Patent ID: 8187383

Claim:
A semiconductor single crystal manufacturing device comprising: a crucible for storing raw material melt for a semiconductor single crystal; a heater that is provided at a periphery of the crucible and that heats and melts the raw material; and a chamber having the crucible and the heater provided therein, in which a seed crystal is immersed in the melt and the single crystal is pulled up, characterized in that a wall forming a purge gas directing path is formed by a cylindrical single crystal side flow-straightening member, a melt surface side flow-straightening member having an inverted conical tube and a cylindrical heater side flow-straightening member, and the wall forming the purge gas directing path defines the crucible and the heater, and an inner wall of the chamber, the purge gas directing path directs purge gas to flow from a purge gas introduction port to a vicinity of a surface of the melt in the crucible, directs the purge gas to above the heater from the surface of the melt in the crucible, and then directs the purge gas to a purge gas discharge port from above the heater, the semiconductor single crystal manufacturing device comprises a flow-straightening member raising/lowering mechanism which moves the single crystal side flow-straightening member and the melt surface side flow-straightening member in a vertical direction of the chamber, and control means that controls the flow-straightening member raising/lowering mechanism so that, when the raw material is introduced into the crucible, the single crystal side flow-straightening member and the melt surface side flow-straightening member are separated from the crucible in an upwards direction and, after the raw material is melted in the crucible, the single crystal side flow-straightening member and the melt surface side flow-straightening member are arranged in predetermined positions, to thereby control a flow speed of the purge gas passing through a vicinity of the surface of the melt in the crucible to a desired value.