Methods of producing substances of highest purity, particularly electric semiconductors

Claim 1

A METHOD OF PRODUCING AN ELECTRIC SEMICONDUCTOR OF HIGH PURITY, COMPRISING CONTACTING THE PERIPHERAL SURFACE OF AN ELONGATED CARRIER BODY OF THE SAME MATERIAL AS THE SEMICONDUCTOR WITH A GAS COMPRISING A CHEMICAL COMPOUND OF THE MATERIAL, THE CARRIER BODY BEING HEATED BY PASSING AN ELECTRIC CURRENT THROUGH THE ELOGNATED BODY LENGTHWISE THEREOF, THE HEATING BEING TO A TEMPERATURE SUFFICIENTLY HIGH TO CAUSE CHEMICAL CONVERSION OF THE CHEMICAL COMPOUND TO SAID MATERIAL AND DEPOSITION OF THE LATTER ON THE LENGTHWISE EXTENDING PERIPHERAL SURFACE OF THE CARRIER BODY, STRETCHING THE ENLARGED BODY, IN A CRUCIBLE-FREE ZONE-PULLING PROCESS, BY PULLING AN END REGION THEREOF IN A DIRECTION AWAY FROM THE OPPOSITE END REGION WHILE MELTING A ZONE OF LIMITED LONGITUDINAL DIMENSION BY HEATING MEANS HAVING NO CONTACT WITH SAID ZONE, THE MOLTEN ZONE BEING CAUSED TO BE DISPLACED LONGITUDINALLY WITH RESPECT TO THE BODY DURING THE PULLING WHEREBY AN ELOGNATED SECTION OF REDUCED CROSS-SECTION IS PRODUCED IN THE BODY, CONTACTING AT LEAST PART OF THE REDUCED SECTION, EMPLOYED AS HEATED ELOGNATED CARRIER BODY, WITH A GASEOUS CHEMICAL COMPOUND OF THE SAID MATERIAL TO ENLARGE SAID PIECE BY DEPOSITION OF THE MATERIAL THEREON.