公开(公告)号：EP1640340A4

公开(公告)日：2007-07-18

申请号：EP04746581

申请日：2004-06-28

申请人： NIPPON CHEMICAL IND COMPANY LT

发明人： ISHIKAWA KENICHI ,  YOKOI KEIZOU ,  TAKEUCHI KOSUKE ,  KURITA YUTAKA ,  UCHIYAMA HEIJI

IPC分类号： C01B25/238 ,  C01B25/18 ,  C01B25/20 ,  C01B25/234 ,  H01L21/308

CPC分类号： C01B25/18 ,  C01B25/234

摘要： A high purity phosphoric acid, characterized in that it has an impurity content wherein the content of Sb is 200 ppb or less and the content of a sulfide ion is 200 ppb or less, in terms of a product having a H3PO4 concentration of 85 wt %. The above high purity phosphoric acid is useful as an etching fluid for a semiconductor element having a silicon nitride film, an etching fluid for a liquid crystalline display panel having an alumina film, an etching fluid for metallic aluminum, an etching fluid for alumina for a ceraminc, a material of a phosphate glass for an optical fiber glass, a food additive and the like.