Determination of oxygen with reactor neutrons

Oxygen in silicon was determined by the secondary nuclear reactions of⁶Li(n, α)T and¹⁶O(t, n)¹⁸F. Lithium fluoride was deposited in vacuum on fused quartz, covered with the sample and irradiated in a nuclear reactor. The depth profiles of¹⁸F in fused quartz and in silicon were observed, and enough depth to eliminate surface oxygen was estimated. On the basis of these results, oxygen was determined by the average cross-section method. Oxygen concentration in CZ silicon with various growing condition was 5–26 ppm and was consistent with those determined by the infrared absorption method. The detection limit of oxygen in silicon is 5 ppm.