Polycrystalline silicon and process and apparatus for producing the same

摘要

Foamed polycrystalline silicon having bubbles therein and an apparent density of 2.20 g/cm<3 >or less. This silicon generates an extremely small amount of fine grains by crushing and can be easily crushed. There is also provided a method of producing foamed polycrystalline silicon. There is further provided a polycrystalline silicon production apparatus in which the deposition and melting of silicon are carried out on the inner surface of a cylindrical vessel, a chlorosilane feed pipe is inserted into the cylindrical vessel to a silicon molten liquid, and seal gas is supplied into a space between the cylindrical vessel and the chlorosilane feed pipe.