Method of producing monocrystalline semiconductor material, particularly silicon, with adjustable dislocation density

Method of producing monocrystalline silicon having a uniform dislocation density in the range of 100,000 dislocations/cm.sup.2 which comprises, in a crucible-free zone melting process, passing a molten zone through a rod situated in a recipient and with the aid of a seed crystal fused to an end of the rod converting the rod into a monocrystalline silicon rod free of dislocations, permitting the rod to cool, and then using the dislocations which exist on the end of the rod due to the zone - melting process as seeds, passing a heated zone through the dislocation-free monocrystalline silicon rod at a maximum temperature of 1370.degree.C in the direction opposite to the direction of the zone melting process at a speed of 1-2 mm/min. to impart to said dislocation-free monocrystalline silicon rod a uniform dislocation density in the range of 100,000 dislocations/cm.sup.2.