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. 18, 1997
Filed:
Feb. 21, 1996
Shinichi Kono, Kanagawa-ken, JP;
Hayato Ohno, Kanagawa-ken, JP;
Hidekatsu Kohara, Kanagawa-ken, JP;
Toshimasa Nakayama, Kanagawa-ken, JP;
Tokyo Ohka Kogyo Co., Ltd., , JP;
Abstract
Proposed is an improved positive-working photoresist composition for use in the photolithographic patterning works for the manufacture of semiconductor devices, which is capable of giving a patterned resist layer on a substrate surface having excellent resolution and heat resistance without formation of scum in the development treatment. The photoresist composition comprises: (a) an alkali-soluble novolac resin as a film-forming ingredient and (b) a naphthoquinone diazide group-containing compound as a photosensitizing ingredient, of which the novolac resin is a condensation product of a phenolic compound and an aldehyde compound, the condensation reaction being undertaken in a solvent system containing, in addition to water, .gamma.-butyrolactone or a combination of .gamma.-butyrolactone and a propyleneglycol monoalkyl ether in a limited proportion.