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. 13, 2001
Filed:
Nov. 02, 1999
Ken Miyagi, Kanagawa, JP;
Kousuke Doi, Kanagawa, JP;
Atsuko Hirata, Kanagawa, JP;
Hidekatsu Kohara, Kanagawa, JP;
Toshimasa Nakayama, Kanagawa, JP;
Tokyo Ohka Kogyo Co., Ltd., Kanagawa, JP;
Abstract
In a positive photoresist composition including (A) an alkali-soluble novolak resin and (B) a naphthoquinonediazide ester, the alkali-soluble novolak resin is obtained synthetically by condensation of phenol compounds and an aldehyde or ketone, and the phenol compounds include, for example, 1% to 20% by mole of hydroquinone, 30% to 95% by mole of m-cresol and 2% to 50% by mole of 2,5-xylenol. Thus, a high-definition positive photoresist composition can be obtained, which inhibits the formation of scum, and is satisfactory in sensitivity, sectional shape, focal depth range and other properties even in a process for the formation of an ultrafine resist pattern of 0.30 &mgr;m or below by lithography using i-ray.