| 摘要 |
The present invention provides a clean and high-purity polycrystalline silicon mass having a small content of chromium, iron, nickel, copper, and cobalt in total, which are heavy metal impurities that reduce the quality of single-crystal silicon. In the vicinity of an electrode side end of a polycrystalline silicon rod obtained by the Siemens method, the total of the chromium, iron, nickel, copper, and cobalt concentrations is high. Accordingly, before a crushing step of a polycrystalline silicon rod 100, a removing step of removing at least 70 mm of a polycrystalline silicon portion from the electrode side end of the polycrystalline silicon rod 100 extracted to the outside of a reactor is provided. Thereby, the polycrystalline silicon portion in which the total of the chromium, iron, nickel, copper, and cobalt concentrations in a bulk is not less than 150 ppta can be removed. |
