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. 06, 1990
Filed:
Apr. 18, 1988
Shingo Asaumi, Fujisawa, JP;
Hidekatsu Kohara, Chigasaki, JP;
Hatsuyuki Tanaka, Samukawa, JP;
Masanori Miyabe, Fujisawa, JP;
Toshimasa Nakayama, Hiratsuka, JP;
Tokyo Ohka Kogyo Co., Ltd., Kanagawa, JP;
Abstract
A positive-working photoresist composition suitable for fine patterning in the manufacturing of semiconductor devices such as VLSIs with high fidelity is proposed. The composition comprises: (A) 100 parts by weight of a phenolic novolac resin prepared by the condensation reaction of a specific ternary mixture of three kinds of phenolic compounds and formaldehyde; and (B) 20-60 parts by weight of a photosensitizer which is preferably an ester of naphthoquinone diazidesulfonic acid and a hydroxylated benzophenone compound. The phenolic mixture is composed of 10-45% by weight of m-cresol, 35-88% by weight of p-cresol and 2-30% by weight of a substituted phenol represented by the general formula R.C.sub.6 H.sub.4.OH, in which R is a monovalent aliphatic hydrocarbon group having 2-6 carbon atoms selected from alkyl and alkenyl groups.