METHOD FOR EVALUATING DEGREE OF CRYSTAL ORIENTATION IN POLYCRYSTALLINE SILICON, SELECTION METHOD FOR POLYCRYSTALLINE SILICON RODS, AND PRODUCTION METHOD FOR SINGLE-CRYSTAL SILICON

摘要

When a plate-like sample 20 extracted from a polycrystalline rod is evaluated, peaks can appear in a Õ-canning chart. The smaller the number of such peaks, and the narrower the half-value width of the peak, the more suitable the polycrystalline silicon rod is as a raw material for producing single-crystal silicon. It is preferable that the number of peaks in the Õ-scanning chart is, for both the Miller index planes <111> and <220>, equal to or smaller than 24/cm 2 when converted into unit per area of the plate-like sample. It is also preferable that the value obtained by multiplying the peak half-value width by ´L=2 1/2 ÀR 0 /360, where R 0 is the radius of the sample, is defined as an inhomogeneous crystal grain size, and that a polycrystalline silicon rod of which all the inhomogeneous crystal grain sizes are smaller than 0.5 mm is selected as a raw material for producing single-crystal silicon.