of solidified material and, while it continues to crystallize, it is withdrawn at the bottom and released by the rollers. Owing to the short period of contact with a vessel wall a silicon rod is obtained that is particularly free of impurites.

Abstract: A process and apparatus for the regeneration of shaped carbon, and especially graphite, bodies used in the presence of molten silicon. The shaped bodies are heated in an inert atmosphere to a temperature in the range of from 1700.degree. to 3000.degree. C. and maintained at this temperature for a defined period of time. The process substantially prolongs the service life of the shaped bodies. The apparatus includes at least one evacuable loading chamber, and evacuable heatable heating chamber connected to the loading chamber and an evacuable coolable cooling chamber connected to the heating chamber. A support capable of moving between the loading, heating and cooling chambers is adpated for receiving the shaped bodies to be regenerated.

Abstract: Crystalline rods or blocks can be sawed into thin wafers by sawing the rod or block into a plurality of wafers that are connected to each other. The wafers can be connected by introducing a connecting agent after each sawing step, into the resulting cutting gaps. The wafers are separated only after the whole rod has been sawed with a two-blade internal-hole saw.

Abstract: Crystalline rods or blocks can be sawed into thin wafers by sawing the rod r block into a plurality of wafers that are connected to each other. The wafers can be connected by introducing a connecting agent after each sawing step, into the resulting cutting gaps. The wafers are separated only after the whole rod has been sawed. The method makes possible the use of multiple-blade internal-hole saws, and preferably two-blade internal-hole saws.

Abstract: A process for the production of a monocrystalline silicon rod by withdrawal rom a silicon melt in a drawing chamber by means of a drawing spindle, comprises passing a stream of a protective gas, such as argon, into said chamber during the drawing operation and through a tube which surrounds the drawing spindle and the growing silicon rod, the chamber being maintained under reduced pressure.

Abstract: A residual melt of liquid silicon is removed from a crucible containing the ame by immersing in the melt a capillary body of carbon felt, the melt being absorbed by the capillary body, and removing the capillary body and absorbed melt from the crucible.