POLYCRYSTALLINE SILICON ROD, METHOD FOR INSPECTING POLYCRYSTALLINE SILICON ROD, AND METHOD FOR MANUFACTURING POLYCRYSTALLINE SILICON ROD

摘要

Disclosed is a high-quality polycrystalline silicon rod in which cracks in a polycrystalline silicon rod are detected in a simplified manner, thereby separating a polycrystalline silicon rod with no cracks. A polycrystalline silicon rod (100) is hit with a hammer (120), the hit sound is recorded on a recorder (140) via a microphone (130). Then, the hit sound is analyzed to calculate a natural frequency (f0), and further the sound signal of the hit sound is fast-Fourier-transformed to display frequency distribution. Furthermore, a peak frequency (f) indicating the loudest sound volume of the frequency distribution after the fast Fourier transformation is detected to compare the natural frequency (f0)(Hz) and the peak frequency (f) (Hz). For example, if a frequency ratio (R) (f0/f) is 0.9=R=1.1, it is determined that there are no cracks inside and outside the polycrystalline silicon rod.