Czochralski method using a member for intercepting radiation from raw material molten solution and apparatus therefor

An apparatus for manufacturing a single crystal, comprising:

• a crucible for containing a raw material melt;
• a lower shaft for supporting said crucible;
• a heater arranged around said crucible for heating said crucible and melt;
• a coracle in said crucible, said coracle having a recess and an opening communicating with said melt of for containing raw material melt such that a surface area of said raw material melt in said coracle recess has a prescribed size;
• a rotatable and vertically movable upper shaft for holding a seed crystal at a lower end of said upper shaft for pulling a single crystal from said raw material melt;
• a first radiation intercepting member having a central hole through which said seed crystal is passed, said first heat radiation intercepting member resting initially on said coracle in a movable manner, said first member covering a melt surface of said raw material melt in said coracle for intercepting heat radiation from said raw material melt to a space above said melt surface;
• a second radiation intercepting member carried by said upper shaft and covering said central hole in said first intercepting member for further intercepting heat radiation through said central hole of said first radiation intercepting member, and means for moving said first intercepting member together with said second intercepting member and with said upper shaft upwardly when said single crystal is being pulled from said melt in said coracle recess.