TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Method: The silicon thin rods are doped with boron in such a manner that it exhibits an electric resistance of 0.05-1 ohm.cm. A tension of maximum 1500 V to the silicon thin rods is applied to ignite the chemical vapor deposition (CVD) process. The silicon thin rods are doped in such a manner with boron that the free silicon rod exhibits such doping which is desired for the silicon crystal produced in a further procedure step. The silicon tetrachloride and the trichlorosilane are separated from the exhaust gas of the Siemens process, which consists of hydrogen, hydrogen chloride, silicon tetrachloride as well as non-converted trichlorosilane, where both components are optionally purified by usual distillation processes and is again supplied to the process. The silicon tetrachloride and the trichlorosilane are separated from the product gas, which is produced during the conversion of silicon tetrachloride to trichlorosilane from the conversion reactor/hydrogenation reactor, where both components are non-purified or purified by usual distillation processes and is again supplied to the process. The silicon rod exhibits a characteristic distribution of the electrical conductivity in the cross section, where the core of the silicon rods, which correspond to the silicon thin rod at the beginning of the CVD process, exhibits a clearly higher electrical conductivity and the electrical conductivity of the cores are determined by the doping of the silicon thin rods. Preferred components: The silicon rod exhibits such base doping with boron, which causes an electrical conductivity of 0.5-10 ohms.cm. The silicon rod exhibits such doping with other n-doping materials, which cause an electrical conductivity of greater than 1.0 ohms.cm. The other metallic impurities in the silicon rod are greater than the factor 100 than in conventional silicon rods. The doping of the silicon-rods corresponds to the desired doping of a silicon crystal to be manufactured. EXAMPLE - No suitable example given.