Patent ID: 7294203

Claim:
A heat shielding member of a silicon single crystal pulling-up device which is provided in a device which pulls up a silicon single crystal rod ( 25 ) from a silicon melt ( 12 ) which is stored in a quartz crucible ( 13 ) which is heated by a heater ( 18 ) surrounding the outer peripheral face of the quartz crucible ( 13 ) and equipped with a tube portion ( 37 ) whose lower end is situated upward at an interval from the surface of the silicon melt ( 12 ) and which shields radiant heat from the heater ( 18 ) surrounding the outer peripheral face of the silicon single crystal rod ( 25 ), a swelling portion ( 41 ) which is provided at the lower portion of the tube portion ( 37 ) by being swollen to a tube direction, and a ring-shape heat accumulating portion ( 47 ) which is provided at the inside of the swelling portion ( 41 ) and surrounds the outer peripheral face of the lower portion of the silicon single crystal rod ( 25 ) and the diameter (d) of the silicon single crystal rod ( 25 ) is 100 mm or more, wherein the heat accumulating portion ( 47 ) consisting essentially of alumina, having a thermal conductivity of 5 W/(m·° C.) or less, and the heat accumulating portion ( 47 ) has an inner peripheral face which is in parallel to the axial line of the silicon single crystal rod ( 25 ), or is slanted at an angle of −30 degrees or more and +30 degrees or less and is formed so that the inner peripheral face of the heat accumulating portion ( 47 ) is a height (H 1 ) of 10 mm or more and d/2 or less, and the minimum distance (W 1 ) between the outer peripheral face of the silicon single crystal rod ( 25 ) and the inner peripheral face of the heat accumulating portion ( 47 ) is 10 mm or more and 0.2 d or less.