PRODUCTION OF POLYCRYSTAL SEMICONDUCTOR

PROBLEM TO BE SOLVED: To produce a polycrystal semiconductor having large crystal particles. SOLUTION: A seed crystal 24 is arranged on the bottom of a conical part 22 of a crucible 9 and a semiconductor material is inserted into the crucible 9. The crucible 9 is heated by a heating furnace 4 to melt only the semiconductor material. Though the crucible 9 is cooled by a pedestal 13, the circumferential part 16 of the pedestal 13 has a transmission of cooling temperature smaller than that in the central part 15, because the circumferential part 16 is brought into contact with the crucible 9 through a heat insulator 11. Water amounts fed to the central part 15 and the circumferential part 16 are controlled so that solidified interface becomes upwardly protruded shape when coagulation is started. Water amount fed to the circumferential part 16 is increased together with growth of the solidified interface and when the solidified interface attains the boundary 25, the interface is made planar form and then coagulation is advanced without changing the water amount.