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. 12, 2000
Filed:
Jan. 08, 1999
David D Ngo, San Jose, CA (US);
Som S Swamy, Danville, CA (US);
Fijitsu Limited, , JP;
Abstract
Normally, a positive photoresist is developed with an alkaline aqueous solution to form patterns, and is subsequently stripped with an organic solvent after the photoresist has served its function. Such strippers are relatively toxic and damaging to the environment, and cannot be handled by standard (community) waste-water treatment facilities. These strippers cannot be easily neutralized, and must be disposed of in a highly specialized and relatively expensive manner. The present invention provides a method of treating positive and negative photoresists during their usage as photo masks such that the photoresists may be removed by less toxic chemicals which can be readily neutralized and handled by conventional waste water treatment facilities.