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

Peaks sometimes appear in a phi scan chart when an evaluation is performed on a disc-shaped sample (20) obtained from a polycrystalline silicon rod. The fewer the number of such peaks and the narrower the half width thereof, the more suitable the sample is for use as a raw material for single-crystal silicon production. It is preferable for the number of peaks appearing in a phi scan chart to be no more than 24/cm2 when converted to a number of peaks per unit surface area of the disc-shaped sample, for both Miller index <111> and <220> planes. It is also preferable to select as the raw material for single-crystal silicon production a material having all heterogeneic crystal particle diameters being less than 0.5 mm, when the heterogeneic crystal particle diameter is defined as the value obtained by multiplying the peak half width by deltaL=21/2piRo/360, when the radius of the disc-shaped sample is Ro.