Nitrogen doping during crystal growth was used to create N–vacancy(–O) complexes. These complexes enhance the nucleation of silicon oxide precipitates. The precipitates and other volume defects in Si wafers serve as gettering centers for metal impurities during the device processing. A study was made of N-doped Si wafers (001) from the origin, middle and end of the ingot, annealed at low (750C) and high (1050C) temperatures, using triple-axis high-resolution X-ray diffraction. The reciprocal space intensity distributions from clusters, stacking faults and dislocation loops were modelled using the Krivoglaz theory and a continuum model of the defect deformation field. Good agreement of the theory with the experimental data was achieved for the model of dislocation loops. The symmetry of measured reciprocal space maps determined the type of dislocation loops and, from extracted linear scans in the <111> direction, it was possible to obtain the radius and concentration of the loops. These parameters were combined with the results of selective etching and infra-red absorption spectroscopy. The concentration of interstitial O, shape, stoichiometry and volume fraction of precipitates were obtained from absorption spectra at room and liquid-N temperatures.

X-Ray Diffuse Scattering from Defects in Nitrogen-Doped Czochralski Grown Silicon Wafers. P.Klang, V.Holý, J.Kubena, R.Stoudek, J.Sik: Journal of Physics D, 2005, 38[10A], A105-10