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:
Oct. 18, 1994
Filed:
Nov. 12, 1992
Motoyuki Yamada, Saitama, JP;
Osamu Watanabe, Niigata, JP;
Akinobu Tanaka, Kanagawa, JP;
Hiroshi Ban, Kanagawa, JP;
Yoshio Kawai, Kanagawa, JP;
Shin-Etsu Chemical Co., Ltd., Tokyo, JP;
Nippon Telegraph and Telephone Corp., Tokyo, JP;
Abstract
A positive resists material for high energy-sensitive positive resists which can be developed in aqueous alkali solution, said material comprising (A) a polyhydroxystyrene resin wherein some hydroxyl groups are substituted by t-butoxycarbonyloxy groups, (B) a solution blocking agent, and (C) an onium salt, and being characterized in that said solution blocking agent contains at least one t-butoxycarbonyloxy group per molecule, said onium salt is bis(p-t-butylphenyl) iodinium trifluormethylsulfonate represented by the following formula (1): ##STR1## and the weight proportions of (A), (B), (C) are given by the relations: 0.07.ltoreq.B-.ltoreq.0.40, 0.005.ltoreq.C.ltoreq.0.15, 0.55.ltoreq.A, A+B+C=1. As the resist has low absorption at the exposure wavelength of a KrF exima laser, a fine pattern having vertical walls is easily formed.