NITROGEN-DOPED SILICON SINGLE CRYSTAL WAFER HAVING LOW DEFECT DENSITY AND IT PRODUCTION

摘要

PROBLEM TO BE SOLVED: To produce a nitrogen-doped silicon single crystal wafer in high productivity by excluding dislocation cluster while remaining excess interstitial silicon atoms over the whole surface or a part of crystal. SOLUTION: A silicon single crystal is grown by Czochralski process by pulling up the crystal while doping the crystal with nitrogen under a condition to hold excess interstitial silicon atoms over the whole area of a part of the crystal. The distribution of defect is shifted to the high-speed side of the pull-up speed and the generation of dislocation cluster ordinarily occuring at an I-rich region is prevented by this process. Accordingly, the controlling tolerance is widened and the control becomes easy when the crystal is pulled up in a region having I-rich region over the whole surface or a part of the crystal and a silicon single crystal having extremely low defect density and free from dislocation cluster even in an I-rich region can be produced in high productivity. Preferably, the amount of doped nitrogen is >=1×10<14> atoms/cm<3> and the oxygen concentration in the crystal is <=1×10<18> atoms/cm<3> .