Procédé et installation pour l'agglomération par fusion de matières pulvérulentes par exemple d'un corps semi-conducteur et produits obtenus par ledit procédé

摘要

Semi-conductor crystals are produced by fusion and progressive re-crystallization of powder fed by means of a stream of gas or vapour to the surface of a melt of the semi-conductor material. Fig. 1 shows a silicon rod 2 which is moved slowly upwards in a quartz vessel 1 so that molten silicon freezes from a depending bead 3 as it moves away from H.F. induction heater 4; the size of bead 3 is kept constant by supplying silicon powder in a stream of hydrogen through a lower extenson 5 of the vessel. Fig. 2 shows the use of a number of helical baffles 11 between which hydrogen passes from an inlet 10 and which produce a turbulent whirling motion which lifts up silicon powder from a heap 9. Instead of adding the powder to a molten zone at the end of a semi-conductor rod, such a rod may be thickened by depositing powder on to a molten zone on its cylindrical surface, or lengthened by depositing it on a central molten zone which is maintained at the same thickness by slowly pulling the ends of the rod apart. In any of these processes the rod may be rotated during the operation. In the embodiment of Fig. 4 a semi-conductor compound (e.g. boron nitride) in powder form is contained in a vessel 37 with a perforated base from which it falls into a stream of hydrogen from cleaners 33, 34 to be carried into a water-cooled vessel 41. Here the boron nitride is atomized in the electric discharge between tungsten electrodes 41d and 41c, and is deposited on to a support 41f which is moved slowly downwards. Conductivity-type-determining additives may also be conveyed by a gas stream for incorporation in the rod. The production of an indium antimonide rod is described. In a modification of the above methods the semi-conductor material may be formed from a powder compound fed in a gas stream to the melt and decomposed by the heat of the molten zone or by an electric discharge.ALSO:Semiconductor crystals are produced by fusion and progressive re-crystallization of powder fed by means of a stream of gas or vapour to the surface of a melt of the semi-conductor material. In one example, powdered indium and powdered antimony are whirled in a stream of rare gas on to a molten zone on an indium antimonide carrier rod which is slowly withdrawn from a heating zone so that a crystallise length of indium antimonide is formed. In a modification indium hydride powder replaces the indium, and is decomposed by the heat from the molten bead.