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. 20, 1998
Filed:
Nov. 01, 1996
Yoichi Osawa, Nakakubiki-gun, JP;
Satoshi Watanabe, Nakakubiki-gun, JP;
Kaysuya Takemura, Nakakubiki-gun, JP;
Shigehiro Nagura, Nakakubiki-gun, JP;
Akinobu Tanaka, Fujisawa, JP;
Yoshio Kawai, Isehara, JP;
Shin-Etsu Chemical Co., Ltd., Tokyo, JP;
Nippon Telegraph and Telephone Corp., Tokyo, JP;
Abstract
The invention provides a novel sulfonium salt having at least one acid labile group attached to a phenyl group in a molecule and a C.sub.2 -C.sub.20 alkylsulfonate or arylsulfonate anion whose alkyl or aryl has as a substituent an electron withdrawing group such as fluorine and nitro group. The novel sulfonium salt is effective for increasing the dissolution contrast between exposed and unexposed areas. Upon exposure, it generates a substituted alkyl or arylsulfonic acid which is a weak acid, minimizing the influence of side reaction and deactivation during PEB step. The sulfonium salt is useful in a chemically amplified positive resist composition which lends itself to fine patterning and features high resolution.