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:
Dec. 25, 1990
Filed:
Sep. 26, 1989
Toshimitsu Kaji, Meguro, JP;
Tadao Takeuchi, Chiba, JP;
Tsutomu Kawashima, Koto, JP;
Eiichi Miyakoshi, Kasukabe, JP;
Yasukatsu Nishikata, Funabashi, JP;
Yasuya Hisatome, Kawasaki, JP;
Nisso Engineering Company, Ltd., Tokyo, JP;
Abstract
A method for recirculating a high-temperature etching solution according to the present invention comprises the steps of continuously removing, from a bath for etching a wafer for a semiconductor device, a portion of an etching solution contained in the etching bath, injecting a predetermined amount of pure water for adjusting the concentration of the etching solution into the removed etching solution, heating the resulting solution to a predetermined temperature, and recirculating the heated solution into the etching bath.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile