| 摘要 |
PURPOSE: To provide a method, capable of effectively evaluating the degree of foreign matter contained in a raw-material polycrystalline silicon, without the need for actually pulling up single crystals. CONSTITUTION: A fixed amount of a polycrystalline silicon piece 1 is housed in a basket 2, and the cage 2 is immersed in an etching tank 4, housing an etchant 3. Then, the predetermined amount of a polycrystalline silicon piece 1 is pulled from the etching tank 4, and the etchant 3 is sampled. The sampled liquid is left standing for a fixed time and then placed in a liquid-borne particle counter 7, when all the polycrystalline silicon particles and powder have dissolved to measure the number of particles in a fixed amount of the liquid.
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