Vorrichtung zur Gewinnung reinsten kristallinen Halbleitermaterials fuer elektrotechnische Zwecke

In the deposition of silicon from a mixture of hydrogen and silico-chloroform or silicon tetrachloride on to an electric resistance heated body of silicon, the electrical terminals are hollow metal bodies which are internally cooled by the passage of a gas therethrough. The cooling gas may be hydrogen, helium, or water vapour. All or a portion of the reactant hydrogen may first be used as cooling gas. The cooling gas may be used under a pressure of 10-20 atmos. As shown, silicon is deposited on two rods 2 and 3 of silicon separated by a bridging member 10 of silicon, carbon, or graphite, each rod being attached to a carbon or graphite cylindrical member 4 or 5 which is in turn attached to a hollow silver terminal piece 6 or 7. The reactant mixture is injected into the reaction vessel through a pipe 21 and a nozzle 22 and the reaction product gas is withdrawn through a pipe 23. Reactant hydrogen is passed through a pipe 13, electrical terminal 6, pipe 14, electrical terminal 7, pipe 16, bores 19 and connecting tubes 20, and pipe 26 to the reactant inlet pipe 21. Specification 861,135 is referred to.