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:
Jun. 05, 2001
Filed:
May. 31, 2000
Yoshiaki Kurimoto, Takasaki, JP;
Katsuhiro Maruyama, Takasaki, JP;
Akira Yoshitomo, Takasaki, JP;
Satoru Yoshida, Takasaki, JP;
Satoru Kitano, Takasaki, JP;
Gun Ei Chemical Industry Co., Ltd., Gunma-Ken, JP;
Abstract
The present invention relates to a novolak type phenol resin, in particular a novolak type phenol resin for resists suitable for forming resist patterns. The novolak type phenol resin of the present invention is obtained by reacting at least a vinylphenol having a vinyl group and a phenolic hydroxyl group, such as parahydroxystyrene, or a polyvinylphenol, which is a polymer of the vinylphenol, a compound (A) such as 4,4′-methylenebis(2-hydroxymethyl-3,6-dimethylphenol) and/or a compound (B) such as 2,6-dihydroxymethyl-4-phenol, in a ratio of 1 to 40 moles of the compound (A) and/or compound (B) to 100 moles of the vinylphenol or 100 moles of structural unit of the vinylphenol contained in the polyvinylphenol in the presence of an acid and having a weight average molecular weight of 2,000 to 20,000. Such a novolak type phenol resin provides good pattern shape, heat resistance, resolution, and sensitivity in resists for lithography.