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1. (WO2018198947) METHOD FOR MANUFACTURING POLYCRYSTALLINE SILICON FRAGMENT AND METHOD FOR MANAGING SURFACE METAL CONCENTRATION OF POLYCRYSTALLINE SILICON FRAGMENT

Pub. No.:    WO/2018/198947    International Application No.:    PCT/JP2018/016217
Publication Date: Fri Nov 02 00:59:59 CET 2018 International Filing Date: Fri Apr 20 01:59:59 CEST 2018
IPC: C01B 33/035
B02C 1/02
B02C 13/00
C30B 29/06
Applicants: TOKUYAMA CORPORATION
株式会社トクヤマ
Inventors: NISHIMURA Shigeki
西村 茂樹
Title: METHOD FOR MANUFACTURING POLYCRYSTALLINE SILICON FRAGMENT AND METHOD FOR MANAGING SURFACE METAL CONCENTRATION OF POLYCRYSTALLINE SILICON FRAGMENT
Abstract:
The present invention relates to a method for manufacturing polycrystalline silicon fragments that includes: a step of manufacturing a polycrystalline silicon rod by the Siemens method; a step of fracturing the polycrystalline silicon rod to obtain polycrystalline silicon fragments; and a step of etching and cleaning the polycrystalline silicon fragments in a cleaning tank. In the cleaning step, small pieces of the polycrystalline silicon having controlled shapes and sizes are caused to be present in the cleaning tank and the weight change of the small pieces of the polycrystalline silicon before and after the etching process is measured to thereby manage the cleaning step. The present invention also relates to a method for managing the surface metal concentration of the polycrystalline silicon fragments.