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1. (WO2013121970) METHOD FOR REMOVING BORON FROM SILICON

Pub. No.:    WO/2013/121970    International Application No.:    PCT/JP2013/052867
Publication Date: Fri Aug 23 01:59:59 CEST 2013 International Filing Date: Fri Feb 08 00:59:59 CET 2013
IPC: C01B 33/037
Applicants: THE FOUNDATION FOR THE PROMOTION OF INDUSTRIAL SCIENCE
一般財団法人生産技術研究奨励会
Inventors: MORITA Kazuki
森田 一樹
YOSHIKAWA Takeshi
吉川 健
MA Xiaodong
馬 暁東
Title: METHOD FOR REMOVING BORON FROM SILICON
Abstract:
Provided is a method for removing boron from silicon, which is capable of efficiently removing boron from a starting material of silicon that is used for solar cells, thereby keeping the concentration of boron contained in the starting material low. This method for removing boron from silicon comprises: a first process wherein a first member that is composed of silicon containing boron and a second member that is composed of a low-melting-point metal are put in a crucible (101) and the first and second members are heated and melted within the crucible (101), thereby forming a desired alloy (102b); a second process wherein a slag (103a) is introduced into the crucible (101) after the first process so as to have the surface layer part of the alloy (102b) covered with the slag (103b), and the slag (103b) and the alloy (102b) are heated and reacted with each other, thereby transferring boron from the alloy (102b) to the slag (103b); and a third process wherein the slag (103c) is removed from the crucible (101) after the second process, thereby leaving only the alloy (102c) in the crucible (101).