Process for investigating single crystal material for precipitations of foreign phases

摘要

In the production and machining of single-crystal material, it is important to be able to detect deviations from the ideal crystal structure. Information on the density and average extent of foreign-phase precipitates is required. …??The object is to carry out automatically the irradiation of discrete crystal regions with wave or particle beams, the measurement of the intensity distribution of the beams diffracted under Bragg conditions and the determination of static Debye Waller factors universally for different sample thicknesses with high resolution and flexibility in relation to wavelength changes. For this purpose, the angle of incidence of the beams with respect to the diffracting lattice planes is varied, the reflectivity is measured with a photon or particle detector and the integrated reflectivity Rint is determined. Swivelling the sample around an axis which is perpendicular to the diffracting lattice planes results in a variation in the sample thickness. Rint is measured as a function of the sample thickness. When matched to a theoretical function, the measured dependence yields the static Debye-Waller factor and, if several diffraction orders are measured, the density or number and the average extent of the precipitates. …??Important applications are the in-situ determination of foreign-phase precipitates, in studies of Si wafers which can be topographically mapped as a function of position in terms of the density and size of SiO2 precipitates, and the like. …IMAGE…