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:
Sep. 05, 1989
Filed:
Mar. 29, 1988
Akihiro Furuta, Osaka, JP;
Makoto Hanabata, Osaka, JP;
Seimei Yasui, Hyogo, JP;
Osamu Hiroaki, Osaka, JP;
Naoyoshi Jinno, Osaka, JP;
Sumitomo Chemical Company, Limited, Osaka, JP;
Abstract
A positive type photoresist composition comprising a novolak resin and O-quinone diazide compound, the novolak resin being one which is obtained by the addition condensation reaction of a phenol and formaldehyde which is performed in one stage by using as a catalyst an organic acid salt of a divalent metal which is more electropositive than hydrogen, or in two stages by using an acid catalyst in the subsequent stage, the phenol being at least one compound represented by the formula ##STR1## wherein R is hydrogen or an alkyl group of carbon number 1 to 4, the compound being such that the average carbon number in the substituent per one phenol nucelus is 0.5 to 1.5 and the ones with the substituent at the ortho- or para-position with respect to the hydroxyl group account for less than 50 mol %, is disclosed. The positive type photoresist composition of the invention has an improved resolving power, i.e., .gamma.-value.