The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 03, 2002
Filed:
Nov. 13, 2000
Kaori Watanabe, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
A mixed aqueous solution containing HCl with a concentration of 10 to 25% by weight, H O with a concentration of 2 to 5% by weight, and HF with a concentration of 0.01 to 2% by weight or a mixed aqueous solution containing H SO with a concentration of 65 to 82% by weight, H O with a concentration of 4 to 16% by weight, and HF with a concentration of 0.01 to 2% by weight is used as a platinum group impurity recovery liquid. The recovery liquid is dripped onto a silicon substrate surface or a film thereon so as to scan the entire surface of the substrate with the droplets. As a result, the platinum group impurity is dissolved into the recovery liquid, and the platinum group impurity is thus recovered.