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:
May. 15, 1990
Filed:
Dec. 14, 1988
Kunihiro Ichimura, Tsukuba, JP;
Teruhiko Yonezawa, Kanagawa, JP;
Hideo Kikuchi, Chiba, JP;
Nariaki Tochizawa, Funabashi, JP;
Keiichi Hayashi, Funabashi, JP;
Director General of Agency of Industrial Science and Technology, Tokyo, JP;
Toyo Gosei Kogyo Co., Ltd., Chiba, JP;
Abstract
The invention provides a novel contrast-enhancing agent for photolithography which is used as an overcoating on a positive-working photoresist layer for enhancing the contrast of the photoresist in a low-contrast exposure to light. The composition comprises, in addition to a watersoluble polymer, e.g., poly(vinyl alcohol), poly(vinyl pyrroilidone) and pullulan, as the binder, a specific photo-bleachable organic compound having, in a molecule, at least one nitrogen-containing heterocyclic aromatic structure represented by the general formula ##STR1## in which Z is a divalent group to form the heterocyclic aromatic ring with the nitrogen atom, X is an anionic group of monovalency and n is a positive integer of, e.g., 1 or 2.