Apparatus for producing polycrystalline silicon and method for producing polycrystalline silicon

Abstract

Raw material gas supply nozzles are arranged within a virtual concentric circle having its center at the center of a disk-like base plate (having an area half as large as an area of the base plate). Raw material gas is ejected at a flow velocity of 150 m/sec or more into a bell jar from the gas supply nozzles. In addition to one gas supply nozzle provided in a center portion of the base plate, three gas supply nozzles can be arranged at the vertex positions of a regular triangle inscribed in a circumscribed circle having its center at the gas supply nozzle in the center portion. With the gas supply nozzles so arranged, a smooth circulating flow is formed within a reactor.

1 - 7 . (canceled) 
     
     
         8 . A polycrystalline silicon production apparatus for producing polycrystalline silicon by a Siemens method, comprising:
 a reactor whose inner portion is hermetically sealed by a bell jar and a disk-like base plate;   a gas flow control unit that supplies raw material gas into the bell jar at a desired flow rate;   electrode pairs that conduct electricity to a plurality of silicon core wires; and   a plurality of gas supply nozzles provided at the disk-like base plate, wherein the gas supply nozzles supply the raw material gas to an inner space of the bell jar;   wherein   all of the gas supply nozzles provided at the disk-like base plate are arranged within a virtual concentric circle having its center at a center of the disk-like base plate, and having an area S(=S 0 /2) half as large as an area S 0  of the disk-like base plate, one of the gas supply nozzles being arranged at the center of the disk-like base plate, and the gas supply nozzles except the gas supply nozzle arranged at the center of the base plate are arranged at vertex positions of a regular polygon inscribed in a second virtual concentric circle having its center at the center of the disk-like base plate, and   the gas flow control unit can control the raw material gas ejected from the gas supply nozzles at a flow velocity of 150 m/sec or more.   
     
     
         9 . The polycrystalline silicon production apparatus according to  claim 8 ,
 wherein a gas ejection hole of each of the gas supply nozzles has a diameter of 7 mmφ to 20 mmφ.   
     
     
         10 . The polycrystalline silicon production apparatus according to  claim 8 ,
 wherein the inner space of the bell jar of the reactor has a height of 2 m to 5 m, and   the second virtual concentric circle has a radius of 20 to 70 cm.   
     
     
         11 . The polycrystalline silicon production apparatus according to  claim 10 ,
 wherein a gas ejection hole of each of the gas supply nozzles has a diameter of 7 mmφ to 20 mmφ.   
     
     
         12 . The polycrystalline silicon production apparatus according to  claim 8 ,
 wherein the regular polygon is a regular n-gon, where n is an integer of 3 to 8.   
     
     
         13 . The polycrystalline silicon production apparatus according to  claim 12 ,
 wherein a gas ejection hole of each of the gas supply nozzles has a diameter of 7 mmφ to 20 mmφ.