SILICON WAFER AND CRYSTAL GROWTH

摘要

PROBLEM TO BE SOLVED: To obtain a silicon wafer for controlling the occurrence of vacancy cluster without reducing a pulling up speed. SOLUTION: A single crystal 13 is grown by a czochralski method. In forming a raw material melt 12, carbon powder 10 is thrown into an inner bottom of a crucible 3 so as to make a carbon concentration in the crystal >=1×10<16> atoms/cm<3> and then a polycrystal raw material 11 is packed into the crucible. A pulling up speed when the single crystal 13 is pulled up from the raw material melamine 12 is made to cause on OSF ring inside the outer peripheral part of the crystal or is made into a higher speed extinguishing at the outside. The number of vacancy clusters having >=0.13 in a vacancy cluster occurring zone per unit area is reduced to <=0.5 /cm<2> at a stage after one SC1 cleaning by making the carbon concentration in the crystal >=1×10<16> atoms/cm<3> .