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:
Mar. 05, 1991
Filed:
Aug. 16, 1989
Tokyo Ohka Kogyo Co., Ltd., Kanagawa, JP;
Abstract
The developer solution of the invention is suitable for use to develop a positive-working resist composition comprising an alkali-soluble novolac resin and a naphthoquinone diazide compound and capable of giving a patterned image of the resist layer with a high contrast and increasing the effective depth of focus. The characteristic ingredient in the inventive developer solution is an alkali-soluble organic cyclic nitrogen compound such as N-hydroxyethyl piperazine, N-methyl-4-piperidone, 1,3-dimethyl-2-imidazolidinone and the like added in a specified concentration to a conventional developer solution containing tetramethyl ammonium hydroxide or choline as the water-soluble alkaline compound.