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:
Feb. 11, 1997
Filed:
Mar. 29, 1995
Kazuhiko Nakayama, Kanagawa-ken, JP;
Taku Nakao, Kanagawa-ken, JP;
Kousuke Doi, Kanagawa-ken, JP;
Nobuo Tokutake, Kanagawa-ken, JP;
Hidekatsu Kohara, Kanagawa-ken, JP;
Toshimasa Nakayama, Kanagawa-ken, JP;
Tokyo Ohka Kogyo Co., Ltd., , JP;
Abstract
Disclosed is an improved positive-working photoresist composition comprising an alkali-soluble resin as a film-forming agent and a quinone diazide group-containing compound as a photosensitive agent. The most characteristic feature of the inventive composition consists in the unique formulation of the alkali-soluble resin which is a combination of two or three kinds of novolac resins selected from novolac resins (a), (b1) or (b2) and (c1) or (c2), each of which is characterized by the unique formulation of the phenolic compounds as a mixture to be subjected to a condensation reaction with an aldehyde compound to form the novolac resin. Namely, the phenolic mixture for the novolac (a) consists of m- and p-cresols, the phenolic mixture for the novolac (b1) consists of m-cresol and a xylenol, the phenolic mixture for the novolac (b2) consists of m- and p-cresols and a xylenol, the phenolic mixture for the novolac (c1) consists of m-cresol and a trimethyl phenol and the phenolic mixture for the novolac (c2) consists of m- and p-cresols and a trimethyl phenol each in a specified molar proportion of the constituent phenolic compounds.