The study on the radial distribution of delta [Oi] in heavily doped Si wafer using X-ray diffraction

The radial distribution of the delta [Oi] for the heavily doped silicon wafers was investigated using X-ray diffraction technique. In order to obtain the correlation between delta [Oi] and X-ray intensity ratio for the lightly doped wafers with different initial [Oi] concentrations, the oxygen concentration using FTIR and X-ray intensity were measured before and after two-step annealing. The relation between delta [Oi] and X-ray intensity ratio showed that it was close to the parabolic correlation rather than the linear correlation. The deviation of this measurement was about +/- 0.4 ppma. This correlation equation could be applied to the heavily doped wafers. It is shown that the radial distribution of the delta [Oi] is not uniform in the radial direction but has the symmetric relation at the wafer center. The bulk micro defect (BMD) density using etching method was measured to confirm these results. (C) 2001 Published by Elsevier Science Ltd.