Abstract: A method for crucible-free zone pulling of silicon monocrystalline rods is described. According to the invention, a polycrystalline silicon rod obtained by crucible pulling according to the Czochralski procedure is used in lieu of the polycrystalline silicon rod produced by vapor deposition.

Abstract: A process for decreasing crystal damages in the production of n-doped silicon by neutron bombardment, in which phosphorus atoms are formed from silicon by nuclear transmutation, wherein the number of desired phosphorus atoms N.sub.31.sbsb.p per cc, can be calculated by the known equationN.sub.31.sbsb.p =N.sub.30.sbsb.Si .multidot..sigma..multidot..phi..multidot.tin which N.sub.30.sbsb.Si is the number of .sup.30 Si-isotopes per cc, .sigma.=0.13 barn effective cross section, .phi. the flux density of the thermal neutrons per cm.sup.2 and t the bombardment time in seconds, the process consisting of adjusting the ratio between thermal and fast neutrons in the neutron flux acting upon the bombarded silicon work piece, so that the higher the ratio, the higher the specific resistance of the bombarded silicon, and thus, the lower the number of N.sub.31.sbsb.p and therewith the acting dose .phi..multidot.t.

Abstract: A process for purifying solid substances by melting and subsequent resoliication, wherein a melted bath of the solid substance is formed, a roller is placed in the bath so that a first portion of its surface is in contact with the melted substance, and the surface of the roller is cooled to a temperature below the melting point of the solid substance. The cooled roller is rotated in the melted substance to collect a solidified film of the substance on the roller surface. A second portion of the roller surface is passed through a heated zone at a temperature above the melting point of the solid substance, so that the solidified film is remelted and collected in an appliance.

Abstract: A process for determining the effective doping agent content of hydrogen the production of semiconductors which comprises zone drawing a silicon rod of highest purity and having a known specific resistance, in the presence of hydrogen to be tested, subsequently redetermining the specific resistance of the silicon rod, and computing the concentration of the doping agent in the hydrogen used from the known relationship between the specific resistance and the amount of doping agent. By stepwise determination of the resistance along the longitudinal axis of the rod, the amount of doping agent built into the rod at different levels can thus be determined.

Abstract: A process for the crucible-free zone pulling of a polycrystalline rod held ertically, together with a seed crystal fixed at its lower end, in which a melting zone is produced by means of an induction heating coil surrounding the rod, which zone, by means of relative movement of the coil and rod, traverses the entire length of the rod starting from the seed crystal, characterized in that after attaching the seed crystal to the rod, a support member is moved, below the induction heating coil, towards the rod, which support member rests gently against the rod and after being positioned, solidifies to form a firm support for the rod. A device for carrying out the process is also included.

Abstract: Device for supporting a crystalline rod during crucible-free zone melting ich comprises a zone-drawing apparatus, a rotating shaft in said apparatus, means for fastening the shaft in the apparatus, a screw bolt mounted for rotation with the shaft, the top end of the screw bolt having a bore for receiving a seed crystal, two or more swivel arms mounted adjacent to the bore and capable of being opened and closed, a ring coaxially surrounding the bolt and means for vertically moving the ring.