Abstract: A silicon ingot is manufactured by pulling a nitrogen doped silicon single crystal. The oxygen concentration in the crystal is controlled during the pulling, so as to maintain a relationship between the oxygen and nitrogen concentration in the ingot, corresponding to the formula Oi=C1?[C2×(Log Ni)], where C1 and C2 are first and second constants, and Oi is the oxygen concentration and Ni is the nitrogen concentration in the ingot. C1 and C2 will vary depending on the defect criteria. For example, for one criteria C1 may equal to 146.3×1017 and C2 may equal to 9×1017, and Ni may be within the range of approximately 3×1015 to approximately 3×1014 atoms/cm3, while for a stricter defect criteria C1 may equal 127×1017 and C2 may equal 8×1017, and Ni may be within the range proximately 1×1015 to approximately 1×1014 atoms/cm3.