PROCESS FOR PRODUCING SINGLE CRYSTAL AND SILICON SINGLE CRYSTAL WAFER

摘要

A process for producing a single crystal, comprising encircling with straightening pipe (4) single crystal (3) having been pulled up from raw material melt (2) while effecting downflow of an inert gas in chamber (1) of single crystal pullup apparatus (11) according to the Czochralski method, characterized in that at the pullup of single crystal of N region outside OSF region occurring in ring form in the direction of diameter of the single crystal, the single crystal of N region is pulled up under conditions such that providing that D(mm) refers to the diameter of single crystal pulled up, the flow rate of inert gas in the interstice between the single crystal and the straightening pipe is 0.6D(L/min) or higher and such that the pressure within the chamber is 0.6D(hPa) or below. It is preferred that as the straightening pipe, use be made of one whose Fe concentration in at least surface portion is 0.05 ppm or less. Thus, there is provided a process for producing a single crystal wherein in the production of a single crystal by the use of an apparatus fitted with straightening pipe according to the CZ method, there can be realized low defect occurrence and suppression of Fe concentration even in circumferential portion to 1x10<10> atoms/cm<3> or below.