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:
Jul. 22, 2008
Filed:
Jun. 10, 2004
Mitsuo Hagihara, Kawasakai, JP;
Taku Nakao, Kawasakai, JP;
Kazuyuki Nitta, Kawasaki, JP;
Tokyo Ohka Kogyo Co., Ltd., Tokyo, JP;
Abstract
A positive resist composition includes a resin (A) that increases alkali solubility due to action of an acid, wherein the resin comprises a copolymer containing a first structural unit (a1) derived from hydroxystyrene, and a second structural unit (a2) derived from a (meth)acrylate with an alcoholic hydroxyl group, and a weight average molecular weight of the copolymer is within a range from 2000 to 8500, and 10 mol % to 25 mol % of a combined total of hydroxyl groups within the structural units (a1) and alcoholic hydroxyl groups within the structural units (a2) are protected with acid dissociable, dissolution inhibiting groups, an acid generator (B) that generates an acid on exposure to light, and polypropylene glycol (C).